JPH085155B2 - Heat-peelable resin composite tube with reinforced layer - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a heat-peelable resin composite pipe of a reinforcing layer, and more specifically, various chemical liquids and hot spring water in which the outer surface of a vinyl chloride resin pipe is coated with a fiber-reinforced thermosetting resin via an adhesive. The present invention relates to a resin composite pipe which is suitable as a transportation pipe for the like, and which is capable of easily peeling the fiber-reinforced thermosetting resin layer by heating the bonded portion at a high temperature when the pipe is installed and which can be peeled by heat.

[Prior art]

Conventionally, as a resin composite pipe in which the outer surface of a vinyl chloride resin pipe is coated with a fiber-reinforced thermosetting resin via an adhesive, for example, one as found in Japanese Patent Publication No. 2-24655 is available. Are known. The resin composite pipe disclosed in Japanese Patent Publication No. 2-24655 has a tensile elongation of 25 to 45% at 23 ° C. between the vinyl chloride resin pipe and the fiber reinforced thermosetting resin layer, and An adhesive layer having a tensile shear adhesive strength of 20 kgf / cm ² or more at 95 ° C between the vinyl chloride resin tube and the fiber-reinforced thermosetting resin layer is provided, and the adhesive is 50-80% at 23 ° C. An unsaturated polyester resin having a tensile elongation rate, an unsaturated polyester resin having a tensile elongation rate of 1 to 6%, and an isocyanate compound as main components. Further, it is a compound in which the isocyanate group of the isocyanate compound is 0.5 to 30 with respect to one hydroxyl group of the unsaturated polyester resin. Further, this adhesive layer contains a thickness maintaining material.

[Problems to be Solved by the Invention]

In the case of connecting such a resin composite pipe to a pipe joint, the connecting portion at the pipe end of the resin composite pipe is heated with a torch lamp, burner or the like, and the fiber-reinforced thermosetting resin layer of the connecting portion is peeled off. Expose the vinyl chloride joint resin tube of the core tube.
And it connects by joining this vinyl chloride resin pipe to a pipe joint. Therefore, the outer surface of the vinyl chloride resin tube, which is the core tube, should be smooth and free of lumps of adhesive or rubber elastic body. However, in the resin composite pipe disclosed in the above Japanese Patent Publication No. 2-24655, since it is a FRP reinforced PVC pipe whose long-term heat resistant temperature is increased to around 95 ° C., it is a vinyl chloride resin pipe and fiber reinforced. Tensile shear adhesive strength with thermosetting resin layer is 95 ℃
In the above-mentioned Japanese Patent Publication No. 2-2465, the adhesive layer having a large adhesive force of 20 kg f / cm ² or more is required.
No. 5, in connection with the above-mentioned connection work, any special means is taken for peeling the vinyl chloride resin pipe and the fiber-reinforced thermosetting resin layer, which are bonded with a strong adhesive force as described above. Since it is not, it is extremely difficult to peel off the fiber-reinforced thermosetting resin layer that is firmly adhered from the outer surface of the vinyl chloride resin tube, and it is necessary to peel off with a rabbit using a peeling tool. The outer surface of the vinyl-based resin pipe may be considerably damaged by the peeling tool, or the fragments of the adhesive layer and the fiber-reinforced thermosetting resin layer may remain. In particular,
If the adhesive layer contains a thickness retaining material such as a rubber elastic body, the outer surface of the vinyl chloride resin pipe can be removed even if a heat peeling method is used to soften the adhesive layer by heating to facilitate peeling. In addition, a part of the adhesive, the resin, the fibers, etc. easily remains. Therefore, after peeling off the adhesive layer and the fiber-reinforced thermosetting resin layer, the outer surface of the vinyl chloride resin pipe must be siding treated and other surface polishing must be carried out. Was to increase the cost of. Further, in order to easily carry out the heat peeling work, it may be considered that the adhesive strength of the adhesive is suppressed to a certain degree, but in this case, by the fiber-reinforced thermosetting resin layer which is rigid and has little elongation, Although it has excellent chemical resistance such as acid resistance and alkali resistance, the original purpose of improving the mechanical strength and heat resistance of a vinyl chloride resin tube having a large elongation and a low softening temperature cannot be achieved. The ease of peeling work at the time of connecting the fiber-reinforced thermosetting resin layer laminated for the purpose of improving the mechanical strength and heat resistance of the vinyl chloride resin pipe and reinforcing the above-mentioned fiber-reinforced heat Development of a resin composite pipe that facilitates the peeling work of the curable resin layer and that can improve the mechanical strength and heat resistance of the vinyl chloride resin pipe of the core pipe and the peeling method when connecting the reinforcing layer I was eager for it. The present invention has been made in view of the above facts,
When used, it contributes to the improvement of mechanical strength and heat resistance of the vinyl chloride resin pipe as a resin composite pipe, and when the heat peeling work of the reinforcing layer is performed at the time of connection etc., the adhesive layer is easily decomposed by heat. Another object of the present invention is to provide a resin composite pipe in which a reinforcing layer is peeled off from the outer surface of a vinyl chloride resin pipe and a reinforced layer is heat-peelable.

[Means for solving problems]

The present invention is a resin composite pipe in which a fiber reinforced thermosetting resin is coated on the outer surface of a vinyl chloride resin pipe through an adhesive, wherein the adhesive comprises a hydroxyl group-terminated polyurethane polymer and an isocyanate compound. A heat-peelable resin composite tube for a reinforcing layer, characterized in that the isocyanate group of the isocyanate compound is 2 to 8 relative to 1 hydroxyl group of the polyurethane polymer. The vinyl chloride resin pipe is a polyvinyl chloride resin, a vinyl chloride resin mainly composed of vinyl chloride, a copolymer resin with another monomer copolymerizable therewith or a resin obtained by chlorinating these resins. Various long pipes produced from compositions containing additives such as stabilizers and plasticizers as necessary, curved pipes, cheeses, sockets, etc. joints required for piping for various purposes using these pipes Class, flange type valves and the like. The above-mentioned fiber reinforced thermosetting resin is an unsaturated polyester resin, epoxy resin, phenol resin, vinyl ester resin, urea resin, melamine resin, diallyl phthalate resin, silicone resin, polyimide resin, polysulfone resin, polyphenylene oxide resin, etc. A composition obtained by adding additives such as a colorant, a filler, and a release agent to a curable resin, if necessary, is an inorganic fiber such as glass fiber, carbon fiber, carbon whiskers, or boron fiber, a natural fiber, or vinylon. It is formed by a hand lay-up method, a spray-up method, a filament winding method or the like by impregnating or mixing and dispersing it in short fibers, long fibers, non-woven fabrics, woven fabrics and the like of organic fibers made of synthetic fibers such as. The adhesive in the present invention is composed of a hydroxyl group-terminated polyurethane polymer and an isocyanate compound, and is mixed so that the isocyanate group of the isocyanate compound is 2 to 8 relative to 1 hydroxyl group of the polyurethane polymer. As the hydroxyl group-terminated polyurethane polymer, various polyether-based polyols generally used for the production of urethane compounds, polyester-based polyols, polyols such as polymer polyols and isocyanate compounds obtained by reacting an isocyanate compound composed of polyisocyanate with the above polyol excess, Examples of the ether-based polyols include bisphenol A, ethylene glycol, propylene glycol, butylene glycol, diols such as 1,6-hexanediol, glycerin, and trimethylol propane. Triols such as down, ethylenediamine, low molecular weight active hydrogen compound having an active hydrogen two or more consisting of amines such as butylene diamine 1
Polymers obtained by ring-opening polymerization of one or more alkylene oxides such as propylene oxide, ethylene oxide and tetrahydrofuran in the presence of one or two or more. Examples of the polyester-based polyol include polybasic acids such as adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid and succinic acid, and bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,4 -Butanediol, diethylene glycol, 1,6-hexanediol, a polymer obtained by dehydration condensation with a polyhydric alcohol such as neopentyl glycol,
Further, examples thereof include polymers of lactones such as ε-caprolactone and α-methyl-ε-caprolactone, and also condensates of hydroxycarboxylic acids such as castor oil, a reaction product of castor oil and ethylene glycol, and the above polyhydric alcohols. To be Examples of the polymer polyol include those obtained by graft-polymerizing an ethylenically unsaturated compound such as acrylonitrile, styrene, and methyl (meth) acrylate onto the polyether-based polyol or polyester-based polyol, or 1,2- or 1,4- Examples thereof include polybutadiene polyol and hydrogenated products thereof. As a raw material for producing the urethane prepolymer, the weight average molecular weight of the polyol compound is preferably about 100 to 50,000, more preferably about 500 to 5.000. The above polyol compounds may be used alone or in combination of two or more. Examples of the polyisocyanate include diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and dicyclohexylmethane diisocyanate, trimers of the above diisocyanates, and triisocyanates such as triphenylmethane triisocyanate. In addition, crude MDI, which is a mixture of diphenylmethane diisocyanate, triphenylmethane triisocyanate, and the like, can also be mentioned. These polyisocyanates may be used alone or in combination of two or more. The hydroxyl group-terminated polyurethane polymer is mixed with 1 hydroxyl group so that the isocyanate groups of the isocyanate compound are 2 to 8 and used as the adhesive. When the compounding ratio of the isocyanate group of the isocyanate compound is less than 2 with respect to 1 hydroxyl group of the hydroxyl group-terminated polyurethane polymer, the cohesive force of the obtained adhesive is insufficient and the sufficient interfacial adhesion performance is deteriorated. When the compounding ratio of the isocyanate group exceeds 8, the cohesive force of the obtained adhesive becomes too large and the releasability deteriorates. . If necessary, a filler, a thixotropic agent, a chlorinated phosphate ester-based plasticizer, an adhesiveness-imparting agent, a curing catalyst, a stabilizer and the like may be added to the adhesive. The amount of the adhesive applied is preferably 7 to 50 g / m ² .

[Action]

In the heat-peelable resin composite pipe of the reinforcing layer of the present invention, the adhesive interposed between the vinyl chloride resin pipe and the fiber reinforced thermosetting resin is a so-called hydroxyl group-terminated polyurethane polymer and an isocyanate compound. As it is a heat-dependent adhesive, it maintains the adhesive strength as an intermediate layer under the usage conditions in the medium to high temperature range from room temperature to about 90 ° C, and the fiber-reinforced heat resistance of the vinyl chloride resin pipe of the corrosion-resistant layer and the reinforcement layer. By being combined with the curable resin, the pressure resistance is maintained. Then, at the time of peeling work, the adhesive is heated to a high temperature from the outside and the adhesive is heated to 180 ° C to 210 ° C.
At around ℃, the adhesive has a low molecular weight due to thermal decomposition,
The adhesive function deteriorates, and the vinyl chloride resin pipe and the fiber-reinforced thermosetting resin are easily separated. Moreover, the isocyanate group of the isocyanate compound is 2 to 8 with respect to 1 hydroxyl group of the hydroxyl group-terminated polyurethane polymer.
Therefore, the isocyanate compound remaining without being consumed by the reaction with the hydroxyl group of the hydroxyl group-terminated polyurethane polymer reacts with the resin component in the fiber-reinforced thermosetting resin. That is, a part of the adhesive is taken into the fiber-reinforced thermosetting resin side, and at the time of high-temperature peeling, the adhesive is easily peeled from the vinyl chloride resin pipe together with the fiber-reinforced thermosetting resin. It will be.

【Example】

Examples of the present invention and comparative examples to be compared with these will be given below to specifically clarify the reason why the present invention is excellent. (Example 1) As an adhesive, a hydroxyl-terminated polyurethane polymer (manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name: Desmo Call 50)
0) 12% by volume solid solution of methyl ethyl ketone solution 10
Isocyanate compound (manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name: Sumidule L-75) based on parts by weight based on solid content
20 parts by weight (1 hydroxyl group of the above hydroxyl group-terminated polyurethane polymer becomes the isocyanate group 8 of the isocyanate compound) were mixed well and used. First, nominal diameter 150 (mm), length 300 mm and nominal diameter 50 (m
m), 1m long vinyl chloride resin pipes (made by Sekisui Chemical Co., Ltd.).
The coated surface was once dried with hot air at ℃. Next, through the adhesive layer on the outer surface of the vinyl chloride resin tube, an unsaturated polyester resin (manufactured by Dainippon Ink and Chemicals, Inc., product name: HN201) # 200 glass cloth (manufactured by Unitika Ltd., product Name: ECM200SE) 4 layers, 1.3mm thick, left for 48 hours at 23 ℃ to completely cure the unsaturated polyester resin to form a fiber reinforced thermoset resin layer Heat-peelable resin composite pipes (two types) were produced. (Example 2) 20 parts by weight of the isocyanate compound of the adhesive of Example 1 in terms of solid content is converted to 10 parts by weight in terms of solid content (1 hydroxyl group of the above hydroxyl group-terminated polyurethane polymer becomes 4 isocyanate groups of the isocyanate compound). A resin composite tube in which the reinforcing layer was heat-peelable was prepared in the same manner as in Example 1 except that the resin composite tube was changed. (Example 3) 20 parts by weight of the isocyanate compound of the adhesive of Example 1 in terms of solid content is converted into 5 parts by weight in terms of solid content (1 hydroxyl group of the above hydroxyl group-terminated polyurethane polymer becomes 2 isocyanate groups of the isocyanate compound). A resin composite tube in which the reinforcing layer was heat-peelable was prepared in the same manner as in Example 1 except that the resin composite tube was changed. (Comparative Example 1) Instead of the adhesive of Example 1, a hydroxyl group-terminated polyurethane polymer and an isocyanate compound (Kyushu Paint Industry Co., Ltd., trade name: Pioneer Sealer, liquid A and liquid B) were used in a ratio of 2:
An adhesive agent was used which was well mixed at a ratio of 1 (weight ratio) (to 1 hydroxyl group of the above hydroxyl group-terminated polyurethane polymer, the isocyanate group of the isocyanate compound was 30). A resin composite tube in which the reinforcing layer was heat-peelable was produced in the same manner as in Example 1 except that the above adhesive was used. (Comparative Example 2) The # 200 glass cloth in which the unsaturated polyester resin used in Example 1 was impregnated directly on the outer surface of the vinyl chloride resin tube without using an adhesive, was heated in the same manner as in Example 1 to heat the reinforcing layer. A peelable resin composite tube was produced. Comparative Example 3 In place of the adhesive of Example 1, a hydroxyl group-terminated polyurethane polymer and an isocyanate compound (Kyushu Paint Industry Co., Ltd., trade name: Pioneer Sealer, A liquid and B liquid) were used.
An adhesive which was well mixed at a ratio of 0: 1 (weight ratio) (to 1 hydroxyl group of the hydroxyl group-terminated polyurethane polymer was 0.5 of the isocyanate group of the isocyanate compound) was used. A resin composite tube in which the reinforcing layer was heat-peelable was produced in the same manner as in Example 1 except that the above adhesive was used. (Performance Evaluation) A hot peel test, an adhesive strength test, and a cold heat repeat test were performed on the resin composite pipes of the reinforcing layer obtained in the above Examples and Comparative Examples, which were heat peelable, by the methods described below. The measurement results and evaluation results are shown in Table 1. Preparation of test pieces The heat-peelable resin composite pipe of the obtained reinforcing layer having a nominal diameter of 150 (mm) is divided into 30 parts in the circumferential direction of the pipe, and the above-mentioned high-temperature peel test and adhesive strength test width 170 mm x length A 150 mm divided piece was obtained, and a test piece defined for each test item was prepared.
Further, the obtained resin composite tube having a nominal diameter of 50 (mm) was used as it was as a test piece for a cold heat repeating test. High temperature peeling test The fiber reinforced thermosetting resin layer of the above test piece is heated evenly with a burner, and the fiber reinforced thermosetting resin layer warps from the end of the vinyl chloride resin layer of the test piece and partly peels off. When the peeled fiber-reinforced thermosetting resin layer is peeled from the surface of the vinyl chloride resin layer by pulling by sandwiching the end portion of the peeled fiber-reinforced thermosetting resin layer with a holding jig such as pliers. While observing the peeling work situation, the difficulty level of the peeling work was qualitatively evaluated in light of the actual practice. Adhesive strength test Tensile shear strength of the above test piece at room temperature (23 ℃) and
Based on JIS K 6850 tensile shear strength at 90 ℃,
The measurement was performed on a two-piece test piece having a width of 25 mm and an adhesive portion length of 200 mm. Cold / heat repeat test A cold / heat pipe was spliced to the above test piece, and polyethylene glycol was used to repeat 20 hours each at -10 ° C for 2 hours and at 90 ° C for 2 hours alternately, vinyl chloride resin layer and fiber reinforced. The adhesion state of the thermosetting resin layer was observed.

【The invention's effect】

The heat-peelable resin composite tube of the reinforcing layer of the present invention is configured as described above, and since the adhesive is a so-called heat-dependent adhesive composed of a hydroxyl group-terminated polyurethane polymer and an isocyanate compound, Under the usage conditions of medium to high temperature up to about 90 ° C, the adhesive strength as an intermediate layer is maintained, and the vinyl chloride resin pipe of the corrosion resistant layer and the fiber reinforced thermosetting resin of the reinforced layer are combined to improve the pressure resistance. It is possible to maintain and obtain excellent performance as a resin composite tube. Also, when the adhesive is heated to a high temperature from the outside, such as during peeling work, and the temperature of the adhesive rises to 180 ° C to 210 ° C, the molecular weight of the adhesive decreases due to thermal decomposition, and the adhesive function deteriorates. The reinforced thermosetting resin is easily peeled off. Moreover, the isocyanate group of the isocyanate compound is 2 to 8 with respect to 1 hydroxyl group of the hydroxyl group-terminated polyurethane polymer.
Since it is compounded so that the isocyanate compound remaining without being consumed in the reaction with the hydroxyl group of the hydroxyl-terminated polyurethane polymer reacts with the resin component in the fiber-reinforced thermosetting resin, part of the adhesive The adhesive is taken into the fiber-reinforced thermosetting resin side, and when heated at high temperature, the adhesive will be easily separated from the vinyl chloride resin tube together with the fiber-reinforced thermosetting resin.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway perspective view of a resin composite pipe in which a reinforcing layer of the present invention can be peeled by heating.

[Explanation of symbols]

 1-Reinforced layer heat-separable resin composite tube 2-Vinyl chloride resin tube 3-Adhesive layer 4-Fiber-reinforced thermosetting resin layer 5-Vinyl chloride resin outer coating layer

Claims (1)

[Claims] 1. A resin composite pipe in which the outer surface of a vinyl chloride resin pipe is coated with a fiber reinforced thermosetting resin via an adhesive, the adhesive comprising a hydroxyl group-terminated polyurethane polymer and an isocyanate compound. And a heat-peelable resin composite tube for a reinforcing layer, characterized in that the isocyanate group of the isocyanate compound is 2 to 8 relative to 1 hydroxyl group of the polyurethane polymer.