JP2001139774A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition having excellent toughness, mechanical strength and heat resistance. SOLUTION: This epoxy resin composition comprises an alicyclic epoxy resin, a polyester containing a constituent unit of general formula (1) (n is an integer of 2-12; the benzene ring may contain a proper substituent) and an acid anhydride compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an epoxy resin composition.

[0002]

2. Description of the Related Art Epoxy resin has heat resistance, mechanical strength,
Because of its excellent electrical properties, chemical resistance, and adhesiveness, it is used in many fields such as electrical insulating materials, electronic materials, civil engineering materials, adhesive materials, and paint materials, but has poor toughness and crack resistance. There was a drawback that the properties were poor. For this reason,
In order to develop an epoxy resin with excellent heat resistance and mechanical strength and toughness, a method of modifying epoxy resin with an elastomer, rubber, engineering plastic (engineering plastic), etc. to modify and toughen it has been attempted. ing.

As such an attempt, a composition containing an epoxy resin, poly (alkylene phthalate) and an acid anhydride as a curing agent for an epoxy resin has been studied, and the cured product has a reduced mechanical strength such as tensile strength and bending strength. It has been reported that the fracture toughness value K _{IC, which} is an index of toughness, is greatly improved without lowering the strength [Journal of Applied Polymer Science (J. Appl. Po.
lym. Sci. 43), pp. 463-474 (1
991). However, the glass transition temperature (Tg) of this cured product is as low as 70 to 90 ° C., and there is a problem that there is room for improvement in heat resistance.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems and provides an epoxy resin composition having excellent heat resistance and excellent mechanical strength and toughness.

[0005]

The epoxy resin composition of the present invention comprises an alicyclic epoxy resin, a polyester containing a structural unit represented by the general formula (1), and an acid anhydride compound. .

Embedded image (However, in the general formula (1), n represents an integer of 2 to 12, and the benzene ring may have a substituent such as a lower alkyl group, a lower alkoxy group, fluorine, chlorine, or bromine as appropriate. When there are a plurality of substituents, those substituents may be the same or different.) In the present invention, the structural unit represented by the above general formula (1) is based on 100 parts by weight of the alicyclic epoxy resin. The epoxy resin composition according to claim 1, comprising 5 to 100 parts by weight of a polyester containing 0.7 to 1.5 equivalents of an acid anhydride compound to the epoxy resin.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As the alicyclic epoxy resin, those having an alicyclic structure and having two or more epoxy groups in one molecule are used, and vinylcyclohexene dioxide, 3,4- Epoxycyclohexylmethyl-
3,4-epoxycyclohexylcarboxylate, bis- (3,4-epoxycyclohexyl) adipate,
2- (3,4-epoxycyclohexyl) -5,5-spiro-3,4-epoxy) cyclohexene-m-dioxane and the like. These alicyclic epoxy resins may be used alone or, if necessary, in combination of two or more. Further, an epoxy resin other than the alicyclic epoxy resin can be used as long as the effect is not particularly impaired in the present invention. Examples of the epoxy resin other than the alicyclic epoxy resin include bisphenol A type epoxy resins [for example, Epicoat 828, Epicoat 827, Epicoat 834, Epicoat 1001, Epicoat 100
4, Epicoat 1009 (all of which are trade names of Yuka Shell Epoxy Co., Ltd.), bisphenol F type epoxy resin [for example, Epicoat 807 (which is a trade name of Yuka Shell Epoxy Co., Ltd.)], bisphenol S-type epoxy resin, phenol novolak-type epoxy resin [for example, Epicoat 152, Epicoat 1
54 (all of which are trade names of Yuka Shell Epoxy Co., Ltd.), EOCN-201 (which is a trade name of Nippon Kayaku Co., Ltd.), a cresol novolak type epoxy resin [for example, EOCN-102S, EOCN -1
04S (these are trade names of Nippon Kayaku Co., Ltd.)], bisphenol A novolak type epoxy resin [for example, N-880, N-865 (all of these are trade names of Dainippon Ink and Chemicals, Inc.) )], Bisphenol F novolak type epoxy resin, glycidyl ester type epoxy resin [for example, CY182, CY1
92 (all are trade names of Ciba-Geigy), Epicoat 871, Epicoat 872 (all are trade names of Yuka Shell Epoxy Co., Ltd.)], glycidylamine type epoxy resin [for example, M
Y720 (this is a trade name of Ciba-Geigy)],
Hydantoin type epoxy resin [for example, CY350 (which is a trade name of Ciba-Geigy)], isocyanurate type epoxy resin [for example, PT810 (which is a trade name of Ciba-Geigy)], aliphatic chain epoxy Resins (for example, Adeka Resin ED506 (which is a trade name of Asahi Denka Kogyo Co., Ltd.), Epicron 707 (which is a trade name of Dainippon Ink and Chemicals, Inc.)), and these epoxy resins are halogenated. Or hydrogenated. Two or more of these epoxy resins may be used in combination.

The polyester has a structural unit represented by the general formula (1), but may optionally contain other structural units. The polyester may include a structural unit represented by the general formula (1 ′) as another structural unit.

Embedded image (However, in the general formula (1 ′), n represents an integer of 2 to 12, two carbonyl groups are bonded to a benzene ring at a meta position or a para position, and the benzene ring is a lower alkyl group as appropriate. May have a substituent such as a lower alkoxy group, fluorine, chlorine, and bromine, and when there are a plurality of substituents, those substituents may be the same or different.)

[0008] The polyester preferably contains 5 to 100 mol%, more preferably 10 to 100 mol%, of the structural unit represented by the general formula (1). If it is less than 5 mol%, the compatibility between the polyester and the epoxy resin is reduced, and the object of the present invention cannot be achieved. Further, the molecular weight of the polyester (peak value measured by gel permeation chromatography and calculated in terms of standard polystyrene) is preferably 2,000 or more.

The polyester includes poly (ethylene phthalate), poly (trimethylene phthalate), poly (tetramethylene phthalate), poly (pentamethylene phthalate), poly (hexamethylene phthalate),
Poly (heptamethylene phthalate), poly (octamethylene phthalate), poly (nonamethylene phthalate),
Poly (decamethylene phthalate), poly (undecamethylene phthalate), poly (dodecamethylene phthalate), poly (ethylene phthalate-co-ethylene isophthalate), poly (trimethylene phthalate-co-
Trimethylene isophthalate), poly (tetramethylene phthalate-co-tetramethylene isophthalate),
Poly (pentamethylene phthalate-co-pentamethylene isophthalate), poly (hexamethylene phthalate-co-hexamethylene isophthalate), poly (heptamethylene phthalate-co-heptamethylene isophthalate), poly (octamethylene phthalate-co- Octamethylene isophthalate), poly (nonamethylene phthalate-co-nonamethylene isophthalate), poly (decamethylene phthalate-co-decamethylene isophthalate), poly (undecamethylene phthalate-co
-Undecamethylene phthalate), poly (dodecamethylene phthalate-co-dodecamethylene isophthalate), poly (ethylene phthalate-co-ethylene terephthalate), poly (trimethylene phthalate-co-
Trimethylene terephthalate), poly (tetramethylene phthalate-co-tetramethylene terephthalate),
Poly (pentamethylene phthalate-co-pentamethylene terephthalate), poly (hexamethylene phthalate-co-hexamethylene terephthalate), poly (heptamethylene phthalate-co-heptamethylene terephthalate), poly (octamethylene phthalate-co-octamethylene terephthalate) ), Poly (nonamethylene phthalate-co-nonamethylene terephthalate), poly (decamethylene phthalate-co-decamethylene terephthalate), poly (undecamethylene phthalate-co)
-Undecamethylene terephthalate), poly (dodecamethylene phthalate-co-dodecamethylene terephthalate) and the like.

For the synthesis of the polyester, a known method shown on pages 146 et seq. Of Shin-Jikken Kagaku Koza Vol. 14 (1) (issued on December 20, 1977 by Maruzen Co., Ltd.) can be employed. For example, compounds such as calcium, magnesium, zinc, cadmium, titanium, germanium, tin, lead, antimony, and manganese are added as catalysts to phthalic anhydride and α, ω-alkanediol, and the mixture is placed in a polymerization tube equipped with a vacuum stirrer. . The polymerization tube is provided with a nitrogen gas introduction tube and a side tube for distillation. The polymerization tube is placed in an oil bath, heated to 180 ° C., and nitrogen gas is passed slowly. When the theoretical amount of water has been distilled off, gradually raise the temperature and start stirring. The degree of vacuum is gradually increased to reach 102 Pa or less. The mixture is heated at 275 ° C. for 2 to 3 hours to distill off water produced by the polycondensation reaction to obtain the desired polyester. The obtained polyester is dissolved in acetone and then reprecipitated in methanol for purification.

In the present invention, other dicarboxylic anhydrides such as isophthalic anhydride and terephthalic anhydride may be used together with phthalic anhydride as long as the effects of the present invention are not impaired. In this case, it is preferable that phthalic anhydride is blended in an amount of 30 mol% or more based on the whole dicarboxylic acid component.

Examples of the α, ω-alkanediol in the above polycondensation reaction include 1,2-ethanediol, 1,2
3-propanediol, 1,4-butanediol, 1,
5-pentanediol, 1,6-hexanediol,
Examples thereof include 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol. The charging ratio of these α, ω-alkanediols is appropriately selected depending on the desired molecular weight, but is 1.2 to 4 with respect to the whole dicarboxylic acid component.
It is preferable that the compound is compounded twice in mole.

In the above polycondensation reaction, examples of the catalyst include acetates or oxides of the above metals. For example, calcium acetate, magnesium acetate, zinc acetate,
Examples include cadmium acetate, titanium oxide, germanium oxide, tin oxide, lead oxide, antimony oxide, and manganese oxide. In the above polycondensation reaction, calcium, magnesium, zinc, and cadmium compounds are used as catalysts in the first-stage transesterification reaction, and titanium, germanium, tin, lead, antimony, and manganese are used as catalysts in the second-stage polycondensation reaction. The compound is effective. Therefore, it is preferable to use a catalyst effective for each reaction. The amount of these polymerization catalysts added is 0.001 to the entire dicarboxylic acid component.
-0.5% by weight, particularly preferably 0.05-0.1% by weight.

The acid anhydride compound includes succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride,
Examples include itaconic anhydride, methylendmethylenetetrahydrophthalic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and the like. These may be used alone or as a mixture of two or more.

[0015] In the epoxy resin composition according to the present invention, the polyester is preferably blended in an amount of 5 to 100 parts by weight per 100 parts by weight of the epoxy resin.
It is preferable to mix it in an amount of 50 parts by weight. If it is less than 5 parts by weight, the effect of improving toughness tends to decrease, and if it exceeds 100 parts by weight, heat resistance tends to deteriorate.

In the epoxy resin composition according to the present invention, the above-mentioned acid anhydride compound is used as a curing agent, but it is preferable to use 0.7 to 1.5 equivalents to the epoxy resin. If it is less than 0.7 equivalent, the curing reaction does not proceed sufficiently, and if it exceeds 1.5 equivalent, the heat resistance is lowered.

Further, a curing accelerator may be used to accelerate the curing reaction, and examples thereof include imidazoles, benzyldimethylamine, pyridine, picoline, piperidine, triethanolamine, dimethylaniline, and tetramethylguanidine. The amount of the curing accelerator is also appropriately determined, and may be blended in consideration of storage stability and curability. The amount is preferably about 0.01 to 5 parts by weight based on 100 parts by weight of the epoxy resin. When the amount is less than 0.01 part by weight, the accelerated curing of the curing reaction is small, and when it is more than 5 parts by weight, the storage stability is deteriorated.

The epoxy resin composition of the present invention may be used by heating and mixing a substance as a component thereof in the absence of a solvent, or may be dissolved in a solvent and used in a varnish form. As the solvent, any solvent can be used as long as it dissolves the above compound, for example, acetone, methyl ethyl ketone,
Toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N, N
-Dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like, and these may be used as a mixture of two or more. In particular, when a liquid alicyclic epoxy resin or a liquid acid anhydride compound is used, the composition can be prepared without using a solvent.

The epoxy resin composition of the present invention includes a reinforcing material (glass fiber, carbon fiber, aromatic polyamide fiber, alumina fiber, potassium titanate fiber, etc.),
Fillers (clay, mica, silica, graphite, glass beads, alumina, calcium carbonate, etc.) and the like can be added in appropriate amounts according to the purpose.

The epoxy resin composition of the present invention comprises:
Furthermore, one or more ordinary additives such as an antioxidant and a heat stabilizer, an ultraviolet absorber, a flame retardant aid, an antistatic agent, a lubricant, and a coloring agent are added within a range that does not impair the object of the present invention. Can be.

The epoxy resin composition may be impregnated into a glass fiber cloth such as a glass cloth or a glass non-woven fabric, or another cloth, or a base material such as paper and dried to obtain a prepreg. At this time, a varnish-like solution dissolved in an organic solvent is used as the epoxy resin composition, and the method of impregnating the epoxy resin composition into the base material includes brushing, spraying, and dipping. Can be. Drying is 8
It is preferably carried out at a temperature of 0 to 200 ° C., for example, those obtained by simply removing the solvent and those obtained by partially curing. The degree of drying is appropriately determined, but is adjusted so as to have a melt viscosity suitable for final molding. The prepreg can be appropriately laminated and cured by heating under pressure to form a laminated plate. At this time, the degree of pressure is 4.9 to 9.8 MPa (5 MPa).
It is preferably about 0 to 100 kg / cm ² ). The heating temperature is as follows. This laminated board is useful as a wiring board substrate.

The epoxy resin composition may be used in a so-called B-stage state in which the epoxy resin composition is generally partially cured without being completely cured in order to adjust the melt viscosity.

The epoxy resin composition, its B-stage state and prepreg are generally kept at 100 ° C. to 3 ° C.
Heat to a temperature in the range of 00 ° C. to cure.

The epoxy resin composition or its B-stage state is molded by a known molding method such as a compression molding method, a transfer molding method, an extrusion molding method, an injection molding method, and put into practical use.

[0025]

EXAMPLES (Synthesis Example 1) [Synthesis of poly (ethylene phthalate) (PEP)] A titanium-based catalyst was added to 174.6 g (0.9 mol) of phthalic anhydride and 86.8 g (1.4 mol) of ethylene glycol. (Ti
2.6 g of (aquaamine complex) was added, and the mixture was placed in a polymerization tube equipped with a vacuum stirring machine. The polymerization tube was equipped with a nitrogen gas inlet tube and a side tube for distillation.
Heat to 0 ° C. and slowly pass nitrogen gas through. After 4.5 hours, the temperature was gradually increased and stirring was started. The degree of vacuum was gradually increased to reach 333 Pa (2.5 Torr). At this time, the temperature was set to reach 275 ° C. 27
The mixture was heated at 5 ° C. for 2 hours to distill water generated by the polycondensation reaction, to obtain a target polyester (PEP). The obtained polyester was dissolved in acetone and then reprecipitated in methanol for purification. The molecular weight of the obtained polyester was 5,500 (peak value in gel permeation chromatography using standard polystyrene).

(Synthesis Examples 2 to 4) Synthesis was performed in the same manner as in Synthesis Example 1 under the ratios and synthesis conditions shown in Table 1.

[0027]

[Table 1]

(Example 1) Polyester (PEP) synthesized in Synthesis Example 1 was mixed with 100 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate (trade name: Celloxide 2021 manufactured by Daicel Chemical Industries, Ltd.). ) Was added in an amount of 20 to 100% by weight based on the entire composition containing the epoxy resin and the polyester.
Mix at 60 ° C. for 1 hour. After cooling to 120 ° C., 1 equivalent of methylhexahydrophthalic anhydride was added to the epoxy resin and mixed at 120 ° C. for 1 hour. This composition was poured into a silicon mold heated to about 100 ° C., and was heated at 100 ° C., 1 hour, 160 ° C., 4 hours, 180 ° C.,
It was cured by heating for 5 hours to obtain a cured product.

(Examples 2 to 7) In the same manner as in Example 1, compositions were prepared with the formulations shown in Table 2, and cured products were obtained.

Comparative Example 1 In Example 1, the polyester (P
A cured product was obtained in the same manner as in Example 1 without using EP).

The results of measuring the physical properties of the cured products obtained in Examples 1 to 4 and Comparative Example 1 are shown in Table 2.

[0032]

[Table 2]

The fracture toughness in Table 2 was determined by ASTM E
The glass transition temperature (Tg) was measured at a heating rate of 10 ° C./min using a differential scanning calorimeter by a three-point bending test method according to -399, and the bending strength was measured. Was measured at a crosshead speed of 1 mm / min according to JIS K7203.

As is evident from the results shown in Table 2, the cured product of the epoxy resin composition containing no polyester (Comparative Example 1) has excellent heat resistance, but has a K _IC which is an index of toughness.
Is as low as 0.51. On the other hand, it was found that the cured product of the epoxy resin composition containing polyester (Examples 1 to 7) greatly improved the K _{IC as} an index of toughness, and the resin was toughened. Further, these resins have a high Tg and have excellent toughness and heat resistance.

[0035]

The epoxy resin composition of the present invention has excellent toughness, mechanical strength and heat resistance.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 CD021 CF042 CF052 CF062 CF072 EF126 EL136 EL146 FD146 GH01 GJ01 GL00 GQ00 GQ01

Claims (2)

[Claims] 1. An epoxy resin composition comprising an alicyclic epoxy resin, a polyester containing a structural unit represented by the general formula (1), and an acid anhydride compound. Embedded image (However, in the general formula (1), n represents an integer of 2 to 12, and the benzene ring may have a substituent as appropriate). 2. 100 parts by weight of an alicyclic epoxy resin, 5 to 100 parts by weight of a polyester containing a structural unit represented by the general formula (1), and an acid anhydride compound in an amount of 0.7 to 2. The epoxy resin composition according to claim 1, comprising 1.5 equivalents.