JP2006199863A - Epoxy resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat curing epoxy resin composition expressing properties having excellent elongation at ordinary temperatures with increasing the adhesive strength of a cured product and excellent in toughness. <P>SOLUTION: The heat curing epoxy resin composition is prepared by reacting the glycidyl ether of a glycol with a phenol compound and comprises an epoxy resin (A) expressed by general formula (1) and a curing agent (B) which is an amine compound or its derivative expressed by general formula (2) or general formula (3). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermosetting epoxy resin composition having excellent elongation at room temperature and excellent toughness while improving the adhesive strength of a cured product.

  Conventionally, epoxy resins are known to have high strength and elastic modulus of cured products, high adhesive strength, excellent heat resistance, and excellent chemical resistance, and are used in a wide range of industrial fields. ing.

  However, although the composition using an epoxy resin has the above-mentioned features, the cured product has a drawback that it is very brittle. This means that after being cured by heat or the like, the cured product is destroyed by some distortion, which is very problematic in various applications. For example, when it is used for electrical parts incorporated in automobiles, home appliances, and other applied products, a brittle cured product is not preferable because it causes cracking due to mechanical vibration or expansion and contraction due to heat, causing corrosion and performance degradation. .

  In order to eliminate the brittleness of the cured product, an attempt has been made to add a rubber-like material having a butadiene skeleton (see Patent Document 1). However, since the amount to be added is not so large, it is difficult to obtain a cured product that is so flexible that the cured product has elasticity like an elastic body such as rubber.

  Attempts have also been made to modify the epoxy resin itself (see Patent Document 2). In this patent, an epoxy resin compound obtained by glycidyl etherification of a compound obtained by adding 5 moles of propylene oxide to bisphenol A is used, and a cured product using the compound has flexibility but excellent elongation. It was not enough.

In addition, the present inventors have proposed an epoxy resin composition that imparts flexibility and toughness to the cured product (see Patent Document 3). However, it was not sufficient in the stretchability of the cured product at room temperature.
Japanese Patent Laid-Open No. 07-268079 JP 2003-246837 A (Claim 4 and paragraph 30) Japanese Patent Application No. 2004-248872 (Claims 1 and 2)

  An object of this invention is to provide the thermosetting epoxy resin composition which expresses the performance which has the outstanding elongation at normal temperature, and is excellent in toughness, improving the adhesive strength of hardened | cured material.

  As a result of intensive studies to solve the above problems, the present inventors have found that a thermosetting resin composition containing an epoxy resin and an amine curing agent described later as essential components can achieve the above-described object. The present invention has been completed.

（ｍは１〜２０の自然数、ｎは１〜１４の自然数、Ｘはハロゲン原子またはＣ１〜５のアルキル基、ａおよびｂは０〜４の整数、Ｇ_１およびＧ_２はグリシジル基又は水素原子（ただし、Ｇ１、Ｇ２が同時に水素原子であることはない）、Ｒ_１はＣ１ 〜１０のアルキレン基またはアルキリデン基、Ｒ_２はアルキレン基、アルキリデン基、スルホニル基、酸素原子または原子団の存在しない直接結合を示す。）

（ｎは１〜４０の自然数、Ｒ_１はＣ１〜１０のアルキレン基またはアルキリデン 基を示す。）

（ｎは１〜４０の自然数、ｍは３〜６の自然数、Ｒ_１はＣ１〜１０のアルキレン基またはアルキリデン基、Ｒ_２はＣ４〜１０のアルキリデン基を示す。） That is, the present invention is a compound obtained by reacting a glycol glycidyl ether with a phenol compound, and the epoxy resin (A) represented by the following general formula (1) and the general formula (2) or the general formula (3) or It has been found that the above object can be achieved by using a thermosetting epoxy resin composition comprising a curing agent (B) which is a derivative thereof.

(M is a natural number of 1 to 20, n is a natural number of 1 to 14, X is an alkyl group, a and b are integers of 0 to 4, _{G 1} and _{G 2} are glycidyl groups or a hydrogen atom a halogen atom or C1~5 (However, G1, G2 are not hydrogen atoms at the same time), _{R 1} is C1 to 10 alkylene group or alkylidene group, _{R 2} is absent alkylene group, an alkylidene group, a sulfonyl group, an oxygen atom or a group of atoms Direct bond is shown.)

(N represents a natural number of 1 to 40, and R ₁ represents a C1-10 alkylene group or an alkylidene group.)

(N represents a natural number of 1 to 40, m represents a natural number of 3 to 6, R ₁ represents a C1-10 alkylene group or alkylidene group, and R ₂ represents a C4-10 alkylidene group.)

  The hardened | cured material obtained by hardening | curing the epoxy resin composition of this invention has the characteristics of showing the outstanding flexibility and adhesiveness, and showing the elongation which should be noted as an epoxy resin hardened | cured material. From these features, by using the epoxy resin composition obtained according to the present invention, it is possible to exhibit the effect of creating a cured product that is not easily destroyed even when stress is applied and that is difficult to crack even if scratched. .

  The epoxy resin represented by the general formula (1) in the present invention (hereinafter also referred to as component (A)) is synthesized from a glycidyl ether compound of glycol and a phenol compound. The glycol glycidyl ether compound is a compound having at least one, preferably two glycidyl ethers. That is, glycidyl ether of methylene glycol, dimethylene glycol, trimethylene glycol and polymethylene glycol, glycidyl ether of ethylene glycol, diethylene glycol, triethylene glycol and polyethylene glycol, glycidyl of propylene glycol, dipropylene glycol, tripropylene glycol and polypropylene glycol Ether, tetramethylene glycol, ditetramethylene glycol, tritetramethylene glycol, glycidyl ether of polytetramethylene glycol, glycidyl ether of 1,4-butanediol, glycidyl ether of 1,6-hexanediol, glycidyl ether of neopentyl glycol Etc., preferably polypropylene Glycidyl ethers of diglycidyl ether and neopentyl glycol recall is used. By introducing these aliphatic skeletons, the flexibility of the component (A) can be improved.

  The other compounds used for synthesizing the component (A) in the present invention are phenolic compounds such as biphenol, bisphenol A, bisphenol F, bisphenol S, tetramethylbiphenol, tetramethylbisphenol A, tetramethyl. Bisphenol F, tetramethylbisphenol S, tetrabromobiphenol, tetrabromobisphenol A, tetrabromobisphenol F, tetrabromobisphenol S and the like can be mentioned, and biphenol and bisphenol A are preferably used. By introducing these aromatic skeletons, the mechanical strength and heat resistance of the component (A) can be improved.

  The component (A) is synthesized using a known technique so that the number average molecular weight is usually in the range of 600 to 5000, preferably in the range of 800 to 4500, more preferably in the range of 900 to 4000.

  When the molecular weight is smaller than 600, a cured product using the molecular weight does not exhibit sufficient elongation and cannot exhibit a desired effect. On the other hand, when the molecular weight is greater than 5,000, the viscosity of the compound increases to several hundreds of thousands mPa · s (25 ° C.) or more, so adding a large amount of the compound increases the viscosity of the compounded resin, making it difficult to handle. .

  Although the component (A) is an essential component, any other epoxy resin can be blended within a range that does not deteriorate the physical properties of the cured product to constitute an epoxy resin as a main component.

  Examples of the resin that can be used as an epoxy resin other than the component (A) include glycidyl ether type epoxy resins and alicyclic epoxy resins having at least one, preferably two or more oxirane rings. These epoxy resins may be used in combination of two or more if necessary.

  The glycidyl ether type epoxy resin is not particularly limited, but polyglycidyl ethers such as glycerin, diglycerin, polyglycerin, and sorbitol, and polyalkylene oxide adducts such as glycerin, diglycerin, polyglycerin, and sorbitol. Glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol or diglycidyl ether of alkylene oxide adduct to polyethylene glycol or polypropylene glycol, neopentyl glycol diglycidyl Ether, 1,4-butanediol diglycid Ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane polyglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated phenol novolac type epoxy resin, phenyl glycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether Bisphenol S diglycidyl ether, halogenated bisphenol type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, halogenated cresol novolak type epoxy resin, phenol novolac type epoxy resin and the like.

  The alicyclic epoxy resin is not particularly limited, and examples thereof include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate and bis (3,4-epoxycyclohexylmethyl) adipate. .

  The blending ratio of the component (A) is usually 60 to 100% by weight, preferably 75 to 100% by weight, based on the entire epoxy resin (the sum of the component (A) and the other epoxy components in the present invention).

  The blending ratio of the epoxy resin other than the component (A) is usually 0 to 40% by weight, preferably 0 to 25% by weight of the entire epoxy resin (the sum of the component (A) and other epoxy components in the present invention). %.

（ｎは１〜４０の自然数、Ｒ_１はＣ１〜１０のアルキレン基またはアルキリデン基を示す。）

（ｎは１〜４０の自然数、ｍは３〜６の自然数、Ｒ_１はＣ１〜１０のアルキレン基またはアルキリデン基、Ｒ_２はＣ４〜１０のアルキリデン基を示す。） The curing agent <hereinafter also referred to as component (B)> used in the thermosetting epoxy resin composition according to the present invention is a so-called amine compound represented by the general formula (2) or general formula (3) or a derivative thereof. is there.

(N represents a natural number of 1 to 40, and R ₁ represents a C1-10 alkylene group or an alkylidene group.)

(N represents a natural number of 1 to 40, m represents a natural number of 3 to 6, R ₁ represents a C1-10 alkylene group or alkylidene group, and R ₂ represents a C4-10 alkylidene group.)

  Although it does not specifically limit as a hardening | curing agent which can be used as (B) component, Polyoxyethylene diamine, polyoxypropylene diamine, polyoxybutylene diamine, polyoxypentylene diamine, polyoxyethylene triamine, polyoxypropylene triamine, poly Examples thereof include oxybutylene triamine and polyoxypentylene triamine. Preferably, polyoxypropylene diamine is used.

  The polyoxyalkylene polyamine derivative as the component (B) is a compound obtained by modifying a part or all of the amine moiety of the general formula (2) or the general formula (3) by a known method. Known modification methods include modification with carboxylic acid (polyaminoamide), modification with epoxy compound (amine-epoxy adduct compound), Michael reaction (Michael addition polyamine), Mannich reaction, reaction with urea or thiourea, modification with ketone. (Ketimine, Schiff base) and the like. These components (B) can be used alone or in combination.

  In addition to the component (B), other curing agents can be used in combination as required. Examples of other curing agents include amine-based curing agents such as aliphatic polyamines, alicyclic polyamines, and aromatic polyamines, and general acid anhydrides. These can be arbitrarily selected and used alone or in combination of two or more.

  The blending ratio of the component (B) is usually 60 to 100% by weight, preferably 75 to 100% of the entire curing agent (the sum of the component (B) in the present invention and the amine compound and the like below it).

  The blending amount of the entire curing agent is determined by the epoxy equivalent of the entire epoxy resin, and the equivalent of the curing agent is usually 0.8 to 1.2, more preferably 0.9 to 1.0 with respect to epoxy equivalent 1. The amount which becomes becomes.

  In the thermosetting epoxy resin composition of the present invention, a curing accelerator can be added in addition to the above components as long as the physical properties of the cured product are not impaired. By adding this curing accelerator, the curing rate can be increased, which leads to an improvement in productivity.

  Although it does not specifically limit as a compound which can be used as a hardening accelerator, 2-ethyl-4-methylimidazole <2E4MZ>, 2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole <2E4MZ-CN>, 2,4-diamino-6- [2-methylimidazolyl- (1)] ethyl-s-triazine <2MZ-A>, 2-phenylimidazoline <2PZL> 2,3-dihydro-1H- Imidazoles such as pyrrolo [1,2-a] benzimidazole <TBZ>, tris (dimethylaminomethyl) phenol <DMP-30>, benzyldimethylamine <BDMA>, 1,8-diazabicyclo (5,4,0) Tertiary amines such as undecene-7 <DBU>, organic phosphine compounds such as triphenylphosphine, Grade amine salts, quaternary ammonium salts, phosphonium salts, known compounds such as metal salts such as tin octylate and the like. These accelerators are appropriately selected with respect to the requirements for the resin composition such as time required for curing and pot life.

  The compounding ratio of the above compound is preferably 0.1 to 2.0 parts with respect to 100 parts of the compounded epoxy resin composition of the component (A) and the component (B).

  In addition to the above components, if necessary, colorants, antioxidants, leveling agents, surfactants, ultraviolet absorbers, silane coupling agents, inorganic fillers, resin particles, wettability improvers, etc. may be added. it can.

  Hereinafter, the details of the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

<Example 1>
Dipentyl glycol (SR-NPG (manufactured by Sakamoto Pharmaceutical Co., Ltd.) epoxy equivalent 145) 690 g of neopentyl glycol (R ₁ in the general formula (1) is 5 carbon atoms) and biphenol (Honshu Chemical Industry Co., Ltd.) A compound obtained by reacting 210 g of hydroxyl group equivalent 93) having an epoxy equivalent of 435 g / eq and a viscosity of 114,000 mPa · s (25 ° C.) and polyoxypropylenediamine (Jefamine D400). 100 grams and 23 grams of active hydrogen equivalent (200, manufactured by Huntsman Advanced Materials Co., Ltd.) are charged so that the epoxy equivalent of the epoxy resin and the active hydrogen equivalent of the curing agent are the same. It heated at 40-60 degreeC and stirred and obtained the resin composition concerning this invention. Furthermore, the said composition was heated over 3 hours at 100 degreeC, the hardened | cured material was created, and physical property evaluation was performed. The results are shown in Table 1.

<Example 2>
A compound reacted in the same manner as in Example 1 except that 359 g of neopentyl glycol diglycidyl ether and 141 g of bisphenol A (reagent hydroxyl group equivalent 114) were used in place of biphenol, an epoxy equivalent of 432 g / eq, and a viscosity of 61000 mPa The physical properties were evaluated in the same manner as in Example 1 except that a compound (hereinafter abbreviated as A-2) which was s (25 ° C.) was used. The results are shown in Table 1.

<Examples 3 to 4>
According to the formulation shown in Table 1, after obtaining a liquid composition (resin composition of the present invention) in the same manner as in Example 1 except that the components (A) and (B) were stirred and mixed, the physical properties were evaluated. Went. The results are shown in Table 1.

<Comparative Examples 1-4>
Addition of 2 moles of propylene oxide to general epoxy resin (bisphenol A diglycidyl ether) or epoxy resin (dimer acid-modified epoxy resin, bisphenol A) that is said to be flexible according to the formulation shown in Table 1. A glycidyl etherified epoxy resin <hereinafter referred to as bisphenol A2PO epoxy resin>) and a hardener were mixed in the same manner as in Examples 1 to 4 except that a cured composition was prepared. Then, physical properties were evaluated. The results are shown in Table 1.

  Below, the evaluation method in the above-mentioned Example etc. is demonstrated.

  Tensile strength, tensile elongation: The tensile strength and fracture elongation of the obtained cured product were determined according to JIS K 7113 using a tensile tester “AG-IS 20 kN” manufactured by Shimadzu Corporation at a tensile rate of 5 mm / min. It was measured. The tensile elongation rate means that the larger the value is, the better the toughness and flexibility are, and the elongation is preferably 100% or more, more preferably 120% or more.

Tensile shear strength: According to JIS K 6850, two steel plates (SUS304) were bonded together with 50 mg of an epoxy resin composition to obtain a test piece (adhesion area 3.125 cm ² ). Each test piece obtained was conditioned at a constant temperature and humidity of 23 ° C. and 50% humidity for a minimum of one day. Using a tensile tester “AG-IS 20 kN” manufactured by Shimadzu Corporation, the tensile shear strength was measured at a tensile speed of 5 mm / min.

  Shore hardness (type A): Each cured product (50 mm × 50 mm × 4 mm) was conditioned at a constant temperature and humidity of 23 ° C. and 50% humidity for a minimum of one day. Under the same conditions, two of the cured products were overlapped and measured according to JIS K 7215.

  Heat-resistant bendability: The condition of the obtained cured product (80 mm × 10 mm × 4 mm) was adjusted under constant temperature and humidity at a temperature of 23 ° C. and a humidity of 50% for a minimum of one day. Under the same conditions, both ends of the cured product were completely folded in half. At this time, those that were broken during bending were marked with ×, and those that could not be folded even when folded in half were marked with ○.

  As shown in Table 1 above, the thermosetting epoxy resin compositions shown in the examples show excellent elongation by blending the component (A) and the component (B), and have a flexible bending resistance. It was found that a cured product having excellent properties can be provided.

For example, it can be used for adhesives, sealants, casting agents, solder resists, and the like that require the adhesiveness and high-temperature heat resistance of the cured product.

Claims (1)

It is a compound obtained by reacting glycol glycidyl ether and a phenol compound, and is an epoxy resin (A) represented by the following general formula (1) and general formula (2) or general formula (3) or a derivative thereof. A thermosetting epoxy resin composition comprising a curing agent (B).

(M is a natural number of 1 to 20, n is a natural number of 1 to 14, X is an alkyl group, a and b are integers of 0 to 4, _{G 1} and _{G 2} are glycidyl groups or a hydrogen atom a halogen atom or C1~5 (However, no G1, G2 are hydrogen atoms at the same time), _{R 1} is an alkylene or alkylidene group of C1-10, _{R 2} is absent alkylene group, an alkylidene group, a sulfonyl group, an oxygen atom or a group of atoms Direct bond is shown.)

(N represents a natural number of 1 to 40, and R ₁ represents a C1-10 alkylene group or an alkylidene group.)

(N represents a natural number of 1 to 40, m represents a natural number of 3 to 6, R ₁ represents a C1-10 alkylene group or alkylidene group, and R ₂ represents a C4-10 alkylidene group.)