JP5213302B2 - Phenolic resin molding material - Google Patents

Description

  The present invention relates to a phenol resin molding material suitable for various sliding parts having excellent sliding characteristics, heat resistance, dimensional stability, and mechanical strength. More specifically, the present invention relates to a phenol resin used for automobile engine parts and the like. It relates to molding materials.

  Phenolic resin molding materials are excellent in heat resistance, dimensional stability, and mechanical strength, and are therefore used as materials for substitute parts for metal parts in the sliding field related to automobiles. In recent years, sliding parts such as automobile engine parts have been required to have required characteristics under high loads, high rotational speeds, and high temperature conditions as performance is improved. In particular, there have been cases where conventional phenolic resin molding materials are difficult to withstand the use environment, such as a problem caused by a decrease in sliding characteristics due to frictional heat during sliding and heat storage from the use environment. As means for improving these, improvement in compatibility between the sliding characteristics and the mechanical strength has been performed by using a high filling property of the lubricity-imparting material and inorganic reinforcing fibers in combination.

  Conventionally, the high filling of powder base materials such as graphite, which is a lubricity imparting material, has the disadvantage that mechanical strength is inferior although there is an effect of improving slidability and thermal conductivity, and its use is limited. there were. In addition, when the mechanical strength is improved by increasing the glass fiber filling, the wear characteristics decrease in proportion to the addition ratio, and the phenolic resin molding material is a resinated part of metal substitutes especially in the automotive field. In many cases, when the highly filled glass fiber is used, there is a problem that not only the molded product but also the metal or aluminum as a counterpart material is greatly worn. In addition, when reinforcing with organic fibers such as aramid fibers and xylon fibers or expensive carbon fibers, the improvement in mechanical strength and sliding properties can be seen, but the cost performance requirement cannot be realized.

On the other hand, it has been conventionally known that when natural organic fibers such as pulp and crushed cloth are blended, the wear characteristics are improved. On the other hand, the heat resistance, strength, etc., which are the characteristics of phenolic resin molding material with glass fiber added, are reduced. Was inevitable. Thus, it has been found that the wear characteristics can be improved without impairing heat resistance and strength by blending glass fiber, organic natural fiber, and silica powder as a filler (see Patent Document 1). It was desired.
JP-A-60-124646

  An object of the present invention is to solve the above-described problems of the prior art and to provide a phenolic resin molding material having excellent sliding characteristics without impairing heat resistance, dimensional stability, and mechanical strength. And

  As a result of intensive studies to overcome the above-mentioned problems, the present inventors have formulated a desired phenol resin molding material by blending inorganic resin fibers, a lubricity-imparting agent, and a metal hydrate in a specific ratio with the phenol resin. Has been found, and the present invention has been completed.

  That is, this invention mix | blends inorganic reinforcing fiber 50-90 mass parts, 10-50 mass parts of lubricity imparting materials, and 30-80 mass parts of metal hydrate as an essential component with respect to 100 mass parts of phenol resins. It is characterized by.

  The inorganic reinforcing fiber of the present invention includes at least one selected from glass fiber, carbon fiber, fibrous calcium silicate, fibrous magnesium sulfate, glass wool, rock wool, slag wool, sepiolite fiber and wollastonite fiber. And

  Further, the lubricity imparting material contains at least one selected from graphite, fluororesin powder and molybdenum disulfide.

  In the present invention, the metal hydrate has a Mohs hardness of 4 or less and a crystal water content of 5% to 40%.

  Furthermore, the phenolic resin molding material of the present invention is used for molding a sliding member, and is characterized in that it is particularly used as a material for molding a thrust washer.

  The phenolic resin molding material of the present invention maintains heat resistance, dimensional stability, and mechanical strength. In particular, the frictional heat during sliding is suppressed by the endothermic reaction of metal hydrate, and further combined with a lubricant imparting material. In addition, the frictional heat was improved by the effect of reducing local frictional heat by the synergistic effect of thermal conductivity. Therefore, since the molded part obtained from this molding material has excellent sliding characteristics, it is suitably used for resinization into a torque converter part for automobiles, which is expected to generate frictional heat in the high-performance sliding field. .

  In the present invention, the novolac type phenol resin or the resol type phenol resin may be used as the phenol resin.

  Examples of inorganic reinforcing fibers used in the present invention include glass fibers, carbon fibers, mineral fibers, silicon carbide fibers, potassium titanate fibers, and the like, and glass fibers, carbon fibers, and mineral fibers are particularly preferable. Is most preferred. These inorganic reinforcing fibers can be used alone or in combination of two or more. Examples of the mineral fibers include artificial mineral fibers obtained by melting glass, rocks and the like and processing them into fibers, such as glass wool, rock wool, slag wool, and glass fibers. Natural mineral fibers that are naturally occurring fibrous minerals can also be used, and specific examples include sepiolite and wollastonite. Particularly preferred are fibrous calcium silicate and fibrous magnesium sulfate.

  In addition, the inorganic reinforcing fiber is subjected to a coupling treatment to prevent falling off during sliding. In the present invention, the coupling treatment means that a coupling agent is uniformly mixed in advance with inorganic fibers before use. By performing this coupling treatment, it is possible to improve the wear resistance and mechanical strength by improving the adhesion between the inorganic reinforcing fiber and the resin. Although the coupling agent used for a process is not specifically limited, A silane system, a titanate system, etc. are mentioned, A silane coupling agent is more preferable at the point of adhesiveness with a phenol resin.

  Furthermore, since the effect of adhesiveness with the inorganic reinforcing fiber can be expected for the resin, it is preferable to subject the phenol resin to a surface treatment with a coupling agent.

  Moreover, the compounding quantity of an inorganic reinforcement fiber is 50-90 mass parts, Preferably it is 60-80 mass parts. In order to prevent deterioration in mechanical strength and dimensional accuracy, it is desirable that the amount be 50 parts by mass or more, and in order not to increase the influence on the aggression against the counterpart material during sliding, it is 90 parts by mass or less. desirable.

  The glass fiber and carbon fiber used as the inorganic reinforcing fiber in the present invention are not particularly limited, but those having an average fiber diameter of 6 to 13 μm are preferable, and the average fiber length is preferably 1 to 3 mm. By using the glass fiber and the carbon fiber in this range, the compound workability at the time of forming a molding material can be improved, and the mechanical strength of the obtained molded body can be improved.

  The average fiber diameter of the mineral fiber used as the inorganic reinforcing fiber in the present invention is preferably in the range of 1 to 15 μm, more preferably 1 to 10 μm. The average fiber length is preferably in the range of 50 to 300 μm, more preferably 100 to 250 μm.

  The lubricity-imparting material used in the present invention is graphite, fluororesin powder, and molybdenum disulfide. These can be used alone or in combination of two or more, and a combination of graphite and fluororesin powder is particularly suitable.

  As the graphite used in the present invention, either natural graphite or artificial graphite can be used. Natural graphite is classified into flake graphite closest to the crystallinity of true graphite, then flake graphite with the highest degree of crystallinity, and soil-like graphite due to the difference in crystallinity. Any graphite can be used. The average particle diameter of the graphite particles is preferably in the range of 1 to 150 μm, more preferably 5 to 50 μm.

  The fluororesin powder used in the present invention preferably has an average particle size of 1 to 50 μm and a maximum particle size of 100 μm, more preferably an average particle size of 1 to 20 μm and a maximum particle size of 50 μm or less.

  The molybdenum disulfide used in the present invention preferably has an average particle size of 1 to 10 μm, and more preferably an average particle size of 0.1 to 3 μm.

  The blending amount of the lubricity imparting material is 10 to 50 parts by mass, preferably 15 to 45 parts by mass. In order to sufficiently obtain the effect of improving the sliding characteristics, the content is desirably 10 parts by mass or more, and in order to prevent a decrease in mechanical strength, it is desirably 50 parts by mass or less.

  Further, since a further effect can be expected when the coupling treatment is performed for the lubricity imparting material to improve the adhesion with the resin, it is preferable to perform a surface treatment by coupling. As a coupling agent, what was used for the coupling process of the inorganic reinforcement fiber can be used similarly.

  The metal hydrate used in the present invention has a Mohs hardness of 4 or less and a crystal water of 5% or more and 40% or less. Aluminum hydroxide, magnesium hydroxide, dosonite, potassium aluminate, calcium hydroxide, There are zinc borate, kaolin clay, and calcium carbonate, and aluminum hydroxide and magnesium hydroxide are particularly preferable. Moreover, these can be used individually or in combination of 2 or more types.

  The metal hydrate used in the present invention preferably has a Mohs hardness of 4 or less. If the Mohs hardness is higher than this, the burden on production equipment such as a mold or a molding machine is large, and the life of the metal hydrate is shortened. May occur. The Mohs hardness is expressed by an integer value and may be 4 or less, but is preferably larger than 1 in order not to cause self-abrasion. The crystal water is preferably 5% or more and 40% or less, preferably 5% or more for improving the heat dissipation of frictional heat, and 40% or less for maintaining dimensional stability and mechanical strength.

  The compounding quantity of a metal hydrate is 30-80 mass parts, Preferably it is 35-75 mass parts. In order to obtain satisfactory thermal conductivity, the amount is desirably 30 parts by mass or more, and in order to prevent a decrease in mechanical strength and improve thermal conductivity, it is desirably 80 parts by mass or less.

  In the present invention, the metal hydrate serves to suppress frictional heat during sliding by its endothermic reaction, and further suppresses localized frictional heat by combining it with a lubricity imparting material having good thermal conductivity. be able to.

  The phenol resin molding material of the present invention includes various additives conventionally used in phenol resin molding materials as desired, such as curing agents, curing catalysts, mold release agents such as zinc stearate and calcium stearate, and coupling agents. , Pigments, solvents and the like can be blended.

  The method for producing the phenolic resin molding material of the present invention is not particularly limited, but the kneaded material heated and kneaded with a pressure kneader, a mixing roll, a twin screw extruder or the like is formed into a sheet, and pulverized using a pelletizer, a power mill, or the like. Manufactured. The molding material thus obtained can be applied to any of injection molding, transfer molding, compression molding and the like.

The present invention will be specifically described with reference examples, but the present invention is not limited to these reference examples. Note that “parts” and “%” in the reference examples indicate “parts by mass” and “% by mass” unless otherwise specified. Moreover, when describing a compounding quantity using a mass part in this specification, a phenol resin is described as a mass part with respect to 100 mass parts.

< Reference Example 1>
As shown in Table 1, phenol resin 100 parts, glass fiber (manufactured by Nittobo Glass, fiber diameter: 11 μm, average fiber length: 3 mm) 70 parts, aluminum hydroxide (made by Nippon Light Metal) 70 parts, graphite (Nippon Graphite Industries) 40 parts), 15 parts of hexamethylenetetramine as a curing agent, 3 parts of calcium stearate as a release agent, and 8 parts of others were mixed and mixed uniformly. Thereafter, the mixture was heated and kneaded uniformly with a hot roll to form a sheet, cooled and pulverized with a power mill to obtain a granulated molding material.

  The obtained molding material was injection molded under the following conditions to obtain the following test pieces.

Cylinder temperature: front 85 ° C, rear 40 ° C
Mold temperature: 170 ° C
Curing time: 60 seconds Using the obtained test piece, the molding shrinkage rate, bending strength, thermal conductivity, and sliding wear test were evaluated. The results are shown in Table 1. Various characteristics were evaluated based on the following.

(1) Molding shrinkage The molding shrinkage was measured according to JISK6911 standard.
(2) Bending strength Bending strength was measured according to JISK7171 standard.
(3) Thermal conductivity A rapid thermal conductivity meter (manufactured by Kyoto Electronics Co., Ltd.) was used to measure a 50 × 150 × 5 mm thick test piece by the probe method.
(4) Sliding wear test Resin: Square plate test piece of 30 × 30 × Thickness 3 mm Mating material: Hollow cylinder with outer diameter 25.6 mm, inner diameter 20 mm, length 15 mm Mating material: S45C
Test surface pressure: 1.47 MPa Test speed: 0.2 m / sec
Test time: 1Hr Environment: No lubrication

< Reference Examples 2-4, Comparative Examples 1-3>
A molding material was produced and evaluated in the same manner as in Reference Example 1 except that the blending ratio was changed as shown in Table 1.

表１から明らかなように、参考例１〜４で得られたフェノール樹脂成形材料は、耐熱性、寸法安定性、機械的強度を損なうことなく、熱伝導性が良好で摺動特性に優れた特性を示している。

As is clear from Table 1, the phenolic resin molding materials obtained in Reference Examples 1 to 4 have good thermal conductivity and excellent sliding characteristics without impairing heat resistance, dimensional stability, and mechanical strength. The characteristics are shown.

As described above, according to the present invention, heat conductivity is improved, that is, heat dissipation is improved while maintaining heat resistance, dimensional stability, and mechanical strength as compared with conventional phenol resin molding materials. Thus, a molded article that suppresses the temperature rise during sliding and does not cause abnormal friction can be obtained, and it is possible to promote the resinization of sliding parts for automobiles, particularly high-performance driving parts.

Claims (3)

At least one lubricity imparting material selected from 50 to 90 parts by mass of inorganic reinforcing fibers, graphite subjected to surface treatment with a silane coupling agent or a titanate coupling agent, and fluororesin powder with respect to 100 parts by mass of phenol resin A sliding member molding material using a phenol resin molding material, comprising 10 to 50 parts by mass and 30 to 80 parts by mass of a metal hydrate of aluminum hydroxide or magnesium hydroxide as essential components.   The inorganic reinforcing fiber includes at least one selected from glass fiber, carbon fiber, fibrous calcium silicate, fibrous magnesium sulfate, glass wool, rock wool, slag wool, sepiolite fiber, and wollastonite fiber. A sliding member molding material using the phenolic resin molding material according to claim 1.   The sliding member molding material using the phenol resin molding material according to claim 1 or 2, wherein the sliding member is a thrust washer.