JP2708833C - - Google Patents

Description

The present invention relates to a silicon-containing group having a hydroxyl group or a hydrolyzable group bonded to a silicon atom and capable of crosslinking by forming a siloxane bond (hereinafter referred to as reaction). Curable composition containing an oxyalkylene-based polymer having a functional silicon group) and an oxyalkylene-based polymer substantially containing no hydroxyl group, wherein the alkyd is coated on a cured product of the composition. The present invention relates to a curable composition with improved drying properties of a system paint. [Problems to be Solved by the Related Art] An oxyalkylene polymer having a reactive silicon group is cured even at room temperature by moisture in the air at room temperature, like a room-temperature-curable silicone rubber, to form a rubber-like material. It is a polymer to give. Since this cured product has excellent elongation properties, strength, adhesiveness, and the like, it is used for applications such as sealants and adhesives. One of the features of the oxyalkylene-based polymer having a reactive silicon group is that, since the main chain is an oxyalkylene-based polymer, most of commonly used paints can be applied to the surface of the cured product. In the case of silicone rubber, there is a problem that the surface is water- and oil-repellent and it is practically impossible to apply a paint. However, even when a cured product of a composition using an oxyalkylene-based polymer having reactive silicon is applied with an alkyd-based paint depending on the type of the composition, the drying property (curability) of the coating film deteriorates. In some cases, there is a problem that it is practically difficult to use the coating material on an object. In such a case, applying an alkyd paint on a cured product of a sealant using an oxyalkylene polymer,
Had given up in the middle. However, the alkyd-based paint dries faster than the oil-based paint, and this coating is hard and glossy, and is excellent in almost all points such as adhesion, weather resistance, oil resistance, and resistance. It can be adjusted over a wide range depending on the type of oil, oil length, type of modification, etc., and is used for various applications. Therefore, it is very beneficial to be able to apply this paint on the surface of the cured product. Until now, even the cause of the deterioration of the drying properties of alkyd paints was completely unknown,
The present inventors have conducted intensive studies on the cause, and found that when a conventional low-molecular plasticizer was added to a curable composition containing an oxyalkylene polymer having a reactive silicon group, the curable composition was dried. It was found that sex deteriorated. The plasticizer is added when it is necessary to lower the viscosity of the composition (improve the workability during use) or to improve the tensile properties of the cured product. Since it is a simple method to use a plasticizer to lower the viscosity of the composition and improve the tensile properties of the cured product, the present inventors have determined whether there is a plasticizer that does not deteriorate the drying property of the alkyd paint. As a result of the search, it has been found that the above problem is improved by using a polymer plasticizer. Among the high-molecular plasticizers, oxyalkylene polymers are inexpensive, and when added to oxyalkylene polymers having reactive silicon groups, they have excellent properties such as excellent tensile properties at low temperatures of cured products. It is a plasticizer. The present inventors have studied various oxyalkylene-based polymers, and as a result, when a specific oxyalkylene-based polymer is used as a plasticizer for an oxyalkylene-based polymer having a reactive silicon group, the cured product has an excellent alkyd. The inventors have found that the paint has a drying property, and have reached the present invention. [Means for Solving the Problems] That is, the present invention provides (A) a compound having a hydroxyl group or a hydrolyzable group bonded to a silicon atom and having at least one silicon-containing group capable of crosslinking by forming a siloxane bond. A curable composition containing an oxyalkylene-based polymer and (B) an oxyalkylene-based polymer substantially containing no hydroxyl group, and drying of an alkyd-based paint applied to a cured product from the composition. The present invention relates to a curable composition having improved properties. [Example] In the present invention, an oxyalkylene polymer having at least one reactive silicon group (hereinafter, also referred to as an oxyalkylene polymer (A)) is used. The oxyalkylene polymer (A) is described in JP-B-45-36319 and JP-B-46-31919.
12154, 49-32673, JP-A-50-156599, 51-
No. 73561, No. 54-6096, No. 55-82123, No. 55-1236
No. 20, 55-125121, 55-131022, 55-135135, and 55-137129. The molecular chain of the oxyalkylene polymer (A) has a general formula: -R ¹ O- (wherein R ¹ is a divalent hydrocarbon group, most of which have 3 or 4 carbon atoms). Is most preferable when it is an alkylene group). Specific examples of R ¹ include: It molecular chain of the alkylene polymer (A) may be composed of repeating units of only one kind, or may be made of two or more repeating units, but especially as R ¹ The main chain of the oxyalkylene polymer may be composed of only a repeating unit represented by the general formula: -R ¹ -O-, or may contain another repeating unit. When the polymer contains other repeating units, the content of the repeating units represented by the general formula: -R ¹ -O- is preferably at least 60% (% by weight, hereinafter the same), more preferably at least 80% in the polymer. preferable. The reactive silicon group which can be crosslinked and / or polymerized by forming a siloxane bond in the oxyalkylene polymer (A) is a well-known functional group and has a feature that it can be crosslinked at room temperature. I have. A typical example of the reactive silicon group is represented by the general formula (I): (Wherein, R ² is a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms or a triorganosiloxy group, and (m (2-a) + 3-b) R ² Good, X is a hydroxyl group or a hydrolyzable group, and (ma + b) Xs may be different, a is 0,
1 or 2, b is 0, 1, 2, or 3, and (ma + b) ≧ 1, m is an integer of 0 to 19, and m A need not be the same). General formula (I)
Among the reactive silicon groups represented by the general formula (II): (Wherein R ² is the same as above, and l is 1, 2 or 3). Specific examples of the hydrolyzable group which is one kind of X in the general formula (I) include, for example, a halogen atom, a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group,
Examples include an amino group, an amide group, an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, an alkoxy group such as a methoxy group and an ethoxy group is preferred from the viewpoint of mild hydrolysis. Specific examples of R ² in the general formula (I) include, for example, alkyl groups such as methyl group and ethyl group, cycloalkyl groups such as cyclohexyl group, aryl groups such as phenyl group, aralkyl groups such as benzyl group, and ( R ') ₃ SiO- (R' is a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms such as a methyl group and a phenyl group, and three R's need not be the same). Triorganosiloxy groups. Of these, a methyl group is particularly preferred. The number of reactive silicon groups in the oxyalkylene polymer (A) may be one or more per molecule, but from the viewpoint of obtaining sufficient curability, the number is 1.1 or more on average, and more preferably 1.5 or more. ~ 4 are preferred. Further, the reactive silicon group is preferably present at the terminal of the molecular chain of the oxyalkylene polymer (A). The number average molecular weight of the oxyalkylene polymer (A) is preferably from 3,000 to 30,000, more preferably from 5,000 to 15,000. The oxyalkylene polymer (A) may be used alone or in combination of two or more. The oxyalkylene polymer (A) is, for example, a hydrosilane compound having a hydrogen atom bonded to a group represented by the general formula (I) and a general formula (III): (Wherein, R ³ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and R ⁴ is a 1 to 1 carbon atom.
A divalent organic group of 20 and c is 0 or 1) by an addition reaction with an oxyalkylene polymer having an olefin group represented by 1) using a Group VIII transition metal compound such as a platinum compound as a catalyst. You. As a method for producing the oxyalkylene polymer (A) other than the above, a hydroxyl group-terminated oxyalkylene polymer is reacted with a polyisocyanate compound such as toluene diisocyanate to obtain an isocyanate group-terminated alkylene oxide polymer, and thereafter, The isocyanate group has a general formula (IV): Wherein W is an active hydrogen-containing group such as a hydroxyl group, a carboxyl group, a mercapto group or an amino group (primary or secondary), and l, R ² , R ⁴ and X are as defined above. A method of reacting a W group, adding a mercapto group of a silicon compound represented by the general formula (IV) wherein W is a mercapto group to an olefin group of an oxyalkylene polymer having an olefin group represented by the general formula (III) The method of reacting, and adding the hydroxyl group of the hydroxyl group-terminated oxyalkylene polymer to the general formula (V): (Wherein, R ² , R ⁴ , X and 1 are the same as above), and the like. Specific examples thereof include, but are not limited to, the method of the present invention. In a method of reacting a hydrosilyl compound in which a hydrogen atom is bonded to a group represented by the general formula (I) and an oxyalkylene polymer having an olefin group represented by the general formula (III), after reacting them, Some or all of the X groups may be further converted to other hydrolyzable groups or hydroxyl groups. For example, when the X group is a halogen atom,
In the case of a hydrogen atom, these groups are preferably used after being converted into an alkoxy group, an acyloxy group, an aminooxy group, an alkenyloxy group, a hydroxyl group or the like. In the general formula (III), R ³ is a hydrogen atom or a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms, preferably a hydrogen atom or a hydrocarbon group,
Particularly, it is preferably a hydrogen atom. Wherein at R ⁴ is a divalent organic group having 1 to 20 carbon atoms, -R ⁵ -, (A divalent hydrocarbon group of 10) or the like, and particularly preferably a methylene group. As a specific method for producing an oxyalkylene polymer having an olefin group represented by the general formula (III), for example, as disclosed in JP-A-54-6097, A method in which a compound having a hydroxyl group and an unsaturated group is reacted to form a bond by an ether bond, an ester bond, a urethane bond, a carbonate bond, or the like, or when polymerizing an epoxy compound such as ethylene oxide or propylene oxide, allyl glycidyl is used. For example, a method of adding an olefin group-containing epoxy compound such as ether and copolymerizing to add an olefin group to a side chain can be exemplified. The oxyalkylene-based polymer (hereinafter, also referred to as oxyalkylene-based polymer (B)) used in the present invention together with the oxyalkylene-based polymer (A) may reduce the viscosity of the composition, reduce the cost, or reduce the composition. It is a component for adjusting the properties such as hardness and elastic modulus of the cured product obtained from the above, and for making it easier to dry the coating film when an alkyd paint is applied to the cured product. The oxyalkylene polymer (B) is an oxyalkylene polymer (hereinafter, referred to as an oxyalkylene polymer (D)) substantially containing no hydroxyl group. In addition, an oxyalkylene polymer having a number average molecular weight of 4000 or more and containing a hydroxyl group (hereinafter referred to as an oxyalkylene polymer (C)) can be used for the same purpose as the oxyalkylene polymer (D). It may be used in combination with the oxyalkylene polymer (D). Since the oxyalkylene polymer (B) is used as a plasticizer, it does not contain a group that can be crosslinked at room temperature, such as a reactive silicon group of the oxyalkylene polymer (A). As in the case of the oxyalkylene polymer (A), the main chain of the oxyalkylene polymer (B) is essentially, that is, 60% or more, preferably 80%, of the monomer units constituting the main chain. The above is a general formula: -R ¹ O- No. The number average molecular weight of the oxyalkylene polymer (C) is required to be 4000 or more,
It is preferably at least 4,500, more preferably 5,000 to 15,000. When the number average molecular weight is less than 4,000, if the polymer contains a hydroxyl group, when the alkyd paint is applied to the cured product, the drying property of the coating tends to be poor. Further, the proportion of the component having a number average molecular weight of 1,000 or less is preferably 10% or less (the proportion from the value measured by the GPC method, the same applies hereinafter), because the drying property of the alkyd paint is improved. It is particularly preferred that there is. The molecular weight of the oxyalkylene-based polymer (C) is narrow in distribution, that is, It is said that the dryness of the painted alkyd paint is improved because the proportion of the minute is small Is more preferred. Specific examples of such an oxyalkylene polymer (C) include, for example, polyoxypropylene glycol having a number average molecular weight of 4,000 or more and having a narrow molecular weight distribution or a small content of 1,000 or less. Propylene glycol in which some of the hydroxyl groups are blocked with a hydrocarbon group such as an alkyloxy group, an alkylphenyloxy group, an alkenyloxy group, an allyloxy group, etc., a urethane bond, an ester bond, a urea bond, and a carbonate bond Examples thereof include those in which a part of a hydroxyl group is blocked by a hydrocarbon group such as an alkyl group, an aryl group, and an alkenyl group through a bond such as, but not limited to. The oxyalkylene polymer (D) is a polymer having substantially no hydroxyl groups. When the oxyalkylene-based polymer (D) substantially contains a hydroxyl group, generally, when the alkyd-based paint is applied to the cured product, the drying property of the coating film tends to be deteriorated. Usually, since an oxyalkylene polymer is produced by ionic polymerization of an alkylene oxide, it usually has a hydroxyl group, particularly a terminal hydroxyl group. There are various methods for obtaining an oxyalkylene polymer (D) from an oxyalkylene polymer having a hydroxyl group. For example, by introducing a substituted or unsubstituted hydrocarbon group using the reactivity of a hydroxyl group, 90 mol% or more, preferably 95 mol% or more of the hydroxyl group is converted to a group other than the hydroxyl group. Examples of the polymer in which the hydroxyl group is converted to another group in this manner include an oxyalkylene polymer having a terminal hydroxyl group as mentioned as a specific example of the oxyalkylene polymer (C), an ether bond, urethane. Aryl such as alkyl group such as methyl group, ethyl group, propyl group, chloromethyl group, benzyl group and glycidyl group, phenyl group, toluyl group and chlorophenyl group through bond such as bond, ester bond, urea bond and carbonate bond Oxyalkylene polymers which are blocked with a substituted or unsubstituted hydrocarbon group such as an alkenyl group such as a group, a vinyl group or an allyl group, preferably a C _{1 to} C ₄₀ hydrocarbon group. However, the present invention is not limited thereto, and other oxyalkylene-based polymers may be used as long as they do not substantially contain a hydroxyl group. Among the oxyalkylene polymers (D), the oxyalkylene polymer containing an alkenyl group is convenient for use because it is a raw material of the oxyalkylene polymer (A). Although the molecular weight of the oxyalkylene polymer (D) is not particularly limited, it is usually 100
It is preferably about 0 or more. In general, when the number average molecular weight of the oxyalkylene polymer (D) is increased, the coatability of the alkyd paint is further improved. For example, when the molecular weight is 4000 or more, the desired coatability of the alkyd paint is obtained. Further, the molecular weight is preferably 4500 or more, particularly preferably 5,000 to 15,000. The content and molecular weight distribution of components having a number average molecular weight of 1,000 or less of the oxyalkylene polymer (D) can be similarly applied to the description of the oxyalkylene polymer (C). The lower the The oxyalkylene polymer (B) may be used alone or in combination of two or more. The oxyalkylene polymer (B) is an oxyalkylene polymer
(A) It may be blended as a solvent during production. The amount of the oxyalkylene polymer (B) used is the oxyalkylene polymer (A
10 to 500 parts, preferably 20 to 2 parts, per 100 parts (parts by weight, hereinafter the same)
00 parts is more preferred. If the amount is less than 10 parts, the plasticizing effect is small, and it is not practical in terms of lowering the elastic modulus and increasing the elongation of the cured product, and if it exceeds 500 parts, the curing tends to be slow. The composition of the present invention may be used by adding a curing accelerator, a filler, and other additives as necessary. Examples of the curing accelerator that can be used in the present invention include organic tin compounds, acidic phosphate esters, reactants of acidic phosphate esters with amines, saturated or unsaturated polycarboxylic acids or acid anhydrides thereof, and organic titanates. Compounds, organic aluminum compounds, organic zirconium compounds and the like. Specific examples of the organotin compound include dibutyltin dilaurate, dioctyltin dimaleate, dibutyltin phthalate, tin octylate, dibutyltin methoxide, and the like. R represents an organic residue). Examples of the organic titanate compound include titanates such as tetrabutyl titanate, tetraisopropyl titanate, and triethanolamine titanate. When a curing accelerator is used, the amount of the added accelerator is oxyalkylene polymer (A) 1
0.1 to 20 parts is preferable for 00 parts. Examples of the filler include heavy calcium carbonate, light calcium carbonate, colloidal calcium carbonate, kaolin, talc, silica, titanium oxide, aluminum silicate, magnesium oxide, zinc oxide, and carbon black. Examples of the other additives include an anti-sagging agent such as hydrogenated castor oil and organic bentonite, a coloring agent, an antiaging agent, and the like. In addition, a low-molecular-weight plasticizer such as dioctyl phthalate may be used together with the composition of the present invention as long as the effects of the present invention are achieved. The composition of the present invention as described above can be usefully used as an adhesive, a paint, a coating film waterproofing agent, a sealing material, a molding material, a cast rubber material, a foam material, and the like. For example, when applied as a building sealant, usually 10 to 300 parts of an inorganic filler such as calcium carbonate, talc, kaolin, etc. is added to 100 parts of the oxyalkylene polymer (A), and if necessary, oxidized. After adding appropriate amounts of pigments such as titanium and carbon black, UV absorbers, anti-aging agents such as radical chain inhibitors, drying oils, and air-drying compounds such as synthetic drying oils, use a kneader or paint roll to make them uniform. By applying the kneaded material and exposing it to moisture in the air, it is quickly cured, for example, in about one hour to several days, and a rubber elastic body having good weather resistance, transparency and tensile elongation can be obtained. When applied as a paint, it cures in the same manner as described above, and a cured product showing high tensile elongation and weather resistance is obtained, and exhibits excellent properties as a high elastic paint for construction, a primer for concrete structures, a waterproofing agent, etc. . Also, when applied as a coating film waterproofing agent, it has an excellent balance between breaking strength and elongation,
Further, since the durability and the water resistance are good, deterioration such as blistering and peeling is improved as compared with those obtained by the existing technology. Further, when applied as an adhesive, it is used as a structural adhesive as an adhesive having excellent adhesive strength, and in particular, having a good balance between peel adhesive strength and shear adhesive strength. When applying an alkyd-based paint on a cured product of the composition of the present invention that can be used for such various applications, it is better to apply the composition after the composition is almost completely cured, and the cured product characteristics have been improved. It is preferable in that it can be easily applied because it can be applied on objects, and there is no stop in the supply of water necessary for curing the oxyalkylene polymer (A) by the coating film.However, the composition is tack-free and the surface layer If can be solidified, it can be painted. There is no particular limitation on the alkyd paint, and a condensate of a polybasic acid (phthalic anhydride, maleic anhydride, etc.) and a polyhydric alcohol (glycerin, pentaerythritol, ethylene glycol, trimethylolethane, etc.) is obtained by using a fatty oil or Oil-modified alkyd resins modified with fatty acids (linseed oil, soybean oil, castor oil, safflower oil, etc.), and alkyd resins modified with various resins or vinyl monomers, etc. Alkyd resin varnish and alkyd resin enamel used for painting for vehicles, aircraft, industry, etc., and alkyd resin formulation used for painting for construction, iron bridges, ships, etc. Paint (also called synthetic resin paint), base paint for automobiles, machinery, electrical products, furniture, etc. Such as alkyd resin undercoat paint used in, it may be of any form. Particularly, the effect is remarkable in a long oil alkyd paint having a large amount of drying oil used for general purposes. Conventionally, when applying a cured alkyd paint using a combination of an oxyalkylene polymer (A) and a conventional low molecular weight plasticizer, drying of the paint is greatly delayed, and even after about one month, stickiness remains. In the case of applying an alkyd-based paint to the cured product, it has been considered that the alkyd-based paint cannot be practically used without first applying a paint (primer) other than the alkyd-based paint. By using the composition described above, a normal alkyd-based coating film can be formed on a cured product of the composition containing the oxyalkylene-based polymer (A) and the plasticizer by a usual method. Next, the composition of the present invention will be specifically described based on examples. Synthesis Example 1 800 g of an oxypropylene-based polymer having an average molecular weight of about 8000 in which an allyl ether group was introduced at 97% of all terminals was placed in a pressure-resistant reaction vessel equipped with a stirrer, and 19 g of methyldimethoxysilane was added. Then, 0.34 ml of a chloroplatinic acid catalyst solution (a solution of 8.9 g of H ₂ PtCl · 6H ₂ O dissolved in 18 ml of isopropyl alcohol and 160 ml of tetrahydrofuran) was added, and the mixture was reacted at 80 ° C. for 6 hours. When the amount of the remaining hydrosilyl groups in the reaction solution was quantified by IR spectroscopy, almost no remaining hydrosilyl groups remained. When the reactive silicon group was quantified by the NMR method, an oxypropylene-based compound having about 1.7 (CH ₃ O) ₂ Si (CH ₃ ) CH ₂ CH ₂ CH ₂ O— groups per molecule at the molecular terminal was obtained. A polymer was obtained. Examples 1 to 4, Reference Example 1 and Comparative Examples 1 and 2 As shown in Table 1, the oxypropylene-based polymer (A) obtained in Synthesis Example 1
Using a composition prepared by blending components such as the oxyalkylene polymer (B) shown in Table 1, a sheet having a thickness of 3 mm was prepared and cured at room temperature for one day.
Apply alkyd paint (trade name: Rock Coat, manufactured by Rock Paint Co., Ltd.)
The curing properties during the days shown in Table 1 were examined by finger touch. The results are shown in Table 1. No oxypropylene polymer, Cypropylene polymer, 4%, hydroxyl-terminated oxypropylene polymer, It is a propylene polymer. It is a propylene polymer. The number in the column of the evaluation result indicates the curability of the alkyd paint, 5 indicates that the applied paint is completely cured, 4 indicates that the applied paint is cured, but a little stickiness remains on the surface, and 3 indicates that the applied paint is cured. When the finger is touched on the surface, the paint is slightly applied to the fingertip. 2 is partially hardened, but when the finger is applied to the coated surface, the paint is applied to the fingertip. 1 is the applied paint is thickening. 0 indicates that there is no change (uncured) in the applied paint. From the results shown in Table 1, when oxypropylene having a terminal hydroxyl group blocked was used as in Examples 1, 2, 3, and 4, a conventional low-molecular plasticizer (dioctyl phthalate) was used. It is apparent that the alkyd paint has superior curability as compared with the case where the coalescing is used. It is also clear that when the oxypropylene polymer having a molecular weight of 4000 or more is used as in Reference Example 1, the alkyd paint has excellent curability as compared with the case where a low molecular weight oxypropylene polymer is used. is there. [Effect of the Invention] The cured product obtained from the composition of the present invention containing the oxyalkylene polymer (A) and the oxyalkylene polymer (B) is coated with an alkyd paint under ordinary conditions. And can be dried, and a good alkyd paint film can be formed.

Claims (1)

Claims 1 (A) An oxyalkylene polymer having a hydroxyl group or a hydrolyzable group bonded to a silicon atom, and having at least one silicon-containing group capable of crosslinking by forming a siloxane bond; B) A curable composition containing an oxyalkylene polymer substantially containing no hydroxyl group (excluding those having an ester bond in the molecule). 2 (A) an oxyalkylene polymer having a hydroxyl group or a hydrolyzable group bonded to a silicon atom and having at least one silicon-containing group capable of crosslinking by forming a siloxane bond; and (B) a substantially hydroxyl group And an oxyalkylene polymer which does not substantially contain oxyalkylene and which does not substantially contain a hydroxyl group as the component (B). The curable composition below. 3. The composition according to claim 1, wherein the proportion of the component having a molecular weight of 1,000 or less in the oxyalkylene polymer substantially containing no hydroxyl group as the component (B) is 10% by weight or less. 4. The composition according to claim 1, wherein the oxyalkylene polymer having substantially no hydroxyl group as the component (B) is a polymer having an allyl ether terminal. 5. The composition according to claim 1, wherein the number-average molecular weight of the oxyalkylene polymer substantially free of a hydroxyl group, which is the component (B), is 1,000 or more.