JPH04353404A - Composite material of high-strength abraisionresisting whisker reinforced resin - Google Patents

Abstract

PURPOSE:To provide high mechanical strength and abraision resistance by a method wherein SiC whisker of high aspect property having specified small diameter and SiC whisker of low aspect property having specified large diameter are dispersed uniformly in a resin matrix at a volume content of 5-45% to form a composition structure. CONSTITUTION:SiC whisker A of high aspect property having a diameter of 0.3-1.4mum and a length of 5-30mum and SiC whisker B of low aspect property having a diameter of 2-7mum and a length of 5-20mum are uniformly dispersed in a resin matrix at a volume content of 5-45% to form a composition structure. In this manner, the SiC whisker A having high aspect ratio and small diameter and SiC whisker B having low aspect ratio and large diameter are combined to form a reinforced material, whereby a composite performance comprising high mechanical strength and abraision resistance can be given to a matrix resin material through the hybrid function of said reinforced material.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a whisker-reinforced resin composite material which uses SiC whiskers as a reinforcing material and has high strength and excellent wear resistance.

0002

[Prior Art] Continuous long fibers, such as glass fibers and carbon fibers, have been widely used as fiber reinforcement materials for reinforcing synthetic resin materials by combining them with fibers. SiC consisting of needle-shaped crystals, Si3 N4
, Al2O3, K2O.nTiO2 and the like are used. Among these, SiC whiskers have excellent performance characteristics in terms of specific strength, specific modulus, heat resistance, chemical stability, etc., and are therefore expected to be useful as fiber reinforcement materials that require particularly high composite performance. ing.

Conventionally, in a resin composite material using SiC whiskers as a reinforcing material, it has been believed that using whiskers having a thin diameter and a large aspect ratio is effective for improving strength. However, when this kind of SiC whiskers with a small diameter and high aspect ratio are mixed with a matrix resin, the whiskers agglomerate with each other, making it difficult to form a highly filled composite, and for this reason, it is difficult to impart wear resistance to the composite material. Can not. Therefore, when trying to impart wear resistance as a composite performance, a diameter of 2 μm with good dispersion filling properties is recommended.
As described above, it is effective to use SiC whiskers with low aspect properties as the reinforcing material, but this property causes the problem that high material strength cannot be obtained.

0004

[Problems to be Solved by the Invention] The present invention provides a composite material with a high degree of properties by hybridizing two types of SiC whiskers, one having a small diameter with a high aspect ratio and the other with a thick diameter and a low aspect ratio, into a resin matrix. This has succeeded in imparting strength and wear resistance.

[0005] Accordingly, an object of the present invention is to provide a SiC whisker-reinforced resin composite material having a composition structure that has both excellent mechanical strength and wear resistance.

[0006]

[Means for Solving the Problems] A high-strength, wear-resistant whisker-reinforced resin composite material according to the present invention to achieve the above object has a diameter of 0.3 to 1.4 μm and a length of 5 to 30 μm.
SiC whiskers A with a small diameter and a high aspect ratio of m and a SiC whisker B with a large diameter and a low aspect ratio of 2 to 7 μm in diameter and 5 to 20 μm in length have a volume content (Vf
) 5 to 45% homogeneously dispersed in a resin matrix.

[0007] SiC whisker manufacturing technology includes SiC whisker manufacturing technology.
Decomposable silicon compounds such as 14, SiHCl3, (CH3)4Si are converted to CH4, C3H8, CCl
4 A method of gas phase reaction with carbonaceous components such as SiO2
Mix powdered silicon source material containing carbon powder with carbon powder, or
For example, there is a method of heating and reacting a substance containing both of these components, such as rice husk charcoal, but the SiC whiskers A and B used in the present invention are not particularly influenced by these manufacturing histories. It may be manufactured by any method. In addition, SiC whisker B can be prepared by heating SiC whisker A to a temperature of 1800 to 2
It can also be manufactured by heat-treating at 200° C. to convert it into a thick diameter and low aspect property.

[0008] As SiC whisker A, the diameter is 0.3~
The reason for selecting a thin diameter of 1.4 μm and a length of 5 to 30 μm and a high aspect ratio is because suitable material strength can be obtained in this property range.
The reason why a large diameter of 2 to 7 μm in diameter and 5 to 20 μm in length and low aspect property is selected is that this property range provides good dispersion filling properties and is effective in improving wear resistance. Therefore, this combination of both properties makes it possible to simultaneously impart high levels of mechanical strength and abrasion resistance to the composite resin material.

[0009] SiC whisker A and SiC whisker B
It is preferable to set the blending ratio in a volume ratio of 70:30 to 30:70. If the amount of SiC whiskers on one side increases beyond this ratio, the hybrid effect will be reduced, making it impossible to have both strength and wear resistance.

[0010] Matrix resins include various thermal resins such as phenolic, epoxy, unsaturated polyester, diallyl phthalate, polyethylene, vinyl chloride, polyvinyl alcohol, polyamide, polyimide, polyurethane, polystyrene, vinyl acetate, and tetrafluoroethylene. Examples include curable or thermoplastic resins, which are used in a liquid state to which components such as a curing agent and a curing accelerator are added as necessary.

[0011] As a means of compounding, it is also possible to apply a dispersion compounding method in which SiC whiskers A and B are gradually added and dispersed while stirring the matrix resin liquid, and then molded. However, for the purpose of the present invention, It is preferable to apply a preform impregnation method, which is advantageous in dispersing SiC whiskers A and B, which have different properties, in a homogeneous state in a resin matrix. That is, SiC whiskers A and B are blended in a predetermined ratio, uniformly dispersed in water or an organic solvent, rapidly filtered, and the filtered cake is dried. The resulting SiC whisker preform is forcibly impregnated with a matrix resin liquid. A composite method is adopted in which the material is then molded.

At this time, the amount of SiC whiskers to be composited into the resin matrix is set in the range of 5 to 45% as the volume content (Vf) of SiC whiskers A and B. If this volume content (Vf) is less than 5%, sufficient composite performance will not be imparted, and if it exceeds 45%, voids may form between the SiC whiskers and the matrix, which may become a starting point for destruction. , leading to a decline in composite properties.

[0013]

[Function] According to the present invention, by combining SiC whiskers A and B, which have different properties, such as thin diameter, high aspect ratio and thick diameter, low aspect ratio, to form a reinforcing material, the matrix is strengthened through their hybrid action. It becomes possible to impart composite performance that combines high-level mechanical strength and wear resistance to resin materials.

[0014]

[Examples] Examples of the present invention will be explained below in comparison with comparative examples. Examples 1 to 11, Comparative Examples 1 to 4 A thin and high aspect ratio SiC whisker A with a diameter of 0.3 to 1.4 μm and a length of 5 to 30 μm, and a SiC whisker A with a diameter of 2 to 8 μm and a length of 5 to 30 μm. SiC whiskers B with a large diameter and a low aspect ratio in the property range of 5 to 20 μm were selected, and these were placed in a juicer mixer with a 1% polyvinyl alcohol aqueous solution at different blending ratios, and stirred and dispersed for 3 minutes. The dispersion was filtered from the top using a closed cylindrical filtration device at 3 kg/c.
Pressure filtration was performed while applying an air pressure of m2, and the resulting filter cake was dried at 80° C. for 12 hours or more. Then, after cutting into a predetermined shape and surface processing, a 1% polyvinyl alcohol aqueous solution was sprayed on the material, and the material was dried at 110.degree. C. for 5 hours to produce preforms having different volume contents (Vf) made of SiC whisker aggregates.

Table 1 shows the properties, compounding ratio, and volume content (Vf) of the SiC whiskers A and B used.
It was shown to. In addition, in Table 1, Comparative Example 1 is an example using only matrix resin, Comparative Example 2 is an example using only SiC whisker A, Comparative Example 3 is an example using only SiC whisker B,
Comparative Example 4 is an example in which SiC whisker B, which does not meet the characteristics of the present invention, was blended.

[0016]

[Table 1]

[0017] Each preform was set in a can container, and an epoxy resin liquid containing a hardening agent [Yuka Shell Epoxy Co., Ltd.] was added.
"Epicoat 828"] was injected into the container and maintained at a reduced pressure of 10 mmHg or less for 12 hours for degassing and impregnation treatment. Subsequently, it was transferred to an autoclave and impregnated under pressure at a pressure of 5 kg/cm2. Next, take out the impregnated material and put it in a mold, 5kg/cm
The matrix resin was cured by heating to 120℃ while applying pressure to 2, and then the cured molded product was heated to 180℃.
A whisker-reinforced epoxy resin composite was obtained by heat treatment for a period of time.

A bending strength test and an abrasion resistance test were conducted on each of the composite materials obtained, and the results are shown in Table 2. For comparison, a single molded product of matrix epoxy resin (
Comparative Example 1) was also tested in the same manner, and the results are also listed in Table 2. The bending strength test is based on JIS K6911 (1).
979) using Autograph S-500, and the wear resistance test was conducted in accordance with JIS K7204 (1977).
According to Taber type abrasion tester (wear wheel CS-17
, 1000 cycles, load 1 kg).

[0019]

[Table 2]

From the results in Table 1, it is recognized that the SiC whisker-reinforced epoxy resin composite materials of each example have significantly improved bending strength and abrasion resistance compared to the material of the comparative example.

[0021]

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a whisker-reinforced resin composite material that has both excellent material strength and wear resistance. Extremely useful for applications.

Claims (2)

[Claims] Claim 1: SiC whisker A with a thin diameter of 0.3 to 1.4 μm and a length of 5 to 30 μm and a high aspect ratio; and a thick SiC whisker A with a diameter of 2 to 7 μm and a length of 5 to 20 μm with a low aspect ratio. A high-strength, wear-resistant, whisker-reinforced resin composite material having a composition structure in which SiC whiskers B are homogeneously dispersed in a resin matrix at a volume content (Vf) of 5 to 45%. 2. The high-strength, wear-resistant, whisker-reinforced resin composite material according to claim 1, wherein the blending ratio of SiC whisker A and SiC whisker B is in the range of 70:30 to 30:70 by volume.