JP6610993B2 - Thermosetting pressure-sensitive adhesive composition and pressure-sensitive adhesive layer - Google Patents

Description

The present invention relates to a thermosetting pressure-sensitive adhesive composition and a pressure-sensitive adhesive layer that achieve both high adhesive strength and removability even when the pressure-sensitive adhesive layer is thinned.

The adhesive strength of the pressure-sensitive adhesive sheet depends not only on the composition of the pressure-sensitive adhesive, but also the amount of pressure-sensitive adhesive applied on the substrate, that is, the thickness of the pressure-sensitive adhesive layer to be formed. Adhesive strength increases. Although the thickness of the pressure-sensitive adhesive layer is set in accordance with various purposes, it is not so often made thinner than 10 μm in order to develop a sufficiently high adhesive force. However, in recent years, it has been desired to reduce the thickness of electronic devices and optical devices and the like, and adhesive sheets used for joining members of electronic devices and optical devices or temporarily bonding during processing are similarly thin films. Is desired.

Various proposals have been made for reducing the thickness of the pressure-sensitive adhesive layer in a pressure-sensitive adhesive sheet used for bonding or processing members of electronic devices and optical devices. For example, in Patent Document 1, in order to improve the removability, the pressure-sensitive adhesive layer is thinned to reduce the adhesive strength.

On the other hand, even if the pressure-sensitive adhesive layer is made thin, it may not be desired to reduce the adhesive strength. In Patent Document 2, even when the pressure-sensitive adhesive layer is thinned to 1 to 15 μm, the purpose is to provide an optical film that can satisfy the durability, and has a large weight average molecular weight composed of a specific monomer (meta ) An optical film using an adhesive containing an acrylic polymer and a crosslinking agent has been proposed.

Further, in Patent Document 3, when the pressure-sensitive adhesive layer is thinned to 10 μm or less, an acrylic type having a crosslinkable functional group is used for the purpose of suppressing high adhesive strength and tearing of the support that is likely to occur at the time of sticking or peeling. A double-sided pressure-sensitive adhesive tape using a pressure-sensitive adhesive containing a copolymer, a urethane resin and a crosslinking agent has been proposed.

However, in the optical films and double-sided pressure-sensitive adhesive tapes disclosed in Patent Documents 2 and 3, a sufficiently high adhesive force is not obtained when the pressure-sensitive adhesive layer is thinned.
JP-A-2005-007618 JP 2007-277510 A JP 2013-75999 A

It is an object of the present invention to provide a thermosetting pressure-sensitive adhesive composition that can exhibit high adhesive force even in a thin film and has excellent removability that does not cause adhesive residue on a glass substrate during peeling.

As a result of intensive studies on the polyurethane composition of the pressure-sensitive adhesive and the thermal crosslinking agent in order to solve the above problems, the present inventors have found that the problem can be solved by a thermosetting pressure-sensitive adhesive composition satisfying specific conditions. It came to complete.

That is, the present invention is a thermosetting pressure-sensitive adhesive composition containing a main agent, a curing agent and an organic solvent, wherein the main agent is a hydrogenated polybutadiene polyol (а-1) (hereinafter referred to as “component (a-1)”). And polyurethane (A) having terminal hydroxyl groups obtained by reacting aliphatic polyisocyanate (а-2) (hereinafter also referred to as “component (a-2)”) (hereinafter referred to as “(A)”). The curing agent is a polyfunctional polyisocyanate (B) having a ring structure, and the polyfunctional polyisocyanate (B) relative to the total number of hydroxyl groups of the polyurethane (A) (hereinafter referred to as “( The thermosetting pressure-sensitive adhesive composition is characterized in that the total number of isocyanate groups in A) component is also 0.1 to 5.0 in terms of equivalent ratio.

Invention 2 is the thermosetting pressure-sensitive adhesive composition according to Invention 1, wherein the component (A) has a weight average molecular weight (polystyrene conversion value by gel permeation chromatography) of 30,000 to 110,000.

Invention 4 relates to Inventions 1 to 3, wherein polyurethane (A) is 100 parts by weight, polyisocyanate (B) is 0.1 to 5.0 parts by weight, organic solvent for dilution (C) (hereinafter referred to as “(C ) Component ”) is 100 to 400 parts by weight, which is a thermosetting pressure-sensitive adhesive composition.

According to the present invention, even if the film is thinned, a high adhesive force can be expressed, and furthermore, it has excellent reworkability that does not cause adhesive residue on the glass substrate during peeling. It can be widely used as a thermosetting pressure-sensitive adhesive for optical use, which is applied to a display panel having a multilayer structure in a digital display device.

The component (A) is a polyurethane having a terminal hydroxyl group obtained by reacting the components (a-1) and (a-2).

The component (a-1) is a polyol obtained by hydrogenating polybutadiene polyol. By using the component (a-1) which is a hydrogenated product, the present composition for forming a cured layer excellent in adhesion and durability can be obtained. Although the molecular weight of (a-1) component is not specifically limited, It is preferable that it is 1,000-5,000 from the point of adhesive force. The iodine value of the component (a-1) is not particularly limited, but is usually 50 or less, preferably 25 or less from the viewpoint of durability, and the hydroxyl value is usually in the range of 10 to 200, and adhesion It is preferable that it is 20-100 from the point of property. In addition, as a commercial item applicable to (a-1) component, Nippon Soda Co., Ltd. product "NISSO-PBGI-1000", "NISSO-PBGI-2000", "NISSO-PBGI-3000", for example. , “Krasol HLBH-P2000”, “Krasol HLBH-P3000” manufactured by CRAY VALLEY, and the like.

Although the molecular weight of the said (a-1) component is not specifically limited, It is preferable that it is 700-4,000 from the point of adhesive force and holding power. When the molecular weight of the component (a-1) is excessively small, the pressure-sensitive adhesive sheet adhesive strength and flexibility obtained are lowered. On the other hand, when the molecular weight of the component (a-1) is excessively large, the holding force of the obtained pressure-sensitive adhesive sheet is deteriorated, and there is a concern of heat dripping after the wet heat resistance test.

Examples of the component (a-2) include dicyclohexylmethane-4,4′-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and dimer or hexamer thereof. Any combination can be used. Among these, for the purpose of improving removability, it is preferable to use a polyisocyanate having a ring structure such as dicyclohexylmethane-4,4′-diisocyanate or isophorone diisocyanate.

As the component (A), a hydroxyl group-terminated polyurethane can be obtained by reacting the component (a-1) with the component (a-2). Although it does not specifically limit in manufacture of (A) component, For example, the batch preparation (method 1) for shortening synthesis time and the (a-1) component division preparation (method 2) for enlarging a weight average molecular weight are used. it can.
Method 1: The (a-1) component and the (a-2) component are collectively reacted, and (A) can be synthesized in a short time.
Method 2: A part of the component (a-1) and the total amount of the component (a-2) are charged and reacted for a certain period of time. Then, the remaining component (a-1) is divided into several times and a certain period of time is opened. Prepare and react. This synthesis method is preferable when the weight average molecular weight of the component (A) is increased.

The weight average molecular weight of the component (A) (polystyrene conversion value by gel permeation chromatography) is not particularly limited, but is preferably 30,000 to 110,000 in terms of adhesive strength and removability, More preferably, it is 40,000-90,000.

The average functional group number of the component (A) is not particularly limited, but is preferably 1.5 to 3.0, more preferably from the viewpoint of durability and removability of the obtained adhesive layer. 1.8-2.2. The average number of functional groups means the average number of hydroxyl groups present in one molecule of the component (A).

Specific examples of the component (B) include diisocyanates having an aromatic ring such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and isophorone. A compound derived from a diisocyanate having an alicyclic structure such as diisocyanate, hexamethylene diisocyanate, or hydrogenated diphenylmethane diisocyanate, that is, the diisocyanurate, trimethylolpropane adduct, biuret type, prepolymer having an isocyanate residue ( Low polymer obtained from diisocyanate and polyol), uretdione having an isocyanate residue, allophanate, or a complex thereof. Gerare, to these may be used alone or may be used even in an arbitrary combination of two or more thereof.

As the component (B), it is preferable to use a polyisocyanate having an isocyanurate ring for the purpose of improving durability and adhesive strength. For example, a multimer (isocyanurate body) of hexamethylene diisocyanate can be mentioned. In order to improve the removability, it is preferable to use a polyisocyanate having an isocyanate nurate structure derived from a diisocyanate having an alicyclic structure.

The component (B) is blended so that the total number of isocyanate groups in the component (B) is 0.1 to 5 in an equivalent ratio with respect to the total number of hydroxyl groups in the polyol (A), preferably It mix | blends in the range of 1.0-2.0. If the isocyanate group of the component (B) is less than 0.1 with respect to the total number of hydroxyl groups of the polyol (A), the adhesive strength and durability after curing may be reduced. When the number of isocyanate groups in the component (B) exceeds 5, the component (B) still remains in the cured pressure-sensitive adhesive layer, and there is a risk that durability and adhesive strength may be reduced.

On the other hand, if the isocyanate group of the component (B) is larger than 5, the component (B) still remains in the cured pressure-sensitive adhesive layer, and there is a risk that durability and adhesive strength may be reduced.

The said (C) component is the organic solvent for dilution which melt | dissolves the adhesive composition of this invention. Specific examples include aliphatic hydrocarbons such as butane, pentane, hexane, isopentane, heptane, octane and isooctane, alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane and ethylcyclohexane, or benzene, Hydrocarbon solvents such as aromatic hydrocarbons such as toluene, ethylbenzene and xylene, chain / cyclic ether solvents such as diethyl ether and tetrahydrofuran, and halogen solvents such as chloroform and dichlorodimethylmethane can be used. These may be used alone or in combination of two or more. In this invention, the solvent which dissolves the adhesive composition of this invention is preferable. The usage-amount of these diluents is 100-1000 weight part with respect to 100 weight part of component (A), Preferably it is 200-500 weight part. In the present invention, it is preferable to use a diluent so that the viscosity of the solution in which the adhesive composition of the present invention is dissolved is 100 to 10000 mpas, preferably 300 to 3000 mpas. Recommended by.

In this invention, in order to improve adhesive force as needed, you may add tackifying resin in the range which does not reduce transparency. Examples of tackifying resins include rosin resins such as rosin and rosin esterified products; terpene resins such as diterpene polymers and α-pinene-phenol copolymers; aliphatic (C5) and aromatic ( Petroleum resin such as C9); styrene resin, phenol resin, xylene resin and the like. From the viewpoint of light resistance, it is preferable to add an esterified product of a hydrogenated rosin or a disproportionated rosin with few unsaturated double bonds, an aliphatic or aromatic petroleum resin, an acrylic resin, or the like to the adhesive. As addition amount of tackifying resin, it is the range of 1-20 mass parts with respect to 100 mass parts of adhesive composition solid components.

Moreover, in this invention, the well-known various additive may be included in the range which does not impair transparency as needed. Examples of the additive include a silane coupling agent, a plasticizer, a surface lubricant, a leveling agent, a softener, an antioxidant, an antistatic agent such as a surfactant, and a dye.

As a known additive used in the present invention, a silane coupling agent is preferably included when it is desired to improve the adhesive strength to the metal foil.

Examples of the silane coupling agent used in the present invention include trialkoxysilane having a vinyl group such as vinyltrimethoxysilane and vinyltriethoxysilane, 3-aminopropyltriethoxysilane, and N- (2-aminoethyl). Trialkoxysilane having an amino group such as 3-aminopropyltrimethoxysilane; 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltriethoxy Examples include trialkoxysilane having a glycidyl group such as silane. These may be used alone or in any combination of two or more.

It is preferable that the addition amount of the silane coupling agent used by this invention is 0.5-5 weight part with respect to 100 weight part of a polyurethane (A). If the addition amount of the silane coupling agent is less than 0.5 parts by weight, the effect of improving the adhesive strength to the metal foil by adding the silane coupling agent is poor, and even if it is added in an amount of more than 5 parts by weight, the performance of more than that There is no improvement.

As a known additive used in the present invention, a known leveling agent or antifoaming agent can be added to the main agent for the purpose of improving the laminate appearance.

Examples of the leveling agent used in the present invention include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl group-containing polydimethylsiloxane, and polyether ester-modified hydroxyl group-containing polydimethylsiloxane. Acrylic copolymer, methacrylic copolymer, polyether-modified polymethylalkylsiloxane, acrylic acid alkyl ester copolymer, methacrylic acid alkyl ester copolymer, lecithin and the like. These may be used alone or in any combination of two or more.

The leveling agent is preferably in the range of 0.05 to 2 parts by weight with respect to 100 parts by weight of the solid content of the polyurethane (A). If the amount of the leveling agent added is less than 0.05 weight, sufficient leveling property may not be improved, and if it is more than 2 parts by weight, the adhesive strength may be greatly deteriorated.

Examples of the antifoaming agent used in the present invention include known resins such as silicone resins, silicone solutions, and copolymers of alkyl vinyl ethers, alkyl acrylates and alkyl methacrylates. These may be used alone or in any combination of two or more.

The antifoaming agent is preferably in the range of 0.05 to 2 parts by weight with respect to 100 parts by weight of the solid content of the polyurethane (A). If the addition amount of the antifoaming agent is less than 0.05 weight, a sufficient antifoaming effect may not be obtained, and if it is more than 2 parts by weight, the adhesive strength of the adhesive may be greatly deteriorated. is there.

The thermosetting pressure-sensitive adhesive composition of the present invention can be produced by mixing the components (A) to (C) at a desired ratio. There are no particular limitations on the mixing method and order of addition of the components.

In addition, in the pressure-sensitive adhesive composition of the present invention, two liquids are preferable in order to improve storage stability. The polyurethane (A) solution and the polyisocyanate (B) can be stored and mixed immediately before application and application.

The pressure-sensitive adhesive composition of the present invention is bonded to a display panel and a decorative plate or an icon sheet, bonded to a transparent substrate on which a transparent electrode is formed on a touch panel and a transparent plate, and bonded to a display body and an optical functional material. It is suitably used for adhesive materials for various optical devices and optical members. Examples of the material of the member include polyethylene terephthalate, polycarbonate, glass, polycarbonate, and acrylic resin. As a display body, display elements, such as a liquid crystal display which stuck the polarizing plate on glass, EL display, EL illumination, electronic paper, and a plasma display, are mentioned. Examples of optical functional materials include acrylic plates (which may be treated with a single-sided or double-sided hard coating or antireflection coating), polycarbonate plates, polyethylene terephthalate plates for the purpose of improving visibility and preventing cracking of display elements from external impacts. And a transparent plastic plate such as a polyethylene naphthalate plate, tempered glass (which may have an anti-scattering film), and a touch panel input sensor.

The pressure-sensitive adhesive layer obtained by applying and thermosetting the pressure-sensitive adhesive composition of the present invention is also one aspect of the present invention. Although the thickness of an adhesion layer is not specifically limited, Usually, it is about 1-1000 micrometers normally, Preferably it is 1-100 micrometers. It is characterized by having a strong adhesive force with a thin film of 10 μm or less.

Examples of the thermosetting method include applying a pressure-sensitive adhesive to the base material with a comma coater or an applicator, and curing in 0.1 minutes to 10 minutes under heating at 60 ° C to 200 ° C. In order for the (A) component and (B) to sufficiently react, the base material suppresses heat deterioration, so that the heating temperature is preferably 80 ° C. to 150 ° C., and the heating time is preferably 0.5 minutes to 5 minutes.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, “%” and “part” mean “% by weight” unless otherwise specified.

<Synthesis of component (A)>
Synthesis example 1
(A-1) Synthesis of Component A reactor equipped with a cooling paddle and a stirrer, a reactor equipped with a cooling paddle and a stirrer, a hydrogenated polybutadiene polyol having a weight average molecular weight of 4,000 (manufactured by Nippon Soda Co., Ltd.) , Trade name “NISSO-PB GI-3000”), 563 parts, 37 parts of dicyclohexylmethane 4,4′-diisocyanate, 400 parts of dilute solvent toluene and 0.4 part of tin octylate. after incubation time, by confirming the completion of the reaction at NCO measurement, the weight average molecular weight 86,000, polyurethane average functionality of 2.0 (hereinafter (referred to a-1) component) was obtained solution. In addition, the said weight average molecular weight is the polystyrene conversion value by a gel permeation chromatography, and this measurement condition is as follows [a measuring apparatus main body (product name "HLC-8220GPC", the Tosoh Corporation make), column. (Product names “TSKGel G1000H”, “TSKGel G2000H”, manufactured by Tosoh Corporation), developing solvent (tetrahydrofuran)]. (The same applies hereinafter)

Synthesis example 2
(A-2) Synthesis of Component 565 parts of a hydrogenated polybutadiene polyol having a weight average molecular weight of 4,000 (manufactured by Nippon Soda Co., Ltd., trade name “NISSO-PB GI-3000”) in the same reactor as in Synthesis Example 1 Then, 35 parts of dicyclohexylmethane 4,4′-diisocyanate, 400 parts of diluent solvent toluene and 0.4 part of tin octylate are added, heated to 80 ° C. and kept for 3 hours, and the completion of the reaction is confirmed by NCO measurement. by weight average molecular weight 56,000, polyurethane average functionality of 2.0 (hereinafter (referred to a-2) component) was obtained a toluene solution of.

Synthesis example 3
(A-3) Synthesis of Component In the same reactor as in Synthesis Example 1, 568 parts of a hydrogenated polybutadiene polyol having a weight average molecular weight of 4,000 (product name “NISSO-PB GI-3000” manufactured by Nippon Soda Co., Ltd.) After adding 32 parts of isophorone diisocyanate, 400 parts of diluent solvent toluene and 0.4 part of tin octylate, the mixture was heated to 80 ° C. and kept for 3 hours, and then the completion of the reaction was confirmed by NCO measurement. 68,000, polyurethane average functionality of 2.0 (hereinafter (referred a-3) component) was obtained a toluene solution of.

Synthesis example 4
Synthesis of Component (A-4) In the same reactor as in Synthesis Example 1, 576 parts of polybutadiene polyol having a weight average molecular weight of 4,000 (manufactured by Nippon Soda Co., Ltd., trade name “NISSO-PB GI-3000”), hexa After adding 24 parts of methylene diisocyanate, 400 parts of diluent solvent toluene and 0.4 part of tin octylate, the temperature was raised to 80 ° C. and kept for 3 hours, and the completion of the reaction was confirmed by NCO measurement. , 000, polyurethane average functionality of 2.0 (hereinafter (referred a-5) component) was obtained a toluene solution of.

Comparative Synthesis Example 1
Synthesis of Component (A-5) In the same reactor as in Synthesis Example 1, 563 parts of polybutadiene polyol having a weight average molecular weight of 4,000 (manufactured by Nippon Soda Co., Ltd., trade name “NISSO-PB G-3000”), isophorone After adding 37 parts of diisocyanate, 400 parts of diluting solvent toluene and 0.4 part of tin octylate, the mixture was heated to 80 ° C. and kept for 3 hours, and then the completion of the reaction was confirmed by NCO measurement. 000, polyurethane average functionality of 2.0 (hereinafter (referred a-5) component) was obtained a toluene solution of.

Comparative Synthesis Example 2
Synthesis of Component (A-6) In the same reactor as in Synthesis Example 1, 494 parts of polypropylene glycol having a weight average molecular weight of 1000 (manufactured by ADEKA Corporation, trade name “Adeka Polyether P-1000”), 106 parts of isophorone diisocyanate , added diluting solvent of toluene 400 parts of 0.6 parts of tin octylate, was kept 5 hours the temperature was raised to 80 ° C., by confirming the completion of the reaction at NCO measurement, the weight average molecular weight 56,000, Rights A toluene solution of a polyurethane having an average functional group number of 2.0 (hereinafter referred to as “component (A-6)”) was obtained.

Comparative Synthesis Example 3
Synthesis of Component (A-7) In the same reaction apparatus as in Synthesis Example 1, 533 parts of polycarbonate polyol having a weight average molecular weight of 2000 (manufactured by Kuraray Co., Ltd., trade name “Kuraray Polyol C-2090”), dicyclohexylmethane 4,4 After adding 67 parts of '-diisocyanate, 400 parts of diluent solvent toluene and 0.4 part of tin octylate, the temperature was raised to 80 ° C. and kept for 3 hours, and then the completion of the reaction was confirmed by NCO measurement. 67,000, polyurethane average functionality of 2.0 (hereinafter (referred a-7) components) to obtain a toluene solution of.

Comparative Synthesis Example 4
Synthesis of component (A-8) A 4-necked flask capable of nitrogen substitution was charged with 95 parts of butyl acrylate, 5 parts of 2-hydroxyethyl methacrylate, and 130 parts of ethyl acetate, and the temperature was raised to 63 ° C. under nitrogen substitution. 0.075 part of the agent AIBN is charged to start the polymerization, and 0.15 part of the initiator AIBN is additionally charged 4 hours after the start of the polymerization, and the polymerization is further performed for 4 hours. After polymerization, 470 parts of ethyl acetate was added to obtain an ethyl acetate solution of an acrylic polymer (A-8) having a weight average molecular weight of 1.3 million. (Product name "Paracron KAR-8", manufactured by Negami Kogyo Co., Ltd.)

<Preparation of pressure-sensitive adhesive composition>
Example 1
(A-1) 100 parts of component, (B) component, hexamethylene diisocyanate trimer (isocyanurate) (manufactured by Nippon Polyurethane Co., Ltd., trade name “Coronate HXR”, hereinafter (B-1) component) 6 parts, 150.9 parts of toluene (hereinafter referred to as (C-1) component) as a diluting solvent (C) component were blended in terms of pure content to prepare an adhesive composition (see Table 1). Further, the viscosity, solid content and compatibility of the composition were evaluated, and the results are shown in Table 2 (the same applies hereinafter).

Example 2
The component (B-1) of Example 1 was 1 part, the component (C-1) was 151.5, and other formulations were prepared in the same manner as in Example 1.

Example 3
5 parts of solid hydrogenated rosin ester (trade name “Pink Listal KE-311”, hereinafter (D) component) manufactured by Arakawa Chemical Industries, Ltd.) was added to Example 1, and 158. 4. A pressure-sensitive adhesive composition was prepared.

Example 4
(B-1) of Example 1 was changed to 0.6 parts of a hexamethylene diisocyanate multimer (isocyanurate) (manufactured by Nippon Polyurethane Co., Ltd., trade name “Coronate HK”, hereinafter referred to as component (B-2)). The other composition was the same as in Example 1 to prepare an adhesive composition.

Example 5
The component (A-1) of Example 1 was changed to the component (A-2), and other formulations were prepared as in Example 1 to prepare a pressure-sensitive adhesive composition.

Example 6
The component (A-1) of Example 1 was changed to the component (A-3), and other formulations were prepared as in Example 1 to prepare an adhesive composition.

Example 7
The component (A-1) in Example 2 was changed to the component (A-4), and the component (B-1) was 1.4 parts of an isophorone diisocyanate trimer (isocyanurate) (product of Evonik Japan) The name was changed to “VESATANAT 1890” (component (B-3) below), and an adhesive composition was prepared.

Comparative Example 1
The component (A-1) of Example 1 was changed to the component (A-5), and the other compositions were prepared in the same manner as in Example 1 to prepare an adhesive composition. (See Table 1). Further, the viscosity, solid content and compatibility of the composition were evaluated, and the results are shown in Table 2 (the same applies hereinafter).

Comparative Example 2
The component (A-1) is changed to the component (A-6), the component (B-1) is blended in 1.1 parts, and the component (C-1) is blended in 151.7 parts to prepare an adhesive composition. did.

Comparative Example 3
The component (A-1) is changed to the component (A-7), the component (B-1) is 0.7 parts, the component (C-1) is blended with 235.0, and an adhesive composition is prepared. did.

Comparative Example 4
Change the component (A-8) to 100 parts, the component (B-1) to 1 part, and the component (C-1) to 945 parts of ethyl acetate (hereinafter referred to as the (C-2) component) to prepare an adhesive composition. did.

Comparative Example 5
(B) The adhesive composition was prepared like Example 1 without using a component.

Comparative Example 6
The component (B-1) of Example 1 was changed to 5 parts, and (C-1) was changed to 157.5 parts.

（Ｂ−２）：ヘキサメチレンジイソシアネートの多量体（イソシアヌレート体）
（日本ポリウレタン社製、商品名「コロネートＨＫ」）
（Ｂ−３）：イソホロンジイソシアネートの三量体（イソシアヌレート体）
（Ｅｖｏｎｉｋ Ｊａｐａｎ社製、商品名「ＶＥＳＡＴＡＮＡＴ １８９０」）
（Ｃ−２）：酢酸エチル
（Ｄ）：固体水添ロジンエステル
（荒川化学工業（株）製、商品名「パインクリスタールＫＥ−３１１」）

(B-2): Hexamethylene diisocyanate multimer (isocyanurate)
(Nippon Polyurethane, trade name “Coronate HK”)
(B-3): Trimer of isophorone diisocyanate (isocyanurate)
(Product name “VESATANAAT 1890”, manufactured by Evonik Japan)
(C-2): Ethyl acetate (D): Solid hydrogenated rosin ester (manufactured by Arakawa Chemical Industries, Ltd., trade name “Pink Listal KE-311”)

<Solid content>
A 1 g sample is dried at 105 ° C. for 3 hours and the residue is expressed in weight%.

<Viscosity>
The viscosity (mPa · s) was measured with an E-type viscometer {TVE-10 (manufactured by Toki Sangyo Co., Ltd.)} at 25 ° C. for 5 minutes.

<Compatibility>
The compatibility was judged based on the following criteria by visually observing the obtained pressure-sensitive adhesive composition.
○: Uniform and completely transparent Δ: No white turbidity, sediment, insoluble matter or liquid layer separation ×: Confirmation of white turbidity, sediment, insoluble matter or liquid layer separation

<Preparation of adhesive layer>
Using an applicator or a comma coater, the compositions according to Examples 1 to 6 and Comparative Examples 1 to 7 were formed on a treated polyester film having a thickness of 100 μm (trade name “Cosmo Shine A-4100”, manufactured by Toyobo Co., Ltd.), 5 μm. The film was applied so as to have a film thickness of 1, and dried at 130 ° C. for 3 minutes in a smooth air dryer, and then heat-cured. Thereafter, this cured product coated surface and a 38 μm-thick lightly peeled polyester film (trade name “SP-PET-01-38BU” manufactured by Panac Co., Ltd.) were bonded together so that the peeled surface was in contact with the PET / adhesive layer / A sample of peeled PET was made.
[Various tests on adhesive layer]

<Adhesion test>
The lightly release-treated polyester films of the prepared adhesive layers of Examples 1 to 6 and Comparative Examples 1 to 7 were peeled and bonded to glass with a 2 kg roller. A 100 μm PET / adhesive layer (5 μm) / glass test piece was prepared. After leaving at 25 ° C. and 50% RH for 24 hours, the adhesive strength was measured by peeling in the 180 ° direction at a speed of 300 mm / min (N / 25 mm). The results are shown in Table 3.

<Haze value, transmittance>
100 μm PET / adhesive layer (5 μm) / glass test piece is prepared from the prepared adhesive layer in the same manner as the adhesive strength test, and the haze value is measured according to JIS K 5400 using a color haze meter manufactured by Murakami Color Research Laboratory. It was measured. The results are shown in Table 3. In addition, each haze value is a numerical value including the haze value of the polyester film which is a base material, and glass.

<Durability test>
In the moisture and heat resistance test, the test piece was left in a constant temperature and humidity chamber having a temperature of 85 ° C. and a humidity of 85% for 500 hours, and then the haze value and transmittance were measured by the same method as described above. The results are shown in Table 3. In addition, each haze value is a numerical value including the haze value of the glass which is a base material.
The durability was evaluated according to the following criteria.
○: No peeling, no adhesion layer misalignment, no bubbles and damage ×: Some peeling, adhesion layer misalignment, bubbles and damage

<Probe tack test>
The produced pressure-sensitive adhesive sample was peeled off from the lightly peeled polyester film, the contact speed was set to 1 cm / s, and a probe tack test was conducted. Take 3 measurements and take the average. The results are shown in Table 3.

<Removability evaluation test>
After the adhesive strength measurement test, visually check the adhesive residue on the glass surface. The results are shown in Table 3.
○: No adhesive residue on the glass surface Δ: A little adhesive residue on the glass surface ×: Residual adhesive residue on the entire glass surface

<Retention force evaluation test>
(Holding power)
In accordance with JISZ-1524, a PET / 5μm adhesive layer / peeled PET prepared was adhered to a stainless steel plate with a 2 kg roller so that the area of 25 mm × 25 mm was in contact, and 1 kg in the vertical direction at a temperature of 60 ° C. The load until the adhesive tape fell off was measured.

Claims (3)

A thermosetting pressure-sensitive adhesive composition comprising a main agent, a curing agent and an organic solvent,
The main agent is a polyurethane (A) having a terminal hydroxyl group obtained by reacting a hydrogenated polybutadiene polyol (a-1) and an aliphatic polyisocyanate (a-2), and the curing agent has a ring structure. It is a functional polyisocyanate (B), the total number of isocyanate groups of the polyfunctional polyisocyanate (B) relative to the total number of hydroxyl groups of the polyurethane (A) is 0.1 to 5.0 ,
The aliphatic polyisocyanate (а-2) is an aliphatic diisocyanate,
The polyfunctional polyisocyanate (B) includes diisocyanate nurate derived from diisocyanate having an aromatic ring or diisocyanate having an alicyclic structure, trimethylolpropane adduct, biuret type, prepolymer having an isocyanate residue (diisocyanate and polyol). A thermosetting pressure-sensitive adhesive composition, characterized in that it is a uretdione body having an isocyanate residue, an allophanate body, or a complex thereof. 2. The thermosetting pressure-sensitive adhesive composition according to claim 1, wherein the polyurethane (A) having a terminal hydroxyl group has a weight average molecular weight (polystyrene conversion value by gel permeation chromatography) of 30,000 to 110,000. An adhesive layer obtained by thermosetting the thermosetting pressure-sensitive adhesive composition according to claim 1 .