KR19980053417A - Nonwoven Mat Prepreg and Manufacturing Method - Google Patents

Abstract

The present invention relates to a prepreg, wherein the prepreg of the present invention is impregnated with a resin in a nonwoven fabric mat, and such a prepreg can be manufactured by a simple manufacturing process, and no demanding tension adjustment is required. In the composite prepreg laminated in the above, there is no defect of the product due to scrim peeling or the like, and thus the product yield is high, and the weight is light, so that the specific strength is high.

Description

Nonwoven Mat Prepreg and Manufacturing Method

1 is a cross-sectional view schematically showing the laminated structure of the nonwoven mat prepreg according to the present invention

2 shows schematically a device for producing a nonwoven mat prepreg according to the invention.

* Description of the symbols for the main parts of the drawings *

1: non-woven mat 2: resin-coated release sheet

2a: release sheet 2b: resin

11: Non-woven mat feed roll 12, 13: Resin-coated release sheet feed roll

14, 14 ': compression roll 15: release paper take-up roll

16: non-woven mat prepreg winding roll

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prepreg, and more particularly, a nonwoven mat prepreg manufactured by impregnating a resin in a non-woven mat manufactured by a fiber dispersion method selected from a dry method, a wet method, and an air spray method. And to a method for producing the same.

In general, prepregs in which reinforcing fibers such as carbon fibers, glass fibers, and aramid fibers are arranged in one direction or woven into a textile state, and then impregnated with resin have high specific strength (strength per unit weight) and specific strength (stiffness per unit weight) It has been widely used in various industries such as sports-leisure goods, aircraft, automobiles, ships, etc. In particular, the unidirectional prepreg, in which the reinforcing fibers are arranged in one direction, has high mechanical properties in the fiber direction, whereas in the fiber traverse direction, due to the weakness of the adhesion between the reinforcing fibers and the impregnating resin. Mechanical properties are very weak.

In order to compensate the directionality of the mechanical properties of the unidirectional prepreg, a scrim material such as glass fiber cloth or thin unidirectional prepreg may be used in the preparation of the prepreg.

In the production of such prepregs, glass fiber thin films having a thickness of about 20 μm are conventionally used to increase the vertical strength of the reinforcing fiber of the final composite product or to prevent the separation of the reinforcing fiber in the vertical direction of the reinforcing fiber in the composite product manufacturing process. It is known to use woven fabric as a scrim, but this method requires very precise control of tension and pressure during prepreg manufacture in order to bond well with the prepreg, and the high density of fiberglass material There is a problem that the weight of the product becomes heavy.

For example, Japanese Patent Laid-Open Nos. 60-165212 and 60-15782 propose a technique for manufacturing prepreg using a scratch cloth, but the cost burden of the control equipment for precise tension control of the bonded fabric is proposed. The difficulty of process control technology can be pointed out as a disadvantage. In addition, Japanese Laid-Open Patent Publication No. 60-163936 also discloses a technique of using a bonded fabric for prepreg, where the process of improvement in process, such as weaving by controlling the density of warp and weft differently for the tension control when weaving the bonded fabric. There is plenty of room. In addition, Korean Patent Publication No. 93-6928 discloses a technique for using a spun bond fabric as a spun fabric, and a high-stiffness fiber such as carbon fiber, glass fiber, aramid fiber, etc. There is a disadvantage that can not be.

Therefore, the present invention can solve the problem of the directionality of the mechanical properties of the existing one-way prepreg in consideration of all the problems of the prior art, and also difficult to adjust the tension of the reinforcing fibers and scrim material when manufacturing the existing scrim application prepreg and final It is an object of the present invention to provide a new prepreg that improves manufacturing productivity while reducing the weight of the product.

According to the present invention for achieving the above object, by applying a method selected from the dry, wet method and air spray fiber dispersion method randomly distributed reinforcing fiber fibers (random), and then apply a binder (paper) There is provided a nonwoven mat prepreg, characterized in that the resin is impregnated into a nonwoven mat prepared in the form.

In addition, according to the present invention, the single-fiber short fibers selected from carbon fiber, glass fiber, polyester fiber, polyaramid fiber, polyethylene fiber and metal-coated carbon fiber are randomly distributed so that the nonwoven mat bonded by a binder is unidirectional. The resin-coated release sheets were fed at the upper and lower positions of the nonwoven mat, respectively, and bonded to each other so that the resin-coated release surfaces of the thermosetting resin-coated release sheet faced on both sides thereof, and bonded to each other. The present invention provides a nonwoven mat prepreg and a manufacturing method comprising pressurizing to transfer and impregnate the release sheet-like resin onto a nonwoven mat.

Hereinafter, the present invention will be described in more detail with reference to the drawings illustrating preferred embodiments.

As shown in FIG. 1, the nonwoven mat prepreg of the present invention has a structure in which the nonwoven mat 1 is impregnated with the resin 2b from the resin-coated release sheet 2. The release sheet 2 attached to one side of the prepreg is peeled off and removed at the time of application of the prepreg.

The nonwoven mat 1 used in the present invention has no problem on the product even if it is adhered well to the resin 2a and the tension control is not precise, and since the final product feels light due to the low density, the specific strength is higher than that of the conventional product. .

The nonwoven mat 1 of the present prepreg is dried with one or more short fibers selected from the group consisting of carbon fibers, glass fibers, polyester fibers, polyaramid fibers, polyethylene fibers, and carbon fibers coated with metal with a binder. Dispersed by the wet and air-jet fiber dispersion methods to prepare a paper phase can be used. According to the characteristics of the material, the short fibers to be used are suitably 1 to 50 mm in length, and the nonwoven mat is suitable to be used within the range of 0.001 to 0.15 mm in thickness and 0.1 to 80 g / m 2 weight per unit area. In this case, styrene acrylate, polyester, polyvinyl alcohol or epoxy resin may be used as the binder. The binder resin imparts strength in the machine direction and the width direction of the nonwoven mat and at the same time serves to stabilize the arrangement of short fibers of reinforcing fibers.

On the other hand, in forming the nonwoven fabric mat 1 on the prepreg as described above, the resin 2b is transferred and impregnated into the nonwoven fabric mat 1 using the resin-coated release sheet 2 so that a complete bonding state is achieved. It is desirable to. According to this invention, the thermosetting resin is preferable for the resin 2b supported and applied to one side of the release sheet 2a. As the thermosetting resin 2b, an epoxy resin, an unsaturated polyester resin, a phenol resin, a cyanate ester resin, a polyimide resin, or the like can be used. The amount of the resin 2b supported on the release sheet 2a is applied to the final prepreg. It is suitable to make resin content in 25 to 70 weight%.

The release sheet 2a is a material capable of withstanding tension during the prepreg manufacturing process and exhibiting releasability. Both sides of the release sheet 2a are coated with polyethylene, PVA, or the like on kraft paper, roll paper, or glass paper with a thickness of 0.05 to 0.2 mm. It is preferable to use a release sheet coated thereon with a silicone- or non-silicone-based release agent such as a condensation reaction of polydiethylsiloxane and polydimethylhydrodienesiloxane or a release agent prepared from addition reaction type silicone.

When impregnating the resin onto the nonwoven fabric mat by using the resin-coated release sheet 2, the resin-coated release sheet 2 is attached to both sides of the nonwoven fabric mat, and then heated and pressurized to resin on the release sheet 2a. (2b) is transferred to the nonwoven mat 1 to be impregnated.

An example of the apparatus for manufacturing the nonwoven mat prepreg of the present invention by such a resin impregnation method is illustrated in FIG. Referring to the method of manufacturing the nonwoven mat prepreg of the present invention in the apparatus of FIG. 2, first, the nonwoven mat supplied from the nonwoven mat feed roll 11 is pulled in a sheet form while maintaining a parallel state, and then 1 to 20 m / min. Supply at a speed of. The speed should then be adjusted so that the nonwoven mat is fed smoothly without tearing. The resin-coated release sheet from the first resin-coated release sheet feed roll 12 and the second resin-coated release sheet feed roll 13 for impregnation of resin in the nonwoven mat downstream of the nonwoven mat feed roll 11 The upper and lower sides of the mat are respectively supplied at the same speed (nonwoven mat feeding speed) so that the surface of the water is bonded to the nonwoven mat. Then, the resultant bonded body was heated and pressed by passing through the pressing rolls 14 and 14 ', and then the resin supplied by the second resin-coated release sheet supplying roll 13 from the release sheet winding roll 15. -The release sheet from which the resin is transferred from the coated release sheet is wound up and peeled off, and the remaining non-woven mat prepreg having the structure as shown in FIG. 1 is wound up on the take-up roll 16.

At this time, it is preferable to make heating temperature into 50-170 degreeC, and to adjust the line pressure of a crimping roll to 0.1-10 kg / cm in the crimping roll 15 (15 '). In the pressing process, the thermosetting resin coated on the release sheet is transferred to and impregnated into a nonwoven mat, thereby producing a high strength, high elasticity prepreg product. Generally, the higher the viscosity of the resin is, the higher the temperature and pressure are required. The lower the temperature, the faster the reaction. In addition, the nonwoven mat prepreg according to the present invention is manufactured to a final thickness of 0.01 ~ 1mm depending on the purpose of use.

As described above, the nonwoven mat prepreg according to the present invention can be manufactured by a simple manufacturing process, it is not necessary to adjust the tension, and there is no defect of the product due to peeling of the bonded fabric, the product yield is high, and the weight It is light and has the advantage of high specific strength.

The following examples illustrate the preparation of the nonwoven mat prepreg of the present invention. Of course, the present invention is not limited to the following examples.

Example 1

A nonwoven mat prepreg was prepared using the apparatus of FIG. In this case, the nonwoven mat is a single fiber, carbon fiber (manufactured by RK Carbon having a tensile modulus of 24 tons and a short fiber length of 12 cm) and a cross-linked polyester resin as a binder resin per unit area. The OPTIMAT 203 nonwoven mat (Technical Fiber Produscts), weighing 17 g / cm 2, was used.As a resin-coated release sheet, epoxy resin was used as a thermosetting resin on a release sheet coated with a 0.1 mm thick polyethylene-based release agent. Wire diameter industry: SKR 2514] used a release sheet coated with a resin content of 40% by weight of the prepreg. In the apparatus of FIG. 2, the feeding speed of the nonwoven mat was 7 m / mim, and the pressing temperature and the pressure were 80 ° C. on the first pressing roll 14, 5 kg / cm linear pressure, and 120 ° C. on the second pressing roll 14 ', respectively. And wire pressure of 8 kg / cm.

The composite nonprep mat prepreg was laminated on a unidirectional carbon fiber prepreg (FAW = 125g / cm 2, using Toray's carbon fiber with 24 ton tensile elasticity), and the composite having a diameter of 10 mm and a thickness of 0.75 mm Material rod-like structures were fabricated and at the same time composite prepreg rolling and surface nodules were evaluated during the manufacturing process. As a result of the evaluation, no phenomenon of prepreg separation after rolling was observed, and hardly any surface defects occurred after the curing process.

Comparative Example 1

One-way carbon fiber prepreg (using Toray's carbon fiber with FAW = 20g / ㎠, 24 ton tensile elasticity) and one-way carbon fiber prepreg (using Toray's carbon fiber with FAW = 125g / cm2, 24 ton tensile elasticity) A composite rod-like structure with an inner diameter of 10 mm and a thickness of 0.75 mm was fabricated using prepregs laminated with an inverted wood layer (90 ° layer) at the same time, and at the same time, the evaluation of composite prepreg rolling and surface nodules occurred during the manufacturing process. It was. As a result of the evaluation, the prepreg was not separated after rolling, and the occurrence of surface defects after the curing process was high.

Example 2

A nonwoven mat prepreg was prepared using the apparatus of FIG. In this case, the non-woven mat is a single fiber, carbon fiber (manufactured by RK Carbon having a tensile modulus of 24 tons and a short fiber length of 12 cm) and a cross-linked polyester resin as a binder resin per unit area. The OPTIMAT 203 nonwoven mat (made by Technical Fiber Produscts) weighing 17 g / cm 2 was used, and as a resin-coated release sheet, an epoxy resin was used as a thermosetting resin on a release sheet treated with a silicone release agent on both sides of a roll of 0.14 mm thickness. Note) Sun-Kyung Industry: SKR 2525] was used as a resin-coated release sheet coated with a resin content of 40% by weight in the prepreg. In the apparatus of FIG. 2, the feeding speed of the nonwoven mat was 5 m / mim, and the pressing temperature and the pressure were 80 ° C. on the first pressing roll 14, 5 kg / cm linear pressure, and 120 ° C. on the second pressing roll 14 ', respectively. And wire pressure of 8 kg / cm.

The prepared nonwoven mat prepreg was laminated on one-way prepreg (FAW = 125g / cm 2, using Mitsubishi Rayon carbon fiber) using carbon fiber having 30 ton tensile elasticity to prepare a composite prepreg.

Comparative Example 2

One-way prepreg (FAW = 20g / cm2, using Toray's carbon fiber with 24 ton tensile elasticity) and one-way prepreg (FAW = 125g / cm2, Mitsubishi Rayon's carbon with 30 ton tensile elasticity) Composite prepreg was prepared by laminating with an inverted wood layer (90 ° layer).

The weight, thickness and equivalent modulus of the prepreg prepared in Example 2 and Comparative Example 2 were measured, and the bending deflection per unit weight (simple cantilever evaluation) was evaluated. The results are shown in Table 1 below.

TABLE 1

As can be seen from Table 1, the prepreg of Example 2 according to the present invention has a lighter weight and higher equivalent modulus of elasticity than the prepreg of Comparative Example 2, and the prepreg of Example 2 in the comparison of simple cantilever bending Relatively bending is small. Therefore, if the fishing rod is manufactured by applying the composite prepreg laminated with the carbon fiber nonwoven mat prepreg, it becomes lighter and increases the rigidity than the existing product, thereby improving the taste of the fishing rod.

Example 3

A nonwoven mat prepreg was prepared using the apparatus of FIG. In this case, the non-woven mat is a short fiber OPTIMAT 201 nonwoven fabric having a weight of 10g / ㎠ by applying a cross-linked polyester resin (E-Glass) with a fiber length of 12.5cm and a binder Mat (Technical Fiber Produscts) was used, and as a resin-coated release sheet, an epoxy resin (SKR 2525) was used as a thermosetting resin on a release sheet treated with a silicone release agent on both sides of a roll paper having a thickness of 0.14 mm. A release sheet coated to have a resin content of 40% by weight in the prepreg was used. In the apparatus of FIG. 2, the feed rates of the nonwoven mat and the resin-coated release sheet were the same at 5 m / mim, and the pressing temperature and the pressure were 80 ° C. and the line pressure 5 kg / cm and the second pressing on the first pressing roll 14, respectively. It was 120 degreeC and the line pressure of 8 kg / cm in the roll 14 '.

The prepared nonwoven mat prepreg was laminated on one-way prepreg (FAW = 125 g / cm 2, using Mitsubishi Rayon Co., Ltd. 12K carbon fiber) using carbon fiber having 24 tons tensile elasticity to prepare a composite prepreg.

Comparative Example 3

Laminated glass fiber thin fabric prepreg (weight = 34g / ㎡, resin included) on one-way prepreg (FAW = 125g / ㎠, Mitsubishi Rayon 12K carbon fiber) using a carbon fiber with 24 tons tensile elasticity Prepregs were prepared.

As a result of evaluating the separation phenomenon by leaving the prepreg of Example 3 and Comparative Example 3 for 20 days under laboratory conditions (25 ° C., 75% relative humidity), in the case of Comparative Example 3, the separation phenomenon in the reinforcing fiber direction was observed. However, in Example 3, there was no separation phenomenon.

Claims (5)

Characterized in that the nonwoven fabric mat bonded by a binder is impregnated with a resin by randomly distributing short fibers of one paper selected from carbon fibers, glass fibers, polyester fibers, polyaramid fibers, polyethylene fibers, and carbon coated carbon fibers. Nonwoven mat prepreg. The nonwoven mat prepreg according to claim 1, wherein the nonwoven mat is manufactured by a method selected from among dry, wet and air spray fiber dispersion methods. The non-woven mat prepreg according to claim 1, wherein the short fibers have a length of 1 to 50 mm and a nonwoven mat has a thickness of 0.001 to 0.15 mm and a weight of 0.1 to 80 g / m 2 per unit area. The non-woven mat prepreg of claim 1, wherein the binder is selected from the group consisting of styrene acrylate, polyester, polyvinyl alcohol or epoxy resin. Randomly distributed single fibers selected from carbon fiber, glass fiber, polyester fiber, polyaramid fiber, polyethylene fiber, and metal-coated carbon fiber randomly distribute the nonwoven mat bonded by the binder in a sheet form in parallel in one direction. After supplying the resin-coated release sheet at the upper and lower positions of the nonwoven fabric mat so as to face the resin coating surface of the thermosetting resin-coated release sheet on both sides thereof, and then joining them, the bonded body was heated and pressed to heat the press-release sheet. A method for producing a nonwoven mat prepreg comprising transferring and impregnating a resin of a phase onto a nonwoven mat.