JP2007177146A - Phenolic resin molding compound, method for producing the same, and rubbing material using the phenolic resin molding compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phenolic molding compound which can provide a molded product that is excellent in abrasion resistance together with the mechanical strength kept in a level for practical use; a method for producing the same; and a rubbing material using the phenolic molding compound. <P>SOLUTION: The phenolic molding compound comprises (a) a phenolic resin, (b) an inorganic filler, and (c) calcium silicate, wherein at least a part of the calcium silicate (c) is coated with (d) a lubricant. The method for producing the compound comprises a process for previously mixing (c) the calcium silicate with (d) the lubricant. The rubbing material comprises the phenolic resin molding compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a phenol resin molding material, a manufacturing method thereof, and a friction material using the phenol resin molding material.

  Molded articles obtained from phenolic resin molding materials are heat-resistant and easy to process products, so they are used in many fields and the number of uses continues to increase. Among them, in the use of mechanical parts such as automobiles, the use of resin for ceramic or metal parts is being studied for the purpose of weight reduction and cost reduction. Among these, although there are many parts (for example, pulleys, pump parts, etc.) that originally need wear resistance, the reality is that they have not been put into practical use so far. For this reason, since mechanical characteristics and heat resistance, which are essential characteristics, have been emphasized, for example, glass fibers, spherical silica, crushed silica, and the like have been used as fillers. In this case, there is a problem that the mechanical strength is improved but the wear resistance is deteriorated. On the other hand, a friction material for an electromagnetic clutch in which a spherical synthetic calcium silicate fiber is contained in a thermosetting resin is disclosed (for example, see Patent Document 1).

JP 2003-74590 A

  The present invention provides a phenol resin molding material, a manufacturing method thereof, and a friction material that can obtain a molded article having excellent wear resistance while maintaining mechanical strength at a practical level.

Such a subject is achieved by the following present inventions (1) to (8).
(1) A phenol resin molding material containing a phenol resin (a), an inorganic filler (b), and calcium silicate (c), wherein the calcium silicate (c) is at least partly a lubricant (d). A phenolic resin molding material characterized by being coated.
(2) Content of the said calcium silicate (c) is a phenol resin molding material as described in (1) which is 1 to 15 weight% with respect to the whole molding material.
(3) The phenol resin molding material according to (1) or (2), wherein the calcium silicate (c) and the lubricant (d) are mixed in advance.
(4) The mixing ratio (c) :( d) of the calcium silicate (c) and the lubricant (d) is 20: 1 to 5: 1. The phenol according to any one of (1) to (3) Resin molding material.
(5) The phenol resin molding material according to any one of (1) to (4), wherein the lubricant (d) contains calcium stearate.
(6) A method for producing the phenol resin molding material according to any one of claims 1 to 5, comprising a step of previously mixing the calcium silicate (c) and the lubricant (d). A process for producing a phenolic resin molding material.
(7) The manufacturing method of the phenol resin molding material as described in (6) whose compounding ratio (c) :( d) of the said calcium silicate (c) and lubricant (d) is 20: 1-5: 1.
(8) A friction material using the phenolic resin molding material according to any one of (1) to (5).

According to the phenol resin molding material of the present invention, a molded product having excellent wear resistance can be obtained while maintaining the mechanical strength at a practical level.
Moreover, according to the manufacturing method of the phenol resin molding material of this invention, the said phenol resin molding material can be manufactured.
Furthermore, the friction material excellent in abrasion resistance can be obtained by using the said phenol resin molding material.

  Hereinafter, the phenol resin molding material of the present invention (hereinafter sometimes simply referred to as “molding material”) will be described.

  The present invention is a phenol resin molding material containing a phenol resin (a), an inorganic filler (b), and calcium silicate (c), wherein the calcium silicate (c) is at least partly a lubricant (d). It is characterized by being covered with.

First, the phenol resin (a) used for the molding material of this invention is demonstrated.
Examples of the phenol resin (a) include novolac type phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A type novolak resin, methylol type resole resin, dimethylene ether type resole resin, tung oil, linseed oil, walnut oil and the like. And resol type phenolic resins such as oil-melted resol phenolic resin melted in (1).
Among these, a novolac type phenol resin is preferable because it is easily available, inexpensive, and has good workability by roll kneading.

  In the phenol resin used in the present invention, when a novolak type phenol resin (hereinafter, sometimes simply referred to as “novolak resin”) is used, hexamethylenetetramine is usually used as a curing agent. Although hexamethylenetetramine is not particularly limited, it is preferably used in an amount of 10 to 25 parts by weight based on 100 parts by weight of the novolak resin. More preferably, it is 13-20 weight part with respect to 100 weight part of novolak resin. If the amount of hexamethylenetetramine used is too small, it will take time for curing during molding, and if it is too large, the molded product may be inflated.

An inorganic filler (b) is used for the molding material of the present invention.
Examples of the inorganic filler (b) include silicates such as talc, fired clay, unfired clay, mica, oxides such as titanium oxide, alumina, silica, and fused silica, calcium carbonate, magnesium carbonate, and hydrotalc. Carbonate of sites, hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, sulfates or sulfites such as barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate And borate salts such as calcium borate and sodium borate, nitrides such as aluminum nitride, boron nitride and silicon nitride, and glass fibers. Among these, glass fiber is preferable. When glass fiber is used, the mechanical strength of the obtained molded product can be maintained.
The content of the inorganic filler (b) is preferably 35 to 65% by weight, more preferably 40 to 60% by weight, based on the entire molding material. By making content of an inorganic filler (b) into the said range, especially workability | operativity of materialization can be ensured and the mechanical strength of the molded article obtained can be improved further.

  The calcium silicate (c) used in the molding material of the present invention is characterized in that at least a part thereof is covered with a lubricant (d). Here, at least a part means that at least a part of the surface of calcium silicate is covered with the lubricant (d). By doing so, the wear characteristics can be particularly improved. Although this mechanism is not clear, it is presumed that the wear of calcium silicate itself can be suppressed and the wear amount of the whole material can be reduced by coating the lubricant with calcium silicate.

The said calcium silicate (c) can use a fibrous thing as a shape.
The fiber diameter is preferably 0.2-2 μm. More preferably, it is 0.5-1 micrometer.
The fiber length is preferably 2 to 15 μm. More preferably, it is 3-10 micrometers. The wear characteristics can be further improved by using calcium silicate (c) having a fiber diameter and fiber length in the above ranges.

  The content of calcium silicate (c) is preferably 1 to 15% by weight with respect to the entire molding material. More preferably, it is 5 to 10% by weight. By making content of calcium silicate (d) into the said range, while being able to improve abrasion resistance, roll kneading workability | operativity and mechanical strength can be made favorable.

  Examples of the lubricant (d) used in the molding material of the present invention include metal soaps such as stearic acid, zinc stearate, calcium stearate, aluminum stearate, magnesium 12-hydroxystearate, aluminum behenate, and calcium montanate. And organic compounds such as paraffin wax. Among these, calcium stearate is preferably used because it is inexpensive and easily available, but the calcium stearate may be used alone or in combination with the other lubricants.

  The blending ratio (c) :( d) between the calcium silicate (c) and the lubricant (d) is preferably 20: 1 to 5: 1. More preferably, it is 15: 1 to 10: 1. By setting the ratio of the two in the above range, particularly when the amount of the lubricant (d) is an optimum amount, the effect of reducing the wear amount can be maintained, and a decrease in strength can be suppressed.

  The calcium silicate (c) and the lubricant (d) are preferably mixed in advance. By doing so, it is possible to improve the wear characteristics, particularly the effect of reducing the wear amount. Examples of the method for performing the mixing treatment include a mixing treatment using a ball mill, a treatment for spraying a release agent solution or the like onto an inorganic substrate, and a treatment for immersing the inorganic substrate in a release agent solution or the like. Among these, a ball mill mixing process is preferable from the viewpoint of preparation of a solution and removal of a solvent.

  As described above, the mechanism of improving the wear characteristics by mixing calcium silicate (c) and the lubricant (d) in advance is not clear, but the lubricant (d) is coated on the calcium silicate (c). Thus, it is presumed that the wear of the calcium silicate (c) itself can be suppressed, and further, the wear amount of the entire material can be reduced.

  In the molding material of the present invention, additives such as a lubricant, a curing aid, and a pigment can be added within the range not impairing the object of the present invention, in addition to the above-mentioned blended materials.

Next, a method for producing the phenol resin molding material of the present invention (hereinafter sometimes simply referred to as “manufacturing method”) will be described.
The manufacturing method of this invention is a manufacturing method which manufactures the said phenol resin molding material, Comprising: The said calcium silicate (c) and a lubricant (d) are mixed, The process is previously characterized by the above-mentioned. By doing so, an improvement in wear characteristics, in particular, an effect of reducing the wear amount can be expected.

  The above-mentioned mixing process includes, for example, a ball mill mixing process, a dry process such as a jet mill and a dynamic mill, a process of spraying a release agent solution or the like onto an inorganic apparatus, and an inorganic apparatus into a release agent solution or the like. The soaking process etc. are mentioned. Among these, from the viewpoint of maintenance and inspection of the processing apparatus, preparation of the solution and removal of the solvent, etc., a mixing process by a ball mill is preferable.

As the process of the production method of the present invention, as described above, calcium silicate (c) and lubricant (d) are premixed and treated with phenol resin (a), inorganic filler (b), colorant, and curing. Auxiliaries and the like are mixed to make a mixture.
Next, the obtained mixture can be obtained by melt-kneading using a heating roll or a biaxial kneader, etc., and pulverizing or granulating after cooling. As conditions for the heating roll, high-speed roll surface temperature: 80 to 90 ° C., low-speed roll surface temperature: 20 to 30 ° C., roll pitch: 2.0 to 3.0 mm, high-speed rotation speed: 20 rpm, low-speed rotation Number: can be carried out at 14 rpm.

  The blending ratio (c) :( d) between the calcium silicate (c) and the lubricant (d) is preferably 20: 1 to 5: 1. More preferably, it is 15: 1 to 10: 1. By setting the ratio of the two in the above range, particularly when the amount of the lubricant (d) is an optimum amount, the effect of reducing the wear amount can be maintained, and a decrease in strength can be suppressed.

  Examples of the inorganic filler (b) other than the calcium silicate include silicates such as talc, calcined clay, unfired clay, mica, oxides such as titanium oxide, alumina, silica, and fused silica, calcium carbonate, and carbonic acid. Carbonates such as magnesium and hydrotalcite, hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide, sulfates or sulfites such as barium sulfate, calcium sulfate and calcium sulfite, zinc borate and barium metaborate And borate salts such as aluminum borate, calcium borate and sodium borate, nitrides such as aluminum nitride, boron nitride and silicon nitride, and glass fiber. Among these, glass fiber is preferable. When glass fiber is used, the mechanical strength of the obtained molded product can be maintained.

  The content of the inorganic filler (b) is preferably 35 to 65% by weight, more preferably 40 to 60% by weight, based on the entire molding material. By making content of an inorganic filler into the said range, especially workability | operativity of materialization can be ensured and the mechanical strength of the molded product obtained can be improved further.

Next, the friction material of the present invention will be described.
The friction material of the present invention uses the phenol resin molding material of the present invention.
The friction material of the present invention can have characteristics excellent in wear resistance while maintaining mechanical strength at a practical level. Furthermore, in order to improve the friction characteristics of the friction material, a solid lubricant (polyethylene, tetrafluoropolyethylene, etc.) and a thermoplastic resin (semiconductor, polyamide, polyacetal, etc.) having sliding characteristics can be added.

In addition, the molding method of the molding material of the present invention is not particularly limited, and any method such as injection molding, transfer molding, and compression molding can be used. Of these, the injection molding method is particularly suitable. As an example of molding conditions for injection molding, various molded products can be molded at a temperature of 160 to 180 ° C., a pressure of 100 to 200 kg / cm ² , and a curing time of 30 seconds to 2 minutes.

  Next, this invention is demonstrated based on an Example and a comparative example.

1. Preparation of Lubricant-Coated Calcium Silicate A cylindrical ceramic container having a diameter of 30 cm and a height of 25 cm is charged with 300 g of calcium silicate and 30 g of calcium stearate, and about 2.5 kg of an iron ball having a diameter of 3 cm. By covering the container and rotating the container for 1 hour, the calcium silicate and calcium stearate contained therein were mixed to obtain calcium silicate coated with a lubricant.

2. Creation of phenolic resin molding materials
<Example 1>
Novolak type phenolic resin 35% by weight, hexamethylenetetramine 7% by weight, glass fiber 45% by weight, lubricant-coated calcium silicate 10% by weight, magnesium oxide 1% by weight as a curing aid, and carbon as a colorant. 1% by weight of black and 1% by weight of calcium stearate as a lubricant were blended to obtain a mixture. The obtained mixture was kneaded with a heating roll of 85 to 90 ° C. for 15 minutes to form a sheet, cooled, and pulverized with a pulverizer to obtain a molding material.

<Example 2>
A molding material was obtained in the same manner as in Example 1 except that the amount of the lubricant-coated calcium silicate was reduced to 3% by weight and the glass fiber was increased to 52% by weight.

<Example 3>
A molding material was obtained in the same manner as in Example 1 except that the amount of the lubricant-coated calcium silicate was increased to 13% by weight and the glass fiber was decreased to 42% by weight.

<Comparative Example 1>
Mixing 35% by weight of novolak-type phenolic resin, 7% by weight of hexamethylenetetramine, 45% by weight of glass fiber, and 10% by weight of calcium silicate uncoated with lubricant on the whole molding material, The mixture was kneaded for 15 minutes to form a sheet, and then pulverized by a pulverizer to obtain a molding material.

<Comparative Example 2>
A molding material was obtained in the same manner as in Comparative Example 1 except that the amount of calcium silicate was reduced to 3% by weight and the glass fiber was increased to 52% by weight.

<Comparative Example 3>
A molding material was obtained in the same manner as in Comparative Example 2 except that the amount of calcium silicate was increased to 13% by weight and the glass fiber was decreased to 42% by weight.
It shows in Table 1 about the mixing | blending of an Example and a comparative example.

<Comparative Example 4>
A molding material was obtained in the same manner as in Comparative Example 1 except that spherical silica was blended in place of calcium silicate.

[Notes on the table]
(1) Novolac type phenolic resin: A-1082G manufactured by Sumitomo Bakelite Co., Ltd.
(2) Hexamethylenetetramine: manufactured by Mitsubishi Gas Chemical Co., Ltd. Hexamine (3) Glass fiber: manufactured by Nippon Sheet Glass Co., Ltd. Chopped strand (average fiber diameter 11 μm, average fiber length 3 mm)
(4) Calcium silicate: Zonotolite (average fiber diameter 1 μm, average fiber length 7 μm) manufactured by Kawai Lime Industry Co., Ltd.
(5) Spherical silica: Silica FB301 (average particle size 6 μm) manufactured by Denki Kagaku Kogyo
(6) Curing aid: Magnesium oxide (7) Lubricant: Calcium stearate (8) Colorant: Carbon black The following evaluations were performed on the molding materials and molded articles obtained in Examples and Comparative Examples. The results are shown in Table 2.

(1) Mechanical properties Using the molding materials obtained in the examples and comparative examples, test pieces for measuring properties by transfer molding were prepared. The molding conditions were a mold temperature of 175 ° C. and a curing time of 3 minutes. Each characteristic was evaluated after molding. The bending strength was measured according to JIS K 6911.

(2) Wear characteristics The molding materials obtained in the examples and comparative examples were transfer-molded (mold temperature: 175 ° C., curing time: 3 minutes) to form test materials for evaluating sliding characteristics. For the sliding characteristics, the amount of wear of the test material and the amount of wear of the mating material were measured by “S-45C” as the mating material by a sliding wear test (Suzuki abrasion tester).

  As is apparent from the results in Table 2, Examples 1 to 3 are molded articles obtained from the phenolic resin of the present invention containing calcium silicate at least partially coated with a lubricant, and a comparison not including this. Compared to Examples 1 to 4, it was possible to significantly reduce the wear resistance, particularly the wear amount of the test material itself, while maintaining the mechanical strength at a practical level.

Claims (8)

A phenol resin molding material containing a phenol resin (a), an inorganic filler (b), and calcium silicate (c), wherein the calcium silicate (c) is at least partially coated with a lubricant (d). A phenolic resin molding material characterized by 2. The phenol resin molding material according to claim 1, wherein a content of the calcium silicate (c) is 1 to 15 wt% with respect to the entire molding material. The phenol resin molding material according to claim 1 or 2, wherein the calcium silicate (c) and the lubricant (d) are mixed in advance. The phenol resin molding material according to any one of claims 1 to 3, wherein a blending ratio (c) :( d) of the calcium silicate (c) and the lubricant (d) is 20: 1 to 5: 1. The phenol resin molding material according to claim 1, wherein the lubricant (d) contains calcium stearate. It is a manufacturing method which manufactures the phenol resin molding material in any one of Claims 1-5, Comprising: The phenol characterized by including the process of previously mixing the said calcium silicate (c) and a lubricant (d). Manufacturing method of resin molding material. The method for producing a phenol resin molding material according to claim 6, wherein a blending ratio (c) :( d) of the calcium silicate (c) and the lubricant (d) is 20: 1 to 5: 1. A friction material using the phenolic resin molding material according to claim 1.