JPH05329945A - Manufacture of continuous fiber reinforced thermoplastic composite material - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing industrially efficiently and economically a continuous fiber reinforced thermoplastic composite material sufficiently impregnated with resin in its reinforced fiber bundle. CONSTITUTION:By the use of fiber with high strength and high elasticity having higher melting point and/or decomposing point than that of at least one or more kinds of matrix components to be a reinforcing component and polyamide to be a matrix component or thermoplastic resin fiber having a compatibility with polyamide, knitted fabric is formed and subsequently treated, and then dried, by a polyamide solution, and it is laminated as desired to subsequently be molded at a higher temperature than the melting of polyamide or the thermoplastic resin having compatibility with polyamide, and at a lower temperature than the melting of the fiber with high strength and high elasticity.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a continuous fiber-reinforced thermoplastic composite material, and more particularly to a continuous fiber-reinforced thermoplastic composite material in which a resin is sufficiently impregnated in a reinforcing fiber bundle, which is industrially efficient and economical. The present invention relates to a method of manufacturing.

[0002]

2. Description of the Related Art In recent years, due to diversification of required physical properties, thermoplastic resins have come to be used in various fields in addition to thermosetting resins conventionally used for composite materials. The fiber-reinforced thermoplastic composite material used here can be roughly classified into two types in the intermediates through which it is obtained. One of them is that the thermoplastic resin and the reinforcing fiber are already sufficiently adhered in the intermediate body, and the molding after laminating the intermediate body is mainly shaping, and is generally called a tape material. It is what The other is when the intermediate is a knitting material consisting of reinforcing fibers and thermoplastic resin fibers.

In the former case, since the reinforcing fiber bundle has already been sufficiently impregnated with the resin in the obtained intermediate, it is sufficient to perform shaping in the molding process. A molding cycle of a relatively low pressure and a short time at a temperature above the melting point is possible. However, this intermediate body is rigid, and it is necessary to devise a special molding method and bagging method in order to insert the laminated product into a mold and perform molding, which complicates the overall work, and You will need skill and experience.

On the other hand, in the latter case, since the knitting and weaving material itself is flexible, it can be used in a complicated mold without the difficulty of the former case. However, in this method, unlike the former case when molding, it is necessary to simultaneously impregnate the resin into the reinforcing fiber bundle and perform shaping, and since thermoplastic resins generally have high melt viscosity, they are reinforced. In order to sufficiently impregnate the fiber bundle with the resin, a relatively high pressure and a long molding cycle are required at a temperature equal to or higher than the melting point of the thermoplastic resin.

Further, in these continuous fiber reinforced thermoplastic composite materials, the high specific strength and high specific rigidity are limited to the direction of the reinforcing fibers, and they are put into practical use after being formed into a plate shape or a curved surface shape. In some cases, it also has a drawback that it is weak against stress generated in directions other than the fiber direction. When a two-dimensional woven fabric or knitted fabric is used as a weaving material, its interlaminar strength is also significantly lower than that in the fiber direction. As one method for compensating for these drawbacks, a method of using a three-dimensional woven fabric, a three-dimensional knitted fabric or a braid for the reinforcing base material has been proposed. However, in order to sufficiently impregnate the reinforcing fiber bundle with the resin, in the case of a structure in which the reinforcing fibers are intricately entangled intricately, such as a three-dimensional woven fabric, a three-dimensional knitted fabric, or a braid, a special, For example, a method such as the RIM molding method is used, and in press molding, molding at a temperature higher than the melting point of the thermoplastic resin and at a relatively high pressure for a long time is required.

In order to solve this, for example, the yarns constituting the woven fabric, the knitted fabric or the braid are made by mixing the reinforcing fibers and the thermoplastic resin fibers, or the thermoplastic fibers are dispersed in the reinforcing fibers. It has been proposed to use such a thing. However, in the former case, there are problems such as breakage of the reinforcing fiber in the mixed fiber process and the resulting cost increase, and in the latter case, there are problems such as the cost increase due to the powdering process and the process of applying the powder to the reinforcing fiber. The organic fiber or glass fiber reinforced polyamide composite material, which cannot be expected to have the added value as high as that of plastic, has a problem in economical efficiency.

Although a method of treating with a solution has been proposed, it is necessary to repeat the impregnation step and the drying step many times in order to increase the volume capacity of the matrix resin from 30% to 40% in the case of treating with only the solution. Yes, it is very complicated work.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a continuous fiber reinforced composite material in which a matrix is a polyamide or a resin compatible with a polyamide, and a reinforcing fiber is sufficiently impregnated with the resin in an industrially efficient manner. It is an object of the present invention to provide a manufacturing method for economical production.

[0009]

That is, the present invention provides a high-strength and high-elasticity fiber having at least one melting point and / or a decomposition point higher than that of a matrix component, which is a reinforcing component, and a polyamide or a polyamide, which is a matrix component. A weaving material composed of compatible thermoplastic resin fibers is previously treated with a polyamide solution and dried, and after laminating this, a temperature at which the thermoplastic resin compatible with polyamide or polyamide is melted or higher. Provided is a method for producing a continuous fiber-reinforced thermoplastic composite material, which comprises molding at a temperature equal to or lower than a temperature at which high-strength and high-elasticity fibers melt.

The present invention also relates to a textile material made of high-strength and high-elasticity fibers having a melting point and / or a decomposition point higher than that of at least one matrix component, which is a reinforcing component, and is previously treated with a polyamide solution and dried, This and
After laminating a weaving material or film made of fibers of a thermoplastic resin having compatibility with polyamide or a polyamide serving as a matrix component at a fixed ratio, a temperature at which a thermoplastic resin having compatibility with polyamide or polyamide is melted, Provided is a method for producing a continuous fiber-reinforced thermoplastic composite material, which is characterized in that the high-strength and high-elasticity fiber is molded at a temperature below the melting temperature.

The high-strength and high-elasticity fiber having a higher melting point and / or decomposition point than the matrix component serving as a reinforcing component used in the present invention may be any fiber usually used as a fiber reinforcing material, for example, carbon fiber or glass. Fibers, aramid fibers, metal fibers and the like can be mentioned. Moreover, the form is a continuous fiber.

In the present specification, "polyamide" means one having a repeating unit of -CO-NH- in the polymer structure, and examples thereof include nylon 6, nylon 66, nylon 46 and the like. These may be used alone or in combination of two or more.

In the present specification, the "resin having compatibility with polyamide" includes a resin which is compatibilized with polyamide by using a compatibilizing agent together, such as polyethylene, polypropylene, polycarbonate, polyphenylene sulfide and polyether. Examples thereof include ether ketone.
When a compatibilizer is used, it can be kneaded in advance at the stage of preparing the thermoplastic resin fiber, or the fiber can be used for surface treatment.

In the present specification, the term "woven fabric" includes not only ordinary two-dimensional woven fabric or knitted ternary structure and its deformation, but also three-dimensional woven fabric, three-dimensional knitted fabric and braid. "Three-dimensional fabric" basically consists of X-axis, Y-axis and Z-axis,
It means that they are orthogonal or entangled at 90 °, respectively, but it does not limit at what angle the X-axis, Y-axis, and Z-axis are in contact or entangled. Furthermore, the "three-dimensional knitted or braided" refers to, for example, one having a structure as described in the material for the Society of Industrial Materials, Japan, and the 8th Industrial Materials Research Society open lecture material, but is not limited to this. Not a thing.

As the solvent for the polyamide, methanol,
Examples thereof include ethylene glycol, halogenated alcohols, phenol, cresol, resorcinol, formic acid, acetic acid, glutaric acid, DMSO, DMF, hydrochloric acid, sulfuric acid, phosphoric acid, etc., all of which require high temperature or low solubility. In addition, the polyamide itself may be deteriorated, which is not preferable for use in the present invention.
On the other hand, various metal halide-alcohol-based solvents can be used at room temperature and have high solubility, which is preferable for use in the present invention. Therefore, a polyamide solution can be obtained by dissolving polyamide in such a solvent at room temperature. The polyamide dissolved in the solvent may be in the form of fiber, chips, powder or film. The concentration of the polyamide solution is preferably 5 to 3
It is 0% by weight, more preferably 1020% by weight.
When the concentration of the polyamide solution is less than 5% by weight, the amount of polyamide finally precipitated is small, and thus the effect is small. On the other hand, when it exceeds 30% by weight, the viscosity of the solution becomes high, and the effect is short. Impregnation into the fiber bundle is not complete.

The method for producing the continuous fiber-reinforced thermoplastic composite material of the present invention will be described in more detail below. First,
A conventional method is used to form a weaving material composed of reinforcing fibers and thermoplastic resin fibers, or a weaving material composed only of reinforcing fibers, and this is dipped in a polyamide solution (normal temperature) for 1 to 2 minutes. In this case, it is preferable that the solution is a liquid flow that penetrates each textile material, and it is more preferable that the opening effect is simultaneously imparted at this stage. Here, in the case of a knitting material composed of reinforcing fibers and thermoplastic resin fibers, it is important that the immersion time is not too long. Then, the product treated with the solution is lightly squeezed and washed with water. As a washing method,
The most effective way is to apply a shower. At this stage, the metal halide and alcohol are washed off and the polyamide is regenerated. It is important to wash thoroughly the polyamide to be regenerated here so that the metal halide does not remain.
Further, this is squeezed and dried.

After treatment with a polyamide solution, in the case of a textile material consisting of reinforcing fibers and thermoplastic resin fibers, this is
In the case of a knitting material consisting of ˜20 sheets and consisting only of reinforcing fibers, a reinforcing fiber knitting material and a thermoplastic resin fiber knitting material having compatibility with polyamide or polyamide are laminated at a fixed ratio, and a three-dimensional woven fabric In the case of a knitting material such as a three-dimensional knitted fabric or a braid, it is subjected to the next step as it is. Next, put this in the mold, pressure 10-50kg
/ Cm ² , and the temperature is 240 to 290 ° C for 10 to 30 minutes to obtain a composite material.

Next, the present invention will be specifically described with reference to examples. Example 1 Glass fibers of 1150 tex and 2000 filaments were used as reinforcing fibers, and 189 was used as thermoplastic resin fibers.
A woven fabric (50 cm x 50 cm x 0.20 cm) composed of 0 denier and 320 filaments of nylon 6 fiber and composed of 10 yarns / inch warp (glass fiber) and 10 yarns / inch weft (nylon 6 fiber) Created. The fabric was previously treated with an oxidizing desizing agent to remove the sizing agent adhering to the glass fibers. Next, 10 g of potassium chloride was completely dissolved in 30 g of methanol, and 5 g of nylon 6 film was gradually added thereto to completely dissolve it to obtain a polyamide solution. The obtained solution was colorless and transparent and had a slight viscosity. This solution was put in a vat, and the woven fabric was cut into a certain size (15 cm × 15 cm), and the mixture was stirred to such an extent that the fiber bundle was loosened. After taking this out of the vat, it was thoroughly washed with shower water. At this stage, nylon 6 was regenerated on the surface of the woven fabric and in the fiber bundle, and white matter was attached to the surface. Then, it was sufficiently dried with a dryer and subjected to the next molding step.

Considering the direction of the reinforcing fibers, 6 pieces of this woven fabric were laminated so that the directions of the fibers were alternately 0 °, 90 °, and a mold (150 mm long, 150 horizontal)
mm) and performed under the following two molding conditions.

(Molding condition 1) After setting a mold in a press machine, deaeration is performed up to 10 Torr, and heating is started while applying a pressure of 5 kg / cm ² . The heating rate was 10 ° C./min. After that, when the temperature of the mold reaches 200 ° C., the pressure applied to the mold is changed within the range of 10 to 50 kg / cm ² ,
In this state, cooling is started 5 minutes after the mold temperature reaches 250 ° C. The temperature lowering rate was 7 ° C./min. When the mold temperature reached 50 ° C., air was introduced and the load was removed, and a molded product (15 cm × 15 cm × 0.1 cm) was taken out from the mold.

(Molding condition 2) When the temperature of the mold reaches 200 ° C., the pressure applied to the mold is set to 30 kg / cm ^2, and in this state the cooling is started from the time when the mold temperature reaches 250 ° C. Was the same as molding condition 1 except that the time until was changed in the range of 0 to 20 minutes.

Next, the void ratio of the obtained molded product was measured (JIS-K7053) and used as a measure of moldability. The results obtained under molding condition 1 are shown in Table 1, and the results obtained under molding condition 2 are shown in Table 2.

[0023]

[Table 1]

[0024]

[Table 2]

Example 2 1150 tex, 2000 filament glass fiber was used for warp and weft, and pre-sized fabric (50 cm × 5) with warp density of 10 yarns / inch and weft density of 10 yarns / inch.
0 cm x 0.2 cm) was prepared. This was treated with a polyamide solution in the same manner as in Example 1, and after washing with water, nylon 6 was regenerated and dried. 18 pieces of this fabric and warp and weft threads
90 denier, 20 filament nylon 66 fiber with a weft density of 10 fibers / inch (50 cm
X 50 cm x 0.2 cm) are alternately laminated by 3 sheets and molded in the same manner as in Example 1 to obtain a composite material (15 cm x 15 cm).
cm × 0.1 cm) was obtained. The void ratio of the obtained composite material was measured. The results are shown in Tables 1 and 2.

Comparative Example 1 A composite material was obtained in the same manner as in Example 1 except that the desizing treatment was performed without the polyamide solution treatment. The void ratio of the obtained composite material was measured. The results are shown in Tables 1 and 2.

As is clear from Table 1, in Examples 1 and 2, even when molded at a lower pressure than in Comparative Example 1, the porosity was considerably low and the impregnability was good. Further, as is clear from Table 2, in Examples 1 and 2, the void ratio is considerably lower than in Comparative Example 1 even when molding is performed for a shorter time, and the impregnation property is good.

Example 3 Glass fiber of 1150 tex and 2000 filaments was used as the reinforcing fiber, and 189 was used as the thermoplastic resin fiber.
Nylon 6 fiber of 0 denier and 320 filaments is used, the density of 4 glass / inch consisting of 2 glass fibers and 2 nylon 6 fibers as X axis, 2 glass fibers and 2 nylon 6 fiber as Y axis. A three-dimensional fabric (15 cm × 15 cm × 0.5 cm) having a density of 4 fibers / inch and a density of 7 fibers / inch composed of two glass fibers and two nylon 6 fibers as the Z axis was prepared. . This three-dimensional woven fabric was previously treated with an oxidizing desizing agent in order to remove the sizing agent adhering to the glass fibers. next,
10 g of potassium chloride was completely dissolved in 30 g of methanol, and 5 g of nylon 6 film was gradually added thereto to completely dissolve it. The obtained polyamide solution was colorless and transparent and had a slight viscosity. This solution is placed in a vat, and the three-dimensional woven fabric previously cut into a certain size (15 cm × 15 cm) is placed in the vat and stirred to such an extent that the fiber bundle is loosened. Next, this is taken out from the vat and thoroughly washed with shower water. At this stage, nylon 6 was regenerated on the surface of the woven fabric and in the fiber bundle, and a white one was attached to the surface. Next, it was sufficiently dried in a dryer and molded in the same manner as in Example 1 to obtain a composite material (15 cm × 15
cm × 0.2 cm) was obtained. Table 3 shows the void content measurement results of the composite material obtained under molding condition 1, and Table 4 shows the void content measurement results of the composite material obtained under molding condition 2.

[0029]

[Table 3]

[0030]

[Table 4]

Comparative Example 2 A composite material was obtained in the same manner as in Example 3 except that the desizing treatment was performed without the polyamide solution treatment. The measurement results of the void ratio of the composite material are shown in Tables 3 and 4.

As is clear from Table 3, Example 3 has a considerably low void ratio even when molded at a lower pressure than Comparative Example 2, and has a good impregnation property. Further, as is clear from Table 4, Example 3 has a considerably low void ratio even when molded in a shorter time than Comparative Example 2, and has good impregnability.

[0033]

According to the present invention, in molding a continuous fiber-reinforced composite material using a textile material as a molding intermediate, it becomes possible to shorten the molding time and reduce the molding pressure. Can be manufactured industrially efficiently and economically.

[Procedure amendment]

[Submission date] January 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

As the solvent for the polyamide, methanol,
Examples thereof include ethylene glycol, halogenated alcohols, phenol, cresol, resorcinol, formic acid, acetic acid, glutaric acid, DMSO, DMF, hydrochloric acid, sulfuric acid, phosphoric acid, etc., all of which require high temperature or low solubility. In addition, the polyamide itself may be deteriorated, which is not preferable for use in the present invention.
On the other hand, various metal halide-alcohol-based solvents can be used at room temperature and have high solubility, which is preferable for use in the present invention. Therefore, a polyamide solution can be obtained by dissolving polyamide in such a solvent at room temperature. The polyamide dissolved in the solvent may be in the form of fiber, chips, powder or film. The concentration of the polyamide solution is preferably 5 to 3
It is 0% by weight, more preferably 10 to 20% by weight. When the concentration of the polyamide solution is less than 5% by weight, the amount of polyamide finally precipitated is small, and thus the effect is small. On the other hand, when it exceeds 30% by weight, the viscosity of the solution becomes high, and the effect is short. Impregnation into the fiber bundle is not complete.

Claims (3)

[Claims] 1. A high-strength and high-elasticity fiber having a melting point and / or a decomposition point higher than that of at least one matrix component, which is a reinforcing component, and polyamide or a fiber of a thermoplastic resin having compatibility with the polyamide, which is a matrix component. The textile material composed of the above is treated with a polyamide solution in advance and dried, and after laminating this, the temperature at which the polyamide or the thermoplastic resin having compatibility with the polyamide is melted or higher, and the temperature at which the high strength and high elasticity fiber is melted A method for producing a continuous fiber-reinforced thermoplastic composite material, characterized by being molded as follows. 2. A textile material made of high-strength and high-elasticity fibers having a melting point and / or a decomposition point higher than that of at least one matrix component as a reinforcing component is previously treated with a polyamide solution and dried. After laminating a weaving material or film made of fibers of a thermoplastic resin having compatibility with polyamide or polyamide as a component at a constant ratio, a temperature at which a thermoplastic resin having compatibility with polyamide or polyamide is melted,
A method for producing a continuous fiber-reinforced thermoplastic composite material, characterized in that the high-strength and high-elasticity fiber is molded at a temperature not higher than its melting temperature. 3. The method for producing a continuous fiber-reinforced thermoplastic composite material according to claim 1, wherein the knitting material is a two-dimensional woven fabric or knitted fabric, a three-dimensional woven fabric, a knitted fabric or a braid.