JP6760535B2 - Adhesive sheet, article and manufacturing method of article - Google Patents

Description

The present invention relates to an adhesive sheet and an article to which the adhesive sheet is attached and a method for manufacturing the article.

A hard coat layer or mat layer is directly applied to the surface of resin molded products used for the exterior of home appliances, the exterior of mobile terminals, the interior and exterior of automobiles, etc. for the purpose of preventing scratches and improving slipperiness. A bonding member that is laminated or has a hard coat layer, a mat layer, or the like laminated on the surface is laminated by a method of bonding to the surface of these molded products, from the viewpoint of productivity of a small amount and a wide variety of products. Therefore, a method of bonding the bonding member to the surface of these molded products is often used (for example, Patent Document 1). A vacuum forming machine or the like is used as a method of bonding the bonded member to the molded product, and in order to soften the bonded member, the bonding member is heated at about 100 to 170 ° C. for about 1 to 300 seconds, and then immediately molded. A method of pressing the product and pasting while stretching the bonded base material is used.

As a method of bonding the bonding member to the molded product, there is a method of heating the bonding member to a temperature higher than the temperature at which adhesiveness occurs to make it in a semi-solid state and then bonding it to the surface of the molded product. Since the surface layer is softened and the appearance is likely to be poor, a method of laminating an adhesive layer having adhesiveness at room temperature on the back surface of the bonding member and bonding it to a molded product is often used.

As the adhesive layer, it is conceivable to use a liquid adhesive that cures with heat or moisture. In this case, the bonding member is cured for about 24 hours from the time it is attached to the molded product until it is cured. Since it takes time, there are problems that the bonded member floats or peels off during curing, the liquid adhesive flows out, and the layer thickness easily changes.

Further, it is conceivable to use a thermoplastic adhesive tape or a hot melt type adhesive as the adhesive layer, but these do not change while the elastic modulus is low, so that the reliability of the molded product is evaluated. When left in a moist heat environment, swelling or floating occurs due to gas generation from the bonded member or molded product, or swelling or floating occurs due to residual stress or strain when the bonded member is stretched and bonded. There was a problem that it was easy to occur. Further, in order to suppress the generation of gas from the bonded member or the molded product, a step of preheating these members to release the gas is required, which is inferior in production efficiency (for example, Patent Document 2). ..

Further, when the bonding member is transparent and light-transmitting, an ultraviolet curing reaction type adhesive or an adhesive sheet (for example, Patent Document 3) can be used as the adhesive layer, but the exterior of an automobile For outdoor use such as parts, a bonding member in which an ultraviolet absorber or light stabilizer is kneaded inside, or a coat layer having an ultraviolet absorber or light stabilizer is laminated on the surface of the bonding member. Is often used. In this case, the bonding member absorbs ultraviolet rays, which makes it difficult to transmit the ultraviolet rays. Therefore, it is difficult to irradiate the adhesive layer laminated on the back surface of the bonding substrate with the ultraviolet rays to cure the adhesive layer. was there.

Japanese Unexamined Patent Publication No. 2014-092580 Japanese Unexamined Patent Publication No. 2014-205335 Japanese Unexamined Patent Publication No. 2015-072343

The problem to be solved by the present invention is to suppress the formation of bubbles due to the gas that can be generated from the surface of the adherend even in a moist heat environment, and there is no protrusion from the end face, and two or more adherends including the adherend. It suppresses floating and peeling that may occur due to factors such as residual stress and distortion when the body is bonded, and UV absorbers and light stabilizers are kneaded inside, and UV absorbers and light stabilizers are applied to the surface. It is an object of the present invention to provide an adhesive sheet that can be cured and adhered by irradiation with active energy rays even if the bonded member has a coated layer laminated, and can also realize excellent transparency and adhesiveness after curing. ..

The present inventor has found that the above problems can be solved by an adhesive sheet having an adhesive layer having various tensile elastic moduli.
That is, in the present invention, the tensile elastic modulus ( _E'A25 ) measured at a temperature of 25 ° C. and a frequency of 1 Hz is 1 × 10 ³ to 1 × 10 ⁶ Pa, and the tensile modulus measured at a temperature of 100 ° C. and a frequency of 1 Hz. An adhesive sheet having an adhesive layer (A) having a storage elastic modulus ( _E'A100 ) of 1 × 10 ³ to 1 × 10 ⁵ Pa, and the adhesive layer (A) is a cured layer (A'). The tensile storage elastic modulus ( _E'A'100 ) measured at a temperature of 100 ° C. and a frequency of 1 Hz is 2 × 10 ⁵ to 1 × 10 ⁹ Pa, and the adhesive (A) has an absorption wavelength in a wavelength region of 380 nm or more. It is used for the purpose of adhering at least two adherends (B1) and (B2), and at least one of the adherends (B1) and (B2) has a temperature of 85. The present invention provides an active energy ray-curable polyurethane adhesive sheet, which is an adherend capable of generating gas when left in an environment of ° C. and a humidity of 85% RH for 24 hours.

The adhesive sheet of the present invention suppresses the floating and peeling of the bonded member caused by the formation of bubbles due to the gas that can be generated from the surface of the molded product and the surface of the bonded member, the residual stress of the bonded member, and the like. , Even if the bonded member has an ultraviolet absorber or light stabilizer kneaded inside or a coat layer having an ultraviolet absorber or light stabilizer laminated on the surface, it can be cured and adhered by irradiation with active energy rays. In addition, since it is possible to realize even better transparency and adhesiveness, it greatly contributes to the manufacture of resin molded products used for the exterior of home appliances, the exterior of mobile terminals, the interior and exterior of automobiles, etc. be able to.

The adhesive sheet of the present invention has a tensile elastic modulus ( _E'A25 ) measured at a temperature of 25 ° C. and a frequency of 1 Hz at 1 × 10 ³ to 1 × 10 ⁶ Pa, and is measured at a temperature of 100 ° C. and a frequency of 1 Hz. An adhesive sheet having an adhesive layer (A) having a tensile storage elastic modulus ( _E'A100 ) of 1 × 10 ³ to 1 × 10 ⁵ Pa, wherein the adhesive layer (A) is cured (A'. ), The tensile storage elastic modulus ( _E'A'100 ) measured at a temperature of 100 ° C. and a frequency of 1 Hz is 2 × 10 ⁵ to 1 × 10 ⁹ Pa, and an ultraviolet absorber and a light stabilizer are kneaded inside. Alternatively, even if the bonding member has a coating layer having an ultraviolet absorber or a light stabilizer laminated on the surface, curing adhesion is possible, and at least two adherends (B1) and (B2) are bonded together. An adherend that can generate gas when at least one of the adherends (B1) and (B2) is left in an environment of a temperature of 85 ° C. and a humidity of 85% RH for 24 hours. It is an active energy ray-curable polyurethane adhesive sheet characterized by being present. The adhesive layer and the adhesive sheet include the concepts of a so-called pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) and a pressure-sensitive adhesive sheet (pressure-sensitive adhesive sheet).

With the adhesive sheet, even a bonded member treated with an ultraviolet absorber or a light stabilizer can be bonded while maintaining excellent transparency. Further, it is possible to achieve both good adhesion and cohesive force to the adherends (B1) and (B2), which is caused by a gas that can be generated from at least one of the adherends (B1) and (B2). It is possible to suppress floating and peeling caused by the formation of the resulting air bubbles and residual stress and strain when the adherends (B1) and (B2) are bonded together.

As the adhesive sheet, a single layer of the adhesive layer (A) or a sheet composed of two or more layers can be used, and in order to obtain excellent transparency, the adhesive layer (A) single layer or , It is preferable to use one composed of a plurality of laminated adhesive layers (A).

[Adhesive layer (A)]
As the adhesive layer (A), one having a tensile elastic modulus ( _E'A25 ) measured at a temperature of 25 ° C. and a frequency of 1 Hz of 1 × 10 ³ to 1 × 10 ⁶ Pa is used, but 1 × 10 ⁴ is preferably ~5 × ¹⁰ 5 Pa, more preferably ^{5 × 10 4 ~5 × 10 5} Pa. By setting _E'A25 in the above range, pressure-sensitive adhesion can be performed to the adherend (B1) or (B2) without heating, and until the adhesive layer (A) is cured by irradiating with active energy rays. , Suppresses floating and peeling caused by residual stress and strain when the adherends (B1) and (B2) are bonded together, and at the time of storage and storage of the adhesive sheet, only from the end face. It is possible to suppress sticking out and crushing.

Further, as the adhesive layer (A), one having a tensile storage elastic modulus ( _E'A100 ) measured at a temperature of 100 ° C. and a frequency of 1 Hz is 1 × 10 ³ to 1 × 10 ⁵ Pa is used. It is preferably 5 × 10 ³ to 8 × 10 ⁴ Pa, and more preferably 1 × 10 ^{4 to} 7 × 10 ⁴ Pa. By setting _E'A100 in the above range, when heat-bonding is performed, it does not become too soft, and it is possible to suppress protrusion and crushing only from the end face, and during heat-bonding, the adherends (B1) and (B2) The formation of bubbles due to the gas that can be generated from at least one of them, and the residual stress and strain when the adherends (B1) and (B2) are bonded until they are cooled to room temperature after bonding. It is possible to obtain an adhesive sheet capable of suppressing floating and peeling that occur as a factor.

The adhesive layer (A) forms a layer (A') [hereinafter, a cured layer (A')] in which the adhesive layer (A) is cured by being irradiated with active energy rays.
The tensile storage elastic modulus ( _E'A'100 ) of the cured layer (A') is 2 × 10 ⁵ to 1 × 10 ⁹ Pa, but more preferably 3 × 10 ⁵ to 1 × 10 ⁷ Pa. .. By _{setting E'A'100} in the above range, a more excellent cohesive force can be imparted, and the formation of bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2) and the adhesion are formed. It is possible to suppress floating and peeling caused by residual stress, strain, and the like when the bodies (B1) and (B2) are bonded together.

Incidentally, the storage elastic modulus tensile at the 25 ℃ (E _'A25), the storage modulus tensile at 100 ℃ (E' _A100) and (E _'A'100) is viscoelastic tester (TA Instruments -The tensile storage elastic modulus (tensile storage elastic modulus) in the temperature range from -40 to 150 ° C under the conditions of frequency 1 Hz and heating rate 3 ° C / min in tensile mode using Japan's product name: RSA III). E') is measured. As the test piece used in the above measurement, the adhesive layer (A) was cut into 50 to 100 μm, a width of 5 mm, a length of the measuring portion of 20 mm, and a length of handles at both ends of 20 mm. Use a rectangular one.

The cured layer (A') formed by irradiation with the active energy rays has a 180 ° peeling adhesive force in the range of 5 to 50 N / 20 mm with respect to a polycarbonate substrate having a smooth surface in an atmosphere of 25 ° C. It is preferably in the range of 7 to 30 N / 20 mm, and more preferably in the range of 7 to 30 N / 20 mm. Within the above range, peeling of the cured layer (A') when the molded product containing the adherends (B1) and (B2) is used at room temperature is suppressed, and the adherend (B1) or (B2) is cured. When the layer (A') is peeled off and the adherend is reused, an adhesive sheet having excellent peelability can be obtained.

The cured layer (A') formed by irradiation with the active energy rays has a peeling adhesive force in the range of 5 to 50 N / 20 mm with respect to a polycarbonate substrate having a smooth surface in an atmosphere of 90 ° C. It is preferably in the range of 7 to 30 N / 20 mm, more preferably. By setting the above range, the formation of bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2), and when the adherends (B1) and (B2) are bonded together. It is possible to suppress floating and peeling caused by residual stress, strain, and the like.

The peeling adhesive force is 160 ° C. after removing the peeling liner on one side of the adhesive sheet of the present invention in which the peeling liner is laminated on both sides and laminating a polyester film having a thickness of 50 μm in an atmosphere of 25 ° C. After heating for 30 seconds at 25 ° C., affixing it to a polycarbonate substrate with a thickness of about 1 to 3 mm and applying pressure with a 2 kg roller for one reciprocation, the thickness is 0.05 to 5 mm, which will be described later. The surface of the polyester film was covered with a transparent resin sheet of the above, and the sample was cured with an active energy ray described later, and the polyester film was subjected to 180 in a Tencilon type tensile tester equipped with a constant temperature bath under an atmosphere of 25 ° C. and 90 ° C. It is obtained by measuring the peeling resistance when pulled at a speed of 50 mm / min in the ° direction.

The gel fraction of the adhesive layer (A) before irradiation with the active energy rays is preferably 0 to 10% by mass, more preferably 0 to 5% by mass. By setting the gel fraction within the above range, pressure-sensitive adhesion to the adherend (B1) or (B2) can be performed without heating. Further, if the adhesive layer is attached to a vacuum forming machine or the like before being attached to the adherend (B1) or (B2) and is heated at 100 to 170 ° C. for about 1 to 300 seconds, the adhesive layer after heating is required. The gel fraction of (A) is preferably 0 to 10% by mass, more preferably 0 to 5% by mass. By setting the gel fraction within the above range, pressure-sensitive adhesion to the adherend (B1) or (B2) can be performed without heating. Further, the gel fraction of the cured layer (A') formed by irradiating the active energy rays is preferably 75 to 95% by mass, more preferably 80 to 90% by mass. By setting the gel fraction in the above range, the adhesive layer (A) has excellent pressure-sensitive adhesiveness, and the cured layer (A') has excellent cohesive force, so that the adherend (B1) and the adherend (B1) and Floating caused by the formation of bubbles due to the gas that can be generated from at least one of (B2), residual stress and strain when the adherends (B1) and (B2) are bonded together, etc. Peeling can be suppressed. The gel fraction can be obtained by the following formula.
Gel fraction (mass%) = [(mass of cured layer (A') after immersion in toluene) / (mass of cured layer (A') before immersion in toluene)] × 100

The adhesive layer (A) can be produced, for example, by applying an adhesive composition to the surface of a release liner or the like and drying it.
As the adhesive composition, for example, an adhesive composition containing a urethane resin (a) having a hydroxyl group and a (meth) acryloyl group can be used.

As the urethane resin (a), for example, a polyol (a1), a polyisocyanate (a2), and a (meth) acrylic compound (a3) having a hydroxyl group or an isocyanate group are reacted under the condition that the hydroxyl group becomes excessive. The obtained one can be used.

As the polyol (a1), for example, a polyether polyol, a polycarbonate polyol, a polyester polyol, a polybutadiene polyol, a hydrogenated polybutadiene polyol, a polyacrylic polyol, a dimerdiol, a polyisoprene polyol and the like can be used. These polyols may be used alone or in combination of two or more. The inclusion of the polyether polyol and / or the polycarbonate polyol can impart excellent cohesive force, and the formation of bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2) and the adhesion. It is preferable to obtain an adhesive sheet capable of suppressing floating and peeling caused by residual stress, strain, etc. when the bodies (B1) and (B2) are bonded together.

Examples of the polyether polyol include polyoxyethylene polyol, polyoxypropylene polyol, polyoxytetramethylene polyol, polyoxyethylene polyoxypropylene polyol, polyoxyethylene polyoxytetramethylene polyol, and polyoxypropylene polyoxytetramethylene polyol. Etc. can be used. These polyether polyols may be used alone or in combination of two or more.

As the polycarbonate polyol, for example, one obtained by reacting a carbonic acid ester and / or phosgene with a compound having two or more hydroxyl groups can be used.

As the carbonic acid ester, for example, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used. These carbonic acid esters may be used alone or in combination of two or more.

Examples of the compound having two or more hydroxyl groups include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, and tripropylene glycol. , 1,2-Butandiol, 1,3-Butandiol, 1,4-Butandiol, 2,3-Butandiol, 1,5-Pentanediol, 1,5-Hexanediol, 1,6-Hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2 -Methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol , 2-Methyl-1,8-octanediol and other aliphatic polyols; 1,2-cyclobutanediol, 1,3-cyclopentanediol, 1,4-cyclohexanedimethanol, cycloheptanediol, cyclooctanediol, hydroxypropyl Alicyclic polyols such as cyclohexanol; aromatic polyols such as bisphenol A, bisphenol F, and 4,4'-biphenol can be used. These compounds may be used alone or in combination of two or more.

The number average molecular weight of the polyol (a1) is preferably in the range of 500 to 7,000, more preferably in the range of 700 to 4,000, and even more preferably in the range of 800 to 3,000. Within the above range, the adhesive layer (A) has pressure-sensitive adhesiveness, does not become too soft when the adhesive sheet is stored and stored, or when heat-bonded, and suppresses sticking out and crushing only from the end face. , It is possible to impart excellent cohesive force to the adhesive layer (A) and the cured layer (A'), and the formation of bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2) and the cover. It is possible to suppress floating and peeling caused by residual stress, strain, etc. when the bodies (B1) and (B2) are bonded together. The number average molecular weight of the polyol (a1) is a value measured under the following conditions by a 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 and used.
"TSKgel G5000" (7.8 mm I.D. x 30 cm) x 1 "TSKgel G4000" (7.8 mm I.D. x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 This "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (Differential Refractometer)
Column temperature: 40 ° C
Eluent: tetrahydrofuran (THF)
Flow velocity: 1.0 mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by 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

As the polyol (a1), a chain extender having a hydroxyl group may be used in combination, if necessary.

As the chain extender having a hydroxyl group, for example, the same compound as the compound having two or more hydroxyl groups can be used.

Examples of the polyisocyanate (a2) include aromatic polyisocyanates such as xylylene diisocyanate, phenylenedi isocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, cyclohexanediisocyanate, isophorone diisocyanate, 4,4. An aliphatic or alicyclic polyisocyanate such as'-dicyclohexylmethane diisocyanate, diisocyanate methylcyclohexane, or tetramethylxylylene diisocyanate can be used. These polyisocyanates may be used alone or in combination of two or more. The adhesive layer (A) has pressure-sensitive adhesiveness, does not become too soft during storage and storage of the adhesive sheet or when heat-bonded, suppresses sticking out and crushing only from the end face, and the adhesive layer (A). And the hardened layer (A') can be imparted with excellent cohesive force, and the formation of bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2), and the adherends (B1) and ( It is preferable to use an alicyclic polyisocyanate in order to obtain an adhesive sheet capable of suppressing floating and peeling caused by residual stress and strain when the B2) and the like are bonded to each other. -It is more preferable to use one or more polyisocyanates selected from the group consisting of dicyclohexylmethane diisocyanate, isophorone diisocyanate, cyclohexanediisocyanate and diisocyanatomethylcyclohexane.

The (meth) acrylic compound (a3) having a hydroxyl group or an isocyanate group is used for the purpose of introducing a (meth) acryloyl group into the urethane resin (a).

In the present invention, "(meth) acrylic" means acrylic and / or methacrylic, "(meth) acrylate" means acrylate and / or methacrylate, and "(meth) acryloyl" means acryloyl. And / or show methacryloyl.

Examples of the (meth) acrylic compound having a hydroxyl group that can be used as the compound (a3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3-hydroxypropyl (meth) acrylate. (Meta) acrylic acid alkyl ester having a hydroxyl group such as 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, hydroxyethyl acrylamide; trimethylpropandi (meth) Polyfunctional (meth) acrylate having a hydroxyl group such as acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate; polyethylene glycol monoacrylate, polypropylene glycol monoacrylate and the like can be used. These compounds may be used alone or in combination of two or more. Among these, acrylic acid (meth) alkyl ester having a hydroxyl group is preferably used, and 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate are used from the viewpoint of easy availability of raw materials, photocurability and adhesive properties. Is more preferable.

Examples of the (meth) acrylic compound having an isocyanate group that can be used as the compound (a3) include 2- (meth) acryloyloxyethyl isocyanate and 2- (2- (meth) acryloyloxyethyloxy) ethyl. Isocyanate, 1,1-bis ((meth) acryloyloxymethyl) ethyl isocyanate and the like can be used. These compounds may be used alone or in combination of two or more. Among these, 2- (meth) acryloyloxyethyl isocyanate is preferably used from the viewpoint of easy availability of raw materials, and 2-acryloyloxyethyl isocyanate is more preferably used from the viewpoint of photocurability.

When a (meth) acrylic compound having a hydroxyl group is used as the compound (a3), the method for producing the urethane resin (a) includes, for example, the polyol (a1) and the (meth) acrylic compound (in a solvent-free manner). A method or the like can be used in which the polyisocyanate (a2) is supplied, mixed, and reacted after charging a3) into the reaction system. The reaction is preferably carried out, for example, under the conditions of 20 to 120 ° C. for 30 minutes to 24 hours.

As a method for producing the urethane resin (A) when a (meth) acrylic compound having an isocyanate group is used as the compound (a3), for example, the polyol (a1) and the polyisocyanate (a2) are used in a solvent-free manner. A urethane prepolymer having a hydroxyl group is obtained by charging and reacting the compound, and then the (meth) acrylic compound (a3) having an isocyanate group is supplied, mixed and reacted to produce the compound. .. The reaction is preferably carried out, for example, under the conditions of 20 to 120 ° C. for 30 minutes to 24 hours.

The urethane resin (a) may be produced in the presence of an organic solvent.

Examples of the organic solvent include ester solvents such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate, ketone solvents such as acetone, methyl ethyl ketone, methyl butyl ketone and cyclohexanone, and ether esters such as methyl cellosolve acetate and butyl cellosolve acetate. A system solvent, an aromatic hydrocarbon solvent such as toluene and xylene, an amide solvent such as dimethylformamide and dimethylacetamide, and the like can be used alone or in combination of two or more.

The reaction between the polyol (a1), the polyisocyanate (a2), and the (meth) acrylic compound (a3) in producing the urethane resin (a) is the hydroxyl group of the polyol (a1) and the (a1). Equivalent ratio of the total amount of hydroxyl groups of the (meth) acrylic compound (a3) to the total amount of isocyanate groups of the polyisocyanate (a2) and the isocyanate groups of the (meth) acrylic compound (a3) [isocyanate group / hydroxyl group] ] = 0.75 to 1 is preferable in controlling the molecular weight of the obtained urethane resin (a), and more preferably 0.79 to 0.995. Further, the reaction may be carried out when the equivalent ratio exceeds 1, but in that case, 1,2-propylene glycol or 1,3-propylene glycol or 1,3-propylene glycol or 1,3-propylene glycol or 1,3-propylene glycol may be used for the purpose of inactivating the isocyanate group of the urethane resin (a). It is preferable to use a bifunctional alcohol composed of primary and secondary hydroxyl groups such as butylene glycol. In that case, the total amount of the hydroxyl group of the polyol (a1), the hydroxyl group of the (meth) acrylic compound (a3) and the hydroxyl group of the alcohol, and the equivalent ratio of the polyisocyanate group [isocyanate group / hydroxyl group] It is preferable to adjust so that the total amount] is within the above range.

Further, as the alcohol that can be used for the purpose of inactivating the isocyanate group of the urethane resin (a), for example, a monofunctional alcohol such as methanol, ethanol, propanol or butanol may be used in combination.

When producing the urethane resin (a), a polymerization inhibitor, a urethanization catalyst, or the like may be used, if necessary.

Examples of the polymerization inhibitor include 3,5-vistershary butyl-4-hydroxytoluene, hydroquinone, methylhydroquinone, hydroquinone monomethyl ether (methoquinone), paraterchary butyl catechol methoxyphenol, and 2,6-disulfide butyl cresol. , Phenothiazine, tetramethylthium disulfide, diphenylamine, dinitrobenzene and the like can be used. These polymerization inhibitors may be used alone or in combination of two or more.

Examples of the urethanization catalyst include nitrogen-containing compounds such as triethylamine, triethylenediamine, and N-methylmorpholin; metal salts such as bismuth carboxylate, potassium acetate, zinc stearate, and tin octylate; dibutyltin laurate and dioctyltin. Organometallic compounds such as dineodecato and zirconium tetraacetylacetonate; metal complexes such as zirconium complex and aluminum complex can be used. These urethanization catalysts may be used alone or in combination of two or more.

The urethane resin (a) has a (meth) acryloyl group that promotes radical polymerization by light irradiation or heating. As for the (meth) acryloyl group equivalent of the urethane resin (a), the adhesive layer (A) has pressure-sensitive adhesiveness, does not become too soft when the adhesive sheet is stored and stored, or when heat-bonded, and the end face. 1,000 to 200,000 g / eq. In order to suppress squeezing and crushing from the adhesive layer and to obtain excellent cohesive force in the adhesive layer (A) and the cured layer (A'). It is preferably in the range of 3,000 to 100,000 g / eq. The range of 5,000 to 80,000 g / eq. The range of is more preferable. The (meth) acryloyl group equivalent indicates a value obtained by dividing the total mass of the raw materials of the urethane resin (a) by the equivalent of the (meth) acrylic group present in the urethane resin (a).

As the mass ratio of the urethane bond in the urethane resin (a), an excellent cohesive force can be imparted, and the formation of bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2), and The total amount of urethane resin (a) in order to obtain an adhesive sheet that can suppress floating and peeling caused by residual stress and strain when the adherends (B1) and (B2) are bonded together. The range is preferably in the range of 4 to 20% by mass, and more preferably in the range of 5 to 15% by mass. The urethane bond amount of the urethane resin (a) indicates the mass ratio of the urethane bond structure to the total mass of the raw materials of the urethane resin (a) in the raw materials.

As for the weight average molecular weight of the urethane resin (a), the adhesive layer (A) has pressure-sensitive adhesiveness, does not become too soft when the adhesive sheet is stored and stored, or is heat-bonded, and is exposed only from the end face. It is possible to suppress crushing and to impart excellent cohesive force to the adhesive layer (A) and the cured layer (A'), which is caused by the gas that can be generated from at least one of the adherends (B1) and (B2). In order to obtain an adhesive sheet that can suppress floating and peeling caused by the formation of air bubbles and residual stress and strain when the adherends (B1) and (B2) are bonded together, 5, The range is preferably in the range of 000 to 200,000, more preferably in the range of 15,000 to 100,000. The weight average molecular weight of the urethane (meth) acrylate (A) indicates a value obtained by measuring in the same manner as the number average molecular weight of the polyol (a1).

Further, as the adhesive composition, those containing a known polyisocyanate cross-linking agent and a polyfunctional (meth) acrylate compound can be used, if necessary.

The term "polyfunctional" as used in the present invention means that the molecule has two or more polymerizable unsaturated double bonds.

Examples of the polyisocyanate cross-linking agent include polyisocyanates such as tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate; these trimethylol propanes. Additives; these isocyanurates; these bullets and the like can be used.

As for the amount of the polyisocyanate cross-linking agent used, the adhesive layer (A) has pressure-sensitive adhesiveness, does not become too soft when the adhesive sheet is stored and stored, or is heat-bonded, and is exposed or crushed only from the end face. And imparts excellent cohesive force to the adhesive layer (A) and the cured layer (A'), and the bubbles caused by the gas that can be generated from at least one of the adherends (B1) and (B2). In order to obtain an adhesive sheet capable of suppressing floating and peeling caused by formation and residual stress and strain when the adherends (B1) and (B2) are bonded together, the urethane resin ( a) The range is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 7 parts by mass with respect to 100 parts by mass.

Examples of the polyfunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, trimethyl propandi (meth) acrylate, and hexamethylene glycol. Di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, trimethylpropantri (meth) acrylate , Pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, di (trimethylol propane) di (meth) acrylate, di (trimethylol propane) tri (meth) acrylate, di (Trimethylol propane) Tetra (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol An aliphatic polyfunctional (meth) acrylate such as hexa (meth) acrylate and a polyfunctional (meth) acrylate having an isocyanurate skeleton such as tris (2- (meth) acryloyloxyethyl) isocyanurate can be used. These (meth) acrylic compounds may be used alone or in combination of two or more. A polypoly having an aliphatic polyfunctional (meth) acrylate and / or isocyanurate skeleton because it can impart excellent cohesive force and suppress foaming caused by the gas generated from the adherend (b). It is preferable to use a functional (meth) acrylate, trimethylolpropane tri (meth) acrylate, di (trimethylolpropane) tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, It is more preferable to use one or more (meth) acrylic compounds selected from the group consisting of tris (2- (meth) acryloyloxyethyl) isocyanurate.

The content of the polyfunctional (meth) acrylate compound is preferably in the range of 1 to 30 parts by mass, more preferably in the range of 2 to 20 parts by mass with respect to 100 parts by mass of the urethane resin (a). The range of 4 to 15 parts by mass is more preferable. Within the above range, the adhesive layer (A) has excellent pressure-sensitive adhesiveness, does not become too soft during storage and storage of the adhesive sheet or when heat-bonded, and suppresses sticking out or crushing only from the end face. At the same time, it imparts excellent cohesive force to the adhesive layer (A) and the cured layer (A'), and forms bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2). It is possible to obtain an adhesive sheet capable of suppressing floating and peeling caused by residual stress, strain, etc. when the adherends (B1) and (B2) are bonded together.

The adhesive composition contains a photopolymerization initiator having an absorption wavelength in a wavelength region of 380 nm or more as the photopolymerization initiator. As a result, either one of the adherends (B1) or (B2) is made of a light-transmitting material, and by having a layer containing an ultraviolet absorber, it absorbs light having a wavelength of 380 nm or less, and the adhesive. Even when it is difficult for the active energy rays to reach the layer (A), it has an absorption wavelength even in a wavelength region exceeding 380 nm, and photopolymerization can be started. Examples of such a photopolymerization initiator include a phenylphosphine oxide type (for example, Omnirad TPO H, Omnirad 819 manufactured by IGM Resin B.V.) and an α-aminoalkylphenone type (for example, IGM Resin B.V.). Omnirad 369, 379) manufactured by Japan, is preferable. The adherend (B2) has a convex three-dimensional shape, and the adherend (B1) or the adhesive layer (A) on which the adhesive layer (A) is laminated is used in a vacuum forming machine or the like. ) Is heated to 100 to 170 ° C. for about 1 to 300 seconds, and then the screw (2,) is attached to the adherend (B2) while being heated and stretched. It is particularly preferable to use 4,6-trimethylbenzoyl) -phenylphosphine oxide (eg, Omnirad TPO H) in order to suppress thermal decomposition under this temperature condition.

The photopolymerization initiator may be used in combination with an anthracene-based or thioxanthone-based sensitizer, if necessary.

Examples of the peroxide that can be used in the radical polymerization initiator include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, cumene hydroperoxide, and peroxy. Conventionally known peroxides such as esters can be used. These may be used alone or in combination of two or more. Among these, peroxyesters and peroxydicarbonates are preferable, and peroxydicarbonates are particularly preferable for curing under high temperature conditions of 80 to 120 ° C. Examples of the peroxydicarbonate include di (4-t-butylcyclohexyl) peroxydicarbonate, and a commercially available product such as perloyl TCP (manufactured by NOF CORPORATION). Among them, as the peroxide, it is preferable to use pearloyl TCP which can be rapidly cured by irradiating with active energy rays such as ultraviolet rays.

The radical polymerization initiator is preferably used in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the urethane resin (a), and more preferably in the range of 0.05 to 5 parts by mass. preferable.

The adhesive composition of the present invention may contain other additives, if necessary.

Examples of the other additives include a silane coupling agent, an antioxidant, a light stabilizer, a rust preventive, a thixo-imparting agent, a sensitizer, a polymerization inhibitor, a leveling agent, a tackifier, and an antistatic agent. , Flame retardants, coloring dyes, coloring pigments and the like can be used. These additives may be used alone or in combination of two or more. Among these, when the adhesive sheet of the present invention is used for applications requiring high adhesive physical properties after moisture resistance and heat resistance, it is preferable to contain a silane coupling agent. Further, when the adhesive sheet of the present invention is used in an application requiring high moisture-resistant thermal yellowing, it is preferable to contain an antioxidant and a light stabilizer.

Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. Silane coupling agents having an epoxy group such as 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ) Ethylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) propyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) propylmethyldimethoxy) Silane coupling agent having an alicyclic epoxy group such as silane, 2- (3,4-epoxycyclohexyl) propyltriethoxysilane, 2- (3,4-epoxycyclohexyl) propylmethyldiethoxysilane; vinyl trichlorosilane, vinyl Trimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltri Ethoxysilane, 3-acryloxipropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, silicone alkoxy oligomer and the like can be used. These silane coupling agents may be used alone or in combination of two or more. Among these, a silane coupling agent having an epoxy group and / or a silane coupling agent having an alicyclic epoxy group is preferably used from the viewpoint of further improving the adhesive strength after moisture resistance and heat resistance, and 2- (3, It is selected from the group consisting of 4-epoxidecyclohexyl) ethyltriethoxysilane, 2- (3,4-epoxidecyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane. It is more preferable to use one or more silane coupling agents.

Examples of the antioxidant include a hindered phenol compound (primary antioxidant) that captures radicals generated by thermal deterioration, a phosphorus compound that decomposes a peroxide generated by thermal deterioration, and a sulfur compound (secondary antioxidant). Agent) and the like can be used.

Examples of the hindered phenol compound include triethylene glycol-bis- [3- (3-t-butyl-5-methyl-4hydroxyphenyl) propionate] and pentaerythritol tetrakis [3- (3,5-di-). tert-Butyl-4-hydroxyphenyl) propionate, octadecyl [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-) 4-Hydroxyphenyl) propionate], benzenepropanoic acid-3,5-bis (1,1-dimethylethyl) -4-hydroxy-C _7- C ₉ side chain alkyl ester, 4,6-bis (dodecylthiomethyl) -O-cresol, reaction product of N-phenylbenzeneamine with 2,4,4-trimethylpentene, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl)- 4-Methylphenyl acrylate, 3,9-bis [2- [3- (t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] 2,4,8,10- Tetraoxaspiro [5.5] undecane, 2,6-di-tert-butyl-4-methylphenol, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,5-di-tert -Amilhydroquinone or the like can be used. These compounds may be used alone or in combination of two or more.

Examples of the phosphorus compound include triphenylphosphine, bis (2,4-di-tert-butyl-6-methylphenyl) = ethyl-phosfit, triphenylphosphite, trisnonylphenylphosphite, and tris (2, 4-Dibutylphenyl) phosphite, tris (2,4-dibutyl-5-methylphenyl) phosphite, tris [2-tertiary butyl-4- (3-butyl-4-hydroxy-5-methylphenylthio)- 5-Methylphenyl] phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tridecylphosphite, octyldiphenylphosphite, di (decyl) monophenylphosphite, di (tridecyl) pentaerythritoldi Phosphite, Di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-dibutylphenyl) pentaerythritol diphosphite, bis (2,6-dibutyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6-dibutyl-4-methylphenyl) 2,4,6-tributylphenyl) pentaerythritol diphosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite, tetra (tridecyl) isopropyridene diphenol diphosphite, tetra (tridecyl) -4, 4'-n-butylidenebis (2-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2-methyl-4-hydroxy-5-butylphenyl) butanetriphosphite, tetrakis ( 2,4-Dibutylphenyl) biphenylenediphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis (4,6-butylphenyl) -2 -Ethylhexyl phosphite, 2,2'-methylenebis (4,6-butylphenyl) -octadecylphosphite, 2,2'-ethylidenebis (4,6-dibutylphenyl) fluorophosphite, tris (2-[(2) , 4,8,10-Tetraxylbutyldibenzo [d, f] [1,3,2] dioxaphosfepin-6-yl) oxy] ethyl) amine, 2-ethyl-2-butylpropylene glycol and 2, Phenyl phosphite of 4,6-tributylphenol or the like can be used. These compounds may be used alone or in combination of two or more.

Examples of the sulfur compound include didodecyl-3,3'-thiopropionate, dilauryl-3,3'-thiodipropionate, laurylthiodithionate, ditridecyl-3,3'-thiodipropionate, and the like. Dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, tetrakis-methylene-3-laurylthiopropionate methane, distearyl-3,3'-methyl-3, 3'-thiodipropionate, laurylstearyl-3,3'-thiodipropionate, bis [2-methyl-4- (3-n-alkylthiopropionyloxy) -5-t-butylphenyl] sulfide, β- Laurylthiopropionate, 2-mercaptobenzoimidazole, 2-mercapto-5-methylbenzoimidazole, dioctadecyl-3,3'-thiodipropionate and the like can be used. These compounds may be used alone or in combination of two or more.

Among these, it is preferable to use a phosphorus compound in order to further improve the adhesive strength and the heat yellowing resistance, and triphenylphosphine and bis (2,4-di-tert-butyl-6-methylphenyl) = ethyl. = It is more preferable to use one or more antioxidants selected from the group consisting of phosphine and tris (2,4-di-tert-butylphenyl) phosphite, and triphenylphosphine, bis (2,4-di). It is more preferable to use −tert-butyl-6-methylphenyl) = ethyl = phosphine.

When the antioxidant is used, the amount used should be in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the urethane resin (a) from the viewpoint of further improving moisture-resistant thermal yellowing. Is preferable.

The light stabilizer captures radicals generated by photodegradation. For example, a radical scavenger such as a thiol compound, a thioether compound or a hindered amine compound; an ultraviolet absorber such as a benzophenone compound or a benzoate compound may be used. it can. These light stabilizers may be used alone or in combination of two or more. Among these, it is preferable to use a hindered amine compound from the viewpoint of further improving moisture-resistant thermal yellowing.

Examples of the hindered amine compound include reaction products of cyclohexane and N-butyl peroxide 2,2,6,6-tetramethyl-4-piperidinamine-2,4,6-trichloro1,3,5-triazine. Reaction products of and 2-aminoethanol, bisdecanoate (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethylhydroperoxide and octane Hindered amine compounds having an amino ether group such as the reaction products of N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrridine-2,5-dione and the like. -Acetyl hindered amine compounds; bis (1,2,2,6,6-pentamethyl-4-piperidyl) = decandioate, bis (1,2,2,6,6, -pentamethyl-4-piperidyl) {[ 3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl} butylmalonate, dimethyl 1- (2-hydroxyethyl) succinate-4-hydroxy-2,2,6,6- Use a tetramethylpiperidine polycondensate, an N-alkyl hindered amine compound of Provandioic acid [{4-methoxyphenyl} methylene] -bis (1,2,2,6,6-pentamethyl-4-piperidyl) ester, etc. Can be done. These compounds may be used alone or in combination of two or more.

When the light stabilizer is used, the amount used is in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the urethane resin (a) from the viewpoint of further improving moisture resistance and thermal yellowing. Is preferable.

Further, for the purpose of suppressing repelling when the adhesive layer (A) is applied on the release liner and improving handling workability such as a process of cutting the adhesive sheet and a process of peeling the release liner, the transparency is not impaired. , Any thermoplastic resin may be used. Examples of the thermoplastic resin include urethane-based resin, acrylic-based resin, polyester-based resin, and epoxy-based resin. The thermoplastic resin is preferably incorporated into the curing reaction system by introducing an unsaturated bond or the like into the molecule, in order to increase the tensile storage elastic modulus of the adhesive layer after the curing reaction.

The thermoplastic resin is preferably semi-solid or solid under an atmosphere of 25 ° C., and the weight average molecular weight is preferably in the range of 5,000 to 200,000, preferably in the range of 15,000 to 100,000. Is more preferable. The weight average molecular weight of the thermoplastic resin (meth) acrylate (A) indicates a value obtained by measuring in the same manner as the number average molecular weight of the polyol (a1).

The amount of the thermoplastic resin used is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the polymerizable resin, and using 3 to 20 parts by mass reduces the cohesive force of the cured layer (A'). The formation of bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2), and the residual stress and strain when the adherends (B1) and (B2) are bonded together. This is particularly preferable in suppressing floating and peeling caused by factors such as.

The molded parts to which the adhesive sheet of the present invention is attached are used to pass microwaves such as automobile emblems and electromagnetic waves such as millimeter waves, and high-frequency electric pulses such as flexible printed substrates are passed in the vicinity to transmit electric signals. For the purpose of adjusting the dielectric loss tangent and the relative permittivity of the adhesive sheet, a polyolefin resin, an inorganic filler, or the like may be added as long as the transparency is not impaired.

The polyolefin resin is preferably an olefin resin such as a polyethylene resin or polypropylene resin having a specific dielectric constant of about 2 to 3, a rubber resin such as an isoprene resin or a butadiene resin, and a phase with the thermoplastic resin or the liquid resin. For the purpose of improving the solubility, a part of the side chain may be chlorinated or modified with a carboxylic acid to partially improve the polarity. Further, it is preferable to introduce an unsaturated bond or the like into the molecule of the polyolefin resin so that it is incorporated into the curing reaction system and the tensile storage elastic modulus of the adhesive layer after the curing reaction is increased.

As the inorganic filler, it is preferable to use an inorganic filler having a dielectric loss tangent of about ^10-4 to ^10-5 , such as boron nitride, forteslite, cordierite, silica, magnesium oxide, and alumina, and the mixed composition. It is more preferable to use silica, which has excellent compatibility with the above and can enhance the transparency of the adhesive sheet.

As the inorganic filler, an arbitrary shape such as spherical or crushed can be used, and in order to enhance compatibility with the urethane resin or (meth) acrylate compound, a titanate coupling or an aluminate cup is provided on the surface. Surface-treated products such as rings and silane couplings may be used.

As for the amount of the polyolefin resin and the inorganic filler used, it is preferable to use 1 to 50 parts by mass in total with respect to 100 parts by mass of the polymerizable resin, and it is preferable to use 5 to 20 parts by mass as the relative permittivity of the adhesive sheet. It is more preferable to suppress a decrease in adhesion of the adherend (B1) or the adherend (B2) to the surface while reducing the rate and the dielectric loss tangent.

As the particle size of the inorganic filler, it is preferable to use one having a 50% particle size distributed under the integrated sieve of less than 10 nm to 50 μm, and more preferably one having a particle size of 10 nm to 20 μm is 1 to 10 μm. It is particularly preferable to use one of the above in order to enhance the transparency of the adhesive sheet, to achieve both good dispersibility of the inorganic filler and ease of coating. For the 50% particle size of the inorganic filler under the integrated sieve, use a laser diffraction type particle size distribution measuring device SALD-3100 manufactured by Shimadzu Corporation, and use a numerical value measured using isopropanol as a dispersion medium. Can be done.

[Adhesive sheet]
In the adhesive sheet of the present invention, for example, the composition of the adhesive layer (A) in which the composition of the adhesive layer (A) is dissolved in a solvent or the like is applied to the surface of the release liner, and dried if necessary. It can be produced by forming an adhesive layer (A).

Examples of the method of applying the composition of the adhesive layer (A) to the surface of the release liner include a method of applying using a comma coater or a lip coater. The drying can be performed using, for example, a dryer set at a temperature of about 60 ° C. to 90 ° C.

The drying is preferably carried out at a temperature of preferably less than 40 to 100 ° C, more preferably about 50 to 90 ° C. By setting the temperature to the above level, it is possible to suppress a curing reaction due to thermal decomposition of the polymerization initiator.

As the adhesive layer (A), one having a thickness of 25 to 300 μm is preferable, and one having a thickness of 50 to 175 μm is more preferable. In particular, when a single layer of the adhesive layer (A) is used as the adhesive sheet, it is preferable to use one having a thickness in the above range. Further, in order to make the thickness within the above range, two or more adhesive layers (A) may be laminated. When the polyisocyanate cross-linking agent is used, it is preferable to laminate it before the cross-linking is completed. The adhesive sheet having a thickness in the above range has excellent pressure-sensitive adhesiveness, does not become too soft when the adhesive sheet is stored and stored or when it is heat-bonded, and suppresses sticking out and crushing only from the end face, and also The adhesive layer (A) and the cured layer (A') can maintain excellent transparency, and the formation of bubbles due to the gas that can be generated from at least one of the adherends (B1) and (B2) and the cover. It is possible to suppress floating and peeling caused by residual stress, strain, etc. when the bodies (B1) and (B2) are bonded together.

As the adhesive sheet of the present invention obtained by the above method, it is preferable to use a sheet having a thickness of 50 to 300 μm, and more preferably a sheet having a thickness of 100 to 250 μm is used. The adhesive sheet having a thickness in the above range has excellent pressure-sensitive adhesiveness, does not become too soft when the adhesive sheet is stored and stored or when it is heat-bonded, and suppresses sticking out and crushing only from the end face, and also The adhesive sheet can maintain excellent transparency and adheres to the adherend (B1) or (B2) by following the step, and becomes a gas that can be generated from at least one of the adherends (B1) and (B2). It is possible to suppress floating and peeling caused by the resulting formation of bubbles and residual stress and strain when the adherends (B1) and (B2) are bonded together. The thickness does not include the release liner.

Examples of the release liner include paper such as kraft paper, glassin paper, and high-quality paper, resin films such as polyethylene, polypropylene (OPP, CPP), and polyethylene terephthalate, and laminated paper in which the paper and the resin film are laminated. It is possible to use paper that has been sealed with clay or polyvinyl alcohol, and one or both sides of which have been peeled off from a silicone-based resin, etc., and the resin film and silicone-based resin, etc. have been peeled off. It is preferable to use the one obtained in order to enhance the transparency of the adhesive sheet of the present invention.

As the thickness of the release liner, it is preferable to use one having a thickness of 38 to 150 μm, and more preferably one having a thickness of 50 to 100 μm. By setting the thickness as described above, the smoothness of the surface of the adhesive layer (A) after drying can be improved, the peeling liner is less likely to stretch in the drying process, and the curl after winding into a roll can be prevented. it can.

Further, as the release liner, the adherend (B2) has a convex three-dimensional shape, and the adherend (B1) or the adherend (B1) on which the adhesive layer (A) is laminated by a vacuum forming machine or the like. In the case of a sticking step in which the release liner on which the adhesive layer (A) is laminated is heated to 100 to 170 ° C. for about 1 to 300 seconds and then stuck to the adherend (B2) while being heat-stretched. It is more preferable to use a release liner made of a resin material having a low softening point and easy to stretch, such as polyethylene or polypropylene (OPP, CPP).

The adhesive sheet of the present invention may be sandwiched by another optional release liner until it is used in the bonding process.

Further, the adhesive sheet of the present invention may have a structure in which an adhesive layer (A) is laminated on both sides of a base material, and the base material has a thickness of about 1/2 or less with respect to the total thickness of the adhesive sheet. It is preferable to use one. By inserting the base material into the adhesive layer (A), the handleability of the adhesive sheet is improved, and when the adhesive sheet is cut, the protrusion of the adhesive layer (A) is reduced, which is excellent. It is preferable to obtain dimensional stability. As the base material, any film or mesh material such as polyethylene terephthalate, polybutylene terephthalate, polyimide, polyphenylene sulfide, polyphenylene ether, polypropylene, polyethylene, polystyrene, etc. can be used, and the thickness is 1 to 30 μm. It is preferable to use one having a thickness of 2 to 15 μm, and more preferably one having a thickness of 2 to 15 μm. Further, the adherend (B2) has a convex three-dimensional shape, and the adherend (B1) or the adhesive layer (B1) or the adhesive layer (B1) in which the adhesive layer (A) is laminated by a vacuum forming machine or the like is used. In the case of a sticking step in which the release liner on which A) is laminated is heated to 100 to 170 ° C. for about 1 to 300 seconds and then stuck to the adherend (B2) while being heat-stretched, polyethylene terephthalate is used. It is more preferable to use a base material of a resin material such as polypropylene, polyethylene, polystyrene, etc., which has excellent colorless transparency, has a low softening point, and is easily stretched by heating.

Further, the adhesive sheet of the present invention can exert the above-mentioned excellent effects even if it is thin as described above. For example, in order to maintain the design and light-shielding properties of the surface of the molded product, scratch prevention and reflection For the purpose of prevention and the like, it can be suitably used for manufacturing a molded product in which a transparent or translucent thin sheet having a hard coat layer or a matte layer is laminated on the surface.

When the adhesive sheet of the present invention is used for manufacturing the molded product or the like, it is preferable to use a sheet having a light transmittance of 80% or more and a haze of 5.0 or less at a wavelength of 380 to 780 nm. It is more preferable to use a light having a wavelength of 380 to 780 nm having a transmittance of 85% or more and a haze of 2.0 or less. By setting the above range, the design of the bonded article can be enhanced.

Further, when the adhesive sheet of the present invention is used for manufacturing the molded product, it transmits light having a wavelength of 380 to 780 nm after being left in an environment of a temperature of 85 ° C. and a relative humidity of 85% RH for 500 hours. It is preferable to use a light having a rate of 80% or more and a haze of 5.0 or less, and a light having a transmittance of 85% or more and a haze of 2.0 or less at a wavelength of 380 to 780 nm. More preferred. By setting the above range, the design of the bonded article can be enhanced.

The adhesive sheet of the present invention is used for adhering adherends (B1) and (B2), one of which can generate gas when left in an environment of a temperature of 85 ° C. and a humidity of 85% RH for 48 hours. ..

[Subject]
Examples of the adherend (B1) to be attached to the adhesive sheet of the present invention include a transparent member made of plastic.

Examples of the transparent member constituting the adherend (B1) include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, cellophane, diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, polyvinyl chloride, and the like. Resin substrates such as polyvinyl chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyether sulfone, polyetherimide, polyimide, nylon, acrylic resin, etc. Can be used. Among them, as the resin base material, polycarbonate and acrylic resin are preferable in order to achieve both high transparency and surface hardness. However, a resin base material such as polycarbonate tends to generate a gas at about 80 ° C., which forms bubbles and causes peeling or the like. With the adhesive sheet of the present invention, even when polycarbonate or the like is used, it is difficult to form bubbles due to gas, so that it does not cause peeling and maintains excellent transparency and hardness due to polycarbonate or the like. it can.

The adherend (B1) preferably has a thickness of 0.05 to 5 mm, more preferably 0.2 to 3 mm, and 0.2 to 1 mm. It is more preferable to use one having a thickness. By setting the thickness as described above, durability for protecting the surface of the light irradiation molded product can be imparted.

Further, the adherend (B1) may be subjected to an arbitrary hard coat layer or the like by directly applying or co-extruding to the surface of the adherend (B1) for the purpose of preventing surface scratches and improving slipperiness. A mat layer or the like may be laminated.

Further, when the adherend (B1) is used for an article used outdoors as an exterior part of a vehicle, the adherend (B1), the cured layer (A') of the adhesive sheet, and the adherend. For the purpose of improving the outdoor weather resistance of the body (B2), a coating agent or the like containing an arbitrary ultraviolet absorber or the like is applied to the surface of the adherend (B1), or the adherend (B1) A layer that absorbs a wavelength of 325 to 380 nm, which corresponds to the ultraviolet region, may be provided on the entire surface or a part of the adherend (B1) by kneading and dispersing an arbitrary ultraviolet absorber inside the body. Further, it may be applied by adding it to the hard coat layer, mat layer or the like. The adherend (B1) preferably has a transmittance of light having a wavelength of 325 to 380 nm of 0 to 20%, and more preferably 0 to 10% in order to impart outdoor weather resistance.

The adherend (B1) preferably has a transmittance of light having a wavelength of 380 to 780 nm of 80 to 100% and a haze of 0 to 5.0%, and transmits light having a wavelength of 380 to 780 nm. It is more preferable to use one having a rate of 85 to 100% and a haze of 0 to 2.0% or less. Within the above range, the design of the adherend article can be enhanced.

When the adherend (B1) has the light transmittance, the active energy rays having a wavelength of 325 to 380 nm, which corresponds to the ultraviolet region, are difficult to transmit, and the activation of the photopolymerization initiator is likely to be inhibited. However, the adhesive sheet of the present invention is used. Then, by using the polymerization initiator having an absorption property in a wavelength region exceeding 380 nm, even in the adherend (B1) provided with a layer for absorbing ultraviolet rays, an active energy ray having a wavelength exceeding 380 nm The curing reaction can be carried out by irradiating with.

Specific examples of the adherend (B2) include a molded product provided with a decorative layer for the purpose of imparting designability, light-shielding property, and the like.

As the adherend (B2), for example, a body having a decorative layer, a plating layer, or the like and having difficulty in transmitting light can be used. Other adherends (B2) include polycarbonate, polymethylmethacrylate, alloy of polycarbonate and acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate, polybutylene terephthalate, polyimide, polyphenylene sulphide, polyphenylene ether, polypropylene, polyethylene, polystyrene. Any material such as, or one bonded to a metal can be used, and due to the ease of moldability, polycarbonate, polymethylmethacrylate, polycarbonate and alloy of acrylonitrile-butadiene-styrene copolymer, etc. are used. Is preferable.

The decorative layer and the plating layer are not particularly limited as long as they impart various design characteristics, and examples thereof include characters and figures, or a border-shaped decorative layer and a plating layer provided in a frame shape. Be done.

The thickness of the decorative layer is preferably in the range of 2 to 50 μm, more preferably in the range of 5 to 40 μm, and even more preferably in the range of 10 to 30 μm. By setting the thickness within the above range, the decorative layer becomes clear, it is easy to impart suitable design, and it is possible to prevent uneven coating of the decorative layer from occurring.

A plurality of the adherends (B1) and (B2) may be bonded to each other. When a plurality of adherends (B1) or (B2) are bonded, the same type may be bonded, or other types listed in the above example may be bonded. ..

As a method for producing an article by adhering the adherends (B1) and (B2) with the adhesive sheet, for example, the adherends (B1) and (B2) are measured at a temperature of 25 ° C. and a frequency of 1 Hz. The tensile elastic modulus ( _E'A25 ) is 1 × 10 ³ to 1 × 10 ⁶ Pa, and the tensile storage elastic modulus ( _E'A100 ) measured at a temperature of 100 ° C. and a frequency of 1 Hz is 1 × 10 ³ to 1. The step of laminating via the active energy ray-curable polyurethane adhesive sheet having the adhesive layer (A) of × 10 ⁵ Pa, and the temperature by irradiating the active energy ray-curable polyurethane adhesive sheet with active energy rays. _Examples thereof include a method including a step of forming a cured layer (A') having a tensile storage elastic modulus ( _E'A'100 ) of 2 × 10 ⁵ to 1 × 10 ⁹ Pa measured at 100 ° C. and a frequency of 1 Hz. At that time, when a part of the adherend is transparent, the active energy ray can be irradiated from the surface of the adherend.

Moreover, it is preferable that the manufacturing method of the article goes through one of the following steps.

A step of adhering the adhesive layer (A) and the adherend (B1) of the adhesive sheet of the present invention by pressure-sensitive adhesion without heating while leaving a release liner on one side [1]. The release liner is removed, a laminate of the adhesive layer (A) and the adherend (B1) is attached to the molding machine, and the surface of the adherend (B1) is heated to about 100 to 170 ° C. The step [2] of pressurizing and attaching the adherend (B2) to the surface of the adhesive layer (A) of the laminate in this state, the adherend (B1) and the adherend (B2). Of these, the production method includes the steps [3] of irradiating at least one transparent surface of the adherend with active energy rays to cure the adhesive (A). As for the adherend (B2), two or more types of adherends may be attached at the same time in the step [2].
The step [1] is preferably performed in an environment of 0 to 50 ° C., and is more preferably performed in an environment of 10 to 40 ° C., considering that the adhesive sheet of the present invention can be bonded without heating. preferable. In the step [2], it is preferable that the adherend (B2) is pressed against the surface of the adhesive layer of the laminate, and the adherend (b1) is stretched and attached.

Alternatively, the adhesive sheet of the present invention is attached to a molding machine while leaving a release liner on one side, the release liner and the adhesive layer (A) are heated to about 100 to 170 ° C., and the adhesive sheet is kept in that state. In the step [4] of pressurizing and attaching the adherend (B2) to the surface of the adhesive layer (A), only the adherend (B1) is heated to about 100 to 170 ° C. with a molding machine. Step [5] of applying pressure to the surface of the laminate of the adhesive layer (A) from which the release liner has been removed, at least one of the adherend (B1) and the adherend (B2). This is a manufacturing method including the steps [6] of irradiating the surface of the transparent adherend of No. 1 with active energy rays to cure the adhesive layer (A). As for the other adherends, two or more types of adherends may be attached at the same time in the step [4].
In the steps [4] and [5], it is preferable that the other adherend is pressed against the surface of the adhesive layer of the laminate, and the release liner and the adherend (B1) are stretched and attached.

The active energy rays are used to cure the adhesive layer (A) constituting the adhesive sheet to form a cured layer (A').

It is preferable to use a light irradiation device as the active energy ray. The light irradiation device may be irradiated in an atmosphere of an inert gas such as nitrogen gas or in an air atmosphere in order to efficiently carry out the curing reaction by light. Further, if necessary, heat may be used in combination as an energy source, irradiated with active energy rays, and then heated.

When using ultraviolet rays or visible light as the active energy ray, low-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, metal halide lamp, high-power metal halide lamp (manufactured by Eye Graphics Co., Ltd., etc.), metal halide lamp B type ( GS Yuasa Co., Ltd.), electrodeless lamp (fusion lamp), chemical lamp, black light lamp, mercury-xenone lamp, xenon-flash lamp, short arc lamp, helium / cadmium laser, argon laser, sunlight, LED lamp, etc. Can be mentioned. When the adherend (B1) or the adherend (B2) that absorbs a wavelength region of 380 nm or less is used, a lamp having a high light emission intensity around 400 nm such as a high-power metal halide lamp or a metal halide lamp B type, or By using an LED lamp having a light emitting intensity of 385 nm or 405 nm, the adhesive layer (A) can be efficiently stored while minimizing the heat storage of the adherend (B1) or the adherend (B2). Is preferable because it can be cured.

As the activation energy ray irradiating device, a germicidal lamp, a carbon arc, a scanning type, a curtain type electron beam accelerator, or the like can be used in addition to the above-mentioned ones.

The article bonded by the bonding method has a structure in which the adherend (B1) and the adherend (B2) are laminated via a cured product of the active energy ray-curable polyurethane adhesive sheet.

The article bonded with the adhesive sheet of the present invention is suitably used for resin molded products used for the exterior of home appliances, the exterior of mobile terminals, the interior and exterior of automobiles, and the like. Parts that are three-dimensionally molded by injection molding, extrusion molding, etc., and a bonding member having a hard coat layer or mat layer on the surface for the purpose of preventing scratches and improving slipperiness on the surface of these molded products. The bonding member is bonded by the adhesive sheet of the present invention, and the bonding member floats due to the formation of bubbles due to the gas that can be generated from the surface of the molded product or the surface of the bonding member, the residual stress of the bonding member, and the like. It is a molded product with excellent appearance quality that suppresses peeling and has both excellent transparency.

<Synthesis of urethane resin (a1) composition>
In a reaction vessel equipped with a stirrer, a reflux cooling tube, and a thermometer, 94.3 parts by mass of polypropylene glycol (number average molecular weight; 1,000), 0.3 parts by mass of 2-hydroxyethyl acrylate, and 1,4-hexane. 19.5 parts by mass of dimethanol, 0.5 parts by mass of 2,6-ditershaributyl cresol, 0.1 parts by mass of p-methoxyphenol, and 57.4 parts by mass of ethyl acetate were added.
After raising the temperature in the reaction vessel to 40 ° C., 50.3 parts by mass of isophorone diisocyanate was added.
Next, 0.01 part by mass of dioctyltin dineodecato was added, the temperature was raised to 75 ° C. over 1 hour, held at 75 ° C. for 12 hours, and then 51.7 parts by mass of ethyl acetate was added to 30 parts. The urethane resin (a1) composition was obtained by stirring and cooling until the mixture became uniform for 1 minute.

<Synthesis of acrylic resin (a2) composition>
In a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas inlet, 80 parts by mass of n-butyl acrylate, 15 parts by mass of methyl methacrylate, 4 parts by mass of acrylic acid, and 2,2 as a polymerization initiator. Acrylic resin (a2) composition was obtained by dissolving 0.2 parts by mass of ′ -azobisisobutylnitrile in ethyl acetate and polymerizing it.

<Synthesis of acrylic resin (a3) composition>
In a reaction vessel equipped with a stirrer, a reflux cooler, a thermometer, a dropping funnel and a nitrogen gas inlet, 95 parts by mass of 2-ethylhexyl acrylate, 4 parts by mass of acrylic acid, 1 part by mass of hydroxyethyl acrylate, and 2, as a polymerization initiator. An acrylic resin (a3) composition having a weight average molecular weight of 200,000 is obtained by dissolving 0.5 parts by mass of 2'-azobisisobutylnitrile in 100 parts by mass of ethyl acetate, substituting with nitrogen, and polymerizing at 80 ° C. for 8 hours. It was.

<Preparation of adhesive composition (b1)>
A mixture of dipentaeristol pentaacrylate and dipenta eristol hexaacrylate (“Aronix M-405” manufactured by Toa Synthetic Co., Ltd., dipenta eristol penta) based on 100 parts by mass of the solid content of the urethane resin (a1) composition. Acrylate content 10 to 20% by mass) 10 parts by mass, 0.5 parts by mass of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Omnirad TPO H manufactured by IGM Resin BV), decanting Add 0.5 parts by mass of acid bis (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester and 0.5 parts by mass of triphenylphosphine in this order to the stirrer. Stirred until uniform.
Next, with respect to 100 parts by mass of the solid content of the urethane resin (a1) composition, 2.8 parts by mass of a hexamethylene diisocyanate nurate compound (“Barnock D-100S” manufactured by DIC Corporation) and dioctyl tinzineodeca were added. 0.004 parts by mass of nate was added, and the mixture was stirred until uniform, and then filtered through a 200 mesh wire mesh to obtain an adhesive composition (b1).

<Preparation of adhesive composition (b2)>
Addition amount of a mixture of dipentaeryristol pentaacrylate and dipentaeryristol hexaacrylate (“Aronix M-405” manufactured by Toagosei Co., Ltd., content of dipentaeryristol pentaacrylate 10 to 20% by mass) is 5 parts by mass. The adhesive composition (b2) was obtained in the same manner as in the preparation of the adhesive composition (b1) except that the composition was changed to.

<Preparation of adhesive composition (b3)>
Adhesive composition except that the mixture of dipentaerystol pentaacrylate and dipentaerystol hexaacrylate was changed to di (trimethylolpropane) tetraacrylate ("Aronix M-408" manufactured by Toagosei Co., Ltd.). An adhesive composition (b3) was obtained in the same manner as in the preparation of the product (b1).

<Preparation of adhesive composition (b4)>
Instead of dipentaeristolpenta and hexaacrylate ("Aronix M-405" manufactured by Toagosei Co., Ltd.), change to trimethylolpropane triacrylate ("Aronix M-309" manufactured by Toagosei Co., Ltd.) and add 20. The adhesive composition (b4) was obtained in the same manner as in the preparation of the adhesive composition (b1) except that the parts were made in parts by mass.

<Preparation of adhesive composition (b5)>
In the adhesive composition (b1), instead of 2,4,6-trimethylbenzoyludiphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (IGM Resin B.V.) An adhesive composition (b5) was obtained in the same manner as in the preparation of the adhesive composition (b1) except that 0.5 parts by mass of Omnirad 819) manufactured by the same company was used.

<Preparation of adhesive composition (b6)>
0.18 parts by mass of E-5XM (5% by mass of solid content manufactured by Soken Kagaku Co., Ltd.) as an epoxy-based cross-linking agent and coronate as an isocyanate-based cross-linking agent with respect to 100 parts by mass of the solid content of the acrylic resin (a2). The adhesive composition (b6) was obtained by adding 0.2 parts by mass of L-45E (manufactured by Tosoh Industries, Ltd., solid content 45% by mass) and stirring for 20 minutes using a stirrer.

<Preparation of adhesive composition (b7)>
2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Omnirad TPO H manufactured by IGM Resin B.V.) 1 as a photopolymerization initiator with respect to 100 parts by mass of the solid content of the acrylic resin (a3). The adhesive composition (b7) was obtained by adding 0 parts by mass and 5 parts by mass of a tetrafunctional acrylate (NK ester ATM-4PL manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) as a cross-linking component and stirring for 15 minutes using a stirrer. ) Was obtained.

<Preparation of adhesive composition (b8)>
Preparation of the adhesive composition (b1) except that the amount of trimethylolpropane triacrylate (“Aronix M-309” manufactured by Toagosei Co., Ltd.) added to the adhesive composition (b4) was 40 parts by mass. The adhesive composition (b8) was obtained in the same manner as above.

<Preparation of adhesive composition (b9)>
Preparation of the adhesive composition (b1) except that the amount of trimethylolpropane triacrylate (“Aronix M-309” manufactured by Toagosei Co., Ltd.) added to the adhesive composition (b4) was 60 parts by mass. The adhesive composition (b9) was obtained in the same manner as above.

<Preparation of adhesive composition (b10)>
35 parts by mass of polyester resin ("Byron BX1001" manufactured by Toyo Boseki Co., Ltd.), 75.8 parts by mass of polyester urethane resin ("Byron UR1350" manufactured by Toyo Boseki Co., Ltd., solid content 33% by mass), bisphenol A type solid epoxy resin (DIC Corporation) 45 parts by mass of "EPICLON 1055" manufactured by the company) and 120 parts by mass of methyl ethyl ketone were added, and the mixture was stirred for 30 minutes using a stirrer. Then, 2.8 parts by mass of Vernock DN980 (manufactured by DIC Corporation, solid content 75% by mass) was added as an isocyanate-based cross-linking agent, and the adhesive composition (b10) was stirred for 20 minutes using a stirrer. Obtained.

<Preparation of adhesive composition (b11)>
In the adhesive composition (b1), 1-hydroxy-cyclohexyl-phenyl-ketone (Omnirad 184 manufactured by IGM Resin BV) is used instead of 2,4,6-trimethylbenzoyludiphenyl-phosphine oxide. An adhesive composition (b11) was obtained in the same manner as in the preparation of the adhesive composition (b1) except that 0.5 parts by mass was used.

(Example 1)
The adhesive composition (b1) was peeled off on one side with a silicone compound on a polypropylene film having a thickness of 60 μm (“60RL-01” manufactured by Oji Ftex Co., Ltd.) so that the thickness after drying was 100 μm. A polyethylene terephthalate film with a thickness of 75 μm (“75E0010BD” manufactured by Fujimori Kogyo Co., Ltd., hereinafter referred to as # 75 release liner), which has been peeled off on one side with a silicone compound, is attached to the film, dried at 85 ° C. for 5 minutes, and shielded from light. Aged at 23 ° C. for 7 days to prepare an active energy ray-curable polyurethane adhesive sheet (c1).

(Example 2)
An adhesive sheet (c2) was obtained in the same manner as in Example 1 except that the adhesive composition (b2) was used instead of the adhesive composition (b1).

(Example 3)
An adhesive sheet (c3) was obtained in the same manner as in Example 1 except that the adhesive composition (b3) was used instead of the adhesive composition (b1).

(Example 4)
An adhesive sheet (c4) was obtained in the same manner as in Example 1 except that the adhesive composition (b4) was used instead of the adhesive composition (b1).

(Example 5)
An adhesive sheet (c5) was obtained in the same manner as in Example 1 except that the thickness of the adhesive composition (b1) after drying was 50 μm.

(Example 6)
An adhesive sheet (c6) was obtained in the same manner as in Example 1 except that the adhesive composition (b5) was used instead of the adhesive composition (b1).

(Comparative Example 1)
An adhesive sheet (c7) was prepared in the same manner as in Example 1 except that the adhesive composition (b6) was applied so as to have a thickness of 50 μm after drying.

(Comparative Example 2)
An adhesive sheet (c8) was prepared in the same manner as in Example 1 except that the adhesive composition (b7) was coated so that the thickness after drying was 100 μm.

(Comparative Example 3)
An adhesive sheet (c9) was prepared in the same manner as in Example 1 except that the adhesive composition (b8) was coated so that the thickness after drying was 100 μm.

(Comparative Example 4)
An adhesive sheet (c10) was prepared in the same manner as in Example 1 except that the adhesive composition (b9) was applied so that the thickness after drying was 100 μm.

(Comparative Example 5)
An adhesive sheet (c11) was prepared in the same manner as in Example 1 except that the adhesive composition (b10) was applied so as to have a thickness of 50 μm after drying.

(Comparative Example 6)
An adhesive sheet (c12) was prepared in the same manner as in Example 1 except that the adhesive composition (b11) was coated so that the thickness after drying was 100 μm.

(Preparation of weather resistant transparent resin sheet (B1'))
A transparent resin sheet made of polycarbonate with a thickness of 0.25 mm ("Polyca Ace ECG101" manufactured by Sumitomo Bakelite Co., Ltd.) is used as an adherend (B1), and the surface thereof is subjected to corona discharge treatment to perform an ultraviolet absorbing coating agent (Co., Ltd.). A paint obtained by diluting "Hals Hybrid UV-G13" manufactured by Nippon Catalyst Co., Ltd. with isopropanol to a solid content of 10% by mass is applied so that the thickness after drying is 3 μm, dried at 80 ° C. for 5 minutes, and then dried at 40 ° C. The weather-resistant transparent resin sheet (B1') was prepared by curing for 3 days. When the light transmittance of the obtained weather-resistant transparent resin sheet (B1') was measured with an ultraviolet-visible near-infrared spectrophotometer ("V-570" manufactured by JASCO Corporation), light rays having a wavelength of 325 to 380 nm were measured. The transmittance was 0% at 325 to 370 nm, and the light transmittance increased after exceeding the wavelength of 370 nm, which was 18% at 380 nm. On the other hand, the uncoated transparent resin sheet (B1) has a light transmittance of 55% at a wavelength of 325 nm, the light transmittance gradually increases at a wavelength of 325 nm or more, and the light transmittance at a wavelength of 350 to 380 nm is high. The light transmittance was 80% or more at all wavelengths.

(Tension storage elastic modulus E')
From the adhesive sheets produced in Examples and Comparative Examples, a rectangular piece obtained by cutting the width of 5 mm and the length of the measuring portion to 20 mm and the length of the handles at both ends to 20 mm was used as a test piece. The peeling liner on both sides is peeled off, and using a tensile dynamic viscoelasticity measuring device (TA Instruments, RSA III), the temperature rise rate is 3 ° C./min, the measurement frequency is 1.0 Hz, and the measurement temperature range is-. measured in the range of 40 to 150 ° C., it was calculated storage modulus tensile at 25 ° C. of the active energy ray irradiation prior to the adhesive layer (E _'A25) and tensile storage modulus at 100 ℃ (E' _A100).

Further, the # 75 release liner was removed from the adhesive sheets obtained in Examples and Comparative Examples, and a metal halide lamp B type (“MBL250NL” manufactured by GS Yuasa Co., Ltd.) was used on the surface of the adhesive sheet to accumulate 1000 mJ / cm ² . A cured product was obtained by irradiating with a light amount of light. In the same manner as described above, the tensile storage elastic modulus ( _E'A'100 ) of the adhesive layer at 100 ° C. after irradiation with active energy rays was calculated.

Further, the # 75 release liner is removed from the adhesive sheets produced in Examples and Comparative Examples, and the weather resistant transparent resin sheet (B1') is placed on the adhesive layer while preventing the # 75 release liner from adhering to the adhesive layer. The tensile elastic modulus ( _E'A''100 ) was measured when the material was irradiated with light and cured by covering with an ultraviolet absorbing sheet having a wavelength of 325 to 380 nm.

(Evaluation method of foam resistance after heating and resistance to protrusion of end face)
The # 75 release liner was peeled off from the adhesive sheets produced in Examples and Comparative Examples, bonded to the surface of the transparent resin sheet (B1) in an atmosphere of 23 ° C., and pressed twice with a 2 kg roller. Was cut to a length of 60 mm and a width of 60 mm.

Next, heating was performed for 30 seconds at a pressure of 160 ° C. and 0.01 MPa using a hot press device, and evaluation was performed according to the following criteria. As a heat press device, a heat press machine "TP-750 Air Press" manufactured by Tester Sangyo Co., Ltd. was used.

<Evaluation of the presence or absence of air bubbles>
⊚: There were no fine bubbles.
〇: There were very few fine bubbles, but it was at a level that was not a problem.
X: There were air bubbles, and air bubble traces remained even when the release liner was removed.

<Evaluation of the difficulty of protruding the end face>
⊚: There was no protrusion from the end face.
〇: There was a slight protrusion, but it was at a level that was not a problem.
X: There was protrusion.

(Evaluation method of foam resistance and peeling after leaving in moist heat)
The # 75 release liner was peeled off from the adhesive sheets produced in Examples and Comparative Examples, bonded to the transparent resin sheet (B1) in an atmosphere of 23 ° C., and pressurized twice with a 2 kg roller. , 60 mm in length and 60 mm in width.

Next, the peeling liner on the remaining one side is removed, and as an adherend (B2), a polycarbonate plate having a length of 75 mm and a width of 75 mm (“Iupilon NF-2000UVNS2 Clear” manufactured by Mitsubishi Gas Chemical Company, Ltd., thickness 1.5 mm) is used. I pasted it. Next, after leaving it in an environment of 0.5 MPa and 50 ° C. for 20 minutes, a metal halide lamp B type (“MBL250NL” manufactured by GS Yuasa Co., Ltd.) is used to irradiate an active energy ray with an integrated light amount of 1000 mJ / cm ^2. Obtained a sticker by doing.

The patch was left to stand in an environment of a temperature of 85 ° C. and a humidity of 85% RH for 500 hours, and then the appearance of the patch was evaluated from the surface side of the transparent resin sheet (B1) according to the following criteria.

<Evaluation of the presence or absence of air bubbles>
⊚: There were no fine bubbles.
〇: There were very few fine bubbles, but it was at a level that was not a problem.
X: There were bubbles.

<Evaluation of the presence or absence of floating>
⊚: There was no floating or peeling.
〇: There was a slight amount of floating and peeling, but it was at a level that was not a problem.
X: There was floating or peeling.

(Gel fraction)
The adhesive sheets obtained in Examples and Comparative Examples were cut into a size of 40 mm × 50 mm, and then only the release liner on one side was removed to obtain a test piece. After measuring the mass of the test piece, it was immersed in toluene adjusted to 23 ° C. for 24 hours.
After the immersion, the test piece was taken out and dried in a dryer at 105 ° C. for 1 hour, and the mass was measured. The gel fraction (D1) of the adhesive layer before irradiation with active energy rays was calculated based on the above mass and the following formula.

Gel fraction (% by mass) of the adhesive layer before irradiation with active energy rays = {(mass of the adhesive layer of the adhesive sheet remaining without being dissolved in toluene) / (adhesive layer of the adhesive sheet before immersion in toluene) Mass)} x 100

The mass of the adhesive layer of the adhesive sheet before immersion refers to a value obtained by subtracting the mass of the release liner used for manufacturing the test piece from the mass of the test piece. The mass of the remaining adhesive layer refers to a value obtained by subtracting the mass of the release liner from the mass of the residue after drying.

The adhesive sheets obtained in Examples and Comparative Examples are heated at 160 ° C. and 0.01 MPa for 30 seconds using a hot press device, and then the adhesive after heating is carried out in the same manner as described above. The gel fraction (D2) of the layer was measured. As a heat press device, a heat press machine "TP-750 Air Press" manufactured by Tester Sangyo Co., Ltd. was used.

The surface of the adhesive sheet obtained in Examples and Comparative Examples is covered with the transparent resin sheet (B1), and a metal halide lamp B type (“MBL250NL” manufactured by GS Yuasa Co., Ltd.) is applied from the # 75 release liner side of the adhesive sheet. A cured product was obtained by irradiating with an active energy ray having an integrated light amount of 1000 mJ / cm ² . The gel fraction (D3) of the adhesive layer after curing was measured in the same manner as the evaluation of the gel fraction of the adhesive layer before irradiation with active energy rays.

Further, when the weather resistant transparent resin sheet (B1') is used instead of the transparent resin sheet (B1) and is cured by covering with an ultraviolet absorbing sheet having a wavelength of 325 to 380 nm in the same manner as described above. The gel fraction (D3') of the adhesive layer after curing was measured.

(Evaluation method of peeling adhesive strength)
The # 75 release liner was peeled off from the adhesive sheets prepared in Examples and Comparative Examples, the surface was affixed to a 50 μm-thick polyethylene terephthalate film treated with corona discharge, and cut into a size of 20 mm in width and 100 mm in length. Was used as a test piece.

Next, heating was performed for 30 seconds at a pressure of 160 ° C. and 0.01 MPa using a heat press device. As a heat press device, a heat press machine "TP-750 Air Press" manufactured by Tester Sangyo Co., Ltd. was used.

Next, the peeling liner on the remaining one side of the test piece was peeled off, and as an adherend (B2), a polycarbonate plate having a width of 70 mm and a length of 150 mm (“Iupilon NF-2000UVNS2 Clear” manufactured by Mitsubishi Gas Chemical Company, Inc., thickness). It was attached to the surface of 1.5 mm). After leaving it in an environment of 5 atm and 50 ° C. for 20 minutes, the weather-resistant transparent resin sheet (B1') is covered with the surface coated with the ultraviolet-absorbing coating agent as the outer surface, and the polyethylene terephthalate film of the adhesive sheet. A metal halide lamp B type (“MBL250NL” manufactured by GS Yuasa Co., Ltd.) was used to irradiate light with an integrated light amount of 1000 mJ / cm ² from the surface side to which the material was attached.

After allowing the patch to stand in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH for 1 hour, a Tensilon type tensile tester (manufactured by A & D Co., Ltd., RTG-1210) equipped with a constant temperature bath is used. The peeling resistance when pulled at a pulling speed of 50 mm / min in the 180 ° direction under an atmosphere of 25 ° C. and 90 ° C. was measured.

(Total light transmittance Tt and haze)
For the total light transmittance Tt and haze, the # 75 release liner was removed from the adhesive sheets prepared in Examples and Comparative Examples, and the exposed adhesive layer was exposed to ultraviolet rays of the weather resistant transparent resin sheet (B1'). The side surface to which the absorbent coating agent was not applied was attached. Then, after leaving it in an environment of 5 atm and 50 ° C. for 20 minutes, from the weather resistant transparent resin sheet side, using a metal halide lamp B type (“MBL250NL” manufactured by GS Yuasa Co., Ltd.), an integrated light amount of 1000 mJ / cm ² A patch was obtained by irradiating with the light of. The peeling liner on the remaining one side of the patch was peeled off, and the total light transmittance Tt and haze were measured using "HR-100 type" manufactured by Murakami Color Technology Research Institute Co., Ltd.

The adhesive sheets of Examples 1 to 6 have good foaming resistance by suppressing protrusion of the adhesive layer from the end face in the heating step before curing, and have good floating resistance when left in a moist heat after curing. It had peeling property and was excellent in transparency and adhesiveness. Further, even in the case of the bonded member on which the ultraviolet absorbing coating agent is laminated, it was possible to cure and bond by irradiation with active energy rays. On the other hand, in the adhesive sheets of Comparative Examples 1 to 6, the adhesive layer protrudes from the end face and bubbles are generated in the heating step before curing, bubbles are generated when the adhesive layer is left in a moist heat after curing, and floating and peeling occur. Since it was a bonding member on which an ultraviolet absorbing coating agent was laminated, it was not possible to perform curing adhesion by irradiation with active energy rays.

Claims (10)

An active energy ray-curable polyurethane adhesive sheet having an adhesive layer (A), which is used for bonding at least two adherends (B1) and (B2).
The adhesive layer (A) has a tensile elastic modulus ( _E'A25 ) measured at a temperature of 25 ° C. and a frequency of 1 Hz at 1 × 10 ³ to 1 × 10 ⁶ Pa, and is measured at a temperature of 100 ° C. and a frequency of 1 Hz. by tensile storage modulus (E _'A100) is Ri ^{1 × 10 3 ~1 × 10 5} Pa der,
The tensile storage elastic modulus ( _E'A'100 ) measured at a temperature of 100 ° C. and a frequency of 1 Hz of the layer (A') obtained by curing the adhesive layer (A) is 2 × 10 ⁵ to 1 × 10 ⁹ Pa. ,
The peeling adhesive force of the cured layer (A') to the polycarbonate substrate at 90 ° C. is in the range of 5 to 50 N / 20 mm.
The adhesive (A) contains a photopolymerization initiator having an absorption wavelength in a wavelength region of 380 nm or more.
The adhesive layer (A) has a gel fraction of 0 to 10% by mass after undergoing a heating step of 1 to 300 seconds at 100 ° C. or higher before irradiation with active energy rays.
At least one of the adherends (B1) and (B2) is an adherend capable of generating a gas when left in an environment of a temperature of 85 ° C. and a humidity of 85% RH for 24 hours. Active energy ray-curable polyurethane adhesive sheet. The active energy ray-curable polyurethane adhesive sheet according to claim 1, wherein the adhesive layer (A) has a thickness in the range of 25 to 300 μm. Claimed that the adhesive layer (A) has a gel fraction of 0 to 10% by mass before being irradiated with active energy rays and a gel fraction of 75 to 95% by mass after being irradiated with active energy rays. Item 2. The active energy ray-curable polyurethane adhesive sheet according to Item 1 or 2. The active energy ray-curable polyurethane adhesive sheet according to any one of claims 1 to 3 , wherein the photopolymerization initiator is a phenylphosphine oxide type and / or an α-aminoalkylphenone type. The active energy ray-curable polyurethane adhesive sheet according to any one of claims 1 to 4 , wherein the peeling adhesive force of the cured layer (A') to the polycarbonate substrate at 25 ° C. is in the range of 5 to 50 N / 20 mm. .. The adherend (B1) and the adherend (B2) are laminated via a cured product of the active energy ray-curable polyurethane adhesive sheet according to any one of claims 1 to 5. Goods. At least one of the adherend (B1) and the adherend (B2) has a transmittance of light having a wavelength of 380 to 780 nm of 80 to 100%, and of light having a wavelength of 325 nm to 380 nm. The article according to claim 6 , which is made of a light-transmitting material having a transmittance of 0 to 20%. At least one of the adherend (B1) and the adherend (B2) has a light transmittance of 80 to 100% at each wavelength of 380 to 780 nm and a thickness of 0.05 mm to 5 mm. The article according to claim 6, which is made of a light-transmitting material. Remain laminated to a release liner on one side, said at pressure sensitive radiation curable polyurethane adhesive sheet wherein the adhesive layer according to any one of claims 1 to 5 and (A) adherend (B1 the) and a step of bonding [1], and removing one side of the release liner, the heated surface of the adherend (B1), to the surface of the adhesive layer (a), the adherend ( In the step [2] of pressurizing and applying B2), the surface of the adherend made of at least one of the adherend (B1) and the adherend (B2) is irradiated with active energy rays. A method for producing an article, which comprises the order of the step [3] in which the adhesive layer (A) forms a cured layer (A'). The release liner and the adhesive layer of the active energy ray-curable polyurethane adhesive sheet according to any one of claims 1 to 5 as a release liner laminated on one side and (A) is heated, the active energy ray-curable polyurethane the adhesive layer of the adhesive sheet wherein the surface of the (a) step [4] for affixing pressing a adherend (B2), the heating only adherend (B1), to remove the release liner wherein Step [5] of applying pressure to the surface of the adhesive layer (A) , to the surface of the adherend made of at least one of the adherend (B1) and the adherend (B2). A method for producing an article, which comprises the steps [6] of irradiating with active energy rays to form a cured layer (A') of the adhesive layer (A) .