WO2025154435A1 - Curable composition and method for producing same - Google Patents

Abstract

Provided is a method for producing a curable composition containing: an organic polymer (A) having a reactive silicon group; an amidine structure-containing compound (b1); a titanium compound or a condensate thereof (b2); and a silane compound (b3) having a hydrolyzable silicon group and an amino group and having a molecular weight of 100-1,500. A catalyst-containing composition (B) obtained by mixing (b1), (b2), and (b3) is prepared, and the organic polymer (A) and the catalyst-containing composition (B) are mixed. The weight ratio (b3)/(b2) is 0.1-2.

Description

Curable composition and method for producing same

The present invention relates to a curable composition containing an organic polymer having a silicon group (hereinafter also referred to as a "reactive silicon group") that has a hydroxyl group or a hydrolyzable group bonded to a silicon atom and that can form a crosslink by forming a siloxane bond, and a method for producing the same.

Organic polymers with reactive silicon groups are known to have the property of crosslinking through the formation of siloxane bonds accompanied by hydrolysis of silyl groups due to moisture, etc., even at room temperature, resulting in a rubber-like cured product. Such organic polymers with reactive silicon groups are already being produced industrially, and are widely used in applications such as sealants, adhesives, paints, and waterproofing materials.

In order to make the curing reaction proceed in a short time, curable compositions containing organic polymers with reactive silicon groups usually contain a curing catalyst (also called a silanol condensation catalyst) such as an organotin compound with a carbon-tin bond, as typified by dibutyltin bis(acetylacetonate). However, from the perspective of environmental safety, care must be taken when using organotin compounds.

For this reason, curing catalysts other than organotin compounds are being considered. Patent Document 1 describes the use of a titanium compound, such as a titanium alkoxide or a titanium chelate compound, in combination with an amine compound, such as DBU (1,8-diazabicyclo[5.4.0]-7-undecene), as a curing catalyst for an organic polymer having a reactive silicon group. Paragraph [0220] of the document describes adding a titanium compound and an amine compound separately to an organic polymer having a reactive silicon group, and then mixing them together.

On the other hand, it is known that by blending a low molecular weight silane compound (a so-called silane coupling agent) that has a hydrolyzable silicon group and a reactive group such as an amino group or a vinyl group with a curable composition containing an organic polymer that has a reactive silicon group, the adhesion to various substrates and storage stability can be improved.

JP 2014-114434 A

The curing catalyst disclosed in Patent Document 1 is composed of a titanium compound and an amine compound, each of which is added to a reactive silicon group-containing organic polymer. In response to this, the present inventors have investigated the use of a titanium compound and an amine compound mixed together before adding them to the polymer, and the resulting mixture used as the curing catalyst.

However, it has been found that a mixture of a titanium compound and an amine compound may become discolored due to the reaction between the two components, and the color deepens over time after mixing. Such a darkening of color is undesirable in terms of the appearance of the mixture, which is a curing catalyst, or the curable composition or cured product.

In view of the above-mentioned current situation, the present invention aims to provide a method for producing a curable composition containing a reactive silicon group-containing organic polymer, in which the mixture of a titanium compound and an amine compound, which is a curing catalyst, can suppress darkening over time while retaining its function as a curing catalyst.

As a result of extensive research into solving the above problems, the inventors discovered that by further adding an amino group-containing silane compound to a mixture of a titanium compound and an amine compound, it is possible to suppress the darkening of the mixture over time, and that by adding this to a reactive silicon group-containing organic polymer, good curing properties can be achieved, thus completing the present invention.

That is, the present invention relates to a compound represented by the following general formula (1):
-SiR ¹ _3-a X _a (1)
(In the formula, R ¹ represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or a triorganosiloxy group represented by R ⁰ ₃ SiO-. The three R ⁰ 's may be the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 1, 2, or 3. When a plurality of ^{R 1's} or X's are present, they may be the same or different.)
(A) an organic polymer having a reactive silicon group represented by
The following general formula (2):
R ² N=CR ³ -NR ⁴ ₂ (2)
(In the formula, R ² , R ³ , and R ⁴ are the same or different and each represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. The two R ^4s may be the same or different. Any two or more of R ² , R ³ , and the two R ^4s may be bonded to form a cyclic structure.)
an amidine structure-containing compound (b1) represented by the formula:
The following general formula (3):
Ti(OR ⁵ ) _d Y _4-d (3)
(In the formula, ^R5 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, Y represents a chelate coordination compound, and d represents 0 or an integer of 1 to 4.)
or a condensate thereof (b2),
A method for producing a curable composition containing a silane compound (b3) having a hydrolyzable silicon group and an amino group and a molecular weight of 100 to 1500, comprising the steps of:
a preparation step of preparing a catalyst-containing composition (B) obtained by mixing the amidine structure-containing compound (b1), the titanium compound or a condensate thereof (b2), and the silane compound (b3); and a mixing step of mixing the organic polymer (A) and the catalyst-containing composition (B),
The present invention also relates to a method for producing a curable composition, wherein a weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1 to 2.
The present invention also provides a curable composition comprising the reactive silicon group-containing organic polymer (A) and a catalyst-containing composition (B),
the catalyst-containing composition (B) comprises a complex of an amidine structure-containing compound (b1) represented by the general formula (2), a titanium compound represented by the general formula (3) or a condensate thereof (b2), and a silane compound (b3) having a molecular weight of 100 to 1500 and having a hydrolyzable silicon group and an amino group,
The present invention also relates to a curable composition, in which the weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1 to 2. The present invention also relates to a cured product obtained by curing the curable composition.
The present invention further provides a catalyst-containing composition (B) for an organic polymer (A) having a reactive silicon group, comprising:
The present invention comprises a complex of an amidine structure-containing compound (b1) represented by the general formula (2), a titanium compound represented by the general formula (3) or a condensate thereof (b2), and a silane compound (b3) having a hydrolyzable silicon group and an amino group and a molecular weight of 100 to 1500,
The present invention also relates to a catalyst-containing composition (B), in which the weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1-2.

The present invention provides a method for producing a curable composition containing a reactive silicon group-containing organic polymer, in which the mixture of a titanium compound and an amine compound, which is a curing catalyst, can suppress darkening over time while retaining its function as a curing catalyst.

The present invention also provides a non-tin catalyst-containing composition that is inhibited from darkening over time and that can achieve good curing properties as a curing catalyst for reactive silicon-containing organic polymers. In a preferred embodiment, a colorless and transparent catalyst-containing composition can be provided.

According to one aspect of the present invention, it is possible to provide a curable composition in which bleeding out of the compound on the surface of the cured product obtained by curing is suppressed.
Moreover, according to one embodiment of the present invention, it is possible to provide a curable composition in which delay in curing due to storage is suppressed and which exhibits favorable storage stability with respect to curability.
Furthermore, according to one aspect of the present invention, a curable composition having good adhesiveness can be provided.
Furthermore, according to one aspect of the present invention, it is possible to provide a curable composition that exhibits good tensile properties after curing.

The following describes an embodiment of the present invention in detail.

(Reactive Silicon Group-Containing Organic Polymer (A))
The reactive silicon group-containing organic polymer (A) has a polymer skeleton (also called a main chain structure) and a polymer chain end bonded to the polymer skeleton. The polymer skeleton is a structure in which a plurality of monomer units are continuously formed by bonding a plurality of monomers by polymerization, condensation, etc. The monomer may be one type, or a mixture of a plurality of types may be bonded.

The polymer chain end refers to the portion located at the end of the reactive silicon group-containing organic polymer (A). The number of polymer chain ends of the reactive silicon group-containing organic polymer (A) is 2 when the polymer skeleton is entirely linear, and is 3 or more when the polymer skeleton is entirely branched. In addition, when the polymer skeleton is a mixture of linear and branched chains, the number can be between 2 and 3 on average.

The reactive silicon groups of the organic polymer (A) may be present in the polymer backbone and/or at the polymer chain end. Two or more reactive silicon groups may also be present at one polymer chain end. When the curable composition according to the present disclosure is used as an adhesive, a sealant, an elastic coating agent, a pressure sensitive adhesive, or the like, it is preferable that the reactive silicon groups are contained at the polymer chain end of the organic polymer (A).

The organic polymer (A) has a reactive silicon group represented by the following general formula (1).
-SiR ¹ _3-a X _a (1)
(In the formula, R ¹ represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or a triorganosiloxy group represented by R ⁰ ₃ SiO-. The three R ⁰ 's may be the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 1, 2, or 3. When a plurality of ^{R 1's} or X's are present, they may be the same or different.)

Examples of R ¹ in the general formula (1) include alkyl groups such as methyl and ethyl groups; alkyl groups having a hetero-containing group such as chloromethyl, methoxymethyl, and 3,3,3-trifluoropropyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl; aralkyl groups such as benzyl; and triorganosiloxy groups represented by R ⁰ ₃ SiO-, where R ⁰ is a methyl group, phenyl group, or the like. Preferred are alkyl groups or alkyl groups having a hetero-containing group, more preferably methyl, ethyl, chloromethyl, and methoxymethyl groups, even more preferably methyl and ethyl groups, and particularly preferably methyl groups. When there are a plurality of R ¹ , they may be the same as or different from each other.

X in general formula (1) represents a hydroxyl group or a hydrolyzable group. The hydrolyzable group is not particularly limited and may be a known hydrolyzable group, such as a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, an alkoxy group, an acyloxy group, a ketoximate group, and an alkenyloxy group are preferred. Because of their mild hydrolysis and ease of handling, an alkoxy group is more preferred, a methoxy group and an ethoxy group are even more preferred, and a methoxy group is particularly preferred. When there are multiple Xs, they may be the same or different from each other.

a is 1, 2, or 3. a is preferably 2 or 3. From the viewpoint of better curability, a is particularly preferably 3.

The reactive silicon group represented by the general formula (1) is not particularly limited, but examples thereof include trimethoxysilyl, triethoxysilyl, tris(2-propenyloxy)silyl, triacetoxysilyl, dimethoxymethylsilyl, diethoxymethylsilyl, dimethoxyethylsilyl, dimethoxyphenylsilyl, (chloromethyl)dimethoxysilyl, (chloromethyl)diethoxysilyl, (methoxymethyl)dimethoxysilyl, (methoxymethyl)diethoxysilyl, (N,N-diethylaminomethyl)dimethoxysilyl, and (N,N-diethylaminomethyl)diethoxysilyl. Of these, the dimethoxymethylsilyl and trimethoxysilyl groups are preferred because they are easy to synthesize. The trimethoxysilyl and methoxymethyldimethoxysilyl groups are preferred because they provide high curing properties. The trimethoxysilyl and triethoxysilyl groups are preferred because they provide cured products that exhibit high recovery rates and low water absorption.

(Main Chain Structure of Reactive Silicon Group-Containing Organic Polymer (A))
The main chain structure (also referred to as polymer skeleton) of the reactive silicon group-containing organic polymer (A) is not particularly limited, and various main chain structures can be used. Specifically, polyoxyalkylene polymers such as polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymers, and polyoxypropylene-polyoxybutylene copolymers; hydrocarbon polymers such as ethylene-propylene copolymers, polyisobutylene, copolymers of isobutylene and isoprene, and hydrogenated polyolefin polymers obtained by hydrogenating these polyolefin polymers; polyolefins obtained by condensation of dibasic acids such as adipic acid with glycols, or ring-opening polymerization of lactones; Examples of such polymers include ester polymers, (meth)acrylic acid ester polymers obtained by radical polymerization of (meth)acrylic acid ester monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and stearyl (meth)acrylate, vinyl copolymers obtained by radical polymerization of (meth)acrylic acid ester monomers, vinyl acetate, acrylonitrile, and styrene, polysulfide polymers, polyamide polymers, polycarbonate polymers, and diallyl phthalate polymers. In the above description, (meth)acrylic means acrylic and/or methacrylic.

Among these, saturated hydrocarbon polymers such as polyisobutylene, hydrogenated polyisoprene, and hydrogenated polybutadiene, polyoxyalkylene polymers, and (meth)acrylic acid ester polymers are preferred because they have relatively low glass transition temperatures and the resulting cured products have excellent cold resistance. Only one of these may be used, or two or more may be used in combination.

Polyoxyalkylene polymers and (meth)acrylic acid ester polymers are particularly preferred because they have high moisture permeability, excellent deep curing properties when made into a one-component curable composition, and excellent adhesion. Polyoxyalkylene polymers are more preferred, and polyoxypropylene is even more preferred.

(Meth)acrylic acid ester polymers are useful because by combining various monomer compositions that make up the polymer, it is possible to obtain effects such as improving adhesion, improving heat resistance and weather resistance, and reducing the water absorption of the cured product obtained by curing the curable composition.

The polyoxyalkylene polymer is preferably a polymer having a repeating unit represented by -R-O- (wherein R is a linear or branched alkylene group having 1 to 14 carbon atoms). R is more preferably a linear or branched alkylene group having 2 to 4 carbon atoms. Specific examples of the repeating unit represented by -R-O- include -CH ₂ O-, -CH 2 CH ₂ O-, -CH ₂ CH(CH 3 )O-, -CH ₂ CH(C ₂ H 5 ) _O- , -CH ₂ C(CH ₃ ) ₍ CH ₃ )O-, and -CH ₂ CH ₂ CH ₂ CH ₂ O-. The main chain structure of the polyoxyalkylene polymer may be composed of only one type of repeating unit, or may be composed of two or _more types of repeating units.

In particular, when the curable composition according to the present disclosure is used in sealants, adhesives, etc., polyoxypropylene-based polymers having oxypropylene repeat units in an amount of 50% by weight or more, more preferably 80% by weight or more, of the polymer main chain structure are preferred because they are amorphous and have a relatively low viscosity.

The main chain structure of the polyoxyalkylene polymer may be linear or may have a branched chain. When the polymer has a branched chain, the number of branches is preferably 1 to 6 (i.e., the number of terminal hydroxyl groups is 3 to 8), more preferably 1 to 4 (i.e., the number of terminal hydroxyl groups is 3 to 6), and most preferably 1 (i.e., the number of terminal hydroxyl groups is 3). By having a branched chain, it is possible to obtain an effect of improving the restorability of the cured product. In addition, it is also expected to have an effect of reducing the water absorption of the cured product. When the polymer has a branched chain and the reactive silicon group is a trimethoxysilyl group, it is possible to obtain a cured product with a particularly low water absorption rate.

The polyoxyalkylene polymer is preferably one obtained by a ring-opening polymerization reaction of a cyclic ether compound using a polymerization catalyst in the presence of an initiator.

Examples of cyclic ether compounds include ethylene oxide, propylene oxide, butylene oxide, tetramethylene oxide, and tetrahydrofuran. These cyclic ether compounds may be used alone or in combination of two or more. Among the cyclic ether compounds, it is particularly preferable to use propylene oxide, since it gives an amorphous polyether polymer with a relatively low viscosity.

Specific examples of initiators include alcohols such as butanol, ethylene glycol, propylene glycol, propylene glycol monoalkyl ether, butanediol, hexamethylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, triethylene glycol, glycerin, trimethylolmethane, trimethylolpropane, pentaerythritol, and sorbitol; and hydroxyl-terminated polyoxyalkylene polymers having a number average molecular weight of 300 to 4,000, such as polyoxypropylene diol, polyoxypropylene triol, polyoxyethylene diol, and polyoxyethylene triol.

　Examples of methods for synthesizing polyoxyalkylene polymers include, but are not limited to, a polymerization method using an alkaline catalyst such as KOH, a polymerization method using a transition metal compound-porphyrin complex catalyst such as the complex obtained by reacting an organoaluminum compound with porphyrin as disclosed in JP-A-61-215623, a polymerization method using a composite metal cyanide complex catalyst as disclosed in JP-B-46-27250, JP-B-59-15336, U.S. Pat. No. 3,278,457, U.S. Pat. No. 3,278,458, U.S. Pat. No. 3,278,459, U.S. Pat. No. 3,427,256, U.S. Pat. No. 3,427,334, U.S. Pat. No. 3,427,335, etc., a polymerization method using a catalyst made of a polyphosphazene salt as exemplified in JP-A-10-273512, and a polymerization method using a catalyst made of a phosphazene compound as exemplified in JP-A-11-060722. Polymerization methods using composite metal cyanide complex catalysts are more preferred due to factors such as production costs and the fact that polymers with narrow molecular weight distributions can be obtained.

As the reactive silicon group-containing organic polymer (A), a polyoxyalkylene polymer containing other bonds such as urethane bonds and urea bonds in the main chain structure may be used as long as it does not significantly impair the effects of the invention. A specific example of such a polymer is a polyurethane prepolymer.

Polyurethane prepolymers can be obtained by known methods, for example, by reacting a polyol compound with a polyisocyanate compound.

Specific examples of polyol compounds include polyether polyols, polyester polyols, polycarbonate polyols, and polyether polyester polyols.

Specific examples of the polyisocyanate compound include diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, methylene-bis(cyclohexyl isocyanate), isophorone diisocyanate, and hexamethylene diisocyanate.
The polyurethane prepolymer may be terminated with either a hydroxyl group or an isocyanate group.

In order to obtain a curable composition with excellent storage stability and workability, it is particularly preferable that the reactive silicon group-containing organic polymer (A) is a polyoxyalkylene polymer that does not contain a urethane bond, a urea bond, an ester bond, or an amide bond in the main chain structure.

The reactive silicon group-containing organic polymer (A) is preferably obtained by introducing reactive silicon groups into a polymer by any one of the following methods (a) to (d).
(a) A method in which the terminal hydroxyl groups of a hydroxyl-terminated organic polymer are converted to carbon-carbon unsaturated groups, and then reacted with HSiR ¹ _3-a X _a (wherein R ¹ , X, and a are the same as the groups shown in general formula (1)).

(b) A method of reacting a terminal hydroxyl group of a hydroxyl-terminated organic polymer with an isocyanate group-containing silane compound represented by the formula OCN-W-SiR ¹ _3-a X _a (wherein W is a divalent organic group, and ^{R 1} , X, and a are the same as the groups shown in relation to the general formula (1)).

(c) A method in which the terminal hydroxyl groups of a hydroxyl-terminated organic polymer are converted to carbon-carbon unsaturated groups, and then the polymer is reacted with a mercapto-containing silane compound represented by the formula HS-W-SiR ¹ _3-a X _a (wherein W is a divalent organic group, and R ¹ , X, and a are the same as the groups shown in relation to the general formula (1)).

(d) A method in which a hydroxyl-terminated organic polymer is reacted with a polyisocyanate compound to synthesize an NCO-terminated organic polymer, and then a silane compound represented by HNR-W-SiR ¹ _3-a X _a (wherein W is a divalent organic group, R is hydrogen or an alkyl group, and ^{R 1} , X, and a are the same as the groups shown in general formula (1)) or HS-W-SiR ¹ _3-a X _a (wherein W is a divalent organic group, ^{R 1} , X, and a are the same as the groups shown in general formula (1)) is reacted.

In the above methods (a) and (c), examples of the terminal carbon-carbon unsaturated group include a vinyl group, an allyl group, a methallyl group, an allenyl group, and a propargyl group.

In each of the above methods, the reactive silicon group-containing organic polymer (A) obtained using a silane compound in which W is a methylene group is preferred in that it exhibits extremely high curability.

Method (a) is preferred because it tends to give a reactive silicon group-containing organic polymer (A) with good storage stability. Methods (b), (c) and (d) are preferred because they give a high conversion rate in a relatively short reaction time.

Introduction of reactive silicon groups by method (a) has been proposed in JP-B-45-36319, JP-B-46-12154, JP-A-50-156599, JP-A-54-6096, JP-A-55-13767, JP-A-55-13468, JP-A-57-164123, JP-B-3-2450, U.S. Patent No. 3,632,557, U.S. Patent No. 4,345,053, U.S. Patent No. 4,366,307, U.S. Patent No. 4,960,844, etc. Examples include those proposed in JP-A-61-197631, JP-A-61-215622, JP-A-61-215623, and JP-A-61-218632, which introduce reactive silicon groups by hydrosilylation or the like into polyoxypropylene polymers with a high molecular weight and narrow molecular weight distribution, with a number average molecular weight of 6,000 or more and Mw/Mn of 1.6 or less, and those proposed in JP-A-3-72527.

The molecular weight distribution (Mw/Mn) of the reactive silicon group-containing organic polymer (A) is not particularly limited, but is preferably 1.6 or less, more preferably 1.5 or less, and particularly preferably 1.4 or less. From the viewpoint of improving various mechanical properties such as durability and elongation of the cured product, a molecular weight distribution of 1.2 or less is preferable.

The number average molecular weight of the reactive silicon group-containing organic polymer (A), as calculated as polystyrene equivalent molecular weight by GPC, is preferably 3,000 to 100,000, more preferably 5,000 to 50,000, and particularly preferably 8,000 to 35,000. When the number average molecular weight is within these ranges, the mechanical properties of the cured product are excellent, and since the amount of reactive silicon groups introduced is appropriate, it is possible to obtain an organic polymer (A) that exhibits good curability, has a manageable viscosity, and is excellent in workability while keeping production costs within an appropriate range.

The molecular weight of the reactive silicon group-containing organic polymer (A) can also be expressed as the end group molecular weight calculated by directly measuring the end group concentration using titration analysis based on the principles of the hydroxyl value measurement method in JIS K 1557 and the iodine value measurement method specified in JIS K 0070, and taking into account the structure of the organic polymer (degree of branching determined by the polymerization initiator used). The end group converted molecular weight of the organic polymer (A) can also be calculated by creating a calibration curve of the number average molecular weight calculated by general GPC measurement of the polymer precursor and the above end group converted molecular weight, and converting the number average molecular weight calculated by GPC of the organic polymer (A) into the end group converted molecular weight.

In order to obtain a good rubber-like cured product, it is preferable that the reactive silicon groups of the organic polymer (A) are present at the polymer chain end. Since this shows good curability and is likely to exhibit rubber elastic behavior, the number of reactive silicon groups per polymer chain end of the organic polymer (A) is preferably 0.5 or more on average, more preferably 0.6 or more, even more preferably 0.7 or more, and particularly preferably 0.8 or more.

The number of polymer chain ends per molecule of the organic polymer (A) is preferably 2 to 8, more preferably 2 to 4, and particularly preferably 2 or 3.
The number of reactive silicon groups in one molecule of the organic polymer (A) is preferably from 1 to 7 on average, more preferably from 1 to 3.4, and particularly preferably from 1 to 2.6.

When the reactive silicon group-containing organic polymer (A) is branched, the reactive silicon group may be at the end of the main chain of the organic polymer, at the end of a side chain (branched chain), or both. In particular, when the reactive silicon group is at the end of the main chain, the molecular weight between crosslinking points becomes longer, which is preferable because it makes it easier to obtain a rubber-like cured product that has high strength, high elongation, and a low elastic modulus.

As described in WO 2013/180203, an organic polymer having two or more carbon-carbon unsaturated bonds at one polymer chain end is used, and the organic polymer (A) obtained by the above methods (a) and (c) has two or more reactive silicon groups at one polymer chain end. Such an organic polymer (A) exhibits high curability, and the obtained cured product is expected to have high strength and high recovery.

Specific examples of reactive silicon group-containing organic polymers (A) include various reactive silicon group-containing polyoxypropylene products under the trade names Kaneka MS Polymer or Kaneka Silyl, Kaneka TA Polymer, Kaneka XMAP, and other reactive silicon group-containing poly(meth)acrylic acid esters, and Kaneka EPION, and other reactive silicon group-containing polyisobutylenes.

(Catalyst-containing composition (B))
The curable composition according to the present disclosure contains a catalyst-containing composition (B) that is used to form a cured product by hydrolyzing and condensing the reactive silicon groups in the organic polymer (A).
The catalyst-containing composition (B) is composed of an amidine structure-containing compound (b1), a titanium compound or its condensate (b2), and an amino group-containing silane compound (b3), and at least these three components are premixed. "Premixed" refers to mixing the amidine structure-containing compound (b1), the titanium compound or its condensate (b2), and the amino group-containing silane compound (b3) in the absence of the organic polymer (A) before adding and mixing them with the organic polymer (A), and is intended to distinguish it from the one in which each component is added to the organic polymer (A) and then mixed all at once as described in Patent Document 1.

When an amidine structure-containing compound (b1) is mixed with a titanium compound or its condensate (b2), some kind of active species is formed by the interaction between (b1) and (b2), and it is presumed that the curability can be improved by mixing this active species with the organic polymer (A). In addition, by mixing (b1) and (b2) in advance, it is also possible to suppress the bleeding out of (b1) from the surface of the cured product by the interaction between (b1) and (b2).

However, due to the reaction between the amidine structure-containing compound (b1) and the titanium compound or its condensate (b2), the mixture of (b1) and (b2) becomes colored, and the color tends to deepen if time passes before it is added to the organic polymer (A).

In this embodiment, an amino group-containing silane compound (b3) is mixed in addition to an amidine structure-containing compound (b1) and a titanium compound or its condensate (b2). This makes it possible to suppress darkening of the resulting mixture over time. This is thought to be because (b3) is involved in the interaction between (b1) and (b2), suppressing the reaction that causes coloring.

The method for mixing the amidine structure-containing compound (b1), the titanium compound or its condensate (b2), and the amino group-containing silane compound (b3) is not particularly limited, but may be, for example, by mixing and stirring the components at room temperature or at an elevated temperature below the decomposition temperature of each component. The mixing may be performed without a solvent, or in the presence of a solvent that is inert to both components. The mixing may be performed in an inert gas (e.g., nitrogen gas, argon gas) atmosphere, or in the presence of air. The time for mixing under stirring is not particularly limited, but may be, for example, about 1 hour to 3 days.

The order in which the three components are mixed is not particularly limited. The three components may be added separately and mixed all at once, or (b1) and (b2) may be mixed and then (b3) may be added and mixed. Also, (b1) and (b3) may be mixed and then (b2) may be added and mixed, or (b2) and (b3) may be mixed and then (b1) may be added and mixed.

In a preferred embodiment, an amidine structure-containing compound (b1), a titanium compound or its condensate (b2), and an amino group-containing silane compound (b3) are mixed in advance to form a complex of (b1), (b2), and (b3). The complex refers to a state in which (b1), (b2), and (b3) do not exist independently of each other, but include a state in which some reaction progresses to form chemical bonds between at least two of (b1), (b2), and (b3), or a state in which the structure of at least one of (b1), (b2), and (b3) has changed. The complex can be formed by mixing (b1), (b2), and (b3) under stirring using the above-mentioned method. When mixed under stirring, the mixture becomes viscous, which allows the formation of the complex to be confirmed.

(Amidine structure-containing compound (b1))
The amidine structure-containing compound can be represented by the following general formula (2).
R ² N=CR ³ -NR ⁴ ₂ (2)
(In the formula, R ² , R ³ , and R ⁴ are the same or different and each represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. The two R ^4s may be the same or different. Any two or more of R ² , R ³ , and the two R ^4s may be bonded to form a cyclic structure.)

^R2 is preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms in order to enhance the curability of the curable composition, and more preferably a hydrocarbon group in which the carbon atom adjacent to the nitrogen atom (the carbon atom at the α-position) does not have an unsaturated bond. The number of carbon atoms in ^R2 is preferably 1 to 10, more preferably 1 to 6, in order to be easily available.

R ³ is preferably a hydrogen atom or an organic group represented by -NR ⁶ ₂ , and more preferably an organic group represented by -NR ⁶ ₂ , in order to enhance the curability of the curable composition. However, each of the two R ⁶ independently represents a hydrogen atom or an organic group having 1 to 20 carbon atoms. In this case, the compound represented by general formula (2) is called a guanidine compound.

In addition, R ³ is preferably an organic group represented by -NR ⁷ -C(=NR ⁸ )-NR ⁹ ₂ or -N=C(NR ¹⁰ ₂ )-NR ¹¹ ₂ , since the physical properties of the resulting cured product are good. However, R ⁷ , R ⁸ and the two R ⁹ each independently represent a hydrogen atom or an organic group having 1 to 6 carbon atoms. The two R ¹⁰ and the two R ¹¹ each independently represent a hydrogen atom or an organic group having 1 to 6 carbon atoms. In this case, the compound represented by general formula (2) is called a biguanide compound.

In general formula (2), the two ^R4s preferably represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and more preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, because these are easily available and enhance the curability of the curable composition.

The number of carbon atoms contained in the amidine structure-containing compound is preferably 2 or more, more preferably 6 or more, and particularly preferably 7 or more. There is no particular upper limit to the number of carbon atoms, but it is preferably 10,000 or less.

The molecular weight of the amidine structure-containing compound is preferably 60 or more, more preferably 120 or more, and particularly preferably 130 or more. There is no particular upper limit to the molecular weight, but it is preferably 100,000 or less.

The amidine structure-containing compound (b1) is not particularly limited, and examples thereof include pyrimidine compounds such as pyrimidine, 2-aminopyrimidine, 6-amino-2,4-dimethylpyrimidine, 2-amino-4,6-dimethylpyrimidine, 1,4,5,6-tetrahydropyrimidine, 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine, 1-ethyl-2-methyl-1,4,5,6-tetrahydropyrimidine, 1,2-diethyl-1,4,5,6-tetrahydropyrimidine, 1-n-propyl-2-methyl-1,4,5,6-tetrahydropyrimidine, 2-hydroxy-4,6-dimethylpyrimidine, 1,3-diazanaphthalene, and 2-hydroxy-4-aminopyrimidine;
Imidazoline compounds such as 2-imidazoline, 2-methyl-2-imidazoline, 2-ethyl-2-imidazoline, 2-propyl-2-imidazoline, 2-vinyl-2-imidazoline, 1-(2-hydroxyethyl)-2-methyl-2-imidazoline, 1,3-dimethyl-2-iminoimidazolidine, and 1-methyl-2-iminoimidazolidine-4-one;
Amidine compounds such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 2,9-diazabicyclo[4.3.0]nona-1,3,5,7-tetraene, and 6-(dibutylamino)-1,8-diazabicyclo[5,4,0]undec-7-ene (DBA-DBU);
Guanidine, dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, 1,1-dimethylguanidine, 1,3-dimethylguanidine, 1,2-diphenylguanidine, 1,1,2-trimethylguanidine, 1,2,3-trimethylguanidine, 1,1,3,3-tetramethylguanidine, 1,1,2,3,3-pentamethylguanidine, 2-ethyl-1,1,3,3-tetramethylguanidine, 1,1,3,3-tetramethyl-2-n-propylguanidine, 1,1,3,3-tetramethyl-2-isopropylguanidine, 2-n-butyl-1,1,3,3-tetramethylguanidine, 2-tert-butyl-1,1,3,3-tetramethylguanidine, 1,2,3-tricyclohexylguanidine, 1-benzyl-2,3-dimethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-ethyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-n-propyl-1,5,7-triazabicyclo[4.4.0] Guanidine compounds such as dec-5-ene, 7-isopropyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-n-butyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-cyclohexyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 7-n-octyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene;
biguanide, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-(2-ethylhexyl)biguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide, 1-morpholinobiguanide, Examples of the amidine structure-containing compound (b1) include biguanide compounds such as 1-n-butyl-N2-ethylbiguanide, 1,1'-ethylenebisbiguanide, 1,5-ethylenebiguanide, 1-[3-(diethylamino)propyl]biguanide, 1-[3-(dibutylamino)propyl]biguanide, and N',N''-dihexyl-3,12-diimino-2,4,11,13-tetraazatetradecanediamine. Only one type of amidine structure-containing compound (b1) may be used, or two or more types may be used in combination.

The amidine structure-containing compound (b1) is preferably an amidine compound or a guanidine compound, since this provides better curability, more preferably DBU, DBA-DBU, DBN, or phenylguanidine, even more preferably DBU, DBA-DBU, or DBN, and particularly preferably DBU.

(Titanium compound or condensate thereof (b2))
The titanium compound (b2) is represented by the following general formula (3).
Ti(OR ⁵ ) _d Y _4-d (3)
(In the formula, ^R5 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, Y represents a chelate coordination compound, and d represents 0 or an integer of 1 to 4.)

A condensation product of a titanium compound represented by the general formula (3) can also be used as (b2). The condensation product can be obtained by adding water to a titanium compound and reacting it. In order to exhibit better curing properties, it is preferable that (b2) is a condensation product of a titanium compound. In addition, a titanium compound and a condensation product of a titanium compound may be used in combination.

The substituted or unsubstituted hydrocarbon group represented by ^R5 is preferably a substituted or unsubstituted aliphatic or aromatic hydrocarbon group, and is preferably an aliphatic hydrocarbon group. 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 preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4.

Examples of the hydrocarbon group represented by ^R5 include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl. Examples of the substituent that the hydrocarbon group may have include a methoxy group, an ethoxy group, a hydroxyl group, and an acetoxy group. When a plurality of ^R5s are present, they may be the same or different.

The chelate coordination compound represented by Y may be a known compound that is known to coordinate to titanium. It is not particularly limited, but examples thereof 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-diphenyl-1,3-propanedione, 1,3-bis(2-pyridyl)-1,3-propanedione, and 1,3-bis(4-methoxyphenyl)-1,3-propanedione, and 3-benzyl Examples of the diketones include 2,4-pentanedione; ketoesters such as methyl acetoacetate, 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'-tetramethyl malonamide and N,N,N',N'-tetraethyl malonamide. Among these, diketones and ketoesters are preferred. When multiple Ys are present, they may be the same or different.

d represents 0 or an integer from 1 to 4. Since the curable composition according to the present disclosure exhibits better curability and can exhibit large elongation after curing, d preferably represents 0 or an integer from 1 to 3, more preferably an integer from 1 to 3, and particularly preferably 2.

Specific examples of titanium compounds represented by general formula (3) or condensates thereof include tetramethoxytitanium, trimethoxyethoxytitanium, trimethoxyisopropoxytitanium, trimethoxybutoxytitanium, dimethoxydiethoxytitanium, dimethoxydiisopropoxytitanium, dimethoxydibutoxytitanium, methoxytriethoxytitanium, methoxytriisopropoxytitanium, methoxytributoxytitanium, tetraethoxytitanium, triethoxyisopropoxytitanium, triethoxybutoxytitanium, diethoxydiisopropoxytitanium, and diethoxydi Examples of the titanium alkoxide condensates include butoxytitanium, ethoxytriisopropoxytitanium, ethoxytributoxytitanium, tetraisopropoxytitanium, triisopropoxybutoxytitanium, diisopropoxydibutoxytitanium, tetrabutoxytitanium, tetratert-butoxytitanium, diisopropoxytitanium bis(acetylacetonate), diisopropoxytitanium bis(ethylacetoacetate), diisobutoxytitanium bis(ethylacetoacetate); tetrabutoxytitanium dimer, tetrabutoxytitanium tetramer, etc. Only one type of titanium compound or its condensate may be used, or two or more types may be used in combination.

The titanium compound represented by general formula (3) is preferably a compound containing a chelate coordination compound represented by Y, since it can provide good curing properties and exhibit large elongation after curing. Specifically, diisopropoxytitanium bis(acetylacetonate), diisopropoxytitanium bis(ethylacetoacetate), and diisobutoxytitanium bis(ethylacetoacetate) are particularly preferred.

(Amino group-containing silane compound (b3))
The amino group-containing silane compound (b3) is a silane compound having a molecular weight of 100 to 1500 and having a hydrolyzable silicon group and an amino group. It is also called a silane coupling agent, and is usually used as an adhesion promoter to improve the adhesion of a curable composition to various adherends. In this embodiment, it is a component that suppresses the darkening of the catalyst-containing composition (B) over time.

The hydrolyzable silicon group of the amino group-containing silane compound (b3) refers to a silicon atom-containing group to which a hydrolyzable group is bonded, and can also be expressed by the general formula (1) described above for the reactive silicon group of the organic polymer (A).

The hydrolyzable group contained in the hydrolyzable silicon group is not particularly limited, and examples thereof include hydrogen atoms, halogen atoms, alkoxy groups, aryloxy groups, alkenyloxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, acid amide groups, aminooxy groups, and mercapto groups. Among these, alkoxy groups such as methoxy groups and ethoxy groups are more preferred, and methoxy groups and ethoxy groups are particularly preferred, as they are mildly hydrolyzable and easy to handle.

The number of hydrolyzable groups bonded to silicon atoms in the amino group-containing silane compound (b3) may preferably be three in order to ensure good adhesion. In addition, two may be better in order to ensure the storage stability of the curable composition.

The molecular weight of the amino group-containing silane compound (b3) may be in the range of 100 to 1,500. The lower limit of the molecular weight may be 150 or more. The upper limit may be 1,000 or less, or 500 or less.

The amino group-containing silane compound (b3) is a compound having a hydrolyzable silicon group and a substituted or unsubstituted amino group, and is sometimes called an aminosilane. The substituent of the substituted amino group is not particularly limited, and examples thereof include an alkyl group, an aralkyl group, and an aryl group.

Specific examples of amino group-containing silane compounds (b3) include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropylmethyldiethoxysilane, γ-(2-(2-aminoethyl)aminoethyl)aminopropyltrimethoxysilane, γ-(6-aminohexyl)aminopropyltrimethoxysilane, 3-(N-ethylamino)-2-methylpropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, Amino group-containing silanes such as amidepropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, N-butylaminopropyltrimethoxysilane, (2-aminoethyl)aminomethyltrimethoxysilane, N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, and bis(trimethoxysilylpropyl)amine; and ketimine type silanes such as N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propaneamine. In addition, the above-mentioned partial hydrolysis condensation products of the amino group-containing silanes and partial hydrolysis condensation products of the amino group-containing silanes and other alkoxysilanes (for example, reaction products of the amino group-containing silanes and the epoxy group-containing silanes, reaction products of the amino group-containing silanes and the (meth)acrylic group-containing silanes) can also be used. Only one type of amino group-containing silane compound (b3) can be used, or two or more types can be used in combination.

In order to achieve good adhesion, the amino group-containing silane compound (b3) is preferably γ-aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, or γ-(2-aminoethyl)aminopropylmethyldimethoxysilane. Silane coupling agents obtained by partially condensing hydrolyzable silicon groups to form oligomers can be used favorably in terms of safety and stability. The silane coupling agents to be condensed may be of one type or of multiple types. Examples of oligomerized silane coupling agents include Dynasylan 1146 from Evonik. In order to ensure the storage stability of the curable composition, γ-aminopropyltrimethoxysilane and γ-(2-aminoethyl)aminopropylmethyldimethoxysilane are preferred.

The amount of amino group-containing silane compound (b3) used is defined in relation to the titanium compound or its condensate (b2), and the weight ratio (b3)/(b2) of (b3) to (b2) is within the range of 0.1 to 2. Within this range, darkening over time of the catalyst-containing composition (B) is suppressed, and good curing properties as a curing catalyst for reactive silicon group-containing organic polymers can be achieved. If (b3)/(b2) is less than 0.1, it becomes difficult to suppress darkening over time.

From the viewpoint of suppressing darkening, the lower limit of (b3)/(b2) is preferably 0.15 or more, more preferably 0.2 or more, and even more preferably 0.25 or more. In addition, since a colorless and transparent catalyst-containing composition (B) is obtained, the lower limit is preferably 0.3 or more, and more preferably 0.5 or more. On the other hand, from the viewpoint of improving curability, the upper limit of (b3)/(b2) is preferably 1.5 or less, more preferably 1 or less, and even more preferably 0.8 or less.

In the curable composition according to the present disclosure, the content of the catalyst-containing composition (B) can be appropriately determined according to the desired curability, but may be, for example, about 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, more preferably 0.75 to 10 parts by weight, and even more preferably 1 to 8 parts by weight, per 100 parts by weight of the reactive silicon group-containing organic polymer (A).

The amount of the amidine structure-containing compound (b1) contained in the curable composition according to the present disclosure can be adjusted appropriately within the above range, but since the bleed-out suppression effect of (b1) is improved, it is preferably 2 parts by weight or less, more preferably 1 part by weight or less, and even more preferably 0.7 parts by weight or less, relative to 100 parts by weight of the reactive silicon group-containing organic polymer (A). In addition, from the viewpoint of curability, the lower limit of the amount of (b1) is preferably 0.1 parts by weight or more, more preferably 0.3 parts by weight or more, even more preferably 0.4 parts by weight or more, and particularly preferably 0.5 parts by weight or more.

The ratio of the amidine structure-containing compound (b1) to the titanium compound or its condensate (b2) can be set appropriately, but the weight ratio of (b2)/(b1) may be, for example, about 0.1 to 20, preferably 0.5 to 15, more preferably 0.8 to 12, and even more preferably 1.0 to 10. Since the effect of improving curability is particularly excellent, the upper limit of the weight ratio is preferably 9 or less, more preferably 6 or less, even more preferably 5 or less, and particularly preferably 4 or less. Furthermore, since the bleed-out suppression effect of (b1) is good, the lower limit of the weight ratio is preferably 1.5 or more, more preferably 2 or more, and even more preferably 2.6 or more.

The curable composition according to the present disclosure may contain a curing catalyst other than the catalyst-containing composition (B). Examples of such a curing catalyst include organotin compounds, metal salts of carboxylates, amine compounds other than the amidine structure-containing compound (b1), carboxylic acids, metal alkoxides other than titanium compounds or their condensates (b2), inorganic acids, etc.

The content of the curing catalyst other than the catalyst-containing composition (B) is not particularly limited and may be set appropriately, but may be, for example, 0 to 10 parts by weight, 0 to 5 parts by weight, 0 to 3 parts by weight, or 0 to 1 part by weight, per 100 parts by weight of the reactive silicon group-containing organic polymer (A). In particular, from the viewpoint of environmental safety, it is preferable to use a small amount of organotin compounds, preferably 0 to 1 part by weight, and more preferably 0 to 0.1 part by weight.

(Silane compound (C) and/or silane compound (D))
The curable composition according to the present disclosure preferably further contains a silane compound (C) having a hydrolyzable silicon group and an amino group and a molecular weight of 100 to 1500, and/or a silane compound (D) having a hydrolyzable silicon group but no amino group and a molecular weight of 100 to 1500. These silane compounds are also known as silane coupling agents.

By blending these silane compounds (C) and/or (D), the adhesion to various substrates and storage stability of the curable composition can be improved. The curable composition according to the present disclosure may contain only silane compound (C), may contain only silane compound (D), or may contain both silane compound (C) and silane compound (D). However, it is not necessary to contain either silane compound (C) or silane compound (D).

Details of the silane compound (C) are the same as those of the amino group-containing silane compound (b3) described above, and so will not be described here. In this application, the amino group-containing silane compound contained in the catalyst-containing composition (B) is referred to as (b3), and the amino group-containing silane compound that is not contained in the catalyst-containing composition (B) and is blended into the curable composition is referred to as (C). However, the same compound or different compounds may be used as (b3) and (C).

On the other hand, the silane compound (D) having a hydrolyzable silicon group and no amino group may be a compound having a hydrolyzable silicon group and a reactive group other than an amino group, or may be a compound having no reactive groups other than a hydrolyzable silicon group.

The type and number of hydrolyzable silicon groups in the silane compound (D) and the molecular weight of (D) are the same as those described above for the amino group-containing silane compound (b3), and therefore will not be described here.

Specific examples of the silane compound (D) include epoxy group-containing silanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane;
Isocyanate group-containing silanes such as γ-isocyanate propyl trimethoxy silane, γ-isocyanate propyl triethoxy silane, γ-isocyanate propyl methyl diethoxy silane, γ-isocyanate propyl methyl dimethoxy silane, (isocyanate methyl) trimethoxy silane, and (isocyanate methyl) dimethoxy methyl silane;
mercapto group-containing silanes, such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, and mercaptomethyltriethoxysilane;
Carboxysilanes such as β-carboxyethyltriethoxysilane, β-carboxyethylphenylbis(2-methoxyethoxy)silane, and N-β-(carboxymethyl)aminoethyl-γ-aminopropyltrimethoxysilane;
silanes containing vinyl-type unsaturated groups, such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, and vinyltriethoxysilane;
(meth)acrylic unsaturated group-containing silanes, such as γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropylmethyltriethoxysilane, and γ-acryloxypropyltrimethoxysilane;
Silanes not containing a reactive group, such as methyltrimethoxysilane, dimethyldimethoxysilane, n-propyltrimethoxysilane, phenyltrimethoxysilane, methylphenyldimethoxysilane, dimethoxydiphenylsilane, hexyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, (methoxymethyl)trimethoxysilane, and p-styryltrimethoxysilane;
Examples of the silane compound (D) include halogen-containing silanes such as γ-chloropropyltrimethoxysilane, and isocyanurate silanes such as tris(trimethoxysilyl)isocyanurate. Only one type of silane compound (D) may be used, or two or more types may be used in combination. In addition, partial hydrolysis condensates of the silane compounds listed above may also be used. For example, Dynasylan 6490 and Dynasylan 6498 from Evonik Corporation may be used.

To achieve good adhesion, the silane compound (D) is preferably gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropyltriethoxysilane, or gamma-glycidoxypropylmethyldimethoxysilane.

In order to achieve good storage stability, the silane compound (D) is preferably vinyltrimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, or (methoxymethyl)trimethoxysilane, more preferably vinyltrimethoxysilane or (methoxymethyl)trimethoxysilane, and particularly preferably vinyltrimethoxysilane.

In order to exhibit better curing properties, it is preferable that the silane compound (D) is a condensate of a silane compound having a hydrolyzable silicon group and a vinyl group. The condensate of the silane compound refers to a silane oligomer that is a partial hydrolysis condensate of a silane compound and has a vinyl group. It is sufficient that at least a part of the silane compound, which is the raw material, has a vinyl group.

The amount of silane compound (C) and the amount of silane (D) are not particularly limited and can be set appropriately depending on the desired physical properties of the silane compound used, but each is preferably 0 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, and even more preferably 1 to 8 parts by weight, per 100 parts by weight of organic polymer (A).

The curable composition according to the present disclosure can contain a large amount of silane compound (C) and/or (D), which was a factor in reducing the curability of conventional curable compositions. From this viewpoint, the amount of silane compound (C) is preferably 3 parts by weight or more, more preferably 4 parts by weight or more, and even more preferably 5 parts by weight or more, per 100 parts by weight of organic polymer (A). The amount of silane compound (D) is also preferably 3 parts by weight or more, more preferably 4 parts by weight or more, and even more preferably 5 parts by weight or more, per 100 parts by weight of organic polymer (A). Furthermore, the total content of silane compound (C) and the silane compound (D) is preferably 5 to 20 parts by weight, more preferably 6 to 15 parts by weight, and even more preferably 7 to 12 parts by weight, per 100 parts by weight of organic polymer (A).

(Method for producing curable composition)
The curable composition according to the present disclosure can be produced by mixing an amidine structure-containing compound (b1), a titanium compound or its condensate (b2), and an amino group-containing silane compound (b3) to obtain a catalyst-containing composition (B), and then adding the catalyst-containing composition (B) to an organic polymer (A) and mixing the two components. This can improve the curability of the produced curable composition.

The method for mixing the organic polymer (A) and the catalyst-containing composition (B) is not particularly limited as long as it can achieve uniform mixing, and can be carried out using a conventionally known device. In addition, the temperature during mixing is not particularly limited, and may be room temperature. It is also possible to purchase the catalyst-containing composition (B) produced by another party and use it.

The order in which the silane compound (C) and/or silane compound (D) are mixed with the organic polymer (A) is not particularly limited. The catalyst-containing composition (B) and the silane compound (C) and/or (D) may be added in parallel to the organic polymer (A) and then mixed, or the organic polymer (A) and the silane compound (C) and/or (D) may be mixed first, and then the catalyst-containing composition (B) may be added and mixed. Alternatively, the organic polymer (A) and the catalyst-containing composition (B) may be mixed first, and then the silane compound (C) and/or (D) may be added and mixed. The order in which the silane compound (C) and the silane compound (D) are mixed is also not particularly limited. The method and temperature for carrying out the mixing are the same as those described above, and are not particularly limited.

The timing of mixing the other compounding agents described below is not particularly limited, and may be the same as in the case of the silane compound (C) and/or the silane compound (D). However, it is preferable to mix the catalyst-containing composition (B) and the silane compound (C) and/or the silane compound (D) after mixing the organic polymer (A) with the other compounding agents.

(Other compounding agents)
The curable composition according to the present disclosure may contain, as necessary, a plasticizer, a filler, a physical property adjuster, an anti-sagging agent (a thixotropy imparting agent), a stabilizer, and the like.

The curable composition according to the present disclosure may contain a plasticizer. The addition of a plasticizer makes it possible to adjust the viscosity and slump of the curable composition, and the mechanical properties such as the tensile strength and elongation of the cured product obtained by curing the curable composition. Specific examples of plasticizers include phthalate ester compounds such as dibutyl phthalate, diisononyl phthalate (DINP), diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate (DIDP), and butyl benzyl phthalate; terephthalate compounds such as bis(2-ethylhexyl)-1,4-benzenedicarboxylate (specifically, product name: EASTMAN 168 (manufactured by EASTMAN CHEMICAL)); non-phthalate compounds such as 1,2-cyclohexanedicarboxylic acid diisononyl ester (specifically, product name: Hexamoll DINCH (manufactured by BASF)); dioctyl adipate, sebaceous acid ester compounds such as terephthalate, ... Examples of such compounds include aliphatic polycarboxylic acid ester compounds such as dioctyl succinate, dibutyl sebacate, diisodecyl succinate, and tributyl acetyl citrate; unsaturated fatty acid ester compounds such as butyl oleate and methyl acetyl ricinoleate; alkylsulfonic acid phenyl esters (specifically, trade name: Mesamoll (manufactured by LANXESS)); phosphate compounds such as tricresyl phosphate and tributyl phosphate; trimellitic acid ester compounds; chlorinated paraffin; hydrocarbon oils such as alkyl diphenyls and partially hydrogenated terphenyls; process oils; epoxy plasticizers such as epoxidized soybean oil and epoxy benzyl stearate. Among these, cured products obtained from curable compositions prepared using aliphatic carboxylic acid esters such as 1,2-cyclohexanedicarboxylic acid diisononyl ester are preferred because they tend to have low water absorption.

Furthermore, polymeric plasticizers can be used. When polymeric plasticizers are used, the initial physical properties can be maintained for a long period of time compared to when low molecular weight plasticizers, which are plasticizers that do not contain polymer components in the molecule, are used. Furthermore, the drying properties (paintability) can be improved when an alkyd paint is applied to the cured product. Specific examples of polymer plasticizers include vinyl polymers obtained by polymerizing vinyl monomers by various methods; esters of polyalkylene glycols such as diethylene glycol dibenzoate, triethylene glycol dibenzoate, and pentaerythritol ester; polyester plasticizers obtained from dibasic acids such as sebacic acid, adipic acid, azelaic acid, and phthalic acid and dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol; polyethers such as polyether polyols having a number average molecular weight of 500 or more, and even 1,000 or more, polytetramethylene glycol, and derivatives in which the hydroxyl groups of these polyether polyols are converted to ester groups, ether groups, and the like; polystyrenes such as polystyrene and poly-α-methylstyrene; polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, and polychloroprene, but are not limited to these.

Among these polymer plasticizers, those compatible with the reactive silicon group-containing organic polymer (A) are preferred. From this point of view, polyethers and vinyl polymers are preferred. Furthermore, when polyethers are used as plasticizers, the surface curability and deep curability are improved, and curing delay after storage does not occur, so they are preferred, and among them, polypropylene glycol is more preferred. Furthermore, from the viewpoints of compatibility, weather resistance, and heat resistance, vinyl polymers are preferred. Among vinyl polymers, acrylic polymers and/or methacrylic polymers are preferred, and acrylic polymers such as polyacrylic acid alkyl esters are more preferred. As a method for synthesizing this polymer, the living radical polymerization method is preferred because it has a narrow molecular weight distribution and can be made low viscosity, and the atom transfer radical polymerization method is more preferred. Furthermore, it is preferred to use a polymer obtained by the so-called SGO process, which is obtained by continuous bulk polymerization of acrylic acid alkyl ester monomers at high temperature and high pressure as described in JP-A-2001-207157.

The number average molecular weight of the polymer plasticizer is preferably 500 to 15,000, more preferably 800 to 10,000, even more preferably 1,000 to 8,000, and particularly preferably 1,000 to 5,000. It is most preferably 1,000 to 3,000. If the molecular weight is too low, the plasticizer will flow out over time due to heat or rain, and the initial physical properties will not be able to be maintained over the long term. Furthermore, if the molecular weight is too high, the viscosity will increase, making it difficult to work with.

The molecular weight distribution of the polymer plasticizer is not particularly limited, but is preferably narrow, and is preferably less than 1.80. It is more preferably 1.70 or less, even more preferably 1.60 or less, even more preferably 1.50 or less, particularly preferably 1.40 or less, and most preferably 1.30 or less.

The number average molecular weight of polymer plasticizers is measured by the GPC method for vinyl polymers and by the end group analysis method for polyether polymers. The molecular weight distribution (Mw/Mn) is measured by the GPC method (polystyrene equivalent).

The polymer plasticizer may or may not have a reactive silicon group. If it has a reactive silicon group, it acts as a reactive plasticizer and can prevent the migration of the plasticizer from the cured product. If it has a reactive silicon group, the number of reactive silicon groups per molecule is preferably 1 or less, more preferably 0.8 or less. When using a plasticizer having a reactive silicon group, particularly a polyether polymer having a reactive silicon group, it is desirable for the number average molecular weight to be lower than that of the reactive silicon group-containing organic polymer (A).

The amount of plasticizer used is preferably 5 to 150 parts by weight, more preferably 10 to 120 parts by weight, and even more preferably 20 to 100 parts by weight, per 100 parts by weight of the reactive silicon group-containing organic polymer (A). In such a range, the effect of the plasticizer can be exerted while maintaining the mechanical strength of the cured product. The plasticizer may be used alone or in combination of two or more kinds. A low molecular weight plasticizer and a polymeric plasticizer may also be used in combination. These plasticizers can also be mixed during the production of the polymer.

The curable composition according to the present disclosure may contain a filler. Examples of fillers include reinforcing fillers such as fumed silica, precipitated silica, crystalline silica, fused silica, dolomite, anhydrous silicic acid, hydrous silicic acid, and carbon black; heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, aluminum fine powder, flint powder, zinc oxide, activated zinc oxide, PVC powder, PMMA powder, and other resin powders; and fibrous fillers such as asbestos, glass fiber, and filaments. When a filler is used, the amount of the filler used is preferably 1 to 300 parts by weight, more preferably 10 to 200 parts by weight, per 100 parts by weight of the reactive silicon group-containing organic polymer (A).

When it is desired to obtain a hardened product with high strength by using these fillers, fillers selected from fumed silica, precipitated silica, crystalline silica, fused silica, dolomite, silicic acid anhydride, hydrated silicic acid, carbon black, surface-treated fine calcium carbonate, calcined clay, clay, and activated zinc oxide can be preferably used. Favorable results can be obtained by using 1 to 200 parts by weight per 100 parts by weight of reactive silicon group-containing organic polymer (A). Also, when it is desired to obtain a hardened product with low strength and high breaking elongation, favorable results can be obtained by using 5 to 200 parts by weight of fillers selected from titanium oxide, calcium carbonate, magnesium carbonate, talc, ferric oxide, zinc oxide, and shirasu balloons per 100 parts by weight of reactive silicon group-containing organic polymer (A).

The curable composition according to the present disclosure may contain spherical hollow bodies such as balloons for the purpose of reducing the weight (specific gravity) of the composition.
A balloon is a spherical filler with a hollow interior. Examples of balloon materials include inorganic materials such as glass, silas, and silica, and organic materials such as phenolic resin, urea resin, polystyrene, saran, and acrylonitrile, but are not limited to these. Inorganic and organic materials can be combined, or laminated to form multiple layers. Inorganic or organic balloons, or combinations of these, can be used. The balloons used may be the same or may be a mixture of multiple types of balloons made of different materials. Furthermore, the balloons may be surface-processed or coated, or may be surface-treated with various surface treatment agents. For example, organic balloons may be coated with calcium carbonate, talc, titanium oxide, or inorganic balloons may be surface-treated with a silane coupling agent.

The particle size of the balloons is preferably 3 to 200 μm, and more preferably 10 to 110 μm. If the particle size is less than 3 μm, it will have little effect on weight reduction and a large amount will need to be added, and if it is 200 μm or more, the surface of the hardened sealant will tend to become uneven and elongation will tend to decrease.

The amount of spherical hollow bodies used is preferably 0.01 to 30 parts by weight per 100 parts by weight of the reactive silicon group-containing organic polymer (A). The lower limit is more preferably 0.1 parts by weight, and the upper limit is more preferably 20 parts by weight. Within this range, the elongation and breaking strength of the cured product can be maintained while improving workability.

The curable composition according to the present disclosure may contain a physical property adjuster to adjust the tensile properties of the cured product, if necessary. The physical property adjuster is not particularly limited, but examples thereof include alkyl alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, and n-propyltrimethoxysilane; alkyl isopropenoxysilanes such as dimethyldiisopropenoxysilane, methyltriisopropenoxysilane, and γ-glycidoxypropylmethyldiisopropenoxysilane; alkoxysilanes having functional groups such as γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyldimethylmethoxysilane, γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropylmethyldimethoxysilane; silicone varnishes; and polysiloxanes. By using the physical property adjuster, the hardness of the cured product obtained by curing the curable composition can be increased, or conversely, the hardness can be decreased and the breaking elongation can be increased. The physical property adjusters may be used alone or in combination of two or more kinds.

In particular, compounds that generate a compound having a monovalent silanol group in the molecule upon hydrolysis have the effect of reducing the modulus of the cured product without increasing the stickiness of the surface of the cured product. In particular, compounds that generate trimethylsilanol are preferred. Examples of compounds that generate a compound having a monovalent silanol group in the molecule upon hydrolysis include the compounds described in JP-A-5-117521. Other examples include compounds that generate silicon compounds that are derivatives of alkyl alcohols such as hexanol, octanol, and decanol and generate trialkylsilanols such as trimethylsilanol upon hydrolysis, and compounds that generate silicon compounds that are derivatives of polyhydric alcohols having three or more hydroxyl groups such as trimethylolpropane, glycerin, pentaerythritol, and sorbitol and generate trialkylsilanols such as trimethylsilanol upon hydrolysis, as described in JP-A-11-241029. Specific examples include phenoxytrimethylsilane, tris((trimethylsiloxy)methyl)propane, etc.

Furthermore, there can be mentioned compounds which are derivatives of oxyalkylene polymers as described in JP-A-7-258534 and which produce silicon compounds which produce trialkylsilanols such as trimethylsilanol upon hydrolysis. Furthermore, it is also possible to use polymers having crosslinkable hydrolyzable silicon-containing groups and silicon-containing groups which can become monosilanol-containing compounds upon hydrolysis as described in JP-A-6-279693.

The property adjusting agent is preferably used in an amount of 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the reactive silicon group-containing organic polymer (A).

The curable composition according to the present disclosure may contain an anti-sagging agent, if necessary, to prevent sagging and improve workability. In addition, the anti-sagging agent is not particularly limited, but examples thereof include polyamide waxes; hydrogenated castor oil derivatives; and metal soaps such as calcium stearate, aluminum stearate, and barium stearate. These anti-sagging agents may be used alone or in combination of two or more types.

The anti-sagging agent is preferably used in the range of 0.1 to 20 parts by weight per 100 parts by weight of the reactive silicon group-containing organic polymer (A).

The curable composition according to the present disclosure may contain an antioxidant (anti-aging agent). The use of an antioxidant can improve the weather resistance of the cured product. Examples of antioxidants include hindered phenols, monophenols, bisphenols, and polyphenols, with hindered phenols being particularly preferred. Examples include Irganox 245, Irganox 1010, Irganox 1035, Irganox 1076, Irganox 1135, Irganox 1330, Irganox 1520 (all manufactured by BASF); SONGNOX 1076 (manufactured by SONGWON), and BHT. Similarly, hindered amine light stabilizers such as TINUVIN 622LD, TINUVIN 144, TINUVIN 292, CHIMASSORB 944LD, CHIMASSORB 119FL (all manufactured by BASF); ADK STAB LA-57, ADK STAB LA-62, ADK STAB LA-67, ADK STAB LA-63, ADK STAB LA-68 (all manufactured by ADEKA Corporation); SANOL LS-2626, SANOL LS-1114, SANOL LS-744 (all manufactured by Sankyo Lifetech Co., Ltd.); and NOCRAC CD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) can also be used. In addition, antioxidants such as SONGNOX 4120, Nauguard 445, and OKABEST CLX050 can also be used. Specific examples of antioxidants are also described in JP-A-4-283259 and JP-A-9-194731.

The amount of antioxidant used is preferably 0.1 to 10 parts by weight, and more preferably 0.2 to 5 parts by weight, per 100 parts by weight of reactive silicon group-containing organic polymer (A).

The curable composition according to the present disclosure may contain a light stabilizer. The use of a light stabilizer can prevent photo-oxidative deterioration of the cured product. Examples of light stabilizers include benzotriazole-based, hindered amine-based, and benzoate-based compounds, with hindered amine-based compounds being particularly preferred. Specific examples of light stabilizers are also described in JP-A-9-194731.

The amount of light stabilizer used is preferably 0.1 to 10 parts by weight, and more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the reactive silicon group-containing organic polymer (A).

When a photocurable substance is blended with the curable composition according to the present disclosure, particularly when an unsaturated acrylic compound is used, it is preferable to use a tertiary amine-containing hindered amine-based light stabilizer as the hindered amine-based light stabilizer in order to improve the storage stability of the composition, as described in JP-A-5-70531. Examples of tertiary amine-containing hindered amine-based light stabilizers include TINUVIN 123, TINUVIN 144, TINUVIN 249, TINUVIN 292, TINUVIN 312, TINUVIN 622LD, TINUVIN 765, TINUVIN 770, TINUVIN 880, TINUVIN 5866, TINUVIN B97, CHIMASSORB 119FL, and CHIMASSORB 944LD (all manufactured by BASF); Adeka STAB LA-57, LA-62, LA-63, LA-67, and LA-68 (all manufactured by BASF). Examples of light stabilizers include Sanol LS-292, LS-2626, LS-765, LS-744, LS-1114 (all manufactured by Sankyo Lifetech Co., Ltd.), SABOSTAB UV91, SABOSTAB UV119, SONGSORB CS5100, SONGSORB CS622, SONGSORB CS944 (all manufactured by SONGWON), and Nocrac CD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.).

The curable composition according to the present disclosure may contain an ultraviolet absorber. The use of an ultraviolet absorber can improve the surface weather resistance of the cured product. Examples of ultraviolet absorbers include benzophenone-based, benzotriazole-based, salicylate-based, triazine-based, substituted acrylonitrile-based, and metal chelate-based compounds, with benzotriazole-based compounds being particularly preferred. Examples include Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 329, Tinuvin 350, Tinuvin 571, Tinuvin 900, Tinuvin 928, Tinuvin 1130, and Tinuvin 1600 (all manufactured by BASF); and SONGSORB 3290 (manufactured by SONGWON). Examples of triazine compounds include TINUVIN 400, TINUVIN 405, TINUVIN 477, and TINUVIN 1577ED (all manufactured by BASF); SONGSORB CS400 and SONGSORB 1577 (manufactured by SONGWON). Examples of benzophenone compounds include SONGSORB 8100 (manufactured by SONGWON).

The amount of UV absorber used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the reactive silicon group-containing organic polymer (A). It is preferable to use a phenol or hindered phenol antioxidant in combination with a hindered amine light stabilizer and a benzotriazole UV absorber.

Addworks IBC760 (manufactured by Clariant) can also be used as a product that contains a mixture of antioxidants, light stabilizers, and UV absorbers.

The curable composition according to the present disclosure may contain an epoxy resin. A composition containing an epoxy resin is particularly preferred as an adhesive, particularly as an adhesive for exterior wall tiles. Examples of epoxy resins include bisphenol A type epoxy resins and novolac type epoxy resins.

The ratio of organic polymer (A) to epoxy resin is not particularly limited, but it is preferable that the weight ratio of organic polymer (A)/epoxy resin is in the range of 100/1 to 1/100.

When an epoxy resin is blended, the curable composition according to the present disclosure is preferably used in combination with a curing agent that cures the epoxy resin. There are no particular limitations on the epoxy resin curing agent that can be used, and any commonly used epoxy resin curing agent can be used. When an epoxy resin curing agent is used, the amount used is preferably in the range of 0.1 to 300 parts by weight per 100 parts by weight of the epoxy resin.

The curable composition according to the present disclosure may contain various additives as necessary for the purpose of adjusting the various physical properties of the curable composition or the cured product. Examples of such additives include flame retardants, curability regulators, radical inhibitors, metal deactivators, antiozone agents, phosphorus-based peroxide decomposers, lubricants, pigments, foaming agents, solvents, and antifungal agents. Examples of flame retardants include aluminum hydroxide and magnesium hydroxide. These various additives may be used alone or in combination of two or more types. Specific examples of additives other than those listed in this specification are described in, for example, JP-B-4-69659, JP-B-7-108928, JP-A-63-254149, JP-A-64-22904, and JP-A-2001-72854.

The curable composition according to the present disclosure can be prepared as a one-component curable composition in which all ingredients are mixed in advance, sealed, and stored, and then cured by moisture in the air after application. It is also possible to prepare a two-component curable composition in which a curing agent containing ingredients such as a curing catalyst, filler, plasticizer, and water is prepared separately from a base agent containing a reactive silicon group-containing organic polymer (A), and the base agent and curing agent are mixed together before use.

When the curable composition is of one component type, all the ingredients are mixed in advance, so it is preferable to dehydrate the ingredients containing water before use, or to dehydrate them by reducing pressure during mixing. When the curable composition is of two component type, there is no need to mix a curing catalyst into the base agent containing the reactive silicon group-containing organic polymer (A), so even if the ingredients contain a small amount of water, there is little risk of gelation. However, when long-term storage stability is required, it is preferable to dehydrate and dry them. As a dehydration method, for solid substances such as powders, the heat drying method is suitable, and for liquid substances, the reduced pressure dehydration method or a dehydration method using synthetic zeolite, activated alumina, silica gel, etc. is suitable. Also, a small amount of isocyanate compound may be mixed to react the isocyanate group with water to dehydrate it. In addition to such dehydration and drying methods, storage stability can be further improved by adding lower alcohols such as methanol and ethanol; or alkoxysilane compounds such as methyltrimethoxysilane, n-propyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, phenyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, and γ-glycidoxypropyltrimethoxysilane. As a dehydrating agent, partially condensed silane compounds such as Evonik's Dynasylan 6490 can also be used preferably from the standpoint of safety and stability.

The amount of the dehydrating agent, particularly a silicon compound that can react with water such as vinyltrimethoxysilane, is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the reactive silicon group-containing organic polymer (A).

The curable composition according to the present disclosure can be used as a construction sealant, industrial adhesive, waterproof coating, adhesive raw material, etc. It can also be used as a sealant for buildings, ships, automobiles, roads, etc. Furthermore, since it can adhere to a wide range of substrates such as glass, porcelain, wood, metal, and resin moldings, either alone or with the aid of a primer, it can also be used as various types of sealing and adhesive compositions. In addition to being used as a normal adhesive, it can also be used as a contact adhesive. It is also useful as a food packaging material, cast rubber material, molding material, and paint.

The following items enumerate preferred aspects of the present disclosure, but the present invention is not limited to the following items.
[Item 1]
The following general formula (1):
-SiR ¹ _3-a X _a (1)
(In the formula, R ¹ represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or a triorganosiloxy group represented by R ⁰ ₃ SiO-. The three R ⁰ 's may be the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 1, 2, or 3. When a plurality of ^{R 1's} or X's are present, they may be the same or different.)
(A) an organic polymer having a reactive silicon group represented by
The following general formula (2):
R ² N=CR ³ -NR ⁴ ₂ (2)
(In the formula, R ² , R ³ , and R ⁴ are the same or different and each represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. The two R ^4s may be the same or different. Any two or more of R ² , R ³ , and the two R ^4s may be bonded to form a cyclic structure.)
an amidine structure-containing compound (b1) represented by the formula:
The following general formula (3):
Ti(OR ⁵ ) _d Y _4-d (3)
(In the formula, ^R5 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, Y represents a chelate coordination compound, and d represents 0 or an integer of 1 to 4.)
or a condensate thereof (b2),
A method for producing a curable composition containing a silane compound (b3) having a hydrolyzable silicon group and an amino group and a molecular weight of 100 to 1500, comprising the steps of:
a preparation step of preparing a catalyst-containing composition (B) obtained by mixing the amidine structure-containing compound (b1), the titanium compound or a condensate thereof (b2), and the silane compound (b3); and a mixing step of mixing the organic polymer (A) and the catalyst-containing composition (B),
A method for producing a curable composition, wherein a weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1 to 2.
[Item 2]
2. The method for producing a curable composition according to item 1, wherein the weight ratio (b2)/(b1) of the titanium compound or its condensate (b2) to the amidine structure-containing compound (b1) is 2.6 to 9.
[Item 3]
3. The method for producing a curable composition according to item 1 or 2, wherein the content of the amidine structure-containing compound (b1) is 0.3 to 0.7 parts by weight based on 100 parts by weight of the organic polymer (A).
[Item 4]
4. The method for producing a curable composition according to any one of items 1 to 3, wherein the curable composition further contains a silane compound (D) having a hydrolyzable silicon group, no amino group, and a molecular weight of 100 to 1,500.
[Item 5]
5. The method for producing a curable composition according to item 4, wherein the silane compound (D) is a condensate of a silane compound having a hydrolyzable silicon group and a vinyl group.
[Item 6]
A curable composition comprising an organic polymer (A) having a reactive silicon group represented by the general formula (1) and a catalyst-containing composition (B),
the catalyst-containing composition (B) comprises a complex of an amidine structure-containing compound (b1) represented by the general formula (2), a titanium compound represented by the general formula (3) or a condensate thereof (b2), and a silane compound (b3) having a molecular weight of 100 to 1500 and having a hydrolyzable silicon group and an amino group,
A curable composition, wherein a weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1 to 2.
[Item 7]
7. A cured product obtained by curing the curable composition according to item 6.
[Item 8]
A catalyst-containing composition (B) for an organic polymer (A) having a reactive silicon group, comprising:
The present invention comprises a complex of an amidine structure-containing compound (b1) represented by the general formula (2), a titanium compound represented by the general formula (3) or a condensate thereof (b2), and a silane compound (b3) having a hydrolyzable silicon group and an amino group and a molecular weight of 100 to 1500,
The catalyst-containing composition (B), wherein the weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1 to 2.

The present invention will be described in more detail below with reference to specific examples, but the present invention is not limited to the following examples.

The number average molecular weight in the examples is a GPC molecular weight measured under the following conditions.
Liquid delivery system: Tosoh HLC-8120GPC
Column: Tosoh TSKgel Super H series Solvent: THF
Molecular weight: polystyrene equivalent Measurement temperature: 40°C

The average number of silyl groups per terminal or per molecule of the polymer shown in the examples was calculated by H-NMR (measured in CDCl ₃ solvent using AVANCE III HD-500 manufactured by Bruker).

<Synthesis of Organic Polymer (A)>
(Synthesis example 1 (A-1))
Polyoxypropylene diol having a molecular weight of about 2,000 was used as an initiator, and propylene oxide was polymerized with a zinc hexacyanocobaltate glyme complex catalyst to obtain polypropylene oxide having a number average molecular weight of 28,500. Subsequently, a methanol solution of 1.2 molar equivalents of NaOMe was added to the hydroxyl groups of this hydroxyl-terminated polypropylene oxide to distill off the methanol, and further allyl chloride was added to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was removed by volatilization under reduced pressure. 100 parts by weight of the obtained unpurified allyl-terminated polypropylene oxide were mixed and stirred with 300 parts by weight of n-hexane and 300 parts by weight of water, and the water was removed by centrifugation. The obtained hexane solution was further mixed and stirred with 300 parts by weight of water, and the water was removed again by centrifugation, and the hexane was removed by volatilization under reduced pressure. As a result, a bifunctional polypropylene oxide having an allyl group at the end and a number average molecular weight of about 28,500 was obtained. 100 parts by weight of the obtained allyl-terminated polypropylene oxide was reacted with 0.8 molar equivalent of trimethoxysilane relative to the allyl groups of the allyl-terminated polypropylene oxide at 90° C. for 5 hours using 150 ppm of a 2-propanol solution of a platinum vinylsiloxane complex with a platinum content of 3 wt % as a catalyst to obtain trimethoxysilyl-terminated polyoxypropylene (A-1). The number of trimethoxysilyl groups per polymer chain end was about 0.8.

In producing each complex, the compounds described below were used.
TC-750: Titanium diisopropoxybis(ethyl acetoacetate), (manufactured by Matsumoto Fine Chemical Co., Ltd.)
Tyzor IBAY: Titanium diisobutoxybis(ethyl acetoacetate), (manufactured by Dorf Ketal)
Ti( ^OiPr ) ₄ : Titanium tetraisopropoxide (manufactured by Tokyo Chemical Industry Co., Ltd.)
Ti(OBu) ₄ : tetrabutoxytitanium (manufactured by Tokyo Chemical Industry Co., Ltd.)
Tyzor 9000: Titanium tetra-tert-butoxide (manufactured by Dorf Ketal)
Hexabutoxy-μ-oxo titanium (Tokyo Chemical Industry Co., Ltd.)
DBU: 1,8-diazabicyclo[5.4.0]-7-undecene (Tokyo Chemical Industry Co., Ltd.)
Dynasylan AMMO (γ-aminopropyltrimethoxysilane, manufactured by Evonik)
Dynasylan 1146 (condensation product of diamino- and alkyl-containing silanes, manufactured by Evonik)

<Production Example 1 (Reference Composite 1)>
20 g of TC-750 was added to a 200 ml eggplant flask. While stirring the contents of the flask, 0.1 g of DBU was slowly dropped into the flask. After the dropping was completed, the flask was closed and the contents were stirred at room temperature for 24 hours to obtain 20.1 g of liquid Reference Complex 1.

<Production Examples 2 to 17 (Reference Complexes 2 to 17)>
Liquid reference composites 2 to 17 were obtained in the same manner as in Production Example 1, except that the amidine compound (b1) and titanium compound (b2) shown in Table 1 were used in the weight ratio shown in Table 1.

(Reference examples 1 to 17)
(Preparation of base material)
To 100 parts by weight of the organic polymer (A-1) having a reactive silicon group, colloidal calcium carbonate (Shiraishi Calcium Co., Ltd., product name: Hakuenka CCR), heavy calcium carbonate (Shiraishi Calcium Co., Ltd., product name: Whiten SB), plasticizer (BASF Corporation, product name: Hexamoll DINCH), pigment (Ishihara Sangyo Kaisha, Ltd., product name: Typen R820), thixotropic agent (ARKEMA Corporation, product name: Crayvallac SLT), antioxidant (BASF Corporation, product name: Irganox 1010), ultraviolet absorber (BASF Corporation, product name: Tinuvin 326), and light stabilizer (BASF Corporation, product name: Tinuvin 770) were added in the amounts (parts by weight) shown in Table 2, respectively, and mixed with a spatula, and then the mixture was passed through a three-roll mill three times to be dispersed. Thereafter, the mixture was dehydrated under reduced pressure using a planetary mixer, and the mixture was filled into a moisture-proof cartridge to form a base material.

(Preparation of Curable Composition)
The base material was extruded from the cartridge under an atmosphere of 23° C. and 50% relative humidity and weighed into a plastic container, to which Dynasylan VTMO (silane compound (D): vinyltrimethoxysilane, manufactured by Evonik) and Dynasylan AMMO (silane compound (C): γ-aminopropyltrimethoxysilane, manufactured by Evonik) were added and mixed in the amounts shown in Table 2.
Subsequently, the reference composites 1 to 17 prepared in Production Examples 1 to 17 were added as curing catalysts in the amounts shown in Table 2 and mixed to obtain curable compositions.

(evaluation)
(Skinning time (hardening))
The obtained curable composition was filled into a mold about 5 mm thick with a spatula, and the time when the surface was smoothed to a flat surface was determined as the curing start time. The surface was touched with the spatula, and the time when the composition no longer adhered to the spatula was measured as the skinning time (curability). The measurement results are shown in Table 2.

(Bleed or not)
Each curable composition was formed into a sheet using a spatula on a cardboard plate under constant temperature and humidity conditions of 23°C and 50% or 70% relative humidity, and the surface was smoothed. After leaving the sheet for 7 days under conditions of 23°C and 50% or 70% relative humidity, the surface of the curable composition was touched with a fingertip to confirm whether or not the liquid compound derived from DBU had bled onto the surface of the cured product. The results are shown in Table 2.

(result)
In Reference Examples 1 to 17, a reference composite consisting of (b1) and (b2) was used as a curing catalyst. Reference Examples 1 to 11, which used Reference Composites 3 to 7, 11 to 15, or 17, in which the weight ratio of (b2)/(b1) was in the range of 2.6 to 9, showed relatively good curability and no bleeding was observed on the surface of the cured product. On the other hand, Reference Examples 12 to 13, which used Reference Composites 1 or 2, in which the weight ratio of (b2)/(b1) was as high as 9 or more, showed a long skinning time and poor curability. In Reference Examples 14 to 17, which used Reference Composites 8 to 10 and 16, in which the weight ratio of (b2)/(b1) was as low as 2.6 or less, bleeding occurred on the surface of the cured product under humid conditions.

Example 1 (Compound 18)
20 g of Ti(O ⁱ Pr) ₄ was added to a 200 ml eggplant flask. While stirring the contents of the flask, 5 g of DBU was slowly dripped into the flask. Then, 3 g of Dynasylan AMMO was slowly dripped into the flask. After the heat subsided, the flask was capped and the contents were stirred at room temperature for 24 hours to obtain 28 g of liquid composite 18.

<Examples 2 to 12 (Composites 19 to 29) and Comparative Example 1 (Comparative Composite 30)>
Liquid composites 19 to 29 or comparative composite 30 were obtained in the same manner as in Example 1, except that the amidine compound (b1), titanium compound (b2), and amino group-containing silane (b3) shown in Table 3 were used in the weight ratios shown in Table 3.

(evaluation)
(Storage Stability)
After each composite was prepared, it was sealed in a transparent container and stored under constant temperature and humidity conditions of 23°C and 50% relative humidity for 1 day or 30 days, and then its color was visually confirmed. If it was colorless and transparent, it was rated as "1", if it was pale yellow, it was rated as "2", if it was yellow, it was rated as "3", and if it was red, it was rated as "4". A smaller rating value is more desirable, but ratings up to "3" were considered to be within the acceptable range. The measurement results are shown in Table 3.

(result)
It can be seen that the composites 18 to 29 (Examples 1 to 12) of the amidine compound (b1), the titanium compound (b2), and the amino group-containing silane (b3) have a weight ratio of (b3)/(b2) in the range of 0.1 to 2, and the increase in coloration over time is suppressed. On the other hand, in the comparative composite 30 (Comparative Example 1) in which the amount of the amino group-containing silane (b3) used is small and the weight ratio of (b3)/(b2) is less than 0.1, and in the reference composite 13 (Comparative Example 2) in which no amino group-containing silane (b3) is used, the color changed from pale yellow after 1 day to red after 30 days, and it can be seen that the color deepened over time.

(Examples 13 to 27)
First, a base material was prepared in the same manner as in Examples 1 to 17.
Next, Dynasylan 6490 (a condensate of vinyltrimethoxysilane compound, manufactured by Evonik) as the silane compound (D), and Dynasylan AMMO, Dynasylan DAMO (2-aminoethyl-3-aminopropyltrimethoxysilane, manufactured by Evonik), or Dynasylan 1146 as the silane compound (C) were added and mixed in the amounts shown in Table 4.
Next, the composites 19 to 22 or 26 to 29 prepared in Examples 2 to 5 or 9 to 12 were added in the amounts shown in Table 4 and mixed, and then the mixture was filled into a moisture-proof cartridge to obtain a one-component curable composition.
Each curable composition was stored at 23° C. for 7 days in an atmosphere of 50% relative humidity, and then the skinning time (curability) was measured and the presence or absence of bleeding was confirmed in the same manner as in Reference Examples 1 to 17. The measurement results are shown in Table 4.

(result)
In Examples 13 to 27, a composite of an amidine compound (b1), a titanium compound (b2), and an amino group-containing silane (b3), in which the weight ratio of (b3)/(b2) was in the range of 0.1 to 2, was used, and good curability was exhibited and no bleeding was observed on the surface of the cured product.

<Examples 28 to 32 (Complexes 31 to 35)>
Liquid composites 31 to 35 were obtained in the same manner as in Example 1, except that the amidine compound (b1), titanium compound (b2), and amino group-containing silane (b3) shown in Table 5 were used in the weight ratios shown in Table 5.

(Examples 33 to 39)
To 100 parts by weight of the organic polymer (A-1) having a reactive silicon group, colloidal calcium carbonate (Hakuenka CCR), heavy calcium carbonate (Whiten SB), plasticizer (Hexamoll DINCH), pigment (Typeak R820), thixotropic agent (Crayvallac SLT), antioxidant (Irganox 1010), UV absorber (Tinuvin 326), and light stabilizer (Tinuvin 770) were added in the amounts (parts by weight) shown in Table 6, respectively, and mixed with a spatula, and then the mixture was passed through a three-roll mill three times to be dispersed. Thereafter, the mixture was dehydrated under reduced pressure using a planetary mixer and cooled to below 50°C. Then, Dynasylan VTMO (vinyltrimethoxysilane, manufactured by Evonik) as the silane compound (D) and Dynasylan AMMO as the silane compound (C) were added and mixed in the amounts shown in Table 6.
Next, the composites 31 to 35, 19, or 26 prepared in Examples 28 to 32, 2, or 9 were added and mixed in the amounts shown in Table 6, and then filled into a moisture-proof cartridge to obtain a one-component curable composition.

(evaluation)
(Skinning time (hardening))
Each curable composition was stored at 23° C. for 7 days under an atmosphere of 50% relative humidity. Thereafter, the skinning time (curing property) was measured by the method described above. The obtained results are shown in Table 6 as "skinning time before storage".
The curable composition was stored at 23° C. for 7 days, then at 50° C. for 28 days, and then at 23° C. for 1 day. Thereafter, the skinning time (curing property) was measured by the method described above. The obtained results are shown in Table 6 as "skinning time after storage".

The curable compositions of Examples 33 to 39, which contain the organic polymer (A) and each complex, exhibited good curability both before and after storage. There was virtually no delay in curing due to storage, and they exhibited good storage stability.

(Bleed or not)
Each curable composition was formed into a sheet using a spatula on a cardboard plate under constant temperature and humidity conditions of 23°C and 50% or 70% relative humidity, and the surface was smoothed. After leaving the composition for 7 days under conditions of 23°C and 50% or 70% relative humidity, the surface of the curable composition was touched with a fingertip to confirm whether or not the liquid compound derived from DBU had bled onto the surface of the cured product. The results are shown in Table 6.

No bleeding of the liquid compound was observed on the surface of the cured product obtained by curing the curable compositions of Examples 33 to 39 containing the organic polymer (A) and each composite.

(Adhesiveness)
Each curable composition was applied to the surface of each of the substrates shown in Table 6, and cured for 7 days under constant temperature and humidity conditions of 23°C and 50% relative humidity. The resulting cured products were subjected to a 90° hand peel test, and the state of failure was visually observed. The state of failure was classified as CF for cohesive failure (failure at the cured product) and AF for interfacial failure (peel at the interface between the cured product and the substrate). The results are shown in Table 6.

All of the curable compositions of Examples 33 to 39, which contained the organic polymer (A) and each composite, showed good adhesion to various substrates.

(Dumbbell Tensile Properties)
Each curable composition was filled into a sheet-shaped mold having a thickness of 3 mm under constant temperature and humidity conditions of 23° C. and 50% relative humidity. After curing for 3 days at 23° C. and 50% RH, the composition was aged in a dryer at 50° C. for 4 days to obtain a sheet-shaped cured product.
The resulting cured product was punched out into a No. 3 dumbbell shape in accordance with JIS K 6251, and a tensile test was carried out using an autograph (tensile speed: 200 mm/min) to measure the stress at 50% elongation, stress at 100% elongation, stress at break, and elongation at break. The results are shown in Table 6.

All of the cured products obtained by curing the curable compositions of Examples 33 to 39 containing the organic polymer (A) and each composite exhibited good tensile properties.

Claims (8)

The following general formula (1):
-SiR ¹ _3-a X _a (1)
(In the formula, R ¹ represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or a triorganosiloxy group represented by R ⁰ ₃ SiO-. The three R ⁰ 's may be the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 1, 2, or 3. When a plurality of ^{R 1's} or X's are present, they may be the same or different.)
(A) an organic polymer having a reactive silicon group represented by
The following general formula (2):
R ² N=CR ³ -NR ⁴ ₂ (2)
(In the formula, R ² , R ³ , and R ⁴ are the same or different and each represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. The two R ^4s may be the same or different. Any two or more of R ² , R ³ , and the two R ^4s may be bonded to form a cyclic structure.)
an amidine structure-containing compound (b1) represented by the formula:
The following general formula (3):
Ti(OR ⁵ ) _d Y _4-d (3)
(In the formula, ^R5 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, Y represents a chelate coordination compound, and d represents 0 or an integer of 1 to 4.)
or a condensate thereof (b2),
A method for producing a curable composition containing a silane compound (b3) having a hydrolyzable silicon group and an amino group and a molecular weight of 100 to 1500, comprising the steps of:
a preparation step of preparing a catalyst-containing composition (B) obtained by mixing the amidine structure-containing compound (b1), the titanium compound or a condensate thereof (b2), and the silane compound (b3); and a mixing step of mixing the organic polymer (A) and the catalyst-containing composition (B),
A method for producing a curable composition, wherein a weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1 to 2. The method for producing a curable composition according to claim 1, wherein the weight ratio (b2)/(b1) of the titanium compound or its condensate (b2) to the amidine structure-containing compound (b1) is 2.6 to 9. The method for producing a curable composition according to claim 1 or 2, wherein the content of the amidine structure-containing compound (b1) is 0.3 to 0.7 parts by weight per 100 parts by weight of the organic polymer (A). The method for producing a curable composition according to claim 1 or 2, wherein the curable composition further contains a silane compound (D) having a hydrolyzable silicon group and no amino group and a molecular weight of 100 to 1500. The method for producing a curable composition according to claim 4, wherein the silane compound (D) is a condensate of a silane compound having a hydrolyzable silicon group and a vinyl group. The following general formula (1):
-SiR ¹ _3-a X _a (1)
(In the formula, R ¹ represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or a triorganosiloxy group represented by R ⁰ ₃ SiO-. The three R ⁰ 's may be the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 1, 2, or 3. When a plurality of ^{R 1's} or X's are present, they may be the same or different.)
A curable composition comprising an organic polymer (A) having a reactive silicon group represented by the formula:
The catalyst-containing composition (B) is represented by the following general formula (2):
R ² N=CR ³ -NR ⁴ ₂ (2)
(In the formula, R ² , R ³ , and R ⁴ are the same or different and each represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. The two R ^4s may be the same or different. Any two or more of R ² , R ³ , and the two R ^4s may be bonded to form a cyclic structure.)
and an amidine structure-containing compound (b1) represented by the following general formula (3):
Ti(OR ⁵ ) _d Y _4-d (3)
(In the formula, ^R5 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, Y represents a chelate coordination compound, and d represents 0 or an integer of 1 to 4.)
or a condensate thereof (b2) represented by the formula (1) and a silane compound (b3) having a hydrolyzable silicon group and an amino group and a molecular weight of 100 to 1500,
A curable composition, wherein a weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1 to 2. A cured product obtained by curing the curable composition according to claim 6. A catalyst-containing composition (B) for an organic polymer (A) having a reactive silicon group, comprising:
The following general formula (2):
R ² N=CR ³ -NR ⁴ ₂ (2)
(In the formula, R ² , R ³ , and R ⁴ are the same or different and each represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. The two R ^4s may be the same or different. Any two or more of R ² , R ³ , and the two R ^4s may be bonded to form a cyclic structure.)
and an amidine structure-containing compound (b1) represented by the following general formula (3):
Ti(OR ⁵ ) _d Y _4-d (3)
(In the formula, ^R5 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, Y represents a chelate coordination compound, and d represents 0 or an integer of 1 to 4.)
or a condensate thereof (b2) represented by the formula (1) and a silane compound (b3) having a hydrolyzable silicon group and an amino group and a molecular weight of 100 to 1500,
The catalyst-containing composition (B), wherein the weight ratio (b3)/(b2) of the silane compound (b3) to the titanium compound or its condensate (b2) is 0.1 to 2.