JP2014177574A - Resin composition, primer and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which imparts excellent adhesiveness eliminating the possibility of detachment even when subjected to an impact of e.g. falling, in being applied to a substrate, e.g. a polyamide film, and forming an upper layer on the substrate to form an article.SOLUTION: A resin composition comprises (A) an urethane resin having carboxyl groups, (B) an isocyanate crosslinking agent and (C) an organic solvent. A primer and an article obtained by using the resin composition are also provided. The resin composition has excellent adhesiveness, or load resistance, to a substrate and an upper layer, e.g. a polyamide film, and excellent falling impact resistance even when an article adhered with the substrate and the upper layer is subjected to an impact, e.g. falling. The resin composition can impart the excellent falling impact resistance even when a humidity-curable urethane hot melt adhesive is used as the upper layer.

Description

  The present invention is a resin composition that can be suitably used for a substrate such as a polyamide film, and when applied to the substrate and further forming an upper layer thereon to form an article, The present invention relates to a resin composition having excellent adhesiveness that does not peel off even under impact.

  Since moisture-curing urethane hot melt adhesives are solvent-free, various researches have been made to date centering on fiber bonding and building material lamination as environmentally friendly adhesives, and they are also widely used in industry.

  In recent years, in response to the growing needs for lighter and thinner optical components, in the pasting of optical components, studies have been made to replace hot-melt adhesives with acrylic adhesives that have been the mainstream until now ( For example, see Patent Document 1.)

  However, as adherends (base materials) used for optical components, difficult-to-adhere base materials such as polyamide films and acrylic resin films may be used, and moisture curable urethane hot melt adhesives are attached to these base materials. Even if the agent is applied directly, there is a problem that satisfactory adhesiveness cannot be obtained.

Special table 2011-521040 gazette

  The problem to be solved by the present invention is excellent adhesion that does not peel even when subjected to impact such as dropping when applied to a substrate such as a polyamide film and further forming an upper layer thereon to form an article. (Hereinafter, abbreviated as “drop impact resistance”).

  As the present inventors proceeded with researches to solve the above-mentioned problems, the inventors focused on urethane resins and cross-linking agents as resin compositions to be used as primers, and conducted earnest research to complete the present invention.

  That is, the present invention relates to a resin composition comprising a urethane resin (A) having a carboxyl group, an isocyanate crosslinking agent (B) and an organic solvent (C), and a primer and an article obtained using the resin composition Is to provide.

The resin composition of the present invention is excellent in adhesion (load resistance) with a base material including a polyamide film and an upper layer (load resistance), and is excellent in drop impact resistance even if an article to which these are bonded receives an impact such as dropping. Is.
Moreover, the resin composition of this invention can provide the outstanding drop impact resistance, even if the layer obtained using the moisture hardening type urethane hot-melt-adhesive is used as said upper layer.

  The resin composition of the present invention contains a urethane resin (A) having a carboxyl group, an isocyanate crosslinking agent (B), and an organic solvent (C).

  The urethane resin (A) having a carboxyl group can impart adhesion to a difficult-to-adhere substrate such as a polyamide film by the carboxyl group. The urethane resin (A) can be produced, for example, by reacting a polyol (a-1) having a carboxyl group, another polyol (a-2), and a polyisocyanate (a-3).

  Examples of the polyol (a-1) having a carboxyl group include 2,2′-dimethylolpropionic acid, 2,2′-dimethylolbutanoic acid, 2,2′-dimethylolbutyric acid, and 2,2′-dimethylol. Valeric acid or the like can be used. These polyols may be used alone or in combination of two or more. Among these, 2,2'-dimethylolpropionic acid and 2,2'-dimethylolbutanoic acid are preferably used from the viewpoint of further improving the ease of reaction control and drop impact resistance.

  As the usage-amount of the polyol (a-1) which has the said carboxyl group, from a viewpoint which can further improve drop impact resistance and load resistance, the said polyol (a-1) and the said other polyol (a-2) The range of 0.1 to 10 parts by mass is preferable, the range of 2.1 to 6 parts by mass is more preferable, and the range of 2.5 to 5 parts by mass is more preferable.

  Examples of the other polyol (a-2) include polyester polyol, polyether polyol, polycarbonate polyol, acrylic polyol, polybutanediene polyol, and low molecular weight polyol. These polyols may be used alone or in combination of two or more. Among these, it is preferable to use a polyester polyol from the viewpoint of further improving the drop impact resistance and load resistance.

  The number average molecular weight of the polyol (a-2) other than the low molecular weight polyol is in the range of 500 to 50,000 from the viewpoint of drop impact resistance, load resistance, ease of reaction control, and the like. The range of 800 to 2,000 is more preferable. In addition, the number average molecular weights of the said polyol (a-2) other than a low molecular weight polyol show the value measured on condition of the following by gel permeation chromatography (GPC) method.

Measuring device: High-speed GPC device (“HLC-8220GPC” manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series.
"TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSKgel G4000" (7.8 mm ID x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 “TSKgel G2000” (7.8 mm ID × 30 cm) × 1 detector: RI (differential refractometer)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL / min Injection amount: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4 mass%)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

  Examples of the polyester polyol include an aliphatic polyester polyol obtained by esterifying a low molecular weight polyol and a polycarboxylic acid, an aromatic polyester polyol, and cyclic ester compounds such as ε-caprolactone and γ-butyrolactone. Polyester obtained by polymerization can be used. Among these, it is preferable to use an aromatic polyester polyol from the viewpoint of further improving the drop impact resistance and load resistance.

  Examples of the low molecular weight polyol include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, and 1,6-hexanediol. 1,4-cyclohexanedimethanol, neopentyl glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane and the like can be used. These low molecular weight polyols may be used alone or in combination of two or more. Among these, it is preferable to use diol from the viewpoint of ease of reaction control and the like, and it is more preferable to use ethylene glycol and neopentyl glycol.

  Examples of the polycarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, azelaic acid, cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and the like. These polycarboxylic acids may be used alone or in combination of two or more. Among these, adipic acid, terephthalic acid, and isophthalic acid are preferably used from the viewpoint of ease of reaction control.

  Examples of the polyisocyanate (a-3) include hexamethylene diisocyanate, dimer diisocyanate, 1,3-diisocyanatomethylcyclohexane, isophorone diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, hydrogenated xylylene diisocyanate, and trimethylhexamethylene. Aliphatic polyisocyanates such as diisocyanate, lysine diisocyanate, lysine diisocyanate, norbornene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, carbodiimidized diphenylmethane diisocyanate, 2,4-tri Range isocyanate, 2,6-trile Diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate, can be used aromatic polyisocyanates such as tetramethyl xylene diisocyanate. These polyisocyanates may be used alone or in combination of two or more. Among these, aliphatic polyisocyanate is preferably used and hexamethylene diisocyanate is more preferably used from the viewpoints of easy reaction control and adhesion to a substrate.

  Examples of the polyisocyanate (a-3) include “Bernock D-750”, “Chrisbon NX” (manufactured by DIC Corporation), “Desmodur L” (manufactured by Sumitomo Bayer Corporation), and “Coronate L”. (Nippon Polyurethane Co., Ltd.), “Takenate D102” (Mitsui Chemicals Co., Ltd.), “Isonate 143L” (Mitsubishi Chemical Co., Ltd.), etc. can be obtained as commercial products.

  As a method for producing the urethane resin (A), for example, the polyol (a-1) having the carboxyl group, the other polyol (a-2) and the polyisocyanate (a-3) are used. Accordingly, it can be produced by performing a known urethanization reaction in the organic solvent (C).

  The total molar ratio of the hydroxyl group of the polyol (a-1) having the carboxyl group and the hydroxyl group of the other polyol (a-2) and the molar ratio of the isocyanate group of the polyisocyanate (a-3) The ratio is preferably in the range of 0.8 to 1.3, and more preferably in the range of 0.9 to 1.2, from the viewpoints of load resistance and storage stability.

  The number average molecular weight of the urethane resin (A) is in the range of 2,000 to 100,000 from the viewpoint of further improving compatibility with the isocyanate crosslinking agent (B), drop impact resistance, load resistance, and the like. Is preferable, and the range of 5,000 to 50,000 is more preferable. In addition, the number average molecular weight of the said urethane resin (A) shows the value measured similarly to the number average molecular weight of the said polyol (a-2).

  The isocyanate crosslinking agent (B) is an essential component for imparting drop impact resistance. This is because high molecular weight after curing of the resin composition can be achieved by using the isocyanate crosslinking agent (B) in combination with the urethane resin (A). Moreover, when other crosslinking agents such as an epoxy crosslinking agent are used in place of the isocyanate crosslinking agent (B), satisfactory drop impact resistance cannot be obtained.

  As said isocyanate crosslinking agent (B), the thing similar to the said polyisocyanate (a-3) can be used, Furthermore, those triisocyanates, such as those of a nurate body, a burette body, an adduct body, and a trimethylol propane adduct, are used. Can be used. These isocyanate crosslinking agents may be used alone or in combination of two or more. Among these, from the viewpoint of further improving impact drop resistance and the like, it is preferable to use triisocyanate, and it is more preferable to use a trimethylolpropane adduct.

  As a usage-amount of the said isocyanate crosslinking agent (B), it is the range of 0.1-30 mass parts with respect to 100 mass parts of said urethane resins (A) from a viewpoint which can improve impact fall resistance etc. further. The range of 0.5 to 10 parts by mass is more preferable.

  The molar ratio [(A) / (B)] of the isocyanate group possessed by the isocyanate crosslinking agent (B) and the carboxyl group possessed by the urethane resin (A) includes impact drop resistance, load resistance, and reaction. From the viewpoint of further improving the ease of control, the range of 1 to 10 is preferable, and the range of 3 to 9 is more preferable.

  Examples of the organic solvent (C) include methyl ethyl ketone, ethyl acetate, toluene, hexane, cyclohexanone, 3-pentanone, acetonitrile, propionitrile, isobutyronitrile, valeronitrile, dimethylformamide, dimethyl sulfoxide, methanol, ethanol, Butanol or the like can be used. These organic solvents may be used alone or in combination of two or more. In addition, it is preferable not to use water together intentionally from the viewpoints of drying property, drop impact resistance, and the like, and the resin composition of the present invention is preferably non-aqueous.

  As the usage-amount of the said organic solvent (C), it is preferable that it is the range of 5-90 mass% in resin compositions from viewpoints, such as viscosity suppression of the said urethane resin (A), and drying property, and 10-80 masses. % Range is more preferred.

  The resin composition of the present invention contains the urethane resin (A), the isocyanate crosslinking agent (B), and the organic solvent (C) as essential components, but contains other additives as necessary. Also good.

  Examples of the other additives include urethanization catalysts, antioxidants, tackifiers, plasticizers, stabilizers, fillers, dyes, pigments, waxes, and the like.

  Examples of the substrate (i) to which the resin composition is applied include cycloolefin resin, acrylic resin, silicon resin, epoxy resin, fluororesin, polystyrene resin, polyester resin, polysulfone resin, polyarylate resin, polyvinyl chloride. Resin, polyvinylidene chloride, amorphous polyolefin resin, polyimide resin, polycarbonate (PC), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyamide, acrylonitrile-butadiene-styrene A plastic substrate such as a polymer (ABS) or acrylonitrile-styrene copolymer (AS), glass or the like can be used. The resin composition of the present invention can impart excellent drop impact resistance even when a hardly adhesive substrate such as polyamide is used as the substrate.

  As a method for applying the resin composition of the present invention to the substrate (i), for example, a roll coater, a spray coater, a T-tie coater, a knife coater, a comma coater or the like can be used.

  Examples of the method for drying the resin composition include a method of drying at a temperature in the range of 50 to 120 ° C. for 5 minutes to 1 hour.

  Since the resin composition of this invention is excellent in adhesiveness, it can be used especially suitably as a primer.

  The thickness of the layer (ii) obtained using the primer (hereinafter abbreviated as primer layer (ii)) is appropriately determined depending on the application, but is generally in the range of 5 to 200 μm.

  Although it does not specifically limit as an upper layer of the said primer layer (ii), For example, the layer obtained using adhesive agents, such as a coating material, ink, and a moisture hardening type urethane hot-melt adhesive agent, can be used. Since the primer layer (ii) is excellent in adhesiveness, a layer (iii) obtained by using the base material (i) and a moisture curable urethane hot melt adhesive (hereinafter abbreviated as an adhesive layer (iii)). .) Can be improved.

  As the moisture curable urethane hot melt adhesive, it is preferable to use one containing a urethane prepolymer having an isocyanate group obtained by reacting a polyol and a polyisocyanate.

  Moreover, as said adhesive bond layer (iii), it is preferable that a midpoint glass transition temperature (Tmg) is -10 degrees C or less from a viewpoint which can improve fall impact resistance further, and is -10 to -40 degreeC. A range is more preferable. In addition, the midpoint glass transition temperature (Tmg) of the said adhesive bond layer (iii) shows the value obtained by measuring based on JISK7121.

  As said polyol, the thing similar to the said polyol (a-2) can be used. Among these, polyether polyol and acrylic polyol are used as essential components from the viewpoint that the midpoint glass transition temperature (Tmg) of the adhesive layer (iii) is set in the above-mentioned preferable range and the drop impact resistance can be further improved. It is preferable.

  Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, and ethylene oxide-modified polypropylene glycol.

  As the acrylic polyol, it is preferable to use an acrylic polyol obtained by polymerizing a (meth) acrylic compound containing a (meth) acrylic compound having a hydroxyl group as an essential component. In the present invention, “(meth) acrylic compound” refers to one or both of a methacrylic compound and an acrylic compound.

  As the (meth) acrylic compound having a hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, trimethylolpropane triacrylate, or the like is used. Can do. Among these, it is more preferable to use 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate from the viewpoint of easy availability of raw materials.

As a (meth) acrylic compound other than the (meth) acrylic compound having a hydroxyl group,
For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, neopentyl (meth) acrylate, 2-ethylhexyl (meth) (Meth) acrylate compounds having an alkyl group having 1 to 14 carbon atoms such as acrylate, octyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, lauryl (meth) acrylate, acrylic acid, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, 2- (perfluorooctyl) ) Ethyl (me ) Acrylate, cyclohexyl (meth) acrylate, sidiclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, Methoxytriethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, benzyl (meth) acrylate, 2-ethyl-2-methyl- [1,3] -dioxolan-4-yl-methyl (meth) acrylate, dimethyl Aminoethyl (meth) acrylate, isobornyl (meth) acrylate, etc. can be used. These (meth) acrylic compounds may be used alone or in combination of two or more. Among these, the intermediate point glass transition temperature (Tmg) of the adhesive layer (iii) is set to the above-described preferable range, and from the viewpoint of further improving the drop impact resistance, the range of 1 to 14 carbon atoms. It is more preferable to use a (meth) acrylate compound having an alkyl group, and it is particularly preferable to use n-butyl (meth) acrylate.

  The number average molecular weight of the acrylic polyol is preferably from 5,000 to 50,000, particularly preferably from 10,000 to 30,000, from the viewpoint of further improving the drop impact resistance. In addition, the number average molecular weight of the said acrylic polyol is the same as that of the measuring method of the number average molecular weight of the said polyol (a-2).

  In addition, the midpoint glass transition temperature of the acrylic polyol is preferably in the range of 5 to 150 ° C, more preferably in the range of 30 to 120 ° C, and more preferably in the range of 50 to 80 ° C from the viewpoint of further improving the drop impact resistance. A range is more preferred. In addition, the midpoint glass transition temperature of the said acrylic polyol is the same as the measuring method of the midpoint glass transition temperature of the said adhesive bond layer (iii).

  As said polyisocyanate, the thing similar to the said polyisocyanate (a-3) can be used.

  The urethane prepolymer is obtained by reacting the polyol and the polyisocyanate, and the moisture present in the adherend (the primer layer (ii)) to which the urethane prepolymer is applied in the air. It has an isocyanate group that can react to form a crosslinked structure at the polymer end or in the molecule.

  As a method for producing the urethane prepolymer, for example, the reaction mixture containing the polyisocyanate is heated after dropping the mixture of the polyol, and the isocyanate group of the polyisocyanate is compared with the hydroxyl group of the polyol. The method of manufacturing by making it react on the conditions which become excess can be used.

  When producing the urethane prepolymer, the equivalent ratio of the isocyanate group of the polyisocyanate to the hydroxyl group of the polyol ([isocyanate group / hydroxyl group)] is 1.1 to The range of 5.0 is preferable, and the range of 1.5 to 3.0 is more preferable.

  The isocyanate group content (hereinafter abbreviated as NCO%) of the urethane prepolymer obtained by the above method is in the range of 1.5 to 8.0% from the viewpoint of further improving the drop impact resistance. Is preferable, the range of 1.7 to 5.0 is more preferable, and the range of 1.8 to 3.0 is particularly preferable. In addition, NCO% of the said urethane prepolymer shows the value measured by the potentiometric titration method based on JISK1603-1.

  As the viscosity of the urethane prepolymer, the melt viscosity at 110 ° C. is preferably in the range of 1,000 to 50,000 mPa · s, and more preferably in the range of 2,000 to 10,000 mPa · s. The melt viscosity at 110 ° C. is a value measured with a cone plate viscometer (manufactured by ICI).

  The softening point of the urethane prepolymer is preferably in the range of 30 to 120 ° C. from the viewpoint of drop impact resistance and the like. The softening point refers to the temperature at which the fluid starts to flow and loses cohesion when the temperature of the ureta prepolymer is raised stepwise. Further, the softening point of the urethane prepolymer indicates a value obtained by a ring and ball method in accordance with JIS K 5902.

  Examples of the method for applying the moisture curable urethane hot melt adhesive include a method using a roll coater, spray coater, T-tie coater, knife coater, comma coater, dispenser, ink jet printing, screen printing, and offset. A method of coating by a printing method or the like can be used. According to an application method such as a dispenser, the moisture curable urethane hot melt adhesive is continuously formed in the primer layer (ii) in various shapes such as dotted, linear, triangular, square, round, and curved. Or can be formed intermittently or intermittently.

  As a curing method after the application of the moisture curable urethane hot melt adhesive, for example, the temperature is in the range of 20 to 80 ° C. and the relative humidity is in the range of 50 to 90% RH, and is performed for 0.5 to 5 days. be able to.

  The thickness of the adhesive layer (iii) is appropriately set depending on the application to be used, but can be preferably set in a range of approximately 10 μm to 5 mm.

  Hereinafter, the present invention will be described in detail with reference to examples.

[Synthesis Example 1]
<Synthesis of acrylic polyol (1)>
Into a reaction vessel equipped with a thermometer, a stirrer and a condenser, 300 parts by mass of methyl ethyl ketone was added and the temperature in the vessel was set to 80 ° C., then 340 parts by mass of methyl methacrylate, 340 parts by mass of butyl methacrylate, 2-hydroxy methacrylate. A solution obtained by adding 10 parts by mass of ethyl and 8.5 parts by mass of azobisisobutyronitrile in 160 parts by mass of methyl ethyl ketone is added, mixed, and reacted for 16 hours, whereby acrylic polyol (1) (nonvolatile content: 52% by mass) , Viscosity; 2,000 mPa · s (23 ° C.)).

[Synthesis Example 2]
<Synthesis of moisture-curing urethane hot melt adhesive (1)>
In a four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser, 15 parts by mass of polypropylene glycol (number average molecular weight; 1,000, hereinafter abbreviated as “PPG1000”), polypropylene glycol (several Average molecular weight: 2,000, hereinafter abbreviated as “PPG2000”) 15 parts by mass, crystalline polyester polyol-1 (reaction of 1,6-hexanediol and adipic acid, number average molecular weight; 2,000) 10 Parts by mass, crystalline polyester polyol-2 (reaction of 1,6-hexanediol and 1,12-dodecanedicarboxylic acid, number average molecular weight; 3,500), 10 parts by mass, amorphous polyester polyol-1 (A product obtained by reacting bisphenol A propylene oxide 6 mol adduct with sebacic acid and isophthalic acid. Number average molecular weight: 2,000) 15 parts by mass, acrylic polyol-1 20 parts by mass, acrylic polyol (1) ([butyl acrylate / butyl methacrylate / ethyl acrylate / 2-hydroxyethyl methacrylate] = 69. A reaction product of 65/25/5 / 0.35 (mass ratio), number average molecular weight; 13,000, glass transition temperature; It dehydrated until the content rate became 0.05 mass% or less.
Next, after cooling to 70 ° C. in the container, 16.5 parts by mass of 4,4′-diphenylmethane diisocyanate (MDI) was added, the temperature was raised to 100 ° C., and the reaction was continued for about 3 hours until the NCO group content became constant. Thus, a moisture-curable urethane hot melt adhesive (1) containing a urethane prepolymer having an isocyanate group was obtained.

[Example 1]
Polyester polyol (reacted with ethylene glycol, neopentyl glycol, terephthalic acid, isophthalic acid and adipic acid, number average molecular weight) in a four-necked flask equipped with a thermometer, stirrer, inert gas inlet and reflux condenser 1,300) 700 parts by mass and adjusted to 35 ° C. or lower. Next, 114 parts of hexamethylene diisocyanate was added, the temperature was raised to 80 ° C., and the reaction was continued for about 3 hours until the NCO% became constant.
Next, the mixture was cooled to 60 ° C. or lower, 21 parts by mass of dimethylolpropionic acid, 450 parts by mass of methyl ethyl ketone, and 0.13 parts by mass of a urethanization catalyst (“Neostan U-28” manufactured by Nitto Kasei Co., Ltd.) were added. Measurement: The reaction was continued at 60 ° C. until Cut Vis (Batch / MEK = 1/1 (material ratio)) was in the range of QR to T.
Thereafter, 285 parts by mass of methyl ethyl ketone and 1.48 parts by mass of methanol were added, and the temperature was raised to 70 ° C. Thereafter, the mixture was stirred at 70 ° C. for 3 hours to obtain a urethane resin (A-1) having a viscosity of 14,000 mPa · s at 25 ° C.
Next, 100 parts by mass of the urethane resin (A-1) and 1 part by mass of an isocyanate crosslinking agent (“Bernock D-750” manufactured by DIC Corporation) are blended, and methyl ethyl ketone is added so that the solid content becomes 10% by mass. And a resin composition (1) was obtained.
The obtained resin composition (1) was applied to one side of each of a polyamide film and an acrylic resin film so that the thickness after drying was 100 μm and allowed to stand at 100 ° C. for 5 minutes. Next, moisture-curable urethane hot melt adhesive-1 was applied onto the polyamide film / primer layer, and an acrylic resin film having the primer layer was bonded. Thereafter, the product was cured for 3 days under the conditions of 23 ° C. and 50% RH, thereby obtaining an article having a configuration of polyamide film / primer layer / moisture curable urethane hot melt adhesive layer / primer layer / acrylic resin film. .

[Example 2]
Polyester polyol (reacted with ethylene glycol, neopentyl glycol, terephthalic acid, isophthalic acid and adipic acid, number average molecular weight) in a four-necked flask equipped with a thermometer, stirrer, inert gas inlet and reflux condenser 1,300) 700 parts by mass and adjusted to 35 ° C. or lower. Next, 132.6 parts of hexamethylene diisocyanate was added, and the mixture was heated to 80 ° C. and reacted for about 3 hours until the NCO% became constant.
Next, the mixture was cooled to 60 ° C. or lower, 48 parts by mass of dimethylolpropionic acid, 450 parts by mass of methyl ethyl ketone, and 0.13 parts by mass of a urethanization catalyst (“Neostan U-28” manufactured by Nitto Kasei Co., Ltd.) were added. Measurement: The reaction was continued at 60 ° C. until Cut Vis (Batch / MEK = 1/1 (material ratio)) was in the range of QR to T.
Thereafter, 285 parts by mass of methyl ethyl ketone and 1.48 parts by mass of methanol were added, and the temperature was raised to 70 ° C. Thereafter, the mixture was stirred at 70 ° C. for 3 hours to obtain a urethane resin (A-2) having a viscosity of 14,000 mPa · s at 25 ° C.
Next, 100 parts by mass of the urethane resin (A-2) and 1 part by mass of an isocyanate crosslinking agent (“Bernock D-750” manufactured by DIC Corporation) are blended, and methyl ethyl ketone is added so that the solid content becomes 10% by mass. And a resin composition (2) was obtained.
Subsequently, an article was obtained in the same manner as in Example 1 except that the resin composition (1) was changed to the resin composition (2).

[Example 3]
100 parts by mass of the urethane resin (1), 5 parts by mass of an isocyanate crosslinking agent (“Bernock D-750” manufactured by DIC Corporation) are blended, and methyl ethyl ketone is further added so that the solid content becomes 10% by mass. (3) was obtained.
Next, an article was obtained in the same manner as in Example 1 except that the resin composition (1) was changed to the resin composition (3).

[Comparative Example 1]
Except not using the said resin composition (1), it carried out similarly to Example 1, and obtained the article | item which has a structure of a polyamide film / moisture hardening type urethane hot melt adhesive layer / acrylic resin film.

[Comparative Example 2]
Methyl ethyl ketone was added so that the urethane resin (1) was 100 parts by mass and the solid content was 10% by mass to obtain a resin composition (4).
Next, an article was obtained in the same manner as in Example 1 except that the resin composition (1) was changed to the resin composition (4).

[Comparative Example 3]
Next, 100 parts by mass of the urethane resin (1) and 1 part by mass of an epoxy cross-linking agent (“Denacol EX-211” manufactured by Nagase ChemteX Corporation) are blended, and methyl ethyl ketone is added so that the solid content becomes 10% by mass. And a resin composition (5) was obtained.
Next, an article was obtained in the same manner as in Example 1 except that the resin composition-1 was changed to the resin composition (5).

[Comparative Example 4]
Polyester polyol (reacted with ethylene glycol, neopentyl glycol, terephthalic acid, isophthalic acid and adipic acid, number average molecular weight) in a four-necked flask equipped with a thermometer, stirrer, inert gas inlet and reflux condenser 1,300) 700 parts by mass and adjusted to 35 ° C. or lower. Next, 114 parts of hexamethylene diisocyanate was added, the temperature was raised to 80 ° C., and the reaction was continued for about 3 hours until the NCO% became constant.
Next, the mixture was cooled to 60 ° C. or less, 450 parts by mass of methyl ethyl ketone and 0.13 parts by mass of a urethanization catalyst (“Neostan U-28” manufactured by Nitto Kasei Co., Ltd.) were added, and the reaction was continued at 60 ° C. for about 3 hours. It was.
Thereafter, 285 parts by mass of methyl ethyl ketone and 1.48 parts by mass of methanol were added, and the temperature was raised to 70 ° C. Thereafter, the mixture was stirred at 70 ° C. for 3 hours to obtain a urethane resin (A-3) having a viscosity of 14,000 mPa · s at 25 ° C.
Next, 100 parts by mass of the urethane resin (A-3) and 1 part by mass of an isocyanate cross-linking agent (“Bernock D-750” manufactured by DIC Corporation) are blended, and methyl ethyl ketone is added so that the solid content becomes 10% by mass. And a resin composition (6) was obtained.
Subsequently, an article was obtained in the same manner as in Example 1 except that the resin composition (1) was changed to the resin composition (6).

[Drop impact resistance evaluation method]
Using the articles obtained in the examples and comparative examples as test pieces, in a DuPont impact tester in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH, through a striker from the polyamide film side, the load: 300 g, Height: The drop impact resistance was evaluated as follows according to the peeled state of the article after the impact of 30 cm was applied five times.
“◯”: No peeling occurred.
“×”: Some peeling occurred.
“XX”: A large peeling portion was confirmed.

  It turned out that the thing of Examples 1-3 which is the articles | goods using the resin composition of this invention is excellent in drop impact resistance.

  On the other hand, Comparative Example 1 is an embodiment that does not use a primer based on the resin composition, but the adhesion between the base material and the moisture-curing urethane hot melt adhesive layer is poor and the drop impact resistance is poor. I understood.

  Comparative Example 2 is an embodiment in which an isocyanate crosslinking agent is not used, but it was found that the drop impact resistance was poor.

  Comparative Example 3 is an embodiment in which an epoxy crosslinking agent is used instead of the isocyanate crosslinking agent, but it has been found that the drop impact resistance and the like are poor.

  Although the comparative example 4 is an aspect using what does not have a carboxyl group as a urethane resin (A), it turned out that drop impact resistance is unsatisfactory.

Claims (5)

A resin composition comprising a urethane resin (A) having a carboxyl group, an isocyanate crosslinking agent (B), and an organic solvent (C). 2. The resin according to claim 1, wherein a molar ratio [(A) / (B)] of an isocyanate group of the isocyanate crosslinking agent (B) and a carboxyl group of the urethane resin (A) is in the range of 1 to 10. 3. Composition. A primer obtained by using the resin composition according to claim 1. The substrate (i), the layer (ii) obtained using the primer according to claim 3 and the layer (iii) obtained using the moisture-curable hot melt urethane resin composition are sequentially laminated. Goods to be. The article according to claim 4, wherein the midpoint glass transition temperature of the layer (iii) is -10 ° C or lower.