Sealant

Abstract

To provide a sealant enabling improvement of stringiness when used at low temperature.SOLUTION: A sealant comprises a polyoxyalkylene-based polymer (A) having a reactive silicon group and a (meth)acrylic-based polymer (B) having a reactive silicon group, wherein the (meth)acrylic-based polymer (B) comprises a structural unit derived from an alkyl (meth)acrylate, and has a number-average molecular weight of 6,000 to 15,000 or a number of reactive silicon groups per molecule of 1.7 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a sealant comprising a polyoxyalkylene polymer (A) having a reactive silicon group and a (meth)acrylic polymer (B) having a reactive silicon group. [Background technology]

[0002] Organic polymers having at least one reactive silicon group in the molecule can be crosslinked even at room temperature by forming siloxane bonds accompanied by hydrolysis of the silyl groups due to moisture, etc. It is known that organic polymers having reactive silicon groups have the property of giving rubber-like cured products through such crosslinking reactions.

[0003] Among organic polymers having reactive silicon groups, polyoxyalkylene polymers having reactive silicon groups and (meth)acrylic polymers having reactive silicon groups are widely used in construction sealants and industrial sealants (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-221501 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a sealing material containing a polyoxyalkylene polymer having a reactive silicon group and a (meth)acrylic polymer having a reactive silicon group is used, there is a problem that the sealing material has poor stringiness at low temperatures.

[0006] The present invention has been made in view of the above problems, and has an object to provide a sealing material that has improved stringiness when used at low temperatures. [Means for solving the problem]

[0007] The present inventors have discovered that in a sealant comprising a polyoxyalkylene polymer (A) having a reactive silicon group and a (meth)acrylic polymer (B) having a reactive silicon group, the above-mentioned problems can be solved by using a (meth)acrylic polymer (B) that contains structural units derived from a (meth)acrylic acid alkyl ester and has a number average molecular weight of 6,000 to 15,000 or has 1.7 or less reactive silicon groups per molecule, and have thus completed the present invention.

[0008] More specifically, the present invention provides the following (1) to (6). (1) A composition comprising a polyoxyalkylene polymer (A) having a reactive silicon group and a (meth)acrylic polymer (B) having a reactive silicon group, the (meth)acrylic polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester, A sealant, wherein the (meth)acrylic polymer (B) has a number average molecular weight of 6,000 to 15,000. (2) The polyoxyalkylene polymer (A) is a polyoxyalkylene polymer (a-1) having 1.6 or more reactive silicon groups per molecule; The sealant according to (1), further comprising a polyoxyalkylene polymer (a-2) having 1.0 or less reactive silicon groups per molecule. (3) Weight W of polyoxyalkylene polymer (a-2) (a-2) The weight W of the polyoxyalkylene polymer (a-1) relative to (a-1) Ratio of W (a-1) / W (a-2) The sealing material according to (2), wherein the value of the surface roughness is 0.56 or less. (4) A polyoxyalkylene polymer (A) having a reactive silicon group and a (meth)acrylic polymer (B) having a reactive silicon group, the (meth)acrylic polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester, A sealant, wherein the (meth)acrylic polymer (B) has 1.7 or less reactive silicon groups per molecule. (5) The polyoxyalkylene polymer (A) is a polyoxyalkylene polymer (a-1) having 1.6 or more reactive silicon groups per molecule; (4) The sealant according to (4), further comprising a polyoxyalkylene polymer (a-2) having 1.0 or less reactive silicon groups per molecule. (6) Weight W of polyoxyalkylene polymer (a-2) (a-2) The weight W of the polyoxyalkylene polymer (a-1) (a-1) Ratio of W (a-1) / W (a-2) The sealing material according to (5), wherein the value of the surface roughness is 0.56 or less. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a sealing material that has improved stringiness when used at low temperatures. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below.

[0011] <Sealing material> The sealant contains a polyoxyalkylene polymer (A) having a reactive silicon group and a (meth)acrylic polymer (B) having a reactive silicon group. The (meth)acrylic polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester. The (meth)acrylic polymer (B) has a number average molecular weight of 6,000 to 15,000, or the number of reactive silicon groups per molecule of the (meth)acrylic polymer (B) is 1.7 or less. The sealant may contain various other additives as needed.

[0012] The essential and optional components that the sealant may contain are described below.

[0013] <Polyoxyalkylene polymer (A)> The polyoxyalkylene polymer (A) (hereinafter sometimes simply referred to as "polymer (A)") has a reactive silicon group at the end of the molecular chain. The reactive silicon group is not particularly limited as long as it can form a siloxane bond. Preferred examples of the reactive silicon group include those represented by the following formula (1): -SiR 1 3-a X a (1) (In formula (1), R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or R 0 3SiO-, and three R 0 are hydrocarbon groups having 1 to 20 carbon atoms, which may be the same or different, X represents a hydroxyl group or a hydrolyzable group; a is 1, 2, or 3; R 1 , X, when there are multiple of them, they may be the same or different.) Examples of reactive silicon groups include those represented by the following formula: Polymer (A) has a polymer backbone and a polymer chain end bonded to the polymer backbone. In the specification and claims of this application, the polymer backbone is also referred to as the "main chain structure." The polymer backbone is a structure in which multiple structural units derived from monomers are bonded in succession. The monomer may be one type or multiple types.

[0014] The polymer chain end is a moiety located at the end of the polymer (A). The number of polymer chain ends of the polymer (A) is 2 when the main chain structure is linear, and 3 or more when the polymer backbone is branched. When the polymer (A) is a mixture of a polymer having a linear main chain structure and a polymer having a branched main chain structure, the number of polymer chain ends is an average value between 2 and 3.

[0015] The reactive silicon group may be present in the polymer backbone or at the polymer chain terminal. Two or more reactive silicon groups may be present at the polymer chain terminal. In the polymer (A), the reactive silicon group is preferably present at the polymer chain terminal.

[0016] <Reactive silicon group> The reactive silicon group is a group that can generate a silanol group by hydrolysis. When the reactive silicon group generates a silanol group, the polymer (A) is crosslinked by a condensation reaction between the silanol groups. As mentioned above, the reactive silicon group is not particularly limited, but the reactive silicon group is preferably a group represented by the following formula (1): -SiR 1 3-a X a (1)

[0017] In formula (1), R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or R 0 3SiO- represents a triorganosiloxy group. 0 are hydrocarbon groups having 1 to 20 carbon atoms, and they may be the same or different. X represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3. R 1 , X, when there are a plurality of them, they may be the same or different.

[0018] R in formula (1) 1Specific examples of R include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-hexyl, 2-ethylhexyl, and n-dodecyl; unsaturated hydrocarbon groups such as vinyl, isopropenyl, and allyl; alkoxymethyl groups such as methoxymethyl; halogenated methyl groups such as chloromethyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, toluyl, and 1-naphthyl; and aralkyl groups such as benzyl. Among these groups, alkyl and aryl groups are preferred, with methyl, ethyl, and phenyl groups being more preferred, methyl and ethyl groups being even more preferred, and methyl being particularly preferred. In formula (1), R 1 If there are multiple R 1 may be the same group or a combination of two or more different groups.

[0019] X in formula (1) is a hydroxyl group or a hydrolyzable group. The hydrolyzable group is not particularly limited and may be a known hydrolyzable group. Specific examples of the hydrolyzable group include 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, and an alkoxy group such as a methoxy group and an ethoxy group is more preferred because of its mild hydrolysis and ease of handling. A methoxy group is preferred because it allows for easy adjustment of the curing property of the sealant.

[0020] The reactive silicon group represented by formula (1) is not particularly limited. Specific examples of the reactive silicon group represented by formula (1) include dimethoxymethylsilyl, diethoxymethylsilyl, trimethoxysilyl, triethoxysilyl, dimethoxyphenylsilyl, methoxymethyldimethoxysilyl, methoxymethyldiethoxysilyl, triisopropenyloxysilyl, and triacetoxysilyl. Among these, dimethoxymethylsilyl and trimethoxysilyl are preferred because they facilitate the synthesis of polymer (A). Trimethoxysilyl and methoxymethyldimethoxysilyl are preferred because they have excellent curability. Dimethoxymethylsilyl is particularly preferred because it has excellent stability.

[0021] (Main chain structure of polymer (A)) The polymer (A) is a polyoxyalkylene polymer. Therefore, the main chain structure of the polymer is made of a polyoxyalkylene polymer. Specific examples of the main chain structure of the polymer (A) include polyoxyalkylene polymers such as polyoxyethylene polymers, polyoxypropylene polymers, polyoxybutylene polymers, polyoxytetramethylene polymers, polyoxyethylene-polyoxypropylene copolymers, and polyoxypropylene-polyoxybutylene copolymers.

[0022] Among polyoxyalkylene polymers, polyoxypropylene is preferred as the main chain structure because it has excellent deep curing properties as a one-component composition due to its high moisture permeability and also has excellent adhesive properties.

[0023] The polyoxyalkylene polymer is -R 3 It is a polymer having a repeating unit represented by -O-. 3 R is a linear or branched alkylene group having 1 to 14 carbon atoms. 3 As —R, a linear or branched alkylene group having 2 to 4 carbon atoms is more preferred. 3Specific examples of the repeating unit represented by -O- include -CHO-, -CHCHO-, -CHCH(CH)O-, -CHCH(CH)O-, -CHC(CH)(CH)O-, and -CHCHCHCHO-. The main chain structure of the polyoxyalkylene polymer may consist of only one type of repeating unit, or may consist of two or more types of repeating units. Polyoxypropylene polymers having oxypropylene repeating units in an amount of 50% by weight or more, preferably 80% by weight or more, of the polymer main chain structure are preferred as polyoxyalkylene polymers. This is because such polyoxyalkylene polymers are amorphous and have relatively low viscosity.

[0024] The main chain structure of the polyoxyalkylene polymer may be linear or branched.

[0025] The polyoxyalkylene polymer is preferably a polymer obtained by ring-opening polymerization of a cyclic ether compound in the presence of an initiator using a polymerization catalyst.

[0026] Examples of the cyclic ether compound include ethylene oxide, propylene oxide, butylene oxide, tetramethylene oxide, tetrahydrofuran, etc. These cyclic ether compounds may be used alone or in combination of two or more. Among these cyclic ether compounds, propylene oxide is particularly preferred because it can give an amorphous polyether polymer having a relatively low viscosity.

[0027] Specific examples of the initiator 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 polyoxyalkylene polymers such as polyoxypropylene diol, polyoxypropylene triol, polyoxyethylene diol, and polyoxyethylene triol.

[0028] The method for synthesizing the polyoxyalkylene polymer is not particularly limited. Examples of methods for synthesizing polyoxyalkylene polymers include a polymerization method using an alkali 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. Nos. 3,278,457, 3,278,458, 3,278,459, 3,427,256, 3,427,334, and 3,427,335; 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. The polymerization method using a composite metal cyanide complex catalyst is more preferred because it has low production costs and can produce a polymer with a narrow molecular weight distribution.

[0029] The main chain structure of the polymer (A) may be a polyoxyalkylene polymer containing bonds other than ether bonds, such as urethane bonds and urea bonds, within the range that does not significantly impair the desired effects. Specific examples of polymers having such a main chain structure include polyurethane prepolymers and polyurea prepolymers.

[0030] The polyurethane prepolymer can be obtained by a known method such as a method of reacting a polyol compound with a polyisocyanate compound, and the polyurea prepolymer can be obtained by a known method such as a method of reacting a polyamine compound with a polyisocyanate compound. The main chain structure may be a prepolymer having a combination of urethane bonds and urea bonds, which is obtained by reacting a polyol compound and a polyamine compound with a polyisocyanate compound.

[0031] Specific examples of the polyol compound include polyether polyol, polyester polyol, polycarbonate polyol, and polyether polyester polyol.

[0032] Specific examples of polyisocyanate compounds include diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, methylene-bis(cyclohexyl isocyanate), isophorone diisocyanate, and hexamethylene diisocyanate.

[0033] The polyurethane prepolymer may have a terminal group of either a hydroxyl group or an isocyanate group, and the polyurea prepolymer may have a terminal group of either an amino group or an isocyanate group.

[0034] In the case of a cured product of a sealant containing, as the polymer (A), a polymer having one or more types of bonds selected from a urethane bond, a urea bond, and an ester bond in the main chain structure, the strength of the cured product may decrease due to cleavage of the urethane bond, urea bond, or ester bond in the main chain structure due to heat or the like.

[0035] When a polymer containing an amide bond in the main chain structure is used as the polymer (A), the curing property of the sealant may be improved. 4 It is represented by -C(=O)-. 4is a hydrogen atom or an organic group which may have a substituent. When the amount of amide bonds in the main chain structure is within an appropriate range, the viscosity of the polymer is low, and a decrease in strength of the cured product due to cleavage of the amide bonds due to heat or the like and an increase in viscosity of the sealant due to storage are unlikely to occur, resulting in good workability of the sealant.

[0036] When the polymer (A) contains an amide bond in its main chain structure, the average number of amide bonds per molecule is preferably 1 to 10, more preferably 1.5 to 5, and even more preferably 2 to 3. When the average number of amide bonds per molecule is within this range, the curing property of the sealant is good, the viscosity of the polymer (A) is low, and the polymer (A) and the sealant are easy to handle.

[0037] As the polymer (A) described above, 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 is most preferred, from the viewpoint of obtaining a sealant that is excellent in storage stability and workability.

[0038] The polymer (A) is preferably a polymer obtained by introducing a reactive silicon group into a polymer by any of the following methods (a) to (d). (a) After converting the terminal hydroxyl groups of the hydroxyl-terminated organic polymer into carbon-carbon unsaturated groups, the carbon-carbon unsaturated groups are converted into HSiR 1 3-a X a A method of hydrosilylation using a hydrosilane represented by the formula R 1 , X, and a are the same as those in general formula (1). (b) OCN-W-SiR 1 3-a X a A method of reacting an isocyanate alkylsilane compound represented by the formula: W is a divalent organic group. 1 , X, and a are the same as those in general formula (1). (c) After converting the terminal hydroxyl groups of the hydroxyl-terminated organic polymer to carbon-carbon unsaturated groups, the carbon-carbon unsaturated groups and HS-W-SiR1 3-a X a A method of carrying out an ene-thiol reaction with a mercaptoalkylsilane compound represented by the formula: W is a divalent organic group. 1 , X, and a are the same as those in general formula (1). (d) A hydroxyl-terminated organic polymer is reacted with a polyisocyanate compound to synthesize an NCO-terminated organic polymer, and then the terminal NCO groups are converted into an NCO-terminated organic polymer by the reaction of HNR 5 -W-SiR 1 3-a X a , or HS-W-SiR 1 3-a X a A method of reacting a silane compound represented by the formula: W is a divalent organic group. 5 is a hydrogen atom or an alkyl group. 1 , X, and a are the same as those in general formula (1).

[0039] 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.

[0040] In any of the above methods (b) to (d), the polymer (A) obtained by using a silane compound in which W is methylene exhibits very high curability.

[0041] Method (a) is preferred because it is easy to obtain a polymer (A) having good storage stability, while methods (b), (c), and (d) are preferred because they can achieve a high conversion rate in a relatively short reaction time.

[0042] The method for introducing a reactive silicon group by method (a) has been proposed in Japanese Patent Publication Nos. 45-36319, 46-12154, Japanese Patent Laid-Open Nos. 50-156599, 54-6096, 55-13767, 55-13468, 57-164123, Japanese Patent Publication No. 3-2450, U.S. Pat. Nos. 3,632,557, 4,345,053, 4,366,307, and 4,960,844. Examples of such methods include the method proposed in Japanese Patent Laid-Open Nos. 61-197631, 61-215622, 61-215623, and 61-218632, in which reactive silicon groups are introduced by hydrosilylation or the like into a high-molecular-weight, narrow-molecular-weight distribution polyoxypropylene polymer having a number-average molecular weight of 6,000 or more and an Mw / Mn ratio of 1.6 or less, as well as the method proposed in Japanese Patent Laid-Open No. 3-72527. Furthermore, a method for introducing more than one reactive silicon group into a molecular terminal is proposed in Japanese Patent No. 6,096,320.

[0043] The number average molecular weight of the polymer (A) is not particularly limited. The number average molecular weight of the polymer (A), as polystyrene-equivalent molecular weight measured by GPC, is preferably 3,000 to 100,000, more preferably 3,000 to 50,000, and particularly preferably 3,000 to 30,000. When the number average molecular weight is within the above range, the amount of reactive silicon groups introduced is appropriate, making it easy to obtain a polymer (A) that has a viscosity that is easy to handle and excellent workability, while keeping production costs within an appropriate range.

[0044] The molecular weight of polymer (A) can also be expressed as an end-group-converted molecular weight calculated by directly measuring the end-group concentration of a polymer precursor before the introduction of reactive silicon groups using titration analysis based on the principles of the hydroxyl value measurement method specified in JIS K 1557 and the iodine value measurement method specified in JIS K 0070, and taking into account the polymer structure (the degree of branching determined by the polymerization initiator used).The end-group-converted molecular weight of polymer (A) can also be calculated by creating a calibration curve of the number average molecular weight determined by general GPC measurement of the polymer precursor and the end-group-converted molecular weight, and converting the number average molecular weight determined by GPC of polymer (A) into an end-group-converted molecular weight.

[0045] The molecular weight distribution (Mw / Mn) of the polymer (A) is not particularly limited. It is preferable that the molecular weight distribution of the polymer (A) is narrow. Specifically, the molecular weight distribution is preferably 1.6 or less, more preferably 1.4 or less, even more preferably 1.3 or less, and particularly preferably 1.2 or less. The molecular weight distribution of the polymer (A) can be determined from the number average molecular weight and weight average molecular weight obtained by GPC measurement.

[0046] To obtain a good rubber-like cured product, the reactive silicon groups of the polymer (A) are preferably present at the polymer chain terminals. The number of reactive silicon groups per polymer chain terminal is preferably 0.5 or more and 3.0 or less on average, more preferably 0.6 or more and 2.5 or less, even more preferably 0.7 or more and 2.2 or less, and particularly preferably 0.8 or more and 2.0 or less. When the number of reactive silicon groups is 0.5 or more, the curability of the polymer (A) and the sealant is good, and the cured sealant has good rubber elasticity.

[0047] The number of reactive silicon groups in one molecule is preferably 1 to 7 on average, more preferably 1 to 4, and particularly preferably 1 to 3.

[0048] Furthermore, as described in WO2013 / 180203, an organic polymer having two or more reactive silicon groups at the polymer chain terminals can also be used as the polymer (A). Such a polymer (A) exhibits high curability, and the resulting cured product is expected to have high strength and high recovery.

[0049] The number of reactive silicon groups per molecule in a polymer is determined by the high resolution of the protons on the carbon to which the reactive silicon groups are directly bonded. 1It is defined as the average number determined by a method for quantifying by H-NMR measurement. Polymers having reactive silicon groups obtained by a method for introducing reactive silicon groups into a polymer may also contain molecules to which reactive silicon groups have not been introduced (molecules contained in the polymer precursor before the introduction of reactive silicon groups). When calculating the number of reactive silicon groups per molecule in a polymer, molecules to which reactive silicon groups have not been introduced are also considered to be part of the components of the polymer having reactive silicon groups, and are included in the parameter (number of molecules) when calculating the number of reactive silicon groups per molecule.

[0050] The polymer (A) preferably contains a polyoxyalkylene polymer (a-1) (hereinafter sometimes simply referred to as "polymer (a-1)") having 1.6 or more reactive silicon groups per molecule, and a polyoxyalkylene polymer (a-2) (hereinafter sometimes simply referred to as "polymer (a-2)") having 1.0 or less reactive silicon groups per molecule. The polymer (a-1) and the polymer (a-2) are the same as the polymer (A) except for the number of reactive silicon groups per molecule.

[0051] When the polymer (A) contains a polymer (a-1) and a polymer (a-2), the weight W of the polyoxyalkylene polymer (a-2) (a-2) The weight W of the polyoxyalkylene polymer (a-1) relative to (a-1) Ratio of W (a-1) / W (a-2) is preferably 0.56 or less. When the polymer (A) contains the polymer (a-1) and the polymer (a-2), W (a-1) / W (a-2) is preferably from 0.20 to 0.56, more preferably from 0.30 to 0.56, further preferably from 0.40 to 0.56, and most preferably from 0.40 to 0.54.

[0052] Specific examples of commercially available polymer (A) products include various reactive silicon group-containing polyoxypropylene products such as Kaneka MS Polymer (registered trademark) and Kaneka Silyl (registered trademark). All of these commercially available polymers (A) are products of Kaneka Corporation. Other usable products include EXCESTAR (registered trademark) from AGC Corporation, GENIOSIL (registered trademark) from WACKER, and STP from RISUN POLYMER.

[0053] <(Meth)acrylic polymer (B)> The (meth)acrylic polymer (B) (hereinafter sometimes simply referred to as "polymer (B)") has a reactive silicon group in the polymer skeleton or at the end of the molecular chain. The polymer (B) preferably has a reactive silicon group in the polymer skeleton. The reactive silicon group is not particularly limited as long as it can form a siloxane bond. The reactive silicon group is preferably a reactive silicon group represented by the above formula (1). The polymer (B) has a polymer backbone and a polymer chain end bonded to the polymer backbone. The polymer backbone is a structure in which multiple structural units derived from monomers are bonded in succession. The monomer may be one type or multiple types.

[0054] The polymer chain end is a moiety located at the end of the polymer (B). The number of polymer chain ends of the polymer (B) is 2 when the main chain structure is linear, and 3 or more when the polymer backbone is branched. When the polymer (B) is a mixture of a polymer having a linear main chain structure and a polymer having a branched main chain structure, the number of polymer chain ends is an average value between 2 and 3.

[0055] The polymer (B) has a number average molecular weight of 6,000 to 15,000, or has 1.7 or less reactive silicon groups per molecule. The number average molecular weight of the polymer (B) is determined by GPC in terms of polystyrene. The number of reactive silicon groups per molecule of the polymer (B) is the same as the number of reactive silicon groups per molecule defined above. When the number average molecular weight of polymer (B) is 6,000 to 15,000, the number of reactive silicon groups per molecule of polymer (B) is not particularly limited as long as the desired effect is not impaired. When the number of reactive silicon groups per molecule of polymer (B) is 1.7 or less, the number average molecular weight of polymer (B) is not particularly limited as long as the desired effect is not impaired. The polymer (B) preferably has a number average molecular weight of 6,000 to 15,000 and contains 1.7 or less reactive silicon groups per molecule.

[0056] The reactive silicon group in the polymer (B) may be the same as or different from the reactive silicon group in the polymer (A).

[0057] (Main chain structure of polymer (B)) The polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester. The polymer (B) may contain structural units derived from two or more types of (meth)acrylic acid alkyl esters. The (meth)acrylic acid alkyl ester means an acrylic acid alkyl ester and / or a methacrylic acid alkyl ester.

[0058] Specific examples of acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-undecyl acrylate, lauryl acrylate, n-tridecyl acrylate, myristyl acrylate, cetyl acrylate, stearyl acrylate, and behenyl acrylate.

[0059] Specific examples of methacrylic acid alkyl esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-decyl methacrylate, n-undecyl methacrylate, lauryl methacrylate, n-tridecyl methacrylate, myristyl methacrylate, cetyl methacrylate, stearyl methacrylate, and behenyl methacrylate.

[0060] The ratio of the weight of the structural units derived from a (meth)acrylic acid alkyl ester to the weight of the polymer (B) is preferably 50% by weight or more, and more preferably 70% by weight or more.

[0061] In terms of the compatibility of polymer (B) with polymer (A) and the like and the stability of polymer (B), the monomer for preparing polymer (B) is preferably a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 30 carbon atoms.

[0062] The (meth)acrylic acid alkyl ester having an alkyl group having 1 to 30 carbon atoms is represented by the following formula (B1): CH2=CR b1 COOR b2 (B1) (In formula (B1), R b1 is a hydrogen atom or a methyl group. b2 is an alkyl group having 1 to 30 carbon atoms. It is expressed as:

[0063] In formula (B1), R b2 Examples of the alkyl group include alkyl groups having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, a 2-ethylhexyl group, a lauryl group, an n-tridecyl group, a cetyl group, and a stearyl group. R b2 The alkyl group as the group preferably has 1 to 20 carbon atoms.

[0064] The monomers for producing the polymer (B) may contain other monomers in addition to the alkyl (meth)acrylate ester. Other monomers include acrylic acid and methacrylic acid; (meth)acrylamides such as acrylamide, methacrylamide, N-methylolacrylamide, and N-methylolmethacrylamide; epoxy group-containing (meth)acrylic acid esters such as glycidyl acrylate and glycidyl methacrylate; amino group-containing unsaturated compounds such as 2-(N,N-diethylamino)ethyl methacrylate and 2-aminoethyl vinyl ether; acrylonitrile and methacrylonitrile; styrenes such as styrene and α-methylstyrene; alkyl vinyl ethers; vinyl chloride; and fatty acid vinyl esters such as vinyl acetate and vinyl propionate.

[0065] The molecular weight distribution (Mw / Mn) of the polymer (B) is not particularly limited. It is preferable that the molecular weight distribution of the polymer (B) is narrow. Specifically, the molecular weight distribution is preferably 1.6 or less, more preferably 1.4 or less, even more preferably 1.3 or less, and particularly preferably 1.2 or less. The molecular weight distribution of the polymer (B) can be determined from the number average molecular weight and weight average molecular weight obtained by GPC measurement.

[0066] The polymer (B) can be produced by a conventional vinyl polymerization method. Examples of the vinyl polymerization method include a solution polymerization method using a radical reaction and a bulk polymerization method. The vinyl polymerization method is not limited to these methods. The above polymerization reaction is typically carried out at 50 to 150° C. in the presence of monomers, a radical initiator, a chain transfer agent, a solvent, and the like. The polymerization reaction conditions are not limited to the above conditions.

[0067] Specific examples of the radical initiator include azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and benzoyl peroxide.

[0068] Specific examples of the chain transfer agent include mercaptans such as n-dodecyl mercaptan, tert-dodecyl mercaptan, and lauryl mercaptan, and halogen-containing compounds.

[0069] As the solvent, for example, a solvent inactive to the polymerization reaction, such as an alcohol-based solvent, an ether-based solvent, a hydrocarbon-based solvent, or an ester-based solvent, can be preferably used. The solvents may be used alone or in combination of two or more.

[0070] Various methods are known for introducing reactive silicon groups into (meth)acrylic polymers. Specific examples include: I) A method of copolymerizing a compound having an ethylenically unsaturated double bond and a reactive silicon group with a (meth)acrylic acid alkyl ester represented by formula (B1); II) A method in which a compound having an ethylenically unsaturated double bond and a reactive functional group (e.g., acrylic acid) is copolymerized with a (meth)acrylic acid alkyl ester represented by formula (B1), and the reactive functional group in the copolymer is reacted with reactive silicon and a compound capable of reacting with the reactive group (e.g., a reactive silicon group-containing isocyanate compound); III) A method of polymerizing a (meth)acrylic acid alkyl ester represented by formula (B1) in the presence of a mercaptan having a reactive silicon group as a chain transfer agent; VI) A method of polymerizing a (meth)acrylic acid alkyl ester represented by formula (B1) using an azobisnitrile compound having a reactive silicon group or a disulfide compound having a reactive silicon group as an initiator; and V) A method of introducing a reactive silicon group into the molecular chain terminal of a polymer obtained by polymerizing an alkyl (meth)acrylate ester represented by formula (B1) by living radical polymerization can be mentioned. The method for introducing a reactive silicon group into a (meth)acrylic polymer is not limited to the above-mentioned method.

[0071] The compound having an ethylenically unsaturated double bond and a reactive silicon group used in the above method I) includes compounds represented by the following formula (B2): CH2=CR b5 COOR b6 -SiR 1 3-a X a (B2) (In formula (B2), R 1 , X, and a are R in formula (1). 1 , X, and a. R b5 is a hydrogen atom or a methyl group. b6 is an alkylene group having 1 to 6 carbon atoms. A compound represented by the following formula is preferred.

[0072] In formula (B2), R b6 The alkylene group as is an alkylene group having 1 to 6 carbon atoms such as a methylene group, an ethane-1,2-diyl group (ethylene group), and a propane-1,3-diyl group (trimethylene group), and is preferably an alkylene group having 1 to 4 carbon atoms.

[0073] Specific examples of compounds having an ethylenically unsaturated double bond and a reactive silicon group include γ-methacryloxypropylalkoxysilanes such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and γ-methacryloxypropyltriethoxysilane; γ-acryloxypropylalkoxysilanes such as γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, and γ-acryloxypropyltriethoxysilane; and vinylalkoxysilanes such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, and vinyltriethoxysilane.

[0074] In the compound having an ethylenically unsaturated double bond and a reactive functional group used in the above method II), examples of the reactive functional group include an amino group, a hydroxyl group, and a carboxyl group. Examples of groups that can react with these reactive functional groups include an isocyanate group. Other examples include allyl groups as reactive functional groups, as described in JP-A-54-36395, JP-A-01-272654, and JP-A-02-214759, etc. Examples of groups that can react with allyl groups include silicon hydride groups (H—Si).

[0075] Examples of mercaptans containing a reactive silicon group that can be used as chain transfer agents in the above method III) include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and γ-mercaptopropyltriethoxysilane.

[0076] Examples of the azobisnitrile compound having a reactive silicon group and the disulfide compound used in the above method IV) include the azobisnitrile compound having an alkoxysilyl group and the disulfide compound having an alkoxysilyl group described in JP-A-60-23405 and JP-A-62-70405.

[0077] The above method V) includes the method described in JP-A-09-272714.

[0078] Other methods include those described in JP-A Nos. 59-168014 and 60-228516, which use a mercaptan having a reactive silicon group in combination with a radical polymerization initiator having a reactive silicon group.

[0079] Weight W of polymer (B) B Weight W of polymer (A) A Ratio of W A / W B may be 2 to 8, or may be 3 to 7.

[0080] It is common knowledge among those skilled in the art that the monomer composition of the polymer (B) is selected depending on the application and purpose of the sealant. When the sealant is used for applications requiring strength, it is preferable that the glass transition temperature (Tg) of the polymer (B) is relatively high. Specifically, the Tg of the polymer (B) is preferably 0 to 200°C, and more preferably 20 to 100°C. Tg can be calculated using the following Fox formula.

[0081] Fox's formula: 1 / (Tg(K))=Σ(Mi / Tgi) (In the formula, Mi is the weight fraction of the monomer i component constituting the polymer, and Tgi is the glass transition temperature (K) of the homopolymer of monomer i.)

[0082] For example, polymethyl methacrylate is known as a (meth)acrylic polymer with a relatively high glass transition temperature (Tg). Therefore, in the monomers used to produce polymer (B), the higher the weight ratio of methyl methacrylate to the weight of the monomer, the higher the glass transition temperature (Tg) of polymer (B) tends to be. Conversely, the lower the weight ratio of methyl methacrylate to the weight of the monomer, the lower the glass transition temperature (Tg) of polymer (B) tends to be. It is preferable that the ratio by weight of methyl methacrylate to the weight of the monomers used in producing the polymer (B) is 50% or more, since this makes it easier to form a high-strength cured product. It is preferable that the ratio of the weight of methyl methacrylate to the weight of the monomers used in producing the polymer (B) is less than 50% in terms of low viscosity of the sealant and good workability.

[0083] <Other additives> The sealant may contain various additives together with the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B) to the extent that the desired effects are not impaired. Examples of other additives include curing catalysts, fillers, adhesion promoters, plasticizers, solvents, diluents, thixotropy-imparting agents, antioxidants, light stabilizers, ultraviolet absorbers, physical property adjusters, tackifying resins, compounds containing epoxy groups, photocurable substances, oxygen-curable substances, epoxy resins, other resins, surface property improvers, foaming agents, curability adjusters, flame retardants, silicates, radical inhibitors, metal deactivators, phosphorus-based peroxide decomposers, lubricants, pigments, and mildew inhibitors.

[0084] (curing catalyst) The sealant may contain a silanol condensation catalyst as a curing catalyst for the purpose of promoting a hydrolysis condensation reaction between the reactive silicon groups of the polymer (A) and the polymer (B) and chain-extending or crosslinking the polymer. Examples of the silanol condensation catalyst include organotin compounds, metal carboxylates, amine compounds, carboxylic acids, and alkoxy metals.

[0085] Specific examples of organotin compounds include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin bis(butyl maleate), dibutyltin diacetate, dibutyltin oxide, dibutyltin diacetylacetonate, dioctyltin diacetylacetonate, dioctyltin dilaurate, dioctyltin distearate, dioctyltin diacetate, dioctyltin oxide, a reaction product of dibutyltin oxide with a silicate compound, a reaction product of dioctyltin oxide with a silicate compound, and a reaction product of dibutyltin oxide with a phthalate ester.

[0086] Specific examples of the metal carboxylate include tin carboxylate, bismuth carboxylate, titanium carboxylate, zirconium carboxylate, iron carboxylate, etc. Furthermore, as the metal carboxylate, salts of the following carboxylic acids combined with various metals can be used.

[0087] Specific examples of the amine compound include amines such as octylamine, 2-ethylhexylamine, laurylamine, and stearylamine; nitrogen-containing heterocyclic compounds such as pyridine, 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), and 1,5-diazabicyclo[4,3,0]nonene-5 (DBN); guanidines such as guanidine, phenylguanidine, and diphenylguanidine; biguanides such as butylbiguanide, 1-o-tolylbiguanide, and 1-phenylbiguanide; amino group-containing silane coupling agents; and ketimine compounds.

[0088] Specific examples of carboxylic acids include acetic acid, propionic acid, butyric acid, 2-ethylhexanoic acid, lauric acid, stearic acid, oleic acid, linoleic acid, neodecanoic acid, and versatic acid.

[0089] Specific examples of alkoxy metals include titanium compounds such as tetrabutyl titanate, titanium tetrakis(acetylacetonate), and diisopropoxytitanium bis(ethylacetoacetate); aluminum compounds such as aluminum tris(acetylacetonate) and diisopropoxyaluminum ethylacetoacetate; and zirconium compounds such as zirconium tetrakis(acetylacetonate). Other silanol condensation catalysts that can be used include fluorine anion-containing compounds, photoacid generators, and photobase generators. Two or more different silanol condensation catalysts may be used in combination. The amount of the silanol condensation catalyst used is preferably 0.001 to 20 parts by weight, more preferably 0.01 to 15 parts by weight, and particularly preferably 0.01 to 10 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0090] (filler) The sealant may contain various fillers, such as reinforcing fillers such as fumed silica, precipitated silica, crystalline silica, fused silica, dolomite, anhydrous silicic acid, hydrous silicic acid, and carbon black; ground calcium carbonate, precipitated calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, fine aluminum powder, flint powder, zinc oxide, activated zinc oxide, and resin powder; and fibrous fillers such as asbestos, glass fiber, and filament. Examples of resin powder include PVC powder and PMMA powder. 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 total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0091] When it is desired to obtain a cured product having high strength by using these fillers, fillers selected from the group consisting of 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 are preferably used. The amount of these fillers used, which is preferable in terms of the strength of the cured product, is preferably 1 to 200 parts by weight per 100 parts by weight of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). Furthermore, when a cured product with low strength and high elongation at break is desired, fillers selected from titanium oxide, calcium carbonate, magnesium carbonate, talc, ferric oxide, zinc oxide, shirasuballoon, and the like can be preferably used. The amount of these fillers used, which is preferable in terms of the elongation at break of the cured product, is preferably 5 to 200 parts by weight per 100 parts by weight of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B).

[0092] Generally, the larger the specific surface area of ​​calcium carbonate, the greater the effect of improving the breaking strength, breaking elongation, and adhesiveness of the cured product. These fillers can be used alone or in combination with two or more types. Fatty acid surface-treated colloidal calcium carbonate can be used in combination with calcium carbonate with a particle size of 1 μm or more, such as untreated ground calcium carbonate.

[0093] The sealing material may contain spherical hollow bodies such as balloons in order to reduce the weight (specific gravity) of the cured product. Balloons are hollow spherical fillers. Examples of balloon materials include inorganic materials such as glass, shirasu, and silica, and organic materials such as phenolic resin, urea resin, polystyrene, saran, and acrylonitrile. The balloon material is not limited to these materials. The balloon material may also be a composite material composed of an inorganic material and an organic material. The balloon material may also be a laminate of multiple layers. One type of balloon may be used alone, or two or more types may be used in combination. The surface of the balloon may be surface-treated, coated, or treated with various surface treatment agents. For example, organic balloons coated with calcium carbonate, talc, titanium oxide, etc., or inorganic balloons surface-treated with a silane coupling agent may be used.

[0094] The particle size of the balloons is preferably 3 μm to 200 μm, and particularly preferably 10 μm to 110 μm. When the particle size of the balloons is within this range, the use of an appropriate amount of balloons can reduce the weight of the cured product to a desired extent, and a cured product can be formed while suppressing the occurrence of surface irregularities and a decrease in elongation.

[0095] When using balloons, anti-slip agents such as those described in JP-A-2000-154368 and amine compounds for imparting a matte finish to the surface of the cured product by providing an uneven surface such as those described in JP-A-2001-164237 can be added to the sealant. Primary and / or secondary amines with a melting point of 35°C or higher are particularly preferred as the amine compounds.

[0096] Specific examples of balloons are described in JP-A-2-129262, JP-A-4-8788, JP-A-4-173867, JP-A-5-1225, JP-A-7-113073, JP-A-9-53063, JP-A-10-251618, JP-A-2000-154368, JP-A-2001-164237, WO97 / 05201, and the like.

[0097] The amount of spherical hollow bodies (balloons) used is preferably 0.01 to 30 parts by weight per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B). The lower limit is more preferably 0.1 part by weight, and the upper limit is more preferably 20 parts by weight. When the amount of spherical hollow bodies used falls within the above range, the sealant has good properties and a cured product having excellent elongation and breaking strength is easily formed.

[0098] (adhesion imparting agent) The sealant may contain an adhesion promoter, such as a silane coupling agent. Silane coupling agents are compounds having a hydrolyzable silicon group and a functional group other than the hydrolyzable silicon group in the molecule. When a sealant is applied to various adherends, such as inorganic substrates such as glass, aluminum, stainless steel, zinc, copper, and mortar, or organic substrates such as vinyl chloride, acrylic, polyester, polyethylene, polypropylene, and polycarbonate, the use of a silane coupling agent exhibits a significant improvement in adhesion under non-primer conditions or primer-treated conditions. When the sealant is used under non-primer conditions, the effect of improving adhesion to various adherends is particularly significant. In addition to the above functions, silane coupling agents can also function as dehydrating agents, property adjusters, dispersibility improvers for inorganic fillers, etc.

[0099] The hydrolyzable group in the hydrolyzable silicon group contained in the silane coupling agent is not particularly limited. Examples of hydrolyzable groups 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, halogen atoms, alkoxy groups, alkenyloxy groups, and aryloxy groups are preferred because of their high activity. Chlorine atoms and alkoxy groups are preferred because they are easily introduced into the silane coupling agent. Alkoxy groups such as methoxy groups and ethoxy groups are more preferred because of their mild hydrolysis and ease of handling, with methoxy groups and ethoxy groups being particularly preferred. Furthermore, ethoxy groups and isopropenyloxy groups are preferred from the standpoint of safety, as the compounds that are eliminated by reaction are ethanol and acetone, respectively. The number of hydrolyzable groups bonded to silicon atoms in the silane coupling agent may be three to ensure good adhesion. Furthermore, two may be preferable to ensure the storage stability of the sealant.

[0100] When a silane coupling agent is used as an adhesion promoter, an aminosilane coupling agent having a hydrolyzable silicon group and a substituted or unsubstituted amino group is preferred because it has a significant effect of improving adhesion. The substituent in the substituted amino group is not particularly limited. Examples of the substituent include an alkyl group, an aralkyl group, and an aryl group.

[0101] Specific examples of aminosilane coupling agents include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltriisopropoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propylmethyldimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(2-aminoethylamino)propyltriisopropoxysilane, 3-(2-(2-aminoethylamino)ethylamino)propyltrimethoxysilane, 3-(6-aminohexylamino)propyltrimethoxysilane, and 3-ethylamino-2-methylpropyltrimethoxysilane. amino group-containing silanes such as methyl silane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-benzylaminopropyltrimethoxysilane, 3-(vinylbenzylamino)propyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, N-butylaminopropyltrimethoxysilane, (2-aminoethylamino)methyltrimethoxysilane, N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, and bis(trimethoxysilylpropyl)amine; and ketimine-type silanes such as N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine.

[0102] Among these, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, and 3-(2-aminoethylamino)propylmethyldimethoxysilane are preferred in terms of good adhesiveness of the cured product. Only one type of aminosilane coupling agent may be used, or two or more types may be used in combination. It has been noted that 3-(2-aminoethylamino)propyltrimethoxysilane is more irritating than other aminosilanes. The irritating effect can be alleviated by using 3-aminopropyltrimethoxysilane in combination with 3-(2-aminoethylamino)propyltrimethoxysilane instead of reducing the amount of 3-(2-aminoethylamino)propyltrimethoxysilane. Furthermore, silane coupling agents oligomerized by partial condensation of hydrolyzable silicon groups are also suitable in terms of safety and stability. The condensed silane coupling agents may be a single type or multiple types. Examples of oligomerized silane coupling agents include Dynasylan 1146 from Evonik. In terms of good storage stability of the sealant, 3-aminopropyltrimethoxysilane and 3-(2-aminoethylamino)propylmethyldimethoxysilane are preferred.

[0103] Specific examples of silane coupling agents other than aminosilane coupling agents include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane; isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropylmethyldiethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, (isocyanatemethyl)trimethoxysilane, and (isocyanatemethyl)dimethoxymethylsilane; and 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane. Examples of suitable coupling agents include mercapto group-containing silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, and mercaptomethyltriethoxysilane; carboxy silane coupling agents such as 2-carboxyethyltriethoxysilane, 2-carboxyethylphenylbis(2-methoxyethoxy)silane, and N-2-(carboxymethylamino)ethyl-3-aminopropyltrimethoxysilane; vinyl-type unsaturated group-containing silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, and 3-acryloyloxypropylmethyltriethoxysilane; halogen-containing silane coupling agents such as 3-chloropropyltrimethoxysilane; and isocyanurate silane coupling agents such as tris(trimethoxysilyl)isocyanurate. Condensates obtained by partially condensing the above silane coupling agents can also be used. Examples of such condensates include Dynasylan 6490 and Dynasylan 6498 manufactured by Evonik.Furthermore, modified derivatives of these compounds, such as amino-modified silyl polymers, silylated amino polymers, unsaturated aminosilane complexes, phenylamino long-chain alkylsilanes, aminosilylated silicones, and silylated polyesters, can also be used as silane coupling agents.

[0104] Of these, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane are preferred in terms of good adhesiveness of the cured product.

[0105] The above silane coupling agents may be used alone or in combination of two or more. The amount of the silane coupling agent used 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 total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0106] (plasticizer) The sealant may contain a plasticizer, which can adjust the viscosity and slump of the sealant, as well as the mechanical properties such as tensile strength and elongation of the cured product.

[0107] 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; hydrogenated phthalate compounds such as 1,2-cyclohexanedicarboxylic acid diisononyl ester; dioctyl adipate, dioctyl sebacate, dibutyl sebacate, dioctyl succinate; Examples of suitable oils include aliphatic polycarboxylic acid ester compounds such as isodecyl and tributyl acetyl citrate; unsaturated fatty acid ester compounds such as butyl oleate and methyl acetylricinoleate; alkylsulfonic acid phenyl esters; phosphate ester compounds such as tricresyl phosphate and tributyl phosphate; trimellitic acid ester compounds; chlorinated paraffins; hydrocarbon oils such as alkyldiphenyls and partially hydrogenated terphenyls; process oils; and epoxy plasticizers such as epoxidized soybean oil and benzyl epoxy stearate. A specific example of a terephthalic acid ester compound is EASTMAN168 (trade name, manufactured by EASTMAN CHEMICAL). A specific example of a non-phthalic acid ester compound is Hexamoll DINCH (trade name, manufactured by BASF). A specific example of an alkylsulfonic acid phenyl ester is Mesamoll (trade name, manufactured by LANXESS).

[0108] Polymeric plasticizers can also be used. The use of polymeric plasticizers allows the initial physical properties of the cured product to be maintained for a longer period of time than when low-molecular-weight plasticizers are used. Furthermore, the drying properties (paintability) of the cured product when coated with an alkyd paint are improved.

[0109] Specific examples of polymeric plasticizers include vinyl polymers, which are polymers of vinyl monomers; esters of polyalkylene glycols and polyols, 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; polyether polyols (polyoxyalkylene compounds), such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, having a number-average molecular weight of 500 or more, or even 1,000 or more; derivatives of these polyether polyols in which the hydroxyl groups have been converted to ester groups, ether groups, or the like; polystyrenes, such as poly-α-methylstyrene; polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, and polychloroprene. Polymeric plasticizers are not limited to these.

[0110] The polymeric plasticizer is preferably compatible with the polyoxyalkylene polymer (A) and / or the (meth)acrylic polymer (B). From this viewpoint, polyethers and vinyl polymers are preferred. When polyethers are used as plasticizers, surface curability and deep curability are improved, and curing delay after storage does not occur. Among polyethers, polypropylene glycol is more preferred. Vinyl polymers are preferred from the viewpoint of compatibility with the polyoxyalkylene polymer (A) and / or the (meth)acrylic polymer (B) and the weather resistance and heat resistance of the cured product. 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 vinyl polymers, living radical polymerization is preferred, and atom transfer radical polymerization is more preferred, because it produces polymers with narrow molecular weight distributions and low viscosity. Furthermore, the so-called SGO process, which is described in Japanese Patent Application Laid-Open No. 2001-207157 and involves continuous bulk polymerization of an acrylic acid alkyl ester monomer at high temperature and pressure, is also preferred as a method for producing a vinyl polymer.

[0111] The number average molecular weight of the polymer plasticizer is preferably 500 to 15,000, more preferably 800 to 10,000, still more preferably 1,000 to 8,000, particularly preferably 1,000 to 5,000, and most preferably 1,000 to 3,000. When the number average molecular weight of the polymer plasticizer is within the above range, the plasticizer is prevented from leaking out of the cured product over time due to heat, rain, etc., while the initial physical properties of the cured product can be maintained for a long period of time, the sealant has an appropriate viscosity, and the workability of the sealant is good. The molecular weight distribution of the polymeric plasticizer is not particularly limited, but is preferably narrow. Specifically, the molecular weight distribution is preferably less than 1.80, more preferably 1.70 or less, even more preferably 1.60 or less, still more preferably 1.50 or less, particularly preferably 1.40 or less, and most preferably 1.30 or less.

[0112] The number average molecular weight of vinyl polymers is measured by GPC. The number average molecular weight of polyether polymers is measured by end group analysis. The molecular weight distribution (Mw / Mn) is measured by GPC (polystyrene equivalent).

[0113] The polymeric plasticizer may or may not have a reactive silicon group. When the polymeric plasticizer has a reactive silicon group, it acts as a reactive plasticizer and can prevent the plasticizer from migrating from the cured product. When the polymeric plasticizer has a reactive silicon group, the number of reactive silicon groups per molecule is preferably 1 or less, more preferably 0.8 or less, on average. When using a plasticizer having a reactive silicon group, particularly a polyether polymer having a reactive silicon group, its number average molecular weight must be lower than the number average molecular weight of the polyoxyalkylene polymer (A) and / or the number average molecular weight of the (meth)acrylic polymer (B).

[0114] Among the plasticizers described above, at least one selected from the group consisting of phthalate esters, hydrogenated phthalate esters, and polyoxyalkylene compounds is preferred.

[0115] 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 total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). When the amount of plasticizer used is within the above range, it is possible to obtain the desired effects of using the plasticizer sufficiently, while forming a cured product excellent in mechanical strength. The plasticizer may be used alone, or two or more types may be used in combination. A low-molecular-weight plasticizer may be used in combination with a polymeric plasticizer. These plasticizers may be blended with the polyoxyalkylene polymer (A) or the (meth)acrylic polymer (B) when producing the polyoxyalkylene polymer (A) or the (meth)acrylic polymer (B).

[0116] (solvent, diluent) The sealant may contain a solvent or a diluent. Preferably, the sealant does not contain a solvent or a diluent. The solvent and diluent are not particularly limited. Examples of solvents and diluents that can be used include aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohols, esters, ketones, and ethers. When using a solvent or a diluent, the boiling point of the solvent is preferably 150°C or higher, more preferably 200°C or higher, and particularly preferably 250°C or higher, in order to prevent air pollution when the sealant is used indoors. The above solvents or diluents may be used alone or in combination of two or more types.

[0117] (thixotropic agent) The sealant may contain a thixotropic agent, if necessary, to prevent sagging and improve workability. The thixotropic agent is not particularly limited. Examples of thixotropic agents include polyamide waxes; hydrogenated castor oil derivatives; and metal soaps such as calcium stearate, aluminum stearate, and barium stearate. Examples of trade names include Disparlon 6500, Disparlon 308, Disparlon 6300, Crayvallac SL, and Crayvallac SLT. These thixotropic agents may be used alone or in combination. The amount of the thixotropy-imparting agent used is preferably 0.1 to 20 parts by weight per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0118] (antioxidant) The sealant 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 phenol compounds, monophenol compounds, bisphenol compounds, and polyphenol compounds, with hindered phenol compounds being particularly preferred. Examples of antioxidants include Irganox 245, Irganox 1010, Irganox 1035, Irganox 1076, Irganox 1135, Irganox 1330, and Irganox 1520 (all manufactured by BASF); SONGNOX 1076 (manufactured by SONGWON), and BHT. Hindered amine light stabilizers such as TINUVIN 622LD, TINUVIN 144, TINUVIN 292, CHIMASSORB944LD, and CHIMASSORB119FL (all manufactured by BASF); ADK STAB LA-57, ADK STAB LA-62, ADK STAB LA-67, ADK STAB LA-63P, and ADK STAB LA-68 (all manufactured by ADEKA Corporation); SANOL LS-2626, SANOL LS-1114, and 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. Other antioxidants that can be used include SONGNOX 4120, Naugard 445, and OKABEST CLX050. Specific examples of antioxidants are also described in Japanese Patent Application Laid-Open Nos. 4-283259 and 9-194731. The amount of the antioxidant 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 total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0119] (light stabilizer) The sealant may contain a light stabilizer. The use of a light stabilizer can prevent photooxidative deterioration of the cured product. Examples of light stabilizers include benzotriazole-based compounds, hindered amine-based compounds, and benzoate-based compounds. Hindered amine-based compounds are particularly preferred as light stabilizers. The amount of the light stabilizer 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 total of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). Specific examples of light stabilizers are described in, for example, JP-A-9-194731.

[0120] When a photocurable substance is incorporated into a sealant, particularly when an unsaturated acrylic compound is used, it is preferable to use a tertiary amine-containing hindered amine light stabilizer as the hindered amine light stabilizer in order to improve the storage stability of the sealant, as described in JP-A-5-70531. Examples of tertiary amine-containing hindered amine 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, CHIMASSORB119FL, and CHIMASSORB944LD (all manufactured by BASF); ADK STAB LA-57, LA-62, LA-63, LA-67, and LA-68 (all manufactured by ADEKA Corporation); SANOL LS-292, LS-2626, LS-765, LS-744, and LS-1114 (all manufactured by Sankyo Lifetech Co., Ltd.), SABOSTAB UV91, SABOSTAB UV119, SONGSORB CS5100, SONGSORB CS622, and SONGSORB Examples include CS944 (all manufactured by SONGWON) and Nocrac CD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.).

[0121] (ultraviolet absorber) The sealant 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 compounds, benzotriazole-based compounds, salicylate-based compounds, triazine-based compounds, substituted tolyl-based compounds, and metal chelate-based compounds. Among these, benzotriazole-based compounds are particularly preferred. Specific examples of benzotriazole-based compounds 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). Specific examples of triazine compounds include TINUVIN 400, TINUVIN 405, TINUVIN 477, and TINUVIN 1577ED (all manufactured by BASF), and SONGSORB CS400 and SONGSORB 1577 (manufactured by SONGWON).Specific examples of benzophenone compounds include SONGSORB 8100 (manufactured by SONGWON). The amount of the ultraviolet absorber used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B). It is preferable to use a phenolic antioxidant or a hindered phenolic antioxidant in combination with a hindered amine light stabilizer and a benzotriazole ultraviolet absorber. Addworks IBC760 (manufactured by Clariant) can be used as a product containing a mixture of antioxidants, light stabilizers, and UV absorbers.

[0122] (Physical property adjuster) The sealant may contain a physical property adjuster to adjust the tensile properties of the cured product, as needed. The physical property adjuster is not particularly limited. Examples of the physical property adjuster include alkylalkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, and n-propyltrimethoxysilane; alkylisopropenoxysilanes such as dimethyldiisopropenoxysilane, methyltriisopropenoxysilane, and 3-glycidoxypropylmethyldiisopropenoxysilane; alkoxysilanes having functional groups such as 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyldimethylmethoxysilane, 3-aminopropyltrimethoxysilane, N-2-aminoethyl-3-aminopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropylmethyldimethoxysilane; silicone varnishes; and polysiloxanes. The use of a physical property modifier can increase the hardness of the cured product, or conversely, decrease the hardness of the cured product and increase the elongation at break. The physical property modifiers may be used alone or in combination of two or more.

[0123] In particular, compounds that hydrolyze to form a compound having a monovalent silanol group in the molecule have the effect of reducing the modulus of the cured product without increasing the stickiness of the surface of the cured product. Compounds that hydrolyze to form a compound having a monovalent silanol group in the molecule are particularly preferred, with compounds that form trimethylsilanol being particularly preferred. Examples of compounds that hydrolyze to form a compound having a monovalent silanol group in the molecule include the compounds described in JP-A-5-117521. Other examples include derivatives of alkyl alcohols such as hexanol, octanol, and decanol that hydrolyze to form trialkylsilanols such as trimethylsilanol, and derivatives of polyhydric alcohols with three or more hydroxyl groups such as trimethylolpropane, glycerin, pentaerythritol, and sorbitol that hydrolyze to form trialkylsilanols such as trimethylsilanol, as described in JP-A-11-241029. Examples include derivatives of oxyalkylene polymers that produce silicon compounds that produce trialkylsilanols such as trimethylsilanol upon hydrolysis, as described in JP-A-7-258534. Furthermore, polymers having crosslinkable hydrolyzable silicon-containing groups and silicon-containing groups that can be hydrolyzed to monosilanol-containing compounds, as described in JP-A-6-279693, can also be used. The physical property adjusting agent is used in an amount of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0124] (tackifying resin) The sealant may contain a tackifier resin for the purpose of increasing the adhesiveness or adhesion of the cured product to a substrate, etc. The tackifier resin is not particularly limited, and any tackifier resin commonly used in various curable compositions can be used. Specific examples of tackifying resins include terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, terpene-phenol resins, phenol resins, modified phenol resins, xylene-phenol resins, cyclopentadiene-phenol resins, coumarone-indene resins, rosin resins, rosin ester resins, hydrogenated rosin ester resins, xylene resins, low-molecular-weight polystyrene resins, styrene copolymer resins, styrene block copolymers, hydrogenated styrene block copolymers, petroleum resins, hydrogenated petroleum resins, and DCPD resins. Examples of petroleum resins include C5 hydrocarbon resins, C9 hydrocarbon resins, and C5C9 hydrocarbon copolymer resins. These may be used alone or in combination. The amount of the tackifier resin used is preferably 2 to 100 parts by weight, more preferably 5 to 50 parts by weight, and even more preferably 5 to 30 parts by weight, per 100 parts by weight of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). Using an amount of the tackifier resin within this range allows for the formation of a cured product with good adhesion and cohesion to the substrate. The sealant has an appropriate viscosity and is easy to handle.

[0125] (compounds containing epoxy groups) The sealant may contain a compound containing an epoxy group. The use of a compound having an epoxy group can improve the recovery of the cured product. Examples of compounds having an epoxy group include epoxidized unsaturated oils and fats, epoxidized unsaturated fatty acid esters, alicyclic epoxy compounds, epichlorohydrin derivatives, and mixtures thereof. Specific examples of compounds having an epoxy group include epoxidized soybean oil, epoxidized linseed oil, bis(2-ethylhexyl)-4,5-epoxycyclohexane-1,2-dicarboxylate (E-PS), epoxy octyl stearate, and epoxy butyl stearate. The amount of the epoxy group-containing compound used is preferably 0.5 to 50 parts by weight per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0126] (epoxy resin) The sealant may contain an epoxy resin. Epoxy resin-containing sealants are preferred as adhesives, particularly adhesives for exterior wall tiles. Examples of epoxy resins include bisphenol A epoxy resins and novolac epoxy resins. The ratio of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B) to the weight of the epoxy resin is preferably in the range of 100 / 1 to 1 / 100, expressed as a weight ratio of (weight of polymer (A) and weight of polymer (B)) / (weight of epoxy resin). When the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B) and the epoxy resin are used in the above ratio, a high-strength cured product having excellent impact strength and toughness is easily formed. When an epoxy resin is used, the sealant may contain a curing agent together with the epoxy resin. The type of curing agent is not particularly limited, and a commonly used curing agent can be used. The amount of the curing agent used is preferably 0.1 to 300 parts by weight based on 100 parts by weight of the epoxy resin.

[0127] (light curing substance) The sealant may contain a photocurable substance. When a photocurable substance is used, a film of the photocurable substance is formed on the surface of the cured product, improving the stickiness and weather resistance of the cured product. Various compounds such as organic monomers, oligomers, and resins are known as photocurable substances. Many compositions containing photocurable substances are also known. Representative photocurable substances include unsaturated acrylic compounds, polyvinyl cinnamates, and azido resins. Examples of unsaturated acrylic compounds include monomers, oligomers, or mixtures thereof having one or more acrylic unsaturated groups or methacrylic unsaturated groups. The amount of the photocurable substance used 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 total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B). When the amount of the photocurable substance used falls within this range, a flexible cured product that is excellent in weather resistance and inhibits the occurrence of cracks is likely to be formed.

[0128] (oxygen curing substance) The sealant may contain an oxygen-curing substance. Examples of oxygen-curing substances include unsaturated compounds that can react with oxygen in the air. When the curable substance contains an oxygen-curing substance, the oxygen-curing substance reacts with oxygen in the air to form a cured film near the surface of the cured product. The formation of a cured film on the surface of the cured product prevents stickiness and the adhesion of dirt and dust to the surface of the cured product. Specific examples of oxygen-curing substances include drying oils such as tung oil and linseed oil; various alkyd resins obtained by modifying drying oils; acrylic polymers, epoxy resins, and silicone resins modified with drying oils; and liquid polymers such as 1,2-polybutadiene, 1,4-polybutadiene, or polymers of C5-C8 dienes obtained by polymerizing or copolymerizing diene compounds such as butadiene, chloroprene, isoprene, or 1,3-pentadiene. These may be used alone or in combination of two or more. The amount of oxygen-curable substance used 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 total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). Using an amount of oxygen-curable substance within this range makes it easier to form a cured product whose surface is less susceptible to contamination by dirt and dust and has excellent mechanical properties such as tensile strength. As described in JP-A-3-160053, the oxygen-curable substance is preferably used in combination with a photocurable substance.

[0129] <Preparation of sealant> The sealant can be prepared as a one-component sealant, in which all ingredients are mixed in advance and stored in a sealed container, and then cured by moisture in the air after application. If the sealant contains a curing catalyst, it can also be prepared as a two-component sealant, in which a compounding material as a curing agent containing the curing catalyst and ingredients such as water is mixed with a separately prepared composition containing a polyoxyalkylene polymer (A) and a (meth)acrylic polymer (B) before use. From the viewpoint of workability, the one-component sealant is preferred. When the sealant is a one-component sealant, all ingredients are premixed, so it is preferable to dehydrate and dry the ingredients containing water before use, or to dehydrate them under reduced pressure during mixing. In addition to the dehydration and drying method, adding an alkoxysilane compound such as methyltrimethoxysilane, phenyltrimethoxysilane, n-propyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, or 3-glycidoxypropyltrimethoxysilane can further improve storage stability. Partially condensed silane compounds such as Evonik's Dynasylan 6490 can also be used as dehydrating agents from the standpoint of safety and stability. The amount of the dehydrating agent, particularly a silicon compound capable of reacting with water such as vinyltrimethoxysilane, used 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 total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0130] The sealant can also be used as a construction sealant, industrial adhesive, waterproof coating film-forming composition, pressure-sensitive adhesive raw material, etc. The sealant can also be used as a sealant for buildings, ships, automobiles, roads, etc. Furthermore, the sealant 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. Therefore, the sealant can also be used as various types of sealing and adhesive compositions. In addition to conventional adhesives, the sealant can also be used as a contact adhesive. Furthermore, the sealant is also useful as a food packaging material, a cast rubber material, a molding material, and a paint. The cured product of the above sealant exhibits low water absorption. Therefore, the above sealant and its cured product are also suitable for waterproof materials such as waterproof adhesives and waterproof coatings.

[0131] <Method for manufacturing cured sealant> Before curing, the sealant is formed into a desired shape by a method such as painting, casting, or filling.

[0132] The sealant that has been applied, cast, or filled and shaped is cured under a desired environment, such as room temperature and humidity.

[0133] The cured product thus formed exhibits good adhesion to a variety of adherends, and in particular, exhibits excellent adhesion to materials commonly used as building materials, such as rigid polyvinyl chloride resin, mortar, and concrete. [Example]

[0134] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0135] (Synthesis Example 1) Propylene oxide was polymerized using polyoxypropylene glycol with a number-average molecular weight of approximately 4500 as an initiator in the presence of a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene (P-1) with a number-average molecular weight of 27,900 (17,700 molecular weight calculated as the terminal group) and a molecular weight distribution (Mw / Mn) of 1.21, bearing hydroxyl groups at both ends. Subsequently, 1.2 molar equivalents of sodium methoxide were added to the hydroxyl groups of the hydroxyl-terminated polyoxypropylene (P-1) as a 28% methanol solution. After removing the methanol by vacuum devolatilization, an additional 1.5 molar equivalents of allyl chloride was added to the hydroxyl groups of the polymer (P-1) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was then removed by vacuum devolatilization. The resulting crude polyoxypropylene was mixed with n-hexane and water, stirred, and the water was removed by centrifugation. The resulting hexane solution was then devolatilized under reduced pressure to remove metal salts from the polymer. This resulted in the production of polyoxypropylene (Q-1) having allyl groups at its termini. 500 g of this polymer (Q-1) was mixed with 50 μL of a platinum divinyldisiloxane complex solution (a 3 wt. % platinum equivalent isopropanol solution), and 4.8 g of dimethoxymethylsilane was slowly added dropwise while stirring. The resulting mixture was reacted at 100°C for 2 hours, after which the unreacted dimethoxymethylsilane was distilled off under reduced pressure to produce polyoxypropylene polymer (A-1) having dimethoxymethylsilyl groups at its termini and a number-average molecular weight of approximately 28,500. Polymer (A-1) contained an average of 0.8 dimethoxymethylsilyl groups at each terminus, with an average of 1.6 per molecule.

[0136] (Synthesis Example 2) Using polyoxypropylene glycol with a number-average molecular weight of approximately 4500 as an initiator, propylene oxide was polymerized in the presence of a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene (P-2) with a number-average molecular weight of 27,900 (17,700 molecular weight calculated as the terminal group) and a molecular weight distribution (Mw / Mn) of 1.21, bearing hydroxyl groups at both ends. Subsequently, 1.0 molar equivalent of sodium methoxide was added as a 28% methanol solution relative to the hydroxyl groups of the hydroxyl-terminated polyoxypropylene (P-2). After distilling off the methanol by vacuum devolatilization, 1.0 molar equivalent of allyl glycidyl ether relative to the hydroxyl groups of the polymer (P-2) was added and the reaction was carried out at 130°C for 2 hours. Subsequently, 0.28 molar equivalent of sodium methoxide in methanol relative to the hydroxyl groups of the polymer (P-2) was added, and the methanol was distilled off. Subsequently, 1.79 molar equivalents of allyl chloride were added relative to the hydroxyl groups of polymer (P-2) to convert the terminal hydroxyl groups to allyl groups, and unreacted allyl chloride was removed by devolatilization under reduced pressure. The resulting crude polyoxypropylene was mixed and stirred with n-hexane and water, and then the water was removed by centrifugation. The resulting hexane solution was then devolatilized under reduced pressure to remove metal salts from the polymer. This yielded polyoxypropylene (Q-2) having allyl groups at its terminals. 50 μL of a platinum divinyldisiloxane complex solution (a 3 wt% isopropanol solution in terms of platinum) was added to 500 g of this polymer (Q-2), and 9.6 g of dimethoxymethylsilane was slowly added dropwise while stirring. The resulting mixture was reacted at 100°C for 2 hours, after which the unreacted dimethoxymethylsilane was distilled off under reduced pressure to yield polyoxypropylene polymer (A-2) having dimethoxymethylsilyl groups at its terminals and a number-average molecular weight of approximately 28,500. The polymer (A-2) has an average of 1.7 dimethoxymethylsilyl groups at each terminal and an average of 3.4 dimethoxymethylsilyl groups per molecule.

[0137] (Synthesis Example 3) Propylene oxide was polymerized using polyoxypropylene glycol with a number-average molecular weight of approximately 4500 as an initiator in the presence of a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene (P-3) with a number-average molecular weight of 21,100 (13,600 molecular weight calculated as the terminal group) and a molecular weight distribution (Mw / Mn) of 1.21, bearing hydroxyl groups at both ends. Subsequently, 1.2 molar equivalents of sodium methoxide were added to the hydroxyl groups of this hydroxyl-terminated polyoxypropylene (P-3) as a 28% methanol solution. After removing the methanol by vacuum devolatilization, an additional 1.5 molar equivalents of allyl chloride was added to the hydroxyl groups of the polymer (P-3) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was then removed by vacuum devolatilization. The resulting crude polyoxypropylene was mixed with n-hexane and water, stirred, and the water was removed by centrifugation. The resulting hexane solution was then devolatilized under reduced pressure to remove metal salts from the polymer. This resulted in the production of polyoxypropylene (Q-3) with allyl groups at the termini. 500 g of this polymer (Q-3) was mixed with 50 μL of a platinum divinyldisiloxane complex solution (a 3 wt. % platinum equivalent isopropanol solution), and 4.8 g of dimethoxymethylsilane was slowly added dropwise while stirring. The resulting mixture was reacted at 100°C for 2 hours, after which the unreacted dimethoxymethylsilane was distilled off under reduced pressure to produce polyoxypropylene polymer (A-3) with a number-average molecular weight of approximately 21,600 and containing dimethoxymethylsilyl groups at the termini. Polymer (A-3) contained an average of 0.7 dimethoxymethylsilyl groups at each terminus, with an average of 1.5 per molecule.

[0138] (Synthesis Example 4) Using polyoxypropylene glycol with a number-average molecular weight of approximately 4500 as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene (P-4) with a number-average molecular weight of 7,800 (5,000 molecular weight calculated as end groups) and a molecular weight distribution (Mw / Mn) of 1.48, bearing hydroxyl groups at both ends. Subsequently, 1.2 molar equivalents of sodium methoxide were added to the hydroxyl groups of this hydroxyl-terminated polyoxypropylene (P-4) as a 28% methanol solution. After removing the methanol by vacuum devolatilization, an additional 2.0 molar equivalents of allyl chloride was added to the hydroxyl groups of the polymer (P-4) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was then removed by vacuum devolatilization. The resulting crude polyoxypropylene was mixed with n-hexane and water, stirred, and the water was removed by centrifugation. The resulting hexane solution was then devolatilized under reduced pressure to remove metal salts from the polymer. This resulted in the production of polyoxypropylene (Q-4) having allyl groups at its termini. 50 μL of a platinum divinyldisiloxane complex solution (a 3 wt. % platinum equivalent isopropanol solution) was added to 500 g of this polymer (Q-4), and 9.5 g of dimethoxymethylsilane was slowly added dropwise while stirring. The resulting mixture was reacted at 100°C for 2 hours, after which the unreacted dimethoxymethylsilane was distilled off under reduced pressure to produce polyoxypropylene polymer (A-4) having dimethoxymethylsilyl groups at its termini and a number-average molecular weight of approximately 7900. Polymer (A-4) primarily consisted of a polymer with dimethoxymethylsilyl groups at only one terminus. Polymer (A-4) contained an average of 0.8 dimethoxymethylsilyl groups per molecule.

[0139] (Synthesis Example 5) A mixture of 43 g of methyl methacrylate, 204 g of butyl acrylate, 45 g of stearyl methacrylate, 7.2 g of γ-methacryloxypropyldimethoxymethylsilane, and 13 g of IBA (180 g) was heated to 105°C. A solution of 1.4 g of azobis-2-methylbutyronitrile as a polymerization initiator was added dropwise over 5 hours, followed by a solution of 0.3 g of azobis-2-methylbutyronitrile as a polymerization initiator in 4.5 g of IBA (4.5 g). Polymerization was then carried out for 2 hours, yielding a (meth)acrylic acid ester copolymer (B-1) with a number-average molecular weight of 17,800 and an average of 1.83 dimethoxymethylsilyl groups per molecule as a resin solution with a solids concentration of 60%.

[0140] (Synthesis Example 6) A mixture of 33 g of methyl methacrylate, 236 g of butyl acrylate, 50 g of stearyl methacrylate, 11.6 g of γ-methacryloxypropyldimethoxymethylsilane, and 39 g of IBA was added dropwise to 180 g of isobutyl alcohol (IBA) heated to 105°C over 4.3 hours. Then, a solution of 0.7 g of azobis-2-methylbutyronitrile as a polymerization initiator in 13.2 g of IBA was added dropwise over 1 hour. After 1 hour of post-polymerization, a (meth)acrylic acid ester copolymer (B-2) with a number-average molecular weight of 10,800 and an average of 1.62 dimethoxymethylsilyl groups per molecule was obtained as a resin solution with a solids concentration of 60%.

[0141] Example 1 The resin solution obtained in Synthesis Example 6, containing 30 parts by weight of the (meth)acrylic acid ester copolymer (B-2), was uniformly mixed with 70 parts by weight of the polyoxyalkylene polymer (A-3) having a reactive silicon group. Isobutyl alcohol was distilled off from the resulting solution using a rotary evaporator to obtain a polymer composition. 100 parts by weight of polymer composition, 76 parts by weight of polyoxyalkylene polymer (A-4), 120 parts by weight of precipitated calcium carbonate (Shiraishi Calcium Co., Ltd., trade name: Hakuenka CCR), 40 parts by weight of heavy calcium carbonate (Shiraishi Calcium Co., Ltd., trade name: Whiten SB), 10 parts by weight of titanium oxide (Ishihara Sangyo Kaisha, Ltd., trade name: Typaque R820), 2 parts by weight of fatty acid amide wax (Kusumoto Chemical Co., Ltd., trade name: Disparlon 6500), 1 part by weight of bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (BASF, trade name: Tinuvin 770), 1 part by weight of 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole (BASF, trade name: Tinuvin 326), 1 part by weight of vinyltrimethoxysilane (Momentive Performance Materials Japan, LLC, trade name: SILQUEST A-171) Two parts by weight of 3-(2-aminoethylamino)propyltrimethoxysilane (manufactured by Momentive Performance Materials Japan, LLC, trade name: SILQUEST A-1120 SILAN) and three parts by weight of 3-(2-aminoethylamino)propyltrimethoxysilane (manufactured by Momentive Performance Materials Japan, LLC, trade name: SILQUEST A-1120 SILAN) were mixed together. The resulting mixture was mixed with two parts by weight of an organotin curing catalyst (manufactured by Nitto Kasei Co., Ltd., trade name: Neostan U-810) to obtain a sealant.

[0142] (viscosity) The viscosity of the polymer composition described in Example 1 was measured at 23° C. using an E-type viscometer (VISCOMEMETER TV-25 manufactured by Toki Sangyo Co., Ltd., measuring cone: CORD-4, 13°×R14, rotation speed: 1.0 rpm). The measurement results are shown in Table 1.

[0143] (Stringiness (5℃)) Approximately 100 g of the sealant obtained in Example 1 was placed in a disposable cup at 5°C. The tip of the nozzle of the one-component cartridge was inserted into the sealant in the disposable cup. The nozzle was then forcefully pulled out of the sealant in the disposable cup. The length of the sealant dripping from the tip of the nozzle was measured. The measurement results are shown in Table 1.

[0144] (tensile properties) The resulting sealant was filled into a mold and cured at 23°C and 50% relative humidity for three days, followed by another four days at 50°C and 50% relative humidity to produce a cured sheet approximately 3 mm thick. The resulting cured material was punched into a No. 3 dumbbell shape according to JIS K 6251 to obtain test specimens. Tensile tests (maximum load = 5 N, tensile speed 200 mm / min) were performed on the resulting test specimens using an autograph (product name: AGS-J, manufactured by Shimadzu Corporation) at 23°C and 50% relative humidity. The measurement results for the 100% modulus (M100) are shown in Table 1.

[0145] (weather resistance) The cured product was cut into 1.5 cm squares to prepare weather resistance test specimens. A weather resistance test was performed on the weather resistance test specimens using a metal weather weathering tester (manufactured by Suga Test Instruments Co., Ltd.). Specifically, the weather resistance test specimens were placed under the following conditions. The weather resistance test specimens were visually observed, and the time until cracks appeared on the weather resistance test specimens was measured. The measurement results are shown in Table 1. Illuminance: 125mW / cm 2 . Shower: Pure water sprayed for 2 minutes every 2 hours.

[0146] (Examples 2 to 5 and Comparative Examples 1 to 3) A polymer composition and a sealant were obtained in the same manner as in Example 1, except that the polymer was changed to the polymer and its content shown in Table 1. The content of each component in Table 1 is shown in parts by weight. The polymer compositions or sealants of Examples 2 to 5 and Comparative Examples 1 to 3 were measured for viscosity, stringiness, tensile properties, and weather resistance in the same manner as in Example 1. The results are shown in Table 1.

[0147] [Table 1] * :W (a-1) The value of the parts by weight of the polymer (A-1) or the polymer (A-2) is expressed as W (a-2) The value of the total parts by weight of the polymer (A-4) is used as the formula.

[0148] Table 1 shows that the polymer compositions of Examples 1 to 5, which contain polymer (A) and polymer (B) having a number average molecular weight of 10,800 and 1.62 reactive silicon groups per molecule, have lower viscosities than the polymer compositions of Comparative Examples 1 to 3, which contain a (meth)acrylic polymer having a number average molecular weight of 17,800 and 1.83 reactive silicon groups per molecule. Furthermore, since the sealants were obtained by mixing equal amounts of polymer (A) and additives with the polymer compositions of Examples 1 to 5 and Comparative Examples 1 to 3, it can be seen that the sealants of Examples 1 to 5 have lower viscosities than the sealants of Comparative Examples 1 to 3. It is also clear that the sealing materials of Examples 1 to 5 are sealing materials with improved stringiness at low temperatures compared to the sealing materials of Comparative Examples 1 to 3.

Claims

1. The composition comprises a polyoxyalkylene polymer (A) having a reactive silicon group and a (meth)acrylic polymer (B) having a reactive silicon group, the (meth)acrylic polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester, The sealant, wherein the (meth)acrylic polymer (B) has a number average molecular weight of 6,000 to 15,000.

2. The polyoxyalkylene polymer (A) is a polyoxyalkylene polymer (a-1) having 1.6 or more reactive silicon groups per molecule; 2. The sealant according to claim 1, further comprising a polyoxyalkylene polymer (a-2) having 1.0 or less reactive silicon groups per molecule.

3. The weight W of the polyoxyalkylene polymer (a-2) （ａ－２） The weight W of the polyoxyalkylene polymer (a-1) relative to （ａ－１） Ratio of W （ａ－１） / W （ａ－２） The sealant according to claim 2, wherein is 0.56 or less.

4. The composition comprises a polyoxyalkylene polymer (A) having a reactive silicon group and a (meth)acrylic polymer (B) having a reactive silicon group, the (meth)acrylic polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester, The sealant, wherein the (meth)acrylic polymer (B) has 1.7 or less reactive silicon groups per molecule.

5. The polyoxyalkylene polymer (A) is a polyoxyalkylene polymer (a-1) having 1.6 or more reactive silicon groups per molecule; The sealant according to claim 4, further comprising a polyoxyalkylene polymer (a-2) having 1.0 or less reactive silicon groups per molecule.

6. The weight W of the polyoxyalkylene polymer (a-2) （ａ－２） The weight W of the polyoxyalkylene polymer (a-1) relative to （ａ－１） Ratio of W （ａ－１） / W （ａ－２） The sealant according to claim 5, wherein is 0.56 or less.

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