KR20160016770A - Photocurable resin and photocurable resin composition - Google Patents

Abstract

An object of the present invention is to provide a photocurable resin composition having high adhesive strength and good adhesiveness under high temperature and high humidity, and a photocurable resin used therefor. The photocurable resin of the present invention has a repeating unit derived from a 1,2-butadiene skeleton at a specific ratio in the main chain (main chain) skeleton and has a (meth) acryloyloxy group And has at least two or more urethane bonds in the main chain skeleton.

Description

[0001] PHOTOCURABLE RESIN AND PHOTOCURABLE RESIN COMPOSITION [0002]

The present invention relates to a photo-curable resin and a photo-curable resin composition.

BACKGROUND ART In recent years, a photo-curable resin composition using a photo-curable resin has been known as an adhesive or pressure-sensitive adhesive for electronic materials.

For example, Patent Document 1 discloses a method in which a polyol having a hydrogenated polybutadiene skeleton in its main chain is made to have a high molecular weight by using a polyfunctional compound, and a polyol having a molecular weight of 10,000 to 100,000 (Meth) acrylate oligomer obtained by introducing a (meth) acryloyl group in an amount of 25 mol% to 100 mol% based on the hydroxyl group of the high molecular weight hydrogenated polybutadiene polyol into the remaining hydroxyl groups of the molecular weight-modified hydrogenated polybutadiene polyol, Curable pressure-sensitive adhesive composition containing a functional (meth) acrylate "(claim 1).

Patent Document 2 discloses a pressure-sensitive adhesive sheet comprising a cured product of a curable resin composition comprising a hydrogenated butadiene polymer having a plurality of photocurable functional groups, a monomer having a single photocurable functional group and a photopolymerization initiator . &Quot; ([Claim 1]).

Patent Document 1: Japanese Patent Application Laid-Open No. 04-183770 Patent Document 2: JP-A No. 2012-62447

However, the photocurable resin compositions using the photocurable resin (urethane (meth) acrylate oligomer, hydrogenated butadiene polymer) described in Patent Documents 1 and 2 and the like sometimes have a low bonding strength, and in particular, the bonding strength .

Therefore, an object of the present invention is to provide a photocurable resin composition having high adhesive strength and good adhesiveness under high temperature and high humidity, and a photocurable resin used therefor.

DISCLOSURE OF THE INVENTION The inventors of the present invention have made intensive studies to solve the above problems. As a result of intensive studies, the present inventors have found that (metha) acryloyloxy groups are bonded through a predetermined urethane bond to the terminals thereof, By using a photocurable resin having a specific ratio of two or more urethane bonds, a photocurable resin composition having high adhesive strength and good adhesiveness under high temperature and high humidity was found, and the present invention was accomplished.

That is, it has been found that the above problems can be solved by the following constitutions.

(1) a photocurable resin having a repeating unit represented by at least the following formula (Ib) among the repeating units represented by the following formulas (Ia) to (Ic) in the main chain skeleton,

, The content of the repeating unit represented by the following formula (Ia) is 0 to 40 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic)

, The content of the repeating unit represented by the following formula (Ib) is 60 to 100 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic)

, The content of the repeating unit represented by the following formula (Ic) is 0 to 10 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic)

(IIa) or (IIb) in at least one of the terminals,

A photo-curable resin having at least two urethane bonds represented by the following formula (III) in its main chain skeleton.

(In the formulas (Ia) to (Ic), the double line of the broken line and the solid line represents a single bond or a double bond, and in the formulas (IIa) and (IIb), R ¹ independently represents a hydrogen atom or a methyl group (IIa), n represents an integer of 1 to 7, and * in the formulas (IIa), (IIb) and (III) represents the bonding position with the main chain.

(2) A photocurable resin composition comprising the photocurable resin according to (1), a monofunctional (meth) acrylate compound having one (meth) acryloyloxy group, and a photopolymerization initiator.

As described below, according to the present invention, a photocurable resin composition having high adhesive strength and good adhesiveness under high temperature and high humidity, and a photocurable resin used therefor can be provided.

[Photocurable resin]

The photocurable resin of the present invention has a structure in which a main chain skeleton has a specified amount of a predetermined repeating unit represented by the formula (Ib) to be described later and a structure represented by formula (IIa) or formula (IIb) , And has at least two urethane bonds represented by the formula (III) described later in the main chain skeleton.

<Backbone framework>

(Repeating unit)

The photocurable resin of the present invention has at least a repeating unit represented by the following formula (Ib) among the repeating units represented by the following formulas (Ia) to (Ic) in the main chain skeleton.

In the present invention, the content of the repeating unit represented by the following formula (Ia) is 0 to 40 mol% and 5 to 30 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic) desirable.

The content of the repeating unit represented by the following formula (Ib) is preferably 60 to 100 mol%, more preferably 65 to 95 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic) And more preferably 70 to 95 mol%.

The content of the repeating unit represented by the following formula (Ic) is preferably 0 to 10 mol%, and preferably 0 to 5 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic).

(In the formulas (Ia) to (Ic), the double line of the broken line and the solid line represents a single bond or a double bond.)

Here, &quot; mol% based on the total repeating units &quot; refers to a value calculated from an addition ratio of monomers (1,3-butadiene, 1,2-butadiene, styrene). In the present invention, . &Lt; / RTI &gt; Specifically, the integral value of the proton of -CH = CH ₂ - or -CH ₂ -CH ₃ of the 1,2 structure and the proton of -CH═CH- or -CH ₂ -CH ₂ - of the 1,4 structure .

The arrangement of the repeating units represented by the above formulas (Ia) to (Ic) may be arranged in a block manner, or may be a mixture of both, whether they are randomly arranged or not.

In the present invention, a photocurable resin composition having such a repeating unit, in particular, a photocurable resin having 60 to 100 mol% of repeating units represented by the above formula (Ib) is used to obtain a photocurable resin composition having excellent adhesiveness under high temperature and high humidity .

This is because the crystal structure is not taken, flexibility is improved, and even under high temperature and high humidity, dimensional changes of the base material can be followed. This is because, as shown in Comparative Example 5 to be described later, when the mol% of the repeating unit represented by the formula (Ib) is not satisfied, that is, when the repeating unit represented by the formula (Ia) Can be estimated from the result that a thinner is required because the photo-curable resin takes a crystal structure and the viscosity increases, and as a result, the adhesiveness decreases.

(Urethane bond)

The photocurable resin of the present invention has at least two or more urethane bonds represented by the following formula (III) in the main chain skeleton.

(In the formula (III), * represents the bonding position with the main chain.)

Here, the urethane bond represented by the formula (III) is a urethane bond contained in the main chain skeleton, unlike the urethane bond included in the terminal structure described later. For example, as shown in the preparing method described later, A urethane bond contained in the structure represented by the following formula (IIIa) produced when the hydrogenated polybutadiene-based polymer having a hydroxyl group at the terminal thereof is reacted (dimerized) with a diisocyanate compound having two isocyanate groups, (Tri-isomerization) of a hydrogenated polybutadiene-based polymer and a triisocyanate compound having three isocyanate groups (for example, a buret resin, an isocyanurate compound, and an adduct of a diisocyanate compound) Is a urethane bond contained in the structure represented by the formula (IIIb).

(In the formula (IIIa), R ² represents a residue other than the isocyanate group of the diisocyanate compound, and * represents a bonding position with the main chain. In the formula (IIIb), R ³ represents a residue other than the isocyanate group of the triisocyanate And * represents the bonding position with the main chain.)

In the present invention, a photocurable resin composition having a high adhesive strength can be obtained by using a photocurable resin having two or more urethane bonds in the main chain skeleton.

It is considered that this is because the NH groups of the urethane bonds contained in the main chain skeleton of the adjacent photocurable resin easily become hydrogen bonds due to inclusion of a urethane bond in the main chain skeleton separately from the urethane bond contained in the terminal structure do. This can also be inferred from the results in the case where the main chain skeleton does not have a urethane bond, as shown in Comparative Example 6 described later.

From the reason that the adhesive strength and the cured product property are higher, the urethane bond in the main chain skeleton is preferably 2 to 10.

<End structure>

The photocurable resin of the present invention has a structure represented by the following formula (IIa) or (IIb) in at least one of its terminals.

(IIa) and (IIb), R ¹ independently represents a hydrogen atom or a methyl group, n in the formula (IIa) represents an integer of 1 to 7, In the formula (IIb), plural R &lt; ¹ &gt; s may be the same or different.)

In the present invention, by using the photocurable resin having such a terminal structure, a photocurable resin composition having high adhesive strength and good adhesiveness under high temperature and high humidity can be obtained.

This is because the urethane bond contained in the terminal structure has a structure in which it is bonded to the main chain through an oxygen atom, so that the degree of polymerization (crosslinking density) after photo-curing unexpectedly increases and radicals are easily generated by electron- . This is presumably from the result that the polymerization degree is low and the bonding strength is low when the structure represented by the following formula (IV) is provided at the terminal as shown in Comparative Examples 1 to 3 to be described later.

(In the formula (IV), R ¹ represents a hydrogen atom or a methyl group, and * in the formula (IV) represents a bonding position with the main chain.)

Further, in the present invention, from the viewpoint that the adhesiveness under high temperature and high humidity becomes better, and the elongation of the cured product becomes also good, it is preferable to have two or more terminal structures represented by the above formula (IIa) , More preferably two or more terminal structures represented by the above formula (IIa).

<Preparation method>

The method for preparing the photocurable resin of the present invention is not particularly limited. For example, a hydrogenated polybutadiene polymer having a hydroxyl group at the terminal (hereinafter referred to as "hydroxyl-terminated polybutadiene (a)") and an isocyanate group (B) having a (meth) acryloyloxy group and a polyisocyanate compound (c) having two or more isocyanate groups are preferable. More specifically, a method of reacting a hydroxyl group-terminated hydrogenated polybutadiene The polyisocyanate compound (c) is reacted with an equivalent ratio (hydroxyl group / isocyanate group) of hydroxyl group and isocyanate group of greater than 1 (for example, 1.1 to 2) (b) is reacted with an isocyanate group to introduce a (meth) acryloyloxy group.

Here, "(meth) acryloyloxy group" means acryloyloxy group and / or methacryloyloxy group.

&Lt; Hydroxyl-terminated hydrogenated polybutadiene (a) &gt;

The hydroxyl-terminated hydrogenated polybutadiene (a) is preferably represented by the following formulas (a1) and (a2) from the viewpoint of satisfying the mole% of the repeating units represented by the above-mentioned formulas (Ia) May suitably include both terminal hydroxyl hydrogenated polybutadiene.

(In the formulas (a1) and (a2), m represents an integer of 15 to 90.)

The number average molecular weight of the hydrogenated polybutadiene-based polymer (a) is preferably from 1,000 to 10,000, more preferably from 1,500 to 5,000.

Here, the number average molecular weight is a value determined by gel permeation chromatography (GPC) measurement in terms of polystyrene conversion.

&Lt; Compound (b) &gt;

The compound (b) is preferably a compound represented by the following formula (b1) or the following formula (b2), for example, from the viewpoint of introducing the terminal structure represented by the formula (IIa) -Isocyanate ethyl (meth) acrylate, and 1,1- (bisacryloyloxymethyl) ethyl isocyanate.

(In the formulas (b1) and (b2), R ¹ independently represents a hydrogen atom or a methyl group, and in the formula (b1), n represents an integer of 1 to 7. In addition, R ¹ may all be the same or different.)

&Lt; Polyisocyanate compound (c) &gt;

The polyisocyanate compound (c) is not particularly limited as long as it has two isocyanate groups in the molecule.

Specific examples of the polyisocyanate compound include TDI (e.g., 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI) ), MDI (for example, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI) Aromatic diesters such as phenylene diisocyanate, xylene diisocyanate (XDI), tetramethyl xylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), and triphenyl methane triisocyanate Isocyanate; Aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate and norbornane diisocyanate (NBDI); Alicyclic diisocyanates such as trans-cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanate methyl) cyclohexane (H6XDI), and dicyclohexylmethane diisocyanate (H12MDI) ; Isocyanurate of diisocyanate, burette, adduct of the above-mentioned diisocyanate; These may be used singly or two or more of them may be used in combination.

[Photo-curable resin composition]

The photocurable resin composition of the present invention can be obtained by mixing the above-mentioned photocurable resin of the present invention (hereinafter also referred to as "photocurable resin (A)") and a monofunctional (meth) acryloyloxy- Acrylate compound (B), and a photopolymerization initiator (C).

&Lt; Photocurable resin (A) &gt;

The photocurable resin (A) is the same as the above-mentioned photocurable resin of the present invention, but the content of the photocurable resin (A) in the photocurable resin composition of the present invention is preferably 10 to 80% by mass , More preferably from 20 to 65 mass%.

<Monofunctional (meth) acrylate compound (B)>

The monofunctional (meth) acrylate compound (B) is not particularly limited as long as it is a compound having one (meth) acryloyloxy group. Specific examples thereof include methyl (meth) acrylate, ethyl (meth) Butyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, carbitol (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (Meth) acrylate, allyl (meth) acrylate, stearyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxyethyl (Meth) acrylates such as methoxybutyl (meth) acrylate, isooctyl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentenyl Acrylate, and the like. It said, mubang also possible to use them alone, and is mubang be used in combination of two or more.

Among these, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate (meth) acrylate and the like are preferable because of their good compatibility with the above-mentioned photo- , And isodecyl (meth) acrylate.

The content of the monofunctional (meth) acrylate compound (B) is preferably 10 to 200 parts by mass, more preferably 30 to 100 parts by mass, per 100 parts by mass of the photocurable resin (A).

&Lt; Photopolymerization initiator (C) &gt;

Examples of the photopolymerization initiator (C) include an alkylphenone compound, a benzoin ether compound, a carbonyl compound such as a benzophenone compound, a sulfur compound, an azo compound, a peroxide compound, a phosphine oxide compound, etc. .

More specifically, there may be mentioned, for example, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, acetone, butyroin, toluoin, benzyl, benzophenone, Hydroxybenzophenone, diethoxyacetophenone,?,? -Dimethoxy-? -Phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4'-bis (dimethylaminobenzophenone) Methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone and other carbonyl compounds represented by the following formula (1); Sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; Azo compounds such as azobisisobutyronitrile and azobis-2,4-dimethylvalero; And peroxide compounds such as benzoyl peroxide, ditertiary butyl peroxide and the like. These may be used singly or in combination of two or more kinds.

Among them, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-hydroxypropyl (meth) acrylate and the like are preferable from the viewpoint of light stability, high efficiency of light cleavage, compatibility with the photocurable resin Methyl-1-phenyl-propan-1-one and 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one are preferred.

As a commercial product of 1-hydroxycyclohexyl phenyl ketone, for example, Irgacure 184 (manufactured by Ciba Specialty Chemicals) can be mentioned.

The content of the photopolymerization initiator (C) is preferably 1 to 10 parts by mass, more preferably 2 to 8 parts by mass with respect to 100 parts by mass of the photocurable resin (A).

&Lt; ester group-containing (meth) acrylate &gt;

The photo-curable resin composition of the present invention preferably uses an ester group-containing (meth) acrylate (D) represented by the following formula for the reason that toughness after curing becomes good.

(Wherein R ¹ represents a hydrogen atom or a methyl group, R ³ represents an alkylene group having 2 to 6 carbon atoms, r represents an integer of 3 to 8, and s represents an integer of 1 to 5.)

Examples of such ester group-containing (meth) acrylates (D) include commercially available products such as "Fraxel FA-1", "Fraxel FA-2", "Fraxel FA- Fraxel FM-4, Fraxel FM-5, Fraxel FM-1, Fraxel FM-2, Fraxel FM- (All available from Daicel Chemical Industries, Ltd.).

The content of the ester group-containing (meth) acrylate (D) is preferably 1 to 50 parts by mass, more preferably 5 to 20 parts by mass, per 100 parts by mass of the photocurable resin (A).

<Solvent, Additive>

The photocurable resin composition of the present invention may contain a solvent from the viewpoint of workability.

Specific examples of the solvent include ethanol, isopropanol, butanol, toluene, xylene, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, cyclohexanone and the like.

The photocurable resin composition of the present invention may contain various additives such as a filler, an antioxidant, an antioxidant, an antistatic agent, a flame retardant, an adhesion imparting agent, a leveling agent , A dispersing agent, a defoaming agent, a gloss removing agent, a light stabilizer (for example, a hindered amine compound), a dye, a pigment and the like.

<Preparation method>

The method for preparing the photocurable resin composition of the present invention is not particularly limited and may be carried out by, for example, a method of adding the above essential components and optional components to a reaction vessel and sufficiently kneading the mixture under reduced pressure using a stirrer such as a mixing mixer Can be manufactured.

Example

Hereinafter, the photocurable resin composition of the present invention will be described in detail with reference to Examples. However, the present invention is not limited to this.

&Lt; Synthesis of photocurable resin (A-1) &gt;

, 100 g of hydroxyl-terminated hydrogenated polybutadiene (GI-3000, manufactured by Nippon Soda Co., Ltd.), 2.3 g of 2-isocyanatoethyl acrylate (manufactured by Showa Denko K.K.) And 3.7 g of diisocyanate were mixed and reacted at 70 DEG C for 2 hours in a nitrogen atmosphere to synthesize a photocurable resin (A-1).

The content of the repeating unit represented by the formula (Ia) in the synthesized photocurable resin (A-1) was 15 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic) , The content of the repeating unit represented by the formula (Ib) is 85 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIa) (R &lt; ¹ &gt; in formula (IIa) is a hydrogen atom) and has two urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (A-2) &gt;

100 g of hydroxyl-terminated polybutadiene (GI-3000, manufactured by Nippon Soda Chemical Co., Ltd.) and 3.7 g of hexamethylene diisocyanate were mixed and reacted at 70 DEG C for 2 hours under a nitrogen atmosphere.

Then, 2.3 g of 2-isocyanatoethyl acrylate (manufactured by Showa Denko) was mixed and reacted at 70 DEG C for 2 hours in a nitrogen atmosphere to synthesize a photocurable resin (A-2).

The content of the repeating unit represented by the above formula (Ia) in the synthesized photocurable resin (A-2) was 15 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic) , The content of the repeating unit represented by the formula (Ib) is 85 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIa) (R &lt; ¹ &gt; in formula (IIa) is a hydrogen atom) and has two urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (A-3) &gt;

100 g of hydroxyl-terminated polybutadiene (GI-3000, manufactured by Nippon Soda Chemical Co., Ltd.) and 3.9 g of isophorone diisocyanate (manufactured by Evonic) were mixed and reacted at 70 DEG C for 2 hours under a nitrogen atmosphere.

Next, 2.4 g of 2-isocyanatoethyl acrylate (manufactured by Showa Denko) was mixed and reacted at 70 DEG C for 2 hours in a nitrogen atmosphere to synthesize a photocurable resin (A-3).

Incidentally, the content of the repeating unit represented by the formula (Ia) in the synthesized photocurable resin (A-3) was 15 mol% based on the total repeating units represented by the above formulas (Ia) , The content of the repeating unit represented by the formula (Ib) is 85 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIa) (R &lt; ¹ &gt; in formula (IIa) is a hydrogen atom) and has four urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (A-4) &gt;

(FA-711MM, manufactured by Hitachi Kasei Kogyo Co., Ltd.) as a catalyst, 100 g of a hydroxyl-terminated hydrogenated polybutadiene (GI-3000, manufactured by Nippon Soda Chemical Co., Ltd.), 3.9 g of isophorone diisocyanate Manufactured by Hitachi Chemical Co., Ltd.) were mixed and reacted at 70 ° C for 2 hours under a nitrogen atmosphere.

Next, 2.4 g of 2-isocyanatoethyl acrylate (Showa Denko Corp.) was mixed and reacted at 70 ° C for 2 hours under a nitrogen atmosphere to synthesize a photocurable resin (A-4).

Incidentally, the content of the repeating unit represented by the formula (Ia) in the synthesized photocurable resin (A-4) was 15 mol% based on the total repeating units represented by the above formulas (Ia) , The content of the repeating unit represented by the formula (Ib) is 85 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIa) (R &lt; ¹ &gt; in formula (IIa) is a hydrogen atom) and has four urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (A-5) &gt;

100 g of hydroxyl-terminated polybutadiene (GI-3000, manufactured by Nippon Soda Chemical Co., Ltd.) and 3.9 g of isophorone diisocyanate (manufactured by Ebonic) were mixed and reacted at 70 DEG C for 2 hours under a nitrogen atmosphere.

Then, 4.23 g of 1,1- (bisacryloyloxymethyl) ethyl isocyanate (manufactured by Showa Denko) was mixed and reacted at 70 ° C for 2 hours in a nitrogen atmosphere to obtain a photo-curable resin (A-5) Respectively.

Incidentally, the content of the repeating unit represented by the formula (Ia) in the synthesized photocurable resin (A-5) was 15 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic) , The content of the repeating unit represented by the formula (Ib) is 85 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIb) (R &lt; ¹ &gt; in the formula (IIb) is a hydrogen atom) and has four urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (A-6) &gt;

95 g of hydroxyl group-terminated polybutadiene (GI-3000, manufactured by Nippon Soda Co., Ltd.), 6.25 g of polyisobutylene terminated polyisoprene and 4.07 g of isophorone diisocyanate were mixed and reacted at 70 DEG C for 3 hours under a nitrogen atmosphere.

Next, 2.4 g of 2-isocyanatoethyl acrylate (manufactured by Showa Denko) was mixed and reacted at 70 DEG C for 2 hours in a nitrogen atmosphere to synthesize a photocurable resin (A-6).

The content of the repeating unit represented by the formula (Ia) was 14.25 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the content of the repeating unit represented by the formula , The content of the repeating unit represented by the formula (Ib) is 80.75 mol% based on the total repeating units represented by the formulas (Ia) to (Ic), and the content of the repeating unit represented by the formula (Ic) Is 5 mol% based on the total repeating units represented by the formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIa) (R ¹ in the formula (IIa) is a hydrogen atom) It was confirmed that there were four urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (A-7) &gt;

100 g of hydroxyl-terminated polybutadiene (100 mol% of recurring units represented by Ib) and 3.9 g of isophorone diisocyanate were mixed and reacted at 70 DEG C for 3 hours under a nitrogen atmosphere.

Next, 2.4 g of 2-isocyanatoethyl acrylate (Showa Denko Co., Ltd.) was mixed and reacted at 70 DEG C for 2 hours in a nitrogen atmosphere to synthesize a photocurable resin (A-7).

Incidentally, the content of the repeating unit represented by the formula (Ib) in the synthesized photocurable resin (A-7) was 100 mol% based on the total repeating units represented by the above formulas (Ia) , It was confirmed that the terminal structure represented by the formula (IIa) (R ¹ in the formula (IIa) is a hydrogen atom) and has four urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (E-1) &gt;

After 100 g of hydroxyl-terminated solid hydrogenated polybutadiene (polytail H, Mitsubishi Chemical Co., Ltd.) (100 g) was dissolved in 100 g of toluene, 2-hydroxyethyl acrylate (manufactured by Tokyo Kasei Kogyo Co., ) And 11.8 g of isophorone diisocyanate were mixed and reacted at 70 DEG C for 2 hours under a nitrogen atmosphere.

After dissolving 30 g of dicyclopentenyl acrylate, the toluene layer was distilled off to synthesize a photocurable resin (E-1).

The content of the repeating unit represented by the formula (Ia) was 80 mol% with respect to the total repeating units represented by the above formulas (Ia) to (Ic), and the content of the repeating unit represented by the formula , The content of the repeating unit represented by the formula (Ib) is 20 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IV) (R &lt; ¹ &gt; in formula (IV) is a hydrogen atom) and has 6 urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (E-2) &gt;

(GI-3000, manufactured by Nippon Soda Chemical Co., Ltd.), 1.5 g of 2-hydroxyethyl acrylate (Tokyo Kasei Kogyo Co., Ltd.) and 8.8 g of isophorone diisocyanate were mixed and heated at 70 deg. C And reacted for a time to synthesize a photocurable resin (E-2).

Incidentally, the photocurable resin (E-2) thus synthesized was found to have a content of the repeating units represented by the above formula (Ia) in an amount of 15 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic) , The content of the repeating unit represented by the formula (Ib) is 85 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IV) (R &lt; ¹ &gt; in the general formula (IV) is a hydrogen atom) and has four urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (E-3) &gt;

First, 3.48 g of tolylene diisocyanate and 2.32 g of 2-hydroxyethyl acrylate were mixed and reacted at 60 DEG C for 3 hours under a nitrogen atmosphere to obtain a half duct body.

Subsequently, 100 g of hydroxyl-terminated hydrogenated polybutadiene (GI-3000, manufactured by Nippon Soda Ash) and 2.17 g of tolylene diisocyanate were mixed and reacted at 70 DEG C for 2 hours under a nitrogen atmosphere. Then, 2.5 g of the previously prepared half- Were mixed and reacted at 70 DEG C for 2 hours to synthesize a photocurable resin (E-3).

Incidentally, the content of the repeating unit represented by the formula (Ia) in the synthesized photocurable resin (E-3) was 15 mol% based on the total repeating units represented by the above formulas (Ia) , The content of the repeating unit represented by the formula (Ib) is 85 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IV) (R ¹ in the general formula (IV) is a hydrogen atom) and has two urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (E-4) &gt;

100 g of a hydroxyl group-terminated solid hydrogenated polybutadiene (polytail H, Mitsubishi Chemical Corporation) was dissolved in 100 parts of toluene, and 11 g of 2-isocyanatoethyl acrylate (manufactured by Showa Denko) was mixed, Followed by reaction at 70 DEG C for 2 hours.

After dissolving 30 parts of dicyclopentenyl acrylate, the toluene layer was removed to synthesize a photocurable resin (E-4).

Incidentally, the content of the repeating unit represented by the formula (Ia) was 80 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the content of the repeating unit represented by the formula , The content of the repeating unit represented by the formula (Ib) is 20 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIa) (R &lt; ¹ &gt; in formula (IIa) is a hydrogen atom) and does not have a urethane bond represented by the formula (III).

&Lt; Synthesis of photocurable resin (E-5) &gt;

After 100 g of hydroxyl-terminated solid hydrogenated polybutadiene (polytail H, Mitsubishi Chemical Corporation) was dissolved in 100 g of toluene, 3.5 g of 2-isocyanatoethyl acrylate (ShoWadenko Co.) and 6 g of isophorone diisocyanate And the mixture was reacted at 70 DEG C for 2 hours in a nitrogen atmosphere.

Then, 30 g of dicyclopentenyl acrylate was dissolved and then the toluene layer was removed to synthesize a photocurable resin (E-5).

The content of the repeating unit represented by the formula (Ia) was 80 mol% with respect to the total repeating units represented by the above formulas (Ia) to (Ic), and the content of the repeating unit represented by the formula , The content of the repeating unit represented by the formula (Ib) is 20 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIa) (R &lt; ¹ &gt; in formula (IIa) is a hydrogen atom) and has four urethane bonds represented by the formula (III).

&Lt; Synthesis of photocurable resin (E-6) &gt;

100 g of hydroxyl group-terminated polybutadiene (GI-3000, manufactured by Nippon Soda Chemical Co., Ltd.) and 7.5 g of 2-isocyanatoethyl acrylate (Showa Denko Corp.) were mixed and reacted at 70 DEG C for 2 hours under a nitrogen atmosphere, Resin (E-6) was synthesized.

Incidentally, the photocurable resin (E-6) thus synthesized was found to have a content of the repeating units represented by the above formula (Ia) in an amount of 15 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic) , The content of the repeating unit represented by the formula (Ib) is 85 mol% based on the total repeating units represented by the above formulas (Ia) to (Ic), and the terminal structure represented by the formula (IIa) (R &lt; ¹ &gt; in formula (IIa) is a hydrogen atom) and does not have a urethane bond represented by the formula (III).

[Examples 1 to 10 and Comparative Examples 1 to 6]

Each component shown in the following Table 1 was mixed with the composition (mass part) shown in Table 1 using a stirrer to obtain each photocurable resin composition shown in Table 1.

Then, each obtained composition was cured under the following curing conditions to obtain a cured product.

(Curing condition)

(GS UVSYSTEM TYPE S250-01, manufactured by GS Yuasa International Ltd.) and using a metal hydro lamp as a light source, ultraviolet light having a wavelength of 250 to 380 nm was irradiated with light having a light quantity of 120 mW / cm Cm &lt; 2 &gt;, so that a cured product was obtained.

<Polymerization degree>

Each photocurable resin composition and its cured product was measured using FT-IR, and the degree of polymerization was calculated by the following method.

That is, with regard to the change in the peak intensity at 810 cm -1, the initial state of the cured composition (composition) was set at 0, the degree of polymerization was set to 100, the state in which the curing (polymerization) Respectively. The results are shown in Table 1.

<Adhesive strength>

Each of the photo-curable resin compositions was coated on a glass substrate so that the adhesion area was 5 mm and the adhesion thickness was 0.3 mm. Another glass substrate was stuck to the glass substrate and cured under the above-mentioned curing conditions to prepare adhesive samples.

As for the adhesive strength, one (one) glass substrate of the adhesive sample was fixed, and another glass substrate was pulled at a tensile test speed of 5 mm / min, and the maximum value when the glass substrate was peeled off was regarded as the adhesive strength. The results are shown in Table 1.

<Adhesive strength under high temperature and high humidity>

The adhesive sample prepared above was placed under a high temperature and high humidity environment of 65 ° C and 95% RH, and the adhesive strength after 100 hours passed was measured by the same method as described above. The results are shown in Table 1.

Among the components shown in the first table, other than the above-mentioned photocurable resins (A-1) to (A-7) and (E-1) to (E-6) are as follows.

Monofunctional acrylate (B-1): Dicyclopentenyl acrylate

· Monofunctional acrylate (B-2): Isobornyl acrylate

Monofunctional acrylate (B-3): Isodecyl acrylate

Ester group-containing acrylate (D-1): unsaturated fatty acid hydroxyalkyl ester modification? -Caprolactone (Fraxel FM1,

Ester group-containing acrylate (D-2): unsaturated fatty acid hydroxyalkyl ester modified? -Caprolactone (Fraxel FM3,

Photopolymerization initiator (C-1): Irgacure 184 (BASF Corporation)

Liquid Plasticizer (F-1): ester plasticizer (TegMeR 804, manufactured by HallStar)

Liquid Plasticizer (F-2): Polyethylene plasticizer (Versafloe EV, manufactured by Shamrock)

From the results shown in the first table, when a photocurable resin having a terminal structure represented by the formula (IV) was used regardless of the mole% of the repeating unit represented by the formula (Ib) in the main chain skeleton , The degree of polymerization was low, the bonding strength was low, and the bonding strength under high temperature and high humidity was also low (Comparative Examples 1 to 3).

When a photocurable resin which does not satisfy the mole% of the repeating unit represented by the formula (Ib) in the main chain skeleton is used regardless of the presence or absence of a urethane bond in the main chain skeleton, However, it was found that the bonding strength was lowered and the bonding strength under high temperature and high humidity was also lower (Comparative Examples 4 and 5).

In addition, when a photo-curing resin having no urethane bond in the main chain skeleton was used, it was found that although the degree of polymerization was high, the adhesive strength was low and the adhesive strength under high temperature and high humidity was also low (Comparative Example 6).

On the other hand, it is preferable that the main chain skeleton has a repeating unit represented by the formula (Ib) at a specific ratio and has a terminal structure represented by the formula (IIa) or the formula (IIb) It has been found that the use of the photocurable resin (A) having at least two photopolymerizable groups results in high polymerization degree, high bonding strength, and good adhesiveness under high temperature and high humidity (Examples 1 to 10).

Claims (2)

Is a photocurable resin having a repeating unit represented by at least the following formula (Ib) among the repeating units represented by the following formulas (Ia) to (Ic) in the main chain (main chain)
, The content of the repeating unit represented by the following formula (Ia) is 0 to 40 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic)
, The content of the repeating unit represented by the following formula (Ib) is 60 to 100 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic)
, The content of the repeating unit represented by the following formula (Ic) is 0 to 10 mol% based on the total repeating units represented by the following formulas (Ia) to (Ic)
(IIa) or (IIb) in at least one of the terminals,
A photo-curable resin having at least two urethane bonds represented by the following formula (III) in its main chain skeleton.
[Chemical Formula 1]

(In the formulas (Ia) to (Ic), the double line of the broken line and the solid line represents a single bond or a double bond, and in the formulas (IIa) and (IIb), R ¹ independently represents a hydrogen atom or a methyl group (IIa), n represents an integer of 1 to 7, and * in the formulas (IIa), (IIb) and (III) represents the bonding position with the main chain. A photocurable resin composition comprising the photocurable resin according to claim 1, a monofunctional (meth) acrylate compound having one (meth) acryloyloxy group, and a photopolymerization initiator.