JPH06285855A - Strand for molding of long fiber reinforced synthetic resin product and its pellet - Google Patents

Abstract

PURPOSE:To enable a resin product having mechanical characteristics and other functional characteristics by a method wherein at least two kinds of long fibers consisting of different materials are impregnated with synthetic resin to make a strand for molding a long fiber reinforced synthetic resin product and its pellet. CONSTITUTION:Different materials supplied from a long fiber supply part, for example, a reinforcing long fiber roving 1a and a functional long fiber roving 1b are arranged properly by being paralleled to be continuously introduced to a synthetic resin impregnator 2. Then, the long fiber roving bundle 1 traveling in a fibrillated state is impregnated with the synthetic resin supplied in a melted state from a synthetic resin feeder 2a. Thereafter, it is cooled or heated with an after-treater 3, and successively coiled as a long fiber strand via a receiving roller 4. When a pellet is prepared, it is obtained by cutting the long fiber strand to a suitable length. Since at least two kinds of long fibers are uniformly mixed in an obtained long fiber reinforced synthetic resin mold product, the molded product which is uniform in strength and in mechanical characteristics can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to long fiber-reinforced synthetic resin product forming strands and pellets, and in particular, it combines two or more kinds of long fibers (for example, reinforcing long fibers and functional long fibers) made of different materials. And then impregnated with synthetic resin,
The present invention relates to strands and pellets for molding long fiber reinforced synthetic resin products having both strength characteristics and functionality.

The strand-shaped material of the present invention can be used by a method such as winding it as it is, or arranging it in the longitudinal direction or the crossing direction and heat-pressing it, while the pellet-shaped material is the above-mentioned strand-shaped material. To
Arbitrary length (usually a few mm to a dozen m depending on the purpose of use)
m) and is used as a raw material for injection molding, injection compression molding, compression molding, etc. In the present specification, the former is referred to as a long fiber reinforced synthetic resin product forming strand (hereinafter simply referred to as a long fiber strand). Also, the latter is classified as a pellet for molding a long fiber reinforced synthetic resin product (hereinafter sometimes simply referred to as a long fiber pellet).

[0003]

2. Description of the Related Art When it is desired to produce a molded product having a desired shape by injection molding a fiber-reinforced resin material, for example, a pellet-shaped raw material containing a reinforcing fiber in a synthetic resin is used.
Reinforcing fibers contained in such pelletized raw materials are generally short fibers, but in recent years, long fibers have been aligned in one direction and impregnated with synthetic resin, that is, long fiber pellets have been developed and have high strength injection. It is evaluated as a raw material for manufacturing molded products.

As a method for producing these, a resin of a screw type or a plunger type extruder is provided on the side surface of an impregnation head in which reinforcing fibers (hereinafter sometimes referred to as rovings) are introduced in a bundle and run in an opened state. Impregnation is performed by providing a liquid discharge port and passing the roving bundle through a molten synthetic resin bath formed by being press-fitted into the impregnation head. Then, the resin impregnated roving is taken out from the outlet nozzle of the impregnation head, and while curing the resin material, it is wound into the long fiber strands, which are cut into arbitrary lengths as described above, and the long fiber pellets are obtained. You can also do it.

On the other hand, the long fiber reinforced resin as described above is widely used as a molding material for casing materials and structural materials of various equipment such as OA equipment and AV equipment. As the reinforcing fiber, various inorganic or organic fibers such as glass fiber, carbon fiber, metal fiber, and aramid fiber are used, but among these, the most commonly used are glass fiber and carbon fiber. is there.

Fiber-reinforced resins using these fibers have excellent characteristics. For example, glass-fiber-reinforced resins give molded products which are very inexpensive and have excellent mechanical properties. In addition, the one using carbon fiber exhibits more excellent characteristics in mechanical properties, and gives a molded product excellent in conductivity and antistatic property.

However, the one using glass fiber or carbon fiber cannot provide the electromagnetic wave shielding property which is often required when it is used as a component of electronic / electrical equipment such as OA equipment and AV equipment. Therefore, a method of giving a function of electromagnetic wave shielding property by using a magnetic powder of metal or the like or a metal flake together with these fibers is also carried out, but with these methods, the mechanical properties of the molded article are deteriorated. However, there is a problem in that the dispersion of metal powder or the like becomes non-uniform and stable electromagnetic wave shielding properties are not exhibited, and it is not suitable as a material for electronic / electrical devices with ever-increasing performance.

[0008]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above circumstances, and the purpose thereof is to effectively exhibit the excellent features of the fiber-reinforced resin while depending on the purpose of use. For example, the present invention aims to provide a strand and a pellet for molding a long fiber reinforced synthetic resin product which imparts, for example, a function of electromagnetic wave shielding and gives a reinforced resin molded product having both strength characteristics and functionality.

[0009]

The constitution of the molding strands and pellets according to the present invention, which have been able to solve the above problems, is two or more kinds of long fibers (for example, a reinforcing long fiber and a functional material) made of different materials. It has the gist of containing long fibers) in a resin-impregnated state.

[0010]

As described above, the long fiber strands and pellets of the present invention are obtained by impregnating two or more kinds of long fibers made of different materials with a synthetic resin, and using the materials of the long fibers used in combination. By appropriately selecting according to the purpose, it is possible to obtain long fiber strands and pellets that give a fiber-reinforced resin molded product having various functions according to the purpose.

For example, when carbon fibers and metal fibers are used in combination, in addition to the excellent reinforcing effect, conductivity and antistatic ability of carbon fibers, the electromagnetic wave shielding properties of metal fibers can be imparted. If fiber and aramid fiber are used together, in addition to the above characteristics of carbon fiber, aramid fiber can give even more excellent impact resistance, and if glass fiber and aramid fiber and metal fiber are used together, material cost It is possible to provide strength characteristics, impact resistance, electromagnetic wave shielding properties, etc. without significantly increasing the value.

That is, as a composite mode of long fibers of different materials, a composite of two or more long fibers having different reinforcing effects,
There are various modes such as a composite of long fibers having a reinforcing effect and a long fiber having an effect of improving functionality, a composite of two or more kinds of long fibers having different functions, and thus two or more kinds are used in combination. By appropriately selecting the type of long fibers, it is possible to obtain long fiber strands and pellets that provide fiber reinforced resin products having strength characteristics and various functions that meet target costs and required performances. Therefore, in the present invention, as long as two or more kinds of long fibers are used in combination, there is no limitation on the kinds of the long fibers, and among the long fibers of all kinds, among them, depending on the required characteristics of the target molded article, Two or three or more kinds may be arbitrarily selected and used. Typical examples include glass fibers, carbon fibers, metal fibers, SiC fibers, alumina fibers, ceramic fibers such as silica fibers, and boron fibers. , Aramid fiber, high-strength polyethylene fiber, high-strength polyester fiber and the like. The combination ratio of these fibers is not limited at all and may be arbitrarily selected according to the required characteristics of the molded product.

Although the fiber diameter and the number of these long fibers are not limited, those having 6 to 20 μm are usually used by aligning about 3K to 96K. Further, there is no particular limitation on the type of synthetic resin for impregnation, and various thermoplastic or thermosetting synthetic resins can be used, but among them, the most common are epoxy, unsaturated polyester, vinyl ester, phenol and polyimide. Thermosetting resin such as polyethylene, polypropylene, polystyrene, ABS, polyamide, polycarbonate, polyethylene terephthalate,
A thermoplastic resin such as polybutylene terephthalate, polyacetal, polyacrylate, polyphenylene oxide, polyphenylene sulfide, polyether sulfone, polyether ketone, and polyetherimide,
The impregnation amount is not limited, but the long fiber 10 is generally used.
It is in the range of 50 to 10,000 parts by weight, more usually 100 to 2,000 parts by weight, relative to 0 parts by weight.

Next, the method for producing the strands and pellets according to the present invention will be briefly described. FIG. 1 is a schematic explanatory view showing a manufacturing example, in which 1a, 1a, ..., 1b, 1 are shown.
b, ... Are long fiber rovings made of different materials, 1 is a roving bundle, 2 is a synthetic resin impregnation device, 2a is a synthetic resin supply device, 3 is a post-processing device, 4 is a take-up roller, and 5 is a take-up device. Shows.

As shown in the figure, in the present invention, the long fiber rovings 1a, 1 of different materials supplied from the long fiber supply section are provided.
, 1b, 1b, ... are aligned and continuously guided to the synthetic resin impregnating device 2, where the synthetic resin supplied from the synthetic resin supplying device 2a in a molten state is impregnated in the opened state. The long fiber roving bundle 2 running in the device 2 is impregnated. Then, after the post-treatment in the post-treatment device 3 (cooling and solidification when a thermoplastic resin is used as the synthetic resin, heat treatment for pre-curing when a thermosetting resin is used), it is passed through the take-up roller 4 for a long time. Sequential winding device 5 as fiber strands
To wind up.

On the other hand, in the case of producing long-fiber pellets, the continuous long-fiber strands may be cut into an arbitrary length (for example, several mm to several tens of mm) in the final step, or once. The wound long fiber strand may then be cut into a long fiber pellet by an appropriate device into an arbitrary length. The strands and pellets of the present invention thus obtained contain two or more kinds of long fibers according to their compounding ratio, and a molded product obtained by using them contains 2 or more long fibers.
Since the long fibers of at least one kind are evenly mixed in uniformly, a molded product which is very homogeneous in terms of strength and function is provided.

Of course, the illustrated method is merely a typical manufacturing method and does not limit the present invention, and other methods can of course be adopted.

By the way, when continuous impregnation and take-up of a long fiber strand is performed by the above method, the strand is opened and
The roving bundle is fluffed due to friction or ironing during the process of passing through the impregnating roller or the like, or when being picked up from the exit nozzle of the impregnation head. In some time, the nodules may grow and grow one after another.

Therefore, as a result of studying a solution to this problem, a twisting mechanism (for example, a rotation mechanism) is provided on the downstream side of the impregnation head 6 in the impregnation apparatus 2, and the twisted resin impregnated strand is taken up. By doing so, the fluff that has begun to be entangled immediately before the outlet nozzle is taken into the twist and is pulled out to the outside of the outlet nozzle, and as a result, the formation of the nodule immediately before the outlet nozzle is achieved. Prevented, even when performing a continuous operation for a long time, without causing trouble of taking the resin-impregnated strand,
It was found that excellent productivity was obtained.

Moreover, by imparting such a twist, the bubbles in the fiber gap are expelled, and the forced moving force acts on the impregnated resin, so that the resin impregnability is enhanced.

In the long fiber strand produced as described above, however, the roving bundle is contained in a twisted state (helical state), so that the tensile elastic modulus is not as large as expected. For example, this is a stampable sheet. There is a problem in using it as a unidirectional reinforcing material. Further, when applied to the filament winding method, it is desired to form a strip-shaped long fiber strand, but the long fibers contained in the twisted state as described above do not form a smooth surface even if it is flattened and flattened on the surface. Therefore, the product obtained by, for example, winding in a pipe shape does not become uniform over the entire length, resulting in non-uniform strength in the product, quality variation among products, and the like.

Therefore, in the case of adopting such a twisting method, the once produced strand is reheated to restore plasticity, and in that state, twisting in the direction opposite to the twisting direction is applied to extend the long fiber. It is desired to return to the state. Further, the one that is re-cured in such a stretched state has an improved tensile elastic modulus, and the one that is flattened and crushed and re-cured becomes a smooth strip-shaped strand, so that the above-mentioned problems can be solved. Moreover, the long fiber pellets obtained by untwisting in this manner have a high tensile elastic modulus because each long fiber made of a different material exists in a state of maintaining straightness, and as a unidirectional functional material. Exhibits excellent characteristics. When applied to the filament winding method, a smooth strip-shaped long fiber strand can be obtained, and a filament winding product having uniform strength characteristics and good functionality can be manufactured.

[0023]

EXAMPLES Hereinafter, the constitution and effects of the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples and may be adapted to the gist of the preceding and following. It is of course possible to appropriately change and implement the range, and all of them are included in the technical scope of the present invention.

Using the apparatus shown in FIG. 1, a long fiber composite strand was produced under the following conditions, and the obtained strand was cut into a length of 6 mm to produce a long fiber composite pellet. Then, the pellets were subjected to injection compression molding under the following conditions, and the physical properties of the obtained injection compression molded articles were examined, and the results shown in Tables 1 to 3 were obtained.

(Conditions for producing long-fiber composite strands) Example 1 Long-fiber roving: carbon fiber (trade name "Torayca T300" manufactured by Toray), roving two 396 tex aramid fibers (trade name "Dupont-Toray Kevlar" Kevlar 49 "), 158 tex (1420 denier)
Roving of 1 impregnating resin: Polycarbonate resin (trade name "Panlite L1250" manufactured by Teijin Chemicals Co., Ltd.) Impregnation condition: Resin temperature 300 to 310 ° C, take-up speed 5m / min, nozzle diameter 2.2mmφ

Comparative Example 1 Long fiber roving: Carbon fiber (trade name "Torayca T300" manufactured by Toray Industries, Inc.), 2 rovings of 396 tex and 1
98 tex roving 1 Impregnating resin: Polycarbonate resin (Teijin Kasei's trade name "Panlite L1250") Impregnation condition: Resin temperature 300-310 ° C Take-off speed 5m / min Nozzle diameter 2.2mmφ

Example 2 Long fiber roving: Glass fiber (E-glass roving manufactured by Nitto Boseki) 1,100 tex roving 1 aramid fiber (Dupont Toray Kevlar Co., Ltd., trade name "Kevlar 49"), 158 tex (1420 denier)
Roving of 1 impregnating resin: Polycarbonate resin (trade name "Panlite L1250" manufactured by Teijin Chemicals Co., Ltd.) Impregnation condition: Resin temperature 300 to 310 ° C, take-up speed 5m / min, nozzle diameter 2.2mmφ

Comparative Example 2 Long fiber roving: Glass fiber (E-glass roving manufactured by Nitto Boseki) 1,100 tex roving 1 impregnating resin: Polycarbonate resin (Teijin Kasei's trade name "Panlite L1250") Impregnation condition: resin temperature 300-310 ° C Take-off speed 5m / min Nozzle diameter 2.2mmφ

Example 3 Long-fiber roving: Carbon fiber (trade name "Torayca T300" manufactured by Toray), 296 tex roving 2 SUS fibers (trade name "Naslon" manufactured by Nippon Seisen Co., Ltd.), 65
1 roving of 0 tex Impregnating resin: Polycarbonate resin (trade name "Panlite L1250" manufactured by Teijin Chemicals Co., Ltd.) Impregnation condition: Resin temperature 300 to 310 ° C, take-up speed 5m / min, nozzle diameter 2.2mmφ

Example 4 Long fiber roving: carbon fiber (trade name "Torayca T300" manufactured by Toray Industries, Inc.), two rovings of 396 tex SUS fiber (trade name "Naslon" manufactured by Nippon Seisen Co., Ltd.), 65
1 roving of 0 tex Aramid fiber (Dupont Toray Kevlar's product name "Kevlar 49"), 158 tex (1420 denier)
Roving of 1 impregnating resin: Polycarbonate resin (trade name "Panlite L1250" manufactured by Teijin Chemicals Co., Ltd.) Impregnation condition: Resin temperature 300 to 310 ° C, take-up speed 5m / min, nozzle diameter 2.2mmφ

Comparative Example 3 Long-fiber roving: Carbon fiber (trade name "Torayca T300" manufactured by Toray), 396 tex rovings 4 impregnating resin: Polycarbonate resin (trade name "Panlite L1250" manufactured by Teijin Chemicals) Impregnation conditions : Resin temperature 300 to 310 ° C. Pulling speed 5 m / min Nozzle diameter 2.2 mmφ

(Injection compression molding conditions): Molding machine Sumitomo Heavy Industries "SG220" Cylinder temperature 280-330 ° C Mold temperature 120 ° C Screw rotation speed 50 rpm Screw diameter 45 mmφ Injection speed 100 mm / sec Cooling time 30 sec Compression pressure 500 kg / cm ³ Molded product shape: width 150 mm x depth 150 mm x depth 2
0 mm lunch box type

Bending test (bending strength, flexural modulus): test piece width 10 mm x length 50 mm x thickness 1.2 m
m Crosshead speed 4 mm / min Roundness of supporting part 2.5 mmR Rounding of pressing part 5.0 mmR Span between supporting parts 40 mm Izod impact strength: JIS7110 Electric resistance: SRIS2301 Voltage / current method Electromagnetic wave shielding property: KEC method

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

As is clear from Table 1, Table 2 and Table 3, according to the present invention, various functionalities are provided according to the type of long fibers to be used in combination and good mechanical properties are obtained. A fiber reinforced resin molded product can be obtained.

[0038]

EFFECTS OF THE INVENTION The present invention is configured as described above, and by combining two or more kinds of long fibers made of different materials and impregnating them with a synthetic resin, not only the mechanical properties but also various functions are achieved. It has now become possible to provide molding strands and pellets which give fiber-reinforced resin products with properties. Moreover, the strands and pellets contain two or more kinds of long fibers made of different materials depending on the mixing ratio, and the molded articles obtained by using them have two or more kinds of long fibers evenly. Since they are uniformly mixed, a very homogeneous molded product can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view illustrating a method for producing a strand of the present invention.

[Explanation of symbols]

 1a, 1a, ..., 1b, 1b ,.

Claims (3)

[Claims] 1. Strands and pellets for molding long-fiber-reinforced synthetic resin products, which contain two or more kinds of long fibers made of different materials in a resin-impregnated state. 2. The long fiber-reinforced synthetic resin product forming strand and pellet according to claim 1, which contains the reinforcing long fiber and the functional long fiber in a resin-impregnated state. 3. Strands and pellets for molding long fiber reinforced synthetic resin products according to claim 2, wherein one or both of the reinforcing long fibers and the functional long fibers are made of two or more different materials. .