JPH0791413B2 - Thermoplastic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition suitable for materials such as flywheels, anti-vibration parts, gears and gears.

(Prior Art) In recent years, a thermoplastic resin having light weight and high moldability has been widely used as a metal substitute material. However, the lightweight nature of thermoplastics can sometimes be a drawback. For example,
Compared with metal, it has less stability against external force and looks cheaper.

As measures against this, for example, in Japanese Patent Laid-Open No. 56-159248,
It is described that a metal powder is mixed with polytetramethylene terephthalate. In addition, JP-A-58-1277
Japanese Patent Publication No. 61 discloses a composite material composed of a metal powder and a thermoplastic resin in which reinforcing fibers such as aromatic polyamide fibers are used alone or in combination.

(Problems to be Solved by the Invention) However, an injection-molded article of a thermoplastic resin containing only metal powder tends to have poor mechanical properties as the amount of metal powder added increases. In addition, in the case of an injection-molded product in which a reinforcing material is further mixed in a composite material composed of metal powder and a thermoplastic resin, warpage caused by the flow of fibers,
There is a difference in the molding shrinkage ratio between the flow direction of the fiber and the direction perpendicular to the flow, which is difficult to commercialize.

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. An object of the present invention is to provide a thermoplastic resin composition having high strength and high specific gravity that can be injection molded.

(Means for Solving Problems) That is, the present invention is based on 100 parts by weight of a thermoplastic resin, 100 parts by weight of iron powder.
-800 parts by weight and inorganic powder 10-1 containing alumina as the main component
A thermoplastic resin composition containing 50 parts by weight.

The thermoplastic resin used in the present invention may be one generally used for injection molding processing, but preferred examples include polyamide, polyester, polycarbonate, ABS, polyphenylene oxide and polyolefin.

Examples of the iron powder used in the present invention include reduced iron powder, atomized iron powder, and other iron powder having a particle size of 50 to 200 μm.

The blending amount of iron powder is 100-based on 100 parts by weight of the thermoplastic resin.
It is essential that the amount is 800 parts by weight. The amount of iron powder is 100
When it is less than the weight part, the high specific gravity becomes poor. on the other hand,
When the amount of the iron powder blended exceeds 800 parts by weight, not only high strength cannot be obtained, but also melt-kneading extrusion becomes difficult.

The inorganic powder whose main component is alumina used in the present invention,
It is sufficient that the content of alumina exceeds the content of components other than alumina. Examples of components other than alumina constituting the inorganic powder containing alumina as a main component include zirconium oxide, silicon oxide, ferric oxide, titanium oxide, calcium oxide, magnesium oxide, sodium oxide and the like. The alumina-based inorganic powder used in the present invention preferably has an average particle size of 8 μm or less. Average particle size is 8
If it exceeds μ, not only high strength cannot be obtained, but also kneading extrusion becomes difficult.

It is important that the amount of the inorganic powder containing alumina as a main component is 10 to 150 parts by weight, and particularly preferably 20 to 100 parts by weight, based on 100 parts by weight of the thermoplastic resin. When the amount of the inorganic powder containing alumina as the main component is less than 10 parts by weight,
High strength cannot be obtained. On the other hand, when the amount of the inorganic powder containing alumina as the main component exceeds 150 parts by weight, not only high strength cannot be obtained, but also the fluidity at the time of melting the resin is lowered and the kneading and extrusion becomes difficult.

If necessary, a colorant, a plasticizer, a crystal engraving agent, etc. can be added to the composition of the present invention.

(Effect of the Invention) The thermoplastic resin composition of the present invention has a high strength and a high specific gravity, and is useful as a molding material in place of a metal.

(Example) Hereinafter, the present invention will be specifically described with reference to examples. In addition, the evaluation method of physical properties followed the following method.

A Tensile strength ASTM D-638 B Flexural modulus ASTM D-790 C Specific gravity ASTM D-792 Example 1-6 and Comparative example 1-4 100 parts by weight of polybutylene terephthalate (manufactured by Kanebo Corp.), mainly alumina Inorganic powder (trade name: FOF, manufactured by Fujimi Abrasives Co., Ltd.) as an ingredient is used as the compounding amount shown in Table 1 and 0.05 part by weight of magnesium stearate is added to the hopper of a biaxial counter-rotating kneading extruder with a screw diameter of 30 mm It was fed from the hole. After the resin was sufficiently spread over the entire screw, iron powder (trade name KIP270M, manufactured by Kawasaki Steel Co., Ltd.) was fed through the first vent hole of the kneading extruder as shown in Table 1. The mixture was pelletized, and the obtained pellets were molded into a test piece using an injection molding machine having a maximum mold clamping pressure of 75 tons. Table 1 shows the evaluation results of the test pieces.

Examples 7-9 and Comparative Examples 5-7 6 Nylon (manufactured by Kanebo Co., Ltd.) 100 weight cormorant and inorganic powder containing alumina as a main component (trade name FOF, particle size 4μ manufactured by Fujimi Abrasives Co., Ltd.) ) And iron powder (trade name KIP270M, manufactured by Kawasaki Steel Co., Ltd.) at the compounding amounts shown in Table 2 were kneaded and extruded in the same manner as in Example 1 and the like to form pellets. The obtained pellet was molded into a test piece using an injection molding machine. Table 2 shows the evaluation results of these test pieces.

Examples 10 and 11 and Comparative Example 8 100 parts by weight of polybutylene terephthalate (manufactured by Kanebo Co., Ltd.), 30 parts by weight of inorganic powder (average particle size 4 μ) shown in Table 3 and iron powder (trade name KIP270M, Kawasaki Steel ( (Manufactured by K.K.) 200 parts by weight were kneaded and extruded, pelletized and injection molded in the same manner as in Example 1 to obtain test pieces. Table 4 shows the evaluation results of these test pieces.

As can be seen from Table 1 and Table 2, the blending amount of the inorganic powder was excellent in mechanical strength in the range of 10 to 150 parts by weight with respect to 100 parts by weight of the thermoplastic resin. In addition, from Tables 3 and 4, those in which the main component of the inorganic powder is alumina were excellent in mechanical strength.

Claims (4)

[Claims] 1. Iron powder 100-based on 100 parts by weight of thermoplastic resin
800 parts by weight and alumina-based inorganic powder 10-150
And a thermoplastic resin composition. 2. The composition according to claim 1, wherein the thermoplastic resin is polyamide, polyester, polycarbonate, ABS, polyphenylene oxide or polyolefin. 3. The composition according to claim 1, wherein the inorganic powder containing alumina as a main component has an average particle size of 8 μm or less. 4. The inorganic powder containing alumina as a main component is 20-10.
The composition of claim 1 which is 0 parts by weight.