JPH0459855A - N-hydroxyphenylmaleimide-based polymer-modified phenolic resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, excellent in mechanical strength, moldability and heat resistance and suitable as mechanical parts, automotive field, etc., by blending a copolymer of an N-hydroxyphenylmaleimide and a vinyl compound with a novolak. CONSTITUTION:The objective composition is obtained by blending 100 pts.-wt. novolak which is an intermediate for phenolic resins with-1-50 pts.wt., preferably 5-30 pts.wt. copolymer of an Nhydroxyphenylmaleimide expressed by the formula ((n) is 1-3) and a vinyl compound (e.g. styrene or alpha-methylstyrene) copolymerizable therewith.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention has excellent both mechanical strength and heat resistance, and can be used in a wide range of fields such as mechanical parts, automobile fields, and electronic materials fields. The present invention relates to a certain thermosetting phenolic resin composition.

(Prior art) Phenolic resins have many excellent physical properties such as mechanical strength, heat resistance, electrical insulation, dimensional stability, chemical resistance, processability, and moldability, so they have been widely used as industrial materials. has been done. For example, molded products using phenolic resin,
It is used as an insulating material in the telecommunications field, and is also in high demand as automotive and mechanical parts.

However, in recent years, improvements in heat resistance and mechanical strength have been desired for the purpose of further expanding applications. Conventionally, methods for improving the heat resistance of phenolic resins include improving crosslinking density by heat treatment or increasing the amount of curing agent, or adding a modifier having heat resistance. However, in many cases, these methods have many problems in practical use, such as, although heat resistance is improved, mechanical strength including bending strength and impact resistance of the resulting molded product is reduced. Furthermore, as a method for improving the mechanical strength of phenolic resins, conventional methods have been used such as adding reinforcing materials such as rubber components and reinforcing materials such as glass fibers.

However, in many cases, although these methods improve mechanical strength, they have the disadvantage of decreasing heat resistance. That is, it is difficult to achieve both improvement in heat resistance and improvement in mechanical strength, and in many cases, there is a drawback that when one is improved, the other is reduced. Therefore, it has been desired to develop a phenolic resin composition that has excellent mechanical strength and heat resistance at the same time.

The present invention has been made in view of these circumstances, and its purpose is to provide a phenol resin composition that is excellent in both mechanical strength and heat resistance.

(Means for Solving the Problems) The present inventors conducted research to improve conventional phenolic resins to obtain a novel phenolic resin composition having excellent mechanical strength and excellent heat resistance. As an improvement method, in the present invention, various polymeric compounds with excellent mechanical strength and heat resistance are blended with novolak, which is a phenolic resin intermediate, and the mixture is cured with a curing agent such as hexamethylenetetramine. We adopted a method that improves the mechanical strength of objects and also improves their heat resistance.

The necessary conditions for the polymer compound to be blended are that it has excellent mechanical strength, excellent heat resistance, is compatible with novolak, and does not reduce moldability.

In the present invention, N-hydroxyphenylmaleimide (hereinafter referred to as HPM) is used as a polymer compound that satisfies these conditions.
It is written as I. ) and a vinyl compound (hereinafter referred to as copolymer).

That is, the above-mentioned copolymer, which has both heat resistance and appropriate flexibility for novolak, which is an intermediate of phenolic resin, and can react with a curing agent to form a crosslinked structure, is used as a modifier. The present inventors have discovered that the mechanical strength and heat resistance of the resulting phenol resin composition can be improved, and the present invention has been completed.

That is, the phenol resin composition of the present invention comprises N-hydroxyphenylmaleimide represented by the formula and 1L
The above object is achieved by blending a copolymer of liEN-hydroxyphenylmaleimide and a copolymerizable vinyl compound with novolak, which is a phenol resin intermediate.

It is possible to produce a copolymer that can be used in the present invention (PMr is ~2-hydroxyphenylmaleimide, N-3-hydroxyphenylmaleimide,
N-4-hydroxyphenylmaleimide, N2.3-dihydroxyphenylmaleimide, N-2,4-dihydroxyphenylmaleimide, N-2,5-dihydroxyphenylmaleimide, N-2,6-dihydroxyphenylmaleimide, N-3, 4-dihydroxyphenylmaleimide, N-3,5-dihydroxyphenylmaleimide,
N-2,4,6-)dihydroxyphenylmaleimide can be exemplified, and one or more of these may be used.

Vinyl compounds include styrene, α-methylstyrene, divinylbenzene, acrylic acid and its esters, methacrylic acid and its esters, acrylonitrile, maleic acid and its esters, fumaric acid and its esters, itaconic acid and its esters, vinyl of fatty acids. Examples include Esthe JI/ and maleimide derivatives. Maleimide derivatives include N-7 enylmaleimide, N-
2-methylphenylmaleimide, N-3-methylphenylmaleimide, N-4-methylphenylmaleimide, N
Examples include -2-chlorophenylmaleimide, N-3-chlorophenylmaleimide, and N-4-chlorophenylmaleimide, but are not limited to these. At least one vinyl compound selected from the group consisting of these is used.

In the present invention, in particular, the above-mentioned HPMI is N-4
-Hydroxyphenylmaleimide is preferably used.

In addition, vinyl compounds include styrene, α-methylstyrene,
Acrylic acid and its esters, methacrylic acid and its esters, and maleimide derivatives are preferably used.

The copolymer used in the present invention can be obtained by polymerizing HPMI and a vinyl compound by known polymerization methods, such as emulsion polymerization, suspension polymerization, and solution polymerization.

The number average molecular weight of the copolymer in the present invention is not particularly limited, but is preferably 1.000 to 100.000.

If the number average molecular weight of the copolymer is less than 1.000, the mechanical strength of the obtained phenol resin composition tends to decrease, and if it exceeds 100.000, the glass transition temperature of the phenol resin composition tends to decrease. increases, and moldability deteriorates.

The phenolic resin composition of the present invention is obtained by mixing a phenolic resin intermediate novolac, a copolymer, and optionally additives such as a curing agent, a lubricant, and a reinforcing material by a known method. In order to mix the novolac, the copolymer, and if necessary, a curing agent, etc., they may be mixed while heating if necessary. The compatibility between the copolymer and the novolak can be determined by measuring the glass transition temperature of each of them alone and the glass transition temperature of a molten mixture of both by DSC. In producing a phenol resin composition, a curing agent such as hexamethylenetetramine is generally used as a curing agent.

The copolymer is a phenolic resin intermediate, Novolac 1.
The desired mechanical strength and heat resistance can be imparted to the phenol resin composition by blending the phenol resin composition in an amount of usually 1 to 50 parts by weight, preferably 5 to 30 parts by weight per 00 parts by weight.

If the amount of the copolymer is less than 1 part by weight, sufficient mechanical strength and heat resistance cannot be obtained, and if it exceeds 50 parts by weight, the glass transition temperature of the phenol resin composition increases and the moldability of this resin composition is poor. Become.

By using the copolymer in the present invention, it is possible to improve the excellent mechanical strength of the phenol resin composition and also to improve the heat resistance.

The reason for this is presumed to be that the copolymer has both a heat-resistant skeleton and appropriate flexibility, and is also compatible with novolak and can react with a curing agent such as hexamethylenetetramine to form a crosslinked structure. be done.

The phenolic resin composition thus obtained can be molded according to ordinary molding methods and can be used in various fields as an engineering plastic with excellent mechanical strength and heat resistance.

(Example) The present invention will be described below with reference to Examples. In the examples, all references to "part" mean "overlapping part".

Example 1 (1) Production of copolymer of N-4-hydroxyphenylmaleimide and styrene A reactor equipped with a stirrer and a reflux condenser was charged with 100% N4-hydroxyphenylmaleimide (hereinafter referred to as 4-HPMI). 0 parts, 55.0 parts of styrene, 28.9 parts of 2,2° azobisisobutyronitrile (hereinafter referred to as AIBN), 4230 parts of N,N-dimethylformamide (hereinafter referred to as DMF). In addition, the temperature was maintained at 70° C. for 6 hours under a nitrogen atmosphere. After the reaction was completed, the reactant was dropped into water to precipitate a copolymer. After filtering the copolymer, it was vacuum dried to remove water, yielding 151.0 parts of a pale yellow 4-4-11P/styrene copolymer. The number average molecular weight of this copolymer was measured by GPC and found to be 16.000. In addition, when the glass transition temperature of this copolymer was measured by DSC, it was found to be 1
The temperature was 99°C.

(2) Preparation and evaluation of phenolic resin composition Novolak, which is a phenolic resin intermediate, and the 4-
100 parts of a mixture blended so that the ratio of HPMI/styrene copolymer was 10=1 (weight ratio), 12.0 parts of hexamethylenetetramine (hereinafter referred to as hexamine) as a hardening agent, and 12.0 parts of a reinforcing material. Glass fiber 112.
0 parts and 2.0 parts of zinc stearate as a lubricant were blended and kneaded using hot rolls heated to 100 to 110°C. After taking out the mixed material and pulverizing it, it is preheated to the extent that it has appropriate fluidity, and then it is molded using a transfer molding machine at 170°C.
It was molded at ℃ to obtain a test piece. Using this test piece, J
Bending strength, flexural modulus, Charpy impact strength, and deflection temperature under load were measured by the method of IS K-6911.

As a result, the bending strength was 17.0 kgf/mm, the bending modulus was 1420 kgf/mm2, the Charpy impact strength was 7.25 kgf-cm/cnf, and the deflection temperature under load was 165°C.These results are shown below. 1
Shown below.

Example 2 (1) Production of copolymer of 4-HPMI and styrene The copolymer obtained in section (1) of Example 1 was used.

(2) Preparation and evaluation of phenolic resin composition Novolak, which is a phenolic resin intermediate, and the 4-
A phenolic resin composition was produced in the same manner as in Example 1, except that the ratio of HPMI/styrene copolymer was blended to be 10=2 (weight ratio), and a test piece was obtained by molding. . Using this test piece, bending strength, bending modulus, Charpy impact strength,
and the deflection temperature under load were measured.

As a result, the bending strength was 19.1 kgf/mm', the bending modulus was 1433 kgf/mm2, and the Charpy strength was 11
The strength huff was 55 kgf=cm/cnf, and the load deflection temperature was 167°C. These results are shown in Table 1.

Example 3 (1) 4-) Production of copolymer of IPMI and styrene 4
-100.0 parts of HPMI, 55.0 parts of styrene, A
147.0 parts of 4-HPM+/styrene copolymer was obtained in the same manner as in Example 1 except that IBN was 2.89 parts and DMF was 1230 parts. The number average molecular weight of this polymer was measured by GPC and found to be 25.000. In addition, when the glass transition temperature of this polymer was measured, it was found that 2
The temperature was 35°C.

(2) Preparation and evaluation of phenolic resin composition Using the 4-4-1 (P/styrene copolymer obtained in section (1)), a phenolic resin composition was produced in the same manner as in Example 1, and molded. Using this test piece, bending strength, flexural modulus, Charpy impact strength, and deflection temperature under load were measured using the same method as in Example 1.

As a result, the bending strength was 16.7 kgf/am', the bending modulus was 1410 kgf/mm'', the Charpy 18 strength Huff was 57 kgf-cm/enf, and the deflection temperature under load was 162°C.These results are shown below. Shown in 1.

Example 4 (1) Production of copolymer of 4-HPMI and styrene The copolymer obtained in section (1) of Example 3 was used.

(2) Preparation and evaluation of phenolic resin composition Novolak, which is a phenolic resin intermediate, and the 4-
A phenolic resin composition was produced in the same manner as in Example 1, except that the ratio of HPMI/styrene copolymer was 1O:2 (weight ratio), and a test piece was obtained by molding. . Using this test piece, flexural strength, flexural modulus, Charpy impact strength, and deflection temperature under load were measured in the same manner as in Example 1.

As a result, the bending strength was 16.8 kgf/mm2, the bending modulus was 1451 kgf/mm2, the Charpy impact strength was 7.60 kgf-cm/cnf, and the deflection temperature under load was 168°C. These results are shown in Table 1.

Comparative Example 4 - A phenolic resin composition was produced in the same manner as in Example 1, except that no HPMI/styrene copolymer was added and only 100 parts of novolac, which is a phenolic resin intermediate, was used, molded, and tested. I got it. Using this test piece, flexural strength, flexural modulus, Charpy impact strength, and deflection temperature under load were measured in the same manner as in Example 1.

As a result, the bending strength was 16.1 kgf/mm', the bending modulus was 1407 kgf/mm', the Charpy impact strength was 7.15 kgf-cm/cl, and the deflection temperature under load was 151°C. These results are shown in Table 1.

As is clear from the Examples and Comparative Examples, the phenolic resin composition of the present invention has improved bending strength by blending a copolymer of N-4-hydroxyphenylmaleimide and styrene with novolak, which is a phenolic resin intermediate. , mechanical strength such as flexural modulus and Charpy impact strength is improved, and heat resistance such as deflection temperature under load is also improved.

Therefore, the phenolic resin composition of the present invention can be used in fields that require both mechanical strength and heat resistance.

(Effects of the Invention) According to the present invention, it is possible to obtain a phenolic resin composition that has improved mechanical strength and moldability and excellent heat resistance, and is used, for example, in mechanical parts, automobile fields, electronic fields, etc. It can be suitably used in a wide range of fields.

that's all

Claims (1)

[Claims] 1. N-hydroxyphenylmaleimide represented by the formula ▲ Numerical formula, chemical formula, table, etc. ▼ (n = an integer of 1 to 3);
- A phenolic resin composition comprising a copolymer of hydroxyphenylmaleimide and a copolymerizable vinyl compound mixed with novolak, which is a phenolic resin intermediate. 2. The vinyl compound is styrene, α-methylstyrene, divinylbenzene, acrylic acid, acrylic ester, methacrylic acid, methacrylic ester, acrylonitrile, maleic acid, maleic ester, fumaric acid, fumaric ester, itaconic acid, The composition according to claim 1, which is at least one selected from the group consisting of itaconic acid esters, vinyl esters of fatty acids, and maleimide derivatives.