JPH0460485B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to epoxy resin compositions used in adhesives, paints, cast products used in electronic and electrical parts, etc., and more particularly, the present invention relates to epoxy resin compositions used in adhesives, paints, and cast products used in electronic and electrical parts. The present invention relates to an epoxy resin composition from which bodies can be manufactured. [Prior Art] Epoxy resin has traditionally been used as a material for various molded products because of its excellent mechanical, chemical, and electrical properties, but its drawback is that it lacks flexibility. It will be done. As one means for improving this drawback, it is known to mix an epoxidized liquid polybutadiene having hydroxyl groups at both ends with an uncured epoxy resin and then perform a curing treatment. However, even this method is still insufficient in terms of imparting flexibility, and in producing the liquid polybutadiene used, it is necessary to use a complicated production process of first producing a liquid polybutadiene having hydroxyl groups and then epoxidizing it. It was something that wasn't there. [Problems to be Solved by the Invention] An object of the present invention is to overcome the above-mentioned problems and provide an epoxy resin composition that provides an epoxy cured product having excellent flexibility. [Means for Solving the Problems] The epoxy composition of the present invention is characterized by the presence of a polymerization initiator and/or chain transfer agent capable of introducing a hydroxyl group into an uncured epoxy resin and a diene monomer and an epoxy group-containing monomer. It is characterized by containing a copolymer having hydroxyl groups and epoxy groups in the molecule obtained by copolymerization below. In the present invention, as the uncured epoxy resin, any known resin can be selected as long as it has at least two epoxy groups per molecule, such as brominated epoxy resin, epoxy novolac resin, Bisphenol A-epichlorohydrin resin, polyfunctional epoxy resin, aliphatic epoxy resin, alicyclic epoxy resin, etc. can be used. A typical example of these epoxy resins is a resin obtained by the reaction of bisphenol and epichlorohydrin, and is represented by the following general formula, (In the formula, n is an integer of 5 or less.) Generally, n is 2 or 3 or less, and the epoxy equivalent is
Those having a value of 170 to 300 are preferred. Furthermore, it is also possible to add to these epoxy resins diluents such as glycidyl ethers of aliphatic alcohols having 3 to 10 carbon atoms, such as butyl glycidyl ether, allyl glycidyl ether, and other commercially available epoxy resin diluents. The diluent can usually be used in an amount of 20% by weight or less of the epoxy resin. The diene monomer is not particularly limited, but usually a diolefin-based unsaturated unsubstituted-, 2-substituted-, or 2,3-substituted-1,3-diene having 4 to 12 carbon atoms is used. Examples of the substituent here include an alkyl group, an aryl group, a halogen, a cyano group, and a nitro group. Specific monomers include 1,3-butadiene, isoprene, 1,
3-pentadiene, chloroprene, 2,3-dichlorobutadiene, 2-cyano-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, etc. are used. The epoxy group-containing monomer is not particularly limited, but unsaturated glycidyl esters such as glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether are used. The polymerization initiator and/or chain transfer agent capable of introducing hydroxyl groups into the copolymer is not particularly limited, but usually δ,δ'-asobis(δ-cyano)-
An aso compound having a hydroxyl group such as n-pentanol, a mixture of an azo compound such as 2,2'-azobisisobutyronitrile and a mercaptoalkanol such as mercaptoethanol, hydrogen peroxide, etc. are used. Among these, hydrogen peroxide is preferred. The blending ratio of the diene monomer and the epoxy group-containing monomer is not particularly limited, but usually the epoxy group-containing monomer is used in an amount of 50 to 2% by weight to 50 to 98% by weight of the diene monomer. The copolymer used in the present invention is basically obtained by copolymerizing a diene monomer and an epoxy group-containing monomer, but if necessary, a part of the diene monomer may be replaced with an ethylenically unsaturated monomer. An α-olefin addition polymerizable monomer having 2 to 22 carbon atoms is used instead. Specifically, styrene, α-methylstyrene, vinyltoluene, methyl methacrylate, acrylic acid, vinyl chloride, vinylidene chloride, acrylonitrile, acrylamide, 2-ethylhexyl acrylate, n-octadecyl acrylate,
These include maleic anhydride, butene, and 2-hydroxyethyl methacrylate. Although the polymerization reaction does not particularly require a solvent, it is usually preferably carried out in a solvent such as alcohol, a mixture of alcohol and water, ether, ketone, aliphatic hydrocarbon, aromatic hydrocarbon, or halogenated hydrocarbon. Such solvents include methanol,
Examples include ethanol, n-propanol, isopropanol, butanol, propyl ether, tetrahydrofuran, ethyl acetate, cellosolve, cellosolve acetate, ethyl cellosolve, acetone, and mixtures thereof. The amount of solvent used is not particularly limited, but usually the total amount (monomer, solvent,
5 to 500% by weight of hydrogen peroxide, etc.), preferably 30% by weight
~300% by weight. When hydrogen peroxide is used as an initiator, there are no particular restrictions, but hydrogen peroxide usually
0.1 to 50 parts by weight per 100 parts by weight, preferably
0.3 to 30 parts by weight are used. Hydrogen peroxide is usually
It is used as a 30-80% aqueous solution, preferably a 50% aqueous solution. Polymerization reaction conditions vary depending on the type of diene monomer used, the amount used, etc., and cannot be unambiguously specified, but are usually under stirring, at a reaction temperature of 50 to 200°C,
Preferably at 80~150℃, reaction pressure 0~200Kg/ ^cm2
G, preferably 1 to 100 Kg/cm ² G for 0.1 to 24 hours,
Preferably by reacting for 0.2 to 20 hours,
A liquid copolymer having a hydroxyl group and an epoxy group in the molecule can be produced. This copolymer preferably has an average number of functional hydroxyl groups of 1.0 or more. It is thought that the hydroxyl group present in the molecule acts as a curing agent during the subsequent curing treatment. The copolymer used in the present invention has, for example, the following structure. (Here, R is a methyl group or hydrogen, and a and b represent the ratio of each structural unit in the copolymer, and are positive decimal numbers that add up to 1. n represents the degree of polymerization of the copolymer. n is a positive number, and is 5 to 500, preferably 10 to 200.) The copolymer thus obtained is blended with uncured epoxy resin, and the necessary curing agent is used for curing the epoxy resin. A cured epoxy product is obtained by curing in the presence of a curing accelerator according to the requirements. The curing agent for epoxy resins is not particularly limited, but polyamines, polyamides, dibasic acids or their anhydrides, etc. are usually used. Specifically, the polyamines include diethylenetriamine, triethylenetetramine, imidazole, metaphenylenediamine, diaminodiphenylmethane, etc., and the polyamides include polyamide oligomers produced by the condensation reaction of dimer acid and polyamines.
Dibasic acids or anhydrides include phthalic acid or anhydride, hexahydrophthalic acid or anhydride, methyl 3,6-endo-methylene-δ ₄ -tetrahydrophthalic acid or methyl 3,6-anhydride. Examples include endo-methylene-δ ₄ -tetrahydrophthalic acid, pyromellitic acid, and pyromellitic anhydride. The curing agent for epoxy resin is not particularly limited, but is usually blended in an amount of 5 to 200 parts by weight based on 100 parts by weight of the total amount of uncured epoxy resin, epoxy resin, and copolymer. Examples of the curing accelerator include, but are not limited to, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylethanolamine, dimethylaminoethanol, and tri(dimethylaminomethyl)phenol, and 2-methylimidazole. , 2-phenylimidazole, 2-phenyl-4-methylimidazole, imidazoles such as 2-heptadecyl imidazole, tributylphosphine, methyldiphenylphosphine, diphenylphosphine,
Examples include organic phosphines such as triphenylphosphine and phenylphosphine, and tetraphenylboron salts such as tetraphenolphosphonium tetraphenylborate and 2-ethyl-4methylimidazoletetraphenylborate. Although the curing accelerator is not particularly limited, it is usually used in an amount of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the total amount of the uncured epoxy resin, copolymer, and curing agent for epoxy resin. The epoxy resin composition of the present invention may also contain inorganic fillers, mold release agents, flame retardants, colorants, coupling agents, and the like, if necessary. The above-mentioned epoxy resin composition is mixed with a curing agent and a curing accelerator to form a molded article by a method such as transfer molding, injection molding, compression molding, or casting, or used as an adhesive or the like. Although the curing reaction is not particularly limited, it is usually carried out at 0 to 200°C, preferably 20 to 160°C. [Examples] The present invention will be explained below with reference to Examples, but the scope of the present invention is not limited to these Examples. Table 1 shows the conditions for producing copolymers of Examples and Comparative Examples of the present invention, and the results of measuring various properties of the copolymers. Table 2 shows the formulations, curing conditions, and physical properties of the epoxy resin compositions of Examples and Comparative Examples of the present invention. [Production example of copolymer] Production examples 1 to 5 The ingredients shown in the proportions shown in Table 1 were charged into a stainless steel pressure-resistant container equipped with a stirrer, and after raising the temperature for 60 minutes, polymerization was carried out under the conditions shown. I went there. After that, air is blown onto the outer surface of the container to lower the temperature.
The indicated post-treatments were carried out to obtain a copolymer. Production Examples 6 to 8 The temperature was raised for 30 minutes, 0.05 parts by weight of 4-t-
A copolymer was obtained by carrying out the reaction in the same manner as in Production Examples 1 to 5, except that 1 part by weight of toluene containing butylcatechol was added to stop the polymerization. In addition, the numerical values in the table mean parts by weight unless otherwise stated. [Manufacture of epoxy cured product] Stir and mix the indicated components in the proportions shown in Table 2,
A cured product was obtained by curing treatment under the indicated curing conditions.

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〔Effect of the invention〕

The epoxy cured product produced using the epoxy resin composition of the present invention has excellent flexibility, and the copolymer of the blend is easy to produce, so the industrial value of the present invention is extremely large. be.

Claims (1)

[Claims] 1. Having a hydroxyl group and an epoxy group in the molecule obtained by copolymerizing a diene monomer and an epoxy group-containing monomer into an uncured epoxy resin in the presence of a polymerization initiator and/or chain transfer agent capable of introducing a hydroxyl group. An epoxy resin composition characterized by containing a copolymer.