JPH02117933A - Filled plastic composition, excellent in strength and containing metallic powder in high concentration - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of readily providing high- specific gravity molded products excellent in molding processability, appearance, surface decorativeness and mechanical strength by filling a large amount of true spherical metallic fine powder having a smooth surface in a plastic material. CONSTITUTION:The objective composition obtained by filling 50-97wt.% substantially true spherical metallic fine powder (e.g., iron, copper or copper alloy) having a smooth surface (preferably having >=0.9 sphericity coefficient and <=100mu average particle diameter) in a plastic material (e.g., PE, PP, ABS resin, nylon or polyethylene terephthalate).

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a high specific gravity plastic composition filled with metal powder or the like at a high concentration. Specifically, the present invention relates to a novel composition that can easily produce high-density molded products with excellent moldability, appearance, surface decoration, and mechanical strength that have not been achieved using conventional techniques.

(b) Conventional technology Traditionally, metal powders, which are made by blending metal powders such as iron (iron) into plastic materials at high concentrations, have been used for mechanical parts, etc. Typical uses include: There is a flywheel of a tape recorder.The following is an example of the conventional technology related to a high specific gravity plastic composition.
No.-212459 is a nylon 6 matrix compounded with 82.5% iron powder, and has a ratio of i1'j3. The f33 is 17゛ζ. In addition, in Special Publication No. 11261/1986, zinc powder 7 was used on a nylon 6 substrate.
By blending 4%, a specific gravity of 3.0 was obtained. Furthermore, as a technology for making materials with higher specific gravity, Japanese Patent Application Laid-Open No. 61-200165
No. 6 is a nylon 6 matrix blended with 90% zinc powder and reinforcing fibers to create a composition with a specific gravity of 4°4.
No. 9858 has a nylon 6 matrix and contains 85% iron powder to obtain a composition with a specific gravity of 4.34.

All of these are intended for mechanical parts such as flywheels, and there are few examples of the mechanical strength of iiP materials, but according to additional tests by the inventors, the tensile strength is 3. The IZOT (door i!3!!) value was about 3 kg/sa', which was significantly lower than that of IAJ fat alone.

However, the flywheel of a home appliance tape recorder was within a range that could be used for practical purposes.

However, in recent years, high-density plastic materials have been applied to many products other than conventional flywheels inside machines due to their good performance and workability. ! 1: I came leaning on it.

An example of this is a single-blade electric razor.

Using high-density abrasive for the exterior frame and body has the effect of softening the vibrations.

However, in order to use this kind of application, conventional seed material f
-Different performance is required from interior parts, which were used for +.

First, since the molded product has a long flow length, is thin, and has a complex shape, it is required to have excellent moldability. This is due to the fluidity of the material, the smooth surface, and the fact that welds are less noticeable.

Furthermore, it is commercially resistant to damage caused by dropping the product during use.
i! Impact strength is required.

When using nylon-based compositions for machine 1M parts such as flywheels, it has been possible to improve impact resistance by adding reinforcing materials such as glass fiber and potassium titanate, but For commercial purposes, blending glass fiber is not a preferable method because of the loss of surface smoothness and the difficulty of painting and plating. Further, since potassium titanate has a fine fiber diameter of 2 to 3 μm, the appearance of the molded product is excellent, but the strength improvement effect is inferior to that of glass fiber combinations, and the unit cost of the material is significantly higher.

As mentioned above, since the high specific gravity materials of the prior art are not satisfactory to the new market requirements, there is a strong demand for improvements.

(c) Problems to be Solved by the Invention The present inventor discovered that high-density plastic (1 material) containing gold mud powder at a high concentration is mainly used due to its mechanical strength, appearance, and moldability limitations. We have improved the current situation where it is used as a single dose for interior mechanical components, and it has excellent mechanical strength without the need for reinforcing materials such as glass fiber, especially high impact resistance, and is easy to mold. This invention was developed as a result of research aimed at developing a high-density composite material that has an excellent appearance as a molded product, has a particularly good paint finish, and has the properties to withstand use as housing parts for home appliances, etc. It is completed.

((1) Means for resolving the problems) The present invention, which has been developed to solve the above-mentioned problems of the prior art, will be described in detail below.

The present invention has a smooth surface and a substantially rectangular shape,
And metal powder with an average particle size of 100μ or less is added to Plus Deck IA'! -1 is a plastic composition with excellent strength, characterized by being filled 50% to 97%.

The metal referred to here is a material with a specific gravity of 6 or more that is effective for the purpose of the present invention, which is a high specific gravity composite material. These include iron, copper and copper alloys such as bronze, brass, brass, phosphor bronze, cupronickel, zinc, lead, tin, and the like.

Further, examples of powders whose metal surfaces are coated with other metals include zinc-coated iron powder and tin-coated copper powder.

The term "transspherical" here refers to the sphericity coefficient (Sρherj) of the powder.
ciLy Coefficient) is 0.85 or more,
It is preferably O19 or higher.

This sphericity coefficient is Van No5trand Re1nh
Old Company version 11andbook or
Fillers for Piastics, l1a
rry 5KaLz & Jobnν old 1ewski
IHr, page 92. It is immediate. If it is a true sphere, this coefficient is 1.

As an example of metal powder, ALCIIN POWDER
5AND PIGMENTS (901Lehigh
Bronze powders 10P, 40P, and 153A are available from Avenue, Union, NJ.

The particle size of the filler of the true spherical metal powder is such that the homogeneous composition is 1
90% or more is less than 200 mesoyu, IjT
Preferably, 70% or more of the powder may pass through 320 mesh.

Particle size is indicated by Tyler standard sieve number.

The advantage of incorporating fine particles that pass through 200 mesh is that, in addition to the excellent strength as described above, the surface of the molded product is smooth and has good secondary processability such as painting. Furthermore, the fluidity of the mixture during injection molding is even better.

In the composition of the present invention, it is preferable that the true spherical metal powder be subjected to a compulsion treatment in advance, or that a force/knobbling agent be added at the same time as blending it with the resin raw material.

For this purpose, organosilane compounds such as γ-aminopropyltriethoxysilane, N-β(aminoethyl)T-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, A silane camping agent such as sidoxypropyltrimethoxysilane or a zircoaluminate camping agent having an organic ligand such as carboxy, aliphatic, or methacryloxy as an organic functional group can be used.

Best! ! The coupling agent differs depending on the IH fat to be blended. Preferred coupling agents are γ-aminopropyltriethoxysilane for nylon, and aliphatic zircoaluminate coupling agents for polybutylene terephthalate.

The coupling agent is 0.001 to 2 for metal powder etc.
It is particularly effective to add 0% by weight, preferably 0.01 to 1.0% by weight.

If the amount is less than this, the effect will be poor, and if more than this is added, the cost will only increase and no improvement in the effect will be seen.

Many thermoplastic plastics can be used as the plastic compounded in the composition of the present invention. General high-density applications include vinyl chloride resin, low-density polyethylene, high-density polyethylene, polypropylene, high-impact polystyrene, and
S resin etc. are suitable. It is also preferable to blend ethylene propylene rubber, polybutadiene rubber, etc. into the polyolefin resin for the purpose of imparting IIi impact resistance.

For high strength and high specific gravity applications, higher performance engineering plastics such as nylon, polybutylene terephthalate, polyethylene terecrate, polyacecool, polyphenylene sulfide, or other crystalline resins, or polycarbonate, polyphenylene ether-polystyrene, etc. Non-crystalline resins such as blend resin, polysulfone, and Boria Relay 1 can be used.

These 7-ring plastics are ~1i
Ji! lI! , are often made into polymer alloys for the purpose of improving stress cracking resistance, moldability, etc., and these are also included in the resin for this composition.

Modifiers added to give particularly high impact properties include ethylene-propylene rubber, styrene-butyl diene block copolymers and their hydrogenated products, and butyl acrylate elastomers.For nylon, these include unsaturated carboxylic acids or their It is well known that there are many elastomers to which anhydrides such as acrylic acid and maleic anhydride have been added. However, the present invention is not limited to the above-mentioned resins.

In addition, stabilizers such as phenol stabilizers and phosphite stabilizers are added to the mixture of true spherical metal powder and JJI fat to prevent coloration during molding, or methylene bisamide, stearic acid, moncitric acid, etc. It is also possible to use a general technique of adding an lh agent such as an ester to improve moldability and surface flatness of a molded article.

A high specific gravity plastic material can be easily produced by melt-mixing (melt compounding) these mixtures using chiral properties.

It is also possible to form this mixture directly into a molded article using a screw injection molding machine.

The A, 1 small molding machine used in this process is particularly suitable for the kneading machine (i
An injection molding machine equipped with the above is highly effective in uniformly dispersing true spherical metal powder, and therefore exhibits an excellent effect in carrying out the present invention.

In the injection molding of the composition according to the present invention, a material supply device is attached that operates in conjunction with the screw of the injection molding machine, and the material is supplied into the molding machine cylinder in a flItm state. It is preferable to adjust it and then mold it.

The effect of this is that the material is sufficiently salty and the high viscosity material during the melting process does not hinder the forward movement of the screw during injection, so the screw can move within the set stroke. This is because it is extremely effective in manufacturing precision molded products by smoothly advancing the screw according to the combination of screw position and injection speed.

111. Of course, the composition itself according to the present invention is not limited by these manufacturing methods.

(e) Effect This invention overcomes the conventional technology by filling a plastic matrix with 50i1% to 97% by weight of metal powder having a flat surface, a substantially true spherical shape, and an average particle size of 100.17 or less. Compared to composite materials with high specific gravity fillers such as irregularly shaped iron powder, dendritic electrolytic copper powder, angular ferrite powder, and fine fibrous brass, which were used in , we have succeeded in developing a high-density, high-strength composite material that has extremely excellent moldability, molded product appearance, and high mechanical strength due to the physical and effective action of true spherical metal powder in a plastic composition. It is.

(f) Examples The structure of the present invention will be specifically explained with reference to Examples below.

Example 1 (1) Alcan Powder with a particle size of 100% passing through 200 mesh and 5% passing through 325 mesh.
ders and Pigments Co., Ltd. Bronze Powder 10P1 Composition: 90% Tears, 10% Tin> 5000g was mixed at low speed in a high speed mixer ([Phase] Kawata Super Mixer) while adding 25g of silane cuff pulling agent (Shin-Etsu Chemical Co., Ltd. KBM 903.25g). (diluted 5 times with denatured alcohol/water-9/1 solution) and then boiled at high speed for 3
Mixing continued for minutes.

The mixture was heated at 120°C for 3 hours in a hot air circulation dryer.
I got it done. This bronze powder was found to be 10% by microscopic observation.
When we measured particles larger than 0, the average particle diameter was 25μ.
The particles of 9494 or more were spherical particles with a sphericity coefficient of 0.9996 and a surface plane h.

(2) 5000g of the silanized bronze powder from the previous section, ! '
5) Late generation nylon 6 resin (Ube Industries + MIOIIF)
500 g were mixed in a drum blender for 5 minutes.

Comparative Example 1゜(1) Iron powder made by an atomization method with 1% passing through 200 mesh and 23% iii passing through 325 mesh (
Example 1. processed in the same way.

(2) Silanized iron powder 5000g, powdered nylon 6
690 g of the resin (same as above) was mixed in a drum blender for 5 minutes.

Comparative example 2゜(1) Comparative example 1. Treated iron powder was prepared in the same manner as in (1).

(2) Continuing, 630g of powdered nylon 6 resin (same as before)
20 g of ethylene-unsaturated carboxylic acid copolymer (Nucrel N1525, manufactured by DuPont Mitsui Chemicals).

0, p-toluenesulponamide mixture (Top Sizer No. 5, manufactured by Fuji Amido Chemical Co., Ltd.) 30 g, methylene bisstearamide (Pan Loop N18, manufactured by Taneyaya Kasei Co., Ltd.)
p) 10 g was added and mixed at 750 r/m for 300 minutes. The temperature of the mixture rose to 140° C. and the ethylenically unsaturated carboxylic acid copolymer melted.

(3) Continue to water-cool the mixer Jacquera I.
Continue mixing at 00r/m for 200 minutes to mix the iron powder and nylon)
A granular mixture with fused powder was produced.

The mixture of Example 1, Comparative Example 1, and Comparative Example 2 was transferred to an injection molding machine equipped with an f6 melt kneading mechanism described in Japanese Patent No. 1104727, from a screw feeder connected to a screw to a molding machine cylinder. The mixture was supplied so that the supply section inside was starved of f11N, and molding was performed.

The molded product is an ASTM D6384 type tensile test piece (thickness 3
, 2 mm) and ASTM D256 impact test piece (total length 64 mm, width 12.7 mm, wall thickness 3.2 m11+
Table 1 shows the results of molding and the results of physical property measurements.

That is, by using the composition of the present invention, a composite material having high strength and high specific gravity, which could not be achieved using conventional techniques, was obtained.

(g) Effects of the Invention This invention provides a high specificity plastic composite material filled with metal powder at a high concentration, by blending a completely curved filler with a substantially surface ratio of lh and a true spherical shape. This makes it possible to produce a high specific gravity composite material with high strength that could not be achieved using conventional technology, without adding reinforcing materials.

Furthermore, since the composite material does not require the addition of fibrous reinforcing materials such as glass fiber, the surface of the molded product is flat and there are no noticeable weld lines, making it particularly suitable for post-processing such as painting and plating. This is a new and effective invention.

Table 1

Claims (1)

[Claims] The surface is smooth and the average particle size is substantially spherical.
50% by weight of metal powder of less than μ in plastic material
A plastic composition characterized in that it is filled at ~97% by weight.