JPH0657100A - Melamine-phenol resin composition - Google Patents

Abstract

(57) [Summary] [Structure] 100 parts by weight of a melamine resin having a number average molecular weight of 300 is mixed with 25 parts by weight of a dimethylene ether type resole resin having a number average molecular weight of 750 containing 50 mol% of a dimethylene ether bond. A melamine / phenol resin composition further comprising 1.1 parts by weight of an amino alcohol salt of imidodisulfonic acid and 2.0 parts by weight of diaminodiphenylmethane. [Effect] It is possible to obtain a molded product that is fast-curing, has excellent tracking resistance, and has extremely good dimensional stability even when used at high temperatures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for a molding material used for wiring equipment, electric equipment and the like. It is intended to provide a melamine / phenolic resin composition which is excellent in flexibility and has excellent dimensional stability even when used at high temperatures and which is unlikely to cause cracks and which is suitable as a molding material.

[0002]

2. Description of the Related Art Melamine resin molding materials are used for wiring appliances, electric appliances, etc. due to their excellent arc resistance, tracking resistance, electrical insulation, etc. Since the dimensional change is large, cracks, cracks, warpage, etc. are likely to occur in the molded product, and there are problems in terms of dimensional stability, crack resistance, and the like. In order to improve such a defect, a solid or liquid phenol resin of a resol type in which a usual methylol group is mainly bonded to a melamine resin has been used so far, to the extent that arc resistance, tracking resistance, and colorability are not impaired. Has been added to. Further, as the curing agent, carboxylic acid esters, acid anhydrides, organic halides, hydrochlorides of amines, amino alcohol salts of imidodisulfonic acid, etc. are blended alone,
It is known to cure.

Although such a material has a smaller dimensional change rate than a molding material composed only of melamine resin,
Sufficient dimensional change rate is not obtained compared to phenol resin molding materials. Further, although the molding shrinkage rate is improved by adding a large amount of the inorganic filler to the melamine resin, there is a drawback that the dimensional change rate after the heat treatment is not sufficient and the specific gravity is large. Further, in terms of moldability, the curability is generally slow, and in a molded product having a large wall thickness, blister is likely to occur, so that the curing time must be long. In addition, when a curing agent is used, the rigidity may be too high,
For this reason, there is a problem in that molding using a submarine gate or the like may cause claw creases to prevent continuous molding or to cause welds on the surface of the molded product. For this reason, melamine resin molding materials do not require a high degree of dimensional accuracy, and are used by molding with a long curing time only for applications that require colorability of electric parts and tableware that require tracking resistance. Is the current situation.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to quickly cure and shorten the curing time, without causing surface curing or welding on a molded product, and breaking the tabs of the submarine gate. It is to provide a melamine / phenolic resin composition suitable for a molding material that can be continuously molded without a crack.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, 100 parts by weight of a melamine resin having a number average molecular weight of 180 to 400 contains 20 to 70 mol% of a dimethylene ether bond and has a number average molecular weight of 500 to 1000. 10 to 50 parts by weight of an ether type resole resin is blended, and 0.1 to 3.0 parts by weight of an amino alcohol salt of imidodiphenylsulfonic acid and 0.1 to 3.0 parts by weight of diaminodiphenylmethane are blended. And a melamine / phenol resin composition.

The phenolic resin used in the present invention is a resole type phenolic resin containing a dimethylene ether bond and dehydrated by thermal decomposition of this bond. The amount of the phenol resin compounded is preferably 10 to 50 parts by weight with respect to 100 parts by weight of the melamine resin. When it is 10 parts by weight or less, improvement in dimensional stability and insert crack resistance is not recognized, and when it is 50 parts by weight or more, tracking resistance is deteriorated. The amino alcohol salt of imidodisulfonic acid is 0.1 parts by weight per 100 parts by weight of the melamine resin.
It is preferably about 3.0 parts by weight. If it is less than 0.1 parts by weight, the curability will be too slow, and if it is more than 30 parts by weight, the curing will be too fast and the rigidity will be high, and the tabs of the submarine gate will break. Further, the diaminodiphenylmethane mixed at the same time is preferably 0.1 to 3.0 parts by weight with respect to 100 parts by weight of the melamine resin. If the amount is less than 0.1 part by weight, sufficient flexibility cannot be obtained when heated. If the amount is more than 3.0 parts by weight, the thermal stability in the cylinder deteriorates. Raw materials used together with a melamine resin, a phenol resin, an amino alcohol salt of imidodisulfonic acid as a curing agent, and diaminodiphenylmethane to produce a molding material are a filler, a colorant, a release agent, and the like.

The melamine resin used in the present invention may be modified with an epoxy resin, rubber or the like. In the method for producing a molding material using the melamine / phenolic resin composition of the present invention, kneading may be carried out by a usual mixing roll or a twin-screw extrusion kneader, or granulation may be carried out by a high-speed rotary mixer. A molding method for obtaining a molded article using the molding material from the melamine / phenolic resin composition of the present invention,
Any of injection molding, transfer molding, compression molding and the like can be applied and is not limited.

[0008]

[Function] The dimensional stability of the melamine / phenol resin molding depends on the shrinkage effect that occurs with the curing of the melamine / phenol resin molding material. The melamine resin has 6 functional groups, which is more than the phenol resin having 3 functional groups. Since there are many melamine resin components, the shrinkage during crosslinking is greater.
The dimethylene ether type resole resin used in the present invention has a longer internuclear distance between the phenol nucleus and the phenol nucleus than the conventionally used phenol resin having a methylene group and a methylol group as main bonds. 8-3.
The dimethylene ether group has a thickness of 5.0 to 5.8 angstroms, compared with 0 angstroms. This dimethylene ether type resole resin having a long bond chain is used as a melamine resin 1
By blending 10 to 50 parts by weight with respect to 00 parts by weight, the curing shrinkage of the melamine resin is alleviated. The number average molecular weight of the melamine resin is suitably 180 to 400. 18
When it is less than 0, the gelation time is too long and the curing is slow. 40
When it exceeds 0, the gelation time is too short and the fluidity of the molding material is lowered. The degree of methylolation is preferably 1.0 to 3.0. If it is less than 1.0, the crosslink density does not increase,
Curing tends to be inadequate, and if it exceeds 3.0, a large amount of gas is generated during molding, and defective molding tends to occur.

The proportion of dimethylene ether bonds in the dimethylene ether type resole resin is 20 to 70 mol%.
When it is less than 20 mol%, the relaxation of the curing shrinkage of the melamine resin due to the dimethylene ether bond is insufficient, and it is difficult to produce a resin which exceeds 70 mol%. Further, the number average molecular weight is suitably 500 to 1000. If it is less than 500, the softening point is low and handling becomes difficult. If it exceeds 1,000, the gelation time is short and the fluidity of the molding material is lowered. The amino alcohol salt of imidodisulfonic acid is
Since the acid is generated by hydrolysis at about 130 ° C. and the pH becomes 2 to 5, the curing speed of the melamine resin which is an acid curing is significantly improved. In addition, the diaminodiphenylmethane that is simultaneously added causes a condensation reaction with this amino group and the methylol group of the melamine resin or a part of the methylol group of the phenol resin to form a long bond chain. For this reason, flexibility is imparted, and the shrinkage upon curing of the melamine resin is alleviated, and at the same time, the melamine resin is rapidly cured during molding. Therefore, it is considered that the melamine phenol resin composition of the present invention is fast-curing and has improved dimensional stability and crack resistance.

[0010]

EXAMPLES The raw materials shown in Table 1 were kneaded by heating with a mixing roll in a predetermined composition and pulverized to produce a molding material.
With respect to the obtained molding material, the molding shrinkage ratio, the post-shrinkage ratio at 110 ° C. after 5 hours of after-baking, the tracking resistance and the Bacol hardness, and the minimum blistering time of a 60φ × 12 mm thick molded product were measured. The results are shown in the lower column of Table 1.

[0011]

[Table 1]

When a dimethylene ether type resole resin, an amino alcohol salt of imidodisulfonic acid and diaminodiphenylmethane are used as in the examples, they are fast-curing and have flexibility and are extremely dimensionally stable even when used at high temperatures. A molded product having good properties was obtained. Further, this molded product is imparted with flexibility and has extremely excellent dimensional stability even when used at high temperatures.

[0013]

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain a molded product which is fast-curing, has a short curing time during molding, is excellent in tracking resistance, and has excellent dimensional stability even when used at high temperatures. Therefore, it is possible to easily manufacture molded products for applications such as those used at high temperatures, which have not been conventionally manufactured, and are excellent in quick-curing and tracking resistance. Therefore, for industrial melamine / phenol resin molding materials. It is suitable.

Claims (1)

[Claims] 1. A dimethylene ether bond is added to 100 parts by weight of a melamine resin having a number average molecular weight of 180 to 400.
Number average molecular weight containing 0 to 70 mol% 500 to 100
0 to 50 parts by weight of dimethylene ether type resole resin, and 0.1 to 3.0 parts by weight of amino alcohol salt of imidodisulfonic acid and 0.1 to 3.0 parts by weight of diaminodiphenylmethane. A melamine / phenolic resin composition characterized in that