Composition for rehabilitated pipe, and rehabilitated pipe

Abstract

To provide a composition for rehabilitated pipes that is capable of improving the appearance of the resulting rehabilitated pipe and enhancing its impact resistance and water resistance.SOLUTION: A composition for rehabilitated pipes according to the present invention comprises a vinyl chloride-based resin, a methyl methacrylate-butadiene-styrene copolymer, and an acrylic modifier, wherein the total content of the methyl methacrylate-butadiene-styrene copolymer and the acrylic modifier is 5 pts.wt. or more and 20 pts.wt. or less relative to 100 pts.wt. of the vinyl chloride-based resin.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a composition for rehabilitating a pipe, which is used to obtain a rehabilitating pipe. The present invention also relates to a rehabilitating pipe using the composition for rehabilitating a pipe. [Background technology]

[0002] The Omega Liner method is known as one method for rehabilitating deteriorated existing pipes. The Omega Liner method is generally carried out in the following steps: (1) The folded rehabilitation pipe is placed inside the existing pipe. (2) The rehabilitation pipe is heated with steam. (3) The diameter of the rehabilitation pipe is expanded with compressed air, and the inner surface of the existing pipe and the outer surface of the rehabilitation pipe are brought into tight contact with each other.

[0003] The following Patent Document 1 discloses a vinyl chloride resin composition for rehabilitating pipes.

[0004] The vinyl chloride resin composition for rehabilitation pipes of Patent Document 1 below contains 100 parts by weight of a complex vinyl chloride resin having an average degree of polymerization of 400 to 2500, and 3 to 30 parts by weight of a thermoplastic elastomer compatible with the complex vinyl chloride resin. The complex vinyl chloride resin is a resin obtained by graft copolymerizing vinyl chloride monomer or vinyl chloride monomer and other copolymerizable monomers at 60% by weight or more and less than 90% by weight with more than 10% by weight and 40% by weight or less of an acrylic copolymer. The acrylic copolymer is a copolymer obtained by copolymerizing 100 parts by weight of a specific acrylic monomer component with 0.01 to 30 parts by weight of a polyfunctional monomer component. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-003689 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a rehabilitating pipe obtained by using the vinyl chloride resin composition for rehabilitating pipes described in Patent Document 1, the mechanical strength (impact resistance) of the rehabilitating pipe can be increased to a certain degree. However, the vinyl chloride resin composition for rehabilitating pipes described in Patent Document 1 has a problem in that it is not possible to sufficiently increase water resistance.

[0007] Furthermore, in conventional pipe rehabilitating compositions such as those described in Patent Document 1, a large amount of an acrylic modifier may be added to improve workability. A rehabilitating pipe obtained using a pipe rehabilitating composition containing a large amount of an acrylic modifier may have white spots on the inner and outer surfaces, resulting in poor appearance.

[0008] The object of the present invention is to provide a composition for rehabilitating pipes which can improve the appearance of the resulting rehabilitating pipes and increase their impact resistance and water resistance. Another object of the present invention is to provide a rehabilitating pipe using the composition for rehabilitating pipes. [Means for solving the problem]

[0009] The present specification discloses the following rehabilitating pipe composition and rehabilitating pipe.

[0010] Item 1. A composition for rehabilitating pipes, comprising a vinyl chloride resin, a methyl methacrylate-butadiene-styrene copolymer, and an acrylic modifier, wherein the total content of the methyl methacrylate-butadiene-styrene copolymer and the acrylic modifier is 5 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

[0011] Item 2. The composition for rehabilitating pipes according to item 1, further comprising a thermoplastic elastomer.

[0012] Item 3. The composition for rehabilitating pipes according to item 1 or 2, wherein the ratio of the content of the methyl methacrylate-butadiene-styrene copolymer to the content of the acrylic modifier is 0.1 or more and 10 or less.

[0013] Item 4. The composition for rehabilitating pipes according to any one of Items 1 to 3, wherein the acrylic modifier is contained in an amount of 10% by weight or less based on 100% by weight of the composition for rehabilitating pipes.

[0014] Item 5. A rehabilitating pipe formed from the composition for rehabilitating pipes according to any one of items 1 to 4. Effect of the Invention

[0015] The rehabilitating pipe composition according to the present invention contains a vinyl chloride resin, a methyl methacrylate-butadiene-styrene copolymer, and an acrylic modifier. In the rehabilitating pipe composition according to the present invention, the total content of the methyl methacrylate-butadiene-styrene copolymer and the acrylic modifier is 5 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the vinyl chloride resin. Since the rehabilitating pipe composition according to the present invention has the above-mentioned configuration, it is possible to improve the appearance of the rehabilitating pipe obtained and to increase the impact resistance and water resistance. [Brief description of the drawings]

[0016] [Figure 1] 1(a) to (c) are cross-sectional views for explaining each step of the method for rehabilitating an existing pipe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention will be described in detail below.

[0018] (Composition for rehabilitated pipes) The rehabilitating pipe composition according to the present invention contains a vinyl chloride resin, a methyl methacrylate-butadiene-styrene copolymer, and an acrylic modifier. In the rehabilitating pipe composition according to the present invention, the total content of the methyl methacrylate-butadiene-styrene copolymer and the acrylic modifier is 5 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

[0019] Since the composition for rehabilitating pipes according to the present invention has the above-mentioned features, it is possible to improve the appearance of the rehabilitating pipes obtained and to increase the impact resistance and water resistance.

[0020] The above-mentioned composition for rehabilitating pipes is suitably used for obtaining rehabilitating pipes.

[0021] The details of each component used in the composition for rehabilitating pipes according to the present invention will be described below. In this specification, "(meth)acrylic" means either or both of "acrylic" and "methacrylic", and "(meth)acrylate" means either or both of "acrylate" and "methacrylate".

[0022] <Vinyl chloride resin> As the vinyl chloride resin, a conventionally known vinyl chloride resin can be used. Examples of the vinyl chloride resin include (1) a homopolymer of a vinyl chloride monomer, (2) a copolymer of a vinyl chloride monomer and a monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer, and (3) a graft polymer in which vinyl chloride is graft-polymerized onto a polymer or copolymer other than vinyl chloride. The vinyl chloride resin may be used alone or in combination of two or more kinds.

[0023] Examples of monomers having unsaturated bonds copolymerizable with the vinyl chloride monomer include α-olefin compounds such as ethylene, propylene, and butylene; vinyl ester compounds such as vinyl acetate and vinyl propionate; vinyl ether compounds such as butyl vinyl ether and cetyl vinyl ether; alkyl (meth)acrylate compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; aryl (meth)acrylate compounds such as phenyl (meth)acrylate; aromatic vinyl compounds such as styrene and α-methylstyrene; dicarboxylic acid compounds such as maleic anhydride; halogenated vinyl compounds such as vinylidene chloride and vinylidene fluoride; and N-substituted maleimide compounds such as N-phenylmaleimide and N-cyclohexylmaleimide. The monomers having unsaturated bonds copolymerizable with the vinyl chloride monomer may be used alone or in combination of two or more.

[0024] The copolymer of the vinyl chloride monomer and the monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer may be a random copolymer, a block copolymer, or a graft copolymer.

[0025] Examples of the polymers and copolymers other than vinyl chloride include copolymers of α-olefin compounds and vinyl ester compounds such as ethylene-vinyl acetate copolymers; copolymers of α-olefin compounds, vinyl ester compounds, and carbon monoxide such as ethylene-vinyl acetate-carbon monoxide copolymers; copolymers of α-olefin compounds and alkyl (meth)acrylate compounds such as ethylene-methyl methacrylate copolymers and ethylene-ethyl acrylate copolymers; and copolymers of α-olefin compounds, alkyl (meth)acrylate compounds, and carbon monoxide such as ethylene-butyl acrylate-carbon monoxide copolymers; copolymers of two or more different α-olefin compounds such as ethylene-propylene copolymers; copolymers of unsaturated nitrile compounds and diene compounds such as acrylonitrile-butadiene copolymers; polyurethane; chlorinated polyolefin compounds such as chlorinated polyethylene and chlorinated polypropylene. The polymers and copolymers other than vinyl chloride may be used alone or in combination of two or more.

[0026] The average degree of polymerization of the vinyl chloride resin is preferably 500 or more, more preferably 600 or more, and even more preferably 800 or more, and is preferably 5000 or less, more preferably 3000 or less, and even more preferably 2000 or less. When the average degree of polymerization of the vinyl chloride resin is above the lower limit, the mechanical strength of the rehabilitating pipe composition and the rehabilitating pipe obtained can be further increased, the impact resistance can be further increased, and long-term performance such as fatigue properties is less likely to be impaired. When the average degree of polymerization of the vinyl chloride resin is below the upper limit, the moldability of the rehabilitating pipe composition can be improved, there is no need to raise the temperature during molding, and the processability is further improved.

[0027] The average degree of polymerization of the vinyl chloride resin can be measured, for example, as follows. The vinyl chloride resin is dissolved in tetrahydrofuran (THF), and insoluble components are removed by filtration. The THF in the filtrate is dried and removed to obtain a measurement sample. The average degree of polymerization of the measurement sample measured in accordance with JIS K6721 "Testing Method for Vinyl Chloride Resins" is regarded as the average degree of polymerization of the vinyl chloride resin.

[0028] The vinyl chloride resin may or may not contain a chlorinated vinyl chloride resin.

[0029] In 100% by weight of the composition for rehabilitating pipes, the content of the vinyl chloride resin is preferably 50% by weight or more, more preferably 60% by weight or more, and even more preferably 70% by weight or more. When the content of the vinyl chloride resin is equal to or more than the lower limit, the impact resistance can be further improved. In 100% by weight of the composition for rehabilitating pipes, the upper limit of the content of the vinyl chloride resin is not particularly limited. In 100% by weight of the composition for rehabilitating pipes, the content of the vinyl chloride resin may be 100% by weight or less, 99% by weight or less, 95% by weight or less, or 90% by weight or less.

[0030] In 100% by weight of the vinyl chloride resin, the content of the structural unit derived from vinyl chloride is preferably 70% by weight or more, more preferably 75% by weight or more, even more preferably 80% by weight or more, particularly preferably 90% by weight or more, and preferably 98% by weight or less, more preferably 95% by weight or less. When the content of the structural unit derived from vinyl chloride is equal to or more than the lower limit, the impact resistance can be further improved. When the content of the structural unit derived from vinyl chloride is equal to or less than the upper limit, the appearance of the rehabilitating pipe obtained can be further improved, and the moldability, flatness, and water pressure resistance can be improved. In addition, the thermal decomposition of vinyl chloride during molding can be suppressed. In addition, the content of the structural unit derived from vinyl chloride in 100% by weight of the vinyl chloride resin may be 100% by weight (total amount).

[0031] <Methyl methacrylate-butadiene-styrene copolymer (MBS resin)> The methyl methacrylate-butadiene-styrene copolymer (MBS resin) is a copolymer of methyl methacrylate, butadiene, and styrene.

[0032] The above-mentioned composition for rehabilitating pipes uses the above-mentioned methyl methacrylate-butadiene-styrene copolymer in combination with an acrylic modifier, and therefore the water resistance of the resulting rehabilitating pipe can be improved.

[0033] The methyl methacrylate-butadiene-styrene copolymer may be particulate. When the methyl methacrylate-butadiene-styrene copolymer is particulate, the particle size of the methyl methacrylate-butadiene-styrene copolymer is preferably 0.1 μm or more, more preferably 0.2 μm or more, and preferably 0.5 μm or less, more preferably 0.4 μm or less. When the particle size of the methyl methacrylate-butadiene-styrene copolymer is the above lower limit or more and the above upper limit or less, it is easy to knead with the vinyl chloride resin and easy to handle.

[0034] In 100% by weight of the above-mentioned rehabilitating pipe composition, the content of the above-mentioned methyl methacrylate-butadiene-styrene copolymer is preferably 0.5% by weight or more, more preferably 1.0% by weight or more, even more preferably 2.0% by weight or more, and preferably 20% by weight or less, more preferably 15% by weight or less, even more preferably 10% by weight or less. When the content of the above-mentioned methyl methacrylate-butadiene-styrene copolymer is equal to or more than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, the water resistance can be further improved.

[0035] The content of the methyl methacrylate-butadiene-styrene copolymer relative to 100 parts by weight of the vinyl chloride resin is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, and even more preferably 2 parts by weight or more, and is preferably 10 parts by weight or less, more preferably 8 parts by weight or less, and even more preferably 7 parts by weight or less. When the content of the methyl methacrylate-butadiene-styrene copolymer is equal to or more than the lower limit and equal to or less than the upper limit, the water resistance can be further improved.

[0036] <Acrylic modifier> The above-mentioned rehabilitating pipe composition contains an acrylic modifier. The above-mentioned acrylic modifier may be used alone or in combination of two or more kinds. The above-mentioned acrylic modifier preferably contains a (meth)acrylic polymer.

[0037] The (meth)acrylic polymer can be obtained by polymerizing a (meth)acrylic monomer. The (meth)acrylic polymer has a structural portion derived from the (meth)acrylic monomer. As the (meth)acrylic monomer, a conventionally known (meth)acrylic monomer can be used. The (meth)acrylic monomer may be used alone or in combination of two or more. The (meth)acrylic polymer may be a homopolymer of one type of (meth)acrylic monomer, or a copolymer of two or more types of (meth)acrylic monomers.

[0038] Examples of the (meth)acrylic monomer include (meth)acrylic monomers having an alkyl group, (meth)acrylic monomers having a hydroxyl group, (meth)acrylic monomers having a carboxyl group, and (meth)acrylic monomers having a glycidyl group.

[0039] Examples of the (meth)acrylic monomer having an alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, n-hexyl (meth)acrylate, normal butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, lauryl methacrylate, and octyl (meth)acrylate.

[0040] Examples of the (meth)acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0041] Examples of the (meth)acrylic monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, and citraconic acid.

[0042] Examples of the (meth)acrylic monomer having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, and 4-hydroxybutyl acrylate glycidyl ether.

[0043] Examples of (meth)acrylic monomers other than the above-mentioned (meth)acrylic monomers include phenyl(meth)acrylate, 2-chloroethyl(meth)acrylate, phenylmethyl(meth)acrylate, hydroxyethyl(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane di(meth)acrylate, and trimethylolpropane tri(meth)acrylate.

[0044] The content of the acrylic modifier in 100% by weight of the composition for rehabilitating pipes is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, even more preferably 1.0% by weight or more, and preferably 10% by weight or less, more preferably 9.0% by weight or less, even more preferably 8.5% by weight or less. When the content of the acrylic modifier is equal to or more than the lower limit and equal to or less than the upper limit, the water resistance can be further improved. In particular, the composition for rehabilitating pipes preferably contains 10% by weight or less of the acrylic modifier in 100% by weight of the composition for rehabilitating pipes.

[0045] The content of the acrylic modifier is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, and even more preferably 2 parts by weight or more, and is preferably 10 parts by weight or less, more preferably 9 parts by weight or less, and even more preferably 8 parts by weight or less, relative to 100 parts by weight of the vinyl chloride resin. When the content of the acrylic modifier is equal to or more than the lower limit, the appearance of the rehabilitated pipe obtained can be improved and the water resistance can be further improved. When the content of the acrylic modifier is equal to or less than the upper limit, the water resistance can be further improved.

[0046] The total content of the methyl methacrylate-butadiene-styrene copolymer and the acrylic modifier is 5 parts by weight or more and 20 parts by weight or less, relative to 100 parts by weight of the vinyl chloride resin. The total content of the methyl methacrylate-butadiene-styrene copolymer and the acrylic modifier is preferably 6 parts by weight or more, more preferably 7 parts by weight or more, even more preferably 10 parts by weight or more, preferably 19 parts by weight or less, more preferably 18 parts by weight or less, and even more preferably 15 parts by weight or less, relative to 100 parts by weight of the vinyl chloride resin. When the total content of the methyl methacrylate-butadiene-styrene copolymer and the acrylic modifier is the above lower limit or more and the above upper limit or less, the water resistance of the obtained rehabilitated pipe can be further improved.

[0047] The ratio of the content of the methyl methacrylate-butadiene-styrene copolymer to the content of the acrylic modifier is the ratio (content of methyl methacrylate-butadiene-styrene copolymer / content of acrylic modifier). The ratio (content of methyl methacrylate-butadiene-styrene copolymer / content of acrylic modifier) ​​is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 1.0 or more, and preferably 10 or less, more preferably 9.0 or less, and even more preferably 8.0 or less. When the ratio (content of methyl methacrylate-butadiene-styrene copolymer / content of acrylic modifier) ​​is equal to or more than the lower limit and equal to or less than the upper limit, the effect of the present invention can be more effectively exhibited.

[0048] <Thermoplastic elastomer> The above-mentioned rehabilitating pipe composition may contain a thermoplastic elastomer. From the viewpoint of improving flexibility at high temperatures, the above-mentioned rehabilitating pipe composition preferably contains a thermoplastic elastomer.

[0049] Examples of the thermoplastic elastomer include ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl acetate-carbon monoxide copolymer (EVACO), acrylonitrile-butadiene copolymer (NBR), etc. The thermoplastic elastomer may be used alone or in combination of two or more kinds.

[0050] From the viewpoint of exerting the effects of the present invention more effectively, the thermoplastic elastomer preferably contains ethylene-vinyl acetate copolymer (EVA) or ethylene-vinyl acetate-carbon monoxide copolymer (EVACO), and more preferably contains ethylene-vinyl acetate-carbon monoxide copolymer (EVACO).

[0051] In 100% by weight of the above-mentioned rehabilitating pipe composition, the content of the above-mentioned thermoplastic elastomer is preferably 3% by weight or more, more preferably 5% by weight or more, even more preferably 7% by weight or more, and is preferably 35% by weight or less, more preferably 25% by weight or less, even more preferably 20% by weight or less. When the content of the above-mentioned thermoplastic elastomer is equal to or more than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, the effects of the present invention can be more effectively exhibited.

[0052] The content of the thermoplastic elastomer relative to 100 parts by weight of the vinyl chloride resin is preferably 3 parts by weight or more, more preferably 5 parts by weight or more, and even more preferably 6 parts by weight or more, and is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and even more preferably 15 parts by weight or less. When the content of the thermoplastic elastomer is not less than the above lower limit and not more than the above upper limit, the effects of the present invention can be more effectively exhibited.

[0053] <Additives> The above-mentioned rehabilitating pipe composition may contain various additives as necessary. Examples of the additives include stabilizers, stabilization aids, lubricants, processing aids, heat resistance improvers, antioxidants, ultraviolet absorbers, light stabilizers, fillers, pigments, and plasticizers. The above-mentioned additives may be used alone or in combination of two or more.

[0054] The stabilizer includes a heat stabilizer and a heat stabilization assistant.

[0055] Examples of the heat stabilizer include an organotin-based heat stabilizer, a lead-based heat stabilizer, a calcium-zinc-based heat stabilizer, a barium-zinc-based heat stabilizer, and a barium-cadmium-based heat stabilizer, etc. The heat stabilizer may be used alone or in combination of two or more kinds.

[0056] The organic tin-based heat stabilizer includes a tin mercapto-based heat stabilizer, a tin malate-based heat stabilizer, and a tin carboxylate-based heat stabilizer. The tin mercapto-based heat stabilizer includes a monoalkyl tin mercapto, a dialkyl tin mercapto, a monoalkyl tin mercapto polymer, a dialkyl tin mercapto polymer, a monoalkyl tin mercapto sulfide, and a dialkyl tin mercapto sulfide. The tin malate-based heat stabilizer includes a monoalkyl tin malate, a dialkyl tin malate, a monoalkyl tin malate polymer, and a dialkyl tin malate polymer. The tin carboxylate-based heat stabilizer includes a monoalkyl tin carboxylate and a dialkyl tin carboxylate. The organic tin-based heat stabilizer may be used alone or in combination of two or more.

[0057] Examples of the heat stabilization assistant include epoxidized soybean oil, phosphoric acid ester, polyol, hydrotalcite, zeolite, etc. The heat stabilization assistant may be used alone or in combination of two or more kinds.

[0058] From the viewpoint of suppressing discoloration of the resulting rehabilitated pipe, the stabilizer is preferably a heat stabilizer, more preferably a tin-based heat stabilizer, and even more preferably an organotin-based heat stabilizer.

[0059] From the viewpoint of improving the thermal stability, the organotin-based heat stabilizer is preferably a tin mercapto-based heat stabilizer, more preferably a dialkyltin mercapto, and even more preferably dioctyltin mercapto.

[0060] Examples of the lead-based heat stabilizer include tribasic lead sulfate, tetrabasic lead sulfate, basic lead sulfite, dibasic lead phosphite, dibasic lead phthalate, tribasic lead maleate, dibasic lead stearate, and basic lead sulfite phosphite.

[0061] The content of the heat stabilizer is preferably 0.5 parts by weight or more, more preferably 1.0 part by weight or more, and preferably 5.0 parts by weight or less, more preferably 4.0 parts by weight or less, relative to 100 parts by weight of the vinyl chloride resin. When the content of the heat stabilizer is equal to or more than the lower limit and equal to or less than the upper limit, the thermal stability can be further improved, and the heat resistance of the obtained rehabilitated pipe can be further improved.

[0062] The lubricant includes an internal lubricant and an external lubricant. The internal lubricant is used to reduce the flow viscosity of the molten resin during molding and to prevent frictional heat generation. The internal lubricant includes butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, and bisamide. The external lubricant is used to increase the sliding effect between the molten resin and the metal surface during molding. The external lubricant includes paraffin wax, polyolefin wax, ester wax, and montanic acid wax. The lubricant may be used alone or in combination of two or more.

[0063] Examples of the processing aid include acrylic processing aids. Examples of the acrylic processing aid include homopolymers or copolymers of alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; copolymers of alkyl methacrylates and alkyl acrylates such as methyl acrylate, ethyl acrylate, and butyl acrylate; copolymers of alkyl methacrylates and aromatic vinyl compounds such as styrene, α-methylstyrene, and vinyltoluene; copolymers of alkyl methacrylates and vinyl cyan compounds such as acrylonitrile and methacrylonitrile. Examples of the acrylic processing aid include alkyl acrylate-alkyl methacrylate copolymers having a weight average molecular weight of 100,000 to 2,000,000. Examples of the alkyl acrylate-alkyl methacrylate copolymers having a weight average molecular weight of 100,000 to 2,000,000 include n-butyl acrylate-methyl methacrylate copolymers and 2-ethylhexyl acrylate-methyl methacrylate butyl methacrylate copolymers. The processing aids may be used alone or in combination of two or more.

[0064] (rehabilitation pipe) The rehabilitating pipe according to the present invention is a rehabilitating pipe molded from the above-mentioned rehabilitating pipe composition. The rehabilitating pipe can be obtained by molding the above-mentioned rehabilitating pipe composition. The rehabilitating pipe is a molded body of the above-mentioned rehabilitating pipe composition. The rehabilitating pipe may be a folded rehabilitating pipe or an unfolded rehabilitating pipe (a tubular rehabilitating pipe). The rehabilitating pipe is installed and used within an existing pipe. The rehabilitating pipe is suitably used for rehabilitating an existing pipe by the Omega Liner method.

[0065] The molding method of the rehabilitating pipe composition is not particularly limited. Examples of the molding method of the rehabilitating pipe composition include extrusion molding, injection molding, calendar molding, and press molding. The molding method of the rehabilitating pipe composition is preferably extrusion molding. The rehabilitating pipe is preferably an extrusion molded body of the rehabilitating pipe composition.

[0066] Examples of molding machines used for molding include a screw-type injection molding machine, a single-screw extruder, a twin-screw counter-rotating parallel extruder, a twin-screw counter-rotating conical extruder, and a twin-screw co-rotating extruder, etc. When molding is performed using the above molding machines, the mold for forming, the resin temperature, etc. are not particularly limited.

[0067] The thickness of the rehabilitating pipe is not particularly limited. The thickness of the rehabilitating pipe may be 2 mm or more, 3 mm or more, 5 mm or more, 20 mm or less, or 10 mm or less.

[0068] The flexural modulus of the rehabilitating pipe at 25°C is preferably 1400 MPa or more, more preferably 1600 MPa or more, and even more preferably 1700 MPa or more. When the flexural modulus of the rehabilitating pipe at 25°C is equal to or more than the lower limit, the impact resistance of the rehabilitating pipe can be further improved. The flexural modulus of the rehabilitating pipe at 25°C may be 3600 MPa or less, or may be 3200 MPa or less.

[0069] The flexural modulus at 25° C. of the above-mentioned rehabilitating pipe can be measured in accordance with the “flexural test method for rigid plastics” described in JIS K7171.

[0070] The storage modulus of the rehabilitated pipe at 80°C can be measured as follows. The rehabilitated pipe is cut out to obtain a test piece having a width of 5 mm, a length of 35 mm, and a thickness of 2 mm. If the thickness of the rehabilitated pipe is less than 2 mm, a test piece having a width of 5 mm, a length of 35 mm, and a thickness of 2 mm may be obtained by stacking a plurality of samples and pressing them using a heat press molding machine (e.g., manufactured by Kodaira Manufacturing Co., Ltd.) heated to 190°C. The storage modulus of the obtained test piece is measured using a dynamic viscoelasticity measuring tester (e.g., "DVA200" manufactured by IT Measurement and Control Co., Ltd.). The measurement temperature conditions are a temperature rise rate of 3°C / min from 25°C to 100°C.

[0071] (Method of rehabilitating existing pipes) The above-mentioned rehabilitation pipe can be used to rehabilitate an existing pipe. The method for rehabilitating an existing pipe is preferably a method for rehabilitating an existing pipe by the Omega Liner method. The method for rehabilitating an existing pipe preferably includes the steps of (1) placing the folded rehabilitation pipe inside the existing pipe, (2) heating the rehabilitation pipe with steam, and (3) bringing the outer peripheral surface of the rehabilitation pipe into close contact with the inner peripheral surface of the existing pipe with compressed air.

[0072] The method for rehabilitating an existing pipe will be described below with reference to the drawings.

[0073] 1(a) to (c) are cross-sectional views for explaining each step of a method for rehabilitating an existing pipe. FIG. 1(a) to (c) are explanatory views for rehabilitating an existing pipe by the Omega Liner method.

[0074] First, the folded rehabilitating pipe 1 is pulled into the existing pipe 20, and the folded rehabilitating pipe 1 is placed inside the existing pipe 20 (Fig. 1(a)). Next, steam is passed through the rehabilitating pipe 1 from a boiler unit vehicle or the like to heat the rehabilitating pipe 1 (Fig. 1(b)). The heating by the steam causes the rehabilitating pipe 1 to gradually return to its tubular shape. Next, compressed air is passed through the rehabilitating pipe 1 to expand its diameter, and the outer circumferential surface of the rehabilitating pipe 1 and the inner circumferential surface of the existing pipe 20 are brought into tight contact (Fig. 1(c)).

[0075] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0076] The following materials were prepared:

[0077] Polyvinyl chloride resin (degree of polymerization 1000) (Tokuyama Sekisui Kogyo Co., Ltd. "TS1000R") Methyl methacrylate-butadiene-styrene copolymer (MBS, manufactured by Kaneka Corporation) Acrylic modifier (Kaneka) Thermoplastic elastomer (EVACO, Mitsui DuPont Polychemicals "Elvaloy 742")

[0078] Other Ingredients: Organotin heat stabilizer (manufactured by Nitto Kasei Co., Ltd.) Polyethylene wax lubricant Complex ester lubricant Processing Aids

[0079] Example 1 The following materials were blended and uniformly stirred and mixed to obtain a rehabilitating pipe composition. 100 parts by weight of vinyl chloride resin. 2.5 parts by weight of methyl methacrylate-butadiene-styrene copolymer. 2.5 parts by weight of acrylic modifier. 15 parts by weight of thermoplastic elastomer. 2 parts by weight of organotin heat stabilizer. 0.2 parts by weight of polyethylene wax lubricant. 0.8 parts by weight of complex ester lubricant. 3 parts by weight of processing aid. 400 g of the obtained rehabilitating pipe composition was kneaded for 3 minutes at a rotation speed of 20 rpm using an 8-inch mixing roll (manufactured by Yasuda Seiki Seisakusho) heated to 190 ° C., and then several samples were stacked and pressed with a hot press molding machine heated to 190 ° C. to obtain a test specimen of 200 mm long x 200 mm wide x 4 mm thick.

[0080] (Examples 2 to 6 and Comparative Examples 1 to 3) A rehabilitating pipe composition and test specimens were obtained in the same manner as in Example 1, except that the amounts of vinyl chloride resin, methyl methacrylate-butadiene-styrene copolymer, acrylic modifier, and thermoplastic elastomer were changed as shown in Tables 1 and 2.

[0081] (evaluation) (1) Appearance The appearance of the obtained test specimen was visually observed and rated according to the following criteria.

[0082] [Appearance criteria] ○: White spots ×: No white spots

[0083] (2) Water resistance The obtained test specimen was cut to prepare a test piece (weight: 6200 mg) of length 25 mm × width 50 mm × thickness 4 mm. In accordance with JSWAS K-19, the obtained test piece was placed in a glass container filled with distilled water, and the container was immersed in a thermostatic bath at 60°C for 5 hours. Thereafter, the test piece was removed, and the weight change per unit surface area of ​​the test piece before and after the test was measured. The water resistance was evaluated according to the following criteria.

[0084] [Water resistance criteria] ○○: Weight change is 0.17mg / cm 2 below ○: Weight change is 0.17mg / cm 2 Exceeds 0.20 mg / cm 2 below ×: Weight change is 0.20mg / cm 2 Exceeds

[0085] (3) Impact resistance Using the obtained test specimens, notched test pieces were prepared in accordance with the "Charpy impact test method for rigid plastics" described in JIS K7111-1, and impact tests were performed to measure the Charpy impact values. Impact resistance was evaluated according to the following criteria.

[0086] [Impact resistance evaluation criteria] ○: No cracks occur ×: Cracks occur

[0087] The composition of the rehabilitating pipe composition and the results are shown in Tables 1 and 2.

[0088] [Table 1]

[0089] [Table 2] [Explanation of symbols]

[0090] 1…Rehabilitation pipe 20...Existing pipe

Claims

1. A polyvinyl chloride resin, Methyl methacrylate-butadiene-styrene copolymer; and an acrylic modifier, The composition for rehabilitating pipes, wherein the total content of the methyl methacrylate-butadiene-styrene copolymer and the acrylic modifier is 5 parts by weight or more and 20 parts by weight or less relative to 100 parts by weight of the vinyl chloride resin.

2. The composition for rehabilitating pipes according to claim 1 , further comprising a thermoplastic elastomer.

3. The rehabilitating pipe composition according to claim 1 or 2, wherein the ratio of the content of the methyl methacrylate-butadiene-styrene copolymer to the content of the acrylic modifier is 0.1 or more and 10 or less.

4. 3. The composition for rehabilitating pipes according to claim 1 or 2, wherein the acrylic modifier is contained in an amount of 10% by weight or less based on 100% by weight of the composition for rehabilitating pipes.

5. A rehabilitating pipe formed from the composition for rehabilitating pipes according to claim 1 or 2.

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