JPH0365769B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a molding intermediate material for use in fiber-reinforced plastics and a method for producing the same.

[Conventional technology]

Conventionally, when using intermediates for unidirectionally aligned fiber-reinforced plastics (hereinafter referred to as UD prepregs), especially intermediates made of carbon fibers as reinforcing fibers, as pipe-shaped molded products, there are roughly three methods: are categorized.

(1) When torsional resistance is required for pipes used in golf shafts, badminton shafts, etc., a layer in which the fibers are oriented at a certain angle with respect to the length direction, a so-called angle ply layer, is used. A method of forming layers in which the orientation angle of the fibers is approximately 0° with respect to the longitudinal direction of the pipe.

(2) When making full use of strength and rigidity in the length direction, fibers arranged in approximately the same direction with respect to the length direction and maintaining some shape retention against forces in the perpendicular direction, or in the perpendicular direction method of using an intermediate material affixed with reinforcing members to resist the forces of

(3) Wrap woven prepreg, yarn prepreg, or UD prepreg in the innermost layer of the pipe so that the main fibers are oriented in the circumferential direction of the pipe, and then wrap the fibers in the innermost layer so that the fibers are oriented in the longitudinal direction.
A method of wrapping UD prepreg itself or its secondary processing intermediate materials.

The secondary processing intermediate material mentioned here is a material in which an extremely thin glass cloth is laminated to the upper layer of UD prepreg, or an extremely thin prepreg with a thickness of 0.025 mm.
Conventionally used materials include materials laminated in a 90° direction, or materials laminated with a non-woven fabric made of reinforcing fibers stretched as thin as possible with the fiber direction approximately perpendicular to the longitudinal direction of the UD prepreg. refers to the material that is used.

The above method has the following problems.
Method (1) requires a minimum of three layers of UD prepreg to be combined, making it difficult to make a thin pipe. The problem with method (2) is that it is difficult to produce a material with well-balanced strength and rigidity in the longitudinal and lateral directions. In other words, this results in excessive performance. In addition, in method (3), even if the cloth or yarn prepregs are arranged so that the main fiber direction is in the circumferential direction, there is a limit to the minimum amount of fibers, and in this case too, the performance is excessive. Furthermore, when wrapping UD prepreg in the circumferential direction, cut prepreg is currently used. Therefore, when forming a pipe that requires a long length, it is necessary to join the pipe in the middle.
There are problems in that the work is complicated, and since the sheet is not continuous, the length cannot be arbitrarily changed when cutting the sheet, and material loss is inevitable.

[Problem that the invention seeks to solve]

The object of the present invention is to provide a fiber-reinforced plastic intermediate material and a method for producing the same, which solve the problems of the prior art described above and exhibit performance more effectively.

[Means for solving problems]

The gist of the present invention is to coat a resin on the mold release surface of a molding intermediate material and a mold release paper (A) consisting of reinforcing fibers and a thermosetting resin arranged at approximately 90 degrees with respect to the longitudinal direction. After arranging reinforcing fibers on top and impregnating the fibers with resin and cutting the obtained prepreg into a certain length, use another release paper (B) to improve the releasability of the release surface of the previous release paper (A). The purpose is to produce an intermediate material for molding by rearranging the fibers of the prepreg on a surface with a higher releasability so that the direction of the fibers is approximately 90 degrees with respect to the longitudinal direction of the release paper. This intermediate material is characterized by having a continuous form.

In the two types of release paper used in the present invention, the ratio of release properties of each release paper must be different by at least three times. The release property of the release paper is preferably expressed by the peel resistance value of the prepreg matrix resin itself or the matrix resin-impregnated prepreg used, but since it is difficult to measure it, in the present invention, the standard It was determined by measuring the peel resistance between the adhesive tape and the release surface of release paper. In other words, take three samples of approximately 180 mm x 25 mm from the paper width of the release paper, and apply standard adhesive tape (length 150 mm x 19 mm width) on top of the sample in the horizontal direction of the paper, gently to avoid air bubbles from entering the treated surface. Crimp. Immediately, a static load of 36 g/cm ² was applied, and the product was placed in a hot air circulation dryer at 70°C and left for 4 hours. Measurement chamber for mold releasability measurement under load (20℃, 65%RH)
Leave to cool for 30 minutes. The test machine is a universal tensile tester, and a suitable splint is applied to measure the peel resistance at 180 degrees at a speed of 300 mm/min. Take the measured values at three points (average value, maximum value) and the average value.

According to this measurement method, if the peel resistance value, which indicates the releasability of the surface to which the resin-impregnated prepreg is pasted, is three times or more the resistance value of the release paper on the side where the prepreg is transferred, the transfer of the prepreg will fail. It happens smoothly and the intended purpose is achieved.

In addition, the procedure for transfer is to cut the UD prepreg pasted on a release paper surface with light release properties to a predetermined length before transfer, and then place the UD prepreg on a release paper surface with a heavier release property than that of the release paper. Then, the fibers of the UD prepreg are arranged in a direction perpendicular to the longitudinal direction of the release paper. The continuous material thus produced is passed through heated nip rolls and nipped at a temperature of approximately 30 to 80°C to remove as much air space as possible between the UD prepreg surface and the continuous release paper to improve adhesion. Improve. Thereafter, by peeling off the release paper conventionally placed on the prepreg with tweezers or the like, it can be easily peeled off, and a continuous prepreg with reinforcing fibers arranged in the longitudinal direction can be obtained.

Examples of thermosetting resins used in the present invention include epoxy resins, unsaturated polyester resins, and phenolic resins.

In addition, as reinforcing fibers, carbon fibers, wholly aromatic polyamide fibers, glass fibers, polyester fibers,
Examples include nylon fiber, but carbon fiber is particularly preferred.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 An epoxy resin composition containing a curing agent was applied to a release paper with a surface peel resistance of 55 g/19 mm obtained by coating a paper with a width of 550 mm, a basis weight of 119 g/m ² , and a thickness of 0.125 mm with silicone resin. The resin was coated using a hot melt method using a coater so that the resin had a basis weight of 24 g/m ² .

After aligning the carbon fibers in one direction so that the weight of the carbon fibers was 25 g/m ² , the fibers were impregnated with resin by pressing onto a film and heating and pressurizing to form a prepreg, which was then rolled up together with release paper.

The prepreg thus obtained was cut to a fixed length of 520 mm, and the ears at both ends were removed to obtain a prepreg with dimensions of approximately 500 mm x 520 mm.

Place this prepreg with the release paper side up and the reinforcing fibers in a continuous release paper (peel resistance value 420).
g/19 mm) on a release paper with heavy releasability so as to be perpendicular to the longitudinal direction, and partially set by heating.

The thus obtained continuous prepreg with fibers in the 90° direction is rolled at a rolling temperature of 80°C and a speed of
It was passed through a heated nip roll at 100 m/h. after that,
By peeling off the upper release paper, a continuous prepreg with easily transferred fibers oriented at 90° to the longitudinal direction was obtained.

〔Effect of the invention〕

The intermediate material for molding of the present invention provides an intermediate body with well-balanced strength and rigidity in the longitudinal and lateral directions, and it is possible to produce a long, thin pipe.

Claims (1)

[Claims] 1. An intermediate material for molding made of reinforcing fibers and a thermosetting resin arranged at approximately 90 degrees with respect to the longitudinal direction. 2 Coat resin on the release surface of release paper (A), arrange reinforcing fibers on it, impregnate the fibers with resin, cut the resulting prepreg into a certain length, and then apply another release paper. The paper pattern (B) has a release surface that is more releasable than that of the release paper (A), and the fiber direction of the prepreg is approximately 90 degrees with respect to the longitudinal direction of the release paper (B). A method for producing a molding intermediate material made of a thermosetting resin and reinforcing fibers arranged at approximately 90 degrees with respect to the longitudinal direction, characterized by rearranging them in the direction of 90 degrees.