JP2001260153A - Method for molding thermosetting resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance filling properties and the thickness accuracy of a molded article in the compression molding of a thin plate-shaped molded article using a thermosetting resin molding material much in the compounding quantity of a filler. SOLUTION: In a method for molding the thin plate-shaped molded article with a surface area of 50-1,500 cm2 and a thickness of 0.1-5 mm using the thermosetting resin molding material, the molding material comprising a material composition consisting of 10-30 weight % of a thermosetting resin and 70-90 weight % of an inorganic filler and having a spiral flow of 10-70 cm is subjected to compression molding under molding pressure of 30-100 MPa and a mold clamping speed at the time of molding is preferably 0.1-1 mm/sec.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thin plate-like molded product by molding a thermosetting resin molding material by compression molding.

[0002]

2. Description of the Related Art Conventionally, in the compression molding of a thermosetting resin molding material, a molding material is put into a mold heated to an appropriate temperature, and when the resin has a suitable fluidity by melting, the molding material is pressed. Is spread to the corners of the mold, and further heated and pressed to be completely cured in the mold to form a molded product having a predetermined shape and dimensions. Generally, in compression molding, a molding pressure of 15 to 30 MPa is sufficient. Here, the thermosetting resin is a phenol resin, an epoxy resin, a melamine resin, an unsaturated polyester resin, a diacryl phthalate resin, a urea resin, a silicone resin, or the like.

A general thermosetting resin molding material has a filler amount of 30 to 60% by weight and a resin amount of 40 to 70% by weight.
It is a material having good fluidity at the time of melting. However, the molding material used in the present invention is a material having a large amount of an inorganic filler of 70% by weight or more and a small resin content, and is a thin plate-like molded product (5).
(0 to 1500 cm ² , 0.1 to ⁵ mm in thickness) is insufficient in fluidity for compression molding, and at present it is not possible to satisfy required qualities such as fillability and thickness accuracy.

[0004]

The present invention relates to the molding of a thermosetting resin, which uses a molding material having a spiral flow of 10 to 70 cm and containing 70 to 90% by weight of an inorganic filler, and having the above dimensions. An object of the present invention is to improve the filling property and improve the thickness accuracy of a molded product in compression molding of a thin plate-shaped molded product.

[0005]

SUMMARY OF THE INVENTION The present invention uses a thermosetting resin molding material and has a molded product having a surface area of 50 to 1500.
cm ^2, in a method of forming a thin plate molded article has a thickness of 0.1 to 5 mm, the material composition is 10 to 30 wt% resin and an inorganic filler 70-90 wt%, the spiral flow in 10~70cm A molding material is subjected to a molding pressure of 30.
The present invention relates to a method for producing a thin plate-shaped molded product, which is characterized by being compression-molded at a pressure of 100 to 100 MPa.
More preferably, the filling property is further improved by setting the mold clamping speed to a low speed of 0.1 to 1 mm / sec.

Hereinafter, the present invention will be described in detail. The thermosetting resin molding material of the present invention comprises 10 to 30% by weight of a resin and 70 to 90% by weight of an inorganic filler. It is a material with low properties. As an index indicating the fluidity, the spiral flow is 10 to 70 cm. The spiral flow is obtained by setting a mold having a spiral flow path of 4 mm in height and 4 mm in width at 150 ° C. and measuring the flow distance of the material at an injection pressure of 46 MPa. Here, the inorganic filler is glass fiber, silica, talc, clay, calcium carbonate, graphite, or the like. In the present invention, by performing compression molding at a high molding pressure of 30 to 100 MPa, even a material having low fluidity can be expanded by high pressure, so that the filling property is improved and the thickness accuracy can be improved. If the pressure is less than 30 MPa, the pressure is insufficient and complete filling is difficult. If it exceeds 100 MPa, the filling properties will be improved, but the strength of the mold will be insufficient and there is a risk of damage to the mold. If the mold is enlarged, it becomes impractical in terms of cost and workability.

[0007] By compression molding at the high pressure, the density of the molded article is increased, and the strength and other properties are also improved. In addition, by setting the mold closing speed to a low speed as described above, it becomes possible to form the material when the material is warmed in a heated mold and in an appropriate molten state after the material is charged, and furthermore, the filling is performed. Performance can be improved. The mold clamping speed is preferably set to be 10 mm before the mold is completely closed in order to mold the mold when the fluidity becomes the best. However, as a problem, the molding cycle is lengthened by lowering the mold clamping speed, and the productivity is reduced.

In order to enable high-pressure molding, it is considered that the strength of the mold is insufficient with ordinary mold dimensions, and the mold may be deformed due to this. Therefore, the thickness of the mold is about 1.5 to 2 times the normal thickness. It is necessary to improve the strength of the mold and prevent deformation. The thickness of a normal mold (lower mold) is about 150 mm, and when strength needs to be improved, it is about 300 mm.

[0009]

[Embodiments] Representative embodiments will be described below. The molding material, molded product dimensions, and molding conditions are as follows. Molding material Phenolic resin molding material Spiral flow 35cm Material composition Phenolic resin 27% by weight Filler (silica, talc equivalent) 73% by weight Molded product size 200 × 200 × 1.5mm Mold temperature 150 ° C Molding pressure 20MPa, 35MPa, 50MPa , 75 MPa Mold clamping speed 0.67 mm / sec, 1.5 mm / sec Table 1 shows the results of measuring the filling property and the thickness accuracy of the molded product. The filling property was visually determined. ：: Good Δ: Partially blurred ×: Insufficient filling The thickness accuracy of the molded product was determined by measuring the nine points of the sample with a micrometer and determining the difference between the maximum value and the minimum value. ：: good △: thickness accuracy is slightly inferior, but practical
×: NG

[0010]

[Table 1] As is clear from Table 1, the molding pressure is 35 MPa, 50 M
At Pa and 75 MPa, the mold closing speed is 0.67 mm /
Good results were obtained in both the case of 1.5 mm / sec and the case of 1.5 mm / sec. The mold clamping speed was better at 0.67 mm / sec than at 1.5 mm / sec.

[0011]

According to the present invention, when a thin plate-like molded product is compression-molded using a thermosetting resin molding material having a small amount of resin and a low fluidity, the molding pressure is increased to 30 to 100 MPa, and Preferably the mold clamping speed is 0.2 to 1 m
By setting the speed as low as m / sec, the filling property and the thickness accuracy can be improved.

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Claims (2)

[Claims] 1. A thermosetting resin molding material is used. The molded product has a surface area of 50 to 1500 cm ² and a thickness of 0.1 to 5 mm.
In a method of molding a thin plate-like molded product, a molding material having a material composition of 10 to 30% by weight of a resin and 70 to 90% by weight of an inorganic filler and a spiral flow of 10 to 70 cm is formed at a molding pressure of 30 to 100 MPa. A method for producing a thin plate-shaped molded product, comprising compression-molding. 2. The mold closing speed during molding is 0.1 to 1 mm /
2. The method for producing a thin plate-like molded product according to claim 1, wherein the time is seconds.