JPH04198225A - Abrasion-resistant wrp material - Google Patents

Abstract

PURPOSE:To obtain the title material improved in abrasion resistance by homogeneously dispersing specified SiC whiskers in the structure of a matrix resin. CONSTITUTION:beta-Crystal-based SiC whiskers of a diameter of 0.3-1.5mum and an aspect ratio of 10-40 are heat-treated at 1800-2200 deg.c in a nonoxidizing atmosphere to obtain large-diameter SiC whiskers having a diameter of 1.5-4.0mum and an aspect ratio of 3-10. 30-50vol.% said whiskers optionally surface-treated is homogeneously dispersed in a matrix resin to obtain the title WRP material of an abrasion wear of 1.5mm<3> or below.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is a WRP material (whisker-reinforced resin) which has excellent abrasion resistance and is composed of thick SiC whiskers with a large diameter and a small aspect ratio as a reinforcing material. related to composite materials).

[Conventional technology]

Whiskers composed of acicular single crystals of 5iCO have excellent performance characteristics in terms of specific strength, specific modulus, heat resistance, chemical stability, etc., and are therefore expected to be useful as composite reinforcing materials for various plastic materials. has been done.

Continuous fibers such as glass fibers and carbon fibers are commonly used as composite reinforcing materials for plastic materials, and these are used in the form of long fibers or short fibers. Among these, when used as short fibers, continuous fibers are cut into units of several C11 to several C11 and dispersed in a matrix resin, and compared to composites using long fibers, non-directional composite performance with no orientation is improved. There are features you can get.

Conventionally, in composite systems using short fibers, it has been believed that properties with a small diameter and a large aspect ratio are effective, and even when whiskers such as SiC are used as reinforcing materials,
A diameter of 1.0 μm or less and an aspect ratio of at least 50 or more are required to provide a high degree of composite performance.

[Problem to be solved by the invention]

However, when this kind of fiber-dispersed reinforced composite was actually made using whiskers as a reinforcing material, it was found that whiskers with small diameters and large aspect ratios tend to coagulate with each other when mixed with matrix resin. As a result, there is a problem in that the property improvement is restricted due to poor uniform dispersion and the composite performance is uneven. This phenomenon becomes particularly noticeable as the composite ratio of whiskers to the matrix resin increases. If the volume content (Vf) of whiskers exceeds 30%, kneading with rolls or the like, or mixing the resin after creating a preform, is recommended. Even with methods such as impregnation, it is impossible to obtain a normal and stable WRP material. Therefore, there are major restrictions on improving the wear resistance of WRP materials by increasing the volume content (Vf) of whiskers.

An object of the present invention is to provide a WRP material that has a high degree of wear resistance and uses thick diameter, low aspect ratio type whiskers as a reinforcing material, unlike conventional recognition.

[Means to solve the problem]

Wear-resistant WR according to the present invention to achieve the above objects
P material has a diameter of 1.5 to 4.0 μ and an aspect ratio of 3 to 4.
The composition is characterized by a composition in which SiC whiskers having a large diameter property of 10 are uniformly dispersed in the structure of the matrix resin at a volume content (Vf) of 30 to 50%.

The WRP material according to the present invention having the above composition has a wear amount of 1.
It has high wear resistance properties of 5-++m' or less.

The SiC whiskers compositely dispersed as a reinforcing material in the present invention are characterized by a large diameter and short length compared to normal whisker properties (diameter 0.1 to 1°0 μ■, aspect ratio 50 to 100). This has a diameter of 0.0 mm, as detailed below.
SiC whiskers mainly composed of β-crystal type with a diameter of 3 to 1.5 μm and an aspect ratio of IO to 40 are heated to 1800 μm in a non-oxidizing atmosphere.
It can be manufactured by a method of heat treatment at a temperature of 2200°C.

The manufacturing technology of SiC whiskers includes 5iCj! n, S
iHCf! A method of reacting a decomposable silicon compound such as s, (CH3)J Si with a subsequent material component such as CH, , C, H, or C(1) in a gas phase, a solid silicon source material containing Sin. There are methods such as mixing carbon powder with carbon powder, or heating and reacting a material containing a complex of these components, such as rice husk charcoal. However, the SiC whisker, which is the raw material of the present invention, is particularly influenced by the manufacturing history of these components. There is no problem,
It may be manufactured by any method.

Properties: diameter 0.3-1.5μ■, aspect ratio 10
The reason why SiC whiskers having a diameter of 40 to 40 is used as a raw material is that SiC whiskers having aspect properties in this range exhibit the most remarkable effect of increasing the diameter by sublimation recrystallization. Further, it is necessary to select a crystal system of SiC whiskers that is mainly of the β crystal type, and if this requirement is not met, the intended diameter cannot be increased. "Mainly β crystal type" means that the SiC whisker crystal type is all β type, or even if it is α/β mixed type, the β type is dominant, but the lower the stacking fault density, the less grainy particles there are. The diameter increases depending on the content. Preferred crystal properties of the β-5iC whisker are that the α degree according to the following formula is 20 or less, and the half width of the (111) diffraction line is 0.14 deg or less.

α degree = (H, x2/HixtO.

However, Hl is 2 when CuKα is used as a radiation source in X-ray diffraction.
6 Diffraction line intensity appearing at about 35.6 degrees, H2 is 33.
This is the intensity of the diffraction line appearing at 5 degrees.

Such SiC whiskers can be heated to 1800~22 in a non-oxidizing atmosphere such as N2 gas, Ar gas or vacuum.
Heat treatment in the temperature range of 00°C. The heat treatment time was 0.
2 to 4 hours is enough. At this time, the processing temperature was 1800°C.
If the temperature is lower than 2200°C, it will take a long time to increase the diameter to 1.5μ or more, making it impractical.If the temperature exceeds 2200°C, SiC will evaporate rapidly, leading to weight loss.
This results in a decrease in yield.

WRP compositing can be performed by the following process.

The surface of SiC whiskers having a large diameter is immersed in a solution in which a commonly used silane cambling agent such as aminosilane is dissolved in an organic solvent, and then the organic solvent is removed by volatilization.

The silane coupling-treated whiskers are then dispersed in a matrix resin.

Matrix resins include phenolic, epoxy, unsaturated polyester, diallyl phthalate, polyethylene, polyvinyl chloride, polyvinyl alcohol,
Examples include various thermosetting or thermoplastic resins such as polyamide, polyimide, polyurethane, polystyrene, vinyl acetate, and tetrafluoroethylene. condition and ready for use.

The blending ratio of the thick whiskers to the matrix resin is 30 to 50% as the volume content (Vf) of the whiskers.
Set within the range. This range of volume content (Vf) is a high blending range where whiskers with small diameters and large aspect ratios cannot achieve uniform dispersion, and by selectively using the above-mentioned large-diameter whiskers, uniform dispersion becomes possible. . However, if the volume content (Vf) is less than 30%, it is not possible to provide wear resistance with a wear amount of less than 1.5 m++'', and if the volume content exceeds 50%, the dispersibility deteriorates. It becomes difficult to obtain a uniform composite structure.

Dispersion of the whiskers is carried out by gradually adding and mixing the matrix resin little by little while stirring, and then kneading the mixture by means of rolling, such as three narrowly spaced rolls.

The kneaded material is subjected to a vacuum defoaming treatment to remove occluded gas components and voids, and then molded using a mold of a desired shape and hardened to obtain a WRP material.

[For production]

According to the present invention, SiC whiskers, which have a larger diameter and a smaller aspect ratio than conventional technology, are used as reinforcing materials, so they are uniform in the structure of the matrix resin in the high blending range of 30 to 50% volume content (Vf). Distributed WRP
It has a composition.

This compositional structure allows for wear reduction of 1% without compromising strength performance.
．． It functions effectively to provide high wear resistance of 5 mm' or less.

〔Example] Hereinafter, examples of the present invention will be explained in comparison with comparative examples.

Examples, Comparative Examples 1 and 2 It has the properties of a diameter of 0.5 to 1.2 μm, an average aspect ratio of 50, and a half width of the (111) diffraction line of 0.1375 d.
A SiC whisker raw material mainly composed of the β crystal type of EG [manufactured by Tokai Carbon ■, 'Toka Whisker S-400''] was packed in a graphite crucible and heated at 2000° in an argon gas atmosphere.
The SiC whiskers were heat-treated at a temperature of C to obtain thick SiC whiskers with a diameter of 2.1 to 3.2 μm and an average aspect ratio of 7.

This large-diameter whisker was immersed in a silane coupling solution in which 1% aminosilane (manufactured by Chisso Corporation, S-330) based on the weight of the whisker was dissolved in toluene, and then the toluene was removed by volatilization using a mantle heater.

When the volume content (Vf) is 10 to 20%, change the amount of surface-treated thick whiskers and use epoxy resin [manufactured by Yuka Shell Epoxy ■, 'Epicoat 828''.
A matrix resin solution prepared by mixing an appropriate amount of curing agent ("Epicure Z" manufactured by Yuka Shell Epoxy Co., Ltd.) was added little by little while stirring.

Then, the mixture was passed through three rolls with a gap of 0.2 mm and mixed for 10 minutes.

The kneaded material was transferred to a vacuum device and subjected to vacuum defoaming to remove internal air bubbles, and then placed in a mold coated with a release agent in advance and subjected to vacuum defoaming treatment again. Continue to put 100kg in the mold
A pressure of /cI11" was applied for 1 minute to form the mold, and a curing treatment was performed at 80 °C for 2 hours and at 150 °C for 2 hours. In addition, when the volume content (Vf) was 30 to 50%, , a preform adjusted to a predetermined 'df is prepared in advance, placed in resin and impregnated with gas pressure in a vacuum impregnation autoclave, then the preform impregnated with resin is placed in a mold, semi-cured under pressure, and finally It was removed from the mold and allowed to harden.

The tensile strength and wear amount of the WRP material thus manufactured were measured, and the results are shown in Tables 1 and 2 in comparison with the volume content (Vf) of SiC whiskers.

For comparison, SjC with an average particle size of 2μ was used as a reinforcing material.
powder (Comparative Example 1) and SiC whiskers with a diameter of 0.2-0.6 μm and an average aspect ratio of 30-40 (Comparative Example 2).
), up to 10% volume content (Vf) for all SiC powders and SIC whiskers, by kneading with three rolls;
) 20 to 50%, the properties of the composite material produced by the method of creating a preform and impregnating it with resin are listed in Tables 1 and 2.

In addition, the tensile strength is determined according to JIS [6911-1979, and the amount of wear is determined according to AsTM D1044-1978 using a taper type abrasion tester at C5-17, 1000 cycles, and a load of 10.
The test was carried out under the condition of 00 g.

Table 1 (Bending strength: kgf/m) Table 2 (Amount of wear: Peng 3) From the results of Tables 1 and 2, WRP materials with a volume content (Vf) of 30 to 50% that meet the requirements of the present invention are It has excellent wear resistance with a wear amount of 1.5 mm or less while maintaining high tensile strength.In contrast, Comparative Example 1, which uses SiC powder as a reinforcing material, has poor tensile strength and wear resistance. In addition, in Comparative Example 2 in which SiC whiskers of conventional properties were used as a reinforcing material, it was impossible to form a composite with a volume content (Vf) exceeding 30%.

〔Effect of the invention〕

As described above, according to the present invention, large-diameter SiC whiskers are present in the structure of the matrix resin at a volume content (Vf).
It is possible to provide a WRP material with a uniformly dispersed composition and excellent wear resistance in a high blending range of 30 to 50%.

Therefore, it is expected to be useful when applied to various application members that involve mechanical sliding under severe conditions.

Applicant: Tokai Carbon Co., Ltd. Agent: Patent Attorney Masaya Takahata

Claims (1)

[Claims] 1. SiC whiskers having a diameter of 1.5 to 4.0 μm and an aspect ratio of 3 to 10 have a volume content (Vf
) A wear-resistant WRP material having a composition of 30 to 50% uniformly dispersed in the matrix resin structure. 2. The wear-resistant WRP material according to claim 1, which has a wear amount of 1.5 mm^3 or less.