JPH0696673B2 - High specific gravity resin composition - Google Patents

Description

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

[Conventional technology and problems]

Polyethylene, chlorinated polyethylene, polyvinyl chloride,
Synthetic rubber, nylon, polypropylene or ethylene-
Resin compositions obtained by mixing glass fibers, carbon fibers, or the like with synthetic resins such as vinyl acetate copolymers have been widely used as high-rigidity materials. Further, not only such fibers, but also inorganic powders such as talc and calcium carbonate are used as fillers, which show the effect of improving the elastic modulus of the synthetic resin.

Further, in recent years, the use of synthetic resin as an electromagnetic wave shielding material in which metal fiber is mixed with synthetic resin or as a plastic magnet material in which ferrite or the like is mixed with synthetic resin has been made.

As described above, the use of a material in which a reinforcing material or a filler is mixed with a synthetic resin as a matrix material is increasing. Such materials are used for their respective purposes by revealing their shapes by using the injection molding method or the extrusion molding method which are generally used at present.

One of these application fields is the flywheel and inertia gears that require high specific gravity materials. These all utilize the inertial force of the object to provide smooth rotation.
Therefore, a large inertial force can be maintained, that is, a material formed of a material having a large specific gravity can obtain a large inertial force even if the material has a small specific gravity, which is advantageous for use in a small space. It is also necessary that these materials be balanced. In the case of imbalance, the inertial force becomes non-uniform, causing shaft runout and uneven rotation.

At the same time, however, the conventionally known resin composition using the above synthetic resin as a matrix material cannot satisfy the above requirements.

[Means for solving problems]

As a result of intensive studies conducted by the present inventors to satisfy these requirements, 1) excellent moldability, 2) sufficient uniformity of molded products, 3) high specific gravity, and The present invention has been accomplished by finding a high specific gravity resin molding material composition that is strong.

That is, the present invention relates to a copolymer 5 having, in the molecule, (a) a polymer component composed of an ω-aminocarboxylic acid or lactam having at least 10 carbon atoms, and (b) a polytetrahydrofuran component as essential components in a molecule. 50% by weight, metal powder
The present invention relates to a high specific gravity resin composition composed of 95 to 50% by weight.

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

One of the essential components of the copolymer used in the present invention is (a) a polymer component composed of ω-aminocarboxylic acid or lactam having at least 10 carbon atoms, ω
Examples thereof include polymers or oligomers of aminoundecanoic acid, lauryllactam or ω-aminododecanoic acid.

The amount of ω-aminocarboxylic acid or lactam in the present copolymer is preferably 80 to 30 parts by weight, more preferably 70 to 40 parts by weight. On the other hand, the amount of the (b) polytetrahydrofuran component which is another essential component is preferably 15 to 60 parts by weight, more preferably 20 to 50 parts by weight. The molecular weight of polytetrahydrofuran is preferably from 500 to 3,000, most preferably around 1,000.

The method of using (c) dicarboxylic acid as a method for binding the polymer component (a) ω-aminocarboxylic acid or lactam of the copolymer of the present invention and the component (b) polytetrahydrofuran. As a modified example in that case, first, (b)
There is also a method in which the terminal of polytetrahydrofuran is aminated and the terminal amino group of the polymer (a) ω-aminocarboxylic acid or lactam is reacted with the terminal amino group by reacting with dicarboxylic acid. In this case, two kinds of aminating agent and dicarboxylic acid are used as the third component.

Examples of the dicarboxylic acid _{formula: HOOC- (CH 2) x-} COOH
Aliphatic dicarboxylic acids of the formula wherein x represents a value of 4 to 11 are used; examples thereof include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid. Furthermore, cycloaliphatic dicarboxylic acids having at least 8 carbon atoms and / or aromatic dicarboxylic acids, such as hexahydroterephthalic acid, terephthalic acid,
Mention may be made of isophthalic acid, phthalic acid or naphthalene dicarboxylic acid.

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

Preferred specific examples of the present 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.

The general method for producing the 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 a plasticizer may be added to the present copolymer within the range in which the preferable properties are not lost.

Such polyamide elastomers have various degrees of polymerization, and in the present invention, it is preferable to use one having a relative viscosity of 1.45 to 2.10 by measuring the solution viscosity using a 0.5% meta-cresol solution according to DIN 53727. The relative viscosity is
If it is less than 1.45, the molding stability is lost, and if it has a relative viscosity of more than 2.10, when the high specific gravity resin composition is used, the melt viscosity at the time of extrusion molding or injection molding is undesirably increased.

Further, as the metal powder, powders of Fe, Zn, Sn, Pb, Cu and its alloys, oxides and the like are used, but iron powder is most preferable from the viewpoint of price, and further, in addition to resin and metal powder, these It is also possible to add a silane coupling or the like corresponding to the above property.

The metal powder used in the present invention may be a metal powder obtained by any method. The metal powder may have any shape,
It is desirable that the shape is closer to a sphere than the angular metal powder. Squared metal powder not only worsens the fluidity of the material,
The device is easily worn when obtaining the resin composition or when obtaining the molded product.

The particle size of the metal powder may be 0.1 to 300μ, preferably 0.1 to 200μ, more preferably 0.1 to 50μ.
Those having a particle size of μ are preferable. If the particle size is smaller than 0.1 μ, it is inconvenient to handle, and if it is larger than 300 μ, the moldability is impaired.

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

[Work]

The method for producing the composition of the present invention is a method in which the above polyamide elastomer is melt-mixed with metal powder, and is usually mixed using a single-screw or twin-screw extruder. In some cases, kneading may be performed using a kneader. At this time, it is possible to use a small amount of lubricant. Specifically, the polyamide elastomer component according to the present invention and metal powder are blended together, and a mixture of the polyamide elastomer granules or powder and metal powder is charged into the extruder hopper. Then, a method of heating, melt-mixing, and granulating, or a method of premixing and kneading in a kneader, and a method of granulating what is discharged from the discharge port at the time of completion of kneading by cutting or crushing, or using an extruder There is a method in which a polyamide elastomer is charged from a hopper portion, heated and melted, and metal powder is added through a hole provided in a cylinder intermediate portion of an extruder and mixed.

The pellets thus obtained can be further molded by injection molding, extrusion molding or the like to obtain a resin molded product.

Further, instead of such two-step molding, a mixture of metal powder and polyamide elastomer may be charged into a molding machine to obtain a molded product at once.

In the present invention, the above polyamide elastomer is used as the base range of the composition containing the metal powder, and if necessary, a stabilizer, a lubricant, a colorant or a dispersant is added, and only under the condition where the metal powder is filled. It is possible to obtain a metal powder-containing high specific gravity polyamide elastomer composition having a good fluidity that is exhibited.

As described above, according to the present invention, it is possible to obtain a high specific gravity composition material having good moldability, which contains uniformly dispersed metal powder, and a high specific gravity material such as a flywheel and an inertia gear is required as a molding material. It can be used for various purposes.

〔Example〕

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

Examples 1-3 As a polyamide elastomer which is a copolymer of lactam or ω-aminocarboxylic acid containing a polytetrahydrofuran component in the molecule, E47MS3 and E62MS3 of Daicel Hurus Co., Ltd. under the trade name "Daiamide PAE" are used. Using. E47
MS3 is laurinlactam 50%, α, ω-dihydroxypolytetrahydrofuran 41% and dodecanedicarboxylic acid 9%.
%, And E62MS3 is laurinlactam 74.2%, α, ω-
It was synthesized from 21.3% dihydroxypolytetrahydrofuran and 4.5% dodecanedicarboxylic acid.

Atomized iron powder (trade name "Atmel 300M-200") manufactured by Kobe Steel, Ltd. was used as the iron powder, and 100 parts by weight of this iron powder was used as a silane coupling agent "Cyla Ace A" manufactured by Chisso Corporation. -320 ", which had been surface-treated in advance with 1 part by weight, was prepared and subjected to the following test.

These raw materials were mixed at the ratios shown in Table 1 and the state of load during heating and kneading was examined. Rheo is a survey of the load during kneading
Using a cord type M (Haak Inc.), the kneading temperature was 220 ° C., the rotation speed was 100 rpm, and the kneading torque was observed 15 minutes after the start of kneading.

Similarly, blend the raw materials so that the component ratios in Table-1 are
Using a KCK kneading extruder, kneading and granulation was performed at a temperature of 180 to 240 ° C. The pellets thus obtained were molded to obtain test pieces for measuring physical properties. For molding, use a Nissei TS-100 injection molding machine,
Molding temperature 210-250 ℃, Injection pressure 100kg / cm ² G, Mold temperature 80
Performed at ~ 85 ° C.

Physical properties were measured by the method of ASTM. The results are shown in Table-1
It was shown to. The impact strength was measured using a flat plate having a thickness of 2 mm and a steel ball having a weight of 500 g.

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

As the nylon 12, a product name “DAIAMID” L-1940 manufactured by Daicel Huls Co., Ltd. was used. The pre-surface-treated iron powder used in the examples was used as the filling material.

The above-prepared materials were mixed at the ratios shown in Table 1, and the load during kneading was measured under the same conditions using the same equipment as in the examples. Further, also in the measurement of the physical properties, the same method and the same apparatus as those in the examples were used. The results are also shown in Table-1.

Claims (1)

[Claims] 1. A copolymer 5 having, in its molecule, (a) a polymer component composed of an ω-aminocarboxylic acid or lactam having at least 10 carbon atoms, and (b) a polytetrahydrofuran component as essential components. 50% by weight, 95 metal powder
A resin composition having a high specific gravity of about 50% by weight.