JP6238461B2 - Curable material for repairing inner surface of tubular molded body and repair method - Google Patents

Description

  The present invention relates to a curable material for repairing an inner surface of a tubular molded body such as a pipe, and a repair method.

  At present, pipes are used to supply various substances such as water and sewage, chemicals, and city gas, and are indispensable for our daily lives. Concrete materials such as concrete, steel, stainless steel, and plastic are commonly used as pipe materials, but in recent years, corrosion and aging of pipes have become a major problem. For example, concrete pipes are mainly used in water and sewage systems, but in addition to physical damage due to external pressure due to long-term burial use, sulphite is associated with the decomposition of contaminants by sulfate-reducing bacteria, especially in sewage systems. There is a problem that the inner surface of the concrete pipe is corroded or aged due to generation of gas and generation of sulfate ions by sulfur-oxidizing bacteria. Therefore, it is necessary to develop an effective repair method for corrosion or aging of the existing pipe as well as improving the corrosion resistance and durability of the new pipe.

If the existing pipe is corroded or aged, there is a method of excavating it and replacing it with a new pipe.However, it may not be possible to physically excavate, or excavation work may cause traffic congestion and cost. There is a problem of rising. Therefore, the request | requirement of the effective repair method with respect to the corrosion or aging of the existing pipe by a non-open cutting method is high.
Non-open cutting methods include methods such as attaching plastics such as vinyl chloride to the inner surface of pipes and newly inserting corrosion-resistant plastic pipes into old pipes. Recently, fibers impregnated with curable resin compositions A method of forming a coating layer by pressing a base material on the inner surface of a pipe and curing it with heat or light has become the mainstream (see, for example, Patent Documents 1 to 3).

Japanese Patent Publication No. 1-15374 JP-A-8-323860 JP-A-11-210981

However, in recent years, in the repair method using the non-open cutting method, the durability of the coating layer over a long period of 50 years is required, but the fiber base material impregnated with the curable resin composition is pressure-bonded to the inner surface of the pipe. The conventional method of curing with heat or light has a problem that the durability of the coating layer over a long period is still insufficient.
The present invention has been made to solve the above-described problems, and is a curable material for repairing the inner surface of a tubular molded body that can form a coating layer having excellent durability over a long period of 50 years. And to provide a repair method.

As a result of intensive studies to solve the above problems, the present inventors formulated a specific antioxidant together with an unsaturated polyester and / or vinyl ester, a polymerizable monomer having a specific molecular weight, and a curing agent. It was found that by impregnating the fiber material with the curable resin composition thus obtained, it becomes a curable material capable of forming a coating layer having excellent durability over a long period of time.
That is, the present invention includes the following [1] to [10].

[1] A fiber material is impregnated with a curable resin composition containing an unsaturated polyester and / or vinyl ester, a polymerizable monomer having a molecular weight of 150 or less, a curing agent, and a hindered phenol antioxidant. that a curable material for repair of the pipe-shaped molded body surface, characterized in that the curable resin composition is B-staged, repair curable material of the tubular shaped body surface.
[2] The curable resin composition is 0.05 to 5 parts by mass of the hindered phenol antioxidant with respect to 100 parts by mass in total of the unsaturated polyester and / or vinyl ester and the polymerizable monomer. The curable material for repairing the inner surface of the tubular molded body according to [1], comprising:
[3] The curable material for repairing the inner surface of the tubular molded body according to [1] or [2], wherein the unsaturated polyester and / or vinyl ester has a symmetrical structure.
[4] The unsaturated polyester and / or vinyl ester is one or more selected from the group consisting of a terephthalic acid residue, a bisphenol A residue, and a bisphenol F residue with respect to all residues having a benzene ring. The curable material for repairing the inner surface of the tubular molded body according to any one of [1] to [3], wherein the residue contains 50 mol% or more in total.

[5] The fiber material is a roving, cloth, mat, or non-woven fabric formed from one or more fibers selected from the group consisting of glass fibers, polyester fibers, vinylon fibers, carbon fibers, aramid fibers, and metal fibers. The curable material for repairing the inner surface of the tubular molded body according to any one of [1] to [4], wherein:
[6] The curable material for repairing the inner surface of the tubular molded body according to any one of [1] to [5], wherein the fiber material is in a sheet shape, a roll shape, a tubular shape, or a tubular shape. .

[ 7 ] The curable material for repairing the inner surface of the tubular molded body according to any one of [1] to [ 6 ] is inserted into the tubular molded body and adhered to the inner surface of the tubular molded body, and then cured. A method for repairing the inner surface of a tubular molded body, characterized by comprising:
[ 8 ] The method for repairing the inner surface of the tubular molded body according to [ 7 ], wherein the tubular molded body is a manhole.
[ 9 ] The method for repairing the inner surface of the tubular molded body according to [ 7 ] or [ 8 ], wherein the metal halide lamp is photocured using a light source.

  ADVANTAGE OF THE INVENTION According to this invention, the curable material for repair of the inner surface of a tubular molded object and the repair method which can form the coating layer excellent in durability over a long period of 50 years can be provided.

The curable material for repairing the inner surface of the tubular molded body of the present invention (hereinafter abbreviated as “curable material”) includes an unsaturated polyester and / or vinyl ester, a polymerizable monomer, a curing agent, an antioxidant, The fiber material is impregnated with a curable resin composition containing
Although it does not specifically limit as unsaturated polyester and / or vinyl ester which can be used in this invention, It is preferable to have a symmetrical structure. If the unsaturated polyester and / or vinyl ester has a symmetric structure, a coating layer having excellent durability over a long period of time can be stably formed. Among them, preferred unsaturated polyester and / or vinyl ester is one or more residues selected from the group consisting of terephthalic acid residue, bisphenol A residue and bisphenol F residue with respect to all residues having a benzene ring. Contains a total of 50 mol% or more of groups. Specific examples of such unsaturated polyesters and / or vinyl esters include unsaturated polyesters using terephthalic acid and bisphenol A as raw materials, and vinyl esters using bisphenol A and bisphenol F as raw materials. Here, the above mol% represents the terephthalic acid residue, the bisphenol A residue, and the bisphenol F residue as one residue, and the residue relative to the sum of the residue and other residues having a benzene ring. Means the percentage of Examples of other residues having a benzene ring include orthophthalic acid residues (ortho unsaturated polyesters), isophthalic acid residues (iso unsaturated polyesters), phenol novolac residues (novolac type vinyl esters), and the like. It is done.

  The unsaturated polyester is generally a condensation product obtained by an esterification reaction between a polyhydric alcohol and an unsaturated polybasic acid (and a saturated polybasic acid if necessary). When manufacturing the curable material of this invention, you may use with the form of the unsaturated polyester resin which melt | dissolved unsaturated polyester in the polymerizable monomer. Such unsaturated polyester resins are described in “Polyester Resin Handbook” (published by Nikkan Kogyo Shimbun, 1988) or “Dictionary of Paint Terms” (edited by Color Material Association, published in 1993).

  The polyhydric alcohol is not particularly limited, but ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol. 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, cyclohexane-1,4-dimethanol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc. Is mentioned. These can be used alone or in combination of two or more.

The unsaturated polybasic acid is not particularly limited, and examples thereof include fumaric acid, maleic anhydride, maleic acid, itaconic acid, and acid anhydrides thereof. These can be used alone or in combination of two or more.
The saturated polybasic acid is not particularly limited, and examples thereof include phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, adipic acid, sebacic acid, and acid anhydrides thereof. These can be used alone or in combination of two or more.

  The unsaturated polyester can be synthesized by a known method using the above components as raw materials. For example, it may be esterified to a desired stage at a temperature of 140 to 230 ° C. in an inert gas stream such as nitrogen. In the esterification reaction, an esterification catalyst can be used as necessary. Examples of the catalyst include known catalysts such as manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, and cobalt acetate. These can be used alone or in combination of two or more.

Although the weight average molecular weight of unsaturated polyester is not specifically limited, Preferably it is 2,000-16,000, More preferably, it is 10,000-15,000. Here, in this specification, “weight average molecular weight” is measured at normal temperature (23 ° C.) under the following conditions using gel permeation chromatography (Shodex GPC-101, Showa Denko KK), and polystyrene. It means what is calculated by conversion (the “weight average molecular weight” of each component below means what is calculated by measurement under the same method and conditions).
Column: Showa Denko LF-804 x 2 Column temperature: 40 ° C
Sample: 0.4 mass% tetrahydrofuran solution of polymer Flow rate: 1 mL / min Eluent: Tetrahydrofuran

  A vinyl ester is a compound having a polymerizable unsaturated bond generally generated by a ring-opening reaction between a compound having a glycidyl group (epoxy group) and a carboxyl group of a carboxyl compound having a polymerizable unsaturated bond. When the curable material of the present invention is produced, it may be used in the form of a vinyl ester resin (also referred to as “epoxy acrylate resin”) in which a vinyl ester is dissolved in a polymerizable monomer. Such vinyl ester resins are described in “Polyester Resin Handbook” (published by Nikkan Kogyo Shimbun, 1988) or “Paint Glossary” (edited by Color Material Association, published in 1993).

The compound having a glycidyl group is not particularly limited, and examples thereof include bisphenol A diglycidyl ether and high molecular weight homologues thereof, novolak glycidyl ethers, and the like.
The carboxyl compound having a polymerizable unsaturated bond is not particularly limited, and examples thereof include unsaturated monobasic acids such as acrylic acid and methacrylic acid; bisphenols (such as A-type), adipic acid, sebacic acid, and dimer acid. Examples include basic acids. In particular, if a dibasic acid is used, flexibility can be imparted to the vinyl ester.

The vinyl ester can be synthesized by a known method using the above components as raw materials. For example, a compound having a glycidyl group and a carboxyl compound having a polymerizable unsaturated bond is a vinyl ester at a temperature of 80 ° C. to 140 ° C. in a ratio of carboxyl group / epoxy group = 1.05 to 0.95. What is necessary is just to make it. In this reaction, a reaction catalyst can be used as necessary. Examples of the catalyst include tertiary amines such as benzyldimethylamine, triethylamine, N, N-dimethylaniline, triethylenediamine, 2,4,6-tris (dimethylaminomethyl) phenol, and 4 such as trimethylbenzylammonium chloride. Well-known catalysts, such as metal salts, such as a quaternary ammonium salt and lithium chloride, are mentioned. These can be used alone or in combination of two or more.
The weight average molecular weight of the vinyl ester is not particularly limited, but is preferably 600 to 6,000, more preferably 800 to 4,000.

  The curable resin composition used in the present invention contains a polymerizable monomer. It does not specifically limit as a polymerizable monomer which can be used in this invention, A well-known thing can be used. Examples of polymerizable monomers include styrene, styrene α-, o-, m-, p-alkyl, nitro, cyano, amide, ester derivatives, styrene monomers such as chlorostyrene, vinyltoluene, divinylbenzene; butadiene, Dienes such as 2,3-dimethylbutadiene, isoprene, chloroprene; ethyl (meth) acrylate, methyl (meth) acrylate, (n) propyl (meth) acrylate, (i) propyl (meth) acrylate, ( Hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofuryl (meth) acrylate , Acetoacetoxyethyl (meth) acrylate, dis (Meth) acrylic acid esters such as lopentenyloxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate (Meth) acrylic acid amide and (meth) acrylic acid N, N-dimethylamide and other (meth) acrylic acid amides; (meth) acrylic acid anilide and other vinyl compounds; diethyl citraconic acid and other unsaturated dicarboxylic acid diesters Monomonimide compounds such as N-phenylmaleimide; N- (meth) acryloylphthalimide and the like. Also, in the molecule such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate and 1,6-hexanediol di (meth) acrylate It is also possible to use a (meth) acrylic acid ester compound having two or more (meth) acryloyl groups. These polymerizable monomers can be used alone or in combination of two or more.

The curable resin composition used in the present invention contains a polymerizable monomer having a molecular weight of 150 or less as an essential component among the above polymerizable monomers. Among these, styrene and methyl methacrylate are preferable from the viewpoints of workability, cost, and curability.
Among the polymerizable monomers contained in the curable material of the present invention, the polymerizable monomer having a molecular weight of 150 or less is preferably 50 mol% or more. When the polymerizable monomer having a molecular weight of 150 or less is less than 50 mol%, it may not be possible to form a coating layer having excellent durability over a long period of time.

  Although content of the polymerizable monomer in the curable resin composition used for this invention is not specifically limited, Preferably it is 20 mass%-80 mass%, More preferably, it is 30 mass%-60 mass%. When the content of the polymerizable monomer is less than 20% by mass, workability may be reduced due to an increase in the viscosity of the curable resin composition. On the other hand, when the content of the polymerizable monomer exceeds 80% by mass, it may not be possible to form a coating layer having excellent durability over a long period of time.

It does not specifically limit as a hardening | curing agent which can be used in this invention, What is necessary is just to select suitably according to various hardening methods, such as normal temperature hardening, heat hardening, and photocuring.
It does not specifically limit as a hardening | curing agent used for normal temperature hardening, A well-known thing can be used. Examples of curing agents used for room temperature curing include a combination of a ketone peroxide and a reducing agent, a combination of a hydroperoxide and a reducing agent, a combination of a diacyl peroxide and a reducing agent, and the like. Here, examples of the reducing agent include cobalt salts such as cobalt naphthenate and cobalt octylate, vanadium compounds such as vanadium pentoxide, and amines such as dimethylaniline. Among these, a combination of a peroxyester and a cobalt salt is particularly effective from the viewpoint of pot life and the like. Alternatively, known radical polymerization initiators such as ketone peroxide, peroxyketal, hydroperoxide, diallyl peroxide, diacyl peroxide, peroxyester, peroxydicarbonate, and azo compound may be used. These can be used alone or in combination of two or more.

  It does not specifically limit as a hardening | curing agent used for heat curing, A well-known thing can be used. Examples of curing agents used for heat curing include benzoyl peroxide, dicumyl peroxide, diisopropyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, 1,1-bis (t-butyl Peroxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, 3-isopropyl hydroperoxide, t-butyl hydroperoxide, dic Milperoxide, dicumyl hydroperoxide, acetyl peroxide, bis (4-tert-butylcyclohexyl) peroxydicarbonate, diisopropylperoxydicarbonate, isobutyl peroxide, 3,3,5-trimethylhexanoyl peroxide, Lauril Parr Kisaido, azobisisobutyronitrile, and azobis carboxamido like. These can be used alone or in combination of two or more.

  It does not specifically limit as a hardening | curing agent used for photocuring, A well-known thing can be used. Among them, as the curing agent used for photocuring, a photopolymerization initiator having photosensitivity in an arbitrary region within a range from the ultraviolet light region to the visible light region is effective, and a known ultraviolet polymerization initiator or visible light polymerization is effective. It is preferred to use an initiator.

  Examples of the ultraviolet polymerization initiator include acetophenone-based, benzyl ketal-based, and (bis) acylphosphine oxide-based ultraviolet polymerization initiators. These ultraviolet polymerization initiators can be used alone or in combination of two or more. In addition, since short wavelength ultraviolet rays have low light transmittance with respect to the curable material of the present invention, (bis) acylphosphine oxide system having photosensitivity up to a relatively long wavelength, preferably in the visible light region of 380 nm or more. It is preferable to use an ultraviolet polymerization initiator.

  More specific examples of ultraviolet polymerization initiators include 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name: Darocur 1173, manufactured by Ciba Specialty Chemicals) and bis (2,6 -Dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide (manufactured by Ciba Specialty Chemicals Co., Ltd.) mixed with a mass ratio of 75% / 25% Irgacure-1700 (Ciba Specialty Chemicals ( 1-hydroxy-cyclohexyl-phenyl-ketone (trade name: Irgakiure 184, manufactured by Ciba Specialty Chemicals) and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine Oxide (Ciba Specialty Chemicals Co., Ltd.) ) And trade name Irgacure-1800 (manufactured by Ciba Specialty Chemicals Co., Ltd.) mixed at a mass ratio of 75% / 25%, trade name Irgacure-1850 (Ciba) mixed at a mass ratio of 50% / 50% Specialty Chemicals); bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (trade name: Irgacure-819, Ciba Specialty Chemicals); 2,4,6-trimethylbenzoyl -Diphenylphosphine oxide (trade name: Lucirin TPO, manufactured by BASF Corporation); 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name: Darocur 1173, manufactured by Ciba Specialty Chemicals Co., Ltd.) 2,4,6-trimethylbenzoyl-diphenylphos In'okisaido (trade name: Lucirin TPO, BASF (Ltd.)) are mixed trade name at a mass ratio of 50% / 50%: Darocur4265, and the like.

Examples of visible light polymerization initiators include Yamaoka et al., “Surface”, 27 (7), 548 (1989), Sato et al., “Summary of the 3rd Polymer Material Forum”, 1BP18 (1994). Single initiator systems such as quinone, benzyl, trimethylbenzoyldiphenylphosphine oxide, methylthioxanthone, biscyclopentadienyltitanium-di (pentafluorophenyl); organic peroxide catalyst / dye system, diphenyliodonium salt / dye, biphenyl Imidazole / keto compound, hexaarylbiimidazole compound / hydrogen donating compound, mercaptobenzothiazole / thiopyrylium salt, metal arene / cyanine dye, hexaarylbiimidazole / radical generator described in JP-B-45-37777, etc. Examples include initiator systems It is. These can be used alone or in combination of two or more.
Specific examples of hexaarylbiimidazole include bis (2,4,5-triphenyl) imidazole, bis (2-o-chlorophenyl-4,5-diphenyl) imidazole, and bis (2-o, p-dichlorophenyl-4). , 5-diphenyl) imidazole, bis (2-o-bromophenyl-4,5-diphenyl) imidazole, and the like. Among these, bis (2-o-bromophenyl-4,5-diphenyl) imidazole is preferable. Further, hexaarylbiimidazoles described in JP-B 41-3545 may be used.

  The amount of the curing agent used is preferably 0.02 to 30 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the total of unsaturated polyester and / or vinyl ester and polymerizable monomer. is there. If the amount of the curing agent used is less than 0.02 parts by mass, the curing reaction may not proceed sufficiently. On the other hand, when the usage-amount of a hardening | curing agent exceeds 30 mass parts, it may be unable to form the coating layer excellent in durability over a long period of time.

  Antioxidants that can be used in the present invention are hindered phenolic antioxidants. Examples of the hindered phenol antioxidant include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 245), 1,6- Hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 259), 2,4-bis- (n-octylthio) -6- (4- Hydroxy-3,5-t-butylanilino) -1,3,5-triazine, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 1010), 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ], Octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (trade name: IRGANOX 1076), N, N′-hexamethylenebis (3,5-di-t-butyl- 4-hydroxy-hydrocinnamamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,3 5-di-t-butyl-4-hydroxybenzyl) benzene, 2,4,6-tris (dimethylaminomethyl) phenol and the like. These can be used alone or in combination of two or more.

  The amount of hindered phenolic antioxidant used is preferably 0.005 to 5 parts by mass, more preferably 0.08, per 100 parts by mass in total of unsaturated polyester and / or vinyl ester and polymerizable monomer. -4 mass parts, 0.01-3 mass parts. When the amount of the hindered phenol-based antioxidant used is less than 0.005 parts by mass, it may be impossible to form a coating layer having excellent durability over a long period of time. On the other hand, if the amount of hindered phenol-based antioxidant used exceeds 5 parts by mass, the curing reaction may not proceed sufficiently.

The curable resin composition used for the curable material of the present invention may contain additives known in the technical field within the range not impairing the effects of the present invention, in addition to the above components. Examples of known additives include UV absorbers, dyes, pigments, thixotropic agents, flame retardants, low shrinkage agents, inorganic / organic fillers, diluent solvents, surface treatment agents, wetting agents, curing accelerators, mold release An agent etc. can be mentioned. The blending ratio of these additives is not particularly limited as long as it does not impair the effects of the present invention.
The curable resin composition used for the curable material of the present invention can be produced by mixing the above components. In this production, the mixing method is not particularly limited, and a known method can be used.

The fiber material impregnated with the curable resin composition is not particularly limited, and may be a material composed of various known inorganic and / or organic fibers.
Examples of inorganic and / or organic fibers include glass fibers, polyester fibers, vinylon fibers, carbon fibers, aramid fibers, and metal fibers. These fibers can be used alone or in combination of two or more.
The shape of the fiber material is also not particularly limited, and for example, roving, cloth, mat, or non-woven fabric can be produced using the above-described fibers, and used in the form of a sheet, roll, tube, or cylinder.

  The amount of the fiber material used is preferably 5 to 400 parts by mass, more preferably 10 to 300 parts by mass with respect to 100 parts by mass of the curable resin composition. When the amount of the fiber material used is less than 5 parts by mass or more than 400 parts by mass, a coating layer having excellent durability may not be formed over a long period of time.

The method for impregnating the fiber material with the curable resin composition is not particularly limited, and can be performed according to a known method. For example, the curable resin composition may be applied to the fiber material using a roller or the like.
The fiber material impregnated with the curable resin composition is preferably left at room temperature for 30 minutes or more. If the standing time is short, the familiarity between the fiber material and the curable resin composition is not sufficient, and it may be impossible to form a coating layer having excellent durability over a long period of time.

The fiber material impregnated with the curable resin composition may be B-staged (semi-cured) from the viewpoint of handling. The method for forming the B stage is not particularly limited, and a known method can be used. Examples of B-stage formation include a metal thickening method using MgO or the like, a chemical thickening method using a reaction between an isocyanate and a hydroxyl group, a polymer swelling method in which PMMA or the like is added, a near infrared radical polymerization method, or the like. . These methods are described in detail in Japanese Patent No. 3479202 and Japanese Patent Application Laid-Open No. 2006-45404.
The curable material of the present invention thus produced is particularly suitable for use in a method for repairing the inner surface of a tubular molded body because a coating layer having excellent durability can be formed over a long period of time.

Next, a method for repairing the inner surface of the tubular molded body of the present invention will be described.
In the method for repairing the inner surface of the tubular molded body, the curable material is inserted into the tubular molded body and adhered to the inner surface of the tubular molded body, and then cured.

  The tubular molded body to which the repair method of the present invention can be applied is not particularly limited, and may be various pipes used for supplying various substances such as water and sewage, chemicals, and city gas. Can do. Examples of the tubular molded body include a fume tube, a culvert, and a manhole. Moreover, these tubular molded bodies can be made of concrete, steel, vinyl chloride, ceramics, or the like. Furthermore, for example, in a sewer pipe, the present invention can be applied to any of a main pipe, a branch pipe, an attachment pipe, and the like.

The curing method is not particularly limited, and various curing methods such as room temperature curing, heat curing, and photocuring can be used.
Although it does not specifically limit as a normal temperature curing method, What is necessary is just to let it stand and harden | cure at normal temperature. Although it does not specifically limit as a heat-curing method, What is necessary is just to harden | cure using 60 degreeC or more hot water and a halogen heater. Although it does not specifically limit as a photocuring method, What is necessary is just to irradiate ultraviolet light and visible light. In the case of photocuring, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a mercury lamp, a metal halide lamp, or the like can be used as a light source. If a light source capable of irradiating in the 360 direction is used, the photocuring reaction can be efficiently performed. The illuminance upon light irradiation varies depending on the type and amount of unsaturated polyester, vinyl ester, curing agent, etc., but is generally 10 mJ / cm ² or more, preferably 100 mJ / cm ² or more. Among these various curing methods, the photocuring method is effective when a curing reaction is desired in a short time. Details of the photocuring method are described in JP-A-2001-322182.

The method for inserting the curable material into the tubular molded body and bonding it to the inner surface of the tubular molded body is not particularly limited, and various known methods can be used.
For example, a sheet-like curable material may be wound around the surface of a rubber-like sleeve and inserted into a tubular molded body, and then the sleeve may be inflated with air pressure. Alternatively, a film may be provided on the inner surface of the cylindrical curable material, and after the cylindrical curable material is inserted into the tubular molded body, air or water may be introduced into the cylindrical curable material. Furthermore, a film may be provided outside the cylindrical curable material, and when inserting the cylindrical curable material into the tubular molded body, the cylindrical curable material may be inserted while being reversed.
When inserting a curable material into a tubular molded body, if a light source such as various lamps or a heater is placed in the sleeve or cylindrical curable material, the curable material is immediately bonded to the inner surface of the tubular molded body. A curing reaction can be performed.

  Thus, the repair method of this invention performed can form the coating layer excellent in durability over a long period of time on the inner surface of the tubular molded body.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited by these. In addition, the following Examples 1-4 and 6 are reference examples.
(Synthesis Example 1)
To a 5 L flask equipped with a stirrer, a distillation condenser, a thermometer, and a nitrogen introduction tube, 1693 parts by mass of terephthalic acid and 1350 parts by mass of propylene glycol are added, and the temperature is increased to 160 ° C. while heating and stirring in a nitrogen stream. Then, the temperature was gradually raised to 210 ° C. to carry out an esterification reaction. When the acid value reached 8.8 mgKOH / g, the mixture was cooled, and 666 parts by mass of maleic anhydride was further added to carry out an esterification reaction. When the acid value reached 26.6 mgKOH / g, the reaction was terminated by cooling to obtain 3170 parts by mass of unsaturated polyester. It was 12,600 when the weight average molecular weight of this unsaturated polyester was measured on the said conditions. Moreover, this unsaturated polyester was 100 mol% of terephthalic acid residues in all the residues having a benzene ring.
Next, 3170 parts by mass of the unsaturated polyester was blended with 0.80 parts by mass of hydroquinone and 1 part by mass of a hindered phenol antioxidant (IRGANOX 245), and then 2040 parts by mass of styrene (molecular weight). 104), a resin composition PE-1 having a viscosity at 25 ° C. of 7.8 dPa · s was obtained.

(Synthesis Example 2)
2238 parts by mass of bisphenol A type epoxy resin (AER 2603, Asahi Kasei Epoxy Co., Ltd., epoxy equivalent 186.2), 258 parts by mass of bisphenol were added to a 5 L flask equipped with a stirrer, condenser, thermometer and dry air introduction tube. A, 3.8 parts by mass of triethylamine (catalyst) was added, the temperature was raised with stirring in a dry air atmosphere, and the mixture was reacted at 145 ° C. for 1 hour. Next, 1.0 part by mass of methylhydroquinone, 828 parts by mass of methacrylic acid, 10 parts by mass of 2,4,6-tris (dimethylaminomethyl) phenol (sequol TDMP) (catalyst) were further added, The esterification reaction was performed at 130 ° C. When the acid value reached 9.5 mgKOH / g, the reaction was terminated by cooling to obtain 3338 parts by mass of vinyl ester. It was 990 when the weight average molecular weight of this vinyl ester was measured on the said conditions. Moreover, this vinyl ester was 100 mol% of bisphenol A residues in all the residues having a benzene ring.
Next, by adding 1.0 part by weight of hydroquinone, 1 part by weight of a hindered phenolic antioxidant (IRGANOX 259), and 1707 parts by weight of styrene (molecular weight 104) to 3338 parts by weight of the above vinyl ester, A resin composition VE-1 having a viscosity of 3.1 dPa · s at 25 ° C. was obtained.

(Synthesis Example 3)
Resin composition VE-2 having a viscosity at 25 ° C. of 7.2 dPa · s was obtained in the same manner as in Synthesis Example 2 except that methyl methacrylate (molecular weight 100) was used instead of styrene (molecular weight 104).

(Comparative Synthesis Example 1)
1130 parts by mass of isophthalic acid and 1350 parts by mass of propylene glycol are added to a 5 L flask equipped with a stirrer, a distillation condenser, a thermometer and a nitrogen introduction tube, and the temperature is raised to 160 ° C. while heating and stirring in a nitrogen stream. Then, the temperature was gradually raised to 210 ° C. to carry out an esterification reaction. When the acid value reached 8.8 mgKOH / g, the mixture was cooled, and 1000 parts by mass of maleic anhydride was further added to carry out an esterification reaction. When the acid value reached 26.6 mgKOH / g, the reaction was terminated by cooling to obtain 3170 parts by mass of unsaturated polyester. When the weight average molecular weight of this unsaturated polyester was measured on the said conditions, it was 13,100. This unsaturated polyester has 100 mol% of isophthalic acid residues in all residues having a benzene ring, and does not have terephthalic acid residues, bisphenol A residues or bisphenol F residues.
Next, after adding 0.80 part by mass of hydroquinone to 3170 parts by mass of the unsaturated polyester, this is dissolved in 2040 parts by mass of styrene (molecular weight 104), whereby the viscosity at 25 ° C. is 8. A resin composition PE-2 of 9 dPa · s was obtained.

(Comparative Synthesis Example 2)
A resin composition having a viscosity of 12 dPa · s at 25 ° C. by adding 1.0 part by weight of hydroquinone and 2719 parts by weight of phenoxyethyl methacrylate (molecular weight 206) to 3338 parts by weight of the vinyl ester prepared in Synthesis Example 2. VE-3 was obtained.

(Comparative Synthesis Example 3)
Resin composition PE-3 having a viscosity at 25 ° C. of 7.6 dPa · s was obtained in the same manner as in Synthesis Example 1 except that the hindered phenol-based antioxidant (IRGANOX 245) was not blended.

(Comparative Synthesis Example 4)
A resin composition VE-4 having a viscosity of 3.1 dPa · s at 25 ° C. was obtained in the same manner as in Synthesis Example 2 except that the hindered phenol-based antioxidant (IRGANOX 259) was not blended.

(Comparative Synthesis Example 5)
A resin composition VE-5 having a viscosity at 25 ° C. of 7.1 dPa · s was obtained in the same manner as in Synthesis Example 3 except that the hindered phenol-based antioxidant (IRGANOX 259) was not blended.

Example 1
To 100 parts by mass of resin composition PE-1, 1.0 part by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 1800, Ciba Specialty Chemicals Co., Ltd.), 0.8 parts by mass of Aerogel 200 (swing) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, using a 2 kW metal halide lamp (trade name Dynabeam 2: Toshiba Lighting & Technology Co., Ltd.), the light was irradiated at an illuminance of 10 mW / cm ² at a distance of 1 m from the polyurethane-coated surface of the photocurable material, It completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
The obtained cured product was subjected to a creep test in accordance with JIS K7116 "Plastics-Test method for creep characteristics-Part 2: Bending creep with a three-point load", and then a creep elastic modulus-time diagram was prepared. The estimated elastic modulus after 50 years was determined based on the curve. Based on the current elastic modulus and the estimated elastic modulus after 50 years (438000 hours later), the elastic modulus retention after 50 years was calculated. The creep test was performed under the following conditions.
Specimen shape: width 15mm x length 150mm x thickness 6mm
Distance between fulcrums: 96mm
Measurement time: 0 to 1000 hours Test weight: calculated by the following formula Test weight M = b · d ² · s · 9.80665 / 14.71L
(Where, M: test weight (N), b: width of test piece (mm), d: thickness of test piece (mm), s: 0.025E ₀ (E ₀ : initial flexural modulus), L : Distance between supporting points (mm)
As a result, the elastic modulus retention after 50 years was 81%. In addition, evaluation of the elastic modulus retention in the following examples and comparative examples was performed by the same method as described above.

(Example 2)
100 parts by mass of resin composition VE-1, 0.8 parts by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 184, Ciba Specialty Chemicals Co., Ltd.), 0.8 parts by mass of Aerogel 200 (change) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, as a result of performing light irradiation on the above-mentioned photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
Further, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 86%.

(Example 3)
To a mixture of 50 parts by mass of resin composition PE-1 and 50 parts by mass of resin composition VE-1, 1.5 parts by mass of perbutyl O, 0.8 parts by mass of Aerogel 200 (thixotropic agent, Nippon Aerogel) Co., Ltd.) was added and mixed to obtain a thermosetting resin composition.
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coated felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned thermosetting resin composition with a roller. After defoaming, the thermosetting material was obtained by leaving it at room temperature for 8 hours. Here, the usage-amount of the thermosetting resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, the above thermosetting material was completely cured by heating at 80 ° C. for 2 hours.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
In addition, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 83%.

Example 4
To 100 parts by mass of the resin composition VE-2, 0.8 parts by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 184, Ciba Specialty Chemicals Co., Ltd.), 0.8 parts by mass of Aerogel 200 (swing) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, as a result of performing light irradiation on the above-mentioned photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
Further, the obtained cured product was subjected to a creep test and the elastic modulus retention after 50 years was calculated to be 88%.

(Comparative Example 1)
To 100 parts by mass of the resin composition PE-2, 1.0 part by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 1800, Ciba Specialty Chemicals Co., Ltd.), 0.8 parts by mass of Aerogel 200 (change) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, as a result of performing light irradiation on the above-mentioned photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
In addition, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 53%.

(Comparative Example 2)
100 parts by mass of the resin composition PE-3, 1.0 part by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 1800, Ciba Specialty Chemicals Co., Ltd.), 0.8 parts by mass of Aerogel 200 (swing) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, as a result of performing light irradiation on the above-mentioned photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
In addition, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 56%.

(Comparative Example 3)
100 parts by mass of the resin composition VE-3, 1.0 part by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 1800, Ciba Specialty Chemicals Co., Ltd.), 0.8 part by mass of Aerogel 200 (change) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, as a result of performing light irradiation on the above-mentioned photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
In addition, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 51%.

(Comparative Example 4)
100 parts by mass of the resin composition PE-3, 1.0 part by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 1800, Ciba Specialty Chemicals Co., Ltd.), 0.8 parts by mass of Aerogel 200 (swing) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, a felt layer of a polyester-fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, as a result of performing light irradiation on the above-mentioned photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
In addition, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 59%.

(Comparative Example 5)
To 100 parts by mass of resin composition VE-4, 0.8 parts by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 184, Ciba Specialty Chemicals Co., Ltd.), 0.8 parts by mass of Aerogel 200 (swing) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, as a result of performing light irradiation on the above-mentioned photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
Further, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 64%.

(Comparative Example 6)
To 100 parts by mass of resin composition VE-5, 0.8 parts by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 184, Ciba Specialty Chemicals Co., Ltd.), 0.8 parts by mass of Aerogel 200 (swing) The photocurable resin composition was obtained by adding and mixing an agent, Nippon Aerogel Co., Ltd.).
Next, the felt layer of a polyester fiber felt-like woven fabric (10 mm thick, coating felt, Nippon Valqua Industries, Ltd.) coated on one side with transparent polyurethane is impregnated with the above-mentioned photocurable resin composition with a roller. After defoaming, it was left at room temperature for 1 hour to obtain a photocurable material. Here, the usage-amount of the photocurable resin composition was 100 mass parts with respect to 10 mass parts felt-like textiles.

Next, as a result of performing light irradiation on the above-mentioned photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 7 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
Further, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 61%.

(Example 5)
To 100 parts by mass of resin composition VE-1, 0.8 parts by mass of bisacylphosphine oxide (photopolymerization initiator, Irgacure 184, Ciba Specialty Chemicals Co., Ltd.), 0.03 parts by mass of 1,1,5 , 5-tetrakis (p-diethylaminophenyl) -2,4-pentadienyl triphenyl n-butyl borate (Showa Denko), 0.15 parts by mass of tetra n-butylammonium triphenyl n-butyl borate (Showa Denko Co., Ltd.) was added and mixed to obtain a photocurable resin composition.
Next, a photocurable material was obtained by impregnating the above photocurable resin composition into 3 plies of # 450 chopped strand mat (Asahi Fiber Glass Co., Ltd., 10 cm × 10 cm). Here, the usage-amount of the photocurable resin composition was 70 mass parts with respect to 30 mass parts # 450 chopped strand mat. Next, this photo-curable material is coated with a Mylar film, and an AL-spotlight (ALF-10) 1 kW (RDS Corporation), which is a light source including a wavelength range of 390 to 1200 nm, is SC60 which is a cut filter of 600 nm or less. (Fuji Film Co., Ltd.) was used in combination and irradiated at a distance of 50 cm to obtain a B-staged photocurable material.

Next, as a result of performing light irradiation on the above-mentioned B-staged photocurable material under the same conditions as in Example 1, it was completely cured to the back surface in 8 minutes.
About the obtained hardened | cured material, when the Barcol hardness (934-1 type | mold was used) was measured, the value of 35 or more was shown on both sides of the hardened | cured material.
In addition, the obtained cured product was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 83%.

(Example 6)
After sanding the inner surface of the concrete manhole, a visible light curing primer (Lipoxy LC-720PT, Showa Denko KK) was applied to the treated surface, and a 2 kW metal halide lamp (Iwasaki Electric Co., Ltd., Eye Mercury Lamp 2000W) was applied. The primer was cured by performing 360-light irradiation at an illuminance of 20 mW / cm ² for 10 minutes.
Next, after applying a visible light curable primer (Lipoxy LC3300P, Showa Denko KK) to the surface of the cured primer, the photocurable material produced in Example 4 was further attached.
Next, when a 2 kW mercury lamp (Iwasaki Electric Co., Ltd., eye mercury lamp 2000 W) was used and 360 · light irradiation was performed at an illuminance of 20 mW / cm ² , the photocurable material was completely cured in a short time of 10 minutes. I was able to.
When the Barcole hardness (using 934-1 type) was measured for the obtained coating layer of the photocurable material, both the front and back of the cured product showed a value of 35 or more.
In addition, the obtained coating layer was subjected to a creep test, and the elastic modulus retention after 50 years was calculated to be 81%.

  As can be seen from the above results, according to the present invention, there is provided a curable material for repairing the inner surface of a tubular molded body and a repair method capable of forming a coating layer having excellent durability over a long period of 50 years. be able to.

Claims (9)

Unsaturated polyester and / or vinyl ester, and a molecular weight of 150 or less of the polymerizable monomer, a curing agent and a hindered phenol-based pipe-shaped ing by impregnating the fiber material a curable resin composition comprising an antioxidant A curable material for repairing an inner surface of a molded body, wherein the curable resin composition is B-staged .   The curable resin composition contains 0.005 to 5 parts by mass of the hindered phenol antioxidant with respect to 100 parts by mass in total of the unsaturated polyester and / or vinyl ester and the polymerizable monomer. The curable material for repairing the inner surface of the tubular molded body according to claim 1.   The curable material for repairing the inner surface of a tubular molded body according to claim 1 or 2, wherein the unsaturated polyester and / or vinyl ester has a symmetrical structure.   The unsaturated polyester and / or vinyl ester contains at least one residue selected from the group consisting of a terephthalic acid residue, a bisphenol A residue and a bisphenol F residue with respect to all residues having a benzene ring. The curable material for repairing the inner surface of the tubular molded body according to any one of claims 1 to 3, wherein the total content is 50 mol% or more.   The fiber material is roving, cloth, mat or nonwoven fabric formed from one or more kinds of fibers selected from the group consisting of glass fibers, polyester fibers, vinylon fibers, carbon fibers, aramid fibers and metal fibers. The curable material for repair of the inner surface of the tubular molded body according to any one of claims 1 to 4.   The curable material for repairing the inner surface of a tubular molded body according to any one of claims 1 to 5, wherein the fiber material is in the form of a sheet, a roll, a tube, or a cylinder. The curable material for repairing the inner surface of the tubular molded body according to any one of claims 1 to 6 is inserted into the tubular molded body and adhered to the inner surface of the tubular molded body, and then cured. A method for repairing the inner surface of a tubular molded body. The method for repairing the inner surface of a tubular molded body according to claim 7 , wherein the tubular molded body is a manhole. The method for repairing the inner surface of a tubular molded body according to claim 7 or 8 , wherein a metal halide lamp is used as a light source for photocuring.