JP3391408B2 - Method for producing thermoplastic composite material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic composite material in which reinforcing fibers are impregnated with a thermoplastic resin, the molded body of which is an automobile part, a structural material such as a cylinder or a tank, or a building. It can be used in a wide range of fields such as reinforcing materials and reinforcing materials for aged buildings.

[0002]

2. Description of the Related Art Resin composite materials have been widely used for automobile parts and the like because they are lightweight and inexpensive. Conventionally, a thermosetting resin has been mainly used as the matrix resin, but it has drawbacks such as long cycle time in the manufacturing process, difficulty in cost reduction, and unsuitable for mass production.
Therefore, in recent years, a thermoplastic composite material has been attracting attention as a material that solves the above drawbacks.

As a method for producing a thermoplastic composite material, a pluto-fusion method is generally used. FIG. 1 shows a schematic side view of an impregnating die used in a general plutotrusion method. The bundle of the reinforcing fibers 4 is supplied with the thermoplastic resin through the impregnation die 5 and then taken out while being cooled and solidified. However, in such a simple pultrusion method, the thermoplastic resin only adheres to the reinforcing fiber bundle in the impregnation die, and a sufficient degree of impregnation cannot be obtained. This is because the thermoplastic resin has a very high viscosity when melted as compared with the thermosetting resin, and thus it is difficult to impregnate the reinforcing fibers between the single yarns.

Therefore, some techniques for improving the impregnating property have been proposed. (1) A method of handling and impregnating a reinforcing fiber bundle inside the impregnation die. In this method, the type of the thermoplastic resin is not limited and there is no problem of a solvent or the like, but the handling tension and the viscous resistance of the resin increase the take-up tension and it is difficult to improve the production rate. (2) A pre-impregnation method in which a solution or emulsion is previously impregnated. This method is not preferable for practical use because it has environmental hygiene and energy loss problems.
(3) Resin is pulverized in advance and adsorbed between the single yarns of the reinforcing fiber bundle,
A method of melting and impregnating after dispersing. (JP-A-52-7
823, Japanese Patent Publication No. 47-36467, etc.). This method requires various equipments for the resin powdering step and the impregnating step, and the process becomes complicated.
There is a problem in efficiency.

As described above, the reality is that a method for producing a thermoplastic composite material having an excellent impregnated state at low cost, efficiently and at high speed has not yet been obtained.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made various studies on a method of uniformly injecting and impregnating a highly viscous thermoplastic resin between individual filaments of a reinforcing fiber. After passing through a die that impregnates the reinforcing fibers with the thermoplastic resin, the thermoplastic composite material melted outside the die is pressed and compressed, so that the thermoplastic resin is press-fitted between each single yarn of the reinforcing fibers. It has been found that it is possible to significantly improve the impregnation degree. In addition, it has been found that it is possible to easily give an arbitrary cross-sectional shape to the thermoplastic composite material in parallel with pressurization / compression on the outside of the die.

The present inventors have completed the present invention as a result of further studies based on such findings.

[0008]

That is, the present invention provides the following method. In a method for producing a thermoplastic composite material in which reinforcing fibers are impregnated with a thermoplastic resin,
After the reinforcing fiber is impregnated with the thermoplastic resin inside the impregnation die, in order to further improve the degree of impregnation, the molten thermoplastic composite material is pressed and compressed in parallel with the outside of the impregnation die.
Then, the thermoplastic composite material is provided with an arbitrary cross-sectional shape, which is a method for producing a thermoplastic composite material. The method for producing a thermoplastic composite material as described above, characterized in that pressurization and compression are carried out by a nipple roller capable of being compressed with a linear pressure of 3 kg / mm or more.

Examples of the reinforcing fiber used in the present invention include carbon fiber, glass fiber, aramid fiber, metal fiber and ceramic fiber, but are not particularly limited thereto. Further, these fibers are preferably surface-treated in order to improve the adhesiveness with the thermoplastic resin.

As the thermoplastic resin used in the present invention, polyamide, polyester, polyarylate, polysulfone, polyarylensfide, polyethersulfone, polyetherimide, polyamideimide, polyetherketone, polycarbonate, Examples thereof include, but are not limited to, polyolefin, polyacetal, polystyrene and the like.

As a method of impregnating the reinforcing fiber with the thermoplastic resin inside the impregnation die used in the present invention, a general method such as a method of dipping and passing the reinforcing fiber in a melt of the thermoplastic resin is used. be able to.

As a method for pressurizing and compressing the thermoplastic composite material melted outside the impregnation die used in the present invention, compression such as a normal flat type nip roller or a pair of concave and convex nip rollers is used. Examples of the method include a method in which the roller is a one-step or multi-step roller with a concave groove, and the roller is passed through with tension applied alternately to the upper and lower sides. The method can be selected depending on the application of the thermoplastic composite material, but especially the wire It is preferable to use a nip roller that can be compressed with a pressure of 3 kg / mm or more. Here, the linear pressure of 3 kg / mm or more is required because when it is less than this, the thermoplastic resin cannot sufficiently enter between the individual filaments of the reinforcing fiber.

Further, as a method for giving an arbitrary cross-sectional shape used in the present invention, there is a method using a grooved roller, etc. Here, the groove shape is arbitrarily selected and pressed.
By compressing, at the same time as the improvement of the impregnation degree or after the improvement of the impregnation degree, a thermoplastic composite material having an arbitrarily selected cross-sectional shape can be molded.

Hereinafter, the present invention will be specifically described with reference to the drawings, but the present invention is not limited thereto. 2 to 9 schematically show an example of an apparatus or a part used in the manufacturing method of the present invention.

FIG. 2 is a schematic side view of a manufacturing apparatus used in the method for manufacturing a thermoplastic composite material according to the present invention.
4 and 5 are schematic front views of an example of a pressure compression roller used in the method for producing a thermoplastic composite material of the present invention. The bundle of the reinforcing fibers 4 passes through the impregnation die 5 to be supplied with the molten resin 3 in the impregnation die to become a molten thermoplastic composite material 6 and is drawn out of the impregnation die. The molten thermoplastic composite material exiting the die is placed between a plurality of sets of compression rollers consisting of a cooling drive roller 8 and a pressure cooling roller 9 cooled by cooling water or cooling air 10. While passing, the molten thermoplastic resin flows between the individual filaments of the reinforcing fiber due to the strong compressive force while being handled, and the impregnation is promoted. At the same time, while passing through each roller, the molten thermoplastic composite material is gradually cooled and solidified while being deformed into a sectional shape along the shape of the roller, so that the thermoplastic composite material has an arbitrary sectional shape. It becomes the material 7 and is taken up by the take-up roller 11. Rollers at this time
It is necessary that the surface temperature of the is adjusted in the range of 4 ° C to 70 ° C. This is because if the temperature drop of the molten thermoplastic resin is too early, it impedes the impregnation action, and if the cooling temperature is too high, the molten thermoplastic resin becomes difficult to separate from the roller surface, making continuous operation impossible. This is because The compression roller applies a linear pressure in the width direction or the diameter direction of the molten thermoplastic composite material in the range of 3 kg / mm to 15 kg /
It is provided in order to increase the impregnation degree by sufficiently press-fitting the resin between the single fibers by applying a pressure of mm. At this time, the temperature of the molten thermoplastic resin at the inlet of the compression roller is, for example, 235 ° C, and the temperature of the cooled and shaped thermoplastic composite material is preferably 70 ° C or lower.

FIG. 3 schematically shows another example of the manufacturing apparatus used in the method for manufacturing a thermoplastic composite material of the present invention. The molten thermoplastic composite material 6 is pressed and compressed by a driving nip roller composed of a cooled semi-circular grooved roller 12 and a semi-circular pressure roller 13 to improve the impregnation degree, and then arranged further up and down. It is cooled and shaped by passing through a plurality of cooling drive rollers 8. At this time, the improvement of the impregnation in the roller after the nip roller and the shaping depend on the tensile tension of the take-up roller 11, for example, from a fiber bundle of 13 μm × 1600 glass fibers and nylon 6. The tension of the molten thermoplastic composite material having a weight ratio of 50/50 is 3 kg to 15 kg, preferably 7 kg.
It is about kg. If the tension is too low, the contact pressure to the roller will be insufficient and the impregnation effect will be reduced, resulting in poor shaping. On the other hand, if the tension is too high, the single yarn of the reinforcing fiber will be broken and the strength of the thermoplastic composite material will be reduced.

In this way, a good quality thermoplastic composite material can be molded, but its cross-sectional shape is not limited to a tape-shaped rectangular cross-section, a circular cross-section, etc. Is what makes it possible. FIG. 6 shows a compression roller for giving a circular cross section, and FIG. 7 shows a schematic front view of an example of a compression roller for giving a deformed cross section (eyebrows type). FIG. 8 shows a band-shaped roller for giving a circular cross section, and FIG. 9 shows a schematic front view of an example of a shaping roller for giving a modified cross section (eyebrows type).
This shaping roller is cooled and shaped by passing through the rollers of the cross-sectional shape such as the groove shape of the rollers 16 and 17 alternately by the tension applied by the take-up roller, while cooling and shaping. It enables molding of a thermoplastic composite material having a cross section or a modified cross section.

[0018]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 Using the apparatus and parts shown in FIGS. 2 and 4, single fiber diameter of 13 μm as reinforcing fiber, glass fiber of 1600 single fibers of reinforcing fiber, nylon 6 as thermoplastic resin, It was supplied into the impregnation die at a weight ratio of 50%, and was pressed and compressed by a grooveless roller outside the impregnation die to produce a tape-shaped molding material. Other conditions of the device are as follows. -Reinforcing fiber feed rate: 50 m / min-Roller surface temperature: 25 ° C-Roller pressure: 11.4 kg / mm The tape-shaped molding material obtained has a density of its air content. When measured by the method, it was a low value of 5%, and the impregnability of the resin and the reinforcing fiber was uniform and good. The conditions and results are shown in Table 1.

[0020]

[Table 1]

(Example 2) The apparatus shown in FIG. 7 having an irregular cross section (eyebrow shape) was used as a compression roller, and the number of reinforcing fibers was 9600 and the supplying speed of the reinforcing fibers was 20 m / m.
A molding material having an irregular cross section (eyebrows shape) was produced under the same conditions as in Example 1 except that the min was set. The obtained molding material had a low air content of 7%, and the impregnability of the resin and the reinforcing fiber was uniform and good. Moreover, the cross-sectional shape was shaped into an eyebrow shape as designed. The conditions and results are shown in Table 1.
It was shown to.

Comparative Example 1 Using the apparatus shown in FIG. 10,
A thermoplastic resin was produced in the same manner as in Example 1. The obtained molding material had a high air content rate of 16%, and the shape of the molding material was somewhat poor. The conditions and results are shown in Table 1.

Comparative Example 2 Using the apparatus shown in FIG. 10,
A thermoplastic resin was produced in the same manner as in Example 2. The obtained molding material had a high air content rate of 19%, and the shape of the molding material was poor. The conditions and results are shown in Table 1.

[0024]

Industrial Applicability As is apparent from the above constitution and explanation, the present invention is capable of producing a thermoplastic composite material having an excellent impregnation property at low cost, efficiently and at a high speed, and is industrially high. A method that has value.

[Brief description of drawings]

FIG. 1 is a schematic side view of an example of an impregnating portion of an apparatus used for conventional pultrusion molding.

FIG. 2 is a schematic side view of an example of an apparatus used in the manufacturing method of the present invention.

FIG. 3 is a schematic side view of another example of the apparatus used in the manufacturing method of the present invention, which is different from FIG.

FIG. 4 is a schematic front view of an example of a compression roller for tape-shaped molding used in the manufacturing method of the present invention.

FIG. 5 is a schematic front view of another example of the compression roller for performing tape-shaped molding used in the manufacturing method of the present invention, which is different from FIG.

FIG. 6 is a schematic front view of a compression roller used in the manufacturing method of the present invention, which imparts a circular cross section.

FIG. 7 is a schematic front view of a compression roller for imparting a modified cross section (eyebrows) used in the manufacturing method of the present invention.

FIG. 8 is a schematic front view of a shaping roller having a circular cross section used in the manufacturing method of the present invention.

FIG. 9 is a schematic front view of a shaping roller that imparts a modified cross section (eyebrows) used in the manufacturing method of the present invention.

FIG. 10 is a schematic side view of an example of an apparatus used in a manufacturing method of a comparative example.

[Explanation of sign]

1 Extruder body 2 Raw material chip hopper 3 Molten resin 4 Reinforcing fiber 5 Impregnation die 6 Molten thermoplastic composite material 7 Impregnated and shaped thermoplastic composite material 8 Cooling drive roller 9 Pressurized cooling roller 10 Cooling water or cooling air 11 Collection Roller 12 Roller with semicircular groove 13 Half circle pressure roller 14 Deformed grooved roller 15 Deformed pressure roller 16 Semi-circular grooved cooling roller 17 Cooling roller with modified groove

Claims (2)

(57) [Claims] 1. A method for producing a thermoplastic composite material in which a reinforcing fiber is impregnated with a thermoplastic resin, wherein the reinforcing fiber is impregnated with the thermoplastic resin inside an impregnation die and then melted to further improve the degree of impregnation. The thermoplastic composite material is pressed and compressed outside the impregnation die in parallel with the thermoplastic composite material.
A method for producing a thermoplastic composite material, which comprises giving the material an arbitrary cross-sectional shape . 2. The method for producing a thermoplastic composite material according to claim 1, wherein the pressurization and compression are performed by a nipple roller capable of being compressed with a linear pressure of 3 kg / mm or more.