JPS6412206B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves impregnating a sheet-like continuous carbon fiber aggregate spread in parallel in one direction with a resin solution dissolved in a solvent, and then impregnating the carbon fibers with the same material as the dissolved resin. The present invention relates to a method for manufacturing a prepreg in which fibers and resin are bonded together by bonding the prepreg to a matrix thermoplastic resin sheet.

Conventionally, composite molded products are known in which continuous carbon fiber aggregates are impregnated with thermosetting matrix resin monomers or low polymers to produce prepregs and then cured. After being impregnated with a catalyst and molded into a predetermined shape, it is necessary to cure the resin through polymerization and crosslinking reactions, which has the drawback of requiring a long time for molding and poor productivity. In addition, the impregnated resin and polymerization catalyst change over time, resulting in a decline in the mechanical properties and moldability of the composite molded product, so there is a problem in that the storage conditions of the prepreg must be strictly controlled. .

On the other hand, thermoplastic resin, which is used as the matrix for composite molded products, has a high degree of polymerization and high chemical and heat resistance, so it can be used for continuous carbon fiber aggregates with good productivity and any resin adhesion rate. It is very difficult to control the adhesion and to make it adhere uniformly and with good affinity.

For example, when dissolving a resin in a solvent and impregnating it onto carbon fibers, thermoplastic resins are often poorly soluble or insoluble in solvents, and even resins with good solvents have low solubility, and a given resin adhesion rate is low. I can't get it. In addition, since the melt viscosity of the resin is extremely high when heat-melting the resin and impregnating it into carbon fibers, it is difficult to achieve good productivity and uniform adhesion.

In order to solve the above-mentioned problems, the present invention has developed a lightweight material that has good productivity, does not change over time, allows the resin adhesion rate to be arbitrarily adjusted, and can firmly bond carbon fiber and matrix. The present invention was arrived at as a result of intensive study on a method for manufacturing a prepreg composite molded article with high performance. The gist is that after a continuous carbon fiber aggregate is expanded using an expansion device, the carbon fibers are impregnated with a low-viscosity resin solution made by dissolving the same resin as the matrix resin sheet described later in a solvent, and the fiber surface is coated with resin. The carbon fibers impregnated with the resin liquid are then taken up with a winding roller to adjust the adhesion rate of the matrix resin. When the resin solvent solution adhering to the carbon fibers is not dried, it is brought into continuous contact with a thermoplastic resin sheet running in the same direction, so that the sheet-like continuous carbon fiber aggregate is uniformly distributed on the surface of the resin sheet. A unidirectional prepreg is obtained which is integrated with the unidirectional prepreg.

By laminating the required number of prepregs and heat-molding them, the molten resin quickly flows between the carbon fibers, making it possible to obtain high-performance composite molded products in a short time. It can be applied to a variety of fields such as structural materials, electrical and electronic parts, sporting goods, and machine tool parts.

Specific examples of the thermoplastic matrix resin used in the present invention include polysulfone, polyethersulfone, polycarbonate, polystyrene, polymethacrylate, polyamide, polyetheretherketone, polyethylene, etc., and molecularly modified types or crystals of these resins. Structural improvement types etc. can also be applied. In the present invention, the same thermoplastic resin as the matrix resin may be different in copolymerization components, degree of polymerization, etc.

Examples of solvents include chlorinated hydrocarbons such as methylene chloride, trichlorethylene, and tetrachloroethylene, and cyclohexane for polysulfone; chlorinated hydrocarbons such as methylene chloride and trichloroethylene; and ketones such as acetone and methyl ethyl ketone for polyether sulfone; For polystyrene, chlorinated hydrocarbons such as methylene chloride, dichloroethylene, dioxane, tetrahydrofuran, etc., for polystyrene, chlorinated hydrocarbons such as methylene chloride, dichloroethylene, and aromatic hydrocarbons such as toluene and xylene, for polymethacrylate, such as methylene chloride, etc. Chlorinated hydrocarbons and aromatic hydrocarbons such as benzene; alcohols such as methanol, ethanol, ethylene glycol, and benzyl alcohol for polyamide; chlorinated hydrocarbons such as methylene chloride for polyethylene; and polyether ether ketone Examples include sulfuric acid, and these solvents may be used not only alone but also in combination, or heated to a temperature other than room temperature to improve solubility.

The method of the present invention will be explained in detail below with reference to the drawings. FIG. 1 shows a side view of an example of an apparatus for carrying out the method of the present invention.

The plurality of continuous carbon fiber bundles 1 pass through a guide roll 2 and are spread out under tension by 37 spreader rolls, thereby forming continuous carbon sheets that are parallel to each other in almost one direction and in contact with each other. This becomes a fiber aggregate 4. Next, this sheet-like carbon fiber aggregate passes through a pair of fiber supply rolls 5 that rotate at a constant speed, and is immersed in a dipping tank 6 containing a resin solution dissolved in a solvent to be impregnated with resin.

The sheet-like carbon fiber aggregate impregnated with resin passes through Nipprol 7, where the resin solvent solution is in an undried state.
A pair of adhering rolls 1 is applied to a resin sheet that is continuously supplied from one or a pair of matrix resin sheet rolls 8 by a pair of resin sheet supply rolls 9.
0 to the sheet surface to form a uniform and integrated unidirectional prepreg, which is then wound up onto a prepreg winding roll 11.

As explained above, according to the present invention, it is possible to arbitrarily adjust the resin adhesion rate, and it is possible to continuously and efficiently manufacture prepreg in which carbon fibers and matrix resin are firmly bonded. .

A low viscosity of 100 centipoise or less is usually used as the viscosity of the resin solvent solution, but 10 to 50 centipoise is preferable from the viewpoint of uniform adhesion to the carbon fiber surface and fiber cohesiveness.

The resin adhesion rate can be adjusted by changing the thicknesses of the sheet-like carbon fiber aggregate and the resin sheet, respectively, and by a combination of these. Resin sheets with a thickness of 0.05 to 0.3 mm are mainly used, but depending on the weight ratio with carbon fibers, sheets with a thickness of 0.05 mm or less or 0.3 mm or more can also be used.

The bonding and integration of the sheet-like continuous carbon fiber aggregate and the resin sheet is achieved by attaching the carbon fibers to one side of the resin sheet as shown in Figure 2, and between the resin sheets as shown in Figure 3. There are cases in which the carbon fibers are attached, and the former is easier to adjust when the proportion of carbon fiber is particularly high, while the latter is easier to adjust when the proportion of resin is particularly high.

Example Polycarbonate resin was dissolved in methylene chloride to prepare a solution with a resin solubility of 2.5% by weight (solution viscosity of about 20 centipoise), and the solution was poured into a dipping tank. Continuous carbon fiber bundles (number of filaments) are added to this resin liquid.
10,000 pieces) Expand 30 pieces using an expansion roll,
After forming a sheet-like continuous carbon fiber aggregate that was parallel to one direction and in contact with each other, it was impregnated, and the resin adhesion rate was adjusted to about 0.3% using Nipprol.
Next, while the resin solvent solution is not dry, the carbon fiber aggregate is attached to the surface of the polycarbonate sheet (thickness 0.1 mm) continuously supplied from one matrix resin sheet roll using an attaching roll. As a result, an integrated unidirectional prepreg was formed and wound onto a prepreg winding roll.

The prepreg thus obtained has a thickness of 0.22 m/m.
The basis weight was 280g/ ^m2 . This prepreg is 110mm long
10 sheets cut to 210 mm wide were laminated, placed in a mold, and pressed for 10 minutes at a temperature of 260° C. and a pressure of 14 kg/cm ² to obtain a flat plate. The properties of the flat plate are carbon fiber content of 60% by weight, tensile strength of 148Kg/mm ² , and tensile modulus.
9100Kg/mm ² , bending strength 117Kg/mm ² , bending modulus
The interlaminar shear strength was 8,400 Kg/mm ² and 8.0 Kg/mm ² .

[Brief explanation of drawings]

FIG. 1 shows an example of an apparatus for carrying out the method of the present invention, and FIGS. 2 and 3 are schematic cross-sectional views of the prepreg sheet of the present invention. 1... Continuous carbon fiber bundle, 2... Guide roll,
3... Expanding rolls (7 rolls), 4... Sheet-like continuous carbon fiber aggregate, 5... Fiber supply roll pair, 6...
...Immersion tank, 7...Nipro roll, 8...One matrix resin sheet roll or pair, 9...Resin sheet supply roll pair, 10...Packing roll, 1
1... Prepreg winding roll, 12... Reinforcing fiber, 13... Matrix resin film layer.

Claims (1)

[Claims] 1. A sheet-like continuous carbon fiber aggregate spread in parallel to one direction is impregnated with a solvent solution of the same thermoplastic resin as the matrix resin, and then
A method for producing prepreg, which is characterized in that it is bonded and integrated with a sheet-like thermoplastic resin that becomes a matrix resin in an undried state.