JPS59114026A - Continuous manufacture of thermosetting resin plate - Google Patents

Abstract

PURPOSE:To improve the accuracy of plate layer and at the same time prevent voids from generating by a method wherein plates are coated and impregnated with thermosetting resin and deaerated in a heated vacuum chamber and more than one sheet of plate are put one on another in order to continuously be molded under heat and pressure. CONSTITUTION:More than one sheet of continuous base material is coated and impregnated with thermosetting resin in fused or powdered state and, after that, deaerated in a heated vacuum chamber. Next, more than one sheet are put one on another and continuously molded under heat and pressure in order to manufacture a thermosetting resin plate. Epoxy resin, polyester resin or the like is employed as said thermosetting resin. Glass cloth, organic fiber cloth or the like is employed as a base material. The heating temperature in the heated vacuum chamber is 40-170 deg.C, preferably 80-140 deg.C. The desirable treating time in the vacuum chamber is 10sec or less.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for continuously manufacturing a thermosetting resin plate without internal voids.

Generally, a thermosetting resin plate is formed by impregnating a base material with thermosetting resin 1- and drying it, then stacking one sheet or a required number of sheets on top of each other, and heating and pressing them. However, this method
Since a solvent is used to impregnate the base material with the resin, it is difficult to handle and requires a large number of steps. On the other hand, as a method that does not use a solvent, a molten or powdered thermosetting resin is coated and impregnated on a continuously conveyed base material, and then one or more sheets are stacked and heated continuously. There is a continuous manufacturing method that involves pressure forming. However, with this method, countless voids occur in the base material coated and impregnated with thermosetting resin, and in order to eliminate these voids, high pressure is applied during molding and the resin inside the base material is fluidized. Due to the flow, the resin inside the coated base material overflowed to the outside, and as a result, the board became thinner and at the same time warped and twisted, which caused problems during the processing process of the manufactured thermosetting resin board. In addition, if voids remain inside the plate-shaped body, blisters will occur during the heating process, which will be a fatal drawback.

2- The object of the present invention is to improve the plate thickness accuracy and suppress the generation of voids in the method for continuously manufacturing a thermosetting resin plate.

In order to achieve the above object, the present invention involves applying and impregnating one or more continuous base materials with a thermosetting resin in a molten state or powder form, and then defoaming the resin in a heated vacuum chamber. After that, one or more sheets are stacked and continuously heated and press-molded.

Thermosetting resins used in the present invention include epoxy resins, polyester resins, diallyl phthalate resins, polyimide resins, polybutadiene resins, etc.
Those that are solid at room temperature are preferred. Examples of the base material include glass cloth, organic fiber cloth, glass mat, inorganic or organic fiber ratio woven cloth, and thread.

In a heated vacuum chamber in which the thermosetting resin is applied, impregnated, and then defoamed, the heating temperature is 40 to 1700C, preferably 80 to 140C. This temperature is determined by the time when the melt viscosity of the thermosetting resin is close to its lowest point, and it can be left in a vacuum chamber for 10 seconds or more.In general, the melt viscosity of the thermosetting resin is , as shown in the drawing, is a function of the heating time, so the heating temperature is 1
If the temperature is 70°C or higher, the time that the product can be placed in the decompression chamber is 10 seconds or less. If the temperature is 10 seconds or more, it is necessary to lengthen the time required for curing, which results in poor productivity during hot-pressure molding.In addition, if the temperature is 40'C or less, the melt viscosity is high and it is difficult to degas sufficiently. If the pressure reduction time is 10 seconds or less, even if the melt viscosity of the thermosetting resin reaches its lowest point, the productivity will deteriorate. This is not preferable because the interior of the coated substrate is not sufficiently defoamed and voids remain in the manufactured thermosetting resin plate.

In the present invention, an inorganic or organic filler may be contained in the thermosetting resin. The thermosetting resin is appropriately blended with commonly used curing agents and curing accelerators. Note that a copper-clad board can be produced by arranging continuous copper foil on both sides or one side of the coated base material during hot-pressure molding.

The present invention will be described in detail.

Example 100 parts by weight of epoxy resin (hereinafter simply referred to as "parts"), 2 parts of dicyanthiaide, and 0.4 parts of imidazole were mixed at 80°C using a kneader, and then mixed continuously using an extruder having a direct-type T-die. 8 sheets of glass cloth substrates were stacked and extruded. A release film was placed on both sides of this structure, and the structure was introduced into a heated vacuum chamber at a temperature of 120°C and a pressure of 20 mmHg for 120 seconds, and then heated using an endless belt at a temperature of 160°C and a pressure of s Ky/d. Pressure molded.

Comparative example 1 0C1 pressure of 40Ky/d (hot and pressure molded).

Comparative Example 2 5 The coated substrate prepared in Example 5 was heated to +60°C1 pressure 5 using an endless belt without passing it through a heated vacuum chamber.
Ky/d was applied and molded under heat and pressure.

Comparative Example 3 The coated base material prepared in Example was passed through a heated vacuum chamber at a temperature of 120°C, 1D and a pressure of mm1 (H) for 5 seconds, and then reduced to a temperature of 160°C, a pressure of 5mm using an endless belt.
Kp/cl was applied and molded under heat and pressure.

Table 1 shows the characteristics test results of the thermosetting resin plates obtained in Examples and Comparative Examples 1 to 3. The size of the molded thermosetting resin plate was 3 o Ox 300 II, and the amount of warpage was measured based on JIS-6481.

Table 1 As is clear from Table 1, according to the present invention, thermosetting resin plates with good plate thickness accuracy (no residual voids) can be produced continuously and efficiently, and the industrial value is extremely large. .

[Brief explanation of drawings]

The drawing is a curve diagram showing changes in temperature and resin melt viscosity over time when the coating substrate is heated. Patent applicant 7-

Claims (1)

[Scope of Claims] L One or more continuous base materials are coated with and impregnated with a thermosetting resin in a molten state or powdered state, and then one or more coated base materials are stacked one on top of the other to make a continuous process. 1. A method for continuous production of a thermosetting resin, characterized in that a base material coated with a thermosetting resin and impregnated with the thermosetting resin is guided into a heated vacuum chamber to be defoamed. 82. The thermosetting method according to claim 1, characterized in that the temperature of the vacuum chamber is a temperature that allows the thermosetting resin to have the lowest melting viscosity, and the coating substrate is left in the vacuum chamber for lθ seconds or more. Continuous manufacturing method for plastic plates.