JPS61157533A - Production of glass fiber-reinforced resin - Google Patents

Abstract

PURPOSE:To obtain FRP containing a large amount of glass fibers having long fiber length, by dissolving a resin in a solvent, mixing glass fibers to the solution, and removing the solvent from the mixture. CONSTITUTION:A resin (thermoplastic resin or thermosetting resin) is dissolved in a solvent (e.g. methylene chloride, carbon tetrachloride, etc.), and glass fibers are added and mixed to the solution. The solvent is removed form the mixture by heating. Glass fibers having relatively long fiber length can be mixed to the resin without breaking the fiber. The mixing can be carried out in a short time preventing the thermal degradation of the resin because the long-term thermal kneading is not necessary in the present process in contrast with the conventional method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in the method of manufacturing glass fiber reinforced resins.

Glass fiber reinforced resin (hereinafter referred to as FRP) is a composite material composed of resin as a matrix and glass fiber as a reinforcing material, and not only FRP made of thermosetting resin but also FRP made of thermoplastic resin are manufactured in various types. . This FRP
Various methods are used to manufacture thermosetting resin FRP, such as the hand lay-up method, Gripreg method, matte die method, and filament winding method.However, in thermoplastic resin FRP, the process is carried out by kneading, etc. A method of mixing glass fiber is used. Also, when producing FRP thermosetting resin, a method of kneading glass fibers into the resin is sometimes used, as in the case of thermoplastic resins, and this is called a premix method.

By the way, the conventional manufacturing method for manufacturing FRP of the above-mentioned thermoplastic resin is to heat the resin above its softening point while using a mixing roll or a Banbury mixer.
Glass fibers are kneaded in by kneading the glass fibers. For this reason, there is a problem in that only 20 to 30 parts by weight of glass fibers can be mixed at most per 100 parts by weight of resin, and only powdered glass fibers or short fibers of about 3 to 1Qw at most can be mixed. As a result, the physical properties of the obtained FRP showed a reduction in molding shrinkage and an improvement in bending strength and other mechanical strengths, but this was achieved by the filament winding method, and the physical properties of the FRP were "stronger than steel," which is the adjective of FRP. It was far from the slogan "It's aluminum and it's lightweight."

For this reason, there has been a desire for a method for manufacturing FRP in which a large amount of glass fiber can be mixed into the thermoplastic resin, and also a long glass fiber can be mixed therein.

The present invention was made in view of the above circumstances, and allows easy production of thermoplastic resin FRP containing a high proportion of long glass fibers, and can also be applied to the production of thermosetting resin FRP. The present invention aims to provide a method for manufacturing glass fiber reinforced resin.

That is, the method for producing glass fiber reinforced resin according to the present invention is as follows:
A step of preparing a resin solution by dissolving the resin raw material in a solvent,
The method includes a step of adding and mixing glass fibers into the resin liquid and uniformly dispersing the resin solution, and a step of removing the solvent from the resin solution in which the glass fibers are dispersed, and separating and recovering the resin mixed with the glass fibers. It is characterized by the fact that

As the resin raw material in the present invention, either a thermoplastic resin or a thermosetting resin may be used.

That is, according to the present invention, both thermoplastic resin and thermosetting resin FRP can be manufactured.

In addition, in the present invention, since the resin raw material is dissolved in a solvent and used, for example, various molded product waste such as molded products, etc.
Resin waste such as foam product waste, factory by-products, defective products, etc. can be used as raw materials.

In the present invention, as a solvent for dissolving the resin raw material to prepare a resin solution, in principle, any solvent may be used as long as it dissolves the resin raw material and does not dissolve the glass fiber. .

However, from the viewpoint of workability, it is desirable to have sufficient dissolving ability at room temperature. The most common such solvents are organic solvents such as methylene chloride, carbon tetrachloride, tetrahydrofuran (THF), ethyl acetate, and acetone.

The glass fiber in the present invention includes powdered glass fiber,
Materials conventionally used for FRP, such as glass wool and chopped strands, may be used.

In the present invention, glass fibers are added and mixed in a solution state in which the resin raw material is dissolved in a solvent, so glass fibers can be mixed in much more easily and without resistance than when kneading into resin as in the past. . Therefore, even in the case of a thermoplastic resin, a large amount of glass fiber, such as 50 to 200 parts by weight, can be mixed into 100 parts by weight of the resin.

Furthermore, glass fibers such as glass fibers having a relatively long fiber length can be mixed in as they are without being crushed. Moreover, since there is no need to knead the thermoplastic resin for a long time at a temperature above its softening point as in the past, it not only reduces the work time required to mix glass fibers, but also prevents the deterioration of the resin due to thermal history. It has the advantage of being avoidable. In addition, in the present invention, even if additives such as stabilizers, plasticizers, colorants, fillers, etc. are dispersed in the resin solution together with the glass fibers, the solvent can be removed from the resin solution to which the glass fibers have been added and mixed. When separating and recovering the resin mixed with glass fibers, the resin solution is directly heated to evaporate the solvent, and the so-called dry-up method is used to remove the solvent. FRP mixed with glass fiber & paraboloid remain separated. The FRP composition separated in this manner can be further dried if necessary, and then formed into an FRP molded body by molding or the like.

As mentioned above, according to the manufacturing method of the present invention, FR of thermoplastic resin containing a large amount of glass fiber, which could not be obtained conventionally, can be produced.
In addition, it is possible to produce FRP in which glass fibers with a long fiber length are mixed. Moreover, it is also the same as mentioned above that it can be similarly applied to the production of FRP made of thermosetting resin.

An embodiment of the present invention will be described below.

Example? ■ 100000000000000000000000000000000000000000000000000000000000000000000
A 20% by weight polystyrene solution was prepared. 20 oz of glass wool was mixed into 1 kg of this polystyrene solution, stirred with a mixer to disperse it approximately evenly, and then heated in an open air to remove methylene chloride, resulting in a porous glass fiber reinforced polystyrene resin. Obtained.

Next, this was pressurized and heated for 10 minutes in a hot press at 140°C, cooled to 70°C, and then taken out to obtain a polystyrene FRP sheet.

Claims (1)

[Claims] A step of preparing a resin solution by dissolving the resin raw material in a solvent,
The method includes a step of adding and mixing glass fibers into the resin solution and uniformly dispersing the resin solution, and a step of removing the solvent from the resin solution in which the glass fibers are dispersed and separating and recovering the resin mixed with the glass fibers. A method for producing glass fiber reinforced resin, characterized by: