JPS5921293B2 - Pressure tape for FRP molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a presser tape for FRP molding.

When manufacturing FRP products, a pressure tape is wrapped around a winding body of a glass fiber base material impregnated with an uncured or semi-cured thermosetting resin, the resin is heated and cured in this state, and then, The 7° presser foot may come off.

For example, in manufacturing FRP pipes using the FW method,
Roping impregnated with thermosetting resin is wound onto a mandrel and then a pressure tape such as cellophane salem,
A polyester film or a polypropylene film is wrapped around it, then the thermosetting resin is heated and cured, and then the pressure tape is peeled off.

However, with conventional presser tapes, if the tape is cut during tape winding, unwinding or loosening of the tape is unavoidable, making it necessary to rewind the tape.

Therefore, there are disadvantages such as not only a decrease in work efficiency but also a significant waste of tape material. Furthermore, when the resin is heated and cured, the resin often seeps into or flows out from the overlapped layers of the presser tape wrapping layer, making it difficult to remove the presser tape after the resin has hardened. be.

Another disadvantage is that the smoothness of the molding surface inevitably deteriorates. According to the present inventors, the above-mentioned difficulties could be solved by using, for example, an adhesive tape using an adhesive mainly composed of natural rubber as the presser tape.

That is, according to the adhesive tape, even if the tape is cut during tape winding, the pressure winding can be completed by continuing to wind the tape from the tape cut point without unwinding or loosening the tape. Furthermore, since the overlapping seams of the presser tape are sealed with the adhesive, resin does not intrude into the overlapping seams of the tape, nor does resin flow out from the overlapping seams, and the surface of the cured product can be made to have a good smooth surface. However, when using an adhesive tape as a holding tape for FRP, the cured product and the adhesive tape are strongly adhered to each other with the above-mentioned ordinary adhesive tape, and it is extremely difficult to remove the tape from the cured product.

Therefore, general-purpose adhesive tapes are not suitable as presser tapes for FRP molding. The present invention provides an adhesive tape suitable for a presser tape for FRP molding.

That is, the presser tape for FRP molding according to the present invention is as follows:
This structure is characterized in that an adhesive layer is provided on the support film via a release layer.

FIG. 1 shows a presser tape for FRP molding according to the present invention.

In FIG. 1, 1 is a support film, 2 is a release agent layer, and 3 is a support film.
is the adhesive layer.

An example of a method for producing an FRP product using the rolled tape of the present invention is as follows.

A fiber base material impregnated with a resin (for example, glass rope impregnated with a thermosetting resin such as an unsaturated polyester resin or an epoxy resin) is wound onto a mandrel to a predetermined thickness to form a molding material, and a pressing tape ( For example, wrap a 1.5 crn width in a spiral shape (
(half wrap, 1/5 wrap, 4/5 wrap, etc.), then placed in a heating oven to heat and cure the resin, and after heat curing, the presser tape may be rewound. During this unwinding, the support film is unwound (that is, the adhesive is transferred to the cured resin side). An FRP pipe is obtained by removing the mandrel before or after unwinding the holding tape. In the present invention, any adhesive may be used, but a heat-curable adhesive is particularly preferred. Further, as the material of the adhesive, various natural rubber-based, synthetic rubber-based, acrylic-based adhesives, etc. can be used. As the presser winding tape of the present invention, in addition to the one shown in FIG. 1, it is also possible to use the one shown in FIG. 2.

21 in FIG. 2 is a release agent layer, and explanations of other symbols are as follows.
It is similar to the figure.

Such a tape is constructed by, for example, making the release force of the release agent layer 21 greater than the release force of the release agent 2 when the tape is stored as a tape roll. When making an FRP product using the pressure-wrapping tape of the present invention, a sheet-like fiber base material such as glass cloth and a prepreg sheet as the base material can also be used instead of the resin-impregnated fiber base material described above.

In the pressure winding tape according to the present invention, even if the tape is cut during tape winding, there is no tape unwinding or loosening, and good tape winding workability can be ensured. Since there is no inflow of water, the surface of the cured product can be made into a good smooth surface. Further, after the resin is cured, since the release agent layer is interposed between the support film and the adhesive layer, it is very easy to peel off the support film constituting the presser tape from the cured product. In the present invention, it is necessary to use a support film for the adhesive tape that has excellent tensile strength and heat resistance; for example, polyester film, polyimide film, biaxially oriented polypropylene film, etc. are suitable.

The width of the tape is usually 1.0 to 5.0 cm, preferably about 1.2 to 2.0 cm (: IIL). When using unsaturated polyester resin, 160℃ x 3
Those that do not exhibit self-flowing properties under conditions (0 to 60 minutes) are generally used.

Examples of the present invention will be described below. Example 1 A release agent (a reaction product of octadecyl alcohol, methyl methacrylate, and acrylonitrile) was applied at a rate of 0.05 to 0.289/l on a polyester film with a thickness of 25 μm, and acrylic rubber (rheochemical 100 parts by weight, melamine resin (J-821, manufactured by Dainippon Ink Co., Ltd.); 1 part by weight, toluene 400
Parts by weight of the mixture were applied and dried at 150° C. for 3 minutes.

The thus obtained adhesive tape with a width of 1.5 mm was wound in a spiral 3/5 wrap around the surface of an unsaturated polyester resin-impregnated glass rope wound body provided on a mandrel, and the tape was wound at 160°C and 60°C. After curing under heating conditions for 1 minute, the adhesive tape was peeled off and was found to be extremely easy to peel off. The peeling force at this time was 80 g/15 kg. Although the adhesive was completely transferred to the surface of the cured product by peeling off the adhesive tape, there was almost no tackiness on the surface of the cured product. Example 2 On the back of the adhesive tape used in Example 1, 100 parts by weight of a silicone resin (KS-705F, manufactured by Shin-Etsu Chemical Co., Ltd.) and 1 part by weight of a catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name PS-3) were applied. Apply the solution at a solid content of 0.05 to 0.11/i at 150°C.
The adhesive tape was dried for 3 minutes to obtain an adhesive tape with a release agent on the back side.

Using this adhesive tape, perform FRP in the same manner as in Example 1.
When the product was manufactured, an FRP product similar to that of Example 1 could be easily obtained. Note that the unwinding force of the tape roll of the adhesive tape used in this example was 209/15U width. A polyester film with a thickness of 25μ was used as a comparative example film.
As in Example 1, ordinary adhesive tapes using acrylic adhesives were used as presser tapes.

After the resin had hardened, an attempt was made to peel off the holding tape, but the adhesive force between the tape and the cured resin body was so strong that the tape would break, making it impossible to peel it off.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views showing examples of the presser winding tape of the present invention. 1... Support film, 2... Release agent layer, 3... Adhesive layer.

Claims (1)

[Scope of Claims] 1. A pressure-wrapping tape for FRP molding, characterized in that an adhesive layer is provided on a support film with a release layer interposed therebetween. 2. The press-wrap tape for FRP molding according to claim 1, which has a release layer on the back surface of the support film.