JPH10306220A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition useful as a molding material of a sliding material used in water at a low cost, by including a thermoplastic resin having melting point or softening point not higher than a specific temperature and a powdery phenol resin cured material having an average particle diameter not larger than a specific value. SOLUTION: This composition is obtained by mixing (A) 50-97 wt.% thermoplastic resin having <= about 330 deg.C melting point or softening point (e.g. polyacetal, polybutylene terephthalate, polyethylene terephthalate, polyamide, polycarbonate, polyphenylene sulfide) with (B) 50-3 wt.%, preferably 30-10 wt.% powdery phenol resin cured material having <= about 500 μm, preferably <=about 100 μm average particle diameter (which may be used after previously packing an inorganic or organic fibrous or powder filler), kneading the mixture by using a twin-screw extruder, etc., pelletizing the kneaded material and molding the pellets.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin composition. More specifically, the present invention relates to a resin composition suitably used as an underwater sliding material molding material and the like.

[0002]

2. Description of the Related Art Conventionally, as a sliding material used under water for a bearing or the like, a material filled with carbon fiber has been particularly used because of its excellent characteristics. There is a problem.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin composition which can be suitably used as a molding material for a sliding material used under water and which can realize a low cost. It is in.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
Thermoplastic resin having a melting point or softening point of about 330 ° C. or less
This is achieved by a resin composition consisting of 50 to 3% by weight of a cured phenolic resin powder having an average particle size of about 500 μm or less.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin which is a main component of the resin composition has a melting point or a softening point of about 330 ° C. or less, such as polyacetal, polybutylene terephthalate, polyethylene terephthalate, polyamide, polycarbonate, polyphenylene sulfide and the like. Is used. When these thermoplastic resins are kneaded with a phenol resin cured product and a twin-screw extruder or the like to form pellets obtained by kneading, the thermoplastic resin is decomposed at around 330 ° C., which is the decomposition temperature of the phenol resin cured product. A material having such a melting point or softening point is selected from the viewpoint of melting or softening at a low temperature and suppressing thermal decomposition of the cured phenol resin.

On the other hand, the phenolic resin cured product is a cured phenolic resin regardless of the type of novolak type or resol type. When it is added to a thermoplastic resin, injection molding, compression molding, transfer molding and the like are performed. Powders having an average particle size of less than about 500 μm, preferably less than about 100 μm are used. On the other hand, when a material having an average particle size larger than this is used, the strength of a molded product obtained therefrom is significantly reduced. These powdered phenol resin cured products can be used after being subjected to a surface treatment with aminosilane or the like in advance.

The powdered phenolic resin cured product is contained in an amount of 50 to 3% by weight, preferably 30 to 10% by weight based on the total amount of the resin and the thermoplastic resin.
Used in percentages by weight. If it is used at a higher ratio, the kneading properties and moldability are impaired, while at lower ratios, good underwater sliding characteristics cannot be obtained.

[0008] The powdered phenolic resin cured product may be filled with an inorganic or organic fibrous or powdered filler such as glass fiber, carbon fiber, polytetrafluoroethylene powder or the like before use. . The filling ratio is about 5 to 80% by weight of the whole powder, preferably about 40 to 80% by weight.
60% by weight, and such a filler-containing phenol resin cured product is used in such a proportion that it accounts for 50 to 3% by weight in the composition.

When the filler-containing cured phenolic resin is not used, the composition comprising the thermoplastic resin and the powdered cured phenolic resin may further contain an inorganic or organic fibrous or powdery material as described above. Fillers can also be added. The addition ratio is about 5 to 80% by weight, preferably about 40 to 60% by weight, based on the total amount of the powdery phenol resin cured product.

The preparation of the composition is carried out by mixing the components at a predetermined mixing ratio, kneading the mixed raw materials using a twin-screw extruder or the like, and pelletizing. The molding is performed by injection molding, compression molding, transfer molding or the like of the pellet.

[0011]

The resin composition according to the present invention exhibits excellent underwater sliding characteristics equivalent to carbon fiber-filled materials, but its cost is extremely low.

[0012]

Next, the present invention will be described by way of examples.

EXAMPLE A cured powdery phenolic resin sieved to have an average particle diameter of 20 μm (glass fiber filling comprising 40% by weight of novolak type phenolic resin and 60% by weight of glass fiber having a fiber diameter of 13 μm and a fiber length of 3 mm) 18 parts by weight of crushed sprue powder generated during injection molding of phenolic resin) and polyacetal (polyplastics product DURACON M90-44)
82 parts by weight were mixed with a blender, and the mixed raw materials were kneaded with a twin-screw extruder, and the resulting pellets were injection-molded to form test pieces having a predetermined shape.

An underwater sliding property test was performed on the obtained test piece under the following conditions in accordance with the JIS K-7218A method, and the friction coefficient, the wear coefficient, and the temperature near the sliding portion were measured. (Test conditions) Environment: room temperature, under water Load: 0.5 MPa Circumferential speed: 0.2 m / sec Time: 24 hours Counterpart material: S45C (1.5 s) Testing machine: Suzuki friction and wear testing machine

Comparative Example 1 In the examples, only the polyacetal was used, and the cured phenolic resin filled with glass fiber was not used.

Comparative Example 2 Using a polyacetal (polyplastic product Duracon GC-25) filled with 25% by weight of glass fiber, the same molding and measurement as in the example were performed.

Comparative Example 3 Using a polyacetal (polyplastic product Duracon CE-20) filled with 20% by weight of carbon fibers, the same molding and measurement as in the example were performed.

The measurement results in the above Examples and Comparative Examples are shown in the following table. The table also shows comparison data of material costs when the value of the example is set to 1. Example ratio -1 ratio -2 ratio-3 [underwater sliding characteristics] Friction coefficient (-) 0.10 0.15 0.10 0.02 Wear coefficient (× 10 ⁵ cm · s / MPa · m · hr) 25 740 70 18 Near sliding part Temperature (℃) 23 23 27 24 [Comparison of material costs] 1 0.9 1.2 8.9

Claims (3)

[Claims] 1. A resin composition comprising 50 to 97% by weight of a thermoplastic resin having a melting point or a softening point of about 330 ° C. or less and 50 to 3% by weight of a cured powdery phenol resin having an average particle diameter of about 500 μm or less. 2. The resin composition according to claim 1, wherein the powdery cured phenolic resin is a fibrous or powdery filler-containing material. 3. The resin composition according to claim 1, which is used as an underwater sliding material molding material.