JPS595198B2 - Manufacturing method of corrosion-resistant pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for manufacturing corrosion-resistant pipes.

Specifically, the present invention uses fiber-reinforced plastics (hereinafter referred to as F
The present invention relates to a method of manufacturing pipes made of RP (referred to as RP). F
RP is generally understood to be a reinforcing fiber base material such as glass fiber impregnated and hardened with a hardening liquid resin such as a hardening polyester resin or an epoxy resin.

FRP is lightweight, has excellent corrosion resistance, and has excellent mechanical strength, so it is widely used in aircraft parts, mechanical parts, and other fields, and pipes also take advantage of FRP's excellent characteristics. As an example of application, it has been put into practical use, especially in the corrosion resistance field. 5
Cured resins used for FRP pipes are polyester resins and epoxy resins, which are generally said to be heat-resistant and corrosion-resistant resins.

However, from the point of view of heat resistance, except for special resin systems that are difficult to mold, polyester resin can
150C is the limit of use for 10 poxy resin, and around this temperature, the bending strength and elastic modulus also decreases. Also, from the point of view of corrosion resistance, neither polyester resin nor epoxy resin is universal, and resins for FRP pipes require a formulation appropriate to the fluid used, and are 15 times less versatile. For example, even epoxy resins that can withstand inorganic acids such as sulfuric acid are attacked by organic solvents, and polyester resins are superior to epoxy resins in terms of corrosion resistance against chlorine compounds. Furthermore, it is a general fact that corrosion resistance decreases as temperature conditions become higher. In addition, even if FRP pipes are called 20 heat-resistant and corrosion-resistant pipes, when used in high humidity and high temperatures, for example, when used as steam exhaust pipes, the resin in the inner layer may have a slight time lag depending on its composition. Although there is some, it gradually disappears and the fiber base material is exposed. Although the cause of this is not certain, it is assumed that this is due to the addition of water to resins in high humidity and high temperatures, and pipes made of polyester resin deteriorate quickly at high humidity and high temperatures. The inner surface of the FRP pipe is coated with a corrosion-resistant layer of 0.1-0.15r whose resin content is adjusted to 80-90%.
In many cases, a wL resin layer is provided, and this layer is provided because the resin has the corrosion-resistant function of the pipe, not the reinforcing fiber base material. hand,
Usually, a nonwoven fabric called Surf Ace Mat is used as the resin layer holding material. However, even if this corrosion-resistant resin layer is provided, the heat resistance and corrosion resistance are not very versatile as described above (and they only add time to high-humidity, high-temperature deterioration). The present invention was developed through research and development into a versatile pipe that takes advantage of the lightweight and mechanical strength of FRP pipes, further improves heat resistance and corrosion resistance, and specifically utilizes fluorocarbon resin, polyphenylene resin, etc. The present invention relates to a method for producing an FRP pipe having a layer on its inner surface in which a thermoplastic resin having excellent heat resistance and corrosion resistance, such as Rensulfide resin, is bonded to a reinforcing fiber base material.

Fluorine resins (polytetrafluoroethylene, polytrifluorochloride ethylene FRP, etc.) and polyphenylene sulfide resins are thermoplastic resins, but they have a high melting point and always have a
There is no change in practical performance even when used at ℃, and its corrosion resistance is unparalleled. Although these resins have poor processability compared to ordinary thermoplastic resins, it is known that they can form pinhole-free films if appropriate processing conditions are selected. The present invention combines the heat resistance and corrosion resistance of fluororesin and polyphenylene sulfide resin into an FRP pipe, and will be explained in detail below with reference to the drawings. First, a powder of fluororesin or polyphenylene sulfide resin (hereinafter simply referred to as resin) 2 is applied to one side of a reinforcing fiber base material 1 and sintered to form a resin film 3.

The fiber base material 1 is preferably a woven or non-woven fabric such as tape or cloth made of inorganic fibers or organic fibers such as glass fiber, aspest fiber, carbon fiber, Kepler fiber, etc., and is preferably a dense base material. . The powder of the resin 2 is not particularly limited in particle size, and is applied in a dry state or in the form of a liquid slurry. The applied resin 2 forms a resin film 3 on one side of the fiber base material 1 by sintering, but some of the resin 2 penetrates into the inside of the fiber base material 1 and forms anchors 4 of the resin film 3. As a result, it is bonded to the fiber base material 1 to form the resin-treated base material 5. The thickness of the resin film 3 can be changed arbitrarily by repeatedly applying and sintering the resin 2, but usually it is 0.1 to 0.2 W1 without pinholes with two overlapping coatings! A film of n is obtained, and the corrosion resistance is sufficient. Next, the resin-treated base material 5 is wound so that the resin film 3 is in contact with the core mold 6. When winding, it is convenient to form the resin-treated base material 5 into a tape shape and wind it with a butt gaiter. One winding is sufficient. In other words, after forming the pipe, only the innermost layer is covered with the resin coating 3.
V.C. It is desirable to be familiar. After winding the resin-treated base material 5, the outer surface of the resin-treated base material 5, that is, the fiber base material 1
The other surface 3' is coated and impregnated with a hardening liquid resin 7 such as VC polyester resin or epoxy resin. It is possible to mix 30 to 70 (11) microscopic hollow bodies (by weight) with this hardening liquid resin 7VC glass balloon (not shown) to function as a heat insulating layer.

Next, the reinforcing fiber base material 8 impregnated with the hardening liquid resin 7 is wound and laminated by a pan lay-up or filament winding method to form an FRP layer 9. The reinforcing fiber base material 8 is an inorganic fiber, an organic fiber, or a tape or cloth processed from these, and the thickness of the FRP layer 9 is determined by the strength design of the pipe. Once the liquid resin 7 is cured, the core mold 6 is pulled out to obtain an FRP pipe having an inner layer of a thermoplastic resin having excellent heat resistance and corrosion resistance. If we summarize the gist of the present invention,
1) On one side of a fiber base material such as woven fabric or non-woven fabric, 2) Heat resistant,
3) Thermoplastic resin with excellent corrosion resistance is sintered and impregnated.
Wrap the fiber base material around the core so that this resin layer becomes the innermost surface of the pipe, and 4) form an FRP reinforcing layer with the thermosetting resin and the fiber base material.

This is a method for manufacturing corrosion-resistant pipes. The inner layer of the pipe made by this method is a resin layer with excellent heat resistance and corrosion resistance bonded to a fiber base material, and is versatile enough to be used regardless of the fluid used, and is mechanically bonded to the FRP layer. This pipe retains the mechanical properties of FRP. Therefore, handling is no different from that of FRP pipes. As explained in the Examples, it was found that there were no problems at all even under conditions of use under high humidity and high temperature. [Example 1] A slurry of Ryton R (product name: polyphenylene sulfide resin, manufactured by Philips Corporation) was sprayed onto one side of a glass fiber plain weave tape having a thickness of 0.18 rfr1n and a width of 50rfr1n, and the tape was baked at 370°C for 50 minutes. This was repeated twice to produce a resin-treated base material.

Ryton R side of this tape is φ50.0×1000m
According to the core and type. I rolled it up one more layer. Next, after coating and impregnating the outer surface of the resin-treated base material with epoxy resin (Epicoat 8157/HHPA combination), the FRP layer is 3rd rated using glass roping! 600 helical windings were carried out by filament winding so that the length of the film was n. After curing the epoxy resin using the usual method, decore it,
An FRP pipe with a Ryton R layer on the inner layer was obtained. This pipe was cut into a length of 300 fm, connected to a steam exhaust pipe in a steam exhaust pit, and after being used for one month, the inner surface was observed, but no particular abnormality was observed. At the same time, for comparison purposes, an FRP pipe made of only epoxy resin was also tested, but the inner layer of resin disappeared and the base material was exposed. [Example 2] Ryton R powder was coated on one side of a glass surf ace mat with a thickness of 0.24 TW 1 L and a width of 1000 m using a roll to pre-form it, and sintered at 370°C for 40 minutes.
The process was repeated several times to produce a resin-treated base material.

After cutting this resin-treated base material into a tape shape with a width of 100wt1n, the inner surface was coated with Ryton R in exactly the same manner as in Example 1.
An FRP pipe with layers was obtained. This FRP pipe 1.
5! /Cd~2.0Kf/Cd was placed in a rubber sulfur sulfur can into which live steam was blown, but no abnormality occurred on the inner surface of the pipe. At the same time, when we conducted a comparative test on an FRP pipe with an epoxy resin layer held on its inner surface by Surf Ace Mat, we found that the resin layer had disappeared and numerous glass fibers were exposed.

[Example 3] Polytetrafluoride resin dispersion was applied three times with a brush to one side of a glass fiber plain weave tape with a thickness of 0.18wn and a width of 50rfm, dried, and baked at 400°C for 30 minutes. Conclusion, Sara VC. A dispersion of polytetrafluoride resin was applied twice with a brush and sintered at 380C for 40 minutes to obtain a resin-treated base material.

Using this resin-treated base material, an FRP pipe with a polytetrafluoride resin layer on the inner layer was obtained in the same manner as in Example 1. This pipe was cut into a length of 600WrIn, and a 2Kf/Cd factory steam pipe was prepared. connected to. After a month, I took it out and observed the inside, but no problems were found.

[Brief explanation of drawings]

Figures 1, 2 and 3 are explanatory diagrams for manufacturing the corrosion-resistant pipe of the present invention, and Figure 4 is a cross-sectional view showing one example of the corrosion-resistant pipe of the present invention, and 1 is a reinforced Fiber base material, 2,3
, 4 is a thermoplastic resin with excellent heat and corrosion resistance, 5 is a resin-treated base material, 6 is a core type, 7 is a thermosetting shelf 8 is a fiber reinforced base material,
9 is an FRP layer.

Claims (1)

[Claims] 1 A thermoplastic resin with excellent heat resistance and corrosion resistance is applied to one side of a reinforcing fiber base material such as woven fabric or non-woven fabric, sintered and bonded to form a pinhole-free film, and then the thermoplastic resin film surface is The reinforcing fiber base material is wound around a core mold so as to be in contact with the core mold surface, and a fiber reinforced plastic layer is formed on the wound layer by hand lay-up or filament winding method, and the core is removed. A method of manufacturing a corrosion-resistant pipe.