JPS61200165A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:The titled composition suitable as various mechanical parts such as flywheel, etc., having improved molding properties, mechanical strength, pellet molding properties, etc., without wearing and damaging molding machine, etc., obtained by blending a polyamide resin with metallic powder whose surface is coated with zinc, potassium titanate fibers, etc. CONSTITUTION:(A) 50-5pts.wt., preferably 40-10pts.wt. polyamide resin (e.g., nylon 6, nylon 66, etc.) is blended with (B) 50-95pts.wt., preferably 60-90pts.wt. metallic (compound) powder (e.g., iron, iron oxide, etc.) whose surface is coated with zinc powder and/or zinc, and (C) 1-10pts.wt. potassium titanate fibers shown by the formula K2O.n(TiO2) or K2O.n(TiO2).1/2H2O (n is 2-8), (D) 1-10 pts. wt. polyolefin modified with liquid rubber and/or unsaturated carboxylic acid and (E) 0.1-10pts.wt. lubricant.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a polyamide resin composition, and more specifically, it can be used for flywheels, magnetic shielding materials, sound insulation housing (acoustic room) materials, speaker boxes, etc. The present invention relates to a polyamide resin composition that can be effectively used as a material for various mechanical parts, structural materials, etc.

[Prior art and problems to be solved by the invention] Thermoplastic resins have excellent properties such as being easier to make larger and lighter than metals, so in recent years they have been used for mechanical parts,
Widely used as a structural material.

However, thermoplastic resins have high tensile strength, impact strength,
In addition to being inferior to metals in mechanical strength such as hardness, heat resistance is 9
Since there are also problems with dimensional stability, etc., resin compositions have been proposed in which thermoplastic resins such as polypropylene, polyethylene, and polyethylene terephthalate are blended with powders and fibers of iron, ferrite aluminum, copper, zinc, etc.

In this case, there is not much of a problem when the amount of metal powder blended is small, but when the amount of metal powder blended is increased to make a material with a high specific gravity, especially when the amount of metal powder blended is 50% by weight or more. ■During molding, metal powder causes significant wear and damage to kneading machines, molding machines, etc. ■Metal powder aggregates inside the kneading machine and molding machine.

The productivity of pellets and molded products is extremely deteriorated due to adhesion, sintering, and solidification. ■The mechanical strength of the molded product is insufficient. ■During continuous production of molded products, there are problems such as large differences in the weight and density of the molded products, resulting in variations in dimensional accuracy. Moreover, especially when the amount of metal powder blended exceeds 70% by weight, the above-mentioned drawbacks ① to ③ become noticeable, and the moldability deteriorates, and even in injection molding, it is necessary to increase the gate diameter and use a direct gate. It was difficult to mold, was limited to small parts, and was unsuitable for large molded products, and was not suitable for practical use.

The present invention solves the above-mentioned conventional problems, has excellent moldability, has low mechanical strength, and has high pellet moldability and productivity, and does not cause significant wear and damage to kneading machines, molding machines, etc. during molding. The purpose of the present invention is to provide a resin composition that is free from damage.

[Means for solving problems]

That is, the present invention provides a total of 100 parts by weight of (A) 50 to 5 parts by weight of polyamide resin, (B) 50 to 95 parts by weight of zinc powder and/or metal powder or metal compound whose surface is coated with zinc. On the other hand, (C) 1 to 10 parts by weight of potassium titanate fiber.

(D) 1 to 10 parts by weight of modified polyolefin and (E
) A polyamide resin composition containing 0.1 to 1.0 parts by weight of a lubricant is provided.

In the present invention, first, a polyamide resin is used as the raw material component (A). Here, there are no particular restrictions on the polyamide thread/fat, and various materials can be used. Broadly speaking, there are three types: ■ring-opening polymerization of cycloaliphatic lactams, ■condensation polymerization of aliphatic diamines and aliphatic dicarboxylic acids or aromatic dicarboxylic acids, ■condensation polymerization of amino acids, and other types of nylon 7. A copolymer is obtained by polymerization of Zimmer. By such a method, 100NH- groups are generated in the long chains to produce various polyamides.

Those belonging to the above ■ include nylon 6 (from ε-caprolactam) and nylon 12 (from ε-caprolactam).
(from lauryl lactam) 6.6 nylon (hexamethylene diamine (HMD) and adipic acid) 6.10 nylon (HMD and sepacic acid) 6.12 nylon (HMD and dodecadionic acid) MXD, 6 nylon (
meta-xylene diamine (MXD) and adipic acid) H2N (CH2)I, NH2+HOOC (CH2),
2 C00N--NH(CH2)II NHCO(CH
z) m-z co-+r 11 nylon HzN (CHz)+o COOH→NH(CH
There are zLoCO-+ HzO, etc. Among these, especially nylon 6.

Preferably, 6.6 nylon is used.

Next, in the present invention, zinc powder and/or metal powder or metal compound powder whose surface is coated with zinc is used as component (B).

Examples of the metal powder or metal compound powder whose surface is coated with zinc include powders of iron dioxide, copper, lead oxide, and the like. There are no particular restrictions on the method of surface coating such metal powder or metal compound powder with zinc, but examples include (1) spraying and coating molten zinc on metal powder or metal compound powder, and (2) coating in molten zinc. An example of this method is to add metal powder or metal compound powder to and stir. The thickness of the zinc coating on the surface is 0.5 to 3μ.
A range of is suitable. In addition, the particle size of the powder is usually 1 to 15
μ, preferably 4 to 6 μ.

The blending ratio of the above (A) component and (B) component is (A) component 5
For 0 to 5 parts by weight, preferably 40 to 10 parts by weight (
The amount of component B) is 50 to 95 parts by weight, preferably 60 to 90 parts by weight. If the blending ratio of component (A) exceeds 50 parts by weight, the molded article will have poor mechanical strength and a low specific gravity, which is not preferable. On the other hand, if the blending ratio of component (A) is less than 5 parts by weight, it may cause abrasion damage to the kneading machine, molding machine, etc., or it may easily adhere to the inside of the machine, sinter, or solidify (and the appearance of the molded product may deteriorate). This is not desirable because it causes roughness.

Furthermore, in the present invention, potassium titanate fibers are used as component (C). Here, the potassium titanate fiber has the general formula K2O・n (TiO□) or KzO
・n (TiOz) ・1/28zO (in the formula, n is 2 to
(representing an integer of 8) is a short crystal fiber of potassium titanate. Specifically, for example, Daijin Chemical
potassium titanate fiber (trade name: Tl5M0. Average fiber diameter 0.2-0.5 μm, average fiber length 10-20 μm
, aspect ratio of 20 to 100), and can be used as is. Further, as the potassium titanate fiber, one that has been surface-treated with a silane coupling agent such as aminosilane or a titanate coupling agent such as isopropyl tristearoyl titanate can be used. By using potassium titanate fibers that have been surface-treated in this manner, the abrasion resistance and mechanical strength of the resin composition obtained may be improved compared to when untreated potassium titanate fibers are used. Here, the abrasion resistance of the resin composition refers to the property that the kneading machine, etc. and the molded product are less likely to be worn or abraded.

Here, component (C) is blended in an amount of 1 to 10 parts by weight, preferably 2 to 8 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B). If the blending ratio of component (C) is less than the above ratio, the coefficient of friction will increase, making it easy to wear and damage the kneading machine etc. during molding, and the mechanical strength of the molded product will be insufficient, and the molded product will not fit into the gear part. If used in contact areas, it may wear out. On the other hand, if the blending ratio of component (C) exceeds the above ratio, it will be mixed during molding.
This is not preferable because it tends to cause abrasion and damage to the machine, etc., and it also causes roughness in the appearance of the molded product.

Next, in the present invention, a modified polyolefin is used as component (D). As the modified polyolefin, polyolefins chemically modified with liquid rubber and/or unsaturated carboxylic acids (including anhydrides) or derivatives thereof are preferably used. Here, terminal hydroxylated polybutadiene is suitable as the liquid rubber. In producing this chemically modified polyolefin, polyolefins such as polypropylene, liquid rubber, and unsaturated carboxylic acids or derivatives thereof are mixed in a solvent such as xylene, toluene, heptane, or monochlorobenzene using a radical generator such as benzoyl peroxide. All you have to do is react. Details of the method for producing this chemically modified polyolefin are disclosed in JP-A-54-124049. By using this chemically modified polyolefin, it is possible to improve the compatibility between the polypropylene resin and zinc powder, and it is also possible to increase the impact strength of the resulting molded product.

Here, component (D) is blended in an amount of 1 to 10 parts by weight, preferably 2 to 8 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B). <D) If the blending ratio of component is less than the above ratio, the mechanical strength of the molded product will decrease. On the other hand, if the blending ratio of component (B) exceeds the above ratio, there will be a difference in weight of the molded product.

This is not preferable because the difference in density increases and the appearance of the molded product becomes rough.

Further, in the present invention, a lubricant is used as component (E). The lubricant here is liquid paraffin.

Hydrocarbon lubricants such as natural paraffin and wax; Fatty acid lubricants such as higher fatty acids and oxyfatty acids; Ester lubricants such as lower alcohol esters of fatty acids; Alcohol lubricants such as fatty alcohols and polyglycols; Calcium stearate.

Metal soaps such as barium stearate; silicones such as silicone oil and modified silicones; and the like. Among these, fatty acid-based lubricants, alcohol-based lubricants, silicones, etc. are particularly suitable.

Here, component (E) is blended in an amount of 0.1 to 10 parts by weight, preferably 0.3 to 8 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B).

If the blending ratio of component (E) is less than the above ratio, the coefficient of friction will increase, making molding difficult, and moreover, it will easily adhere to the inside of the kneader, sinter, and solidify, and the difference in weight of the molded product will increase. This is not preferable because the density difference becomes large. On the other hand, if the blending ratio of component (E) exceeds the above ratio, it is easy to cause scratches and scratches during molding, and the lubricant will separate the components (A) and (B), resulting in a kneading machine, etc. It is undesirable because it tends to adhere to the inside of the molded product, sinter and harden, and bleeds out onto the surface of the molded product.

The present invention uses the above-mentioned components (A) to (E) as raw materials, but if necessary, antistatic agent 2, coloring agent,
Various additives such as flame retardants, antioxidants, ultraviolet absorbers, plasticizers, inorganic fillers, and heat stabilizers can be added.

Here, various surfactants are used as the antistatic agent. In addition, colorants include poorly soluble azo dyes, red colorants, cadmium yellow, cream yellow, titanium white, etc. Flame retardants include inorganic antimony oxide, zirconium oxide, etc., and organic phosphate esters, trichloride, etc. Examples include cresyl phosphate. As the antioxidant, a phenol type is used, and as the ultraviolet absorber, a triazole type, salicylic acid type, or acrylonitrile type is used. Furthermore, phthalic acid diester and butanol diester are used as plasticizers.

Examples include phosphoric acid esters. Inorganic fillers include calcium carbonate, gypsum, talc, and mica.

Barium sulfate, glass fiber, wollastonite magnesium hydroxide, aluminum hydroxide, etc. are used in the present invention, and a mixture of the above-mentioned raw materials is used, and this is first mixed in a high speed mixer at a temperature of 100 to 250°C for 5 to 20 minutes. Knead for a minute. The rotation speed of the high-speed mixer at this time is usually 2.
00 to 1000r, p, m, preferably 400
~900r, p, m. Here the rotation speed is 20 O
If the rotation speed is less than 100 Or, p, m, gelation may be insufficient and kneading may not be possible, and if the rotation speed exceeds 100 Or, p, m, the temperature of the raw material may rise abnormally, causing deterioration of the raw material. be.

After the above kneading, the mixture is further kneaded with a low speed mixer at a temperature of 80 to 110°C. In this kneading step, since the kneading proceeds at a relatively low temperature, the kneaded material is gradually cooled and becomes fine lumps. Here, the rotational speed of the low-speed mixer is not particularly limited, but is usually 100 to 200 r, p, m.

The kneaded material obtained through the two-stage kneading process in this way is 1.
- Kneading and extrusion is carried out using a screw extruder, usually at 190 to 250°C. In this step, it is important not only to perform a simple extrusion operation but also to perform sufficient kneading together with extrusion.

In this way, the kneading is divided into three stages and thoroughly carried out, but because the proportion of metal components in the compound to be kneaded is high, the kneading machine or extruder used for kneading is different from that for ordinary resin compounding. may be used for plastics, but is more preferably used in the ceramic industry.

The polyamide resin composition of the present invention can be obtained by sufficiently kneading the blend of raw material components in this manner.

The polyamide resin composition of the present invention thus obtained can be molded into an appropriate shape by a molding means such as injection molding, extrusion molding, or press molding to produce various molded products. By appropriately changing the blending amount of each raw material component, the polyamide resin composition of the present invention can be used to produce molded products for various uses, such as speaker boxes, electromagnetic wave shielding materials, sound insulation housing (acoustic room) materials, and video decks. It is possible to manufacture flywheels used in record players, tape recorders, etc. In particular, the polyamide resin composition of the present invention can be blended with a relatively large amount of metal powder to obtain a product with high mechanical strength.
Suitable for manufacturing flywheels.

〔Effect of the invention〕

The polyamide resin composition of the present invention includes the above (A) to (E).
Because it is made of a combination of ingredients, there is less wear and tear on kneading machines, molding machines, etc. due to metal powder during molding, and metal powder does not adhere to kneading machines, molding machines, etc. during pellet production.
It does not sinter or solidify, and has high pellet formability and productivity. Further, according to the polyamide resin composition of the present invention, during continuous production of molded products, it is possible to obtain molded products that have uniform weight and density and have no variation in dimensional accuracy. Furthermore, the polyamide resin composition of the present invention has good moldability and can be molded into large molded products, and the resulting molded products also have high mechanical strength and slidability.

Therefore, the polyamide resin composition of the present invention can be effectively used as a material for various mechanical parts, structural materials, and the like.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Production Example' - Production of Polyolefin Polypropylene (melt index (M
I) 8g/10min, density 0.91g/d, product name: J7
00G, Idemitsu Petrochemical (manufactured by 411) 100 parts by weight of terminal hydroxylated 1,4-polybutadiene (number average molecule i3000. Trade name: Poly bd R45HT)
, ARCOChem, Div.

), 20 parts by weight of maleic anhydride, 1.72 parts by weight of dicumyl peroxide, and 600 parts by weight of xylene, heated in an oil bath using an immersion heater, and heated to 120°C with stirring. React for 1 hour, then 140"
The reaction was continued for 3 hours at C.

After the reaction was completed, the reaction mixture was placed in a discharger and extracted with acetone for 16 hours to remove unreacted polybutadiene and maleic anhydride to obtain a modified polyolefin, which is component (C) of the present invention.

Examples 1 to 26 and Comparative Examples 1 to 18 The formulations shown in Table 1 were fed to a high-speed mixer heated to 180°C and stirred and mixed for 15 minutes. The mixture was heated to a temperature of 100.degree. C., gelled, and thoroughly kneaded. After this kneading, the mixture was cooled to 110° C. using a low-speed mixer at 20° C. and stirred until it became a fine lump.

The obtained kneaded product was then extruded using a single screw extruder (a vent-type extruder with a diameter of 50 mm, manufactured by Nakatani Kikai Co., Ltd., NVC-50) at a resin temperature of 240° C. to produce a pellet of 3φ×5 mm. Table 1 shows the productivity of this pellet and the evaluation results of the molded product obtained by molding this pellet. In addition, the evaluation was performed by the following method.

Reviewer 1, flexural modulus compliant with ASTM D-638 2, wear amount Extrusion molding was performed at a resin temperature of 250°C for a total of 200 hours using a uniaxial extruder (manufactured by Nakatani Kikai, NVC-50),
The amount of wear of the nitrided steel-treated screw (Yama diameter: 50.1 Tsuruφ, grain diameter: AS, OWφ) was measured.

3. Pin gate (1
The box-shaped molded product of Ryu φ) is made using an injection molding machine (manufactured by Toshiba Machine,
15-125) and the cylinder temperature is 220-250.
℃, mold temperature 70-80℃, injection pressure 60 kg/co
! , 20 shots were continuously molded under conditions of a waiting time of 20 seconds, and the variation in density of the molded products was measured.

4. Retention In an injection molding machine (manufactured by Toshiba Machine, 1S-125), the cylinder temperature was set at 260°C, the mixture was retained, and its decomposition and solidification state were evaluated.

O... No decomposition or solidification even after residence for 1 hour or more △ ・
... Decomposition and solidification occur after 30 minutes of residence × ... Decomposition and solidification occur after 5 minutes of residence (Showing sliding properties) *1 Polyamide Examples 1 to 15. Examples 17-25 and Comparative Examples 1-1
8 is 6 nylon (manufactured by Hitomi Kagaku Kogyo.

Product name: LM-102) (represented by A in Table 1),
Examples 16 and 26 are 6.6 nylon (manufactured by Asahi Kasei ■,
Product name: 1200S) (represented by B in Table 1) *2 Metal powder Examples 1 to 16. Examples 22-25. Comparative Examples 1 to 11 and Comparative Examples 16 to 18 were zinc powder (manufactured by Sakai Chemical Co., Ltd., specific gravity 7.
12 particle size 4-5μ) (hereinafter, all zinc powders are made by Sakai Chemical and have a specific gravity of 7.1), Example 17 is zinc powder with particle size 1-3μ, and Example 18 is zinc powder with particle size 10-15μ. Examples 19 and 26 are iron powder whose surface is coated with zinc (Dowa iron powder type 9 powder diameter 5-7μ, specific gravity 7.2), and Example 20 is iron oxide powder whose surface is coated with zinc (Dowa iron powder type 9 powder, specific gravity 7.2). Powder 9 particle size 6
~10μ, specific gravity 7.1), and Example 21 was copper powder surface-coated with zinc (Dowa iron powder type 2, diameter 6~10μ, specific gravity 7.1).
4), Comparative Example 12 is iron powder (Dowa iron powder type 1 diameter 10-15
μ, specific gravity 7.8), comparative example 13 is copper powder (Dowa iron powder type 9 powder diameter 5-7μ, specific gravity 8.9), comparative example 14 is lead oxide powder (Dowa iron powder type 2 diameter 15-20μ) , specific gravity 9.4), comparative example 1
5 is zinc powder (2 manufactured by Sakai Chemical Co., Ltd., particle size 20-30μ, specific gravity 7.
1) were used.

*3 Potassium titanate fiber Manufactured by Otsuka Chemicals, average fiber diameter 0.2-0.5μ.

Average fiber length 10-20μ, aspect ratio 20-100,
Product name: TI SMO was used.

*4 Modified polyolefin The one obtained in the above production example was used.

*5 Lubricant Examples 1 to 20 and Comparative Examples 1 to 18 were stearic acid,
Example 21 is stearyl alcohol, Example 22 is silicone (Shin-Etsu Silicon Co., Ltd., KF-96), Example 23 is magnesium stearate, Examples 24 and 25 are benzenesulfone butyramide (Ohe Chemical Co., Ltd., BM-4>
were used respectively.

Monk - No. 11 Note 1: The appearance of the molded product becomes rough.

Note 2: During continuous molding, the nozzle gets clogged with metal powder, making molding impossible.

Note 3: The lubricant bleeds out on the surface of the molded product. Also, air bubbles are generated inside the molded product.

Note 4 Poor appearance of molded product (metal dispersion is insufficient) Procedural amendment cap button April 2, 1985

Claims (1)

[Claims] (1) (A) 50 to 5 parts by weight of polyamide resin, (B)
Total amount of 50 to 95 parts by weight of zinc powder and/or metal powder or metal compound powder whose surface is coated with zinc: 100
A polyamide resin containing (C) 1 to 10 parts by weight of potassium titanate fiber, (D) 1 to 10 parts by weight of modified polyolefin, and (E) 0.1 to 1.0 parts by weight of a lubricant, based on the weight part. Composition.