Two-part curing type composition for coating inner wall of city water pipe, cured product thereof, and city water pipe with coated inner wall

Abstract

To provide a two-part curing type composition for coating the inner wall of a city water pipe, which exhibits excellent curing properties inside the city water pipe and forms a coating layer having excellent mechanical properties after being cured.SOLUTION: The present disclosure provides a two-part curing type composition for coating the inner wall of a city water pipe, which comprises a main agent (A) and a curing agent (B) and cures by contact between the agent (A) and the agent (B) to thereby coat the inner wall of the city water pipe. In the two-part curing type composition, the main agent (A) includes a urethane prepolymer having an isocyanate group, the prepolymer is produced from an isocyanate compound and a first polyhydric alcohol compound as reaction raw materials, and has a viscosity of 10 mPa s or more and 500,000 mPa s or less at 25°C, and the curing agent (B) contains an amine compound and a second polyhydric alcohol compound, and has a viscosity of 100 mPa s or more and 50,000 mPa s or less at 25°C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a two-component curing composition for coating the inner walls of water pipes, a cured product thereof, and a water pipe with an inner wall coating. [Background technology]

[0002] When water pipes such as distribution pipes and drainage pipes deteriorate over time after installation, deposits such as rust, limescale, and dust form inside the water pipes, which causes a change in the friction coefficient with respect to the fluid flowing through the water pipes, a decrease in the cross-sectional area of ​​the water pipes, etc. This not only causes a loss of pressure or a decrease in the flow rate of the fluid flowing through the water pipes, but also causes red water, etc., which may result in a complete loss of the function of the water pipes. This creates a need to repair deteriorated areas in the water pipes themselves or in their joints, etc. However, repair work on water pipes that run through the common areas of apartment complexes or on water pipes in factories requires a great deal of labor, expense, time, etc. to stop and restore water and sewerage supplies, so there is a need for a simple method of repairing water pipes or a technology to suppress deterioration of water pipes over time.

[0003] Furthermore, water pipes buried underground require a great deal of labor and expense, as they require work such as discovering deteriorated sections, repairing the pipes by excavating them, or replacing them with new pipes, and backfilling the excavated areas. Furthermore, replacing pipes with new ones is extremely difficult on major roads, etc., as it would cause problems such as long-term traffic disruptions and construction noise.

[0004] For this reason, as a method for repairing existing pipes by effectively utilizing deteriorated existing pipes, for example, Patent Document 1 proposes a technique in which a steel pipe with a smaller diameter than the hollow pipe is inserted into the hollow pipe, and then an inorganic-based compound emulsion is filled and solidified in the gap between the hollow pipe and the steel pipe. Also, Patent Document 2 proposes a lining construction technique in which the inner surface of a water pipe is coated with a lining composition. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-221292 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-119199 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology of Patent Document 1 makes it difficult to insert a steel pipe into a bent water pipe, which makes it difficult to coat the entire inner wall of the water pipe with an inorganic-based compound emulsion according to the shape of the existing water pipe itself. Furthermore, the technology of Patent Document 2 makes it difficult to coat the entire inner wall of the water pipe with a lining layer formed by crosslinking the lining composition, which results in problems such as the lining layer peeling off and the peeled lining layer itself becoming new deposits inside the water pipe.

[0007] Therefore, an object of the present disclosure is to provide a two-component curing composition for coating the inner walls of water pipes, which exhibits excellent curing properties inside the water pipes and, after curing, forms a water pipe with a coating layer that has excellent mechanical properties. Another aspect of the present disclosure is to provide a cured product of a two-component curing composition for coating the inner wall of a water pipe, which shows excellent conformability to any shape of the water pipe and forms a water pipe having a coating layer with excellent mechanical properties, and a water pipe with an inner wall coating. [Means for solving the problem]

[0008] The present inventors have conducted extensive research in light of the above problems and have confirmed that when a two-component curing composition containing a base agent (A) having a predetermined composition and a curing agent (B) having a predetermined composition is supplied into a water pipe, the composition exhibits excellent curing properties inside the water pipe and, after curing, forms a water pipe having a coating layer with excellent mechanical properties. Furthermore, it has been confirmed that the coating layer, which is a cured product of the two-component curing composition, can be formed even inside a bent water pipe. Therefore, based on the above findings, the present invention has been completed. That is, the present disclosure is as follows.

[0009] [1] A two-component curing composition for coating the inner wall of a water pipe, which cures upon contact of a base agent (A) with a curing agent (B) to coat the inner wall of a water pipe, the main component (A) contains a urethane prepolymer having an isocyanate group, the prepolymer being produced from an isocyanate compound and a first polyhydric alcohol compound as reaction raw materials, and has a viscosity at 25°C of 10 mPa s or more and 500,000 mPa s or less; the curing agent (B) contains an amine compound and a second polyhydric alcohol compound, and has a viscosity at 25°C of 100 mPa·s or more and 50,000 mPa·s or less; A two-component curing composition for coating the inner walls of water pipes.

[0010] [2] The two-component curing composition for coating the inner wall of a water pipe according to [1] above, wherein the amine compound contains a first amine compound having a molecular weight of 1,000 or more and a second amine compound having a molecular weight of less than 1,000.

[0011] [3] The two-component curing composition for coating the inner wall of a water pipe according to [1] or [2] above, wherein the isocyanate compound is an aromatic isocyanate compound having an aromatic ring.

[0012] [4] The two-component curing composition for coating the inner wall of a water pipe according to any one of [1] to [3] above, wherein the main agent (A) and the curing agent (B) come into contact with each other and cure, thereby forming a coating layer that covers the inner wall of the water pipe, thereby coating the inner wall of the water pipe.

[0013] [5] The two-component curing composition for coating the inner walls of water pipes according to any one of [1] to [4] above, wherein the weight-average molecular weight (Mw) of the first polyhydric alcohol compound is 100 to 20,000.

[0014] [6] The two-component curing composition for coating the inner walls of water pipes according to any one of [1] to [5] above, wherein the weight-average molecular weight (Mw) of the second polyhydric alcohol compound is 100 to 2,000.

[0015] [7] The two-component curing composition for coating the inner walls of water pipes according to any one of [1] to [6] above, wherein the isocyanate compound contains two or more aromatic isocyanate compounds having an aromatic ring.

[0016] [8] The two-component curing composition for coating the inner wall of a water pipe according to any one of the above [1] to [7], wherein the amine compound has an amine value of 20 mgKOH / g to 800 mgKOH / g.

[0017] [9] The two-component curing composition for coating the inner wall of a water pipe according to any one of the above [1] to [8], wherein the water pipe is a drainage pipe.

[0018]

[10] A cured product obtained by curing the two-component curing composition for coating the inner wall of a water pipe according to any one of [1] to [9] above.

[0019]

[11] An inner wall coated water pipe comprising a water pipe body and the cured product according to

[10] above coated on the inner wall of the water pipe body. [Effects of the Invention]

[0020] According to the present disclosure, a coating layer is formed that exhibits excellent hardening properties inside a water pipe and exhibits excellent mechanical properties after hardening. According to the present disclosure, it is possible to provide a cured product of a two-component curing composition for coating the inner wall of a water pipe, which exhibits excellent conformability to any shape of the water pipe and has excellent mechanical properties after curing, and a water pipe with an inner wall coating. DETAILED DESCRIPTION OF THE INVENTION

[0021] The following describes in detail an embodiment of the present disclosure (hereinafter referred to as the "present embodiment"); however, the scope of the present disclosure is not limited to the following description, and various modifications can be made within the scope of its gist.

[0022] In this specification, the term "water pipe" refers collectively to pipes through which fluids, including water, flow. This term includes distribution pipes, which deliver clean water from a reservoir or the like to homes; supply pipes, which branch off from homes and reach faucets; conveyance pipes, which transport water pumped from dams, rivers, lakes, or wells to water purification plants; water transmission pipes, which transport water to purified water reservoirs or distribution reservoirs; drainage pipes, which transport used water (sewage) to sewage treatment plants; and pipes that transport water to factories or other places where people are active. Among these, the use of two-component curing compositions for coating the inner walls of drainage pipes is particularly preferred.

[0023] This embodiment is a two-component curing composition for coating the inner wall of a water pipe, which cures upon contact between a main agent (A) and a curing agent (B) to coat the inner wall of a water pipe. The main component (A) contains a urethane prepolymer having an isocyanate group, the reaction raw materials of which are an isocyanate compound and a first polyhydric alcohol compound, and has a viscosity at 25°C of 10 mPa·s or more and 500,000 mPa·s or less. The curing agent (B) contains an amine compound and a second polyhydric alcohol compound, and has a viscosity at 25°C of 100 mPa·s or more and 50,000 mPa·s or less. This results in the formation of a cured product that exhibits excellent curing properties inside the water pipe and functions as a coating layer with excellent mechanical properties after curing. Furthermore, since the main component (A) and the curing agent (B) contain the first polyhydric alcohol compound and the second polyhydric alcohol compound, which act as solvents, a cured product of any shape can be formed, and therefore the cured product exhibits excellent conformability to any shape of the water pipe.

[0024] The main component (A) contains a urethane prepolymer having an isocyanate group, the reaction raw materials of which are an isocyanate compound and a first polyhydric alcohol compound, and the content of the urethane prepolymer is preferably 20% by mass to 100% by mass, and the content of the first polyhydric alcohol compound is preferably 0% by mass to 80% by mass, relative to the total amount of the main component (A) (100% by mass). The reaction raw materials may contain, in addition to the urethane prepolymer, one or more compounds selected from the group consisting of an isocyanate compound and a first polyhydric alcohol compound. In addition, in the reaction between the isocyanate compound and the first polyhydric alcohol compound, unreacted isocyanate compound and first polyhydric alcohol compound may be present in the main component (A). In this specification, the term "reaction raw material" refers to a compound that is used to obtain a target compound through a chemical reaction such as synthesis or decomposition and that partially constitutes the chemical structure of the target compound, and does not include substances that act as auxiliary agents in the chemical reaction, such as solvents, catalysts, or additives. Therefore, in this specification, the term "reaction raw material" refers to a precursor for obtaining the target urethane prepolymer through a chemical reaction.

[0025] The curing agent (B) contains an amine compound and a second polyhydric alcohol compound, and the content of the amine compound is preferably 10% by mass to 80% by mass, and the content of the second polyhydric alcohol compound is preferably 90% by mass to 20% by mass, relative to the entire curing agent (B) (100% by mass).

[0026] The main agent (A) and the curing agent (B) will be described below. "Main ingredient (A)" The main component (A) of this embodiment contains an isocyanate group-containing urethane prepolymer produced from an isocyanate compound and a first polyhydric alcohol compound as reaction raw materials. The content of the urethane prepolymer having an isocyanate group contained in the main component (A) is preferably 20% to 100% by mass, more preferably more than 20% to less than 100% by mass, even more preferably 20% to 80% by mass, still more preferably 20% to 60% by mass, even more preferably 20% to 50% by mass, still more preferably 20% to 40% by mass, and particularly preferably 20% to 30% by mass, based on the total amount of the main component (A). In another embodiment, the content of the urethane prepolymer is 80% to 100% by mass, 91% to 100% by mass, 95% to 100% by mass, or 98% to less than 100% by mass, based on the total amount of the main component (A).

[0027] The viscosity of the main agent (A) of this embodiment at 25°C is preferably 30 mPa·s or more and 50,000 mPa·s or less. The viscosity of the main agent (A) at 25°C is more preferably 50 mPa·s or more and 5,000 mPa·s or less, and even more preferably 100 mPa·s or more and 2,000 mPa·s or less. When the viscosity of the main agent (A) at 25°C is within the above range, it exhibits excellent conformability to the shape of the water pipe. In another aspect of this embodiment, the viscosity of the main agent (A) at 25°C is preferably 10 mPa·s or more and 1,000 mPa·s or less, more preferably 20 mPa·s or more and 800 mPa·s or less, even more preferably 50 mPa·s or more and 700 mPa·s or less, still more preferably 100 mPa·s or more and 600 mPa·s or less, and particularly preferably 200 mPa·s or more and 500 mPa·s or less. The viscosity at 25° C. in this specification is calculated by measuring the viscosity of a sample at 25° C. using a Brookfield viscometer. Specifically, as described in the Examples section below, the viscosity in this specification is measured in accordance with JIS K 7117-1:1999, using a Brookfield viscometer at a measurement temperature of 25° C., by setting the base agent (A) and the curing agent (B) respectively, and measuring the viscosity after 2 minutes.

[0028] When forming the urethane prepolymer having an isocyanate group of the present embodiment, the amount of the isocyanate compound relative to the total reaction raw materials is preferably 30% by mass to 90% by mass, more preferably 50% by mass to 90% by mass, even more preferably 60% by mass to 90% by mass, and even more preferably 70% by mass to 90% by mass. Furthermore, the amount of the first polyhydric alcohol compound relative to the total amount of the reaction raw materials is preferably 5% by mass to 70% by mass, more preferably 10% by mass to 60% by mass, even more preferably 10% by mass to 50% by mass, and even more preferably 10% by mass to 40% by mass. When the main component (A) and the curing agent (B) come into contact with each other and harden to coat the inner wall of the water pipe, the main component (A) usually contains a urethane prepolymer formed by the reaction of the isocyanate compound with the first polyhydric alcohol compound, and residues of the isocyanate compound that remain unreacted with the first polyhydric alcohol compound.

[0029] (Preferred form of main component (A)) A particularly preferred main component (A) in this embodiment contains a urethane prepolymer having an isocyanate group, the reaction raw materials of which are an isocyanate compound and a first polyhydric alcohol compound, and has a viscosity at 25°C of 100 mPa·s or more and 1,000 mPa·s or less.

[0030] (urethane prepolymer) The urethane prepolymer of this embodiment is a compound made from an isocyanate compound and a first polyhydric alcohol compound as reaction raw materials. The molecular weight of the urethane prepolymer is preferably in the range of 1,000 to 10,000, more preferably in the range of 1,500 to 9,000, even more preferably in the range of 2,000 to 8,500, and particularly preferably in the range of 2,500 to 8,000. In this specification, the molecular weight was measured by calculating the weight average molecular weight (Mw) in terms of polystyrene using GPC as described in the Examples below.

[0031] The main component (A) according to this embodiment contains a urethane prepolymer (for example, an isocyanate-terminated prepolymer that is a reaction product of an isocyanate compound and a first polyhydric alcohol compound). The main component (A) preferably contains a urethane prepolymer and, if necessary, one or more components selected from the group consisting of an isocyanate compound and a first polyhydric alcohol compound. Furthermore, the main component (A) may contain any additives described below if necessary. When the main component (A) contains a urethane prepolymer and an isocyanate compound, the content of the isocyanate compound is preferably from 0% to 100% by mass, more preferably from 20% to 100% by mass, even more preferably from 40% to 100% by mass, still more preferably from 50% to less than 100% by mass, even more preferably from 60% to 90% by mass, still more preferably from 70% to 90% by mass, and particularly preferably from 75% to 90% by mass. Furthermore, when the main component (A) contains a urethane prepolymer and an isocyanate compound, in another embodiment, the content of the isocyanate compound is preferably 0% by mass or more and 20% by mass or less, more preferably more than 0% by mass and 11% by mass or less, and even more preferably more than 0% by mass and 4% by mass or less, based on the total amount of the main component (A). When the main component (A) contains a first polyhydric alcohol compound, the content of the first polyhydric alcohol compound is preferably 0% by mass or more and 10% by mass or less, more preferably 0% by mass or more and less than 7% by mass, even more preferably 0% by mass or more and less than 5% by mass, still more preferably 0% by mass or more and 3% by mass or less, and even more preferably 0% by mass or more and 2% by mass or less, based on the total amount of the main component (A).

[0032] In the main component (A) according to the embodiment, the total content of the urethane prepolymer, the isocyanate compound, and the first polyhydric alcohol compound is preferably 90% by mass to 100% by mass, more preferably 92% by mass to 100% by mass, even more preferably 93% by mass to 100% by mass, even more preferably 94% by mass to 100% by mass, even more preferably 95% by mass to 100% by mass, even more preferably 96% by mass to 100% by mass, and particularly preferably 98% by mass to less than 100% by mass, based on the total content of the main component (A). In the main component (A) according to the embodiment, the total content of the urethane prepolymer, the isocyanate compound, the first polyhydric alcohol compound, and the optional additives described below is preferably 90.5% by mass to 100% by mass, more preferably 91% by mass to 100% by mass, even more preferably 93% by mass to 100% by mass, still more preferably 94% by mass to 100% by mass, even more preferably 95% by mass to 100% by mass, still more preferably 96% by mass to 100% by mass, and particularly preferably 98% by mass to less than 100% by mass, based on the total content of the main component (A).

[0033] The main component (A) of this embodiment may contain a urethane prepolymer, and the urethane prepolymer is preferably liquid at room temperature (25°C).

[0034] The isocyanate compound constituting the urethane prepolymer of this embodiment is preferably a compound containing two or more isocyanate groups in the molecule. The isocyanate compound may be a compound partially trimerized using a trimerization catalyst, a compound partially allophanated using an allophanation catalyst, or a compound prepolymerized using a known polyol or the like as a modifier. The isocyanate compound and the first polyhydric alcohol compound, which are reaction raw materials for the urethane prepolymer, will be described below.

[0035] <Isocyanate compounds> The isocyanate compound of the present embodiment is not particularly limited as long as it is a compound having one or more isocyanate groups, but is preferably an aromatic isocyanate compound having an aromatic ring, and more preferably an aromatic isocyanate compound having an aromatic ring and two or more isocyanate groups.

[0036] The isocyanate compound of the present embodiment preferably contains one or more compounds represented by the following general formula (1). [ka] (In the above general formula (1), M represents an n-valent organic group having 4 or more carbon atoms, each L independently represents a single bond or an alkylene group having 1 to 3 carbon atoms, and n is an integer of 2 or more.)

[0037] In the general formula (1), M is an organic group having 4 to 30 carbon atoms, preferably an organic group having 5 to 24 carbon atoms, and more preferably an organic group having 6 to 18 carbon atoms. When M has 4 to 30 carbon atoms, it is preferable from the viewpoint of curability. In the general formula (1), each L is independent, and the n Ls may be the same or different. Examples of the alkylene group having 1 to 3 carbon atoms include a methylene group, an ethylene group, an n-propylene group, and a propan-2-ylidene group. In the above general formula (1), n ​​is preferably an integer of 2 or more and 5 or less, more preferably an integer of 2 or more and 4 or less, and even more preferably an integer of 2 or more and 3 or less. When the value of n is an integer of 2 or more and 5 or less, multiple isocyanate groups can bond not only to the amine compound in the curing agent (B) but also to the first polyhydric alcohol compound and / or the second polyhydric alcohol compound, resulting in excellent curability.

[0038] Furthermore, the term "organic group" as used herein refers to a group whose chemical structure is constituted by an organic compound containing one or more carbon atoms being in the form of an n-valent group, and refers to an atomic group formed by removing n hydrogen atoms from an organic compound containing one or more carbon atoms (where n is a natural number, for example, between 2 and 3). Therefore, for example, a divalent organic group refers to an atomic group formed by removing two hydrogen atoms from an organic compound containing one or more carbon atoms.

[0039] A preferred organic group in this embodiment is specifically a group having a hydrocarbon group, and preferably a linear or branched saturated hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group having an aromatic ring, or a cyclic hydrocarbon group in which two or more aromatic rings are linked by a linking group (for example, an alkylene group).

[0040] The linear or branched saturated hydrocarbon group is preferably an alkylene group having 4 to 10 carbon atoms. Examples of the alkylene group include a 1,1-dimethylethylene group, a 1,2-dimethylethylene group, a 1,4-butanediyl group, a butane-2,3-diyl group, a 1-methylpropylene group, a 2-methylpropylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a trimethylhexamethylene group, and a decamethylene group.

[0041] Preferred examples of the alicyclic hydrocarbon group include divalent monocyclic alicyclic hydrocarbon groups such as cyclohexanediyl, cyclooctanediyl, cyclononanediyl, bicyclohexanediyl, bicyclooctanediyl, bicyclononanediyl, methylenebis(cyclohexane-1,4-diyl), methylenebis(cyclohexane-1,2-diyl), and methylenebis(cyclohexane-1,3-diyl), as well as divalent polycyclic alicyclic hydrocarbon groups such as adamantanediyl, norbornane, or isobornane. In the alicyclic hydrocarbon group, one or more hydrogen atoms in the cyclic group may be substituted with a substituent. Examples of the substituent include alkyl groups having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms), such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; aromatic hydrocarbon groups having 6 to 10 carbon atoms, such as phenyl and naphthyl groups; and halogen atoms, such as fluorine, chlorine, bromine, and iodine atoms.

[0042] The aromatic hydrocarbon group having an aromatic ring may be any hydrocarbon group having one or more aromatic rings. Here, the term "aromatic ring" as used herein includes a monocyclic aromatic ring, a condensed aromatic ring, and an aromatic ring assembly. Examples of the monocyclic aromatic ring include benzene, furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, triazine, etc. Examples of the fused aromatic ring include naphthalene, anthracene, phenalene, phenanthrene, quinoline, isoquinoline, quinazoline, phthalazine, pteridine, coumarin, indole, benzimidazole, benzofuran, acridine, etc. Examples of the ring assembly aromatic ring include biphenyl, binaphthalene, bipyridine, bithiophene, phenylpyridine, phenylthiophene, terphenyl, diphenylthiophene, quaterphenyl, etc.

[0043] In the aromatic hydrocarbon group having an aromatic ring, one or more hydrogen atoms in the aromatic ring may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms), an alkenyl group having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms), an alkoxy group having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms), and a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0044] The "alkyl group" in this specification may be linear, branched, or cyclic, and examples thereof include a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, neopentyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, (n-)heptyl group, (n-)octyl group, (n-)nonyl group, (n-)decyl group, (n-)undecyl group, (n-)dodecyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclononyl group. The "alkyl group" includes a "cycloalkyl group", and examples of the "cycloalkyl group" include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, and an adamantyl group. Unless otherwise specified, the "alkyl group" in this specification refers to the "alkyl group" having a specified number of carbon atoms from the above examples.

[0045] Examples of the "alkenyl group" in this specification include an ethynyl group, a 1-propynyl group (hereinafter also simply referred to as a propenyl group), a 2-propynyl group, a 2-butynyl group, a pentynyl group, a hexynyl group, a vinyl group, an allyl group, and an isopropenyl group. Unless otherwise specified in this specification, the "alkenyl group" refers to the "alkoxy group" having a specified number of carbon atoms from the above examples.

[0046] Examples of the "alkoxy group" in this specification include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a 2-ethylhexyloxy group, an octyloxy group, and a nonyloxy group. Unless otherwise specified, the "alkoxy group" in this specification refers to the "alkoxy group" having a specified number of carbon atoms from the above examples.

[0047] Examples of the aromatic hydrocarbon group having an aromatic ring include groups represented by the following formulas (i-1) to (i-5). [ka] (In the above formulas (i-1) to (i-5), R 1 , R 2 and R 5 each independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; L 1 represents a single bond or an alkylene group having 1 to 3 carbon atoms, n1 and n2 each independently represent an integer of 0 to 4, and n5 represents an integer of 0 to 6. Note that * represents a bond bonded to L in the above general formula (1). The cyclic hydrocarbon group in which two or more aromatic rings are linked by a linking group (for example, an alkylene group) is preferably represented by the following formula (i-6). [ka] (In the above formula (i-6), R 3 and R 4 each independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; L 3 and L 4 represents a linking group, for example, a single bond or an alkylene group having 1 to 3 carbon atoms; each n3 independently represents an integer of 0 to 4; each n4 independently represents an integer of 0 to 3; m1 represents the degree of polymerization, for example, an integer of 0 to 3. Note that * represents a bond bonded to L in the above general formula (1).

[0048] The isocyanate compound of the present embodiment preferably contains one or more compounds represented by the general formula (1), and more preferably contains two to ten compounds represented by the general formula (1), which makes it easier to design the curability with the curing agent (B) and the viscosity within a predetermined range.

[0049] The isocyanate compound of the present embodiment may be, other than the compound represented by the general formula (1), for example, a carbodiimide-modified MDI obtained by modifying the compound represented by the general formula (1) with a carbodiimide (for example, the carbodiimide-modified MDI described in Japanese Patent No. 5041794).

[0050] The isocyanate compound of the present embodiment preferably contains an aromatic isocyanate compound having an aromatic ring. From the viewpoints of curability and mechanical properties (e.g., elongation or impact resistance), an aromatic isocyanate compound having an aromatic ring is used as the isocyanate compound.

[0051] The isocyanate compound of the present embodiment is preferably an aromatic isocyanate compound represented by the following general formula (2). [ka] (In the above general formula (2), R 1 , R 2 and R 3 each independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; L 1 and L 2 each independently represents a single bond or an alkylene group having 1 to 3 carbon atoms, n1 and n2 each independently represents an integer of 0 to 4, n3 each independently represents an integer of 0 to 3, and m2 represents the degree of polymerization and is an integer of 0 to 3 or more. In the above general formula (2), m2 is preferably in the range of 0 to 4, more preferably in the range of 0 to 3, and even more preferably in the range of 0 to 2.

[0052] The isocyanate compound of the present embodiment preferably contains two or more aromatic isocyanate compounds having an aromatic ring, which can further improve the curability and mechanical properties.

[0053] In particular, the isocyanate compound of the present embodiment is preferably an isocyanate composition containing, as main components, an aromatic isocyanate (a1) represented by the following general formula (2-1) and an aromatic isocyanate (a2) represented by the following general formula (3): In this specification, the phrase "containing as a main component" means that a predetermined component accounts for 50% by mass to 100% by mass (preferably 90% by mass to 100% by mass) of the total. Therefore, for example, "containing as main components an aromatic isocyanate (a1) represented by the following general formula (2-1) and an aromatic isocyanate (a2) represented by the following general formula (3)" means that the total content of the aromatic isocyanate (a1) represented by the following general formula (2-1) and the aromatic isocyanate (a2) represented by the following general formula (3) accounts for 50% by mass to 100% by mass (preferably 90% by mass to 100% by mass) of the total isocyanate compound. [ka] (In the above general formula (2-1), R 1 , R 2 and R 3 each independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; L 1 and L 2 each independently represents a single bond or an alkylene group having 1 to 3 carbon atoms, n1 and n2 each independently represents an integer of 0 to 4, n3 each independently represents an integer of 0 to 3, and p represents the degree of polymerization and is an integer of 0 to 3. [ka] (In the above general formula (3), R 1 and R 2each independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; L 1 represents a single bond or an alkylene group having 1 to 3 carbon atoms, and n1 and n2 each independently represent an integer of 0 to 4. In the aromatic isocyanate compound represented by the general formula (3), the positional relationship between the two benzene rings is such that the isocyanate group bonded to one benzene ring is at the ortho-position, meta-position, or para-position of the other benzene ring. 1 can be coupled via

[0054] The content of the aromatic isocyanate (a1) represented by the general formula (2-1) can be preferably 40% by mass to 90% by mass, more preferably 45% by mass to 90% by mass, even more preferably 50% by mass to 90% by mass, and still more preferably 55% by mass to 90% by mass, based on the total amount of the reaction raw materials. The content of the aromatic isocyanate (a2) represented by general formula (3) is preferably 5% by mass to 40% by mass, more preferably 5% by mass to 35% by mass, even more preferably 5% by mass to 30% by mass, and still more preferably 5% by mass to 25% by mass, based on the total amount of the reaction raw materials.

[0055] The weight average molecular weight of the aromatic isocyanate (a1) represented by the general formula (2-1) is preferably in the range of 100 to 1,000, more preferably in the range of 200 to 800, and even more preferably in the range of 400 to 600. On the other hand, the molecular weight of the aromatic isocyanate (a2) represented by the above general formula (3) is preferably in the range of 150 to 500, more preferably in the range of 180 to 400, and even more preferably in the range of 200 to 300. When the isocyanate compound of the present embodiment is an isocyanate composition containing, as main components, an aromatic isocyanate (a1) represented by the above general formula (2-1) and an aromatic isocyanate (a2) represented by the above general formula (3), the weight average molecular weight of the entire isocyanate composition is preferably in the range of 150 to 800, more preferably in the range of 200 to 750, and even more preferably in the range of 300 to 500.

[0056] When the isocyanate compound of the present embodiment is an isocyanate composition containing, as main components, an aromatic isocyanate (a1) represented by the above general formula (2-1) and an aromatic isocyanate (a2) represented by the above general formula (3), the mixing ratio of the aromatic isocyanate (a1) to the aromatic isocyanate (a2) ((a1) / (a2)) is preferably in the range of 80 / 10 to 10 / 80, more preferably in the range of 75 / 15 to 15 / 77, and even more preferably in the range of 72 / 15 to 43 / 37. It is preferable from the viewpoints of curability and handling that the mixing ratio of the aromatic isocyanate (a1) to the aromatic isocyanate (a2) is within the above range.

[0057] The aromatic isocyanate compound (a2) of the present embodiment preferably contains, as a main component, one or more compounds selected from the group consisting of compounds represented by the following general formula (3-1) and the following general formula (3-2): [ka] [ka] (In the above general formulas (3-1) and (3-2), R 1 and R 2 each independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; L 1 represents a single bond or an alkylene group having 1 to 3 carbon atoms, and n1 and n2 each independently represent an integer of 0 to 4.

[0058] The isocyanate compound or isocyanate composition of this embodiment preferably contains a compound represented by the general formula (3-1) and a compound represented by the general formula (3-2). In this case, the mixing ratio ((3-1) / (3-2)) of the compound represented by the general formula (3-1) to the compound represented by the general formula (3-2) is preferably in the range of 90 / 10 to 10 / 90, more preferably in the range of 78 / 22 to 22 / 78, and even more preferably in the range of 70 / 30 to 30 / 70.

[0059] The aromatic isocyanate compound is particularly preferably one or more compounds selected from the group consisting of compounds represented by the following general formula (3-1.1) and compounds represented by the following general formula (3-2.1). [ka] [ka] (In the above general formulas (3-1.1) and (3-2.1), R 1 and R 2 each independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms, and n1 and n2 each independently represent an integer of 0 to 4.

[0060] <First polyhydric alcohol compound> The first polyhydric alcohol compound of this embodiment is not particularly limited as long as it contains two or more hydroxyl groups, but considering the reaction with the isocyanate compound coexisting in the main component (A), a compound with a weight-average molecular weight (Mw) of 1,000 to 10,000 is preferred. Furthermore, from the viewpoint of compatibility between the main component (A) and the curing agent (B), compounds that can be used as the second polyhydric alcohol compound described below can be used as the first polyhydric alcohol compound. The average number of functional groups (average number of hydroxyl groups) of the first polyhydric alcohol compound of this embodiment may be 2 or more and 10 or less, preferably 2 or more and 6 or less, more preferably 2 or more and 4 or less, even more preferably 2 or more and 3 or less, and particularly preferably 2 or more and 2.5 or less, per molecule. The hydroxyl value of the first polyhydric alcohol compound of this embodiment is, for example, preferably 20 mgKOH / g or more and 800 mgKOH / g or less, more preferably 20 mgKOH / g or more and 500 mgKOH / g or less, and even more preferably 20 mgKOH / g or more and 100 mgKOH / g or less. The hydroxyl value in this specification was measured by the method described in the Examples below. The weight average molecular weight of the first polyhydric alcohol compound suitable for this embodiment is preferably 500 to 10,000, more preferably 800 to 7,000, and even more preferably 1,000 to 5,000.

[0061] A suitable first polyhydric alcohol compound in this embodiment is preferably one or more compounds selected from the group consisting of polypropylene glycol, polyethylene glycol, polyether polyols, polytetramethylene ether glycols, polycaprolactone polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, polyisoprene polyol, polyolefin polyols, hydrogenated polyisoprene polyol, low molecular weight polyols, polycarbonate polyol, castor oil, castor oil-modified polyol, pentaerythritol-based polyether polyol, polymer polyol, and flame-retardant polyols containing phosphorus or the like. Examples of the polyether polyols include polyether polyol compounds obtained by reacting one or more selected from the group consisting of bisphenol A, glycerin, trimethylolpropane, ethylenediamine, pentaerythritol, triethanolamine, monoethanolamine, methylglycoside, sorbitol, sorbitolamine, diethylenetriamine, sucrose, sucroseamine, toluenediamine, aminoethylpiperazine, aniline, and metaxylenediamine with an alkylene oxide (e.g., propylene oxide or ethylene oxide). The reaction is mainly achieved by addition polymerization. Examples of the polyolefin polyols include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,3-propanediol, and 1,9-nonanediol. Examples of the low molecular weight polyols include neopentyl glycol, methylpentanediol, diethylene glycol, and propylene glycol. The polytetramethylene ether glycols (PTMG) are obtained by ring-opening polymerization of tetrahydrofuran (THF). The first polyhydric alcohol compound of the present embodiment may be used alone or in combination of two or more.

[0062] (Preferred embodiment of reaction raw materials) The reaction raw materials for the urethane prepolymer constituting the main component (A) of this embodiment may consist essentially of an isocyanate compound, a first polyhydric alcohol compound, and any additives. In this specification, "consisting essentially of an isocyanate compound, a first polyhydric alcohol compound, and any additives" means that the total content of the isocyanate compound, the first polyhydric alcohol compound, and any additives accounts for 90% to 100% by mass, preferably 95% to 100% by mass, and more preferably 98% to 100% by mass of the reaction raw materials. In another embodiment, the reaction raw materials for the urethane prepolymer constituting the main component (A) of the present embodiment may consist essentially of only an isocyanate compound and a first polyhydric alcohol compound.

[0063] In the reaction raw materials of this embodiment, the equivalent ratio of the reaction raw materials that produce the urethane prepolymer (isocyanate compound / first polyhydric alcohol compound) is preferably 99 / 1 to 60 / 40, more preferably 99 / 1 to 70 / 30, even more preferably 99 / 1 to 80 / 20, still more preferably 99 / 1 to 90 / 10, and particularly preferably 99 / 1 to 95 / 5. The equivalent ratio here refers to the equivalent ratio of the functional groups of the isocyanate compound and the first polyhydric alcohol compound. By setting the equivalent ratio within this range, it is possible to prepare a main component (A) containing a urethane prepolymer with a predetermined viscosity.

[0064] "Hardening agent (B)" The curing agent (B) of the present embodiment contains an amine compound and a second polyhydric alcohol compound. The curing agent (B) may also contain any additives described below, if necessary. The content of the amine compound relative to the total amount of the curing agent (B) may be preferably 5% by mass to 90% by mass, more preferably 10% by mass to 80% by mass, even more preferably 12% by mass to 70% by mass, still more preferably 15% by mass to 60% by mass, and particularly preferably 20% by mass to 40% by mass. The content of the second polyhydric alcohol compound relative to the total amount of the curing agent (B) is preferably 10% by mass to 95% by mass, more preferably 30% by mass to 90% by mass, even more preferably 40% by mass to 85% by mass, and even more preferably 50% by mass to 80% by mass.

[0065] In the curing agent (B) according to the embodiment, the total content of the amine compound and the second polyhydric alcohol compound is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, even more preferably 70% by mass to 100% by mass, still more preferably 80% by mass to 100% by mass, even more preferably 85% by mass to 100% by mass, still more preferably 90% by mass to 100% by mass, and particularly preferably 95% by mass to 100% by mass, based on the total amount of the curing agent (B). In the curing agent (B) according to the embodiment, the total content of the amine compound, the second polyhydric alcohol compound, and any additives described below is preferably 60% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, still more preferably 85% by mass to 100% by mass, even more preferably 90% by mass to 100% by mass, still more preferably 95% by mass to 100% by mass, and particularly preferably 97% by mass to 100% by mass, based on the total amount of the curing agent (B).

[0066] The viscosity of the curing agent (B) of this embodiment at 25°C is preferably 100 mPa·s or more and 10,000 mPa·s or less. The viscosity of the curing agent (B) at 25°C is more preferably 100 mPa·s or more and 5,000 mPa·s or less, even more preferably 1,000 mPa·s or more and 3,000 mPa·s or less, still more preferably 500 mPa·s or more and 3,000 mPa·s or less, and particularly preferably 1,000 mPa·s or more and 3,000 mPa·s or less. When the viscosity of the curing agent (B) at 25°C is within the above range, it exhibits excellent conformability to the shape of the water pipe. In another aspect of this embodiment, the viscosity of the curing agent (B) at 25°C is preferably 100 mPa·s or more and 10,000 mPa·s or less, more preferably 100 mPa·s or more and 5,000 mPa·s or less, even more preferably 500 mPa·s or more and 3,000 mPa·s or less, and still more preferably 1,000 mPa·s or more and 3,000 mPa·s or less.

[0067] (amine compounds) The amine compound of this embodiment is preferably a compound having two or more amino groups (primary amine (-NH2) and / or secondary amine (-NH-)). The amine compound of this embodiment preferably contains one or more types selected from the group consisting of first amine compounds having a molecular weight of 1,000 or more and second amine compounds having a molecular weight of less than 1,000, and more preferably contains a first amine compound having a molecular weight of 2,000 or more and a second amine compound having a molecular weight of less than 800. In another aspect, the amine compound of this embodiment preferably contains one or more types selected from first amine compounds having a molecular weight of 1,000 or more and one or more types selected from second amine compounds having a molecular weight of less than 800, more preferably contains one or more types selected from first amine compounds having a molecular weight of 1,500 or more and one or more types selected from second amine compounds having a molecular weight of less than 800, and even more preferably contains one or more types selected from first amine compounds having a molecular weight of 2,000 or more and one or more types selected from second amine compounds having a molecular weight of less than 800. When the curing agent (B) contains the first amine compound, it has the effect of imparting flexibility to the coating film, while when the curing agent (B) contains the second amine compound, it has the effect of imparting low-temperature curing properties to the coating film. When the curing agent (B) contains both a first amine compound having a molecular weight of 1,000 or more, preferably a molecular weight of 1,500 or more, and a second amine compound having a molecular weight of less than 1,000, preferably a molecular weight of less than 800, a coating having high hardness and a predetermined crosslink density can be formed upon curing with the main component (A), and therefore the curing agent (B) has excellent curability and excellent mechanical properties.

[0068] In the amine compound of this embodiment, the content of the first amine compound having a molecular weight of 1,000 or more (preferably a molecular weight of 2,000 or more) is preferably 10% by mass to 100% by mass, more preferably 12% by mass to 80% by mass, even more preferably 15% by mass to 70% by mass, still more preferably 18% by mass to 60% by mass, even more preferably 20% by mass to 50% by mass, still more preferably 25% by mass to 45% by mass, and particularly preferably 30% by mass to 40% by mass, based on the total amount of the amine compound. In the amine compound of the present embodiment, the content of the second amine compound having a molecular weight of less than 1,000, preferably less than 800, relative to the total amount of the amine compound is preferably 20% by mass to 100% by mass, more preferably 25% by mass to 90% by mass, even more preferably 30% by mass to 85% by mass, still more preferably 35% by mass to 80% by mass, even more preferably 40% by mass to 75% by mass, still more preferably 50% by mass to 70% by mass, and particularly preferably 60% by mass to 70% by mass.

[0069] <First amine compound> The first amine compound of this embodiment may be any compound having a molecular weight of 1,000 or more and having either an -NH2 or -NH- amino group. When the curing agent (B) contains a first amine compound having a molecular weight of 1,000 or more, it has the effect of imparting flexibility to the coating film. The first amine compound having a molecular weight of 1,000 or more in this embodiment is an alkylene oxide group [—(CHR) nb -O-] mb and a compound having at least two amino groups (-NH2). nb -O-] mb In the formula, R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. nb -O-] mb In the formula, nb represents an integer of 1 or more and 5 or less, and mb represents an integer of preferably 3 or more and 1,000 or less, more preferably 3 or more and 300 or less.

[0070] The first amine compound is preferably, for example, a polyetheramine compound. When the curing agent (B) contains a polyetheramine compound as the first amine compound, the flexibility of the cured product after curing is improved, which is thought to result in improved conformability to the shape of the water pipe and improved mechanical properties. Examples of the polyetheramine compound include primary polyetherdiamine (functional groups: 2, molecular weight: 1500 to 2500), primary polyethertriamine (functional groups: 3, molecular weight: 1500 to 2500), poly(propylene glycol)triamine (CAS number: 64852-22-8), secondary polyetherdiamine, and secondary polyethertriamine. The primary polyether diamine is preferably a compound represented by the following formula (b1-1). [ka] (In the above formula (b1-1), each nb1 independently represents an integer of 0 to 80, preferably 28 to 78.) The primary polyether triamine is preferably a compound represented by the following formula (b1-2). [ka] (In the above formula (b1-2), nb2, nb3, and nb4 each independently represent an integer of 0 to 30.) In this embodiment, the molecular weight (weight average molecular weight) of the first amine compound having a molecular weight of 1,000 or more is preferably in the range of 1,000 to 8,000, more preferably in the range of 2,000 to 6,000, and even more preferably in the range of 2,000 to 5,000.

[0071] The first amine compound of this embodiment having a molecular weight of 1,000 or more preferably contains a primary amine and / or a secondary amine. More specifically, the first amine compound of this embodiment preferably contains one or more amine compounds selected from the group consisting of amine compounds (b1) containing a primary amine and amine compounds (b2) containing a secondary amine. Examples of the primary amine compound (b1) include primary polyether diamine (functional groups: 2, molecular weight: 1500 to 2500), primary polyether triamine (functional groups: 3, molecular weight: 1500 to 2500), poly(propylene glycol) triamine (CAS number: 64852-22-8), and polyoxypropylene diamine. Similarly, examples of the secondary amine compound (b2) include secondary polyetherdiamines and secondary polyethertriamines (see, for example, the secondary polyetheramines described in JP-A-2010-511639). In the first amine compound of the present embodiment, the mixing ratio of the primary amine compound (b1) to the secondary amine compound (b2) (primary amine compound (b1) / secondary amine compound (b2)) is preferably in the range of 90 / 10 to 100 / 0, more preferably in the range of 95 / 5 to 100 / 0. In addition to the primary amine compound (b1), the first amine compound of this embodiment may also contain a secondary amine compound (b2) and / or a known tertiary amine, as long as the purpose or effect of the present disclosure is not impaired. In this case, the proportion of the primary amine compound (b1) in the total first amine compounds is preferably 90% by mass or more, more preferably 94% by mass or more, and even more preferably 100% by mass. By setting the proportion of the primary amine compound (b1) in the total first amine compounds within the above range, the reactivity with the main component (A) can be improved. As a result, a composition with excellent mechanical properties and curability can be obtained.

[0072] <Second amine compound> The second amine compound having a molecular weight of less than 1,000 in this embodiment may be any compound having a molecular weight of less than 1,000 and having either an -NH or -NH- amino group. The inclusion of the second amine compound as the curing agent (B) has the effect of imparting low-temperature curing properties to the coating film. The second amine compound of this embodiment is preferably one or more compounds selected from the group consisting of amino acid ester compounds or amino acid ester derivative compounds, and cyclic amine compounds.

[0073] <Amino acid ester compound or amino acid ester derivative compound> The amino acid ester compound or amino acid ester derivative compound of this embodiment may be any compound having a chemical structure in which the hydrogen atom of one or more carboxyl groups (-COOH) in an amino acid molecule is substituted with an alkyl group having 1 to 8 carbon atoms. The term "amino acid" is a general term for compounds having an amino group (including -NH, -NH-, and ≡N) and a carboxyl group in the same molecule. Therefore, any amino acid that is a precursor to the amino acid ester compound or amino acid ester derivative compound of this embodiment can be any amino acid classified as α-amino acids, β-amino acids, γ-amino acids, or δ-amino acids based on the position of the carbon atom to which the amino group is bonded relative to the carbon atom to which the carboxyl group is bonded. Furthermore, α-amino acids have an asymmetric carbon and are classified as L- or D-isomers based on their configuration. However, any of these amino acids, or a racemic mixture of these, can also be used as the amino acid. When the curing agent (B) contains an amino acid ester compound or an amino acid ester derivative compound, low-temperature curing properties are improved. In view of the curing reaction with the main component (A), the amino acid of this embodiment is preferably an α-amino acid or a β-amino acid. Amino acids, which are precursors of the amino acid ester compound or amino acid ester derivative compound of this embodiment, are mainly derived from natural products and are classified into neutral amino acids (monoaminomonocarboxylic acids), acidic amino acids (monoaminodicarboxylic acids), and basic amino acids (diaminomonocarboxylic acids, etc.). Specific examples of the neutral amino acids include glycine, alanine, valine, leucine, isoleucine, serine, threonine, cysteine, cystine, methionine, phenylalanine, tyrosine, tryptophan, glutamine, and proline. Specific examples of the acidic amino acids include glutamic acid and aspartic acid. Specific examples of the basic amino acids include lysine, arginine, ornithine, and histidine.

[0074] Among these, a preferred embodiment of the amino acid ester compound or amino acid ester derivative compound of this embodiment is a compound in which the hydrogen atoms of one or more carboxyl groups of an amino acid are substituted with alkyl groups having 1 to 8 carbon atoms, and which has a partial structure of the following general formula (I): [ka] (In the above general formula (I), * represents a bond to a carbon atom.) This further improves low-temperature curing properties.

[0075] The amino acid ester compound or amino acid ester derivative compound of this embodiment is preferably a compound represented by the following general formula (I.1), for example. [ka] (In the above general formula (I.1), M I is n I represents a hydrocarbon group having 1 to 28 carbon atoms, I1 each independently represents an alkyl group having 1 to 30 carbon atoms, provided that one or more -CH2- in the alkyl group may be replaced by -O-, -C(=O)-, -OC(=O)- or -C(=O)-O-; RI2 represents an alkyl group having 1 to 6 carbon atoms, and n I represents an integer between 1 and 4.)

[0076] In the above general formula (I.1), M I is preferably a monovalent to tetravalent hydrocarbon group having 1 to 18 carbon atoms, and more preferably a monovalent to trivalent hydrocarbon group having 1 to 16 carbon atoms. Therefore, in the above general formula (I.1), n I is preferably an integer of 1 to 3. The hydrocarbon group, like the above-mentioned "organic group," is a group obtained by removing n hydrogen atoms from an organic compound containing one or more carbon atoms. I Therefore, the hydrocarbon group is preferably a linear or branched saturated hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group having an aromatic ring, or a cyclic hydrocarbon group in which two or more aromatic rings are linked by a linking group (for example, an alkylene group) and the number of bonds is n. I The linear or branched saturated hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group having an aromatic ring, and the cyclic hydrocarbon group in which two or more aromatic rings are linked by a linking group (for example, an alkylene group) are the same as those described above.

[0077] In the above general formula (I.1), R I1 R each independently represents an alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, and more preferably 1 to 8 carbon atoms, provided that one or more -CH2- groups in the alkyl group may be substituted with -O-, -C(=O)-, -OC(=O)-, or -C(=O)-O-. I1 For example, R I3 -O(O=)C-(CH2) m4 -(R I3 represents an alkyl group having 1 to 5 carbon atoms, and m4 represents an integer of 0 to 4.) is preferred.

[0078] The compound represented by the general formula (I.1) includes n IWhen is 2, that is, it is preferably an amino acid ester compound or an amino acid ester derivative compound represented by the following general formula (I.2). [ka] (In the above general formula (I.2), M I represents a divalent hydrocarbon group having 1 to 18 carbon atoms, and R I1 each independently represents an alkyl group having 1 to 15 carbon atoms, provided that one or more -CH2- in the alkyl group may be replaced by -O-, -C(=O)-, -OC(=O)- or -C(=O)-O-; R I2 represents an alkyl group having 1 to 6 carbon atoms, and n I represents an integer between 1 and 4.)

[0079] Examples of the hydrocarbon group in the general formula (I.2) include a 1,1-dimethylethylene group, a 1,2-dimethylethylene group, a 1,4-butanediyl group, a 2-methyl-1,5-pentanediyl group, a butane-2,3-diyl group, a 1-methylpropylene group, a 2-methylpropylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a trimethylhexamethylene group, a decamethylene group, a cyclohexanediyl group, Divalent monocyclic alicyclic hydrocarbon groups such as cyclooctanediyl, cyclononanediyl, bicyclohexanediyl, bicyclooctanediyl, bicyclononanediyl, methylenebis(cyclohexane-1,4-diyl), methylenebis(cyclohexane-1,2-diyl), and methylenebis(cyclohexane-1,3-diyl), as well as divalent polycyclic alicyclic hydrocarbon groups such as adamantanediyl, norbornane, and isobornane, are preferred. In the hydrocarbon groups, one or more hydrogen atoms may be substituted with a substituent. Examples of the substituent include alkyl groups having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms), such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; aromatic hydrocarbon groups having 6 to 10 carbon atoms, such as phenyl and naphthyl groups; and halogen atoms, such as fluorine, chlorine, bromine, and iodine atoms.

[0080] <Cyclic amine compounds> The cyclic amine compound of this embodiment is preferably a compound represented by the following general formula (II). [ka] (In the above general formula (II), R II1 and R II2 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; M 1 is unsubstituted or substituted R II3 represents a cyclic group which may be substituted with one or more of the substituents R II3 represents an alkyl group having 1 to 10 carbon atoms, a halogen atom, -SH, a hydroxyl group, and -SR II4 (The above R II4 represents one or more selected from the group consisting of: In the above general formula (II), R II1 and R II2 are preferably each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms.

[0081] In the above general formula (II), M 1 is unsubstituted or substituted R II3 It is preferable that the aryl group represents a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, or a divalent cyclic group represented by the following general formula (II-1), which may be substituted with one or more groups. [ka] (In the above general formula (II-1), M 2 and M 3 each independently represents a phenylene group or a cyclohexylene group; L II1is a linking group, and represents a single bond or an alkylene group having 1 to 50 carbon atoms, provided that one or more -CH2- in the alkylene group may be substituted with -O-, -C(=O)-, -OC(=O)- or -C(=O)-O-. Note that * in the above general formula (II-1) is bonded to the nitrogen atom in the above general formula (II).

[0082] In the above general formula (II-1), L II1 represents a single bond, an alkylene group having 1 to 10 carbon atoms, an alkyleneoxy group, -C(=O)-O-(CH2) n6 -O-(O=)C- (n6 represents an integer of 1 to 5) or -C(=O)-O-[(CH2) n7 -O] m6 It is preferably -(O=)C- (n7 represents an integer of 1 or more and 5 or less, and m6 represents an integer of 1 or more and 20 or less). Examples of the alkyleneoxy group include -[(CH2) n5 -O] m5 Preferably, n5 represents an integer of 1 or more and 5 or less, and m5 represents an integer of 1 or more and 15 or less. Furthermore, m5 is preferably an integer of 1 or more and 11 or less, more preferably an integer of 2 or more and 7 or less, and even more preferably an integer of 3 or more and 5 or less. Furthermore, m6 is preferably 1 or more and 10 or less, more preferably 2 or more and 8 or less, and even more preferably 3 or more and 6 or less.

[0083] The cyclic amine compound of the present embodiment is preferably one or more compounds selected from the group consisting of monocyclic aromatic diamine compounds, ring-assembly aromatic diamine compounds, and alicyclic amine compounds. More specifically, a preferred embodiment of the cyclic amine compound of this embodiment is one or more compounds selected from the group consisting of monocyclic aromatic diamine compounds represented by the following general formula (II.1), ring-assembly aromatic diamine compounds represented by the following general formula (II.2), and alicyclic amine compounds represented by the following general formula (II.3). [ka] (In the above general formula (II.1), R II5are each independently an alkyl group having 1 to 5 carbon atoms, -SH, a hydroxyl group, or -SR II4 (The above R II4 represents an alkyl group having 1 to 3 carbon atoms; II1 represents an integer between 0 and 4.) [ka] (In the above general formula (II.2), R II6 and R II7 each independently represents one or more selected from the group consisting of a halogen atom, an alkyl group having 1 to 8 carbon atoms, and a halogen atom; L II1 is a linking group, which represents a single bond or an alkylene group having 1 to 50 carbon atoms, provided that one or more -CH2- in the alkylene group may be replaced by -O-, -C(=O)-, -OC(=O)- or -C(=O)-O-; n II2 and n II3 each independently represents an integer of 0 or more and 4 or less.) [ka] (In the above general formula (II.3), R II1 and R II2 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; L II2 is a linking group, which represents a single bond or an alkylene group having 1 to 6 carbon atoms; R II8 and R II9 each independently represents one or more alkyl groups selected from the group consisting of alkyl groups having 1 to 8 carbon atoms; n II2 and n II3 each independently represents an integer of 0 or more and 4 or less.)

[0084] In the monocyclic aromatic diamine compound represented by the general formula (II.1), R II5 are each independently an alkyl group having 1 to 5 carbon atoms or -SR II4 (The above R II4 represents an alkyl group having 1 to 3 carbon atoms).

[0085] In the ring-assembly aromatic diamine compound represented by the general formula (II.2), L in the general formula (II.2) II1 is an alkylene group having 1 to 5 carbon atoms, -[(CH2) n5 -O] m5 - (n5 represents an integer of 1 or more and 3 or less, and m5 represents an integer of 1 or more and 30 or less, preferably 1 or more and 10 or less, more preferably 2 or more and 8 or less, and even more preferably 3 or more and 6 or less), -C(=O)-O-(CH2) n6 -O-(O=)C- (n6 represents an integer of 1 to 5) or -C(=O)-O-[(CH2) n7 -O] m6 It is preferably -(O=)C- (n7 represents an integer of 1 or more and 5 or less, and m6 is 1 or more and 30 or less, preferably 1 or more and 10 or less, more preferably 2 or more and 8 or less, and even more preferably 3 or more and 6 or less).

[0086] In the alicyclic amine compound represented by the general formula (II.3), in the general formula (II.3), R II1 and R II2 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; L II2 represents a single bond or an alkylene group having 1 to 3 carbon atoms, and R II8 and R II9 each independently represents one or more alkyl groups selected from the group consisting of alkyl groups having 1 to 3 carbon atoms; n II2 and n II3 Preferably, each independently represents an integer of 0 or more and 2 or less.

[0087] In the present embodiment, the second amine compound having a molecular weight of less than 1,000 is preferably one or more compounds selected from the group consisting of an amino acid ester compound or an amino acid ester derivative compound represented by the general formula (I.1), a monocyclic aromatic diamine compound represented by the general formula (II.1), a ring-assembly aromatic diamine compound represented by the general formula (II.2), and an alicyclic amine compound represented by the general formula (II.3). Specific examples of preferred second amine compounds having a molecular weight of less than 1,000 include, for example, N,N-(methylenedi-4,1-cyclohexanediyl)bis-tetraethyl ester (or N,N'-[methylenebis(cyclohexane-4,1-diyl)]bisaspartic acid tetraethyl ester, CAS number: 136210-30-5), N,N-methylenebis(2-methyl-4,1-cyclohexanediyl)bis-tetraethyl ester (or N,N'-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bis(aspartic acid diethyl ester), CAS number: 136210-30-5), 0-32-7), N,N'-(2-methyl-1,5-pentanediyl)bis-1,1',4,4'-tetraethyl ester) (CAS number: 168253-59-6), diethyltoluenediamine, dimethylthio-toluenediamine, 4,4'-methylenebis[N-sec-butylaniline], N,N'-bis(1-methylpropyl)-1,4-phenylenediamine, 4,4'-methylenebis(2-chloroaniline), 4,4'-methylenebis(2-ethyl-6-methylaniline), N,N'-di-sec-butyl-4,4'-methylenebis(cyclohexylamine)), and trimethylene bis(4-aminobenzoate) or poly(1,4-butanediol) bis(4-aminobenzoate).

[0088] The second amine compound of this embodiment preferably contains a primary amine and / or a secondary amine. More specifically, the second amine compound of this embodiment preferably contains one or more amine compounds selected from the group consisting of amine compounds (b3) containing a primary amine and amine compounds (b4) containing a secondary amine. The primary amine compound (b3) containing the primary amine may be one or more compounds selected from the group consisting of monocyclic aromatic diamine compounds represented by the general formula (II.1) above and ring-assembly aromatic diamine compounds represented by the general formula (II.2) above. Similarly, examples of the amine compound (b4) containing a secondary amine include one or more compounds selected from the group consisting of amino acid ester compounds or amino acid ester derivative compounds represented by the above general formula (I.1) and alicyclic amine compounds represented by the above general formula (II.3). In the second amine compound of this embodiment, the mixing ratio of the primary amine compound (b3) to the secondary amine compound (b4) (primary amine compound (b3) / secondary amine compound (b4)) is preferably in the range of 10 / 90 to 0 / 100, more preferably in the range of 5 / 95 to 0 / 100.

[0089] (Preferred form of amine compound) The curing agent (B) of this embodiment preferably contains a first amine compound, a second amine compound, and a second polyhydric alcohol compound. The total content of the first amine compound and the second amine compound relative to the total content of the curing agent (B) is preferably 5% by mass to 90% by mass, more preferably 10% by mass to 80% by mass, even more preferably 15% by mass to 60% by mass, and even more preferably 20% by mass to 40% by mass. The content of the second polyhydric alcohol compound relative to the total amount of the curing agent (B) is preferably 10% by mass to 95% by mass, more preferably 30% by mass to 90% by mass, even more preferably 40% by mass to 85% by mass, and even more preferably 50% by mass to 80% by mass. A preferred embodiment of the amine compound of this embodiment, focusing on a primary amine and a secondary amine, comprises a primary amine component containing a primary amine (for example, the sum of the amine compound (b1) containing a primary amine and the amine compound (b3) containing a primary amine), a secondary amine component containing a secondary amine (for example, the sum of the amine compound (b2) containing a secondary amine and the amine compound (b4) containing a secondary amine), a second polyhydric alcohol compound, and, if necessary, an imine compound containing a tertiary amine. A particularly preferred curing agent (B) of this embodiment contains the primary amine component (e.g., a total of an amine compound (b1) containing a primary amine and an amine compound (b3) containing a primary amine), the secondary amine component (e.g., a total of an amine compound (b2) containing a secondary amine and an amine compound (b4) containing a secondary amine), a second polyhydric alcohol compound, and an optionally added imine compound containing a tertiary amine, and the content of the primary amine component is preferably 1% by mass to 50% by mass, the content of the secondary amine component is preferably 5% by mass to 80% by mass, the content of the imine compound is preferably 0.001% by mass to 5% by mass, and the content of the second polyhydric alcohol compound is preferably 20% by mass to 90% by mass, relative to the total amount (100% by mass) of the curing agent (B).

[0090] <Amine value> In the curing agent (B) of the present embodiment, the amine value of the amine compound is preferably 20 mgKOH / g to 500 mgKOH / g, more preferably 20 mgKOH / g to 400 mgKOH / g, and even more preferably 20 mgKOH / g to 300 mgKOH / g. Similarly, the amine value of the entire curing agent (B) of this embodiment is preferably 100 mgKOH / g to 500 mgKOH / g, more preferably 150 mgKOH / g to 450 mgKOH / g, and even more preferably 200 mgKOH / g to 400 mgKOH / g. The amine value of the amine compound and the amine value of the curing agent (B) of the present embodiment are values ​​obtained by converting the amine value (mgKOH / g) measured in accordance with the method of ASTM D2074 into a solid content, as shown in the Examples section described later.

[0091] <Primary amine component containing primary amine> The primary amine component containing a primary amine of this embodiment (for example, the sum of the amine compound (b1) containing a primary amine and the amine compound (b3) containing a primary amine) is a compound having a primary amine (-NH2) in the molecule, and preferably has a molecular weight of 1,000 to 5,000. The primary amine component is preferably a compound having two or more primary amines (-NH2) in one molecule. The use of a primary amine component can impart flexibility during curing.

[0092] The amine value of the primary amine component is, for example, preferably 20 mgKOH / g to 200 mgKOH / g, more preferably 20 mgKOH / g to 150 mgKOH / g, and even more preferably 20 mgKOH / g to 100 mgKOH / g.

[0093] Preferred examples of the primary amine component include the above primary amine compound (b1) and the above primary amine compound (b3). The primary amine compound (b1) may be one or more compounds selected from the group consisting of primary polyether diamine (functional groups: 2, molecular weight: 1500 to 2500), primary polyether triamine (functional groups: 3, molecular weight: 1500 to 2500), poly(propylene glycol) triamine (CAS number: 64852-22-8), and polyoxypropylene diamine. The primary amine compound (b3) may be one or more compounds selected from the group consisting of monocyclic aromatic diamine compounds represented by the general formula (II.1) above and ring-assembly aromatic diamine compounds represented by the general formula (II.2) above.

[0094] The molecular weight of the primary amine component is, for example, preferably 500 to 5,000, more preferably 1,000 to 5,000, more preferably 1,500 to 5,000, and even more preferably 2,000 to 5,000. When the curing agent (B) of the present embodiment contains a primary amine component, the content of the primary amine component relative to the entire curing agent (B) (100% by mass) is preferably 1% by mass to 50% by mass, more preferably 2% by mass to 40% by mass, even more preferably 3% by mass to 32% by mass, and particularly preferably 5% by mass to 10% by mass.

[0095] (Secondary amine component containing secondary amine) The secondary amine component containing a secondary amine in this embodiment (the total of the amine compound (b2) containing a secondary amine and the amine compound (b4) containing a secondary amine) is a compound having a secondary amine (—NH—) in the molecule, and preferably has a molecular weight of 200 to 1,000. In the case of a compound having both a primary amine and a secondary amine, the content is calculated as that of the primary amine component. Use of the secondary amine component can impart the effect of low-temperature curing.

[0096] The amine value of the secondary amine component is, for example, preferably 100 mgKOH / g to 600 mgKOH / g, more preferably 120 mgKOH / g to 500 mgKOH / g, and even more preferably 150 mgKOH / g to 400 mgKOH / g.

[0097] Preferred examples of the secondary amine component of this embodiment include the above-mentioned secondary amine compound (b1) and the above-mentioned amine compound (b4) containing a secondary amine. The secondary amine compound (b1) may be a secondary polyether diamine or a secondary polyether triamine. The amine compound (b4) containing a secondary amine may be one or more compounds selected from the group consisting of an amino acid ester compound or an amino acid ester derivative compound represented by the general formula (I.1) above and an alicyclic amine compound represented by the general formula (II.3) above.

[0098] The molecular weight of the secondary amine component is, for example, preferably 200 to 1,000, more preferably 250 to 800, and even more preferably 300 to 600. When the curing agent (B) of the present embodiment contains a secondary amine component, the content of the secondary amine component relative to the entire curing agent (B) (100% by mass) is preferably 5% by mass to 80% by mass, more preferably 7% by mass to 70% by mass, even more preferably 8% by mass to 64% by mass, and particularly preferably 10% by mass to 20% by mass.

[0099] (Second polyhydric alcohol compound) The second polyhydric alcohol compound of this embodiment is not particularly limited as long as it contains two or more hydroxyl groups. For example, a compound having a number average molecular weight of 200 to 800 is preferred. Therefore, the average number of functional groups (average number of hydroxyl groups) of the second polyhydric alcohol compound of this embodiment may be 2 or more and 12 or less, preferably 2 or more and 10 or less, more preferably 2 or more and 8 or less, even more preferably 2 or more and 6 or less, and particularly preferably 2 or more and 5 or less, per molecule. By using the second polyhydric alcohol compound of the present embodiment, it is possible to achieve a long pot life, high hardness, and high crosslink density because the second polyhydric alcohol compound has a milder reactivity than primary and secondary amines, and an alcohol compound with a large average number of functional groups forms a network structure. The number average molecular weight of the suitable second polyhydric alcohol compound of this embodiment is preferably 300 to 12,000, more preferably 500 to 9,000, and even more preferably 600 to 5,000. The hydroxyl value of the second polyhydric alcohol compound of this embodiment is, for example, preferably 200 mgKOH / g or more and 1,000 mgKOH / g or less, more preferably 250 mgKOH / g or more and 900 mgKOH / g or less, and even more preferably 300 mgKOH / g or more and 900 mgKOH / g or less.

[0100] A suitable second polyhydric alcohol compound in this embodiment is preferably one or more compounds selected from the group consisting of polypropylene glycol, polyethylene glycol, polyether polyols, polytetramethylene ether glycols, polycaprolactone polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, polyisoprene polyol, polyolefin polyols, hydrogenated polyisoprene polyol, low molecular weight polyols, polycarbonate polyol, castor oil, castor oil-modified polyol, pentaerythritol-based polyether polyol, polymer polyol, and flame-retardant polyols containing phosphorus or the like. Examples of the polyether polyols include polyether polyol compounds obtained by reacting one or more selected from the group consisting of triethanolamine, monoethanolamine, methyl glycoside, sorbitol, sorbitolamine, diethylenetriamine, sucrose, sucroseamine, toluenediamine, aminoethylpiperazine, aniline, and metaxylenediamine with an alkylene oxide (e.g., propylene oxide or ethylene oxide) as reaction raw materials. The reaction is mainly obtained by addition polymerization. Examples of the polyolefin polyols include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,3-propanediol, and 1,9-nonanediol. Examples of the low molecular weight polyols include neopentyl glycol, methylpentanediol, diethylene glycol, and propylene glycol. The polytetramethylene ether glycols (PTMG) are obtained by ring-opening polymerization of tetrahydrofuran (THF). The second polyhydric alcohol compound of the present embodiment may be used alone or in combination of two or more.

[0101] The curing agent (B) of this embodiment may contain an imine compound containing a tertiary amine, if necessary. The imine compound is not particularly limited as long as it has a tertiary amine (-N=) in the molecule, but a compound having a molecular weight of 50 to 300 is preferred. The imine compound containing a tertiary amine is preferably an imidazole. Use of the imine compound containing a tertiary amine can promote the promotion of post-curing properties.

[0102] The molecular weight of the imine compound is, for example, preferably 50 to 300, more preferably 60 to 250, and even more preferably 70 to 200.

[0103] The curing agent (B) of this embodiment may optionally contain a urethane-forming amine catalyst such as a quaternary ammonium salt. When the curing agent (B) contains a urethane-forming amine catalyst such as a quaternary ammonium salt, the content of the urethane-forming amine catalyst such as a quaternary ammonium salt is preferably more than 0% by mass and not more than 8% by mass based on the total curing agent (B) (100% by mass). Specific examples of the quaternary ammonium salt include chloride salts of tetramethylammonium cation, methyltriethylammonium cation, tetraethylammonium cation, tributylmethylammonium cation, tetrabutylammonium cation, phenyltrimethylammonium cation, benzyltrimethylammonium cation, phenyltriethylammonium cation, benzyltriethylammonium cation, and benzyltributylammonium cation; and bromide salts of tetramethylammonium cation, trimethylpropylammonium cation, tetraethylammonium cation, and tetrabutylammonium cation. These compounds may be used alone or in combination.

[0104] The curing agent (B) of this embodiment may contain a known urethanization metal catalyst such as an organotin compound, an organolead compound, or an organobismuth compound, instead of or in combination with the quaternary ammonium salt, as necessary. When the curing agent (B) contains the urethanization metal catalyst, the content of the urethanization metal catalyst is preferably more than 0% by mass and not more than 8% by mass relative to the total amount of the curing agent (B) (100% by mass). Examples of the organotin compounds include stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin oxide, and dibutyltin dichloride. The organic lead compounds include lead octoate and lead naphthenate. The organic bismuth compounds include bismuth octoate, bismuth neodecanoate, and bismuth naphthenate. These compounds may be used alone or in combination of two or more.

[0105] The curing agent (B) of this embodiment may consist essentially of an amine compound, a second polyhydric alcohol compound, and any additives. In this specification, "consisting essentially of an amine compound, a second polyhydric alcohol compound, and any additives" means that the total content of the amine compound, the second polyhydric alcohol compound, and any additives accounts for 90% by mass to 100% by mass, preferably 95% by mass to 100% by mass, and more preferably 98% by mass to 100% by mass of the curing agent (B). In another embodiment, the curing agent (B) of the present embodiment may consist essentially of only the amine component and the second polyhydric alcohol compound.

[0106] "Additives" The base agent (A) and / or curing agent (B) of this embodiment may contain any additives as needed, such as one or more components selected from the group consisting of antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, plasticizers, inorganic fillers, antifoaming agents, dehydrating agents, colorants, and dispersants. The total content of the additives in the main component (A) can be preferably 0 to 15% by mass, and more preferably 0 to 11% by mass, based on the total amount of the main component (A). The total content of the additives in the curing agent (B) may be preferably 0% by mass to 30% by mass, more preferably 0% by mass to 16% by mass, and even more preferably 0% by mass to 12% by mass, based on the total amount of the curing agent (B).

[0107] As the antioxidant, known antioxidants can be used. Examples of the antioxidant include one or more selected from the group consisting of phenolic compounds, phosphorus compounds, and thioether compounds. The antioxidant is preferably contained in the curing agent (B).

[0108] Examples of the phenolic antioxidant include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid amide], 4,4'-thiobis(6-tert-butyl-m-cresol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylene Bis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl-m-cresol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4-sec-butyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate, 1,3,5-tris(3 ,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5-methylbenzyl)phenol, stearyl [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate methyl ester ] methane, thiodiethylene glycol bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,6-hexamethylene bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butylic acid] glycol ester, bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl] terephthalate, 1,3,5-tris[(3,Examples of suitable phenolic antioxidants include 3,9-bis[1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]isocyanurate, 3,9-bis[1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, and triethylene glycol bis[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]. These phenolic antioxidants may be used alone or in combination of two or more.

[0109] Examples of the phosphorus-based antioxidant include tris(2,4-di-tert-butylphenyl)phosphite, trisnonylphenyl phosphite, tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite, tridecyl phosphite, octyldiphenyl phosphite, di(decyl)monophenyl phosphite, di(tridecyl)pentaerythritol diphosphite, and di(nonylphenyl)pentaerythritol. Diphosphite, bis(2,4-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, tetra(tridecyl)isopropylidenediphenol diphosphite, tetra(tridecyl)-4,4'-n-butyl Hexylidenebis(2-tert-butyl-5-methylphenol)diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butanetriphosphite, tetrakis(2,4-di-tert-butylphenyl)biphenylene diphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis(4,6-tert-butylphenyl)-2-ethylhexylphosphi phosphate, 2,2'-methylenebis(4,6-tert-butylphenyl)-octadecyl phosphite, 2,2'-ethylidenebis(4,6-di-tert-butylphenyl)fluorophosphite, tris(2-[(2,4,8,10-tetrakis-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine, phosphite of 2-ethyl-2-butylpropylene glycol and 2,4,6-tri-tert-butylphenol, etc. These phosphorus-based antioxidants may be used alone or in combination of two or more.

[0110] Examples of the thioether antioxidant include dialkyl thiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, and pentaerythritol tetra(β-alkylmercaptopropionate)s. These thioether antioxidants may be used alone or in combination of two or more.

[0111] The ultraviolet absorber may be a known ultraviolet absorber. Specific examples of the ultraviolet absorber include benzophenone compounds, benzotriazole compounds, salicylate compounds, substituted acrylonitrile compounds, and metal chelate compounds. Benzotriazole-based ultraviolet absorbers are particularly preferred, including Tinuvin P, Tinuvin 213, Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 329, and Tinuvin 571 (all manufactured by BASF). These ultraviolet absorbers may be used alone or in combination of two or more. The ultraviolet absorber is preferably contained in the curing agent (B).

[0112] The light stabilizer is not particularly limited, and known light stabilizers can be used. Specific examples of the light stabilizer include benzotriazole compounds, hindered amine compounds, and benzoate compounds, and these light stabilizers may be used alone or in combination of two or more. The light stabilizer is preferably contained in the curing agent (B).

[0113] The flame retardant is not particularly limited, and known flame retardants can be used. Specific examples of the flame retardant include red phosphorus; phosphate esters such as triphenyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(t-butylated phenyl)phosphate, and tris(i-propylated phenyl)phosphate; phosphate-containing flame retardants such as ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, magnesium hydrogen phosphate, and trimagnesium phosphate; bromine-containing flame retardants such as tetrabromobisphenol A (TBBA), TBBA-epoxy oligomer, TBBA-polycarbonate oligomer, and TBBA-bis(dibromopropyl ether); borax, diboron trioxide, Examples of suitable flame retardants include boron-containing flame retardants such as antimony trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, boric acid, lithium borate, sodium borate, and potassium borate; antimony-containing flame retardants such as antimony trioxide, antimony pentoxide, and sodium antimonate; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; and compounds having a cyclic structure containing a heterocyclic or aromatic ring and a functional group containing an ethylenically or acetylenically unsaturated carbon bond (e.g., triallyl isocyanurate (TAIC), trimethyl isocyanurate (TMAIC), triallyl cyanurate (TAC), and ethoxylated isocyanuric acid triacrylate (TEAIC)). These flame retardants may be used alone or in combination of two or more. The flame retardant is preferably contained in the curing agent (B).

[0114] The plasticizer is not particularly limited, and known plasticizers can be used, specific examples of which include phthalate ester plasticizers, adipate ester plasticizers, aliphatic dibasic acid ester plasticizers, glycol ester plasticizers, phosphate ester plasticizers, and epoxy plasticizers. Examples of the phthalate ester plasticizer include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, diisooctyl phthalate, di-2-ethylhexyl phthalate, dinonyl phthalate, diisodecyl phthalate, ditridecyl phthalate, dibutylpentyl phthalate, and dicyclohexyl phthalate. Examples of the adipate ester plasticizer include dimethyl adipate, diethyl adipate, dibutyl adipate, diheptyl adipate, diisononyl adipate, di-n-octyl adipate, diisooctyl adipate, di-2-ethylhexyl adipate, dinonyl adipate, diisononyl adipate, diisodecyl adipate, ditridecyl adipate, dibutylpentyl adipate, and dicyclohexyl adipate. These plasticizers may be used alone or in combination of two or more. The plasticizer is preferably contained in the curing agent (B).

[0115] The inorganic filler is not particularly limited, and known inorganic fillers can be used. Specific examples of the inorganic filler include silicas such as fused silica, crystalline silica, and cristobalite, alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, glass fiber, and magnesium oxide. These inorganic fillers may be used alone or in combination of two or more. The average particle size and shape of the inorganic filler can be selected depending on the application. The inorganic filler is preferably contained in the curing agent (B).

[0116] The defoaming agent is not particularly limited, and known defoaming agents can be used. Specific examples of the defoaming agent include silicone-based defoaming agents such as dimethylpolysiloxane, polyoxyalkylene alkyl ethers, synthetic resin particles, and unsurface-treated silica. These defoaming agents may be used alone or in combination of two or more. The defoaming agent is preferably contained in the curing agent (B).

[0117] The colorant is not particularly limited, and known colorants can be used. Specific examples of the colorant for the defoaming agent include carbon black, chrome yellow, Hansa Yellow, benzidine yellow, threne yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, Balkan orange, watch young red, permanent red, brilliant carmine 3B, brilliant carmine 6B, DuPont oil red, pyrazolone red, lithol red, rhodamine B lake, lake red C, pigment red, rose bengal, aniline blue, and Examples of suitable colorants include various pigments such as tetramarine blue, chalco oil blue, methylene blue chloride, phthalocyanine blue, pigment blue, phthalocyanine green, and malachite green oxalate; and various dyes such as acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindigo, dioxazine, thiazine, azomethine, indigo, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, and thiazole. These colorants may be used alone or in combination of two or more. The colorant is preferably contained in the curing agent (B).

[0118] The dehydrating agent is not particularly limited, and known dehydrating agents can be used. Specific examples of the dehydrating agent include synthetic zeolite, activated alumina (Al2O3), silica gel (SiO2), quicklime, magnesium oxide, etc. These dehydrating agents may be used alone or in combination of two or more. The dehydrating agent is preferably contained in the curing agent (B).

[0119] The dispersant is not particularly limited, and known dispersants can be used. Specific examples of the dispersant include BYK-W961 and BYK-W935 (manufactured by BYK Japan K.K.), and Polyflow No. 77 (manufactured by Kyoeisha Chemical Co., Ltd.). The dispersant is preferably contained in the curing agent (B).

[0120] "Use of two-component curing composition for coating the inner walls of water pipes" The two-component curing composition for coating the inner wall of a water pipe of this embodiment is a resin composition in the form of a two-component kit including a base agent (A) and a curing agent (B) that are separately prepared. The base agent (A) and the curing agent (B) can be a two-component kit for forming a polyurethane urea resin cured product. The base agent (A) and the curing agent (B) are blended (mixed) at the time of use and cured to produce a cured product. In the two-component curing composition for coating the inner wall of a water pipe of this embodiment, when the main agent (A) (also simply referred to as (A) liquid) and the curing agent (B) (also simply referred to as (B) liquid) are brought into contact with each other to coat the inner wall of a water pipe with the cured product, the mixing ratio (mass ratio) of the main agent (A) to the curing agent (B) (main agent (A) / curing agent (B)) is preferably in the range of 80 / 20 to 20 / 80, more preferably in the range of 70 / 30 to 30 / 70, and even more preferably in the range of 60 / 40 to 40 / 60.

[0121] "Curing of two-component curing composition for coating the inner walls of water pipes" In the two-component curing composition for coating the inner walls of water pipes, when the main component (A) (also referred to simply as "liquid (A)") comes into contact with the curing agent (B) (also referred to simply as "liquid (B)"), the isocyanate groups of the prepolymer (made from an isocyanate compound and a first polyhydric alcohol in the main component (A) as reaction raw materials) and / or the isocyanate compound in the main component (A) undergo urea formation and urethanization reactions with the so-called active hydrogen groups of each amine compound in the curing agent (B). More specifically, upon initial contact between the (A) and (B) components, the active hydrogen groups and the isocyanate groups undergo urea formation reactions. Subsequently, as the amine compound reacts with moisture in the air or the second polyhydric alcohol, the active hydrogen groups in the amine compound gradually become apparent. This gradually leads to a cured product, whereby the active hydrogen groups and the isocyanate groups react with each other.

[0122] The curing temperature of the base agent (A) and the curing agent (B) is, for example, 10°C to 40°C, preferably 20°C to 30°C. The curing time for the curing reaction between the base agent (A) and the curing agent (B) is, for example, 10 minutes to 50 minutes, preferably 20 minutes to 40 minutes. The curing time refers to the time (pot life) from when the base agent (A) and the curing agent (B) come into contact until the viscosity reaches 50,000 mPa·s / 25°C. As a result, the main agent (A) and the curing agent (B) come into contact with each other and harden, forming a coating layer that covers the inner wall of the water pipe, thereby coating the inner wall of the water pipe.

[0123] "Method of using a two-component curing composition for coating the inner walls of water pipes" The method for coating and curing the two-component curing composition for coating the inner wall of a water pipe according to this embodiment within the inner wall of a water pipe is not particularly limited, and known devices and methods can be used. Specifically, the method for coating and curing the two-component curing composition for coating the inner wall of a water pipe according to this embodiment includes the steps of mixing a base agent (A) and a curing agent (B), an optional cleaning step, applying a mixture of the base agent (A) and the curing agent (B) to the inner wall of the water pipe, and an optional drying step. Alternatively, the mixing step and the application step may be performed in the same step, i.e., the base agent (A) and the curing agent (B) may be mixed and then applied to the inner wall of the water pipe. Alternatively, the base agent (A) and the curing agent (B) may be mixed to prepare a mixture, and then the mixture may be applied to the inner wall of the water pipe.

[0124] An example of how the two-component curing composition for coating the inner wall of a water pipe is coated on the inside of the water pipe and cured will be described below. <Mixing process> The mixing step may be a step of measuring the main agent (A) and the curing agent (B) using a scale, adding them to the same container at a mixing ratio (main agent (A) / curing agent (B) (mass ratio)) of 80 / 20 to 20 / 80, and mixing them with a stirrer (for example, an electric stirrer) to prepare a mixed liquid of the main agent (A) and the curing agent (B).

[0125] Another embodiment of the mixing step includes a step of pressure-feeding the main agent (A) and the curing agent (B) into two hoses using a pressure-feeding means such as a gear pump or a plunger pump at a mixing ratio of the main agent (A) to the curing agent (B) (mass ratio) of 80 / 20 to 20 / 80, and connecting a static mixer such as a static mixer to the tip of each of the two hoses to mix the main agent (A) and the curing agent (B) to prepare a mixed liquid.

[0126] Furthermore, another embodiment of the mixing step includes a step in which a main component (A) and a curing agent (B) are pressure-fed into two hoses using a pressure-fed means such as a gear pump or a plunger pump at a mixing ratio of the main component (A) to the curing agent (B) (mass ratio) of 80 / 20 to 20 / 80, and two-component mixing injector nozzles connected to the respective ends of the two hoses and an air hose connected to the two-component mixing injector nozzles are used to feed the main component (A), the curing agent (B) and compressed air (for example, 0.1 MPa to 0.5 MPa) into the two-component mixing injector nozzles, and then sprayed from the injector nozzles to mix them by a collision reaction.

[0127] <Cleaning process> Next, if necessary, the inner surface of the water pipe to be coated with the two-component curing composition for coating the inner wall of a water pipe may be cleaned to prepare the surface. Specifically, a cleaning process may be performed in which a known suction device is connected to the lower side of the water pipe to be coated and operated to circulate air through the water pipe at high speed, and an abrasive (e.g., natural stone, silica sand, ceramic powder) is introduced from the upper side of the water pipe. This process generates a high-speed airflow (e.g., air velocity of 20 to 40 msec) due to the suction force of the suction device, causing the abrasive to flow from the upper side to the lower side of the water pipe, thereby polishing the inner surface of the water pipe. Note that the removed deposits, rust, iron powder, or abrasive may be collected in the suction device. Furthermore, fine impurities remaining in the water pipe after polishing may be washed away by running water from the upper side and sucking it down. If necessary, the water pipe may then be dried by suction or air-dried. The cleaning process is not limited to the polishing method described above, and may employ a rotary polishing jig, polishing with a rotary chain, or a pressurized method such as high-pressure washing.

[0128] <Coating process> If necessary, after confirming that the interior of the water pipe to be coated has dried, a mixture of the base agent (A) and the curing agent (B) is applied. As in the cleaning process described above, the mixture is mixed by hand, using a gear pump, static mixer, or the like. After or while a high-speed airflow (wind speed 20-40 ms) is generated inside the water pipe from the lower side using a known suction device, the mixture of the base agent (A) and the curing agent (B) is poured into the water pipe from the upper side. This allows the poured mixture to be uniformly dispersed and spread throughout the water pipe according to the principle of annular two-layer flow. As a result, a smooth coating is formed over the entire inner surface of the water pipe. Note that after pouring the paint, a jig or auxiliary tool may be inserted into the water pipe to adjust the coating thickness. Alternatively, a known two-component mixing injector nozzle may be connected to a known air hose, and compressed air (for example, 0.1 MPa to 0.5 MPa) may be sent using a compressor to spray the base agent (A), the curing agent (B), or the mixed liquid from the tip of the two-component mixing injector nozzle, which may then be pulled up at a constant speed from the bottom to the top of the water pipe to apply the mixture. If necessary, after the spray coating, an air current may be circulated through the water pipe using a suction device to make the coating surface uniform and adjust the coating thickness.

[0129] <Drying process> After the coating film has been formed over the entire inside of the water pipe, it may be allowed to dry naturally, or, if necessary, hot air may be blown into the water pipe to speed up the drying time. The guideline for complete curing depends on the weather, the solids concentration in the base resin (A) and the curing agent (B), etc., but is, for example, about 6 hours when the temperature is 33° C., 2.5 hours when the temperature is 25° C., and 1.5 hours when the temperature is 40° C. The coating thickness is usually preferably about 0.3-0.3 mm to 5 mm. This allows the two-component curing composition for coating the inner wall of a water pipe to be cured, thereby obtaining a cured product (for example, a coating layer). Because such a cured product is formed from the above-mentioned two-component curing composition for coating the inner wall of a water pipe, it exhibits excellent curability and conformability within the water pipe, and also exhibits excellent mechanical properties after curing.

[0130] The present disclosure relates to an inner-wall-coated water pipe having a water pipe body and a cured product of the two-component curing composition for coating the inner wall of a water pipe of the present embodiment coated on the inner wall of the water pipe body. As described above, it has been confirmed that an inner-wall-coated water pipe, in which the two-component curing composition for coating the inner walls of water pipes of this embodiment has been applied to the inside of the water pipe and cured, has significantly improved mechanical strength such as impact resistance and elongation compared to a water pipe body that is not coated with the cured two-component curing composition for coating the inner walls of water pipes of this embodiment. Furthermore, even if the shape of the water pipe body is curved, the two-component curing composition for coating the inner wall of a water pipe of this embodiment has an appropriate viscosity, so the cured product can be coated on the inner wall of the water pipe body in accordance with the shape of the water pipe body, and it has been confirmed that the composition has excellent conformability. [Example]

[0131] The present disclosure will be described below by way of examples and comparative examples, but the scope of the present disclosure is not limited by the following examples.

[0132] 1. Preparation of a two-component curing composition for coating the inner walls of water pipes Example 1 <Synthesis Example 1: Preparation of main agent (A1)> 20 parts by weight of polypropylene glycol (AGC, trade name: EXCENOL 2020, number-average molecular weight 2000, average number of hydroxyl groups 2) as the first polyhydric alcohol, 60 parts by weight of polymeric MDI (polymethylene polyphenyl polyisocyanate: 4,4'-MDI = 55:45 (mass ratio)), and 20 parts by weight of monomeric MDI (2,4'-MDI: 4,4'-MDI = 55:45 (mass ratio)) were placed in a flask and heated and mixed at 80°C for 3 hours under a nitrogen atmosphere to prepare main component (A1). The formation of an isocyanate-terminated prepolymer in main component (A1) was confirmed by NCO% measurement using an automatic potentiometric titrator. The viscosity of main component (A1) at 25°C was 400 mPa·s.

[0133] <Synthesis Example 2: Preparation of Curing Agent (B1)> As a second polyhydric alcohol, 36 parts by mass of a castor oil-modified polyol (manufactured by Ito Oil Mills, trade name: URIC F-97, average number of hydroxyl groups: 3.0, hydroxyl value: 335 mg KOH / g) and 36 parts by mass of a pentaerythritol-based polyether polyol (manufactured by KPX Chemical Co., Ltd., trade name: KONIX HD-402, number average molecular weight: 505, average number of hydroxyl groups: 4.0, hydroxyl value: 400 mg KOH / g, CAS number: 9051-49-4), a total of 23.02 parts by mass of an amine-based compound, 0.1 parts by mass of Pigment Blue 15 (phthalocyanine copper (α-type)), 5 parts by mass of a dehydrating agent, and 0.01 parts by mass of a silicone-based antifoaming agent were placed in a flask and mixed to obtain a mixed solution. In this case, the amine compound contained 8 parts by mass of poly(propylene glycol) bis(2-aminopropyl ether) (HUNTSMAN, trade name: JEFFAMINE D-2000, functionality 2, molecular weight 2000, amine value 56 mg KOH / g), 10 parts by mass of tetraethyl N,N'-[methylenebis(cyclohexane-4,1-diyl)]bisaspartate (Desmophen NH1420, functionality 2, molecular weight 555, amine value 199 mg KOH / g), 5 parts by mass of tetraethyl N,N'-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bis(diethyl aspartate) (Desmophen NH1520, functionality 2, molecular weight 583, amine value 191 mg KOH / g), and 0.02 parts by mass of 1-methylimidazole (an imine compound containing a tertiary amine). The mixed solution was then heated and mixed under a nitrogen atmosphere at 50°C for 30 minutes to prepare a curing agent (B1). The viscosity of the curing agent (B1) at 25°C was 2,400 mPa·s.

[0134] A two-component curing composition (1) for coating the inner walls of water pipes was prepared using the main component (A1) and curing agent (B1) obtained in Synthesis Examples 1 and 2. The main component (A1):curing agent (B1) mixture was stirred and mixed at a mixing ratio (weight ratio) of 100:100, thereby producing a cured product from the two-component curing composition (1) for coating the inner walls of water pipes comprising the main component (A1) and the curing agent (B1).

[0135] Example 2 <Synthesis Example 3: Preparation of main agent (A2)> 20 parts by weight of polypropylene glycol (AGC, trade name: EXCENOL 2020, number-average molecular weight 2000, average number of hydroxyl groups 2) as the first polyhydric alcohol, 60 parts by weight of polymeric MDI (polymethylene polyphenyl polyisocyanate: 4,4'-MDI = 55:45 (mass ratio)), and 20 parts by weight of monomeric MDI (2,4'-MDI: 4,4'-MDI = 55:45 (mass ratio)) were placed in a flask and heated and mixed at 80°C for 3 hours under a nitrogen atmosphere to prepare main component (A1). The formation of an isocyanate-terminated prepolymer in main component (A1) was confirmed by NCO% measurement using an automatic potentiometric titrator. The viscosity of main component (A1) at 25°C was 400 mPa·s.

[0136] Synthesis Example 44: Preparation of curing agent (B2) A mixed solution was obtained by mixing 65 parts by mass of a castor oil-modified polyol (manufactured by Ito Oil Mills, trade name: URIC H-420, average number of hydroxyl groups: 3.0, hydroxyl value: 335 mgKOH / g) as a second polyhydric alcohol, a total of 30.02 parts by mass of amine compounds, 0.1 part by mass of Pigment Blue 15 (phthalocyanine copper (α-type)), a total of 5 parts by mass of dehydrating agents, and 0.01 part by mass of a silicone-based antifoaming agent in a flask. In this case, the amine compound contained 10 parts by mass of poly(propylene glycol) bis(2-aminopropyl ether) (HUNTSMAN, trade name: JEFFAMINE D-2000, functionality 2, molecular weight 2000, amine value 56 mg KOH / g), 15 parts by mass of tetraethyl N,N'-[methylenebis(cyclohexane-4,1-diyl)]bisaspartate (Desmophen NH1420, functionality 2, molecular weight 555, amine value 199 mg KOH / g), 5 parts by mass of tetraethyl N,N'-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bis(diethyl aspartate) (Desmophen NH1520, functionality 2, molecular weight 583, amine value 191 mg KOH / g), and 0.02 parts by mass of 1-methylimidazole (an imine compound containing a tertiary amine). The mixed solution was then heated and mixed in a nitrogen atmosphere at 50°C for 30 minutes to prepare curing agent (B2). The viscosity of curing agent (B2) at 25°C was 1,100 mPa·s.

[0137] A two-component curing composition (2) for coating the inner walls of water pipes was prepared using the base agent (A2) and curing agent (B2) obtained in Synthesis Examples 3 and 4. A cured product was produced from the two-component curing composition (2) for coating the inner walls of water pipes, comprising the base agent (A2) and the curing agent (B2), by stirring and mixing the base agent (A2):curing agent (B2) at a mixing ratio (weight ratio) of 100:100.

[0138] Example 3 <Synthesis Example 5: Preparation of main agent (A3)> 20 parts by weight of polypropylene glycol (AGC, trade name: EXCENOL 2020, number-average molecular weight 2000, average number of hydroxyl groups 2) as the first polyhydric alcohol, 60 parts by weight of polymeric MDI (polymethylene polyphenyl polyisocyanate: 4,4'-MDI = 55:45 (mass ratio)), and 20 parts by weight of monomeric MDI (2,4'-MDI: 4,4'-MDI = 55:45 (mass ratio)) were placed in a flask and heated and mixed at 80°C for 3 hours under a nitrogen atmosphere to prepare main component (A1). The formation of an isocyanate-terminated prepolymer in main component (A1) was confirmed by NCO% measurement using an automatic potentiometric titrator. The viscosity of main component (A1) at 25°C was 400 mPa·s.

[0139] <Synthesis Example 6: Preparation of curing agent (B3)> A mixed solution was obtained by mixing 70 parts by mass of a castor oil-modified polyol (manufactured by Ito Oil Mills, trade name: URIC H-420, average number of hydroxyl groups: 3.0, hydroxyl value: 335 mgKOH / g) as a second polyhydric alcohol, a total of 25.02 parts by mass of amine compounds, 0.1 part by mass of Pigment Blue 15 (phthalocyanine copper (α-type)), 5 parts by mass of a dehydrating agent, and 0.01 part by mass of a silicone-based antifoaming agent in a flask. In this case, the amine compound contained 5 parts by mass of poly(propylene glycol)triamine (HUNTSMAN, trade name: JEFFAMINE T-5000, functionality 3, molecular weight 5000, amine value 34 mg KOH / g), 15 parts by mass of tetraethyl N,N'-[methylenebis(cyclohexane-4,1-diyl)]bisaspartate (Desmophen NH1420, functionality 2, molecular weight 555, amine value 199 mg KOH / g), 5 parts by mass of tetraethyl N,N'-[methylenebis(2-methyl-4,1-cyclohexanediyl)]bis(diethyl aspartate) (Desmophen NH1520, functionality 2, molecular weight 583, amine value 191 mg KOH / g), and 0.02 parts by mass of 1-methylimidazole (an imine compound containing a tertiary amine). The mixed solution was then heated and mixed in a nitrogen atmosphere at 50°C for 30 minutes to prepare curing agent (B2). The viscosity of curing agent (B2) at 25°C was 1,000 mPa·s.

[0140] A two-component curing composition (3) for coating the inner walls of water pipes was prepared using the base agent (A3) and curing agent (B3) obtained in Synthesis Examples 5 and 6. The base agent (A3):curing agent (B3) was mixed at a mixing ratio (weight ratio) of 100:100 with stirring, to produce a cured product from the two-component curing composition (3) for coating the inner walls of water pipes comprising the base agent (A3) and the curing agent (B3).

[0141] (Comparative Example 1) In Comparative Example 1, the following two-component curing epoxy resin composition was used. As the comparative main resin (a1), a bisphenol A type epoxy resin (Nippon America Resin Co., Ltd., trade name "Alpron L-HR") was used. A mixture of modified aliphatic polyamine and isophoronediamine (Nippon America Resin Co., Ltd., trade name "ALPRON L-HR") was used as the comparative curing agent (b1). The comparative main agent (a1) and the comparative curing agent (b1) were prepared to obtain a two-component curing epoxy resin composition for comparison. The comparative main agent (a1) and the comparative curing agent (b1) were stirred and mixed in a weight ratio of 5:1 (=main agent (a1):curing agent (b1)), thereby producing a cured product from the two-component curing composition (1) for forming an epoxy resin comprising the comparative main agent (a1) and the comparative curing agent (b1).

[0142] 2. Evaluation Method (2-1) Measurement of pot life 60 g of each of the main components (A1) to (A3) prepared in the examples was weighed and placed in a stirring vessel, and then 60 g of each of the curing agents (B1) to (B3) prepared in the examples was added, followed by stirring and mixing at room temperature (25°C) for 30 seconds. The resulting mixture was then used to measure the thickening behavior. Specifically, 120 g of the resulting mixture was placed in a 200 cc plastic cup, and the viscosity was automatically measured using a TV-100 rotational viscometer at 12 rpm with a No. 4 rotor at 25°C, with the viscosity measured every minute. Each of the main components (A1) to (A3) and each of the curing agents (B1) to (B3) were mixed together, and the time until the viscosity reached 50,000 mPa·s / 25°C was measured as the pot life. On the other hand, for the two-component curing epoxy resin composition of Comparative Example 1, 60 g of 100 g of the comparative base resin (a1) was weighed out and placed in a stirring vessel, and 20 g of the comparative curing agent was added. The mixture was stirred and mixed at room temperature (25°C) for 30 seconds to prepare a comparative mixture for measurement. Thereafter, the pot life was measured under the same conditions as for the mixtures of the above examples, and the time until the viscosity reached 50,000 mPa s / 25°C was measured.

[0143] (2-2) Measurement of mechanical properties 100 g of each base resin prepared in the Examples and Comparative Examples was weighed into a stirring vessel, and then 100 g of each curing agent prepared in the Examples and Comparative Examples was added. The mixture was then stirred and mixed for 1 minute in a vacuum casting machine to obtain a mixture. The mixture was then poured into a Teflon-coated mold to produce 3 mm thick sheets. Each sheet was then left to stand at 60°C for 1 hour, demolded, and further left to stand at 60°C for 24 hours, followed by another 24 hours at room temperature (25°C). Test specimens were then prepared from the two-component curing compositions for coating water pipe inner walls of the Examples and the two-component curing epoxy resin compositions of the Comparative Examples. The Shore D hardness of the obtained test pieces was measured using a durometer hardness tester (type D) in accordance with ISO-868. In addition, the breaking elongation was measured in accordance with JIS A 6021 (2011). The results are shown in Table 1 below.

[0144] (2-3) Measurement of gel time, tack-free time, and complete curing time 10 g of each base resin prepared in the Examples and Comparative Examples was weighed into a stirring vessel, and then 10 g of each curing agent prepared in the Examples and Comparative Examples was added. The mixture was then stirred and mixed for 30 seconds at room temperature (25°C) to obtain a mixture. The mixture was then applied to a metal plate and adjusted to a coating thickness of 0.2 mm. The gelation time was measured at 3°C, room temperature (25°C), and 40°C, respectively, and the time until the uncured resin no longer adhered to the finger when lightly touched with a finger was recorded. The tack-free time was measured as the time until the coating no longer felt sticky when touched with a finger. The complete cure time was measured as the time until the surface condition of the coating no longer changed after water was applied. The results are shown in Table 2 below.

[0145] (2-4) Viscosity measurement In accordance with JIS K 7117-1:1999, the base resin and curing agent of each of the examples and comparative examples were set using a TV-100 type viscometer at a measurement temperature of 25°C, and the viscosity was measured after 2 minutes.

[0146] (2-6) Measurement of amine value and hydroxyl value The amine value of the amine compound and the hydroxyl value of the first and second polyhydric alcohol compounds used in the examples and comparative examples are measured by the following method when catalog values ​​or the like are not available. The amine value (mgKOH / g) is determined according to the method specified in ASTM D2074 by measuring the amount of potassium hydroxide (mg) equivalent to the amount of hydrochloric acid required to neutralize the compounds with amine groups contained in 1 g of sample. The hydroxyl value (mgKOH / g) was measured according to the methods described in JIS K 0070-1992 and JIS K 1557-1.

[0147] [Table 1]

[0148] [Table 2]

[0149] From the experimental results in Table 1 above, it was confirmed that the cured products of the two-component curing compositions (1) to (3) for coating the inner walls of water pipes in Examples 1 to 3 had approximately 10 times the elongation while maintaining high hardness compared to the cured product of Comparative Example 1.

[0150] From the experimental results in Table 2 above, it was confirmed that the cured products of the two-component curing compositions (1) to (3) for coating the inner walls of water pipes in Examples 1 to 3 completed curing in a shorter time than the cured product of Comparative Example 1. Furthermore, it was confirmed that the two-component curing compositions (1) to (3) for coating the inner walls of water pipes in Examples 1 to 3 had little temperature dependency of the curing rate and were able to exhibit excellent curability, particularly at low temperatures. From the above, it was confirmed that the two-component curing composition for coating the inner wall of water pipes of the present disclosure exhibits excellent curing properties and, after curing, can form a coating layer with excellent mechanical properties. [Industrial Applicability]

[0151] The present disclosure can provide a two-component curing composition for coating the inner walls of water pipes, which exhibits excellent curing properties inside water pipes and, after curing, forms a coating layer that combines excellent mechanical properties. In another aspect of the present disclosure, it is possible to provide a cured product of a two-component curing composition for coating the inner wall of a water pipe, which exhibits excellent conformability to any shape of the water pipe and has excellent mechanical properties, and a water pipe with an inner wall coating. This makes it possible to provide a simple means for repairing water pipes or to suppress deterioration of water pipes over time.

Claims

1. A two-component curing composition for coating the inner wall of a water pipe, which cures upon contact of a base agent (A) with a curing agent (B) to coat the inner wall of the water pipe, the main component (A) contains a urethane prepolymer having an isocyanate group, the prepolymer being produced from an isocyanate compound and a first polyhydric alcohol compound as reaction raw materials, and has a viscosity at 25°C of 10 mPa s or more and 500,000 mPa s or less; the curing agent (B) contains an amine compound and a second polyhydric alcohol compound, and has a viscosity at 25°C of 100 mPa·s or more and 50,000 mPa·s or less; A two-component curing composition for coating the inner walls of water pipes.

2. 2. The two-component curing composition for coating the inner wall of a water pipe according to claim 1, wherein the amine compound comprises a first amine compound having a molecular weight of 1,000 or more and a second amine compound having a molecular weight of less than 1,000.

3. 3. The two-component curing composition for coating the inner wall of a water pipe according to claim 1, wherein the isocyanate compound is an aromatic isocyanate compound having an aromatic ring.

4. 3. The two-component curing composition for coating the inner wall of a water pipe according to claim 1 or 2, wherein the main agent (A) and the curing agent (B) come into contact with each other and cure to form a coating layer that covers the inner wall of the water pipe, thereby coating the inner wall of the water pipe.

5. 3. The two-component curing composition for coating the inner wall of a water pipe according to claim 1, wherein the weight average molecular weight (Mw) of the first polyhydric alcohol compound is 100 to 20,000.

6. 3. The two-component curing composition for coating the inner wall of a water pipe according to claim 1, wherein the second polyhydric alcohol compound has a weight average molecular weight (Mw) of 100 to 2,000.

7. The two-component curing composition for coating the inner wall of a water pipe according to claim 1 or 2, wherein the isocyanate compound contains two or more aromatic isocyanate compounds having an aromatic ring.

8. 3. The two-component curing composition for coating the inner wall of a water pipe according to claim 1, wherein the amine compound has an amine value of 20 mgKOH / g to 800 mgKOH / g.

9. The two-component curing composition for coating the inner wall of a water pipe according to claim 1 or 2, wherein the water pipe is a drainage pipe.

10. A cured product obtained by curing the two-component curing composition for coating the inner wall of a water pipe according to claim 1 or 2.

11. The water pipe body, The cured product according to claim 10 coated on the inner wall of the water pipe body; A water pipe with an inner wall coating.

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