JPS62212460A - Resin composition having high specific gravity - Google Patents

Abstract

PURPOSE:To provide a resin compsn. having a high specific gravity and excellent moldability, impact resistance, etc., by mixing a copolymer comprising a high-molecular component composed of a 10C or higher omega-aminocarboxylic acid, etc., and a polytetrahydrofuran component as essential components with metallic powder. CONSTITUTION:A high-molecular component (A) composed of a 10C or higher aminocarboxylic acid or lactam (e.g., a omega-aminoundecanoic acid polymer, a laurolactam polymer) is bonded to a polytetrahydrofuran component (B) by using a dicarboxylic acid (C) (e.g., terephthalic acid) to produce a copolymer. 5-50wt% copolymer is mixed with 95-50wt% metallic powder (e.g., iron powder) to obtain the desired resin compsn. having a high specific gravity. In this way, the resin compsn. contg. metallic powder uniformly dispersed therein can be obtd. and moldings of uniform quality can be easily obtd. therefrom. The resin compsn. is suitable for use in the production of a flywheel, etc.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a resin composition containing metal powder.

More specifically, the present invention relates to a high specific gravity resin composition containing metal powder, particularly iron powder, having good moldability and impact properties.

[Conventional technology and problems]

polyethylene, chlorinated polyethylene, polyvinyl chloride,
Synthetic rubber, nylon, polypropylene or ethylene
Resin compositions in which glass fibers, carbon fibers, etc. are blended with synthetic resins such as vinyl acetate copolymers have conventionally been widely used as highly rigid materials. Also, all these fibers.

Inorganic powders such as talc and calcium carbonate are also used as fillers, and have shown the effect of improving the elastic modulus of synthetic resins.

Furthermore, in recent years, synthetic resins have been used as electromagnetic wave shielding materials made by blending metal fibers with synthetic resins, or as plastic magnet materials made by blending ferrite and the like with synthetic resins.

As described above, the use of materials in which a synthetic resin is used as a matrix material and a reinforcing agent or filler is blended therein is increasing. These materials are formed into shapes using currently commonly used injection molding or extrusion molding methods, and are used for their respective purposes.

One such application field is flywheels and inertia gears, which require materials with high specific gravity. All of these utilize the inertia of an object to provide smooth rotation.

Therefore, a device that can maintain a large inertial force, that is, one made of a material with a large specific gravity, can obtain a large inertial force even if it is small, and is therefore advantageous for use in a small space. It is also necessary that these materials be well balanced. If it is unbalanced, the inertial force will be uneven, resulting in shaft wobbling and uneven rotation.

However, conventionally known resin compositions using the above synthetic resin as a matrix material cannot satisfy the above requirements.

[Means for solving problems]

As a result of intensive studies to satisfy these requirements, the inventors of the present invention found that: 1) it has excellent moldability, 2) the molded product has sufficient uniformity, and 3) it has a high specific gravity and is resistant to external forces. We have discovered a high specific gravity resin molding material composition that is strong, and have arrived at the present invention.

That is, the present invention provides copolymers 5 to 5 having in their molecules as essential components (a) a polymeric component made of an ω-aminocarboxylic acid or lactam having at least 10 carbon atoms, and (b) a polytetrahydrofuran component. This relates to a high specific gravity resin composition consisting of 50% by weight and 95 to 50% by weight of metal powder.

Hereinafter, the high specific gravity resin composition of the present invention will be explained in detail.

It is one of the essential components of the copolymer used in the present invention (
b) As the polymer component consisting of ω-aminocarboxylic acid or lactam having at least 10 carbon atoms, ω
Examples include polymers or oligomers of -aminoundecanoic acid, lauryllactam, or ω-aminododecanoic acid.

The amount of ω-aminocarboxylic acid or lactam in this copolymer is preferably 80 to 30 parts by weight, more preferably 70 to 40 parts by weight. The amount of the tetrahydrofuran component is preferably 15 to 60 parts by weight, more preferably 20 to 50 parts by weight. The molecular weight of polytetrahydrofuran is preferably 500 to 3.000, most preferably around 1.000.

The method for bonding (a) the polymer component of ω-aminocarboxylic acid or lactam and (b) the polytetrahydrofuran component of the copolymer of the present invention is a method using (c) dicarboxylic acid.

As a variation in that case, first, (b) the terminal end of polytetrahydrofuran is aminated, and this is then transferred to (b) the terminal amino group of the ω-aminocarboxylic acid or lactam polymer which has been reacted with dicarboxylic acid. There is also a method of reactive binding.

In this case, two types of third components are used: an aminating agent and a dicarboxylic acid.

The dicarboxylic acid has the general formula: HOOC-(CHg)-
Aliphatic dicarboxylic acids of COOH, in which X represents a value of 4 to 11, are used; for example adipic acid, pimelic acid,
Examples include suberic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid. Mention may also be made of cycloaliphatic dicarboxylic acids having at least 8 carbon atoms and/or aromatic dicarboxylic acids, such as hexahydroterephthalic acid, terephthalic acid, isophthalic acid, phthalic acid or naphthalic dicarboxylic acid.

Moreover, in addition to the above-mentioned essential components (a) and (b), (d) an optional fourth component may be used in this copolymer.

Preferred specific examples of this copolymer include polyether ester amide in which nylon 12 and polytetrahydrofuran are ester bonded using a dicarboxylic acid such as dodecanedicarboxylic acid or terephthalic acid.

A general method for producing this copolymer is the method disclosed in JP-A-52-12297 or JP-A-53-119997.

The same homopolymer as the polymer component (a) (for example, nylon 12 homopolymer) or a relatively small amount of plasticizer may be added to this copolymer as long as the above-mentioned preferred properties are not lost.

Such polyamide elastomers have various degrees of polymerization, and in the present invention, the relative viscosity is 1.45 to 2.0 as measured by solution viscosity using a 0.5% metacresol solution according to DIN 53727. It is preferable to use 1O. If the relative viscosity is lower than 1.45, the stability of molding will be lost, and if the relative viscosity exceeds 2.10, it will be difficult to make a high specific gravity resin composition during extrusion molding. Alternatively, the melt viscosity increases too much during injection molding, which is undesirable.

In addition, as metal powder, Fex Zns Sns PbS
Powders of Cu, its alloys, oxides, etc. are used, but iron powder is most preferred from the point of view of price, and in addition to resin and metal powder, a silane coupling agent, etc. corresponding to these properties may be added. You can also do it.

The metal powder used in the present invention may be obtained by any method, and the shape of the metal powder may be any shape.
It is preferable to use spherical metal powder rather than angular metal powder, as angular metal powder will only worsen the fluidity of the material.
Equipment used to obtain resin compositions or molded products is likely to be worn out.

The metal powder may have a particle size of 0.1 to 300μ, preferably 0.1 to 200μ, more preferably 0.1 to 50μ. If the particle size is smaller than 0.1μ, it is inconvenient to handle;
If it is larger, moldability will be inhibited.

The blending amount of these metal powders is 95 to 50% by weight based on 5 to 50% by weight of the polyamide elastomer resin component.

[For production]

The composition of the present invention is produced by melt-mixing the polyamide elastomer with metal powder, usually using a screw or twin-screw extruder.

In some cases, kneading is performed using a nigu.

It is also possible to use a small amount of lubricant at this time. Specifically, the polyamide elastomer component and metal powder according to the present invention are blended together, and a mixture of granular or powdered polyamide elastomer and metal powder is charged into an extruder hopper. A method of granulating by heating and melting and mixing, or a method of kneading the premixed material in a Nigu, and granulating it by cutting or crushing the material discharged from the discharge port when the kneading is completed, or using an extruder, There is a method in which polyamide elastomer is charged from a portion of a hopper, heated and melted, and metal powder is added and mixed through a hole provided in the middle of the cylinder of an extruder.

The pellet thus obtained can be further molded by injection molding, extrusion molding, etc. to obtain a resin molded product.

Furthermore, instead of such two-stage molding, a molded product can be obtained in one step by charging a mixture of metal powder and polyamide elastomer into a molding machine.

In the present invention, the above-mentioned polyamide elastomer is used as a base resin for a composition containing metal powder, and stabilizers, lubricants, colorants, or dispersants are blended as necessary, and only under conditions where metal powder is filled. A metal powder-containing high-density polyamide elastomer composition having good fluidity can be obtained.

As described above, according to the present invention, it is possible to obtain a high specific gravity composition material containing uniformly dispersed metal powder and having good moldability. It can be used for various purposes.

〔Example〕

Next, the present invention will be explained with reference to examples.

Examples 1 to 3 The polyamide elastomer, which is a copolymer of lactam or ω-aminocarboxylic acid containing a polytetrahydrofuran component in its molecule, is manufactured by Daicel Hiels ■ under the trade name “
Diamid PAf! J's 847MS3 and E62MS
3 was used. 11147M53 is laurin lactam 5
0%, α, ω-dihydroxy polytetrahydrofuran 4
1% and dodecanedicarboxylic acid 9%, also H62M5
No. 3 was synthesized from 74.2% laurinlactam, 21.3% α,ω-dihydroxypolytetrahydrofuran, and 4.5% dodecanedicarboxylic acid.

As the iron powder, ■Kobe Steel's type atomized iron powder (trade name "Atomel 300M-200J") was used, and this iron powder 1
00 parts by weight was previously subjected to surface treatment with 1 part by weight of a silane coupling agent "SiLa Ace A-320J" manufactured by Chisso ■, and was prepared and subjected to the following test.

These raw materials were mixed in the proportions shown in Table 1, and the load conditions during heating and kneading were examined. Rh is used to investigate the load during crosstalk.
eocord Type M (Haake Inc.
), the crosstalk torque was observed 15 minutes after the start of crosstalk at a kneading temperature of 220° C. and a rotational speed of 1100 rpm.

Similarly, blend the raw materials to the component ratio shown in Table 1,
Kneading and granulation was performed at a temperature of 180 to 240°C using a KCK kneading extruder. The pellet thus obtained was molded to obtain a test piece for measuring physical properties.

Molding was carried out using a TS-100 injection molding machine at a molding temperature of 2.
The experiment was carried out at a temperature of 10 to 250°C, an injection pressure of 100 kg/cm"G, and a mold temperature of 80 to 85°C.

Physical properties were measured by the ASTH method. The results are shown in Table-1. In addition, the falling hammer impact strength was measured using a 2m-thick
The measurement was carried out using a steel ball weighing 500 g.

Comparative Example 1 As a comparative example, nylon 12, which is a polymer containing only laurin lactam and not containing polytetrahydrofuran, was selected.

Nylon 12 is manufactured by Daicel Hüls ■, which has the product name "
Diamid J L-1940 was used. As the filling material, the previously surface-treated iron powder used in the examples was used.

The materials prepared above were mixed at the ratio shown in Table 1, and the load during kneading was measured using the same equipment as in the example and under the same conditions. Furthermore, physical properties were measured using the same method and the same equipment as in the examples. The results are also listed in Table-1.

Claims (1)

[Claims] (a) a polymer component consisting of an ω-aminocarboxylic acid or lactam having at least 10 carbon atoms, and (b)
5 to 50% by weight of a copolymer having polytetrahydrofuran component as an essential component in the molecule, and 95 to 50% by weight of metal powder.
A high specific gravity resin composition consisting of % by weight.