JPH07227913A - Manufacture of rolled film for molding prepreg and frp product prepared by using the same - Google Patents

Abstract

PURPOSE:To provide both a rolled film for molding with all the required properties such as strength, clamping properties, heat resistance and smooth peeling off and a method for manufacturing an FRP product by using such a rolled film for molding of a prepreg like this. CONSTITUTION:A rolled film for molding of a prepreg is constituted by providing heat-shrinkable non polar films 12 and 12 such as a biaxially drawn polypropylene film on both faces of a base film 11 with strength and heat resistance such as a biaxially drawn polyester film. An FRP product with good dimensional accuracy and surface condition can be manufactured by minding the rolled film 1 for molding of a prepreg on the prepreg provided on the outer face of a core body and heating the whole body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prepreg forming winding film used for forming a prepreg using a reinforcing fiber such as carbon fiber.
In addition, using the winding film for prepreg molding, F
The present invention relates to a method of manufacturing an RP product.

[0002]

2. Description of the Related Art A reinforcing material made of reinforcing fibers such as carbon fibers impregnated with a resin such as an epoxy resin is called a prepreg. If this prepreg is placed in a furnace and heat-treated, an FRP (fiber reinforced plastics) product is manufactured.

When manufacturing tubular FRP products such as golf club shafts and fishing rods, a prepreg in which a reinforcing material is impregnated with a resin is placed on the outer surface of a mandrel, and then a tape shape is applied from above the prepreg. The prepreg forming wrapping film is strongly spirally wound, and then the whole is supplied to a furnace for heat treatment to perform shaping and curing reaction, and finally, the prepreg forming wrapping film is obtained from the obtained FRP product. Peel off.

The reason why the tape-shaped winding film for forming a prepreg is wound on the prepreg is that during the heat treatment, the fluidization (gelation) of the resin occurs in the first stage and then the curing reaction of the resin occurs in the latter stage. Since this occurs, it is necessary to strongly tighten the prepreg in order to determine the shape and push out bubbles generated during gelation from the gaps in the film in the previous stage of the heating step. Particularly when a thin prepreg is used, the amount of impregnated resin is small, and therefore it is difficult to perform molding unless it is tightly tightened.

Therefore, the wrapping film for forming a prepreg has strength to withstand the tension during winding, has a property of appropriately shrinking during heat treatment to strongly tighten the prepreg, and endures high temperature during heat treatment. It is required that the FRP product after prepreg molding can be smoothly unwound and peeled off.

Conventionally, as a wrapping film for prepreg molding for this purpose, a biaxially stretched polypropylene simple film having a thickness of about 30 to 40 μm, a biaxially stretched polyethylene terephthalate film (generally referred to as a polyester film) A film with releasability is used by baking a silicone-based release agent on one side.

[0007]

However, the wrapping film for prepreg molding made of a biaxially stretched polypropylene simple film is not always sufficient in heat resistance and tensile strength, and the film is wound when tension is applied. There is a problem that it tends to elongate, and as a result, the tightening force during heat treatment becomes insufficient.

A wrapping film for prepreg molding made of a film obtained by baking a silicone-based release agent on one side of a polyester film does not cause elongation even if it is wound by tension, but it hardly shrinks at the time of heat treatment, so the tightening force As a result, when the resin of the prepreg gels, the force that pushes bubbles out of the gap between the films does not work, and FR
There is a problem that voids tend to remain on the surface of the P product. In addition, since it is not possible to completely prevent the silicone release agent from migrating to the surface of FRP products, when the final coating is applied to the FRP products after peeling off the film after prepreg molding, repellency or insufficient adhesion is produced. There is also a problem that it may occur.

Recently, it has been studied to use a two-layer film obtained by laminating a biaxially oriented polypropylene film on one surface of a biaxially oriented polyester film as a winding film for prepreg molding.

However, this 2 from the top of the prepreg
When the biaxially stretched polypropylene film side of the layer film is inwardly spirally wound and subjected to heat treatment, and when the fluidized resin slightly exudes from the gap of the winding film and also extrudes bubbles, the exuded resin Since the cured product firmly adheres to the biaxially stretched polyester film, there is a problem that a tape break occurs when the spirally wound film is unwound and peeled off.

In such a case, it is necessary to cut only the portion of the winding film by scanning the cutter in the axial direction and then peel the winding film, which is a work. In addition to bad performance, even if you are skilled, you often damage the FRP product with the blade of the cutter and make a failed product.

Under such circumstances, the present invention provides a winding film for prepreg molding which has all the required properties of strength, tightening property, heat resistance and smooth peeling property, and for such prepreg molding. It is an object of the present invention to provide a method for producing an FRP product using a winding film.

[0013]

The winding film for prepreg molding of the present invention comprises a non-polar film (1) which is heat-shrinkable on both sides of a base film (11) having strength and heat resistance.
2) and (12) are provided.

The method for producing an FRP product of the present invention comprises a core body
The prepreg (2) installed on the outer surface of (3) has a structure in which heat-shrinkable non-polar films (12) and (12) are provided on both sides of a base film (11) having strength and heat resistance. The wrapping film (1) for forming a prepreg is wound and then the whole is heat-treated.

The present invention will be described in detail below.

Wrapping film for prepreg molding (1) The wrapping film for prepreg molding (1) of the present invention comprises a non-polar film (12) capable of heat shrinkage on both sides of a base film (11) having strength and heat resistance. , (12) are provided.

As the base film (11), a biaxially oriented polyester film such as a biaxially oriented polyethylene terephthalate film, a biaxially oriented polybutylene terephthalate film or a biaxially oriented polyethylene naphthalate film is preferably used. In addition to these, films such as aromatic polyamide films, polyimide films, polyether sulfone films, polyphenylene sulfide films, polyether ether ketone films, and stretched films thereof can also be used.

As the non-polar film (12), a biaxially oriented polyolefin film, particularly a biaxially oriented polypropylene film is preferably used. In addition, stretched films such as ultra-high molecular weight polyethylene film, high-density polyethylene film, polymethylpentene film, and fluororesin can also be used.

The thickness of the above-mentioned base film (11) and non-polar film (12) is about 5 to 30 μm (preferably 7 to 20 μm, more preferably 8 to 15 μm) for the former,
The latter is about 2 to 10 μm (preferably 3 to 8) per layer.
μm) is suitable. The total thickness of the prepreg forming winding film (1) having a layer structure of (12) / (11) / (12) is preferably about 15 to 40 μm (preferably 17 to 30 μm). If the thickness is too thin, the strength, heat resistance, and the tightening force at the time of shrinkage are insufficient, and if it is too thick, a step is formed during winding, which deteriorates the surface condition of the FRP product.

As a method for forming the non-polar films (12) and (12) on both sides of the base film (11), various methods including a dry laminating method are adopted. In this case, in order to increase the interlayer adhesion, both surfaces of the base film (11) are subjected to surface treatments such as corona discharge treatment, oxidative flame treatment, surface roughening treatment and anchor coating treatment, especially corona discharge treatment. Is desirable.

Forming method of prepreg In forming the prepreg, a method of heating the prepreg forming tightening film (1) on the prepreg (2) wound around the outer surface of the core body (3) and then heat-treating Is adopted. As a result, the desired molded product is obtained.

As the core body (3), a pipe or rod made of metal having good heat conductivity such as stainless steel, iron and brass is used (the diameter is smaller than about 25 mm as a boundary. When the rod, when it is larger than the diameter is often a pipe).

As the prepreg (2), carbon fiber,
Yarns, rovings, yarns made of fibers such as glass fibers, boron fibers, aromatic polyamide fibers, and alumina fibers,
A prepreg impregnated with a resin such as epoxy resin, polyester resin, phenol resin, polyimide resin, diallyl phthalate resin is used as a reinforcing material in which cloth and mat are laminated, and epoxy resin is particularly used as a reinforcing material made of carbon fiber. What is impregnated is important.

From the top of the prepreg (2) installed on the outer surface of the core (3), a winding film for prepreg molding
Wind (1). As a winding method at that time, a spiral winding method using a tape-shaped film having an appropriate width as the prepreg forming winding film (1) is preferably adopted. The winding tension is 3 to 6 kg when the width is 15 mm.
It is often about the same.

In the heat treatment, it is usual to employ a two-step heating method, that is, a method of performing shaping at a relatively low temperature in the preceding stage, then raising the temperature and performing a heat treatment at a high temperature.
When the prepreg (2) is a carbon fiber reinforcing material impregnated with an epoxy resin, it is often heated in the former stage at about 80 ° C. for several tens of minutes and in the latter stage at about 130 ° C. for several hours.

After the heat treatment in the latter stage is completed, the prepreg forming winding film (1) is peeled off after allowing to cool. As a result, a desired FRP product can be obtained, and the product is subjected to a finishing process such as painting if necessary. FRP
Examples of products include golf club shafts, fishing rods, mechanical device shafts, automobile parts, industrial parts, consumer parts, and the like.

[0027]

[Function] Wrapping film for forming prepreg of the present invention
(1) has a layered structure of heat-shrinkable non-polar film (12) / strength and heat resistant base film (11) / heat-shrinkable non-polar film (12). The base film (11) plays a role of ensuring strength and heat resistance, and also plays a role of suppressing excessive heat shrinkability of the non-polar film (12). The non-polar film (12) plays a role of ensuring heat-shrinking action when heated and tightening the prepreg and smooth peeling property when peeling the film (1) from the FRP product.

Since the winding film for prepreg molding (1) has such a specific three-layer structure, it has the strength required for winding even if the thickness is thin, and also exhibits appropriate shrinkage when heated. Exhibits strong tightening force and has heat resistance to withstand heat treatment.

Also, when the wrapping film (1) is peeled off after being left to cool after the subsequent heat treatment, the wrapping film
Since both surfaces of (1) are composed of the non-polar film (12), the peeling can be performed smoothly and the rewinding can be performed mechanically. Although the resin flows and oozes out a little from the gap of the wrapping film (1) during the heat treatment in the previous stage, since both sides are made of non-polar film (12), the wrapping film ( At the time of rewinding in 1), the cured product of the leaching resin falls off and the peelability is not impaired.

As described above, according to the present invention, a series of operations from the winding of the prepreg forming winding film (1) to the rewinding and peeling thereof can be smoothly performed, and the winding force is large. FRP products with excellent dimensional accuracy can be manufactured.

[0031]

EXAMPLES The present invention will be further described with reference to examples.

Example 1 Production of Prepreg Molding Film (1) FIG. 1 is a perspective view showing an example of a prepreg molding winding film of the present invention, a part of which is cut away.

A base film having strength and heat resistance (1
As 1), a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm and corona-discharged on both sides was prepared. Also, as a heat-shrinkable non-polar film (12), the thickness is 5 μm.
The biaxially oriented polypropylene film of was prepared.

After coating the polyurethane-based adhesive solution on one surface of the above-mentioned biaxially stretched polyethylene terephthalate film, the solvent is volatilized by drying, and then the above-mentioned biaxially stretched polypropylene film is laminated and cured. A biaxially oriented polypropylene film was similarly laminated on the other surface of the axially oriented polyethylene terephthalate film. As a result, a winding film (1) for forming a prepreg having a thickness of about 25 μm was obtained.
This was cut into a tape with a width of 15 mm.

Production of FRP Product FIG. 2 is an explanatory view showing an example of the production method of the FRP product of the present invention.

A prepreg (2) with a release sheet impregnated with an epoxy resin is prepared by aligning and arranging carbon fibers on the release sheet, and the two prepregs (2) are arranged so that the fiber array directions are orthogonal to each other. The core body (3) was wound around once (the winding ends were slightly overlapped).
As the core body (3), a rod made of stainless steel having an outer diameter of 10 mm and having a slight taper was used.

Next, from the top of the prepreg (2), a winding film for forming a prepreg having a width of 15 mm prepared above is formed.
4kg / (1) so that the edges overlap by 1/3 of the width
A single spiral wound with a tension of 15 mm width.

In this state, the material is supplied to the furnace, heated from room temperature to 80 ° C. in 10 minutes and heat-treated at this temperature for 20 minutes, and then heated to 130 ° C. in 10 minutes and heated to this temperature. After heating for 2 hours to proceed the curing reaction of the resin, it was left to cool to near room temperature.

After cooling, the prepreg forming winding film (1) was rewound and peeled from the FRP product (fishing rod).
The peeling operation was smooth, and the tape did not break. The dimensional accuracy and surface condition of the obtained FRP product were good. It should be noted that during the heat treatment in the previous stage, the resin flowed and leached out slightly from the gap of the winding film (1),
Even when the leached resin was cured, the releasability of the winding film (1) was not impaired at all.

[0040]

As described in the section of the operation, since the prepreg forming winding film (1) of the present invention has a specific three-layer structure, it has sufficient strength for winding even if it is thin. In addition, it has an appropriate shrinkage when heated, exerts a strong tightening force, and has heat resistance to withstand heat treatment.

Also, when the wrapping film (1) is peeled off after being left to cool after the heat treatment in the latter stage, since the non-polar film (12) is formed on both sides of the wrapping film (1), the peeling can be carried out smoothly. It can be done, and the unwinding can be done mechanically. Although the resin flows and oozes out a little from the gap of the wrapping film (1) during the heat treatment in the previous stage, since both sides are made of non-polar film (12), the wrapping film ( The rewinding peelability of 1) is not impaired at all.

As described above, according to the present invention, the series of operations from the winding of the prepreg forming winding film (1) to the rewinding and peeling thereof can be smoothly performed, and the winding force is large. FRP products with excellent dimensional accuracy can be manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a wrapping film for prepreg molding of the present invention, a part of which is cut away.

FIG. 2 is an explanatory view showing an example of a method for producing an FRP product of the present invention.

[Explanation of symbols] (1) ... winding film for prepreg molding, (11) ... base film, (12) ... non-polar film, (2) ... prepreg, (3) ... core body

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B32B 27/16 8413-4F 27/32 C 8115-4F 27/36 7421-4F // B29K 23: 00 67:00 105: 08 B29L 9:00

Claims (6)

[Claims] 1. A base film (1) having strength and heat resistance.
A winding film for prepreg molding having a structure in which heat-shrinkable non-polar films (12) and (12) are provided on both sides of 1). 2. The winding film for prepreg molding according to claim 1, wherein the base film (11) is a biaxially stretched polyester film. 3. The winding film for prepreg molding according to claim 2, wherein the biaxially stretched polyester film is surface-treated on both sides. 4. The winding film for prepreg molding according to claim 1, wherein the non-polar film (12) is a biaxially oriented polypropylene film. 5. A prepreg (2) installed on the outer surface of a core (3)
From the top, a base film with strength and heat resistance (11)
Wrapping film for prepreg molding (1) having a structure in which heat-shrinkable non-polar films (12), (12) are provided on both sides of
After being wound, the whole is heat-treated F
RP product manufacturing method. 6. The method for producing an FRP product according to claim 5, wherein the winding film (1) for forming a prepreg is wound by spiral winding.