JPH0735430B2 - Method for producing vinylbenzyl ether group-containing oligomer - Google Patents

Description

The present invention relates to a vinylbenzyl ether group-containing oligomer obtained by a reaction of a phenol vinylbenzyl ether compound and an epoxy resin, which has excellent curability and physical properties of a cured product. With regard to the production method, it is particularly useful for applications such as adhesives, paints, laminated materials and molding materials.

[Prior Art] A resin having a vinylbenzyl ether group has been relatively newly developed and is widely regarded as a kind of heat-resistant resin, and at the same time, a resin having no ester bond in its molecular structure is used. Since it can be designed, it is attracting attention as a resin with excellent chemical resistance represented by alkali resistance.

The most typical production method of this resin is to synthesize a halomethylstyrene and a polyhydric phenol by reacting them in the presence of an alkali, as described in U.S. Pat. No. 4,116,936. , It is described that many polyvinyl benzyl ether compounds can be synthesized. The reaction formulas of the representative examples are shown below.

However, when considering a cured product of the obtained resin having excellent physical properties, a polyvinyl benzyl ether compound having a relatively large molecular weight may be desirable. For example, when a cured product having excellent toughness is required, it may be desirable to have a phenoxy structure as described below.

However, when such an oligomer type polyvinyl benzyl ether compound is to be synthesized by the above-mentioned method, there is a disadvantage that the salt solution produced as a by-product and the produced oligomer are emulsified, which makes production very difficult.

[Problems to be Solved by the Invention] In view of the present circumstances, the present invention has completed a method for producing a polyvinylbenzyl ether compound that does not generate a saline solution, which has been inconvenient in the conventional method, and reacts it with an epoxy resin. It is an object of the present invention to provide a vinylbenzyl ether group-containing oligomer which gives excellent physical properties of a cured product obtained by the method.

[Means for Solving the Problems] The present invention has solved the above problems by using a phenol vinyl benzyl ether compound as a raw material for producing a vinyl benzyl ether group-containing oligomer.

The phenol vinyl benzyl ether compound used in the present invention is obtained by substituting at least one phenolic hydroxyl group of a polyhydric phenol with a vinyl benzyl ether group, but still leaves at least one unreacted phenolic hydroxyl group. Moreover, both a vinylbenzyl ether group and a phenolic hydroxyl group are used in the molecule.

When producing a vinylbenzyl ether group-containing oligomer, the present inventors first prepared a polyhydric phenol and a halomethylstyrene in the presence of an alkali in the amount of halomethylstyrene based on 1 equivalent of the phenolic hydroxyl group of the polyhydric phenol. The dehydrohalogenation reaction is carried out using 1 mol or less,
A step of synthesizing the above-mentioned phenol vinyl benzyl ether compound and then reacting this with an epoxy resin using an etherification catalyst as necessary to produce a by-product such as sodium chloride which is inevitable in the conventional production method. The inventors have found that vinylbenzyl ether group-containing oligomers having a wide variety of structures can be produced without going through the process, and arrived at the present invention.

[Action] The phenol vinyl benzyl ether compound used in the present invention reacts polyhydric phenol with halomethylstyrene at an equivalence ratio of halomethylstyrene to phenolic hydroxyl group of less than the equivalent ratio, so that the unreacted phenolic hydroxyl group is still present in the molecule. A phenol vinyl benzyl ether compound having a vinyl benzyl ether group is synthesized, but the unreacted polyhydric phenol used as the raw material in this step becomes soluble in an alkaline aqueous solution. Ether compounds are BTX such as benzene
It becomes soluble in the system solvent and can be efficiently separated by solvent extraction. Therefore, by reacting this with an epoxy compound in the presence of an etherification catalyst as needed, the objective vinylbenzyl ether group-containing oligomer can be efficiently produced without the formation of by-products such as sodium chloride. Become.

In order to facilitate understanding of the present invention, a phenol vinyl benzyl ether compound obtained by reacting chloromethyl styrene as halomethyl styrene and bisphenol A as a polyhydric phenol, and a vinyl obtained by reacting it with a diepoxy resin are shown below. A typical reaction formula for synthesizing a benzyl ether group-containing oligomer is shown.

[However, R represents a residue obtained by removing a glycidyl group from an epoxy resin] The resulting phenol vinyl benzyl ether compound is
It can be confirmed by means such as infrared spectroscopy, liquid chromatography and NMR.

The phenol vinyl benzyl ether compound used in the present invention is obtained by reacting a polyhydric phenol with a halomethylstyrene in an excess state of the polyhydric phenol, the chemical formula of which is represented by the general formula (I ′). Be done.

However, X'is a polyhydric phenol residue, and n'and m '
Is 1 or more, and the total number of n'and m'is the same as the number of phenolic hydroxyl groups of the polyhydric phenol. Generally, it is practical to use polyhydric phenols up to tetrahydric, and therefore the maximum number of n'or m'is 3.

Examples of polyhydric phenols usable in the present invention include mononuclear polyhydric phenols such as resorcinol, catechol, and hydroquinone, bisphenol A, bisphenol F, bisphenol AH, biphenol, bisphenol S, tetramethylbisphenol A, bisphenol ether, dihydroxynaphthalene, and the like. The polynuclear polyhydric phenol of is mentioned. In addition, among the novolac resins which are formalin condensates such as phenol, alkylphenol or bisphenol A, those having a relatively low molecular weight can be used, but dihydric phenol is preferable in consideration of reactivity and practicality.

Examples of the halomethylstyrene to be reacted with the polyhydric phenol include bromomethylstyrene and chloromethylstyrene, but practically chloromethylstyrene is sufficient.

In the present invention, the phenol vinyl benzyl ether compound preferably used includes those represented by the following general formula (I).

[However, X represents a polyhydric phenol residue obtained by removing a phenolic hydroxyl group from a dihydric phenol] Typical examples of the compound represented by the general formula (I) include mononuclear dihydric phenol such as hydroquinone, bisphenol A and the like. The mononuclear benzyl ether of dinuclear dihydric phenol can be mentioned.

In the dehydrohalogenation reaction of polyhydric phenol and halomethylstyrene, 1 mol or less of halomethylstyrene is preferably added in an amount of 0.5 to 0.1 mol per 1 equivalent of the phenolic hydroxyl group of the polyhydric phenol in the presence of a solvent and an alkali. Using, 60 ~
It is carried out at 120 ° C for 2 to 5 hours. The solvent is a polar aqueous solvent, for example, glycol ether, ketone,
Examples include cyclic ethers, nitriles, sulfones, phosphoramides, and the like. Particularly suitable solvents include dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidinone, dioxane, acetonitrile, tetrahydrofuran, ethylene glycol dimethyl ether, 1,2-dimethoxypropane, tetramethylene sulfone, hexamethylphosphoramide, methyl ethyl ketone, methyl. Examples include isobutyl ketone, acetone, or a mixture thereof.

Further, as the alkali, for example, sodium hydroxide,
Mention may be made of potassium hydroxide, lithium hydroxide and mixtures thereof.

After completion of the reaction, the phenol vinyl benzyl ether compound is purified by extraction with a BTX solvent such as benzene, toluene, xylene, neutralization, washing with water and drying.

The phenol vinyl benzyl ether compound thus obtained can be used as a useful reactive monomer in itself, but is extremely convenient as a raw material for producing the vinyl benzyl ether group-containing oligomer of the present invention. That is, by reacting a phenol benzyl ether compound with an epoxy resin, a vinyl benzyl ether group-containing oligomer can be very easily synthesized without producing byproducts such as sodium chloride.

The epoxy resin used is not particularly limited, and for example, a glycidyl ether type epoxy resin obtained by condensation of the above-mentioned polyhydric phenol such as resorcinol or bisphenol A with epihalohydrin, or a condensation of the above-mentioned phenol with formaldehyde. Novolak type epoxy resin obtained by reacting novolak resin and epihalohydrin, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, glycidyl ester type epoxy resin obtained by condensation of epihalohydrin with dimer acid, Glycidyl ether / ester type epoxy resin obtained by reaction of benzoic acid and epihalohydrin, cyclopentadiene glycol, hydrogenated bisphenol A,
Glycidyl ether type epoxy resin obtained by condensation of glycols such as propylene glycol and epihalohydrin, glycidyl amine type epoxy resin obtained by condensation of amino compound such as diaminodiphenylmethane, xylylenediamine, hydantoin, triazine and epihalohydrin or these Known epoxy resins such as a mixture can be used.

The phenol vinyl benzyl ether compound and the epoxy resin are subjected to an addition reaction of a phenolic hydroxyl group in an equivalent ratio to 1 equivalent of an epoxy group in the presence of an etherification catalyst and a polymerization inhibitor, if necessary, to give vinyl benzyl in the molecule. A curable resin mainly comprising a vinylbenzyl ether group-containing oligomer having an ether group and a hydroxy group and substantially free of an epoxy group is produced.

In a preferred reaction mode, an etherification catalyst such as a tertiary amine, a quaternary amine, triphenylphosphine, potassium naphthenate, sodium naphthenate, lithium naphthenate, chromium naphthenate, lithium chloride, chromium chloride or potassium hydroxide is used as a raw material. It is present in an amount of 1 to 0.01 parts by weight per 100 parts by weight, and the reaction is carried out at 80 to 160 ° C, preferably 90 to 140 ° C until the phenolic hydroxyl group disappears. In addition, in order to facilitate stirring, it is possible to react not only in a solvent but also in a reactive diluting monomer such as styrene or trimethylolpropane triacrylate. Further, it is desirable to add a known polymerization inhibitor such as hydroquinone, quinone or copper salt.

The curable resin of the present invention containing a vinylbenzyl ether-based oligomer as a main component thus obtained is photocurable and heat curable.

The curable resin of the present invention can be widely used for adhesives, insulating materials, paints, composite structural materials, etc. by selecting the composition thereof.

Incidentally, the curable resin of the present invention, in order to improve the coatability,
It can be used by dissolving it in an organic solvent to reduce the viscosity.

Further, in the curable resin of the present invention, other known monomers such as styrene, chloromethylstyrene, chlorostyrene, vinyltoluene, diallyl carbonate, diallyl phthalate, acrylic acid, methacrylic acid, acrylic ester, methacrylic acid. Ester, vinylpyrrolidone, phenylmaleimide, cyclohexylmalemade,
Lauryl maleimide, a monofunctional maleimide compound such as dimethylmalate, dimethyl fumarate, diethyl fumarate, a maleate such as dibutyl fumarate, a fumarate compound or the like, or an epoxy acrylate, a urethane acrylate, an oligomer such as a polyester acrylate,
It is possible to mix within the range which does not deviate from the idea of the present invention. It goes without saying that hydroquinone, benzoquinone, a copper salt or the like may be added for adjusting the curing, and a radical initiator may be added for promoting the curing.

The curable resin of the present invention is a kneader, a blender, a roll, etc., talc, barium sulfate, silica powder, glass beads, a filler such as aerial, a defoaming agent such as silicone oil, a leveling agent, a dye and pigment, a reinforcing fiber. As a molding material or composite material, and dissolved in a solvent as a varnish, paint, adhesive, and impregnated into reinforcing fibers such as glass fiber, carbon fiber, aromatic polyamide fiber, silicon carbide fiber and alumina fiber. , A molding material or a structural material useful as a prepreg or as a filament window.

Next, reference examples and examples will be shown in order to explain the present invention in detail, but these do not limit the scope of the present invention. Unless otherwise specified, the parts in the examples are parts by weight.

Reference Example 137 parts (1.20 equivalents) of bisphenol A was dissolved in 300 parts of dimethyl sulfoxide, and 67 parts of caustic potash was dissolved in 90 parts of water and added. Commercially available chloromethylstyrene (23 parts, 0.15 equivalent) was dissolved in dimethylsulfoxide (150 parts) and added dropwise at 70 to 80 ° C over 2 hours. After completion of the addition, the reaction was continued for 2 hours. After the reaction, the mixture was diluted with 300 parts of water and extracted twice with 300 parts of benzene. The benzene layer was neutralized with hydrochloric acid, washed with water, and repeated until the pH became neutral. Then, benzene was removed under reduced pressure to obtain a monovinylbenzyl ether compound of bisphenol A (yield based on chloromethylstyrene). Was 92%). Analysis of this compound by liquid chromatography revealed that the formation of divinylbenzyl ether of bisphenol A was small. The IR chart of this compound is shown in FIG. 1, the NMR chart is shown in FIG. 2, and the liquid chromatography chart is shown in FIG.

Example 1 34 parts (0.1 equivalent) of monovinylbenzyl ether compound of bisphenol A obtained in Reference Example, 24 parts (0.1 equivalent) of bisphenol epoxy resin (Epicoat 834 (epoxy equivalent 240) of Yuka Shell Co., Ltd.), reactivity Styrene monomer 12 parts as a diluting monomer, lithium chloride 0.2 part as an etherification catalyst, hydroquinone 0.03 as a polymerization inhibitor
After the reaction was carried out at 130 ° C for 4 hours, it was confirmed to be constant at 910 cm ^-1 by infrared spectroscopic analysis and that the epoxy group had disappeared by chemical analysis of the epoxy group by the dioxane hydrochloride method. And 46 parts of styrene monomer were added to obtain a brown vinylbenzyl ether group-containing oligomer having a viscosity of 8 poise. Add BPO paste to this resin 100
2 parts per part were mixed and cured at 80 ° C for 120 minutes, 120 ° C for 8 hours, but the bending strength according to JIS 6911 is 13.8 kg / mm ² ,
The flexural modulus was 328 kg / mm ² .

Example 2 34 parts (0.1 equivalent) of monovinylbenzyl ether compound of bisphenol A of Reference Example, 18.7 parts (0.1 equivalent) of bisphenol epoxy resin (330L (Epoxy equivalent 187) of Ciba Co., 0.1 equivalent), 0.3 parts of triphenylphosphine, polymerization inhibitor Hydroquinone was reacted with 0.011 g at 135 to 140 ° C. for 4 hours, and 50 parts of styrene monomer was added after the reaction. The viscosity of this resin is
It was 4 poise.

Example 3 A resin in which 25 parts of styrene monomer and 25 parts of phenylmaleimide were used instead of 50 parts of styrene monomer in the resin of Example 2 was prepared. 5 g of each of this resin and the resin of Example 3 was placed in a test tube, and the gelation time was examined in an oil bath at 120 ° C., whereas this resin containing phenylmaleimide gelled in 3 to 4 minutes. The resin of Example 2 gelled in 38 minutes
Hardened after a minute. To accelerate the curability of this type of resin,
Maleimide compounds are effective.

[Effect of the Invention] According to the method of the present invention, since a phenol vinyl benzyl ether compound is used as a raw material, a by-product such as salt is not generated, and a curable resin mainly composed of a high-quality vinyl benzyl ether group-containing oligomer is used. Can be manufactured very easily. A wide variety of curable resins can be produced, and they are useful for applications such as adhesives, paints, molding materials and laminated materials.

[Brief description of drawings]

FIG. 1 shows the infrared (IR) spectrum of bisphenol A monovinylbenzyl ether obtained in Reference Example, FIG. 2 shows the same nuclear magnetic resonance (NMR) spectrum, and FIG. 3 shows the chart obtained by liquid chromatography. In FIG. 3, A represents bisphenol A monovinyl benzyl ether and B represents bisphenol A divinyl benzyl ether.

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Claims (1)

[Claims] 1. A phenol vinyl benzyl ether compound having a vinyl benzyl ether group and a phenolic hydroxyl group in the molecule and an epoxy resin are subjected to an addition reaction of a phenolic hydroxyl group with respect to an epoxy group in an equivalent ratio in the presence of an etherification catalyst. A method for producing a vinylbenzyl ether group-containing oligomer having a vinylbenzyl ether group and a hydroxy group in the molecule and substantially free of an epoxy group, which is characterized in that.