JPH11269341A - Phenolic resin molding composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition useful for e.g. automotive transmission parts by combined use of melamine with a resol-type phenolic resin so as to afford high (long-term) heat resistance while maintaining its moldability comparable to conventional materials. SOLUTION: This molding composition is obtained by compounding (A) 100 pts.wt. of a resol-type phenolic resin (e.g. a liquid or solid one including that of methylol type and dimethylene ether type) with (B) 30-100 pts.wt. of melamine and (C) 180-300 pts.wt. of an inorganic filler (e.g. calcium carbonate, clay, talc, aramid fiber, carbon fiber, glass fiber; in particular, glass fiber treated with a silane coupling agent such as an epoxysilane) through e.g. thoroughly kneading with a mixing hot roll.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenolic resin molding material having excellent heat resistance and moldability, and more particularly to a phenol resin suitable for substituting various metal parts such as automobile parts. The present invention relates to a resin molding material.

[0002]

2. Description of the Related Art Phenolic resin molding materials are widely used in various fields as materials having excellent balance between heat resistance, dimensional accuracy, mechanical strength and cost. However, the required characteristics of the market are becoming increasingly severe. In particular, in recent years, the automotive industry has replaced plastics such as transmission parts and parts near engines used in high-temperature atmospheres, or commutators that are already plasticized. Demands for high durability in the next generation such as
The heat resistance of conventional phenolic resins has reached its limits.

As this improved material, a material using a Xyloc resin (phenol aralkyl) or a polycyclic aromatic phenol resin has been developed. The resin used as these materials has a structure with few phenolic hydroxyl groups,
It has high long-term heat resistance due to its excellent oxidation resistance. However, since the curing reaction of the phenolic resin is promoted by the phenolic hydroxyl group, the Xyloc resin and the polycyclic aromatic phenolic resin have a curing time three to four times as long as that of the conventional phenolic resin. The material used had a problem in moldability. In addition, there is also a problem that the strength during hot is lower than that of a conventional phenol resin.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has an object to have moldability equivalent to that of a conventional phenolic resin molding material, and An object of the present invention is to provide a molding material having excellent heat resistance, especially long-term heat resistance.

[0005]

Means for Solving the Problems The present inventors have conducted various studies especially for the purpose of improving long-term heat resistance, and as a result, have found that the object can be achieved by using melamine in combination with a resole-type phenol resin. It came to be. That is, the present invention is a phenolic resin molding material characterized by mixing 30 to 100 parts by weight of melamine and 180 to 300 parts by weight of an inorganic filler with respect to 100 parts by weight of a resole type phenolic resin.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The resole type phenol resin used in the present invention includes a methylol type and a dimethylene ether type, and may be liquid or solid.

The melamine used in the present invention is preferably used in an amount of 30 to 100 parts by weight based on 100 parts by weight of the resol type phenol resin. More preferably 30 to
70 parts by weight. If the amount is less than 30 parts by weight, the heat resistance is not so improved. If the amount is more than 100 parts by weight, the mechanical strength is reduced, and the workability in forming a molding material is also deteriorated.

The inorganic filler used in the present invention is not particularly limited, and any of those added to conventional phenolic resins can be used. Examples thereof include calcium carbonate, clay, talc, silica, and aramid. Fibers, carbon fibers, glass fibers and the like can be mentioned. In particular, an inorganic filler mainly composed of glass fiber is effective for strength and heat resistance. At this time, it is desirable to treat the glass fiber with a silane coupling agent during compounding. As the silane coupling agent, those added to a conventional phenol resin can be used, and in particular, epoxy silanes are preferable in terms of mechanical strength, heat resistance, and workability in forming a molding material.

[0009] The mold release property during the operation of forming a molding material and the mold release property during molding of the molding material are equal to or higher than those of the conventional phenolic resin molding material. What is added to the conventional phenol resin is sufficient.

The method for producing the phenolic resin molding material of the present invention is not particularly limited. However, in order to more effectively improve the heat resistance, it is preferable that the phenolic resin molding material is sufficiently kneaded. It is valid. The molding method of the phenolic resin molding material of the present invention, injection molding,
It can be applied to any of transfer molding, compression molding and the like.

The reason why a molded article using the phenolic resin molding material of the present invention is particularly excellent in long-term heat resistance is not yet clear, but is presumed as follows. That is,
Since the nitrogen atom of melamine forms a hydrogen bond with a phenolic hydroxyl group, the melamine has a protected structure, and the oxidative deterioration of the hydroxyl group is suppressed. This point is the same as that of a Xyloc resin or a polycyclic aromatic phenol resin having a low hydroxyl group density, which is hardly oxidized and deteriorated. However, since the activity of the phenolic hydroxyl group is not impaired by the hydrogen bond with melamine, the curing reaction of the phenolic resin is not suppressed, and good moldability is obtained.

Melamine has reactivity with a methylol group or a dimethylene ether group, as is well known for melamine resins. That is, since it has reactivity with the resol-type phenol resin, it is presumed that it exhibits characteristics different from those of a simple filler.

[0013]

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

Examples 1-2 Dimethylene ether type resole resin (manufactured by Asahi Organic Materials Co., Ltd., number average molecular weight 700), melamine (manufactured by Mitsui Toatsu Chemicals, Inc.), glass fiber (NEC Glass Co., Ltd.) )
And other additives (hardening agent, release agent, etc.) were mixed in the weight ratios shown in Table 1, kneaded with a mixing hot roll, and pulverized with a power mill to obtain a molding material.

The obtained molding material was injection-molded under the following conditions to obtain a JIS bending test piece (80 × 10 × 4 mm).

The obtained test piece was subjected to after-curing at 180 ° C. × 3 hours + 220 ° C. × 3 hours,
, And a hot strength test in a 160 ° C. atmosphere. The results are shown in Table 1.

Comparative Examples 1-2 A heat resistance test was conducted in the same manner as in Example 1 except that test pieces were obtained by mixing at the ratios shown in Table 1. Table 1 shows the results.

[0018]

[Table 1]

From Table 1, it can be seen that a molded article using the phenolic resin molding material of the present invention has the same hot strength as a general phenolic resin molding material as in the comparative example and is excellent in long-term heat resistance. .

[0020]

The phenolic resin molding material of the present invention has excellent thermal properties (especially long-term heat resistance) in a high-temperature atmosphere and can be used in a high-temperature atmosphere, which has been impossible so far. It is possible to substitute metal for automobile parts such as in the vicinity of transmissions and transmissions. In addition, compared to molding materials using the heat resistance improving material Xyloc resin or polycyclic aromatic phenolic resin, the curing speed is clearly higher, so that the moldability is excellent, and the cost is also higher than that of conventional general materials. Since it is equivalent to a phenolic resin molding material, it is a very industrially suitable material.

Claims (1)

[Claims] 1. A phenol resin molding material characterized by mixing 30 to 100 parts by weight of melamine and 180 to 300 parts by weight of an inorganic filler with respect to 100 parts by weight of a resole type phenol resin.