JP4857598B2 - Epoxy compound, method for producing the same, and epoxy resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy compound excellent in workability, because the epoxy compound does not cause coagulation at a low temperature and providing the cured product excellent in flexibility at a low temperature and having rubber elasticity. <P>SOLUTION: The epoxy compound is composed of a neopentylene oxide structural unit represented by a structural unit N of the formula: -CH<SB>2</SB>-C(-CH<SB>3</SB>)<SB>2</SB>-CH<SB>2</SB>O- and a tetramethylene oxide structural unit represented by a structural unit T of the formula: -CH<SB>2</SB>CH<SB>2</SB>CH<SB>2</SB>CH<SB>2</SB>O-. The epoxy compound is obtained by reacting a copolymer polyether glycol having the structural unit N and the structural T on the skeleton as recurring units with epichlorohydrin. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to an epoxy compound of copolymer polyether glycol, a method for producing the same, and an epoxy resin composition in which the epoxy resin and a curing agent for epoxy resin are blended, and the cured product of the epoxy resin composition has rubber elasticity. And has excellent low-temperature flexibility and adhesiveness, it is useful in applications such as sealing agents, adhesives, coating agents, and thermosetting elastomers.

Epoxy resins are excellent in heat resistance, adhesiveness, water resistance, mechanical strength, electrical properties, etc., so they are used in various fields such as adhesives, paints, materials for civil engineering and construction, insulating materials for electrical and electronic parts, etc. Used in. As the normal temperature or heat curable epoxy resin, aromatic epoxy resins such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, phenol or cresol novolac type epoxy resin are generally used.

  The epoxy resin is a resin having various chemical structures and excellent properties as described above, but in recent years, various points to be improved have been clarified as the required performance in various applications increases. One of them is that epoxy resins are hard and brittle. That is, the epoxy resin represented by the bisphenol A type is generally poor in flexibility, and particularly when used as an elastic coating material or a sealing agent, there is a problem that cracks are likely to occur and it cannot be used industrially.

  Under such circumstances, studies for imparting flexibility to epoxy resins are still being actively conducted. Among them, a method of improving flexibility by blending an elastomer such as carboxyl group-terminated butadiene / acrylonitrile copolymer (CTBN) or a thermoplastic elastomer into an epoxy resin, or diglycidyl ester of dimer acid, diglycidyl of polypropylene glycol A method of adding a flexible epoxy resin having a flexible skeleton in a molecule such as ether is known.

  However, the method of adding an elastic body has great technical difficulty because it is necessary to disperse the elastic body in an epoxy resin with an appropriate particle size and with good reproducibility, and is extremely difficult industrially. In addition, the method of adding flexible epoxy simply softens the cured product, and the cured product has insufficient mechanical properties, particularly rebound resilience, so that a cured product having a satisfactory elastic body can be obtained. Not.

  Then, the flexible epoxy resin which epoxidized the reaction product of the bisphenol compound and divinyl ether with epichlorohydrin is proposed (patent document 1). However, this epoxy resin is excellent in flexibility but does not exhibit rubber-like elasticity, and further has a small tensile elongation, so it is unsuitable for applications that require repeated bendability.

  On the other hand, polyurethane or polyester using polytetramethylene ether glycol as a raw material has been widely used as an industrially important material because of its excellent elastic body and hydrolysis resistance. A method for improving the flexibility of a cured epoxy resin by using diglycidyl ether obtained from polytetramethylene ether glycol as an additive for a bisphenol type epoxy resin has been proposed (Patent Documents 2 and 3). .

  However, diglycidyl ether obtained from polytetramethylene ether glycol has a problem of workability of solidifying when used at a low temperature, and an epoxy resin having no flexibility and having flexibility has been desired instead. .

JP 2004-156024 A JP-A 49-114611 JP 51-88599 A

  Since the epoxy resin of the present invention has rubber elasticity and is excellent in low-temperature flexibility and adhesiveness, it can be advantageously used as a sealing agent or an epoxy resin for thermosetting elastomers. Conventional polytetramethylene ether glycol diglycidyl ether The present invention provides an epoxy resin obtained from a copolymerized polyether glycol, a method for producing the same, and an epoxy resin composition, which have improved the problem of solidifying at a low temperature as shown.

構造単位Ｎ：

構造単位Ｔ：

（式中、ｍは１〜６０、ｎは１〜５０の数を示す。） The present invention includes the following inventions.
(1) It consists of a neopentylene oxide structural unit represented by the following structural unit N and a tetramethylene oxide structural unit represented by the following structural unit T, and has the following general formula ( An epoxy compound obtained by reacting the copolymerized polyether glycol represented by 1) with epichlorohydrin.

Structural unit N:

Structural unit T:

(In the formula, m is 1 to 60, and n is 1 to 50.)

(2) pre-Symbol number average molecular weight of the copolymer polyether glycol represented by one general formula (1) is characterized in that it is a 300 to 3000 (1) term epoxy compounds described.

構造単位Ｎ：

構造単位Ｔ：

（式中、ｍは１〜６０、ｎは１〜５０の数を示す。） (3) It consists of a neopentylene oxide structural unit represented by the following structural unit N and a tetramethylene oxide structural unit represented by the following structural unit T, and has the following general formula ( The copolymerized polyether glycol shown in 1) and epichlorohydrin are reacted in the presence of a catalyst selected from an acidic catalyst and a phase transfer catalyst to produce a chlorohydrin ether body, and then the produced chlorohydrin ether body is removed. A method for producing an epoxy compound, comprising reacting with a hydrogen halide agent to cause ring closure .

Structural unit N:

Structural unit T:

(In the formula, m is 1 to 60, and n is 1 to 50.)

(4) The method for producing an epoxy compound according to (3 ), wherein the copolymer polyether glycol represented by the general formula (1) has a number average molecular weight of 300 to 3,000 .

(5) The compounding ratio of the epoxy compound according to the item (1) or (2) and another epoxy resin is 10 to 90% by mass of another epoxy resin with respect to 10 to 90% by mass of the epoxy compound. Epoxy resin composition .

(6) Item (5), wherein 8 to 25 parts by mass of an epoxy resin curing agent is blended with respect to 100 parts by mass in total of the epoxy compound according to item (1) or (2) and another epoxy resin. The epoxy resin composition as described.

(7) Item (5) or Item (6 ), wherein the other epoxy resin is a bifunctional epoxy resin having at least one aromatic ring and / or alicyclic structure in one molecule. of the epoxy resin composition.

(8) The epoxy resin curing agent is a compound selected from amines, acid anhydrides, polyhydric phenols, imidazoles, Bronsted acid salts, dicyandiamides, organic acid hydrazides and polycarboxylic acids. The epoxy resin composition according to any one of items (5) to (7), wherein:

  Since the epoxy compound of the present invention does not solidify at a low temperature, workability can be improved, and the cured product is excellent in low-temperature flexibility and adhesiveness. Therefore, it can be advantageously used as an epoxy resin for thermosetting elastomers.

Below, embodiment of the epoxy compound of this invention, its manufacturing method, and an epoxy resin composition is described in detail.
(Epoxy compound)
The epoxy compound of the present invention comprises a neopentylene oxide structural unit represented by the following structural unit N and a tetramethylene oxide structural unit represented by the following structural unit T, and has the structural unit N and the structural unit T as a repeating unit in the skeleton. It can be obtained by reacting a copolymerized polyether glycol with epichlorohydrin.

（１）


（式中、ｍは１〜６０、ｎは１〜５０の数を示す。）
Specific examples of the copolymer polyether glycol include copolymer polyether glycol represented by the following general formula (1).

(1)


(In the formula, m is 1 to 60, and n is 1 to 50.)

(Copolymer polyether glycol)
The copolymerized polyether glycol used as the raw material of the epoxy compound of the present invention is, for example, made from neopentyl glycol and tetrahydrofuran (hereinafter referred to as THF) as raw materials, and reacted at a temperature of 85 ° C. for 10 hours using a phosphotungsten catalyst. Thereafter, the mixture is allowed to stand, and the upper liquid layer part is taken out and purified to obtain a copolymerized polyether glycol.
The number average molecular weight of the copolymerized polyether glycol used is preferably 300 to 3000, more preferably 600 to 2000. If the number average molecular weight of the copolymerized polyether glycol is less than 300, the flexibility of the epoxy cured product is lowered, and if it exceeds 3000, the resulting epoxy compound is solidified, which is not preferable.

The epoxy compound of the present invention contains epichlorohydrin in an amount of 0.8 to 20 mol, preferably 1 to 10 mol, based on 1 equivalent of the hydroxyl group of copolymer polyether glycol, sulfuric acid, boron trifluoride ethyl ether, tin tetrachloride. In the presence of a catalyst selected from phase transfer catalysts such as acidic catalysts such as quaternary ammonium salts, quaternary phosphonium salts, crown ethers, etc., at a temperature of 20 to 100 ° C. for 0.5 to 10 hours. To produce a chlorohydrin ether form, followed by ring-closing reaction of this chlorohydrin ether form with a dehydrohalogenating agent such as sodium hydroxide at a temperature of 20 to 100 ° C. for 0.1 to 10 hours. Can be obtained.

(Curing agent for epoxy resin)
The epoxy compound obtained from the copolymerized polyether glycol of the present invention can be cured using a curing agent for epoxy resin. As the curing agent for the epoxy resin, a general curing agent for epoxy resin is used, and examples thereof include the following.

(1) amines;
Bis (4-aminocyclohexyl) methane, bis (aminomethyl) cyclohexane,
Aliphatic and alicyclic amines such as m-xylylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5,5] undecane, metaphenylenediamine, diaminodiphenylmethane Aromatic amines such as diaminodiphenylsulfone, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo- (5,4,0) -undecene-7, 1, Tertiary amines such as 1,5-diazabicyclo- (4,3,0) -nonene-7 and salts thereof.

(2) acid anhydrides;
Aromatic anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride,
Cyclic aliphatic acid anhydrides such as tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, dodecenyl succinic anhydride, trialkyltetrahydrophthalic anhydride Kind.

(1) polyhydric phenols;
Bivalent phenol novolacs such as catechol, resorcin, hydroquinone, bisphenol F, bisphenol A, bisphenol S, biphenol, phenol novolacs, cresol novolacs, bisphenol A, etc. Compounds, trishydroxyphenylmethanes, aralkylpolyphenols, dicyclopentadiene polyphenols and the like.

(2) Other;
Bronsted acid salts such as imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole and 2-phenylimidazole and their salts, BF3 complex compounds of amines, aliphatic sulfonium salts and aromatic sulfonium salts Organic acid hydrazides such as dicyandiamides, adipic acid dihydrazide and phthalic acid dihydrazide, and polycarboxylic acids such as adipic acid, sebacic acid, terephthalic acid, trimellitic acid and carboxyl group-containing polyester.

  These epoxy resin curing agents may be used singly or in combination of two or more.

(Other epoxy resins)
The epoxy compound of the present invention can be used in combination with other epoxy resins as long as the effects of the present invention are not impaired. Examples of other epoxy resins that can be used in combination include the following.

(1) a bifunctional epoxy resin having an aromatic ring and / or an alicyclic structure;
Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, diglycidyl ether of bisphenol A-alkylene oxide adduct, alkylene of bisphenol F Diglycidyl ether of oxide adduct, bisphenol S type epoxy resin, tetramethyl bisphenol A type epoxy resin, tetramethyl bisphenol F type epoxy resin, thiodiphenol type epoxy resin, dihydroxy diphenyl ether type epoxy resin, terpene diphenol type epoxy resin, Biphenol type epoxy resin, tetramethyl biphenol type epoxy resin, hydroquinone type epoxy resin, methyl hydroquinone type epoxy Resin, dibutyl hydroquinone type epoxy resins, resorcin type epoxy resin, methyl resorcin type epoxy resin, dihydroxynaphthalene type epoxy resin.

(2) Multifunctional epoxy resin;
Phenol novolac type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, dicyclopentadiene phenol type epoxy resin, terpene phenol type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol novolak type epoxy resin , Polyphenol resin obtained by condensation reaction with various aldehydes such as hydroxybenzaldehyde, crotonaldehyde, glyoxal, heavy petroleum oil or pitches, formaldehyde polymer and phenols in the presence of an acid catalyst. An epoxy resin produced from various phenolic compounds such as condensed modified phenolic resin and epihalohydrin.

(3) Epoxy resins having other structures;
Epoxy resins produced from various amine compounds such as diaminodiphenylmethane, aminophenol and xylenediamine and epihalohydrin, epoxy resins produced from various carboxylic acids such as methylhexahydroxyphthalic acid and dimer acid, and epihalohydrin, Reactive diluents for epoxy resins such as glycidyl ethers of aliphatic monoalcohols or polyhydric alcohols other than glycidyl compounds of the present invention, glycidyl esters of aliphatic carboxylic acids, glycidyl ethers of monophenols, or 3,4-epoxycyclohexyl An alicyclic epoxy resin represented by methyl-3 ′, 4′-epoxycyclohexanecarboxylate.
Among these epoxy resins, a bifunctional epoxy resin having two glycidyl ether groups having one or more aromatic rings and / or alicyclic structures in one molecule is excellent in compatibility with the epoxy compound of the present invention. This is particularly preferable in terms of workability.

The combined proportion of the epoxy compound of the present invention and the other epoxy resin is preferably 10 to 90% by mass of the epoxy compound of the present invention and 10 to 90% by mass of the other epoxy resin.

(Optional component)
In the epoxy resin composition of the present invention, the following components can be added and blended as necessary.
(1) Powdery reinforcing agents and fillers, for example, metal oxides such as aluminum oxide and magnesium oxide, silicon compounds such as fine powder silica, fused silica and crystalline silica, transparent fillers such as glass beads, aluminum hydroxide, etc. Metal hydroxide, kaolin, mica, quartz powder, graphite, molybdenum disulfide, etc.
These blending amounts are suitably 10 to 1000 parts by mass with respect to 100 parts by mass of the epoxy resin composition of the present invention.

(2) Colorants or pigments such as titanium dioxide, molybdenum red, bitumen, ultramarine blue, cadmium yellow, cadmium red, and organic dyes.
(3) Flame retardants such as antimony trioxide, bromine compounds and phosphorus compounds.
(4) Ion adsorbent.
(5) Coupling agent, antioxidant, ultraviolet absorber.

  These blending amounts are suitably 0.01 to 30 parts by mass with respect to 100 parts by mass of the epoxy resin composition of the present invention.

(6) Furthermore, various curable monomers, oligomers and synthetic resins can be blended for the purpose of improving the properties of the cured epoxy resin. For example, diols or triols, vinyl ethers, oxetane compounds, fluorine resins, acrylic resins, silicone resins and the like can be used alone or in combination of two or more. Although the compounding ratio of these compounds and resins can be arbitrarily selected depending on the use conditions, a range of 50 parts by mass or less is preferable with respect to 100 parts by mass of the epoxy resin composition of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, the part in an example means a mass part.

Example 1
In a 1 L glass flask equipped with a stirrer, a dropping funnel and a thermometer, 250 g of copolymer polyether glycol (Asahi Kasei Fibers Co., Ltd., product name: PTXG1000) of tetrahydrofuran and neopentyl glycol having a number average molecular weight of 1000 preheated to 45 ° C., 1.046 g of boron trifluoride ethyl ether was charged and heated to 80 ° C. Epichlorohydrin 50.9 g (1.1 equivalent per 1 equivalent of hydroxyl group of diol) was added dropwise over 1 hour so as not to exceed 85 ° C. The mixture was aged for 1 hour while maintaining at 80 to 85 ° C, and then cooled to 45 ° C. 82.5 g of 48.5 mass% sodium hydroxide aqueous solution was added, and it heated at 70 degreeC, and stirred vigorously for 4 hours. After cooling to 60 ° C., 250 g of methyl isobutyl ketone was added and dissolved, 150 g of water was added and washed with water, and the generated salt was removed by separating the aqueous phase. After repeating this washing with water three times, the organic layer was separated, heated to 150 ° C. at normal pressure to distill off methyl isobutyl ketone, and then desolvated at 150 ° C. for 30 minutes under reduced pressure to remove colorlessness. A transparent copolymer polyether glycol epoxy compound 260 g was obtained. The analytical value of this product was an epoxy equivalent of 667 g / equivalent and a viscosity at 25 ° C. of 490 mPa.s. s. Infrared spectrum (IR) and ¹ H nuclear magnetic resonance spectrum (NMR) were measured and confirmed to be an epoxy compound of a polyether glycol copolymer of tetrahydrofuran and neopentyl glycol. FIG. 1 and FIG. 2 show an IR chart and an NMR chart of the obtained epoxy compound.
The obtained epoxy compound had a freezing point temperature determined by DSC of 3.5 ° C., and even when stored in a refrigerator at 5 ° C. for 1 week, it did not solidify and kept a colorless and transparent liquid.

Example 2
To a 1 L glass flask equipped with a stirrer, a dropping funnel and a thermometer, 180 g of a copolymer polyether glycol of tetrahydrofuran and neopentyl glycol (Asahi Kasei Corporation, trade name: PTXG1800) having a number average molecular weight of 1800, which has been heated to 45 ° C. in advance. 0.426 g of boron trifluoride ethyl ether was charged and heated to 80 ° C. Epichlorohydrin (20.4 g) (1.1 equivalent per hydroxyl group equivalent of diol) was added dropwise over 1 hour so as not to exceed 85 ° C. The mixture was aged for 1 hour while maintaining at 80 to 85 ° C, and then cooled to 45 ° C. 48.5 mass% sodium hydroxide aqueous solution 19.8g was added, and it heated at 70 degreeC and stirred vigorously for 4 hours. Thereafter, the same operation as in Example 1 was performed to obtain 185 g of a colorless and transparent copolymer polyether glycol epoxy compound. The analytical value of this product is that epoxy equivalent is 1180 g / equivalent and viscosity at 25 ° C. is 1600 mPa.s. s.
The resulting DSC chart of the epoxy compound showed a broad peak, but the freezing point temperature was 8.4 ° C., and even when stored in a refrigerator at 5 ° C. for 1 week, it did not solidify and kept a colorless and transparent liquid.

Comparative Example 1
The same operation as in Example 1 was carried out except that the copolymerized polyether glycol was changed to polytetramethylene ether glycol having a number average molecular weight of 1000 to obtain 260 g of a colorless and transparent epoxy compound. The analytical value of this product was 670 g / equivalent epoxy equivalent, and the viscosity at 25 ° C. was 420 mPa.s. s.
The obtained epoxy compound had a freezing point temperature determined by DSC of 19.9 ° C. When stored in a refrigerator at 5 ° C. for 1 day, it solidified and became a white solid.

Example 3
As an epoxy resin curing agent, 20 parts of an epoxy compound of copolymer polyether glycol obtained in Example 1, 80 parts of Epicoat 828 (trade name of Japan Epoxy Resin Co., Ltd .; bisphenol A type liquid epoxy resin, epoxy equivalent; 186 g / equivalent) 16 parts of m-xylylenediamine was mixed at a temperature of 15 ° C. until uniform for 2 minutes to obtain an epoxy resin composition.
This composition was degassed under reduced pressure, poured into a mold, and cured in an oven at 80 ° C. for 3 hours and then at 140 ° C. for 3 hours to obtain a cured product. The physical property values of this epoxy cured product are shown in Table 1.

Examples 4-7 and Comparative Examples 2-3
Except for changing the epoxy compound, other epoxy resin, and epoxy resin curing agent as shown in Table 1, the same operation as in Example 3 was performed to obtain an epoxy resin composition, and a cured product was obtained. Table 1 shows the physical property values of the cured epoxy resins.

* 1: Measured according to JIS-K-6255.
* 2: Measured according to JIS-K-6911.
* 3: Tensile bond shear strength of iron-iron (measured according to JIS-K-68502)
* 4: Water absorption after a pressure cooker test at 121 ° C. for a disk-shaped cured product having a thickness of 3 mm and a diameter of 50 mm.
* 5: Bisphenol A type liquid epoxy resin-epoxy equivalent 186 (manufactured by Japan Epoxy Resin Co., Ltd.)
* 6; m-xylylenediamine * 7; methylhexahydrophthalic anhydride (manufactured by Shin Nippon Rika Co., Ltd.)
* 8; Tetra-n-butylphosphonium o, o-diethyl phosphorodithioate (Nippon Chemical Industry Co., Ltd.)

  As is apparent from the results in Table 1, the epoxy compound of the present invention does not solidify at a low temperature, so it has good compatibility with the curing agent, can improve workability, and the cured product is flexible. Since it has excellent adhesiveness, it can be advantageously used as an epoxy resin for thermosetting elastomers that can be used in a wide range of applications.

1 is an IR chart of the epoxy compound of the present invention produced in Example 1. FIG. 1 is a diagram showing an NMR chart of the epoxy compound of the present invention produced in Example 1. FIG.

Claims (7)

It is composed of a neopentylene oxide structural unit represented by the following structural unit N and a tetramethylene oxide structural unit represented by the following structural unit T, and has the structural unit N and the structural unit T as a repeating unit in the skeleton. An epoxy compound that is liquid at 15 ° C., obtained by reacting a copolymerized polyether glycol having a number average molecular weight of 300 to 3000 with epichlorohydrin.

Structural unit N:

Structural unit T:

(In the formula, m is 1 to 60, and n is 1 to 50.) It is composed of a neopentylene oxide structural unit represented by the following structural unit N and a tetramethylene oxide structural unit represented by the following structural unit T, and has the structural unit N and the structural unit T as a repeating unit in the skeleton. The copolymerized polyether glycol and epichlorohydrin shown are reacted in the presence of a catalyst selected from an acidic catalyst and a phase transfer catalyst to produce a chlorohydrin ether body, and then the resulting chlorohydrin ether body is dehydrohalogenated. A method for producing an epoxy compound having a number average molecular weight of 300 to 3000 and being liquid at 15 ° C., wherein the ring reaction is caused to react with an agent .

Structural unit N:

Structural unit T:

(In the formula, m is 1 to 60, and n is 1 to 50.) The epoxy resin composition formed by mix | blending 8-25 mass parts of hardening | curing agents for epoxy resins with respect to a total of 100 mass parts of the epoxy compound of Claim 1, and another epoxy resin . The epoxy resin composition according to claim 3 , wherein a blending ratio of the epoxy compound according to claim 1 and another epoxy resin is 90 to 10% by mass of the other epoxy resin with respect to 10 to 90% by mass of the epoxy compound . . The epoxy resin composition according to claim 3 or 4, wherein the other epoxy resin is a bifunctional epoxy resin having at least one aromatic ring and / or alicyclic structure in one molecule . The epoxy resin curing agent is a compound selected from amines, acid anhydrides, polyhydric phenols, imidazoles, Bronsted acid salts, dicyandiamides, organic acid hydrazides and polycarboxylic acids. to the epoxy resin composition according to any one of claims 3-5. The epoxy resin composition according to any one of claims 3 to 6, wherein the epoxy resin curing agent is an amine .

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