JP4524481B2 - Manufacturing method of fiber reinforced resin composite - Google Patents

Description

  The present invention relates to a method for producing a fiber reinforced resin composite in which a resin is reinforced with fibers, and a fiber reinforced resin that can be used as various vehicle parts, industrial equipment parts such as gears and pulleys. The present invention relates to a method for producing a composite.

  Conventionally, fiber reinforced resin composites can be obtained by combining various fibers and resins into composites to obtain materials exhibiting various characteristics, and can be used as a substitute for metal materials for the purpose of weight reduction. Widely used. For example, for fiber gears, fiber reinforced resin composites are used, and gears for high loads where metal materials such as conventional steel are generally used in recent years for the purpose of reducing weight and eliminating gear meshing noise. Those using reinforced resin composites are being studied.

  Conventionally, for the purpose of reducing the weight of gears made of metal materials, a fiber reinforced resin composite made by impregnating a woven or knitted fabric such as cotton, glass fiber, carbon fiber, or aramid fiber with a phenol resin, an epoxy resin, or the like into a gear shape. There exists what was cut and processed (refer to patent documents 1). However, a fiber reinforced resin composite impregnated and cured with a woven or knitted fabric is processed into a gear shape by mechanical cutting, so there is a problem of high costs due to a large amount of material loss, and a large amount of cutting waste is generated by cutting. There is a problem that it occurs and places a load on the environment.

  In recent years, a load applied to a vehicle gear is further increased, and in response to a demand for a high-performance gear, a fiber reinforced resin composite made of a fiber reinforcing material including a heat-resistant, high-strength, high-modulus fiber (Patent Documents 2 and 3) However, it is difficult to form gears using only high-strength and high-modulus fibers, and it is difficult to form gears using only high-strength and high-modulus fibers. In consideration of an increase in load accompanying rotation and long-term use in a higher temperature atmosphere, the disclosed technology cannot always provide a gear that exhibits sufficient performance.

On the other hand, a fiber-reinforced resin gear is disclosed in which reinforcing fibers and thermosetting resin are kneaded, an alignment material extruded from a nozzle is filled in a mold, and heat-press molding is performed (see Patent Document 6). ). However, since the fiber reinforced resin gear obtained in this manner orients the kneaded reinforcing fibers, the orientation material extruded from the nozzle needs to have fluidity, so that the orientation material has fluidity. Therefore, it cannot be said that the amount of reinforcing fiber for this purpose can cope with the increase in load accompanying the recent high-speed rotation of gears.
JP-A-2-241729 Japanese Patent Laid-Open No. 5-240325 JP-A-7-113458 JP-A-8-17489 JP 2002-273729 A JP-A-60-206628

  In view of the background of the prior art, the present invention is to provide a method for producing a fiber-reinforced resin composite that is excellent in heat resistance and can be used for a long time even when a high load is applied. Furthermore, it is providing the manufacturing method of the fiber reinforced resin composite which can reduce cutting waste etc. markedly compared with the manufacturing method of the conventional fiber reinforced resin composite, and can manufacture at low cost.

In order to solve the above problems, the present invention employs the following means. That is, the method for producing a fiber-reinforced resin composite of the present invention is a method for producing a fiber-reinforced resin composite comprising a resin and a fiber reinforcing material . B. introducing the fiber reinforcing material together with a fluid into a molding die having a fluid outlet when filling the fiber reinforcing material into the molding die ; C. a step of heating and pressurizing the molding die of A; B. injecting resin into the mold of B; It is characterized by passing through a step of molding the fiber reinforced resin composite by pressurizing the C mold .

  According to the present invention, when a fiber reinforced resin composite comprising a resin and a fiber reinforcing material is filled into a molding die, the fiber is introduced into the molding die having a fluid outlet with the fluid. By manufacturing by the method of filling, the fiber reinforcement can be prevented from being scratched, etc., so it has excellent heat resistance, can be used for a long time even when high load is applied, and compared with the conventional one Cutting waste and the like can be greatly reduced, and it can be manufactured at low cost.

  The present invention has the above-mentioned problem, that is, it has excellent heat resistance, can be used for a long time even when a high load is applied, and can be manufactured at a low cost by greatly reducing cutting waste and the like compared to the conventional one. As a result of diligent research on possible fiber reinforced resin composites, in the method for producing fiber reinforced resin composites composed of resin and fiber reinforcement, the fibers are identified together with the fluid when filling the mold with the fiber reinforcement. It was clarified that this problem can be solved all at once by adopting a method of introducing into a mold and filling it.

  That is, the feature of the present invention is that, as a means for producing a fiber reinforced resin composite obtained by impregnating and curing a resin in a fiber reinforcing material, when the fiber reinforcing material is filled into a molding die, a specific, ie, fluid A specific means of introducing and filling the fiber together with the fluid into a molding die having an outlet is employed.

  By adopting such specific means, conventionally, for example, when using a fiber reinforced resin composite as a gear, when filling the fiber reinforcing material, the fiber has to be filled in a random direction. In addition, when the molded fiber reinforced resin composite is to be formed into a gear shape, the fiber reinforcing material is filled in a specific direction while being cut into a gear shape. In addition, the filling density can be freely adjusted, and further, for example, by using a specific molding die pre-shaped in a gear shape, further cutting process and the like are unnecessary, and the manufacturing process is simplified. This makes it possible to reduce costs and reduce cutting waste. In addition, since the fiber is not passed through the process of processing it into a woven or knitted fabric or nonwoven fabric as in the prior art, the fiber is free of scratches, etc., so it has excellent heat resistance and can be used for a long time even under high loads. A fiber reinforced resin composite can be obtained.

The fluid referred to in the present invention may be any fluid as long as the fibers can be uniformly filled in the molding die, and examples thereof include gases and liquids. Preferably, the fluid does not chemically degrade the fibers. More preferably, air or water is preferable from the viewpoints of economic efficiency and environmental impact. Examples of a method for filling a mold with fibers together with a fluid include, for example, a method in which fibers are dispersed and transported and filled in a gas, a liquid in which fibers are dispersed is poured into a mold, and the liquid is evaporated and dried. Thus, a method of filling fibers can be exemplified. The fiber reinforced resin composite of the present invention is preferably molded through the following steps,
A. Filling the specific mold with a fiber together with a fluid;
B. Heating and pressurizing the molding die of A,
C. Injecting resin into the mold of B,
D. Pressurizing the mold of C to form a fiber-reinforced resin composite;
It is.

  According to the specific filling means of the present invention, it is possible to fill a molding die together with a fluid with a fiber amount necessary for a fiber-reinforced resin composite having a desired strength, and in the next step by heating the molding die. When the resin is injected, the resin sufficiently flows and can be uniformly integrated with the fiber reinforcing material. The heating temperature here is not particularly limited, and is usually a temperature at which the resin to be injected in the next step sufficiently flows. In addition, by pressurizing the molding die filled with fibers and compressing the resulting fiber-reinforced resin composite to a predetermined size, the fiber reinforcement flows when the resin is injected in the next step, and the fibers It is possible to reinforce the resin with fibers uniformly without shifting. The pressure applied here is not particularly limited, and a pressure capable of compressing to + 10% or less of the dimension of the finally obtained fiber-reinforced resin composite is preferable. Next, a resin is injected into a molding die filled with fibers, heated and pressurized to impregnate the fiber reinforcing material with the resin. The injection of the resin is not particularly limited as long as the fiber reinforcing material and the resin can be uniformly integrated, for example, by injecting the resin after depressurizing the inside of the mold before injecting the resin, It is also possible to prevent formation of bubbles and the like in the obtained fiber reinforced resin composite. Finally, the fiber reinforced resin composite is molded by pressurizing the mold. The pressurizing pressure condition here may be any condition as long as it falls within the dimensions of the predetermined fiber-reinforced resin composite, and is preferably + 3% or less of the predetermined dimension. Moreover, the temperature of the molding die after injecting the resin is not particularly limited. For example, when a thermosetting resin is used, the temperature is preferably equal to or higher than the curing temperature of the resin to be used.

  The fiber-reinforced resin composite molded in this way can be used as a part as it is, but as a post-processing, the surface of the composite is polished to remove resin burrs and fiber fluff, resulting in a cleaner product. It is also possible to finish. By forming the fiber reinforcing material in this way, it becomes possible to omit the process of processing the conventional fiber reinforcing material into a woven or knitted fabric or a non-woven fabric, and when processing the fiber into a spun yarn or a non-woven fabric. Damage such as scratches received by passing the passing card process and crimping process can be prevented, and a fiber-reinforced resin composite with high heat resistance can be obtained. In this way, by molding the fiber reinforced resin composite by the production method of the present invention, it is possible to reduce the cost by omitting the step of cutting into the shape of the part by performing cutting or the like as in the past. It is possible to reduce the load on the environment by eliminating the generation of cutting waste and the like.

  In the present invention, the molding die is not particularly limited as long as it has a fluid outlet, and has substantially the same shape as the molded body when the obtained fiber-reinforced resin composite is actually used. It is preferable to use a molding die. For example, if the fiber-reinforced resin composite obtained is used as a gear, it is preferable to use a gear-shaped molding die. The present invention is characterized in that a molding die having a fluid outlet introduced into the molding die together with fibers is used as the molding die, and can be obtained by using such a specific molding die. The fiber reinforced resin composite is obtained in the shape of a mold, and the process of creating a shape by cutting the fiber reinforced resin composite once created as in the past, and cutting waste accompanying cutting is said to be reduced In addition to demonstrating the advantages, it is possible to reduce costs and reduce the burden on the environment. In addition, by using such a specific molding die, the amount of fibers filled in the die can be freely adjusted, and the physical properties of the fiber reinforced resin composite can be controlled, For example, in the case of a vehicle gear, it is possible to create and provide a fiber reinforced resin composite that meets the required characteristics freely from low to high loads on the gear.

  The fiber reinforcing material in the present invention is not particularly limited as long as it has a property that can withstand the heating by the molding die, the processing temperature in the pressure molding, and the processing pressure, and preferably the resin used It is preferable from the viewpoint of the physical properties of the resulting fiber reinforced resin composite to use fibers having good adhesion. The length of the fiber used as the fiber reinforcing material is preferably a short fiber of 1 mm or more and 30 mm or less, and more preferably the ratio of the fiber length L (mm) to the fiber warp D (mm) is L / D = 200 or more. Some are preferable, and short fibers having a fiber length of 3 mm to 10 mm are particularly preferable. By using such short fibers, it is easy to fill the molding die, and the resin can be uniformly mixed with the resin, and the strength of the obtained fiber-reinforced resin composite can be adjusted to a desired one. The ratio of the fiber reinforcing material contained in the fiber reinforced resin composite varies depending on the desired strength of the fiber reinforced resin composite, but is preferably 10% by volume or more and 75% by volume or less, and more preferably 25% by volume. % Or more and 60% by volume or less is preferable. When the ratio of the fiber reinforcing material in the fiber reinforced resin composite is less than 10% by volume, the effect of reinforcing the resin with fibers is hardly seen. Further, when the fiber ratio exceeds 75% by volume, the fiber occupies a too high ratio, and the fiber reinforced resin composite causes problems such as easy fiber dropout during use.

  Moreover, it is preferable that the fiber reinforcing material of the fiber reinforced resin composite contains at least 10% by volume or more of high-strength and high-modulus fibers having a tensile strength of 15 cN / dtex or more and a tensile modulus of 350 cN / dtex or more. The fiber reinforced resin composite thus obtained can withstand such a high load during use. The fiber reinforcing material is preferably composed of fibers having a melting point or decomposition temperature of preferably 250 ° C. or higher, more preferably 300 ° C. or higher. By forming a fiber reinforced resin composite using such fibers, the fibers of the fiber reinforced resin composite can be heat-resistant without causing thermal degradation at the processing temperature during molding and the ambient temperature during actual use. It becomes possible to make a fiber reinforced resin composite having excellent properties. Examples of such fibers include nylon 66 fiber, polyethylene terephthalate fiber, polyphenylene sulfide fiber, fluorine-based fiber, aramid fiber, carbon fiber, glass fiber, boron fiber, ceramic fiber, polyimide fiber, polyparaphenylene benzobisoxazole (hereinafter, (Abbreviated as PBO) or the like.

  The high-strength and high-modulus fiber is preferably a straight, cut fiber that has not been crimped or the like, and the use of such a cut fiber makes it possible to produce scratches in the crimping process as compared to a fiber that has been crimped. Therefore, the fiber reinforced resin composite obtained can be provided with a high heat resistance. Such high-strength and high-modulus fibers include para-aramid fibers, carbon fibers, glass fibers, boron fibers, ceramic fibers, ultra-high strength polyethylene fibers, polyketone fibers, PBO fibers, wholly aromatic polyester fibers, polyimide fibers, and polyvinyl chloride. It may be at least one or more kinds of fibers selected from alcohol-based fibers, and more preferably at least one or more kinds selected from para-aramid fibers, carbon fibers, glass fibers, PBO fibers, and wholly aromatic polyester fibers. Are good from the point of heat resistance. As such fibers, para-aramid fibers are “Kevlar” (R) manufactured by Toray DuPont Co., Ltd. or “Technora” (R) manufactured by Teijin Limited, and carbon fibers are manufactured by Toray Industries, Inc. “Torayca” (R), “Zeylon” (R) manufactured by Toyobo Co., Ltd. can be used as the PBO fiber, and “Vectran” (R) manufactured by Kuraray Co., Ltd. can be used as the fully aromatic polyester fiber.

  The resin used in the present invention may be any resin such as a thermosetting resin or a thermoplastic resin, such as a phenol resin, an epoxy resin, an unsaturated polyester resin, a polyimide resin, a polyaminoamide resin, a polyether sulfone resin, a polyresin. Ether ether ketone resin, polyamideimide resin, CP resin (crosslinked polyesteramide resin, crosslinked polyaminoamide resin), polyamide resin, polyester resin, polyphenylene sulfide resin, polyethylene resin, polypropylene resin and the like are used. Among these, thermosetting resins are preferable from the viewpoint of resin strength, heat resistance, and the like. For example, epoxy resins, phenol resins, polyimide resins, CP resins (crosslinked polyesteramide resins, crosslinked polyaminoamide resins), and the like are preferably used. .

  Next, the manufacturing method of the fiber reinforced resin composite of this invention is demonstrated in detail using figures in the example of a gearwheel. What is shown in FIG. 1 is a concave part of a molding die whose horizontal section (FIG. 3) has a gear shape, and is provided with a fluid outlet on the bottom side. The fibers introduced together with the fluid into the mold from the upper fiber inlet of FIG. 1 are separated into the fluid and the fibers at the fluid outlet, and only the fiber reinforcement remains in the mold as shown in FIG. Next, as shown in FIG. 5, the mold upper lid (FIG. 4) is placed on the fiber reinforcement, the mold lower lid is attached to close the fluid outlet, and the fiber reinforcement is compressed by pressing from the upper lid. Then, it is heated to the resin injection temperature in the next step. Further, a resin is injected into the fiber reinforcing material and pressed to form a fiber reinforced resin composite. Thus, by providing a fluid outlet in a part of the mold, it is possible to introduce the fiber together with the fluid into the molding mold and fill it. The shape of the fluid outlet is not particularly limited as long as the fiber and the fluid introduced into the mold can be separated and only the fluid can be discharged out of the mold. Preferably, a large number of fluid outlets are provided. More preferably, the entire surface of the mold on which the outlet is provided is the fluid outlet, and the size of one outlet is not more than 10 times the diameter of the fiber to be filled. As such a thing, what has air permeability and liquid permeability, such as a wire mesh, a knitted fabric, a nonwoven fabric, can be illustrated. Further, the fluid outlet is preferably fixed by screwing or the like so that it does not come off from the concave portion of the molding die due to the pressure when the fiber is introduced together with the fluid. When the fiber is introduced together with the fluid into a mold having no fluid outlet as in the conventional mold, the fluid without the escape field returns to the introduction port together with the fiber, so that the fiber cannot be filled into the mold. In addition, when only a small number of fluid outlets are provided, for example, when only one outlet is provided, the flow of fluid is concentrated at the outlet, and the distribution density of the fibers introduced in the entire mold is increased, so that it is uniform. It is difficult to obtain a fiber reinforced resin composite reinforced with fibers.

  Next, the present invention will be described in more detail with reference to a gear as an example.

Using the fiber reinforced resin composites prepared in Examples and Comparative Examples, characteristics were evaluated by the following methods. For the evaluation, assuming long-term use, the obtained sample was heat-treated in a dryer at a temperature of 230 ° C. for 7 days, and the properties before and after the heat treatment were evaluated.
[Tensile test]
Regarding the tensile strength of the fiber reinforced resin composite, in accordance with “JIS K 7073-1998 Tensile Test Method for Carbon Fiber Reinforced Plastic”, Autograph AG-10TE manufactured by Shimadzu Corporation was used and the tensile speed was 2 mm / min. The test was conducted. In addition, the test piece used what cut out the produced fiber reinforced resin composite in the following dimensions, and adhere | attached the tab made from a glass fiber reinforced plastic on both ends using the epoxy resin.
A. Total length: 200 mm or more Width at both ends: about 12.5mm
C. Gauge length: 100mm
D. Length of grip part: 35 mm or more Tab thickness: 1-2mm
F. Tab length: 50 mm or more [bending test]
Regarding the bending properties of the fiber reinforced resin composite, in accordance with “JIS K 7017: 1999 Fiber Reinforced Plastics—How to Obtain Bending Properties” Method A (3-point bending), a tensile compression tester SDW500S manufactured by Imada Manufacturing Co., Ltd. was used. The test was conducted at a test speed of 2 mm / min. In addition, the dimension of a test piece is as follows.
A. Test piece length: 60 mm or more Distance between outer fulcrums: 40mm
C. Specimen width: about 15mm
Example 1
A figure showing the amount of 35% by volume of a fiber reinforced resin composite that can obtain a para-aramid fiber “Kevlar” 29 (manufactured by Toray DuPont Co., Ltd.) having a fiber length of 3 mm and a single yarn fineness of 1.67 dtex together with a pressure of 98 kPa. It was introduced and filled in the molding die recess shown in FIG. The bottom of the recess is provided with a metal 300 mesh wire mesh as a fluid outlet. Thereafter, the fluid outlet at the bottom of the concave portion was closed, and the upper lid shown in FIG. 4 was placed from the fiber inlet, heated and pressurized to a temperature of 160 ° C. and a pressure of 5 MPa, and the inside of the mold was reduced to 67 kPa. Further, 68.6 parts by weight of 1,3-PBO (manufactured by Mikuni Pharmaceutical Co., Ltd.) and 31.4 parts by weight of MDA (manufactured by Mitsui Chemicals) were mixed and dissolved at 140 ° C., and stearyl bromide 1 weight A part added and stirred was poured into the mold and heated and pressurized at 160 ° C. and a pressure of 30 MPa for 30 minutes to form a fiber reinforced resin composite. Subsequently, the molded body taken out from the mold was heat-treated at each temperature in the order of 160 ° C., 180 ° C., and 200 ° C. for 1 hour, and finally heat-treated in a dryer at a temperature of 220 ° C. for 2 hours to obtain a fiber-reinforced resin composite. Obtained.

Examples 2 and 3
In the same manner as in Example 1, 20% by volume and 50% by volume of a fiber reinforced resin composite were obtained.

Comparative Examples 1-3
Using “Kevlar” 29 having a fiber length of 3 mm and a single yarn fineness of 1.67 dtex, the fluid flow was adjusted so that the nonwoven fabric produced by a known card and needle punch method would be 20% by volume, 35% by volume and 50% by volume. A fiber reinforced resin composite was obtained in the same manner as in Example 1 except that the nonwoven fabric was rounded into a concave portion of a conventional molding die having no outlet and was packed manually.

  Table 1 shows the results of Examples 1 to 3 and Comparative Examples 1 to 3 described above, which were subjected to heat treatment at a temperature of 230 ° C. for 7 days, cut out test pieces from those before and after the heat treatment, and subjected to a tensile test and a bending test.

上記実施例に示すとおり、本発明にかかる繊維強化樹脂複合体は、歯車形状の成形金型を用いて成形しているため、比較例に代表される従来の方法で得られる繊維強化樹脂複合体を切削加工することなく、歯車形状のものを得ることが可能であり、切削加工工程、切削屑を削減することが可能である。また、表１に示すとおり、本発明に係る繊維強化樹脂複合体は、比較例に代表される従来の方法で得られる繊維強化樹脂複合体に比べ、熱処理前、つまり初期の物性は同等であり、熱処理後、つまり長期間使用後の物性は高いことがわかる。つまり、繊維を直接成形金型へ充填しているため、繊維に引掻き傷等がなく、耐熱性に優れ、長期間の使用に耐えることができる。

As shown in the above examples, the fiber reinforced resin composite according to the present invention is molded using a gear-shaped molding die, so that the fiber reinforced resin composite obtained by a conventional method represented by a comparative example is used. It is possible to obtain a gear-shaped one without cutting, and it is possible to reduce the cutting process and cutting waste. Further, as shown in Table 1, the fiber reinforced resin composite according to the present invention has the same physical properties before heat treatment, that is, the initial physical properties, compared to the fiber reinforced resin composite obtained by the conventional method represented by the comparative example. It can be seen that the physical properties after heat treatment, that is, after long-term use are high. That is, since the fibers are directly filled into the molding die, the fibers are free from scratches, have excellent heat resistance, and can withstand long-term use.

It is a recessed part schematic diagram of the shaping die of the present invention. It is a recessed part perpendicular direction cross-sectional schematic diagram of the molding die of this invention. It is a recessed part bottom schematic diagram of the shaping die of this invention. 1 is a schematic view of an upper lid of a molding die of the present invention. It is the schematic at the time of the fiber reinforced resin composite shaping | molding of this invention.

Explanation of symbols

1: molding mold concave mold 2: fiber inlet 3: fluid outlet 4: fiber reinforcing material 5: resin inlet 6: molding mold upper lid 7: molding mold lower lid 8: fiber reinforcing material and resin

Claims (5)

In a method for producing a fiber reinforced resin composite comprising a resin and a fiber reinforcing material, A. B. introducing the fiber reinforcing material together with a fluid into a molding die having a fluid outlet when filling the fiber reinforcing material into the molding die ; C. a step of heating and pressurizing the molding die of A; B. injecting resin into the mold of B; A method for producing a fiber-reinforced resin composite, comprising a step of forming a fiber-reinforced resin composite by pressurizing the C mold . Method for producing a fiber reinforced resin composite according to claim 1 Symbol placement forming metal mold is characterized in that in the shape of a gear. The method for producing a fiber-reinforced resin composite according to claim 1 or 2 , wherein the fiber reinforcing material is a short fiber having a fiber length of 1 mm or more and 30 mm or less. Fiber-reinforced proportion to resin complex occupying the fiber reinforcing material The method for producing a fiber reinforced resin composite according to any one of claims 1 to 3, characterized in that 10 vol% or more 75% by volume or less . Fiber維補strong material, method for producing a fiber reinforced resin composite according to any one of claims 1 to 4, wherein the para-aramid.

Images