Blocked urethane, blocked urethane composition, resin composition, cured product and adhesive, and method for producing blocked urethane and blocked urethane composition

Abstract

To provide blocked urethane which is used as a raw material of an adhesive excellent in low temperature impact strength, and is excellent in storage stability.SOLUTION: Blocked urethane includes a structural unit derived from polyol (A) and a structural unit derived from a polyisocyanate compound (B), and includes at least a structural unit derived from polyether polycarbonate diol (A-1) represented by the following formula (1), as the structural unit derived from the polyol (A), wherein a carbonate equivalent of the polyol (A) is 200 g / eq or more. In the formula (1), R1 represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n1 is 2 to 30, and m1 is 1 to 20. In the formula (1), the plurality of R1 may be the same or different, and the plurality of n1 may be the same or different.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a blocked urethane, a blocked urethane composition, a resin composition, a cured product, an adhesive, and a method for producing the blocked urethane and the blocked urethane composition. [Background technology]

[0002] Urethane resins used in structural adhesives and resin compositions containing them have conventionally been composed of various components and have been used in a variety of applications. When an epoxy resin, known as a thermosetting resin, is contained in the resin composition, the epoxy resin is hard and brittle, and therefore, a method of adding a specific toughening agent is known as a method for improving the toughness of the epoxy resin.

[0003] For example, Patent Document 1 describes a structural adhesive containing an epoxy resin and a polytetrahydrofuran-based toughening agent having blocked or capped isocyanate groups as a blocked urethane. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2008 / 157571 Summary of the Invention [Problem to be solved by the invention]

[0005] Although polytetrahydrofuran-based toughening agents, such as those described in Patent Document 1, can improve the toughness of epoxy resins, their high crystallinity due to their structure causes crystal precipitation during long-term storage, resulting in poor storage stability. Furthermore, for example, structural adhesives for automotive applications require low-temperature impact strength, and improvements in these properties are desired.

[0006] The present invention has been made in view of the above-mentioned problems of the prior art. That is, an object of the present invention is to provide a blocked urethane that can be used as a raw material for adhesives that have excellent low-temperature impact strength and excellent storage stability. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by preparing a blocked urethane containing a polyol containing a specific structural unit, in which the carbonate equivalent of the polyol is controlled within a specific range.

[0008] That is, the gist of the present invention is as follows. [1] A polyol (A) containing structural units derived from a polyisocyanate compound (B), The structural unit derived from the polyol (A) contains at least a structural unit derived from a polyether polycarbonate diol (A-1) represented by the following formula (1): The carbonate equivalent of the polyol (A) is 200 g / eq or more. Blocked urethane. [ka] (In the formula (1), R 1 represents a divalent hydrocarbon group having 2 to 10 carbon atoms, and n 1 is 2 to 30, and m 1 is 1 to 20. In the formula (1), a plurality of R 1 may be the same or different, and multiple n 1 may be the same or different.) [2] The blocked urethane according to [1], wherein the polyol (A) has a number average molecular weight calculated from the hydroxyl value of 600 or more and 10,000 or less. [3] The blocked urethane according to [1] or [2], wherein the proportion by mass of the polyether polycarbonate diol represented by the formula (1) relative to the mass of all polyols contained in the polyol (A) is 50% or more. [4] R in the formula (1) 1 The blocked urethane according to any one of [1] to [3], wherein each of the groups is an n-butylene group. [5] n in the formula (1) 1 The blocked urethane according to any one of [1] to [4], wherein each of [6] The blocked urethane according to any one of [1] to [5], wherein the polyisocyanate compound (B) is a diisocyanate. [7] The blocked urethane according to [6], wherein the polyisocyanate compound (B) is an aliphatic diisocyanate or an alicyclic diisocyanate. [8] The blocked urethane according to any one of [1] to [7], wherein the terminal of the urethane prepolymer chain of the blocked urethane has a structure derived from a phenol compound. [9] The blocked urethane according to any one of [1] to [8], wherein the weight average molecular weight of the blocked urethane is 3,000 or more and 24,000 or less.

[10] The structural units derived from the polyol (A) further include structural units derived from a polyol (A-2) that does not contain a carbonate group, The blocked urethane according to any one of [1] to [9], which contains at least one of a structural unit derived from polytetramethylene ether glycol and a structural unit derived from polypropylene glycol as the structural unit derived from the polyol (A-2) that does not contain a carbonate group.

[11] A blocked urethane (I) according to any one of [1] to

[10] , and a blocked urethane (II) containing structural units derived from a carbonate group-free polyol (A'-2) and structural units derived from a polyisocyanate compound (B), wherein the structural units derived from the polyol (A'-2) include at least one of a structural unit derived from polytetramethylene ether glycol and a structural unit derived from polypropylene glycol; Blocked urethane composition.

[12] A resin composition comprising the blocked urethane according to any one of [1] to

[10] , an epoxy resin (D), and a curing agent (E).

[13] The resin composition according to

[12] , further comprising polymer fine particles (F).

[14] The resin composition according to

[12] or

[13] , wherein the curing agent (E) is a latent curing agent.

[15] A cured product obtained by curing the resin composition according to any one of

[12] to

[14] .

[16] An adhesive comprising the resin composition according to any one of

[12] to

[14] .

[17] Polyol (A) and polyisocyanate compound (B) are reacted to form a urethane Obtaining a prepolymer; and a step of blocking a terminal isocyanate group of the urethane prepolymer with a blocking agent (C), As the polyol (A), at least a polyether polycarbonate diol (A-1) represented by the following formula (1) is used, The carbonate equivalent of the polyol (A) is 200 g / eq or more. A method for manufacturing blocked urethane. [ka] (In the formula (1), R 1 represents a divalent hydrocarbon group having 2 to 10 carbon atoms, and n 1 is 2 to 30, and m 1 is 1 to 20. In the formula (1), a plurality of R 1 may be the same or different, and multiple n 1may be the same or different.)

[18] The polyol (A) further contains a polyol (A-2) that does not contain a carbonate group, At least one of polytetramethylene ether glycol and polypropylene glycol is used as the carbonate group-free polyol (A-2).

[17] A method for producing a blocked urethane.

[19] A method for producing a blocked urethane, comprising a step of mixing the blocked urethane (I) obtained by the method for producing a blocked urethane according to

[17] or

[18] and the blocked urethane (II), the blocked urethane (II) contains a structural unit derived from a polyol (A'-2) containing no carbonate group and a structural unit derived from a polyisocyanate compound (B), A method for producing a blocked urethane composition, which is a blocked urethane containing at least one of a structural unit derived from polytetramethylene ether glycol and a structural unit derived from polypropylene glycol as the structural unit derived from the polyol (A'-2). [Effects of the Invention]

[0009] According to the present invention, a blocked urethane can be provided which can be used as a raw material for adhesives having excellent low-temperature impact strength and excellent storage stability. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes in detail an embodiment of the present invention, but the description of the constituent elements described below is one example of an embodiment of the present invention, and the present invention is not limited to the following description as long as it does not deviate from the gist of the present invention. Note that when the expression "to" is used in this specification, it is used as an expression that includes the numerical values ​​or physical property values ​​before and after it. The blocked urethane of this embodiment is a heat-reactive urethane resin with blocked isocyanate groups in the urethane skeleton. The terminal active isocyanate groups are protected with a blocking agent, and the resin remains stable at room temperature. When subjected to heat treatment, the blocking agent dissociates, regenerating the active isocyanate groups, which initiate a curing and crosslinking reaction, thereby developing adhesive strength. Furthermore, although a number of embodiments are described in this specification, various conditions in each embodiment may be applied to each other to the extent that they are applicable.

[0011] <Blocked urethane composition> A blocked urethane according to one embodiment of the present invention (hereinafter simply referred to as "blocked urethane") (also referred to as "blocked urethane") is a blocked urethane containing structural units derived from a polyol (A) and structural units derived from a polyisocyanate compound (B), containing at least structural units derived from a polyether polycarbonate diol (A-1) represented by the following formula (1) as the structural units derived from the polyol (A), and the carbonate equivalent of the polyol (A) is 200 g / eq or more.

[0012] [ka]

[0013] In the formula (1), R 1 represents a divalent hydrocarbon group having 2 to 10 carbon atoms, and n 1 is 2 to 30, and m 1 is 1 to 20. In addition, in formula (1), multiple R 1 may be the same or different, and multiple n 1 may be the same or different.

[0014] [Polyol (A)] The blocked urethane contains, as the polyol (A), at least a structural unit derived from the polyether polycarbonate diol (A-1) represented by the above formula (1). The structural unit derived from the polyether polycarbonate diol (A-1) contained as the polyol (A) in the blocked urethane may be of one type or two or more types.

[0015] In formula (1), R 1 is a divalent hydrocarbon group having 2 to 10 carbon atoms, preferably a linear or branched alkylene group having 2 to 10 carbon atoms, more preferably a linear or branched alkylene group having 3 to 6 carbon atoms, particularly preferably a butylene group having 4 carbon atoms or a 2-methylbutylene group having 5 carbon atoms, and most particularly preferably an n-butylene group. 1 R related to the part represented by 1 It is preferable that --O-- is derived from polytetramethylene ether glycol from the viewpoints of industrial availability and excellent physical properties of the resulting blocked urethane.

[0016] In the above formula (1), n 1 is an average value of 2 to 30, preferably 3 to 20, more preferably 4 to 20, and further preferably 4 to 15. 1 If the content is less than the lower limit, the low-temperature impact strength of the resulting adhesive tends to be poor, whereas if the content exceeds the upper limit, the viscosity and crystallinity of the polyether polycarbonate diol increase, leading to poor handleability and poor storage stability of the resulting blocked urethane.

[0017] In the above formula (1), m 1 is an average value of 1 to 20, preferably 1 to 15, and more preferably 1 to 10. 1 If the viscosity is less than the lower limit, the performance of the resulting blocked urethane as a reinforcing agent tends to be inferior, whereas if the viscosity is greater than the upper limit, the viscosity increases, which may impair handling during production of the blocked urethane.

[0018] The mass ratio of the polyether polycarbonate diol represented by formula (1) to the mass (100%) of all polyols contained in polyol (A) is not particularly limited, but is preferably 30% or more, more preferably 50% or more, and even more preferably 70% or more, and the upper limit is not particularly limited, and may be 100% or less. When the ratio is equal to or greater than the lower limit of the above range, an excellent balance of effects of storage stability and low-temperature impact strength is achieved.

[0019] The polyol (A) contained in the blocked urethane may contain, as a structural unit derived from the polyol (A), a structural unit derived from a polyol other than the structural unit derived from the polyether polycarbonate diol (A-1) represented by the above formula (1) (hereinafter also referred to as "other polyols"). The structural unit derived from the other polyol may be of one type or of two or more types.

[0020] The other polyols are not particularly limited as long as they are those that are commonly used in the production of polyurethanes, and examples thereof include polyether polyols, polyester polyols, polycaprolactone polyols, and polycarbonate polyols. In particular, from the viewpoint of low-temperature impact strength when used as an adhesive, the blocked urethane preferably contains a structural unit derived from a polyol (A-2) that does not contain a carbonate group, and from the viewpoint of hydrolysis resistance, it is more preferable that the blocked urethane contains a structural unit derived from a polyether polyol.

[0021] Examples of polyether polyols include polytetramethylene ether glycol, polypropylene glycol, and polyethylene glycol. In particular, from the viewpoint of low-temperature impact strength when used as an adhesive, the blocked urethane preferably contains either a structural unit derived from polytetramethylene ether glycol or a structural unit derived from polypropylene glycol.

[0022] When the blocked urethane contains structural units derived from polyol (A-2), the mass ratio of the structural units derived from polyol (A-1) to the structural units derived from polyol (A-2) is preferably 1:9 to 9:1, and more preferably 2:8 to 8:2. Having this ratio within the above range improves the storage stability and the low-temperature impact strength when used as an adhesive.

[0023] From the viewpoint of storage stability and low-temperature impact strength when used as an adhesive, the carbonate equivalent of the polyol is not particularly limited as long as it is 200 g / eq or more, but is preferably 300 g / eq or more, more preferably 500 g / eq or more, even more preferably 800 g / eq or more, and particularly preferably 1000 g / eq or more, and is preferably 10000 g / eq or less, more preferably 5000 g / eq or less, even more preferably 4000 g / eq or less, and particularly preferably 3000 g / eq or less. If the carbonate equivalent is above the lower limit of the above range, the low-temperature impact strength when used as an adhesive is further improved. Furthermore, if the carbonate equivalent is below the upper limit of the above range, the storage stability is excellent.

[0024] The carbonate equivalent (g / eq) of a polyol (hereinafter referred to as "polyol X" in this description) is calculated using the following formula: The number average molecular weight of polyol X in the following formula can be measured by the method described below. Carbonate equivalent of polyol X (g / eq) = number average molecular weight of polyol X / average number of carbonate groups per molecule of polyol X When the blocked urethane contains structural units derived from x types (x is an integer of 1 or greater) of polyols (polyol 1, polyol 2, ..., polyol x) as structural units derived from polyol (A), the carbonate equivalent of polyol (A) is represented by the following formula: In the formula, "parts by mass" represents the parts by mass of the polyol component contained in the blocked urethane (parts by mass of the structural units derived from the polyol). Carbonate equivalent weight (g / eq) of polyol (A) = (parts by mass of polyol 1 + parts by mass of polyol 2 + + parts by mass of polyol x) / {(parts by mass of polyol 1 / carbonate equivalent weight of polyol 1) + (parts by mass of polyol 2 / carbonate equivalent weight of polyol 2) + + (parts by mass of polyol x / carbonate equivalent weight of polyol x)} In addition, in the case of polyol k having a carbonate equivalent of 0 g / eq, (parts by mass of polyol k / carbonate equivalent of polyol k) is set to 0 g / eq.

[0025] The content of structural units derived from polyol (A) contained in the block urethane is not particularly limited, but is preferably 44% by mass or more, more preferably 46% by mass or more, even more preferably 48% by mass or more, and particularly preferably 50% by mass or more, relative to 100% by mass of the block urethane. It is also preferably 85% by mass or less, more preferably 84% by mass or less, even more preferably 83% by mass or less, and particularly preferably 80% by mass or less. When the content is equal to or greater than the lower limit of the above range, the storage stability and low-temperature impact strength of the adhesive are further improved. When the content is equal to or less than the upper limit of the above range, the storage stability and low-temperature impact strength of the adhesive are further improved.

[0026] The number average molecular weight calculated from the hydroxyl value of the polyol (A) is not particularly limited, but is preferably 500 or more, more preferably 600 or more, even more preferably 800 or more, and particularly preferably 1000 or more, and is preferably 15000 or less, more preferably 10000 or less, even more preferably 4000 or less, and particularly preferably 3000 or less. If the number average molecular weight is at least the lower limit of the above range, the low-temperature impact strength of the resulting adhesive is further improved. Furthermore, if the number average molecular weight is at most the upper limit of the above range, the storage stability is excellent.

[0027] The number average molecular weight can be determined by the following method. First, the hydroxyl value of a polyol is measured in accordance with the American Society for Testing and Materials (ASTM) standard by preparing a tetrahydrofuran solution and subjecting the hydroxyl groups to urethanization with p-toluenesulfonyl isocyanate. The excess urethanization reagent is then hydrolyzed with water, and the sulfonylamide ester formed from the sample hydroxyl groups is titrated with a base to determine the hydroxyl value. Next, the number average molecular weight (Mn) is calculated from the obtained hydroxyl value using the following formula (I): Number average molecular weight = 2 × 56.1 / (hydroxyl value × 10 -3 ) ···(I)

[0028] The polyol (A) used as a raw material that provides the structural units derived from the polyol (A) may be a commercially available product.

[0029] [Polyisocyanate] The blocked urethane contains structural units derived from a polyisocyanate compound (B). The polyisocyanate compound (B) may be any compound having two or more isocyanate groups, and examples thereof include various known aliphatic, alicyclic, and aromatic polyisocyanate compounds. The structural unit derived from the polyisocyanate compound (B) contained in the blocked urethane may be of one type or two or more types.

[0030] Examples of the polyisocyanate compound (B) include aliphatic diisocyanate compounds such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and dimer diisocyanate in which the carboxyl groups of dimer acid are converted to isocyanate groups; and aliphatic diisocyanates such as 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, and 1,5-pentamethylene diisocyanate. cyclic diisocyanate compounds; aromatic diisocyanate compounds such as xylylene diisocyanate, 4,4'-diphenyl diisocyanate, toluene diisocyanate (2,4-toluene diisocyanate, 2,6-toluene diisocyanate), m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, polymethylene polyphenyl isocyanate, phenylene diisocyanate, and m-tetramethylxylylene diisocyanate;

[0031] Among these, diisocyanates are preferred because they help to suppress gelation during urethane production. Aliphatic diisocyanates and alicyclic diisocyanates are preferred because the resulting blocked urethane has favorable physical properties, and 4,4'-dicyclohexylmethane diisocyanate, 1,6-hexamethylene diisocyanate, and isophorone diisocyanate are particularly preferred because they are available industrially in large quantities at low cost.

[0032] The content of structural units derived from polyisocyanate compound (B) contained in the block urethane is not particularly limited, but is preferably 11% by mass or more, more preferably 12% by mass or more, even more preferably 13% by mass or more, and particularly preferably 14% by mass or more, relative to 100% by mass of the block urethane. It is also preferably 26% by mass or less, more preferably 25% by mass or less, even more preferably 24% by mass or less, and particularly preferably 23% by mass or less. When the content is equal to or greater than the lower limit of the above range, the storage stability and low-temperature impact strength of the adhesive are further improved. When the content is equal to or less than the upper limit of the above range, the storage stability and low-temperature impact strength of the adhesive are further improved, resulting in excellent storage stability.

[0033] As the polyisocyanate compound (B) as a raw material that provides the structural units derived from the polyisocyanate compound (B), a commercially available product may be used.

[0034] [Blocking agent (C)] In blocked urethane, active isocyanate groups are protected with a blocking agent, but the blocking agent is not particularly limited. Examples of blocking agents include monofunctional phenols such as phenol, cresol, xylenol, nitrophenol, ethylphenol, hydroxydiphenyl, butylphenol (e.g., pt-butylphenol), isopropylphenol, nonylphenol, octylphenol, and methyl hydroxybenzoate; bisphenols such as bisphenol A, bisphenol F, bisphenol E, bisphenol Z, bisphenol S, bisphenol AD, bisphenolacetophenone, bisphenoltrimethylcyclohexane, bisphenolfluorene, tetramethylbisphenol A, tetramethylbisphenol F, tetra-t-butylbisphenol A, and tetramethylbisphenol S; and bisphenols such as bisphenol A, bisphenol F, tetramethylbisphenol F, tetra-t-butylbisphenol A, and tetramethylbisphenol S. Biphenols such as phenol, tetramethylbiphenol, dimethylbiphenol, and tetra-t-butylbiphenol; benzenediols such as hydroquinone, methylhydroquinone, dibutylhydroquinone, resorcin, and methylresorcin (here, "benzenediols" refers to compounds having one benzene ring, with two hydroxyl groups directly bonded to the benzene ring); dihydroanthrahydroquinones such as dihydroanthrahydroquinone; dihydroxydiphenyl ethers such as dihydroxydiphenyl ether; thiodiphenols such as thiodiphenol; dihydroxynaphthalenes such as dihydroxynaphthalene; dihydroxystilbenes such as dihydroxystilbene;α,α-Bis(4-hydroxyphenyl)-4-(4-hydroxy-α,α-dimethylbenzyl)-ethylbenzene, 4,4',4''-trihydroxytriphenylmethane, 4,4',4''-ethylidinetris(2-methylphenol), 4,4'-(2-hydroxybenzylidene)bis(2,3,6-trimethylphenol), 2,3,4-trihydroxydiphenylmethane, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine, 1,3,5-tris(4-hydroxyphenyl)- polyfunctional phenols such as 4,4'-(1-{4-[1-(4-hydroxy-3,5-dimethylphenyl)-1-methylethyl]phenyl}ethylidene)bis(2-methylphenol), 2,6-bis(4-hydroxy-3,5-dimethylbenzyl)-4-methylphenol; lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-propiolactam; methanol, ethanol, propyl alcohol, Aliphatic alcohols such as butyl alcohol, amyl alcohol, and lauryl alcohol; ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and methoxymethanol; alcohols such as benzyl alcohol, glycolic acid, methyl glycolate, ethyl glycolate, butyl glycolate, lactic acid, methyl lactate, ethyl lactate, butyl lactate, methylol urea, methylol melamine, diacetone alcohol, 2-hydroxyethyl acrylate, and 2-hydroxyethyl methacrylate; oximes such as formamide oxime, acetamide oxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzophenone oxime, and cyclohexane oxime; activated methylenes such as dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, and acetylacetone;Mercaptans such as butyl mercaptan, t-butyl mercaptan, hexyl mercaptan, t-dodecyl mercaptan, 2-mercaptobenzothiazole, thiophenol, methylthiophenol, and ethylthiophenol; acid amides such as acetanilide, acetanisidide, acetotoluide, acrylamide, methacrylamide, acetic amide, stearic acid amide, and benzamide; imides such as succinimide, phthalic acid imide, and maleic acid imide; diphenylamine, phenylnaphthylamine, Examples of suitable compounds include amine-based compounds such as xylidine, N-phenylxylidine, carbazole, aniline, naphthylamine, butylamine, dibutylamine, and butylphenylamine; imidazole-based compounds such as imidazole and 2-ethylimidazole; urea-based compounds such as urea, thiourea, ethyleneurea, ethylenethiourea, and diphenylurea; carbamate-based compounds such as N-phenylphenylcarbamate; imine-based compounds such as ethyleneimine and propyleneimine; sulfite-based compounds such as sodium bisulfite and potassium bisulfite; and azole-based compounds. Examples of the azole compounds include pyrazoles or pyrazole derivatives such as pyrazole, 3,5-dimethylpyrazole, 3-methylpyrazole, 4-benzyl-3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3,5-dimethylpyrazole, and 3-methyl-5-phenylpyrazole; imidazoles or imidazole derivatives such as imidazole, benzimidazole, 2-methylimidazole, 2-ethylimidazole, and 2-phenylimidazole; and imidazoline derivatives such as 2-methylimidazoline and 2-phenylimidazoline.

[0035] In order to provide a blocked urethane with excellent storage stability, it is preferable that the terminal of the urethane prepolymer chain of the blocked urethane has a structure derived from a phenol compound. Therefore, among the blocking agents (C), it is preferable to use monofunctional phenol-based or polyfunctional phenol-based blocking agents.

[0036] As the blocking agent (C), a commercially available product may be used.

[0037] The content of structural units derived from the blocking agent (C) contained in the block urethane is not particularly limited, but is preferably 3% by mass or more, more preferably 4% by mass or more, and even more preferably 5% by mass or more, relative to 100% by mass of the block urethane. It is particularly preferably 6% by mass or more, and also preferably 29% by mass or less, more preferably 27% by mass or less, even more preferably 25% by mass or less, and particularly preferably 23% by mass or less. When the content is equal to or greater than the lower limit of the above range, the storage stability and low-temperature impact strength when used as an adhesive are further improved. On the other hand, when the content is equal to or less than the upper limit of the above range, the storage stability and low-temperature impact strength when used as an adhesive are further improved.

[0038] The weight-average molecular weight of the blocked urethane is not particularly limited, but is preferably 2,000 or more, more preferably 3,000 or more, even more preferably 4,000 or more, and particularly preferably 5,000 or more, and is preferably 30,000 or less, more preferably 24,000 or less, even more preferably 20,000 or less, and particularly preferably 16,000 or less. If the weight-average molecular weight is at least the lower limit of the above range, the storage stability and low-temperature impact strength when used as an adhesive are further improved. On the other hand, if the weight-average molecular weight is at most the upper limit of the above range, the storage stability and low-temperature impact strength when used as an adhesive are further improved.

[0039] The weight-average molecular weight can be measured as a polystyrene equivalent value using a gel permeation chromatograph (GPC apparatus) (for example, HLC-8420GPC manufactured by Tosoh Corporation). In this case, the measurement conditions can be, for example, as follows. Column: Tosoh Corporation's "TSKgel superHZM-H" + "TSKgel superHZ4000" x 2 + "TSKgel super3000" + "TSKgel Super 2000" Eluent: tetrahydrofuran ·Flow rate: 0.5mL / min Detection: RI ·Temperature: 40℃ Sample concentration: 0.4% by mass Injection volume: 10 μL Weight average molecular weight Mw of blocked urethane: Calculated from the peak at elution time 0-28 min

[0040] The structure of the blocked urethane can be analyzed by NMR or the like, and from this analysis, the average number of carbonate groups per polyol molecule and the like can be evaluated.

[0041] The content of structural units derived from the blocking agent (C) contained in the block urethane can be evaluated by the above-mentioned analytical method, but it may also be evaluated from the amount of each raw material used.

[0042] <Method of manufacturing blocked urethane> The method for producing the blocked urethane is not particularly limited as long as it is a commonly used method, but examples include a method comprising a step of reacting a polyol (A) and a polyisocyanate compound (B) to obtain a urethane prepolymer (hereinafter referred to as a prepolymerization step), and a step of blocking the terminal isocyanate groups of the urethane prepolymer with a blocking agent (C) (hereinafter referred to as a blocking step). In this example, at least a polyether polycarbonate diol (A-1) represented by the following formula (1) is used as the polyol (A), and the carbonate equivalent of the polyol (A) is 200 g / eq or more.

[0043] [Prepolymerization process] In the prepolymerization step, polyol (A) is reacted with an excess equivalent of polyisocyanate compound (B) relative to the hydroxyl group equivalent of polyol (A) to produce a prepolymer having an isocyanate group at the molecular chain terminal. the isocyanate group of the polyisocyanate compound (B) in the prepolymerization step; The molar ratio of the isocyanate groups of the polyisocyanate compound (B) to the hydroxyl groups derived from the polyol (A) (isocyanate groups of the polyisocyanate compound (B) / hydroxyl groups derived from the polyol (A)) is preferably 1.2 to 5.0, more preferably 1.4 to 3.0, and particularly preferably 1.6 to 2.5. By keeping it within the above range, a decrease in the number of functional groups as a blocked urethane and an increase in the amount of unreacted polyisocyanate monomer remaining in the prepolymerization step can be suppressed, and the performance as a toughening agent can be fully exhibited.

[0044] The polyol (A) used may be one type, or as mentioned above, two types may be used. When two types of polyols are used, it is preferable to use a polyol (A-2) that does not contain a carbonate group together with the polyether polycarbonate diol (A-1) represented by the following formula (1), particularly from the viewpoint of low-temperature impact strength when formed into an adhesive. As mentioned above, the polyol (A-2) is preferably a polyether polyol, and more preferably polytetramethylene ether glycol or polypropylene glycol.

[0045] In the prepolymerization step, a catalyst can be added as needed. Examples of the catalyst include amine catalysts such as triethylamine, tributylamine, N-ethylmorpholine, and triethylenediamine; acid catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid; tin compounds such as trimethyltin laurate, dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin dineodecanoate; and organometallic salts of titanium compounds. One catalyst may be used alone, or two or more catalysts may be used in combination. The amount of the catalyst added is preferably 1 ppm by mass or more and 3000 ppm by mass or less with respect to 100 parts by mass of the total amount of the polyurethane resin.

[0046] The reaction temperature in the prepolymerization reaction is not particularly limited, but from the viewpoint of controlling heat generation during the reaction, it is preferably 60 to 100°C, more preferably 65 to 95°C, and even more preferably 70 to 90°C. The reaction time in the prepolymerization reaction is not particularly limited, but from the viewpoint of disappearance of isocyanate groups, it is preferably 30 to 210 minutes, more preferably 60 to 180 minutes, and even more preferably 90 to 150 minutes. The reaction atmosphere in the prepolymerization reaction is not particularly limited, and may be an air atmosphere, but is preferably an inert gas atmosphere such as nitrogen gas or argon gas.

[0047] [Blocking process] In the blocking step, the terminal isocyanate groups of the prepolymer having isocyanate groups at the molecular chain terminals produced in the prepolymerization step are blocked with a blocking agent (C) to produce a blocked urethane. The molar ratio of the blocking agent (C) to the terminal isocyanate groups of the prepolymer in the blocking step (blocking agent (C) / terminal isocyanate groups of the prepolymer) is preferably 1.0 to 5.0, more preferably 1.1 to 3.0, and particularly preferably 1.2 to 2.0. If the ratio is less than the lower limit, the isocyanate groups of the prepolymer will remain, shortening the storage stability of the blocked urethane and the pot life of the curable resin composition. If the ratio exceeds the upper limit, the amount of remaining monomer of the blocking agent will increase, impairing the adhesiveness when used as an adhesive, which is undesirable.

[0048] In the blocking step, a catalyst can be added as needed. Examples of the catalyst include amine catalysts such as triethylamine, tributylamine, N-ethylmorpholine, and triethylenediamine, acid catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid, tin compounds such as trimethyltin laurate, dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin dineodecanoate, and organometallic salts such as titanium compounds. One catalyst may be used alone. Two or more kinds may be used in combination, and the same one as that used in the prepolymerization step may be used, or a different one may be used. The amount of the catalyst added is preferably 1 ppm by mass or more and 3000 ppm by mass or less with respect to 100 parts by mass of the total amount of the polyurethane resin.

[0049] The reaction temperature in the blocking reaction is not particularly limited, but from the viewpoint of controlling heat generation during the reaction, it is preferably 70 to 110°C, more preferably 75 to 105°C, and even more preferably 80 to 100°C. The reaction time in the blocking reaction is not particularly limited, but from the viewpoint of disappearance of isocyanate groups, it is preferably 1 to 20 hours, more preferably 2 to 18 hours, and even more preferably 3 to 16 hours. The reaction atmosphere in the blocking reaction is not particularly limited, and may be an air atmosphere, but is preferably an inert gas atmosphere such as nitrogen gas or argon gas.

[0050] <Configuration of Blocked Urethane Composition> A blocked urethane composition (hereinafter also referred to simply as a "blocked urethane composition") which is another embodiment of the present invention is a blocked urethane composition which contains the above-mentioned blocked urethane (hereinafter also referred to as blocked urethane (I)), as well as a blocked urethane (hereinafter also referred to as blocked urethane (II)) which contains structural units derived from a polyol (A'-2) which does not contain a carbonate group and structural units derived from a polyisocyanate compound (B), and which contains at least one of a structural unit derived from polytetramethylene ether glycol and a structural unit derived from polypropylene glycol as the structural unit derived from the polyol (A'-2).

[0051] The blocked urethane (II) contains structural units derived from the polyol (A') and structural units derived from the polyisocyanate compound (B'), and the polyol (A') contains structural units derived from a polyol (A'-2) that does not contain a carbonate group. The conditions for the structural units derived from the polyol (A'-2) not containing a carbonate group in the description of the blocked urethane above can be applied to the same extent as possible. In other words, similar to the conditions for the structural units derived from the polyol (A-2) above, the structural units derived from the polyol (A'-2) may contain structural units other than the structural units derived from polytetramethylene ether glycol and the structural units derived from polypropylene glycol. Furthermore, the conditions for the polyisocyanate compound (B') in the above description of the blocked urethane can be similarly applied to the polyisocyanate compound (B') to the extent that they are applicable.

[0052] The blocked urethane (II) may contain a structural unit derived from a polyol other than the polyol (A'-2) as a structural unit derived from the polyol (A'). The structural unit derived from a polyol other than the polyol (A'-2) is not particularly limited, but from the viewpoints of storage stability and low-temperature impact strength when formed into an adhesive, a structural unit derived from a polyether polycarbonate diol (A'-1) represented by the following formula (2) is preferred.

[0053] [ka]

[0054] R in the above formula (2) 2 , n 2 , and m 2 The condition is expressed by R in the above formula (1). 1 , n 1 , and m 1 can be similarly applied to each of the above conditions. Furthermore, the conditions for the polyether polycarbonate diol (A'-1) represented by the above formula (2) can be the same as those for the polyether polycarbonate diol (A-1) represented by the above formula (1) to the extent that they are applicable.

[0055] When the blocked urethane (I) contains at least one of a structural unit derived from polytetramethylene ether glycol and a structural unit derived from polypropylene glycol, or when the blocked urethane (II) contains a structural unit derived from the polyether polycarbonate diol (A'-1) represented by the above formula (2), the blocked urethane (I) and the blocked urethane (II) become substantially indistinguishable. In other words, in this case, the blocked urethane composition essentially contains two types of blocked urethane (I), but because one blocked urethane satisfies the conditions of the blocked urethane (I) and the other blocked urethane satisfies the conditions of the blocked urethane (II), the above conditions of the blocked urethane composition are treated as being satisfied.

[0056] The blocked urethane composition may contain components other than the blocked urethane (I) and the blocked urethane (II) as long as the effects of the present invention are obtained.

[0057] When blocked urethane (I) and blocked urethane (II) can be distinguished, the content of blocked urethane (I) in the blocked urethane composition is preferably 5% by mass or more, more preferably 7% by mass or more, even more preferably 8% by mass or more, and particularly preferably 9% by mass or more, and is preferably 50% by mass or less, more preferably 44% by mass or less, even more preferably 42% by mass or less, and particularly preferably 40% by mass or less. When the content is at least the lower limit of the above range, the low-temperature impact strength of the resulting adhesive is further improved. On the other hand, when the content is at most the upper limit of the above range, the low-temperature impact strength of the resulting adhesive is further improved, and a decrease in heat resistance can be suppressed.

[0058] When blocked urethane (I) and blocked urethane (II) can be distinguished, the content of blocked urethane (II) in the blocked urethane composition is preferably 5% by mass or more, more preferably 7% by mass or more, even more preferably 8% by mass or more, and particularly preferably 9% by mass or more, and is preferably 50% by mass or less, more preferably 44% by mass or less, even more preferably 42% by mass or less, and particularly preferably 40% by mass or less. When the content is at least the lower limit of the above range, the low-temperature impact strength of the resulting adhesive is further improved. On the other hand, when the content is at most the upper limit of the above range, the low-temperature impact strength of the resulting adhesive is further improved, and a decrease in heat resistance can be suppressed.

[0059] When the blocked urethane (I) and the blocked urethane (II) cannot be distinguished from each other, the total content of the blocked urethane (I) and the blocked urethane (II) in the blocked urethane composition is preferably 5% by mass or more, more preferably 7% by mass or more, even more preferably 8% by mass or more, and particularly preferably 9% by mass or more, and is preferably 50% by mass or less, more preferably 44% by mass or less, even more preferably 42% by mass or less, and particularly preferably 40% by mass or less. When the content is at least the lower limit of the above range, the low-temperature impact strength of the resulting adhesive is further improved. When the content is at most the upper limit of the above range, the low-temperature impact strength of the resulting adhesive is further improved, and a decrease in heat resistance can be suppressed.

[0060] In the blocked urethane composition, the mass ratio of the blocked urethane (I) to the blocked urethane (II) is preferably in the range of 1:9 to 9:1, and more preferably 2:8 to 3:1. It is more preferable that the ratio is 8:2. By setting the ratio within the above range, the effect of improving the toughness can be obtained. Furthermore, the blocked urethane composition may contain other components as needed.

[0061] The total carbonate equivalent of all polyols contained in the entire blocked urethane in the blocked urethane composition (hereinafter also referred to as the "total carbonate equivalent of the blocked urethane composition") is not particularly limited, but is preferably 300 g / eq or more, more preferably 500 g / eq or more, even more preferably 800 g / eq or more, and particularly preferably 1000 g / eq or more, and is preferably 10000 g / eq or less, more preferably 5000 g / eq or less, even more preferably 4000 g / eq or less, and particularly preferably 3000 g / eq or less. If the total carbonate equivalent is at least the lower limit of the above range, the low-temperature impact strength of the resulting adhesive is further improved. Furthermore, if the total carbonate equivalent is at most the upper limit of the above range, the storage stability is excellent.

[0062] When a blocked urethane composition contains one or more blocked urethanes, and the entire blocked urethane contains y types of structural units derived from polyols (polyol 1, polyol 2, ..., polyol y) (y is an integer of 1 or greater), the total carbonate equivalent of the blocked urethane composition is represented by the following formula: For example, if a blocked urethane composition contains two types of blocked urethanes, A and B, where blocked urethane A has structural unit 1 derived from a polyol and blocked urethane B has structural unit 2 derived from a polyol, the total carbonate equivalent of the blocked urethane composition is calculated taking into account polyol-derived structural unit 1 and polyol-derived structural unit 2. For example, if a blocked urethane composition contains two types of blocked urethanes, A and B, where blocked urethane A has structural unit 1 derived from a polyol and structural unit 2 derived from a polyol, and blocked urethane B has structural unit 3 derived from a polyol, the total carbonate equivalent of the blocked urethane composition is calculated taking into account polyol-derived structural unit 1, polyol-derived structural unit 2, and polyol-derived structural unit 3. In the formula, "parts by mass" represents the parts by mass of the polyol component contained in the blocked urethane (the parts by mass of the structural units derived from the polyol), and means the parts by mass relative to the mass of the entire blocked urethane (when multiple types of blocked urethanes are contained, the total mass of these multiple types of blocked urethanes). Total carbonate equivalent of blocked urethane composition (g / eq)=(parts by mass of polyol 1+parts by mass of polyol 2+···+parts by mass of polyol y) / {(parts by mass of polyol 1 / carbonate equivalent of polyol 1)+(parts by mass of polyol 2 / carbonate equivalent of polyol 2)+···+(parts by mass of polyol y / carbonate equivalent of polyol y)} In addition, in the case of polyol k having a carbonate equivalent of 0 g / eq, (parts by mass of polyol k / carbonate equivalent of polyol k) is set to 0 g / eq.

[0063] The method for producing the blocked urethane (II) is not particularly limited, and it can be produced, for example, by a method including the same steps as in the above-mentioned method for producing the blocked urethane (I).

[0064] The blocked urethane composition can be used in the same applications as the oil composition described below.

[0065] <Method for producing blocked urethane composition> A method for producing a blocked urethane composition according to another embodiment of the present invention is a method comprising a step of mixing the blocked urethane (I) produced by the above-described method for producing a blocked urethane and the above-described blocked urethane (II). ) is a blocked urethane containing structural units derived from a polyol (A'-2) that does not contain a carbonate group and structural units derived from a polyisocyanate compound (B), and containing at least one of structural units derived from polytetramethylene ether glycol and structural units derived from polypropylene glycol as the structural units derived from the polyol (A'-2). The method for producing the blocked urethane composition may include a step other than the above-mentioned mixing step.

[0066] The method for mixing the blocked urethane (I) and the blocked urethane (II) is not particularly limited, and can be carried out by a known method.

[0067] <Resin composition> A resin composition according to another embodiment of the present invention (hereinafter also simply referred to as "resin composition") contains the above-described blocked urethane (blocked urethane (I)) or blocked urethane composition, an epoxy resin (D), and a curing agent (E). Furthermore, the resin composition according to this embodiment can appropriately contain other curing accelerators, other components, and the like, as needed.

[0068] [Epoxy resin] The epoxy resin (D) is not particularly limited as long as it has difunctional or higher epoxy groups, and examples thereof include glycidyl ether epoxy resins such as bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, biphenyl epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, tetrabromobisphenol A epoxy resins, and other polyfunctional phenol epoxy resins, epoxy resins in which the aromatic rings of the above aromatic epoxy resins have been hydrogenated, glycidyl ester epoxy resins, glycidyl amine epoxy resins, linear aliphatic epoxy resins, alicyclic epoxy resins, and heterocyclic epoxy resins. Among these, bisphenol A epoxy resins and bisphenol F epoxy resins are particularly preferred from the viewpoint of industrial availability. The above-mentioned other epoxy resins may be used alone or in combination of two or more. In addition to the epoxy resin, a reactive diluent may also be used.

[0069] The amount of the blocked urethane blended in the resin composition per 100 parts by mass of the epoxy resin (D) is preferably 5 to 80 parts by mass, more preferably 10 to 75 parts by mass, and particularly preferably 20 to 70 parts by mass, based on the total mass of the epoxy resin (D) and the blocked urethane. By setting the blending amount of the blocked urethane within the above range, the effect of the blocked urethane as a reinforcing agent can be improved and the elasticity inherent in the epoxy resin can be maintained.

[0070] [Hardening agent (E)] The curing agent (E) is a substance that contributes to a crosslinking reaction and / or a chain extension reaction between epoxy groups of the epoxy resin. In this specification, even substances that are normally called "curing accelerators" are considered to be curing agents as long as they contribute to the crosslinking reaction and / or chain extension reaction between epoxy groups in epoxy resins.

[0071] The content of the curing agent in the resin composition is not particularly limited, but is preferably 0.1 to 1000 parts by mass, more preferably 100 parts by mass or less, even more preferably 80 parts by mass or less, and particularly preferably 60 parts by mass or less, relative to 100 parts by mass of the epoxy resin component. More preferred amounts of the curing agent are described below depending on the type of curing agent.

[0072] The curing agent (E) used in the resin composition is preferably a latent curing agent. In this embodiment, the term "latent" refers to a property in which the curing agent does not act as a curing agent at room temperature and normal pressure, but acts as a curing agent when heated. In the resin composition, it is preferable to use, as the curing agent, at least one selected from the group consisting of polyfunctional phenols, polyisocyanate compounds, amine compounds, acid anhydride compounds, imidazole compounds, urea compounds, amide compounds, cationic polymerization initiators, organic phosphines, phosphonium salts, and tetraphenylboron salts. Examples of polyfunctional phenols include bisphenols such as bisphenol A, bisphenol F, bisphenol S, bisphenol B, bisphenol AD, bisphenol Z, and tetrabromobisphenol A; biphenols such as 4,4'-biphenol and 3,3',5,5'-tetramethyl-4,4'-biphenol; catechol, resorcinol, hydroquinone, and dihydroxynaphthalenes; and compounds in which the hydrogen atoms bonded to the aromatic rings of these compounds have been substituted with non-interfering substituents such as halogen groups, alkyl groups, aryl groups, ether groups, ester groups, or organic substituents containing heteroatoms such as sulfur, phosphorus, or silicon. Further examples include novolaks, which are polycondensates of these phenols, or monofunctional phenols such as phenol, cresol, or alkylphenol with aldehydes, or resols.

[0073] Examples of polyisocyanate compounds include tolylene diisocyanate, methylcyclohexane diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, dimer acid diisocyanate, trimethylhexamethylene diisocyanate, lysine triisocyanate, etc. Further examples include polyisocyanate compounds obtained by reacting these polyisocyanate compounds with compounds having at least two active hydrogen atoms such as amino groups, hydroxyl groups, carboxyl groups, and water, and trimers to pentamers of the above polyisocyanate compounds.

[0074] Examples of amine compounds include aliphatic primary, secondary, and tertiary amines, aromatic primary, secondary, and tertiary amines, cyclic amines, guanidines, and urea derivatives, and specific examples include triethylenetetramine, diaminodiphenylmethane, diaminodiphenyl ether, metaxylenediamine, dicyandiamide, 1,8-diazabicyclo(5,4,0)-7-undecene, 1,5-diazabicyclo(4,3,0)-5-nonene, dimethylurea, and guanylurea.

[0075] Examples of the acid anhydride compound include phthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, or a condensate of maleic anhydride and an unsaturated compound.

[0076] Examples of imidazole compounds include 1-isobutyl-2-methylimidazole, 2-methylimidazole, 1-benzyl-2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, benzimidazole, etc. Although imidazole compounds also function as curing accelerators (described later), they are classified as curing agents in this specification.

[0077] Examples of the urea compound include p-chlorophenyl-N,N-dimethylurea, 3-phenyl-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-N,N-dimethylurea, and N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea. Note that although urea compounds also function as curing accelerators, which will be described later, they are categorized as curing agents in this specification.

[0078] Examples of the amide-based compound include dicyandiamide and its derivatives, polyamide resins, and the like.

[0079] The cationic polymerization initiator generates cations when exposed to heat or active energy rays, and examples thereof include aromatic onium salts. - , BF4 - , AsF6 - , PF6 - , CF3SO3 2- , B(C6F5)4 - and an aromatic cation component containing an atom such as iodine, sulfur, nitrogen, phosphorus, etc. Diaryliodonium salts and triarylsulfonium salts are particularly preferred.

[0080] Examples of organic phosphines include tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, and phenylphosphine. Examples of phosphonium salts include tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium ethyltriphenylborate, and tetrabutylphosphonium tetrabutylborate. Examples of tetraphenylboron salts include 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate.

[0081] When a polyfunctional phenol, an amine compound, or an acid anhydride compound is used as the curing agent, it is preferable to use them so that the equivalent ratio of the number of functional groups in the curing agent (the number of hydroxyl groups in a polyfunctional phenol, the number of amino groups in an amine compound, or the number of acid anhydride groups in an acid anhydride compound) to the total number of epoxy groups in the resin composition is in the range of 1:0.8 to 1:1.5. When a polyisocyanate compound is used as a curing agent, it is preferable to use it so that the equivalent ratio of the number of isocyanate groups in the polyisocyanate compound to the number of hydroxyl groups in the resin composition is in the range of 1:0.01 to 1:1.5.

[0082] When an imidazole compound is used as a curing agent, it is preferably used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the epoxy resin component. When an amide compound is used as the curing agent, the amount of the amide compound relative to the total amount of the epoxy resin component and the amide compound is preferably 0.1 to 20% by mass. When a cationic polymerization initiator is used as a curing agent, it is preferably used in an amount of 0.01 to 15 parts by mass per 100 parts by mass of the epoxy resin component. When organic phosphines, phosphonium salts or tetraphenylboron salts are used as the curing agent, it is preferable to use them in an amount of 0.1 to 20 mass % based on the total amount of the epoxy resin component and the organic phosphines, phosphonium salts or tetraphenylboron salts.

[0083] In addition to the curing agents listed above, for example, mercaptan compounds, organic acid dihydrazides, boron halide amine complexes, etc. can also be used as curing agents in the resin composition. These curing agents may be used alone or in combination of two or more. As the curing agent, dicyandiamide is preferred from the viewpoint of ensuring the pot life of the resin composition.

[0084] [Modifier] The resin composition may contain a modifier other than the blocked urethane according to the embodiment described above in order to improve the adhesiveness and toughness when used as an adhesive. Examples of modifiers include rubber-modified epoxy resins, urethane-modified epoxy resins, and rubber particles. When these modifiers are used, they may be used alone or in combination of two or more.

[0085] The resin composition is at least one of a rubber-modified epoxy resin and a urethane-modified epoxy resin (F). By using at least one of the rubber-modified epoxy resin and the urethane-modified epoxy resin in combination with the above-mentioned blocked urethane, the toughness-improving effect of the resulting resin composition can be improved.

[0086] (rubber-modified epoxy resin) The rubber-modified epoxy resin is a reaction product obtained by reacting rubber with an epoxy group-containing compound, and has an average of 1.1 or more, preferably 2 or more, epoxy groups per molecule. Examples of the rubber include polybutadiene, acrylonitrile butadiene rubber (NBR), and carboxyl-terminated NBR (CTBN). From the viewpoint of the toughness-improving effect of the resulting resin composition, the rubber-modified epoxy resin is preferably a carboxy-terminated butadiene-nitrile copolymer epoxy resin or an acrylonitrile-butadiene copolymer-modified epoxy resin. The rubber-modified epoxy resins may be used either alone or in combination of two or more.

[0087] The rubber-modified epoxy resin can be produced by any method, for example, by reacting rubber with an epoxy resin in a large amount of epoxy. The epoxy (e.g., epoxy resin) used in producing the rubber-modified epoxy resin is not particularly limited, and examples thereof include conventionally known epoxy resins.

[0088] The rubber-modified epoxy resin may be a commercially available product, specifically, for example, EPR-1 630 (manufactured by ADEKA Co., Ltd.) or the like can be used.

[0089] (urethane-modified epoxy resin) The urethane-modified epoxy resin is a reaction product obtained by reacting a compound containing an epoxy group and a group reactive with an isocyanate group with a urethane prepolymer containing an isocyanate group, and has an average of 1.1 or more epoxy groups per molecule, preferably 2 or more. For example, a urethane-modified epoxy resin can be obtained by reacting a hydroxyl-containing epoxy compound with a urethane prepolymer. The urethane-modified epoxy resins can be used either alone or in combination of two or more.

[0090] There are no particular limitations on the method for producing the urethane-modified epoxy resin. For example, it can be produced by reacting urethane with epoxy in a large amount of epoxy (e.g., epoxy resin). There are no particular limitations on the epoxy used in producing the urethane-modified epoxy resin. For example, conventionally known epoxy can be used.

[0091] As the urethane-modified epoxy resin, commercially available products may be used.

[0092] The amount of rubber-modified epoxy resin and / or urethane-modified epoxy resin in the resin composition is preferably 5 to 80 parts by mass, more preferably 10 to 70 parts by mass, and particularly preferably 20 to 50 parts by mass, per 100 parts by mass of epoxy resin (including rubber-modified epoxy resin and / or urethane-modified epoxy resin). By keeping the amount of rubber-modified epoxy resin and / or urethane-modified epoxy resin within the above range, the toughness-improving effect of the resin composition can be improved and the elasticity inherent in the epoxy resin can be maintained.

[0093] (Polymer particles (G)) The resin composition preferably further contains polymer fine particles (G). By using the blocked urethane according to the embodiment described above and the polymer fine particles (G) in combination as a reinforcing agent in an epoxy resin, the toughness-improving effect of the resulting resin composition can be improved.

[0094] The volume average particle diameter (Mv) of the polymer fine particles (G) is preferably 1 nm to 50 μm, and in consideration of industrial productivity, more preferably 5 nm to 10 μm, even more preferably 10 nm to 1 μm, and particularly preferably 50 nm to 500 nm. By setting the volume average particle diameter of the polymer fine particles within this range, there is an advantage that the toughness-improving effect is improved and a highly stable resin composition can be obtained.

[0095] In this specification, the "volume average particle diameter (Mv) of polymer microparticles (G)" refers to the volume average particle diameter of primary particles of polymer microparticles (G) unless otherwise specified. The volume average particle diameter (Mv) of polymer microparticles (G) can be measured using a dynamic light scattering particle size distribution analyzer (e.g., Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.)) using an aqueous latex containing polymer microparticles (G) as a sample. Alternatively, the volume average particle diameter of polymer microparticles (G) can be measured by cutting a cured product of a curable resin composition, photographing the cut surface using an electron microscope or the like, and using the obtained photographed data (photographed image).

[0096] The polymer fine particles (G) are preferably dispersed, but do not necessarily have to be dispersed.

[0097] In order to balance the ease of handling of the resulting resin composition and the toughness improving effect, the content of the polymer fine particles (G) is preferably 1 to 80 parts by mass, more preferably 5 to 50 parts by mass, and particularly preferably 10 to 40 parts by mass, per 100 parts by mass of the epoxy resin.

[0098] The polymer particles (G) preferably contain a rubber-containing graft copolymer, where the rubber-containing graft copolymer refers to one having an elastomer and a graft portion graft-bonded to the elastomer.

[0099] For details of the elastomer, graft portion, etc. related to the rubber-containing graft copolymer according to this embodiment, the contents described in JP 2020-164601 A can be cited.

[0100] The rubber-containing graft copolymer may be a commercially available product, for example, Kane Ace MX-154 (manufactured by Kaneka Corporation).

[0101] The rubber-containing graft copolymer may be used alone or in combination of two or more kinds.

[0102] The polymer fine particles (G) may be a combination of a rubber-containing graft copolymer and a polymer fine particle other than the rubber-containing graft copolymer. When the rubber-containing graft copolymer is used in combination with polymer particles other than the rubber-containing graft copolymer, the total mass proportion of the rubber-containing graft copolymer in the entire polymer particles according to this embodiment is preferably 10 mass% or more, and more preferably 30 mass% or more.

[0103] (Other ingredients) The resin composition may contain other components in addition to the components listed above. Examples of other components include a curing accelerator (which may be a curing agent), a coupling agent, a flame retardant, an antioxidant, a light stabilizer, a plasticizer, a reactive diluent, a pigment, an inorganic filler, or an organic filler (excluding those that fall under the modifier). The other components listed above can be used in appropriate combinations depending on the desired physical properties of the resin composition.

[0104] <Cured product> A cured product according to another embodiment of the present invention is a cured product obtained by curing the above-described resin composition. The method for curing the resin composition is not particularly limited, and can be performed by a known method. The curing conditions can be appropriately set depending on the components contained in the resin composition.

[0105] <Application> The above-mentioned resin composition has high peel strength, and the cured product obtained by curing the resin composition also has high adhesive strength and is highly reliable. Therefore, the resin composition and its cured product can be effectively used in any application requiring these physical properties. For example, the resin composition and its cured product can be suitably used in applications in the coating field, such as electrodeposition coatings for automobiles, heavy-duty corrosion-resistant coatings for ships and bridges, or coatings for the interior of beverage cans; in the electrical and electronic fields, such as laminates, semiconductor encapsulants, insulating powder coatings, or coil impregnation; or in the civil engineering, construction, and adhesive fields, such as earthquake reinforcement for bridges, concrete reinforcement, building flooring, water facility linings, drainage and permeable pavements, or adhesives for vehicles and aircraft. Among these, the resin composition is particularly useful for adhesive applications. Furthermore, when the resin composition and its cured product are used in these applications, there are no particular limitations on the manner of use. For example, the resin composition or its cured product can be incorporated into adhesives or the like. [Example]

[0106] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Note that the values ​​of various production conditions and evaluation results in the following examples represent preferred upper or lower limit values ​​in the embodiments of the present invention, and a preferred range may be defined by a combination of the above-mentioned upper or lower limit values ​​and the values ​​in the following examples or values ​​between the examples.

[0107] <Raw materials, etc.> The raw materials used in the following examples and comparative examples are as follows.

[0108] [Polyol (A)] A-1a: Polyether polycarbonate diol (constituent monomer PTMG1000(R 1 = n-butylene group, n 1 =14, m 1 =1) Number average molecular weight 1900)) A-1b: Polyether polycarbonate diol (PEPCD NT2006 manufactured by Mitsubishi Chemical Corporation; constituent monomer: PTMG650 (R 1 = n-butylene group, n 1 =9, m 1 =2) Number average molecular weight 2000)) A-1c: Polyether polycarbonate diol (PEPCD NT2002 manufactured by Mitsubishi Chemical Corporation; constituent monomer: PTMG250 (R 1 = n-butylene group, n 1 =3.5, m 1 =6) Number average molecular weight 2000)) A-1d: Polyether polycarbonate diol (constituent monomer PTMG650(R 1 = n-butylene group, n 1 =9, m 1 =1) Number average molecular weight 1300) A-1e: Polyether polycarbonate diol (PEPCD NT1002 manufactured by Mitsubishi Chemical Corporation; constituent monomer: PTMG250 (R 1 = n-butylene group, n 1 =3.5, m 1 =2.5) Number average molecular weight 1000)) A-2a: Polytetramethylene ether glycol (PTMG2000 (number average molecular weight 2000) manufactured by Mitsubishi Chemical Corporation) A-2b: Polypropylene glycol (Sanyo Chemical Industries, Ltd., Sannix PP2000 (number average molecular weight 2000)) A-3: Polycarbonate diol (NL1030B (number average molecular weight 1000) manufactured by Mitsubishi Chemical Corporation)

[0109] (carbonate equivalent) The carbonate equivalent (g / eq) in the polyol was calculated using the following formula: The number average molecular weight of polyol X in the following formula can be measured by the method described above. Carbonate equivalent of polyol X (g / eq) = number average molecular weight of polyol X / average number of carbonate groups per molecule of polyol X When the blocked urethane contains structural units derived from x types (n is an integer of 1 or greater) of polyols (polyol 1, polyol 2, ..., polyol x) as structural units derived from polyol (A), the carbonate equivalent of polyol (A) is expressed by the following formula: In the formula, "parts by mass" represents the parts by mass of the polyol component contained in the blocked urethane. Carbonate equivalent weight (g / eq) of polyol (A) = (parts by mass of polyol 1 + parts by mass of polyol 2 + + parts by mass of polyol x) / {(parts by mass of polyol 1 / carbonate equivalent weight of polyol 1) + (parts by mass of polyol 2 / carbonate equivalent weight of polyol 2) + + (parts by mass of polyol x / carbonate equivalent weight of polyol x)} In addition, in the case of polyol k having a carbonate equivalent of 0 g / eq, (parts by mass of polyol k / carbonate equivalent of polyol k) is set to 0 g / eq.

[0110] (Number average molecular weight of polyol) The hydroxyl value of the polyol was determined in accordance with the American Society for Testing and Materials (ASTM) standard by urethanizing the hydroxyl groups of the polyol in a tetrahydrofuran solution with p-toluenesulfonyl isocyanate, hydrolyzing the excess urethanizing reagent with water, and titrating the sulfonylamide ester formed from the hydroxyl groups of the sample with a base. The number average molecular weight (Mn) was calculated from the obtained hydroxyl value according to the following formula (I). Number average molecular weight = 2 × 56.1 / (hydroxyl value × 10 -3 ) ···(I)

[0111] [Polyisocyanate compound (B)] B-1: Isophorone diisocyanate (Tokyo Chemical Industry Co., Ltd.)

[0112] [Blocking agent (C)] C-1: pt-butylphenol (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0113] [Epoxy resin (D)] D-1: Bisphenol A liquid epoxy resin (Mitsubishi Chemical Corporation jER828, epoxy equivalent: 186 g / eq)

[0114] [Hardening agent (E)] E-1: Dicyandiamide (DICY7, manufactured by Mitsubishi Chemical Corporation, latent hardener)

[0115] [Polymer particles (F)] F-1: Kane Ace MX-154 (manufactured by Kaneka Corporation, volume average particle diameter 220 nm, polymer particles dispersed at 40% by mass in bisphenol A epoxy resin that is liquid at room temperature)

[0116] [Curing accelerator] DCMU: 3-(3,4-dichlorophenyl)-1,1-dimethylurea (Tokyo Chemical Industry Co., Ltd.)

[0117] [Glass beads] J-60: Glass beads with a particle size of approximately 250 μm (Potters-Barotini)

[0118] <Characteristics evaluation> The methods for evaluating the various properties in the following examples and comparative examples are as follows.

[0119] [Storage stability] The blocked urethanes of Examples 1 to 8, Comparative Examples 1 and 2, and Production Example 3 were stored at 23° C. for 7 days, and the presence or absence of crystal precipitation was visually confirmed.

[0120] [Method for measuring molecular weight] The molecular weight of the blocked urethane was measured using a gel permeation chromatograph (GPC device) (HLC-8420GPC, manufactured by Tosoh Corporation) to measure the weight average molecular weight Mw in terms of polystyrene. The measurement conditions were as follows: Column: Tosoh Corporation's "TSKgel superHZM-H" + "TSKgel superHZ4000" x 2 + "TSKgel super3000" + "TSKgel Super 2000" Eluent: tetrahydrofuran ·Flow rate: 0.5mL / min Detection: RI ·Temperature: 40℃ Sample concentration: 0.4% by mass Injection volume: 10 μL Weight average molecular weight Mw of blocked urethane: Calculated from the peak at elution time 0-28 min

[0121] [Wedge impact test JIS K6865] The resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were applied to a 0.8 mm thick bent steel plate (JIS G3141, SPCC-SD, Engineering Test Services Co., Ltd.) coated with rust-preventive oil (P-5960, Nippon Kogyo Oil Co., Ltd.). The bent steel plate coated with rust-preventive oil was then bonded to the coated steel plate and cured by heating at 170°C for 20 minutes. After curing, any excess cured material was removed from the steel plate to obtain symmetrical wedge test specimens. Using a Hydroshot HITS-T10 high-speed tensile tester (Shimadzu Corporation, 10 kN load cell), the symmetrical wedge test specimens were driven into the test pieces at -40°C and 2 m / s, and the dynamic cleavage resistance was measured during the cleavage of a 20 mm wide, 30 mm long cured epoxy resin specimen. The average dynamic cleavage resistance values ​​for the first 25% and last 10% of the travel distance were used to determine the low-temperature impact strength. Higher low-temperature impact strength indicates better performance.

[0122] <Production of polyol> [Polyol (A-1a)] A 0.5 L separable flask was charged with 204 parts by weight of polytetramethylene ether glycol (PTMG1000 (number average molecular weight 1000) manufactured by Mitsubishi Chemical Corporation), 21.9 parts by weight of diphenyl carbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.14 parts by weight of tetraammonium butyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.63 parts by weight of dibutyltin laurate (manufactured by Tokyo Chemical Industry Co., Ltd.) as catalysts, and heated to 80 ° C. When the diphenyl carbonate was melted, the pressure in the system was reduced to 10 kPa, the dissolved water was distilled off, and the pressure was returned to normal pressure. 0.34 parts by weight of tetra-n-butoxytitanium (manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the temperature was raised to 150 ° C. while stirring under a nitrogen gas atmosphere. After heating and stirring at 150 ° C. for 30 minutes, the pressure was gradually reduced to 1.5 kPa over 170 minutes, and the carbonate reaction was carried out while phenol was removed from the system. The mixture was further heated and stirred for 220 minutes while maintaining the reduced pressure of 1.5 kPa, to obtain polyether polycarbonate diol (A-1a) having a hydroxyl value of 59.91 mgKOH / g.

[0123] <Production of polyol> [Polyol (A-1d)] A 0.5 L separable flask was charged with 230 parts by weight of polytetramethylene ether glycol (PTMG650 (number average molecular weight 650) manufactured by Mitsubishi Chemical Corporation), 38.2 parts by weight of diphenyl carbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.24 parts by weight of tetraammonium butyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 1.10 parts by weight of dibutyltin laurate (manufactured by Tokyo Chemical Industry Co., Ltd.) as catalysts, and heated to 80 ° C. When the diphenyl carbonate was melted, the pressure in the system was reduced to 10 kPa, the dissolved water was distilled off, and the pressure was returned to normal pressure. Then, 0.60 parts by weight of tetra-n-butoxytitanium (manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the temperature was raised to 150 ° C. while stirring under a nitrogen gas atmosphere. After heating and stirring at 150 ° C. for 20 minutes, the pressure was gradually reduced to 2.0 kPa over 160 minutes, and the carbonate reaction was carried out while phenol was removed from the system. The mixture was further heated and stirred for 210 minutes while maintaining the reduced pressure of 2.0 kPa, to obtain a polyether polycarbonate diol (A-1d) having a hydroxyl value of 85.50 mgKOH / g.

[0124] <Production of blocked urethane> [Example 1] 88 parts by mass of polyether polycarbonate diol (A-1a) and 24 parts by mass of isophorone diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) (B-1) were placed in a 0.5 L separable flask and heated to 60°C under a nitrogen gas atmosphere. Next, 0.0088 parts by mass (100 ppm by mass relative to the polyether polycarbonate diol) of Neostan U-830 (hereinafter sometimes referred to as "U-830"; manufactured by Nitto Kasei Co., Ltd.) was added as a urethanization catalyst to the separable flask. After the heat generation subsided, the temperature was raised to 80°C and the mixture was stirred for approximately 2 hours. The isocyanate group concentration was analyzed, and it was confirmed that the theoretical amount of isocyanate groups had been consumed. Next, 18 parts by mass of pt-butylphenol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (C-1) was added to the separable flask, and the temperature was raised to 90°C. After that, the reaction was carried out with stirring until the peak derived from the isocyanate group disappeared in the IR spectrum, thereby obtaining blocked urethane No. (1).

[0125] [Examples 2 to 8, Comparative Examples 1 and 2, Production Example 3] Blocked urethanes were produced in the same manner as in Example 1, except that the polyol (A), polyisocyanate compound (B-1), and blocking agent (C-1) were changed to the raw materials and amounts shown in Table 1, thereby obtaining blocked urethanes Nos. (2) to (11).

[0126] For Comparative Example 2 in Table 1, the low-temperature impact strength when used as an adhesive was low, so the weight-average molecular weight Mw was not measured.

[0127] [Table 1]

[0128] [Example 9] A resin composition was obtained by mixing 2 parts by mass of the blocked urethane No. (1) produced in Production Example 1, 3 parts by mass of epoxy resin (E-1), 0.61 parts by mass of curing agent (F-1), 5 parts by mass of polymer fine particles (G-1) (2 parts by mass of polymer fine particles, 3 parts by mass of bisphenol A type epoxy resin), 0.15 parts by mass of curing accelerator (DCMU), and 0.05 parts by mass of spacer (glass beads J-60).

[0129] [Examples 10 to 19, Comparative Examples 3 to 4] A resin composition was obtained in the same manner as in Example 9, except that in Example 1, the blocked urethane, epoxy resin (E), curing agent (F), polymer fine particles (G), curing accelerator, and glass beads were changed to the raw materials and amounts shown in Table 2-1.

[0130] The impact strength was evaluated by the above-mentioned wedge impact test for the resin compositions obtained in Examples 9 to 19 and Comparative Examples 3 and 4. The evaluation results are shown in Table 2-2.

[0131] In Table 2-2, the total carbonate equivalent weight in the blocked urethane polyol was calculated as follows. In the case of Example 13, the carbonate equivalent (g / eq) of polyol (A) = (parts by mass of polyol A-1a + parts by mass of polyol A-1c) / {(parts by mass of polyol A-1a / carbonate equivalent of polyol A-1a) + (parts by mass of polyol A-1c / carbonate equivalent of polyol A-1c)} = (0.68 + 0.72) / {(0.68 / 1870) +(0.72 / 330)}=550 In the case of Example 15, the carbonate equivalent (g / eq) of polyol (A) = (parts by mass of polyol A-1a + part by mass of polyol A-1e) / {(parts by mass of polyol A-1a / carbonate equivalent of polyol A-1a) + (parts by mass of polyol A-1e / carbonate equivalent of polyol A-1e)} = (0.68 + 0.56) / {(0.68 / 1870) +(0.56 / 400)}=700 In Example 16, as described above, when polyol k has a carbonate equivalent of 0 g / eq, (parts by mass of polyol k / carbonate equivalent of polyol k) is 0 g / eq. Here, since the carbonate equivalent of Polyol A-2a in (parts by mass of Polyol A-2a / carbonate equivalent of Polyol A-2a) is 0 g / eq, Carbonate equivalent (g / eq) of polyol (A) = (parts by mass of polyol A-1b + part by mass of polyol A-2a) / {(parts by mass of polyol A-1b / carbonate equivalent of polyol A-1b) + (parts by mass of polyol A-2a / carbonate equivalent of polyol A-2a)} = (parts by mass of polyol A-1b + part by mass of polyol A-2a) / (parts by mass of polyol A-1b / carbonate equivalent of polyol A-1b) = (0.73 + 0.70) / (0.73 / 1000) = 1970

[0132] In the case of Example 17, as described above, when the polyol has a carbonate equivalent of 0 g / eq, (parts by mass of polyol n / carbonate equivalent of polyol n) is 0 g / eq. Here, since the carbonate equivalent of Polyol A-2a in (parts by mass of Polyol A-2a / carbonate equivalent of Polyol A-2a) is 0 g / eq, Carbonate equivalent (g / eq) of polyol (A) = (parts by mass of polyol A-1b + part by mass of polyol A-2a) / {(parts by mass of polyol A-1b / carbonate equivalent of polyol A-1b) + (parts by mass of polyol A-2a / carbonate equivalent of polyol A-2a)} = (parts by mass of polyol A-1b + part by mass of polyol A-2a) / (parts by mass of polyol A-1b / carbonate equivalent of polyol A-1b) = (0.72 + 0.72) / (0.72 / 1000) = 2000 In Example 18, as described above, polyol k having a carbonate equivalent of 0 g / eq was used. In this case, (parts by mass of polyol k / carbonate equivalent of polyol k) is 0 g / eq. Here, since the carbonate equivalent of polyol A-2b in (parts by mass of polyol A-2b / carbonate equivalent of polyol A-2b) is 0 g / eq, Carbonate equivalent (g / eq) of polyol (A) = (parts by mass of polyol A-1b + part by mass of polyol A-2b) / {(parts by mass of polyol A-1b / carbonate equivalent of polyol A-1b) + (parts by mass of polyol A-2b / carbonate equivalent of polyol A-2b)} = (parts by mass of polyol A-1b + part by mass of polyol A-2b) / (parts by mass of polyol A-1b / carbonate equivalent of polyol A-1b) = (0.72 + 0.72) / (0.72 / 1000) = 2000

[0133] [Table 2-1]

[0134] [Table 2-2]

[0135] <Evaluation results> As can be seen from the above, by using a blocked urethane containing specific structural units in which the carbonate equivalent of the polyol is controlled within a specific range, it is possible to achieve excellent storage stability and improve the low-temperature impact strength of the epoxy resin. [Industrial Applicability]

[0136] According to the resin composition of the present invention, by using a blocked urethane containing a specific structural unit in which the carbonate equivalent of the polyol is controlled within a specific range, the resin composition has excellent storage stability and can improve the low-temperature impact strength of the epoxy resin, making it suitable for use in adhesives.

Claims

1. Contains structural units derived from a polyol (A) and structural units derived from a polyisocyanate compound (B), The structural unit derived from the polyol (A) contains at least a structural unit derived from a polyether polycarbonate diol (A-1) represented by the following formula (1): The carbonate equivalent of the polyol (A) is 200 g / eq or more. Blocked urethane. 【Chemical 1】 (In the formula (1), R １ represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n １ is 2 to 30, and m １ is 1 to 20. In the formula (1), １ may be the same or different, and multiple n １ may be the same or different.)

2. 2. The blocked urethane according to claim 1, wherein the polyol (A) has a number average molecular weight calculated from a hydroxyl value of 600 or more and 10,000 or less.

3. 2. The blocked urethane according to claim 1, wherein the proportion by mass of the polyether polycarbonate diol represented by formula (1) relative to the mass of all polyols contained in the polyol (A) is 50% or more.

4. R in the formula (1) １ The blocked urethane according to claim 1, wherein each of

5. n in the formula (1) １ 2. The blocked urethane according to claim 1, wherein each of

6. 2. The blocked urethane according to claim 1, wherein the polyisocyanate compound (B) is a diisocyanate.

7. 7. The blocked urethane according to claim 6, wherein the polyisocyanate compound (B) is an aliphatic diisocyanate or an alicyclic diisocyanate.

8. 2. The blocked urethane according to claim 1, wherein the terminal of the urethane prepolymer chain of the blocked urethane has a structure derived from a phenol compound.

9. 2. The blocked urethane according to claim 1, wherein the weight average molecular weight of the blocked urethane is 3,000 or more and 24,000 or less.

10. the structural units derived from the polyol (A) further include a structural unit derived from a polyol (A-2) that does not contain a carbonate group, The blocked urea according to claim 1, wherein the structural unit derived from the polyol (A-2) not containing a carbonate group contains at least one of a structural unit derived from polytetramethylene ether glycol and a structural unit derived from polypropylene glycol. Tan.

11. The blocked urethane (I) according to any one of claims 1 to 10, and a blocked urethane (II) containing a structural unit derived from a carbonate group-free polyol (A'-2) and a structural unit derived from a polyisocyanate compound (B), wherein the structural unit derived from the polyol (A'-2) contains at least one of a structural unit derived from polytetramethylene ether glycol and a structural unit derived from polypropylene glycol; Blocked urethane composition.

12. A resin composition comprising the blocked urethane according to any one of claims 1 to 10, an epoxy resin (D), and a curing agent (E).

13. The resin composition according to claim 12, further comprising polymer fine particles (F).

14. The resin composition according to claim 12, wherein the curing agent (E) is a latent curing agent.

15. A cured product obtained by curing the resin composition according to claim 12.

16. An adhesive comprising the resin composition according to claim 12.

17. A step of reacting the polyol (A) and the polyisocyanate compound (B) to obtain a urethane prepolymer; and a step of blocking a terminal isocyanate group of the urethane prepolymer with a blocking agent (C), As the polyol (A), at least a polyether polycarbonate diol (A-1) represented by the following formula (1) is used, The carbonate equivalent of the polyol (A) is 200 g / eq or more. A method for manufacturing blocked urethane. 【Chemistry 2】 (In the formula (1), R １ represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n １ is 2 to 30, and m １ is 1 to 20. In the formula (1), １ may be the same or different, and multiple n １ may be the same or different.)

18. As the polyol (A), a polyol (A-2) containing no carbonate group is used, As the carbonate group-free polyol (A-2), at least one of polytetramethylene ether glycol and polypropylene glycol is used. A method for producing the blocked urethane of claim 17.

19. A method for producing a blocked urethane comprising: mixing the blocked urethane (I) and the blocked urethane (II) obtained by the method for producing a blocked urethane according to claim 17; The blocked urethane (II) is a polyol (A'-2) containing no carbonate group. ) and a structural unit derived from a polyisocyanate compound (B), A method for producing a blocked urethane composition, which is a blocked urethane containing at least one of a structural unit derived from polytetramethylene ether glycol and a structural unit derived from polypropylene glycol as the structural unit derived from the polyol (A'-2).

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