Curable composition and cured product thereof

Abstract

A curable composition that can provide a cured product with excellent tensile properties and shear strength is provided, as is a curable composition comprising a polymer with reactive silicon groups, and a cured product thereof.The curable composition of the present invention comprises: (A) A polyether-polycarbonate polymer having three or more end groups in one molecule and having a carbon dioxide-based unit and an alkylene oxide-based unit, wherein at least one of the end groups is a specific reactive silicon group and wherein the polyether-polycarbonate polymer has a number-average molecular weight (Mn) of 2000 to 50000; and (B) an oxyalkylene polymer having two or more end groups, wherein at least one of the end groups is a specific reactive silicon group and wherein the oxyalkylene polymer (B) does not have a carbon dioxide-based unit.

Description

Technical area

[0001] The present invention relates to a curable composition suitable for sealants, adhesives and the like, and a cured product thereof, the composition comprising a polymer having a reactive silicon group. State of the art

[0002] Polymers containing reactive silicon groups form rubbery, flexible cured products due to the formation of siloxane bonds through hydrolysis and condensation reactions of the reactive silicon groups and are therefore widely used in applications such as sealants and adhesives.

[0003] For example, Patent Document 1 discloses that a polyether-polycarbonate polymer having reactive silicon groups provides a cured product having advantageous strength and elongation.

[0004] Furthermore, Patent Document 2 discloses a silicone resin composition containing a silicone resin having trialkoxysilyl groups as reactive silicon groups and a polyoxyalkylene structure as the main chain or a silicone resin having dialkoxysilyl groups as reactive silicon groups and a polyoxyalkylene structure as the main chain, and discloses that the silicone resin composition enables bonding in an extremely short time. Document listPatent documents PTL1: JP 2021-59722 A PTL2: JP 10-245484 A Summary of the inventionTechnical problem

[0005] Specifically, Patent Document 1 discloses only a polymer having two reactive silicon groups, such as a polyether-polycarbonate polymer with reactive silicon groups. Such a polyether-polycarbonate polymer has high viscosity and is difficult to handle. The tensile properties and shear strength of the cured product of the silicone resin composition described in Patent Document 2 are insufficient depending on the testing method, and there is room for improvement.

[0006] The present invention has been made under such circumstances, and it is an object of the present invention to provide, as a curable composition comprising a polymer having reactive silicon groups, a curable composition capable of providing a cured product having excellent tensile properties and excellent shear strength suitable for a sealant, and a cured product thereof. Solution to the problem

[0007] The present invention is based on the finding that a cured product has good tensile properties and good shear strength when a polyfunctional polyether-polycarbonate polymer having reactive silicon groups and a polyfunctional oxyalkylene polymer having reactive silicon groups are used in combination for a curable composition comprising a polymer having reactive silicon groups.

[0008] The present invention provides the following objects.

[0009] [1] A curable composition comprising: (A) a polyether-polycarbonate polymer having three or more terminal groups in one molecule and having a carbon dioxide-based unit and an alkylene oxide-based unit, wherein at least one of the terminal groups is a reactive silicon group represented by the following formula (1), and wherein the polyether-polycarbonate polymer has a number-average molecular weight (Mn) of 2,000 to 50,000; and (B) an oxyalkylene polymer having two or more terminal groups, wherein at least one of the terminal groups is a reactive silicon group represented by the following formula (1), and wherein the oxyalkylene polymer does not have a carbon dioxide-based unit, -SiX a R 3-a (1) where X is a halogen atom, a hydroxyl group or a hydrolyzable group, R is a monovalent organic group having 1 to 20 carbon atoms and containing no hydrolyzable group, and a is an integer from 1 to 3, where when a is 1, two R's are identical or different, and when a is 2 or 3, the majority of X's are identical or different.

[0010] [2] The curable composition according to [1], wherein the alkylene oxide-based unit of the polyether-polycarbonate polymer (A) comprises a propylene oxide-based unit.

[0011] [3] The curable composition according to [1] or [2], wherein the content of the carbon dioxide-based unit in the polyether-polycarbonate polymer (A) is from 10 to 30 mass% based on a total of 100 mass% of the carbon dioxide-based unit and the alkylene oxide-based unit.

[0012] [4] The curable composition according to any one of [1] to [3], wherein the polyether-polycarbonate polymer (A) has a silylation rate of 70 to 100 mol%.

[0013] [5] The curable composition according to any one of [1] to [4], wherein a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn), Mw / Mn, of the polyether-polycarbonate polymer (A) is from 1.0 to 3.0.

[0014] [6] The curable composition according to any one of [1] to [5], wherein the polyether-polycarbonate polymer (A) has a urethane bond.

[0015] [7] Curable composition according to [6], wherein the number of urethane bonds and the number of reactive silicon groups in one molecule of the polyether-polycarbonate polymer (A) are identical.

[0016] [8] The curable composition according to any one of [1] to [7], wherein the oxyalkylene polymer (B) has a number average molecular weight (Mn) of 10,000 to 50,000.

[0017] [9] The curable composition according to any one of [1] to [8], wherein the content of the polyether-polycarbonate polymer (A) is from 5 to 100 parts by mass per 100 parts by mass of the oxyalkylene polymer (B).

[0018]

[10] The curable composition according to any one of [1] to [9], further comprising a curing catalyst.

[0019]

[11] Cured product of the curable composition according to any one of [1] to

[10] . Advantageous effects of the invention

[0020] According to the present invention, a curable composition capable of providing a cured product having excellent tensile properties and shear strength can be provided as a curable composition comprising a polymer having reactive silicon groups and a cured product thereof.

[0021] The curable composition of the present invention is useful, for example, in applications to sealants and adhesives. Description of embodiments

[0022] The definitions and meanings of the terms and information used herein are set out below.

[0023] A number average molecular weight (Mn) and a weight average molecular weight (Mw) are each a molecular weight based on polystyrene determined by gel permeation chromatography (GPC) and based on a calibration curve generated using a polystyrene standard sample.

[0024] The terminal group in the polyether-polycarbonate polymer includes not only a functional group at one end of the main chain of the polymer, but also a functional group at one end of a branched chain equivalent to the main chain.

[0025] The main chain in the oxyalkylene polymer contains an initiator residue and repeating units based on the alkylene oxide monomer (polyoxyalkylene chain). The end group in the oxyalkylene polymer is the group of atoms that contains the oxygen atom closest to the end of the molecule among the oxygen atoms in the polyoxyalkylene chain. “(Meth)acrylic” is a general term for acrylic and methacrylic.<Aushärtbare Zusammensetzung>

[0026] The curable composition of the present invention comprises: (A) a polyether-polycarbonate polymer having three or more terminal groups in one molecule and having a carbon dioxide-based unit and an alkylene oxide-based unit, wherein at least one of the terminal groups is a reactive silicon group represented by the following formula (1), and wherein the polyether-polycarbonate polymer has a number-average molecular weight (Mn) of 2,000 to 50,000; and (B) an oxyalkylene polymer having two or more terminal groups, wherein at least one of the terminal groups is a reactive silicon group represented by the following formula (1): -SiX a R 3-a (1) where X is a halogen atom, a hydroxyl group or a hydrolyzable group, R is a monovalent organic group having 1 to 20 carbon atoms and containing no hydrolyzable group, and a is an integer from 1 to 3, where when a is 1, two R's are identical or different, and when a is 2 or 3, the majority of X's are identical or different.

[0027] From the curable composition containing such a polyether-polycarbonate polymer (A) and oxyalkylene polymer (B) in combination, a cured product having excellent tensile properties and excellent shear strength can be obtained. [Polyether-polycarbonate polymer (A)]

[0028] The polyether-polycarbonate polymer (A) has three or more terminal groups in one molecule and has a carbon dioxide-based unit and an alkylene oxide-based unit, wherein at least one of the terminal groups is a reactive silicon group represented by the formula (1), and wherein the polyether-polycarbonate polymer (A) has a number average molecular weight (Mn) of 2,000 to 50,000.

[0029] One kind of the polyether-polycarbonate polymer (A) may be used alone, or two or more kinds thereof may be used in combination.

[0030] Examples of the alkylene oxide in the alkylene oxide-based unit include, in view of availability, ethylene oxide, propylene oxide, butylene oxide, and tetramethylene oxide. One type of alkylene oxide may be used alone, or two or more types may be used in combination. In view of compatibility between the polyether-polycarbonate polymer (A) and the oxyalkylene polymer (B), ease of handling of the curable composition, and improvement of the tensile properties and shear strength of the cured product of the curable composition, the alkylene oxide-based unit preferably comprises a propylene oxide-based unit.

[0031] The carbon dioxide-based unit forms a carbonate group. Since the polyether-polycarbonate polymer (A) has a carbonate group containing a carbon dioxide-based unit, the tensile properties and shear strength of the cured product of the curable composition are improved.

[0032] From the viewpoint of improving the tensile properties and shear strength of the cured product of the curable composition, the content of the carbon dioxide-based unit in the polyether-polycarbonate polymer (A) is preferably from 10 to 30 mass%, more preferably from 10 to 25 mass%, and even more preferably from 10 to 20 mass%, based on a total of 100 mass% of the carbon dioxide-based unit and the alkylene oxide-based unit.

[0033] The content of the carbon dioxide-based unit in the polyether-polycarbonate polymer (A) can be determined by nuclear magnetic resonance (NMR) analysis and, in particular, by the method described in the examples below.

[0034] The polyether-polycarbonate polymer (A) has three or more end groups in one molecule, at least one of the end groups being a reactive silicon group represented by the above formula (1).

[0035] If the polyether-polycarbonate polymer (A) has fewer than three terminal groups in one molecule, the number of reactive silicon groups in the polyether-polycarbonate polymer (A) is smaller, and as a result, the tensile properties and shear strength of the cured product of the curable composition may deteriorate. In this regard, it is preferable that the polyether-polycarbonate polymer (A) has four or more terminal groups in one molecule. Furthermore, in view of ease of handling in curing the curable composition and ease of coating, the polyether-polycarbonate polymer (A) preferably has 10 or fewer terminal groups in one molecule, and more preferably 8 or fewer.

[0036] Examples of the three or more terminal groups in one molecule of the polyether-polycarbonate polymer (A) other than the reactive silicon group represented by the above formula (1) include an active hydrogen-containing group and an isocyanate group.

[0037] Examples of the active hydrogen-containing group include a hydroxyl group, a carboxy group, an amino group, a monovalent functional group obtained by removing a hydrogen atom from a primary amine, a hydrazide group, and a mercapto group.

[0038] The polyether-polycarbonate polymer (A) may have a reactive silicon group other than those represented by the formula (1), but in view of good crosslinking reactivity of the curable composition and improvement of the tensile properties and shear strength of the product, it is preferable that the reactive silicon groups are only the groups represented by the formula (1). (Reactive silicon group)

[0039] The reactive silicon group represented by formula (1) is a crosslinking site of the polyether-polycarbonate polymer (A) and can form a crosslinked structure through a siloxane bond.

[0040] In formula (1), X is a halogen atom, a hydroxyl group, or a hydrolyzable group. The hydrolyzable group is a group that forms a silanol group (-Si-OH) upon hydrolysis, and examples thereof include an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a sulfanyl group, and an alkenyloxy group. The number of carbon atoms in the alkyl group or alkenyl group that may be contained in the hydrolyzable group is preferably from 1 to 6, and more preferably from 1 to 3.

[0041] From the viewpoint of mild hydrolyzability, X is preferably an alkoxy group, more preferably an alkoxy group having 1 to 3 carbon atoms, and even more preferably a methoxy group, an ethoxy group, or an isopropoxy group. From the viewpoint of accelerating curing by forming a crosslinked structure through a siloxane bond, a methoxy group or an ethoxy group is particularly preferred.

[0042] R is a monovalent organic group having 1 to 20 carbon atoms and containing no hydrolyzable group. Examples of the organic group include a hydrocarbon group, a halohydrocarbon group, and a triorganosiloxy group. The number of carbon atoms in the organic group is preferably from 1 to 6, and more preferably from 1 to 3.

[0043] R is preferably an alkyl group, a cycloalkyl group, an aryl group, a 1-chloroalkyl group, or a triorganosiloxy group, more preferably a straight-chain or branched-chain alkyl group having 1 to 4 carbon atoms, a cyclohexyl group, a phenyl group, a benzyl group, a 1-chloroalkyl group, a trimethylsiloxy group, a triethylsiloxy group, or a triphenylsiloxy group, and even more preferably an alkyl group having 1 to 3 carbon atoms or a 1-chloroalkyl group having 1 to 3 carbon atoms. Of these, a methyl group or an ethyl group is preferred from the viewpoints of good curability of the polymer having a reactive silicon group and good stability of the curable composition; a 1-chloromethyl group is preferred from the viewpoint of good curing speed of the curable composition; and a methyl group is preferred from the viewpoint of availability.

[0044] a is an integer from 1 to 3. If a is 1, the two R's may be the same or different. If a is 2 or 3, the two X's may be the same or different.

[0045] a is preferably 2 or 3, and more preferably 2.

[0046] Examples of the reactive silicon group represented by formula (1) include a trimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilyl group, a tris(2-propenyloxy)silyl group, a triacetoxysilyl group, a dimethoxymethyl group, a diethoxymethylsilyl group, a dimethoxyethylsilyl group, a diisopropoxymethylsilyl group, a chloromethyldimethoxysilyl group, and a chloromethyldiethoxysilyl group. Of these, from the viewpoint of suitable curability of the curable composition, a trimethoxysilyl group, a triethoxysilyl group, a dimethoxymethylsilyl group, or a diethoxymethylsilyl group is preferable; a dimethoxymethylsilyl group or a trimethoxysilyl group is more preferable, and a dimethoxymethylsilyl group is more preferable.

[0047] The average number of reactive silicon groups in the polyether-polycarbonate polymer (A) is preferably more than 0.5 and 1.0 or less, more preferably 0.6 or more and 1.0 or less, even more preferably 0.7 or more and 1.0 or less per terminal group from the viewpoint of improving the tensile properties and shear strength of the cured product of the curable composition.

[0048] The average number of reactive silicon groups per end group can be determined by 1 H-NMR analysis or calculated from the equivalents (molar ratio) of the compound used. (molecular weight)

[0049] The molecular weight (Mn) of the polyether-polycarbonate polymer (A) is from 2,000 to 50,000. If the Mn is less than the above lower limit, the tensile properties and shear strength of the cured product of the curable composition may decrease. If the Mn exceeds the above upper limit, the viscosity tends to be high, and the curable composition may be difficult to handle during operations such as mixing. In this regard, the Mn of the polyether-polycarbonate polymer (A) is preferably from 5,000 to 30,000, and more preferably from 6,000 to 25,000.

[0050] The molecular weight distribution of the polyether-polycarbonate polymer (A), ie, Mw / Mn, is preferably from 1.0 to 3.0, more preferably from 1.0 to 2.5, and even more preferably from 1.0 to 2.0, from the viewpoint of obtaining a curable composition having a low viscosity and easy handling.

[0051] The Mn and Mw / Mn of the polyether-polycarbonate polymer (A) can be adjusted by the type of catalyst and the polymerization conditions (temperature, stirring conditions, pressure, and others).

[0052] When two or more kinds of the polyether-polycarbonate polymer (A) are used, the Mn and Mw / Mn described above are preferably applied to each of the two or more kinds.

[0053] The same applies to the oxyalkylene polymer (B) described later. (Manufacturing process)

[0054] The polyether-polycarbonate polymer (A) can be produced, for example, by a process which comprises reacting, with a silylating agent, (a) a precursor polymer which contains a carbon dioxide-based unit and an alkylene oxide-based unit and which has, in one molecule, three or more terminal groups, into each of which a reactive silicon group can be introduced.

[0055] The method for producing the precursor polymer (a) is not specifically limited. Examples of the method include a method comprising reacting an alkylene oxide and carbon dioxide with an initiator having three or more terminal groups in one molecule in the presence of a catalyst to conduct ring-opening addition polymerization, thereby obtaining the precursor polymer (a).

[0056] A preferred process for producing the precursor polymer (a) is a process which comprises reacting an alkylene oxide and carbon dioxide with an initiator having three or more active hydrogen-containing groups in one molecule in the presence of a catalyst to conduct ring-opening addition polymerization, thereby obtaining the precursor polymer (a).

[0057] This process yields a precursor polymer (a) comprising a polycarbonate chain having an alkylene oxide-based unit and a carbon dioxide-based unit, a polyoxyalkylene chain having an alkylene oxide-based unit, and three or more active hydrogen-containing groups in one molecule as terminal groups. For example, when the active hydrogen-containing groups of the initiator are hydroxyl groups, a precursor polymer (a) having three or more hydroxyl groups at the terminals can be obtained.

[0058] Furthermore, according to this method, a main chain structure in which the carbon dioxide-based unit and the alkylene oxide-based unit are randomly arranged can be easily formed. It is believed that the polyether-polycarbonate polymer (A) obtained from a precursor polymer (a) having such a randomly arranged main chain structure can contribute to improving the tensile properties and shear strength of the cured product of the curable composition.

[0059] The initiator is preferably a polyol having three or more hydroxyl groups in one molecule. Specific examples of the initiator include glycerin, polyglycerin, trimethylolethane, trimethylolpropane, triglycerin, pentaerythritol, dipentaerythritol, tripentaerythritol, glucose, sorbitol, dextrose, fructose, sucrose, methyl glucoside, and trihydric or higher alcohols such as saccharides or derivatives thereof other than the above-mentioned initiators. These initiators may be in the form of various optical isomers. The initiator may also be a polyether polyol having a molecular weight based on hydroxyl number of 50 to 8000, which is obtained by reacting any of the above-mentioned initiators with a small amount of an alkylene oxide.

[0060] Examples of the catalyst for ring-opening addition polymerization include a double metal cyanide complex catalyst (hereinafter sometimes referred to as a “DMC catalyst”) such as a TBA-based double metal cyanide complex catalyst; a metal-salen complex catalyst such as a cobalt-salen-based catalyst; an alkali catalyst such as sodium hydroxide, potassium hydroxide, or cesium hydroxide; a Ziegler-Natta catalyst composed of an organoaluminum compound and a transition metal compound; a metal coordination porphyrin catalyst as a complex obtained by reacting a porphyrin; a phosphazene catalyst; an imino group-containing phosphazenium salt; tris(pentafluorophenyl)borane; or a reduced macrocyclic ligand catalyst of the reduced Robson type. These can be used individually or in a combination of two or more.

[0061] Examples of the DMC catalyst include a zinc hexacyanocobaltate complex with t-butyl alcohol as a ligand (hereinafter sometimes referred to as "TBA-DMC catalyst"), a zinc hexacyanocobaltate complex with ethylene glycol dimethyl ether (also referred to as "glyme") as a ligand, and a zinc hexacyanocobaltate complex with diethylene glycol dimethyl ether (also referred to as "diglyme") as a ligand. These can be used individually or in a combination of two or more.

[0062] Of these, the TBA-DMC catalyst is preferred in view of having higher activity during polymerization, achieving a narrower Mw / Mn of the precursor polymer (a), and achieving a lower viscosity.

[0063] Examples of the metal-salen complex catalyst include cobalt-salen complexes, chromium-salen complexes, and aluminum-salen complexes described in WO 2012-500867, JP 2015-129306 A, and JP 2015-28182 A. These can be used singly or in a combination of two or more.

[0064] The catalyst preferably contains at least one selected from the group consisting of a DMC catalyst and a metal-salen complex catalyst in view of easily adjusting the rate of carbon dioxide introduced into the polyether-polycarbonate polymer (A) to the range preferred in the present application.

[0065] With a view to obtaining a precursor polymer (a) of a random polymer, the catalyst is preferably a DMC catalyst or a reduced Robson type macrocyclic ligand catalyst.

[0066] The amount of the catalyst added is not specifically limited as long as it is the amount required for the polymerization of carbon dioxide and a ring-opening polymerization of alkylene oxide. However, the amount is preferably as small as possible, and is preferably from 0.001 to 10 parts by mass, more preferably from 0.002 to 5 parts by mass, and even more preferably from 0.05 to 3 parts by mass per 100 parts by mass of the obtained precursor polymer (a).

[0067] Examples of the alkylene oxide to be subjected to ring-opening addition polymerization include ethylene oxide, propylene oxide, butylene oxide, and tetramethylene oxide. In view of ease of preparation and improvement in the tensile properties and shear strength of the cured product of the curable composition, it is preferable to include propylene oxide.

[0068] In view of reactivity, the ring-opening addition polymerization is preferably carried out at a pressure of 0.1 to 15 MPa, more preferably at a pressure of 0.2 to 10 MPa, and even more preferably at a pressure of 0.3 to 8 MPa.

[0069] The polymerization temperature for the ring-opening addition polymerization is not specifically limited, but is preferably from 30 to 180°C, more preferably from 70 to 160°C, and even more preferably from 80 to 140°C. When the polymerization temperature is 30°C or higher, carbon dioxide polymerization and alkylene oxide ring-opening polymerization can be reliably initiated, and when the temperature is 180°C or lower, a reduction in the polymerization activity of the catalyst can be prevented.

[0070] The polymerization time for the ring-opening addition polymerization is not specifically limited, but is preferably from 2 to 18 hours, and more preferably from 2 to 16 hours. When the polymerization time is 2 hours or more, the reaction efficiency is excellent, and when the polymerization time is 18 hours or less, the economic performance is excellent.

[0071] The amount of the alkylene oxide used is not particularly limited, but is preferably from 40.0 to 99.0 parts by mass, more preferably from 45.0 to 98.0 parts by mass, and even more preferably from 50.0 to 97.0 parts by mass per 100 parts by mass of the obtained precursor polymer (a).

[0072] When the amount of alkylene oxide used is within the above range, the resulting curable composition has low viscosity and therefore improved workability during coating, and the cured product tends to have better flexibility.

[0073] The amount of carbon dioxide used is not specifically limited, but is preferably from 0.05 to 40 parts by mass, more preferably from 0.10 to 35 parts by mass, and even more preferably from 1.15 to 30 parts by mass per 100 parts by mass of the obtained precursor polymer (a).

[0074] When the amount of carbon dioxide used is within the above range, the tensile properties and shear strength of the resulting cured product of the curable composition tend to be more improved.

[0075] A known method can be used to react the precursor polymer (a) with the silylating agent. Examples of the method include: a method in which a precursor polymer (a) having active hydrogen-containing groups at terminals is subjected to a urethanization reaction with a silylating agent having an isocyanate group (Method 1); and a method in which isocyanate groups are introduced into the precursor polymer (a) having active hydrogen-containing groups at terminals, followed by a urethanization reaction with a silylating agent having a functional group capable of reacting with the isocyanate groups and a reactive silicon group represented by the formula (1) (Method 2). Therefore, it is preferable that the polyether-polycarbonate polymer (A) has a urethane bond.It is also preferable that the number of urethane bonds and the number of reactive silicon groups in one molecule of the polyether-polycarbonate polymer (A) are identical.

[0076] Examples of the silylating agent having an isocyanate group in Method 1 include the isocyanate silane compounds described in JP 2011-178955 A. Specifically, examples include 1-isocyanatomethyldimethoxymethylsilane, 1-isocyanatomethyldiethoxyethylsilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatopropylethyldiethoxysilane, 3-isocyanatopropylmethyldiethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, isocyanatomethyltrimethoxysilane, and isocyanatomethyltriethoxysilane. These silylating agents can be used singly or in a combination of two or more. Of these, 1-isocyanatomethyldimethoxymethylsilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatopropyltrimethoxysilane and isocyanatomethyltrimethoxysilane are preferred.

[0077] The active hydrogen-containing group of the precursor polymer (a) which reacts with the silylating agent having an isocyanate group is also preferably a hydroxyl group derived from ethylene oxide in view of good reactivity in the silylation reaction.

[0078] In method 2, for example, the precursor polymer (a) having hydroxyl groups as the active hydrogen-containing groups is subjected to a urethanization reaction at the hydroxyl groups with a polyisocyanate compound to introduce isocyanate groups, and then the isocyanate groups are reacted with a silylating agent having a functional group that can react with the isocyanate groups and a reactive silicon group represented by formula (1). According to this method, three or more urethane bonds and a residue of the silylating agent that has been reacted with an isocyanate group are introduced into the terminals of the precursor polymer (a).

[0079] Examples of the polyisocyanate compound in Method 2 include aromatic polyisocyanates such as naphthalene-1,5-diisocyanate, polyphenylenepolymethylene polyisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, xylylene diisocyanate and tetramethylxylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and 4,4'-methylenebis(cyclohexyl isocyanate); and urethane-modified products, biuret-modified products, allophanate-modified products, carbodiimide-modified products and isocyanurate-modified products obtained therefrom. These polyisocyanate compounds can be used singly or in a combination of two or more. Of these, compounds with two isocyanate groups are preferred.Hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate are preferred, and in view of improving the tensile properties and shear strength of the cured product of the curable composition, tolylene diisocyanate is more preferred.

[0080] In Method 2, examples of the functional group that can react with the isocyanate groups of the silylating agent having a functional group that can react with the isocyanate groups and a reactive silicon group represented by the formula (1) include a hydroxyl group, a carboxyl group, a mercapto group, an amino group, and an amino group in which one hydrogen atom is substituted by an alkyl group having 1 to 6 carbon atoms. Of these, groups having one or two active hydrogen atoms are preferred. A hydroxyl group, a mercapto group, an amino group, a methylamino group, an ethylamino group, or a butylamino group is preferred, and a hydroxyl group, an amino group, a methylamino group, an ethylamino group, or a butylamino group is more preferred.

[0081] It is preferable that the functional group capable of reacting with the isocyanate groups be bonded to the reactive silicon group represented by the formula (1) via a divalent organic group having 1 to 20 carbon atoms. The organic group is preferably a divalent hydrocarbon group having 1 to 20 carbon atoms, more preferably an aromatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 1 to 10 carbon atoms substituted with an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 1 to 10 carbon atoms, and a linear hydrocarbon group having 1 to 12 carbon atoms, even more preferably a linear hydrocarbon group having 1 to 8 carbon atoms, and particularly preferably a linear hydrocarbon group having 1 to 6 carbon atoms.

[0082] The number of moles of reactive silicon groups bonded to the hydroxyl groups of the precursor polymer (a) via a urethane bond per 1 mole of the hydroxyl groups in the process 1, or the number of moles of reactive silicon groups introduced into the active hydrogen-containing groups of the precursor polymer (a) via a urethane bond per 1 mole of the active hydrogen-containing groups in the process 2, or in other words, the silylation rate of the polyether-polycarbonate polymer (A), is preferably from 70 to 100 mol%, and more preferably from 80 to 100 mol%, from the viewpoint of improving tensile properties and shear strength by an appropriate degree of crosslinking of the curable composition.

[0083] The silylation rate can be adjusted in a suitable manner by the amount of the silylating agent used and the reaction conditions of the silylation reaction.

[0084] The silylation rate can be measured by NMR analysis. If the reaction rate of the silylating agent is considered to be approximately 100 mol%, a calculated value (theoretical value) based on the amounts of the precursor polymer (a) and the silylating agent used can also be used as the silylation rate value.

[0085] In Methods 1 and 2, in a case where the amount of the silylating agent used is 1 mol per 1 mol of the groups at the terminals of the precursor polymer (a) into which the reactive silicon groups can be introduced, and even if the silylation rate is 100 mol%, the number of the reactive silicon group in the polyether-polycarbonate polymer (A) is one per terminal group. [Oxyalkylene polymer (B)]

[0086] The oxyalkylene polymer (B) is a polymer having two or more terminal groups, at least one of which terminal groups is a reactive silicon group represented by the formula (1), and the polymer does not have a carbon dioxide-based unit.

[0087] If the number of terminal groups per molecule of the oxyalkylene polymer (B) is less than 2, the tensile properties and shear strength of the cured product of the curable composition may deteriorate. In this regard, the number of terminal groups per molecule of the oxyalkylene polymer (B) is preferably from 2 to 6, and more preferably from 2 to 4.

[0088] In the curable composition, the reactive silicon group of the oxyalkylene polymer (B) may be identical to or different from the reactive silicon group of the polyether-polycarbonate polymer (A).

[0089] One kind of the oxyalkylene polymer (B) may be used alone, or two or more kinds thereof may be used in combination.

[0090] The oxyalkylene polymer (B) can be prepared by a process which comprises reacting, with a silylating agent, (b) a precursor polymer having terminal groups into which a reactive silicon group can be introduced.

[0091] It is preferred that the terminal groups of the precursor polymer (b) are each independently an unsaturated group or an active hydrogen-containing group.

[0092] Examples of the unsaturated group include a vinyl group (CH2=CH-) and an ethynyl group (CH=C-). An allyl group (CH2=CH-CH2-), an acryloyl group (CH2=CH-C(=O)-), a methacryloyl group (CH2=C(CH3)-C(=O)-), a methallyl group (CH2=C(CH3)-CH2-), and a propargyl group (CH=C-CH2-) are preferable, and an allyl group is more preferable.

[0093] The same description applies to the active hydrogen-containing group as above for the polyether-polycarbonate polymer (A).

[0094] The precursor polymer (b) is preferably prepared by addition polymerization of an alkylene oxide with an initiator having two or more active hydrogen-containing groups. That is, the oxyalkylene polymer (B) and the precursor polymer (b) contain an alkylene oxide-based unit. The oxyalkylene polymer (B) and the precursor polymer (b) do not contain a carbon dioxide-based unit.

[0095] The precursor polymer (b) is preferably (b'1) a precursor polymer containing a polyoxyalkylene chain and having two or more active hydrogen-containing groups as end groups, or (b'2) a precursor polymer containing a polyoxyalkylene chain and having two or more unsaturated groups as end groups.

[0096] The precursor polymer (b'1) can be prepared by a ring-opening addition polymerization of an alkylene oxide with an initiator having two or more active hydrogen-containing groups in the presence of a catalyst.

[0097] The active hydrogen-containing group of the initiator is preferably a hydroxyl group. Examples of the initiator include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, a polypropylene glycol with a molecular weight based on hydroxyl number of 50 to 8,000, glycerin, a polyoxypropylene triol with a molecular weight based on hydroxyl number of 50 to 8,000, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, 1,2,6-hexanetriol, diglycerin, and dipentaerythritol. These initiators can be used individually or in combination with two or more.

[0098] Examples of the alkylene oxide and catalyst used for the ring-opening addition polymerization include the alkylene oxide and catalyst described above for the preparation of the precursor polymer (a). The alkylene oxide and catalyst used in the preparation of the precursor polymer (b'1) may be the same as or different from those used in the preparation of the precursor polymer (a).

[0099] The precursor polymer (b'2) is obtained by a process in which a compound having a functional group reactive with the active hydrogen-containing groups and an unsaturated group is reacted with the precursor polymer (b'1) to introduce an unsaturated group, for example, via an ester bond or a urethane bond. When the terminal groups of the precursor polymer (b'1) are hydroxyl groups, the precursor polymer (b'2) can be prepared by a known reaction process in which these hydroxyl groups are metal-oxidized to form an alkoxide, which is then reacted with a halogenated hydrocarbon containing an unsaturated group, such as allyl chloride, methallyl chloride, or propargyl bromide.The precursor polymer (b'2) can also be prepared by a known method in the following manner: The hydroxyl groups of the precursor polymer (b'1) are metal-oxidized to form an alkoxide, which is then reacted with an epoxy compound having an unsaturated group such as allyl glycidyl ether, and the resulting material is then reacted with an unsaturated group-containing halogenated hydrocarbon.

[0100] The method for introducing reactive silicon groups into the active hydrogen-containing groups at the terminals of the precursor polymer (b'1) to obtain the oxyalkylene polymer (B) may be identical to the method used for introducing reactive silicon groups into the active hydrogen-containing groups at the terminals of the precursor polymer (a). An example of the method for obtaining the oxyalkylene polymer (B) by introducing reactive silicon groups into the unsaturated groups at the terminals of the precursor polymer (b'2) is a method in which a precursor polymer (b'2) having an unsaturated group at one terminal is reacted with a silylating agent capable of undergoing an addition reaction with the unsaturated group (Method 3).

[0101] In Method 3, examples of the silylating agent that can undergo an addition reaction with the unsaturated group include a hydrosilane compound (e.g., HSiX a R 3-a(X, R, and a are the same as those in formula (1))), and a compound having a reactive silicon group and a mercapto group. Specifically, examples include trimethoxysilane, triethoxysilane, triisopropoxysilane, tris(2-propenyloxy)silane, triacetoxysilane, dimethoxymethylsilane, diethoxymethylsilane, dimethoxyethylsilane, diisopropoxymethylsilane, (α-chloromethyl)dimethoxysilane, (α-chloromethyl)diethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxysilane. These silylating agents can be used singly or in a combination of two or more. Of these, trimethoxysilane, triethoxysilane, dimethoxymethylsilane, and diethoxymethylsilane are preferable, and dimethoxymethylsilane or trimethoxysilane is more preferable in view of the fact that the reactivity is high and good curability can be obtained.

[0102] When the curable composition is cured, molecules of the oxyalkylene polymer (B) are crosslinked with each other, and a portion of the oxyalkylene polymer (B) also reacts with the polyether-polycarbonate polymer (A). The polyether-polycarbonate polymer (A) has three or more end groups in one molecule, and at least one of these end groups is a reactive silicon group. Accordingly, when a large number of reactive silicon groups are present in the oxyalkylene polymer (B), the proportion of the oxyalkylene polymer (B) that can be uniformly cured with the polyether-polycarbonate polymer (A) increases.On the other hand, the number of reactive silicon groups in the oxyalkylene polymer (B) may be small, whereas the number of reactive silicon groups in the polyether-polycarbonate polymer (A) is large. In this case, a difference in the number of reactive silicon groups occurs between the polyether-polycarbonate polymer (A) and the oxyalkylene polymer (B), and this makes uniform curing within the system difficult, leading to a deterioration in tensile properties and shear strength. Therefore, a balance of the number and amount of reactive silicon groups between the polyether-polycarbonate polymer (A) and the oxyalkylene polymer (B) is important for improving the tensile properties and shear strength of the cured product of the curable composition and also for preventing curing defects.As the number of reactive silicon groups in the oxyalkylene polymer (B) increases, the crosslinking reaction is less likely to be inhibited due to the quantitative ratio and consequently the polymer is less likely to remain uncured even if a large amount of the polyether-polycarbonate polymer (A) is added.

[0103] Therefore, the larger the number of reactive silicon groups in the oxyalkylene polymer (B), the better the curability of the curable composition, and the larger the amount of the polyether-polycarbonate polymer (A) used, the more the tensile properties and shear strength are improved.

[0104] The proportion of the reactive silicon groups introduced to the unsaturated groups or active hydrogen-containing groups which are the terminal groups of the precursor polymer (b), or in other words, the silylation rate of the oxyalkylene polymer (B), is preferably from 50 to 100 mol%, more preferably from 55 to 100 mol%, and even more preferably from 60 to 100 mol%, in view of good curability of the cured product of the curable composition.

[0105] From the viewpoint of improving the tensile properties and shear strength of the cured product of the curable composition and obtaining a viscosity that enables easy handling of the curable composition, the Mn of the oxyalkylene polymer (B) is preferably from 10,000 to 50,000, more preferably from 12,000 to 40,000, and even more preferably from 14,000 to 30,000.

[0106] From the viewpoint of obtaining a viscosity that enables easy handling of the curable composition and improving the tensile properties and shear strength of the cured product of the curable composition, Mw / Mn of the oxyalkylene polymer (B) is preferably from 1.0 to 1.8, more preferably from 1.0 to 1.7, and even more preferably from 1.0 to 1.5.

[0107] The oxyalkylene polymer (B) has, for example, an unsaturated group, an active hydrogen-containing group, or an isocyanate group as a terminal group other than the reactive silicon group represented by formula (1). Examples and preferred modes of the unsaturated group and the active hydrogen-containing group are as described above.

[0108] The curable composition may contain other components in addition to the polyether-polycarbonate polymer (A) and the oxyalkylene polymer (B). Known additives can be used as such other components according to the use of the curable composition. Examples include a curing catalyst, a filler, a plasticizer, a thixotropic agent, an antioxidant, a UV absorber, a photostabilizer, a dehydrating agent, an adhesion-promoting agent, an amine compound, an oxygen-curable compound, a light-curable compound, an epoxy compound, an acrylic compound, and an acrylic silicone. Each of these components can be used in a combination of two or more.For example, the known components listed in WO 2013 / 180203, WO 2014 / 192842, WO 2016 / 002907, WO 2014-88481, JP 2015-10162 A, JP 2015-105293 A, JP 2017-039728 A, and JP 2017-214541 A can be used in a suitable combination. These other components may be included as long as they do not impair the effects of the present invention.

[0109] The total content of the polyether-polycarbonate polymer (A) and the oxyalkylene polymer (B) in the curable composition is preferably from 10 to 60 mass%, more preferably from 15 to 55 mass%, and even more preferably from 20 to 50 mass% based on 100 mass% of the curable composition, from the viewpoint of improving the tensile properties and the shear strength of the cured product of the curable composition.

[0110] The curable composition preferably contains a curing catalyst for promoting crosslinking through the formation of siloxane bonds based on the reactive silicon groups. When a curing catalyst is included in the curable composition, the content of the curing catalyst is preferably from 0.1 to 10 parts by mass, more preferably from 0.2 to 5 parts by mass, and even more preferably from 0.5 to 2 parts by mass per 100 parts by mass of the polyether-polycarbonate polymer (A) and the oxyalkylene polymer (B) in total, in order to obtain a uniform cured product by promoting a suitable degree of crosslinking.

[0111] The curable composition may be a one-component type composition in which all components are premixed, stored in a sealed manner, and cured by moisture in the air after application, or a two-component type composition in which a main composition containing the polyether-polycarbonate polymer (A) and the oxyalkylene polymer (B) is stored separately from a curing composition containing a curing catalyst, and the main composition is mixed with the curing composition before use. In view of ease of application, a one-component type is preferred.

[0112] In the case of a one-component type, it is preferable that the curable composition contains no water. It is preferable to dehydrate and dry the water-containing components in advance, or to dehydrate these components under reduced pressure or the like during mixing and kneading.

[0113] In the case of a two-component type, the main composition does not easily convert into a gel even if it contains a small amount of water, but in order to ensure good storage stability, it is preferable to dehydrate and dry the components in advance.

[0114] In order to ensure good storage stability, a dehydrating agent may be added to the one-component type curable composition and the two-component type composition.

[0115] The curable composition of the present invention can be cured at room temperature to obtain a cured product and can be used in various applications. In particular, the curable composition of the present invention is suitable for use in sealants (e.g., elastic sealants for construction, sealants for double-glazed units, sealants for rust prevention and waterproofing of glass edges, sealants for the back of solar cells, sealants for buildings, sealants for ships, sealants for automobiles, and sealants for roads), electrical insulating materials (insulating coating materials for electrical wires and cables), adhesives, and potting materials.The curable composition of the present invention is particularly well suited for applications requiring excellent tensile properties and shear strength, such as sealants and adhesives used outdoors. Examples

[0116] Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited to the examples, and various modifications can be made without departing from the gist of the present invention. [Measurement method]

[0117] The methods for measuring various physical properties in synthesis examples and preparation examples described later were as follows. (hydroxyl number)

[0118] The hydroxyl value was calculated using a method according to JIS K 1557:2007 using an acetylation reagent. (Molecular weight based on the hydroxyl number)

[0119] The molecular weight based on the hydroxyl number was calculated by the following formula from the hydroxyl number [mgKOH / g] measured as above (molecular weight of potassium hydroxide: 56.1). (Molecular weight based on the hydroxyl number) = 56.1 × 1000 × (number of hydroxyl groups per molecule) / (hydroxyl number)

[0120] The number of hydroxyl groups per molecule of the initiator used for the synthesis of the polymer was considered as the number of hydroxyl groups per molecule.

[0121] (Quantification of PO-PO-PO chains, PO-PO-CO2 chains and CO2-PO-CO2 chains in the polyol, proportion of propylene carbonate in the polyol and content of the unit based on carbon dioxide (CO2 unit))

[0122] Nuclear magnetic resonance ( 1H-NMR) proton spectrum (the same applies below) of the precursor polymer (polyol) sample was obtained under the following conditions. <messbedingungen> - Equipment used: "JNM-ECZ400S FT-NMR", manufactured by JEOL Ltd. - Solvent: Deuterated Chloroform - Polymer concentration in the sample: 10 mass%

[0123] The proportion of CO2-PO-CO2 chains in the polyol (proportion of a fully alternating copolymer), the proportion of PO-PO-CO2 chains (proportion of a random copolymer), the proportion of PO-PO-PO chains (the proportion of PPG), and the proportion of propylene carbonate were calculated from the formulas described below based on the area S1 of the signal (δ 1.34 ppm, 3H) assigned to the methyl groups in an oxypropylene group whose both ends are bonded to a carbonate group, the area S2 of the signal (δ 1.29 ppm, 3H) assigned to the methyl groups in an oxypropylene group whose one end is bonded to a carbonate group and the other end is bonded to an oxypropylene group, the area S3 of the signal (δ 1.14 ppm, 3H) assigned to the methyl groups in an oxypropylene group (formula weight: 58), whose both ends bound to an oxypropylene group, and the area S4 of the signal (δ 1.49 ppm, 3H),which is assigned to the methyl groups of the byproduct propylene carbonate (formula weight 102) was calculated in the obtained NMR diagram. In the following formula, the formula weight of an oxypropylene group with both ends bonded to a carbonate group is 102, and the formula weight of an oxypropylene group with one end bonded to a carbonate group and the other end bonded to an oxypropylene group is 102.

[0124] Furthermore, the content of the CO2 unit based on a total of 100 mass% of the CO2 unit (formula weight 44) and the unit based on an alkylene oxide in the polyol was calculated from the following formulas. (Fraction of CO2-PO-CO2 chains [mass%]) = S1×102 / (S1×102+S2×102+S3×58+S4×102)×100 (Fraction of PO-PO-CO2 chains [mass%]) = S2×102 / (S1×102+S2×102+S3×58+S4×102)×100 (Fraction of PO-PO-PO chains [mass%]) = S3 × 58 / (S1 × 102 + S2 × 102 + S3 × 58 + S4 × 102) × 100 (Proportion of propyl carbonate [mass%]) = S4×102 / (S1×102+S2×102+S3×58+S4×102)×100 (Content of CO2 unit [mass−%]) = (S1 + S2) / {(S1 × 102 + S2 × 102 + S3 × 58)} × 44 × 100 (Viscosity)

[0125] The viscosity of the precursor polymer (polyol) at 25 °C was measured using an E-type viscometer (VISCOMETER TV-22, manufactured by Toki Sangyo Co., Ltd.). (Number average molecular weight (Mn) and weight average molecular weight (Mw))

[0126] Mn and Mw were measured by gel permeation chromatography (GPC) under the following measurement conditions (relative to polystyrene) and the molecular weight distribution (Mw / Mn) was calculated from these values. <messbedingungen> - Device used: "HLC-8220GPC", manufactured by Tosoh Corporation - Column used: "TSKgel (registered trademark) Super Multipore HZ-M", manufactured by Tosoh Corporation - Detector: Refractive index difference (RI) detector - Detection temperature: 40°C - Eluent: tetrahydrofuran - Flow rate: 0.350 mL / min - Sample concentration: 0.5 mass% - Amount of injected sample: 10 µL - Standard sample: polystyrene (Silylation rate)

[0127] For polymer B2, the proportion of the number of moles of reactive silicon groups added per 1 mole of allyl groups of the precursor polymer was determined on the basis of 1 H-NMR spectrum, and the result was used as the silylation rate.

[0128] The silylation rate of polymers A1, A2 and B1 was determined as the proportion of the amount [mol] of 3-isocyanatopropylmethyldimethoxysilane introduced per mole of hydroxyl groups of the precursor polymer. [Connections used]

[0129] Details of the various compounds used in the synthesis examples are shown below. - TBA-DMC catalyst: zinc hexacyanocobaltate complex with t-butyl alcohol as ligand - U-860: Dioctyltin bis(isooctyl thioglycolate); "Neostane (registered trademark) U-860", manufactured by Nitto Kasei Co., Ltd. - KBM-803: 3-Mercaptopropyltrimethoxysilane; "KBM-803", manufactured by Shin-Etsu Chemical Co., Ltd. [Synthesis of the precursor polymer (polyol)] (Synthesis Example 1)

[0130] A reactor was charged with 46.0 g of polypropylene polyol (number-average molecular weight 870), obtained by adding propylene oxide (hereinafter referred to as "PO") to sorbitol as an initiator, and 0.04 g of a TBA-DMC catalyst as a catalyst, and the reactor was then heated to 130 °C. Carbon dioxide was introduced to increase the pressure (to about 2.0 MPa), and then the pressure was reduced (to about 0.1 MPa). A series of operations were performed three times, and the reactor was then degassed at 130 °C for 2 hours. After degassing, the carbon dioxide pressure was increased to 1.5 MPa to activate the catalyst.

[0131] Next, the carbon dioxide pressure was maintained at 1.5 MPa during the synthesis, and 26.0 g of PO was added. After confirming that heat was being generated, the liquid temperature was reduced to 110 °C, and 232 g of PO was further added over 14 hours. The reaction was carried out at 110 °C for 3 hours, then the liquid temperature was raised to 130 °C, and the system was maintained under reduced pressure for 5 hours to remove the byproduct propylene carbonate.

[0132] The reaction product was taken out of the reactor to obtain a polyether polycarbonate polyol (precursor polymer a1; hydroxyl value 44.1 mgKOH / g, carbon dioxide-based unit content 12.3 mass%, viscosity at 25 °C 6000 mPa s, 6 hydroxyl groups per molecule). (Synthesis example 2)

[0133] A reactor was charged with 51.0 g of polypropylene polyol (number-average molecular weight 1000), obtained by adding PO to glycerol as an initiator, and 0.07 g of a TBA-DMC catalyst as a catalyst, and the reactor was then heated to 130 °C. Carbon dioxide was introduced to increase the pressure (to approximately 2.0 MPa), and the pressure was reduced (to approximately 0.1 MPa). A series of operations were performed three times, and the reactor was then degassed at 130 °C for 2 hours. After degassing, the carbon dioxide pressure was increased to 1.5 MPa to activate the catalyst.

[0134] Next, the carbon dioxide pressure was maintained at 1.5 MPa during the synthesis, and 30.0 g of PO was added. After confirming that heat was generated, the liquid temperature was reduced to 110 °C, and 270 g of PO was further added over 16 hours. The reaction was carried out at 110 °C for 3 hours, then the liquid temperature was raised to 130 °C, and the system was maintained under reduced pressure for 5 hours to remove the byproduct propylene carbonate.

[0135] The reaction product was taken out of the reactor to obtain a polyether polycarbonate polyol (precursor polymer a2; hydroxyl value 28.9 mgKOH / g, carbon dioxide-based unit content 11.4 mass%, viscosity at 25 °C 9000 mPa s, 3 hydroxyl groups per molecule). (Synthesis Example 3)

[0136] A reactor was charged with 46.0 g of polypropylene polyol (number-average molecular weight 870), obtained by adding PO to sorbitol as an initiator, and 0.04 g of a TBA-DMC catalyst as a catalyst, and the reactor was then heated to 130 °C. Nitrogen was introduced to increase the pressure (to about 0.5 MPa), and the pressure was reduced (to about 0.1 MPa). A series of operations were performed three times, and the reactor was then degassed at 130 °C for 2 hours. After degassing, the nitrogen pressure was increased to 0.1 MPa. Next, 35.0 g of PO was added, and after confirming that heat was generated, 319 g of PO was further added over 18 hours. The reaction was carried out at 130 °C for 2 hours, and then the system was maintained at 130 °C for 2 hours under reduced pressure.

[0137] The reaction product was removed from the reactor to obtain a polypropylene polyol (precursor polymer b1; hydroxyl number 44.2 mgKOH / g, viscosity at 25 °C 1200 mPa s, 6 hydroxyl groups per molecule).

[0138] The details of each precursor polymer prepared in the above Synthesis Examples 1 to 3 are shown in Table 1 below. Table 1 Synthesis example 1 2 3 Pre-stage a1 a2 b1 Number of hydroxyl groups per molecule 6 3 6 Hydroxyl number [mgKOH / g] 44,1 28,9 44,2 Molecular weight based on the hydroxyl number 7633 5824 7615 CO2 unit content [mass%] 12,3 11,4 0,0 Proportion of the PO-PO-PO chain [mass%] 71,4 73,4 100,0 Proportion of PO-PO-CO2 chain [mass%] 23,6 23,1 0,0 Proportion of CO2-PO-CO2 chain [mass%] 4,8 3,2 0,0 Proportion of propylene carbonate [mass%] 0,2 0,3 0,0 Viscosity at 25 °C [mPa s] 6000 9000 1200 [Synthesis of a polymer](Synthesis Example 4)

[0139] A reactor charged with the precursor polymer a1 obtained in Synthesis Example 1 was purged with nitrogen gas, and while maintaining the internal temperature at 80 °C, 3-isocyanatopropylmethyldimethoxysilane was added in a ratio of 0.97 mol of isocyanate groups to 1 mol of the hydroxyl groups of the precursor polymer a1 (NCO / OH molar ratio), and U-860 was added as a catalyst. The liquid temperature was raised to 80 °C, maintained at this temperature, and the mixture was stirred.After confirming the completeness of the reaction of the isocyanate groups with the hydroxyl groups using a Fourier transform infrared spectrophotometer KBM-803, a storage stabilizer was added in an amount of 0.06 parts by mass per 100 parts by mass of the precursor polymer a1, and a polyether-polycarbonate polymer (polymer A1) in which a urethane bond and a dimethoxymethylsilyl group were introduced into the main chain was thus obtained. (Synthesis Example 5)

[0140] A polyether-polycarbonate polymer (polymer A2) in which a urethane bond and a dimethoxymethylsilyl group were introduced into the main chain was obtained in the same manner as in Synthesis Example 4, except that the precursor polymer a2 obtained in Synthesis Example 2 was used. (Synthesis Example 6)

[0141] An oxypropylene polymer (polymer B1) in which a urethane bond and a dimethoxymethylsilyl group were introduced into the main chain was obtained in the same manner as in Synthesis Example 4, except that the precursor polymer b1 obtained in Synthesis Example 3 was used. (Synthesis Example 7)

[0142] A polypropylene triol (molecular weight based on hydroxyl number: 1000) obtained by ring-opening addition polymerization of PO with glycerol was used as the initiator. PO was added to the initiator in the presence of a TBA-DMC catalyst, and the reaction was continued at 125 °C until a pressure drop was no longer observed in the reaction system, thus obtaining a polypropylene triol (precursor polymer b2-1; hydroxyl number: 16.8 mgKOH / g, 3 hydroxyl groups per molecule).

[0143] Next, a methanol solution containing sodium methoxide was added in an amount of 1.15 mol of sodium methoxide per 1 mol of the hydroxyl groups of the precursor polymer b2-1 to form an alkoxide. The methanol was distilled off by heating under reduced pressure, allyl chloride was added in an excess amount based on the amount of hydroxyl groups in the mixture, and the resulting mixture was reacted at 130 °C for 2 hours to obtain an allylated polyether (precursor polymer b2; 3 allyl groups per molecule).

[0144] Next, dimethoxymethylsilane was added in an amount of 0.66 mol per 1 mol of the allyl group of precursor polymer b2 in the presence of chloroplatinic acid hexahydrate, and the mixture was reacted at 85 °C for 4 hours to obtain an oxypropylene polymer (polymer B2) into which a dimethoxymethylsilyl group had been introduced. The number of end groups of polymer B2 corresponded to the number of allyl groups per molecule of precursor polymer b2 and was 3.

[0145] The details of each of the polymers prepared in the above Synthesis Examples 4 to 7 are shown in Table 2 below. Table 2 Synthesis example 4 5 6 7 polymer A1 A2 B1 B2 Number of end groups per molecule 6 3 6 3 Content of the CO2 unit [mass%] 12,3 11,4 0 0 Mn 5700 7200 9000 15000 Mf / Mn 1,87 1,28 1,33 1,23 Silylation rate [mol%] 97 97 97 66 [Manufacture of curable compositions]

[0146] Curable compositions for a sealant were prepared using polymers prepared in the synthesis examples described above and various additives.

[0147] The additives used are shown below. - Plasticizer: DINP, diisononyl phthalate; "Vinycizer (registered trademark) 90", manufactured by Kao Corporation - Thixotropic agent: "Disparlon (registered trademark) 6500" (a thixotropic agent based on hydrogenated castor oil; trade name of Kusumoto Chemicals, Ltd.) - Filler-1: "HAKUENKA CC-R" (colloidal calcium carbonate; trade name of Shiraishi Calcium Kaisha, Ltd.) - Filler-2: "Whiton (registered trademark) SB" (heavy calcium carbonate; manufactured by Shiraishi Calcium Kaisha, Ltd.) - Dehydrating agent: "KBM-1003" (Vinyltrimethoxysilane; trade name of Shin-Etsu Chemical Co., Ltd.) - Adhesion-imparting agent-1: "BM-603" (3-(2-Aminoethylamino)propyltrimethoxysilane; trade name of Shin-Etsu Chemical Co., Ltd.) - Adhesion-imparting agent-2: "KBM-403" (3-Glycidyloxypropyltrimethoxysilane; trade name of Shin-Etsu Chemical Co., Ltd.) - Stabilizer-1: "Irganox (registered trademark) 1010" (hindered phenol antioxidant; trade name of BASF) - Stabilizer-2: "HS Ester 765" (hindered amine ester; light stabilizer; manufactured by Hokoku Corporation) - Stabilizer-3: "Tinuvin (registered trademark) 326" (benzotriazole ultraviolet absorber; trade name of BASF) - Curing catalyst: "NEOSTANN (registered trademark) U-220H" (dibutyltin bis(acetylacetonate)) (Example 1)

[0148] A mixture obtained by mixing 30 parts by mass of polymer A1, 40 parts by mass of a plasticizer, and 3 parts by mass of a thixotropic agent and then heating at 90 °C to swell, and 75 parts of filler-1 and 75 parts of filler-2 was added to 70 parts by mass of polymer B2, and the resulting material was mixed by stirring with a planetary stirrer (manufactured by Kurabo Industries, Ltd.).

[0149] The temperature of the resulting mixture was lowered to 25°C. 3 parts by mass of a dehydrating agent, 1 part by mass of adhesion-imparting agent-1, 1 part by mass of adhesion-imparting agent-2, 1 part by mass of stabilizer-1, 1 part by mass of stabilizer-2, and 1 part by mass of stabilizer-3 were added, and the resulting material was further stirred and mixed. Then, 1 part by mass of a curing catalyst was added, and the resulting material was stirred and mixed to prepare a curable composition. (Examples 2 to 4)

[0150] Curable compositions were prepared in the same manner as in Example 1, except that the formulation of the composition in Example 1 was changed to that shown in Table 3 below. [Evaluation of the cured product]

[0151] A tensile test and a shear test were performed on the cured product obtained using the curable composition obtained in each of the above-described examples. Table 3 shows the evaluation results of each test. Examples 1 and 2 are examples, and Examples 3 and 4 are comparative examples. (tensile test)

[0152] The curable composition was filled into a 2 mm thick mold, aged for 3 days in an atmosphere at a temperature of 23 °C and a relative humidity of 50%, and then aged for 4 days in an atmosphere at a temperature of 50 °C and a relative humidity of 65% to cure. The cured product was punched out to produce a dumbbell-shaped No. 3 test specimen according to JIS K 6251:2017.

[0153] A tensile test was carried out on each specimen using a Tensilon tester (temperature 23 °C, tensile speed 500 mm / min) and the stress at 50% elongation (M50) [N / mm 2 ], the cohesive force at the maximum point (Tmax) [N / mm 2 ] and the strain at the maximum point (Emax) [%] were measured.

[0154] In this test it can be assumed that an M50 of 1.0 N / mm 2 or more, a Tmax of 1.5 N / mm 2 or more and an Emax of 100% or more are the appropriate tensile properties for a waterproofing material. (Shear test)

[0155] Aluminum sheets (A1050P, specified in JIS H 4000, manufactured by Engineering Test Service) with a length of 100 mm × width of 25 mm × thickness of 2 mm were provided. According to JIS K 6850:1999, a 1 mm thick spacer was placed between two aluminum sheets, and the curable composition was applied to a length of 25 mm × width of 25 mm × thickness of 1 mm and aged for 3 days in an atmosphere with a temperature of 23 °C and a relative humidity of 50%. The spacer was then removed, and aging was carried out for another 4 days in an atmosphere with a temperature of 50 °C and a relative humidity of 65% to obtain a test specimen.

[0156] A tensile shear test was performed on each specimen using a Tensilon tester (temperature: 23 °C, tensile speed: 50 mm / min). The load at the maximum point (Tmax) [N / mm 2 ] as the maximum value of tensile shear stress and the elongation at maximum load (Emax) [mm].

[0157] In this test it can be assumed that a Tmax of 0.8 N / mm 2 or more and an Emax of 1.9 mm or more is the appropriate shear strength for a waterproofing material.

[0158] Furthermore, the peeling surface of the specimen was visually inspected after the shear test. The ratio of the area where the cured product layer peeled due to cohesive failure across the entire peeling surface was calculated, and the result was used as the cohesive failure rate (%). Table 3 Example 1 2 3 4 Formulation of composition [parts by mass] Polymer A1 30 - - - Polymer A2 - 30 - - Polymer B1 - - 30 - Polymer B2 70 70 70 100 plasticizers 40 40 40 40 Thixotropic agent 3 3 3 3 Filler-1 75 75 75 75 Filler-2 75 75 75 75 Dehydrating agents 3 3 3 3 Adhesion-imparting agent-1 1 1 1 1 Adhesion-imparting agent-2 1 1 1 1 Stabilizer-1 1 1 1 1 Stabilizer-2 1 1 1 1 Stabilizer-3 1 1 1 1 Curing catalyst 1 1 1 1 Mechanical properties Tensile properties M50 [N / mm 2 ] 1,31 1,09 1,44 0,81 Tmax [N / mm 2 ] 1,83 1,59 1,78 1,40 Emax [%] 104 121 81 164 Shear strength Tmax[N / mm 2 ] 0,95 0,86 0,77 0,97 Emax [mm] 2,13 1,95 2,44 1,85 Cohesive failure rate (%) 100 100 100 100

[0159] As is apparent from the evaluation results shown in Table 3, it was found that the curable composition of the present invention (Examples 1 and 2) can provide a cured product having excellent tensile properties and shear strength. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2021-59722 A

[0004] JP 10-245484 A

[0004] WO 2012-500867

[0063] JP 2015-129306 A

[0063] JP 2015-28182 A

[0063] JP 2011-178955 A

[0076] WO 2013 / 180203

[0108] WO 2014 / 192842

[0108] WO 2016 / 002907

[0108] WO 2014-88481

[0108] JP 2015-10162 A

[0108] JP 2015-105293 A

[0108] JP 2017-039728 A

[0108] JP 2017-214541 A

[0108] Cited non-patent literature

[0000] JIS K 6251:2017

[0152] JIS K 6850:1999

[0155] < / messbedingungen> < / messbedingungen>

Claims

[1] A curable composition comprising: (A) a polyether-polycarbonate polymer having three or more terminal groups in one molecule and having a carbon dioxide-based unit and an alkylene oxide-based unit, wherein at least one of the terminal groups is a reactive silicon group represented by the following formula (1), and wherein the polyether-polycarbonate polymer has a number-average molecular weight (Mn) of 2,000 to 50,000; and (B) an oxyalkylene polymer having two or more terminal groups, wherein at least one of the terminal groups is a reactive silicon group represented by the following formula (1), and wherein the oxyalkylene polymer does not have a carbon dioxide-based unit, -SiX a R 3-a (1) where X is a halogen atom, a hydroxyl group or a hydrolyzable group, R is a monovalent organic group having 1 to 20 carbon atoms and containing no hydrolyzable group, and a is an integer from 1 to 3, where when a is 1, two R's are identical or different, and when a is 2 or 3, the majority of X's are identical or different. [2] The curable composition according to claim 1, wherein the alkylene oxide-based unit of the polyether-polycarbonate polymer (A) comprises a propylene oxide-based unit. [3] The curable composition according to claim 1 or 2, wherein the content of the carbon dioxide-based unit in the polyether-polycarbonate polymer (A) is from 10 to 30 mass% based on a total of 100 mass% of the carbon dioxide-based unit and the alkylene oxide-based unit. [4] The curable composition according to claim 1 or 2, wherein the polyether-polycarbonate polymer (A) has a silylation rate of 70 to 100 mol%. [5] The curable composition according to claim 1 or 2, wherein a ratio of a weight average molecular weight (Mw) to a number average molecular weight (Mn), Mw / Mn, of the polyether-polycarbonate polymer (A) is from 1.0 to 3.

0. [6] The curable composition according to claim 1 or 2, wherein the polyether-polycarbonate polymer (A) has a urethane bond. [7] The curable composition according to claim 6, wherein the number of urethane bonds and the number of reactive silicon groups in one molecule of the polyether-polycarbonate polymer (A) are identical. [8] The curable composition according to claim 1 or 2, wherein the oxyalkylene polymer (B) has a number average molecular weight (Mn) of 10,000 to 50,000. [9] The curable composition according to claim 1 or 2, wherein the content of the polyether-polycarbonate polymer (A) is from 5 to 100 parts by mass per 100 parts by mass of the oxyalkylene polymer (B). [10] The curable composition according to claim 1 or 2, further comprising a curing catalyst. [11] A cured product of the curable composition according to claim 1 or 2.