CN111094443B

CN111094443B - Curable composition, sealing material composition, and adhesive composition

Info

Publication number: CN111094443B
Application number: CN201880060544.3A
Authority: CN
Inventors: 望月克信
Original assignee: Toagosei Co Ltd
Current assignee: Toagosei Co Ltd
Priority date: 2017-09-20
Filing date: 2018-08-07
Publication date: 2022-07-05
Anticipated expiration: 2038-08-07
Also published as: PH12020550087A1; CN111094443A; WO2019058795A1

Abstract

The invention provides a curable composition, a sealing material composition and an adhesive composition which have excellent operability and excellent mechanical properties and weather resistance of a cured product. The curable composition contains a (meth) acrylic polymer (A) having a weight-average molecular weight of 500 or more and less than 10,000 and a (meth) acrylic polymer (B) having a weight-average molecular weight of 10,000 or more and 100,000 or less, wherein the (meth) acrylic polymer (A) has a double bond of 0.01meq/g or more and 1.0meq/g or less in the molecule, and the (meth) acrylic polymer (B) has a reactive silyl group in the molecule.

Description

Curable composition, sealing material composition, and adhesive composition

Technical Field

The present invention relates to a curable composition, and more particularly, to a curable composition which is cured at room temperature by moisture in the atmosphere or the like to form a cured product exhibiting excellent mechanical properties, a sealant composition of the curable composition, and an adhesive composition containing the curable composition.

Background

Examples of the curable composition containing a polymer having a room temperature curing type reactive group include compositions containing various polymers such as modified silicone polymers, urethane polymers, polythioether polymers and acrylic polymers, and the curable composition is widely used as an adhesive, a sealant, a coating material and the like in architectural applications, electric/electronic field-related applications, automobile-related applications and the like. For example, the modified silicone polymer is a curable composition based on an oxyalkylene polymer having a hydrolyzable silyl group, and is a material having good handling properties and a good balance of mechanical properties such as elongation at break and breaking strength, and therefore is widely used as a base polymer for adhesives and sealing materials.

However, it is known that a curable composition containing a modified silicone polymer as a base polymer has a problem that the cured product obtained therefrom has insufficient weather resistance. Therefore, a curable composition containing an acrylic polymer has been proposed.

Patent document 1 discloses a sealing material composition containing a specific vinyl polymer having an alkoxysilyl group, a polyoxyalkylene compound having an alkoxysilyl group at a terminal, and polypropylene glycol having a specific molecular weight or a specific vinyl polymer having no alkoxysilyl group. Patent document 2 discloses a sealing material composition containing an oxyalkylene polymer having a hydrolyzable silyl group and a specific vinyl polymer having a crosslinkable functional group. Patent document 3 discloses that a curable resin composition comprising a specific vinyl polymer and an oxyalkylene polymer containing a hydrolyzable silyl group can be suitably used for a sealing material and an adhesive for exterior tiles, and that the specific vinyl polymer contains a (meth) acrylate monomer having a hydrolyzable silyl group as a constituent monomer.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2004-18748

Patent document 2: international publication No. 2008/059872

Patent document 3: japanese patent laid-open No. 2014-118502

Disclosure of Invention

Problems to be solved by the invention

Cured products obtained from the compositions described in patent documents 1 to 3 exhibit good mechanical properties and improved weather resistance. However, the demand for improvement of weather resistance is high, and further improvement of weather resistance is also required for the curable composition. In addition, it is known that: generally, a polymer having a high molecular weight tends to improve weather resistance, and the composition has a high viscosity, which causes problems in coating properties and handling properties.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a curable composition, a sealant composition, and an adhesive composition which have excellent workability due to low viscosity and which provide a cured product having excellent mechanical properties and weather resistance.

Means for solving the problems

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that: a curable composition comprising a (meth) acrylic polymer having a reactive silyl group as a base resin and a low-molecular-weight (meth) acrylic polymer, wherein the low-molecular-weight (meth) acrylic polymer has a specific amount of double bonds, thereby improving the weather resistance of a cured product and an adhesive containing the cured product. The present invention has been completed based on this finding. According to the present specification, the following means are provided.

[ 1] A curable composition comprising a (meth) acrylic polymer (A) having a weight-average molecular weight of 500 or more and less than 10,000 and a (meth) acrylic polymer (B) having a weight-average molecular weight of 10,000 or more and 100,000 or less,

the (meth) acrylic polymer (A) has a double bond of 0.01meq/g or more and 1.0meq/g or less in the molecule,

the (meth) acrylic polymer (B) has a reactive silyl group in the molecule.

The curable composition according to [ 1] above, wherein the viscosity of the (meth) acrylic polymer (A) at 25 ℃ is 1,000 to 100,000 mPas.

[ 3] the curable composition according to [ 1] or [ 2] above, wherein the viscosity of the (meth) acrylic polymer (B) at 25 ℃ is 5,000 to 300,000 mPas.

The curable composition according to any one of [ 1] to [ 3], wherein the (meth) acrylic polymer (A) has a reactive silyl group in a molecule.

The curable composition according to any one of [ 1] to [ 4] above, wherein the (meth) acrylic polymer (B) has 0.1 to 2.2 reactive silyl groups in the molecule.

The curable composition according to any one of [ 1] to [ 5] above, wherein the (meth) acrylic polymer (B) has a dialkoxysilyl group as a reactive silyl group.

The curable composition according to any one of [ 1] to [ 6], wherein the (meth) acrylic polymer (B) contains an alkyl (meth) acrylate having an alkyl group having 10 or more carbon atoms in an amount of 5% by mass or more based on the total monomer units constituting the (meth) acrylic polymer.

The curable composition according to any one of [ 1] to [ 7] above, wherein the concentration of double bonds contained in the whole of the (meth) acrylic polymer (A) and the (meth) acrylic polymer (B) is 0.01meq/g or more and 0.50meq/g or less.

The curable composition according to any one of [ 1] to [ 8 ], wherein the (meth) acrylic polymer (A) and the (meth) acrylic polymer (B) are used in an amount of 10to 90/90 to 10 by mass ratio.

The curable composition according to any one of [ 1] to [ 9 ] above, further comprising an oxyalkylene polymer.

The curable composition according to any one of [ 1] to [ 10 ] above, which comprises at least one compound selected from a tin-based catalyst, a titanium-based catalyst and a tertiary amine as a curing accelerator.

A sealant composition comprising the curable composition according to any one of [ 1] to [ 11 ] above.

An adhesive composition comprising the curable composition according to any one of [ 1] to [ 11 ] above.

Effects of the invention

The curable composition of the present invention has a low viscosity and is excellent in workability. Further, a cured product having excellent strength, elongation and weather resistance is obtained from the composition. Therefore, the composition is suitably used as an adhesive such as a sealing material or an adhesive for exterior tiles, which are required to have excellent mechanical properties and high weather resistance.

Detailed Description

The present invention will be described in detail below. In the present specification, "(meth) acrylic acid" means acrylic acid and/or methacrylic acid, and "(meth) acrylate" means acrylate and/or methacrylate. Further, "(meth) acryloyl" means acryloyl and/or methacryloyl.

The curable composition of the present invention contains, as essential components, a (meth) acrylic polymer having a weight average molecular weight of 500 or more and less than 10,000 (hereinafter referred to as "low molecular weight (meth) acrylic polymer") as the component (a) and a (meth) acrylic polymer having a weight average molecular weight of 10,000 or more and 100,000 or less (hereinafter referred to as "high molecular weight (meth) acrylic polymer") as the component (B). Further, the component (C) may contain, as necessary, an oxyalkylene polymer having a reactive silyl group. The curable composition of the present invention will be described below, including the details of the respective components.

< (A) component: low molecular weight (meth) acrylic polymer

The low molecular weight (meth) acrylic polymer is a polymer having a structural unit derived from a (meth) acrylic monomer, and can be obtained, for example, by polymerizing a monomer mixture containing a (meth) acrylic monomer. The (meth) acrylic monomer is a monomer having a (meth) acryloyl group in the molecule, and examples thereof include (meth) acrylic acid, alkyl (meth) acrylates, alkoxyalkyl (meth) acrylates, and the like. The amount of the (meth) acrylic monomer used is preferably in the range of 10to 100% by mass, more preferably in the range of 30 to 100% by mass, and still more preferably in the range of 50 to 100% by mass, based on the total constituent monomers of the (meth) acrylic polymer.

Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, and mixtures thereof, Pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, stearyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, heneicosyl (meth) acrylate, docosyl (meth) acrylate, ditetradecyl (meth) acrylate, hexacosyl (meth) acrylate, dioctadecyl (meth) acrylate, triacontyl (meth) acrylate, tridecyl (meth) acrylate, triacontyl (meth) acrylate, forty-alkyl (meth) acrylate, isodecyl (meth) acrylate, isoundecyl (meth) acrylate, isolauryl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, lauryl acrylate, stearyl (meth) acrylate, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl acrylate, stearyl acrylate, and (meth) acrylate, lauryl acrylate, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl, Isotridecyl (meth) acrylate, isotetradecyl (meth) acrylate, isotentadecyl (meth) acrylate, isocetyl (meth) acrylate, isoheptadecyl (meth) acrylate, isostearyl (meth) acrylate, isonnonadecyl (meth) acrylate, isoeicosyl (meth) acrylate, isoheneicosyl (meth) acrylate, isodocosyl (meth) acrylate, isotetradecyl (meth) acrylate, isohexacosyl (meth) acrylate, isostearyl (meth) acrylate, isotridecyl (meth) acrylate, and mixtures thereof, Alkyl (meth) acrylates having a linear or branched aliphatic alkyl group or an alicyclic alkyl group such as iso-forty alkyl (meth) acrylate, and one or two or more kinds of these may be used. Among them, alkyl (meth) acrylates having an alkyl group having 1 to 8 carbon atoms are preferable from the viewpoint of mechanical properties of the cured product. The amount of the alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms is preferably 10% by mass or more, more preferably 30% by mass or more, and still more preferably 50% by mass or more, based on the total constituent monomers of the low-molecular-weight (meth) acrylic polymer. The upper limit value may be 100% by mass, 90% by mass, 80% by mass, or 50% by mass.

Among the above, the use of an alkyl (meth) acrylate having an alkyl group having 10 or more carbon atoms is preferable in that, when the curable composition contains an oxyalkylene polymer, good compatibility with the oxyalkylene polymer is secured and mechanical properties and weather resistance are good. The number of carbon atoms of the alkyl group is preferably 10to 20, more preferably 12 to 20. The amount of the alkyl (meth) acrylate having an alkyl group having 10 or more carbon atoms to be used is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 20% by mass or more, based on the total constituent monomers of the low-molecular-weight (meth) acrylic polymer. The upper limit is 100 mass% or less, may be 90 mass% or less, may be 80 mass% or less, and may be 50 mass% or less.

Specific examples of the alkoxyalkyl (meth) acrylate include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, methoxyhexyl (meth) acrylate, ethoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethoxybutyl (meth) acrylate, ethoxyhexyl (meth) acrylate, butoxymethyl (meth) acrylate, butoxyethyl (meth) acrylate, butoxybutyl (meth) acrylate, and butoxyhexyl (meth) acrylate, and one or two or more kinds of these can be used. Among them, from the viewpoint of mechanical properties of the cured product, an alkoxyalkyl (meth) acrylate having an alkoxyalkyl group having 2 to 8 carbon atoms is preferable, and an alkoxyalkyl (meth) acrylate having an alkoxyalkyl group having 2 to 4 carbon atoms is more preferable. The amount of the alkoxyalkyl (meth) acrylate to be used is preferably 10% by mass or more, more preferably 30% by mass or more, and still more preferably 50% by mass or more, based on the total constituent monomers of the low-molecular-weight (meth) acrylic polymer. The upper limit is 100 mass% or less, may be 90 mass% or less, may be 80 mass% or less, and may be 50 mass% or less.

The low molecular weight (meth) acrylic polymer may have a reactive silyl group in the molecule. When the low-molecular weight (meth) acrylic polymer has a reactive silyl group, the cured product tends to have good mechanical properties. The type of the reactive silyl group is not particularly limited, and examples thereof include an alkoxysilyl group, a halogenated silyl group, and a silanol group, but an alkoxysilyl group is preferable from the viewpoint of easiness of control of the reactivity. Specific examples of the alkoxysilyl group include: trialkoxysilyl groups such as trimethoxysilyl, triethoxysilyl, dimethoxyethoxysilyl and methoxydiethoxysilyl; dialkoxysilyl groups such as methyldimethoxysilyl group, methyldiethoxysilyl group, ethyldimethoxysilyl group and ethyldiethoxysilyl group; monoalkoxysilyl groups such as dimethylmethoxysilyl, dimethylethoxysilyl, diethylmethoxysilyl and diethylethoxysilyl. Among them, dialkoxysilyl groups are preferred because cured products exhibit good elongation and excellent heat resistance stability.

When the low-molecular weight (meth) acrylic polymer has a reactive silyl group, the average number of reactive silyl groups contained in 1-molecule polymer is preferably 0.1 or more, and more preferably 0.2 or more, from the viewpoint of the tensile strength of the cured product. The average number of reactive silyl groups may be 0.3 or more, 0.5 or more, or 1.0 or more. From the viewpoint of ensuring the elongation of the cured product, the upper limit value is preferably 5.0 pieces or less, more preferably 4.0 pieces or less, further preferably 3.0 pieces or less, further preferably 2.5 pieces or less, and further preferably 2.2 pieces or less. The range of the average value of the number of reactive silyl groups may be set by combining the above upper limit and lower limit, and is, for example, 0.1 or more and 5.0 or less, may be 0.1 or more and 3.0 or less, may be 0.1 or more and 2.2 or less, and may be 0.2 or more and 2.2 or less.

The position of the reactive silyl group contained in the (meth) acrylic polymer is not particularly limited, and may be a side chain and/or a terminal of the polymer.

The reactive silyl group can be obtained, for example, by polymerizing a monomer mixture containing a (meth) acrylic monomer and a vinyl monomer having a reactive silyl group.

Examples of the vinyl monomer having a reactive silyl group include: vinylsilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane and vinyldimethylmethoxysilane; silyl group-containing (meth) acrylates such as trimethoxysilylpropyl (meth) acrylate, triethoxysilylpropyl (meth) acrylate, dimethylmethoxysilylpropyl (meth) acrylate, and methyldimethoxysilylpropyl (meth) acrylate; silyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether; vinyl esters containing a silyl group such as vinyl trimethoxysilylundecanoate, and one or two or more of them may be used.

The low molecular weight (meth) acrylic polymer may be copolymerized with other monomers copolymerizable with them in addition to the above-mentioned monomers.

Examples of the other monomers include: functional group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycidyl (meth) acrylate, 2-aminoethyl (meth) acrylate, and ethylene oxide adducts of (meth) acrylic acid;

aromatic (meth) acrylates such as phenyl (meth) acrylate, methylphenyl (meth) acrylate and benzyl (meth) acrylate;

fluorine-containing (meth) acrylates such as trifluoromethyl (meth) acrylate, 2-trifluoromethyl ethyl (meth) acrylate, 2-perfluoroethyl-2-perfluorobutyl ethyl (meth) acrylate, 2-perfluoroethyl (meth) acrylate, perfluoromethyl (meth) acrylate, diperfluoromethylmethyl (meth) acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth) acrylate, 2-perfluorohexylethyl (meth) acrylate, 2-perfluorodecylethyl (meth) acrylate, and 2-perfluorohexadecylethyl (meth) acrylate;

fluorine-containing olefins such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride;

aromatic monomers such as styrene, vinyl toluene, α -methylstyrene, chlorostyrene, styrene sulfonic acid and salts thereof;

maleic anhydride; unsaturated dicarboxylic acids such as maleic acid and fumaric acid, and monoalkyl esters and dialkyl esters thereof;

maleimide compounds such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, phenylmaleimide and cyclohexylmaleimide;

nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile;

amide group-containing vinyl monomers such as acrylamide and methacrylamide;

vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate;

olefins such as ethylene and propylene;

conjugated dienes such as butadiene and isoprene;

vinyl chloride, vinylidene chloride, allyl alcohol, etc., but are not limited to these monomers. In addition, one or two or more of them may be used.

The weight average molecular weight (Mw) of the low molecular weight (meth) acrylic polymer is 500 or more, preferably 1,000 or more, and more preferably 2,000 or more in terms of polystyrene equivalent molecular weight based on gel permeation chromatography (hereinafter also referred to as "GPC") from the viewpoint of the strength and weather resistance of the cured product. The Mw may be 3,000 or more. On the other hand, from the viewpoint of workability (low viscosity), the upper limit value of Mw may be less than 10,000, and may be 9,500 or less, or may be 9,000 or less, or may be 8,000 or less. The Mw range is 500 or more and less than 10,000, and may be set by combining the above upper limit value and lower limit value. The Mw may be, for example, 1,000 or more and less than 10,000, 2,000 or more and less than 10,000, or 3,000 or more and 90,000 or less.

The molecular weight distribution of the low molecular weight (meth) acrylic polymer is calculated as a value (Mw/Mn) obtained by dividing a weight average molecular weight (Mw) by a number average molecular weight (Mn). From the viewpoint of the balance between tensile physical properties and workability, Mw/Mn is preferably 5.0 or less, more preferably 4.0 or less, further preferably 3.0 or less, further preferably 2.5 or less, and further preferably 2.0 or less. The lower limit of Mw/Mn is usually 1.0.

The viscosity of the low-molecular-weight (meth) acrylic polymer is preferably 1,000 mPas or more, and more preferably 2,000 mPas or more at 25 ℃. The viscosity may be 3,000 mPas or more, 5,000 mPas or more, or 10,000 mPas or more. The upper limit of the viscosity is preferably 100,000 mPas or less, more preferably 80,000 mPas or less, and still more preferably 60,000 mPas or less. When the viscosity is 1,000 mPas or more, sagging at the time of application to a vertical surface is suppressed, and therefore, it is preferable to make the viscosity 100,000 mPas or less, whereby the workability of the curable composition becomes good. The viscosity range may be set in combination with the above upper limit and lower limit, and may be, for example, 1,000 to 100,000mPa · s, 2,000 to 80,000mPa · s, or 3,000 to 60,000mPa · s.

In the present invention, the low molecular weight (meth) acrylic polymer has a double bond in the molecule. When the low-molecular weight (meth) acrylic polymer has an appropriate amount of double bonds, the double bonds react and the molecular weight increases moderately during exposure of the cured product to the outside, for example, and thus the weather resistance is improved. Therefore, in the present invention, the viscosity of the low molecular weight (meth) acrylic polymer can be suppressed to ensure the workability, and the cured product thereof can exhibit excellent weather resistance. The mechanism described above is assumed to be, and is not intended to limit the scope of the present invention.

From the viewpoint of exhibiting the above effect on weather resistance, the amount of double bonds contained in the low molecular weight (meth) acrylic polymer needs to be 0.01meq/g or more. The amount of double bonds may be 0.05meq/g or more, 0.10meq/g or more, 0.20meq/g or more, or 0.30meq/g or more. On the other hand, if the amount of double bonds is too large, the degree of crosslinking of the cured product becomes too high during exposure, and flexibility becomes insufficient, so that cracks tend to be easily generated. Therefore, the amount of double bonds is 1.0meq/g or less, preferably 0.50meq/g or less, and more preferably 0.30meq/g or less. The amount of the double bond may be set in combination with the above upper limit and lower limit, and may be, for example, 0.01meq/g or more and 1.0meq/g or less, 0.05meq/g or more and 1.0meq/g or less, or 0.10meq/g or more and 0.50meq/g or less.

The method for introducing the double bond is not particularly limited, and a method known to those skilled in the art can be used. Examples thereof include: a method of copolymerizing a monomer having a plurality of double bonds in a molecule; a method of producing a (meth) acrylic polymer having a functional group and then reacting the polymer with a compound having a functional group capable of reacting with the functional group and a double bond.

Further, by producing the (meth) acrylic polymer under high temperature conditions, a double bond can be introduced. For example, if the polymerization temperature is 100 ℃ or higher, a cleavage reaction from the dehydrogenation reaction of the polymer chain occurs due to high-temperature polymerization, and thus a polymer having an ethylenically unsaturated bond represented by the following general formula (1) at the molecular terminal is obtained. The polymerization temperature is preferably 120 ℃ or higher, more preferably 150 ℃ or higher. The higher the polymerization temperature, the higher the concentration of double bonds in the polymer tends to be. According to the above method, a (meth) acrylic polymer having a double bond can be obtained easily and with good productivity. Further, the resin composition can be easily produced without containing a large amount of impurities such as an initiator and a chain transfer agent in controlling the molecular weight. Chain transfer agents such as mercaptans are preferably not used because they cause a decrease in weather resistance. On the other hand, the upper limit of the polymerization temperature is preferably 350 ℃ or lower in order to eliminate the risk of coloring of the polymerization liquid, lowering of the molecular weight, and the like due to the decomposition reaction. By carrying out the polymerization in the above temperature range, a copolymer having an appropriate molecular weight, a low viscosity, no coloration, and few inclusions can be efficiently produced. That is, according to this polymerization method, a very small amount of a polymerization initiator is used, and a high-purity copolymer can be obtained without using a chain transfer agent such as thiol or a polymerization solvent.

[ solution 1]

In the formula, M represents a monomer unit, and n is a natural number representing the degree of polymerization. R¹Represents a monovalent organic group. Angle (c)

As R in the above general formula (1)¹And is an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkyl group which may have other substituents, a phenyl group, a benzyl group, a polyalkylene glycol group, a dialkylaminoalkyl group, a trialkoxysilylalkyl group, an alkyldialkoxysilylalkyl group, or a hydrogen atom.

The low-molecular weight (meth) acrylic polymer can be produced by a general radical polymerization. Any of solution polymerization, bulk polymerization and dispersion polymerization may be used, and living radical polymerization may also be used. The reaction process may be any of a batch type, a semi-batch type, and a continuous polymerization method. Among them, a high-temperature continuous polymerization method at 100 to 350 ℃ is preferable.

In general, when crosslinkable functional groups are uniformly introduced into a polymer, the curable composition containing the polymer has excellent properties such as curability and weather resistance of the resulting cured product. In this regard, when a stirred tank reactor is used as the reactor, a (meth) acrylic polymer having a narrow composition distribution (distribution of crosslinkable functional groups) and a narrow molecular weight distribution can be obtained, and therefore, such a reactor is preferable. Further, a process using a continuous stirring tank type reactor is more preferable in terms of narrowing the composition distribution and the molecular weight distribution.

The high-temperature continuous polymerization method may be a known method disclosed in, for example, Japanese patent application laid-open Nos. 57-502171, 59-6207, and 60-215007. Examples thereof include the following methods: after a pressurizable reactor is filled with a solvent and set to a predetermined temperature under pressure, a monomer mixture comprising each monomer and a polymerization solvent as needed is supplied to the reactor at a constant supply rate, and a polymerization liquid in an amount corresponding to the supply amount of the monomer mixture is withdrawn. Further, a polymerization initiator may be blended in the monomer mixture as necessary. The amount of the monomer mixture is preferably 0.001 to 2 parts by mass per 100 parts by mass of the monomer mixture. The pressure depends on the reaction temperature and the boiling points of the monomer mixture and the solvent used, and may be any pressure that does not affect the reaction but can maintain the reaction temperature. The residence time of the monomer mixture is preferably 1 to 60 minutes. If the residence time is less than 1 minute, there is a risk that the monomer is insufficiently reacted, and if the unreacted monomer exceeds 60 minutes, the productivity may be deteriorated. The preferable residence time is 2 to 40 minutes.

As an example of the polymerization initiator used for obtaining the low molecular weight (meth) acrylic polymer, any initiator may be used as long as it generates a radical at a predetermined reaction temperature. Specifically, the following are listed: organic peroxides such as di-t-butyl peroxide, di-t-hexyl peroxide, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, cumene hydroperoxide, t-butyl hydroperoxide, etc.; azo compounds such as 2,2 '-azobis (isobutyronitrile), 2' -azobis (2-methylbutyronitrile), azobiscyclohexanecarbonitrile, azobis (2, 4-dimethylvaleronitrile), 2 '-azobis (2-amidinopropane) dihydrochloride, and 4, 4' -azobis (4-cyanopentanoic acid). One of them may be used alone, or two or more thereof may be used in combination. When an initiator having a high dehydrogenation ability is used as the polymerization initiator, the double bond concentration of the resulting polymer tends to be high. For example, when an organic peroxide is used, a polymer having a higher double bond concentration tends to be obtained as compared with an azo compound.

The amount of the polymerization initiator to be used may be appropriately adjusted depending on the kind of the polymerization initiator and the monomer, the desired molecular weight, the polymerization conditions, and the like, and is generally 0.001 to 10 parts by mass based on 100 parts by mass of the monomer to be used. In the case of obtaining polymers of the same molecular weight, there is a tendency that: the smaller the amount of the polymerization initiator used, the higher the double bond concentration in the resulting polymer.

When an organic solvent is used in the production of the low molecular weight (meth) acrylic polymer, the organic hydrocarbon compound is suitable, and examples thereof include: cyclic ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbon compounds such as benzene, toluene and xylene; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; one or more kinds of alcohols such as methanol, ethanol, and isopropyl alcohol can be used. In a solvent in which the (meth) acrylate copolymer is not sufficiently dissolved, scale (scale) tends to grow on the wall of the reactor, and a problem in production tends to occur in a cleaning step or the like. In addition, for example, when an organic solvent having high chain transfer ability such as isopropyl alcohol is used, the concentration of double bonds in the obtained polymer tends to be low.

The amount of the solvent used is preferably 80 parts by mass or less based on 100 parts by mass of the total vinyl monomers. By setting the amount to 80 parts by mass or less, a high conversion rate can be obtained in a short time. More preferably 1 to 50 parts by mass. In addition, a dehydrating agent such as trimethyl orthoacetate or trimethyl orthoformate may be added.

A known chain transfer agent can be used for producing the low-molecular weight (meth) acrylic polymer. When a chain transfer agent is used, the double bond concentration in the resulting polymer tends to be low. In addition, the double bond concentration is generally reduced by increasing the amount of the chain transfer agent used.

The reaction solution withdrawn from the reactor may be directly subjected to the next step, or may be subjected to distillation such as distillation to remove volatile components such as unreacted monomers, solvents, and low-molecular-weight oligomers, thereby separating the polymer. A part of volatile components such as unreacted monomers, solvents, and low-molecular-weight oligomers distilled off from the reaction solution may be returned to the raw material tank or directly returned to the reactor to be reused for the polymerization reaction.

Thus, a method of recycling the unreacted monomer and the solvent is preferable from the viewpoint of economy. In the case of recycling, it is necessary to determine the mixing ratio of the newly supplied monomer mixture in such a manner that the desired monomer ratio and the desired amount of solvent are maintained in the reactor.

The double bonds introduced in the polymer can be reduced in their amount by adding a free-radical generator and carrying out a post-treatment under heating. The amount of the radical generator added is about 0.1 to 10 parts by mass per 100 parts by mass of the polymer, and the effect of reducing the double bond concentration increases as the amount of the free radical generator added increases.

The heating temperature during the heat treatment is about 50 to 130 ℃, but the effect of reducing the double bond concentration is greater as the temperature is lower. The heating temperature is preferably 50 to 110 ℃, and more preferably 50 to 100 ℃.

The heat treatment time is not particularly limited, and is preferably set so that the residual radical generating amount is less than 1% by mass relative to the polymer. If it is a person skilled in the art, the residual radicals can be calculated from the activation energy of the radical generator used, the frequency factor and the reaction temperature.

The double bond concentration can also be reduced by hydrogenating the (meth) acrylic polymer as a post-treatment. The hydrogenation may be carried out by a conventionally known method.

That is, after adding a homogeneous catalyst or an inhomogeneous catalyst to a polymer reaction solution, the system is heated under a hydrogen atmosphere at a pressure of about normal pressure to 10MPa and a temperature of about 20 to 180 ℃ to react about 2 to 20. Specific examples of the homogeneous catalyst include: rhodium complexes such as chlorotris (triphenylphosphine) rhodium; ruthenium complexes such as dichlorotris (triphenylphosphine) ruthenium and chlorohydrogenocarbonyltris (triphenylphosphine) ruthenium; platinum complexes such as dichlorobis (triphenylphosphine) platinum; iridium complexes such as carbonylbis (triphenylphosphine) iridium, and the like. On the other hand, examples of the heterogeneous catalyst include solid catalysts in which a transition metal such as nickel, rhodium, ruthenium, palladium, or platinum is supported on carbon, silica, alumina, fibers, or an organic gel. The heterogeneous catalyst is preferable in that the catalyst can be easily removed by filtration or the like, and the catalyst has stable quality and can be reused at high cost. The amount of the catalyst to be added is about 10to 1,000ppm based on the vinyl polymer in the case of a homogeneous catalyst. In the case of the heterogeneous catalyst, the amount is about 1,000 to 10,000 ppm.

< (B) component: high molecular weight (meth) acrylic polymer

The high molecular weight (meth) acrylic polymer is a polymer having a structural unit derived from a (meth) acrylic monomer, similarly to the low molecular weight (meth) acrylic polymer. Examples of the (meth) acrylic monomer include (meth) acrylic acid and alkyl (meth) acrylate. The amount of the (meth) acrylic monomer used is preferably in the range of 10to 100% by mass, more preferably in the range of 30 to 100% by mass, and still more preferably in the range of 50 to 100% by mass, based on the total constituent monomers of the (meth) acrylic polymer.

As the alkyl (meth) acrylate, the same compounds as those described in the description of the low molecular weight (meth) acrylic polymer can be used. Among them, alkyl (meth) acrylates having an alkyl group having 1 to 8 carbon atoms are preferable from the viewpoint of mechanical properties of the cured product. The amount of the alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms to be used is preferably 10% by mass or more, more preferably 30% by mass or more, and still more preferably 50% by mass or more, based on the total constituent monomers of the high molecular weight (meth) acrylic polymer. The upper limit is 100 mass% or less, may be 90 mass% or less, may be 80 mass% or less, and may be 50 mass% or less.

Among the above, the use of an alkyl (meth) acrylate having an alkyl group having 10 or more carbon atoms is preferable in that, when the curable composition contains an oxyalkylene polymer, good compatibility with the oxyalkylene polymer is secured and mechanical properties and weather resistance are good. The number of carbon atoms of the alkyl group is preferably 10to 20, more preferably 12 to 20. The amount of the alkyl (meth) acrylate having an alkyl group having 10 or more carbon atoms to be used is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 20% by mass or more, based on the total constituent monomers of the high molecular weight (meth) acrylic polymer. The upper limit is 100 mass% or less, may be 90 mass% or less, may be 80 mass% or less, and may be 50 mass% or less.

The high molecular weight (meth) acrylic polymer has a reactive silyl group in the molecule. Therefore, a cured product obtained from the curable composition containing the high molecular weight (meth) acrylic polymer exhibits good mechanical properties. The type of the reactive silyl group is not particularly limited, and examples thereof include an alkoxysilyl group, a halosilyl group, and a silanol group, and the alkoxysilyl group is preferable from the viewpoint of easiness of control of the reactivity. Specific examples of the alkoxysilyl group include: trialkoxysilyl groups such as trimethoxysilyl, triethoxysilyl, dimethoxyethoxysilyl and methoxydiethoxysilyl; dialkoxysilyl groups such as methyldimethoxysilyl group, methyldiethoxysilyl group, ethyldimethoxysilyl group and ethyldiethoxysilyl group; monoalkoxysilyl groups such as dimethylmethoxysilyl, dimethylethoxysilyl, diethylmethoxysilyl and diethylethoxysilyl. Among them, a dialkoxysilyl group is preferable in that the cured product exhibits good elongation and is excellent in heat resistance stability.

From the viewpoint of tensile strength of the cured product, the average number of reactive silyl groups contained in a 1-molecule high-molecular-weight (meth) acrylic polymer is preferably 0.1 or more, more preferably 0.2 or more, and still more preferably 0.3 or more. The average number of reactive silyl groups may be 0.5 or more, 0.8 or more, or 1.0 or more. From the viewpoint of ensuring the elongation of the cured product, the upper limit value is preferably 5.0 pieces or less, more preferably 4.0 pieces or less, further preferably 3.0 pieces or less, further preferably 2.5 pieces or less, and further preferably 2.2 pieces or less. The range of the average value of the number of reactive silyl groups may be set by combining the above upper limit and lower limit, and is, for example, 0.1 or more and 5.0 or less, may be 0.1 or more and 3.0 or less, may be 0.1 or more and 2.2 or less, and may be 0.2 or more and 2.2 or less.

The position of the reactive silyl group is not particularly limited, and may be a side chain and/or a terminal of the polymer.

As the vinyl monomer having a reactive silyl group, the same compounds as those described in the description of the low molecular weight (meth) acrylic polymer can be used.

The high molecular weight (meth) acrylic polymer may be copolymerized with other monomers copolymerizable with them in addition to the above-mentioned monomers.

Examples of the other monomers include: the same compounds as those described in the description of the low molecular weight (meth) acrylic polymer; and alkoxyalkyl (meth) acrylates such as methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, methoxyhexyl (meth) acrylate, ethoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethoxybutyl (meth) acrylate, ethoxyhexyl (meth) acrylate, butoxymethyl (meth) acrylate, butoxyethyl (meth) acrylate, butoxybutyl (meth) acrylate, and butoxyhexyl (meth) acrylate, but are not limited to these monomers. In addition, one or two or more of them may be used.

From the viewpoint of strength and weather resistance of the cured product, the weight average molecular weight (Mw) of the high molecular weight (meth) acrylic polymer is 10,000 or more, preferably 11,000 or more, more preferably 15,000 or more, further preferably 20,000 or more, and further preferably 25,000 or more in terms of molecular weight in terms of polystyrene based on gel permeation chromatography (hereinafter also referred to as "GPC"). The Mw may be 30,000 or more, or 40,000 or more. On the other hand, from the viewpoint of handling properties (low viscosity), the upper limit value of Mw is 100,000, preferably 90,000 or less, and more preferably 80,000 or less. The upper limit may be 70,000 or less, 60,000 or less, or 50,000 or less. The Mw range may be set in combination with the above upper and lower limits, and may be, for example, 10,000 to 100,000, 10,000 to 80,000, 10,000 to 50,000, or 15,000 to 50,000.

The molecular weight distribution of the high molecular weight (meth) acrylic polymer is calculated as a value (Mw/Mn) obtained by dividing a weight average molecular weight (Mw) by a number average molecular weight (Mn). From the viewpoint of the balance between tensile properties and workability, Mw/Mn is preferably 6.0 or less, more preferably 5.0 or less, further preferably 4.0 or less, further preferably 3.0 or less, and further preferably 2.0 or less. The lower limit of Mw/Mn is usually 1.0.

The viscosity of the high-molecular-weight (meth) acrylic polymer is preferably 300,000 mPas or less, more preferably 200,000 mPas or less, still more preferably 100,000 mPas or less, yet more preferably 80,000 mPas or less, yet more preferably 60,000 mPas or less, and most preferably 40,000 mPas or less at 25 ℃. A viscosity of 200,000 mPas or less is preferred because the workability of the curable composition is good. The lower limit of the viscosity may be 5,000 mPas or more, may be 10,000 mPas or more, and may be 20,000 mPas.

In the present invention, the high molecular weight (meth) acrylic polymer may have a double bond in the molecule. When the compound has a double bond in the molecule, the weather resistance of the resulting cured product tends to be improved, which is preferable. The double bond can be introduced by the same method as in the case of the low molecular weight (meth) acrylic polymer.

From the viewpoint of the effect on weather resistance, the amount of double bonds contained in the high molecular weight (meth) acrylic polymer is preferably 0.01meq/g or more, more preferably 0.03meq/g or more, and still more preferably 0.05meq/g or more. On the other hand, the amount of the double bond is preferably 1.0meq/g or less, more preferably 0.50meq/g or less, and still more preferably 0.30meq/g or less, from the viewpoint of weather resistance. The range of the amount of the double bond may be set by combining the above upper limit value and lower limit value, and may be, for example, 0.01meq/g or more and 1.0meq/g or less, 0.05meq/g or more and 1.0meq/g or less, or 0.10meq/g or more and 0.50meq/g or less.

The high molecular weight (meth) acrylic polymer can be produced by a general radical polymerization in the same manner as the low molecular weight (meth) acrylic polymer. Any of solution polymerization, bulk polymerization and dispersion polymerization may be used, and living radical polymerization may also be used. The reaction process may be any of batch, semi-batch, and continuous polymerization. Among them, a high-temperature continuous polymerization method at 100 to 350 ℃ is preferable.

When the living radical polymerization method is used, the kind thereof is not particularly limited, and various polymerization methods such as a reversible addition-fragmentation chain transfer polymerization method (RAFT method), a nitroxide radical method (NMP method), an atom transfer radical polymerization method (ATRP method), a polymerization method using an organotellurium compound (TERP method), a polymerization method using an organoantimony compound (SBRP method), a polymerization method using an organobismuth compound (BIRP method), and an iodine transfer polymerization method can be used. Among them, the RAFT method, NMP method and ATRP method are preferable from the viewpoint of controllability of polymerization and easiness of implementation.

In the RAFT method, polymerization controlled via a reversible chain transfer reaction is carried out in the presence of a specific polymerization controller (RAFT agent) and a general radical polymerization initiator. As the RAFT agent, various known RAFT agents such as dithioester compounds, xanthate compounds, trithiocarbonate compounds, and dithiocarbamate compounds can be used.

The RAFT agent may be a monofunctional RAFT agent having an active site at only one site, or a bifunctional or higher RAFT agent may be used. The amount of the RAFT agent to be used is appropriately adjusted depending on the monomer to be used, the kind of the RAFT agent, and the like.

As the polymerization initiator used in the polymerization by the RAFT method, a known radical polymerization initiator such as an azo compound, an organic peroxide, or a persulfate can be used, but an azo compound is preferable in terms of safety, ease of handling, and difficulty in causing side reactions in the radical polymerization.

Specific examples of the azo compound include 2,2 '-azobisisobutyronitrile, 2' -azobis (2, 4-dimethylvaleronitrile), 2 '-azobis (4-methoxy-2, 4-dimethylvaleronitrile), methyl 2, 2' -azobis (2-methylpropionate), 2 '-azobis (2-methylbutyronitrile), 1' -azobis (cyclohexane-1-carbonitrile), 2 '-azobis [ N- (2-propenyl) -2-methylpropionamide ], 2' -azobis (N-butyl-2-methylpropionamide), and the like.

The radical polymerization initiator may be used alone or in combination of two or more.

The ratio of the radical polymerization initiator to be used is not particularly limited, and the amount of the radical polymerization initiator to be used is preferably 0.5mol or less, more preferably 0.2mol or less based on 1mol of the RAFT agent, from the viewpoint of obtaining a polymer having a smaller molecular weight distribution. From the viewpoint of stably performing the polymerization reaction, the lower limit of the amount of the radical polymerization initiator used is 0.01mol per 1mol of the RAFT agent. Therefore, the amount of the radical polymerization initiator used is preferably in the range of 0.01mol or more and 0.5mol or less, and more preferably in the range of 0.05mol or more and 0.2mol or less, based on 1mol of the RAFT agent.

The reaction temperature in the polymerization reaction by the RAFT method is preferably 40 ℃ or more and 100 ℃ or less, more preferably 45 ℃ or more and 90 ℃ or less, and still more preferably 50 ℃ or more and 80 ℃ or less. When the reaction temperature is 40 ℃ or higher, the polymerization reaction proceeds smoothly. On the other hand, if the reaction temperature is 100 ℃ or lower, side reactions can be suppressed, and restrictions on initiators and solvents that can be used are alleviated.

In the NMP method, polymerization is performed via nitroxide radicals derived from a specific alkoxyamine compound or the like having nitroxide radicals (nitroxides) as a living radical polymerization initiator. In the present disclosure, the type of the nitroxide radical used is not particularly limited, but from the viewpoint of polymerization controllability when polymerizing a monomer containing an acrylate, a compound represented by general formula (2) is preferably used as the nitroxide radical compound.

[ solution 2]

{ formula (II) wherein R¹Is an alkyl group having 1 to 2 carbon atoms or a hydrogen atom, R²Is an alkyl group having 1 to 2 carbon atomsOr a nitrile group, R³Is- (CH)₂) m-, m is 0to 2, R⁴、R⁵Is an alkyl group having 1 to 4 carbon atoms }

The nitroxide radical compound represented by the general formula (2) is once dissociated by heating at about 70 to 80 ℃ and undergoes an addition reaction with a vinyl monomer. In this case, a polyfunctional polymerization precursor can be obtained by adding a nitroxide compound to a vinyl monomer having two or more vinyl groups. Then, the vinyl monomer can be living-polymerized by secondarily dissociating the polymerization precursor under heating.

The amount of the nitroxyl radical compound to be used is appropriately adjusted depending on the monomer to be used, the kind of the nitroxyl radical compound, and the like.

In the case of producing a high molecular weight (meth) acrylic polymer by the NMP method, it is possible to polymerize the nitroxide radical represented by the general formula (3) in an amount of 0.001 to 0.2mol based on 1mol of the nitroxide radical compound represented by the general formula (2).

[ solution 3]

{ formula (II) wherein R⁴、R⁵Is an alkyl group having 1 to 4 carbon atoms. }

By adding 0.001mol or more of the nitroxide radical represented by the above general formula (3), the time until the concentration of the nitroxide radical reaches a steady state is shortened. This enables polymerization to be controlled more highly, and a polymer having a narrower molecular weight distribution can be obtained. On the other hand, if the amount of the nitroxide radical added is too large, polymerization may not proceed. The amount of the nitroxide is more preferably in the range of 0.01 to 0.5mol, and still more preferably in the range of 0.05 to 0.2mol, based on 1mol of the nitroxide compound.

The reaction temperature in the NMP method is preferably 50 ℃ to 140 ℃, more preferably 60 ℃ to 130 ℃, further preferably 70 ℃ to 120 ℃, and particularly preferably 80 ℃ to 120 ℃. When the reaction temperature is 50 ℃ or higher, the polymerization reaction can be smoothly carried out. On the other hand, if the reaction temperature is 140 ℃ or lower, side reactions such as radical chain transfer tend to be suppressed.

In the ATRP method, an organic halide is generally used as an initiator, and a transition metal complex is used as a catalyst to perform polymerization. The organic halide used as the initiator may be a monofunctional organic halide, or may be a bifunctional or higher organic halide. The halogen is preferably a bromide or a chloride.

The reaction temperature in the ATRP method is preferably 20 ℃ to 200 ℃, more preferably 50 ℃ to 150 ℃. When the reaction temperature is 20 ℃ or higher, the polymerization reaction can be smoothly carried out.

The living radical polymerization can be carried out in the presence of a known chain transfer agent.

In addition, a known polymerization solvent can be used in living radical polymerization. Specifically, there may be mentioned: aromatic compounds such as benzene, toluene, xylene, and anisole; ester compounds such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; ketone compounds such as acetone and methyl ethyl ketone; dimethylformamide, acetonitrile, dimethyl sulfoxide, alcohol, water, and the like. Further, bulk polymerization or the like may be carried out without using a polymerization solvent.

< (C) component: oxyalkylene polymer having reactive silyl group

The oxyalkylene polymer having a reactive silyl group is not particularly limited as long as it is a compound containing a repeating unit represented by the following general formula (4).

-O-R²- (4)

(wherein R is²Is a 2-valent hydrocarbon group. )

As R in the above general formula (1)²The following groups can be exemplified.

(CH₂) n (n is an integer of 1 to 10)

CH(CH₃)CH₂

CH(C₂H₅)CH₂

C(CH₃)₂CH₂

The oxyalkylene polymer may contain one kind of the repeating unit or two or more kinds of the repeating units in combination. Among them, CH (CH) is preferable from the viewpoint of excellent workability₃)CH₂。

The reactive silyl group contained in the reactive silyl group-containing oxyalkylene polymer is not particularly limited, and examples thereof include an alkoxysilyl group, a halogenosilyl group, a silanol group and the like, but an alkoxysilyl group is preferable from the viewpoint of easiness of control of reactivity. Specific examples of the alkoxysilyl group include trimethoxysilyl group, methyldimethoxysilyl group, dimethylmethoxysilyl group, triethoxysilyl group, methyldiethoxysilyl group, and dimethylethoxysilyl group.

The method for producing the oxyalkylene polymer is not particularly limited, and examples thereof include a polymerization method using a base catalyst such as KOH using a corresponding epoxy compound or diol as a raw material, a polymerization method using a transition metal compound-porphyrin complex catalyst, a polymerization method using a composite metal cyanide complex catalyst, and a polymerization method using phosphazene.

The oxyalkylene polymer may be either a linear polymer or a branched polymer. Further, they may be used in combination.

The average number of reactive silyl groups contained in the 1-molecule oxyalkylene polymer is preferably in the range of 1 to 4, more preferably in the range of 1.5 to 3, from the viewpoint of the properties such as adhesiveness and tensile properties of the cured product.

The position of the reactive silyl group contained in the oxyalkylene polymer is not particularly limited, and may be a side chain and/or a terminal of the polymer.

From the viewpoint of mechanical properties, the number average molecular weight (Mn) of the oxyalkylene polymer having a reactive silyl group is preferably 5,000 or more, more preferably 10,000 or more, and further preferably 15,000 or more. The Mn may be 18,000 or more, 22,000 or more, and 25,000 or more. From the viewpoint of workability (viscosity) at the time of coating of the curable composition, the upper limit value of Mn is preferably 60,000 or less, more preferably 50,000 or less, and further preferably 40,000 or less. The range of Mn may be set in combination with the above upper and lower limits, and may be, for example, 5,000 to 60,000, 15,000 to 60,000, 18,000 to 50,000, or 22,000 to 50,000.

As the oxyalkylene polymer having a reactive silyl group, a commercially available product can be used. Specific examples thereof include: "MS Polymer S203", "MS Polymer S303", "MS Polymer S810", "Silyl SAT 200", "Silyl SAT 350", "Silyl EST 280" and "Silyl SAT 30", manufactured by KANEKA, Inc.; and Asahi glass company "EXCESTAR S2410", "EXCESTAR S2420" and "EXCESTAR S3430" (trade names).

< curable composition >

As described above, the curable composition of the present invention contains the components (a) and (B) as essential components. The ratio ((A)/(B)) of the component (A) to the component (B) is preferably 10to 90/90 to 10, more preferably 30 to 70/70 to 30, in terms of mass ratio, from the viewpoint of improving the weather resistance and mechanical properties of the resulting cured product.

The amount of the double bond contained in the curable composition is preferably 0.01meq/g or more, more preferably 0.05meq/g or more from the viewpoint of weather resistance. The amount of the double bond may be 0.10meq/g or more, or 0.15meq/g or more. On the other hand, if the amount of double bonds is too large, the degree of crosslinking of the cured product becomes too high during exposure and the flexibility becomes insufficient, so that cracks tend to be easily generated. Therefore, the amount of double bonds is preferably 1.0meq/g or less, more preferably 0.80meq/g or less, still more preferably 0.60meq/g or less, yet more preferably 0.50meq/g or less, and still more preferably 0.40meq/g or less. The amount of the double bond may be set in combination with the above upper limit and lower limit, and may be, for example, 0.01meq/g or more and 1.0meq/g or less, 0.01meq/g or more and 0.5.0meq/g or less, or 0.05meq/g or more and 0.50meq/g or less.

The curable composition of the present invention may contain components other than the component (a) and the component (B) as long as the effects exerted by the present invention are not impaired. The component includes a filler, a plasticizer, an antiaging agent, a curing accelerator, a releasing agent, an adhesion imparting agent and the like.

Examples of the filler include light calcium carbonate having an average particle size of about 0.02 to 2.0 μm, heavy calcium carbonate having an average particle size of about 1.0 to 5.0 μm, titanium oxide, carbon black, synthetic silicic acid, talc, zeolite, mica, silica, calcined clay, kaolin, bentonite, aluminum hydroxide and barium sulfate, glass microspheres, silica microspheres, and polymethyl methacrylate microspheres. These fillers can improve the mechanical properties of the cured product and can improve the strength and elongation.

Among them, light calcium carbonate, heavy calcium carbonate and titanium oxide having a high effect of improving physical properties are preferable, and a mixture of light calcium carbonate and heavy calcium carbonate is more preferable. The amount of the filler added is preferably 20 to 300 parts by mass, more preferably 50 to 200 parts by mass, based on 100 parts by mass of the total amount of the components (A) and (B). When the mixture of the light calcium carbonate and the heavy calcium carbonate is prepared as described above, the weight ratio of the light calcium carbonate/the heavy calcium carbonate is preferably in the range of 90/10 to 50/50.

Examples of the plasticizer include: a liquid polyurethane resin, a polyester plasticizer obtained from a dicarboxylic acid and a diol; etherified or esterified polyalkylene glycols such as polyethylene glycol and polypropylene glycol; polyether plasticizers such as saccharide polyethers obtained by addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide to saccharide polyols such as sucrose and subsequent etherification or esterification; polystyrene plasticizers such as poly-alpha-methylstyrene; poly (meth) acrylates having no crosslinkable functional group, and the like. Among these, poly (meth) acrylates having no crosslinkable functional group are preferable in terms of durability such as weather resistance of the cured product. Among them, poly (meth) acrylates having Mw in the range of 1,000 to 7,000 and having a glass transition temperature of-30 ℃ or lower and no crosslinkable functional group are more preferable.

When the total amount of the components (a) and (B) is 100 parts by mass, the amount of the plasticizer used in the curable composition is preferably in the range of 0to 100 parts by mass, may be in the range of 0to 80 parts by mass, and may be in the range of 0to 50 parts by mass.

As the age resister, there can be used: ultraviolet absorbers such as benzophenone-based compounds, benzotriazole-based compounds and oxanilide-based compounds; light stabilizers such as hindered amine compounds; antioxidants such as hindered phenol type antioxidants; a heat stabilizer; or an anti-aging agent as a mixture thereof.

Examples of the ultraviolet absorber include those sold under the trade names "Tinuvin 571", "Tinuvin 1130" and "Tinuvin 327" manufactured by BASF corporation. Examples of the light stabilizer include: trade names "Tinuvin 292", "Tinuvin 144", "Tinuvin 123" manufactured by BASF corporation; trade name "Sanol 770" manufactured by Sanko Co. Examples of the heat stabilizer include those sold under the trade names "Irganox 1135", "Irganox 1520", and "Irganox 1330" manufactured by BASF corporation. The product "Tinuvin B75" manufactured by BASF corporation, which is a mixture of an ultraviolet absorber, a light stabilizer and a heat stabilizer, may also be used.

As the curing accelerator, known compounds such as tin-based catalysts, titanium-based catalysts, tertiary amines, and the like can be used.

Examples of the tin-based catalyst include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dipropionate, and dioctyltin dilaurate. Specifically, the trade names "NEOSTANN U-28", "NEOSTANN U-100", "NEOSTANN U-200", "NEOSTANN U-220H", "NEOSTANN U-303", and "SCAT-24" manufactured by Nissanghua corporation may be exemplified.

Examples of the titanium-based catalyst include tetraisopropyl titanate, tetra-n-butyl titanate, titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetylacetonate, titanium dibutoxybisacetylacetonate, titanium diisopropoxybutylacetate, titanium octyleneglycolate (titanium octylene glycol), and titanium lactate.

Examples of the tertiary amines include triethylamine, tributylamine, triethylenediamine, hexamethylenetetramine, 1, 8-diazabicyclo [ 5,4,0 ] undec-7 (DBU), Diazabicyclononene (DBN), N-methylmorpholine and N-ethylmorpholine.

The amount of the curing accelerator used is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 2 parts by mass, based on 100 parts by mass of the total of the components (A) and (B).

Examples of the release agent include: the acrylic oligomer is available under the trade names "ARONIX M8030", "M8100", "M309", manufactured by east asia synthesis company, or a mixture thereof with a photopolymerization initiator; saturated fatty acid oils such as tung oil and linseed oil; trade name "R15 HT" manufactured by gloss oil corporation; trade name "PBB 3000" manufactured by Nippon Caoda corporation; a trade name "Gohselac 500B" manufactured by Nippon synthetic chemical Co., Ltd.

Examples of the adhesion-imparting agent include aminosilanes such as trade names "KBM 602", "KBM 603", "KBE 602", "KBE 603", "KBM 902" and "KBM 903" manufactured by shinylen silicone corporation.

In addition, a dehydrating agent such as methyl orthoformate, methyl orthoacetate, or vinyl silane, an organic solvent, or the like may be added.

The curable composition of the present invention may be prepared as a one-pack type composition in which all the components are mixed in advance, and the composition is stored in a sealed state and cured by absorbing moisture in the air after application. In addition, a two-component type in which a curing catalyst, a filler, a plasticizer, water and other components separately added as a curing agent are blended in advance and the blended materials and the polymerization composition are mixed before use may be adjusted. More preferably, the one-pack type is easy to handle and has less mixing errors during coating.

The curable composition of the present invention is cured at room temperature to obtain a cured product having excellent weather resistance and mechanical properties. Therefore, it can be suitably used as a sealing material composition which requires high durability. The sealant composition of the present invention contains the curable composition and, if necessary, other components are blended according to a conventional method.

The curable composition can be suitably used for adhesives. In the field of adhesives for building materials, it is required to ensure high weather resistance and high durability for 10 years or longer, and the adhesive composition of the present invention can satisfy this requirement. In particular, in tile bonding of an outer wall, it is required to maintain appearance and adhesiveness for a long period of time, and the requirements can be met. The adhesive composition of the present invention contains the above curable composition, and if necessary, other components are blended according to a conventional method.

The adhesive composition of the present invention may be an adhesive composition to which an epoxy resin is added. Examples of the epoxy resin include epichlorohydrin-bisphenol a type epoxy resins, epichlorohydrin-bisphenol F type epoxy resins, phenol novolac type epoxy resins, hydrogenated bisphenol a type epoxy resins, glycidyl ether type epoxy resins of bisphenol a propylene oxide adducts, glycidyl ether p-hydroxybenzoate type epoxy resins, m-aminophenol type epoxy resins, diaminodiphenylmethane type epoxy resins, urethane modified epoxy resins, various alicyclic epoxy resins, N-diglycidylaniline, N-diglycidylolotylamine, triglycidyl isocyanurate, polyalkylene glycol diglycidyl ether, hydantoin type epoxy resins, and the like. Further, flame-retardant epoxy resins such as glycidyl ether of tetrabromobisphenol a, glycidyl ethers of polyhydric alcohols such as glycerin, and epoxides of unsaturated polymers such as petroleum resin can be exemplified, but the epoxy resins are not limited thereto, and commonly used epoxy resins can be used. Among these epoxy resins, epoxy resins having at least two epoxy groups in the molecule are preferred, in particular, because they have high reactivity during curing and the cured product is likely to form a three-dimensional network. Among them, bisphenol a type epoxy resins, phenol novolac type epoxy resins, and the like are more preferable.

The epoxy resin is preferably used in an amount of 1 to 100 parts by mass based on 100 parts by mass of the total polymer (total mass of the low-molecular weight (meth) acrylic polymer (a) and the high-molecular weight (meth) acrylic polymer (B)) of the present invention. When the amount of the epoxy resin exceeds 100 parts by mass, the weather resistance may be lowered.

When an epoxy resin is used, a curing agent for the epoxy resin is preferably used in combination. Examples of the curing agent for epoxy resin include: primary amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, diethylaminopropylamine, N-aminoethylpiperazine, isophoronediamine, diaminodicyclohexylmethane, m-xylylenediamine, m-phenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone; (CH)₃)₂N(CH₂)_nN(CH₃)₂(wherein n is an integer of 1 to 10) or a linear diamine (CH)₃)₂-N(CH₂)_n-CH₃A linear tertiary amine, tetramethylguanidine, and N { (CH) (wherein N is an integer of 0to 10)₂)nCH₃}₃(wherein N is an integer of 1 to 10), alkyl tertiary amine, triethanolamine, piperidine, N' -dimethylpiperazine, triethylenediamine, pyridine, picoline, diazabicycloundecene, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4, 6-tris (dimethylaminomethyl) phenol, Lamiron C-260 manufactured by BASF corporation, Araldit HY-964 manufactured by CIBA corporation, and Rohm&Secondary or tertiary amines such as menthane diamine (menthane diamine) manufactured by Haas corporation; ketimines such as 1, 2-ethylenebis (isoamylene amine), 1, 2-hexylenebis (isoamylene amine), 1, 2-propylenebis (isoamylene amine), p' -biphenylylenebis (isoamylene amine), 1, 2-ethylenebis (isopropylene amine), 1, 3-propylenebis (isopropylene amine), and p-phenylenebis (isoamylene amine); anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenone tetracarboxylic anhydride; various polyamide resins; dicyandiamide and derivatives thereof; and various imidazoles and the like. The amount of the curing agent to be used is preferably 5 to 100 parts by mass per 100 parts by mass of the epoxy resin.

Since the adhesive composition provided by the present invention has a reactive silyl group, when the epoxy resin is used in combination, the strength of the cured adhesive composition can be improved by adding a compound having a group capable of reacting with both the reactive silyl group and the epoxy group. Specific examples of the compound having a group capable of reacting with both a reactive silyl group and an epoxy group include N- (β -aminoethyl) - γ -aminopropyltrimethoxysilane, N- (β -aminoethyl) - γ -aminopropylmethyldimethoxysilane, N- (β -aminoethyl) - γ -aminopropyltriethoxysilane, γ -aminopropyltrimethoxysilane and γ -aminopropyltriethoxysilane.

The adhesive composition provided by the invention contains the curable composition. Therefore, the effect of the curable composition can be exhibited in the application of the adhesive, and the adhesion to the top-coat paint can be improved. In particular, the effect of the curable composition can be exhibited to a high degree in an exterior tile adhesive.

Examples

The present invention will be specifically described below based on examples. The present invention is not limited to these examples. In the following, unless otherwise specified, "parts" and "%" mean parts by mass and% by mass.

The methods for analyzing the polymers obtained in the production examples, examples and comparative examples and the method for evaluating the cured product obtained from the curable composition are described below.

< method for quantifying double bond amount >

By passing¹The H-NMR measurement is based on the ratio of the integrated value of the signal from hydrogen bonded to a double bond in the vicinity of 5.5ppm to the integrated value of the signal from hydrogen bonded to a carbon adjacent to an ester group in the range of 3.0 to 4.5ppm, the composition of the polymer, and the double bond concentration per unit mass of the polymer.

< determination of molecular weight >

The number average molecular weight (Mn) and the weight average molecular weight (Mw) were obtained in terms of polystyrene using a gel permeation chromatography apparatus (type name "HLC-8320", manufactured by Tosoh corporation) under the following conditions. From the obtained values, the molecular weight distribution (Mw/Mn) was calculated.

Measurement conditions

A chromatographic column: TSKgel SuperMultiporeHZ-Mx 4 root, made by Tosoh

Column temperature: 40 deg.C

Eluent: tetrahydrofuran (THF)

A detector: RI (Ri)

<theaverage number of reactive silyl groups contained in a (meth) acrylic polymer

The number (average number) f (si) of alkoxysilyl groups as reactive silyl groups was calculated from the mass parts of the monomer having reactive silyl groups, assuming that all the constituent monomers were 100 mass parts, using the following formula.

(si) ((silyl monomer mass part/(silyl monomer molecular weight × 100/Mn) }

Viscosity of (meth) acrylic polymer

The E-type viscosity was measured under the following conditions using a TVE-20H-type viscometer (salt water/plate system, manufactured by Toyobo industries Co., Ltd.).

Measurement conditions

The shape of the cone is as follows: angle 1 degree 34', radius 24mm (less than 10000 mPa. s)

Angle 3 °, radius 7.7mm (10000mPa s or more)

Temperature: 25 ℃ plus or minus 0.5 DEG C

< weather resistance test (1) >

Each curable composition was applied to a Teflon (registered trademark) sheet at a thickness of 2mm, and cured at 23 ℃ and 50% RH for 1 week to prepare a cured sheet. The resulting cured product was put into a metal tube Weather resisting apparatus (DAIPLA METAL WEATHER KU-R5NCI-A, manufactured by DAIPLA WINTES Co.) to carry out a Weather resistance acceleration test. The conditions were 63 ℃ irradiation, 70% RH irradiation and 80mW/cm illuminance²The test was carried out with 2 hour 1-time and 2 minute shower (shower) each. The time at which the appearance started to develop abnormalities such as cracking, bleeding, etc. was recorded.

< weather resistance test (2) >

Each curable composition was applied to a Teflon (registered trademark) sheet in a thickness of 2mm, and cured at 23 ℃ and 50% RH for 1 week to prepare a cured sheet. The resulting cured product was put into a weather resistant metal lamp (product of DAIPLA WINTES, DAIPLA METAL WEATHER KU-R5 NCI-A) and subjected to accelerated weather resistance test. The conditions were 63 ℃ irradiation, 70% RH irradiation and 80mW/cm illuminance²The test was carried out 2 hours 1 time for 1000 hours with 2 minutes showers each time. After 1000 hours, the surface state was visually checked (presence or absence of cracks), and the color difference (Δ E) was obtained by a color difference meter (spectrocolorimeter SE-2000, manufactured by japan electric colorimeter) to evaluate the weather resistance from the degree of color fading. The color difference (. DELTA.E) is determined by the luminance (L) measured by a spectrocolorimeter^＊) Chromaticity in the red-green direction (a)^＊) And chromaticity in the yellow-blue direction (b)^＊) The value of (b) is obtained by substituting the following equation.

[ number 1]

L after 1000 hours^＊

Initial L^＊

A after 1000 hours^＊

Initial a^＊

100B after 0 hours^＊

Initial b^＊

< tensile test >

Each of the curable compositions was applied to a Teflon (registered trademark) sheet in a thickness of 2mm, and cured at 23 ℃ and 50% RH for 1 week to prepare a cured sheet. A tensile test dumbbell (JIS K62513 type) was prepared from the resulting cured product, and the elongation at break and the strength at break were measured at a tensile rate of 200 mm/min using a tensile tester (automatic plotter AGS-J, Shimadzu corporation).

< adhesion Strength test >

The test was carried out using a mortar board and an exterior mosaic tile according to JIS a5557(2006) method for testing the adhesion strength of an organic adhesive for exterior tile adhesion.

An adhesive was applied to a mortar board (TP technical standard, 10X 50mm) to a thickness of about 5mm, and after the adhesive was combed with a comb trowel, a commercially available exterior mosaic tile (45X 45mm) suitable for the specification of JIS A5209 was bonded. After curing the mixture at 23 ℃ and 50% RH for 4 weeks, a special jig was attached to the tile side and the mortar side, and a tensile test was performed at 23 ℃ and a tensile rate of 3 mm/min using a tensile tester (AGS-J, Shimadzu corporation), thereby measuring the adhesive strength.

Component (A): production of Low molecular weight (meth) acrylic Polymer

Synthesis example 1 (production of (meth) acrylic Polymer A-1)

Polymerization step

The temperature of a pressurized stirred tank reactor having a capacity of 1000mL and equipped with an oil jacket (oil jack) was maintained at 265 ℃. Then, while the pressure in the reactor was kept constant, a monomer mixture comprising 10 parts of tetradecyl acrylate (hereinafter referred to as "TDA"), 70 parts of 2-ethylhexyl acrylate (hereinafter referred to as "HA"), 20 parts of methyl methacrylate (hereinafter referred to as "MMA"), 20 parts of methyl ethyl ketone (hereinafter referred to as "MEK") as a solvent, and 0.2 parts of di-tert-butyl peroxide (daily oil preparation, trade name "perbutylD", hereinafter referred to as "DTBP") as a polymerization initiator was continuously supplied from a raw material tank to the reactor at a constant supply rate (48 g/min, residence time: 12 min), and a reaction liquid corresponding to the supply amount of the monomer mixture was continuously withdrawn from an outlet. Immediately after the start of the reaction, the reaction temperature is temporarily lowered, and then a temperature rise due to the heat of polymerization is confirmed, and the reaction temperature is maintained at 264 to 266 ℃ by controlling the temperature of the oil jacket.

The reaction was continued for 25 minutes after the start of the supply of the monomer mixture and the stabilization of the temperature, and as a result, 1.2kg of the monomer mixture was supplied and 1.2kg of the reaction mixture was recovered. Thereafter, the reaction solution was introduced into a thin film evaporator, and volatile components such as unreacted monomers were separated to obtain a concentrated solution.

O post-treatment step

Then, 100 parts by weight of the concentrated solution obtained in the polymerization step was added to the flask after the replacement with nitrogen, and the mixture was heated and stirred until the liquid temperature reached 90 ℃ while nitrogen gas was passed therethrough. When the temperature reached 90 ℃, 0.5 part of tert-butyl peroxy-2-ethylhexanoate (product name "PERHEXYL O" manufactured by Nichigan oil Co., Ltd.) was added as a radical generator, and the mixture was stirred for 16 hours while being maintained at 90 ℃ to obtain a (meth) acrylic polymer A-1. The properties of the polymer are shown in Table 1.

Synthesis examples 2 to 4 (production of (meth) acrylic polymers A-2 to A-4)

(meth) acrylic polymers A-2 to A-4 were obtained in the same manner as in Synthesis example 1, except that the amount of the radical generator (PERHEXYL O) added and the treatment conditions in the post-treatment step were changed as shown in Table 1 using the concentrated solution obtained after the polymerization step in Synthesis example 1. The properties of each polymer are shown in table 1.

Synthesis examples 5 to 10 (production of (meth) acrylic polymers A-5 to A-10)

(meth) acrylic polymers A-5 to A-10 were obtained in the same manner as in Synthesis example 1, except that the raw materials and reactor internal temperature used in the polymerization step, and the amount of the radical generator (PERHEXYL O) added and the treatment conditions used in the post-treatment step were changed as shown in Table 1. In addition, in synthetic example 10 ((meth) acrylic polymer a-10), post-treatment of the concentrated solution obtained after the polymerization step was not performed. The properties of each polymer are shown in table 1.

Synthesis example 11 (production of (meth) acrylic Polymer A-11)

Butyl acetate (150 parts) was added to a flask equipped with a reflux condenser, and the internal temperature was maintained at 94 ℃ in an oil bath, followed by stirring. A mixture of HA (80 parts), TDA (10 parts), MMA (10 parts) and ABN-E (8 parts) was added dropwise over 4 hours from a dropping funnel. The mixture was stirred for 2 hours while maintaining the temperature at 94 ℃. Thereafter, the reaction mixture was desolventized at 90 ℃ and 10mmHg by an evaporator to separate volatile components, thereby obtaining a (meth) acrylic polymer A-11. The properties of the polymer are shown in Table 1.

[ Table 1]

Component (B): production of high molecular weight (meth) acrylic Polymer

Synthesis example 12 (production of (meth) acrylic Polymer B-1)

O. polymerization Process

The temperature of a pressurized stirring tank type reactor having a capacity of 1000mL and equipped with an oil jacket was maintained at 184 ℃. Then, while keeping the reactor pressure constant, 2.8 parts of 3-methacryloxypropyldimethoxysilane (trade name "Z6033", hereinafter referred to as "DMS", manufactured by Toray-Dow Corning Co., Ltd.), 10 parts of TDA, 20 parts of HA, 60.2 parts of n-butyl acrylate (hereinafter referred to as "BA"), 7 parts of MMA, a monomer mixture comprising 10 parts of isopropyl alcohol (hereinafter referred to as "IPA"), 5 parts of trimethyl orthoacetate (hereinafter referred to as "MOA"), 5 parts of MEK, and 0.1 part of di-t-hexylperoxide (trade name "PERHEXYL H", hereinafter referred to as "DTHP") as a polymerization initiator was continuously supplied from a stock tank to a reactor at a constant supply rate (48 g/min, residence time: 12 min), and a reaction liquid corresponding to the amount of the monomer mixture supplied was continuously withdrawn from an outlet. Immediately after the start of the reaction, the reaction temperature was temporarily lowered, and then a temperature rise due to the heat of polymerization was observed, and the reaction temperature was maintained at 264 to 266 ℃ by controlling the temperature of the oil jacket.

The reaction was continued for 25 minutes after the start of the supply of the monomer mixture and the temperature was stabilized, and as a result, 1.2kg of the monomer mixture was supplied and 1.2kg of the reaction mixture was recovered. Thereafter, the reaction solution was introduced into a thin film evaporator, and volatile components such as unreacted monomers were separated to obtain a concentrated solution.

O post-treatment step

(meth) acrylic polymer B-1 was obtained in the same manner as in Synthesis example 1, except that the kind and amount of the radical generating agent and the treatment conditions in the post-treatment step were changed as shown in Table 2 using the concentrated solution obtained after the polymerization step. The properties of the polymer are shown in Table 2.

Synthesis examples 13 to 22 and 24 (production of (meth) acrylic polymers B-2 to B-11 and B-13)

(meth) acrylic polymers B-2 to B-11 and B-13 were obtained in the same manner as in Synthesis example 12, except that the raw materials and reactor internal temperature used in the polymerization step, the type and amount of the radical generator used in the post-treatment step, and the treatment conditions were set as shown in tables 2 and 3. In addition, in Synthesis example 18 ((meth) acrylic polymer B-7), post-treatment of the concentrated solution obtained after the polymerization step was not performed. The properties of each polymer are shown in tables 2 and 3.

Synthesis example 23 (production of (meth) acrylic Polymer B-12)

Synthesis of RAFT agent (1, 4-bis (n-dodecylmercaptothiocarbonylthio methyl) benzene)

1-dodecylmercaptan (42.2g), a 20% KOH aqueous solution (63.8g), and trioctylmethylammonium chloride (1.5g) were charged into an eggplant-type flask, and the mixture was cooled in an ice bath, carbon disulfide (15.9g) and tetrahydrofuran (hereinafter referred to as "THF") (38ml) were added thereto, and the mixture was stirred for 20 minutes. A THF solution (170ml) of α, α' -dichloro-p-xylene (16.6g) was added dropwise over 30 minutes. After allowing to react at room temperature for 1 hour, the mixture was extracted from chloroform, washed with pure water, dried over anhydrous sodium sulfate, and concentrated on a rotary evaporator. The obtained crude product was purified by column chromatography and then recrystallized from ethyl acetate, whereby 1, 4-bis (n-dodecylmercaptothiocarbonylthiomethyl) benzene (hereinafter also referred to as "DLBTTC") represented by the following formula (5) was obtained in a yield of 80%. By¹Peaks of the target substance were observed at 7.2ppm, 4.6ppm and 3.4ppm by H-NMR measurement.

[ solution 4]

Production of high molecular weight (meth) acrylic Polymer

Into a 1L flask equipped with a stirrer and a thermometer were charged RAFT agent (DLBTTC) (9.13g) obtained in the above 1, 2' -azobis (2-methylbutyronitrile) (hereinafter referred to as "ABN-E") (0.53g), BA (560g) and anisole (230g), sufficiently degassed by bubbling nitrogen gas, and polymerization was initiated while stirring in a thermostatic bath at 60 ℃. After 3 hours and 30 minutes, the reaction was cooled to room temperature and stopped. The polymerization solution was reprecipitated and purified from methanol, and vacuum-dried to obtain a polymer.

Subsequently, the polymer (320g) was charged into a 1L flask equipped with a stirrer and a thermometer, and BA (138.9g), DMS (5.3g), ABN-E (0.40g) and anisole (285g) were further charged, and the mixture was sufficiently degassed by bubbling nitrogen gas, and polymerization was initiated again while stirring in a thermostatic bath at 60 ℃. After 8 hours, the reaction was cooled to room temperature and stopped. The polymerization solution was reprecipitated and purified from methanol and dried under vacuum to obtain (meth) acrylic polymer B-12. The properties of the polymer are shown in Table 3.

[ Table 2]

[ Table 3]

The details of the compounds shown in tables 1 to 3 are as follows.

BA: acrylic acid butyl ester

HA: 2-ethylhexyl acrylate

TDA: acrylic acid tridecyl ester

MMA: methacrylic acid methyl ester

DMS: 3-methacryloxypropylmethyldimethoxysilane

TMS: 3-methacryloxypropyltrimethoxysilane

IPA: isopropanol (I-propanol)

MOA: acetic acid methyl ester

MEK: methyl ethyl ketone

BAC: acetic acid butyl ester

DTBP: di-tert-butyl peroxide

DTHP: di-tert-hexyl peroxide

ABN-E: 2, 2' -azobis (2-methylbutyronitrile)

PHO: tert-butyl peroxy-2-ethylhexanoate (product name "PERHEXYL O" manufactured by Nichio oil Co., Ltd.)

AIBN: 2, 2' -azobis (isobutyronitrile)

Preparation and evaluation of curable composition

Examples 1 to 28 and comparative examples 1 to 4

The low molecular weight (meth) acrylic polymer (component a) and the high molecular weight (meth) acrylic polymer (component B) obtained in the above synthesis examples and commercially available raw materials were mixed at the ratios shown in tables 4 to 6, and mixed for 1 hour at 60 ℃ and 10Torr using a planetary mixer, thereby obtaining a curable composition. The weather resistance test and the tensile test were performed on the cured products obtained from each composition, and the results are shown in tables 4 to 6.

[ Table 4]

[ Table 5]

[ Table 6]

The details of the compounds shown in tables 4 to 6 are as follows.

ES-S2420: modified Silicone (trade name "EXCESTAR S2420", manufactured by Asahi glass Co., Ltd.)

PPG: exenol2020 (manufactured by Asahi glass Co., Ltd.)

CCR: light calcium carbonate (trade name "Bai Yan Hua CCR" manufactured by Bai Shi Ca Co., Ltd.)

Super SS: ground calcium carbonate (Super SS, product name of pill tail calcium Co.)

R820: titanium oxide (manufactured by stone original product Co., Ltd.)

Tinuvin B75: anti-aging agent (manufactured by BASFJAPAN Co., Ltd.)

U220H: dibutyltin bisacetoacetonate (manufactured by Ridong Kasei Co., Ltd.)

Nacem Titan: titanium dibutoxybisacetylacetonate (product name "Nacem Titan" manufactured by Nippon chemical industries Co., Ltd.)

DBU: 1, 8-diazabicyclo [ 5,4,0 ] undec-7-ene

SH 6020: 3- (2-aminoethyl) aminopropyltrimethoxysilane (manufactured by DONGLI-DAOCHANG Co., Ltd.)

SZ 6030: vinyl trimethoxy silane (manufactured by Dongli-dao kang Ning Co., Ltd.)

Examples 1 to 28 are evaluations of the curable composition of the present invention, and show good weather resistance and good mechanical properties. When the ratio of the low molecular weight (meth) acrylic polymer to the high molecular weight (meth) acrylic polymer is in the range of 10/90 to 90/10, the cured product obtained has excellent weather resistance (examples 16 and 23 to 26).

In the weather resistance test and the tensile test, the workability (ease of application) was good when each curable composition was applied to a teflon (registered trademark) sheet in a thickness of 2 mm. Therefore, the curable composition provided by the present invention is excellent in weather resistance, mechanical properties, and workability, and can be suitably used as a sealing material composition.

On the other hand, in comparative example 1, the high molecular weight (meth) acrylic polymer (component B) had no reactive silyl group, and the cured product had insufficient weather resistance. In comparative examples 2 and 3, the double bond concentration of the low molecular weight (meth) acrylic polymer (component A) was outside the range specified in the present invention, and the cured product was inferior in weather resistance. In comparative example 4 containing no high molecular weight (meth) acrylic polymer as the component (B), the cured product was also insufficient in weather resistance.

Preparation and evaluation of adhesive composition

Examples 29 to 32 and comparative examples 5 to 6

The low molecular weight (meth) acrylic polymer (component a) and the high molecular weight (meth) acrylic polymer (component B) obtained in the above synthesis examples and commercially available raw materials were mixed at the ratio shown in table 7, and mixed for 1 hour at 60 ℃ and 10Torr using a planetary mixer, thereby obtaining an adhesive composition. The weather resistance test (2) and the adhesive strength test were performed on each composition, and the results are shown in table 7.

[ Table 7]

Details of the compounds shown in table 7 are shown below.

S-3430: modified organosilicon (manufactured by Asahi glass Co., Ltd.)

jER 828: epoxy resin (manufactured by Mitsubishi chemical Co., Ltd.)

jER curing H30: epoxy hardener (Mitsubishi chemical corporation)

Super SS: ground calcium carbonate (Super SS product name of pill tail calcium Co.)

# 45: carbon black (manufactured by Mitsubishi chemical Co., Ltd.)

R820: titanium oxide (manufactured by stone original product Co., Ltd.)

Tinuvin B75: anti-aging agent (manufactured by BASFJAPAN Co., Ltd.)

U220H: dibutyltin bisacetoacetonate (manufactured by Ridong Kasei Co., Ltd.)

S340: ketimine silane coupling agent Sila-Ace (JNC Co., Ltd.)

The results of the adhesion strength test show that: in examples 29 to 32 and comparative examples 5 to 6, both the strength and the broken state were not problematic, and the level was such that the adhesive could be used as an adhesive. In the weather resistance test (2), the workability (ease of application) when each curable composition was applied to a teflon (registered trademark) sheet in a thickness of 2mm was good in each of the examples and comparative examples. In the adhesion strength test, workability in each step was good in a series of bonding operations such as applying an adhesive to a mortar board to a thickness of about 5mm, scraping with a comb trowel, and bonding exterior mosaic tiles.

On the other hand, the results of the weather resistance test (2) show that: in examples 29 to 32 using adhesive compositions having a suitable amount of double bonds, there was no change in the surface state and the color difference (Δ E) was small. In contrast, it is known that: in comparative example 5 using an adhesive composition containing an excessive amount of double bonds, cracks were generated on the surface, and the weather resistance was insufficient. As one reason, it is presumed that: the reaction of the double bond proceeds more than a proper amount, and thus the flexibility of the surface and the like are lost. In addition, it can be seen that: in comparative example 6 using an adhesive composition containing too few double bonds, discoloration was significant and the weather resistance was insufficient. As one reason, it is presumed that: the increase in molecular weight due to the reaction of the double bond is insufficient, and therefore, the force for holding calcium carbonate inside the adhesive is insufficient, and the calcium carbonate is exposed on the surface of the adhesive, whereby discoloration (whitening) progresses.

From the results of the adhesive strength test and the weather resistance test (2), it is understood that the adhesive composition provided in the present invention is excellent in adhesive strength, weather resistance and workability.

Industrial applicability

The curable composition of the present invention is cured at room temperature by moisture in the atmosphere or the like, and a cured product having excellent weather resistance and mechanical properties is obtained. Further, since the resin composition has an appropriate viscosity, the workability is also excellent. Therefore, the curable composition is suitable for adhesives such as sealing materials and exterior tile adhesives.

Claims

1. A curable composition comprising a (meth) acrylic polymer (A) having a weight-average molecular weight of 500 or more and less than 10,000 and a (meth) acrylic polymer (B) having a weight-average molecular weight of 10,000 or more and 100,000 or less,

the (meth) acrylic polymer (A) has a double bond of 0.01meq/g to 1.0meq/g in the molecule,

the (meth) acrylic polymer (B) has a reactive silyl group in a molecule;

the concentration of double bonds contained in the whole of the (meth) acrylic polymer (A) and the (meth) acrylic polymer (B) is 0.01meq/g or more and 0.50meq/g or less;

the amount of the (meth) acrylic polymer (A) and the amount of the (meth) acrylic polymer (B) used are 10to 90/90 to 10 in terms of mass ratio.

2. The curable composition according to claim 1,

the (meth) acrylic polymer (A) has a viscosity of 1,000 mPas to 100,000 mPas at 25 ℃.

3. The curable composition according to claim 1,

the (meth) acrylic polymer (B) has a viscosity of 5,000 mPas or more and 300,000 mPas or less at 25 ℃.

4. The curable composition according to claim 1,

the (meth) acrylic polymer (A) has a reactive silyl group in the molecule.

5. The curable composition according to claim 1,

the (meth) acrylic polymer (B) has 0.1 to 2.2 reactive silyl groups in the molecule.

6. The curable composition according to claim 1,

the (meth) acrylic polymer (B) has a dialkoxysilyl group as a reactive silyl group.

7. The curable composition according to claim 1,

the (meth) acrylic polymer (B) contains an alkyl (meth) acrylate having an alkyl group having 10 or more carbon atoms in an amount of 5% by mass or more based on the total monomer units constituting the (meth) acrylic polymer.

8. The curable composition according to claim 1,

also disclosed is an oxyalkylene polymer.

9. The curable composition according to claim 1,

contains at least one compound selected from tin catalysts, titanium catalysts and tertiary amines as a curing accelerator.

10. A sealant composition characterized in that,

a curable composition comprising the curable composition according to any one of claims 1 to 9.

11. An adhesive composition characterized by comprising, in a specific ratio,