JPS61254662A - Resin composition - Google Patents

Abstract

PURPOSE:A resin composition suitable for small-sized electronic devices, etc., capable of being made lighter and smaller, having improved reinforcement, dimensional stability and molding properties, obtained by blending aromatic polyamide resin with specific amounts of carbon fibers, glass fibers, etc. CONSTITUTION:(A) 40-80vol% aromatic polyamide resin is blended with (B) 0.1-40vol% carbon fibers having 0.5-0.01m/m length, (C) 0.1-40vol% glass fibers having 0.5-0.01m/m length, (D) 0.1-40vol% inorganic needle-like crystal (e.g., whisker of potassium titanate or silicon carbide) and, (E) 0.01-5vol% zinc stearate. A preferable blending ratio of the components is 55-70vol% component A, 10-30vol% component B, 10-30vol% component C, 5-10vol% component D, and 0.1-1.0vol% component E.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a thermoplastic 4kj material that can replace precision metal parts.
119 M+ d? :Ah tr 14M-? [Summary of the Invention] The present invention is useful in the fields of small electronic devices, magnetic/optical memory devices, and handheld information devices, in which carbon fibers, glass fibers, inorganic acicular crystals, and zinc stearate are added to aromatic polyamide resin. Composite and molding improves reinforcement, dimensional stability, and moldability, making it possible to reduce weight and size.

[Prior art]

Conventionally, the structural material for the chassis of a proppy disk drive is an At die-cast product that has been cut and polished. Portable audio equipment has been put into practical use (by combining metal press parts with At chassis and other components).

[Problems and objects to be solved by the invention] Injection molded products of thermoplastic synthetic resin are considered as materials that are lightweight and compact and can be expected to improve productivity.

However, its practical properties are insufficient due to its advantages such as high strength, dimensional stability, and improved formability.

Physical properties that can be applied include specific gravity K -, 71121.7 or less Tensile strength K-71152000 or more 4f/- Bending strength K-72032500 or more Kpflcd curve 1f Elastic modulus 1-7205 15XID' or more Kpf/aA Linear expansion coefficient -2 , 5X10cm or less cm 7cm/”(:.

Mold shrinkage rate -a2 or less% Rockul hard FRD-785100 or higher (M scale) Flow value (flow tester) K7210 10 or more (-j/5ec) The condition is that the following conditions are met.

The purpose of the present invention is to propose a resin composition that can be applied in a well-balanced manner with respect to the above-mentioned physical properties [Means for solving the problems] The resin composition of the present invention includes: (1) aromatic polyamide resin 40 - b (2) Carbon fiber (length 0.5-0.01%) α1-40 Yododai (8) Cass fiber (length 0.5-Q, o 1%
) (L1-401-40 volumeless m-type acicular crystal body [L1-401-40 volume zinc stearate α01-5 volume f% composition.

[Effect]

According to the above composition of the present invention, specific gravity (1) and (2) (8) (4) total specific tensile strength (2) (a) (4) bending strength (2) (8) (4) bending elasticity rate
(2) (1) (4) Linear expansion coefficient (2) (3
) (4) Molding shrinkage <2) (8) (4) Rockwell hardness (2) (8) Flow value (6) Composition effects appear in the following correlations.

Carbon fibers and glass fibers have a length α5z or more or (1,01
If it is less than x, it is not possible to achieve balanced physical properties in terms of linear expansion coefficient and molding shrinkage rate due to fiber orientation.

〔Example〕

The following will be explained based on examples. The aromatic polyamide resin used is MXD-6 (manufactured by Mitsubishi Gas Chemical Co., Ltd.). The reinforcing effect is weakened when the composition is 1% or more by 8o volume14
If it is less than 0%, molding becomes difficult and the flexural modulus decreases. Preferably it is 55 to 70% by volume. Carbon fibers and glass fibers are less effective when α is less than 1% by volume, and cannot be molded when α is more than 40% by volume. Preferably it is 10 to 30% by volume. Examples of inorganic needle-like crystals include potassium titanate whiskers and silicon carbide whiskers. The above-mentioned fibers and acicular crystals are less effective if the content is less than 1% by volume, and if the content exceeds 40% by volume, the physical properties cannot be maintained and workability deteriorates. Preferably it is 5 to 10% by volume. Furthermore, the surface may be coated with a silane-based surface treatment agent, or a titanium-based surface treatment agent may also be used. Zinc stearate is thought to have a main effect as a lubricant, but other effective agents include silicone oil, stearic acid, and fatty acid amide. As for the quantity, [L.

If it is less than 1% by volume, there will be no effect, and if it is more than 5% by volume, the fluidity will be too good and the physical properties will deteriorate, making it difficult to process. Preferably (L1 to 1.0% by volume is good. The kneader used is a twin-screw presser CPCM-30 manufactured by Ikegai Iron Works), but a Bamba IJ-Migosu- may also be used. The injection molding machine is I'S-4
01nSA, manufactured by Nisshin Jushi Kogyo Co., Ltd., was used to evaluate the molding of J-Ko S standard test pieces. The results are shown in Table 1.

〔Effect of the invention〕

As described above, the resin composition of the present invention is a useful industrial material suitable for high strength, dimensional stability, improved molding, light weight, and small size as a structural material for small electronic devices and information devices.

Claims (4)

[Claims] (1) Aromatic polyamide resin 40-80% by volume (2) Carbon fiber (length 0.5-0.01m/m) 0.1
~40% by volume (3) Glass fiber (length 0.5-0.01m/m) 0.
1-40% by volume (4) A resin composition having a composition of 0.1 to 40% by volume of inorganic acicular crystals (5) 0.01 to 5% by volume of zinc stearate.