JPS63265620A - Inorganic fiber reinforced plastic composite and its preparation - Google Patents

Abstract

PURPOSE:To improve mechanical characteristics, by reinforcing a matrix plastic with a bundle of continuous filaments on the surfaces of which fine particles and short fibers and/or whiskers are adhered or with a woven fabric made of the bundle of continuous filaments. CONSTITUTION:A bundle of continuous filaments made of continuous filaments whose constitutional components is at least one selected from a group consisting of ceramic, carbon and metal or a woven fabric made of a bundle of continuous filaments is immersed in a treating liquid wherein fine particles consisting of at least one selected from heat resistant substances such as ceramic, carbon, metal and so on and short fibers and/or whiskers are suspended. Fibers prepared by adhering fine particles and said short fibers and/or whiskers in the surface of each continuous filament are impregnated with a plastic and thereafter solidified.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to inorganic fiber reinforced plastic composites (FRP).
and its manufacturing method.

(Prior Art) Conventionally, surface-treated carbon fibers have been widely used as fibers for reinforcing plastics such as epoxy resins, modified epoxy resins, polyester resins, and polyimide resins.

Furthermore, silicon carbide fibers disclosed in Japanese Patent Application Laid-open No. 52-141S87 are said to have superior mechanical strength (compared to carbon fibers) and are used as fibers for reinforcing plastics.

When FRP is manufactured using the injection method using these reinforcing fibers, the fiber distribution tends to be coarser in some areas and denser in others. For this reason, the fiber volume fraction (Vf
) is difficult to control, and especially when Vf is small, the reinforcing fibers are uniformly dispersed, making it difficult to obtain FR, P, and the degree of freedom in design, which is the original feature of 1'RP, is impaired. 7j FRP reinforced only with inorganic fibers has a large strength anisotropy, and the strength in the longitudinal direction of the fibers is high, but the strength in the direction perpendicular to it is extremely small. Tomo F using only short fibers
Although RP is isotropic, its strength is generally low.

Regarding FRP composite materials, a method has also been proposed in which continuous fibers (te) are used in combination with long fibers and short fibers or whiskers as reinforcing fibers used in the composite material. For example, there is a method of using long fibers on the inside of the composite member and short fibers on the outside.

(Problems to be Solved by the Invention) However, even in the above method, the method of separately using long fibers and short fibers inside the member complicates the manufacturing process, and furthermore, the strength of the resulting composite material is not sufficient. Furthermore, in the method of mixing long fibers and short fibers during prepreg production, although Q short fibers can be attached to the surface of a long fiber bundle using a brush, etc., the surface of each long fiber inside It is difficult to adhere the fibers uniformly to the fibers, resulting in uneven quality of the fibers.

In order to solve the above problems, the present inventors first suspended short fibers, whiskers, or powder and immersed a continuous fiber bundle in a t solution to coat the surface of each fiber with short fibers and whiskers. Alternatively, he proposed a method of attaching powder, etc. Although this method is excellent for producing F-P, it was found that the short fibers, whiskers, and holes may not always be sufficient depending on the adhesion form of the powder.

The present invention is intended to solve the above-mentioned problems in the prior art, and its purpose is to improve the wettability with the plastic matrix, and at the same time uniformly disperse continuous fibers in the composite material to increase the fiber volume. By combining continuous fibers with different properties, the ratio can be controlled.
To provide an inorganic fiber-reinforced plastic composite with excellent performance reinforced with fibers for composite materials, which can reduce stress concentration between continuous fibers and matrix and improve the mechanical properties of the composite material, and a method for producing the same. There is a particular thing.

(A precautionary measure to solve the problem) In other words, the inorganic fiber reinforced plastic composite of the present invention has the following features:
selected from the group consisting of ceramics, carbon and metals
A continuous fiber bundle consisting of continuous fibers containing at least one of the following as a constituent component, a woven fabric made from the continuous fiber bundle, and a heat-resistant substance such as ceramic, carbon, metal, etc., present in the vicinity of the continuous fiber. f'L7'c fine particles consisting of at least one ridge, and short fibers consisting of at least one heat-resistant substance such as cefmic, carbon, metal, etc., uniformly dispersed and interposed in the fiber gaps of the continuous fibers; and/or whiskers and a matrix of plastic.

Preferred embodiments of the composite of the present invention include, for example, the following.

(7) A composite in which the average particle diameter of fine particles is 1/30 or less of the average length of short fibers and/or whiskers.

(a) A composite in which the ceramic is at least one selected from carbide, nitride, oxide, and boride ceramics.

(i) The composite of (a) above, wherein the carbide ceramic is silicon carbide, the nitride ceramic is silicon nitride, and the antide ceramic is alumina.

(1) Ceramic is (+) an amorphous material consisting essentially of silicon, M, carbon and oxygen, or (11) substantially consisting of β-SiC, MO, β-SiC and MC.
solid solution and/or particle size of MC(1-x) is 500
Each crystalline ultrafine particle and amorphous 5iO1 and M below A
O, also the aggregate, is (lli) above (1)
A mixture of the amorphous substance and the aggregate consisting of crystalline ultrafine particles and amorphous as described in (ii) above (However, in the above formula, M represents Ti primary and Zr, and X represents O
a number greater than and less than 1).

(3) Fine particles for continuous fibers and short fibers and/or
Or a composite in which the volume fraction of whiskers is 15 to 500 cm.

(a) The blending ratio of continuous fibers to the composite is 10 to 7.
A complex with zero volume.

(To) The plastic that is the matrix of the composite is epoxy resin, modified epoxy resin, polyester resin, polyimide resin, phenol resin, polyurethane resin, polyamide resin, polycarbonate resin, silicone resin, phenoxy type resin, polyphenylene sulfide, fluororesin, carbonized A composite material selected from the group consisting of hydrogen-based resin, halogen-poor resin, acrylic acid-based resin, ABS resin co-contained polyester, and polyneedle.

The method for producing an inorganic fiber-reinforced plastic composite of the present invention also includes a continuous fiber bundle made of continuous fibers containing at least one type of f'L7c selected from the group consisting of ceramic, carbon, and metal fibers, or the continuous fiber bundle. A woven fabric made of 1 is immersed in a treatment solution in which fine particles made of at least one selected from heat-resistant substances such as ceramics, carbon, and metals, and short fibers and/or whiskers are suspended. The fine particles, short fibers and/or whiskers are attached to the surface of a single book, and the resulting fibrous body is impregnated with plastic and then solidified.

Preferred embodiments of the method for producing a composite of the present invention include, for example, the following.

(Improvement) A manufacturing method in which each component is one of the above (7) to (4).

(A manufacturing method in which many fine particles are attached near the surface of continuous fibers, and many short fibers and/or whiskers are attached to the outside of the continuous fibers.)

((b) A manufacturing method that applies ultrasonic vibration to the processing liquid.

Seki: A manufacturing method that uses one nine processing tank containing processing liquid.

Manufacturing method using two or more treatment tanks containing treatment liquid.

2) A continuous fiber bundle or woven fabric is immersed in a treatment liquid in which fine particles are suspended, and then immersed in a treatment liquid in which short fibers and/or whiskers are suspended, so that many fine particles are attached near the surface of the continuous fibers. The manufacturing method of the above-mentioned (goods), in which a large amount of short fibers and/or whiskers are attached to the outside of the fiber.

Continuous fibers include ceramics such as silicon carbide, silicon nitride, boron nitride, aluminum nitride, alumina, silica, and fired products of polymetallocarbosilane! (9) Inorganic fibers made of heat-resistant nonmetallic elements such as carbon, boron, heat-resistant metals or alloys, such as steel, stainless steel, and tungsten can be used alone or in combination. Properties such as fiber thickness and cross-sectional shape are selected depending on the application.

As the fine particles, particles manufactured using the same material as that used for the continuous inorganic fiber can be used.

These may be used alone or in combination of two or more.

The short fibers and whiskers can be manufactured using the same materials as those used for the continuous inorganic fibers or fine particles.

Either one or a combination of two or more types may be used.

The length, thickness, and cross-sectional shape of short fibers and whiskers should be selected by taking into consideration the properties such as the average particle diameter of the fine particles, the combination with continuous fibers, and the required characteristics. The average diameter of 1/3000 to 115 of
It is preferable that the aspect ratio is 50 to 1000, and the fine particles have an average diameter of 1/3000 to 1/2 of the average diameter of the continuous fibers.

The amount of fine particles to be attached to the inside of the continuous fibers, short fibers to be attached to the outside of the continuous fibers, and/or the amount of whiskers depends on the properties of both, the properties of the fibers being manufactured, the reinforcement thereof, etc. Although it varies depending on
The total volume ratio of the short fibers, whiskers and fine particles to the continuous fibers is preferably about 1 to 500% CL. The weight ratio of fine particles to short fibers and/or whiskers is 0. The range of 1:5 to 40:1 is preferred.

Examples of the plastic matrix in the present invention include those described in the above-mentioned embodiments (Kari).These may be used alone or in combination.

The method for manufacturing the fibers used in the inorganic fiber-reinforced plastic composite of the present invention is a suspension dipping method, which is preferred from the viewpoint of simplicity and wide applicability. As an example of this suspension dipping method, for example, continuous fibers are wound around a bobbin, etc., and then the continuous fiber bundle or the woven fabric made of this continuous fiber bundle is rewound to remove fine particles, short fibers, and/or whiskers. An example of this method is to simultaneously suspend the material, immerse it in a liquid, and then wind it onto a bobbin again. The resulting fiber bundle ta is a woven fabric in which fine particles, short fibers, and/or whiskers are attached to the surface of each continuous fiber. in this case,
The number of processing tanks containing processing liquids may be one, but two or more processing tanks containing processing liquids of different compositions may be used for various modified methods.

As a processing solution, a solution in which fine particles, short fibers and/or whiskers are simultaneously suspended may be used, or a processing solution containing turbid microparticles, short fibers and/or whiskers may be used. A turbid treatment solution may be used by placing it in two treatment tanks.In the latter case, the order in which the continuous fiber bundle te is dipped into the woven fabric may be changed from the treatment solution in which fine particles are suspended to short fibers and/or Alternatively, a treatment solution in which whiskers are suspended may be used.

Here, many fine particles are attached near the continuous fiber surface,
A continuous fiber bundle or woven fabric having many short fibers and/or whiskers attached to the outside thereof can be produced as follows.

That is, a continuous fiber bundle or woven fabric is immersed in a treatment liquid in which fine particles are suspended, and then immersed in a treatment liquid in which short fibers and/or whiskers are suspended. In this case, the fine particles first penetrate into the continuous fiber bundle and adhere to the surface of each fiber. This widens the fiber gap and facilitates subsequent short fibers and/or whiskers to penetrate into the continuous fiber bundle.

Alternatively, a continuous fiber bundle or woven fabric is immersed in a treatment solution in which fine particles with an average particle diameter of 1/30 or less of the average length of short fibers and/or whiskers are suspended simultaneously with short fibers and/or whiskers. do. In this case, the fine particles mainly first enter the fiber gaps, adhere to the surfaces of the fibers, and completely spread out the fibers, thereby facilitating the penetration of short fibers and/or whiskers into the fiber gaps. By applying vibration using a microwave or ultrasonic wave, each fiber can be uniformly attached to the fibers inside the fiber bundle.

Ultrasonic waves may be applied to an ultrasonic adder placed outside the container containing the processing liquid, or an appropriate number of ultrasonic transducers, such as ceramic oscillators, may be applied to the processing liquid. It may be placed and given. The ultrasonic irradiation pattern may be continuous or pulsed. The intensity, vibration frequency, and irradiation time depend on the concentration of continuous fibers, short fibers, whiskers, or fine particles attached thereto, or the density of the deposits in the liquid.
The selection is made depending on the processing conditions such as the soaking time of the continuous fibers, but for example, the frequency is 10K[lz ~ 2QOOKHz].
The degree is easy to use.

The liquid for suspending the substance to be adhered may be water, but if a sizing agent is applied to the surface of the continuous fibers, a surfactant or a solvent for the sizing agent may be used. For example, organic solvents such as ethanol, methanol, acetone, and especially ethanol have higher volatility than water, so they dry quickly and have the advantage of improving productivity. Yes, all mixtures of the organic solvents and water may be used.

The concentration of deposits in the treatment solution is not particularly limited in both cases where a plurality of processing solutions containing one type of deposit are used and when a single processing solution containing two or more types of deposits is used. If it is too small, uniform adhesion will not be observed on the continuous fibers and the effect will be lost.If it is too large, the amount of adhesion will be larger than necessary.For example, silicon carbide whiskers with an average diameter of 13 μm and average particle diameter ( When processing a continuous fiber bundle of 6000 fibers/yarn using silicon carbide fine particles of 13 μm, the concentration of these deposits is 1lL5/l~5
A value of about ay71 is desirable.

The immersion time can be adjusted by a conventional method such as using a movable roller. If necessary, the continuous fiber bundle is treated and dried using a drying oven, an infrared dryer, a hot air dryer, etc. before being wound onto a bobbin. Further, stirring means such as a stirrer or gas may be blown to prevent precipitation of short fibers and fine particles during treatment.

Continuous fibers used in the composite of the present invention, fine particles, short fibers, and whiskers to be attached to the surface thereof can be commercially available products as they are.

From the thus obtained secondary fibrous body or its woven fabric, a fabric P can be produced according to a method known per se.

The manufacturing methods include 1-strand lay-up method, matted metal die method, break-aqua method, filament winding method, hot press method, autoclave method,
Examples include continuous drawing method. - Taking the hot press method as an example, according to this method, a fibrous body or its woven fabric is impregnated with plastic, pre-cured to produce a prepreg sheet 1i, the sheets are laminated, and then hot press is applied. It can be made into a plate-like composite by applying pressure and heating.

(Example) The present invention will be explained in further detail in the following example. Note that the present invention is not limited to the following examples.

Example 1 Silicon carbide whiskers (average diameter of about 0.2 μm, average length of about 100 μm) 100f and silicon carbide particles (average particle diameter of about 12 μm)
8μm) 2505'f Ethyl alcohol 5000c
After putting it into a processing tank containing c, ultrasonic vibration was applied using an ultrasonic adder to suspend it, and a processing liquid was prepared. A fiber bundle of silicon carbide fibers (500 threads) was unwound from the bobbin, and the immersion time was adjusted to 15 seconds using a movable roller, and the fiber bundle was immersed in the processing solution. At the same time, ultrasonic waves were applied to the processing solution. Then, air was blown into the product to stir it, and then it was pressed with a pressure roller, wound up again on a bobbin, and dried in the atmosphere at room temperature. The fibers, which were black before treatment, took on a grayish-green color after treatment, and as a result of electron microscopy observation, it was observed that fine particles were attached to the surface of the continuous fibers, and furthermore, Weiss force was attached to the outside.9. To be sure, the result of weighing after processing is 1 in volume ratio.
Next, it was discovered that a continuous fibrous body with zero-chip particles and whiskers attached was generated.

The treated fibrous body was aligned in the uniaxial direction, impregnated with a commercially available bisphenol A type epoxy resin, and precured to a thickness of 0.1511! A prepreg of Ill was obtained. After laminating this, hot pressing was carried out at 170°C and 7.4/cd for 4 hours to obtain a composite with a thickness of 2fi.

A cross-section of this complex was examined using a scanning electron microscope.
Some of the silicon carbide particles adhere to the inorganic fiber interface, and the inorganic fibers are uniformly dispersed in the matrix, with no visible places where the fibers are in contact with each other. It was also confirmed that silicon carbide whiskers were dispersed between the fibers.

The fiber content of this composite is 55% by volume. The tensile strength of the composite is 165 Kf/mj, and the interlaminar shear strength is 12
．． It is 3Kp/-.

Example 2 Continuous fibers similar to those in Example 1 were arranged in a sheet shape in one direction, impregnated with a commercially available phenol/novolac type modified epoxy resin, and then precured to a thickness of α15! In
I received a prepreg sheet from a friend.

After the sheets were laminated, they were hot pressed at 170° C. and 17 cm for 4 hours to obtain a composite with a thickness of 52 wm.

The fiber content of the composite was 55% by volume.

When we examined a cross section of this complex using a scanning electron microscope, we found that
Part of the silicon carbide particles adhered to the inorganic fiber interface, the inorganic fibers were uniformly dispersed in the matrix, and no fibers were found to be in contact with each other. Furthermore, it was confirmed that silicon carbide whiskers were dispersed between the fibers.

The fiber content of this composite is 55% by volume. The tensile strength of the composite was 178 Kg/ysJ, and the interlaminar shear strength was 12.6 S/IJ.

After examining the cross section of F and P of the present invention with an electron microscope, we found that
F) The continuous fibers of LP are kept at an appropriate spacing by the adhesion of fine particles and whiskers on the outside, and are then uniformly dispersed in the matrix plastic, reducing contact between fibers compared to when no adhesion occurs. friend.

In the case of FRP reinforced by adding only fine particles to continuous fibers, the fiber spacing increases, but the reinforcing effect in the vertical direction of the fibers is small. Second, in the case of FRP reinforced by adding only 9 isca or short fibers to continuous fibers, the spacing between the fibers is difficult to widen, and the reinforcing effect is small in both the fiber axial direction and the fiber perpendicular direction.

(Effects of the Invention) As described above, the inorganic fiber-reinforced plastic composite of the present invention has fine particles, short fibers, and/or whiskers attached to the surface of continuous fibers to form a continuous fiber bundle or the continuous fibers. Since the matrix plastic is reinforced with a woven fabric consisting of fiber bundles, each continuous fiber can be uniformly dispersed in the composite, making it possible to control the fiber volume fraction over a very wide range. It is. In addition, contact between continuous fibers is reduced, short fibers and/or whiskers interposed between them strengthen the fibers in the vertical direction, and the composition of the composite becomes uniform, improving mechanical properties such as compaction strength. Ta.

Friend, in the fiber-reinforced plastic composite materials up to this point, when the fiber content was low, the fibers tended to be unevenly distributed and it was difficult to obtain the theoretical strength according to the composite agent.
In the composite of the present invention, even when the fiber content is small, the continuous fibers are very uniformly dispersed in the plastic matrix, and the strength according to the composite rule can be obtained, thereby improving the degree of freedom in design.

Further, the above composite can be easily obtained by the production method of the present invention.

Patent applicant Toyota Central Research Institute Co., Ltd. Same Ube Industries Co., Ltd.

Claims (1)

[Scope of Claims] (1) A continuous fiber bundle made of continuous fibers containing at least one member selected from the group consisting of ceramic, carbon, and metal, or a woven fabric made from the continuous fiber bundle; Fine particles consisting of at least one type of heat-resistant material selected from ceramic, carbon, metal, etc., existing in the vicinity of the continuous fibers, and heat-resistant material, such as ceramic, carbon, metal, etc., uniformly dispersed and interposed in the fiber gaps of the continuous fibers. An inorganic fiber-reinforced plastic composite comprising short fibers and/or whiskers made of at least one substance selected from substances, and a plastic matrix. (2) The inorganic fiber-reinforced plastic composite according to claim 1, wherein the average particle diameter of the fine particles is 1/30 or less of the average length of the short fibers and/or whiskers. (3) The inorganic fiber-reinforced plastic composite according to claim 1, wherein the ceramic is at least one selected from carbide, nitride, oxide, and boride ceramics. (4) The inorganic fiber reinforced plastic composite according to claim 3, wherein the carbide ceramic is silicon carbide, the nitride ceramic is silicon nitride, and the oxide ceramic is alumina. . (5) The ceramic is (i) an amorphous material consisting essentially of silicon, M, carbon and oxygen, or (ii) essentially consisting of β-SiC, MC, β-SiC and MC.
A solid solution of and/or an aggregate consisting of each crystalline ultrafine particle with a particle size of 500 Å or less of MC_(_1_-_X_) and amorphous SiO_2 and MO_2, or (iii
) A mixture of the amorphous substance of the above (i) and the aggregate of the crystalline ultrafine particles and the amorphous of the above (ii), (However, in the above formula, M represents Ti or Zr, and X is 0.
The inorganic fiber-reinforced plastic composite according to claim 1 or 2, wherein the inorganic fiber-reinforced plastic composite is characterized in that the composite material is larger than 1 and less than 1. (6) Fine particles for continuous fibers and short fibers and/or
The inorganic fiber-reinforced plastic composite according to claim 1, wherein the volume percentage of whiskers is 0.5 to 500%. (7) The blending ratio of continuous fibers to the composite is 10 to 7
The inorganic fiber-reinforced plastic composite according to claim 1, characterized in that the content is 0% by volume. (8) The plastic that is the matrix of the composite is epoxy resin, modified epoxy resin, polyester resin, polyimide resin, phenol resin, polyurethane resin, polyamide resin, polycarbonate resin, silicone resin, phenoxy type resin, polyphenylene sulfide, fluororesin, carbonized The inorganic fiber-reinforced plastic composite according to claim 1, which is selected from the group consisting of hydrogen-based resins, halogen-containing resins, acrylic acid-based resins, ABS resin copolyesters, and polyethers. body. (9) Continuous fiber bundles made of continuous fibers containing at least one component selected from the group consisting of ceramics, carbon, and metals or woven fabrics made of the continuous fiber bundles are made of heat-resistant materials such as ceramics, carbon, and metals. Fine particles consisting of at least one kind selected from A method for producing an inorganic fiber-reinforced plastic composite, which comprises impregnating a fibrous body produced by attaching whiskers with plastic and then solidifying it. (10) The method for producing an inorganic fiber-reinforced plastic composite according to claim 9, wherein the average particle diameter of the fine particles is 1/30 or less of the average length of the short fibers and/or whiskers. (11) The method for producing an inorganic fiber-reinforced plastic composite according to claim 9, wherein the ceramic is at least one selected from carbide, nitride, oxide, and boride ceramics. (12) Claim 11, characterized in that the carbide ceramic is silicon carbide, the nitride ceramic is silicon nitride, and the oxide ceramic is alumina.
A method for producing an inorganic fiber-reinforced plastic composite as described in Section 1. (13) The ceramic is (i) an amorphous material consisting essentially of silicon, M, carbon and oxygen, or (ii) essentially consisting of β-SiC, MC, β-SiC and MC.
A solid solution of and/or an aggregate consisting of each crystalline ultrafine particle with a particle size of 500 Å or less of MC_(_1_-_X_) and amorphous SiO_2 and MO_2, or (iii
) A mixture of the amorphous substance of the above (i) and the aggregate of the crystalline ultrafine particles and the amorphous of the above (ii), (However, in the above formula, M represents Ti or Zr, and X is 0. The method for producing an inorganic fiber-reinforced plastic composite according to claim 9 or 10, wherein the number is greater than 1 and less than 1. (14) The method for producing an inorganic fiber-reinforced plastic composite according to claim 9, wherein the volume ratio of fine particles, short fibers and/or whiskers to continuous fibers is 0.5 to 500%. (15) The blending ratio of continuous fibers to the composite is 10 to
Claim 9, characterized in that the content is 70% by volume.
A method for producing an inorganic fiber-reinforced plastic composite as described in Section 1. 5. The plastic that is the matrix of the composite is epoxy resin, modified epoxy resin, polyester resin, polyimide resin, phenol resin, polyurethane resin, polyamide resin, polycarbonate resin, silicone resin, phenoxy type resin, polyphenylene sulfide, fluororesin, hydrocarbon. The inorganic fiber-reinforced plastic composite according to claim 9, wherein the inorganic fiber-reinforced plastic composite is selected from the group consisting of resins, halogen-containing resins, acrylic acid resins, ABS resin copolyesters, and polyethers. manufacturing method. (17) The inorganic fiber-reinforced plastic according to claim 9, characterized in that many fine particles are attached near the surface of continuous fibers, and many short fibers and/or whiskers are attached to the outside thereof. Method of manufacturing the composite. (18) The method for producing an inorganic fiber-reinforced plastic composite according to claim 9, which comprises applying ultrasonic vibration to the treatment liquid. (19) The method for producing an inorganic fiber-reinforced plastic composite according to claim 9, characterized in that one treatment tank containing a treatment liquid is used. (20) The method for producing an inorganic fiber-reinforced plastic composite according to claim 9, characterized in that two or more treatment tanks containing treatment liquid are used. (21) A continuous fiber bundle or woven fabric is immersed in a treatment liquid in which fine particles are suspended, and then immersed in a treatment liquid in which short fibers and/or whiskers are suspended, so that many fine particles are placed near the surface of the continuous fibers. 21. The method for producing an inorganic fiber-reinforced plastic composite according to claim 20, wherein a large number of short fibers and/or whiskers are attached to the outside of the composite.