JP2875758B2 - Adhesive sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive sheet coated with a silicone pressure-sensitive adhesive, and more particularly, to a base material treated with a primer, whereby the adhesion of the silicone pressure-sensitive adhesive to the substrate is extremely excellent. It relates to an adhesive sheet.

[0002]

2. Description of the Related Art Silicone pressure-sensitive adhesives are pressure-sensitive adhesives having excellent properties such as adhesive strength, holding power, surface tack, and tackiness. In addition, silicone-specific pressure-sensitive adhesives such as heat resistance, cold resistance, and electrical insulation. It is widely used in various adhesive products requiring heat resistance and cold resistance, such as electrical insulating tapes and splicing tapes for release paper. In general, as the silicone pressure-sensitive adhesive, a type which is cured by an organic peroxide and a type which is cured by an addition reaction between an alkenyl group-containing organopolysiloxane and a silicon-bonded hydrogen atom-containing organopolysiloxane are known.

Usually, a polypropylene (OPP) film, a polyethylene terephthalate (PET) film, a polyimide film, an organic fluoropolymer film, a glass cloth, or the like is used as a pressure-sensitive adhesive sheet substrate, and a silicone pressure-sensitive adhesive is formed on the substrate. Is applied and then cured by heating to produce an adhesive tape or the like, which is used. However, when these tapes are adhered to an adherend and peeled off after use, interfacial peeling occurs between the silicone pressure-sensitive adhesive and the tape substrate, and a part of the adhesive remains on the adherend, so-called glue. Remaining phenomena may occur. In addition, there is a problem in that the peeling of the interface between the pressure-sensitive adhesive and the base material affects the holding power, the pressure-sensitive adhesive strength, and the like, and the inherent properties of the pressure-sensitive adhesive tape are lost.

[0004] In order to solve these problems,
For example, Japanese Patent Publication No. 54-44017 discloses a method of providing a cured layer of a primer composition comprising a diorganopolysiloxane having hydroxyl groups, an organohydrogenpolysiloxane and a tin salt of an organic carboxylic acid, and providing a silicone pressure-sensitive adhesive layer thereon. However, this method requires a high-temperature treatment for the primer treatment, does not provide sufficient adhesion, and furthermore, when an addition-curable silicone pressure-sensitive adhesive is applied, a primer layer is required. There is a problem that curing inhibition occurs. Japanese Patent Publication No. 60-11950 discloses that the above-mentioned disadvantages are improved by providing a cured layer of a primer composition comprising a vinyl group-containing diorganopolysiloxane, an organohydrogenpolysiloxane and a platinum catalyst. Because the pot life of the primer composition is short and the curing temperature needs to be high,
There is a problem that it cannot be applied to a substrate having low heat resistance. Japanese Patent Publication No. 6-39584 discloses curing of a primer composition comprising a diorganopolysiloxane having a hydroxyl group terminal, an organohydrogenpolysiloxane, a hydrolyzable silyl group-containing vinyl copolymer and an organic carboxylic acid metal salt. Although a method of providing a layer has been proposed, the pot life of the primer composition and the adhesion to the substrate were still insufficient.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer having good adhesion to a substrate.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the disadvantages of the prior art, and as a result, provided a specific primer layer on a base material, and subsequently applied a silicone pressure-sensitive adhesive. The present invention has been found to provide a pressure-sensitive adhesive sheet having no adhesive residue at the time of peeling and without impairing the properties of the pressure-sensitive adhesive sheet such as the original adhesive strength and holding power.

That is, the pressure-sensitive adhesive sheet of the present invention comprises: (A) 100 parts by weight of a polyorganosiloxane containing two or more monovalent aliphatic unsaturated hydrocarbon groups bonded to a silicon atom in one molecule; A polyorgano hydrogen siloxane having at least three hydrogen atoms bonded to silicon atoms in one molecule, a hydrogen atom bonded to silicon atom for one monovalent aliphatic unsaturated hydrocarbon group in component (A) (C) an epoxy ring-containing group or an alkoxy group, which is a γ-glycidoxypropyl group or a β- (3,4-epoxycyclohexyl) ethyl group, is bonded to a silicon atom. Organic silicon compound 0.1 to 20 parts by weight (D) organoaluminum compound 0.01 to 10 parts by weight (E) organotin compound 0.001 to 1 part by weight (F) a catalyst selected from the group consisting of platinum and platinum compounds, (A) Min and treating the substrate with a primer composition containing 0.1 ～500Ppm platinum atom with respect to, further characterized by comprising applying a silicone pressure sensitive adhesive.

Hereinafter, the substrate, the primer composition, and the silicone pressure-sensitive adhesive used in the present invention will be described.

The substrate used in the present invention is not particularly limited as long as it is used for a pressure-sensitive adhesive sheet. Polyolefin films such as polyethylene film and polypropylene film, polyester films such as polyethylene terephthalate film, and polytetrafluoroethylene Examples include various types of plastic films such as an organic fluoropolymer film such as an ethylene film, a polyimide film, a polyamide film and a polyamideimide film, a glass cloth and a metal foil, and the features of the pressure-sensitive adhesive sheet of the present invention are favorably found. Therefore, a plastic film is preferable. Usually, when using these film substrates, in order to improve the adhesion between the substrate and the silicone pressure-sensitive adhesive, the substrate is preliminarily subjected to a chemical treatment with, for example, potassium dichromate, an electric discharge by corona discharge or the like. Surface treatment may be performed by mechanical treatment or mechanical treatment such as etching.

[0010] The primer composition used in the present invention comprises:
The purpose is to improve the adhesion between the substrate and the silicone pressure-sensitive adhesive.

(A) in the primer composition of the present invention
The component polyorganosiloxane has at least two aliphatic unsaturated hydrocarbon groups (alkenyl groups) bonded to silicon atoms in one molecule, and may be linear, branched or cyclic, or a mixture thereof. But it may be.
Here, examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group. Is preferred. Substituents bonded to silicon atoms other than alkenyl groups include methyl, ethyl, propyl, butyl, hexyl,
Alkyl group such as dodecyl group, aryl group such as phenyl group and tolyl group, aralkyl group such as β-phenylethyl group and β-phenylpropyl group, cycloalkyl group such as cyclohexyl group, or bonding to carbon atom of these groups The same or different unsubstituted or substituted monovalent hydrocarbon groups in which part or all of the hydrogen atoms are substituted with halogen atoms, cyano groups, etc., are exemplified, and synthesis is easy,
A methyl group or a phenyl group is preferable, and a methyl group is particularly preferable, since the compatibility with the silicone pressure-sensitive adhesive is maintained well.

The polyorganosiloxane of the component (A) is
It is sufficient that at least two alkenyl groups are contained in one molecule, and preferably 0.1 to 50 of all the substituents in one molecule.
It is preferable that the alkenyl group accounts for mol%, particularly 0.5 to 4 mol%, from the viewpoint of the curability of the composition obtained, the strength of the cured film, and the like.

The alkenyl group bonded to the silicon atom of the polyorganosiloxane of the component (A) may be present either at the terminal or in the middle of the molecular chain of the polyorganosiloxane, or may be present at both. In order for the cured film to have excellent mechanical strength, it is preferably located at least at the terminal.

The polyorganohydrogensiloxane of the component (B) in the present invention forms a cured film by a cross-linking reaction with the polyorganosiloxane of the component (A), and converts one hydrogen atom bonded to a silicon atom into one molecule. It is necessary to have at least two of them. Examples of the substituent bonded to a silicon atom other than a hydrogen atom include the same as the component (A), but an alkyl group and an aryl group are preferable since a cured film having easy synthesis and good physical properties can be obtained. And particularly preferably a methyl group. Such a polyorganohydrogensiloxane may be linear, branched or cyclic, or may be a mixture thereof.

As the polyorganohydrogensiloxane of the component (B), the following components (a) to (b) are used to impart good properties to the resulting composition and the cured film.
The compound shown in (c) is preferred.

(A): a branch consisting of _0.5 units of (CH ₃ ) ₂ HSiO ₂ and ₂ units of SiO ₂ , wherein the content of hydrogen atoms (effective hydrogen amount) bonded to silicon atoms is in the range of 0.3 to 1.2% by weight. Polyorganohydrogensiloxane having a morphological structure. (B): The following equation

[0017]

Embedded image (Wherein, m represents an integer of 3 to 100 and n represents an integer of 0 to 100), and the content of hydrogen atoms bonded to silicon atoms is in the range of 0.5 to 1.6% by weight. Hydrogen siloxane. (C) The following equation

[0018]

Embedded image (Wherein, p represents an integer of 1 to 100 and q represents an integer of 0 to 100), wherein the content of silicon-bonded hydrogen atoms is in the range of 0.5 to 1.6% by weight. Hydrogen siloxane.

The amount of the polyorganohydrogensiloxane used as the component (B) is determined based on the amount of hydrogen bonded to the silicon atom per one monovalent unsaturated aliphatic hydrocarbon group in the polyorganosiloxane used as the component (A). The amount is such that the number of atoms is 1.0 to 10 and the amount is preferably 1.5 to 4.0 because the curability of the primer composition is good.

(C) used in the primer composition of the present invention
The component is a component used for imparting adhesion together with the organoaluminum compound (D) and the organotin compound (E). This component (C) is composed of a γ-glycidoxypropyl group bonded to a silicon atom in one molecule or
Is a β- (3,4-epoxycyclohexyl) ethyl group
Any organosilicon compound having an epoxy ring-containing group and an alkoxy group bonded to a silicon atom can be used, but the resulting polyorganosiloxane composition exhibits excellent self-adhesiveness. The component (C) contains γ- bonded to a silicon atom in one molecule.
Glycidoxypropyl group or β- (3,4-epoxycyclyl
It is preferable that the organic silicon compound has at least one epoxy ring-containing group (lohexyl) ethyl group and at least two alkoxy groups bonded to silicon atoms. As the compound of the component (C),

[0021]

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[0022]

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[0023]

Embedded image (In the above formulas, R is a monovalent hydrocarbon group having 1 to 6 carbon atoms, n
Is 0 or a positive integer), an organic silicon compound exemplified by one or more of these partially hydrolyzed condensates, or one or more of these compounds and (C)
Examples include partial hydrolysis condensates with alkoxysilanes other than the components. Specific examples of the component (C) include the following.

[0024]

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[0025]

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[0026]

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[0027]

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The amount of component (C) is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of component (A). If the amount is less than 0.1 part by weight, the obtained primer composition does not show a sufficient adhesive effect, and if it exceeds 20 parts by weight, the pot life of the obtained primer composition is reduced. It is.

The organoaluminum compounds (D) used in the present invention include (CH ₃ O) ₃ Al and (C ₂ H).
Aluminum alcoholates such as ₅ O) ₃ Al and (n-C ₃ H ₇ O) ₃ Al; aluminum salts such as naphthenic acid, stearic acid, octylic acid, and benzoic acid; aluminum alcoholates and acetoacetic esters or dialkyl malonates; Obtained by reacting,

[0030]

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[0031]

Embedded image Examples thereof include aluminum chelates; organic acid salts of aluminum oxide; aluminum acetyl acetate, and the like, with preference given to aluminum chelates and aluminum alcoholates. These may be mixtures.

The amount of component (D) is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of component (A). If the amount is less than 0.01 part by weight, the obtained primer composition does not show a sufficient adhesive effect,
On the other hand, when the amount exceeds 10 parts by weight, the pot life of the obtained primer composition is reduced.

The method of blending the component (D) is not particularly limited. However, in order to blend a solid organoaluminum compound at room temperature, a method of dissolving the solid organoaluminum compound in a solvent and blending it into the composition is preferred. . The solvent that can be used is not particularly limited as long as it can dissolve the solid organoaluminum compound, but from the ease of removal of the solvent,
Low boiling solvents are preferred. Examples of such a solvent include ethers such as diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether, and ethyl propyl ether; pentane, hexane, heptane,
Aliphatic hydrocarbons such as octane, nonane and decane; halogenated hydrocarbons such as chloroform and carbon tetrachloride;
Examples thereof include aromatic hydrocarbons such as benzene, toluene, and xylene. The component (D) may be preliminarily reacted with the component (C) and blended as an organic compound having an Al-O-Si bond.

As the organotin compound as the component (E), those generally used in polycondensation-reactive polyorganosiloxane compositions can be used. For example, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dibenzylmalate, dibutyltin dioctoate, tin dioctylate, di-n-butyldimethoxytin, bisethylmaleyldibutyltin oxide, dibutyltin benzylmalate, tetrabutyl Examples thereof include bis (ethylmalate) ditin oxide, dibutyltin bis (isooctyl phthalate), dibutyltin bis (3-methyl-3-methoxybutylmalate), and dioctyltin dilaurate. Further, it is previously reacted with an alkoxy group-containing silicon compound,
It may be compounded as the following organic compound having an n-O-Si bond.

[0035]

Embedded image (R ′ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, R ″ is an alkoxy group and / or a monovalent hydrocarbon group having 1 to 6 carbon atoms, p and q are 0 or positive integers) The amount of the component is based on 100 parts by weight of the component (A).
It is 0.001 to 1 part by weight, preferably 0.001 to 0.5 part by weight. When the amount is less than 0.001 part by weight, the obtained primer composition does not show a sufficient adhesive effect,
Exceeding the parts by weight, as taught in U.S. Pat.No. 3,532,649, the organotin compound inherently has a curing inhibiting effect on the addition-curable polyorganosiloxane composition, so that the curability is significantly reduced. I do.

The catalyst selected from the group consisting of platinum and the platinum compound of the component (F) used in the present invention is a component (A).
It is a catalyst for promoting an addition reaction between a monovalent aliphatic unsaturated hydrocarbon group and a hydrosilyl group in the component (B).

The component (F) includes platinum simple substance (platinum black), chloroplatinic acid, platinum-olefin complex, complex obtained from platinum and alcohol, platinum-vinylsiloxane complex, other platinum coordination compounds, or alumina. In addition, a carrier in which a simple substance of platinum is supported on a carrier such as silica can be used. When chloroplatinic acid or a platinum-olefin complex is used, it is preferable to use one dissolved in an alcohol solvent, a ketone solvent, an ether solvent, a hydrocarbon solvent, or the like. Further, a solid material needs to be finely pulverized in order to improve dispersibility, and it is preferable to use a carrier having a small particle size and a large specific surface area.

The amount of component (F) used is preferably in the range of 0.1 to 500 ppm as platinum atom with respect to component (A).
If the amount is less than 0.1 ppm, the effect is small. Even if the amount exceeds 500 ppm, no improvement in the curing speed can be expected, and the pot life is undesirably reduced.

The primer composition of the present invention may further contain an addition reaction inhibitor in order to impart the storage stability of the composition at room temperature. Methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentene
Acetylene-based alcohols such as -3-ol and phenylbutynol, acetylene-based compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-1-hexyn-3-yne, and these acetylenic compounds Reaction products of silane with alkoxysilane or siloxane or hydrogen silane or siloxane, vinyl siloxane such as tetramethyl vinyl siloxane, organic nitrogen compounds such as benzotriazole, and other organic phosphorus compounds, oxime compounds, and organic chromium compounds. Is exemplified. The amount of the addition reaction inhibitor may be any amount as long as good storage stability is obtained, and is generally 0.001 to 100 parts by weight of the component (A).
10 parts by weight, preferably 0.01 to 1 part by weight are used. Further, the composition of the present invention, spherical or amorphous inorganic fillers such as silica and titanium oxide, polyorganosilsesquioxane, silicone powder as a cured product powder such as polyorganosiloxane, other pigments, The addition of a dye or the like is optional.

When the viscosity of the composition is low, the primer composition of the present invention can be used by directly applying it to a substrate. However, in general, the workability during application and treatment is improved, and It is used by dissolving it in a solvent to further improve the storage stability. Examples of the solvent in this case include aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as heptane, hexane, and pentane; halogenated hydrocarbons such as trichloroethylene and perchloroethylene; ethyl acetate; and methyl ethyl ketone. You.

The primer composition of the present invention can be obtained by uniformly mixing the above-mentioned components (A) to (F), and if necessary, other components and a solvent.

The primer composition of the present invention can be applied to a substrate by using a roll coater, a reverse coater, a gravure coater or the like, and can be treated by heating at 80 to 180 ° C. for 5 to 60 seconds. It may be approximately in the range of 0.2 to 2.0 g / m ^{2 in} terms of siloxane.

The silicone pressure-sensitive adhesive used in the present invention is not particularly limited as long as it is a silicone-based pressure-sensitive adhesive. In general, a silicone pressure-sensitive adhesive mainly containing a mixture or a reaction product of a copolymer of SiO ₂ units and _0.5 units of (CH ₃ ) ₃ SiO 2 and a silanol group-containing polydimethylsiloxane is used. Thus, those in which the substituents of these siloxane units are substituted by a group other than a methyl group, for example, a phenyl group or a vinyl group are used.

The silicone pressure-sensitive adhesive can be used by applying it to a substrate, and when a solvent is used, it can be used by further volatilizing the solvent, but the cohesive force of the applied silicone pressure-sensitive adhesive can be used. It is preferred to crosslink and use since good adhesiveness is obtained and good tackiness is obtained. Silicone pressure-sensitive adhesives are generally classified into an addition reaction type and a peroxide-curable type by this crosslinking method.

The addition reaction type silicone pressure sensitive adhesive is generally R
_0.5 SiO ₃ units (where R is a monovalent hydrocarbon group) and S
The condensation reaction product or a mixture of i O ₂ of the copolymers and silanol-terminated solvent-soluble comprising units alkenyl group-containing polyorganosiloxane, in which an addition reaction with poly organohydrogensiloxane.

The peroxide-curable silicone pressure-sensitive adhesive is a solvent-soluble copolymer comprising _0.5 units of R ₃ SiO 2 (where R is a monovalent hydrocarbon group) and ₂ units of SiO ₂ , and a silanol terminal silanol. The condensation reaction product or mixture with the polyorganosiloxane is crosslinked with an organic peroxide such as benzoyl peroxide.

In the pressure-sensitive adhesive sheet of the present invention, it is preferable to use a cross-linkable silicone pressure-sensitive adhesive since the effect of improving the adhesion by the primer can be favorably obtained. It can be used preferably. Since there is no influence of curing inhibition as in the case of the conventional condensation-type primer, in addition to the peroxide-curable pressure-sensitive adhesive by using the primer of the present invention, a good effect is obtained particularly when an addition-reaction-type pressure-sensitive adhesive is used. can get.

The pressure-sensitive adhesive sheet of the present invention can be obtained by applying a primer composition to a substrate, curing by heating, subsequently applying a silicone pressure-sensitive adhesive, and preferably heating.

[0049]

The pressure-sensitive adhesive sheet of the present invention has excellent adhesion of the silicone pressure-sensitive adhesive to the substrate by treating the substrate with a primer composition having a specific composition and applying a silicone pressure-sensitive adhesive thereon. The adhesive remaining phenomenon when the adhesive sheet is peeled off from the adherend is improved, so that the adherend is not stained, and when the adhesive sheet is used again, the original adhesive strength of the adhesive sheet , And has a feature that the holding power and the like are favorably maintained.

In the case of producing a pressure-sensitive adhesive tape, a pressure-sensitive adhesive is applied to a substrate and wound up, and then rewinding may be performed in order to cut it into a slit shape. When the pressure-sensitive adhesive tape is used, good rewinding without peeling of the silicone pressure-sensitive adhesive from the base material can be performed, and rewinding at a higher speed can be performed, so that there is a feature that workability and production efficiency are excellent.

The pressure-sensitive adhesive sheet of the present invention may be any of various pressure-sensitive adhesive tapes,
Useful as labels and adhesive films.

[0052]

The present invention will be described in more detail with reference to the following examples. Parts and% in Examples are parts by weight and% by weight, respectively, unless otherwise specified.
The value at ° C is shown.

The following abbreviations were used in the examples. M unit: (CH ₃ ) ₃ SiO _{2 0.5} unit ^DH unit: (CH ₃ ) HSiO _{2 1.0} unit Q unit: SiO ₂ unit H / Vi ratio: molar ratio of Si—H group / Si—Vi group (Vi
: Vinyl group) The evaluation was performed by the following method.

1) T-type peeling force A sheet obtained by applying a silicone pressure-sensitive adhesive to a substrate is cut into 2.5 cm × 15 cm, and the two adhesive surfaces are stuck together to form a 20 g / cm ² sheet. The specimen was cured at 70 ° C. for 5 hours under a load. Next, the test piece is taken using a tensile tester.
The film was peeled off at a speed of 5 cm / min in the direction of 80 degrees, and the peeling force at that time was measured to obtain a T-shaped peeling force.

2) SUS board peeling force A sheet obtained by applying a silicone pressure-sensitive adhesive to a substrate was cut into a piece of 2.5 cm x 15 cm, and a stainless steel sheet (JIS) was cut out.
C2107), pressed with a 2 kg rubber roller, and cured at 70 ° C. for 5 hours to obtain a test piece. Next, the adhesive film was peeled off from the stainless steel plate of the test piece in the direction of 180 ° at a speed of 0.3 m / min using a tensile tester, and the peeling force was measured at that time to obtain the SUS plate peeling force.

3) State of Release Surface When the T-type release force was measured, the release surface was observed, and the presence or absence of adhesive residue and the adhesion between the primer layer, the substrate and the adhesive were evaluated. The evaluation was performed as follows. ：: Peeled between adhesives, no adhesive residue. ×: Peeling between the pressure-sensitive adhesive and the substrate, and transfer of the pressure-sensitive adhesive to one of the pressure-sensitive adhesive sheets. (× ¹ : Peeling between primer and substrate, × ² Peeling between adhesive and primer).

Preparation Example 1 (Primer I) As a component (A), both ends of the molecular chain were blocked with a dimethylvinylsilyl group, and the vinyl group content was 1.0 mol% of all the substituents.
100 parts of polymethylvinylsiloxane having an average degree of polymerization of 5,000, both ends of the molecular chain are blocked with a trimethylsilyl group as component (B), the effective hydrogen amount is 1.6%, and the viscosity is 1%.
5 cP polymethyl hydrogen siloxane (MD ^H ₆₀
M) 2.6 parts, 3.0 parts of γ-glycidoxypropyltrimethoxysilane as the component (C), 0.15 parts of aluminum acetylacetate as the component (D), and 246 parts of toluene as a diluting solvent were mixed and stirred to obtain a uniform mixture A.
I got (H / Vi ratio = 1.5).

To 10 parts of the mixture A, 50 parts of toluene was added, and the mixture was stirred until it became uniform. Further, as the component (E), dibutyltin diacetate was added in an amount of 320 ppm based on the total amount of the polysiloxane, and As a component (F), a reaction complex of chloroplatinic acid and vinyl siloxane was added in an amount of 150 ppm in terms of platinum atoms with respect to the total amount of polysiloxane, and the mixture was stirred and mixed until the mixture became uniform. Primer I, a composition, was obtained.

Preparation Example 2 (Primer II) A mixture B was obtained in the same manner as the mixture A, except that the components (C) and (D) were not added to the mixture A. Further, the components were prepared in the same manner as the primer I except that the component (E) was not added, and a primer which was a primer composition for comparison was used.
I got II.

Preparation Example 3 (Primer III) 100 parts of polydimethylsiloxane capped with silanol at both ends,
Both molecular chain terminals blocked with trimethylsilyl groups, polymethyl hydrogen siloxane (MD ^H ₆₀ M) 1.0 parts of a viscosity 15 cP at effective amount of hydrogen 1.6%, and 73 parts of toluene were mixed and stirred as dilution solvent uniform To obtain a mixture C. To 10 parts of this mixture, 50 parts of toluene was added and mixed and stirred until uniform, and then dibutyltin diacetate was added in an amount of 4.0% based on the total amount of polysiloxane, and mixed and stirred until uniform. Primer III, which is a primer composition for use in the present invention, was obtained.

Preparation Example 4 (Primer IV) β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane instead of γ-glycidoxypropyltrimethoxysilane as component (C), dibutyltin diacetate as component (E) The components were prepared in the same manner as in Preparation Example 1 except that dibutyltin dilaurate was used instead of the above, to obtain a primer IV as a primer composition of the present invention.

Preparation Example 5 (Primer V) The components were prepared in the same manner as in Preparation Example 1, except that γ-methacryloxypropyltrimethoxysilane was used instead of γ-glycidoxypropyltrimethoxysilane as the component (C). And primer V, which is a primer composition for comparison,
I got

Preparation Example 6 (Adhesive I) Consisting of M units and Q units, the molar ratio of M: Q was 4: 5, the hydroxyl group content was 6.0%, and the viscosity of the xylene solution (60%) was 10
and cSt siloxane resin 65 parts, with both molecular chain terminals blocked with hydroxyl groups, the condensation reaction product 100 parts of the average polymerization degree of vinyl group-containing polydimethylsiloxane 35 parts 5,000, polymethyl hydrogen siloxane (MD ^H ₅₆ M) 0.4 parts,
Add 2.0 parts of an isopropyl alcohol solution of chloroplatinic acid as a reaction catalyst (platinum content: 0.05%) and 50 parts of toluene as a diluting solvent, mix and stir until uniform, and add an adhesive-type silicone pressure-sensitive adhesive. Agent I was obtained.

Preparation Example 7 (Adhesive II) An adhesive II was obtained in the same manner as in Preparation Example 6, except that the siloxane resin was 55 parts and the vinyl group-containing polydimethylsiloxane was 45 parts.

Preparation Example 8 (Adhesive III) Condensation reaction between 50 parts of the siloxane resin of Preparation Example 6 and 50 parts of a vinyl group-containing polydimethylsiloxane having both ends of a molecular chain blocked with hydroxyl groups and having an average degree of polymerization of 5,000. 100 parts
Add benzoyl peroxide (1.0 part) as a reaction catalyst and toluene (50 parts) as a diluting solvent and mix and stir until uniform,
PSA, a peroxide-curable silicone pressure-sensitive adhesive II
I got

Example 1 Primer I was applied to a polyimide film (50 μm thick).
0.8 g / m ² (solid content)
The coating was cured by heating at 00 ° C. for 30 seconds to perform a primer treatment. Next, the pressure-sensitive adhesive I was applied to the primer-treated surface so as to have a thickness of 25 to 30 μm (solid content), and was heated and cured at 120 ° C. for 2 minutes to prepare a pressure-sensitive adhesive sheet. The above-mentioned evaluation was performed using the obtained pressure-sensitive adhesive sheet, and the results are shown in Table 1.

Example 2 An adhesive sheet was prepared in the same manner as in Example 1 except that adhesive II was used in place of adhesive I. Do the same evaluation,
Table 1 shows the results.

Example 3 A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1, except that pressure-sensitive adhesive III was used instead of pressure-sensitive adhesive I. Evaluation was performed in the same manner, and the results are shown in Table 1.

Example 4 An adhesive sheet was prepared in the same manner as in Example 1 except that Primer IV was used instead of Primer I. Evaluation was performed in the same manner, and the results are shown in Table 1.

Comparative Example 1 An adhesive sheet was prepared in the same manner as in Example 1 except that no primer was used. Evaluation was performed in the same manner, and the results are shown in Table 1.

Comparative Example 2 A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that pressure-sensitive adhesive III was used instead of pressure-sensitive adhesive I, and no primer was used. Evaluation was performed in the same manner, and the results are shown in Table 1.

Comparative Example 3 An adhesive sheet was prepared in the same manner as in Example 1 except that Primer II was used instead of Primer I. Evaluation was performed in the same manner, and the results are shown in Table 1.

Comparative Example 4 An adhesive sheet was prepared in the same manner as in Example 1 except that Primer III was used instead of Primer I. Evaluation was performed in the same manner, and the results are shown in Table 1.

Comparative Example 5 An adhesive sheet was prepared in the same manner as in Example 1 except that Primer V was used instead of Primer I. Evaluation was performed in the same manner, and the results are shown in Table 1.

Comparative Example 6 An adhesive sheet was prepared in the same manner as in Example 1 except that Primer II was used instead of Primer I and Adhesive III was used instead of Adhesive I. Evaluation was performed in the same manner, and the results are shown in Table 1.

[0076]

[Table 1]

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ identification symbol FI C09J 183/07 C09J 183/07 (58) Investigated field (Int.Cl. ⁶ , DB name) C09J 7/00-7/04 C08K 5/56 C08L 83/06 C08L 83/07 C09J 183/06 C09J 183/07

Claims (3)

(57) [Claims] (A) 100 parts by weight of a polyorganosiloxane containing two or more monovalent aliphatic unsaturated hydrocarbon groups bonded to a silicon atom in one molecule; and (B) hydrogen bonded to a silicon atom. A polyorganohydrogensiloxane having three or more atoms in one molecule, wherein the number of hydrogen atoms bonded to silicon atoms is 1.0 to 1.0 relative to one monovalent unsaturated aliphatic hydrocarbon group in component (A); (C) an organic silicon compound in which an epoxy ring-containing group or an alkoxy group, which is a γ-glycidoxypropyl group or β- (3,4-epoxycyclohexyl) ethyl group, is bonded to a silicon atom 0.1 (D) organoaluminum compound 0.01 to 10 parts by weight (E) organotin compound 0.001 to 1 part by weight (F) a catalyst selected from the group consisting of platinum and platinum compounds, platinum for component (A) 0.1 as an atom Processing the substrate with a primer composition containing 500 ppm, obtained by further coating a silicone pressure sensitive adhesive a pressure-sensitive adhesive sheet. 2. The pressure-sensitive adhesive sheet according to claim 1, wherein the silicone pressure-sensitive adhesive is heat-curable with an organic peroxide. 3. The pressure-sensitive adhesive sheet according to claim 1, wherein the silicone pressure-sensitive adhesive is heat-cured by an addition reaction.