JP6388792B2 - Curable resin composition - Google Patents

Description

  The present invention relates to a curable resin composition having a low dielectric constant and capable of providing a cured product excellent in transparency in which white turbidity due to moisture absorption is suppressed even in a high temperature and high humidity environment, and in particular, a capacitive touch panel. Suitable for large-sized image display devices such as car navigation systems, personal computer displays, televisions, and electronic blackboards equipped with a mobile phone, and small-sized image display devices equipped with capacitive touch panels such as portable terminals such as smartphones, tablet terminals, and media players The present invention relates to a curable resin composition that can be used in the present invention, a cured product of the curable resin composition, and an image display device that includes the cured product of the curable resin composition.

  In optical displays such as liquid crystal display devices and organic EL display devices, heat and chemical resistance are required for attaching protective sheets to display screens, bonding various functional optical sheets, and filling gaps between optical equipment members. In general, a curable resin composition having electrical properties such as insulation, adhesion, and transparency is used.

  A curable resin composition using a (meth) acryloyl group-containing polymer having a polymerizable functional group such as an acryloyl group or a methacryloyl group (collectively referred to as “(meth) acryloyl group” when these are not particularly distinguished) is cured. The reaction can be precisely controlled, and a cured product having excellent electrical properties such as heat resistance, chemical resistance, insulation, adhesion, and transparency can be obtained. It is generally known as an adhesive or filler used.

  In recent years, an adhesive having excellent resistance to white turbidity under humidified conditions has been demanded so that the screen of an image display device does not become clouded even under high humidity.

  As a cloud point-resistant adhesive that can be used for an optical display or the like, for example, in JP 2012-504512 A (Patent Document 1), 1 to 25 parts with respect to 100 parts of alkyl acrylate and a copolymerizable polar monomer. Compositions comprising these hydrophilic polymers have been proposed. Here, examples of the hydrophilic polymer include a polyethylene oxide segment, a hydroxyl functional group, or a combination thereof (paragraph 0020).

  In recent years, portable terminals such as a tablet type in which a touch panel is mounted on an image display device such as a liquid crystal display have become widespread, and among them, a capacitive touch panel has been widely used due to its functionality. With the demand for higher sensitivity for such tablet-type portable terminals, members used for capacitive touch panels are required to be low dielectric constant materials that do not affect the sensitivity at the time of input. ing.

  However, as described in Patent Document 1, in order to improve the turbidity resistance under humidified conditions, generally, a hydrophilic monomer or hydrophilic polymer containing a large amount of polar groups such as hydroxyl groups is used. . It has been confirmed that adhesives and fillers using compounds containing a large amount of polar groups tend to have a high dielectric constant. For this reason, studies have been made on adhesives and fillers that have a low dielectric constant and excellent white turbidity resistance under humidified conditions for display devices equipped with a capacitive touch panel.

  As an adhesive having a low dielectric constant and white turbidity under humidification, Japanese Patent Application Laid-Open No. 2012-173354 (Patent Document 2) has a relative dielectric constant of 4 or less at a frequency of 100 kHz and an environment of 95% RH. An optical pressure-sensitive adhesive sheet that can provide a pressure-sensitive adhesive layer having a moisture content of 0.65% by mass or more after storage for 120 hours has been proposed. Such an optical pressure-sensitive adhesive sheet includes an alkyl acrylate ester having a linear or branched alkyl group having 6 to 10 carbon atoms, and an alkyl methacrylate ester having a linear or branched alkyl group having 1 to 10 carbon atoms. An acrylic polymer composed of one or more monomer components selected from the group consisting of a (meth) acrylic acid ester having an alicyclic hydrocarbon group and a nitrogen-containing monomer, wherein the proportion of the monomer components is 60% by mass or more. An acrylic pressure-sensitive adhesive layer is included (claim 3).

Special table 2012-504512 gazette JP 2012-173354 A

  The optical pressure-sensitive adhesive sheet proposed in Patent Document 2 is directed to a low dielectric constant. However, when the relative dielectric constant is 4.0 or less, a large image such as a television or personal computer display equipped with a capacitive touch panel is used. Adhesives and fillers used in small image display devices such as display devices, tablet terminals and smartphones are insufficient, and further reduction in dielectric constant is required.

  In addition, as an adhesive used in a display device such as a liquid crystal display device or an organic EL display device, at present, either an adhesive sheet of a type processed into a film or a sheet shape in advance or a fluid liquid type is used. . As a filler and adhesive used to improve the quality of images by laminating surface shaped sheets and films with uneven unevenness, or filling the gaps between optical members, liquid type with fluidity Is preferred. On the other hand, even if it is a liquid type adhesive agent and filler, it needs to have a certain amount of mechanical strength as a film or sheet which is a cured product.

  The present invention has been made in view of the circumstances as described above, and is a liquid adhesive that can be suitably used for adhesion between members of an image display device equipped with a capacitive touch panel, filling a gap, In addition, the present invention provides a curable resin composition that has a low dielectric constant and is suppressed in white turbidity under high humidity, is excellent in transparency, and can obtain a cured product having mechanical hardness comparable to a film type as a cured product. There is.

  As a result of various investigations on liquid polymers that can achieve a low dielectric constant, the present inventors have found that polymers having a small number of polar groups, particularly polybutene and / or polyisobutylene, are effective in reducing the dielectric constant of an adhesive. . On the other hand, when used in combination with a (meth) acryloyl group-containing polymer or (meth) acryloyl group-containing monomer that is excellent in curability in order to impart curability, (meth) acryloyl group-containing is used due to compatibility issues. It turned out that transparency falls with the kind and content of a compound. In particular, when used in combination with a (meth) acryloyl group-containing polymer or a (meth) acryloyl group-containing monomer into which a polar group such as a hydroxyl group is considered effective for preventing white turbidity under humidification, a colorless and transparent cured product is obtained. It was found that it was difficult to achieve both low dielectric constant and low dielectric constant.

  The present inventors have further studied and can provide a cured product having a low dielectric constant and a transparent cured product, and further capable of providing a cured product capable of achieving both white turbidity resistance and mechanical strength under humidified conditions. A curable resin composition was completed.

That is, the curable resin composition of the present invention comprises (A) 100 parts by mass of polybutene and / or polyisobutylene having a number average molecular weight of 300 to 1500; (B) hydrogenated polybutadiene, hydrogenated polyisoprene, and polyisoprene. Α, β-unsaturated multimeric conjugated diene polymers in which conjugated diene polymer units selected from the group consisting of them are linked via a urethane bond-containing group and the terminal is α, β-unsaturated carbonyl-modified. 5 to 50 parts by mass of an α, β-unsaturated carbonyl modified product which is a saturated carbonyl modified product and has a number average molecular weight of 3000 to 50000 of the α, β-unsaturated carbonyl modified product ; (C) (meth) acrylic acid 10 to 80 parts by mass of an alkyl and / or cycloalkyl ester having 6 to 20 carbon atoms; and (D) a primary average particle diameter of 50 nm or less Containing 0.5 to 15 parts by mass of fumed silica.

Before SL alpha, beta-unsaturated carbonyl modified body, alpha through the multimeric forms conjugated diene polymer urethane group or ester bond-containing group, it is preferred that beta-unsaturated carbonyl group is linked.

  (A) The pour point of polybutene and / or polyisobutylene is preferably 0 ° C. or lower.

  The (B) α, β-unsaturated carbonyl modified product is obtained by subjecting the (A) polybutene and / or polyisobutylene to the α, β-unsaturated carbonyl modification reaction. It is preferable.

  The (C) (meth) acrylate compound is preferably a monofunctional (meth) acrylate having a cyclic structure. The fumed silica having a primary average particle diameter of 50 nm or less (D) is preferably hydrophilic fumed silica.

  The curable resin composition of the present invention may further contain (E) a photopolymerization initiator and / or (F) an adhesion improver.

  It is preferable that the relative dielectric constant of the cured product obtained by curing the curable resin composition is less than 3.0.

  The present invention also includes a cured product obtained by curing the curable resin composition of the present invention as described above by energy ray irradiation, and an image display device having the cured product.

  The curable resin composition of the present invention has a suitable mechanical strength, can obtain a cured product satisfying both requirements of low dielectric constant and suppression of white turbidity under high humidity conditions, and at room temperature. It is liquid and can be filled even on an uneven adherend without gaps.

  The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and is not limited to these contents.

<Energy beam curable resin composition>
The curable resin composition of the present invention comprises (A) 100 parts by mass of polybutene and / or polyisobutylene having a number average molecular weight of 300 to 1500;
(B) α, β of a multimeric (hydrogenated) conjugated diene polymer having a plurality of one or more units selected from the group consisting of hydrogenated polybutadiene units, hydrogenated polyisoprene units, and polyisoprene units -5-50 mass parts of unsaturated carbonyl modified body;
(C) 10 to 80 parts by mass of an alkyl or cycloalkyl ester having 6 to 20 carbon atoms of (meth) acrylic acid; and (D) a fumed silica having a primary average particle diameter of 50 nm or less (Fumed silica) 0.5 to Contains 15 parts by weight.
Hereinafter, each component will be described.

(A) Polybutene and / or polyisobutylene Polybutene is obtained by copolymerizing 1-butene and 2-butene mainly with isobutylene, and polyisobutylene is a homopolymer of isobutylene. These are commercially available in molecular weights ranging from liquid to solid at room temperature depending on molecular weight, but polybutene and polyisobutylene used in the present invention are low molecular weight types having a number average molecular weight of 300 to 1500.

  If the number average molecular weight is less than 300, it may separate from the cured product over time after curing and cause bleed-out. If the number average molecular weight exceeds 1500, the fluidity of the composition will decrease, so When workability is lowered and it is used as a filler, voids are easily generated, which is not preferable. On the other hand, since polybutene and polyisobutylene having a number average molecular weight of 300 to 1500 are liquid at normal temperature, it is possible to provide a liquid composition without diluting the composition with a solvent or the like. Moreover, since it is liquid at normal temperature, it can be used as a solvent when the component (B) is synthesized. The product synthesized in the presence of the component (A) solvent can be used as it is as the component (B) without performing an isolation operation.

  The polybutene and / or polyisobutylene having the above molecular weight range is liquid at room temperature, but preferably has a pour point of 0 ° C. or lower.

  As such polybutene, commercially available products can also be used, for example, Jiss Nippon Polybutene LV-7, Nisseki Polybutene LV-10, Nisseki Polybutene LV-25, Nisseki Polybutene LV manufactured by JX Nippon Oil & Energy Corporation. -50, Nisseki Polybutene LV-100, Nisseki Polybutene HV-15, Nisseki Polybutene HV-35, Nisseki Polybutene HV-50, Nisseki Polybutene HV-100, Nisseki Polybutene HV-300; Indopol made by ENEOS L-8, Indopol L-14, Indopol H-7, Indopol H-15, Indopol H-25, Indopol H-25, Indopol H-50, Indopol H-100, Indopol H-300 and the like. Examples of commercially available products of polyisobutylene include TPC595 and TPC1105 manufactured by Texas Petrochemicals; Glissopal 1000, Glissopal 1300, Glissopal V190, Glissopal V500, and Glissopal V640 manufactured by BASF.

  Polybutene and polyisobutylene do not have a polar group in the molecular chain, and contribute to lowering the dielectric constant of the composition and cured product. Polybutene and polyisobutylene may be used alone or in combination. The content of the polybutene and / or polyisobutylene in the composition is preferably 30% by mass or more, more preferably 40% by mass or more, based on the total amount of the polybutene and polyisobutylene.

(B) α, β of a multimeric (hydrogenated) conjugated diene polymer having a plurality of one or more units selected from the group consisting of hydrogenated polybutadiene units, hydrogenated polyisoprene units, and polyisoprene units -Unsaturated carbonyl modification

  Component B is a component that imparts curability to the composition, is excellent in compatibility with polybutene and / or polyisobutylene that is component A, and can impart curability and adhesion without impairing transparency. it can.

  Here, the multimeric (hydrogenated) conjugated diene polymer is distinguished from a hydrogenated polybutadiene unit, a polyisoprene unit, and a hydrogenated polyisoprene unit (hereinafter referred to as a hydrogenated polybutadiene unit, a polyisoprene unit, and a hydrogenated polyisoprene unit). When not, it contains one or more units selected from the group consisting of “(hydrogenated) conjugated diene polymer unit” or simply “diene polymer unit”).

  The multimeric (hydrogenated) conjugated diene polymer is obtained by reacting (b-1) (hydrogenated) conjugated diene polymer polyol with (b-2) a linking compound having a functional group that reacts with a hydroxyl group. Can be obtained. (B-1) (hydrogenated) conjugated diene polymer polyol is hydrogenated polybutadiene polyol, polyisoprene polyol, hydrogenated polyisoprene polyol (hereinafter referred to as “(hydrogenated) conjugated diene polymer polyol unless they are distinguished from each other). 1 or 2 or more types selected from the group consisting of:

  The terminal of the multimeric (hydrogenated) conjugated diene polymer is (b-1) (hydrogenated) conjugated diene polymer polyol used as a raw material and (b-2) a linking compound having a functional group L that reacts with a hydroxyl group. Depending on the molar equivalent ratio. When the amount of the hydroxyl group of the diene polymer polyol (b-1) is larger than the amount of the functional group in the linking compound (b-2), it becomes a hydroxyl group, and when it is less, it becomes the functional group L in the linking compound. .

The α, β-unsaturated carbonyl-modified product of the multimeric (hydrogenated) conjugated diene polymer that is the component B comprises (b-3) a multimeric (hydrogenated) conjugated diene polymer, and (b-4) a multimeric type. (Hydrogenated) It is obtained by reacting an α, β-unsaturated carbonyl compound having a functional group that reacts with a terminal functional group (hydroxyl group or functional group L) of a conjugated diene polymer.
Hereinafter, each component and reaction will be described in detail.

(B-1) (hydrogenated) conjugated diene polymer polyol (hydrogenated) conjugated diene polymer polyol is (hydrogenated) conjugated diene polymer unit hydrogenated polybutadiene, polyisoprene or hydrogenated polyisoprene, and A polymer polyol having two or more hydroxyl groups.

  The hydroxyl group may be present at either the side chain or the terminal, but is preferably a (hydrogenated) conjugated diene polymer polyol of a terminal hydroxyl group-containing type at the main chain terminal. The hydroxyl group may be directly bonded to hydrogenated polybutadiene, polyisoprene or hydrogenated polyisoprene main chain, or may be bonded via an intervening group.

  Hydrogenated polybutadiene is obtained by hydrogenating polybutadiene synthesized by 1,2-addition polymerization and / or 1,4-addition polymerization of butadiene. The hydrogenation may be a partial hydrogenation product as long as the compatibility with the component A and the transparency of the cured product are not impaired. In addition, Formula (1) has shown the hydrogenated polybutadiene (completely hydrogenated product) mentioned as an example. (1) In the formula, p and q are each an integer of 0 to 100, and p + q = an integer of 10 to 150.

  Polyisoprene is obtained by addition polymerization of isoprene, and may be any of 1,4-addition polymer, 1,2-addition polymer, and 3,4-addition polymer. In the case of 1,4-addition polymer, It may be a cis isomer or a trans isomer. Polyisoprene may or may not be hydrogenated. When hydrogenated, polyisoprene may be either fully hydrogenated or partially hydrogenated.

(B-2) Linking Compound Having Functional Group L Reacting with Hydroxyl Linking Compound (b-2) is a functional group L capable of reacting with the hydroxyl group of (hydrogenated) conjugated diene polymer polyol (b-1). Examples of the compound having two or more include a bifunctional compound represented by the following formula (2a), a trifunctional compound represented by (2b), and a tetrafunctional compound represented by (2c). Preferably it is a bifunctional compound. In the formulas (2a), (2b), and (2c), L is a functional group that reacts with a hydroxyl group, and M, M ′, and M ″ are organic groups.

  Specific examples of the functional group L include (i) an isocyanate group, (ii) a carboxyl group (including a halogenated carbonyl group and an ester), and (iii) an epoxy group. The organic groups M, M ′, and M ″ may be any of aliphatic, aromatic, and alicyclic groups having the above functional groups and 2, 3, and 4 free bonds, From the viewpoint of reactivity and compatibility with the component (b-1), an aliphatic or alicyclic group having 2 to 18 carbon atoms, preferably 3 to 15 carbon atoms, particularly preferably 8 to 12 carbon atoms is preferable.

(I) Isocyanate group-containing linking compound The isocyanate group-containing linking compound is an aliphatic or aromatic polyisocyanate having 2 or more, preferably 2 to 4, isocyanate groups, and preferably a diisocyanate.

Examples of the diisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate (1,6-diisocyanatohexane), octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate; lysine diisocyanate, tetramethylxylylene diisocyanate, Aliphatic diisocyanates such as trimethylhexane diisocyanate or tetramethylhexane diisocyanate derivatives; 1,4-, 1,3- or 1,2-diisocyanatocyclohexane, 4,4′- or 2,4′-di (isocyanato) Cyclohexyl) methane, 1-isocyanato-3,3,5-trimethyl-5- (isocyanatomethyl) cyclohexane (isophorone diisocyanate) ), 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane, or 2,4- or 2,6-diisocyanato-1-methylcyclohexane, etc .; 2,4- or 2,6 -Tolylene diisocyanate, m- or p-xylylene diisocyanate, 2,4'- or 4,4'-diisocyanatodiphenylmethane, 1,3- or 1,4-phenylene diisocyanate, 1-chloro-2,4- Phenylene diisocyanate, 1,5-naphthylene diisocyanate, diphenylene 4,4′-diisocyanate, 4,4′-diisocyanato-3,3′-dimethylbiphenyl, 3-methyldiphenylmethane 4,4′-diisocyanate or diphenyl ether 4,4 ′ -Aromatic diisocyanates such as diisocyanates.
Triisocyanates such as tris (phenyl isocyanate) thiophosphate and tetraisocyanates such as 1,3,5,7-adamantanetetrayltetraisocyanate may be used.

  The isocyanate group-containing linking compound as described above reacts with the hydroxyl group of the diene polymer polyol (b-1) to form a urethane bond. Therefore, the polyol is dimerized, trimerized, or tetramerized according to the number of functional group equivalents, with the urethane bond as the linking moiety.

  The reaction between the isocyanate group-containing linking compound and the diene polymer polyol (b-1) is carried out under conditions that do not cause gelation. Usually, conditions that do not cause gelation can be appropriately selected depending on the type of reaction catalyst, adjustment of the ratio of charged amount of polyol and linking compound, adjustment of reaction temperature, charging rate (dropping rate), and the like.

(Ii) Carboxyl group-containing linking compound Examples of linking compounds having two or more carboxyl groups include dicarboxylic acids, tricarboxylic acids, polycarboxylic acids, or anhydrides or esters thereof; pyridine 2,6-dicarboxylic acid dichloride, etc. Halogenated carbonyl group-containing linking compounds can be used, such as saturated aliphatic carboxylic acids, unsaturated carboxylic acids, substituted carboxylic acids in which hydrogen atoms other than carboxyl groups are substituted with halogens, hydroxyl groups, carbonyl groups, etc. A saturated carboxylic acid having 2 to 18, preferably 3 to 15, more preferably 8 to 12 carbon atoms, such as an aromatic carboxylic acid. Of these, dicarboxylic acid or an ester thereof is preferable.

  Specifically, examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, citric acid, and propanetricarboxylic acid. These anhydrides, or alkyl esters having 1 to 20 carbon atoms thereof; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, maleic anhydride, citraconic acid, and mesaconic acid; aromatic dicarboxylic acids such as phthalic acid, etc. It is done.

  The carboxyl group-containing linking compound as described above reacts with the hydroxyl group of the polyol (b-1) to form an ester bond. Therefore, dimerization, trimerization, or tetramerization of a polyol multimer can be obtained with an ester bond as a linking moiety, depending on the number of functional group equivalents.

  The reaction between the carboxyl group-containing linking compound and the polyol (b-1) is carried out under conditions that do not cause gelation due to rapid multimerization.

(Iii) Epoxy group-containing linking compound The epoxy group-containing linking compound has two or more three-membered ring structures (epoxy group, oxirane group, glycidyl group, etc.) composed of carbon and oxygen atoms as functional groups that react with hydroxyl groups. An epoxy resin obtained by reacting, for example, bisphenol A, bisphenol F or a hydrogenated product thereof with epichlorohydrin, having 2 to 18 carbon atoms, preferably 3 to 15 carbon atoms, more preferably 8 to Twelve epoxy resins are preferably used. Specifically, bisphenol A diglycidyl ether, diglycidyl ether, or the like can be used.

  Such an epoxy group-containing linking compound reacts with the hydroxyl group of the diene polymer polyol (b-1) to open an epoxy ring and form an ether bond.

  The reaction between the epoxy group-containing linking compound and the (hydrogenated) conjugated diene polymer polyol (b-1) is carried out under conditions that do not cause gelation due to rapid multimerization.

(B-3) Multimer of (hydrogenated) conjugated diene polymer polyol (multimer type (hydrogenated) conjugated diene polymer)
(B-1) (hydrogenated) conjugated diene polymer polyol and (b-2) (hydrogenated) conjugated diene polymer polyol in a multimer by reaction with a linking compound having a functional group L that reacts with a hydroxyl group. Turn into. A multimer of (hydrogenated) conjugated diene polymer polyol is referred to as “multimeric (hydrogenated) conjugated diene polymer” or simply “multimeric diene polymer”.
Hereinafter, the multimerization reaction and the resulting multimeric diene polymer will be described with a focus on the case of using a typical bifunctional type (LML) as the linking compound.

  (Hydrogenation) Multimerization of a conjugated diene polymer polyol is performed using a bond formed by a reaction between a hydroxyl group of the polyol and a functional group L of a linking compound as a linking portion. Therefore, when an isocyanate group-containing linking compound is used as the linking compound, the linking part is an organic group containing a urethane bond, and when a carboxyl group-containing linking compound is used as the linking compound, the linking part is When an epoxy group-containing linking compound is used as the linking compound, the linking part is an organic group containing an ether bond.

When one kind of (hydrogenated) conjugated diene polymer polyol is used in the multimerization reaction, the equivalent of the diene polymer polyol (b-1) and the linking compound (b-2) used in the synthesis reaction Depending on the ratio, as shown in the following formula (3a) or (3b), a multimeric diene polymer in which a plurality of (hydrogenated) conjugated diene polymer units are connected by a connecting portion is obtained. In the formula, n ₁ and n ₂ are each independently an integer of 1 to 20.

  Formula (3a) shows the case where the diene polymer polyol is excessive (the terminal functional group is —OH derived from the polymer polyol), and Formula (3b) is the case where the coupling compound is excessive (the terminal functional group is the coupling compound). Is derived from L).

  When two or three (hydrogenated) conjugated diene polymer polyols are subjected to a multimerization reaction, for example, when two diene polymer polyols are used and the diene polymer polyol is excessive, the following formula (4 ), A multimeric diene polymer having 1 unit of (hydrogenated) conjugated diene polymer and 2 units of (hydrogenated) conjugated diene polymer is obtained. When different types of (hydrogenated) conjugated diene-based polymer units are contained, the content ratio (l: m) of each polymer unit is adjusted by the charge ratio at the time of the synthesis reaction. The mode of connection may be a random type connected at random, or a block type in which blocks connected by the same kind of (hydrogenated) conjugated diene polymer units are connected.

  In the formulas (3a), (3b), and (4), Z is a bond generated as a result of the reaction between the functional group L of the linking compound used and the hydroxyl group, and is a urethane bond, an ester bond, or an ether bond. A urethane bond and an ester bond are preferable, and a urethane bond is more preferable.

  When a trifunctional linking compound is used as the linking compound (b-2), or when a polyol having three or more hydroxyl groups is used as the diene polymer polyol (b-1), the following formula Multimerization occurs three-dimensionally as in (5a) and (5b).

  The terminal of the multimeric diene polymer depends on the equivalent ratio of the polymer polyol (b-1) and the linking compound (b-2) subjected to the synthesis reaction. The formulas (4) and (5) show that (b) the diene polymer polyol has an excess of hydroxyl group equivalent, and the resulting multimeric diene polymer terminal is a hydroxyl group. When the functional group L is excessive, the terminal of the resulting multimeric diene polymer is the functional group L.

(B-4) α, β unsaturated carbonyl compound ((meth) acryloylating agent)
The α, β-unsaturated carbonyl compound (b-4) used to modify the multimeric (hydrogenated) conjugated diene polymer (b-3) by α, β-unsaturated carbonyl has a general formula of the following formula (6) An α, β unsaturated carbonyl compound represented by the formula: (6) In the formula, Q is a functional group that reacts with the terminal functional group (hydroxyl group or functional group L of the linking compound) of the multimeric diene polymer (b-3), or an atomic group having the functional group, or halogen. It is.

(A) When the terminal functional group is a hydroxyl group Examples of the functional group that reacts with a hydroxyl group include an isocyanate group, a carboxyl group (including a halogenated carbonyl group and an ester), and an epoxy group.
Accordingly, the α, β unsaturated carbonyl compound (b-4) having a functional group that reacts with a hydroxyl group includes an isocyanato group-containing unsaturated carbonyl compound represented by the general formula (7a); a carboxyl represented by the general formula (7b). Group-containing unsaturated carbonyl compound; epoxy group-containing unsaturated carbonyl compound represented by formula (7c); Q is —OH or —OR (where R is a linear or branched alkyl group having 1 to 20 carbon atoms or aryl) A carboxylic acid or a carboxylic acid ester which is a group; and a carboxylic acid halide in which Q is a halogen.

In the general formulas (6), (7a)-(7c), R ¹ and R ² are each hydrogen or a linear or branched alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, etc. R ¹ and R ² may be the same or different.

  (7a)-(7c) In the formula, X is an intervening group, and is a linear or branched alkylene group having 1 to 6 carbon atoms such as methylene, ethylene, propylene, trimethylene, tetramethylene, preferably methylene, Ethylene.

  Examples of the isocyanato group-containing unsaturated carbonyl compound represented by the formula (7a) include 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, 1,1-bis (acryloyloxymethyl) ethyl isocyanate, and the like. It is done.

  As the carboxyl group-containing unsaturated carbonyl compound represented by the formula (7b), (meth) acryloyloxycarboxylic acid such as 2-acryloyloxyethyl succinic acid can be used.

  As the epoxy group-containing unsaturated carbonyl compound represented by (7c), (meth) acrylic acid glycidyl ester and the like can be used.

  Examples of the carboxylic acid or carboxylic acid ester in which Q is —OH or —OR (R is a linear or branched alkyl group having 1 to 20 carbon atoms) include carboxylic acid compounds such as (meth) acrylic acid; ) Methyl acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert (meth) acrylate -Butyl, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, (meth) acryl 2-ethylhexyl acid, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, (meth Phenyl acrylate, (meth) toluyl acrylate, or the like can be used (meth) benzyl acrylate.

  In the case where Q is halogen, unsaturated acid halides such as chloro (meth) acrylic acid and bromated (meth) acrylic acid can be used.

(B) When the terminal functional group is a functional group L derived from a linking compound The α, β unsaturated carbonyl compound (b-4) having a functional group that reacts with the functional group L is represented by the following general formula (8a). The unsaturated carboxylic acid represented or the unsaturated carboxylic acid hydroxy ester represented by the general formula (8b) is applicable. (8b) In the formula, R (OH) is a hydroxylalkyl group in which one of straight-chain or branched alkyl hydrogen atoms having 1 to 6 carbon atoms is substituted with a hydroxyl group.

  Therefore, when Q is —OH, examples of the α, β-unsaturated compound represented by the formula (8a) include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, tiglic acid, and angelic acid. Of these, acrylic acid and methacrylic acid are preferably used.

  In the case of an α, β-unsaturated carbonyl compound in which Q is an atomic group containing R (OH) as represented by the formula (8b), 2-hydroxyethyl (meth) acrylate, (meth) acrylic And unsaturated carboxylic acid hydroxy esters such as acid 2-hydroxypropyl.

The α, β-unsaturated carbonyl compound having the above-described configuration is preferably an acryloyl group or methacryloyl group in which R ¹ is hydrogen or methyl group and R ² is hydrogen in the α, β unsaturated carbonyl group. Hereinafter, when the α, β-unsaturated carbonyl group is a (meth) acryloyl group, a case where a “(meth) acryloylating agent” is used will be described as a representative.

[Synthesis of α, β-unsaturated carbonyl modified product of multimeric diene polymer: reaction of multimeric diene polymer (b-3) with unsaturated carbonyl compound (b-4)]
The above-mentioned multimeric diene polymer (b-3) is reacted with the above-mentioned α, β unsaturated carbonyl compound ((meth) acryloylating agent) (b-4) to produce α, β of the multimeric diene polymer. -Synthesize unsaturated carbonyl modifications.

  The terminal functional group (hydroxyl group or functional group L derived from the linking compound) of the multimeric diene polymer (b-3) reacts with the functional group in the (meth) acryloylating agent (b-4). , A bond is formed, and the end of the multimeric diene polymer (b-3) is capped with a (meth) acryloyl group, as represented by the following general formula (9).

  (9) In the formula, Y is the result of the reaction of the terminal functional group (—OH or L) of the multimeric diene polymer (b-3) with the functional group of the α, β unsaturated carbonyl compound (b-4). , A linking bond-containing group to be produced, which is a urethane bond, an ester bond, an ether bond, or an organic group containing these bonds, depending on the type of compound and functional group used.

  Among the α, β-unsaturated carbonyl modification reactions as described above, a multimeric diene polymer (b-3) preferably having a terminal functional group as a hydroxyl group and a (meth) acryloylating agent represented by the formula (7a) This is a reaction using an isocyanate-containing (meth) acrylate, and an α, β-unsaturated carbonyl modified product represented by the following formula (10) is obtained.

  When the multimeric diene polymer used includes a plurality of types of diene polymer units, the multimeric diene polymer segment contains a plurality of types of diene polymer units.

  (Hydrogenated) The reaction for introducing an α, β-unsaturated carbonyl group into a conjugated diene polymer (α, β-unsaturated carbonyl modification reaction) is usually performed in the presence of a solvent. In the composition of the present invention, the A component (polybutene, polyisobutylene) can be used as a reaction solvent since the polybutene and polyisobutylene as the A component are liquid at room temperature. The product obtained by the synthesis can be used as a mixture of the component (A) and the component (B) without an operation such as solvent removal. This has an advantage that not only simplification of the process of solvent removal operation but also contamination of impurities such as residual solvent derived from component B can be avoided in the composition. Since the residual solvent can cause voids in the cured product, avoiding the use of the B component in which the solvent other than the essential components of the composition remains, in turn, makes the adhesive layer transparent and improves image quality. The effect can be expected.

  The number average molecular weight and viscosity of the unsaturated carbonyl-modified product (B) of the resulting multimeric (hydrogenated) conjugated diene polymer (B) vary depending on the type of conjugated diene as a repeating unit, the presence or absence of multimerization, etc. The molecular weight and viscosity are increased by formation, and the molecular weight and viscosity are further increased as the number of conjugated diene polymer segments is increased.

  The number average molecular weight (Mn) of the component B depends on the kind of (hydrogenated) conjugated diene contained and the number of (hydrogenated) conjugated diene polymer units contained, but it is 3000 to 50000, preferably 4000 to 40000. More preferably, it is a high molecular weight compound of 5000-30000, and more preferably 5000-20000. The viscosity at 25 ° C. is 5 to 2000 Pa · s, preferably 8 to 1500 Pa · s, although it varies depending on the type of (hydrogenated) conjugated diene polymer unit to be a linking unit, reaction conditions, and the like.

  In addition, the number average molecular weight as used in this specification is the value measured using the gel permeation chromatography (solvent: tetrahydrofuran). The viscosity can be measured using a B-type viscometer (model “RB80L” manufactured by Toki Sangyo Co., Ltd.) under a temperature of 25 ° C.

  The α, β-unsaturated carbonyl modified product of the multimeric (hydrogenated) conjugated diene polymer used as the component (B) in the present invention includes two or more α, β-unsaturated carbonyls per polymer molecular chain. Α, β-unsaturated carbonyl-modified (hydrogenated) conjugated diene polymer having a group, and α, β-unsaturated carbonyl-modified (water) having only one α, β-unsaturated carbonyl group per polymer chain A) A mixture with a conjugated diene polymer may be used. The α, β-unsaturated carbonyl-modified (hydrogenated) conjugated diene polymer as a whole preferably has an average of 1.5 or more α, β-unsaturated carbonyl groups per polymer molecular chain.

  The α, β-unsaturated carbonyl modified product of the multimeric (hydrogenated) conjugated diene polymer as described above is excellent in compatibility with the A component, and can be used in the composition without impairing the effect of reducing the dielectric constant by the A component. Curability can be imparted. In addition, the multimeric α, β-unsaturated carbonyl-modified (hydrogenated) conjugated diene polymer is a single type (hydrogenated) conjugated diene polymer in which only one (hydrogenated) conjugated diene polymer unit is contained. Compared with the α, β-unsaturated carbonyl modified product, mechanical strength such as elongation at break tends to be excellent.

  The above B component is mix | blended in the ratio of 5-50 mass parts with respect to 100 mass parts of A component. If it is less than 5 parts by mass, polybutene and polyisobutylene are easily separated over time or at high temperatures. On the other hand, if it exceeds 50 parts by mass, the ratio of the A component in the cured product is relatively lowered, so that the reduction of the dielectric constant is insufficient. Moreover, since the viscosity of the whole composition rises excessively, it exists in the tendency for workability | operativity to be inferior. The compounding quantity of B component becomes like this. Preferably it is 10-45 mass parts, More preferably, it is 20-40 mass parts.

(C) Alkyl or cycloalkyl ester of 6 to 20 carbon atoms of (meth) acrylic acid Alkyl or cycloalkyl ester of 6 to 20 carbon atoms of (meth) acrylic acid is a multimeric (hydrogenated) conjugated diene system. It is used as a polymerizable compound capable of co-curing with the α, β-unsaturated carbonyl modified product (B) of the polymer.

  A (meth) acrylate compound having less than 6 carbon atoms has a high dielectric constant, and a (meth) acrylate compound having more than 20 carbon atoms has a high viscosity of the curable resin composition, which is not preferable. . Of these, a cycloalkyl ester of (meth) acrylic acid is particularly preferable because the dielectric constant can be kept low.

  As a C6-C20 alkyl or cycloalkyl ester of (meth) acrylic acid, for example, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, tridecyl ( C6-C20 alkyl group-containing (meth) acrylates such as meth) acrylate; cyclohexyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, norbornanyl (meth) acrylate, dicyclopentenyl (meth) ) Acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate Such cycloalkyl group-containing (meth) acrylate are preferably used.

  (C) The compounding ratio of the alkyl or cycloalkyl ester having 6 to 20 carbon atoms of (meth) acrylic acid is 10 to 80 parts by mass with respect to 100 parts by mass of (A) polybutene or polyisobutylene. If it is 10 parts by mass or less, the viscosity of the composition becomes high, and if it is 80 parts by mass or more, the dielectric constant of the cured adhesive becomes high. More preferably, it is 10-75 mass parts, More preferably, it is 15-50 mass parts.

In the curable resin composition of the present invention, the polymerizable compound that can be co-cured with the component B is an alkyl having 6 to 20 carbon atoms of (meth) acrylic acid as long as it does not inhibit the effects of the present invention. Alternatively, a polymerizable compound other than the cycloalkyl ester may be used in combination.
Examples of other polymerizable compounds that can be used in combination include (meth) acrylates having less than 6 carbon atoms described in paragraph 0095 of JP2013-014718; methyl-2-allyloxymethyl acrylate, 2-hydroxylpropyl acrylate, and the like. (Meth) acrylates having a substituent other than the alkyl group or cycloalkyl group; vinyl monomers described in paragraph 0096 of JP2013-014718A, and the like.
However, it is preferable that an unsaturated compound containing a hydroxyl group (for example, hydroxyl acrylate) or the like generally used for the purpose of imparting hydrophilicity to the cured product is not included from the viewpoint of dielectric constant.

(D) Fumed silica The fumed silica used in the present invention is a compound containing silicon oxide as a main component and preferably has a primary average particle diameter of 50 nm or less. Fumed silica has a silanol group on the particle surface, a hydrophobic type in which a part of the silanol group is modified with an organic group, and a hydrophilic type in which the silanol group remains unmodified. Any type can be used, but it can effectively suppress the white turbidity of the adhesive particularly under high humidity, and it can effectively suppress the temporal separation of polybutene and polyisobutylene from the cured product even at high temperatures. A hydrophilic type is preferably used.

  Moreover, it is preferable that the primary average particle diameter of fumed silica is 50 nm or less, More preferably, it is 20 nm. If it exceeds 50 nm, the transparency of the cured product tends to decrease. In addition, the primary average particle diameter of fumed silica can be observed, for example with an electron microscope (5 to 200,000 times), and can be measured using an image analyzer.

  Commercially available products can be used as such fumed silica. For example, as the hydrophilic type, AEROSIL 90, AEROSIL 130, AEROSIL 150, AEROSIL 200, AEROSIL 255, AEROSIL 300, AEROSIL 300, AEROSIL 380 manufactured by Evonik Industries, Inc .; CABOT CAB-O-SIL LM-150, CAB-O-SIL M5, CAB-O-SIL H5, CAB-O-SIL EH5; WACKER HDK S13, WACKER HDK V15, WACKER HDK N20, WACKER from WACKER HDK T30, WACKER HDK T40, etc. can be used. In addition, as hydrophobic types, AEROSIL R972, AEROSIL R974, AEROSIL R104, AEROSIL R106, AEROSIL R202, AEROSIL R805, AEROSIL R812, AEROSIL R816 manufactured by Evonik Industries, CAB-O-SIL TS-720 manufactured by CABOT, Use CAB-O-SIL TS-710, CAB-O-SIL TS-610, CAB-O-SIL TS-530; WACKER HDK H15, WACKER HDK H18, WACKER HDK H20, WACKER HDK H30, etc. Can do.

  The fumed silica as described above has a role of suppressing white turbidity of the cured product under humidified conditions. Although the mechanism that can suppress white turbidity under high humidity by blending fumed silica is unclear, it seems to be because water droplets can be prevented from being produced in the cured product. In addition, the formation of a network by silanol groups is considered to be useful for maintaining the shape of the cured product at a high temperature. Together with the above components (A), (B), and (C), by adding the characteristics of fumed silica, it is difficult to achieve low dielectric constant and white turbidity prevention, which is difficult with polar group-containing polymers or polar group-containing compounds. It becomes possible to plan.

  The blending ratio of such fumed silica is 0.5 to 15 parts by mass with respect to 100 parts by mass of the total amount of (A) polybutene and polyisobutylene. If it is 0.5 parts by mass or less, the white turbidity of the cured product at the time of humidification becomes insufficient, and it becomes easy to separate from polybutene and polyisobutylene over time at the time of curing and at a high temperature. On the other hand, when blending 15 parts by mass or more, the dielectric constant of the cured product is increased, which is not preferable. From the point which makes low dielectric constant of hardened | cured material and the white turbidity suppression at the time of moisture absorption compatible, Preferably it is 1-12 mass parts, More preferably, it is 1.5-10 mass parts.

(E) Photopolymerization initiator The curable resin composition of the present invention may further contain (E) a photopolymerization initiator in addition to the components (A), (B), (C), and (D). preferable. Thereby, it becomes possible to harden a composition by energy ray irradiation for a short time.

  As the photopolymerization initiator, a photopolymerization initiator conventionally used in the field of energy beam curable resin compositions can be used. Examples include photopolymerization initiators described in paragraphs 0089 and 0090 of JP2013-014718A. Among them, acetophenones, oxy-phenyl-acetic acid 2- [2-oxo-2-phenyl-acetoxy- Ethoxy] ethyl ester, oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy] ethyl ester, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl- Diphenyl-phosphine oxide and the like are preferable.

  As content of the photoinitiator in an adhesive resin composition, although it changes with uses, it is suitable that it is 0.1-10 mass% normally with respect to 100 mass% of the said resin compositions. When the content is 0.1% by mass or more, the resin composition can be sufficiently cured, and when the content is 10% by mass or less, generation of odor and coloring of the cured product can be sufficiently suppressed. More preferably, it is 0.3-5 mass%, More preferably, it is 0.3-3 mass%.

(F) Adhesion improver The curable resin composition of the present invention preferably further contains an adhesion improver in addition to the above components. The tackifier can improve the elastic modulus of the cured body and increase the adhesive strength. Examples of the adhesion improver include, for example, phenol resins, modified phenol resins, cyclopentadiene-phenol resins, xylene resins, chroman resins, petroleum resins, terpene resins, terpene phenol resins, rosin ester resins, and hydrogenated products of the above resins. Can be given.

  The content of the adhesion improver in the resin composition varies depending on the use, but it is usually preferably 5 to 50% by mass with respect to 100% by mass of the resin composition. When it is 5% by mass or more, an appropriate elastic modulus is given, and when it is 50% by mass or less, an increase in viscosity, an excessive elastic modulus, and an increase in hardness can be suppressed. More preferably, it is 10-40 mass%, More preferably, it is 15-30 mass%.

(G) Other components In addition to the above components, the curable resin composition of the present invention, if necessary, within the range that does not inhibit the effects of the present invention, particularly the dielectric constant reduction effect, (A) polybutene and It may also contain non-reactive resins other than polyisobutylene, (B) an α, β-unsaturated carbonyl modified product of a multimeric (hydrogenated) conjugated diene polymer, and (F) an adhesion improver.

  Other non-reactive resins that can be used in the present invention include monomeric α, β-unsaturated carbonyl-modified (hydrogenated) conjugated diene polymers; polyethylene glycol, polypropylene glycol, ethylene oxide and propylene oxide copolymers, etc. Polyether polyols; Polyolefin resins such as polyethylene, polypropylene, and polystyrene; (meth) acrylic polymers that do not have polymerizable functional groups or double bonds in the side chains such as polymethyl methacrylate and polyacrylic acid; polyethylene terephthalate, etc. Polyester resins; polyamide resins such as nylon 6 and 6; conjugated diene polymers other than hydrogenated or non-hydrogenated polyisoprene and hydrogenated polybutadiene; thermoplastic elastomers and the like.

  Moreover, you may contain a plasticizer other than the said component as needed. The plasticizer is a conventionally known plasticizer, for example, a compound having no (meth) acryloyl group, and examples thereof include the plasticizers described in paragraphs 0091 and 0092 of JP2013-014718A.

  Furthermore, as long as the effects of the present invention are not impaired as required, thermosetting catalyst, ultraviolet absorber, chain transfer stabilizer, light stabilizer, polymerization inhibitor, antioxidant, leveling agent, thickener, You may include a viscosity reducing agent, a thixotropy imparting agent, a defoaming agent, a coloring agent, etc.

  For example, each compound described in paragraphs 0078 to 0082 of JP2012-162705A can be used.

  Examples of the antioxidant include hindered phenol AO-10, AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, AO-80 (manufactured by Adeka), Antage W-300, W-400, W-500 (manufactured by Kawaguchi Chemical Co., Ltd.) and Tinuvin 765 (manufactured by BASF Corp.), which are light stabilizers, are mentioned. Preferably used.

  The other components as described above are appropriately selected depending on the use of the resin composition, but are usually preferably 0 to 40% by mass, more preferably 0 to 20% by mass, and particularly preferably 0 to 10% by mass. %.

  In addition, it is preferable that the content rate of (A) polybutene and / or polyisobutylene which concerns on this invention shall be 30 mass% or more of the whole resin composition. When the content of the A component is too low, the effect of reducing the dielectric constant is reduced.

[Method for preparing curable resin composition]
The curable resin composition of this invention should just mix the above components in a predetermined ratio. Since component A is liquid at room temperature, other components can be added and mixed using component A as a solvent. In particular, by synthesizing the B component, that is, the multimerization reaction of the (hydrogenated) conjugated diene polymer polyol, followed by the reaction with the α, β-unsaturated carbonyl compound in the presence of the solvent comprising the A component. A mixture of a predetermined ratio of the A component and the B component can be obtained. What is necessary is just to add and mix the deficient A component, the predetermined amount of C component, D component, E component, and F component if desired. The order of adding and mixing the C, D, E, and F components is not particularly limited.

  For the addition and mixing of fumed silica, it is preferable to use a stirrer such as a homomixer to stir the mixture so as to be homogeneous.

[Curing method of curable resin composition]
The curable resin composition of the present invention can be applied to a predetermined site by a method such as coating, dropping filling, or pouring. What is necessary is just to select suitably according to the property of a composition, a viscosity, and an application location.

  The curable composition of the present invention having the above composition comprises (C) an alkyl or cycloalkyl ester of (C) (meth) acrylic acid having 6 to 20 carbon atoms and (B) α, β of a multimeric diene polymer. -It can be cured by a polymerization reaction with an α, β-unsaturated carbonyl group ((meth) acryloyl group) of the unsaturated carbonyl-modified product. The curing reaction can be initiated by heat, light, or irradiation with various energy rays. Photocuring is preferable from the viewpoint of curing speed and workability. It is possible to use both curing by light irradiation and curing by heating.

As the energy rays, electron beams, radiation, ultraviolet rays, and the like can be used, and ultraviolet rays having a wavelength of 150 to 450 nm are preferable. Examples of light sources that emit such wavelengths include solar rays, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, gallium lamps, xenon lamps, flash type xenon lamps, carbon arc lamps, and LED type UV light sources. It is done. Irradiation integrated light quantity is preferably 0.1~10J / cm ^2, more preferably 0.2~5J / cm ^2, more preferably in the range of 0.3~3J / cm ^2.

  In the case of thermosetting, infrared rays, far infrared rays, hot air, high frequency heating or the like may be used. The heating temperature may be appropriately adjusted according to the decomposition temperature of the thermosetting catalyst, the type of base material used, and the like, and is not particularly limited, but is preferably 50 to 150 ° C, more preferably 50 to 100 ° C. More preferably, it exists in the range of 60-90 degreeC. The heating time may be appropriately adjusted according to the decomposition temperature or coating thickness of the thermosetting catalyst, and is not particularly limited, but is preferably 1 minute to 12 hours, more preferably 10 minutes to 6 hours, Preferably, it is within the range of 10 minutes to 3 hours.

  Furthermore, you may obtain by using together hardening by electron beam irradiation with hardening by light irradiation. In this case, the acceleration voltage is preferably 0 to 500 kV, more preferably 20 to 300 kV, and even more preferably 30 to 200 kV. The irradiation amount is preferably in the range of 2 to 500 kGy, more preferably 3 to 300 kGy, and still more preferably 4 to 200 kGy.

  The curable resin composition is cured by the curing reaction as described above. The term “curing” as used herein means a state having no fluidity, and is a state in which the shape can be maintained. The component A is liquid at room temperature and does not participate in the curing reaction, but a cured product can be obtained with the composition of the present invention. Although the detailed curing mechanism is unknown, since the A component and the B component are excellent in compatibility, the A component can be finely dispersed in the composition, cured in such a state, and a network structure obtained by curing. It is presumed that the bleed-out from the cured product is prevented by being confined inside.

  Therefore, the curable resin composition of the present invention depends on the content ratio of the components (A) to (D), the composition of the B component (the type of conjugated diene polymer unit included, the number of linkages, etc.), and the molecular weight. It is possible to provide a cured product having a low dielectric constant, excellent heat resistance, light resistance, moisture resistance and elongation, and capable of maintaining transparency even at high humidity.

<Use of resin composition>
Since the cured product of the resin composition of the present invention has a low dielectric constant and excellent transparency, it goes without saying that it has a conventionally known use such as an adhesive and a filler between optical display members, and is particularly transparent. For example, it can be suitably used as an adhesive between a transparent glass plate of a capacitive touch panel and a display, a protective sheet or the like, or a filler for a gap.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to description of a following example.
In the examples, “part” means mass basis unless otherwise specified.

<Measurement and evaluation method>
The evaluation methods employed in this example are as follows.
〔Evaluation method〕
(1) Number average molecular weight (Mn)
Using Tosoh columns TSK-gel SuperHM-H and TSK-gel SuperH2000, using Tosoh gel permeation under conditions where the temperature is 40 ° C. and the flow rate is 0.3 mL / min. It is a value obtained by chromatography (GPC) apparatus HLC-8220GPC and converted to standard polystyrene.

(2) Composition viscosity (mPa · s)
The viscosity of the obtained resin composition was measured using an R / S Rheometer (manufactured by BROOKFIELD, cone plate C50-2) under the condition of a temperature of 25 ° C., and the value at 1 rpm was taken as the measured value.

(3) Curability (J / cm ² )
The obtained resin composition was coated on a glass plate so as to have a thickness of 4 mm, and a conveyor type UV irradiator (irradiation lamp: lamp manufactured by Fusion, D bulb, illuminance: 200 mW / cm ² , conveyor speed: 1 .2 m / min, UV sensor: UIT-250 (manufactured by USHIO INC.) Was irradiated with UV light at 1 J / cm ² , and the light irradiation amount at which the hardness value became constant was measured.

(4) Turbidity About the test piece (width 25 mm x length 25 mm x resin thickness 4 mm) in a state where the obtained resin composition is cured and sandwiched between glass plates (thickness 1 mm), the degree of turbidity is confirmed visually. Evaluation was made in the following three stages.
○: Transparent (no turbidity)
Δ: Slightly cloudy ×: Cloudy

(5) Light transmittance (%)
For a test piece (width 50 mm × length 70 mm × thickness 0.3 mm) in a state where the obtained resin composition is cured and sandwiched between glass plates (thickness 1 mm), the light transmittance at 400 nm is measured with a spectrophotometer (type “ UV-3100 ", manufactured by Shimadzu Corporation).

(6) Relative permittivity ε (100 kHz)
A sheet-like test piece (width 50 mm × length 50 mm × thickness 1 mm) formed by curing the obtained resin composition is sandwiched between electrodes (Solartron SH2-Z, electrode diameter 10 mm), and impedance analyzer (Solartron) In S1-1260), the capacitance was measured, and the relative dielectric constant was calculated.

(7) Heat resistance A test piece (width 50 mm × length 70 mm × thickness 0.5 mm) in which the obtained resin composition is cured and sandwiched between glass plates (thickness 1 mm) is prepared in an oven at 100 ° C. For 250 hours or 500 hours. The shape retention property of the test piece after heating was confirmed visually and evaluated in the following three stages.
◯: No change in shape Δ: Slight change in shape ×: Significant change in shape

(8) Moisture resistance The obtained resin composition is cured and a test piece (width 50 mm × length 70 mm × thickness 0.3 mm) in a state of being sandwiched between glass plates (thickness 1 mm) is produced in a thermostatic chamber. After holding at a temperature of 85 ° C. and a humidity of 85% RH for 250 hours or 500 hours, the evaluation was made in the following three stages.
◯: Less than 1% decrease in light transmittance compared to 0 hour test (no turbidity)
Δ: Decrease in light transmittance by 1-5% compared to test 0 hour
X: The decrease in light transmittance is 5% or more compared to 0 hour test.

(9) Elongation at break (%)
A dumbbell-shaped test piece (center: length 25 mm, width 10 mm, thickness 0.5 mm) is prepared from the obtained cured product, and the test piece is pulled at a pulling speed of 300 mm / min. %) Was calculated.
The case where the elongation is 1000% or more is good.

<Synthesis of α, β-unsaturated carbonyl modified conjugated diene polymer>
(1) Acryloyl-modified product of simple hydrogenated polybutadiene Urethane catalyst dibutyltin diversate 0.16g, polymerization inhibitor Adekastab AO-60 0.16g, polybutene Nisseki polybutene HV-15 manufactured by JX Nippon Mining & Energy (Mn = 630) 1717 g, and Nippon Soda NISSOPB GI-3000 (hydrogenated polybutadiene diol having hydroxyl groups at both ends, Mn = 3000, iodine value of 21 or less, the same applies hereinafter) as a hydrogenated conjugated diene polymer polyol in a container The mixture was charged and heated to 77 ° C. with stirring under bubbling. As an α, β-unsaturated carbonyl compound, 2-acryloyloxyethyl isocyanate (manufactured by Showa Denko KK, product number Karenz AOI, the same applies hereinafter) 21.6 g (corresponding to 1.0 equivalent to the hydroxyl group contained in GI-3000) ) And reacted at 80 ° C. for 120 minutes to obtain an acryloyl modified body (Mn = 4800) of unit-type hydrogenated polybutadiene.
In addition, the mixing ratio (A: B) of the polybutene (A) used as a solvent and the acryloyl modified body (B) of the synthesized hydrogenated polybutadiene by the above synthesis is 80:15 (mass ratio). Obtained as a mixture.

(2) Multimeric hydrogenated polybutadiene acryloyl-modified product 1 (0.75 equivalent)
Urethane catalyst dibutyltin diversate 0.21 g, polymerization inhibitor ADK STAB AO-60 0.21 g, JX Nippon Mining & Energy Niseki Polybutene HV-15 as polybutene, 849.2 g, and hydrogenated conjugated diene polymer 400 g of Nippon Soda NISSOPB GI-3000 as a polyol was charged into a container and heated to 77 ° C. with stirring under bubbling. Next, 17.0 g (corresponding to 0.75 equivalent to the hydroxyl group contained in GI-3000) of isophorone diisocyanate (manufactured by Sumika Bayer Urethane Co., Ltd., part number Desmodur I, the same applies below) was added as a linking compound. And then reacted at 80 ° C. for 120 minutes to polymerize. Subsequently, 7.2 g of 2-acryloyloxyethyl isocyanate (corresponding to 0.25 equivalent to the hydroxyl group contained in GI-3000) was added as an α, β-unsaturated compound and reacted at 80 ° C. for 120 minutes. As a result, an acryloyl modified product 1 (Mn = 17000) of a multimer type hydrogenated polybutadiene was obtained.
In addition, the mixing ratio (A: B) of the polybutene (A) used as a solvent and the acryloyl modified body (B) of the synthesized multimer-type hydrogenated polybutadiene by the above synthesis is 30:15 (mass ratio). Obtained as a mixture.

(3) Multimeric hydrogenated polybutadiene acryloyl modified product 2 (0.5 equivalent)
Urethane catalyst dibutyltin diversate 0.14g, polymerization inhibitor Adekastab AO-60 0.14g, polybutene, Nisshi polybutene HV-15 made by JX Nippon Oil & Energy, 554.1g, and hydrogenated conjugated diene polymer As a polyol, 260 g of Nippon Soda NISSOPB GI-3000 was charged into a container and heated to 77 ° C. with stirring under bubbling. Next, 7.4 g of isophorone diisocyanate (corresponding to 0.5 equivalent to the hydroxyl group contained in GI-3000) was added as a linking compound and reacted at 80 ° C. for 120 minutes to multimerize. Subsequently, 9.3 g of 2-acryloyloxyethyl isocyanate (corresponding to 0.5 equivalent to the hydroxyl group contained in GI-3000) was added as an α, β-unsaturated compound, and the reaction was carried out at 80 ° C. for 120 minutes. By doing so, an acryloyl modified product 2 (Mn = 8000) of multimer-type hydrogenated polybutadiene was obtained.

  In addition, the mixing ratio (A: B) of the polybutene (A) used as a solvent and the acryloyl modified body (B) of the synthesized multimer-type hydrogenated polybutadiene by the above synthesis is 30:15 (mass ratio). Obtained as a mixture.

<Curable resin composition No. Preparation of 1-8>
In the above-mentioned (1)-(3), the acryloyl-modified product of single-unit hydrogenated polybutadiene obtained in the state of a mixture with polybutene, or the acryloyl-modified products 1 and 2 of multimer-type hydrogenated polybutadiene are added to an insufficient amount of polybutene (A ) HV-15, isobornyl acrylate (IB-A) (Tg = 94 ° C.) (manufactured by Nippon Shokubai) as polymerizable compound (C), Irgacure TPO (monoacylphosphine oxide) as photopolymerization initiator (E) (BASF) and KE-311 (trade name of hydrogenated rosin ester manufactured by Arakawa Chemical Co., Ltd.) as a tackifier (F) were mixed at a ratio shown in Table 1, and then fumed silica (D) (Evonik) Aerosil # 300) manufactured by Japan was added at a ratio shown in Table 1, and dispersed and stirred with a homomixer (manufactured by Primics Co., Ltd.). 1-8 were prepared.
About the prepared resin composition, it measured and evaluated based on the said measurement evaluation method. The measurement results are shown in Table 1.

Resin composition No. containing no fumed silica (D) component No. 6 was inferior in durability such as moisture resistance and heat resistance.
In addition, as a B component, a resin composition No. 1 using an acryloyl-modified product of a simple hydrogenated polybutadiene is used. No. 7 has a breaking elongation of 250%, and resin composition No. 7 using an acryloyl modified product of multimer-type hydrogenated polybutadiene. Compared with 1-5 (all 1000% or more), it was considerably low.

  In addition, a resin composition No. 1 containing an acryloyl-modified product of a multimer-type hydrogenated polybutadiene as the B component in an amount of more than 50% by mass of the resin component. In No. 8, no. Not only did the elongation decrease significantly to 580% compared to 1-5, but also the dielectric constant increased to 3.2, probably because the content of the A component decreased relatively. Moreover, since the viscosity increased significantly, the workability was also inferior.

  The curable resin composition of the present invention provides a cured product having a low dielectric constant, excellent moisture resistance and elongation, so that the dielectric constant of the member to be used affects the operating sensitivity like a capacitive touch panel. It is suitable as an adhesive used between transparent members of a tablet-type terminal and a filler filling a gap, and can also be suitably used as a filler and an adhesive between other optical members.

Claims (12)

(A) 100 parts by mass of polybutene and / or polyisobutylene having a number average molecular weight of 300 to 1500;
(B) Conjugated diene polymer units selected from the group consisting of hydrogenated polybutadiene, hydrogenated polyisoprene, and polyisoprene are linked via a urethane bond-containing group, and the terminal is α, β-unsaturated carbonyl. An α, β-unsaturated carbonyl modified product of a modified multimeric conjugated diene polymer , wherein the α, β-unsaturated carbonyl modified product has a number average molecular weight of 3000 to 50000 5-50 parts by mass of a modified product ;
(C) 10 to 80 parts by mass of an alkyl and / or cycloalkyl ester having 6 to 20 carbon atoms of (meth) acrylic acid; and (D) 0.5 to 15 parts by mass of fumed silica having a primary average particle diameter of 50 nm or less. A curable resin composition containing The curable resin composition according to claim 1, wherein the urethane bond-containing group is a reaction product group of isocyanate or isocyanatomethyl bonded to a cyclohexyl skeleton and an alcoholic hydroxyl group . The alpha, beta-unsaturated carbonyl modified compounds, the multimeric conjugated diene polymer via a urethane group or an ester bond-containing group alpha, beta-claim-unsaturated carbonyl group is linked 1 or 2 The curable resin composition described in 1. (A) The pour point of polybutene and / or polyisobutylene is 0 degrees C or less, The curable resin composition of any one of Claims 1-3 . The (B) α, β-unsaturated carbonyl-modified product is obtained by an α, β-unsaturated carbonyl-modified reaction in the presence of the polybutene and / or polyisobutylene solvent of (A). The curable resin composition according to any one of 1 to 4 . The curable resin composition according to any one of claims 1 to 5 , wherein the (C) (meth) acrylate compound is a monofunctional (meth) acrylate having a cyclic structure. Wherein (D) the average primary particle diameter 50nm less fumed silica, curable resin composition according to item 1 to any one of claims 1 to 6, which is a hydrophilic fumed silica. Additionally, (E) The curable resin composition according to any one of claims 1 to 7, comprising a photopolymerization initiator. The curable resin composition according to any one of claims 1 to 8 , further comprising (F) an adhesion improver. The curable resin composition according to any one of claims 1 to 9 , wherein a relative permittivity of a cured product obtained by curing the curable resin composition is less than 3.0. The cured product obtained by curing the energy ray irradiation curable resin composition according to any one of claims 1-10. An image display device comprising the cured product according to claim 11 .