JPH044258A - Engineering plastics capable of post-treatment - Google Patents

Abstract

PURPOSE:To obtain the subject engineering plastic capable of stable precise cutting as post-treatment after molding by blending a powdery light alloy as a reinforcing material instead of glass fiber powder with a molding material composed of polycarbonate, etc. CONSTITUTION:With a molding material consisting of a synthetic resin such as polycarbonate or polybutylene terephthalate, a reinforcing material mainly composed of powdery light alloy (e.g. powdery aluminum alloy) having reinforcing properties and expansion coefficient-lowering properties almost as same as glass fiber powder is blended in >=40wt.% ratio. The particle shape of the powdery aluminum alloy is fiber-shape, granule, scale, etc., and the particle size is controlled to 100-200 mesh-pass grain size in order to improve affinity to the above-mentioned resin material blended therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to engineering plastics suitable for stably performing precise cutting as post-processing after molding.

(Conventional technology) Traditionally, along with metal materials, so-called engineering materials have been used as materials for parts and housings of machines and devices.
Reinforced plastics called plastics (engineering plastics) are known.

However, typical engineering plastics include polycarbonate (PC) and polybutylene terephthalate (P).
10 to 30% by weight of synthetic resin materials such as B T)
There are molded products that contain glass fiber powder as a reinforcing material, and their molded products have strength and expansion coefficients that are comparable to molded products made of metal.

In addition, the molded product can naturally be molded as an injection molded part and can be mass-produced with high productivity, so it is often used as a component of various precision instruments.

By the way, the linear expansion coefficient of PC, PBT, etc. is 6~8X10
-5- The linear expansion coefficient of numerical glass is less than 1゜0XIO-5, and the linear expansion coefficient of aluminum alloy is 2.5X10-5.
However, the swelling coefficient of PC and PRT containing 10 to 30% by weight of glass fiber powder is also equivalent to that of aluminum alloy.

(Problems to be Solved by the Invention) Although such engineering plastics have excellent properties as described above, the molded products are not easily formed because glass fiber powder is mixed into the molding materials such as PC and PBT. If the molded product is cut after molding, a cutting tool such as a cutting tool will be worn away by the glass fibers, resulting in the disadvantage that necessary post-processing cannot be carried out stably and easily.

However, for example, parts that make up the zoom mechanism of a camera must be formed so that they can move in a straight line while rotating due to their mechanism, and they often have complicated groove shapes, so engineering plastics are not used. If molding is performed by injection molding, the productivity can be rationalized, but the parts that are difficult to mold by injection must be cut after molding.

However, in the case of such molded products, as mentioned above, they have the disadvantage of abrasion of cutting tools due to glass fibers, so they are considered unsuitable for injection molding, and as a result, mass production is difficult. It is manufactured by cutting a metal material instead of using engineering plastic, which has excellent properties, and has the problem of high cost.

This invention was made in view of the above-mentioned circumstances, and its purpose is to stably perform precise cutting as a post-processing after molding, which could previously only be produced by metal processing. The purpose of the present invention is to provide engineering plastics that can be mass-produced at low cost as injection molded parts for various parts that previously could not be produced.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention, as set forth in claim 1, comprises reinforcing glass fiber powder into a molding material made of a synthetic resin such as polycarbonate or polybutylene terephthalate. In the case of engineering plastics mixed as a material, the reinforcing material mixed into the molding material is mainly a light alloy powder that has substantially the same reinforcing properties and expansion rate reduction properties as the glass fiber powder, replacing the glass fiber powder. It is characterized by being an ingredient.

Further, as claimed in claim 2, the main component of the reinforcing material mixed into the molding material is aluminum alloy powder.

Aluminum alloys include 2000 series and 7000 series high-strength aluminum, and 5000 series with excellent corrosion resistance.
In addition, the particle size of the powder is preferably 100 to 200 mesh particles in the form of fibrous 9 particles, scales, etc. in order to improve the affinity with the resin material to be mixed.

Note that by coating the particle surface of the aluminum alloy powder with a synthetic resin or the like, the affinity with the -layer resin material can be improved.

Furthermore, although pure aluminum has inferior strength compared to aluminum alloys, it can be used as a reinforcing material for this type of molding material.

Furthermore, the mixing ratio range of the reinforcing material is preferably at least 40% by weight or more in order to ensure the strength of the molding material.

(Explanation of Examples) Hereinafter, the engineering plastic according to the present invention will be explained using Examples.

Example 1 - Polycarbonate (PC), a thermoplastic resin with excellent mechanical properties, heat resistance, electrical properties, etc., was prepared as a synthetic resin material, and 50% by weight of this polycarbonate was prepared.
On the other hand, an engineering plastic containing 50% by weight of reinforcing material made of aluminum alloy is obtained.

The aluminum alloy powder in this example was A7075 Te2.
A 50 mesh bath particle size was selected.

Example 2 As the synthetic resin material and reinforcing material, the same polycarbonate and aluminum alloy powder as in Example 1 were selected, but the mixing ratio was 50% by weight as in Example 1:
The mixture was changed from 50% by weight to 40% by weight: 60% by weight.

Example 3- As a synthetic resin material, it has excellent creep resistance.

Polybutylene terephthalate (PBT), which does not easily cause stress clutches, is prepared, and an engineering plastic is obtained by mixing 50% by weight of aluminum alloy powder with A2024 and 250 mesh bath size into 50% by weight of polybutylene terephthalate.

Example 4 - Polyphenylsulfide (PPS), which has excellent mechanical properties, heat resistance, chemical resistance, etc. as a synthetic resin material
An engineering plastic is obtained by mixing 60% by weight of this polyphenylsulfide with 40% by weight of aluminum alloy powder of A3056 with a particle size of 250 mesh pass.

Example 5 As the synthetic resin material and reinforcing material, the same synthetic resin material (PC) and aluminum alloy powder (A7075, 250 mesh bath particle size) as in Example 1 and Example 2 are used. Mixing ratio with reinforcing material is 45% by weight
: 55% by weight, and the breakdown of the 55% by weight of the reinforcing material was that 50% by weight was aluminum alloy powder and the remaining 5% by weight was glass fiber powder.

Next, injection molded parts were molded using each of the engineering plastics of Examples 1 to 4, and the hardness and machinability of the molded parts were tested.

According to the test results, these engineering plastics have a specific gravity of less than or around 2, and an expansion rate close to that of aluminum alloys.
Moreover, it was found to have the same strength and expansion rate range as conventional engineering plastic molded products containing glass fiber powder, and it was possible to perform cutting at desired locations without wearing out cutting tools such as bits.

In addition, as a result of molding a molded article using the engineering plastic of Example 5 and conducting the same test as above, it was found that the degree of wear on cutting tools caused by glass fiber powder was not as severe as in the past, and sufficient cutting could be performed. It was found that the expansion rate range was also satisfactory.

In addition to aluminum alloy powder, magnesium alloy powder or the like may be used as the reinforcing material.

(Effects of the Invention) As explained above, according to the engineering fist plastic according to the invention as claimed in claims 1 and 2, the reinforcing material mixed into the molding material can be replaced with the conventionally used glass fiber powder. As the main component is a light alloy powder that has reinforcing properties almost equivalent to glass fiber powder and properties that reduce swelling ratio, it has strength equivalent to that of conventional engineering plastics, and has a strength similar to that of conventional engineering plastics. It is possible to perform post-processing such as cutting, which could not be done with other machines.

Therefore, various parts that were conventionally made using metal can now be molded by injection molding, and precise cutting can be stably performed as post-processing after molding, allowing for the production of necessary parts. It is possible to streamline the process and reduce costs.

Claims (1)

[Claims] 1. In engineering plastics in which glass fiber powder is mixed as a reinforcing material into a molding material made of synthetic resin such as polycarbonate or polybutylene terephthalate, the reinforcing material mixed into the molding material is glass. An engineering plastic that can be post-processed, characterized in that the main component is a light alloy powder that is substituted for fiber powder and has substantially the same reinforcing properties and expansion rate reduction properties as the above-mentioned glass fiber powder. 2. The post-processable engineering plastic according to claim 1, wherein the main component of the reinforcing material mixed into the molding material is aluminum alloy powder.