JPH0550517A - Fiber reinforced thermoplastic resin structure and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide an efficient and economical manufacturing method of fiber reinforced thermoplastic resin structure, which is reinforced by long fiber so as to develop high mechanical strength and, at the same time, the dispersion properties and the like of reinforcing fibers in which are remarkably improved. CONSTITUTION:In order to manufacture fiber reinforced thermoplastic resin structure containing 5-80wt.% of reinforcing fibers, which are removed in the form of continuous reinforcing fiber bundle from reinforcing fiber bundle aggregate, impregnated with molten thermoplastic resin under the condition being drawn and substantially arranged parallel to one another, as the reinforcing fiber bundle, reinforcing fiber bundle obtained by drying the fiber bundle, which is sized, bundled and wound in the form of cake, is employed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fiber-reinforced thermoplastic resin structure which is reinforced with long fibers and has a high degree of mechanical strength, and in which the dispersibility of reinforcing fibers is remarkably improved, and its efficient and economical structure. Manufacturing method.

[0002]

2. Description of the Related Art As a means for improving the strength and rigidity of a thermoplastic resin, it has been known to incorporate a reinforcing fiber such as glass fiber, and generally, a thermoplastic resin is used. Fiber-reinforced thermoplastic resin is manufactured by mixing and short fibers such as chopped strands and extruding with an extruder. However, the short fiber reinforced resin as described above, in which the fiber used is short, and the fiber is further broken during kneading in an extruder, is naturally limited in improving the mechanical strength. It cannot fully meet the demand for mechanical strength. On the other hand, pultrusion has recently attracted attention as a method for improving the above-mentioned drawbacks and producing a thermoplastic resin reinforced with long fibers without causing breakage of the fibers (US Pat. No. 2,877,501). U.S. Pat.No. 4,439,387, U.S. Pat.No. 3,022,210, JP-A-57-1818.
No. 52). In such pultrusion molding, as a reinforcing fiber, a large number of single fibers pulled out from a bushing are treated with an aqueous solution or an aqueous emulsion of a sizing agent, and then bundled and wound into a cylindrical shape to dry. So-called direct roll roving packages have been commonly used. However, when such a commercially available reinforcing fiber is usually used to produce a fiber-reinforced resin structure by the above-mentioned pultrusion method, impregnation of the resin with respect to the fiber and adhesion are likely to be non-uniform, and Fibers are easily disentangled and scattered from the obtained fiber reinforced resin structure, which not only impairs the working environment and impairs moldability, but also causes a lack of uniform dispersion of reinforcing fibers when molded. It has the drawback of impairing the appearance and physical properties of the molded product. Also, when taking out the fiber bundle from the fiber bundle assembly or when pulling the fiber bundle under tension, fluffing occurs due to partial breakage of the fiber, impairing operability, and it becomes impossible to operate due to increased fluffing. There is also.

[0003]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that the resin has good impregnation property and adhesion between the resin and the fiber, and has high mechanical strength. In order to efficiently obtain a fiber-reinforced thermoplastic resin structure whose dispersibility and the like are remarkably improved,
The present inventors have found that it is extremely effective to use a reinforcing fiber bundle in which the amount of the sizing agent attached to the reinforcing fibers locally varies, and have reached the present invention. That is, the present invention relates to a fiber-reinforced thermoplastic resin which comprises a continuous reinforcing fiber bundle, is impregnated with a molten thermoplastic resin, and contains 5 to 80% by weight of the total reinforcing fibers arranged substantially in parallel. In producing a resin structure, as a reinforcing fiber bundle, a fiber-reinforced thermoplastic resin characterized by using a reinforcing fiber bundle obtained by drying a sizing-treated and bundled fiber bundle in a cake roll and drying. The present invention relates to a method for producing a resin structure and a fiber-reinforced thermoplastic resin structure obtained by such a production method.

In the present invention, the kind of the thermoplastic resin used as the substrate of the fiber reinforced thermoplastic resin structure is not particularly limited, and examples thereof include polyethylene, polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon 6, and the like. Polyamide such as nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, polyacetal, polycarbonate, thermoplastic polyurethane, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyetherketone, polyetheramide, and polyetherimide. ..

Next, the reinforcing fiber used in the present invention will be described. Conventionally, in pultrusion molding, a large number of fiber filaments pulled out from a bushing are treated with an aqueous solution or an aqueous emulsion of a sizing agent, and then bundled and wound into a cylindrical shape to dry a bundle of fibers,
Commercially available packages have been used as so-called direct roving packages. However, according to the studies conducted by the present inventors, the roving package thus obtained has a sizing agent that is not uniformly distributed over the entire reinforcing fiber bundle because the sizing agent causes migration during drying. The variation in the amount of sizing agent adhered locally is extremely large, and particularly, the concentration of sizing agent becomes particularly high on both end surfaces of the wound cylindrical roving package, near the outer circumference and the inner circumference of the cylinder. It turned out that Further, the present inventors have found that such a large variation in the amount of the sizing agent attached causes various problems in the pultrusion molding, that is, poor impregnation of the resin, poor adhesion between the resin and the fiber, and the resulting reinforced resin structure from the reinforced resin structure. Easily disintegrates and scatters, which is the root cause of damaging the work environment and impairing moldability.
Furthermore, it has been clarified that this is a cause of poor dispersion of reinforcing fibers when such a reinforced resin structure is molded. The present invention has been made based on such findings, and as the reinforcing fibers, a reinforcing fiber bundle obtained by drying the sizing-treated and bundled fiber bundle in a cake roll is used. And The fiber bundle thus obtained has little local variation in the sizing agent, which remarkably improves the above problems. A wound body obtained by winding a fiber bundle into a cake can be obtained by a known method. In general, molten glass is drawn out from a bushing equipped with a large number of nozzles to form single fibers, which are coated with a sizing agent and bundled to form a fiber bundle, which is wound by a traverse member that reciprocates. It is obtained by winding the tube on a collet rotating at high speed while moving it in the axial direction of the take-up portion. As described above, in the case of direct roving which is a cylindrical wound body, the sizing agent migrates due to drying, and the amount of the sizing agent attached to the fiber bundle locally becomes extremely high at both end face portions of the cylinder, causing various problems. In the cake-wound fiber bundle wound body, since the cylindrical end surface is substantially absent, even if it is dried, there is little local variation in the amount of the sizing agent attached, and good results are obtained. Even in this case, the sizing agent is likely to be concentrated in the vicinity of the inner peripheral surface and the outer peripheral surface of the cake-wound body due to migration of the sizing agent during drying. There are few problems. Further, it is extremely easy to remove only the fiber bundle in this portion, and it is more effective to remove it in advance and use it, or leave it unused and use roving in the effective portion. As a result, a fiber-reinforced resin structure having good dispersibility of the reinforcing fibers can be obtained. In addition, as described above, a cake-wound and dried fiber bundle rewound into a cylindrical shape is particularly preferable because it is easy to transport and handle. The type of sizing agent used for bundling the reinforcing fibers is not particularly limited, and for example, olefin, urethane, polyester, acrylic, AS resin, epoxy, etc. sizing agents are all possible. .. The appropriate amount of the sizing agent applied to the fiber is about 0.1 to 1.0% by weight as a solid content. Further, the type of reinforcing fiber used is not particularly limited, and for example, glass fiber, carbon fiber, metal fiber, high melting point (high softening point) fiber such as aromatic polyamide fiber and the like can be used. In the case of glass fiber, a roving (fiber bundle) having a fiber diameter of 6 to 25 μm and a weight per 1000 m of 500 to 4400 g is generally used. These fibers may be treated with a known surface treatment agent.

In the present invention, the compounding amount of such reinforcing fibers is 5 to 80% by weight of the whole. If the content of the reinforcing fiber is less than 5% by weight, a sufficient reinforcing effect cannot be obtained. On the contrary, if it exceeds 80% by weight, the production of the reinforced structure and its molding become extremely difficult. The preferred amount of the reinforcing fiber is 10 to 75% by weight, more preferably 20 to 70% by weight.

A pultrusion method is used to manufacture the long fiber reinforced thermoplastic resin structure of the present invention. Pultrusion molding is basically impregnating a resin while pulling continuous fibers. The form of pultrusion molding used for producing the long fiber reinforced thermoplastic resin structure of the present invention is not particularly limited, but it is preferable to use an impregnation die, particularly a crosshead die, from the viewpoint of operability.

[0008]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 A glass fiber bundle wound body was obtained by forming a wet glass fiber bundle treated with an emulsion containing a sizing agent into a cake and drying it. A glass fiber bundle taken out from this roll is impregnated with molten polypropylene while being pulled through a crosshead, shaped, and shredded to form a pellet-shaped fiber-reinforced resin structure with a glass content of 50% by weight (A ) Got. Next, pelletized fiber reinforced resin structure
The glass content was diluted to 15% by weight by blending (A) with pellets of non-reinforced polypropylene, and injection molded to obtain a flat plate molded product of 100 mm square. The evaluation was performed by the operability during the production of the fiber-reinforced resin structure (A) and the dispersibility of the reinforcing fibers in the flat plate molded article. The results are shown in Table 1. Incidentally, the evaluation of dispersibility is a relative evaluation in consideration of the degree and number of the unevenly dispersed portions of the reinforcing fiber in the molded product while being bundled, and the lower the score, the higher the dispersibility. Indicates good.

Example 2 A glass fiber bundle which had been cake-wound and dried was rewound to obtain a cylindrical wound body. A glass fiber bundle taken out from this roll was impregnated with a molten resin in the same manner as in Example 1 to produce a fiber-reinforced resin structure, which was molded and evaluated. The results are also shown in Table 1. In this case, there is an advantage that the glass fiber bundle wound body can be easily transported and handled.

Comparative Example 1 A fiber reinforced resin structure was produced, molded and evaluated in the same manner as in Example 1 using a normal direct roll glass fiber bundle. The results are also shown in Table 1.

[0012]

As is apparent from the above description and Examples, in producing a long fiber reinforced thermoplastic resin structure, the fiber bundles sized as reinforcing fiber bundles and bundled into a cake are dried. According to the method of the present invention using the reinforcing fiber bundle obtained by the above, it is possible to obtain a fiber-reinforced thermoplastic resin structure having excellent operability during production and the like, and also having excellent dispersibility of reinforcing fibers during molding. ..

[0013]

[Table 1]

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 12, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction content]

Next, the reinforcing fiber used in the present invention will be described. Conventionally, in pultrusion molding, a large number of fiber filaments pulled out from a bushing are treated with an aqueous solution or an aqueous emulsion of a sizing agent, and then bundled and wound into a cylindrical shape to dry a bundle of fibers,
Commercially available packages have been used as so-called direct roving packages. However, according to the studies conducted by the present inventors, the roving package thus obtained has a sizing agent that is not uniformly distributed over the entire reinforcing fiber bundle because the sizing agent causes migration during drying. The variation in the amount of sizing agent adhered locally is extremely large, and particularly, the concentration of sizing agent becomes particularly high on both end surfaces of the wound cylindrical roving package, near the outer circumference and the inner circumference of the cylinder. It turned out that Further, the present inventors have found that such a large variation in the amount of the sizing agent attached causes various problems in the pultrusion molding, that is, poor impregnation of the resin, poor adhesion between the resin and the fiber, and the resulting reinforced resin structure from the reinforced resin structure. Easily disintegrates and scatters, which is the root cause of damaging the work environment and impairing moldability.
Furthermore, it has been clarified that this is a cause of poor dispersion of reinforcing fibers when such a reinforced resin structure is molded. The present invention has been made on the basis of such findings, as a reinforcing fiber, a sizing-treated and bundled fiber bundle, for example, roving, sliver, yarn, etc. It is characterized by using a fiber bundle. The fiber bundle thus obtained has little local variation in the sizing agent, which remarkably improves the above problems. The cake-wound roll in the present invention refers to a roll wound in such a manner that it does not have a cylindrical end face or an end face similar thereto. As a typical shape of the cake-wound body, the number of windings of the fiber bundle is smaller and the thickness is smaller in a portion closer to the upper circumference and the lower circumference of the winding body, and the number of windings of the fiber bundle is larger in the central portion. The shape is large, but is not particularly limited to this shape. For example, there may be a portion having a relatively small thickness in the vicinity of the central portion. A wound body obtained by winding a fiber bundle into a cake can be obtained by a known method. In general, molten glass is drawn out from a bushing equipped with a large number of nozzles to form single fibers, which are coated with a sizing agent and bundled to form a fiber bundle, which is wound by a traverse member that reciprocates. It is obtained by winding the tube on a collet rotating at high speed while moving it in the axial direction of the take-up portion. As mentioned above, in the case of direct roving which is a cylindrical wound body, the sizing agent causes migration due to drying,
In both end face portions of the cylinder, the amount of the sizing agent attached to the fiber bundle locally becomes extremely high and causes various problems, but in the case of a cake-wound fiber bundle wound body, such a cylinder end face is substantially absent, and therefore even when dried. Local variations in the sizing agent deposition amount are small, and good results are obtained regardless of the degree of focusing of the fiber bundle and the shape of the bundled fiber bundle. Even in this case, in the vicinity of the inner peripheral surface and the outer peripheral surface of the cake-wound body, the sizing agent is likely to be concentrated due to the migration of the sizing agent during drying, but the local variation is relatively small, and therefore the operability with respect to the operability is reduced. There are few problems. Also, it is extremely easy to remove only the fiber bundle in this portion, and it is more effective to remove it in advance and use it, or leave it unused and use the fiber bundle in the effective portion. .. As a result, a fiber-reinforced resin structure having good dispersibility of the reinforcing fibers can be obtained. Further, as described above, a cake-wound and dried fiber bundle rewound into a cylindrical shape is particularly preferable because it is easy to transport and handle. The type of sizing agent used for bundling the reinforcing fibers is not particularly limited, and for example, olefin, urethane, polyester, acrylic, AS resin, epoxy, etc. sizing agents are all possible. . The appropriate amount of the sizing agent applied to the fibers is about 0.1 to 1.0% by weight as a solid content. Also, there is no particular limitation on the type of reinforcing fiber used, for example, glass fiber, carbon fiber, metal fiber,
Any of high melting point (high softening point) fibers such as aromatic polyamide fibers can be used. In the case of glass fiber, fiber diameter 6-25
In general, a fiber bundle having a weight of 500 to 4400 g per 1000 m, such as roving, is generally used. These fibers may be treated with a known surface treatment agent.

Claims (3)

[Claims] 1. A fiber-reinforced thermoplastic comprising a continuous reinforcing fiber bundle, impregnated with a molten thermoplastic resin, and containing 5 to 80% by weight of the total reinforcing fibers arranged substantially parallel to each other. In producing a resin structure, as a reinforcing fiber bundle, a fiber-reinforced thermoplastic resin characterized by using a reinforcing fiber bundle obtained by drying a sizing-treated and bundled fiber bundle in a cake roll and drying. Method of manufacturing resin structure. 2. The method for producing a fiber-reinforced thermoplastic resin structure according to claim 1, wherein the molten thermoplastic resin is impregnated using a crosshead while pulling the reinforcing fiber bundle. 3. The reinforcing fiber obtained by the method according to claim 1 or 2, wherein the reinforcing fibers are arranged substantially continuously over the entire length of the structure in a substantially parallel state. Strand, pellet, tape or sheet fiber reinforced thermoplastic resin structure.