JP4079728B2 - Chlorinated vinyl chloride resin composition for rehabilitation pipe and rehabilitation pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chlorinated vinyl chloride resin composition for rehabilitation pipes and a chlorinated vinyl chloride resin rehabilitation pipe comprising the chlorinated vinyl chloride resin composition.
[0002]
[Prior art]
In recent years, aging existing pipes (ceramic pipes, fume pipes, steel pipes, etc.) are increasing, but such existing pipes may be cracked or damaged due to corrosion or deterioration. As one of the methods for rehabilitating and restoring old pipes, vinyl chloride resin pipes having excellent mechanical strength and chemical resistance are used.
[0003]
As a straight pipe made of such a vinyl chloride resin, a method of repairing with a vinyl chloride resin pipe added with a thermoplastic elastomer that can be mixed with the vinyl chloride resin is disclosed (for example, see Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent No. 3229319 (page 1-3)
[0005]
However, in this method, since the main component of the rehabilitation pipe is vinyl chloride resin, heat resistance becomes insufficient in applications that are used at high temperatures, such as when rehabilitating power cable protection pipes. There was a problem of thermal deformation.
[0006]
[Problems to be solved by the invention]
In view of the above problems, an object of the present invention is to provide a chlorinated vinyl chloride resin composition for a rehabilitated pipe suitable for obtaining a rehabilitated pipe having excellent heat resistance and excellent workability, and its chlorinated vinyl chloride type. It is providing the rehabilitation pipe | tube using a resin composition.
[0007]
[Means for Solving the Problems]
The present invention has been made to achieve the above object, and the invention according to claim 1 (hereinafter referred to as invention 1) is a chlorinated vinyl chloride resin having a chlorine content of 58 to 71% by weight. The molded body has a flexural modulus of not less than 450 MPa at 75 ° C., and the ratio (E, 20 ° C.) / (E, 75 ° C.) of the flexural modulus of 20 ° C. and 75 ° C. is 1. Vicat softening temperature (5 kg load) according to JIS K 7026, which is over 20 and the ratio of flexural modulus between 75 ° C. and 105 ° C. (E, 75 ° C.) / (E, 105 ° C.) is 2 or more. ) Is 80 ° C. or higher, and a chlorinated vinyl chloride resin composition for rehabilitation pipes is provided.
In this specification, the flexural modulus at T ° C. of the molded body is expressed as (E, T ° C.).
[0008]
The invention according to claim 2 (hereinafter referred to as invention 2) is inserted into an existing pipe and heated, or is brought into close contact with the inner surface of the existing pipe by being heated and subjected to internal pressure. A rehabilitation pipe comprising the chlorinated vinyl chloride resin composition according to claim 1 is provided.
[0009]
Hereinafter, the present invention will be described in more detail.
The chlorine content of the chlorinated vinyl chloride resin used in the present invention is limited to 58 to 71% by weight. If it is less than 58%, the heat resistance of the resulting chlorinated vinyl chloride resin composition and rehabilitation pipe is insufficient, and conversely, if the chlorine content exceeds 71%, molding becomes difficult. Preferably it is 59-70 weight%, More preferably, it is 60-69 weight%.
In addition, said chlorine content rate is a value determined by the neutralization titration by an oxygen flask combustion method based on JISK7229.
[0010]
The above chlorinated vinyl chloride resin can be obtained by chlorinating a vinyl chloride resin. As the chlorination method, a conventionally known suspension method, solution chlorination method or the like is used, and the suspension method is preferred industrially. As a method of adjusting the chlorine content to the above range, it may be adjusted in the chlorination reaction stage, or a high chlorine content chlorinated vinyl chloride resin and a low chlorine content chlorinated vinyl chloride resin, It may be adjusted by blending with a vinyl chloride resin.
[0011]
The vinyl chloride resin used for the production of the chlorinated vinyl chloride resin is not particularly limited as long as it is a vinyl chloride resin. However, from the viewpoint of moldability, heat resistance, and the like, JP-A-8-120007 and JP-A-8. A vinyl chloride resin obtained by a production method described in JP-A-295701, JP-A-9-132612, or JP-A-9-227607 is preferred. The degree of polymerization is preferably 800 to 2000, more preferably 800 to 1400.
[0012]
Examples of the vinyl chloride resin before chlorination include a vinyl chloride homopolymer, a copolymer of a monomer having an unsaturated bond copolymerizable with a vinyl chloride monomer and a vinyl chloride monomer, and a vinyl chloride as a polymer. A graft copolymer obtained by graft copolymerization of a monomer is used. In the present invention, these polymers may be used alone or in combination of two or more.
[0013]
Examples of the monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer include α-olefins such as ethylene, propylene and butylene; vinyl esters such as vinyl acetate and vinyl propionate; butyl vinyl ether and cetyl. Vinyl ethers such as vinyl ether; (meth) acrylic ester condyles such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl acrylate, and phenyl methacrylate; aromatic vinyls such as styrene and α-methylstyrene; vinylidene chloride, fluorine Halogenated vinyl vinyls such as vinylidene fluoride; N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide, and the like. These may be used alone or in combination of two or more. .
[0014]
The above-mentioned polymer for graft copolymerization with vinyl chloride is not particularly limited as long as vinyl chloride is graft-polymerized. For example, ethylene-vinyl acetate copolymer; ethylene-vinyl acetate-carbon oxide copolymer Ethylene-ethyl acrylate copolymer; ethylene-butyl acrylate-carbon oxide copolymer; ethylene-methyl methacrylate copolymer; ethylene-propylene copolymer; acrylonitrile-butadiene copolymer; polyurethane; chlorinated polyethylene; Modified polypropylene or the like, and these may be used alone or in combination of two or more.
[0015]
The vinyl chloride polymerization method is not particularly limited, and conventionally known suspension polymerization method, bulk polymerization method, solution polymerization method, emulsion polymerization method and the like are used, and the suspension polymerization method is preferable from the viewpoint of productivity.
[0016]
The chlorinated vinyl chloride resin composition for rehabilitation pipe of the present invention has a flexural modulus of the molded body of 450 MPa or more at 75 ° C., and the ratio of the flexural modulus at 20 ° C. to 75 ° C. (E, 20 ° C.) / (E , 75 ° C.) is more than 1 and less than 20, and the ratio (E, 75 ° C.) / (E, 105 ° C.) of the flexural modulus between 75 ° C. and 105 ° C. is 2 or more.
If the flexural modulus at 75 ° C. is less than 450 MPa, the strength in the operating temperature range is insufficient in applications that require heat resistance. Increasing the thickness of the rehabilitation pipe to compensate for this is not suitable because it reduces the formability and increases the cost.
When the ratio of the flexural modulus at 20 ° C. to 75 ° C. exceeds 20, the flexural modulus at 20 ° C. is as large as 9000 MPa, and the workability at the time of extrusion molding is significantly deteriorated. The lower limit of the elastic modulus in this range is not particularly limited from the viewpoint of moldability, but in practice it does not occur when the above ratio is 1 or less, so it may be 1 or more. Preferably it is more than 1 and less than 15, more preferably more than 1 and less than 10. Also, if the ratio of the flexural modulus of 75 ° C to 105 ° C is out of the above range, the renovated pipe is heated so that it can be easily inserted into the existing pipe before construction (for example, the cross-sectional shape is Ω). When it is constructed, the properties of being restored and closely attached to the inner peripheral surface of the existing pipe are deteriorated, and it is necessary to significantly increase the construction temperature. Preferably it is 3 or more. In order to achieve the above range, the chlorine content of the chlorinated vinyl chloride resin is set to 58 to 71% by weight, and a compounding agent that improves the extrudability is added as necessary without significantly reducing the heat resistance. It will be necessary.
[0017]
The chlorinated vinyl chloride resin composition has a Vicat softening temperature (5 kg load) in accordance with JIS K 7026 of 80 ° C. or higher. When the Vicat softening temperature is lower than 80 ° C., when it is used as a rehabilitation pipe, it is insufficient for an application requiring heat resistance, for example, a power cable protection pipe.
[0018]
The chlorinated vinyl chloride resin composition for rehabilitation pipes of the present invention comprises the chlorinated vinyl chloride resin composition having the above-mentioned specific chlorine content as a main component and further contains an additive. Examples of additives appropriately selected and contained include impact modifiers, thermoplastic elastomers, stabilizers, lubricants, processing aids, heat resistance improvers, antioxidants, ultraviolet absorbers, light stabilizers, filling Agents, pigments and the like.
[0019]
The impact modifier is not particularly limited, and for example, methyl methacrylate-butadiene-styrene copolymer (MBS), chlorinated polyethylene, acrylic rubber and the like are used.
[0020]
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 oxide copolymer (EVACO), vinyl chloride. -Vinyl chloride thermoplastic elastomers such as vinyl acetate copolymers and vinyl chloride-vinylidene chloride copolymers, styrene thermoplastic elastomers, olefin thermoplastic elastomers, urethane thermoplastic elastomers, polyester thermoplastic elastomers, polyamides A thermoplastic elastomer or the like is used. These thermoplastic elastomers may be used alone or in combination of two or more.
[0021]
The stabilizer is not particularly limited, and for example, a heat stabilizer, a heat stabilization aid and the like are used. The heat stabilizer is not particularly limited. Organotin stabilizers such as laurate and dibutyltin laurate polymer; Lead stabilizers such as lead stearate, dibasic lead phosphite, and tribasic lead sulfate; calcium-zinc stabilizer; barium-zinc Stabilizer; Barium-cadmium stabilizer and the like are used. These may be used alone or in combination of two or more.
[0022]
The stabilization aid is not particularly limited, and for example, epoxidized soybean oil, phosphate ester, polyol, hydrotalcite, zeolite, and the like are used. These may be used alone or in combination of two or more.
[0023]
As the lubricant, an internal lubricant and an external lubricant are used.
The internal lubricant is used for the purpose of lowering the flow viscosity of the molten resin during molding and preventing frictional heat generation. The internal lubricant is not particularly limited, and for example, butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, bisamide and the like are used. These may be used alone or in combination of two or more.
The above external lubricant is used for the purpose of increasing the sliding effect between the molten resin and the metal surface during the molding process. The external lubricant is not particularly limited, and for example, paraffin wax, polyolefin wax, ester wax, montanic acid wax and the like are used. These may be used alone or in combination of two or more.
[0024]
The processing aid is not particularly limited, and for example, an acrylic processing aid such as an alkyl acrylate-alkyl methacrylate copolymer having a weight average molecular weight of 100,000 to 2,000,000 is used. The acrylic processing aid is not particularly limited, and for example, n-butyl acrylate-methyl methacrylate copolymer, 2-ethylhexyl acrylate-methyl methacrylate-butyl methacrylate copolymer and the like are used. These may be used alone or in combination of two or more.
[0025]
The heat resistance improver is not particularly limited, and for example, α-methylstyrene-based, N-phenylmaleimide-based resins and the like are used.
[0026]
Said antioxidant is not specifically limited, For example, a phenolic antioxidant etc. are used.
[0027]
The light stabilizer is not particularly limited, and for example, a light stabilizer such as a hindered amine is used.
[0028]
The ultraviolet absorber is not particularly limited, and for example, salicylic acid ester-based, benzophenone-based, benzotriazole-based, cyanoacrylate-based ultraviolet absorbers, and the like are used.
[0029]
Said filler is not specifically limited, For example, calcium carbonate, a talc, etc. are used.
[0030]
The above-mentioned pigment is not particularly limited, and examples thereof include organic pigments such as azo-based, phthalocyanine-based, selenium-based, dye lake-based; oxide-based, molybdenum chromate-based, sulfide / selenide-based, ferrocyanide-based, etc. Inorganic pigments are used.
[0031]
In the above chlorinated vinyl chloride resin composition, a plasticizer may be added for the purpose of improving the workability at the time of molding, but it may reduce the heat resistance of the molded product. It is not preferable to use it. The plasticizer is not particularly limited, and for example, dibutyl phthalate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate and the like are used.
[0032]
The method for mixing the above additives with the above chlorinated vinyl chloride resin is not particularly limited. For example, a method using hot blending, a method using cold blending, or the like is used.
[0033]
The rehabilitation pipe of the invention 2 is usually prepared by performing extrusion molding with an extruder using the chlorinated vinyl chloride resin composition of the invention 1, and is inserted into an existing pipe and heated, or It is characterized by being in close contact with the inner surface of the existing pipe by being heated and subjected to internal pressure.
[0034]
The cross-sectional shape of the rehabilitation pipe can be inserted into the existing pipe to be rehabilitated and repaired, and is heated or heated and subjected to internal pressure so that the inner surface of the existing pipe is The shape is not particularly limited as long as the shape can be closely adhered, but an Ω shape is preferable.
[0035]
【Example】
In order to describe the present invention in more detail, examples are given below, but the present invention is not limited to these examples. In the examples, “part” means “part by weight” and “%” means “% by weight”.
[0036]
(Examples 1 and 2 and Comparative Examples 4 to 6)
(1) Production of Chlorinated Vinyl Chloride Resin Composition According to the composition shown in Table 1, the raw materials were stirred and mixed with 200L “Supermixer” (manufactured by Kawata) to obtain a chlorinated vinyl chloride resin composition. .
The grades and manufacturer names of each material are as follows.
Chlorinated vinyl chloride resin A; “HA-54K” manufactured by Tokuyama Sekisui Industry Co., Ltd., polymerization degree 1000
Chlorinated vinyl chloride resin B; “HA-54H” manufactured by Tokuyama Sekisui Industry Co., Ltd., polymerization degree 1000
Chlorinated vinyl chloride resin C; “HA-54F” manufactured by Tokuyama Sekisui Industry Co., Ltd., polymerization degree 1000
Chlorinated vinyl chloride resin D: Chlorination degree 73%, “TS-1000R” (polymerization degree 1050) Chlorinated product manufactured by Tokuyama Sekisui Industry Co., Ltd. Vinyl chloride resin A; “TS-1000R” (polymerization degree 1050) ) Tokuyama Sekisui Industry Co., Ltd.
Thermoplastic Elastomer A (EVACO); “Elvalloy 742” Mitsui DuPont Polychemical Co., Ltd. Thermal Stabilizer A; “ONZ-100F”, Mitsui Organic Synthesis Co., Ltd., Organic Tin Stabilizer Thermal Stabilizer B; “ONZ-6F” manufactured by Mitsui Organic Synthesis Co., Ltd., organic tin stabilizer lubricant A; “Hiwax 2203A” manufactured by Mitsui Chemicals, Inc., polyethylene wax lubricant B; “SL800” manufactured by Riken Vitamin Co., Ltd., stearyl stearate lubricant C: “Loxiol G21” manufactured by Cognis Japan, 12-hydroxystearic acid impact modifier A; “M511” manufactured by Kaneka Chemical Co., Ltd., MBS resin
(2) Molding of rehabilitated pipe The chlorinated vinyl chloride resin composition obtained by the above method was subjected to a biaxial counter-rotating extruder “SLM-50” (manufactured by Nagata Manufacturing Co., Ltd.) having a diameter of 50 mm, Obtained. 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. The tubular body is allowed to stand in a gear opening heated to 110 ° C. for 20 minutes, and then the tubular body cross-section is made into a four-fold shape until the temperature of the molded body reaches 20 ° C. while maintaining this shape. A rehabilitation tube was obtained after cooling.
[0038]
(3) Evaluation was made on the chlorine content of the resin, and the Vicat softening temperature, flexural modulus, insertability and restorability of the rehabilitated pipe. The evaluation method is as follows. The results are summarized in Table 2.
(1) Measurement of chlorine content
CPVC chlorine content (Cl%) was measured according to JIS K 7229.
(2) 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.
(3) Flexural modulus Flexural modulus at 20 ° C., 75 ° C., and 105 ° C. was measured according to a bending test method (JIS K 7171) for hard plastics.
[0039]
(4) Evaluation of insertability After 80 ° C hot air was blown into the rehabilitation pipe from one end of the rehabilitation pipe for 10 minutes, the rehabilitation pipe was inserted into a 45 ° L-shaped steel pipe with an inner diameter of 50 mm. Thus, insertability was evaluated.
○ ...... It can be inserted and there was no damage such as cracking or whitening.
× ······ Insertion was impossible, or there was damage such as cracking or whitening.
(5) Restoration evaluation Insert a rehabilitation pipe into a steel pipe with an inner diameter of 50 mm and blow 110 ° C steam from one end of the rehabilitation pipe into the rehabilitation pipe for 10 minutes, and attach the rehabilitation pipe to the inner surface of the steel pipe. I let you. Next, after cooling by blowing air at 20 ° C. for 30 minutes, the close contact state between the steel pipe and the rehabilitated pipe was visually observed, and restorability was evaluated according to the following criteria.
○ The rehabilitation pipe was in full contact with the steel pipe.
X ... ・ The rehabilitation pipe was not in close contact with the steel pipe.
[0040]
(Comparative Examples 1 to 3)
(1) Preparation of vinyl chloride resin composition
In the same manner as in Examples 1 and 2 and Comparative Examples 4 to 6 , each raw material was agitated and mixed with a 200 L “Supermixer” (manufactured by Kawata Corporation) according to the composition shown in Table 1 to obtain a vinyl chloride resin composition.
[0041]
(2) Production of Chlorinated Vinyl Chloride Resin D of Comparative Example 3 180 kg of deionized water and 20 kg of PVC (trade name “TS-1000R” Tokuyama Sekisui Industry Co., Ltd.) in a glass-lined pressure-resistant reaction tank having an internal volume of 300 liters. The mixture was stirred and dispersed to disperse PVC in water, and the internal air was sucked with a vacuum pump, and the pressure was reduced until the gauge pressure was -78.4 KPa. The pressure was returned with nitrogen gas (returned until the gauge pressure reached 0), and the oxygen in the reaction vessel was removed by suction again with a vacuum pump. During this time, the heated oil was passed through the jacket to warm the inside of the reactor.
When the temperature in the reaction tank reached 80 ° C., chlorine gas began to be supplied and the reaction was allowed to proceed at a constant temperature of 110 ° C. The chlorine content of PVC in the reactor is calculated from the hydrogen chloride concentration generated in the reaction tank. When the chlorine content reaches 63% by weight, the reaction temperature is increased to 120 ° C, and hydrogen peroxide water with a concentration of 500 ppm is added. The reaction was continued with continuous addition at 0.5 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 chlorination 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 relative to the charged resin. Further, nitrogen gas was blown into the reaction tank to remove unreacted chlorine, and the resulting resin was washed with water, dehydrated and dried to obtain a powdery chlorinated vinyl chloride resin. The obtained chlorinated vinyl chloride resin had a chlorine content of 73% by weight.
[0042]
(3) Preparation of rehabilitation pipe According to the composition shown in Table 1, the above vinyl chloride resin was stirred and mixed with a 200 L super mixer (manufactured by Kawata) to obtain a vinyl chloride resin composition. A rehabilitated tube was produced by the same method as in Examples 1 and 2 and Comparative Examples 4 to 6 .
[0043]
(4) Evaluation
In the same manner as in Examples 1 and 2 and Comparative Examples 4 to 6 , the chlorine content of the resin, the Vicat softening temperature of the rehabilitated pipe, the flexural modulus, the insertability and the restorability were evaluated. The results are summarized in Table 1 .
[0044]
[Table 1]
[0045]
In Table 1, ( ) Exceeded the measurement limit, so it was estimated.
[0046]
【The invention's effect】
The chlorinated vinyl chloride resin composition for rehabilitation pipes of the present invention is suitably used as a chlorinated vinyl chloride resin composition for rehabilitation pipes suitable for obtaining rehabilitation pipes having excellent heat resistance and excellent workability. It is done. Moreover, since the rehabilitation pipe | tube of this invention consists of said chlorinated vinyl chloride type-resin composition of this invention, it has the outstanding heat resistance, and is used suitably for the rehabilitation (restoration) of an existing pipe | tube.

Claims (1)

A rehabilitation pipe that is inserted into an existing pipe and heated, or is heated and subjected to internal pressure to be in close contact with the inner surface of the existing pipe,
It contains 1.5 to 5 parts by weight of thermoplastic elastomer with respect to 100 parts by weight of chlorinated vinyl chloride resin having a chlorine content of 60 to 64% by weight , and the flexural modulus of the molded body is 450 MPa at 75 ° C. The ratio (E, 20 ° C.) / (E, 75 ° C.) of the flexural modulus at 20 ° C. and 75 ° C. is greater than 1 and less than 20, and the ratio of the flexural modulus at 75 ° C. and 105 ° C. (E , 75 ° C.) / (E, 105 ° C.) is 2 or more, and a rehabilitated pipe comprising a chlorinated vinyl chloride resin composition having a Vicat softening temperature (5 kg load) in accordance with JIS K 7026 of 80 ° C. or more. .