JPH0618861B2 - Thermosetting resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermosetting resin composition which is easily moldable and hardenable, and has excellent oxidation resistance and thermal decomposition resistance.

Prior art Thermosetting resins include phenolic resins, urea resins, melamine resins, epoxy resins, unsaturated polyester resins,
Polyimide resin is known (June 15, 1985)
Japan, New Technology Development Center Co., Ltd., "Engineering Plastic Handbook", pages 149-151).

Generally, these resins have excellent resistance compared to thermoplastic resins, but except polyimide resin,
The long-term usable temperature is about 150 to 200 ° C. at maximum.

On the other hand, polyimide resin has a long-term usable temperature of 250.
It has a very high heat resistance of up to 300 ° C, but on the other hand, it has the drawback of poor moldability.

Recently, a condensed polycyclic polynuclear aromatic resin has been attracting attention as a novel thermosetting resin.

The condensed polycyclic polynuclear aromatic resin is used as a condensed polycyclic aromatic hydrocarbon, such as bilene, phenanthrene, naphthalene, anthracene, pitches containing them alone or in a mixture, and p-xylylene glycol as an crosslinking agent, an acid catalyst. It can be obtained by carrying out a polycondensation reaction in an inert gas atmosphere, using p-toluenesulfonic acid, etc.
Proceedings of the 51st Annual Meeting of the Chemical Society of Japan, held on October 3, 2000, pages 539-541, and December 1985
Held on 11th to 13th of a month, the 12th annual meeting of the Japan Society for Carbon Materials, page 183).

However, in this condensed polycyclic polynuclear aromatic resin, since crosslinking proceeds by a condensation reaction, the generation of gas during molding is unavoidable. Therefore, pressure molding is necessary to obtain a dense molded product, but it is impossible to completely suppress the generation of voids in the cured product.

Further, the condensed polycyclic polynuclear aromatic resin is usually used as a cross-linking agent.
-Xylylene glycol is used, but in order to realize high heat resistance, it is necessary to increase the crosslinking density, and therefore it is necessary to use a certain amount or more of the crosslinking agent. However, p-
As for xylylene glycol, industrially advantageous production technology has not been established at present, and establishment of a synthetic method satisfying economic efficiency and development of a substitute product have become important issues.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above condensed polycyclic polynuclear aromatic resin, no gas is generated during molding and curing, and -CH ₂ X (where X = OH, Cl) such as xylylene glycol is not generated. , Br), which provides a thermosetting resin composition capable of reducing the addition rate of an aromatic compound having two or more functional groups.

Details of the Invention The inventors of the present invention have conducted various test studies on countermeasures against gas generation during molding and curing of the condensed polycyclic polynuclear aromatic resin and substitutes for p-xylylene glycol as a cross-linking agent. Along with condensed polycyclic aromatic hydrocarbons as a cross-linking raw material, using phenols, after primary condensation, by using a polyvalent epoxide as a cross-linking agent during curing,
The inventors have found that the above problems can be solved and completed the present invention.

That is, the present invention is directed to condensed polycyclic aromatic hydrocarbons, phenols, and general formula —CH ₂ X (where X = OH, Cl, Br).
A thermosetting resin composition comprising a polycondensate obtained by heating and reacting an aromatic compound having two or more functional groups represented by, in the presence of an acid catalyst, and a polyvalent epoxide.

The conventional condensed polycyclic polynuclear aromatic resin is cured by the condensed polycyclic aromatic hydrocarbon and the general formula —CH ₂ X (where X = OH, Cl, B
Generation of gas during molding is unavoidable because it proceeds by a condensation reaction of an aromatic compound having two or more functional groups represented by r). Therefore, pressure molding is required to obtain a dense molded and hardened body, but it is impossible to completely suppress the generation of voids in the cured product.

On the other hand, since the resin of the present invention is cured by the addition reaction between the hydroxyl group in the resin skeleton and the epoxy group of the cross-linking agent, the generation of gas during molding, which is a disadvantage of the condensation-type thermosetting molding material, does not occur. It has the characteristic that it does not exist. Therefore, a compact and void-free molded cured product can be obtained even by normal pressure curing.

Further, by using a polyvalent epoxide as a cross-linking agent during curing, it is possible to reduce the amount of p-xylylene glycol used.

Furthermore, the resulting thermosetting product inherits the excellent heat resistance and moisture resistance of the conventional condensed polycyclic polynuclear aromatic resins, and is extremely superior in oxidation resistance and heat resistance to general phenolic resins and epoxy resins. It has degradability and moisture resistance.

As the condensed polycyclic aromatic hydrocarbon in the present invention, naphthalene, phenanthrene, anthracene, birene, fluoranthene, acenaphthene, methylnaphthalene, derivatives thereof, or a coal tar fractionated fraction containing them can be used alone or as a mixture. .

Examples of phenols include monovalent or polyvalent mononuclear phenols such as phenol, alkylphenol, resorcin, and naphthol, or phenols represented by phenol and alkylphenol, and formaldehyde,
It is possible to use a polynuclear phenol bonded via a cross-linking group obtained by acid-catalyzed condensation with paraformaldehyde or a ketone such as acetone, which still has an active reactive hydrogen in the phenol nucleus.

As the aromatic compound having two or more functional groups represented by the general formula —CH ₂ X (where X = OH, Cl, Br), xylylene glycol, naphthalene dimethanol, biphenyl dimethanol, xylylene dichloride, Xylylene range bromide etc. can be used.

As the acid catalyst, various organic acids such as toluenesulfonic acid, phenolsulfonic acid, xylenesulfonic acid, sulfuric acid, tin chloride, aluminum chloride and zinc chloride, inorganic acids and Lewis acids can be used.

As the polyvalent epoxide, an epoxy resin produced from dihydric or higher phenol and epichlorohydrin, for example, bisphenol A, bisphenol F, brominated bisphenol A, phenol novolac resin, o-cresol novolac resin, tetraphenolethane, tetrabromobisphenol. Various compounds having two or more epoxy groups in one molecule can be used, such as an epoxy resin manufactured from A and the like and epichlorohydrin, an epoxy resin manufactured from an aliphatic compound, and the like.

Polycondensation of condensed polycyclic aromatic hydrocarbons and phenols of the present invention with an aromatic compound having two or more functional groups represented by the general formula —CH ₂ X (where X = OH, Cl, Br). In the product, the compounding ratio of phenols / (condensed polycyclic aromatic hydrocarbons + phenols) is preferably 0.2 to 0.9 in molar ratio. If it is less than 0.2, the phenolic hydroxyl group in the polycondensate, which is the reaction point with the polyepoxide, becomes poor and the curability becomes insufficient. On the other hand, when it exceeds 0.9, the oxidation resistance, thermal decomposition resistance and moisture resistance are slightly lowered.

Further, the compounding ratio of the aromatic compound having two or more functional groups represented by the general formula —CH ₂ X (where X = OH, Cl, Br) is
The molar ratio is preferably 0.3 to 1.0 with respect to the total amount of the phenols and the condensed polycyclic aromatic hydrocarbons which are the materials to be crosslinked. A more preferable range is 0.4 to 0.9. If it is 0.3 or less, a large amount of unreacted condensed polycyclic aromatic hydrocarbons and phenols remain, so when blending a polyvalent epoxide and thermosetting, it does not show sufficient thermosetting property. Gelation is likely to occur in the system during the polycondensation reaction. Further, it is an economically expensive cross-linking agent represented by the general formula —CH ₂ X (where X =
It is not preferable because the amount of the aromatic compound having two or more functional groups represented by (OH, Cl, Br) increases.

The amount of the acid catalyst added is preferably 0.05 to 20% by weight, particularly preferably 0.2 to 10% by weight, based on the total weight of the raw material and the crosslinking agent.

The above-mentioned condensed polycyclic aromatic hydrocarbons and phenols and a cross-linking agent, a compound of an aromatic compound having two or more functional groups represented by the general formula —CH ₂ X (where X = OH, Cl, Br) are added. In the condensation reaction, an acid catalyst is added at a predetermined ratio, and the temperature is 50 to 200 ° C.
It can be easily progressed by heating with. When carrying out this polycondensation reaction, it is desirable that the condensed polycyclic aromatic hydrocarbon and the crosslinking agent are reacted to some extent in advance, and then phenols are added to further advance the reaction. When phenols are added from the beginning, the cross-linking agent selectively reacts with phenols, so that condensed polycyclic aromatic hydrocarbons remain in the polycondensate as unreacted products, and there are no phenolic hydroxyl groups in the molecule. It is not preferable because oligomers are easily formed.

The thermosetting resin composition of the present invention comprises the polycondensate and a polyepoxide. The compounding ratio of the polyvalent epoxide to the polycondensate is 0.5 to 0.5 in terms of the ratio of (the number of epoxy groups in the polyvalent epoxide) / (the number of hydroxyl groups in the condensate).
2.0, more preferably 0.7 to 1.5 is suitable. If it is less than 0.5, the crosslinking density does not increase, and if it exceeds 2.0, the reaction product between epoxy groups increases, which is not preferable in terms of mechanical properties, oxidation resistance, thermal decomposition resistance, and the like.

The resin obtained by the present invention has high heat resistance, is easily moldable and curable as compared with the conventional fused polycyclic polynuclear aromatic resin, and is also advantageous in terms of cost. It is judged to be extremely valuable as a structural material and electronic material.

Examples will be shown below, but the present invention is not limited thereto.

Example Phenanthrene 44.6 parts by weight (hereinafter, parts by weight are simply referred to as parts) [0.25 mol], p-xylylene glycol 51.8 parts [0.375 mol], p-toluenesulfonic acid (monohydrate) 6
Parts were charged into a glass reactor and reacted in a nitrogen stream at 120 ° C. for 15 minutes while stirring, then 23.5 parts of phenol [0.25 mol] was added and the condensation reaction was continued for another 105 minutes. A resin was obtained.

Next, 30.3 parts [0.17 mol] of phenanthrene, 34.5 parts [0.25 mol] of p-xylylene glycol and 4.8 parts of p-toluenesulfonic acid (monohydrate) were charged into a glass reactor,
After reacting at 120 ° C. for 15 minutes in a nitrogen stream, 31.0 parts [0.33 mol] of phenol was added and the condensation reaction was continued for 105 minutes to obtain a resin of Sample 2 in Table 1.

Each of the obtained resins did not cure even when heat-treated at 200 ° C. for 180 minutes, and the pour point did not change.

After adding 18.9 parts of bisphenol A type epoxy resin (epoxy equivalent: 184 to 194) to 45.0 parts of the resin of the sample 1 and mixing them well, heat treatment was carried out at 200 ° C. for 30 minutes under normal pressure. The produced resin was a void-free, dense molded body, had no pour point, and was a thermosetting body.

In addition, 27.5 parts of the resin of Sample 2 above Novolac type epoxy resin (epoxy equivalent 176-181) 17.
9 parts was added and the same heat treatment as in Sample 1 was performed. The produced resin was a void-free, dense molded body, had no pour point, and was a thermosetting body.

After each of these cured products was post-cured at 200 ° C for 180 minutes, the temperature was raised in air at 5 ° C / min under normal pressure.
The temperature at the time of 10% weight loss was measured. The results are shown in Table 2.

For comparison, a thermosetting product of a phenol / novolak-hexamine resin on the market (average molecular weight 600, hexamine 8 wt%, high carbonization yield grade, curing condition 200 ° C-18
(0 minutes) and a commercially available bisphenol A type epoxy resin thermoset (curing agent: methylendomethyltetrahydroanhydride, curing condition 200 ° C. for 180 minutes) are heated under the same conditions as above and heated to 10% weight. The temperature at the time of decrease was measured. The results are also shown in Table 2.

As is clear from Tables 1 and 2, even in the case of the resins of Samples 1 and 2 in which the compounding amount of p-xylylene glycol was small and which was not heat-cured, it was easy to add the polyvalent epoxide as a crosslinking agent. It becomes a thermoset.

Moreover, the obtained thermosetting product gives a void-free and dense molded product despite the curing under normal pressure.

Furthermore, this cured product has a feature that its oxidation resistance and thermal decomposition resistance are extremely superior to those of conventional phenol resins and epoxy resins.

Comparative Example Phenanthrene 89.3 parts [0.5 mol], p-xylylene glycol 51.8 parts [0.375 mol], and p-toluenesulfonic acid (monohydrate) 7 parts were charged into a glass reactor and stirred under nitrogen stream. A condensation reaction was carried out at 120 ° C. for 120 minutes to obtain a resin having the properties shown in Table 3. The obtained resin did not cure even when heat-treated at 200 ° C. for 180 minutes, and the pour point did not change.

Next, p-xylylene glycol 38.0 was added to this sample.
Part [0.275mol] was added and mixed well, then under normal pressure,
Heat treatment was performed at 200 ° C. for 30 minutes. The resin produced had no pour point and was thermoset, but was a pumice-like foam.

Claims (2)

[Claims] 1. A condensed polycyclic aromatic hydrocarbon, a phenol,
A polycondensate obtained by heating an aromatic compound having two or more functional groups represented by the general formula —CH ₂ X (where X = OH, Cl, Br) in the presence of an acid catalyst and a polyvalent epoxide. A thermosetting resin composition comprising: 2. The general formula --CH ₂ X (where X = OH, Cl,
The thermosetting resin composition according to claim 1, wherein the aromatic compound having two or more functional groups represented by Br) is xylylene glycol.