Moisture-curable composition containing a curing catalyst for use in curing polymers, and method for producing the cured product

Abstract

To provide a curing catalyst having a cure rate fit for practical use with high safety properties.SOLUTION: A curing catalyst [B] is to be used to cure a polymer [A] having a reactive hydrolyzable silicon-containing group. The curing catalyst [B] includes a phosphazene [B1]. The phosphazene [B1] is expressed by a chemical formula (1).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a curing catalyst used for curing a polymer, a moisture-curable composition, and a method for producing a cured product. [Background technology]

[0002] One-component moisture-curing rubber compositions generally have a fast curing rate and are easier to work with than two-component compositions because they do not require weighing and mixing various additives such as base polymers, crosslinking agents, and catalysts before use.

[0003] Known examples of these one-liquid moisture-curable rubber compositions include silicone rubbers, modified silicone rubbers, urethane rubbers, and polysulfide rubbers. Organopolysiloxane compositions are widely used as one-liquid moisture-curing rubber compositions for silicone rubber, and they cure at room temperature to produce rubber elastomers. Polymeric siloxane compounds with -Si-O- bonds formed by cross-linking organosiloxane as the main chain are widely used in the fields of construction, civil engineering, electrical and electronics, and automotive industries, because of their excellent properties such as water repellency, heat resistance, weather resistance, cold resistance, and electrical insulation.

[0004] One-liquid moisture-curable rubber compositions of modified silicone rubber include compositions containing a polymer having a crosslinkable reactive hydrolyzable silicon functional group with a polyether backbone. This polymer curable composition has better storage stability, weather resistance, foaming resistance and discoloration resistance than polyurethane rubber, and has better curing properties than polysulfide rubber, is less polluting to the environment and is non-toxic.

[0005] The reaction mechanism in the process in which the silicone rubber and modified silicone rubber become a cured product is said to be a condensation reaction or addition reaction of reactive hydrolyzable silicon-containing groups in the presence of water, and it is believed that polymerization proceeds to form a polymer cured product with a three-dimensional network structure. In order to rapidly proceed with curing in this reaction, a curing catalyst is used (Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 8-41358 [Patent Document 2] Japanese Patent Application Laid-Open No. 60-161457 [Patent Document 3] Special Publication No. 63-42942 [Patent Document 4] JP 2003-147220 A Summary of the Invention [Problem to be solved by the invention]

[0007] Tin carboxylate compounds, alkyl tin salt compounds, and the like have traditionally been used as curing catalysts for curing compositions of silicone rubbers and modified silicone rubbers having this reactive hydrolyzable silicon-containing group. However, due to concerns that they may have an effect on living organisms as endocrine disruptors, a combined catalyst of carboxylic acid and amine has been proposed as a moisture-curing composition that does not use these substances (Patent Document 1). However, there is a problem in that a sufficient curing speed cannot be obtained during application.

[0008] Patent Documents 2 and 3 propose using titanate compounds such as diisopropoxytitanium bis(alkylacetoacetonate) as catalysts, but these compounds are susceptible to decomposition by moisture contained in additives or fillers in the composition, and the curing speed varies depending on the humidity during application, making it difficult to obtain a stable cured product.

[0009] Patent Document 4 proposes using a titanium tetracarboxylate compound as a catalyst, but there is a problem in that the curing speed is not satisfactory for practical use.

[0010] Therefore, there has been a demand for the development of a curing catalyst that is highly safe (low toxicity and low environmental pollution) and has a practical curing speed.

[0011] In view of the above-mentioned conventional techniques, an object of the present invention is to provide a curing catalyst which is highly safe and has a practical curing rate. [Means for solving the problem]

[0012] According to the present invention, there is provided a curing catalyst [B] for curing a polymer [A] having a reactive hydrolyzable silicon-containing group, the curing catalyst [B] containing a phosphazene [B1], the phosphazene [B1] being represented by chemical formula (1).

[0013] The inventors of the present invention have conducted extensive research and found that the curing rate of the polymer [A] is significantly increased when a curing catalyst [B] containing phosphazene [B1] is used, leading to the completion of the present invention. This catalyst does not contain tin, so it is highly safe. In addition, it can be produced at low cost. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described in detail below.

[0015] The curing catalyst [B] of the present invention is used for curing a polymer [A] having a reactive hydrolyzable silicon-containing group. The polymer [A] is preferably a polymer that is liquid at room temperature.

[0016] 1. Polymer [A] The polymer [A] has at least one reactive hydrolyzable silicon-containing group at the molecular end or side chain per molecule. The reactive hydrolyzable silicon-containing group may be present at the end of the polymer [A] molecule, or at the side chain, or may be present at both the end and the side chain. The reactive hydrolyzable silicon-containing group may be at least one per molecule of the polymer [A], but from the viewpoint of curing speed and cured physical properties, it is preferable that there are 1.5 or more groups per molecule on average. A known method can be used to bond the reactive hydrolyzable silicon-containing group to the main chain polymer.

[0017] The reactive hydrolyzable silicon-containing group is a group having a silicon atom bonded to a reactive group consisting of a hydrolyzable group (e.g., halogen, alkoxy, alkenyloxy, acyloxy, amino, aminooxy, oxime, amide) or a hydroxyl group, and has the property of undergoing a condensation reaction in the presence of moisture or a crosslinking agent, and if necessary, by using a catalyst, etc. Specific examples include halogenated silyl groups, alkoxysilyl groups, alkenyloxysilyl groups, acyloxysilyl groups, aminosilyl groups, aminooxysilyl groups, oximesilyl groups, and amidosilyl groups.

[0018] Here, the number of reactive hydrolyzable groups bonded to one silicon atom is selected from the range of 1 to 3. The reactive hydrolyzable groups bonded to one silicon atom may be one type or multiple types. Furthermore, a reactive hydrolyzable group and a non-reactive hydrolyzable group may be bonded to one silicon atom, or a hydrolyzable group and a hydroxyl group may be bonded to one silicon atom. As the reactive hydrolyzable silicon-containing group, an alkoxysilyl group (including a monoalkoxysilyl group, a dialkoxysilyl group, and a trialkoxysilyl group) is particularly preferable in terms of ease of handling.

[0019] Among the above alkoxysilyl groups, trialkoxysilyl groups are preferred because they have high activity and provide good curability, and the resulting cured product has excellent recovery, durability, and creep resistance, whereas dialkoxysilyl and monoalkoxysilyl groups are preferred because they have excellent storage stability and provide cured products with high elongation and strength. The combined use of a polymer [A] in which the reactive hydrolyzable silicon-containing group is a dialkoxysilyl group and a polymer [A] in which the reactive hydrolyzable silicon-containing group is a trialkoxysilyl group is preferable because it provides a good balance between the physical properties and curability of the cured product.

[0020] The polymer [A] used in the present invention has a main chain containing carbon atoms, such as alkylene oxide polymers, polyester polymers, ether-ester block copolymers, polymers of ethylenically unsaturated compounds, and polymers of diene compounds.

[0021] The alkylene oxide polymer may be [CH2CH2O] n [CH(CH3)CH2O] n [CH(C2H5)CH2O] n [CH2CH2CH2CH2O] n Examples include those having one or more of the repeating units such as those mentioned above. Here, n is the same or different and is an integer of 2 or more. These alkylene oxide polymers may be used alone or in combination of two or more. Copolymers containing two or more of the above repeating units may also be used.

[0022] Examples of polyester polymers include those having, as repeating units, carboxylic acids such as acetic acid, propionic acid, maleic acid, phthalic acid, citric acid, pyruvic acid, and lactic acid, their anhydrides, and their intramolecular and / or intermolecular esters and their substitution products.

[0023] Examples of ether-ester block copolymers include those having both the repeating units used in the alkylene oxide polymers described above and the repeating units used in the polyester polymers described above as repeating units.

[0024] Examples of the polymer of the ethylenically unsaturated compound and the diene compound include homopolymers of ethylene, propylene, acrylic acid esters, methacrylic acid esters, vinyl acetate, acrylonitrile, styrene, isobutylene, butadiene, isoprene, chloroprene, etc., or copolymers of two or more of these. More specifically, examples include polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, ethylene-butadiene copolymer, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid ester copolymer, polyisoprene, styrene-isoprene copolymer, isobutylene-isoprene copolymer, polychloroprene, styrene-chloroprene copolymer, acrylonitrile-chloroprene copolymer, polyisobutylene, polyacrylic acid ester, polymethacrylic acid ester, etc. These may be used alone or in combination of two or more.

[0025] As the polymer [A], an organic polymer having a polar group such as a nitrogen-containing characteristic group in the molecule can also be used. Specific examples of the nitrogen-containing characteristic group include (thio)urethane group, allophanate group, other N-substituted urethane group, N-substituted allophanate group and other (thio)urethane group-derived linking groups, (thio)urea group, biuret group, other N-substituted urea group, N,N'-substituted urea group, N-substituted biuret group, N,N'-substituted biuret group and other (thio)urea group-derived linking groups, amide group, N-substituted amide group and other amide group-derived linking groups, imino group-derived linking groups, (thio)ester group, (thio)ether group, etc., but are not limited thereto. Among these, nitrogen-containing characteristic groups are preferred from the viewpoint of high curability, and (thio)urethane group-derived linking groups and (thio)urea-derived linking groups are more preferred from the viewpoint of ease of synthesis. The polymer [A] may contain only one nitrogen-containing characteristic group, or may contain one or more types of nitrogen-containing characteristic groups. Here, the terms "(thio)" and "N-substituted" are as defined above.

[0026] When the polymer [A] contains a polar group such as the nitrogen-containing characteristic group, the toughness of the cured product is improved, and the curability and adhesive strength are also increased. In particular, when the crosslinkable silicon group is linked to the main chain via a polar group such as a nitrogen-containing characteristic group, the curability is further increased. The reason for this is that the polar groups of the nitrogen-containing characteristic group strongly attract each other due to interactions such as hydrogen bonds. It is believed that the strong attraction between the polar groups of the nitrogen-containing characteristic group causes the molecules of the curable resin to be strongly bonded (domain formation), which results in the toughness of the cured product. In addition, when the crosslinkable silicon group is linked to the main chain via a polar group such as a nitrogen-containing characteristic group, when the nitrogen-containing characteristic groups form a domain, the crosslinkable silicon groups also come close to each other, which increases the contact probability between the crosslinkable silicon groups, and further, it is believed that the condensation reactivity between the crosslinkable silicon groups is improved by catalytic curing by the polar group in the nitrogen-containing characteristic group.

[0027] Such polymer [A] (modified silicone-based polymer) can be produced by known methods such as the method described in Japanese Patent Publication No. 61-18569, or is commercially available. Examples of commercially available products include Kaneka MS Polymer Series (MS Polymer S203, MS Polymer S303, MS Polymer S903, MS Polymer S911, MS Polymer SAX520, etc.), Silyl Series (Silyl Polymer SAT200, Silyl Polymer MA430, Silyl Polymer MAX447, etc.), MA Series, SA Series, OR Series, and Asahi Glass Co., Ltd.'s ES Series (ES-GX3440ST, etc.), ESGX Series, etc.

[0028] The number average molecular weight of the polymer [A] used in the present invention is not particularly limited, but since excessively high molecular weight polymers have high viscosity and are difficult to use when used in a curable composition, the number average molecular weight is preferably 30000 or less. Such polymers can be produced by known methods, but commercial products such as Kaneka MS Polymer manufactured by Kaneka Corporation may also be used.

[0029] 2.Curing catalyst [B] The curing catalyst [B] contains a phosphazene [B1].

[0030] <Phosphazene [B1]> Phosphazene [B1] is represented by the following formula:

[0031] [ka]

[0032] X is a monovalent organic group having 1 to 18 carbon atoms, and Y is the same or different and is a monovalent organic group or a divalent organic group formed by two Ys linked together.

[0033] The number of carbon atoms in the monovalent organic group constituting X is preferably 1 to 10, more preferably 1 to 4, and specifically, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18, and may be within the range between any two of the numerical values ​​exemplified here. This organic group may be composed of only carbon and hydrogen, or may contain other atoms (for example, at least one of an oxygen atom and a nitrogen atom). This organic group is, for example, an aromatic or aliphatic hydrocarbon group which may have a substituent, and an aliphatic hydrocarbon group is preferable. As the aliphatic hydrocarbon group, an alkyl group is preferable.

[0034] The number of carbon atoms in the monovalent organic group constituting Y is, for example, 1 to 18, preferably 1 to 10, more preferably 2 to 4, and specifically, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18, and may be within a range between any two of the numerical values ​​exemplified here. The organic group preferably contains carbon and hydrogen. The organic group preferably contains a nitrogen atom, and the atom directly bonded to the phosphorus atom in the chemical formula (1) is preferably a nitrogen atom. The number of nitrogen atoms contained in the organic group is, for example, 1, 2, 3, or 4. The organic group may or may not contain a phosphorus atom. The number of phosphorus atoms contained in the organic group is preferably 0 or 1. The phosphorus atom is preferably bonded to a nitrogen atom. The organic group may contain other atoms (for example, at least one of an oxygen atom, a sulfur atom, and a halogen atom).

[0035] The number of phosphorus atoms contained in the phosphazene [B1] is, for example, 1, 2, 3, or 4. The number of nitrogen atoms contained in the phosphazene [B1] is, for example, 1 to 13, specifically, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, and may be within a range between any two of the numerical values ​​exemplified here. The number of double bonds between nitrogen atoms and phosphorus atoms contained in the phosphazene [B1] is, for example, 1, 2, 3, or 4.

[0036] At least one of Y's is preferably represented by chemical formula (2) or chemical formula (3).

[0037] [ka]

[0038] In the chemical formula (2), * is a bond, and R 1 is a monovalent organic group or two R 1 is a divalent organic group formed by linking together.

[0039] R 1 The description of the monovalent organic group constituting the formula (I) is the same as the description of the monovalent organic group constituting X.

[0040] The Two R's 1 The number of carbon atoms in the divalent organic group formed by linking together is, for example, 1 to 18, preferably 1 to 10, more preferably 2 to 4, and specifically, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18, and may be within the range between any two of the numerical values ​​exemplified here. A cyclic structure is formed by this organic group and the nitrogen atom to which this organic group is bonded. This organic group may be composed only of carbon and hydrogen, or may contain other atoms (for example, at least one of an oxygen atom and a nitrogen atom). This organic group is, for example, an aromatic or aliphatic hydrocarbon group which may have a substituent, and an aliphatic hydrocarbon group is preferable. As the aliphatic hydrocarbon group, an alkylene group is preferable.

[0041] [ka]

[0042] In the chemical formula (3), * is a bond. Y is defined as in the chemical formula (1).

[0043] The number of carbon atoms in the divalent organic group formed by linking two Ys in the chemical formula (1) to each other is, for example, 1 to 18, preferably 1 to 10, specifically, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and may be within a range between any two of the numerical values ​​exemplified here. A ring structure is formed by this organic group and the phosphorus atom to which this organic group is bonded. This organic group preferably contains carbon and hydrogen. This organic group preferably contains a nitrogen atom, and the atom directly bonded to the phosphorus atom in the chemical formula (1) is preferably a nitrogen atom. The number of nitrogen atoms contained in this organic group is, for example, 2. This organic group may contain other atoms (for example, at least one of an oxygen atom, a phosphorus atom, a sulfur atom, and a halogen atom).

[0044] The divalent organic group formed by linking two Y's in chemical formula (1) to each other is preferably represented by chemical formula (4). [ka]

[0045] In the chemical formula (4), * is a bond, and R 2 is a divalent organic group, R 3 is a monovalent organic group or two R 3 is a divalent organic group formed by linking together.

[0046] R 2 Explanation of the divalent organic groups that make up the R 3 The explanation of a divalent organic group formed by linking together is as follows: 1 The same as the description of the divalent organic group formed by linking together R 3 The description of the monovalent organic group constituting the formula (I) is the same as the description of the monovalent organic group constituting X.

[0047] Specific examples of Y in chemical formula (1) include dialkylamino groups such as N,N'-dimethylamino group, N,N'-diethylamino group, N,N'-dipropylamino group, N,N'-diisopropylamino group, N,N'-dibutylamino group, N,N'-dioctylamino group, N-methyl,N'-propylamino group, N-methyl,N'-butylamino group, N,N'-di(2-ethylhexyl)amino group, and N,N'-dimethyl-1,3propyldiamino; cyclic amino groups such as pyrrolyl group, morpholino group, piperazino group, pyrrolidino group, and N-alkylpiperazino group; tris(N,N'-dimethylamino)phosphoranylideneamino group, tris(N,N'-diethylamino)phosphoranylideneamino group, tris(N,N'- and the like. Examples of such phosphoranylideneamino groups include a tris(N,N'-dipropylamino)phosphoranylideneamino group, a tris(N,N'-diisopropylamino)phosphoranylideneamino group, a tris(N,N'-dibutylamino)phosphoranylideneamino group, a tris(N-methyl,N'-phenylamino)phosphoranylideneamino group, a tris(N-ethyl,N'-phenylamino)phosphoranylideneamino group, a trisaziridinophosphoranylideneamino group, a trispirolidinophosphoranylideneamino group, and a trispiperidinophosphoranylideneamino group.

[0048] <Titanium compounds [B2]>

[0049] The curing catalyst [B] may further contain a titanium compound [B2].

[0050] The titanium compound [B2] is a compound containing a titanium atom, and at least one of the ligands coordinated to the titanium atom is preferably an alkoxy group. The number of ligands is preferably 4. The number of alkoxy groups contained in the ligand is, for example, 1, 2, 3, or 4. The ligand may contain a group other than an alkoxy group, and examples of such a group include an alkyl group, a carboxyl group, and a β-diketone group. The number of carbon atoms in these ligands is, for example, 1 to 18, preferably 1 to 10, more preferably 2 to 4, and specifically, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18, and may be within a range between any two of the numerical values ​​exemplified here.

[0051] The titanium compound [B2] is preferably represented by chemical formula (5). (R 4 -O) n Ti-A 4-n (5)

[0052] In chemical formula (5), R 4 is a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, n is an integer from 1 to 4 (that is, 1, 2, 3, or 4), and A is a β-diketone group.

[0053] R 4 The substituted or unsubstituted hydrocarbon group represented by the formula (I) is a substituted or unsubstituted aliphatic or aromatic hydrocarbon group, and an aliphatic hydrocarbon group is preferable. Examples of the aliphatic hydrocarbon group include saturated or unsaturated hydrocarbon groups. Examples of the saturated hydrocarbon group include linear or branched alkyl groups. The number of carbon atoms in the hydrocarbon group is 1 to 10, preferably 1 to 6, and more preferably 1 to 4. Specifically, the number of carbon atoms is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, and may be within a range between any two of the numerical values ​​exemplified here. Examples of the hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl.

[0054] Examples of the β-diketone group represented by A include 1-aryl-1,3-butanediones such as 2,4-pentanedione, 2,4-hexanedione, 2,4-pentadecanedione, 2,2,6,6-tetramethyl-3,5-heptanedione, 1-phenyl-1,3-butanedione, and 1-(4-methoxyphenyl)-1,3-butanedione, 1,3-diaryl-1,3-propanedione such as 1,3-bis(2-pyridyl)-1,3-propanedione and 1,3-bis(4-methoxyphenyl)-1,3-propanedione, and 3-benzyl-2,4-pentanedione, diketones such as methyl acetoacetate. ketoesters such as ethyl acetoacetate, butyl acetoacetate, t-butyl acetoacetate, and ethyl 3-oxohexanoate; ketoamides such as N,N-dimethyl acetoacetamide, N,N-diethyl acetoacetamide, and acetoacetanilide; malonic acid esters such as dimethyl malonate, diethyl malonate, and diphenyl malonate; and malonic acid amides such as N,N,N',N'-tetramethylmalonamide and N,N,N',N'-tetraethylmalonamide. Diketones such as 2,4-pentanedione, 1-aryl-1,3-butanedione, and 1,3-diaryl-1,3-propanedione are particularly preferred.

[0055] Specific examples of titanium compounds [B2] include tetramethoxytitanium, trimethoxyethoxytitanium, trimethoxyisopropoxytitanium, trimethoxybutoxytitanium, dimethoxydiethoxytitanium, dimethoxydiisopropoxytitanium, dimethoxydibutoxytitanium, methoxytriethoxytitanium, methoxytriisopropoxytitanium, methoxytributoxytitanium, tetraethoxytitanium, triethoxyisopropoxytitanium, triethoxybutoxytitanium, diethoxydiisopropoxytitanium, diethoxydibutoxytitanium, ethoxytriisopropoxytitanium, ethoxytributoxytitanium, tetraisopropoxytitanium, triisopropoxybutoxytitanium, diisopropoxydibutoxytitanium, tetrabutoxytitanium, and diisopropoxytitanium bis(acetylacetonate). From the viewpoints of catalytic activity, stability of the compound and ease of handling, titanium tetraisopropoxide is more preferred. The titanium compounds [B2] may be used alone or in combination of two or more kinds.

[0056] The content ratio (B1 / B2) of the phosphazene [B1] and the titanium compound [B2] is in the range of 3 / 1 to 1 / 2 in terms of molar ratio, and from the viewpoint of obtaining good curability, is preferably 3 / 1 to 1 / 1, and more preferably 2 / 1 to 1 / 1.

[0057] 3. Moisture-curable composition The moisture-curable composition of the present invention contains the above-mentioned curing catalyst [B] and polymer [A], and may contain other additives described below as necessary. The moisture-curable composition of the present invention can be prepared by mixing the two under dry conditions, and the mixing form is not particularly limited. Usually, mixing is performed under an atmosphere of a temperature of about 15 to 30°C and 60% RH or less.

[0058] In the moisture-curable composition of the present invention, the content of the curing catalyst [B] is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, and particularly preferably 3 to 8 parts by weight, relative to 100 parts by weight of the polymer [A]. If the content of the curing catalyst [B] is less than 0.1 parts by weight, the curing performance is insufficient, and if it exceeds 20 parts by weight, the recovery rate of the cured product after curing, physical properties such as weather resistance, and stability during storage may be deteriorated. The content of the curing catalyst [B] is specifically, for example, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts by weight relative to 100 parts by weight of the polymer [A], and may be within the range between any two of the numerical values ​​exemplified here.

[0059] The moisture-curable composition of the present invention may further contain a filler [C]. Examples of fillers include calcium carbonate, kaolin, talc, fumed silica, precipitated silica, anhydrous silicic acid, hydrous silicic acid, clay, calcined clay, glass, bentonite, organic bentonite, silasburn, glass fiber, asbestos, glass filament, crushed quartz, diatomaceous earth, aluminum silicate, aluminum hydroxide, zinc oxide, magnesium oxide, and titanium dioxide. The filler may be used alone or in combination of two or more. The addition of a filler improves the handling of the moisture-curable composition. It also acts as a rubber reinforcement agent for the cured product. The greatest advantage is that the amount of resin used can be reduced by adding it as an extender, thereby reducing costs.

[0060] Among these, calcium carbonate and titanium oxide are preferred from the viewpoint of maintaining excellent surface non-tackiness, 50% modulus, workability, weather resistance, etc. of the curable composition after curing. When calcium carbonate is used, its proportion is preferably 1 to 200 parts by weight, more preferably 50 to 200 parts by mass, per 100 parts by weight of the polymer [A]. Within the above range, the properties after curing are not impaired.

[0061] The moisture-curable composition of the present invention may further contain additives that are usually added to curable compositions, such as other curing catalysts, curing accelerators, colorants, plasticizers, curing retarders, anti-sagging agents, anti-aging agents, and solvents.

[0062] Other curing catalysts include, for example, metal curing catalysts such as organotin compounds such as dibutyltin dilaurate and dibutyltin bis(acetylacetonate), organoaluminum compounds such as aluminum tris(acetylacetonate) and aluminum tris(ethylacetoacetate), organozirconium compounds such as zirconium tetra(acetylacetonate) and zirconium tetrabutylate, and amine compounds such as 1-amino-2-ethylhexane, 3-(trimethoxysilyl)propylamine, N-2-aminoethyl-3-aminopropyltrimethoxysilane, N,N,N',N'-tetramethyl-N''-[3-(trimethoxysilyl)propyl]guanidine, 1,5,7-triazabicyclo-[4,4,0]dec-5-ene, and 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine.

[0063] As the curing accelerator, for example, various known amino group-substituted alkoxysilane compounds or their condensates can be used. Specific examples include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(trimethoxysilylpropyl)ethylenediamine, δ-aminobutyl(methyl)diethoxysilane, N,N-bis(trimethoxysilylpropyl)ethylenediamine, and partial hydrolysis thereof, which also have the effect of improving adhesion to the substrate.

[0064] Specifically, the coloring agent may be iron oxide, carbon black, phthalocyanine blue, phthalocyanine green, or the like.

[0065] Specific examples of the plasticizer that can be used include phthalate esters such as dibutyl phthalate, dioctyl phthalate, and butyl benzyl phthalate; fatty acid carboxylate esters such as dioctyl adipate, dioctyl succinate, diisodecyl succinate, and butyl oleate; glycol esters such as pentaerythritol esters; phosphate esters such as trioctyl phosphate and tricresyl phosphate; epoxy plasticizers such as epoxidized soybean oil and epoxy benzyl stearate; and chlorinated paraffin.

[0066] Specific examples of the anti-sagging agent that can be used include hydrogenated castor oil, silicic anhydride, organic bentonite, and colloidal silica.

[0067] Other additives that may be used include adhesion promoters such as phenolic resins and epoxy resins, ultraviolet absorbers, radical chain inhibitors, peroxide decomposers, and various types of antioxidants.

[0068] The curable composition of the present invention is sufficiently stable at room temperature, and therefore has excellent storage properties, and when it comes into contact with moisture, the curing reaction proceeds spontaneously due to the curing catalyst [B] added. In addition, the snap time (the time until the composition becomes semi-gelled and loses fluidity) and tack-free time (the time until the surface tack disappears) are short, and the composition has excellent workability.

[0069] Due to the above-mentioned characteristics, the curable composition of the present invention can be used as a one-component sealant. Specifically, it is suitable for use as a sealant, adhesive, sealant, waterproofing material, etc. for buildings, ships, and vehicles such as automobiles. EXAMPLES

[0070] The present invention will now be described in detail with reference to examples, but the scope of the present invention is not limited thereto.

[0071] 1. Manufacturing Example Catalyst compositions 1 to 4 and titanium acetate triisopropoxide were produced according to the following production examples. Catalyst compositions 1 to 4 are curing catalysts composed of a mixture of phosphazene compound 1 and titanium tetraisopropoxide.

[0072] <Production example 1 (catalyst composition 1)> Into a 50 mL recovery flask, 1.42 g (0.005 mol) of tetraisopropoxytitanium and 3.12 g (0.01 mol) of phosphazene compound 1 were weighed and mixed by heating in a water bath at 70° C., yielding 4.54 g of a yellow liquid in the flask.

[0073] <Production example 2 (catalyst composition 2)> Into a 50 mL recovery flask, 2.84 g (0.01 mol) of tetraisopropoxytitanium and 3.12 g (0.01 mol) of phosphazene compound 1 were weighed and mixed by heating in a water bath at 70° C., yielding 5.96 g of a yellow liquid in the flask.

[0074] <Production example 3 (catalyst composition 3)> 1.42 g (0.005 mol) of tetraisopropoxytitanium, 3.12 g (0.01 mol) of phosphazene compound 1, and 1.6 g (0.05 mol) of methanol were weighed into a 50 mL recovery flask, heated in a water bath at 70°C, and concentrated under reduced pressure (final reduced pressure of 12 mmHg), yielding 3.98 g of a yellow liquid in the flask.

[0075] <Production example 4 (catalyst composition 4)> 2.84 g (0.01 mol) of tetraisopropoxytitanium, 3.12 g (0.01 mol) of phosphazene compound 1, and 3.2 g (0.1 mol) of methanol were weighed into a 50 mL recovery flask, and the mixture was heated in a water bath at 70°C and concentrated under reduced pressure (final reduced pressure of 12 mmHg), yielding 4.56 g of a yellow liquid in the flask.

[0076] <Comparative Production Example 1 (Titanium Acetate Triisopropoxide)> In a 1000ml four-necked eggplant flask equipped with a nitrogen inlet tube, 200.00g (0.70368mol) of tetraisopropoxytitanium and 42.2g (0.703681mol) of acetic acid were weighed and thoroughly mixed with a stirrer. After stirring was continued until the internal temperature reached approximately 110°C, the pressure was reduced to distill off the isopropyl alcohol, and 196g (98%) of yellow liquid titanium acetate triisopropoxide was obtained.

[0077] 2. Preparation of Moisture-Curable Composition Moisture-curable compositions were prepared by mixing and kneading the components obtained in the above Production Examples and commercially available components in the mixing ratios (parts by mass) shown in Tables 1 and 2. The operations of mixing the materials, kneading, and curing were carried out in an atmosphere of 25±1°C and 50-60% RH.

[0078] 3. Measurement of tack-free time The obtained moisture-curable composition was measured for tack-free time (the time required from the end of kneading until the sample no longer adheres to the fingertip when the surface is lightly touched at three points with a fingertip cleaned with ethyl alcohol). The results of the tack-free time measurement are shown in Tables 1 and 2.

[0079] As shown in Tables 1 and 2, the moisture-curable compositions of the examples had significantly shorter tack-free times than the comparative examples.

[0080] [Table 1]

[0081] [Table 2]

[0082] Details of the above Production Examples and materials shown in Tables 1 and 2 are as follows.

[0083] (Polymer [A]) MS Polymer SAX520: Silyl group-containing organic polymer (manufactured by Kaneka Corporation) MS Polymer S303: Silyl group-containing organic polymer (Kaneka Corporation) STP-15E: Silyl group-containing organic polymer GENIOSIL STP-15E (manufactured by WACKER Chemical Corporation)

[0084] (Curing catalyst [B]) Phosphazene compound 1 (chemical formula (6)): manufactured by Sigma-Aldrich Phosphazene compound 2 (chemical formula (7)): manufactured by Sigma-Aldrich Phosphazene compound 3 (chemical formula (8)): manufactured by Sigma-Aldrich Phosphazene compound 4 (chemical formula (9)): manufactured by Sigma-Aldrich Phosphazene compound 5 (chemical formula (10)): 75% hexane solution manufactured by Sigma-Aldrich Catalyst compositions 1 to 4: those produced in Production Examples 1 to 4

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] (Other catalysts) Titanium tetraisopropoxide: manufactured by Tokyo Chemical Industry Co., Ltd. Titanium acetate triisopropoxide: Produced in Comparative Production Example 1

[0091] (Filler) Carlex 300: Calcium carbonate (manufactured by Maruo Calcium Co., Ltd.) FR-41: Titanium oxide (manufactured by Furukawa Chemicals Co., Ltd.) REOLOSIL PM-20: Fumed silica (manufactured by Tokuyama Corporation)

[0092] (Other additives) DINP: Plasticizer (manufactured by JPlus Corporation) PPG1000: Plasticizer (Kishida Chemical Co., Ltd.) Disparlon 6500: Anti-sagging agent (Kusumoto Chemical Co., Ltd.) Songsorb 3260P: UV absorber (manufactured by SONGWON) Sabostab UV70: Light stabilizer (SONGWON) Irganox245: Antioxidant (BASF Japan Ltd.) KBE-1003: Dehydrating agent (Shin-Etsu Silicone Industries Co., Ltd.) KBM-903: Adhesion promoter (Shin-Etsu Silicone Industries Co., Ltd.)

Claims

1. A moisture-curable composition comprising a curing catalyst [B] and a polymer [A], The polymer [A] has a reactive hydrolyzable silicon-containing group and contains a carbon atom in its main chain, The polymer [A] is an alkylene oxide polymer, The curing catalyst [B] contains a phosphazene [B1], The phosphazene [B1] is a moisture-curable composition represented by chemical formula (1) (excluding those in which the phosphazene [B1] is an organosilicon compound). 【Chemistry 1】 (In the formula, X is a monovalent organic group having 1 to 18 carbon atoms, and Y is the same or different and is a monovalent organic group, or a divalent organic group formed by bonding two Ys together.)

2. The moisture-curable composition according to claim 1, The moisture-curable composition, wherein Y is a nitrogen atom, and the atom directly bonded to the phosphorus atom in the chemical formula (1) is a nitrogen atom.

3. The moisture-curable composition according to claim 1 or 2, At least one of the Y's is represented by chemical formula (2) or chemical formula (3), 【Chemistry 2】 (Wherein, * is a bond, R １ are the same or different and are monovalent organic groups, or two R １ is a divalent organic group formed by linking together. 【Chemistry 3】 (In the formula, * is a bond.)

4. The moisture-curable composition according to any one of claims 1 to 3, The divalent organic group formed by linking the two Ys together is represented by chemical formula (4), 【Chemistry 4】 (Wherein, * is a bond, R ２ is a divalent organic group, R ３ are the same or different and are monovalent organic groups, or two R ３ is a divalent organic group formed by linking together.

5. The moisture-curable composition according to any one of claims 1 to 4, The curing catalyst [B] further contains a titanium compound [B2], The titanium compound [B2] is a moisture-curable composition in which at least one alkoxy group is coordinated to a titanium atom.

6. The moisture-curable composition according to claim 5, The titanium compound [B2] is a moisture-curable composition represented by chemical formula (5). (R ４ -O) ｎ Ti-A ４－ｎ (5) (In the formula R ４ is a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms, n is an integer of 1 to 4, and A is a β-diketone group.

7. A method for producing a cured product, comprising a step of contacting the moisture-curable composition according to any one of claims 1 to 6 with moisture.

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