JPH01163221A - Molded body of thermoplastic synthetic resin composition - Google Patents

Abstract

PURPOSE:To obtain the title inexpensive molded body, containing whiskery calcium carbonate, having excellent surface smoothness, gloss and sliding properties and capable of holding mechanical strength with hardly any coloring properties by materials used. CONSTITUTION:The aimed molded body, obtained by blending a thermoplastic resin, such as polyethylene or polypropylene, with whiskery calcium carbonate and normally melt molding the resultant blend and containing the whiskery calcium carbonate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a molded article of a thermoplastic synthetic resin composition. Specifically, a thermoplastic synthetic resin that exhibits functionality by containing or using the whisker-like calcium carbonate described in the claims as a reinforcing material or functional material. The present invention relates to a composition molded article.

[Prior art and problems to be solved by the invention]

In recent years, plastic materials with high heat resistance, economy, mass production, functionality, and material supply stability have been in demand for parts such as automobile parts, general machinery, mackerel machinery, optical W, and home appliances. There is.

However, conventional fiber-reinforced thermoplastic synthetic resin composition moldings have various drawbacks in terms of toxicity to the human body, functionality, economic efficiency, and the like.

For example, when asbestos is used as a reinforcing material, it worsens the working environment during the manufacturing process and poses a major problem in maintaining the health of workers, and thermoplastic synthetic resin molded products that use glass fiber as a reinforcing material warp. In addition, the reinforcing glass fibers scattered on the surface of the molded product deteriorate the surface properties and reduce the product value. In particular, if there is glass fiber on the surface of a molded product, its high hardness will cause poor sliding characteristics, and in the case of bearings or sliding parts, it may cause wear of the mating material, or damage to the molding machine or the like. It can also cause major damage to the mold. Recently, various carbon fibers and fibrous potassium titanate have been developed and sold in the market, but they are considerably more expensive than the inexpensive whisker-like calcium carbonate used in the thermoplastic synthetic resin composition of the present invention. Therefore, for economic reasons, the spread of industrial mass production is not making any progress.

[Means to solve problems]

What the present invention aims to provide is to solve the conventional problems, and is inexpensive, maintains mechanical strength,
It is a molded article of a thermoplastic synthetic resin composition that has particularly excellent surface smoothness, gloss, and mobility, and is less likely to be colored by the materials used. Furthermore, since the molded article of the resin composition of the present invention has a -like smooth surface, an excellent painted surface can be obtained as a result.

That is, the thermoplastic synthetic resin composition molded article of the present invention can be produced by mixing and kneading whisker-like calcium carbonate in a thermoplastic resin to form a resin composition, and then melt-molding it. do not have.

That is, it can be done in a very numerical way.

The amount of whisker-like calcium carbonate to be added is not particularly limited, and may be determined in consideration of functionality, cost, etc. In addition, it is not necessary that all the filler in the wood resin composition molded product is whisker-like calcium carbonate, and it may be used in combination with other fillers, taking into consideration strength, functionality, cost, etc.

The molded article of the thermoplastic synthetic resin composition of the present invention contains a thermoplastic synthetic resin and whisker-like calcium carbonate as shown in Table 1 as essential components, and other fillers may be added as necessary. Of course, additives such as antistatic agents, antistatic agents, and flame retardants may also be added.

As the thermoplastic resin which is the main component of the thermoplastic synthetic resin composition molded article of the present invention, most synthetic resins having thermoplasticity can be used, but there are only a few such as polypropylene, polyethylene,
In addition to polyvinyl chloride and polystyrene, engineering plastics such as 6-nylon, 6-row nylon, polyacetal, polybutylene terephthalate, modified polyphenylene ether, polyphenylene oxide, and polymer alloys can be used.

Margins below [Effects of the Invention] The molded article of the thermoplastic synthetic resin composition of the present invention is highly functional and has excellent economic efficiency. In addition, the whisker-like calcium carbonate used in the present composition is not harmful because the component itself is so-called calcium carbonate, which has been familiar to the human body.

The thermoplastic composition molded article of the present invention has excellent surface smoothness while maintaining appropriate reinforcing properties, is rich in gloss, and contains whisker-like calcium carbonate with low hardness, so it is easy to use. Dynamic characteristics also produce good results.

In addition, as is clear from Example 2, the resin composition molded article of the present invention has a yield point in the tensile strength test and has a very high elongation. In other words, it has the property of being difficult to break.

Furthermore, if the molded article of the thermoplastic composition of the present invention is treated with an acid such as hydrochloric acid, the whisker-like calcium carbonate contained therein will be eluted, resulting in a porous molded article with micron-sized holes. In that case, if strength is required, a reinforcing material that does not dissolve in acid may be mixed into the composition. This can be applied to breathability, water permeability, micron-level sieves, weight reduction, etc. Therefore, if the thermoplastic synthetic resin composition molded article of the present invention is applied to automobile parts 5 general machinery, precision machinery, optical products, home appliances, etc., it will be excellent in terms of economy, mass production, functionality, and material stability. We can offer products to the market.

〔Example〕

Hereinafter, the structure and various physical properties of a thermoplastic synthetic resin composition molded article of the present invention and a thermoplastic synthetic resin composition molded article that does not use whisker-like calcium carbonate for comparison will be specifically explained using examples. do.

Example 1 Whisker-like calcium carbonate [trade name/CCW minor axis 0.
2 to 1.0 μm, long axis lO to 30 μm, manufactured by Yabashi Kogyo Co., Ltd.] 20 parts by weight and polypropylene resin (commercial product) 80
Parts by weight were mixed in a mixer to obtain a thermoplastic synthetic resin composition (a) of the present invention.

Similarly, a thermoplastic synthetic resin composition (b) was prepared using potassium titanate whiskers (commercially available product, minor axis: 0.2 to 0.7 μm, major axis: 10 to 20 μm), and a natural product, pulverized talc. (Commercial product, 325 mesh bath) was used to prepare a thermoplastic synthetic resin composition (C) for comparison.

In addition, both (b) and (C) used the same propylene resin as (a), and the composition ratios were also the same.

The thermoplastic synthetic resin compositions (a), (b), and (c) thus obtained were melt-kneaded using a screw extrusion kneader, and then made into pellets using a pelletizer to obtain each pellet-shaped molded product. Ta. Next, each pellet-shaped molded body was
Based on IS, test specimens such as bending and impact were injection molded into molds with dimensions.

In addition, the temperature control of the screw extrusion kneading machine is based on the barrel temperature,
The nozzle temperature is 220~230'e', the injection molding machine has an injection temperature of 230°C, a mold temperature of 40~50°C, an injection pressure of 600g/cta'', an injection rate of 30cc/sec, and an injection hold time of 10sec. there were.

Table 2 shows various physical properties of each injection molded test piece.

In Table 2, the evaluation of the items of surface smoothness, appearance, and dispersion was expressed using the following symbols.

0... Good △... Normal
．． 2-1. Opm, major axis 10-30 μm, Yabashi Kogyo (
Co., Ltd.] 30 parts by weight and 6-nylon resin (commercial product) 70
Parts by weight were mixed in a mixer to obtain a thermoplastic synthetic resin composition (a) of the present invention. Similarly, a thermoplastic synthetic resin composition (b) for comparison was prepared using milled glass fibers (average minor axis 10 μm, major axis 50 μm, commercially available),
Layer zo+s10□ ceramic fiber (short diameter average 3
μI, maximum major axis 25mm, shot content approximately 2.5%,
A commercially available product) was used to prepare a thermoplastic synthetic resin composition (C) for comparison.

In addition, both (b) and (c) used the same 6-nylon resin as (a), and the composition ratio was also the same weight ratio.

The thermoplastic synthetic resin compositions (a), (b) and (C) thus obtained were melt-kneaded using a screw extrusion kneader and then shaped into pellets using a pelletizer to obtain respective pellet-shaped molded products. . Next, each pellet-shaped molded body was
Tensile, bending and impact specimens with dimensions based on S were injection molded into molds. In addition, the temperature control of the screw extrusion kneader is barrel temperature, nozzle temperature 250 to 260°C, and for injection molding, injection temperature 260°C, mold temperature 80°C,
Injection pressure 600kg/cm, injection rate 30cc/sec,
The injection and holding pressure time was 10 seconds.

Table 3 shows various physical properties of each injection molded test piece.

In Table 2, the evaluation of the items of surface smoothness, foreignness, and dispersion is indicated by the following symbols.

0...good △・・・Unfortunate X...Bad Below margin

Claims (2)

[Claims] (1) A thermoplastic synthetic resin composition molded article that exhibits functionality by containing or using whisker-like calcium carbonate. (2) The thermoplastic synthetic resin composition molded article according to claim 1, which contains whisker-like calcium carbonate having a major axis of 1 to 100 μm and a minor axis of 0.1 to 10 μm as a filler.