JP3259471B2 - Parts for hydraulic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic component made of a polyamide resin composition.

[0002]

2. Description of the Related Art Conventionally, various hydraulic devices have been used for stress transmission devices such as clutches and brakes of automobiles and hydraulic pumps, and components for applying the oil have been made of various metal materials. However, there has been a point to be improved in that parts made of a metal material have a large specific gravity and are not easily formed. As an improvement measure, in recent years, the use of plastics has been replaced by metal instead of plastics in view of energy saving by weight reduction and cost reduction by simplification of moldability, especially in automobile parts and the like. However, in the oil-resistant device parts, it has been difficult to replace metal with plastic material because of the reliability of parts such as oil resistance, heat resistance, fatigue resistance, and wear resistance.

[0003]

[Problems to be solved by the invention] In view of such circumstances,
An object of the present invention is to provide a hydraulic device component made of a plastic material and having excellent oil resistance, heat resistance, and fatigue resistance.

[0004]

Means for Solving the Problems The present inventors have made intensive studies for such purpose, and as a result, have found that a specific resin composition can solve the above-mentioned problems, and have reached the present invention. That is, the present invention provides a polyamide resin composition comprising (A) 90 to 60% by weight of polytetramethylene adipamide and (B) 10 to 40% by weight of carbon fiber, and (A) 90 to 60% by weight of polytetramethylene adipamide. %, (B) 10 to 40% by weight of carbon fiber and (C) 0 to 15% by weight of high density polyethylene and / or fluorocarbon polymer.

The polytetramethylene adipamide (nylon 46 resin) used in the present invention has polytetramethylene adipamide obtained from tetramethylene diamine and adipic acid and a polytetramethylene adipamide unit as main components. Including copolymerized polyamide. Further, another polyamide may be contained as a mixed component as long as the properties of nylon 46 are not impaired. The copolymerization component is not particularly limited, and a known amide-forming component can be used. As representative examples of the copolymerization component, 6-aminocaproic acid, 11
Amino acids such as -aminoundecanoic acid, 12-aminoundecanoic acid, and paraaminomethylbenzoic acid; lactams such as ε-caprolactam and ω-lauryl lactam; hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylenediamine, paraxylenediamine,
1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (3-methyl-4-aminocyclohexyl) ) Methane, 2,2
Diamines such as -bis (aminoprosyl) piperazine and aminoethylpiperazine and adipic acid, suberic acid, azelaic acid, sebacic acid, dodecane diacid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5 -Methylisophthalic acid, 5-Natri
Um sulfoisophthalic acid, hexahydroterephthalic acid,
Examples thereof include dicarboxylic acids such as hexahydroisophthalic acid and diglycolic acid, and other polyamides used as mixed components include those composed of these components. The method for producing nylon 46 used in the present invention is optional. For example, JP-A-56-1
49430, JP-A-56-149431,
JP-A-58-83029 and JP-A-61-43
No. 631, for example, a method in which a prepolymer having a small number of cyclic end groups is first produced under specific conditions, and then this is subjected to solid phase polymerization in a steam atmosphere to prepare a high viscosity nylon 46. There is a method of obtaining it by heating in a polar organic solvent such as -pyrrolidone or N-methylpyrrolidone. The degree of polymerization of nylon 46 is not particularly limited, but nylon 46 having a relative viscosity at 25 g and 96% sulfuric acid at 1 g / dl within the range of 2 to 6.
Resins are preferably used.

The (B) carbon fiber used in the present invention is, for example, a polyacrylonitrile filament, a rayon filament or a carbon fiber obtained by firing petroleum pitch, and particularly preferably a polyacrylonitrile filament. These carbon fibers are preferably surface-treated by ozone or electrolytic oxidation, and then treated with a sizing agent such as an epoxy resin or a polyamide resin. The fiber diameter is preferably in the range of 0.1 to 30μ, more preferably 1 to 20μ, and the fiber length is 0.1 to 20m
m, preferably 0.5 to 10 mm. The average fiber length of the carbon fibers in the molded product is preferably 50 to 300 μm, more preferably 100 to 1000 μm, and the aspect ratio is 10 μm.
~ 100 are preferred. The amount of the carbon fiber in the composition of the present invention is 10 to 40% by weight, preferably 15 to 30% by weight. When the amount exceeds 40% by weight, pelletization by a twin-screw extruder is difficult. If the addition amount is less than 10% by weight, the mechanical strength of the resin composition is not sufficient.

[0007] High density polyethylene (hereinafter abbreviated as HDPE) is not particularly limited.
The density is 0.93 g / cm obtained by a low pressure method (under normal pressure and at 100 ° C. or less)
^Three or more are usually used.

The above-mentioned HDPE can be used in the form of powder or pellets, and has a molecular weight of 50.
000 or more are preferred. When the molecular weight is 50,000 or more, it is possible to prevent the composition from being deformed by shearing stress during the mixing process in an extruder or during injection molding to form a thin layer or a film, and to prevent peeling of HDPE on the surface of the molded product. Can be. The above-mentioned HDPE may not be added to the composition of the present invention, but the addition of 15% by weight or less of the blending amount is preferable since the sliding characteristics can be improved. If it exceeds 15% by weight, the mechanical strength is significantly reduced.
Examples of the (C) fluorocarbon polymer used in the present invention include polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, polytrichlorofluoroethylene, and tetrerafluoroethylene-perfluoroalkylvinyl ether copolymer. Among them, polytetrafluoroethylene (hereinafter abbreviated as PTFE) is particularly preferred. Among PTFE, those having an average particle diameter of 30 μm or less are preferable, and more preferably 20 μm or less. The fluorocarbon polymer may not be added to the composition of the present invention, but it is preferable to add the fluorocarbon polymer at a blending amount of 15% by weight or less, since the effects of improving the self-wear amount and the dynamic friction coefficient can be obtained. If the addition amount of the fluorocarbon polymer exceeds 15% by weight, the decrease in mechanical strength is not preferred. The preferred range of the component (C) is 1
When used in this range, an excellent effect of adding the component (C) can be obtained. The polyamide resin composition of the present invention may have other components such as pigments, dyes, fibrous additives such as aromatic polyamide fibers other than carbon fibers, fillers, and heat stabilizers as long as the moldability and physical properties are not impaired. ,
Antioxidants, ultraviolet absorbers, lubricants, crystal nucleating agents, mold release agents,
Plasticizers, flame retardants, antistatic agents, and other polymers can be added.

In the present invention, the method of blending the components (A) to (C) is not particularly limited, and a usual known method can be employed. That is, after uniformly mixing the components (A) to (C) of the composition of the present invention in the form of pellets, powders, and pieces using a high-speed stirrer or the like, uniaxial or multiaxial with sufficient kneading ability. And the method of melt-kneading using an internal mixer such as a Banbury mixer. The hydraulic device part of the present invention can be molded by a known molding method, for example, a molding method used for a normal thermoplastic resin such as injection molding, extrusion molding, blow molding, vacuum molding, compression molding and the like. . The hydraulic device parts of the present invention
Components such as hydraulic cylinders, hydraulic pistons, and hydraulic pumps, such as clutches, brakes, anti-skids, power-shift cylinders and piston parts for automobiles and machine tools, building materials such as doors, doors, and shutters, jacks, and presses Shows a hydraulic pressurizing device such as a machine.

Examples and Comparative Examples Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The following raw materials were used for the materials in the examples and comparative examples. Nylon 46 : DSM, Netherlands, Stanyl K
S300 (relative viscosity 3.5, 96% sulfuric acid, concentration 1 g / d
l) Carbon fiber: Vesfight HT, manufactured by Toho Rayon Co., Ltd.
A-C6-NRS (PAN-based carbon fiber, fiber diameter 7 μ, fiber length 6 mm) fluorocarbon polymer : PTFE, manufactured by Asahi Glass Co., Ltd., Fluon L-169J (polytetrafluoroethylene powder, average particle diameter 5 μ), high-density polyethylene : Hi, manufactured by Mitsui Petrochemical Industries, Ltd.
-Zex3300FP (average molecular weight 55000, average particle size 30μ)

In the performance measurement of the embodiment and the comparative example, a performance test was performed by preparing a resin piston part shown in FIG. 1 and a test was performed by inserting the piston into an iron cylinder shown in FIG. .

[0012] Piston Compression set test piston end surfaces at room temperature over 100 Kg / cm ² over 100 times the compressive force of the pressure 500 Kg f at the piston into the cylinder containing the strain amount measured repeatedly withstand voltage test brake oil added at room temperature, at room temperature over 200 Kg / cm ² -10
0 times, 120 ° C. over 100 Kg / cm ² over 100 times, was tested by the leakage of 120 ° C. over 200 Kg / cm ² over 100 times the piston of the fracture state and the brake oil after the test, the profile change of the piston after the test Was measured. Endurance test 200,000 strokes at room temperature -50kg / cm ² -1000 strokes / hour with a piston in cylinder containing brake oil, 120
200,000 times at -50Kg / cm ² -2000 times / hour, -4
Piston breaking and cylinder scratching at 20,000 times at 0 ℃ -50kg / cm ² -300 times / hour

[0013]

FIG.

[0014]

FIG. 2

Examples 1 to 5 and Comparative Examples 1 to 5 According to the composition shown in Table 1, each component was mixed using a Henschel mixer and then melt-kneaded at a temperature of about 300 ° C. using a twin-screw extruder. A pellet composition was obtained. The obtained pellets were dried with a dehumidifying dryer at 80 ° C. for 24 hours, and after confirming that the moisture content in the pellets was 0.05% or less,
Cylinder temperature 320 ° C, mold temperature 80 by injection molding
A test piece having a diameter of 18 mm and a length of 50 mm was formed at a temperature of ° C., cut into dimensions shown in FIG. 1 and used for measurement. The results are shown in Tables 1 and 2.

[0016]

[Table 1]

[0017]

[Table 2]

All of the products shown in Examples 1 to 5
Excellent compressive strength, dimensional stability at high temperature and repeated fatigue strength. Regarding the scratching property of the mating material, products using the high-density polyethylene and the PTFE-added composition are small. In Comparative Examples 1 and 2, since the amount of the carbon fiber of the present invention was not added or was small, the compressive strength and the repeated fatigue strength were not sufficient. Comparative Examples 3 and 4 are high density polyethylene, P
Due to the large amount of TFE added, the compressive strength was insufficient and the amount of strain in the compression test increased. In Comparative Example 5, pellets could not be formed in a twin-screw extruder because of the large amount of carbon fiber added, and physical properties could not be measured. .

[0019]

As specifically shown in the examples, the present invention relates to (A) 90 to 60% by weight of nylon 46 resin, and (B)
(C) high-density polyethylene and / or fluorocarbon polymer 1 if necessary in 10 to 40% by weight of carbon fiber
A hydraulic device part comprising a polyamide resin composition comprising up to 15% by weight, more specifically a hydraulic cylinder,
Parts such as hydraulic pistons, hydraulic pumps, etc.For example, clutches, brakes, anti-skids, power shift cylinders, piston parts, building materials such as doors, doors, shutters, jacks, press machines, etc. Compression characteristics, oil resistance,
Parts with excellent heat resistance, fatigue resistance and wear resistance can be obtained.

[Brief description of the drawings]

FIG. 1 shows a resin piston part produced in an example.

FIG. 2 shows an iron cylinder used in Examples.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // (C08L 77/06 (C08L 77/06 27:12) 27:12) (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 77/06 F16J 1/00-1/24 F16J 7/00-10/04

Claims (2)

(57) [Claims] (A) Polytetramethylene adipamide 90
A hydraulic device part comprising a polyamide resin composition comprising 60 to 60% by weight and (B) 10 to 40% by weight of carbon fiber. (A) Polytetramethylene adipamide 90
A hydraulic device part comprising a polyamide resin composition comprising from 60% by weight to 60% by weight, (B) 10 to 40% by weight of carbon fiber, and (C) 1 to 15% by weight of high-density polyethylene and / or fluorocarbon polymer.