JP2017002130A - Polyurethane modified epoxy resin and adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyurethane modified epoxy resin excellent in flexibility and toughness at a cured article, a curable composition containing the same and the cured article thereof and an adhesiveness.SOLUTION: There are provided a polyurethane modified epoxy resin obtained by reacting a hydroxyl group-containing epoxy resin (A) and an isocyanate group-containing urethane resin (B) and having epoxy equivalent in a range of 240 to 400 g/equivalent, a curable composition containing the same, a cured article thereof and an adhesive.SELECTED DRAWING: None

Description

  The present invention relates to a polyurethane-modified epoxy resin excellent in flexibility and toughness in a cured product, a curable composition containing the same, a cured product thereof, and an adhesive.

  In recent years, lightweight materials such as aluminum, magnesium, and plastics have been adopted as automobile body materials from the viewpoint of energy saving, and the use of adhesives instead of welding is also increasing in assembly. Automobile adhesives are characterized by the fact that they are used for bonding between different materials, and the temperature changes in the usage environment are extremely severe. Currently, epoxy resin adhesives with excellent heat resistance and mechanical properties are mainly used. ing. However, conventional epoxy resin adhesives have insufficient flexibility and toughness in the cured product, and cannot follow the thermal deformation of the member, so that there is a problem that distortion and peeling are likely to occur in a high temperature / low temperature environment. In particular, when different materials such as a metal material and a non-metal material are bonded, the difference in thermal expansion coefficient between the two is large, and the problem of distortion and peeling is remarkable.

  As an epoxy resin excellent in flexibility in a cured product, a lactone-modified epoxy resin obtained by reacting a bisphenol A type epoxy resin and ε-caprolactone at a mass ratio of 90/10 to 80/20 is known ( The flexibility and toughness of the cured product are not of a level that can be used for automotive adhesives.

JP 58-32628 A

  Therefore, the problem to be solved by the present invention is to provide an epoxy resin excellent in flexibility and toughness in a cured product, a curable composition containing the epoxy resin, a cured product thereof, and an adhesive.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a polyurethane obtained by reacting a hydroxyl group-containing epoxy resin and an isocyanate group-containing urethane resin, and has an epoxy equivalent in the range of 240 to 400 g / equivalent. The modified epoxy resin has been found to be excellent in flexibility and toughness in a cured product and suitable for adhesive use, and has completed the present invention.

  That is, the present invention is a polyurethane-modified epoxy obtained by reacting a hydroxyl group-containing epoxy resin (A) and an isocyanate group-containing urethane resin (B), and having an epoxy equivalent in the range of 240 to 400 g / equivalent. It relates to resin.

  The present invention further relates to a curable composition containing the polyurethane-modified epoxy resin and a curing agent or a curing accelerator.

  The present invention further relates to a cured product obtained by curing the curable composition.

  The present invention further relates to an adhesive containing the polyurethane-modified epoxy resin and a curing agent or a curing accelerator.

  ADVANTAGE OF THE INVENTION According to this invention, the polyurethane modified epoxy resin excellent in the softness | flexibility and toughness in hardened | cured material, the curable composition containing this, its hardened | cured material, and an adhesive agent can be provided.

1 is a GPC chart of the polyurethane-modified epoxy resin (1) obtained in Example 1. FIG. FIG. 2 is a GPC chart of the polyurethane-modified epoxy resin (2) obtained in Example 2.

Hereinafter, the present invention will be described in detail.
The polyurethane-modified epoxy resin of the present invention is obtained by reacting a hydroxyl group-containing epoxy resin (A) and an isocyanate group-containing urethane resin (B), and has an epoxy equivalent in the range of 240 to 400 g / equivalent. .

  The hydroxyl group-containing epoxy resin (A) is not particularly limited as long as it has a hydroxyl group and an epoxy group in the molecular structure. In particular, since it becomes a urethane-modified epoxy resin excellent in flexibility and toughness in a cured product, A bifunctional epoxy resin is preferred. Specifically, the bifunctional epoxy resin has the following structural formula (1).

［式中Ｘはそれぞれ独立に下記構造式（２−１）〜（２−８）

[In the formula, each X independently represents the following structural formulas (2-1) to (2-8).

（式中、Ｒ^２はそれぞれ独立に水素原子、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基の何れかであり、Ｒ^３はそれぞれ独立に炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基の何れかであり、ｎは０又は１以上の整数である。）
の何れかで表される構造部位である。］
で表されるものが挙げられる。

(In the formula, each R ² is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and R ³ is independently each having 1 to 4 carbon atoms. Or an alkyl group having 1 to 4 carbon atoms, and n is 0 or an integer of 1 or more.)
It is a structural part represented by either. ]
The thing represented by is mentioned.

  X in the structural formula (1) is a structural site represented by any of the structural formulas (2-1) to (2-8), and a plurality of Xs present in the molecule are the same structural site. There may be different structural sites. Especially, since it becomes the urethane modified epoxy resin excellent in the softness | flexibility and toughness in hardened | cured material, it is preferable that it is a structure site | part represented by the said General formula (2-1) or (2-2).

  The epoxy equivalent of the hydroxyl group-containing epoxy resin (A) is preferably in the range of 155 to 300 g / equivalent because it becomes a urethane-modified epoxy resin excellent in flexibility and toughness in the cured product. The hydroxyl value is preferably in the range of 10 to 100 mgKOH / g.

  The isocyanate group-containing urethane resin (B) used in the present invention is not particularly limited as long as it has an isocyanate group and a urethane bond site in the molecular structure. Specifically, the polyisocyanate compound (C) and the polyol compound (D) are used under the condition that the isocyanate group contained in the polyisocyanate compound (C) is excessive with respect to the hydroxyl group contained in the polyol compound (D). The thing obtained by making it react is mentioned.

  The polyisocyanate compound (C) includes, for example, a diisocyanate compound (C1), a nurate modified product (C2) of the diisocyanate compound (C1), an adduct modified product (C3) of the diisocyanate compound (C1), and the diisocyanate compound ( C1) biuret modified body (C4) and the like.

  Examples of the diisocyanate compound (C1) include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, m- Aliphatic diisocyanates such as tetramethylxylylene diisocyanate; cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, etc. 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2 -Aromatic diisocyanates such as bis (paraphenyl isocyanate) propane, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, etc. Is mentioned.

  The nurate-modified product (C2) of the diisocyanate compound (C1) can be obtained, for example, by subjecting the diisocyanate compound (C1) having two isocyanate methyl groups in the molecular structure to a nuration reaction in the presence of a monoalcohol or a diol. Things. The monoalcohol is hexanol, octanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-heptadecanol, n-octadecanol, n -Nonadecanol etc. are mentioned. The diol is ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentane. Examples include diol, neopentyl glycol, 1,6-hexanediol. These monoalcohols and diols may be used alone or in combination of two or more.

  Examples of the adduct modified product (C3) of the diisocyanate compound (C1) include those obtained by reacting a diisocyanate compound (C1) having two isocyanate methyl groups in the molecular structure with a polyol compound. Examples of the polyol compound include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5 -Polyol monomers such as pentanediol, neopentyl glycol, 1,6-hexanediol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol; the polyol monomer and succinic acid, adipic acid, azelaic acid, Sebacic acid, terephthalic acid, isophthalic acid, orthophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, 1,4-cyclohexanedicarboxylic acid Polyester polyol obtained by co-condensation of dicarboxylic acid with a lactone type obtained by polycondensation reaction of the polyol monomer with various lactones such as ε-caprolactone, δ-valerolactone, and 3-methyl-δ-valerolactone Polyester polyol; polyether polyol obtained by ring-opening polymerization of the polyol monomer and a cyclic ether compound such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, and propyl glycidyl ether. These polyol compounds may be used alone or in combination of two or more.

  In the biuret modified product (C4) of the diisocyanate compound (C1), for example, the diisocyanate compound (C1) having two isocyanate methyl groups in the molecular structure is present in the presence of water, acid anhydride, tertiary alcohol, diamine or the like. And those obtained by biuretization reaction.

  The polyisocyanate compounds (C) listed above may be used alone or in combination of two or more. Among them, the diisocyanate compound (C1) is preferable because it is a urethane-modified epoxy resin excellent in flexibility and toughness in a cured product, and a diisocyanate compound having a ring structure in the molecular structure, that is, an alicyclic diisocyanate or an aromatic diisocyanate. Is more preferable.

  The polyol compound (D) is not particularly limited as long as it is a compound having two or more hydroxyl groups in the molecular structure, and any of various diol compounds, triol compounds, and tetrafunctional or higher polyol compounds can be used. Among these, a diol compound is preferable because it becomes a urethane-modified epoxy resin excellent in flexibility and toughness in the cured product.

  Examples of the diol compound include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5- Aliphatic diols such as pentanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol;

  Hydroquinone, 2-methylhydroquinone, 1,4-benzenedimethanol, 3,3′-biphenyldiol, 4,4′-biphenyldiol, biphenyl-3,3′-dimethanol, biphenyl-4,4′-dimethanol , Aromatic ring-containing diols such as bisphenol A, bisphenol B, bisphenol F, bisphenol S, 1,4-naphthalenediol, 1,5-naphthalenediol, 2,6-naphthalenediol, naphthalene-2,6-dimethanol;

  Ring-opening polymerization of various cyclic ether compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, or the above aliphatic or aromatic ring-containing diols and these A polyether-modified diol obtained by polymerization with a cyclic ether compound;

  Lactone-modified diol obtained by ring-opening polymerization of a lactone compound such as ε-caprolactone, or polymerization of the aliphatic or aromatic ring-containing diol with a lactone compound:

  The aliphatic or aromatic ring-containing polyol and an aliphatic dicarboxylic acid such as malonic acid, succinic acid, glutaric acid, adipic acid, and pimelic acid, and an aromatic such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, and orthophthalic acid And polyester diols obtained by reacting an aromatic dicarboxylic acid and its anhydride. These may be used alone or in combination of two or more.

  The weight average molecular weight (Mw) of the polyol compound (D) is preferably in the range of 1,000 to 4,000 because it becomes a urethane-modified epoxy resin excellent in flexibility and toughness in the cured product. A range of 500 to 3,500 is more preferable.

In the present invention, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene Sample: Filtered 0.2% by mass tetrahydrofuran solution in terms of resin solids with a microfilter (100 μl)

  The method for producing the isocyanate group-containing urethane resin (B) by reacting the polyisocyanate compound (C) with the polyol compound (D) is, for example, an isocyanate group contained in the polyisocyanate compound (C) and a polyol. The molar ratio [(NCO) / (OH)] with the hydroxyl group of the compound (D) is used in a ratio of 1.5 / 1 to 4.5 / 1, and both are used in a temperature range of 20 to 120 ° C. Among them, a method of using a known and usual urethanization catalyst may be mentioned as necessary.

  The isocyanate content of the isocyanate group-containing urethane resin (B) is preferably in the range of 2 to 4% by mass.

  The method for obtaining the polyurethane-modified epoxy resin of the present invention by reacting the hydroxyl group-containing epoxy resin (A) and the isocyanate group-containing urethane resin (B) is, for example, within a temperature range of 20 to 120 ° C., if necessary. And a conventional urethanization catalyst, and a method in which the mass ratio [(A) / (B)] of the two is reacted in a ratio of 80/20 to 55/45.

  The curable composition of this invention contains the said polyurethane modified epoxy resin and a hardening | curing agent or a hardening accelerator.

  As the curing agent or curing accelerator, those generally used for curing epoxy resins can be widely used. For example, polyamine compounds, amide compounds, acid anhydrides, phenolic hydroxyl group-containing resins, phosphorus compounds Imidazole compound, imidazoline compound, urea compound, organic acid metal salt, Lewis acid, amine complex salt and the like.

  Examples of the polyamine compound include trimethylenediamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, pentamethyldiethylenetriamine, triethylenediamine, dipropylenediamine, N, N, N ′, N′-tetramethyl. Propylenediamine, tetramethylenediamine, pentanediamine, hexamethylenediamine, trimethylhexamethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine, N, N-dimethylcyclohexylamine, diethylenetriamine, triethylenetetramine, tetra Ethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine, 1,4-diazabicyclo (2,2,2) octane (triethylene Amine), polyoxyethylene diamine, polyoxypropylene diamine, bis (2-dimethylaminoethyl) ether, dimethylaminoethoxy ethoxyethanol, triethanolamine, aliphatic amine compounds such as dimethylamino hexanol;

  Piperidine, piperazine, menthanediamine, isophoronediamine, methylmorpholine, ethylmorpholine, N, N ′, N ″ -tris (dimethylaminopropyl) hexahydro-s-triazine, 3,9-bis (3-aminopropyl) -2, 4,8,10-tetraoxyspiro (5,5) undecane adduct, N-aminoethylpiperazine, trimethylaminoethylpiperazine, bis (4-aminocyclohexyl) methane, N, N′-dimethylpiperazine, 1,8-diazabicyclo -Alicyclic and heterocyclic amine compounds such as [5.4.0] -undecene (DBU);

  Aromatic amines such as o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, benzylmethylamine, dimethylbenzylamine, m-xylenediamine, pyridine, picoline, α-methylbenzylmethylamine Compound;

  Epoxy compound addition polyamine, Michael addition polyamine, Mannich addition polyamine, thiourea addition polyamine, ketone-capped polyamine, dicyandiamide, guanidine, organic acid hydrazide, diaminomaleonitrile, amine imide, boron trifluoride-piperidine complex, boron trifluoride-mono Examples include modified amine compounds such as ethylamine complexes.

  Examples of the amide compound include dicyandiamide and polyamidoamine. Examples of the polyamidoamines include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid, carboxylic acid compounds such as fatty acid and dimer acid, aliphatic polyamines and polyoxyalkylenes. Examples thereof include those obtained by reacting a polyamine having a chain.

  Examples of the acid anhydride include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydro And phthalic anhydride.

  Examples of the phenolic hydroxyl group-containing resin include a phenol novolak resin, a cresol novolak resin, an aromatic hydrocarbon formaldehyde resin-modified phenol resin, a dicyclopentadiene phenol addition resin, a phenol aralkyl resin (Zylock resin), a naphthol aralkyl resin, Trimethylol methane resin, tetraphenylol ethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol resin (polyhydric phenol compound in which phenol nucleus is linked by bismethylene group) , Biphenyl-modified naphthol resin (polyvalent naphthol compound in which phenol nucleus is linked by bismethylene group), aminotriazine-modified phenol resin (melamine, benzo Polyhydric phenol compounds such as polyphenol compounds in which phenol nuclei are linked with anamin and the like, and alkoxy group-containing aromatic ring-modified novolak resins (polyhydric phenol compounds in which phenol nuclei and alkoxy group-containing aromatic rings are linked with formaldehyde) Can be mentioned.

  Examples of the phosphorus compound include: alkylphosphine such as ethylphosphine and butylphosphine; first phosphine such as phenylphosphine; dialkylphosphine such as dimethylphosphine and dipropylphosphine; second phosphine such as diphenylphosphine and methylethylphosphine; And tertiary phosphine such as triethylphosphine and triphenylphosphine.

  Examples of the imidazole compound include imidazole, 1-methylimidazole, 2-methylimidazole, 3-methylimidazole, 4-methylimidazole, 5-methylimidazole, 1-ethylimidazole, 2-ethylimidazole, 3-ethylimidazole, 4 -Ethylimidazole, 5-ethylimidazole, 1-n-propylimidazole, 2-n-propylimidazole, 1-isopropylimidazole, 2-isopropylimidazole, 1-n-butylimidazole, 2-n-butylimidazole, 1-isobutyl Imidazole, 2-isobutylimidazole, 2-undecyl-1H-imidazole, 2-heptadecyl-1H-imidazole, 1,2-dimethylimidazole, 1,3-dimethylimidazole, 2,4-dimethyl Ruimidazole, 2-ethyl-4-methylimidazole, 1-phenylimidazole, 2-phenyl-1H-imidazole, 4-methyl-2-phenyl-1H-imidazole, 2-phenyl-4-methylimidazole, 1-benzyl- 2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl- 2-phenylimidazole, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, - include cyanoethyl-2-phenyl-4,5-di (2-cyanoethoxy) methylimidazole, 1-dodecyl-2-methyl-3-benzyl-imidazolium chloride, 1-benzyl-2-phenylimidazole hydrochloride etc.

  Examples of the imidazoline compound include 2-methylimidazoline and 2-phenylimidazoline.

  Examples of the urea compound include p-chlorophenyl-N, N-dimethylurea, 3-phenyl-1,1-dimethylurea, 3- (3,4-dichlorophenyl) -N, N-dimethylurea, N- (3 -Chloro-4-methylphenyl) -N ', N'-dimethylurea and the like.

  Among these curing agents or curing accelerators, either an amine compound or an amide compound is preferred because of its high adhesive strength when used in adhesive applications. Of the amine compounds, polyether amines having a polyoxyalkylene structure moiety in the molecular structure are more preferred.

  The curable composition of the present invention may be used in combination with other epoxy resins other than the polyurethane-modified epoxy resin of the present invention. Other epoxy resins include, for example, bisphenol type epoxy resins such as bisphenol A type, F type, and S type, alkoxy modified bisphenol type epoxy resins, phenol novolak type, naphthol novolak type, cresol novolak type, phenol-cresol co-condensed novolak type Novolak type epoxy resins such as urethane modified epoxy resins, triphenylmethane type epoxy resins and the like.

  In the present invention, the compounding amount of the epoxy resin component and the curing agent or the curing accelerator is cured with respect to 1 mol of the epoxy group in the epoxy resin component when a curing agent having a functional group capable of reacting with an epoxy group is used. It is preferable that the functional group in the agent is blended in such a ratio that it is in the range of 0.5 to 1.1 mol. Moreover, when using a hardening accelerator, it is preferable to mix | blend in the ratio of 0.5-10 mass parts with respect to 100 mass parts of epoxy resin components.

  In addition to this, the curable composition of the present invention includes an organic solvent, an ultraviolet absorber, an antioxidant, a silicon additive, a fluorine additive, a flame retardant, a plasticizer, a silane coupling agent, organic beads, inorganic fine particles, An inorganic filler, a rheology control agent, a defoaming agent, an antifogging agent, a colorant and the like may be contained. These various components may be added in any amount depending on the desired performance.

  In the curable composition of the present invention, the polyurethane-modified epoxy resin, the curing agent or the curing accelerator, and the various optional components are pot mill, ball mill, bead mill, roll mill, homogenizer, super mill, homodisper, universal mixer, Banbury. It can prepare by mixing uniformly using a mixer, a kneader, etc.

  The application of the curable composition of the present invention is not particularly limited, and can be used for various applications such as paints, coating agents, molding materials, insulating materials, sealants, sealants, and fiber binding agents. Especially, it can be suitably used as an adhesive for structural members in the fields of automobiles, trains, civil engineering architecture, electronics, aircraft, and space industry, taking advantage of the excellent flexibility and toughness of cured products. The adhesive of the present invention can maintain high adhesion without being affected by changes in temperature environment even when used for bonding different materials such as between metal and non-metal, and peeling or the like occurs. hard. Moreover, the adhesive of the present invention can be used as an adhesive for general office work, medical use, carbon fiber, electronic materials, etc. in addition to structural member applications. As an adhesive for electronic materials, for example, build-up Interlayer adhesives for multilayer substrates such as substrates, optical component bonding adhesives, optical disk laminating adhesives, printed wiring board mounting adhesives, die bonding adhesives, semiconductor adhesives such as underfill, BGA reinforcement unders Examples thereof include mounting adhesives such as a fill, an anisotropic conductive film, and an anisotropic conductive paste.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Production Example 1 Production of Isocyanate Group-Containing Urethane Resin (B-1) A flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, and polycaprolactone diol ["Placcel 230" manufactured by Daicel Corporation, weight average molecular weight (Mw) 3,000] 871 parts by mass and 129 parts by mass of isophorone diisocyanate were mixed, and 0.1 part by mass of dioctyltin catalyst (“Neostan U-820” manufactured by Nitto Kasei Co., Ltd.) was added as a catalyst. It was made to react for 3 hours and the isocyanate group containing urethane resin (B-1) was obtained. The isocyanate group content of the isocyanate group-containing urethane resin (B-1) was 2.4% by mass.

Production Examples 2 to 4
Except having changed the reaction raw material as shown in Table 1, it carried out similarly to manufacture example 1, and obtained the isocyanate group containing urethane resin (B-2)-(B-4).

Details of the polyol compound (D) in Table 1 are as follows: “PTMG3000” —Mitsubishi Chemical Co., Ltd. Polytetramethylene glycol Weight average molecular weight (Mw) 3,000
“P-3010”: Kuraray Co., Ltd. poly (3-methyl-1,5-pentanediol adipate) Weight average molecular weight (Mw) 3,000
“D-2000”: Polypropylene glycol manufactured by Mitsui Chemicals, Ltd. Weight average molecular weight (Mw) 2,000

Production Example 5 Production of Hydroxyl-Containing Epoxy Resin (A-1) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with a bisphenol F-type epoxy resin (“EPICLON 830” epoxy equivalent, manufactured by DIC Corporation) in a nitrogen atmosphere. 167 g / equivalent) 481 parts by mass, 69 parts by mass of bisphenol F, and 0.07 part by mass of tetramethylammonium chloride as a catalyst, heated to 140 ° C. and reacted with stirring, epoxy equivalent 250 g / equivalent, hydroxyl value 85 mgKOH / g of a hydroxyl group-containing epoxy resin (A-1) was obtained.

Example 1 Production of polyurethane-modified epoxy resin (1) A flask equipped with a thermometer, a stirrer, and a reflux condenser was replaced with nitrogen, 350 parts by mass of an isocyanate group-containing urethane resin (B-1), and a bisphenol F-type epoxy. 650 parts by mass of resin (“EPICLON 830” manufactured by DIC Corporation, epoxy equivalent: 167 g / equivalent, hydroxyl value: 20 mgKOH / g), heated to 70 ° C., and reacted until the isocyanate group content is almost zero. A polyurethane-modified epoxy resin (1) was obtained. The epoxy equivalent of the polyurethane-modified epoxy resin (1) was 255 g / equivalent.

Examples 2-5
Polyurethane-modified epoxy resins (2) to (5) were obtained in the same manner as in Example 1 except that the reaction raw materials were changed as shown in Table 2. “EPICLON 850” is a bisphenol A type epoxy resin manufactured by DIC Corporation having an epoxy equivalent of 188 g / equivalent and a hydroxyl value of 20 mgKOH / g.

Comparative Production Example 1 Production of polyurethane-modified epoxy resin (1 ′) A flask equipped with a thermometer, a stirrer, and a reflux condenser was charged with a bisphenol F-type epoxy resin (“EPICLON 830” epoxy equivalent, manufactured by DIC Corporation) in a nitrogen atmosphere. 167 g / equivalent) 850 parts by mass and 150 parts by mass of an isocyanate-containing urethane resin (B-4) were added. The mixture was heated to 70 ° C. and reacted until the isocyanate group content was almost 0 to obtain a polyurethane-modified epoxy resin (1 ′). The epoxy equivalent of the obtained polyurethane-modified epoxy resin (1 ′) was 200 g / equivalent.

Examples 6 to 10, Comparative Example 1
Preparation and Evaluation of Curable Composition (I) Using the polyurethane-modified epoxy resins obtained in Examples 1 to 5 and Comparative Production Example 1, the curable composition (I) was prepared in the following manner, and various kinds of cured products were obtained. An evaluation test was conducted. The results are shown in Table 3.

Preparation of curable composition (I) Modified epoxy resin, polyetheramine ("JEFFAMINE D-230" active hydrogen equivalent 57 g / equivalent by Huntsman) was blended in the ratio shown in Table 3, and curable composition (I) Got.

Tensile test The curable composition (I) obtained above was poured into a mold having a thickness of 2 mm and cured at 80 ° C., 100 ° C., and 120 ° C. for 3 hours each. A No. 1 dumbbell-shaped sample was cut out from the cured product, a tensile test was performed using “AUTOGRAPH AG-IS 1 kN” manufactured by Shimadzu Corporation, and the elongation percentage (%) was evaluated.

Adhesion test Two steel plates were thermoset bonded using the curable composition (I) obtained above. The film thickness of the adhesive layer was 0.2 mm and cured at 80 ° C., 100 ° C., and 120 ° C. over 3 hours each. The obtained adhesion test steel plate was subjected to a tensile shear test using “AUTOGRAPH AG-IS 10 kN” manufactured by Shimadzu Corporation based on JIS K6859 (creep rupture test of adhesive), and evaluated by breaking strength (MPa). .

Examples 11-20
Preparation and evaluation of curable compositions (II) and (III) Using the polyurethane-modified epoxy resins obtained in Examples 1 to 5, curable compositions (II) and (III) were prepared in the following manner and cured. Various evaluation tests were performed on the products. The results are shown in Tables 4 and 5.

Preparation of curable composition (II) Polyurethane-modified epoxy resin, dicyandiamide, and 3,4-dichlorophenyl-N, N-dimethylurea were blended in the proportions shown in Table 4 to obtain curable composition (II).

Tensile test The curable composition (II) obtained above was poured into a mold so that the film thickness was 2 mm, and heated at 180 ° C. for 1 hour to be cured. A No. 1 dumbbell-shaped sample was cut out from the cured product, a tensile test was performed using “AUTOGRAPH AG-IS 1 kN” manufactured by Shimadzu Corporation, and the elongation percentage (%) was evaluated.

Adhesion test Two steel plates were thermoset bonded using the curable composition (II) obtained above. The thickness of the adhesive layer was 0.2 mm, and it was cured by heating at 180 ° C. for 1 hour. The obtained adhesion test steel plate was subjected to a tensile shear test using “AUTOGRAPH AG-IS 10 kN” manufactured by Shimadzu Corporation based on JIS K6859 (creep rupture test of adhesive), and evaluated by breaking strength (MPa). .

Preparation of Curable Composition (III) A polyurethane-modified epoxy resin and an amide resin (“Lacamide TD-960” active hydrogen equivalent 78 g / equivalent by DIC Corporation) were blended at a ratio shown in Table 5 to obtain a curable composition (III )

Tensile test The curable composition (III) obtained above was poured into a mold so as to have a film thickness of 2 mm, and heated and cured in order at 80 ° C., 100 ° C., and 120 ° C. for 3 hours each. A No. 1 dumbbell-shaped sample was cut out from the cured product, a tensile test was performed using “AUTOGRAPH AG-IS 1 kN” manufactured by Shimadzu Corporation, and the elongation percentage (%) was evaluated.

Adhesion test Two steel plates were thermoset bonded using the curable composition (III) obtained above. The film thickness of the adhesive layer was 0.2 mm, and was cured by heating at 80 ° C., 100 ° C., and 120 ° C. for 3 hours each. The obtained adhesion test steel plate was subjected to a tensile shear test using “AUTOGRAPH AG-IS 10 kN” manufactured by Shimadzu Corporation based on JIS K6859 (creep rupture test of adhesive), and evaluated by breaking strength (MPa). .

Claims (8)

A polyurethane-modified epoxy resin obtained by reacting a hydroxyl group-containing epoxy resin (A) with an isocyanate group-containing urethane resin (B) and having an epoxy equivalent in the range of 240 to 400 g / equivalent. The polyurethane modification according to claim 1, wherein the reaction mass ratio [(A) / (B)] of the hydroxyl group-containing epoxy resin (A) and the isocyanate group-containing urethane resin (B) is in the range of 80/20 to 55/45. Epoxy resin. The hydroxyl group-containing epoxy resin (A) is represented by the following structural formula (1)

[In the formula, each X independently represents the following structural formulas (2-1) to (2-8).

(In the formula, each R ² is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and R ³ is independently each having 1 to 4 carbon atoms. Or an alkyl group having 1 to 4 carbon atoms, and n is 0 or an integer of 1 or more.)
It is a structural part represented by either. ]
The polyurethane-modified epoxy resin according to claim 1, which has a molecular structure represented by: The polyurethane-modified epoxy resin according to claim 1, wherein the epoxy equivalent of the hydroxyl group-containing epoxy resin (A) is in the range of 155 to 300 g / equivalent. A curable composition comprising the polyurethane-modified epoxy resin according to claim 1 and a curing agent or a curing accelerator. The curable composition according to claim 5, wherein the curing agent or curing accelerator is a polyetheramine compound or an amide compound. Hardened | cured material obtained by hardening the curable composition of Claim 5 or 6. The adhesive agent containing the polyurethane modified epoxy resin as described in any one of Claims 1-4, and a hardening | curing agent or a hardening accelerator.

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