JPH06340731A - Phenolic resin molding material - Google Patents

Abstract

PURPOSE:To obtain a phenolic resin molding material, providing effects on flexibilization and prevention of metal corrosion, suitably used for moldings such as a coil bobbin having a thin-wall flange and capable of preventing cracking and chipping in wire winding steps. CONSTITUTION:The phenolic resin molding material is obtained by blending 100 pts.wt. dimethylene ether resol type phenolic resin with 3-40 pts.wt. bisphenol A type epoxy resin having 800-4000 epoxy equiv.

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 having excellent flexibility, which is preferably used for molded products such as coil bobbins such as power source bobbins.

[0002]

2. Description of the Related Art Conventionally, a phenol resin molding material has been used for a coil bobbin such as a power source bobbin from the viewpoint of heat resistance, strength and moldability.
The coil bobbin has become thinner due to the recent miniaturization of electric and electronic parts, and the conventional phenol resin molding materials are not cracked or chipped during deburring after molding, winding process such as winding, and transportation of parts. Such problems often occur. In order to deal with such a problem, a phenol resin molding material mixed with glass fiber is sometimes used as a reinforcing filler, but it is not often used due to problems such as wear of the molding die and high cost. Further, a phenol resin molding material containing a large amount of organic fibers such as cotton fibers may be used as a reinforcing material, but there is a performance problem that heat resistance, flame retardancy, and electrical insulation performance are deteriorated. Further, for a coil bobbin, an ammonia-free molding material is desired in order to prevent metal corrosion due to the molded product.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been studied to solve the above-mentioned drawbacks of conventional phenol resin molding materials, and as a result, by adding a specific epoxy resin,
We obtained the finding that the flexibility of the cured product is improved, and based on this finding, we investigated the ammonia-free process and completed the present invention. The object of the present invention is to have excellent flexibility without deteriorating electrical characteristics and other characteristics,
An object of the present invention is to provide a phenol resin molding material suitable for a coil bobbin such as a transformer coil having no metal corrosiveness.

[0004]

The present invention is characterized in that 100 parts by weight of a dimethylene ether resol type phenolic resin is mixed with 3 to 40 parts by weight of a bisphenol A type epoxy resin having an epoxy equivalent of 800 to 4000. It is a phenol resin molding material that has excellent flexibility and does not corrode metals.

As the epoxy resin of the present invention, a powdery bisphenol A type epoxy resin having an epoxy equivalent of 800 to 4000 is preferably used. Epoxy equivalent 800
When the amount is less than 4.0, sufficient flexibility cannot be obtained when compounded with the phenol resin, and when it exceeds 4000, compatibility with the phenol resin decreases and sufficient compounding effect cannot be obtained. The amount of the epoxy resin compounded is 3 to 40 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the phenol resin. If the amount is smaller than this, the effect of imparting flexibility is not sufficiently observed. On the other hand, even if added in this range or more, the above effect is not improved so much, the curability and moldability are lowered, and the cost is increased.

In the present invention, as the phenol resin, a resole resin which does not generate ammonia, particularly a dimethylene ether type resole resin is used. Dimethylene ether type resole resin has excellent reactivity with epoxy resin,
The reaction cured product has excellent flexibility while maintaining strength. Furthermore, the cured product of the dimethylene ether type resole resin and epoxy resin can prevent the corrosion of the molding die, and the obtained molded product does not generate ammonia for a long time after molding, and the coil winding Does not cause metal corrosion or disconnection. In the present invention, the filler preferably has a small content of ammonium compound, specifically 1
Use 0 ppm or less. Preferred as the filler of the present invention are crushed products of cotton, pulp, etc., organic substances such as crushed products of thermosetting resin moldings or laminates, clay, aluminum hydroxide, calcium carbonate, glass powder, glass fibers, etc. It is an inorganic substance.

The specific formulation of the phenol resin molding material of the present invention will be described. To 100 parts by weight of dimethylene ether type resole resin, 3 to 40 of the epoxy resin is added.
Parts by weight, filler 50 to 150 parts by weight, lubricant and pigment 5 to
7 parts by weight, and if necessary, a curing accelerator, etc. are added and mixed,
It is obtained by kneading and pulverizing. The molding of the phenolic resin molding material of the present invention can be applied to any of transfer molding and compression molding, including injection molding. When the phenol resin molding material of the present invention was molded and subjected to metal corrosiveness and destructive tests, it was confirmed that there was no metal corrosion, improvement of bending strength and improvement of elongation were observed, and the effect of improving flexibility. Was found to be large.

[0008]

EXAMPLES Examples and comparative examples will be described below. <Examples 1 and 2> 100 parts by weight of dimethylene ether clay sol type phenol resin, 50 parts by weight of powder of cured phenol resin, 15 parts by weight of crushed cloth, 20 parts by weight of clay,
5 parts by weight of slaked lime, 6 parts by weight of lubricant and pigment, and 5 parts by weight of bisphenol A type epoxy resin having an epoxy equivalent of 900 and 20 parts by weight were respectively added and kneaded by a hot roll to obtain a phenol resin molding material. Examples 3 and 4 100 parts by weight of dimethylene ether resol type phenol resin, 50 parts by weight of powder of a cured phenol resin, 15 parts by weight of crushed cloth, 20 parts by weight of clay, 5 parts by weight of slaked lime, 6 parts by weight of lubricant and pigment. Epoxy equivalent to 2
5 and 20 parts by weight of bisphenol A type epoxy resin of 000 were respectively added and kneaded by a hot roll to obtain a phenol resin molding material.

Comparative Example 1 105 parts by weight of dimethylene ether resol type phenol resin, 50 parts by weight of powder of a cured phenol resin, 15 parts by weight of crushed cloth, 20 parts by weight of clay, 5 parts by weight of slaked lime, 6 parts by weight of lubricant and pigment. Parts were added and kneaded with a hot roll to obtain a phenol resin molding material. << Comparative Example 2 >> Dimethylene ether type phenolic resin 12
0 parts by weight, 50 parts by weight of powdered phenol resin, 15 parts by weight of powder cloth, 20 parts by weight of clay, 5 parts by weight of slaked lime,
Lubricants and 6 parts by weight of pigments were added and kneaded with a hot roll to obtain a phenol resin molding material. The composition of each Example and Comparative Example is summarized in Table 1. Further, the molding material of each example was molded into a test piece by transfer molding, and the performance of the obtained molded product is also shown in Table 1.

[0010]

[Table 1] As is clear from Table 1, it is understood that the molded product made of the phenolic resin molding material of the present invention has a significantly improved flexural elongation and is excellent in flexibility.

[0011]

INDUSTRIAL APPLICABILITY The phenol resin molding material of the present invention uses a dimethylene ether type resole resin as a phenol resin, and by adding a small amount of a specific bisphenol A type epoxy resin thereto, an effect of imparting flexibility can be obtained. ,
It is suitably used for molded products such as coil bobbins with thin flanges. That is, when used for a coil bobbin, it is possible to prevent cracking and chipping in the winding process. Furthermore, by using a filler having a low ammonium compound content, the effect of preventing metal corrosion is great, and a phenol resin molding material more suitable as a coil bobbin can be obtained.

Claims (2)

[Claims] 1. An epoxy equivalent of 800 to 400 per 100 parts by weight of a dimethylene ether resol type phenol resin.
A phenol resin molding material comprising 3 to 40 parts by weight of 0 bisphenol A type epoxy resin. 2. A coil bobbin formed by molding the phenol resin molding material according to claim 1.