JPH0651842B2 - Composite resin composition - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a composite resin composition composed of a fibrous filler and a matrix resin, and more particularly to a composite resin composition excellent in the dispersing effect of the fibrous filler.

[Technical Background of the Invention and Problems Thereof] For matrix resins conventionally used for injection molding,
When filling a fibrous filler such as glass fiber or carbon fiber, 400 to 10,000 fibers are hardened with a sizing agent of thermoplastic resin, cut into a length of 3 to 5 mm, and mixed with matrix resin. Further, the mixture was heated and kneaded to obtain a composite material.

However, in this method and the sizing agent used in this method,
In order to disperse the fibrous filler and disperse it, it is necessary to sufficiently knead it in the kneading machine, so that the fibers of the fibrous filler are often cut or bent, and the conductive material such as carbon fiber or stainless fiber is also used. In the case where the resin is filled with a conductive fiber to make the resin electrically conductive, there is a problem that the fiber length is cut, or if the fiber is bent and shortened, the electrical conductivity is lowered.

[Object of the Invention] An object of the present invention is to eliminate the above-mentioned problems and drawbacks. A fibrous filler is added to a matrix resin,
An object of the present invention is to provide a composite resin composition that can be mixed and dispersed without being cut or bent. Another object of the present invention is to provide a composite resin composition in which a conductive fibrous filler is dispersed in a matrix resin under effective conductivity.

[Summary of the Invention] The present inventors have conducted extensive studies to achieve the above-mentioned object, and as a result, by adding a foaming agent to the sizing agent of the thermoplastic resin, the fibrous filler is cut into the matrix resin. The present invention has been completed by finding out that they can be mixed and dispersed without causing any trouble.

That is, the present invention provides (B) a fibrous filler which is (A) composed of a thermoplastic resin, (B) a solvent, and (C) a foaming agent, and (B) a fibrous filler, and It relates to a composite resin composition comprising:

Examples of the (A) thermoplastic resin, which is one component of the (A) sizing agent used in the present invention, include polystyrene, EVA (ethylene vinyl acetate) resin, AS (styrene acrylonitrile) resin, and polycarbonate resin. Alternatively, mix two or more and use. The thermoplastic resin is not particularly limited as long as it is compatible with the (C) matrix resin described later. Other components of the sizing agent (b) solvent include methylene chloride (methylene chloride), (ethylene chloride), tetrachloroethane,
Examples thereof include benzene and the like, as long as the thermoplastic resin (a) is dissolved therein, and there is no particular limitation. Further, (a) a foaming agent which is another component of the sizing agent, includes azodicarbonamide, azobisformamide, azobisisobutyronitrile, p, p-oxybisbenzenesulfonylhydrazide,
Examples thereof include N, N-dinitrosopentamethylenetetramine, p-toluenesulfonyl semicarbazit, p-toluenesulfonylhydrazide, trihydrazotriazine and the like, which have excellent compatibility with the matrix resin. Used as a mixture of two or more species. The sizing agent can be easily prepared by dissolving the thermoplasticity described above in a resin solvent and further adding a foaming agent. The amount of the foaming agent added is preferably 1 to 10% by weight with respect to the thermoplastic resin. If the addition amount is less than 1% by weight, the effect of dispersing the fibrous filler is not effective, and if it exceeds 10% by weight, the characteristics of the matrix resin are deteriorated, which is not preferable.

The (B) fibrous filler used in the present invention includes copper fibers,
Examples thereof include metal fibers such as stainless fibers and nickel fibers, carbon fibers, glass fibers, and organic fibers such as vinylon and nylon. These can be used alone or in combination of two or more. The filler is not particularly limited as long as it is fibrous, and the more the filler is, the more effectively it can be dispersed.

Examples of the (C) matrix resin used in the present invention include polyolefin, polystyrene, styrene-acrylonitrile, ABS, nylon, polyphenylene sulfide,
Examples thereof include polyacetal, polysulfone, polycarbonate, polypropylene, polyphenylene oxide, etc. These may be used alone or in admixture of two or more.
In the method of converging the fibrous filler with the converging agent composed of the above-mentioned components, for example, about 400 to 10,000 stainless fiber fillers are passed through a converging material tank, and the solvent is volatilized with a die to condense. Next, the bundled Steres fiber filler is coated with a matrix resin, and then cut into an appropriate length to form a master pellet. Then, it can be mixed with a natural pellet of a matrix resin to obtain a conductive composite resin composition. Alternatively, a composite resin composition can be prepared by cutting the fibrous filler at a stage where the fibrous filler is bundled into appropriate lengths and simply mixing it with a matrix resin.
When this composite resin composition is used, it is melted in an extruder,
When the fibrous filler is dispersed in the matrix resin or when injection molding is performed, a gas is generated by the foaming agent contained in the sizing agent, and the gas pressure causes the fibrous filler to be cut or bent and solidified. It is effectively dispersed without any damage.

[Examples of the Invention] Next, the present invention will be described using examples, but the present invention is not limited to these examples. In the examples, "part" means "part by weight".

EXAMPLE A bundle of 10,000 stainless fibers with a diameter of 8 μm was added to styrene 10
Part, methylene chloride 90 parts, and azodicarbonamide 3 parts were mixed to prepare a sizing agent. The stainless fiber bundle was passed through a sizing agent, squeezed with a die to volatilize the solvent content, and then cut into 5 mm lengths to make chips. This chip was mixed with polystyrene so that the content of stainless fiber was 10% by weight to obtain a composite resin composition, which was directly injection-molded to produce a molded product. When the molded product was tested for the dispersion state and volume resistivity of the stainless fiber filler using X-ray, the remarkable effect of the present invention was recognized. The result is first
Shown in the table.

COMPARATIVE EXAMPLE A molding material and a molded article were obtained in the same manner as in Example except that azodicarbonamide as a foaming agent was not added, and the same test was conducted. The results are shown in Table 1. Indicated.

EFFECTS OF THE INVENTION The composite resin composition of the present invention uses a fibrous filler bundled with a sizing agent to which a foaming agent is added, so that the filler is cut in the matrix resin or bent and hardened. It is possible to disperse sufficiently without doing. Further, when a conductive filler is used, this composite resin composition is suitable for electromagnetic wave shielding of electronic devices and the like, and it is possible to manufacture highly reliable electronic devices.

Claims (3)

[Claims] 1. (a) a thermoplastic resin, (b) a solvent, and (c)
A composite resin composition comprising (A) a fibrous filler which is composed of a foaming agent and which is converged by a converging agent, and (C) a matrix resin. 2. A foaming agent is azodicarbonamide, azobisformamide, azobisisobutyronitrile, p, p-oxybisbenzenesulfonyl hydrazide, N, N-dinitrosopentamethylenetetramine, p-toluenesulfonyl semi. The composite resin composition according to claim 1, which is a compound selected from the group consisting of carbazit, p-toluenesulfonylhydrazide, and trihydrazotriazine. 3. The composite resin composition according to claim 1 or 2, wherein the foaming agent is contained in a proportion of 1 to 10% by weight based on the thermoplastic resin.