JP2002283454A - Rehabilitation pipe - Google Patents

Abstract

(57) [Summary] (Modifications required) [Problem] Aged existing pipes may be cracked or damaged due to corrosion or deterioration, and widely used as a material for rehabilitating these old pipes. Although resin is used, it is not always sufficient for applications requiring heat resistance. SOLUTION: In order to solve this problem, a rehabilitation pipe of the present invention is molded using a chlorinated vinyl chloride resin composition, and after being inserted into an existing pipe, is heated or heated and the internal pressure is reduced. It is a rehabilitation pipe characterized by being brought into close contact with the inner surface of an existing pipe by being hung.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a rehabilitation pipe.

[0002]

2. Description of the Related Art Aged existing pipes may be cracked or damaged due to corrosion and deterioration. Since vinyl chloride resin is a material having excellent mechanical strength, chemical resistance and the like, it is widely used as a material for rehabilitating these deteriorated existing pipes. For example, Japanese Patent Publication No. Hei 6-508647 discloses a method for rehabilitating an existing pipe using a vinyl chloride resin.

However, in the case of this method, the main component of the rehabilitation pipe is a vinyl chloride resin, so that it is not always sufficient for applications requiring more heat resistance.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rehabilitating pipe having excellent heat resistance in view of the above-mentioned problems of the prior art.

[0005]

The rehabilitating pipe of the present invention is formed by using a chlorinated vinyl chloride resin composition, and is inserted into an existing pipe and then heated or heated and subjected to internal pressure. It is characterized in that it comes into close contact with the inner surface of the existing pipe.

The chlorinated vinyl chloride resin (hereinafter referred to as CP)
VC) is obtained by chlorinating a vinyl chloride resin by an ordinary method, and the vinyl chloride resin and the chlorination method are not particularly limited. The average chlorine content of the chlorinated vinyl chloride resin composition is preferably from 60 to 72% by weight. If the average chlorine content is less than 60% by weight, heat resistance tends to be insufficient, and if it exceeds 72% by weight, molding processing becomes difficult and gelation may be insufficient. Also, the workability tends to decrease. A more preferred average chlorine content is 63 to 70% by weight.

The vinyl chloride resin may be a vinyl chloride monomer (hereinafter, referred to as VCM) alone, or a mixture of VCM and VC.
It is a resin obtained by polymerizing a mixture of M with another copolymerizable monomer by a known method. Other monomers copolymerizable with the VCM are not particularly limited, and include, for example, alkyl vinyl esters such as vinyl acetate; α-monoolefins such as ethylene and propylene; vinylidene chloride; and styrene. These may be used alone,
Two or more kinds may be used in combination.

[0008] The vinyl chloride resin (hereinafter, referred to as PVC) used in the production of the CPVC of the present invention is not particularly limited as long as it is the above-mentioned vinyl chloride resin. No., JP-A-8-
PVC obtained by the production method described in JP-A-295701, JP-A-9-132612 or JP-A-9-227607 is preferred.

The chlorinated vinyl chloride resin composition contains C
Even if PVC is used alone, the above C having a different chlorine content may be used.
Even if a combination system of PVC is used, the above-mentioned CPVC and the above-mentioned PVC
May be used.

In the present invention, if necessary, a stabilizer, a lubricant, a processing aid, an impact modifier, a heat resistance improver, an antioxidant, an ultraviolet absorber, and the like may be added to the chlorinated vinyl chloride resin composition. Additives such as light stabilizers, fillers, thermoplastic elastomers and pigments may be added.

The stabilizer is not particularly limited, and includes, for example, a heat stabilizer and a heat stabilizing aid. The heat stabilizer is not particularly limited, for example, dibutyltin mercapto, dioctyltin mercapto, dimethyltin mercapto, dibutyltin mercapto, dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, dioctyltin maleate polymer, dibutyl Tin laurate,
Organic tin stabilizers such as dibutyltin laurate polymer; lead stabilizers such as lead stearate, dibasic lead phosphite, and tribasic lead sulfate; calcium-zinc stabilizer; barium-
Zinc-based stabilizers; barium-cadmium-based stabilizers; These may be used alone or in combination of two or more.

The above stabilizing aid is not particularly limited.
For example, epoxidized soybean oil, phosphate, polyol, hydrotalcite, zeolite and the like can be mentioned.
These may be used alone or in combination of two or more.

The above lubricant includes an internal lubricant and an external lubricant. The internal lubricant is used for the purpose of lowering the flow viscosity of the molten resin at the time of molding and preventing frictional heat generation. The internal lubricant is not particularly limited, and includes, for example, butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, bisamide and the like. These may be used alone or in combination of two or more. The external lubricant is used for the purpose of enhancing the sliding effect between the molten resin and the metal surface during molding. The external lubricant is not particularly limited, and includes, for example, paraffin wax, polyolefin wax, ester wax, montanic acid wax and the like. These may be used alone or in combination of two or more.

The processing aid is not particularly restricted but includes, for example, acrylic processing aids such as alkyl acrylate-alkyl methacrylate copolymers having a weight average molecular weight of 100,000 to 2,000,000. The acrylic processing aid is not particularly limited, and includes, for example, an n-butyl acrylate-methyl methacrylate copolymer, a 2-ethylhexyl acrylate-methyl methacrylate-butyl methacrylate copolymer, and the like. These may be used alone or in combination of two or more.

The impact modifier is not particularly limited.
For example, methyl methacrylate-butadiene-styrene copolymer (MBS), chlorinated polyethylene, acrylic rubber and the like can be mentioned.

The heat resistance improver is not particularly limited.
For example, α-methylstyrene-based, N-phenylmaleimide-based resins and the like can be mentioned.

The antioxidant is not particularly limited.
For example, phenolic antioxidants and the like can be mentioned.

The light stabilizer is not particularly limited, and examples thereof include hindered amine-based light stabilizers and the like.

The ultraviolet absorber is not particularly limited, and examples thereof include salicylic acid ester, benzophenone, benzotriazole and cyanoacrylate ultraviolet absorbers.

The filler is not particularly restricted but includes, for example, calcium carbonate and talc.

The above-mentioned pigments are not particularly restricted but include, for example, organic pigments such as azo, phthalocyanine, sulene and dye lakes; oxides, molybdenum chromates, sulfides / selenides, ferrocyanides. And inorganic pigments.

Further, a plasticizer may be added to the chlorinated vinyl chloride resin composition for the purpose of improving the processability at the time of molding, but it may lower the heat resistance of the molded article. It is not preferable to use a large amount. The plasticizer is not particularly limited, for example, dibutyl phthalate, di-2-ethylhexyl phthalate,
Di-2-ethylhexyl adipate and the like.

A thermoplastic elastomer may be added to the chlorinated vinyl chloride resin composition for the purpose of improving workability. The thermoplastic elastomer is not particularly limited, for example, acrylonitrile-butadiene copolymer (NBR), ethylene-vinyl acetate copolymer
(EVA), ethylene-vinyl acetate-carbon monoxide copolymer
(EVACO), vinyl chloride-based thermoplastic elastomers such as vinyl chloride-vinyl acetate copolymers and vinyl chloride-vinylidene chloride copolymers, styrene-based thermoplastic elastomers,
Examples include olefin-based thermoplastic elastomers, urethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers. These thermoplastic elastomers may be used alone or in combination of two or more.

The method of mixing the above additives with the above chlorinated vinyl chloride resin is not particularly limited, and examples thereof include a method using hot blending and a method using cold blending.

The rehabilitating pipe of the present invention is made of a chlorinated vinyl chloride resin composition, and after being inserted into the existing pipe, is heated or adhered to the inner surface of the existing pipe by being heated and subjected to internal pressure. Rehabilitation pipe characterized by doing.

The rehabilitating pipe is manufactured by using the chlorinated vinyl chloride resin composition and extruding it into a tubular body having a desired cross-sectional shape. The cross-sectional shape of the rehabilitating pipe may be any shape as long as it can be inserted into an existing pipe to be rehabilitated and repaired, and can be in close contact with the inner surface of the existing pipe by heating or heating and applying internal pressure. However, there is no particular limitation.

The bending elastic modulus of the rehabilitating pipe is preferably 1470 MPa or more at room temperature and less than 1470 MPa at the temperature of insertion into the existing pipe. If the flexural modulus is less than 1470 MPa at room temperature, the mechanical strength of the rehabilitating pipe becomes insufficient, and it is necessary to increase the thickness of the rehabilitating pipe, so that the cross-sectional area (hollow portion) of the rehabilitating pipe is reduced. Failure occurs. Further, if the bending elastic modulus is 1470 MPa or more at the insertion temperature into the existing pipe, the insertability of the rehabilitation pipe into the existing pipe is impaired.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 [Preparation of chlorinated vinyl chloride resin composition] 100 parts by weight of CPVC (manufactured by Tokuyama Sekisui Kogyo Co., Ltd., trade name "HA-54K"), an organic tin-based stabilizer (manufactured by Sankyoki Gosei Co., Ltd.) , Product name "ON
1.5 parts by weight of Z-100F "), 8 parts by weight of an impact modifier (trade name" M511 ", manufactured by Kaneka Chemical Co., Ltd.), 1 part by weight of lubricant (trade name," Hiwax 2203A ", manufactured by Mitsui Chemicals, Inc.), lubricant (Manufactured by Riken Vitamin Co., trade name "SL800") 0.5
5 parts by weight of a thermoplastic elastomer (manufactured by DuPont-Mitsui Polychemicals Co., Ltd., trade name "Elvaloy 742F") is mixed with a 200 L supermixer (manufactured by Kawata) to obtain a chlorinated vinyl chloride resin composition. Was.

[Preparation of Rehabilitated Pipe] The obtained chlorinated vinyl chloride resin composition was subjected to a 50 mm-diameter biaxially different-direction rotary extruder SLM-50 (manufactured by Nagata Seisakusho) to obtain a melt.
The obtained melt was cooled with water at 20 ° C., and the outer diameter was 50 mm.
A fat tubular body having a thickness of 4.5 mm was obtained. This tubular body is
After standing for 20 minutes in a gear oven heated to
The cross section of the tubular body was made into a four-fold shape, and while maintaining this shape, the molded body was cooled until the temperature reached 20 ° C. to obtain a rehabilitated tube.

[Evaluation] The Vicat softening temperature, flexural modulus, insertability and resilience of the rehabilitated pipe were evaluated by the following methods. The results are summarized in Table 1. (Vicat softening temperature) The Vicat softening temperature was measured in accordance with the Vicat softening temperature test method (JIS K 7206) for thermoplastics. A 5 kg weight was used for the measurement. (Flexural modulus) Bending test method of hard plastic (JI
The flexural modulus at 20 ° C. and 80 ° C. was measured according to SK 7203). (Evaluation of insertability) From one end of the rehabilitation pipe to the inside of the rehabilitation pipe, 8
After blowing hot air of 0 ° C for 10 minutes, the rehabilitation pipe is 50 m inside diameter.
m into a 45 ° L-shaped steel pipe, and the insertability was evaluated according to the following criteria.・: Insertable, no damage such as cracking or whitening. ×: Impossible to insert or damaged such as cracking and whitening. (Resilience evaluation) Insert the rehabilitation pipe into a steel pipe with an inner diameter of 50 mm,
Steam at 110 ° C. was blown into the inside of the rehabilitation pipe from one end of the rehabilitation pipe for 10 minutes to bring the rehabilitation pipe into close contact with the inner surface of the steel pipe. Then, after cooling by blowing air at 20 ° C. for 30 minutes, the adhesion between the steel pipe and the rehabilitated pipe was visually observed, and the resilience was evaluated according to the following criteria.・: The rehabilitated pipe was in full contact with the steel pipe. ×: The rehabilitated pipe was not completely adhered to the steel pipe.

Example 2 CPVC (trade name "HA-54H" manufactured by Tokuyama Sekisui Industry Co., Ltd.)
70 parts by weight and PVC (manufactured by Tokuyama Sekisui Industry Co., Ltd., trade name "TS
-1000R ") 30 parts by weight, 1.5 parts by weight of an organotin-based stabilizer (manufactured by Sankyoki Gosei Co., Ltd., trade name" ONZ-100F "), and an impact modifier (manufactured by Kanebuchi Chemical Co., Ltd., trade name" M511 ") ")
8 parts by weight, lubricant (trade name “Hiwax2” manufactured by Mitsui Chemicals, Inc.)
203A)) and 0.5 parts by weight of a lubricant (manufactured by Riken Vitamin Co., trade name "SL800") are stirred and mixed with a 200 L super mixer (manufactured by Kawata) to obtain a chlorinated vinyl chloride resin composition. Was. Next, a rehabilitation pipe was manufactured in the same manner as in Example 1. The same evaluation as in Example 1 was performed on the obtained rehabilitated tube. The results are shown in Table 1.

Comparative Example 1 [Preparation of Vinyl Chloride Resin Composition] 100 parts by weight of PVC (trade name “TS-1000R” manufactured by Tokuyama Sekisui Industry Co., Ltd.)
Organotin-based stabilizer (trade name “ONZ-
6F ") 1 part by weight, lubricant (trade name" Hi "manufactured by Mitsui Chemicals, Inc.)
wax2203A ") 1 part by weight, a lubricant (manufactured by Cognis Co., Ltd.)
0.5 parts by weight (trade name “G21”) were stirred and mixed with a 200 L super mixer (manufactured by Kawata Corporation) to obtain a vinyl chloride resin composition.

[Preparation of Rehabilitating Pipe] The obtained vinyl chloride resin composition was extruded from a 50 mm-diameter two-axis counter-rotating extruder SLM.
-50 (manufactured by Nagata Seisakusho) to obtain a melt. The obtained melt was cooled with water at 20 ° C. to obtain a tubular body having an outer diameter of 50 mm and a wall thickness of 4.5 mm. After leaving this tubular body to stand in a gear oven heated to 100 ° C. for 20 minutes, the cross section of the tubular body is made into a four-fold shape, and the temperature of the molded body is kept at 20 ° C. while maintaining this shape. Upon cooling, a rehabilitated tube was obtained.

[Evaluation] The Vicat softening temperature, flexural modulus, insertability and resilience of the rehabilitated pipe were evaluated by the following methods. The results are summarized in Table 1. (Vicat softening temperature) The Vicat softening temperature was measured in accordance with the Vicat softening temperature test method for thermoplastics (JIS K 7206). A 5 kg weight was used for the measurement. (Flexural modulus) Bending test method of hard plastic (JI
The flexural modulus at 20 ° C. and 80 ° C. was measured according to SK 7203). (Evaluation of insertability) From one end of the rehabilitation pipe to the inside of the rehabilitation pipe, 8
After blowing hot air of 0 ° C for 10 minutes, the rehabilitation pipe is 50 m inside diameter.
m into a 45 ° L-shaped steel pipe, and the insertability was evaluated according to the following criteria.・: Insertable, no damage such as cracking or whitening. ×: Impossible to insert or damaged such as cracking and whitening. (Resilience evaluation) Insert the rehabilitation pipe into a steel pipe with an inner diameter of 50 mm,
Steam at 100 ° C. was blown into the inside of the rehabilitation pipe from one end of the rehabilitation pipe for 10 minutes to bring the rehabilitation pipe into close contact with the inner surface of the steel pipe. Next, after cooling by blowing air at 20 ° C. for 30 minutes, the adhesion between the steel pipe and the rehabilitated pipe was visually observed, and the resilience was evaluated according to the following criteria.・: The rehabilitated pipe was in full contact with the steel pipe. ×: The rehabilitated pipe was not completely adhered to the steel pipe.

Comparative Example 2 [Preparation of CPVC] 180 kg of deionized water and PVC were placed in a pressure-resistant reaction vessel made of glass lining having an internal volume of 300 liters.
(Product name "TS-1000R" manufactured by Tokuyama Sekisui Industry Co., Ltd.) 20
kg, agitate to disperse PVC in water, suction internal air with a vacuum pump, gauge pressure is -78.4 kP
The pressure was reduced until a. The pressure was returned with nitrogen gas (returned until the gauge pressure became 0), and the inside of the reaction tank was removed by suction with a vacuum pump again. During this time, the heated oil was passed through the jacket to heat the inside of the reactor. When the temperature in the reactor reaches 80 ° C, start supplying chlorine gas,
The reaction was allowed to proceed at a constant temperature of 110 ° C. Calculate the chlorine content of PVC in the reactor from the concentration of hydrogen chloride generated in the reactor,
When the chlorine content reaches 63% by weight, the reaction temperature is raised to 1%.
Raise the temperature to 20 ° C and add a 500 ppm concentration of hydrogen peroxide in water.
The reaction was continued while continuously adding 5 kg / hr. Further, when the chlorine content reached 68% by weight, the concentration of the hydrogen peroxide solution was changed to 1000 ppm, and the reaction was continued.
When the chlorine content reached 72% by weight, the supply of chlorine gas was stopped, and the chlorination reaction was terminated. The amount of hydrogen peroxide added during the reaction was 2500 ppm based on the charged resin amount. Furthermore, nitrogen gas was blown into the reaction tank to remove unreacted chlorine, and the obtained resin was washed with water, dehydrated and dried to obtain a powdery CPVC. The chlorine content of the obtained PVC was 73.1% by weight.

[Measurement of chlorine content] The chlorine weight content (Cl%) of CPVC was measured in accordance with JIS K7229.

[Preparation of chlorinated vinyl chloride resin composition]
100 parts by weight of the above-mentioned CPVC, 2 parts by weight of an organic tin-based stabilizer (trade name "ONZ-100F" manufactured by Sankyoki Gosei Co., Ltd.), and 8 parts by weight of an impact modifier (trade name "M511" manufactured by Kanebuchi Chemical Co., Ltd.) , A lubricant (trade name “Hiwax2203” manufactured by Mitsui Chemicals, Inc.)
A ") 1 part by weight, lubricant (manufactured by Riken Vitamin Co., trade name" S "
L800 ") was stirred and mixed with a 200 L super mixer (manufactured by Kawata Corporation) to obtain a chlorinated vinyl chloride resin composition.

From the obtained chlorinated vinyl chloride resin composition, a rehabilitation pipe was produced in the same manner as in Example 1. The obtained rehabilitated tube was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0040]

[Table 1]

[0041]

The rehabilitating pipe of the present invention has the above-mentioned structure, is formed by using a specific chlorinated vinyl chloride resin composition, and is heated or heated after being inserted into an existing pipe. A rehabilitated pipe characterized in that it is brought into close contact with the inner surface of an existing pipe by applying internal pressure, and can significantly improve heat resistance, and is suitably used for applications requiring heat resistance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16L 9/04 F16L 9/16 9/16 B29K 27:06 // B29K 27:06 B29L 9:00 B29L 9 : 00 23:00 23:00 F16L 1/02 R F term (reference) 3H111 AA01 BA02 BA15 CA08 CA52 CB03 CB14 CB22 CC12 CC18 DA08 DA11 DB03 EA12 4F071 AA24 AF45 AH19 BA01 BB06 BC05 4F211 AA15 AD12 AG03 AG08 AH43 SC03 SD06 SH06 SP15 SP20 SP25 SP41 4J002 BD181 FD010 FD030 FD060 FD090 FD170 GT00

Claims (2)

[Claims] 1. A rehabilitating pipe comprising a chlorinated vinyl chloride resin composition. 2. After the rehabilitation pipe is inserted into an existing pipe,
A rehabilitation pipe characterized by being heated or being heated and subjected to an internal pressure so as to adhere to the inner surface of an existing pipe.