JPH0333237A - Fibrous composite material precursor - Google Patents

Abstract

PURPOSE:To obtain the subject precursor for hot press molding, etc., having excellent bending moldability and impregnating property imparting excellent physical properties and appearance to molded material by mixing thermoplastic continuous fiber and continuous glass fiber in a specific mixing ratio. CONSTITUTION:For instance, (A) thermoplastic continuous fiber as non-twisted multifilament having >=10 Turn/m twist, <=15% thermal shrinkage at (melting point -50 deg.C) and 0-0.3wt.% emulsion uptake is mixed with (B) 5-80wt.% (to total) continuous glass fiber as non-twisted multifilament having <=10 Turn/m, 8-23mum single filament diameter and 0.05-0.4wt.% emulsion uptake in >=30% mixing degree to afford the aimed precursor.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a fibrous composite material precursor for obtaining a thermoplastic composite material, and more specifically, to a composite material precursor for obtaining a thermoplastic composite material. The present invention relates to a fibrous composite material precursor that has excellent bendability and particularly impregnability.

(Prior art) Conventionally, in order to obtain a thermoplastic composite material precursor, a method of melting and impregnating a thermoplastic resin between reinforcing fibers is known. The tape was extremely stiff, making it difficult to mold it into a curve along a mold with a complex shape. In order to solve the above-mentioned drawbacks, methods of wrapping thermoplastic continuous fibers around continuous reinforcing fibers are disclosed in British Patent GB2105247, Japanese Patent Application Laid-Open No. 60-58545, and the like. However, it takes sufficient time and sufficient pressure to mold the fibrous composite material precursor obtained by this method, melt the thermoplastic fibers, and sufficiently impregnate the thermoplastic matrix between the reinforcing fibers. This increases the molding cycle time and increases costs.

Therefore, in order to solve this problem, a method of mixing thermoplastic continuous fibers and continuous reinforcing fibers to obtain a composite material precursor has been proposed in Japanese Patent Application Laid-open No. 80-209034 and No. 82-135537.
, disclosed in Japanese Patent Application Laid-Open No. 63-154745. However, in these methods, the fiber mixing method is complicated, productivity is low, and the degree of fiber mixing is not sufficient, and impregnation of molten thermoplastic fibers between reinforcing fibers by heat treatment is insufficient.

(Problems to be Solved by the Invention) In the fibrous composite material precursor that is a mixture of the above-mentioned thermoplastic continuous fibers and continuous reinforcing fibers, especially a fibrous composite material that is a mixture of thermoplastic continuous fibers and continuous glass fibers. In the precursor, the thermoplastic continuous fiber usually has convergence,
Smoothing agent to improve operability such as lubricity and prevention of static electricity generation.
A treatment agent such as an antistatic agent is applied. However, this treatment agent increases the convergence force between the thermoplastic fibers, so that the thermoplastic continuous fibers do not open at the single fiber stage and cannot be uniformly mixed with the continuous glass fibers. Furthermore, this treatment agent deteriorates and discolors due to the heat during hot molding, resulting in coloring of the appearance of the molded product. On the other hand, a coupling agent, a film former 1 lubricant, etc. are added to the continuous glass fiber in order to increase the adhesive strength with the matrix, further prevent damage to the glass fiber, and improve operability during spinning. However, because of this treatment agent, the glass fibers have a high convergence property, and the glass fibers do not open at the single filament stage, making it impossible to uniformly mix them with the thermoplastic continuous fibers. This means that a higher blending degree cannot be obtained, which makes it difficult to impregnate the thermoplastic matrix between the glass fibers in the composite material molded product, and the glass fibers are poorly dispersed, resulting in poor physical properties of the composite material molded product. Become. Also,
In order to achieve sufficient impregnation, sufficient time and pressure are required, which increases the molding cycle time and increases costs.

(Means for Solving the Problems) In order to solve the above problems, as a result of intensive research, the present invention was achieved. That is, the present invention is a fibrous composite material precursor having a blending degree of 30% or more of the following (a) thermoplastic continuous fibers and (b) continuous glass fibers, (a) thermoplastic continuous fibers: substantially It is a non-twisted multifilament, and the amount of processing agent applied is 0 to 0.3% by weight.

(b) Continuous glass fiber: substantially untwisted multifilament, with a treatment agent applied amount of 0.05 to 0.4% by weight
It is.

The present invention will be explained in detail below. Examples of the thermoplastic continuous fibers used in the present invention include polyolefin, vinyl polymer polyester, nylon, polyphenylene sulfide, polyether ketone, polyether ether ketone, etc. Any continuous fiber extruded from a nozzle in a molten state and spun may be used, and there is no particular limitation. This thermoplastic continuous fiber must be a multifilament of 10 to 10,000 fibers and must be substantially untwisted.

This "substantially nothing" means 10 turns/m or less. In addition, it is desirable that the thermoplastic continuous fiber has a small heat shrinkage rate, and the heat shrinkage rate at about melting point -50°C is 15%.
It is particularly preferably 10% or less. Generally, immediately after spinning thermoplastic continuous fibers, in order to improve convergence, give slipperiness, prevent static electricity generation, and improve post-processability,
Usually about 1.0% of processing agent is applied. However, in the present invention, it is necessary that the processing agent is not applied at all or is applied in an amount of 0.3% by weight or less. If it is not added at all, winding after spinning may become impossible due to the generation of static electricity, so it is preferable to add 0.3% by weight or less, preferably 0.1 to 0.2% by weight. Further, the type of processing agent may be one commonly used and is not particularly limited. As described above, since the thermoplastic continuous fibers are substantially untwisted and the amount of the processing agent is reduced, the thermoplastic continuous fibers are easily opened and mixed with the continuous glass fibers. Furthermore, coloration due to thermal deterioration of the processing agent can be almost eliminated. On the other hand, the continuous glass fiber is preferably a substantially untwisted multifilament with a single thread diameter of 8 to 23 μm, preferably a multifilament of 13 to 23 μm. This virtual nothingness means 10 turns/m
The following is particularly preferred, and less than 5 Turn/m is particularly preferred. Generally, immediately after spinning continuous glass fibers, coupling agents, film former 1 lubricants, etc. are added to enhance adhesion with the matrix, prevent damage to the glass fibers, and improve operability during spinning. There is.

Although the amount of these processing agents varies depending on the purpose, the total amount of the coupling agent, film former lubricant, etc. is usually about 0.5 to 1.0% by weight. but,
In the present invention, it is necessary to reduce the amount of the processing agent and apply it in an amount of 0.05 to 0.4% by weight. Desirably 0.20~
It is 0.30% by weight. Regarding the type of processing agent, it is necessary to select it depending on the type of matrix.

In particular, coupling agents need to be carefully examined.

In general, epoxy-based materials are preferred for polyester, and amine-based, urethane-based, and acrylic materials are preferred for nylon, but the materials are not limited to these. Further, the ratio of the coupling agent and the film former to the lubricant may be the same as usual, but it is desirable to reduce the ratio of the film former. In this way, by reducing the amount of treatment agent for continuous glass fibers, continuous glass fibers are easier to open, and by reducing the amount of treatment agent for thermoplastic continuous fibers, it is easier to open them. Fiber mixing becomes easier, and the thermoplastic matrix is better impregnated between the glass fibers in the composite material after thermoforming. As mentioned above, the method of mixing thermoplastic continuous fibers with a reduced amount of processing agent and continuous glass fibers includes general fiber processing methods, and is particularly limited as long as it can achieve a mixing degree of 30% or more. However, it is preferable to use the interlacer method, the raslan method, or a combination of these methods because they can easily obtain a high degree of blending. The degree of blending is determined by taking a photograph of the cross section of the blended fibrous composite material precursor under a microscope, counting the number of glass fibers in contact with the thermoplastic fibers, and determining the degree of blending using the following formula.

Further, the mixing ratio of the thermoplastic continuous fibers and the continuous glass fibers is preferably 5 to 80% by weight of the continuous glass fibers based on the total weight, and may be determined depending on the purpose.

The fibrous composite material precursor obtained in this manner can be applied to filament winding or pultrude beta molding in its fibrous state, or can be knitted and woven and applied to hot press molding. In this way, since it is in the form of fibers or cloth, it is flexible and can be curved and molded along a mold with a complicated shape. Furthermore, due to the high degree of blending,
The thermoplastic matrix sufficiently impregnates and bonds between the glass fibers under relatively short and low pressure molding conditions, and the glass fibers are sufficiently opened, so that the glass fibers in the composite molded product are Since the dispersion is good, the obtained composite material molded product has excellent physical properties.

(Function) Normally, when thermoplastic continuous fibers are spun, processing agents such as smoothing agents and antistatic agents are added in an amount of about 1.0% by weight, depending on the type.
Give degree. This increases the convergence force between the thermoplastic continuous fibers, making it difficult to open them and making it difficult to mix them with glass fibers. Therefore, it is desirable not to apply any processing agent at all, but the generation of static electricity may make operation and winding difficult. Therefore, when we investigated the amount of processing agent that could be used during operation by minimizing the amount of processing agent, we found that it is sufficient to apply about 0.3% by weight, although it varies depending on the type of fiber. This applied amount was measured according to JIS L1013 for solvent extracted bone. In this way, by reducing the amount of processing agent, the opening properties of the thermoplastic continuous fibers are dramatically increased, the fibers can be mixed with continuous glass fibers very easily, and the degree of fiber mixing can be greatly increased. Further, these processing agents usually undergo thermal deterioration and discoloration at high temperatures. That is, coloring occurs at acidic processing temperatures. However, at about 0.3% by weight, no uneven coloring occurs. On the other hand, for continuous glass fibers, coupling agents, film former 1 lubricants, etc.
Approximately 1.0% by weight is added. With this treatment agent, the glass fibers are tightly converged and do not spread, and do not mix with the thermoplastic continuous fibers. In this case as well, the amount of processing agent can be reduced as described above, but damage to the glass fibers must be prevented in order to ensure adhesion with the matrix and maintain the strength of the molded product. Therefore, the amount of processing agent was reduced to 0.0
It has been found that the above problem can be solved by adding 5 to 0.4% by weight.

This applied amount was measured by loss on ignition.

Even with this amount of application, it is possible to ensure adhesion with the matrix and prevent damage to the glass fibers.Moreover, it is possible to prevent damage to the glass fibers, and to greatly improve the opening properties of the glass fibers. I found out that it can be done. This dramatically facilitates the mixing of continuous glass fibers and thermoplastic continuous fibers, and improves the dispersion of glass fibers in the fibrous composite material precursor. However, it is necessary to change the composition of the processing agent depending on the type of matrix. That is, it is important to select the optimal treatment agent. In this way, thermoplastic continuous fibers and continuous glass fibers, which are easier to spread by reducing the amount of processing agent, can be mixed and the degree of blending can be increased. This means that the thermoplastic matrix sufficiently impregnates and adheres between the glass fibers under relatively short and low pressure molding conditions, and that the glass fibers are sufficiently opened to form a fibrous composite material precursor. Since the glass fibers are well dispersed in the body and in the composite material molded product after heat and pressure molding, a composite material molded product with excellent physical properties can be obtained.

(Example) The present invention will be explained below with reference to Examples, but the present invention is not limited thereto.

Example 1 Polyethylene terephthalate fibers were used as thermoplastic continuous fibers. The fiber is a 450 denier, 96 filament, untreated, substantially pure multifilament. Align 4 of these, 18
The multifilament was a substantially solid multifilament of 00 denier, 384 filament. Also, the temperature of this fiber at 200℃
The heat shrinkage rate was 8.7%. On the other hand, a substantially untwisted multifilament of 180TX and 400 filaments was used as the continuous glass fiber. The glass fibers are treated with significantly less treatment agent than usual. When the ignition loss of this glass fiber was measured, it was found to be 0.
It was 31% by weight. Both fibers were taken aside and mixed using an interlacer without twisting. The cross section of the fibrous composite material precursor thus obtained was photographed under a microscope, and the fineness a was determined using the method described in the text, and was found to be 48%. This fibrous composite material precursor was made into a plain weave. 10 cm of this plain weave
24 sheets were cut out to a size of 10 cm x 10 cm, stacked on top of each other, and pressed at 280° C. for 3 minutes at a pressure of 15 kg/cJ.

The obtained composite material molded product was a flat plate with a thickness of 31 mm. This flat plate was cut into 15 m square pieces and subjected to a bending test according to JIS K7055.The bending test revealed that the bending strength was 51 kgf/mm2 and the bending modulus was 4700 kgf/mm2. The glass fiber content of this test piece was measured by loss on ignition.
It was 7% by weight. When the cross section of the test piece was observed using a scanning electron microscope, it was found that the glass fibers were uniformly dispersed in the matrix, and all the glass fibers were sufficiently wet. Moreover, the appearance of the molded product was white.

Comparative Example 1 Except that the ignition loss of the continuous glass fiber was 0.6% by weight,
The same procedure as in Example 1 was carried out. The degree of blending was 18%. A flat plate was prepared in the same manner and a cracking test was conducted. ■Barge strength is 37
kg f / square millimeter, support rate 3900 kg f
/ square millimeter. The glass fiber content of this test piece was measured by loss on ignition and was found to be 46% by weight. When the cross section of the test piece was observed using a scanning electron microscope, glass fibers were found to be solidified in the matrix. Also,
The appearance of the molded product was white.

Comparative Example 2 Same as Example 1 except that the thermoplastic continuous fibers were treated with about 1.0% by weight of the treatment agent. The degree of blending was 23%. A flat plate was prepared in the same manner and the 1111 test was conducted. The bending strength was 32 kg f /mm², and the bending modulus was 3750 kg f /mm². The glass fiber content of this test piece was measured by loss on ignition and was found to be 47% by weight. When the cross section of the test piece was observed using a scanning electron microscope, it was found that the glass fibers were dispersed in the matrix and the matrix was clumped together. Moreover, the appearance of the molded product was brownish-brown.

(Effects of the Invention) The glass fibers in the composite material molded product obtained by molding the fibrous composite material precursor of the present invention are well dispersed, and the thermoplastic resin is well impregnated, so that the physical properties of the molded product are improved. Are better.

Moreover, since no discoloration occurs during molding, a molded product with good appearance can be obtained.

Claims (1)

[Scope of Claims] A fibrous composite material precursor comprising the following (a) thermoplastic continuous fibers and (b) continuous glass fibers having a blending degree of 30% or more. (a) Thermoplastic continuous fiber: substantially untwisted multifilament, with a processing agent applied amount of 0 to 0.3% by weight. (b) Continuous glass fiber: substantially untwisted multifilament, with a treatment agent applied amount of 0.05 to 0.4% by weight
.