JPS59157121A - Production of reinforced polyamide sheet - Google Patents

Abstract

PURPOSE:A fibrous reinforcing material is impregnated with a liquid containing lactam and a basic polymerization catalyst, then they are heated into a sheet, thus giving the titled sheets with good polysical properties, not including bubbles inside. CONSTITUTION:(A) A mat of fibrous reinforcing material such as glass fiber, carbon fiber or metal fiber is impregnated with a liquid containing (B) a lactam such as epsilon-caprolactam and (C) a basic polymerization catalyst such as sodium caprolactam, preferably containing a polyol, formed into a sheet under heating to give the objective sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing reinforced polyamide sheets.

Manufacturing reinforced resin sheets for molding by coating and impregnating a mantle, which also serves as a fibrous reinforcing material, with resin has been done for a long time, and products using thermosetting resins have been widely used as sheet molding compounds. It is very popular.

On the other hand, reinforced polyamide sheets have been manufactured using polyamide, which is one of the two thermoplastic resins, but due to the melt viscosity of polyamide (it is difficult to completely impregnate the inside of the mat with resin), The inventors of the present invention have conducted intensive research to solve the problems of the prior art, and have developed the present invention. Achieved an invention.

An object of the present invention is to provide a reinforced polyamide sheet with good physical properties that does not contain air bubbles inside. Another object is to provide a method for manufacturing such polyamide sheets industrially and easily.

That is, the method of the present invention is characterized by impregnating a fibrous reinforcing material with a liquid containing a lactam and a basic lactam polymerization catalyst, followed by heating and forming it into a sheet.

・The fibrous reinforcing material used in the present invention is one that can be formed into a cloak shape.However, from the viewpoint of the physical properties of the resulting reinforced polyamide sheet, glass fibers, carbon fibers, and metal fibers can be used. is preferred.

- The thickness of the cloak is usually 0.1 to 1 Qvs, preferably 0.5 to 6 Qvs. The areal density of the mat is usually 2
0~1200g/n? and 30~1000g/rd
is preferred.

For applications where electrical conductivity is required, metal fibers or carbon fibers may be used as reinforcing materials, or they may be used in combination with other reinforcing materials.

The metal fibers used in the present invention include a drawing method, a melt spinning method, 1. Metal fibers made of pure metals such as cauldron, copper, aluminum, lead, silver, magnesium, and nickel, and alloys containing these metals, and metals manufactured by reduction of metal halides, etc. Examples include metallized fibers in which non-metallic fibers such as whiskers and glass fibers are coated with metals such as aluminum and silver.

Examples of heavy lactams used in the present invention include ε-caprolactam, α-pyrrolidone, lauryllactam, capryllactam, and others, and particularly preferred monomers are ε-caprolactam, α-pyrrolidone, lauryllactam, capryllactam, and others.
-It is caprolactam.

The basic polymerization catalyst used in the present invention may be any basic catalyst commonly used for anionic polymerization of lactams, such as alkali metals or alkaline earth metals, hydrides, alkyl halides, oxides, and hydroxides of these metals. In addition, organometallic compounds of the above-mentioned metals, such as metal alkyls, metal phenyls, metal amides, and the like, are also useful.

The basic polymerization catalysts listed here react with lactam monomers to form metal lactams and have an active catalytic effect on lactam polymerization reactions.

Examples of metal lactams include sodium caprolactam, magnesium JA caprolactam, bromomagnesium caprolactam, chlorocalcium caprolactam, and others.

The catalyst concentration is usually 0.1 to 10 mol% relative to the amount of lactam to be polymerized as a metal lactam.

In addition to the basic polymerization catalyst, N-acyl-lactams such as N-acetyl-caprolactam and carbodiimides 1. It is preferable to use both cyanamide and other active agents such as isocyanate compounds in combination in order to quickly carry out the lactam polymerization reaction. The activator is used in a concentration of 0.1 to 1 mol %, based on the amount of lactam to be polymerized.

It is preferable that the liquid used in the present invention contains a polyol from the viewpoint of improving the physical properties, especially the loaf impact resistance, of the resulting reinforced polyamide sheet.

As for your polio, an example is ;!,,,:)1
Polyoxyalkylene glycols such as dichloromethane glycol, polypropylene glycol, polytrimethylene glycol, polytrimethylene glycol, and copolymers thereof, or polyester polyols obtained by ring-opening polymerization of lactones, such as poly-ε-caprolactone and polyoxyalkylene glycols Examples include Shio-bropiolactone.
□The reinforced polyamide sheet obtained by the method of the present invention can be manufactured without using a crosshead die for extrusion coating, which is used in the production of ordinary reinforced polyamide sheets.・For example, by placing a mat made of fibrous reinforcing material in a mold and injecting the liquid component used in the present invention, applying pressure or vibration to defoam, and then heating it, it is possible to create a mat that does not contain air bubbles inside. 1 reinforced poly-5'mi 1 sea 1
− can be easily obtained. Moreover, it is also possible to manufacture continuously using a bell l-m1 conveyor or the like. In addition, reinforced polyamide sheets that use carbon fibers and metal fibers as reinforcing materials can be used in applications that require electrical conductivity, such as electronic device housings such as electromagnetic shielding materials and combiners.

Hereinafter, a more detailed explanation of the present invention will be given in Examples.

Example 1 Each component was mixed at 100° CT in the composition ratio shown in Table 1. In addition, in Table 1, the numerical values indicate parts by weight.

Then, 1,500 g of the obtained mixture was heated to 100'C and heated to 1 m x 1 m x 2 c in length x width x depth.
Pour into m mold. The metal frame has length x width x thickness of 0 in advance.
．． 998mX0.998mX1.5ns, areal density 100
Leave the 0g/M glass fiber cloak in place.

Next, after performing a pressure degassing treatment, the container was heated to 180° C. and the contents were taken out after 1.15 minutes.

The physical properties of the reinforced polyamide sheet thus obtained are shown in Table 2.

The reinforced polyamide sheet of the present invention can be obtained without any air bubbles by simple defoaming treatment, and its physical properties are also very good as shown in Table 2.
Blank below *Average molecular weight 2. (Another Example 2) Each component was mixed at 100°C with the composition shown in Table 3. The numerical values shown in Table 3 represent parts by weight.

Then, 1200 g of the obtained mixture is poured into a mold having dimensions of 1 m x 1 m x 2 cm (length x width x depth) heated to 100°C.

The mold frame has length x width x thickness of 0.998m x 0.9m in advance.
A carbon fiber cloak with a surface density of 500 g/rd is placed.

Next, after performing a pressure degassing treatment, it was heated to 180°C,
After 15 minutes, the contents are removed from the mold.

Table 4 shows the physical properties of the reinforced polyamide sheet thus obtained. Blank below* Average molecular weight 1.
0 [X)

Claims (1)

[Scope of Claims] l) A method for producing a reinforced polyamide sheet, which comprises impregnating a mantle made of a fibrous reinforcing material with a liquid containing a lactam and a basic polymerization catalyst, and then heating and forming it into a sheet. . 2) The manufacturing method according to claim 1, wherein the fibrous reinforcing material is glass fiber. ,, 3) Claim 1 in which the fibrous reinforcing material is carbon fiber.
Manufacturing method described in section. □・4) The manufacturing method according to claim 1, wherein the fibrous reinforcing material is a metal fiber. 5) The production method according to claim 1, wherein the lactam is ε-caprolactam. 6) The manufacturing method according to claim '1, wherein the liquid contains a polyol. 7> The manufacturing method according to claim 1, wherein the liquid contains an activator.・