JPS5853441B2 - Denkizetsentaino Seizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing electrical insulation from glass fiber reinforced thermosetting resins.

Conventionally, glass fiber-reinforced synthetic resin molded products have been used for electrical insulators such as electrical printed wiring boards, but such electrical insulators are required to have electrical and physical properties such as insulation and strength. In addition, moldability, surface smoothness, punching properties, etc. are often required.

For this purpose, the reinforcing fibers used are chopped strand mats made of many glass fiber filaments,
Continuous strand mats, glass cloth, etc. are used, but continuous strand mats are especially prized.

However, conventional molded products in which these reinforcing bodies are impregnated with porcelain resin and cured after molding have not yet fully satisfied these characteristics.

As a result of repeated studies to meet these demands, the present invention has been developed by impregnating these reinforcing fibers with a synthetic resin, molding and curing the electrical insulator, and using a synthetic resin with a diameter of 5 to 10 cm for a total of 1 meter of impregnated resin. 25μ, length 10~500μ, shape factor (
It has been discovered that the physical properties and electrical characteristics of electrical insulators can be improved by using a liquid thermosetting resin mixed with short glass single fibers (length to diameter ratio) of 2 to 20, and proposed as the present invention. It is something to do.

For the present invention, the diameter is 5 to 25μ, preferably 9 to 13μ
μ, length 10-500μ, preferably 100-200μ
, short glass single fibers with a shape factor (length to diameter ratio) of 2 to 20, preferably 5 to 20 are suitable, and these can be produced by cutting the single fibers to a predetermined length. However, chopped strands (which are aggregates of single fibers)
It is also suitable to manufacture the strands by cutting the strands into pieces of about 2 to 10 cm), milling them, opening and cutting the strands.

In this case, the length of short fibers varies by 60%.
As mentioned above, it is appropriate that preferably 80% or more is within the above range.

For the present invention, such short glass single fibers may be subjected to a rerun treatment to form unsaturated polyester resin,
5 to 30% by weight of thermosetting resins such as epoxy resins and phenolic resins, and if necessary, thickeners,
Fillers, curing agents, hardening agents, coloring agents, etc. are appropriately blended.

Since the short glass single fibers having a small diameter as described above used in the present invention have good fluidity and dispersibility,
By mixing this with a liquid thermosetting resin and impregnating it into a glass strand mat, thin and short single fibers are interposed within the strand mat to form a homogeneous composite, and at the same time, the glass fiber content can be easily increased. It is possible to obtain products with high glass fiber content.

In addition, in the case of general glass strand mats and roving cloth, it is two-dimensional reinforcement, but short glass single fibers are interposed between these two-dimensional reinforcing layers, and combined with the layers to form a tertiary reinforcement. It is possible to form an original reinforcing structure and increase the strength.

In addition, the short single fibers are well dispersed in the resin and blend into it, increasing the adhesion between the glass reinforcement and the resin, preventing the separation of the strand mat from the synthetic resin that occurs during curing and shrinkage, and providing a cushioning effect against impact. This is thought to prevent the occurrence of cracks, resulting in the following properties.

(1) Because the short glass single fibers mentioned above are homogeneously interposed, the surface is smoothed and adhesive properties are increased, improving prevention of deformation and breakage, and exerting a cushioning effect against impact. It is possible to prevent the occurrence of cracks even when subjected to impact such as punching, and the punching cross section can be made clean, thereby improving the punching characteristics.

(2) Mixing of single glass fibers reduces stress transmission and acts as stress relaxation, so even if stress is applied, fracture due to creep is less likely to occur, and rigidity can be improved by 10 to 20%.

(3) Since the single glass fibers are homogeneously mixed, the electrical insulation property is improved, and since the short single fibers are interposed homogeneously without being continuous, even if an arc occurs, it will be interrupted and the fire extinguishing effect will be effective. This can improve arc resistance and prevent deterioration of insulating materials due to spark generation.

(4) Strength can be increased because the amount of resin used is reduced and the glass fiber content increases.

Next, examples of the present invention will be shown.

(Hereinafter, "excellent" means weight φ) Continuous Strand Pine) 20% single fiber
A blend example of 20% resin (unsaturated polyester) and 60% was produced by impregnating a continuous strand mat with the liquid unsaturated polyester resin mixed with the above-mentioned glass single fibers, and then heat-curing it using a conventional method. The electrical properties of the electrical insulating board are compared with those of conventional products and are shown in Table 1 below.

(2) (1) The product of the present invention is a product according to the above embodiment.

(2) Conventional product (I) is an unsaturated polynisder resin (manufactured by Dainippon Ink Co., Ltd., trade name Polylye) 801 with a glass fiber (continuous strand mat) content of 40%.
0) A molded plate consisting of

(3) Conventional product (2) is a molded plate made of glass fiber (continuous strand mat) 20φ, Al (OH) 320%, and unsaturated polyester resin (manufactured by Inu Nippon Ink Co., Ltd., trade name: Polylite 8010) 60 rolls.

(4) Conventional product ■ is a molded plate made of 20% glass fiber (continuous strand mat), 20% CaCO3, and 60 parts of unsaturated polyester resin (manufactured by Inu Nippon Ink Co., Ltd., trade name Polylite 8010).

The conventional product, a'Iil, contains Al(OH) 3.0 to improve arc resistance. CaCO3 (3-5μ particle size)
It is a mixture of

(5) Dielectric strength is the time required for dielectric breakdown when a voltage of 40 kV is applied.

(6) Arc resistance is based on JIS K6911 arc resistance test.

Next, Epoquin resin (Table 2) and phenol resin (Table 3)
Examples based on Table) are shown below.

Although the foregoing description has been made with respect to continuous strand mats, the present invention can equally be practiced with chopped strand mats and glass fiber reinforcements such as glass cloth.

Claims (1)

[Claims] 1. When producing an electrical insulator by impregnating a glass fiber reinforcement with a thermosetting resin and curing it after molding,
1. A method for producing an electrical insulator, characterized by using a liquid thermosetting resin mixed with glass single fibers having a diameter of 25μ, a length of 10 to 500μ, and a shape factor (length to diameter ratio) of 2 to 20.