JP6650125B2 - Polyester modified epoxy resin and adhesive - Google Patents

Description

  The present invention relates to a polyester-modified epoxy resin having excellent 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 plastic have been adopted as automobile body materials from the viewpoint of energy saving, and adhesives have been increasingly used in assembling instead of welding. The characteristics of automotive adhesives are that they are used for bonding between different materials and that the temperature of the operating environment changes very sharply.Currently, epoxy resin adhesives with excellent heat resistance and mechanical properties are mainly used. ing. However, conventional epoxy resin-based adhesives have insufficient flexibility and toughness in cured products and cannot follow thermal deformation of members, and thus have a problem that distortion and peeling easily occur in high-temperature and low-temperature environments. 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 materials is large, and the problems of distortion and peeling have been remarkable.

  For example, as an epoxy resin composition for an adhesive, an epoxy resin composition containing a bisphenol A epoxy resin having an epoxy equivalent of 188 g / equivalent and a propylene oxide-modified bisphenol epoxy resin is known (see Patent Document 1). ), The flexibility and toughness of the cured product were not sufficient, and were not of a level that could be used for automotive adhesives.

JP 2007-284467 A

  Accordingly, an object of the present invention is to provide an epoxy resin having excellent flexibility and toughness in a cured product, a curable composition containing the same, a cured product thereof, and an adhesive.

  The present inventors have conducted intensive studies to solve the above problems, and as a result, an epoxy resin having a polyester structure site in the main skeleton of the resin is excellent in flexibility and toughness in a cured product, and is suitable for use in an adhesive. This led to the completion of the present invention.

  That is, the present invention relates to a polyester-modified epoxy resin having a molecular structure obtained by reacting an acid group-containing polyester resin (A) with a bifunctional epoxy compound (B).

The present invention further provides the following structural formula (2)

［式中Ｘは下記構造式（３−１）〜（３−８）

[Wherein X is the following structural formulas (3-1) to (3-8)

（式中、Ｒ^１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^２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る。）
の何れかで表される構造部位であり、Ｙはポリエステル構造部位である。ｎは繰り返し単位数であり１以上の整数である。］
で表される樹脂構造を有することを特徴とするポリエステル変性エポキシ樹脂に関する。

(Wherein, R ¹ is independently any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms, and R ² is each independently a group having 1 to 4 carbon atoms. Or an alkoxy group having 1 to 4 carbon atoms.)
And Y is a polyester structural site. n is the number of repeating units and is an integer of 1 or more. ]
The present invention relates to a polyester-modified epoxy resin having a resin structure represented by the following formula:

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

  The present invention further relates to a method for producing a polyester-modified epoxy resin in which an acid group-containing polyester resin (A) is reacted with a bifunctional epoxy compound (B).

  According to the present invention, it is possible to provide a polyester-modified epoxy resin having excellent flexibility and toughness in a cured product, a curable composition containing the same, a cured product thereof, and an adhesive.

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

Hereinafter, the present invention will be described in detail.
The polyester-modified epoxy resin of the present invention has a molecular structure obtained by reacting an acid group-containing polyester resin (A) with a bifunctional epoxy compound (B). That is, by having a polyester structure site derived from the acid group-containing polyester resin (A) in the structure of the epoxy resin, the cured product has an effect of being excellent in flexibility and toughness.

  The acid group-containing polyester resin (A) is, for example, a polyester resin obtained by reacting a polyol compound and a polycarboxylic acid compound, and having an acid group capable of reacting with the bifunctional epoxy resin (B). Is mentioned.

  Examples of the polyol compound include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, and 2,2-dimethyl-3-isopropyl-1,3. -Propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, Diol compounds such as 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-bis (hydroxymethyl) cyclohesan;

  Trifunctional or higher functional polyol compounds such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol;

  Polyol obtained from the diol compound or a polyol compound having three or more functional groups and various cyclic ether compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether. Examples include ether-modified polyols. These may be used alone or in combination of two or more.

  On the other hand, the polycarboxylic acid compound is, for example, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid Dicarboxylic acid compounds such as, hexahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, and glutaconic acid;

  Examples thereof include tricarboxylic acid compounds such as 1,2,5-hexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, trimellitic acid, and 2,5,7-naphthalenetricarboxylic acid. These may be used alone or in combination of two or more.

  Among them, a linear polyester resin having a carboxyl group at both terminals, which is obtained by reacting a diol compound and a dicarboxylic acid compound, is preferable since the effect of excellent flexibility and toughness in the cured product becomes more remarkable.

  The reaction between the polyol compound and the polycarboxylic acid compound includes, for example, a method in which a reaction is performed under a temperature condition of about 180 to 250 ° C. in the presence of a suitable esterification catalyst. The reaction ratio of the two is preferably such that the carboxyl group in the polycarboxylic acid compound is in the range of 1.5 to 2 mol per 1 mol of the hydroxyl group in the polyol compound.

  The acid value of the acid group-containing polyester resin (A) is preferably in the range of 100 to 300 mgKOH / g, and more preferably 150 to 250 mgKOH / g, since the acid value of the acid-containing polyester resin (A) is a polyester-modified epoxy resin having excellent flexibility and toughness in the cured product. More preferably, it is within the range.

  The bifunctional epoxy compound (B) is not particularly limited as long as it has two epoxy groups in the molecular structure, and examples thereof include diglycidyl ethers of various diol compounds. Among them, a diglycidyl ether of an aromatic ring-containing diol compound is preferable, and a diglycidyl ether of bisphenol or biphenol is particularly preferable because it becomes a polyester-modified epoxy resin having excellent flexibility and toughness in a cured product.

  The diglycidyl ether of bisphenol or biphenol is specifically represented by the following structural formulas (1-1) to (1-8)

（式中Ｇはグリシジル基を表し、Ｒ^１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^２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る。）
の何れかで表されるものが挙げられる。これらはそれぞれ単独で用いても良いし、２種類以上を併用しても良い。中でも、硬化物における柔軟性と靱性に優れることから、前記一般式（１−１）又は（１−２）で表される化合物が好ましい。

(Wherein G represents a glycidyl group, R ¹ is each 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 ² is each independently Any of an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms.)
And those represented by any of the above. These may be used alone or in combination of two or more. Among them, the compound represented by the general formula (1-1) or (1-2) is preferable because the cured product has excellent flexibility and toughness.

  The reaction between the acid group-containing polyester resin (A) and the bifunctional epoxy compound (B) is carried out, for example, by a method of reacting at a temperature of about 80 to 140 ° C. in the presence of a catalyst such as triphenylphosphine. No. The reaction ratio of the two is preferably such that the carboxyl group in the polyester resin (A) is in the range of 0.3 to 0.8 mol per 1 mol of the epoxy group in the epoxy compound (B). .

  The polyester-modified epoxy resin of the present invention uses, for example, a linear polyester resin having a carboxyl group at the terminal as the polyester resin (A), and the structural formula (1-1) to the bifunctional epoxy resin (B). When the compound represented by any of (1-8) is used, specifically, the following structural formula (2)

［式中Ｘは下記構造式（３−１）〜（３−８）

[Wherein X is the following structural formulas (3-1) to (3-8)

（式中、Ｒ^１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^２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る。）
の何れかで表される構造部位であり、Ｙはポリエステル構造部位である。ｎは繰り返し単位数であり１以上の整数である。］
で表される樹脂構造を有するものが挙げられる。

(Wherein, R ¹ is independently any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms, and R ² is each independently a group having 1 to 4 carbon atoms. Or an alkoxy group having 1 to 4 carbon atoms.)
And Y is a polyester structural site. n is the number of repeating units and is an integer of 1 or more. ]
And those having a resin structure represented by

  In addition, the epoxy equivalent of the polyester-modified epoxy resin of the present invention is preferably in the range of 450 to 800 g / equivalent, and more preferably in the range of 500 to 700 g / equivalent, since the cured product is excellent in flexibility and toughness. preferable.

  The curable composition of the present invention contains the polyester-modified epoxy resin and a curing agent or a curing 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 compounds, imidazoline compounds, urea compounds, organic acid metal salts, Lewis acids, amine complex salts and the like.

  Examples of the polyamine compound include trimethylenediamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, pentamethyldiethylenetriamine, triethylenediamine, dipropylenediamine, N, N, N ′, N′-tetramethyl. Propylene diamine, tetramethylene diamine, pentane diamine, hexamethylene diamine, trimethyl hexamethylene diamine, N, N, N ', N'-tetramethyl hexamethylene diamine, N, N-dimethylcyclohexylamine, diethylene triamine, triethylene tetramine, tetraethylene 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 added polyamine, Michael added polyamine, Mannich added polyamine, thiourea added polyamine, ketone-blocked polyamine, dicyandiamide, guanidine, organic acid hydrazide, diaminomaleonitrile, amine imide, boron trifluoride-piperidine complex, boron trifluoride-mono Modified amine compounds such as an ethylamine complex are exemplified.

  Examples of the amide compound include dicyandiamide and polyamidoamine. The polyamidoamines include, for example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, aliphatic dicarboxylic acids such as azelaic acid, fatty acids, carboxylic acid compounds such as dimer acid, and aliphatic polyamines and polyoxyalkylenes. Those obtained by reacting a polyamine having a chain and the like can be mentioned.

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

  Examples of the phenolic hydroxyl group-containing resin include phenol novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin-modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin (Xyloc resin), naphthol aralkyl resin, Trimethylolmethane resin, tetraphenylolethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin (polyphenol compound with phenol nucleus linked by bismethylene group) , Biphenyl-modified naphthol resin (a polyvalent naphthol compound having a phenol nucleus linked by a bismethylene group), aminotriazine-modified phenol resin (melamine, benzo Polyhydric phenol compounds such as a polyhydric phenol compound having a phenol nucleus linked with an anamine or the like and an alkoxy group-containing aromatic ring-modified novolak resin (a polyphenol compound having a phenol nucleus and an alkoxy group-containing aromatic ring linked with formaldehyde) are used. No.

  Examples of the phosphorus compound include: alkyl phosphines such as ethyl phosphine and butyl phosphine; first phosphines such as phenyl phosphine; dialkyl phosphines such as dimethyl phosphine and dipropyl phosphine; second phosphines such as diphenyl phosphine and methyl ethyl phosphine; trimethyl phosphine And tertiary phosphines such as triethylphosphine and triphenylphosphine.

  Examples of the imidazole compound include, for example, imidazole, 1-methylimidazole, 2-methylimidazole, 3-methylimidazole, 4-methylimidazole, 5-methylimidazole, 1-ethylimidazole, 2-ethylimidazole, 3-ethylimidazole, -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 Louisimidazole, 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, and N- (3 -Chloro-4-methylphenyl) -N ', N'-dimethylurea and the like.

  Among these curing agents or curing accelerators, any of an imidazole compound, an amine compound, and an amide compound are preferable because of high adhesive strength when used for an adhesive. Further, among the amine compounds, a polyetheramine having a polyoxyalkylene structure site in the molecular structure is more preferable.

  The curable composition of the present invention may be used in combination with another epoxy resin other than the polyester-modified epoxy resin of the present invention. Other epoxy resins, for example, diglycidyl ether of polyoxyalkylene diol, bisphenol type epoxy resin, biphenol type epoxy resin, polyalkylene oxide modified bisphenol type epoxy resin, polyalkylene oxide modified biphenol type epoxy resin, phenol novolak type epoxy resin Novolak epoxy resins such as naphthol novolak epoxy resin, cresol novolak epoxy resin, phenol-cresol co-condensed novolak epoxy resin, and triphenylmethane epoxy resin. Among them, bisphenol-type epoxy resin, biphenol-type epoxy resin, polyalkylene oxide-modified bisphenol-type epoxy resin, polyalkylene oxide-modified biphenol, in combination with the polyester-modified epoxy resin of the present invention, since the cured product has excellent flexibility and toughness It is preferable to use a bifunctional epoxy resin having a bisphenol or biphenol skeleton, such as a type epoxy resin.

  Examples of the bisphenol-type epoxy resin or biphenol-type epoxy resin include those obtained using various bisphenol compounds or biphenol compounds and epihalohydrin as resin raw materials. More specifically, the following structural formula (4)

［式中Ｘは下記構造式（３−１）〜（３−８）

[Wherein X is the following structural formulas (3-1) to (3-8)

（式中、Ｒ^１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^２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る。）
の何れかで表される構造部位である。ｍは繰り返し単位数であり０又は１以上の整数である。］
で表されるものなどが挙げられる。これらはそれぞれ単独で用いても良いし、２種類以上を併用しても良い。中でも、硬化物における柔軟性と靱性に優れることから、式中のＸが構造式（３−１）又は（３−２）で表される構造部位であるものがより好ましい。

(Wherein, R ¹ is independently any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms, and R ² is each independently a group having 1 to 4 carbon atoms. Or an alkoxy group having 1 to 4 carbon atoms.)
Is a structural site represented by any of the above. m is the number of repeating units and is 0 or an integer of 1 or more. ]
And the like. These may be used alone or in combination of two or more. Among them, those in which X in the formula is a structural part represented by the structural formula (3-1) or (3-2) are more preferable because the cured product has excellent flexibility and toughness.

  The polyalkylene oxide-modified bisphenol-type epoxy resin or polyalkylene oxide-modified biphenol-type epoxy resin includes, for example, various bisphenol compounds or biphenol compounds, and ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, and the like. And diglycidyl etherified alkylene oxide-modified bisphenols or biphenols obtained from the above cyclic ether compounds. Specifically, the following structural formula (5)

［式中Ｘは下記構造式（３−１）〜（３−８）

[Wherein X is the following structural formulas (3-1) to (3-8)

（式中、Ｒ^１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^２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る。）
の何れかで表される構造部位である。Ｒ^３は炭素原子数２〜６のアルキル基であり、ｌはそれぞれ独立に１以上の整数である。］
で表されるものなどが挙げられる。これらはそれぞれ単独で用いても良いし、２種類以上を併用しても良い。中でも、硬化物における柔軟性と靱性に優れることから、式中のＸが構造式（３−１）又は（３−２）で表される構造部位であるものがより好ましい。

(Wherein, R ¹ is independently any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms, and R ² is each independently a group having 1 to 4 carbon atoms. Or an alkoxy group having 1 to 4 carbon atoms.)
Is a structural site represented by any of the above. R ³ is an alkyl group having 2 to 6 carbon atoms, and 1 is each independently an integer of 1 or more. ]
And the like. These may be used alone or in combination of two or more. Among them, those in which X in the formula is a structural site represented by the structural formula (3-1) or (3-2) are more preferable because the cured product has excellent flexibility and toughness.

In the structural formula (5), R ³ is an alkyl group having 2 to 6 carbon atoms. However, R ³ is an alkyl group having 2 or 3 carbon atoms because a cured product having excellent softness and toughness can be obtained. Is preferred. L in the structural formula (5) is the number of repeating units of the alkylene oxide, and is an integer of 1 or more. However, from the viewpoint of obtaining a cured product having excellent flexibility and toughness, each is preferably an integer of 1 to 6. Preferably, the sum of two l in the structural formula is in the range of 2 to 12. The epoxy equivalent of the epoxy resin represented by the structural formula (5) is preferably in the range of 250 to 550 g / equivalent, since a cured product having excellent flexibility and toughness can be obtained.

  In the curable composition of the present invention, when the other epoxy resin is used, the effect of the present invention is exhibited, which is excellent in flexibility and toughness in the cured product. It is preferable to use the polyester-modified epoxy resin of the present invention in a proportion of 30% by mass or more.

  In the curable composition of the present invention, a cured product excellent in flexibility and toughness can be obtained. Therefore, the polyester-modified epoxy resin of the present invention and the polyalkylene oxide-modified bisphenol type epoxy represented by the structural formula (5) are used. It is preferable to use a resin or a polyalkylene oxide-modified biphenol type epoxy resin in combination, and it is particularly preferable that the compounding mass ratio of both is in the range of 40/60 to 60/40.

  Moreover, since the curability is excellent, the epoxy equivalent of the entire epoxy resin component is preferably in the range of 300 to 600 g / equivalent.

  In the curable composition of the present invention, the mixing amount of the epoxy resin component and the curing agent or the curing accelerator is such that when a curing agent having a functional group capable of reacting with an epoxy group is used, the epoxy group in the epoxy resin component It is preferable to blend the functional group in the curing agent in a ratio of 0.5 to 1.1 mol based on the mol. When a curing accelerator is used, it is preferable to mix the curing accelerator in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin component.

  The curable composition of the present invention may further include an organic solvent, an ultraviolet absorber, an antioxidant, a silicon-based additive, a fluorine-based additive, a flame retardant, a plasticizer, a silane coupling agent, an organic bead, inorganic fine particles, It may contain an inorganic filler, a rheology control agent, a defoaming agent, an antifogging agent, a colorant, and the like. These various components may be added in optional amounts depending on the desired performance.

  The curable composition of the present invention, the polyester resin-modified epoxy resin, a curing agent or a curing accelerator, and the various optional components, a pot mill, a ball mill, a bead mill, a roll mill, a homogenizer, a super mill, a homodisper, a universal mixer, It can be prepared by mixing uniformly using a Banbury mixer, a kneader or the like.

  The use of the curable composition of the present invention is not particularly limited, and the curable composition can be used for various uses such as a paint, a coating agent, a molding material, an insulating material, a sealant, a sealant, and a fiber binding agent. Above all, the cured product can be suitably used as an adhesive for structural members in the fields of automobiles, trains, civil engineering, electronics, aircraft, and the space industry, taking advantage of its excellent flexibility and toughness. The adhesive of the present invention can maintain high adhesiveness without being affected by changes in the temperature environment, for example, even when used for bonding different materials such as a metal and a non-metal. hard. In addition, the adhesive of the present invention can be used as an adhesive for general office work, medical use, carbon fiber, electronic materials, and the like, in addition to structural members, and as an adhesive for electronic materials, for example, build-up Adhesives for interlayer of multi-layer substrates such as substrates, adhesives for bonding optical components, adhesives for bonding optical disks, adhesives for mounting printed wiring boards, die bonding adhesives, adhesives for semiconductors such as underfill, BGA reinforcement under An adhesive for mounting such as a fill, an anisotropic conductive film, and an anisotropic conductive paste may be used.

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

Production Example 1 Production of Acid-Containing Polyester Resin (A-1) In a flask equipped with a thermometer, a stirrer, and a reflux condenser, under a nitrogen atmosphere, 220 parts by mass of ethylene glycol, 780 parts by mass of adipic acid, and a catalyst 0.035 parts by mass of tetraisopropyl titanate was added, and the mixture was heated to 140 ° C. and stirred and mixed for 1 hour. Subsequently, the temperature was raised to 220 ° C. to cause a reaction, and an acid group-containing polyester resin (A-1) having an acid value of 224 mgKOH / g was obtained.

Production Examples 2 and 3 Production of Acid-Group-Containing Polyester Resins (A-2) and (A-3) Acid group-containing polyester resins were prepared in the same manner as in Production Example 1 except that the types of raw materials and the amounts charged were changed as shown in Table 1. Polyester resins (A-2) and (A-3) were obtained.

Production Example 4 Production of Acid-Containing Polyester Resin (A-4) Under a nitrogen atmosphere, 196 parts by mass of ethylene glycol, 284 parts by mass of sebacic acid and a catalyst were placed in a flask equipped with a thermometer, a stirrer, and a reflux condenser. 0.035 parts by mass of tetraisopropyl titanate was charged, heated to 140 ° C., and stirred and mixed for 1 hour. Then, the temperature was raised to 220 ° C. to cause a reaction. When the acid value became 3 or less, the temperature was lowered to 110 ° C., and 519 parts by mass of phthalic anhydride was added. The temperature was raised to 200 ° C., and the mixture was further reacted to obtain an acid group-containing polyester resin (A-4) having an acid value of 209 mgKOH / g.

Example 1 Production of Polyester-Modified Epoxy Resin (1) An acid group-containing polyester resin (A-1) obtained in Production Example 1 was placed in a flask equipped with a thermometer, a stirrer, and a reflux condenser under a nitrogen atmosphere. After charging 422 parts by mass and 578 parts by mass of a bisphenol F type epoxy resin ("EPICLON 830" epoxy equivalent: 167 g / equivalent, manufactured by DIC Corporation), the temperature was raised to 70 ° C, and then 0.3 parts by mass of triphenylphosphine was charged as a catalyst. It is. Thereafter, the temperature was raised to 120 ° C., and the reaction was carried out until the acid value became approximately 0 mg KOH / g, to obtain a polyester-modified epoxy resin (1) having an epoxy equivalent of 567 g / equivalent.

Examples 2 to 4 Production of polyester-modified epoxy resin (2) to (4) Polyester-modified epoxy resin (2) in the same manner as in Example 1 except that the types of raw materials and the amounts charged were changed as shown in Table 2. To (4) were obtained.

（※１）「ＥＰＩＣＬＯＮ ８５０」：ＤＩＣ株式会社製のビスフェノールＡ型エポキシ樹脂、エポキシ当量１８８ｇ/当量

(* 1) "EPICLON 850": bisphenol A type epoxy resin manufactured by DIC Corporation, epoxy equivalent 188 g / equivalent

Example 5 Preparation of Epoxy Resin Composition (1) 1000 parts by mass of the polyester-modified epoxy resin (1) obtained in Example 1 was heated to 100 ° C., and a polyalkylene oxide-modified epoxy resin [Shin Nippon Rika Co., Ltd. Rica Resin BEO-60E ", bisphenol A bis (triethylene glycol diglycidyl ether) ether, epoxy equivalent 351 g / equivalent] (1000 parts by mass) were added and mixed to obtain an epoxy resin composition (1).

Examples 6 to 8 Preparation of Epoxy Resin Compositions (2) to (4) Epoxy resin compositions (2) to (4) were obtained in the same manner as in Example 5, except that the mixing ratios were as shown in Table 3.

Comparative Example 1 Preparation of Epoxy Resin Composition (1 ') An epoxy resin composition (1') was obtained in the same manner as in Example 5, except that the mixing ratio shown in Table 3 was used.

Examples 9 to 12, Comparative Example 2
Preparation and evaluation of curable composition (I) Using the epoxy resin compositions obtained in Examples 5 to 8 and Comparative Example 1, curable composition (I) was prepared in the following manner, and various types of cured products were prepared. An evaluation test was performed. Table 4 shows the results.

Preparation of Curable Composition (I) An epoxy resin composition, 2-ethyl-4-methylimidazole, and 3- (3,4-dichlorophenyl) -N, N-dimethylurea were blended in the proportions shown in Table 4, A curable composition (I) was obtained.

Tensile test The curable composition (I) obtained above was poured into a mold having a thickness of 2 mm, and cured at 150 ° C for 1 hour. A No. 1 dumbbell-shaped sample was cut out from the cured product, and a tensile test was performed using “AUTOGRAPH AG-IS 1 kN” manufactured by Shimadzu Corporation to evaluate the elongation (%).

Adhesion test Two sheets of steel sheet were bonded by thermosetting using the curable composition (I) obtained above. The thickness of the adhesive layer was set to 0.2 mm, and it was cured by heating at 150 ° C. for 1 hour. The obtained adhesion test steel sheet was subjected to a tensile shear test using “AUTOGRAPH AG-IS 10 kN” manufactured by Shimadzu Corporation based on JIS K6859 (creep breaking test of adhesive), and evaluated by breaking strength (MPa). .

Examples 13 to 24
Preparation and Evaluation of Curable Compositions (II) to (IV) Using the epoxy resin compositions obtained in Examples 1 to 4, curable compositions (II) to (IV) were prepared in the following manner, and Various evaluation tests were performed on the cured product. The results are shown in Tables 5 to 7.

Preparation of Curable Composition (II) An epoxy resin composition and a polyetheramine ("JEFFAMINE D-230" manufactured by Huntsman) having an active hydrogen equivalent of 57 g / equivalent) were blended in the ratio shown in Table 5 to obtain a curable composition (II). ) Got.

Tensile test The curable composition (II) obtained above was poured into a mold so as to have a film thickness of 2 mm, and was heated 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, and a tensile test was performed using “AUTOGRAPH AG-IS 1 kN” manufactured by Shimadzu Corporation to evaluate the elongation (%).

Adhesion test Two sheets of steel sheet were bonded by thermosetting using the curable composition (II) obtained above. The thickness of the adhesive layer was 0.2 mm, and the coating was heated and cured at 80 ° C., 100 ° C., and 120 ° C. in this order for 3 hours. The obtained test steel sheet was subjected to a tensile shear test using “AUTOGRAPH AG-IS 10 kN” manufactured by Shimadzu Corporation based on JIS K6859 (creep fracture test of adhesive), and evaluated by breaking strength (MPa).

Preparation of Curable Composition (III) An epoxy resin composition, dicyandiamide, and 3,4-dichlorophenyl-N, N-dimethylurea were blended in the ratio shown in Table 6 to obtain a curable composition (III).

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

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

Preparation of Curable Composition (IV) An epoxy resin composition and an amide resin ("Lacamide TD-960" manufactured by DIC Co., Ltd., active hydrogen equivalent: 78 g / equivalent) were blended at a ratio shown in Table 7 to obtain a curable composition (IV). ) Got.

Tensile test The curable composition (IV) obtained above was poured into a mold so as to have a film thickness of 2 mm, and heated 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, and a tensile test was performed using “AUTOGRAPH AG-IS 1 kN” manufactured by Shimadzu Corporation to evaluate the elongation (%).

Adhesion test Two sheets of steel sheet were bonded by thermosetting using the curable composition (IV) obtained above. The thickness of the adhesive layer was 0.2 mm, and the coating was heated and cured at 80 ° C., 100 ° C., and 120 ° C. in this order for 3 hours. The obtained adhesive test steel sheet was subjected to a tensile shear test using “AUTOGRAPH AG-IS 10 kN” manufactured by Shimadzu Corporation based on JIS K6859 (creep fracture test of adhesive), and evaluated by breaking strength (MPa). .

Claims (7)

The following structural formula (2) obtained by reacting an acid group-containing polyester resin (A) with a bifunctional epoxy compound (B )

[Wherein X is the following structural formulas (3-1) to (3-8)

(Wherein, R ¹ is independently any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms, and R ² is each independently a group having 1 to 4 carbon atoms. Or an alkoxy group having 1 to 4 carbon atoms.)
And Y is a polyester structural site. n is the number of repeating units and is an integer of 1 or more. ]
Represented by, a polyester-modified epoxy resin having an epoxy equivalent in the range of 450 to 800 g / equivalent ,
A curable composition containing a curing agent or a curing accelerator, and a polyalkylene oxide-modified bisphenol-type epoxy resin or a polyalkylene oxide-modified biphenol-type epoxy resin. The curable composition according to claim 1, wherein the epoxy equivalent of the polyester-modified epoxy resin is in the range of 500 to 700 g / equivalent. The curable composition according to claim 1, wherein the polyester resin (A) is a linear polyester resin obtained by reacting a diol compound and a dicarboxylic acid compound. The curable composition according to claim 1, wherein the polyester resin (A) has an acid value in a range of 100 to 300 mgKOH / g. The curable composition according to any one of claims 1 to 4 , wherein the curing agent or the curing accelerator is any of an imidazole compound, a polyetheramine compound, and an amide compound. Cured product obtained by curing the curable composition according to any one of claims 1-5. Adhesive containing curable composition according to any one of claims 1-5.

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