JP2011043226A - Retainer and roller bearing equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive retainer made of a synthetic resin having a moderate heat resistance and an excellent resistance to gas and chemicals such as oxygen causing deterioration. <P>SOLUTION: After the retainer 4 is injected and molded using 66 nylon reinforced with glass fiber, the retainer 4 is obtained by forming a specified epoxy resin cured coating film onto the surface of obtained molding. The epoxy resin cured coating film is formed by using a two-component epoxy resin comprising an epoxy resin having a glycidylamine moiety derived from metaxylylenediamine, and an amine-based curing agent comprising a reaction product of metaxylylenediamine or paraxylylenediamine and acrylic acid, methacrylate, a derivative of acrylic acid or a derivative of methacrylic acid. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rolling bearing characterized by a cage.

Conventionally, as a synthetic resin cage for a rolling bearing, one made of polyamide resin (66 nylon, 46 nylon) reinforced with glass fiber or carbon fiber, polyphenylene sulfide resin, or polyether ether ketone resin has been used. It is properly used according to temperature and usage environment.
Of these, polyphenylene sulfide resins and polyether ether ketone resins are excellent in heat resistance and chemical resistance, but are expensive. In contrast, 66 nylon cages reinforced with glass fibers are most often used because of a good balance of heat resistance, strength and cost. However, 66 nylon is easily deteriorated by chemicals, oxygen gas, and the like due to amide bonds contained in the molecular structure.

Therefore, even in an environment where there is no problem with a 66 nylon cage in terms of heat resistance, if there is a problem in terms of chemical resistance, it is made of expensive polyphenylene sulfide resin or polyether ether ketone resin. The cage needs to be used, which increases the cost.
In addition, Patent Documents 1 and 2 listed below are resin compositions containing an epoxy resin and an amine curing agent, and describe a resin composition having high gas barrier properties in addition to the excellent performance of the epoxy resin. Yes. Examples of the use include paints for anticorrosion and cosmetics, and packaging materials such as foods and pharmaceuticals that require high gas barrier properties.

In this resin composition, an epoxy resin and an amine curing agent are used as paint forming components, and the amine curing agent is a reaction product of the following (A) and (B), or (A), (B) and (C) The epoxy resin is characterized by having a glycidylamine moiety derived from metaxylylenediamine.
(A) Metaxylylenediamine or paraxylylenediamine. (B) A polyfunctional compound having at least one acyl group capable of forming an amide group site by reaction with a polyamine and forming an oligomer. (C) A monovalent carboxylic acid having 1 to 8 carbon atoms and / or a derivative thereof.

  Patent Document 2 further describes a gas barrier resin composition containing a layered silicate in the resin composition.

JP 2002-256208 A JP 2004-26880 A

  An object of the present invention is to provide a synthetic resin cage that is inexpensive but has appropriate heat resistance and excellent resistance to gases such as oxygen and chemicals that cause deterioration.

In order to solve the above-mentioned problems, the present invention is a cage for a rolling bearing, comprising a polyamide resin reinforced with glass fiber or carbon fiber, and having a cured epoxy resin film having gas barrier properties on the surface. Features.
The epoxy resin coating can be obtained by curing the resin composition described in Patent Documents 1 and 2. The epoxy resin coating is preferably obtained by curing an epoxy resin satisfying the following (1) with an amine curing agent satisfying the following (2).
(1) An epoxy resin having a glycidylamine moiety derived from metaxylylenediamine.
(2) An amine curing agent comprising a reaction product of metaxylylenediamine or paraxylylenediamine and acrylic acid, methacrylic acid, a derivative of acrylic acid, or a derivative of methacrylic acid.

The amine curing agent (2) is an amine curing agent constituting the resin compositions of Patent Documents 1 and 2, and corresponds to the reaction product of (A) and (B).
Since the amide groups produced by the reaction of (A) and (B) have a high cohesive force and the amide groups are present in a high proportion in the amine-based curing agent (2), the epoxy resin The cured film has a high gas barrier property and a high adhesion strength to a polyamide resin having a similar molecular structure.

Therefore, this cage is made of a polyamide resin reinforced with glass fiber or carbon fiber. Therefore, the cage has an appropriate heat resistance while being inexpensive, and has the cured epoxy resin film, thereby providing gas barrier properties and chemical resistance. Therefore, it has excellent resistance to gases such as oxygen and chemicals.
Examples of the polyamide resin forming the cage include 66 nylon, 46 nylon, modified polyamide 6T, and polyamide 9T.

  According to the present invention, it is possible to obtain a synthetic resin cage that is inexpensive but has appropriate heat resistance and excellent resistance to gases such as oxygen and chemicals that cause deterioration.

It is sectional drawing which shows the rolling bearing corresponded to one Embodiment of this invention. It is a perspective view which shows the holder | retainer of the rolling bearing of FIG.

Embodiments of the present invention will be described below.
As shown in FIG. 1, the rolling bearing of this embodiment is a deep groove ball bearing including an inner ring 1, an outer ring 2, a ball (rolling element) 3, a cage 4, and a seal 5. As shown in FIG. 2, the cage 4 is a crown-shaped cage in which a pocket 41 is formed at one axial end of the annular ring.
As the cage 4, a cage for a deep groove ball bearing having a nominal number 6203 is injection-molded using 66 nylon and 46 nylon (polyamide resin) reinforced with glass fiber, respectively, and then the surface of the obtained molded body It was obtained by forming an epoxy resin cured film on the surface.

  As 66 nylon reinforced with glass fiber, “Ultramid A3HG5” (glass fiber content 25 mass%, amine-based antioxidant added grade) manufactured by BASF was used. As 46 nylon reinforced with glass fiber, “Danyl (registered trademark) TW241F6” (glass fiber content 30 mass%, copper-based heat stabilizer added grade) manufactured by Royal DSM was used.

The cured epoxy resin film was formed by the following method using a two-pack type epoxy resin “MAXIVE” manufactured by Mitsubishi Gas Chemical Co., Ltd. and a solvent. “MAXIVE” is composed of a main agent “M-100” and a curing agent “C-93”. The main agent “M-100” is an epoxy resin that satisfies the above (1), and the curing agent “C-93” is an amine-based curing agent that satisfies the above (2).
As a solvent, what mixed so that it might become methoxypropanol: methanol: ethyl acetate = 20: 2: 3 by mass ratio was prepared.

A mixture of these in a mass ratio of “M-100”: “C-93”: solvent = 5: 16: 25 was applied to the surface of the cage by an air spray method and air-dried (as it was 30 The film was completely cured by heat treatment at 80 ° C. for 30 minutes.
As a comparative example, a cage prepared by the same method and not forming a film was also prepared. A test for examining the performance of the cage in a high-temperature air environment was conducted using the cage obtained with the cured epoxy resin coating and the cage without any coating.

  Specifically, with respect to each cage, before and after the start of the test, the tensile strength of the annular portion (portion “42” in FIG. 2) of the cage 4 (a pair of jigs are placed in the annular portion, and The force required until the annular portion was broken by pulling to the opposite side was measured, and the relative value of the strength after the test was calculated when the strength before the test was taken as 100. In the case of a 66 nylon cage reinforced with glass fibers, the test conditions were 2000 hours at 150 ° C., and in the case of a 46 nylon cage reinforced with glass fibers, 1000 hours at 180 ° C. .

  As a result, in the 66 nylon cage reinforced with glass fiber, the strength (relative value) when the epoxy resin cured coating was provided was 95, and the strength (relative value) without the coating was 73. It was. In the 46 nylon cage reinforced with glass fiber, the strength (relative value) when the epoxy resin cured coating was provided was 90, and the strength (relative value) without the coating was 68.

  As is apparent from the results, the cage is made of 66 nylon reinforced with glass fiber having a coating formed by curing a specific two-component epoxy resin, and the coating has the coating, It can be seen that the cage made of 46 nylon reinforced with glass fiber is inexpensive but has moderate heat resistance and excellent air deterioration resistance at high temperatures.

1 Inner ring 2 Outer ring 3 Ball (rolling element)
4 Cage 41 Pocket 42 Ring part 5 Seal

Claims (3)

A rolling bearing cage,
A cage made of a polyamide resin reinforced with glass fibers or carbon fibers, and having a cured epoxy resin film having gas barrier properties on the surface. 2. The cage according to claim 1, wherein the epoxy resin film is obtained by curing an epoxy resin satisfying the following (1) with an amine-based curing agent satisfying the following (2).
(1) An epoxy resin having a glycidylamine moiety derived from metaxylylenediamine.
(2) An amine curing agent comprising a reaction product of metaxylylenediamine or paraxylylenediamine and acrylic acid, methacrylic acid, a derivative of acrylic acid, or a derivative of methacrylic acid.   A rolling bearing having the cage according to claim 1.

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