JPH07216193A - Phenol resin molding material - Google Patents

Abstract

PURPOSE:To obtain a phenol resin molding material having high apparent density and molding stability and capable of forming a molded product having a low specific gravity and an excellent impact strength. CONSTITUTION:This molding material comprises a phenol resin and a reinforcement comprising flax fibers of 0.1 to 5mm in fiber length in an amt. of 5 to 50wt.% based on the total amt. of the phenol resin molding material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenol resin molding material used for, for example, machine structural parts.

[0002]

BACKGROUND OF THE INVENTION Phenolic resin molding materials are widely used as materials for machine structural parts, automobile parts, electric equipment parts, communication equipment parts, daily necessities, sundries, etc. because of their excellent heat resistance and physical properties. There is.

Conventionally, reinforcing materials such as glass fiber and cotton fiber have been used to improve impact resistance. However, glass fiber has high abrasion resistance and causes equipment to be worn during production. The life is shortened, and the specific gravity of the obtained molded product is increased, which is a negative factor for weight reduction.
Regarding the cotton fiber, the obtained molding material has a small apparent density, lacks molding stability, and is high in cost.

Therefore, the cost is low, the apparent density of the molding material is large, the molding stability is high, the specific gravity of the molding is small,
Phenolic resin molding materials with excellent impact resistance have become necessary.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and an object of the present invention is to provide a molding material with a large apparent density and molding stability, and a specific gravity of a molded product is small. , To provide a phenolic resin molding material having excellent impact resistance.

[0006]

The phenol resin molding material according to the present invention is a phenol resin molding material obtained by mixing a reinforcing material with a phenol resin, wherein the reinforcing material has a fiber length of 0.1 to 5 mm. Is contained in an amount of 5 to 50% by weight based on the total amount of the phenol resin molding material.

The present invention will be described in detail below. The phenol resin used in the present invention is phenol novolac obtained by condensation reaction of phenol and formaldehyde under an acid catalyst. Hemp fiber is used as a reinforcing material for improving impact resistance. Hemp fibers have high strength, low elongation, water resistance, and rot resistance. The fiber length of hemp fibers used as a reinforcing material is limited to 0.1 to 5 mm. When the fiber length of hemp fiber is less than 0.1 mm,
The mechanical strength such as Charpy impact strength will be low. When the fiber length of the hemp fiber exceeds 5 mm, the apparent density of the phenol resin molding material is 0.6 g / c.
Since it is less than m ³ , the molding stability becomes poor.
Furthermore, the content of hemp fibers is limited to 5 to 50% by weight with respect to the total amount of phenolic resin molding material. When the content of the hemp fibers is less than 5% by weight based on the total amount of the phenol resin molding material, mechanical strength such as Charpy impact strength becomes low. When the hemp fiber content exceeds 50% by weight based on the total amount of the phenol resin molding material, the apparent density of the phenol resin molding material is 0.6 g.
Since it is less than / cm ³ , the molding stability becomes poor.

As in the present invention, since the hemp fiber having a fiber length of 0.1 to 5 mm is contained as a reinforcing material in an amount of 5 to 50% by weight based on the total amount of the phenol resin molding material, the cost is low and the molding material It is possible to provide a phenol resin molding material having a large apparent density, molding stability, a small specific gravity of a molded product, and excellent impact resistance.

[0009]

EXAMPLES The present invention will be described in detail below with reference to examples.

The ingredients shown in Table 1 were mixed and kneaded with a heating roll to form a sheet. This sheet-shaped material was cooled and then pulverized by a pulverizer to obtain a granular phenol resin molding material. Here, phenol novolac having a number average molecular weight of 600 was used as the phenol resin.

Using these phenolic resin molding materials, test pieces were molded according to JIS K 6911, and Charpy impact strength and specific gravity were measured. The apparent density was measured using an apparent density meter. The results are shown in Table 1.

[0012]

[Table 1]

As shown in Table 1, in Example 1 and Example 2 of the present invention, as in Comparative Example 1 and Comparative Example 3, the fiber length of the hemp fiber was less than 0.1 mm, or the content of the hemp fiber was The Charpy impact strength is large and the mechanical strength is excellent as compared with the phenol resin molding material when the amount of the phenol resin molding material is less than 5% by weight based on the total amount. In addition, as in Comparative Examples 2, 4, and 5, the fiber length of the hemp fibers is 5 mm.
Or the content of hemp fibers exceeds 50% by weight based on the total amount of the phenolic resin molding material, or when cotton fibers are used, as compared with Examples 1 and 2 of the present invention, Since the apparent density is small and less than 0.6 g / cm ³ , the molding stability becomes poor. And
As in Comparative Example 5, when glass fiber is used, the specific gravity becomes large as compared with Examples 1 and 2 of the present invention.

Therefore, in Examples 1 and 2 of the present invention, a phenol resin molding material having a large apparent density of the molding material, a molding stability, a small specific gravity of the molding, and an excellent impact resistance was obtained. Was given.

[0015]

According to the phenol resin molding material of the present invention, since hemp fibers having a fiber length of 0.1 to 5 mm are contained as a reinforcing material in an amount of 5 to 50% by weight based on the total amount of the phenol resin molding material, molding is possible. The material has a large apparent density and molding stability, and the specific gravity of the molded product is small, and it has excellent impact resistance.

Claims (1)

[Claims] 1. A phenol resin molding material comprising a phenol resin and a reinforcing material blended therein, wherein hemp fibers having a fiber length of 0.1 to 5 mm are used as the reinforcing material in an amount of 5 to 50% by weight based on the total amount of the phenol resin molding material. % Of a phenol resin molding material.