JPS6326695B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing FRP pipes, and more particularly to a method for manufacturing high-quality FRP pipes with high productivity.

Conventional methods for producing FRP pipes include two methods: roving is impregnated in a resin bath, then wrapped around a core mold, and after hardening, the core mold is removed from the mold.The other method is to prepare prepregs in which roving is impregnated with resin in advance. There are two main methods: wrapping the resin around a core mold, completely curing the resin, and removing the core mold. However, with this method, more resin than required adheres to the roving during the impregnation process, so it is necessary to collect the excess resin during winding and return it to the resin bath for recycling, and the resin must have a long pot life. It is not practical. Therefore, it takes a long time to harden, especially for thick FRP.
In the case of pipes, productivity is extremely poor. In addition, a method of using a squeegee roller, etc. to adjust the amount of resin in the impregnation process has been implemented, but the resin hardens at the roller part and the impregnation rate fluctuates, and in some cases, the hardened resin may cause It may also be impossible to feed the roving. Therefore, especially in the continuous molding of FRP pipes, the squeegee roller and ancillary equipment must be frequently replaced, and the entire impregnated resin may also have to be replaced, which is a huge burden in terms of workability and economy. was forced. If you do not use a squeegee roller, etc., the amount of resin impregnated will be large and you will only be able to obtain a product with a low glass content.
Another problem is that defective products with a large amount of air bubbles frequently occur.

In addition, the above method requires preliminary equipment to prepare the resin-impregnated roving into prepreg, which increases the burden on the equipment.Also, it is necessary to ensure a certain pot life in the prepreg state, so the curing time is short. The resin is difficult to use and the curing time is also quite long. Moreover, the resin impregnation process for producing prepregs imposes economic and physical burdens, such as replacing impregnating equipment and equipment and completely replacing the impregnated resin, as in the above-mentioned method.

The inventors of the present invention focused on the above-mentioned circumstances and developed a system that satisfies all aspects of workability, productivity, and performance.
We have been conducting intensive research to provide a manufacturing method for FRP pipes. As a result, it was found that the above object could be successfully achieved by adopting the method shown below, and the present invention was finally completed.

In other words, the configuration of the FRP pipe manufacturing method according to the present invention is as follows:
In forming the FRP layer on the core mold, a glass fiber coated with a curing accelerator composition that does not substantially contain a curable resin is wound onto the core mold, and before winding, the FRP layer is preliminarily coated on the core mold. The gist lies in allowing a curable resin composition substantially containing a curable resin and a curing agent, which has been applied to the core mold and/or which is applied after winding, to adhere and penetrate into the glass fiber layer on the core mold. do.

In the present invention, after a curable resin composition containing a curable resin and a curing agent is applied onto a core mold, a glass fiber to which a curing accelerator composition substantially free of a curable resin is attached is wound. or applying the curable resin composition after winding the glass fiber,
A curable resin composition containing a curable resin and a curing agent is allowed to adhere to and penetrate the glass fibers to which the curing accelerator composition is attached on the core mold, and is cured. Since the hardening accelerator composition that is previously attached to the glass fibers by impregnation or the like does not harden at all by itself, there is no risk of hardening in the impregnating equipment, and the process from impregnation to winding can be carried out extremely smoothly. can. Furthermore, the curable resin composition is attached to and permeated into the wound glass fiber layer, and if the supply amount is properly adjusted, no excess resin will be produced. Moreover, since it is sufficient to mix an appropriate amount of curing agent with the curable resin depending on the amount used immediately before supplying, even a curable resin composition with a relatively short pot life can be used without any problem. In addition, as this curable resin composition adheres and penetrates, it also reacts with the curing accelerator composition and rapidly cures, so the time required for curing is significantly shortened compared to the conventional FRP pipe manufacturing method, reducing production costs. You can dramatically improve your sexuality.

By the way, as a method similar to the above method, a method can be considered in which glass fiber is first wound alone and then a fast-curing resin containing a curing agent and a curing accelerator is attached and penetrated into the curable resin, but the method of the present invention This is an even better method. In other words, when using a two-component curing resin, a mixture of resin and curing accelerator (liquid A) and a mixture of resin and curing agent (liquid B) are prepared before use. Liquid A and B just before
A method of mixing liquids is adopted, but if the pot life of the A/B mixture is short, there are maintenance problems such as the resin easily curing in a coating tool such as a spray gun or flow coater. Moreover, when mixing parts A and B at a ratio of 1:1, twice the amount of curing agent must be added to part B, and curing agents such as methyl ethyl ketone peroxide cannot be used with unsaturated polyesters. B The pot life of resins etc. is getting shorter.
The stability of the liquid itself is significantly impaired.

On the other hand, in the present invention, as mentioned above, the curing accelerator is attached to the glass fibers in advance, and the curing agent is mixed with the curable resin according to the consumption amount and used sequentially. There is almost no fear that the resin will harden inside the filling.

The curable resin used in the present invention includes conventionally known curable resins such as unsaturated polyester resin, epoxy resin, phenolic resin, and vinyl ester resin.
Any resin for FRP materials or improved resins thereof can be used, and the curing agent and curing accelerator are appropriately selected and determined depending on the type of the curable resin. Among these, peroxides such as methyl ethyl ketone peroxide, benzoyl peroxide, cyclohexane peroxide, cumene hydroperoxide, and lauroyl peroxide are exemplified as curing agents for unsaturated polyester resins, which are the most common resins for FRP materials. , as hardening accelerators cobalt, manganese,
Metal soaps such as vanadium, tertiary amines, quaternary
Examples include grade ammonium salts. All of these curable resin compositions can be used regardless of whether they are room temperature curable or thermosetting, but in view of the characteristics of the present invention, resins with short pot lives that are quick curable at room temperature or relatively low temperatures are preferred. By using it, its characteristics will be most effectively demonstrated.

The present invention is roughly constructed as described above, and its effects can be summarized as follows.

Since this is a method in which a curing accelerator is attached to glass fibers in advance and wound, and the curable resin composition is allowed to adhere and penetrate onto the core mold, even resins with a short pot life can be used without any problems in the final formulation. Curing time can be significantly shortened and productivity can be significantly increased.

Since the resin and curing agent are mixed in the required amounts each time and all are consumed one after the other, there is no wastage of the curing resin.

The final curing reaction of the resin proceeds rapidly from the moment the curable resin composition comes into contact with the curing accelerator attached to the glass fibers, so there is no risk of curing in painting equipment, etc., and maintenance is easy. But it's excellent. Therefore, the burden on workers is small, and it is extremely advantageous in terms of production management and equipment management.

Since the resin is supplied to the glass fiber layer by a combination of an impregnation method and an adhesion/penetration method, a high-performance FRP pipe with less air entering the FRP layer and fewer air bubbles can be obtained.

Claims (1)

[Claims] 1 A method for manufacturing an FRP pipe, in which, in forming an FRP layer, a glass fiber coated with a curing accelerator composition that does not substantially contain a curable resin is wound around a core mold, and this winding is performed. A curable resin composition comprising substantially a curable resin and a curing agent, previously applied on the core mold and/or applied after winding, adheres to and penetrates the glass fiber layer on the core mold. A method for manufacturing FRP pipes characterized by: