JPS5950694B2 - Method for producing filler-containing styrenic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of a filled styrenic resin composition in which the filler is uniformly dispersed.

In producing synthetic resin molding materials containing fillers, a method is usually employed in which resin pellets and fillers are mixed and this mixture is kneaded. However, in general, the average particle size, external shape, etc. of resin pellets and fillers are significantly different, and when these materials with significantly different average particle sizes, external shapes, etc. are mixed, it is difficult to make them uniform. difficult to mix. Therefore, even if such a mixture is melted using an extruder or the like and the resin and filler are kneaded, it is extremely difficult to obtain a product in which the filler is uniformly dispersed in the resin. Have difficulty. In order to improve these shortcomings, it is necessary to knead the filler with a kneader that has a strong shearing force to ensure uniform dispersion of the filler in the resin, or to mix the filler to be mixed with the resin in advance. Attempts have been made to improve the dispersion of the filler in the resin by using a filler treated with a surfactant, but none of these efforts have yielded satisfactory results. The main cause of these drawbacks is that the resin pellets and the filler are extremely different in average particle size and external shape. Therefore, it is presumed that the above drawbacks can be eliminated by finely pulverizing the resin to have an average particle size close to the size of the filler. However, when a filler is contained in a styrenic resin, it is very difficult to pulverize the styrene resin that is normally used for molding because it is relatively tough.

Cryogenic pulverization is used as a method for finely pulverizing styrene resins, but this method is very costly and is not generally used. As a result of various studies conducted by the present inventors in this situation, we found that better results (obtainable We discovered this and arrived at the present invention.

An object of the present invention is to provide a method for producing a styrenic resin in which a filler material is uniformly dispersed in a styrenic resin serving as a matrix.

The gist of this is that, for 100 parts by weight of filler, 5 to 50% of fine powder resin having a softening point equal to or lower than that of styrene-based resin and an average particle size almost the same as that of the filler is used. 100 parts by weight of the filler is obtained, and then this mixture powder is mixed with 2 to 1 part of the filler per 100 parts by weight of the styrene resin.
A method for producing a filler-containing styrenic resin composition, characterized in that the filler-containing styrenic resin composition is mixed with a styrene resin in powder form and kneaded so as to have a total weight of 0.00 parts by weight.

In the present invention, the styrenic resins include general purpose polystyrene, high-impact polystyrene, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), and methyl methacrylate-butadiene-styrene copolymer. Polymer (MBS resin),
A general term for methyl methacrylate-styrene copolymers, copolymers of styrene and other synthetic resins, etc.

The fillers used in the present invention include calcium carbonate, magnesium carbonate, calcium sulfate, calcium silicate, aluminum silicate, magnesium hydroxide, zinc oxide, titanium oxide, hydrated silicic acid, anhydrous silicic acid, clay, silica, talc, diatomaceous earth, and white clay. , red iron, mica powder, asbestos powder,
Inorganic fillers such as carbon black, glass powder, glass fiber powder, metal powder, and organic fillers such as wood powder, various thermosetting resin powders, synthetic fibers, and natural fibers can be used depending on the purpose. In the present invention, a resin (
Hereinafter, it will be referred to as [resin A].

) include unsaturated hydrocarbons having 5 or more carbon atoms, such as styrene, o-vinyl . Petroleum resin, which is a copolymer mainly composed of lutoluene, m-vinyltoluene, p-vinyltoluene, 0-vinyl ketone, m-vinyl ketone, p-vinyl ketone, indene, etc.: mainly composed of indene, coumaron, styrene, etc. Coumaron is a copolymer. Resin; terpene resin; low molecular weight polystyrene having an average molecular weight of about 1000 to 3000, and the like. In order to produce a filler-containing styrenic resin composition by the method of the present invention, first, a mixture of the filler and the filler is obtained.

Such a mixture can be prepared by first grinding "Resin A" to an average particle size almost the same as that of the filler, or blending it with the filler.
Alternatively, it can be manufactured by blending "Resin A" in the form of lumps or irregular pellets with a filler, mixing this mixture with a pulverizer such as a pen shell mixer or turbo mill, and pulverizing "Resin A". can. The blending ratio of the filler and "resin A" is 5 to 100 parts by weight of "resin A" to 100 parts by weight of the filler.

If the amount of "Resin A" is less than 5 parts by weight, it is not preferable because it has no effect on improving the dispersibility in the styrene resin that becomes the filler matrix, and if it is more than 100 parts by weight, the styrene resin This is not preferable because it deteriorates the physical properties of the resin. In order to produce a filler-containing styrenic resin composition by the method of the present invention, a styrenic resin is then blended into a mixture of the filler and "resin A" obtained by the above method, and this mixture is Mix in a tumbler mixer. The blending ratio at this time varies depending on the purpose of use of the resin composition finally obtained, but generally - 1 part styrene resin
The ratio of the filler is 2 to 100 parts by weight to 00 parts by weight. The tree strength components of such a mixture are melted and kneaded.

The kneading machines that can be used at this time are batch-type kneaders such as kneaders,
Any continuous kneader such as a "Gar Compounder" or a screw extruder can be used. At this time"
"Resin A" has a softening point equal to or lower than that of the styrene resin, and "Resin A" is first melted in a bath to incorporate the filler or fill in the spaces between the filler particles. Prevents large agglomeration of material particles. Next, the styrene resin is also melted and kneaded to create a uniform,
In addition, a styrene thread resin composition in which the optical filler is uniformly dispersed can be obtained. As described above, in the present invention, the filler is pre-mixed with a finely powdered resin having a softening point equal to or lower than that of the styrene resin and having an average particle size almost the same as that of the filler. When kneading this mixture with a styrene resin, the softening point of the fine powder resin is equal to or lower than that of the styrene thread resin, so the imitation powder resin is first melted in the bath. It contains a filling material or fills the space between filler particles to prevent a large number of filler particles from agglomerating.

Therefore, the resin composition prepared by the method of the present invention is
The filler is more uniformly dispersed in the matrix resin than that obtained by conventional methods, and its industrial utility value is extremely high. Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 Petroleum resin (ASTM-Dl525 Vicat softening point 80°C
) 10 parts by weight and 30 parts of calcium carbonate (particle size 1-20μ)
parts by weight were stirred at high speed for 3 minutes using a pen shell mixer.

By this stirring, the petroleum resin was pulverized to a size of about 1 to 20 microns, and a homogeneous mixture of both was obtained. Next, 60 parts by weight of impact-resistant polystyrene pellets (HT-88 manufactured by Mitsubishi Monsanto Chemical Co., Ltd., Bicat softening point: 85 DEG C.) were added to this mixture and mixed at low speed for 1 minute. This mixture was kneaded using an extruder. The pellets thus obtained had calcium carbonate uniformly dispersed in high-impact polystyrene.

Example 2 Mixing was carried out in the same manner as in Example 1, using a Banbury mixer instead of the Penn shell mixer, and kneading was carried out using an extruder.

The pellets thus obtained had calcium carbonate uniformly dispersed in high-impact polystyrene, as in Example 1.

Example 3 First, low molecular weight polystyrene (Vicatto softening point 82°C)
By stirring 20 parts by weight of talc and 40 parts by weight of talc (equivalent particle size of 7 to 12 μm) in the same manner as in Example 1, low-molecular polystyrene is ground to a size of 5 to 15 μm, and a homogeneous mixture of the two is obtained. I got it.

Claims (1)

[Claims] 1. 100 parts by weight of the filler is mixed with 5 to 100 parts by weight of a finely powdered resin having a softening point equal to or lower than that of the styrene resin and having an average particle size almost the same as that of the filler. A mixture powder consisting of
1. A method for producing a filler-containing styrenic resin composition, which comprises mixing the filler-containing styrenic resin composition in a powder state with a styrene resin in an amount of up to 100 parts by weight.