WO2010044367A1

WO2010044367A1 - Curable composition

Info

Publication number: WO2010044367A1
Application number: PCT/JP2009/067548
Authority: WO
Inventors: 耕太郎米田; 道弘河合
Original assignee: 東亞合成株式会社
Priority date: 2008-10-16
Filing date: 2009-10-08
Publication date: 2010-04-22
Also published as: JP5370369B2; JPWO2010044367A1

Abstract

Provided is a curable composition with high practical utility which has favourable workability, is cured by atmospheric moisture or the like, gives hardened material with a high elongation at break, and has outstanding heat resistance and weather resistance. The curable composition contains a vinyl copolymer (A) having a hydrolysable silyl group and a (meth)acrylic copolymer (B) having a hydroxyl group value of 50-300 mgKOH/g and a weight average molecular weight of 1500-6000, wherein the vinyl copolymer (A) having a hydrolysable silyl group is produced by living free radical polymerization, and the content of the aforementioned (meth)acrylic copolymer (B) is 20-200 parts by mass to 100 parts by mass of the aforementioned vinyl copolymer (A).

Description

Curable composition

The present invention relates to a curable composition, and more particularly relates to a curable composition that cures at room temperature with moisture such as in the air, has high elongation at break, and exhibits excellent heat resistance and weather resistance. is there.

Conventionally, as a room temperature curable composition having excellent weather resistance and heat resistance, a curable composition based on an oxyalkylene polymer having a hydrolyzable silyl group has been well known, Widely used in adhesives, sealants, paints, etc. for electrical and electronic fields and automotive applications. In these applications, since a balance between good workability, high elongation at break, weather resistance, and heat resistance is required, various studies have been made so far. A vinyl polymer having a hydrolyzable silyl group (particularly a (meth) acrylic polymer) has characteristics such as high weather resistance, heat resistance and transparency as compared with the oxyalkylene polymer. For example, Patent Document 1 discloses a method in which an oxyalkylene polymer having a hydrolyzable silyl group and a vinyl polymer having a hydrolyzable silyl group are used in combination. Patent Document 2 discloses that as a vinyl polymer having a hydrolyzable silyl group, a polymer obtained by continuous bulk polymerization at high temperature and high pressure is particularly excellent in weather resistance. Patent Document 3 discloses a curable composition containing a vinyl polymer having a reactive silicon group, a polyoxyalkylene polymer having a reactive silicon group, and a plasticizer having an acrylic component. . Furthermore, Patent Document 4 discloses a method of producing a vinyl polymer by using a living radical polymerization method, modifying both ends thereof to hydrolyzable silyl groups, and a curable composition containing the obtained polymer. It is disclosed. Unlike the general radical polymerization method, the living radical polymerization method is a method of growing a polymer chain by successive growth, and is a method capable of controlling the molecular weight, molecular weight distribution, terminal group, and block structure.
JP 59-122541 A JP 2004-18748 A JP 2004-2604 A JP-A-11-130931

However, in recent years, higher heat resistance and durability than conventional ones have been demanded for the curable compositions as described above. In a system in which an oxyalkylene polymer having a hydrolyzable silyl group and a vinyl polymer having a hydrolyzable silyl group as disclosed in Patent Document 1 are used in combination, heat resistance and weather resistance satisfying market requirements It is becoming impossible to achieve sex. The reason is that although a curable composition containing a vinyl polymer having a hydrolyzable silyl group is excellent in weather resistance, it is compared with a curable composition comprising only an oxyalkylene polymer having a hydrolyzable silyl group. This is because the elongation at break is low. Also, when a plasticizer having an acrylic component is added to a mixture of an oxyalkylene polymer having a hydrolyzable silyl group and a vinyl polymer having a hydrolyzable silyl group, the weather resistance is improved, but the elongation at break The problem of low is not solved. Further, in the case of a curable composition containing a vinyl polymer having a hydrolyzable silyl group obtained by living radical polymerization as disclosed in Patent Document 4, although it is excellent in weather resistance, the elongation at break is insufficient. These improvements are required.

An object of the present invention is to provide a highly practical curable composition having good workability, high elongation at break of a cured product, and excellent heat resistance and weather resistance.

As a result of intensive studies in view of the above problems, the present inventors have a hydrolyzable silyl group produced by a living radical polymerization method using a (meth) acrylic copolymer having a specific hydroxyl value and a weight average molecular weight. It has been found that when a specific amount is added to the vinyl polymer, a curable composition exhibiting high breaking elongation and excellent heat resistance and weather resistance can be obtained, and the present invention has been completed.

That is, the curable composition according to the present invention has a vinyl copolymer (A) having a hydrolyzable silyl group, a hydroxyl value of 50 to 300 mgKOH / g, and a weight average molecular weight of 1500 to 6000. A curable composition containing a (meth) acrylic copolymer (B), wherein a vinyl copolymer (A) having a hydrolyzable silyl group is produced by a living radical polymerization method The content of the (meth) acrylic copolymer (B) is 20 to 200 parts by mass with respect to 100 parts by mass of the vinyl copolymer (A).

The living radical polymerization is preferably polymerization using a nitrooxide radical.

Furthermore, the (meth) acrylic copolymer (B) is preferably produced by continuous polymerization at a temperature of 150 to 350 ° C.

In the above production method of the (meth) acrylic copolymer (B), it is preferable not to use mercaptans.

The curable composition according to the present invention, as described above, has a vinyl copolymer having a hydrolyzable silyl group produced by a living radical polymerization method, a specific hydroxyl value and a weight average molecular weight (meth). Contains a specific amount of an acrylic copolymer. Therefore, it has the effects of being cured at room temperature with moisture in the atmosphere, exhibiting high elongation at break, and having excellent heat resistance and weather resistance. Moreover, since the curable composition of this invention is a moderate viscosity, it is excellent in workability | operativity.

An embodiment of the present invention will be described as follows, but the present invention is not limited to this.

The vinyl copolymer (A) having hydrolyzable silyl groups according to the present invention (hereinafter also referred to as “component (A)”). ] Is an organic polymer containing a silyl group in the molecule, and is a base resin of the curable composition.

Although it does not specifically limit as a vinyl-type monomer used for manufacture of a component (A), It is a (meth) acrylic-acid type copolymer from the point of the mechanical physical property and weather resistance when it is set as a curable composition. It is preferable to use an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms in the ester chain, a vinyl monomer having an alkoxysilyl group, and other vinyl monomers. A preferred ratio of each monomer is an acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms in the ester chain: 40 to 99.5 parts by mass, a vinyl monomer having an alkoxysilyl group as a crosslinkable functional group: 0.5 to 20 parts by mass, other vinyl monomers: 0 to 59.5 parts by mass are preferably used. The more preferable ratio of each monomer is 60 to 99 parts by weight, 0.5 to 7 parts by weight, and 0 to 39 parts by weight (based on 100 parts by weight of all monomers used for producing the vinyl polymer). Ratio).
If the alkyl acrylate ester having an alkyl group having 1 to 8 carbon atoms in the ester chain is less than 40 parts by mass, the glass transition temperature may be high and the rubber elasticity may be lowered. If it exceeds 99.5 parts by mass, the glass becomes soft. The strength of the cured product may decrease. If the vinyl monomer having an alkoxysilyl group is less than 0.5 parts by mass, the crosslink density may be low and the strength may be reduced. .

Specific examples of the alkyl acrylate ester having an alkyl group having 1 to 8 carbon atoms in the ester chain include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, and acrylic acid. s-Butyl, t-butyl acrylate, neopentyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, etc., aliphatic alkyl acrylate, 2-methoxyethyl acrylate, dimethylaminoethyl acrylate, chloroethyl acrylate, acrylic acid Examples include, but are not limited to, heteroatom-containing acrylates such as trifluoroethyl and tetrahydrofurfuryl acrylate. Moreover, you may superpose | polymerize 1 type, or 2 or more types of these.

Examples of vinyl monomers having an alkoxysilyl group include vinyl silanes such as vinyl trimethoxysilane, vinyl triethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, trimethoxysilylpropyl acrylate, triethoxysilyl acrylate. Silyl group-containing acrylic esters such as propyl and methyldimethoxysilylpropyl acrylate, trimethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate, methyldimethoxysilylpropyl methacrylate, and silyl groups such as dimethylmethoxysilylpropyl methacrylate Silyl group-containing vinyl ethers such as methacrylic acid esters, trimethoxysilylpropyl vinyl ether, silicic acid such as vinyl trimethoxysilylundecanoate Group-containing vinyl esters, and the like. A preferable monomer is an acrylic acid ester or a methacrylic acid ester having a methoxysilyl group or an ethoxysilyl group, more preferably methyl methacrylate because of copolymerization with an acrylic acid ester and flexibility of the copolymer. Dimethoxysilylpropyl, trimethoxysilylpropyl methacrylate, methyldiethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate.

Other vinyl monomers can be used as long as the physical properties of the component (A) and its blend are not impaired. Examples of such monomers include alkyl acrylates having an alkyl group having 12 or more carbon atoms, such as lauryl acrylate, tridecyl acrylate, and stearyl acrylate. Further, methacrylic acid esters, specifically, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, tricyclodecynyl methacrylate, lauryl methacrylate, methacrylic acid, Examples include acid stearyl. Among these, methacrylic acid esters are preferable. Those having 4 or more carbon atoms in the alcohol residue of the ester are preferable because the viscosity of the polymer is low and the water resistance and weather resistance of the curable composition are excellent.

Furthermore, it is also possible to use a monomer having ultraviolet absorbing ability, a monomer having light stability, and a monomer having various functional groups. Examples of the monomer having ultraviolet absorbing ability include 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole, methacryloxyhydroxypropyl-3- [3- (2H-benzotriazole-2 -Yl) -5-tertiarybutyl-4-hydroxyphenyl] propionate and 2-hydroxy-4- (methacryloxyethoxy) benzophenone. Examples of the light-stable monomer include 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate and 2,2,6,6-tetramethyl-4-piperidyl methacrylate.

Examples of the functional group-containing monomer include epoxy group-containing monomers such as glycidyl (meth) acrylate and vinyl glycidyl ether, acrylic acid and methacrylic acids, acrylamide, N-methylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, methacrylamide, N-methylmethacrylamide, N, N-dimethylmethacrylamide and the like can be mentioned.

Further, α-olefins such as ethylene, propylene, 1-butene and isobutylene, chloroethylenes such as vinyl chloride and vinylidene chloride, and fluoroethylenes such as tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene and vinylidene fluoride , Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether and cyclohexyl vinyl ether, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, Veova 9, Veova 10 (manufactured by Shell Chemical, carbon number 9 and 10 fatty acid vinyl) and vinyl esters such as vinyl laurate, and allyl ethers such as ethyl allyl ether and butyl allyl ether.
Preferred monomers are methacrylic acid esters, and particularly preferred are methyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate.

Component (A) can be produced by a living radical polymerization method. In the living radical polymerization method, a polymer having a narrow molecular weight distribution and a low viscosity can be obtained, and a monomer having a specific functional group can be introduced into any position of the polymer.

Examples of the living radical polymerization method include an ATRP method using copper bromide as a catalyst disclosed in JP-A-11-130931, and a vinyl monomer in the presence of a thiocarbonylthio compound disclosed in JP 2000-515181 A. Examples include an addition-cleavage chain transfer method (RAFT method) for polymerizing a living radical polymerization method using a nitrooxide radical disclosed in JP-T-2003-500378. Among them, the living radical polymerization method using a nitrooxide radical is preferable because there is no need to use a highly toxic copper compound unlike the ATRP method.

The living radical polymerization can be carried out in the range of 0 to 200 ° C., preferably 50 to 150 ° C.

The weight average molecular weight of component (A) is a polystyrene equivalent molecular weight determined by gel permeation chromatography (hereinafter also referred to as “GPC”), and the number average molecular weight (Mn) is preferably 5000 to 50000. More preferred is 8000 to 25000. When Mn is lower than 5000, the crosslink density of the cured product becomes too high, and the elongation of the cured product becomes extremely small. When Mn is higher than 50000, the viscosity becomes very high and workability is remarkably deteriorated. The glass transition temperature of component (A) is preferably −70 to 30 ° C., more preferably −70 to 10 ° C. If it exceeds 30 ° C., there is a risk that the rubber will not have sufficient rubber elasticity in winter, and the workability will also deteriorate.

The hydrolyzable silyl group contained in the component (A) is a group having a hydroxyl group or a hydrolyzable group bonded to a silicon atom and capable of crosslinking by forming a siloxane bond by a reaction with a curing catalyst. Although it does not specifically limit as a hydrolysable silyl group, The thing of the following general formula (1) is preferable at the point which is easy to bridge | crosslink and is easy to manufacture.

(Wherein R represents a hydrocarbon group, preferably an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms. X is a halogen atom, hydrogen A reactive group selected from an atom, a hydroxyl group, an alkoxy group, an acyloxy group, a ketoximate group, an amide group, an acid amide group, a mercapto group, an alkenyloxy group, and an aminooxy group. (It may be the same group or different groups. X is preferably an alkoxy group. N is an integer of 0, 1 or 2.)

As the alkoxysilyl group of component (A), those having a trimethoxysilyl group, a methyldimethoxysilyl group, a dimethylmethoxysilyl group, a triethoxysilyl group, a methyldiethoxysilyl group, or a methyldimethoxyethoxysilyl group are preferable. A trimethoxysilyl group or a methyldimethoxysilyl group is particularly preferred from the viewpoint of the balance between curing speed and flexibility.
In addition, the number of alkoxysilyl groups in one molecule of component (A) is preferably 0.1 to 4, more preferably 0.3 to 3. If it is less than 0.1, curing is insufficient, and if it exceeds 4, the cured product becomes hard.

The radical polymerization initiator used for the production of the component (A) may be any initiator that generates radicals at a predetermined reaction temperature. Specifically, peroxides such as diisopropyl peroxydicarbonate, di-2-ethoxyethyloxydicarbonate, tertiary butyl peroxypivalate, ditertiary butyl peroxide, benzoyl peroxide and lauroyl peroxide, or 2, Azo compounds such as 2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile) and 2,2'-azobis (2,4-dimethylvaleronitrile), ammonium persulfate and persulfate Examples thereof include inorganic peroxides such as potassium and metal complexes used for living polymerization. Further, a thermally initiated radical generated from styrene or the like may be used.
Particularly preferably, ditertiary butyl peroxide, ditertiary hexyl peroxide, ditertiary amyl peroxide, and azo initiator are inexpensive and the initiator radicals are less likely to cause hydrogen abstraction. When the hydrogen abstraction reaction occurs frequently, the molecular weight distribution becomes wide, and a low molecular weight component into which no crosslinkable functional group is introduced is likely to be formed, and the weather resistance may be deteriorated.

(Meth) acrylic copolymer (B) according to the present invention [hereinafter also referred to as “component (B)”. ] Is an organic polymer having a hydroxyl value of 50 to 300 mgKOH / g and a weight average molecular weight of 1500 to 6000. The component (B) functions as a plasticizer in the curable composition, and has an effect of adjusting workability and improving workability before the composition is cured. Moreover, after hardening of a composition, it has the effect | action which adjusts the mechanical physical property of hardened | cured material and improves durability, such as a weather resistance.
In the present specification, “(meth) acryl” means “acryl or methacryl”.

Component (B) is a copolymer of a hydroxyl group-containing (meth) acrylic monomer and another (meth) acrylic monomer, which is one or two (meth) acrylic monomers When polymerizing more than seeds, a small amount of a hydroxyl group-containing (meth) acrylic monomer is used as a copolymer component. The ratio of the hydroxyl group-containing (meth) acrylic monomer to the total monomers used in the production of component (B) is adjusted so that the hydroxyl value of component (B) falls within the range of 50 to 300 mgKOH / g.

Hydroxyl group-containing (meth) acrylic monomers include ε-caprolactone addition reaction of hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and hydroxyethyl (meth) acrylate And (meth) acrylic acid hydroxyalkyl compounds. Among these, hydroxyethyl acrylate is preferable from the viewpoint of elongation at break and workability of the curable composition.

The other (meth) acrylic monomers are not particularly limited, but (meth) acrylic acid alkyl esters having an alkyl group having 1 to 8 carbon atoms in the ester chain are preferable from the viewpoint of mechanical properties of the cured product. .

Specific examples of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms in the ester chain include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) Isopropyl acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, neopentyl (meth) acrylate, (meth) acrylic acid 2 -Aliphatic alkyl (meth) acrylates such as ethylhexyl, cyclohexyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, chloroethyl (meth) acrylate, (meth) acrylic Such as trifluoroethyl acid and tetrahydrofurfuryl (meth) acrylate Atom-containing (meth) acrylic acid esters include but are not limited to. Moreover, you may superpose | polymerize 1 type, or 2 or more types of these.

Component (B) can be produced by ordinary radical polymerization, and any of solution polymerization, bulk polymerization, and dispersion polymerization may be used, and a living radical polymerization method developed in recent years may be used. The reaction process may be any of batch, semi-batch and continuous polymerization. However, it is most preferable that it is obtained by a high temperature continuous polymerization method at 150 to 350 ° C. Moreover, it is preferable not to use chain transfer agents such as mercaptans because they lead to a decrease in weather resistance.

When the component (B) is obtained by ordinary radical polymerization, a high temperature continuous polymerization method at 150 to 350 ° C. is preferred. When the polymerization temperature is less than 150 ° C., branching reaction occurs and the molecular weight distribution is widened, and a large amount of initiator and chain transfer agent are required to lower the molecular weight, thus adversely affecting durability such as weather resistance and heat resistance. give. In addition, production problems such as heat removal may occur. On the other hand, if it is higher than 350 ° C., a decomposition reaction occurs and the polymerization solution is colored or the molecular weight is lowered. By polymerizing in this temperature range, it is possible to efficiently produce a copolymer having an appropriate molecular weight, a low viscosity, no coloration and little impurities. That is, according to the polymerization method, a very small amount of polymerization initiator may be used, and it is not necessary to use a chain transfer agent such as mercaptan or a polymerization solvent, and a highly pure copolymer can be obtained. In general, it is important to uniformly introduce a crosslinkable functional group into a polymer in order to maintain physical properties such as curability and weather resistance. It is preferable to use a stirred tank reactor as the reactor because a (meth) acrylic acid ester copolymer having a relatively narrow composition distribution (distribution of crosslinkable functional groups) and molecular weight distribution can be obtained. Also, a process using a continuous stirred tank reactor is more preferable than a tubular reactor because the composition distribution and molecular weight distribution are narrowed.

As the high temperature continuous polymerization method, a known method disclosed in JP-A-57-502171, JP-A-59-6207, JP-A-60-215007, or the like may be used. For example, after filling a pressurizable reactor with a solvent and setting it to a predetermined temperature under pressure, the reactor is charged with a monomer mixture composed of each monomer and, if necessary, a polymerization solvent at a constant supply rate. And a method of extracting a polymerization solution in an amount commensurate with the supply amount of the monomer mixture. Moreover, a polymerization initiator can also be mix | blended with a monomer mixture as needed. The blending amount when blended is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the monomer mixture. The pressure depends on the reaction temperature, the monomer mixture used and the boiling point of the solvent, and does not affect the reaction, but may be any pressure that 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, the monomer may not sufficiently react, and if the unreacted monomer exceeds 60 minutes, the productivity may deteriorate. The preferred residence time is 2 to 40 minutes.

The hydroxyl value of component (B) is 50 to 300 mgKOH / g, preferably 70 to 130 mgKOH / g, more preferably 90 to 120 mgKOH / g. If the hydroxyl value is less than 50 mgKOH / g, the elongation at break is insufficient, and if it exceeds 300 mgKOH / g, the viscosity becomes high, so that the effect as a plasticizer is lowered and the workability of the curable composition is lowered. In addition, the weather resistance also decreases. The hydroxyl value in the present invention is a value determined according to JIS K 0070.

The weight average molecular weight of the component (B) is 1500 to 6000, preferably 1500 to 5000, more preferably 1500 to 3000, in terms of polystyrene by GPC. When the weight average molecular weight is less than 1500, the weather resistance may be insufficient. When the weight average molecular weight exceeds 6000, the viscosity becomes high, so that the effect as a plasticizer is lowered and the workability of the curable composition is lowered.

The viscosity of component (B) at 25 ° C. is preferably 500 to 15000 mPa · s, more preferably 800 to 12000 mPa · s. If the viscosity is less than 500 mPa · s, sagging may occur during construction, and if it exceeds 15000 mPa · s, the workability of the curable composition is deteriorated.

The glass transition temperature of component (B) is preferably −10 ° C. or lower, more preferably −20 ° C. or lower. When the glass transition temperature is −10 ° C. or higher, the rubber elasticity of the curable composition tends to be insufficient in winter, and the workability also deteriorates.

The content of the component (B) in the curable composition according to the present invention is 20 to 200 parts by weight, preferably 30 to 150 parts by weight, more preferably 40 to 40 parts by weight with respect to 100 parts by weight of the component (A). 130 parts by mass. When the content of the component (B) is less than 20 parts by mass, the workability of the curable composition is deteriorated, and when it exceeds 200 parts by mass, the crosslinking density of the curable composition is lowered and the durability may be lowered.

The curable composition according to the present invention may contain components other than the components (A) and (B). Such components include fillers, thixotropic agents, anti-aging agents, curing accelerators, adhesion enhancing agents, dehydrating agents and the like.

Fillers include light calcium carbonate with an average particle size of about 0.02 to 2.0 μm, heavy calcium carbonate with an average particle size of about 1.0 to 5.0 μm, titanium oxide, carbon black, synthetic silicic acid, talc, Examples include zeolite, mica, silica, calcined clay, kaolin, bentonite, aluminum hydroxide and barium sulfate, glass balloon, silica balloon, and polymethyl methacrylate balloon. With these fillers, the mechanical properties of the cured product are improved, and the strength and elongation can be improved.
Among these, light calcium carbonate, heavy calcium carbonate, and titanium oxide, which are highly effective in improving physical properties, are preferable, and a mixture of light calcium carbonate and heavy calcium carbonate is more preferable. The amount of filler added is preferably 20 to 300 parts by weight, more preferably 50 to 200 parts by weight, based on 100 parts by weight of the total amount of component (A) and component (B). As described above, when a mixture of light calcium carbonate and heavy calcium carbonate is used, it is preferable that light calcium carbonate / heavy calcium carbonate = 90/10 to 50/50.
If the amount of filler is too small or too large, the mechanical properties may be impaired.

Further, an ultraviolet absorber such as a benzophenone compound, a benzotriazole compound and an oxalic acid anilide compound, a light stabilizer such as a hindered amine compound, an antioxidant such as a hindered phenol, or an antioxidant that is a mixture thereof, Tin curing accelerators such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diacetacetonate, amide wax, silica-based thixotropy imparting agent, adhesion imparting agents such as aminosilane, epoxysilane, vinylsilane, methylsilanes Or a dehydrating agent such as methyl orthoformate and methyl orthoacetate, or an organic solvent.

Examples of the ultraviolet absorber include trade names “Tinubin 571”, “Tinubin 1130”, and “Tinubin 327” manufactured by Ciba Specialty Chemicals. Examples of the light stabilizer include trade names “Tinuvin 292”, “Tinuvin 144”, “Tinuvin 123” manufactured by the same company, and a trade name “Sanol 770” manufactured by Sankyo. Examples of the heat stabilizer include trade names “Irganox 1135”, “Irganox 1520”, and “Irganox 1330” manufactured by Ciba Specialty Chemicals. Mixture of ultraviolet absorber / light stabilizer / heat stabilizer; trade name “Tinubin B75” manufactured by Ciba Specialty Chemicals may be used.

As the tin-based catalyst, trade names “U28”, “U100”, “U200”, “U220”, “U303”, “SCAT-7”, “SCAT-46A” manufactured by Nitto Kasei Co., Ltd. The product name “No. 918” is exemplified. Examples of the thixotropic agent include trade names “Dispalon 3600N”, “Dispalon 3800”, “Dispalon 305”, and “Dispalon 6500” manufactured by Enomoto Kasei Co., Ltd.

Anti-tacking agents include trade names “Aronix M8030”, “M8060”, “M8100”, “M309” manufactured by Toagosei Co., Ltd., which are acrylic oligomers, or mixtures with photopolymerization initiators, tung oil, linseed oil Examples include unsaturated fatty acid oils, trade name “R15HT” manufactured by Idemitsu Petrochemical Co., Ltd., trade name “PBB3000” manufactured by Nippon Soda Co., Ltd., and trade name “GOSELAC 500B” manufactured by Nippon Synthetic Chemical.

Examples of aminosilanes include “KBM602”, “KBM603”, “KBE602”, “KBE603”, “KBM903”, and “KBE903” manufactured by Shin-Etsu Silicone.

The curable composition according to the present invention contains the above components, but the production method is not particularly limited. Specifically, it can be produced by mixing using a stirrer, a planetary stirrer, or the like.

The curable composition of the present invention can also be prepared as a one-component type that cures by preliminarily blending and storing all the blended components and absorbing moisture in the air after coating, and is separately prepared as a curing agent. Components such as a curing catalyst, a filler, a plasticizer, and water may be blended, and the blended material and the polymer composition may be adjusted as a two-component type that is mixed before use. A one-component type that is easy to handle and has few errors during coating is more preferable.

The present invention will be described more specifically based on synthesis examples and examples, but the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the scope of the present invention. In this example, the polymer and the curable composition were evaluated as follows. In the following, “parts” means parts by mass.

[Molecular weight]
Apparatus: HLC-8120 (manufactured by Tosoh Corporation)
Column: 4 TSKgel SuperMultipore HZ-M (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran 0.35ml / min
Detector: RI
The molecular weight measured by GPC was converted based on the molecular weight of polystyrene.

[Hydroxyl value]
The hydroxyl value in the present invention was measured according to JIS K 0070.

〔viscosity〕
The viscosity in the present invention was measured with an E-type viscometer under the conditions of 25 ° C. and 5 rpm.

〔Workability〕
The workability (ease of application) when applying the curable composition was evaluated according to the following criteria.
○: Good, △: Somewhat bad, ×: Very bad

[Tensile test]
The curable composition was applied at a thickness of 2 mm, and cured for one week under conditions of 23 ° C. and 50% RH to prepare a cured sheet. A tensile test dumbbell (JIS K 6251 No. 3 type) was prepared from the obtained cured product, and the breaking strength and breaking elongation were measured with a tensile tester (manufactured by Toyo Seiki Co., Ltd., Tensilon 200).
Measurement environment: 23 ° C, 50% RH
Tensile speed: 50 mm / min

[Heat resistance test]
A part of the cured sheet was put in an oven at 150 ° C., taken out after 24 hours, and the surface state was observed. No change was indicated by ○, and change was indicated by ×.

[Weather resistance test]
The curable composition was applied at a thickness of 0.4 mm, and cured for one week under the conditions of 23 ° C. and 50% RH to prepare a cured sheet. An accelerated weather resistance test was performed with a metering weather meter (DAIPLA METALWEATHER KU-R5NCI-A, manufactured by Daipura Wintes Co., Ltd.), and the time when abnormalities such as cracks and bleeds began to appear was recorded.

[Synthesis Example of Component (A)]
(Polymer A) A 1-liter pressurized stirred tank reactor equipped with an oil jacket is charged with 500 parts by mass of butyl acrylate (hereinafter also referred to as “BA”), a living polymerization initiator [Formula (2)]. A mixed liquid consisting of 5 parts by mass, 5.6 parts by mass of 3-glycidoxypropyltrimethoxysilane, and 3.6 parts by mass of tetrabutylammonium bromide (hereinafter also referred to as “TBAB”) was charged, and the mixed liquid was subjected to nitrogen bubbling. Fully evacuated. The jacket temperature was raised to 120 ° C. to initiate the polymerization reaction, and the jacket temperature was adjusted so that the reaction solution temperature was maintained at 120 ° C. After 6 hours, the polymerization rate of BA was 90%. Thereto was added 4.9 parts by mass of 3-methacryloxypropyltrimethoxysilane (hereinafter also referred to as “MTMS”), and the mixture was reacted at 120 ° C. for 4 hours. At this time, the polymerization rate of BA was 99%, and the polymerization rate of MTMS was 79%. After cooling, the reaction solution was taken out and dried under reduced pressure with an evaporator at a reduced pressure of 0.3 kPa and 90 ° C. for 5 hours to obtain about 490 parts by mass of a polymer. The properties of the polymer were Mw32400, Mn23100, Mw / Mn1.4, E-type viscosity (25 ° C.) 152000 mPa · s. The acid value was 0.2 mgKOH / g, and the reaction rate of the carboxyl group of the living polymerization initiator [Formula (2)] was 88%. The number of alkoxysilyl groups f (Si) per one polymer chain of the polymer was 1.7.

(Polymer B) A pressurized stirring tank reactor having a capacity of 1 liter equipped with a soot oil jacket was charged with 360 parts by weight of BA, 9.0 parts by weight of a living polymerization initiator [Formula (2)], and butyl acetate (hereinafter referred to as “BAc”). This was mixed with 108 parts by mass, 6.1 parts by mass of 3-glycidoxypropyltrimethoxysilane, and 1.8 parts by mass of TBAB, and the mixture was sufficiently deaerated by nitrogen bubbling. The jacket temperature was raised to 120 ° C. to initiate the polymerization reaction, and the jacket temperature was adjusted so that the reaction solution temperature was maintained at 120 ° C. After 6 hours, the polymerization rate of BA was 88%. MTMS 6.5 mass part was added there, and it was made to react with it at 120 degreeC for 4 hours. At this time, the polymerization rate of BA was 95%, and the polymerization rate of MTMS was 98%. After cooling, the reaction solution was taken out and dried under reduced pressure with an evaporator at a reduced pressure of 0.3 kPa and 90 ° C. for 5 hours to obtain about 320 parts by mass of a polymer. The properties of the polymer were Mw 39900, Mn 14800, Mw / Mn 2.7, E-type viscosity (25 ° C.) 354000 mPa · s. The reaction rate of the carboxyl group of the living polymerization initiator [Formula (2)] was 97%. The number of alkoxysilyl groups f (Si) per one polymer chain of the polymer was 1.9.

(Polymer C) In a 1 liter pressurized stirred tank reactor equipped with a soot oil jacket, 500 parts by mass of BA, 7.5 parts by mass of a living polymerization initiator [Formula (2)], 3-glycidoxypropyltrimethoxy A liquid mixture consisting of 5.6 parts by mass of silane and 1.3 parts by mass of TBAB was charged, and the liquid mixture was sufficiently degassed by nitrogen bubbling. The jacket temperature was raised to 120 ° C. to initiate the polymerization reaction, and the jacket temperature was adjusted so that the reaction solution temperature was maintained at 120 ° C. After 6 hours, the polymerization rate of BA was 89%. 4.9 parts by mass of 3-methacryloxypropylmethyldimethoxysilane (hereinafter also referred to as “MDMS”) was added thereto, and the mixture was reacted at 120 ° C. for 4 hours. At this time, the polymerization rate of BA was 99%, and the polymerization rate of MDMS was 79%. After cooling, the reaction solution was taken out and dried under reduced pressure with an evaporator at a reduced pressure of 0.3 kPa and 90 ° C. for 5 hours to obtain about 490 parts by mass of a polymer. The properties of the polymer were Mw28100, Mn17000, Mw / Mn1.7, E-type viscosity (25 ° C.) 94000 mPa · s. The acid value was 0.3 mgKOH / g, and the reaction rate of the carboxyl group of the living polymerization initiator [Formula (2)] was 78%. The number of alkoxysilyl groups f (Si) per one polymer chain of the polymer was 1.6.

[Synthesis Example of Component (B)]
<Synthesis Example 1>
The temperature of a 1000 ml capacity pressurized stirred tank reactor equipped with an oil jacket was kept at 200 ° C. Next, while maintaining the reactor pressure constant (2.3 MPa), 87.5 parts of 2-ethylhexyl acrylate (hereinafter also referred to as “HA”) and 2-hydroxyethyl acrylate (hereinafter also referred to as “HEA”) are used. ) 12.5 parts, isopropyl alcohol (hereinafter also referred to as “IPA”) 10 parts, a monomer mixture comprising 1.5 parts of ditertiary butyl peroxide as a polymerization initiator, at a constant feed rate (48 g / Min., Residence time: 12 minutes), continuous supply from the raw material tank to the reactor was started, and a reaction liquid corresponding to the supply amount of the monomer mixture was continuously withdrawn from the outlet. Immediately after the start of the reaction, once the reaction temperature decreased, a temperature increase due to the heat of polymerization was observed, but the reaction temperature was maintained at 246 to 248 ° C. by controlling the oil jacket temperature.
The time when the temperature was stabilized after the start of the monomer mixture supply was taken as the reaction liquid collection start point, and the reaction was continued for 25 minutes. As a result, 1.2 kg of the monomer mixture was supplied and 1.2 kg of the reaction was started. The liquid was collected. Thereafter, the reaction solution was introduced into a thin film evaporator to separate volatile components such as unreacted monomers to obtain a concentrated solution. Tetrahydrofuran was used as the solvent, and the polystyrene-equivalent number average molecular weight (hereinafter also referred to as “Mn”) measured by GPC was 1310, and the weight average molecular weight (hereinafter also referred to as “Mw”) was 2140. The hydroxyl value was 50 mgKOH / g. The component (B) obtained by the reaction is referred to as “polymer 1”.

<Synthesis Examples 2-5, 7, 9-11>
Polymerization and treatment were carried out in the same manner as in Synthesis Example 1 except that the conditions shown in Table 1 were changed, and component (B) was synthesized. The obtained polymers are referred to as polymers 2 to 5, 7, and 9 to 11, respectively. The evaluation results of these polymers are shown in Table 1. The evaluation method is as follows.
In Table 1, “4HBA” is 4-hydroxybutyl acrylate.

<Synthesis Example 6>
Copolymerization and treatment were carried out in the same manner as in Synthesis Example 1 except that 37 parts of HA as the monomer mixture, 63 parts of HEA, 50 parts of IPA, and 3 parts of ditertiary butyl peroxide as the polymerization initiator were changed. Was synthesized. Mw was 1500. The hydroxyl value was 250 mgKOH / g. The copolymer obtained by the reaction is referred to as “polymer 6”.

<Synthesis Example 8>
Into a 3 liter flask equipped with a dropping funnel, a nitrogen introduction tube, a thermometer, and a stirrer, 500 parts of methyl ethyl ketone (hereinafter referred to as “MEK”) was charged as a solvent, and the temperature was raised to 80 ° C. while purging with nitrogen. After confirming that the temperature became constant, a mixture of 800 parts HA, 200 parts HEA, 181 parts dodecyl mercaptan, 200 parts MEK and 30 parts azobisisobutyronitrile was added dropwise over 4 hours. Furthermore, after stirring for 1 hour, the polymerization was stopped, and after MEK was distilled off, 1070 parts of a liquid copolymer was obtained. Mn = 1200 and Mw = 2200. The copolymer obtained by the reaction is referred to as “polymer 8”.

<Synthesis Example 12>
The monomer mixture was changed to 52 parts BA, 30 parts HA, 18 parts HEA, 12 parts IPA, 8 parts MOA, 10 parts MEK, and 0.2 part ditertiary hexyl peroxide as a polymerization initiator. A copolymer was synthesized by performing polymerization and treatment in the same manner as in Synthesis Example 1 except that the reaction temperature was changed to 169 to 171 ° C. Mn was 3360 and Mw was 9800. The copolymer obtained by the reaction is referred to as “polymer 12”.

<Synthesis Example 13>
Synthetic Example 1 except that the monomer mixture is changed to 80 parts HA, 20 parts HEA, 50 parts IPA, 3 parts ditertiary butyl peroxide as the polymerization initiator, and the reaction temperature is changed to 249-251 ° C. Polymerization and treatment were performed in the same manner to synthesize a copolymer. Mw was 1000. The copolymer obtained by the reaction is referred to as “polymer 13”.

<Synthesis Example 14>
82 parts HA as monomer mixture, 18 parts HEA, 10 parts MEK, 3 parts IPA, ditertiary butyl peroxide as polymerization initiator to 1.5 parts, and reaction temperature to 204-206 ° C Was polymerized and treated in the same manner as in Synthesis Example 1 to synthesize a copolymer. Mw was 5820. The copolymer obtained by the reaction is referred to as “polymer 14”.

<Examples 1 to 12, Comparative Examples 1 to 8>
The compositions of Examples and Comparative Examples and the evaluation results of the compositions are shown in Tables 2 and 3.
In Tables 2 and 3, the following components were used other than the polymer.
Synthetic calcium carbonate: Shiraishi Calcium Co., Ltd.
Heavy calcium carbonate: Maruo Calcium Co., Ltd. Trade name “Super SS”
Titanium oxide: Product name “R-820” manufactured by Ishihara Sangyo Co., Ltd.
Anti-aging agent: Product name “Tinubin B75” manufactured by Ciba Specialty Chemicals
Dehydrating agent: Vinylsilane Adhesion imparting agent: N-2- (aminoethyl) -3-aminopropyltrimethoxysilane Curing accelerator: Dibutyltin diacetylacetonate
In addition, the composition of the comparative example 3 had too high a viscosity, and could not produce the test piece for evaluation.

As described above, the curable composition of the present invention includes a vinyl copolymer having a hydrolyzable silyl group produced by a living radical polymerization method, and a (meth) acrylic compound having a specific hydroxyl value and a weight average molecular weight. Since it contains a copolymer, it is cured at room temperature with moisture in the atmosphere and the resulting cured product exhibits high elongation at break and has excellent heat resistance and weather resistance. Therefore, the curable composition of the present invention can be used as a sealing material, an adhesive, a paint, and the like, and can be widely applied in the architectural field, the electric / electronic field, the automobile field, and the like.

Claims

A vinyl copolymer (A) having a hydrolyzable silyl group and a (meth) acrylic copolymer (B) having a hydroxyl value of 50 to 300 mgKOH / g and a weight average molecular weight of 1500 to 6000 A curable composition comprising:
The vinyl copolymer (A) having a hydrolyzable silyl group is produced by a living radical polymerization method, and the content of the (meth) acrylic copolymer (B) is the vinyl copolymer. A curable composition comprising 20 to 200 parts by mass with respect to 100 parts by mass of the polymer (A).
The curable composition according to claim 1, wherein the living radical polymerization is polymerization using a nitrooxide radical.
The curable composition according to claim 1 or 2, wherein the (meth) acrylic copolymer (B) is produced by continuous polymerization at a temperature of 150 to 350 ° C.
The curable composition according to claim 3, wherein no mercaptan is used in the production method of the (meth) acrylic copolymer (B).