JP5049144B2 - Image display device manufacturing method, and image display device manufactured using the manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing an image display device, and an image display device manufactured using the method.

  In an image display device such as a liquid crystal display device (LCD), a plasma light emitting display device (PDP), and an organic electroluminescence (EL), when an impact is applied to the surface, an image display panel included in the image display device is provided by the impact. A protective panel is provided on the surface of the image display panel so as not to be damaged. In addition, an air layer is provided between the image display panel and the protection panel to disperse and absorb the impact applied to the image display device, thereby preventing the image display panel from being damaged.

  However, in the structure in which an air layer is provided between the image display panel and the protective panel, the reflection of light due to the refractive index difference between the air layer and the protective panel is large, so that sunlight or backlight light is scattered. There has been a problem that the brightness and contrast are lowered and visibility is deteriorated.

  Until now, in order to solve the above problem, a method of filling an air layer between the image display panel and the protection panel with an elastic resin has been proposed. For example, the image display panel and the protection panel include at least one layer or more. An image display device having improved impact resistance and visibility has been disclosed (see, for example, Patent Document 1).

  However, the transparent adhesive material is weak, and it may be difficult to incorporate the transparent adhesive material into the image display device. In addition, bubbles may be caught when sticking the transparent adhesive material to the image display panel or protection panel.If the transparent adhesive material is replaced when the bubbles are caught, the transparent adhesive material In some cases, a part of the image display panel or the protection panel remains, that is, a so-called adhesive residue is generated.

  Among the problems described above, as a method for solving the difficulty of assembling work, the pressure-sensitive adhesive material (pressure-sensitive adhesive sheet) is made firm by using a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on the surface of the base film as the transparent pressure-sensitive adhesive material. A method is conceivable. Here, Patent Documents 2 and 3 disclose a laminate in which a polyester film and rubber are bonded together through at least one adhesive layer.

  However, in the polyester film disclosed in the above document, the surface orientation of the polyester film is limited to a specific range in order to impart the moldability of the laminate. For this reason, although the laminate disclosed in the above document has a feature that the moldability is good, there is a problem that the heat resistance, dimensional stability, thickness accuracy, etc. of the polyester film are deteriorated, and it has a high heat resistance. In applications that require high performance, dimensional stability, and thickness accuracy, market demands may not be met. In addition, since the polyester film and the rubber are laminated using an adhesive, there may be a problem in adhesion and adhesion durability.

  From the above background, development of a polyester film that is excellent in heat resistance, dimensional stability, thickness accuracy, and the like and that can be firmly bonded to rubber has been strongly desired.

Moreover, the present inventors have disclosed the manufacturing method of the silicone rubber film composite body which laminated | stacked the silicone rubber film on the polyester film until now (for example, refer patent documents 4-9).
JP 2003-29644 A JP 2001-322167 A JP 2001-330881 A JP 10-53659 A Japanese Patent Laid-Open No. 10-58605 JP-A-10-86282 Japanese Patent Laid-Open No. 10-95071 Japanese Patent Laid-Open No. 10-119394 Japanese Patent Laid-Open No. 10-226022

  The above-mentioned patent document discloses an embodiment in which the polyester film is an easy-adhesive polyester film in which a compound that improves adhesion is laminated on the surface thereof, thereby improving the adhesion between the polyester film and the silicone rubber film. An excellent composite can be obtained. However, although the above composite is excellent in the adhesion between the polyester film and the silicone rubber film in a normal state, for example, the durability of the adhesion between the polyester film and the silicone rubber film in a harsh environment such as high temperature and high humidity. Had the problem of being inferior.

  Some image display devices are used in an environment where the ambient temperature varies greatly from a high temperature to a low temperature, such as car navigation. For this reason, it has been desired to further improve the durability of adhesion between the polyester film (base film) and the silicone rubber film (adhesive layer) so that it can withstand such severe use conditions.

  The present invention has been made in view of the above problems, has a sufficient stiffness, by using a double-sided pressure-sensitive adhesive sheet that does not deteriorate the adhesion between the base film and the pressure-sensitive adhesive layer even under harsh use environments, To provide a manufacturing method of an image display device that not only has excellent impact resistance and visibility, but is easy to assemble and does not deteriorate the adhesion between the image display panel and the protective panel even when installed under harsh conditions. As an issue.

  The method for producing an image display device of the present invention that solves the above-mentioned problems is a pressure-sensitive adhesive containing a crosslinked silicone compound having a polydimethylsiloxane skeleton on at least one surface of a polyester-based substrate film via a heat-resistant water adhesion improving layer. An image display panel and a protective panel for protecting the image display panel are bonded together using a double-sided pressure-sensitive adhesive sheet in which layers are laminated.

  Since the double-sided pressure-sensitive adhesive sheet used in the present invention is constituted by laminating a pressure-sensitive adhesive layer on a polyester-based substrate film, the sheet is stiff. Further, since at least one surface of the base film is laminated with a pressure-sensitive adhesive layer containing a crosslinked silicone compound having a polydimethylsiloxane skeleton, the double-sided pressure-sensitive adhesive sheet used in the present invention not only has elasticity, It has both excellent adhesiveness and removability. Furthermore, since the adhesive layer containing the silicone compound is laminated on the base film via the heat resistant water adhesion improving layer, the base film and the adhesive are adhered even in a harsh environment where the temperature varies greatly from high temperature to low temperature. The layer will maintain good adhesion.

  Here, when the hot-water adhesive property of the double-sided PSA sheet is evaluated by the method defined below, it is a preferred embodiment that the PSA layer does not peel off.

  Moreover, it is preferable that the said hot water resistant adhesiveness improvement layer contains the reaction product of 1 or more types of polymers selected from the group which consists of polyester, a polyurethane, and an acryl-type polymer, and a crosslinking agent. Or it is preferable that the said hot-water-resistant adhesive improvement layer contains what self-crosslinked 1 or more types selected from the group which consists of a self-crosslinking type polyester, a polyurethane, and an acrylic polymer.

  The crosslinked silicone compound is preferably a crosslinked silicone compound having a polydimethylsiloxane skeleton having a number average molecular weight of 50,000 to 500,000.

  In the present invention, it is a preferred embodiment that an acrylic adhesive layer or a rubber adhesive layer is laminated on one side of the polyester base film.

  Moreover, it is preferable that the thickness of the said heat-resistant water adhesive improvement layer is 0.01-0.5 micrometer.

  Moreover, it is a preferable embodiment that the total light transmittance of the double-sided pressure-sensitive adhesive sheet is 90% or more and the haze is 1.5% or less.

  In the production method of the present invention, after preparing a double-sided pressure-sensitive adhesive sheet with a separate film in which a separate film is laminated on the surface of each pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive sheet, the separate film is peeled off from the pressure-sensitive adhesive layer, and the image It is a preferred embodiment that the display panel and the protective panel are bonded together.

  Here, it is preferable that the peel strength between the adhesive layer containing silicone rubber and the separate film in the adhesive layer is 0.03 to 1.0 N / 20 mm.

  In addition, a separate film laminated on the pressure-sensitive adhesive layer containing silicone rubber is provided with a release layer, and is laminated with the surface of the pressure-sensitive adhesive layer containing silicone rubber via the release layer, and the release layer is a binder. It preferably contains a resin, a polymer wax component and an antistatic agent.

  The present invention also includes an image display device manufactured using the above manufacturing method.

  In the present invention, since the image display panel and the protective panel are bonded together using the above double-sided pressure-sensitive adhesive sheet, not only excellent visibility but also easy bonding and re-peeling and a harsh environment Even when used below, an image display device having excellent adhesion between the image display panel and the protective panel could be obtained.

  The manufacturing method of the image display apparatus of this invention bonds an image display panel and a protection panel using the double-sided adhesive sheet by which the adhesion layer was laminated | stacked on both surfaces of the polyester-type base film. For this reason, the visibility of the image display device is excellent. In addition, since the double-sided pressure-sensitive adhesive sheet is stiff, the work for attaching the image display panel and the protection panel becomes easy.

  In addition, at least one of the adhesive layers includes a crosslinked silicone compound having a polydimethylsiloxane skeleton. Thereby, the double-sided pressure-sensitive adhesive sheet used in the present invention is excellent in removability and excellent in shock absorption.

  Here, the pressure-sensitive adhesive layer configured to contain the silicone compound is laminated on the base film via the heat resistant water adhesion improving layer. Thereby, since the double-sided pressure-sensitive adhesive sheet used in the present invention is difficult to peel off the pressure-sensitive adhesive layer, the image display device configured using this double-sided pressure-sensitive adhesive sheet can be used as an image display panel even when used in a harsh environment. Adhesion with the protective panel can be maintained well.

  Hereinafter, the manufacturing method of the image display apparatus of this invention is demonstrated.

(Polyester base film)
The polyester base film is a film for imparting stiffness to the double-sided pressure-sensitive adhesive sheet used in the present invention, and is a film mainly composed of polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate or the like (80% by mass or more). Can be used arbitrarily.

  The polyester base film is preferably biaxially stretched. As a method for producing a biaxially stretched polyester film, for example, after drying the polyester as necessary, it is supplied to a known melt extruder and extruded into a sheet form from a slit-shaped die, by a method such as electrostatic application. A method in which the unstretched sheet is biaxially stretched after being brought into close contact with the casting drum and cooled and solidified to obtain an unstretched sheet can be mentioned. The biaxial stretching method may be either simultaneous biaxial stretching or sequential biaxial stretching.

  The polyester base film may be subjected to known adhesion improving treatment such as corona treatment, frame treatment, plasma treatment and the like.

(Heat resistant water adhesion improvement layer)
The heat-resistant water adhesion improving layer is a layer for preventing the pressure-sensitive adhesive layer containing a crosslinked silicone compound having a polydimethylsiloxane skeleton from being peeled in the evaluation of heat-resistant water adhesion described later.

  The thickness of the heat resistant water adhesion improving layer is preferably 0.01 μm or more (more preferably 0.05 μm or more), and is 0.5 μm or less (more preferably 0.4 μm or less, more preferably 0.3 μm or less). preferable. If the thickness of the heat resistant water adhesion improving layer is 0.01 to 0.5 μm, good heat resistant water adhesion is exhibited. However, outside the above range, the heat resistant water adhesion does not become “◯” by the evaluation method described later. This is not preferable.

  The heat resistant water adhesion improving layer is preferably a crosslinked polymer layer (crosslinked polymer layer), and can be formed by crosslinking a polymer with a crosslinking agent or by self-crosslinking a self-crosslinking polymer.

<Polymer crosslinked with crosslinking agent>
The polymer that can be used in the method of crosslinking with a crosslinking agent is not particularly limited, but is preferably at least one selected from the group consisting of polyesters, polyurethanes, and acrylic polymers. The above polymers may be used alone or in combination of two or more.

≪Polyester for heat resistant water adhesion improvement layer≫
The polyester has an ester bond in the main chain or side chain, and is obtained by polycondensation of a polyvalent carboxylic acid component and a glycol component.

  As the polyvalent carboxylic acid component constituting the polyester, aromatic, aliphatic, and alicyclic dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, and ester derivatives thereof can be used.

  Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxy Ethane-p, p′-dicarboxylic acid, phenylindanedicarboxylic acid and the like, and ester-forming derivatives thereof can be used. From the viewpoint of strength and heat resistance of the heat resistant water adhesion improving layer, these aromatic dicarboxylic acids are preferably 30 mol% or more, more preferably 35 mol% or more, more preferably 100 mol% of the polyvalent carboxylic acid component. It is preferable to use polyester occupying 40 mol% or more.

  Examples of the aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like, and ester-forming derivatives thereof can be used.

  The glycol component constituting the polyester includes ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol. 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1,3 -Diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2, 2,4-trimethyl-1,6-hexanediol, 1,2 Cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4′-thiodiphenol, bisphenol A, 4,4′-methylenediphenol, 4,4 ′-(2-norbornylidene) diphenol, 4,4′-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4′-isopropylidenephenol 4,4′-isopropylidenevindiol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, and the like can be used.

  In addition, when using polyester as an aqueous liquid as a coating liquid, a compound containing a carboxylic acid (salt) group or a compound containing a sulfonic acid (salt) group is used to facilitate water-solubilization or water-dispersion of the polyester. It is preferable to copolymerize a compound containing a phosphonic acid (salt) group.

  Examples of the compound containing a carboxylic acid (salt) group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, 1 , 2,3,4-butanetetracarboxylic acid, 1,2,3,4-pentanetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 5- (2,5-dioxotetrahydro Furfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5- (2,5-dioxotetrahydrofurfuryl) -3-cyclohexene-1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bistrimellite 2,2 ′, 3,3′-diphenyltetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid, ethylenetetracarboxylic acid, etc., or alkali metal salts, alkaline earth metal salts thereof, An ammonium salt etc. are mentioned.

  Examples of the compound containing a sulfonic acid (salt) group include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, sulfo-p-xylylene glycol, Examples thereof include 2-sulfo-1,4-bis (hydroxyethoxy) benzene, and alkali metal salts, alkaline earth metal salts, and ammonium salts thereof.

  Examples of the compound containing a phosphonic acid (salt) group include phosphoterephthalic acid, 5-phosphoisophthalic acid, 4-phosphoisophthalic acid, 4-phosphonaphthalene-2,7-dicarboxylic acid, phospho-p-xylylene glycol, Examples include 2-phospho-1,4-bis (hydroxyethoxy) benzene, and alkali metal salts, alkaline earth metal salts, and ammonium salts thereof.

  In the present invention, for example, a modified polyester copolymer such as a block copolymer or a graft copolymer modified with acrylic, urethane, epoxy, or the like can be used as the polyester.

  Preferred polyesters are selected from terephthalic acid, isophthalic acid, sebacic acid, 5-sodium sulfoisophthalic acid as the polyvalent carboxylic acid component, and ethylene glycol, diethylene glycol, 1,4-butanediol, and neopentyl glycol as the glycol component. Examples thereof include copolymers using those. When water resistance is required, a copolymer or the like containing trimellitic acid as its copolymer component can be suitably used instead of 5-sodium sulfoisophthalic acid.

  The polyester can be produced by various production methods. For example, a polyester having a polyvalent carboxylic acid component consisting of terephthalic acid, isophthalic acid and 5-sodiumsulfoisophthalic acid and a glycol component consisting of ethylene glycol and neopentyl glycol will be described. Or the method etc. which are manufactured by the 1st step which transesterifies and the 2nd step which carries out the polycondensation reaction of the reaction product of this 1st step are mentioned.

  At this time, for example, alkali metal, alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, titanium compound, or the like can be used as the reaction catalyst.

  Further, as a method for obtaining a polyester having many carboxyl groups at the terminal and / or side chain, JP-A-54-46294, JP-A-60-209073, JP-A-62-240318, JP JP 53-26828, JP 53-26829, JP 53-98336, JP 56-116718, JP 61-124684, JP 62-240318 A method of copolymerizing a trivalent or higher polyvalent carboxylic acid can be mentioned as described in the gazette and the like, but other methods may be used.

  Further, as the water-dispersed polyester resin, for example, a commercially available “Vaironal (registered trademark)” series (manufactured by Toyobo Co., Ltd.) can also be used.

  The intrinsic viscosity of the polyester is not particularly limited, but is preferably 0.3 dl / g or more (more preferably 0.35 dl / g or more, most preferably 0.4 dl / g or more) in terms of adhesiveness. The glass transition temperature (hereinafter sometimes simply referred to as “Tg”) of the polyester is preferably 0 ° C. or higher (more preferably 10 ° C. or higher), and 130 ° C. or lower (more preferably 85 ° C. or lower). Preferably there is. Use of polyester with a Tg of 0 ° C. or higher improves hot water adhesion, and suppresses blocking phenomena such as when the hot water adhesion improved layer is laminated on the surface of the polyester-based substrate film and then wound up. be able to. Moreover, stability and water dispersibility can be favorably maintained by using polyester with Tg of 130 ° C. or lower.

≪Polyurethane for heat resistant water adhesion improvement layer≫
Next, polyurethane will be described. The polyurethane is not particularly limited as long as it has a urethane bond, and the main component is obtained by polymerizing a polyol compound and a polyisocyanate compound.

  Examples of the polyol compound include polyethylene glycol, polypropylene glycol, polyethylene / propylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone, polyhexamethylene. Examples include adipate, polytetramethylene adipate, trimethylolpropane, trimethylolethane, glycerin, and acrylic polyol.

  Examples of the polyisocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, an adduct of hexamethylene diisocyanate and trimethylolethane, and the like.

  In the synthesis of the polyurethane, a known chain extender, a crosslinking agent, and the like may be included in addition to the polyol compound and the polyisocyanate compound. Examples of the chain extender or crosslinking agent include ethylene glycol, propylene glycol, butanediol, diethylene glycol, ethylenediamine, diethylenetriamine and the like.

  In order to obtain a stable polyurethane water dispersion, it is preferable to synthesize a polyurethane having an increased affinity for water. For example, an appropriate amount of an anionic group may be introduced into the polyurethane. The polyurethane having an anionic group includes, for example, a method using a compound having an anionic group for a polyol compound, a polyisocyanate compound, a chain extender, etc., and a compound having an unreacted isocyanate group and an anionic group of the produced polyurethane. It can be produced by a method of reacting or a method of reacting a specific compound with a group having active hydrogen of polyurethane.

  The anionic group in the polyurethane is preferably used as a sulfonic acid group, a carboxylic acid group, and an ammonium salt, lithium salt, sodium salt, potassium salt or magnesium salt thereof.

  The amount of the unit having an anionic group in the polyurethane is preferably 0.05% by mass to 15% by mass from the viewpoint of water dispersibility of the polyurethane.

  Moreover, as the polyurethane water dispersion, “Hydran (registered trademark)” series (manufactured by Dainippon Ink & Chemicals, Inc.) can be used.

≪Acrylic polymer for heat resistant water adhesion improvement layer≫
Examples of the monomer component constituting the acrylic polymer include alkyl acrylate and alkyl methacrylate (the alkyl group is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl group, lauryl group, stearyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group and the like); hydroxy group-containing monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; Amides such as (meth) acrylamide N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-phenyl (meth) acrylamide Containing monomer; amino group-containing monomer such as N, N-diethylaminoethyl (meth) acrylate; epoxy group-containing monomer such as glycidyl (meth) acrylate; (meth) acrylic acid and salts thereof (lithium salt, sodium salt, potassium salt) And the like, and the like. These monomers are (co) polymerized using one kind or two or more kinds. Furthermore, these may be used in combination with other types of monomers.

  Examples of other types of monomers include epoxy group-containing monomers such as allyl glycidyl ether; sulfonic acids such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.) Monomer containing a group and a salt thereof; a monomer containing a carboxyl group or a salt thereof such as crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (lithium salt, sodium salt, potassium salt, ammonium salt, etc.) Monomers containing acid anhydrides such as maleic anhydride and itaconic anhydride; vinyl isocyanate, allyl isocyanate, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleic acid monoester, alkyl fumaric acid monoe Ether, acrylonitrile, methacrylonitrile, alkyl itaconic acid monoester, vinylidene chloride, vinyl acetate, vinyl chloride and the like.

  Moreover, as said acrylic polymer, a modified acrylic polymer, for example, a block copolymer modified with polyester, polyurethane, epoxy resin, etc., a graft copolymer, etc. can be used.

  The lower limit of Tg of the acrylic polymer is preferably −10 ° C., more preferably 0 ° C., and most preferably 10 ° C. from the viewpoint of hot water adhesion and blocking resistance. On the other hand, the upper limit of Tg of the acrylic polymer is preferably 90 ° C., more preferably 50 ° C., and most preferably 40 ° C. from the viewpoints of heat resistant water adhesion and film-forming properties. Further, the weight average molecular weight (Mw) of the acrylic polymer is preferably 50,000 or more, and more preferably 300,000 or more from the viewpoint of heat resistant water adhesion.

  Preferred as the acrylic polymer is a copolymer comprising a monomer selected from methyl methacrylate, ethyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, acrylamide, N-methylol acrylamide, and acrylic acid.

  It is preferable to dissolve, emulsify, or suspend an acrylic polymer in water and use it as an aqueous liquid from the viewpoint of environmental pollution and explosion-proof properties during coating. Such water-based acrylic polymers are copolymerized with monomers having a hydrophilic group (acrylic acid, methacrylic acid, acrylamide, vinyl sulfonic acid and salts thereof, etc.) and emulsion polymerization using reactive emulsifiers and surfactants, It can be prepared by a method such as suspension polymerization or soap-free polymerization.

  Commercially available acrylic emulsions may be used, for example, “Jonkrill (registered trademark)” series (manufactured by BASF Japan Ltd.).

<Crosslinking agent used to form heat resistant water adhesion improving layer>
In the present invention, the polyester, polyurethane and acrylic polymer are preferably crosslinked. Examples of the crosslinking agent used for crosslinking the polymer include those capable of undergoing a crosslinking reaction with a functional group present in the polymer, such as a carboxyl group, a hydroxyl group, a methylol group, and an amide group. For example, melamine crosslinking agent, oxazoline crosslinking agent, isocyanate crosslinking agent, aziridine crosslinking agent, epoxy crosslinking agent, methylolated or alkylolized urea, acrylamide, polyamide resin, amide epoxy compound, various silanes A coupling agent, various titanate coupling agents, etc. can be used. In particular, a melamine-based crosslinking agent and an oxazoline-based crosslinking agent can be suitably used from the viewpoints of compatibility with the above polymer and adhesiveness to hot water.

  The melamine-based crosslinking agent is not particularly limited, but is a melamine, a methylolated melamine derivative obtained by condensing melamine and formaldehyde, a compound partially or completely etherified by reacting a methylolated melamine with a lower alcohol, or these A mixture of the above can be used. Moreover, as a melamine type crosslinking agent, a monomer, the condensate which consists of a multimer more than a dimer, these mixtures, etc. can be used. As the lower alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like can be used. Methylolated melamine resins such as methylated trimethylolmelamine and butylated hexamethylolmelamine are preferred. In addition, in order to accelerate | stimulate the thermosetting of a melamine type crosslinking agent, you may use acidic catalysts, such as p-toluenesulfonic acid, for example.

  Further, the oxazoline-based crosslinking agent is not particularly limited as long as it has an oxazoline group as a functional group in the compound, but includes at least one monomer containing an oxazoline group, and at least one kind of What consists of an oxazoline group containing copolymer obtained by copolymerizing another monomer is preferable.

  Monomers containing an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be used, and one or a mixture of two or more thereof can also be used. Of these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

  In the oxazoline group-containing copolymer, the at least one other monomer used together with the oxazoline group-containing monomer is not particularly limited as long as it is a monomer copolymerizable with the oxazoline group-containing monomer. (Meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid and maleic acid Unsaturated nitriles such as (meth) acrylonitrile; unsaturated amides such as (meth) acrylamide and N-methylol (meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; methyl vinyl ether and ethyl vinyl ether vinyl Ethers; olefins such as ethylene and propylene; halogen-containing α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; α, β-unsaturated aromatics such as styrene and α-methylstyrene Monomers etc. can be used and these can use 1 type, or 2 or more types of mixtures.

  As the oxazoline group-containing copolymer, for example, “Epocross (registered trademark)” series (manufactured by Nippon Shokubai Co., Ltd.) is available.

  The isocyanate-based crosslinking agent is not particularly limited as long as it has an isocyanate group as a functional group in the compound, but it is preferable to use a polyfunctional isocyanate compound containing two or more isocyanate groups in one molecule.

  As the polyfunctional isocyanate compound, a low-molecular or high-molecular aromatic or aliphatic diisocyanate or a trivalent or higher polyisocyanate can be used. Examples of the polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds. Furthermore, an excess amount of these isocyanate compounds and low molecular active hydrogen compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, or polyester polyols, poly The terminal isocyanate group containing compound obtained by making it react with polymer active hydrogen compounds, such as ether polyols and polyamides, can be mentioned.

  In addition, when using an isocyanate compound as a crosslinking agent, it is also possible to use a blocked isocyanate compound. The blocked isocyanate can be prepared by subjecting the above isocyanate compound and blocking agent to an addition reaction by a conventionally known appropriate method. Examples of the blocking agent include phenols such as phenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol; thiophenols such as thiophenol and methylthiophenol; oximes such as acetoxime, methyl etiketooxime, and cyclohexanone oxime. Alcohols such as methanol, ethanol, propanol and butanol; halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; tertiary alcohols such as t-butanol and t-pentanol; Lactams such as ε-caprolactam, δ-valerolactam, ν-butyrolactam, β-propyllactam; aromatic amines; imides; acetylacetone, acetoacetate, ethyl malonate, etc. Sex methylene compound; mercaptans; imines; ureas; diaryl compounds; can be mentioned sodium bisulfite and the like.

  The epoxy-based crosslinking agent is not particularly limited as long as it has an epoxy group as a functional group in the compound. However, it is preferable to use a polyfunctional epoxy compound having two or more epoxy groups in one molecule. .

  Examples of the polyfunctional epoxy compound include diglycidyl ether of bisphenol A and oligomer thereof, diglycidyl ether of hydrogenated bisphenol A and oligomer thereof, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, p-oxybenzoic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene Glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and Polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl Examples include ether, triglycidyl ether of glycerol alkylene oxide adduct, and the like.

  As the cross-linking agent, a phenol formaldehyde resin which is a condensate of alkylated phenols, cresols and the like with formaldehyde; an adduct of urea, melamine, benzoguanamine and the like with formaldehyde, this adduct and an alcohol having 1 to 6 carbon atoms An amino resin such as an alkyl ether compound consisting of can also be used.

  Examples of the phenol formaldehyde resin include alkylated (methyl, ethyl, propyl, isopropyl or butyl) phenol, p-tert-amylphenol, 4,4′-sec-butylidenephenol, p-tert-butylphenol, o-, m-, p-cresol, p-cyclohexylphenol, 4,4'-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl-o-cresol, p-phenylphenol, xylenol, etc. And the condensates of phenols and formaldehyde.

  Examples of amino resins include methoxylated methylol urea, methoxylated methylol N, N-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine, and the like. However, preferably, methoxylated methylol melamine, butoxylated methylol melamine, methylolated benzoguanamine and the like can be mentioned.

  The polymer (polyester, polyurethane, acrylic polymer) and the crosslinking agent can be mixed and used in an arbitrary ratio. However, in order to express the hot water adhesive effect of the present invention more remarkably, the crosslinking agent is: The addition of 2 parts by mass or more (more preferably 3 parts by mass or more) and 50 parts by mass or less (more preferably 25 parts by mass or less) in terms of solid content mass ratio is preferable with respect to 100 parts by mass of the polymer. When the addition amount of the crosslinking agent is less than 2 parts by mass, the effect of addition is small, and when it exceeds 50 parts by mass, the hot water resistant adhesiveness tends to be lowered.

<Self-crosslinking polymer>
In the present invention, in addition to the above method, for example, improvement in hot water adhesion using a self-crosslinking polymer (self-crosslinking polyester, polyurethane, acrylic polymer) in which a crosslinkable functional group is introduced into the above-described polymer. A layer may be formed. The crosslinking method in the case of using a self-crosslinking polymer may be, for example, thermal crosslinking, or may be crosslinking with high energy active rays such as ultraviolet rays, electron beams and γ rays. Hereinafter, a specific method will be illustrated for the case of polyester as the self-crosslinking polymer.

≪Self-crosslinking polyester≫
The self-crosslinking type polyester preferably used in the present invention is a polyester-based graft copolymer obtained by grafting at least one radical polymerizable monomer to a hydrophobic copolymerized polyester. The “grafting” of the polyester-based graft copolymer in the present invention is to introduce a branched polymer made of a polymer different from the main chain into the backbone polymer which is the main chain. Graft polymerization is usually carried out by reacting at least one radically polymerizable monomer using a radical initiator in a state where a hydrophobic copolyester is dissolved in an organic solvent. Hydrophobic copolyesters are essentially water-insoluble polyesters that do not inherently dissolve in water. Therefore, compared to using a polyester resin that is soluble in water as a backbone polymer for graft polymerization, Excellent adhesion.

  The hydrophobic copolyester is composed of 60 to 99.5 mol% of aromatic dicarboxylic acid, 0 to 39.5 mol% of aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid in 100 mol% of dicarboxylic acid component, radical It is preferable that the dicarboxylic acid containing a polymerizable double bond is 0.5 to 10 mol%. More preferably, the aromatic dicarboxylic acid is 68 to 98 mol%, the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid is 0 to 30 mol%, and the dicarboxylic acid containing a polymerizable unsaturated double bond is 2 to 7 Mol%.

  When the aromatic dicarboxylic acid is 60 mol% or more and the aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid is 39.5 mol% or less, the heat resistant water adhesion is good. Moreover, the grafting of the radically polymerizable monomer with respect to hydrophobic copolyester can be performed efficiently by using 0.5 mol% or more of dicarboxylic acid containing a radically polymerizable double bond. On the other hand, by setting the dicarboxylic acid containing a radical polymerizable double bond to 10 mol% or less, it is possible to suppress the viscosity of the reaction solution from significantly increasing in the later stage of the grafting reaction and to proceed the reaction uniformly. .

  As the aromatic dicarboxylic acid, aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid, any of the compounds exemplified above can be used. Examples of the dicarboxylic acid containing a radical polymerizable double bond include fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid and other α, β-unsaturated dicarboxylic acids; 2,5-norbornene dicarboxylic acid anhydride, Examples thereof include alicyclic dicarboxylic acids containing a polymerizable unsaturated double bond such as tetrahydrophthalic anhydride. Of these dicarboxylic acids containing a polymerizable unsaturated double bond, fumaric acid, maleic acid, and 2,5-norbornene dicarboxylic acid anhydride are preferred from the viewpoint of polymerizability.

  As the glycol component used for obtaining the hydrophobic copolyester, any of the compounds exemplified above can be used. Two or more glycol components may be used in combination. Especially, C2-C10 aliphatic glycol, C6-C12 alicyclic glycol, etc. are preferable.

  The hydrophobic copolymerized polyester can be copolymerized with 0 to 5 mol% of a trifunctional or higher polycarboxylic acid and / or polyol. The tri- or higher functional polycarboxylic acid includes (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) benzophenone tetracarboxylic acid, trimesic acid, ethylene glycol bis (anhydrotrimellitate), glycerol tris (anne) Hydrotrimellitate) and the like. As the trifunctional or higher functional polyol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, or the like is used.

  The tri- or higher functional polycarboxylic acid and / or polyol is copolymerized in the range of 0 to 5 mol%, preferably 0 to 3 mol%, based on the total acid component or the total glycol component. Gelation can be suppressed.

  In addition, the lower limit of the weight average molecular weight of the hydrophobic copolyester is preferably 5,000 from the viewpoint of heat resistant water adhesion. Moreover, it is preferable that an upper limit is 50,000 at points, such as gelatinization at the time of superposition | polymerization.

  After synthesizing the hydrophobic copolyester, graft polymerization is performed. Graft polymerization is performed by reacting at least one radical polymerizable monomer using a radical initiator in a state where the hydrophobic copolyester is dissolved in an organic solvent. The reaction product after completion of the grafting reaction is not limited to the graft copolymer of the desired hydrophobic copolymerized polyester and the radically polymerizable monomer, but also the hydrophobic copolymerized polyester and the hydrophobic copolymer that were not subjected to grafting. It also contains a (co) polymer obtained from a radically polymerizable monomer that has not been grafted to the polyester. The polyester-based graft copolymer in the present invention is obtained not only from the above-described graft copolymer, but also from a hydrophobic copolymerized polyester that has not undergone grafting and a radically polymerizable monomer that has not been grafted. Also included are reaction mixtures that contain (co) polymers and monomers (residual monomers).

In the present invention, the acid value of the polyester-based graft copolymer is preferably 600 eq / 10 ⁶ g or more from the viewpoint of adhesiveness to hot water. More preferably, it is 1200 eq / 10 ⁶ g or more. When the acid value of the polyester-based graft copolymer is less than 600 eq / 10 ⁶ g, the heat resistant water adhesion may be lowered.

  In addition, the mass ratio of the desired hydrophobic copolymerized polyester and the radical polymerizable monomer suitable for the purpose of the present invention is desirably in the range of hydrophobic copolymerized polyester / radical polymerizable monomer = 40/60 to 95/5, more desirably. Is in the range of 55/45 to 93/7, most preferably 60/40 to 90/10.

  By setting the mass ratio of the hydrophobic copolyester to 40% by mass or more, the excellent adhesiveness of the polyester can be exhibited. On the other hand, when the mass ratio of the hydrophobic copolymerized polyester is 95% by mass or less, the blocking resistance can be improved and the acid value of the polyester-based graft copolymer can be adjusted to the above range.

  The polyester-based graft copolymer is in the form of an organic solvent solution or dispersion or an aqueous solvent solution or dispersion. In particular, a dispersion of an aqueous solvent, that is, a form of an aqueous dispersion is preferable in terms of working environment and applicability. Therefore, as the radical polymerizable monomer to be grafted, it is preferable to use a radical polymerizable monomer that essentially contains a hydrophilic radical polymerizable monomer. And after carrying out the graft polymerization in an organic solvent, the aqueous dispersion can be obtained by distilling off the organic solvent and adding water.

  The hydrophilic radical polymerizable monomer means a radical polymerizable monomer having a hydrophilic group or a group that can be changed to a hydrophilic group later. Examples of the radical polymerizable monomer having a hydrophilic group include a radical polymerizable monomer containing a carboxyl group, hydroxyl group, phosphoric acid group, phosphorous acid group, sulfonic acid group, amide group, quaternary ammonium base and the like. . On the other hand, examples of the radical polymerizable monomer having a group that can be changed into a hydrophilic group include radical polymerizable monomers containing an acid anhydride group, a glycidyl group, a chloro group, and the like. Among these, from the viewpoint of water dispersibility, a carboxyl group is preferable, and a radical polymerizable monomer having a carboxyl group or a group capable of generating a carboxyl group is preferable.

  In order to make the acid value of the polyester-based graft copolymer within the above-mentioned preferable range, the hydrophilic radical polymerizable monomer includes a radical polymerizable monomer that contains a carboxyl group or a group that generates a carboxyl group. It is preferable. Such monomers include fumaric acid, monoethyl fumarate; maleic acid and its anhydride, monoethyl maleate; itaconic acid and its anhydride, monoester of itaconic acid; acrylic acid, methacrylic acid; and salts thereof (sodium Salt, potassium salt, ammonium salt) and the like. Maleic anhydride is preferable. The said monomer can be copolymerized using 1 type, or 2 or more types.

  The radically polymerizable monomer to be grafted may contain other types of monomers as long as the acid value is within the above-mentioned preferable range. Examples of other types of monomers include monomers that can be used when synthesizing the acrylic polymer described above.

  Examples of the graft polymerization initiator used in the present invention include organic peroxides and organic azo compounds known to those skilled in the art. Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxypivalate, and examples of the organic azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2, 4-dimethyl pareronitrile). The amount of the polymerization initiator used for the graft polymerization is at least 0.2% by mass, preferably 0.5% by mass or more, based on the radical polymerizable monomer.

  In addition to the polymerization initiator, a chain transfer agent for adjusting the chain length of the branched polymer, for example, octyl mercaptan, mercaptoethanol, 3-t-butyl-4-hydroxyanisole may be used as necessary. In this case, it is desirable to add in the range of 0 to 5 mass% with respect to the radical polymerizable monomer.

  The reaction product after completion of the grafting reaction is preferably neutralized with a basic compound, and can be easily dispersed in water by neutralization. As the basic compound, a compound that volatilizes at the time of coating film formation is desirable, and ammonia, organic amines, and the like are preferable. Desirable compounds include, for example, triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine , 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanol An amine etc. can be mentioned.

  In the basic compound, the pH value of the aqueous dispersion is in the range of 5.0 to 9.0 by at least partial neutralization or complete neutralization depending on the carboxyl group content contained in the reaction product after completion of the grafting reaction. It is desirable to use it as follows. If a basic compound with a boiling point of 100 ° C. or less is used, there are few residual basic compounds in the coating film after drying, and for example, improved hot water adhesion in harsh environments such as high temperature and humidity To do.

  In the polyester-based graft copolymer, the weight average molecular weight of the graft polymer (branched polymer) of the radical polymerizable monomer is preferably 500 to 50,000. It is generally difficult to control the weight average molecular weight of the graft polymer (branched polymer) of the radically polymerizable monomer to less than 500, the grafting efficiency is lowered, and hydrophilic groups are sufficiently imparted to the hydrophobic copolyester. There is a tendency not to be done. In addition, the graft polymer (branched polymer) of the radical polymerizable monomer forms a hydrated layer of dispersed particles, but in order to provide a hydrated layer of sufficient thickness and obtain a stable aqueous dispersion, the radical polymerizable monomer is used. The weight average molecular weight of the graft polymer (branched polymer) is preferably 500 or more.

  In addition, the upper limit of the weight average molecular weight of the graft polymer (branched polymer) of the radical polymerizable monomer is preferably 50,000 from the viewpoint of polymerizability in solution polymerization.

  In order to make the weight average molecular weight of the graft polymer (branched polymer) of the radical polymerizable monomer within the range of 500 to 50,000, the amount of initiator, monomer dropping time, polymerization time, reaction solvent, monomer composition, or necessary Depending on the case, it is preferable to carry out by appropriately combining a chain transfer agent and a polymerization inhibitor.

  The Tg of the polyester-based graft copolymer is not particularly limited, but is preferably 20 ° C. or higher, more preferably 40 ° C. or higher in consideration of the hot water adhesiveness.

  In the present invention, a polyester-based graft copolymer obtained by graft-polymerizing a radically polymerizable monomer to a hydrophobic copolymerized polyester has a self-crosslinking property because a hydroxyl group in the polyester reacts with a carboxyl group present in the graft portion. Have. Moreover, although it does not bridge | crosslink at normal temperature, it carries out intermolecular reaction, such as a hydrogen abstraction reaction by a thermal radical, with the heat at the time of drying at the time of coating film formation, and bridge | crosslinks without a crosslinking agent. As a result, a high degree of heat-resistant water adhesion is exhibited. The degree of crosslinking of the coating can be evaluated by various methods. For example, the insoluble fraction in a chloroform solvent or the like that dissolves both the hydrophobic copolymerized polyester and the grafted polymer (polyester-based graft copolymer) can be determined. The measuring method etc. are mentioned.

  The insoluble fraction of the coating film obtained by drying at about 80 ° C. and heat-treating at 120 ° C. for 5 minutes is preferably 50% by mass or more, more preferably 70% by mass from the viewpoints of heat resistant water adhesion and blocking resistance. That's it.

  As the self-crosslinking polyester resin aqueous dispersion, for example, a commercially available product such as “Vylonal (registered trademark) AGN702” (manufactured by Toyobo Co., Ltd.) can be used.

  In addition, a grafted polyurethane can be prepared by a method similar to the above.

<Additive for heat resistant water adhesion improving layer>
Various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, and a pigment are included in the heat resistant water adhesion improving layer as long as the effects of the present invention are not impaired. , Dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents and the like may be blended.

  In particular, when the inorganic particle is added to the heat resistant water adhesion improving layer, for example, when the heat resistant water adhesion improving layer is laminated on the surface of the polyester base film and wound once, Since blocking property improves, it is preferable.

  In this case, silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, or the like can be used as the inorganic particles to be added. The inorganic particles used preferably have an average particle size of 0.005 μm or more (more preferably 0.01 μm or more, most preferably 0.05 μm or more), preferably 5 μm or less (more preferably 3 μm or less, most preferably 2 μm or less). . Although the usage-amount of an inorganic particle is not specifically limited, 0.05 mass part or more (more preferably 0.1 mass part or more) in solid content with respect to 100 mass parts of polymers in a heat-resistant water-adhesion improvement layer, 10 mass parts It is preferable to mix below (more preferably 5 parts by mass or less).

<Method for forming heat resistant water adhesion improving layer>
The heat resistant water adhesion improving layer uses an aqueous dispersion of a mixture of one or more polymers selected from the group consisting of the above polyester, polyurethane and acrylic polymer and a crosslinking agent, or an aqueous dispersion of a self-crosslinking polymer. It is most convenient to form by a coating method in which this aqueous dispersion is coated on the surface of the polyester base film. For example, a method of applying the aqueous dispersion to an unstretched film of a polyester-based substrate film and then stretching in at least one direction, a method of applying the aqueous dispersion after longitudinal stretching, and the above-described film surface after orientation treatment Examples thereof include a method of applying an aqueous dispersion. In particular, when producing a polyester base film, the aqueous dispersion is applied before the film crystal orientation is completed, and after stretching in at least one direction, the crystal orientation of the polyester base film is completed. The so-called in-line coating method is preferable because a thin film can be easily formed and the effects of the present invention can be exhibited more remarkably.

  When applying the aqueous dispersion to an unstretched film of a polyester base film, various coating methods such as reverse coating, gravure coating, rod coating, bar coating, Mayer bar coating, and die coating are used. A spray coating method or the like can be used.

  You may provide a heat-resistant water adhesive improvement layer on both surfaces of a polyester-type base film.

(Adhesive layer)
<Adhesion layer containing a crosslinked silicone compound having a polydimethylsiloxane skeleton>
Among the pressure-sensitive adhesive layers provided on both surfaces of the polyester-based substrate film, at least one pressure-sensitive adhesive layer is laminated via the heat-resistant water adhesion improving layer, and the pressure-sensitive adhesive layer has a polydimethylsiloxane skeleton. The main component (70 mass% or more, More preferably, 90 mass% or more, More preferably, 100 mass%) is included. The double-sided pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer is excellent in removability from the adherend, and can disperse and absorb an impact applied to the surface of the adherend. Moreover, when the said adhesion layer is laminated | stacked through a heat-resistant water adhesive improvement layer, an adhesion layer becomes difficult to peel from a polyester-type base film.

  The crosslinked silicone compound having a polydimethylsiloxane skeleton has a number average molecular weight (Mn) of 50,000 or more (more preferably 80,000 or more, more preferably 100,000 or more) and 500,000 or less (more preferably 400,000). In the following, it is preferable to crosslink an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton of 350,000 or less). By using an uncrosslinked product of a silicone compound, solubility in a solvent and fluidity can be secured, and formation of an adhesive layer is facilitated. Further, it is superior in quality, quality stability, operability during production, and the like, compared to the case where a conventionally known millable type silicone compound is used as a raw material. Specifically, a compound plasticizing step by kneading or the like necessary for dissolving a conventional millable type silicone rubber compound in a solvent is unnecessary. In addition, the obtained coating solution has good storage stability, and does not cause a thickening phenomenon such as gelation, which is often seen when preparing a solution of a silicone rubber compound. Furthermore, since the production | generation of the foreign material by the undissolution of the silicone rubber compound which may generate | occur | produce in the solutionization of a silicone rubber compound is suppressed, the coating liquid with high clarity is obtained.

  Here, if Mn of an uncrosslinked body is 50,000 or more, the crosslinkability is improved. Moreover, if Mn of an uncrosslinked body is 500,000 or less, the deterioration of the operativity at the time of production, such as the viscosity of a coating liquid becoming too high, can be suppressed.

  Examples of the uncrosslinked product of the silicone compound include those commercially available as silicone oil. When silicone oil is used, straight silicone oil, particularly non-reactive dimethyl silicone oil is preferred. Thereby, the silicone compound after crosslinking has a polydimethylsiloxane skeleton.

  The uncrosslinked product of the silicone compound is most preferably composed only of a silicone compound having a polydimethylsiloxane skeleton, but may contain a silicone compound having a polyalkylalkenylsiloxane skeleton as long as it is less than 10% by mass. . In addition, the crosslinkability is lowered in the methylphenyl type silicone oil, and the reactive methylhydrogen type silicone oil is not preferable because it has poor storage stability and may adversely affect the quality and operability. If it is less than 30% by mass (more preferably less than 5% by mass), a silicone compound having no polydimethylsiloxane skeleton of methylphenyl type, methylhydrogen type or other various modified types may be blended.

  The lower limit of the thickness of the pressure-sensitive adhesive layer containing the silicone compound is preferably 3 μm (more preferably 5 μm, still more preferably 8 μm) from the viewpoint of adhesive strength. On the other hand, the upper limit of the thickness of the pressure-sensitive adhesive layer may be determined within a range where the pressure-sensitive adhesive force can be stably maintained from the viewpoint of economy. For example, 200 μm (more preferably 180 μm) is preferable.

  The pressure-sensitive adhesive layer containing the silicone compound has an adhesion improver for increasing the adhesive strength between the pressure-sensitive adhesive layer and the heat resistant water adhesion improving layer so that the pressure-sensitive adhesive layer is more difficult to peel off from the polyester base film. May be included.

  As the adhesion improver, it is preferable to use a compound containing a reactive group active against a radical reaction. Examples of this compound include (meth) acrylic acid derivatives and allyl derivatives. Among them, derivatives having 2 or more, particularly 3 or more unsaturated bonds are preferable. These compounds are widely used as rubber co-crosslinking agents, such as polyhydric alcohol and (meth) acrylic acid esters, polyhydric carboxylic acid allyl esters, triallyl isocyanurate, triallyl cyanurate, and the like. Can be mentioned.

  The ester of the polyhydric alcohol and (meth) acrylic acid is an ester compound obtained by esterifying two or more alcoholic hydroxyl groups of a polyhydric alcohol having two or more alcoholic hydroxyl groups with (meth) acrylic acid. Specifically, for example, ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, 2,2′-bis [4- (meth) acryloxydiethoxyphenyl] propane, glycerin di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tetramethylolmethane di (meth) acrylate, tetramethylolmethanetri (meth) acrylate, Lame Chi roll tetra (meth) acrylate, dimer diol di (meth) acrylate and the like, particularly compounds containing three or more (meth) acryloyl group is preferred. In addition, although said compound illustrated each single ester compound of acrylic acid and methacrylic acid, the form of mixed ester of acrylic acid and methacrylic acid may be sufficient.

  Examples of the allyl ester of polyvalent carboxylic acid include phthalic acid diarylate, trimellitic acid diarylate, and pyromellitic acid tetraarylate.

  The said adhesive improvement agent may be used independently, or may be used in combination of 2 or more type.

  The blending amount of the adhesion improver is preferably 0.2 parts by mass or more (more preferably 0.5 parts by mass or more) and 100 parts by mass or less (more preferably 10 parts by mass) with respect to 100 parts by mass of the silicone compound component. The following is preferable. By making the compounding amount of the adhesion improver 0.2 parts by mass or more, the effect of improving the hot water adhesion of the pressure-sensitive adhesive layer is further increased. On the other hand, when the compounding amount of the adhesion improver exceeds 20 parts by mass, the effect of improving the hot water adhesiveness not only reaches saturation, but conversely, this effect may be deteriorated.

  In the present invention, the method for forming the pressure-sensitive adhesive layer is not limited, but an uncrosslinked product of the silicone compound is dissolved or dispersed in a solvent, and an adhesion improver is added as necessary to prepare a coating solution. In a preferred embodiment, the film is formed by crosslinking after coating by a coating method. Specifically, for example, a coating liquid containing the silicone oil or the like is applied to the surface of the heat-resistant water adhesion improving layer formed on the surface of the polyester base film or the release layer formed on the surface of the polyester film ( It can be formed by coating on the surface of (described later) and laminating another layer (heat resistant water adhesion improving layer) or performing a crosslinking treatment without laminating.

  Since the uncrosslinked product of the silicone compound dissolves well in aromatic hydrocarbons such as toluene, it is preferable to dissolve it in these solvents and apply it by a coating method.

  The crosslinking method of the silicone compound may be, for example, thermal crosslinking, or may be crosslinking with high energy active rays such as electron beams and γ rays. It is considered that when an active ray is irradiated on a silicone compound, hydrogen is extracted from the methyl group of polydimethylsiloxane, and a crosslinking reaction occurs between adjacent silicone compounds from which hydrogen is extracted from the methyl group. Therefore, in the crosslinking method using actinic radiation, it is not necessary to add additives such as peroxide for radical generation and crosslinking catalyst to the silicone compound. For this reason, the contamination with respect to the adherend by the residue of these additives is suppressed, and it is not necessary to consider the pot life after blending the crosslinking catalyst or the like. Furthermore, productivity is increased because crosslinking is completed efficiently in a short time.

  Among the crosslinks using actinic radiation, the electron beam cross-linking method is preferable because of the availability of an irradiation apparatus (EB irradiation apparatus). As an electron beam irradiation amount in an EB irradiation apparatus, the range of 5-50 Mrad is preferable. By setting the electron beam irradiation amount to 5 Mrad or more, the crosslinking reaction of the silicone compound can be promoted, and the adhesive residue on the adherend can be reduced and the repairability can be improved when re-peeling. On the other hand, by setting the electron beam irradiation amount to 50 Mrad or less, it is possible to suppress a decrease in adhesiveness due to excessive progress of the crosslinking reaction.

  The lower limit of the adhesive strength of the pressure-sensitive adhesive layer containing the silicone compound is 0.01 N / 20 mm (against glass 180 degree peel test, pulling speed 300 mm / min) from the point of reliability when used for bonding articles. Preferably, it is 0.05 N / 20 mm. On the other hand, the upper limit of the adhesive strength is preferably 1.0 N / 20 mm, more preferably 0.5 N / 20 mm, from the viewpoint of improving removability and ensuring good repairability. Moreover, it is preferable from the point of repair property that the adhesion layer does not remain on the glass surface when evaluated by the above evaluation method, that is, there is no adhesive residue.

  In the present invention, the pressure-sensitive adhesive layer containing the silicone compound (hereinafter sometimes referred to as “silicone compound-based pressure-sensitive adhesive layer”) preferably contains no reinforcing agent at all, but does not interfere with the effects of the present invention. If present, a reinforcing agent such as silica may be included.

[Adhesiveness]
In the present invention, it is preferable that the silicone compound pressure-sensitive adhesive layer, the heat-resistant water adhesion improving layer, the heat-resistant water adhesion improving layer, and the polyester base film are firmly bonded. That is, when a cutter knife is inserted between the silicone compound pressure-sensitive adhesive layer and the polyester-based substrate film, and peeling is performed by applying force with a finger (exposing the interface), the adhesive strength is strong and the interface cannot be provided. It is preferable. In the present invention, although the heat resistant water adhesion improving layer exists between the silicone compound pressure-sensitive adhesive layer and the polyester base film, the thickness of the heat resistant water adhesion improving layer is thin. However, it is preferable that the silicone compound pressure-sensitive adhesive layer and the polyester-based substrate film are firmly bonded and the interface cannot be formed. Hereinafter, in the present invention, the above characteristics may be simply referred to as “adhesiveness”.

  Moreover, even if the double-sided adhesive sheet of this invention is preserve | saved for a long time in hot water, it is preferable that the said adhesiveness is maintained. Specifically, it is preferable that the pressure-sensitive adhesive layer does not peel when evaluated by the following hot water resistant adhesiveness evaluation method. Hereinafter, the adhesive hot water durability may be referred to as “heat resistant water adhesiveness”.

[Heat resistant water adhesion]
The double-sided pressure-sensitive adhesive sheet of the present invention having a size of 50 mm × 50 mm (referred to as a double-sided pressure-sensitive adhesive sheet after the separation film is peeled off when a separate film is laminated on the surface of the pressure-sensitive adhesive layer, as will be described later. These double-sided pressure-sensitive adhesive sheets may be simply referred to as “samples”), and the silicone compound pressure-sensitive adhesive layer is placed in a 500 cc cylindrical glass container with a lid containing 400 cc of distilled water. Submerge in the water so that it is on the side, and cover the container with the entire sample immersed in water. If the sample itself is not immersed in water, place the weight on the sample so that the entire sample is immersed in water. The size and material of the weight are not particularly limited. For example, a polyester film having a size of 60 mm × 60 mm and a thickness of 188 μm can be used.

  Next, the container containing the sample is placed in a gear oven set at 80 ° C. and allowed to stand for 24 hours. After heat treatment, take out the container from the oven, quickly take out the sample, apply force with the finger pad from the silicone compound adhesive layer side to the end and rub it 10 times, and this adhesive layer peels from the polyester base film side Evaluate whether to do.

  Since the double-sided pressure-sensitive adhesive sheet of the present invention has the silicone compound-based pressure-sensitive adhesive layer laminated via a heat-resistant water-adhesive improvement layer, the silicone compound-based pressure-sensitive adhesive layer can be peeled even in the method for evaluating heat-resistant water-adhesiveness. There is no. For this reason, for example, when the double-sided pressure-sensitive adhesive sheet of the present invention is used as a member such as a touch panel for car navigation, interfacial peeling at the interface between the silicone compound-based adhesive layer and the polyester-based substrate film can be suppressed. Improves.

<Acrylic adhesive layer or rubber adhesive layer (hereinafter also referred to as "non-silicone compound adhesive layer")>
The double-sided pressure-sensitive adhesive sheet used in the present invention may be one in which the silicone compound-based pressure-sensitive adhesive layer is laminated on both sides of the polyester-based substrate film via the heat-resistant water adhesion improving layer. It may have an adhesive layer containing the silicone compound on one side of the material film and a non-silicone compound-based adhesive layer on the other side. Thereby, the double-sided pressure-sensitive adhesive sheet used in the present invention is useful for bonding different members. Examples of the non-silicone compound-based adhesive layer include an acrylic adhesive layer and a rubber-based adhesive layer.

≪Acrylic adhesive layer≫
The acrylic pressure-sensitive adhesive layer can be constituted, for example, by containing an acrylic polymer having a main monomer component of (meth) acrylate having 1 to 18 carbon atoms in the alkyl group as a main component or base polymer.

  Examples of the (meth) acrylate having an alkyl group having 1 to 18 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, Isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) Examples include acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl acrylate (meth) acrylate, decyl acrylate (meth) acrylate, and dodecyl (meth) acrylate. These (meth) acrylates may be used alone or in combination of two or more.

  The acrylic pressure-sensitive adhesive layer may include a monomer component (copolymerizable monomer) having copolymerizability with the (meth) acrylate. In particular, when the acrylic polymer is crosslinked, the copolymerizable monomer is preferably a monomer for modifying the acrylic adhesive layer. A copolymerizable monomer may be used independently or may be used in combination of 2 or more type.

  Specifically, as the copolymerizable monomer, any of the monomer components constituting the acrylic polymer for the heat resistant water adhesion improving layer and the monomers exemplified as other types of monomers can be used, and further, ethylene, propylene, etc. Examples include α-olefin monomers.

  As the modifying monomer, any of the known modifying monomers can be used, but the functional group-containing monomers as exemplified in the acrylic polymer for the heat resistant water adhesion improving layer are suitable. Of these, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferable, and acrylic acid is particularly preferable. The acrylic polymer can be crosslinked using a functional group (particularly a polar group) derived from the modifying monomer.

  Polymerization methods for obtaining acrylic polymers include solution polymerization methods using emulsion initiators such as azo compounds and peroxides, emulsion polymerization methods and bulk polymerization methods, and light and radiation using photoinitiators. A polymerization method performed by irradiation can be employed. In the present invention, a method of polymerizing using a polymerization initiator that decomposes to generate radicals (radical polymerization method) can be suitably employed. In this radical polymerization, polymerization initiators such as peroxides such as benzoyl peroxide and tert-butyl permaleate, and azo compounds such as 2,2′-azobisisobutyronitrile and azobisisovaleronitrile are usually used. To do. The amount of the polymerization initiator used may be the amount usually used in the polymerization of the acrylic monomer, and for example, about 0.005 to 10 parts by mass, preferably 0.1 to 100 parts by mass of the total amount of monomer components. About 5 parts by mass.

  The proportion of the (meth) acrylate having an alkyl group having 1 to 18 carbon atoms as the main monomer component of the acrylic polymer is 50% by mass or more (more preferably 80% by mass) in 100% by mass of the monomer component from the viewpoint of adhesive properties. % Or more, more preferably 90% by mass or more). Therefore, the proportion of the copolymerizable monomer other than the (meth) acrylate is 50% by mass or less in 100% by mass of the monomer component.

  The acrylic polymer obtained by polymerizing the monomer component can be used as it is. It is also possible to cure the acrylic polymer by crosslinking. When the polymer is crosslinked, the cohesive force of the pressure-sensitive adhesive can be further increased. For crosslinking, a crosslinking agent can be used. That is, the acrylic pressure-sensitive adhesive may contain a crosslinking agent together with the acrylic polymer. For the crosslinking of the polymer, a heat crosslinking method is preferably used.

  As the crosslinking agent, any of the crosslinking agents exemplified as the crosslinking agent that can be used in the hot water resistant adhesion improving layer can be used. As the crosslinking agent, melamine crosslinking agent, epoxy crosslinking agent, and isocyanate crosslinking agent are particularly preferable. A crosslinking agent can be used individually or in mixture of 2 or more types. The amount of the melamine crosslinking agent and / or epoxy crosslinking agent used is preferably 0.001 part by mass or more (more preferably 0.01 part by mass or more), preferably 10 parts by mass with respect to 100 parts by mass of the acrylic polymer. The following (more preferably 5 parts by mass or less) is preferable. The amount of the isocyanate-based crosslinking agent used is preferably 0.01 parts by mass or more (more preferably 0.05 parts by mass or more), and 20 parts by mass or less (more preferably 15 parts by mass) with respect to 100 parts by mass of the acrylic polymer. Part or less) is preferred.

  You may add various additives to an acrylic adhesive as needed. For example, a tackifier resin (for example, a rosin resin, a terpene resin, a petroleum resin, a coumarone / indene resin, a styrene resin, or the like) may be blended to adjust the adhesion characteristics. From the viewpoint of increasing the colorless transparency of the double-sided pressure-sensitive adhesive sheet and suppressing the change in color tone, a hydrogenated tackifying resin is preferable, and the blending ratio is preferably set in a range that does not increase the haze of the double-sided pressure-sensitive adhesive sheet. Further, as additives other than the tackifying resin, various known additives such as plasticizers, fillers such as fine powder silica, colorants, ultraviolet absorbers, surfactants and the like can be blended. The amount of these additives used may be a normal amount applied to the acrylic pressure-sensitive adhesive.

  The adhesive strength of the acrylic pressure-sensitive adhesive layer can be controlled by adjusting the ratio of the modifying monomer (functional group-containing monomer) or the crosslinking agent, or using a surfactant.

  The thickness of the acrylic adhesive layer is not particularly limited, and is preferably 3 μm or more (more preferably 5 μm or more, more preferably 10 μm or more), and 200 μm or less (more preferably 50 μm or less, more preferably 30 μm or less). preferable.

  As the acrylic pressure-sensitive adhesive, for example, “SK Dyne” series (manufactured by Soken Chemical Co., Ltd.) can also be used. Among these, use of a brand of optical pressure-sensitive adhesive is preferable.

  The formation method of the said acrylic adhesive layer is not limited. For example, a solution type coating solution of an organic solvent or a coating solution in the form of an aqueous dispersion is prepared and applied by a coating method. In addition, a layer having the same composition as the heat resistant water adhesion improving layer is provided between the acrylic pressure-sensitive adhesive layer and the polyester base film so as to enhance the adhesion between the acrylic pressure-sensitive adhesive layer and the polyester base film. It may be configured.

  The adhesive strength of the acrylic adhesive layer may be the same as that of the adhesive layer including the silicone compound, or may be small or large. It is preferable to select and set appropriately according to the method of using the double-sided pressure-sensitive adhesive sheet of the present invention. For example, in order to apply to a method of use that requires removability on both sides, the adhesive layer containing the silicone compound has a range equivalent to the adhesive strength, that is, 0.01 to 1.0 N / 20 mm (relative to 180 ° glass). The range of the test and the pulling speed of 300 mm / min is preferable. On the other hand, when firmly fixing one side, it is good to set it higher than the said range. For example, it is preferably 5.0 N / 20 mm or more, and 5.0 to 25 N / 20 mm is a suitable range. A more preferable range is 8.0 to 20 N / 20 mm.

≪Rubber adhesive layer≫
Moreover, the double-sided pressure-sensitive adhesive sheet used in the present invention may have a rubber-based pressure-sensitive adhesive layer in place of the acrylic pressure-sensitive adhesive layer.

  The rubber component which comprises a rubber-type adhesion layer is not limited. For example, natural rubber (NR), ethylene propylene diene rubber (EPDM), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber, acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), acrylic rubber (ACM) Any rubber such as fluoro rubber (FKM), or a mixture thereof may be used, and may be appropriately selected depending on the required properties according to the purpose of use.

  Styrenic elastomers (SBS, SEBS, SEPS, etc.) may also be used.

  In the present invention, in order to further improve the heat-resistant water adhesion between the polyester base film and the rubber adhesive layer, it is preferable to add an adhesion improver to the rubber adhesive layer. As the adhesion improver that can be blended in the rubber-based pressure-sensitive adhesive layer, those similar to those described above as the adhesion improver that can be blended in the pressure-sensitive adhesive layer containing the silicone compound can be used.

  The compounding amount of the adhesion improver is 0.2 parts by mass or more (more preferably 0.5 parts by mass or more), 20 parts by mass or less (more preferably 10 parts by mass or less) with respect to 100 parts by mass of all rubber components. It is preferable to do this. If the blending amount is less than 0.2 parts by mass, the adhesive strength with the polyester base film tends to be insufficient. On the other hand, even if blending exceeds 20 parts by mass, the effect of improving the adhesive strength commensurate with the blending amount is achieved. Is difficult to obtain, rather the physical properties of the rubber tend to be reduced.

  Moreover, in order to make the adhesive improvement effect by an adhesive improvement agent more remarkable, you may mix | blend a peroxide compound with respect to a rubber-type adhesion layer. Thereby, the heat-resistant water adhesiveness of a rubber-type adhesion layer and a polyester-type base film improves further.

  The peroxide compound may be either acyl-based or alkyl-based, such as benzoyl peroxide, monochlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2, 5-bis (t-butylperoxy) hexane, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-bis-t-butylperoxy-3,3,5 -Trimethylcyclohexane, di-t-butyl peroxide, t-butyl cumyl peroxide and the like.

  The amount of the peroxide compound is 0.05 parts by mass or more (more preferably 1 part by mass or more) and 10 parts by mass or less (more preferably 8 parts by mass or less) with respect to 100 parts by mass of the rubber component. preferable. When the blending amount is less than 0.05 parts by mass, it is difficult to see contribution to the effect of improving adhesiveness. Moreover, even if it mixes exceeding 10 mass parts, the above-mentioned adhesive improvement effect will be saturated, and the physical property of a rubber-type adhesive layer and a double-sided adhesive sheet may fall rather.

Moreover, it is preferable to mix | blend uncrosslinked silicone rubber with the said rubber-type adhesion layer. As the uncrosslinked silicone rubber, an organopolysiloxane represented by an average unit formula: R _a SiO 2 _{(4-a) / 2} is preferable.

In the above formula, R is a substituted or unsubstituted monovalent hydrocarbon group, for example, an alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, vinyl group, allyl group, Alkenyl groups such as butenyl, pentenyl and hexenyl; aryl groups such as phenyl, tolyl, xylyl and naphthyl; cycloalkyl such as cyclopentyl and cyclohexyl; aralkyl such as benzyl and phenethyl; Examples include halogenated alkyl groups such as 3-chloropropyl group and 3,3,3-trifluoropropyl group. A methyl group, a vinyl group, a phenyl group, and a 3,3,3-trifluoropropyl group are preferable. In the above formula, a is a number in the range of 1.9 to 2.1. The silicone rubber component is represented by the above average unit formula. Specific siloxane units constituting the silicone rubber component include, for example, R ₃ SiO _1/2 units, R ₂ SiO _2/2 units, and R SiO _3/2. Units and SiO _4/2 units. R ₂ (HO) SiO _1/2 units may also be used.

The main component of the silicone rubber component is a linear polymer essentially comprising R ₂ SiO _2/2 units and R ₃ SiO _1/2 units or R ₂ (HO) SiO _1/2 units, and in some cases a small amount RSO _3/2 units and / or R ₃ SiO _1/2 units may be contained, and a part thereof may have a branched structure. In addition, a dendritic polymer composed of R ₃ SiO _1/2 units and SiO _4/2 units can be blended as a part of the silicone rubber component.

In addition, the molecular structure of the uncrosslinked silicone rubber component is not particularly limited, and examples thereof include a straight chain, a partially branched straight chain, a branched chain, and a dendritic chain. Is preferably a linear polymer or a mixture mainly composed of a linear polymer. Examples of the silicone rubber component include, for example, molecular chain both ends trimethylsiloxy group-capped dimethylpolysiloxane, molecular chain both ends trimethylsiloxy group-capped methylvinylpolysiloxane, molecular chain both ends trimethylsiloxy group-capped methylphenylpolysiloxane, molecule Trimethylsiloxy group-capped dimethylsiloxane / methylvinylsiloxane copolymer, both ends of the chain trimethylsiloxy group-capped dimethylsiloxane / methylphenylsiloxane copolymer, trimethylsiloxy group-capped dimethylsiloxane / methyl (3,3) 3,3-trifluoropropyl) siloxane copolymer, trimethylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, both ends of molecular chain dimethyl Nylsiloxy group-blocked dimethylpolysiloxane, molecular chain both ends dimethylvinylsiloxy group-blocked methylvinylpolysiloxane, molecular chain both ends dimethylvinylsiloxy group-blocked methylphenylpolysiloxane, molecular chain both ends dimethylvinylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane Copolymer, dimethylvinylsiloxy group-capped dimethylvinylsiloxy group-blocked dimethylvinylsiloxy group, dimethylvinylsiloxy group-capped dimethylsiloxane-methyl (3,3,3-trifluoropropyl) siloxane copolymer Dimethylvinylsiloxy group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, silanol group-blocked dimethylpolysiloxane, molecular chain Silanol group-blocked methylvinylpolysiloxane, molecular chain both-end silanol-blocked methylphenylpolysiloxane, molecular chain both-end silanol-blocked dimethylsiloxane / methylvinylsiloxane copolymer, molecular chain both-end silanol-blocked dimethylsiloxane / methylphenyl Siloxane copolymer, silanol group-blocked dimethylsiloxane / methyl (3,3,3-trifluoropropyl) siloxane copolymer, both ends of molecular chain silanol group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane Polymer, molecular chain both ends trimethoxysiloxy-blocked dimethylpolysiloxane, molecular chain both ends trimethoxysiloxy group-blocked dimethylsiloxane / methylvinylsiloxane copolymer, molecular chain both ends trimethoxysiloxane Si-blocked dimethylsiloxane / methylphenylsiloxane copolymer, trimethoxysiloxy group-blocked dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer, both ends of the molecular chain, from R ₃ SiO _1/2 unit and SiO _4/2 unit An organopolysiloxane copolymer comprising R ₂ SiO _2/2 units and RSiO _3/2 units, R ₃ SiO _1/2 units, R ₂ SiO _2/2 units and RSIO _3/2 Examples thereof include an organopolysiloxane copolymer composed of units, and a mixture of two or more of these. The viscosity of the silicone rubber component at 25 ° C. is not particularly limited, but is practically preferably 100 centistokes or more, particularly 1,000 centistokes or more.

  The amount of the uncrosslinked silicone rubber is 5 parts by mass (more preferably 10 parts by mass) or more and 100 parts by mass (more preferably 70 parts by mass) with respect to 100 parts by mass of rubber components other than silicone rubber. Is preferred. When the blending amount is less than 5 parts by mass, the contribution to the effect of improving the adhesiveness is small. On the other hand, when it exceeds 100 parts by mass, the improvement effect of the hot water adhesiveness not only reaches saturation, but is also preferable from the economical aspect. Absent. Moreover, the heat resistance of a rubber-type adhesion layer may improve by mix | blending silicone rubber.

  Also, instead of blending uncrosslinked silicone rubber into the rubber-based adhesive layer, an uncrosslinked silicone rubber blended with an adhesion improver as an intermediate layer between the polyester base film and the rubber-based adhesive layer You may improve the heat-resistant water adhesiveness of a polyester-type base film and a rubber-type adhesion layer by interposing the layer of a composition. In this case, as the uncrosslinked silicone rubber, any of those described above can be used, and the same adhesion improver as that blended in the rubber-based pressure-sensitive adhesive layer can also be used. In addition, the compounding quantity of the adhesive improvement agent with respect to silicone rubber is 0.5 mass with respect to 100 mass parts of uncrosslinked silicone rubber, for example, when using the said (meth) acrylic acid ester as an adhesive improvement agent. Parts (particularly 1 part by mass) or more and 30 parts by mass (particularly 20 parts by mass) or less. If the blending amount is less than 0.5 parts by mass, the adhesive strength between the intermediate layer (the layer of the uncrosslinked silicone rubber composition) and the polyester base film becomes insufficient, while if it exceeds 30 parts by mass, the adhesive strength is saturated. , It becomes economically disadvantageous.

  The thickness of the uncrosslinked silicone rubber layer is preferably 0.0005 to 0.05 mm.

  The rubber-based adhesive layer may contain reinforcing fillers, pigments, dyes, anti-aging agents, antioxidants, mold release agents, flame retardants, thixotropy imparting agents, filler dispersants, etc., as necessary. You may mix | blend. Moreover, a peroxide can be mix | blended as an adhesive improvement promoter for promoting the adhesive improvement effect by said adhesive improvement agent.

  The method of blending the above compounding agent into the rubber-based adhesive layer is not particularly limited. For example, when a rubber compound is prepared, a rubber kneader such as a two-roll, Banbury mixer, or dough mixer (kneader) is used. In addition, when rubber is dissolved in a solvent and a film is formed by the casting method, various compounding agents are added and mixed either when the rubber compound is dissolved in a solvent to prepare a solution or after it is made into a solution. May be.

(Optical characteristics of double-sided PSA sheet)
The double-sided pressure-sensitive adhesive sheet of the present invention preferably has a total light transmittance of 90% or more and a haze of 1.5% or less in applications requiring high transmittance. More preferably, the total light transmittance is 92% or more and the haze is 1.1% or less. Furthermore, it is preferable that the total light transmittance and haze are within the above-mentioned preferable range even after storage at 65 ° C. and 85 RH% for 200 hours. Although the double-sided pressure-sensitive adhesive sheet of the present invention has the above-mentioned properties, it can be suitably used for bonding optical members, but is not limited to this application.

(Image display panel)
Examples of the image display panel used in the present invention include an image display panel used in a device selected from the group consisting of a liquid crystal display device, a plasma display device, an organic electroluminescence display device, a cathode ray tube display device, and a field emission display device.

(Protective panel)
The protective panel used in the present invention protects the surface of the image display panel, while having transparency, so that characters and figures displayed on the image display panel can be clearly seen through the protective panel. I just need it. Examples of the resin that can be used to form the protective panel include acrylic resins, polycarbonate resins, and alicyclic polyolefin resins. Various glasses can also be used.

(Method for manufacturing image display device)
In the present invention, the method for bonding the image display panel and the protective panel using the double-sided pressure-sensitive adhesive sheet is not particularly limited. For example, when the double-sided pressure-sensitive adhesive sheet is prepared as a double-sided pressure-sensitive adhesive sheet with a separate film laminated on the surface of the pressure-sensitive adhesive layer, the separation film is peeled from the surface of the pressure-sensitive adhesive layer, and then the image display panel or the protective panel. There is a method in which a double-sided pressure-sensitive adhesive sheet is attached in advance to either one, and then the remaining panels are appropriately attached. In addition, it is preferable to arrange | position a double-sided adhesive sheet so that the adhesion layer containing the said silicone compound may oppose the panel side where re-sticking operation | work is calculated | required or estimated to be calculated | required. This is because the pressure-sensitive adhesive layer containing the silicone compound is excellent in removability. Hereinafter, the double-sided pressure-sensitive adhesive sheet with a separate film will be described.

<Double-sided PSA sheet with separate film>
When a non-silicone compound-based adhesive layer is formed, the separate film laminated on the surface of the adhesive layer is not particularly limited as long as the peelability from the non-silicone compound-based adhesive layer is good. Or a commercially available release polyester film in which a release layer made of a fluorine-based compound is laminated.

  On the other hand, as a separate film to be laminated on the surface of the silicone-based adhesive layer, a commercially available polyester film for release having a release layer made of a silicone compound or a fluorine-based compound, as used for a general adhesive layer. Is used, the cross-linking adhesion reaction occurs between the silicone pressure-sensitive adhesive layer and the release layer during the above-described crosslinking treatment of the silicone pressure-sensitive adhesive layer, and there is a problem that the peelability of the separate film is reduced. A solution is needed.

  Here, in the double-sided pressure-sensitive adhesive sheet with a separate film used in the present invention, the peel strength between the silicone compound pressure-sensitive adhesive layer and the separate film is preferably 0.03 to 1.0 N / 20 mm. When the peel strength is 0.03 N / 20 mm or more, it exhibits good peelability, and when the double-sided pressure-sensitive adhesive sheet with a separate film is wound, the separation film can be prevented from floating, and the quality of the double-sided pressure-sensitive adhesive sheet can be improved. Can be kept high. On the other hand, if it is 1.0 N / 20 mm or less, the peelability of a separate film is favorable.

  In order to control the peel strength between the silicone compound pressure-sensitive adhesive layer and the separate film within the above range, a release layer having the following constitution is preferably provided on the surface of the separate film. The release layer constitutes a part of the separate film, and the release of the silicone compound adhesive layer and the separate film strictly means the release of the silicone compound adhesive layer and the release layer. In addition, the measuring method of peeling strength is as follows.

[Peel strength]
About the double-sided pressure-sensitive adhesive sheet with a separate film having a length of about 200 mm and a width of 20 mm, the surface (two surfaces) on which the peel strength is to be measured is exposed, and the double-sided pressure-sensitive adhesive sheet with a separate film is The laminate is divided into the laminates including the above, and each is set on a chuck of a tensile tester. For example, when measuring the peel strength at the interface between the release layer and the silicone compound adhesive layer provided in the separate film, the double-sided adhesive sheet with a separate film is slightly peeled off at the interface between the release layer and the silicone compound adhesive layer. Each of the mold layer and the silicone compound adhesive layer is exposed. Then, with one chuck, the separate film having the release layer is held, and with the other chuck, the remaining layers including at least the silicone compound-based pressure-sensitive adhesive layer, the heat resistant water adhesion improving layer, and the polyester-based substrate film are held. Grab. Then, the T-type peel strength is measured by the method described in JIS K6854-3. The tensile tester used is a trade name “Autograph” (manufactured by Shimadzu Corporation), and the conditions are a distance between chucks of 50 mm, a temperature of 23 ° C., and a tensile speed of 200 mm / min. During peeling, the end of the film is lifted with a stick so that the T-shape is maintained. The maximum strength at the time of T-type peeling is defined as peeling strength.

<Release layer>
The release layer provided in the separate film is preferably made of a non-silicone compound in view of the peelability from the silicone compound-based adhesive layer. When this release layer is made of a cured product of a curable silicone compound that is widely used as a release layer, it has high affinity with the silicone compound-based adhesive layer, so that the silicone compound of the silicone compound-based adhesive layer is crosslinked. In some cases, the silicone compound pressure-sensitive adhesive layer and the release layer may undergo a crosslinking reaction, and the peelability may be reduced. In order to obtain stable peelability, the release layer is preferably formed using a release agent that does not substantially contain a silicone compound. Here, “the release layer is made of a non-silicone compound” means that the release layer is formed from a compound (or composition) containing 10% by mass or less of a silicone compound, and more preferable silicone. The amount of the compound is 5% by mass or less, and most preferably 0% by mass.

  The release layer may be composed of a metal or an inorganic thin film, but is composed of a composition containing a binder resin, a polymer wax component and an antistatic agent from the viewpoint of peeling stability and cost. It is preferable that

≪Binder resin≫
The binder resin used in the present invention is preferably one or more polymers selected from the group consisting of polyesters, polyurethanes and acrylic polymers, and these polymers may be used alone or in combination. A combination of the above may also be used.

  As the polyester, polyurethane, and acrylic polymer, the same polymers as those described above can be used as the constituent polymer of the heat resistant water adhesion improving layer. Although the binder resin has a low necessity for crosslinking, a crosslinking agent may be used in the same manner as in the heat resistant water adhesion improving layer, or a self-crosslinking polymer may be used.

≪Polymer wax component≫
Conventionally known materials can be used for the polymer wax component used in the present invention. For example, wax emulsions such as polyethylene, polypropylene, acrylic, and fatty acid are shown, but a polymer wax agent that is particularly hard and does not have a sticky feeling and has excellent thermal decomposition stability is effective in improving peelability. In addition, since the transfer of the wax to the surface of the silicone compound-based adhesive layer can be suppressed when winding the double-sided adhesive sheet with a separate film, it is preferable. Moreover, the preferable number average molecular weights of these wax agents are 1000 or more (more preferably 1500 or more) and 10,000 or less (more preferably 6000 or less).

  The polymer wax component has a solid content of 2% by mass or more (more preferably 3% by mass or more), 10% by mass or less (more preferably 8% by mass or less) when the total amount with the binder resin is 100% by mass. ) Is preferably included. By setting the content of the polymer wax component to 2% by mass or more, the peelability from the silicone compound-based pressure-sensitive adhesive layer after the crosslinking treatment can be improved, and the slipperiness of the separate film can be improved. On the other hand, by setting the content of the polymer wax component to 10% by mass or less, it is possible to maintain the peeling force and suppress the occurrence of the channeling phenomenon in the manufacturing process of the double-sided PSA sheet with a separate film. Furthermore, since the migration of the polymer wax component from the release layer can be suppressed, the surface of the silicone compound adhesive layer after the crosslinking treatment is less likely to be contaminated.

≪Antistatic agent≫
The antistatic agent used in the present invention is not particularly limited in ionicity as long as it is miscible with the binder resin or is compatible, and conventionally known commercially available materials can be used. . For example, anionic, cationic, nonionic, amphoteric surfactants, polymer surfactants and the like can be mentioned. In particular, a polymer type antistatic agent with little bleed-out to the laminated surface is preferable.

  The polymer type antistatic agent may be any of anionic type, cationic type, and nonionic type. Among them, anionic type and nonionic type polymeric antistatic agents are preferable.

  As the anionic polymer antistatic agent, for example, a polar polymer having at least one polar group selected from a sulfonic acid group, a carboxyl group, and a sulfate ester group or a salt thereof is preferable. The polar group needs 5 mol% or more per polymer molecule. These polar polymers having electrical conductivity may contain hydroxyl groups, amino groups, epoxy groups, aziridine groups, active methylene groups, sulfinic acid groups, aldehyde groups, and vinyl sulfone groups as polar groups. Among these, an antistatic agent (specifically, polystyrene sulfonic acid or a salt thereof) containing styrene sulfonic acid or a salt thereof as a repeating unit is preferable.

  Examples of the salt include ammonium salt, lithium salt, and sodium salt. Polystyrene sulfonic acid or a salt thereof is, for example, commercially available from Nippon SC under the trade name VERSA-TL (registered trademark) and various types of unneutralized salts having different molecular weights.

  Further, as an antistatic agent containing styrene sulfonic acid or a salt thereof as a repeating unit, a styrene sulfonic acid-maleic acid copolymer can also be used and is commercially available from Nippon SC.

  On the other hand, nonionic high molecular surfactants include aniline or derivatives thereof, pyrrole or derivatives thereof, isothianaphthene or derivatives thereof, acetylene or derivatives thereof, thiophene or derivatives thereof, and the like. Is preferred. Among them, a π-electron conjugated conductive polymer containing thiophene or a derivative thereof as a structural unit is preferable because it is less colored. The π-electron conjugated conductive polymer may be a homopolymer containing only one type of structural unit as a repeating unit or a copolymer containing two or more types of structural units as a repeating unit.

  Examples of the conductive polymer containing thiophene or a derivative thereof as a constitutional unit include, for example, “BYTRON (registered trademark) P” series manufactured by Starck Vitech, and “Denatron (registered trademark) P-502RG” manufactured by Nagase ChemteX. "Denatron (registered trademark) P-502S", Conisole F202, F205, F210, P810 (above, trade name) manufactured by Inscontec, CPS-AS-X03 (trade name) manufactured by Shin-Etsu Polymer, etc. are commercially available. .

  The blending amount of the antistatic agent in the release layer cannot be uniquely determined because the preferred range varies depending on the type of the binder resin and the type of the antistatic agent. What is necessary is just to adjust peeling strength so that it may become the said range.

  For example, when an anionic surfactant is used as an antistatic agent, the blending amount of the antistatic agent is such that the peel strength between the silicone compound adhesive layer and the release layer is within the above range. When the total is 100% by mass, the solid content is preferably 2% by mass or more (more preferably 3% by mass or more) and 10% by mass or less (8% by mass or less). When the content of the anionic surfactant is 2% by mass or more, the peelability from the silicone compound pressure-sensitive adhesive layer after the crosslinking treatment is improved and the antistatic property of the separate film is also improved. On the other hand, by setting the content of the anionic surfactant to 10% by mass or less, the peeling force can be maintained and the occurrence of the channeling phenomenon in the production process of the double-sided PSA sheet with a separate film can be suppressed. Furthermore, since the migration of the polymer wax component from the release layer can be suppressed, the surface of the silicone compound pressure-sensitive adhesive layer after the crosslinking treatment is rarely contaminated.

  A separate film having a release layer is formed by mixing a predetermined amount of a binder resin, a polymer wax component, an antistatic agent, and, if necessary, other additives such as a surface roughening material in advance. And may be applied to a base film constituting a separate film. The resin composition may contain a surfactant for improving coatability, an ultraviolet ray inhibitor, an antioxidant, and the like. The coating method may be applied using a normal coating apparatus such as a gravure coater, reverse roll coater, reverse kiss coater, air knife coater, bar coater and the like. Specifically, as in the case of the heat resistant water adhesion improving layer, a so-called in-line coating method in which a resin composition is applied to one side of a uniaxially stretched polyester film and then stretched in a direction perpendicular to the previous uniaxial stretch. Or, a so-called off-line coating method in which coating is performed after biaxial stretching is exemplified.

  The thickness of the release layer is preferably 0.03 μm or more (more preferably 0.05 μm or more) and 1 μm or less (more preferably 0.5 μm or less) in a dry state in order to make the peeling force within an appropriate range. .

<Method for producing double-sided PSA sheet with separate film>
The double-sided PSA sheet with a separate film is preferably produced by any of the methods shown below. This is because the above-described characteristics can be stably expressed and the economy is excellent. Basically, each manufacturing method performs each step in the order described, but other steps not described may be performed between a certain step and the next step.

  In addition, the separate film laminated | stacked on the surface of the said adhesion layer peels from an adhesion layer and uses it at the time of bonding of an image display panel and a protection panel.

≪First method≫
A step of laminating a heat resistant water adhesion improving layer on one side of the polyester base film to form a laminate (1);
A step of laminating a layer containing an uncrosslinked body of a silicone compound having a polydimethylsiloxane skeleton on the surface of the heat resistant water adhesion improving layer of the laminate (1) to form a laminate (2);
A step of laminating a release layer on one side of the polyester film to form a separate film (3a);
The laminate (2) and the separate film (3a) so that the release layer of the separate film (3a) is in contact with the surface of the layer (2) containing the uncrosslinked silicone compound having a polydimethylsiloxane skeleton. And a step of forming a laminate (4),
A step of forming a laminate (4 ′) having a silicone compound adhesive layer by crosslinking an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton of the laminate (4);
A non-silicone compound-based adhesive layer and a separate film (3b) are laminated in this order on the surface of the polyester-based substrate film of the laminate (4 ′) with or without another heat-resistant water adhesion improving layer. Process,
including.

«Second method»
A step of laminating a non-silicone compound-based adhesive layer on one side of the separate film (3b) to form a laminate (5);
Each step of forming the laminate (1), laminate (2), separate film (3a), laminate (4) and laminate (4 ′),
The laminated body (4 ′) and the laminated body (5) are passed through a separate heat resistant water adhesion improving layer or not, and the laminated base material film of the laminated body (4 ′) is formed of the laminated body (5). A step of laminating to be on the non-silicone compound-based adhesive layer side,
including.

«Third method»
Forming the separate film (3a);
A step of laminating a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of the release layer of the separate film (3a) to form a laminate (6);
Forming the laminate (1);
Laminate (6) and laminate so that the layer of the laminate (6) containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton is in contact with the surface of the layer (1) of the hot water resistant adhesion improving layer. (1) and a step of forming a laminate (4),
Forming the laminate (4 ′);
The non-silicone compound-based adhesive layer and the separate film (3b) are applied to the surface of the polyester-based substrate film of the laminate (4 ′) with or without another heat-resistant water adhesion improving layer (D). Step of laminating in order,
including.

«Fourth method»
Forming the laminate (5);
Forming the separate film (3a);
Forming the laminate (6);
Forming the laminate (1);
Laminate (6) and laminate so that the layer of the laminate (6) containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton is in contact with the surface of the layer (1) of the hot water resistant adhesion improving layer. (1) and a step of forming a laminate (4),
Forming the laminate (4 ′);
The laminated body (4 ′) and the laminated body (5), with or without another hot water resistant adhesion improving layer, the surface of the polyester base film of the laminated body (4 ′) is laminated body (5). A step of laminating so as to be on the non-silicone compound-based pressure-sensitive adhesive layer side of
including.

≪Fifth method≫
Each step of forming the laminate (1), laminate (2), separate film (3a) and laminate (4),
A non-silicone compound-based adhesive layer and a separate film (3b) are laminated in this order on the polyester-based substrate film surface of the laminate (4), with or without another heat-resistant water adhesion improving layer, Forming the laminate (7);
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
including.

≪Sixth method≫
Forming the laminate (5);
Each step of forming the laminate (1), laminate (2), separate film (3a) and laminate (4),
The laminated body (4) and the laminated body (5), with or without another hot water resistant adhesion improving layer, the surface of the polyester-based substrate film of the laminated body (4) is non-layered (5). Laminating so as to be on the silicone compound adhesive layer side, forming the laminate (7),
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
including.

≪Seventh method≫
Forming the separate film (3a);
Forming the laminate (6);
Forming the laminate (1);
Laminate (6) and laminate so that the layer of the laminate (6) containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton is in contact with the surface of the layer (1) of the hot water resistant adhesion improving layer. (1) is laminated to form the laminate (4),
Forming the laminate (7);
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
including.

<< Eighth Method >>
Forming the laminate (5);
Forming the separate film (3a);
Forming the laminate (6);
Forming the laminate (1);
Laminate (6) and laminate so that the layer of the laminate (6) containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton is in contact with the surface of the layer (1) of the hot water resistant adhesion improving layer. (1) is laminated to form the laminate (4),
The laminated body (4) and the laminated body (5), with or without another hot water resistant adhesion improving layer, the surface of the polyester-based substrate film of the laminated body (4) is non-layered (5). Laminating to be on the silicone compound adhesive layer side, forming the laminate (7),
Cross-linking the uncrosslinked body of the silicone compound having a polydimethylsiloxane skeleton of the laminate (7),
including.

<< Ninth Method >>
Each step of forming the laminate (1), laminate (2), separate film (3a), laminate (4), laminate (4 ′),
Forming the laminate (5);
A step of laminating another separate film (3b ′) on the surface of the non-silicone compound-based adhesive layer of the laminate (5) to form a laminate (8);
Laminate so that the non-silicone compound-based adhesive layer is in contact with the surface of the polyester-based substrate film of the laminate (4 ′) while peeling the separate film (3b) or the separate film (3b ′) of the laminate (8). The process of
including.

≪Tenth method≫
Forming the separate film (3a);
Forming the laminate (6);
Forming the laminate (1);
Laminate (6) and laminate so that the layer of the laminate (6) containing an uncrosslinked silicone compound having a polydimethylsiloxane skeleton is in contact with the surface of the layer (1) of the hot water resistant adhesion improving layer. (1) and a step of forming the laminate (4),
Forming the laminate (4 ′);
Forming the laminate (8);
Laminate so that the non-silicone compound-based adhesive layer is in contact with the surface of the polyester-based substrate film of the laminate (4 ′) while peeling the separate film (3b) or the separate film (3b ′) of the laminate (8). The process of
including.

≪Eleventh method≫
A step of laminating a heat resistant water adhesion improving layer on both sides of the polyester base film to form a laminate (9);
A step of laminating a layer containing an uncrosslinked body of a silicone compound having a polydimethylsiloxane skeleton on the surface of the heat resistant water adhesion improving layer of the laminate (9) to form a laminate (10);
A step of laminating a release layer on one side of the polyester film to form a separate film (3a);
The laminate (10) and the separate film (3a) so that the release layer of the separate film (3a) is in contact with the surface of the layer (10) containing a non-crosslinked silicone compound having a polydimethylsiloxane skeleton. And a step of forming a laminate (11),
Cross-linking the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton of the laminate (11) to form a laminate (11 ′) having a silicone compound-based adhesive layer;
including.

≪Twelfth method≫
Forming the separate film (3a);
A step of laminating a layer containing an uncrosslinked product of a silicone compound having a polydimethylsiloxane skeleton on the surface of the release layer of the separate film (3a) to form a laminate (6);
Forming the laminate (9);
Laminate (9) and laminate so that the layer containing the uncrosslinked product of the silicone compound having a polydimethylsiloxane skeleton in laminate (6) is in contact with the surface of the heat resistant water adhesion improving layer of laminate (9). (6) and a step of forming a laminate (11),
Forming the laminate (11 ′);
including.

  In the present invention, any of the first to twelfth methods described above may be adopted, and the method may be produced by a production method different from these methods.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, but may be implemented with appropriate modifications within a scope that can meet the gist of the present invention. These are all included in the technical scope of the present invention. The measurement / evaluation methods employed in the examples are as follows. In the examples, “parts” means “parts by mass”, and “%” means “% by mass” unless otherwise specified.

(Measurement and evaluation method)
1. Peel strength About the double-sided pressure-sensitive adhesive sheet with a separate film having a length of about 200 mm and a width of 20 mm, the double-sided pressure-sensitive adhesive sheet with a separate film is peeled off slightly at the interface between the release layer and the silicone compound-based pressure-sensitive adhesive layer. Each was exposed. Next, with one chuck, the separate film including the release layer is gripped, and with one chuck, the remaining layers including at least the silicone compound pressure-sensitive adhesive layer, the heat resistant water adhesion improving layer, and the polyester base film are gripped. Thus, the double-sided PSA sheet with a separate film was set on the chuck of a tensile tester. And T-type peeling strength was measured by the method as described in JIS K6854-3. The tensile tester used was a trade name “Autograph” (manufactured by Shimadzu Corporation), and was performed under the conditions of a distance between chucks of 50 mm, a temperature of 23 ° C., and a tensile speed of 200 mm / min. During peeling, the end of the film was lifted with a bar so that the T-shape was maintained. The maximum strength at the time of T-type peeling was defined as the peeling strength. When the separate film did not peel, it was not measured as being difficult to peel. In this case, the release layer does not function as a release layer.

2. Adhesiveness A cutter knife was inserted between the silicone compound-based pressure-sensitive adhesive layer and the polyester-based substrate film, and peeling was performed by applying force with a finger (exposing the interface). The case where the peel strength was strong and the interface could not be evaluated was evaluated as ◯, and the case where the interface could be aligned was evaluated as ×.

3. Heat-resistant water adhesion A double-sided pressure-sensitive adhesive sheet with a separate film was cut into 50 mm x 50 mm, and the separate film on the silicone compound pressure-sensitive adhesive layer side was peeled off to prepare a sample. Next, the sample was submerged in a 500 cc cylindrical glass container with a lid containing 400 cc of distilled water so that the silicone compound adhesive layer was on the bottom, and the entire sample was immersed in water. The container was covered. When the sample did not immerse itself in water by its own weight, a polyester film of 60 mm × 60 mm and a thickness of 188 μm was placed on the sample to make a weight. The container containing the sample was placed in a gear oven set at 80 ° C. and allowed to stand for 24 hours. After heat treatment, take out the container from the oven, quickly take out the sample, apply force with the finger pad from the silicone compound adhesive layer side to the end and rub it 10 times, and the silicone compound adhesive layer peels off from the polyester base film Whether the silicone compound adhesive layer does not peel off was evaluated as “◯”, and that from which the silicone adhesive layer peeled off was evaluated as “x”.

4). Adhesive strength A double-sided pressure-sensitive adhesive sheet with a separate film was cut to a width of 20 mm, and the separate film on the silicone compound-based pressure-sensitive adhesive layer side was peeled to prepare a sample. Next, the sample was stuck to glass so that the silicone compound type adhesion layer side might contact glass. The sample was attached to the glass by placing the sample on the glass and then reciprocating twice on the sample at a speed of about 29 mm / second using a 2 kg roller. As the glass, heat resistant glass having a thickness of 3 mm and a width of 30 mm was used.

  The adhesive force of the silicone compound adhesive layer to glass was measured by a 180 degree peeling method according to JIS Z0237. The tensile speed was 300 mm / min, a tensile test was performed in an atmosphere at 23 ° C., and the maximum tensile strength was the adhesive strength (N / 20 mm).

5. Total light transmittance and haze The total light transmittance was measured according to JIS K7361-1, and the haze was measured according to JIS K7136 using a Nippon Denshoku Industries Co., Ltd. haze measuring instrument “NDH-2000”. These measurements were performed in a state where the double-sided separate films were peeled from the double-sided pressure-sensitive adhesive sheet with separate films.

6). Clarity of coating solution 100cc of silicone compound-based adhesive layer forming coating solution is filtered through a wire mesh of 200mm (wire diameter 0.04mm) of 40mmφ, and the presence or absence of insoluble matter is confirmed with the naked eye. The case was marked with ○ and the case with insoluble matter was marked with ×.

7). Solution Stability of Coating Liquid The silicone compound-based adhesive layer forming coating liquid was evaluated in terms of change in viscosity of the solution when stored in a sealed state at room temperature (23 ° C.) for 90 days to determine solution stability. The case where the change in viscosity of the solution was within ± 20% was marked as ◯, and the case where the change in viscosity of the solution exceeded ± 20% was marked as x. The viscosity was measured with a B-type viscometer.

8). Measurement of number average molecular weight After dissolving the sample with a solvent (toluene), the molecular weight was measured by gel permeation chromatography (GPC). The measurement conditions are as follows.
(Measurement condition)
Device: Waters 410
Column: Shodex K806M + K802
Flow rate: 1.0 ml / min
Injection volume: 200 μl
Solvent: Toluene polystyrene conversion Detector: Differential refractometer

(Example)
Example 1
(1) Preparation of coating solution for forming heat resistant water adhesion improving layer [Preparation of water-dispersible copolymer polyester]
A copolyester was synthesized in a batchwise manner using one pressure esterification reaction vessel with a distillation column and two polycondensation reaction vessels with a vacuum generator.

  First, 229 kg of terephthalic acid, 222 kg of isophthalic acid, 191 kg of 5-sodiumsulfoisophthalic acid di (hydroxyethyl) ester (34% ethylene glycol solution) in an esterification reaction tank, and neopentyl glycol melted at 140 ° C. in a nitrogen atmosphere 213 kg, and 87 kg of the recovered and purified ethylene glycol and neopentyl glycol mixed solution (mass ratio 45:55) were charged, and further stirred with an antimony trioxide ethylene glycol solution (antimony trioxide concentration 1.3%). 39 kg (0.05 mol% as antimony trioxide with respect to the acid component) was added, then pressurized with nitrogen, the reaction vessel was heated with a heating medium, and the glycol was added to the reaction vessel while controlling the top temperature to 150 ° C. 235 ° C under a pressure of 0.3 MPa (gauge pressure) It performed 130 minutes esterification reaction to obtain an oligomer of copolyester.

  Next, the oligomer was transferred to the first polycondensation reaction tank, and the pressure was reduced while stirring (pressure reduction rate of 5 kPa / min up to 40 kPa, then pressure reduction rate of 0.8 kPa / min up to 0.3 kPa), and initial condensation at 255 ° C. for 160 minutes. To obtain a copolyester prepolymer. Thereafter, the prepolymer was transferred to a second polycondensation reaction tank in which a spiral stirring blade was rotated under a vacuum of 0.13 kPa, and the latter condensation was performed at a temperature of 265 ° C. for 120 minutes to obtain a reduced viscosity of 0.41. It was set as the copolymer ester polymer of this. Nitrogen was introduced into the second polycondensation reaction tank, and the copolymerized ester polymer was taken out as a 7 mm thick sheet with a gear pump, and crushed with a sheet cutter while cooling with water to obtain a crushed copolymerized polyester.

[Preparation of coating solution]
100 parts of the crushed material was dispersed in water by a conventional method. With respect to 100 parts of the solid content of this aqueous dispersion, 5 parts of methylol melamine resin “Cymel (registered trademark) 303” (manufactured by Mitsui Cytec Co., Ltd.) is used as the catalyst, and “Catalyst 600” (Mitsui Cytec Co., Ltd.) as the catalyst. (0.025 parts) was added and stirred well to obtain a coating solution.

(2) Production of polyester base film and lamination of heat resistant water adhesion improving layer Polyethylene terephthalate containing 0.04% of amorphous silica (Silycia; manufactured by Fuji Silysia) having an average particle diameter (SEM method) of 1.5 μm After sufficiently drying the pellets (inherent viscosity 0.65 dl / g) in vacuum, the pellets are supplied to an extruder heated to 280 ° C., extruded into a sheet form from a T-shaped die, and using an electrostatic application casting method. It was wound around a mirror casting drum having a surface temperature of 30 ° C. and cooled and solidified. The unstretched film was stretched 3.5 times in the longitudinal direction while passing through a heating roll group at 95 ° C. to obtain a uniaxially stretched film. Both surfaces of this film were subjected to corona discharge treatment, and the coating solution was applied to both treatment surfaces. The uniaxially stretched film was guided to a preheating zone while being held with a clip, dried at 110 ° C., and continuously stretched 3.5 times in the width direction in a heating zone at 125 ° C. Further, heat treatment was performed for 6 seconds at 225 ° C. while relaxing 6% in the width direction. A 50 μm-thick laminate (1) was obtained in which a 0.08 μm-thick crosslinked heat resistant water adhesion improving layer was laminated on both sides of the biaxially stretched polyethylene terephthalate base film.

(3) Preparation of release layer-forming coating solution “Vylonal (registered trademark) MD-1200” (manufactured by Toyobo Co., Ltd.), which is a water-dispersible copolyester resin, is used as a binder resin, and polyethylene is used as a polymer wax component. An emulsion wax agent (manufactured by Riken Vitamin Co., Ltd.), an anionic antistatic agent (sodium dodecyl diphenyl oxide disulfonate; trade name TB702; manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) as an antistatic agent, and an average particle size of 2 μm as a surface roughening substance Styrene-benzoguanamine-based spherical organic particles “Eposter (registered trademark) MS” (manufactured by Nippon Shokubai Co., Ltd.) and colloidal silica “Snowtex (registered trademark) XL” (manufactured by Nissan Chemical Industries, Ltd.) having an average particle size of 0.05 μm And were used respectively.

  Using a homogenizer, the organic spherical fine particles of the surface roughening material are sufficiently dispersed in a mixed solution of water and isopropyl alcohol (mass ratio 80/20), and then the binder with respect to the total mass of the coating solution. The coating solution is thoroughly mixed so that the resin is 2.5%, the polymer wax component is 0.13%, the antistatic agent is 0.13%, the organic spherical fine particles are 0.025%, and the colloidal silica is 0.3%. Was prepared.

(4) Manufacture of separate film (Manufacture of polyester film and lamination of release layer)
Polyethylene terephthalate (intrinsic viscosity 0.65 dl / g) pellets are sufficiently dried in vacuum, then supplied to a heated extruder at 280 ° C., extruded into a sheet from a T-shaped die, and an electrostatic application casting method is used. Then, it was wound around a mirror casting drum having a surface temperature of 30 ° C. and solidified by cooling. The unstretched film was stretched 3.5 times in the longitudinal direction while passing through a heating roll group at 95 ° C. to obtain a uniaxially stretched film. The coating solution prepared by the above method was applied to both surfaces of this uniaxially oriented film. The coated uniaxially stretched film was guided to a preheating zone while being held with a clip, dried at 110 ° C., and continuously stretched 3.5 times in the width direction in a heating zone at 125 ° C. Further, heat treatment was performed for 6 seconds at 225 ° C. while relaxing 6% in the width direction. A separate film (2) was obtained which was a 50 μm thick laminate in which a release layer having a thickness of 0.15 μm was laminated on both sides of the polyester film.

(5) Lamination of silicone compound-based pressure-sensitive adhesive layer Non-reactive material composed of an uncrosslinked polydimethylsiloxane skeleton having substantially no reinforcing agent such as silica and having a number average molecular weight of 150,000 (measured by GPC method, converted to polystyrene). The silicone compound (KF-96H-500,000 cs; manufactured by Shin-Etsu Chemical Co., Ltd.) was weighed so that the mass ratio to toluene was 23%, and was put together with toluene into a stirrer equipped with a vacuum defoaming device. The mixture was stirred at room temperature for 15 hours and dissolved in toluene. To the obtained solution, trimethylolpropane trimethacrylate was added to 100 parts of the silicone compound so as to be 1.0 part, and after stirring uniformly, the vacuum deaerator was driven and the gauge pressure was- The mixture was further stirred for 20 minutes under a vacuum of 750 mmHg and defoamed. Next, the defoamed silicone compound solution is supplied to a roll coater, and the silicone compound solution is applied to one side of the laminate (1) so that the thickness after drying is 175 μm, and then introduced into an oven. Dry at 80 ° C. A laminate (3) in which an uncrosslinked adhesive layer was formed on the surface of the laminate (1) was obtained.

While the separate film (2) was stacked on the surface of the uncrosslinked adhesive layer of the laminate (3), it was pressed with a pressure roller (pressure 30 N / cm ² ) and continuously laminated. The obtained laminate (4) was further continuously introduced into an electron beam irradiation apparatus, and the adhesive layer was irradiated with 700 KV and 18 Mrad energy from the side of the separate film (2) to crosslink the adhesive layer. The laminate (4 ′) having the adhesive layer was wound into a roll. In the manufacturing process so far, the occurrence of the channeling phenomenon of the separate film (2) was not observed.

(6) Lamination of acrylic pressure-sensitive adhesive layer SK Dyne 2094 (manufactured by Soken Chemical Co., Ltd.), which is an acrylic pressure-sensitive adhesive for optics, is dried on the surface of the heat resistant water adhesion improving layer of the laminate (4 ′). The film was applied to a thickness of 25 μm and dried at 130 ° C. for 3 minutes to form an acrylic pressure-sensitive adhesive layer. A separate film (5) (E7002; manufactured by Toyobo Co., Ltd.) having a thickness of 38 μm made of silicone-treated polyethylene terephthalate was laminated on the surface of the pressure-sensitive adhesive layer so that the silicone-treated surface side was in contact, and the separate film was formed on both surfaces. Were provided, and a double-sided PSA sheet with a separate film in which each adhesive layer was protected was obtained. Even in this step, the occurrence of the channeling phenomenon of the separate film (2) was not observed.

  Table 1 shows the characteristics of the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 1 and the characteristics of the coating liquid for forming the silicone compound-based pressure-sensitive adhesive layer.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 1 is excellent in transparency (total light transmittance and haze value), and the silicone compound-based pressure-sensitive adhesive layer is polyester-based through the heat resistant water adhesion improving layer. It was firmly bonded to the base film. Moreover, the peeling force of the release layer of a separate film film (2) and a silicone compound type adhesion layer was also moderate, and it was a high-quality double-sided adhesive sheet with a separation film. Furthermore, it is also excellent in the clarification and stability of the coating liquid for forming the silicone compound adhesive layer in the production of the double-sided pressure-sensitive adhesive sheet with a separate film, and it can be confirmed that it is excellent in operability and operational stability. It was.

Comparative Example 1
In the method of Example 1, a double-sided PSA sheet with a separate film was obtained in the same manner as in Example 1 except that the application of the coating solution for forming the heat resistant water adhesion improving layer was stopped. Table 1 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided PSA sheet with a separate film obtained in Comparative Example 1 was inferior in the adhesiveness between the silicone compound-based adhesive layer and the polyester-based substrate film and the heat-resistant water adhesive property, and was of low quality.

Comparative Example 2
In the method of Example 1, a double-sided pressure-sensitive adhesive sheet with a separate film was obtained in the same manner as in Example 1 except that the composition of the methylol melamine resin as a crosslinking agent was stopped in the coating solution for forming the heat resistant water adhesion improving layer. Got. Table 1 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 2 was inferior in heat-resistant water adhesion between the silicone compound-based pressure-sensitive adhesive layer and the polyester-based substrate film, and was of low quality.

Comparative Example 3
In the method of Comparative Example 1, a double-sided PSA sheet with a separate film was obtained in the same manner as in Comparative Example 1 except that the combination of the polymer wax component and the antistatic agent in the coating liquid for forming the release layer was stopped. It was. Table 1 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  In addition to the problem of the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 1, the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 3 tried to peel the separate film (2) from the silicone compound-based pressure-sensitive adhesive layer. Could not be peeled. Therefore, it could not be used as a double-sided PSA sheet.

Comparative Examples 4 and 5
Comparative Example 1 except that in the method of Comparative Example 1, the release layer-forming coating solution was stopped by adding the polymer wax component in Comparative Example 4 and the antistatic agent in Comparative Example 5. A double-sided PSA sheet with a separate film was obtained in the same manner as described above. Table 1 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  In addition to the problem of the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 1, the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 4 can peel the separate film (2) from the silicone compound pressure-sensitive adhesive layer. could not. Moreover, in Comparative Example 5, in addition to the problem of the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 1, the peel strength of the separate film (2) was high, and the peelability of the separate film (2) was inferior.

Comparative Example 6
In place of the separate film (2) in the method of Comparative Example 1, a separation-treated polyester film with a thickness of 38 μm treated with silicone (E7002; manufactured by Toyobo Co., Ltd.) was used. A double-sided PSA sheet with a film was obtained. Table 1 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  As with Comparative Example 3, the double-sided PSA sheet with a separate film obtained in Comparative Example 6 tried to peel the separate film from the silicone compound adhesive layer, but could not be peeled off. It is presumed that the cross-linking adhesion phenomenon occurred due to the EB cross-linking. Therefore, it could not be used as the double-sided pressure-sensitive adhesive sheet of the present invention.

Comparative Example 7
In the method of Comparative Example 1, a double-sided PSA sheet with a separate film was obtained in the same manner as in Comparative Example 1, except that the thickness of the heat resistant water adhesion improving layer was changed to 0.7 μm. Table 1 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 7 was inferior in heat resistant water adhesion of the silicone compound pressure-sensitive adhesive layer, and was of low quality.

Comparative Example 8
In the method of Comparative Example 1, a double-sided PSA sheet with a separate film was obtained in the same manner as in Comparative Example 1 except that the preparation of the silicone compound adhesive layer forming coating solution was changed as shown below. Table 1 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

[Preparation of coating solution for forming silicone compound adhesive layer]
High transparency silicone rubber compound ("TSE260-3U"; rubber hardness 30 degrees) consisting of 60 parts of a polydimethylsiloxane skeleton silicone compound, 25 parts of a polydimethylalkenylsiloxane skeleton silicone compound and 15 parts of silica; Momentive Performance Materials (Made by Japan) was weighed so that the mass ratio with respect to toluene might be 23%, and it poured into the stirrer with a vacuum degassing apparatus with toluene, and it stirred at room temperature for 15 hours under atmospheric pressure, and was dissolved in toluene. To the obtained solution, trimethylolpropane trimethacrylate was added so as to be 2 parts with respect to 100 parts of the rubber compound, and after stirring uniformly, the vacuum deaerator was driven and the gauge pressure was -750 mmHg. The mixture was further stirred for 20 minutes and degassed. In addition, the said silicone rubber compound used what passed 6 months after purchase.

  In addition to the problem of the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 1, the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 8 was inferior in the clarity and storage stability of the coating solution.

Reference example 1
In the method of Example 1, 8 parts of organic silicone (“KS-744”; manufactured by Shin-Etsu Chemical Co., Ltd.) and catalyst “PL-3” (Shin-Etsu Chemical Co., Ltd.) (Manufactured) A double-sided PSA sheet with a separate film was obtained in the same manner as in Example 1 except that 0.06 part was changed to a solution in which 100 parts by mass of toluene was dissolved. Table 1 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Reference Example 1 was inferior in heat-resistant water adhesion between the silicone compound-based pressure-sensitive adhesive layer and the polyester base film, and was of low quality.

Example 2
A copolymerized polyester resin solution (“Byron (registered trademark) 30SS”; manufactured by Toyobo Co., Ltd.) and a polyisocyanate-based crosslinking agent (“Coronate (registered trademark) HX”; manufactured by Nippon Polyurethane Co., Ltd.) in a solid content ratio of 100: 3 parts were blended to prepare a coating solution for the heat resistant water adhesion improving layer.

  The coating solution is applied to both sides of the polyester base film after corona discharge treatment in Example 1 using a coater, dried, and cross-linked to both sides of the polyester base film. As a result, a laminated body was obtained.

  Using this laminate, a double-sided PSA sheet with a separate film was obtained in the same manner as in Example 1. In addition, the thickness of the hot-water-resistant adhesion improving layer after biaxial stretching was 0.3 μm. Table 2 shows the evaluation results of the characteristics of the obtained double-sided PSA sheet with a separate film.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in this example had the same characteristics as the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 1, and was of high quality.

Comparative Example 9
In the preparation of the coating liquid of Example 2, the double-sided PSA sheet with a separate film was prepared in the same manner as in Example 2 except that the formulation of the “Coronate HX” crosslinking agent was stopped and only “Byron 30SS” was used. Obtained. Table 2 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 9 was inferior in heat resistant water adhesion of the silicone compound pressure-sensitive adhesive layer, and was of low quality.

Examples 3-6
A double-sided pressure-sensitive adhesive sheet with a separate film was obtained in the same manner as in Example 1 except that the coating solution for the hot water resistant adhesion improving layer in Example 1 was changed to the following composition. Table 2 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided PSA sheet with a separate film obtained in these examples had the same characteristics as the double-sided PSA sheet with a separate film obtained in Example 1, and was of high quality.

[Coating liquid of Example 3]
10 parts of the above-mentioned “Cymel 303” and 0.04 part of the above-mentioned “Catalyst 600” with respect to 100 parts of a solid content of an acrylic emulsion (“Joncrill (registered trademark) PDX-7630A”; manufactured by BASF Japan). Were mixed to obtain a coating solution for a heat resistant water adhesion improving layer.

[Coating liquid of Example 4]
As an oxazoline-based cross-linking agent ("Epocross (registered trademark) WS-700"; Nippon Shokubai Co., Ltd.) with respect to 100 parts of a solid content of a polyurethane-based aqueous dispersion ("Hydran (registered trademark) AP40"; manufactured by Dainippon Ink and Industry). Product) was added in a solid content of 3 parts to give a coating solution for a heat resistant water adhesion improving layer.

[Coating liquid of Example 5]
7.5 parts of water-dispersible copolyester “Vylonal (registered trademark) MD-1200” (manufactured by Toyobo Co., Ltd.), 20% aqueous solution of self-crosslinking polyurethane containing isocyanate groups blocked with sodium bisulfite (“Elastron ( (Registered trademark) H-3 "; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 11.3 parts, catalyst for elastron (" Cat 64 "; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts, water 39.8 parts and isopropyl alcohol Four parts were placed in a container and mixed well.

  Further, 0.6 parts of a 10% aqueous solution of a fluorine-based nonionic surfactant (“Megafac (registered trademark) F142D”; manufactured by Dainippon Ink & Chemicals, Inc.), colloidal silica (“Snowtex (registered trademark) OL”) Average particle size 40 nm; 2.3 parts of 20% aqueous dispersion of Nissan Chemical Industries, Ltd., dry silica (“Aerosil OX50”; “Aerosil” is a registered trademark of Degussa; average particle size 200 nm; average primary particle; 0.5 parts of a 3.5% aqueous dispersion of 40 nm in diameter; manufactured by Nippon Aerosil Co., Ltd. was added. Next, the pH of the coating solution is adjusted to 6.2 with a 5% aqueous sodium bicarbonate solution, and the solution is precisely filtered through a felt type polypropylene filter having a filtration particle size (initial filtration efficiency: 95%) of 10 μm, and is resistant to hot water. A coating liquid for an improved layer was obtained.

[Coating liquid of Example 6]
40 parts of a self-crosslinking polyester resin aqueous dispersion “Vylonal (registered trademark) AGN702” (manufactured by Toyobo Co., Ltd.), 24 parts of water and 36 parts of isopropyl alcohol are mixed, and a 10% aqueous solution of an anionic surfactant 0.6 Part, propionate 1 part, colloidal silica particles (“Snowtex (registered trademark) OL”; average particle size 40 nm; manufactured by Nissan Chemical Industries, Ltd.)) 1.8% 20% aqueous dispersion, dry process silica particles (“ Aerosil OX50 ”; average particle size 200 nm; average primary particle size 40 nm; manufactured by Nippon Aerosil Co., Ltd.) was added 1.1 parts of a 4% aqueous dispersion to give a coating solution for a heat resistant water adhesion improving layer.

Example 7
In the method of Example 1, except that the polymer wax of the release layer coating liquid used for the production of the separate film (2) is changed to an acrylic wax agent emulsion (“ST-200”; manufactured by Nippon Shokubai Co., Ltd.). Obtained the double-sided adhesive sheet with a separate film by the same method as Example 1. Table 2 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 7 had the same characteristics as the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 1, and was of high quality. In addition, as in Example 1, the separation film was not lifted during the production of the double-sided PSA sheet with a separate film.

Example 8
In the method of Example 1, except that the antistatic agent of the release layer coating solution used for the production of the separate film (2) is changed to an anionic antistatic agent (“TB214”; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). A double-sided PSA sheet with a separate film was obtained in the same manner as in Example 1. Table 3 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 8 had the same characteristics as the double-sided pressure-sensitive adhesive sheet obtained in Example 1 and was of high quality. In addition, as in Example 1, the separation film was not lifted during the production of the double-sided PSA sheet with a separate film.

Example 9
In the method of Example 1, except that the polymer wax component of the release layer coating solution used for the production of the separate film (2) is changed to 0.2% and the antistatic agent to 0.2%. A double-sided PSA sheet with a separate film was obtained in the same manner as in Example 1. Table 3 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 9 had the same characteristics as the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 1, and was of high quality. In addition, as in Example 1, the separation film was not lifted during the production of the double-sided PSA sheet with a separate film.

Comparative Example 10
In the method of Comparative Example 1, except that the polymer wax component of the release layer coating solution used for the production of the separate film (2) is changed to 1.3% and the antistatic agent to 1.5%. A double-sided PSA sheet with a separate film was obtained in the same manner as in Comparative Example 1. Table 3 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

  In addition to the problem of the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 1, the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Comparative Example 10 has a peel strength of the separate film of approximately 0 N / 20 mm, and the peelability is Although very good, the separation film sometimes floated during the production of a double-sided PSA sheet with a separate film.

Example 10
In the method of Example 1, a double-sided PSA sheet was obtained in the same manner as in Example 1 except that the lamination method of the silicone compound adhesive layer was changed as follows. Table 3 shows the evaluation results of the properties of the obtained double-sided PSA sheet with a separate film.

[Lamination of silicone compound adhesive layer]
A non-reactive silicone compound (KF-96H-1 million) comprising an uncrosslinked polydimethylsiloxane skeleton having substantially no reinforcing agent such as silica and having a number average molecular weight of 170,000 (measured by GPC method, converted to polystyrene) cs; manufactured by Shin-Etsu Chemical Co., Ltd.) was weighed so that the mass ratio with respect to toluene was 23%, and was put together with toluene into a stirrer equipped with a vacuum deaerator and stirred in atmospheric pressure at room temperature for 15 hours to dissolve in toluene. I let you. To the obtained solution, trimethylolpropane trimethacrylate was added to 100 parts of the silicone compound so as to be 2 parts, and after stirring uniformly, the vacuum deaerator was driven and the gauge pressure was -750 mmHg. Stir under vacuum for another 20 minutes and degas. Next, the defoamed silicone compound solution was supplied to a roll coater, and the silicone compound solution was applied to one side of the separate film (2) produced in Example 1 so that the thickness after drying was 150 μm. It introduce | transduced into oven and dried at 80 degreeC. A laminate (5) in which an uncrosslinked silicone compound-based adhesive layer was formed on the surface of the separate film (2) was obtained.

While pressing the surface of the uncrosslinked silicone compound adhesive layer of the laminate (5) on both sides of the laminate (1) produced in Example 1, it is pressed with a pressure roller (pressure 30 N / cm ² ) and continuously. Laminated. The obtained laminate was further continuously introduced into an electron beam irradiation apparatus, and the silicone compound adhesive layer was crosslinked by irradiating an electron beam with energy of 700 KV and 18 Mrad from the side of the separate film. Was wound into a roll. In the manufacturing process so far, the occurrence of the channeling phenomenon of the separate film (2) was not observed.

  The double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 10 had the same properties as the double-sided pressure-sensitive adhesive sheet with a separate film obtained in Example 1, and was of high quality.

Example 11
The surface protection panel and the image display panel were bonded to each other with a double-sided PSA sheet obtained by peeling the separate film from the double-sided PSA sheet with Examples 1-10. About the double-sided adhesive sheet obtained in Examples 1-9, the surface protection panel was first stuck on the acrylic adhesive layer side, and the image display panel was subsequently stuck on the silicone adhesive layer side. The workability of the sticking work was good. In addition, since the silicone-based adhesive layer is excellent in repairability, it could be easily repaired even if a sticking failure occurred. Therefore, it is possible to eliminate the loss of the image display panel which is an expensive member due to the sticking failure. On the other hand, the double-sided pressure-sensitive adhesive sheet obtained in Example 10 has both sides made of a silicone-based pressure-sensitive adhesive layer, and both surfaces are excellent in repairability. Therefore, the loss due to failure of bonding of both the surface protection panel and the image display panel is reduced. I was able to lose it.

Example 12 and Comparative Example 11
The surface protection panel of a commercially available mobile phone is removed, and the removed image display panel and the surface protection panel are bonded to each other with a double-sided pressure-sensitive adhesive sheet obtained by peeling the separate film from the double-sided pressure-sensitive adhesive sheet with a separator film of Examples 1-10. The visibility of the image was evaluated between the case (Example 12) and the case where a space corresponding to the thickness of the double-sided PSA sheet was provided between the image display panel and the surface protection panel (Comparative Example 11). . The same image was visually observed, and the visibility of both images was compared. As a result, the visibility of the image was better when the two-sided PSA sheet was used (Example 12).

  The image display device of the present invention is excellent in visibility because the image display panel and the protective panel are configured by bonding together with the double-sided pressure-sensitive adhesive sheet. Further, the bonding operation between the image display panel and the protection panel is easy, and the removability is excellent. Furthermore, the image display panel and the protection panel are hardly peeled even when used in a harsh environment. Therefore, the image display device of the present invention can be an excellent liquid crystal display device (LCD), plasma light emitting display device (PDP), organic electroluminescence (EL) or the like having these characteristics.

Claims (12)

Polyester base film is provided on at least one surface with a heat resistant water adhesion improving layer containing a reaction product of at least one polymer selected from the group consisting of polyester, polyurethane and acrylic polymer and a crosslinking agent. An image display characterized in that an image display panel and a protective panel for protecting the image display panel are bonded using a double-sided pressure-sensitive adhesive sheet in which an adhesive layer containing a crosslinked silicone compound having a dimethylsiloxane skeleton is laminated. Device manufacturing method. A heat resistant water adhesion improving layer comprising a self-crosslinked one or more self-crosslinked polymers selected from the group consisting of self-crosslinked polyester, polyurethane and acrylic polymer on at least one side of the polyester base film The image display panel and a protective panel for protecting the image display panel are bonded to each other using a double-sided pressure-sensitive adhesive sheet in which an adhesive layer containing a crosslinked silicone compound having a polydimethylsiloxane skeleton is laminated. A method for manufacturing an image display device. The method for producing an image display device according to claim 1 or 2 , wherein the crosslinked silicone compound is obtained by crosslinking an uncrosslinked silicone compound having a polydimethylsiloxane skeleton having a number average molecular weight of 50,000 to 500,000. The manufacturing method of the image display apparatus as described in any one of Claim 1 to 3 by which the acrylic adhesive layer or the rubber-type adhesive layer was laminated | stacked on the single side | surface of the said polyester-type base film. The method of manufacturing an image display device, wherein the thickness of the heat-resistant water adhesion improving layer is claim 1 which is 0.01~0.5μm to an item either 4. The method for manufacturing an image display device according to any one of claims 1 to 5 , wherein the double-sided pressure-sensitive adhesive sheet has a total light transmittance of 90% or more and a haze of 1.5% or less. After preparing a double-sided pressure-sensitive adhesive sheet with a separate film in which a separate film is laminated on the surface of each pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive sheet, the separate film is peeled off from the pressure-sensitive adhesive layer, and the image display panel and the protective panel are attached. The manufacturing method of the image display apparatus as described in any one of Claim 1 to 6 . The method for manufacturing an image display device according to claim 7 , wherein a peel strength between the adhesive layer containing a silicone compound and the separate film in the adhesive layer is 0.03 to 1.0 N / 20 mm. A separate film laminated to the pressure-sensitive adhesive layer containing the silicone compound includes a release layer, and is configured to be laminated with the surface of the pressure-sensitive adhesive layer containing the silicone compound via the release layer, and the release layer is a binder resin, The manufacturing method of the image display apparatus of Claim 7 or 8 containing a polymeric wax component and an antistatic agent. The said crosslinking agent is 2 mass parts or more and 50 mass parts or less are added by solid content mass ratio with respect to 100 mass parts of said polymers, The manufacture of the image display apparatus as described in any one of Claims 1-9. Method. The method for manufacturing an image display device according to claim 1, wherein the adhesive strength of the adhesive layer is 0.01 to 1.0 N / 20 mm.   An image display device manufactured using the manufacturing method according to claim 1.