JPH1030048A - Phenolic resin molding material and its moldings - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenolic resin molding material which has excellent heat resistance, mechanical and electrical properties, strength after hot and cold cycle and good balance between characteristics comparable to the phenolic resin containing asbestos as a base material, despite that it is asbestos-free and the molded products therefrom. SOLUTION: This phenolic composition contains (A) a novolak type phenolic resin with a weight-average molecular weight of 10,000-50,000 and (B) an N-(p- hydroxyphenyl)maleimide, for example, N-(p-hydroxyphenyl)maleimide or a copolymer thereof with a vinyl monomer such as n-butyl acrylate, as essential components. In this case, the content of (B) N-hydroxyphenylmaleimide is 0.1-50wt.% based on the whole amount of the molding material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a phenolic resin molding material having excellent heat resistance, mechanical and electrical properties, which is equivalent to an asbestos base molding material, even if it is asbestos-free. The present invention relates to a phenolic resin molded product molded by the method described above.

[0002]

2. Description of the Related Art Hitherto, a phenol resin has been widely used as a molding material by kneading with a base material, a plasticizer, a coloring agent, a release agent and the like. In particular, in recent years, phenolic resin molded articles have been used in the fields of electric parts, automobile parts, and the like, and heat resistance under severe conditions, mechanical properties, electrical properties, and strength after a warm / cold cycle are required.

As a phenolic resin molding material satisfying many of these characteristics, asbestos has been used as a suitable filler. Recently, however, asbestos has been banned because it deteriorates the working environment and is harmful to the human body. For these reasons, various methods have been studied as asbestos-free materials. However, there is no filler other than asbestos having properties equal to or higher than asbestos, and there has been a demand for development of a phenolic resin molding material having a well-balanced property.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and has a heat resistance, which is asbestos-free even if it is asbestos-free.
An object of the present invention is to provide a phenolic resin molding material having excellent mechanical / electrical properties and strength after a warm / cold cycle and a good balance of properties, and a molded article thereof.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, together with a novolak type phenol resin having a weight average molecular weight of 10,000 to 50,000, N- (p-hydroxyphenyl) maleimide has been obtained. It has been found that the above objects can be achieved by using the above-mentioned types, and the present invention has been completed.

[0006] That is, the present invention relates to (A) a weight average molecular weight of 1
0,000 to 50,000 novolak type phenolic resin, and
(B) a molding material comprising N- (p-hydroxyphenyl) maleimide selected from the group consisting of N- (p-hydroxyphenyl) maleimide and N- (p-hydroxyphenyl) maleimide / vinyl compound copolymer as an essential component; A phenolic resin molding material containing the N-hydroxyphenylmaleimide (B) in an amount of 0.1 to 50% by weight based on the whole, and a phenolic resin molded product obtained by molding the same. It is. Hereinafter, the present invention will be described in detail.

The phenolic resin (A) used in the present invention includes phenols such as phenol and cresol, phenols modified with molasses, lignin, xylene and naphthalene petroleum aromatic hydrocarbons, and formalin and paraformaldehyde. Was blended in a molar ratio of 0.85 to 0.90, and reacted under an acidic catalyst such as oxalic acid, and a weight average molecular weight of 10,000 to
It is 50,000, preferably 30,000 to 40,000 novolak type phenol resin, which is used in the state of initial condensation. The weight average molecular weight of this novolak type phenol resin is 10,0
If it is less than 00, a significant difference from a generally used novolak type phenol resin is small, and it becomes difficult to obtain sufficient original properties. If it exceeds 50,000, it becomes difficult to produce by dry method, which is not preferable. It is also possible to use a resol type phenol resin, but it is difficult to obtain the original characteristics sufficiently, which is not preferable.

It is desirable that the phenolic resin component (A) be blended in an amount of 0.1 to 70% by weight, more preferably 30 to 60% by weight, based on the whole molding material. If this proportion is less than 0.1% by weight, there is no effect of improving the mechanical strength and electrical properties, and if it exceeds 70% by weight, not only it becomes difficult to produce a molding material by a dry method, but also N- ( The effect of p-hydroxyphenyl) maleimides cannot be sufficiently exerted, which is not preferable.

As the (B) N- (p-hydroxyphenyl) maleimide used in the present invention, N- (p-hydroxyphenyl) maleimide, N- (p-hydroxyphenyl) maleimide and a vinyl compound are copolymerized. N-
(P-hydroxyphenyl) maleimide / vinyl compound copolymer, etc., and these can be used alone or as a mixture of two or more. Examples of the vinyl compound to be copolymerized with N- (p-hydroxyphenyl) maleimide include styrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate, and these may be used alone or as a mixture of two or more. can do. Among them, n-butyl acrylate can be preferably used. N-
The composition ratio of the (p-hydroxyphenyl) maleimide / vinyl compound copolymer is N- (p-hydroxyphenyl)
The amount of the vinyl compound is preferably in the range of 0.1 to 10 moles, more preferably 1 to 5 moles per mole of the maleimide.
Range of moles. The compounding ratio of N- (p-hydroxyphenyl) maleimide is 0.1 to
It is desirable to mix so as to contain 50% by weight. If the proportion is less than 0.1% by weight, there is no effect of improving heat resistance, mechanical / electrical properties, and warm / cold cycle.
If the amount is more than 10% by weight, it cannot be uniformly dispersed in the phenol resin molding material, which is not preferable.

The phenolic resin molding material of the present invention contains the above-mentioned phenolic resin having a specific molecular weight and N- (p-hydroxyphenyl) maleimide as essential components. Accordingly, for example, release agents such as natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, and paraffin, and flame retardants such as chlorinated paraffin, bromtoluene, hexabromobenzene, and antimony trioxide , A curing agent such as hexamethylenetetramine, various curing accelerators, and the like can be appropriately added and blended.

The phenolic resin molding material of the present invention can be usually produced as follows. The above-mentioned novolak-type phenol resin having a weight average molecular weight of 10,000 to 50,000, the above-mentioned N- (p-hydroxyphenyl) maleimides and a curing agent, a coloring agent, a curing accelerator, if necessary,
After mixing and uniformly dispersing a flame retardant, a release agent, a coupling agent, a plasticizer, etc., the mixture is heated and kneaded by a kneader, then solidified by cooling and pulverized to an appropriate size to obtain a molding material. . The phenolic resin molding material can be molded into a molded part.

[0012]

The phenolic resin molding material of the present invention has improved heat resistance and mechanical properties by incorporating N- (p-hydroxyphenyl) maleimide into a novolak type phenolic resin having a weight average molecular weight of 10,000 to 50,000. In addition, a phenolic resin molding material having good electrical properties and having well-balanced properties even when the composition was asbestos-free, and a molded article thereof were obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, “%” means “% by weight”.

Example 1 Novolak type phenol resin 50 having a weight average molecular weight of 38,000 50
%, N- (p-hydroxyphenyl) maleimide 5%,
Hexamethylenetetramine (7%), glass fiber (35%), and other additives (3%) were mixed at room temperature, kneaded and cooled at 90 to 110 ° C, and then pulverized to produce a phenolic resin molding material.

Example 2 Novolak type phenolic resin 48 having a weight average molecular weight of 38,000 48
%, N- (p-hydroxyphenyl) maleimide / n-
Butyl acrylate copolymer (copolymer molar ratio 1: 3.6)
Example 1 5%, glass fiber 20%, kaolin clay 15%, hexamethylenetetramine 7%, other additives 5%
A phenolic resin molding material was produced in the same manner as in the above case.

Comparative Example 1 Novolak type phenol resin 45 having a weight average molecular weight of 5,000
%, Hexamethylenetetramine 7%, glass fiber 40%,
A phenol resin molding material was produced in the same manner as in Example 1 except for using 8% of other additives.

Comparative Example 2 Resol type phenol resin 50%, glass fiber 40%, N-
A phenol resin molding material was produced in the same manner as in Example 1 except that 5% of (p-hydroxyphenyl) maleimide and 5% of other additives were used.

The phenolic resin molding materials produced in Examples 1 and 2 and Comparative Examples 1 and 2 were molded and cured in a mold heated to 170 ° C. by compression molding and injection molding to obtain molded parts. The resulting molded parts were tested for mechanical properties, electrical properties, hot / cold cycle test, heat distortion temperature, and appearance. The results are shown in Table 1. The present invention is excellent in various properties and well balanced. Thus, the effect of the present invention could be confirmed.

[0019]

[Table 1] * 1: A copper plate of 20 × 25 × 5 mm is embedded in the bottom of a molded product of 30 × 25 × 5 mm, put in a constant temperature bath at −40 ° C. and + 200 ° C. for 30 minutes, and the resin mold after repeating 15 cycles The rack was investigated. * 2: ○: good, x: bad.

[0020]

As is clear from the above description and Table 1, the phenolic resin molding material of the present invention and the molded parts thereof have the same heat resistance and mechanical properties as the asbestos base material even if they are asbestos-free. It has excellent electrical and electrical characteristics, strength and appearance after a warm / cold cycle, and good balance of properties, and is suitable as an electronic / electric component, an automobile component and the like.

Claims (2)

[Claims] 1. A group of (A) a novolak type phenol resin having a weight average molecular weight of 10,000 to 50,000 and (B) a copolymer of N- (p-hydroxyphenyl) maleimide and N- (p-hydroxyphenyl) maleimide / vinyl compound N- (p-hydroxyphenyl) maleimides selected from the group consisting of an essential component, and 0.1 to 50% by weight of the N-hydroxyphenylmaleimide (B) based on the whole molding material.
A phenolic resin molding material characterized by containing. 2. A novolak phenol resin having a weight average molecular weight of 10,000 to 50,000 and (B) N- (p-
N- (p-hydroxyphenyl) maleimide selected from the group consisting of hydroxyphenyl) maleimide and N- (p-hydroxyphenyl) maleimide / vinyl compound copolymer is an essential component, and the above (B)
A phenolic resin molded product obtained by molding a phenolic resin molding material containing 0.1 to 50% by weight of the N-hydroxyphenylmaleimide described above.