JPH0939021A - Production of fiber reinforced resin composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a molded product high in fiber coatent by laminating reinforcing fiber mats and a mate like material or corrugated reticulated material high in resin circulation properties in a mold for reactive injection molding and injecting a reactive raw material resin to allow the same to penetrate into resin circulation spaces and simultaneously allowing the resin to flow out to the adjacent reinforcing fiber mats. SOLUTION: After two reinforcing fiber mats 2 are set to the interior of a mold 5 in such a state that a metal net (corrugated reticulated material) 1a is held between the mats 2, polyol and isocyanate being reactive liquids are respectively sent to a mixing head 7 from tanks 8a, 8b to be mixed and the obtained polyurethane resin raw material is injected into the mold 5. At this time, the polyurethane resin raw material penetrates into the resin circulating spaces 4a formed by the reinforcing fiber mats 2 and the metal net 1a from the injection direction A to flow out toward the reinforcing fiber mats 2 in a B-direction through the meshes 4b of the metal net 1a. As a result, the polyurethan resin raw material is infiltrated into the mats from the end parts thereof from a thickness direction.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a fiber-reinforced resin composite.

[0002]

2. Description of the Related Art Conventionally, there has been a reaction injection molding method (RIM molding method) as a method for manufacturing a synthetic resin molded article. In this method, two kinds of reactive liquids stored in different containers are collided with each other at high pressure or mixed by a mixer attached to a discharge port of a mold, and then the mixed reactive raw material resins are mixed. Molding is performed by injecting into a mold.

In the reaction injection molding method, unlike other molding methods of thermosetting resins, the reactivity of the raw material resin is high, and the molding cycle time can be greatly shortened. Is low, and a large mold clamping force is not required, so that there is an advantage that the equipment cost can be kept low.

Polyurethane resin, epoxy resin, dicyclopentadiene resin, nylon resin and the like are used as the raw material resin. In particular, polyurethane resins are widely used mainly for automobile parts due to their toughness and quick reactivity.

[0005] The reactive liquid of the raw material resin is, for example, an isocyanate and a polyol in the case of a polyurethane resin, and a bisphenol A type resin and an acid anhydride (curing agent) in the case of an epoxy resin.

[0006] The reaction injection molding method is usually carried out using only a resin, but when high strength is required for a molded product, glass fiber or the like is used in combination for reinforcement. As a molding method in this case, a mat-like reinforcing fiber made of glass fiber or the like is placed in a previously opened mold, the mold is closed, and the raw material resin obtained by mixing the above-described reactive liquid is placed in the mold. Injection-filling and curing by heating (Structural-R
eaction Injection Molding = S-RIM molding method).

As means for accelerating the impregnation of the raw resin into the mat-like reinforcing fibers, JP-A-2-21
What is described in 5510 gazette is known. This method is to apply the raw material resin in advance to a portion where the raw material resin is hardly impregnated or a portion having a high fiber content,
During the molding, the resin is sufficiently impregnated into the entire mat-like reinforcing fiber.

[0008]

As a general problem of the S-RIM molding method, the density of the mat-like reinforcing fibers is high, and the mat-like reinforcing fibers are impregnated with the raw resin at a low pressure. If the fiber volume content (Vf) of the product is high, the raw material resin is not sufficiently impregnated into the mat-like reinforcing fibers, so that the fiber volume content may not be too high. Specifically, the upper limit of Vf is 15 to
It is about 20%.

Further, in the method described in Japanese Patent Application Laid-Open No. 2-215510, the raw resin is partially applied to the mat-like reinforcing fiber in advance, and then the mold is closed and the raw resin is injected to some extent. Therefore, in the case of a polyurethane resin having a high reaction rate, there is a problem that the applied raw material resin is cured first, resulting in unevenness in a molded product. In addition, applying the raw material resin only to the portion of the mat-shaped reinforcing fiber which is difficult to impregnate with the resin or the portion having a high fiber content in advance complicates the molding process.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a method for producing a fiber-reinforced resin composite from which a molded article having a high fiber content can be easily obtained. Is what you do.

[0011]

In order to achieve the above-mentioned object, the method of the present invention comprises:
One or a plurality of mat-like reinforcing fibers and one or a plurality of mat-like bodies or corrugated nets having higher resin flowability than the mat-like reinforcing fibers, and these mat-like reinforcing fibers and mat-like bodies or corrugated nets. Are laminated so that they are adjacent to each other, the mold is closed, and the reactive raw material resin is injected to impregnate the raw material resin from the end of the mat-like reinforcing fiber and form a mat-like body or a corrugated net-like body. The resin distribution space or the mat-shaped reinforcing fiber and the resin distribution space formed by the mat-shaped body or the corrugated mesh body are allowed to enter and simultaneously flow out to the adjacent mat-shaped reinforcing fiber.

As the mat-like reinforcing fiber, glass fiber,
Chopped strand mats, continuous mats, cloths and the like made of carbon fibers, aramid fibers and the like can be mentioned. Further, it is preferable that the tensile strength of the mat-like reinforcing fiber is 3000 kg / mm ² or more and the tensile strength is 200 kg / mm ² or more. When the elastic modulus and the strength are less than the above values, the reinforcing effect is not exhibited even if the fiber volume content in the fiber reinforced resin composite is increased.

As the mat-like body and the corrugated net-like body, those having higher resin flowability than the mat-like reinforcing fiber are used. Usually, the mat-like body itself has a resin distribution space, and in the corrugated reticulate body, the resin distribution space is formed by the reticulate body and the mat-like reinforcing fibers, but in a special product, it may be the opposite. . These resin flow spaces serve as resin flow passages through which the reactive raw material passes without resistance. The mat-like body and the corrugated net-like body may or may not enhance the strength of the molded product. As the corrugated net, for example, a wire diameter of 0.5 mm or more and a mesh width of 5
A wire mesh of mm or more is included. As a mat-shaped body,
A relatively coarse mat in which synthetic fibers such as nylon fibers and polypropylene fibers are intertwined randomly or regularly is mentioned.

In the molding, only one mat-shaped body or corrugated net having a resin flow space is arranged on the mat-shaped reinforcing fiber, and the mat-shaped reinforcing fiber and the mat-shaped body or corrugated net are alternately arranged. A plurality of layers are laminated. In this case, it is preferable in terms of strength that the mat-like body or the corrugated net-like body is sandwiched between the respective mat-like reinforcing fibers.

When the basis weight per mat-shaped reinforcing fiber is less than 300 g / m ² , the mat has a coarse mesh and the strength of the molded product varies greatly, resulting in 600 g / m ^2.
If it exceeds, the impregnating property of the reactive raw material resin in the mat-like reinforcing fiber is deteriorated and only a part of the mat-like reinforcing fiber is produced. Therefore, it is preferably about 300 to 600 g / m ² .

Incidentally, when the above-mentioned mat-like body or corrugated net-like body is not present, the matting reinforcing fiber is not sufficiently impregnated with the reactive raw material, so that it becomes difficult to impregnate the reactive raw material of 300 g / m ² or more.

The thickness of the mat-like body or the corrugated mesh body is 0.
If it is less than 5 mm, the flowability of the reactive raw material resin deteriorates, and 4
If it exceeds mm, the proportion of the mat-like body or the corrugated net-like body in the fiber-reinforced resin composite becomes too large, and the reinforcing effect of the mat-like reinforcing fibers becomes insufficient, so the range is 0.5 to 4 mm. Is preferred.

Examples of the reactive raw material resin include a polyurethane resin in which an isocyanate and a polyol are mixed, an epoxy resin in which a bisphenol A type resin is mixed with an acid anhydride type curing agent, and a dicyclopentadiene resin. Of these reactive raw material resins, the production method of the present invention is particularly effective when a polyurethane resin or a dicyclopentadiene resin, which has a fast curing reaction and needs to be impregnated into the mat-like reinforcing fiber in a short time, is used. .

As the shape of the molded product manufactured by the manufacturing method of the present invention, in addition to a flat plate-shaped product made entirely of a fiber-reinforced resin composite, as shown in FIG. The fiber-reinforced resin composite (3
b) are mentioned.

As a method for manufacturing the above box-shaped product, the core mold is provided at a position corresponding to a place where reinforcement of the molded product is required.
The mat-like reinforcing fiber (2) and the mat-like or corrugated net (1
a) and each of which are shaped and set along the core mold, and then the mold is closed, and the reactive raw material resin is a resin distribution space of the mat-like body or the mat-like reinforcing fiber (2) and the corrugated net ( 1a)
It is carried out by injecting so as to flow into the resin circulation space formed by. The box-shaped product manufactured by this method, as shown in FIG. 8, is a part (3
a) and the part (3b) reinforced by the matt reinforcing fiber (2)
It will be composed of and.

[0021]

Next, an embodiment of the present invention will be described. [Example 1] Using the following material and molding method, a flat fiber-reinforced resin composite having a thickness of 3 mm and a size of 300 x 300 mm shown in Fig. 5 was obtained, and the volume content of the mat-shaped reinforcing fibers (2) was Vf =. It was manufactured to be 30%. Mat-shaped reinforcing fiber: Continuous mat Weight of 450 g / m ² (manufactured by Asahi Fiber Co., Ltd.) Corrugated mesh: As shown in FIG. 1, a corrugated wire mesh (1a) having a total thickness of 1.6 mm and a linear shape of 0 0.8 mm Gradient 10 mm Corrugated part height 0.8 mm Reactive raw material: Polyurethane resin (Sumitomo Bayern Co., Ltd. product name: Bayjoule 60) A liquid: polyol, B liquid: isocyanate Reaction time: 17 seconds First, as a manufacturing method, As shown in FIG. 2, a wire mesh (1a) was sandwiched between two continuous mats (2), and this was set in a mold (5) as shown in FIG. Tank (8a) and tank containing isocyanate
A predetermined amount of each of these reactive liquids was sent from (8b) to the mixing head (7) and mixed, and then this polyurethane resin raw material was injected into the mold (5) at an injection speed of 200 cc / sec for 0.8 seconds. .

At this time, as shown in FIG. 4, the polyurethane resin raw material enters the resin distribution space (4a) formed by the continuous mat (2) and the wire mesh (1a) from the direction of the arrow A from which it is injected. At the same time, it flows out through the mesh (4b) of the wire mesh (1a) in the direction of arrow B, that is, toward the continuous mat (2) side. Therefore, the continuous mat (2) is impregnated with the polyurethane resin raw material from the end portion thereof, and is also impregnated in the thickness direction over the entire surface of the mat. Therefore, the continuous mat (2) can be quickly and sufficiently impregnated with the polyurethane resin raw material.

[Embodiment 2] The same material as in Embodiment 1 was used and the thickness was 3 mm and 300 × 300 m by the following manufacturing method.
m of the flat plate fiber-reinforced resin composite has a volume content of continuous mat (2) (mat-shaped reinforcing fiber) of Vf
= 40%.

As shown in FIG. 6, the wire mesh (1a) was interposed between each of the three continuous mats (2), and this was set in the mold (5) as in the first embodiment. Molding was performed by injecting the polyurethane resin raw material at an injection speed of 200 cc / sec for 0.8 seconds.

[Example 3] A flat fiber-reinforced resin composite having a thickness of 3 mm and a size of 300 x 300 mm was formed into a mat-like reinforcing fiber having a volume content of Vf = 30% by the following material and molding method. As manufactured. Mat-shaped reinforcing fiber: Continuous mat 450 g / m ² (Asahi Fiber Co., Ltd.) Mat-shaped body: Nylon mat-shaped body (1b) shown in FIG. 9, in which nylon fibers are continuously and randomly formed. The shape is intertwined. Unit weight 100g / m ² Thickness about 1.5mm Resin distribution space (4c) Average 6mm square Reactive raw material: Polyurethane resin (Sumitomo Bayern Co., Ltd. product name: Bayjoule 60) A liquid: polyol, B liquid: isocyanate Reaction time: 17 As a manufacturing method, as shown in FIG. 10, a mat-like body (1b) is interposed between two continuous mats (2), and a polyurethane resin raw material is injected under the same injection conditions as in Example 1. went. In this case, the polyurethane resin raw material enters the resin distribution space (4c) of the mat-like body (1b) from the injection direction A of the resin raw material as in the case of using the wire net (1a) in Examples 1 and 2 above. Further, it will flow out to the continuous mat (2) and be impregnated into the continuous mat.

[Comparative Example 1] A tabular fiber-reinforced resin composite having a thickness of 3 mm and a size of 300 x 300 mm was obtained by the following material and molding method, and the volume content of the mat-shaped reinforcing fibers was Vf = 30%. As molded. Mat-shaped reinforcing fiber: Continuous mat 900 g / m ² (manufactured by Asahi Fiber Co., Ltd.) Reactive raw material: Polyurethane resin (Sumitomo Bayern Co., Ltd. product name: Bayur 60) Liquid A: polyol, liquid B: isocyanate Reaction time: 17 Seconds The above continuous mat was set in a mold, and a polyurethane resin raw material was injected at an injection speed of 200 cc / second for 0.8 seconds.

[Comparative Example 2] The same material as in Comparative Example 1 was used, and the thickness was 3 mm and 300 x 300 m by the following molding method.
The plate-shaped fiber-reinforced resin composite of m was molded so that the volume content of the mat-shaped reinforcing fibers was Vf = 30%. The continuous mat is set in the mold, the polyurethane resin raw material is partially applied to the continuous mat before the mold is closed, the mold is then closed, and the polyurethane resin raw material is injected under the same injection conditions as in Comparative Example 1. And molded.

[Comparative Example 3] A tabular fiber-reinforced resin composite having a thickness of 3 mm and a size of 300 x 300 mm was obtained by the following material and molding method, and the volume content of the mat-shaped reinforcing fibers was Vf = 30%. As molded. Reinforcing fiber mat: Continuous mat Weight per unit area 450g / m ² (Asahi Fiber Co., Ltd.) Reactive raw material: Polyurethane resin (Sumitomo Bayern Co., Ltd. product name: Bayjoule 60) Liquid A: polyol, liquid B: isocyanate Reaction time: 17 Seconds The above continuous mat was set in a mold, and a polyurethane resin raw material was injected at an injection speed of 200 cc / second for 0.8 seconds. With respect to the flat plate-shaped molded products manufactured by the manufacturing method of each of the above-described Examples and Comparative Examples, the resin impregnation state of the mat-shaped reinforcing fibers was visually observed, and a bending strength test according to JIS K7203 was performed.
As for the mat-like reinforcing fibers having a portion that was not sufficiently impregnated with the resin raw material, a test was performed on a portion that was sufficiently impregnated. The results are shown in Table 1 below.

[0029]

[Table 1] As is clear from the above results, the molded article produced by the method of each example was obtained by impregnating the entire mat-shaped reinforcing fiber with the polyurethane resin raw material, and the bending strength was also produced by the method of each comparative example. High compared to the product.

[0030]

According to the manufacturing method of the present invention, the injected reactive raw material resin is impregnated from the end portion of the mat-like reinforcing fiber, and the resin distribution space formed in the mat-like body or the corrugated net-like body. Or, it flows out to the adjacent mat-like reinforcing fibers through the resin distribution space formed by the mat-like reinforcing fibers and the mat-like body or the corrugated mesh body, and is impregnated also in the thickness direction of the mat-like reinforcing fibers. Therefore, the impregnation of the mat-shaped reinforcing fiber with the reactive raw material resin is carried out quickly and sufficiently. Therefore, according to the production method of the present invention, a molded product of a fiber-reinforced resin composite having a high fiber content can be obtained, and a reactive raw material resin is preliminarily provided in a necessary portion of the mat-shaped reinforcing fiber before injection molding. Like the conventional method of applying,
There is no unevenness in the molded product.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view of a corrugated net (wire net) used in an embodiment of the present invention.

FIG. 2 is a perspective view showing a laminated state of the corrugated net body and the mat-like reinforcing fibers in FIG.

FIG. 3 is a perspective view showing a molding procedure of a fiber-reinforced resin composite.

FIG. 4 is a perspective view of a laminate showing a flow state of the injected reactive resin raw material in the manufacturing method of the present invention.

FIG. 5 is a partially cutaway perspective view of a flat plate-shaped fiber-reinforced resin composite manufactured by the manufacturing method of the present invention.

FIG. 6 is a perspective view showing a laminated state of a corrugated net body and mat-like reinforcing fibers in Example 2.

FIG. 7 is a perspective view of a box-formed product manufactured according to the present invention.

FIG. 8 is an enlarged sectional view taken along line AA in FIG. 7;

FIG. 9 is a perspective view of a mat-like body used in Example 3.

FIG. 10 is a perspective view showing a laminated state of the mat-like body and the mat-like reinforcing fiber of FIG.

[Explanation of symbols]

 (1a): Corrugated net (1b): Mat (2): Reinforcing fiber in mat (4a): Resin distribution space (4b): Mesh

Claims (1)

[Claims] 1. One or a plurality of mat-like reinforcing fibers and one or a plurality of mat-like bodies or corrugated nets having a higher resin flowability than the mat-like reinforcing fibers are provided in a mold for performing reaction injection molding. After the mat-like reinforcing fiber and the mat-like body or the corrugated net-like body are laminated so as to be adjacent to each other, the mold is closed and the reactive raw material resin is injected, so that the raw material resin is added to the end of the mat-like reinforcing fiber. While impregnating from the part,
To allow the resin distribution space formed in the mat-shaped body or the corrugated net-like body or the resin distribution space formed by the mat-shaped body and the corrugated net-shaped body to flow into the adjacent mat-shaped reinforcing fiber at the same time. A method for producing a fiber-reinforced resin composite, comprising: