JPS60159006A - Manufacture of molding material - Google Patents

Abstract

PURPOSE:To enable a molding material having a constant quality to be provided at all times, by performing a step of stirring for the granulation before kneading. CONSTITUTION:A step of stirring a resin, a filler and additives for the granulation is followed by a step of stirring by a kneader. By previously stirring a resin in the form of powder or fiber, a filler and additives together with heating for the formation of granules, the mixture can be fed to a kneader without classification or bridging.

Description

[Detailed description of the invention] The present invention relates to a method for producing a molding material.

Conventionally, molding materials have been manufactured using rolls, kneaders, and the like. Production using rolls tends to generate dust at the beginning of kneading, and requires considerable skill to obtain a molding material with suitable fluidity for molding. When kneading with a kneader, a molding material with constant fluidity can be obtained by keeping the kneading temperature and the composition and amount of raw materials constant. but,
In this case, many of the resins, fillers, and additives are powders;
If these materials are simply mixed, it will be necessary to classify them according to their different specific gravity and particle size, and to change the crosstalk conditions over time. Furthermore, if there are fibrous materials, they become entangled with each other, creating bridges within the supply device, making it impossible to supply the raw material.

In order to eliminate such drawbacks, the present invention is characterized by a step of stirring and granulating the resin, filler, and additives, followed by a step of kneading with a kneader. By heating powdered or fibrous resins, fillers, and additives while stirring and grinding them into granules, they can be fed to a kneader without causing classification or bridging.

A kneader is used to control fluidity suitable for molding, so stable production can be achieved. Although it is possible to control fluidity by stirring alone, it becomes difficult to select and manage conditions as with roll cross-talk.

The resin used in the present invention includes thermosetting resins such as phenol resin, melamine resin, and epoxy resin, and the fillers and additives include glass powder, silica powder, calcium carbonate, talc powder, mica powder, asbestos, etc. Reinforcing materials such as fillers, chopped glass strands, carbon fibers, aramid fibers, etc.
Coupling agents such as aminosilane, epoxysilane, and titanate; coloring agents such as carbon black, red iron oxide, and titanium white; and mold release agents such as stearic acid and montan wax.

These are weighed to the specified size and granulated by stirring with a mixer or the like. The resin may be melted by the heat generated by stirring or, if necessary, by additional heating, or a solvent may be added. Since the fluidity and particle size of the molding material are adjusted using the next kneader, it is not necessary to complete the granulation by stirring (fillers, additives, etc.) do not need to be so large that they do not fly apart and do not interfere with the feeding equipment. Therefore, the stirring time is short and the range of stirring conditions can be widened considerably.

Next, the present invention will be explained in detail.

30 parts by weight of novolac type phenolic resin, 4 parts by weight of hexamine
Mixed parts by weight, 35 parts by weight of glass fiber, 30 parts by weight of talc, 0.5 parts by weight of stearic acid, and 0.5 parts by weight of carbon black were mixed and molded by the method shown in Examples and Comparative Examples. I got the material.

30 parts by weight of methanol was added to Example Formulation A, placed in a 20/Henschel mixer, and mixed at 90° rpm without cooling water.
Stirred for 0 minutes. Subsequently, the mixture was fed to a biaxial continuous kneader using a quantitative feeder, kneaded at 60°C, and sequentially crushed to obtain a molding material.

Comparative Example Compound A was fed to a biaxial continuous kneader using a quantitative feeder, kneaded at 60°C, and sequentially ground to obtain a molding material.

The drawings show the fluidity (disk flow) of the molding materials obtained sequentially and the change in ash content in the molding materials over time. Curve 1 shows flowability and curve 2 shows ash content. As is clear from this figure, in the comparative example (Fig. 1), the ash content in the produced molding material decreases at the end of the crosstalk due to separation of the raw materials, and the fluidity increases accordingly. On the other hand, in the example (FIG. 2), it is almost constant.

In this way, by carrying out the stirring and granulation process before kneading with a kneader, a molding material of consistently stable quality can be obtained, which is of great industrial value.

[Brief explanation of drawings]

Fig. 1 is a curve diagram showing changes over time in fluidity and ash content of molding materials sequentially produced in comparative examples of the present invention, and Fig. 2 is a curve diagram showing changes in fluidity and ash content over time of molding materials sequentially produced in comparative examples of the present invention. It is a curve diagram. 1 is fluidity and 2 is ash content. Patent applicant Figure 1 Time (hr) (m, 3) Child 2 Figure H Morima (hr) (Shuto J)

Claims (1)

[Claims] ) A method for producing a molding material, which comprises a step of stirring and granulating a resin, a filler, and an additive, followed by a step of mixing in a kneader.