JPH0725995B2 - 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,
Published by New Technology Development Center Co., Ltd., "Engineering Plastic Handbook", pp. 149-151).

Generally, these resins have excellent heat resistance as compared with thermoplastic resins, but even if polyimide resins are excluded, 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 to 300.
It has a very high heat resistance of ℃, 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 includes pyrene, phenanthrene, naphthalene, anthracene, pitches containing them as a condensed polycyclic aromatic hydrocarbon, used alone or in a mixture, and p-xylylene glycol as an crosslinking agent, an acid catalyst. It can be obtained by polycondensation using p-toluenesulfonic acid or the like as an inert gas atmosphere (1960, 1985).
Of the 51st Annual Meeting of the Chemical Society of Japan, held on March 3rd,
(See pages 539-541 and December 11-13, 1960, Abstracts of the 12th Annual Meeting of the Carbon Material Society of Japan, page 183).

This condensed polycyclic polynuclear aromatic resin is three-dimensionalized by heating the B-stage resin at 100 to 300 ° C., and the cured product thereof exhibits extremely excellent oxidation resistance and thermal decomposition resistance.

However, this condensed polycyclic polynuclear aromatic resin has a slower curing rate than other general-purpose thermosetting resins such as phenol resin and epoxy resin, and its processability is an important issue.

Further, p-xylylene glycol is usually used as a cross-linking agent, but in order to realize high heat resistance, it is necessary to increase the cross-linking density, so it is necessary to use a certain amount or more of cross-linking agent. However, p-xylylene glycol is
At present, industrially advantageous production techniques have not been established, and establishment of synthetic methods that satisfy economic efficiency and development of alternative products have become important issues.

DISCLOSURE OF THE INVENTION The present invention provides a thermosetting resin composition in which the above-mentioned condensed polycyclic polynuclear aromatic resin has improved moldability and hexamethylenetetramine can be used as a crosslinking agent. .

DETAILED DESCRIPTION OF THE INVENTION As a result of various tests, the present inventors have found that when polyphenols are used together with polycyclic aromatic hydrocarbons as a raw material, hexamethylenetetramine can be used as a cross-linking agent during curing, and the condensed polycyclic polynuclear aroma is used. The inventors have found that the curability is greatly improved without impairing the heat resistance of the group resin and completed the present invention.

That is, the present invention provides a condensed polycyclic aromatic hydrocarbon, a phenol, and an aromatic compound having two or more functional groups represented by the general formula —CH ₂ X (where X═OH, Cl, Br) as an acid compound. A thermosetting resin composition comprising a polycondensate which is heated in the presence of a catalyst and hexamethylenetetramine.

A conventional condensed polycyclic polynuclear aromatic resin is usually used as a crosslinking agent.
-Xylylene glycol is used, but when the cross-linking agent is 0.8 or less in molar ratio with respect to the material to be cross-linked, the resulting resin generally does not show thermosetting property. On the other hand, since the resin of the present invention has a phenol nucleus in the resin skeleton, it has a property that conventional condensed polycyclic polynuclear aromatic resins do not have, that is, hexamethylenetetramine is added as a crosslinking agent during curing. It has the characteristic that a heat-cured product can be easily obtained by heat treatment.

Therefore, without adding a large amount of p-xylylene glycol to the condensed polycyclic aromatic hydrocarbon to form a thermosetting product, inexpensive hexamethylenetetramine is added and heat treatment is performed to obtain p-xylylene glycol. When a large amount of is used, the same thermosetting body can be obtained.

Moreover, since the resin of the present invention has a phenol nucleus having high condensation reactivity, curability is greatly improved as compared with the conventional condensed polycyclic polynuclear aromatic resin.

Furthermore, the resulting thermosetting product inherits the excellent heat resistance of conventional condensed polycyclic polynuclear aromatic resins, and has extremely excellent oxidation resistance and thermal decomposition resistance as compared with general phenol resins. There is.

As the condensed polycyclic aromatic hydrocarbon in the present invention, naphthalene, phenanthrene, anthracene, pyrene, fluoranthene, acenaphthene, methylnaphthalene, derivatives thereof, or coal tar fractionated fraction containing them can be used alone or in 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 bridging group obtained by condensation with paraformaldehyde or a ketone such as acetone by an acid catalyst, and having a 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.

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 products, phenols / (condensed polycyclic aromatic hydrocarbons +
The compounding ratio of (phenols) is 0.2 or more in molar ratio, especially 0.2 to
0.8 is preferable. If it is less than 0.2, the active sites with hexamethylenetetramine become poor and the curability becomes insufficient.
On the other hand, if it exceeds 0.8, a slight decrease in heat resistance is observed.

In addition, 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 such that the raw materials to be crosslinked are phenols and condensed polycyclic aromatic compounds. A molar ratio of 0.3 to 5.0, particularly 0.3 to 1.0, is preferable with respect to the total amount of group hydrocarbons. A more preferable range is 0.4 to 0.9.
If the molar ratio is 0.3 or less, even if a large amount of hexamethylenetetramine is added, sufficient thermosetting property will not be exhibited. On the contrary, if it exceeds 1.0, gelation tends to occur in the system during the polycondensation reaction. In addition, it is an economically expensive crosslinking agent of the general formula --CH ₂ X.
(However, the amount of the aromatic compound having two or more functional groups represented by X = OH, Cl, Br) increases, which is not preferable.

The addition amount of the acid catalyst is preferably 0.05 to 20% by weight, particularly preferably 0.2, with respect to the total weight of the raw material and the crosslinking agent.
Is in the range of up to 10% by weight.

Reaction of the above-mentioned condensed polycyclic aromatic hydrocarbon and phenol with an aromatic compound having two or more functional groups represented by the general formula --CH ₂ X (where X = OH, Cl, Br) which is a cross-linking agent. Is
A polycondensate can be easily obtained by adding an acid catalyst in a predetermined ratio and heating and reacting at 50 to 200 ° C.
When carrying out this reaction, it is desirable that the condensed polycyclic aromatic hydrocarbon and the cross-linking agent are reacted 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, or oligomers that do not have a phenol nucleus in the molecule. Is easily generated, which is not preferable.

The thermosetting resin composition of the present invention is composed of the above polycondensate and hexamethylenetetramine. The compounding ratio of hexamethylenetetramine to the polycondensate varies depending on the ratio and type of the phenols to the condensed polycyclic aromatic hydrocarbons in the polycondensate, but usually hexamethylenetetramine to 100 parts by weight of the polycondensate. Is preferably added in the range of 3 to 20 parts by weight. If it is less than 3 parts by weight, sufficient thermosetting property is not exhibited, and if it exceeds 20 parts by weight, unreacted hexamethylenetetramine and its decomposition products (for example, ammonia) remain in the system, which is not preferable.

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] were 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 was not cured and the pour point did not change even if heat-treated at 200 ° C. for several minutes.

Hexamethylenetetramine (15% by weight) was added to each of the resins of Samples 1 and 2, and curing at 160 ° C where no outflow from the nozzle of the flow tester (nozzle diameter 1 mm, length 1 mm, pressure 10 kgf / cm ² ) was achieved. When the curing characteristics were measured, it was cured in 5 minutes and 4 minutes, respectively.

When this was post-cured at 200 ° C. for 180 minutes, curing proceeded further, and a black thermosetting body was obtained.

The post-cure thermoset is in air at atmospheric pressure, 5 ℃ / min
The temperature was raised by heating at, and the temperature when the weight was reduced by 10% was measured. The results are shown in Table 2.

For comparison, a commercially available phenol-novolak-hexamine resin thermoset (average molecular weight 600, hexamine 8
wt%, high carbonization yield grade, The curing conditions (200 ° C.-180 minutes) were heated and heated under the same conditions as above, and the temperature at the time of 10% weight loss was measured. The result is the second
Shown in the table.

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 hexamethylenetetramine as a crosslinking agent. It becomes a thermoset.

Moreover, the thermosetting product obtained is characterized in that its oxidation resistance and thermal decomposition resistance are far superior to those of conventional phenol resin cured products.

Comparative Example 1 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 a nitrogen stream. While carrying out a condensation reaction at 120 ° C. for 120 minutes, a resin having the properties shown in Table 3 was obtained. The obtained resin did not cure even if heat-treated at 200 ° C. for several minutes, and the pour point did not change.

Hexamethylenetetramine was added at 15% by weight,
When heat-treated at 0 ° C for 30 minutes, it was thermoplastic with a pour point of 113 ° C and did not become a cured product. 200 more
The heat treatment was carried out at 180 ° C. for 180 minutes, but the same result was obtained.

Comparative Example 2 Phenanthrene 89.3 parts [0.5 mol], p-xylylene glycol 69.1 parts [0.5 mol], p-toluenesulfonic acid (1
7.9 parts of a hydrate) was placed in a glass reactor and subjected to a condensation reaction at 120 ° C. for 120 minutes while stirring under a nitrogen stream to obtain a resin having the properties shown in Table 3. When the curing characteristics of the obtained resin were measured under the same conditions as in the examples, 15 minutes were required for curing.

Claims (4)

[Claims] 1. A condensed polycyclic aromatic hydrocarbon, a phenol,
Hexamethylenetetramine and 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. A thermosetting resin composition comprising: 2. The thermosetting resin composition according to claim 1, wherein the phenols are in a molar ratio of 0.2 or more with respect to the total moles of the condensed polycyclic aromatic hydrocarbon and the phenols. 3. The general formula --CH ₂ X (where X = OH, Cl, Br).
The aromatic compound having two or more functional groups represented by: is a molar ratio of 0.3 to 5.0 with respect to the total moles of the condensed polycyclic aromatic hydrocarbon and the phenols. The thermosetting resin composition. 4. The general formula --CH ₂ X (where X = OH, Cl, Br).
The thermosetting resin composition according to any one of claims 1 to 3, wherein the aromatic compound having two or more functional groups represented by is xylylene glycol.