JP2926326B2 - Composition for curable paint - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silyl group-terminated compound capable of curing at room temperature with moisture, an organotin compound as a silanol condensation catalyst, and a mercapto group-containing compound as a pot life regulator. The present invention relates to a novel curable coating composition containing a compound as an active ingredient. [0002] Moisture-curable compounds having silyl functional groups at the terminals are useful materials as paints, coatings, adhesives, sealants and the like. [0003] Since the curing characteristics of a silyl group-containing compound are greatly affected by the type of curing agent, it is essential to select a curing agent suitable for the intended use. . For example, when a silyl group-containing compound-organotin compound is used as a paint for repairing automobiles, the pot life, appearance, and curability are poorly balanced, and there are many problems in practical use. That is, if the amount of the organotin compound is reduced, the pot life and the appearance are improved, but the curability is deteriorated. On the other hand, if the amount of the organotin compound is increased, the curability is practically no problem, but the pot life and Since the appearance was extremely reduced, it was a large barrier in practical use. The present inventors have made intensive studies on this problem, and as a result, when a mercapto group-containing compound is added to an organotin compound, the catalyst activity hardly decreases. It has been found that this can be a practically important curing agent that improves pot life and appearance. That is, the present invention provides: (A) the following general formula: [Wherein, R ¹ and R ² are hydrogen or a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group, and an aralkyl group, X is a halogen, an alkoxy group, an acyloxy group, a ketoximate group, A group selected from an amide group, an acid amide group, an aminooxy group and a mercapto group, a =
Polyester, ether ester block copolymer, vinyl polymer, diallyl phthalate compound, diallyl phthalate copolymer, epoxy compound having at least one silyl group in the molecule represented by an integer of 0, 1 or 2] (B) Organotin compound (C) Mercapto group-containing compound A curable coating composition containing the above components (A), (B) and (C) as active ingredients, wherein The component (B) is contained in an amount of 0.0001 to 50 parts by weight based on 100 parts by weight of the component (A), and the component (C) is added in a weight ratio of 0.1 to 50 parts by weight of the component (B).
It contains 0.5-20. DETAILED DESCRIPTION OF THE INVENTION The production of the silyl group-containing compound (A) of the present invention can be carried out by various methods. For example, a hydrosilylation reaction between a vinyl resin having a carbon-carbon double bond and a hydrosilane, a copolymerization of a vinyl compound and a silyl compound having a polymerizable double bond, a compound having an epoxy group and an aminosilane or mercaptosilane, etc. There is a reaction. Are disclosed in JP-A-54-36395, JP-A-57-63351, JP-B-59-1423 and the like. The epoxy compound in the method of, for example, bisphenol A type, epoxy urethane type, epoxy resin such as novolak type and γ-aminopropyltrimethoxysilane,
It is obtained by reacting an aminosilane compound such as γ (2-aminoethyl) -aminopropyltrimethoxysilane or a mercaptosilane compound such as γ-mercaptopropyltrimethoxysilane. The reaction conditions are as follows.
What is necessary is just to stir and mix these at -80 degreeC for several hours. The organotin compound (B) used in the present invention
Are carboxylic acid-type organic tin compounds such as tin octylate, dibutyltin dilaurate, and dioctyltin malate; sulfide-type and mercaptide-type organic tin compounds such as monobutyltin sulfide and dioctyltin mercaptide; organic tin oxides such as dioctyltin oxide; A compound obtained by reacting an organic tin oxide with an ester compound such as ethyl silicate, ethyl silicate 40, dimethyl maleate, or dioctyl phthalate is effective. These catalysts are used in an amount of 0.0001 to 5 per 100 parts by weight of the silyl group-containing compound.
0 parts by weight, preferably 0.001 to 30 parts by weight. The compound (C) containing a mercapto group used in the present invention includes n-dodecyl mercaptan, ter
alkyl mercaptans such as t-butyl mercaptan; γ-
Mercaptosilanes such as mercaptopropyltrimethoxysilane; carboxylic acids such as 2-mercaptopropionic acid and thiosalicylic acid; ester compounds such as 2-ethylhexyl thioglycolate; Capcure 3-800 (manufactured by Diamond Shamrock Chemicals Co., Ltd. Polymers such as certain polyethers), thiophenol, and thiobenzoic acid are used. These mercapto group-containing compounds are used in a weight ratio of 0.05 to 2 with respect to the organotin compound.
0, preferably in the range of 0.1 to 10. The organotin compound and the mercapto group-containing compound may be added to the silyl group-containing compound in a predetermined mixture, or may be added separately. [0009] The curable coating composition according to the present invention can also be prepared by adding a stabilizer to a mixture in advance by a method of mixing a silyl group-containing compound with an organotin compound and a mercapto group-containing compound before use (two-pack type). A method (one-pack type) of preserving in a state free of water and using as it is may be used. The composition for a curable coating composition of the present invention includes component (A),
In addition to (B) and (C), conventional additives such as various other fillers, pigments, ultraviolet absorbers, antioxidants, matting agents, leveling agents, and the like can be contained at known effective concentrations. The composition for a curable coating composition of the present invention can be used at room temperature to
It can be cured in a short time in a high temperature range, and has excellent physical properties such as adhesion and weather resistance of the cured product, so it is useful as a paint, coating agent, primer, adhesive, etc. for inorganic and organic surfaces. is there. In particular, since it can be cured at a low temperature, it is also effective as a coating for corrosion protection of bridges and the like, a top coating, a repair coating for automobiles, a coating for organic material surfaces, and the like. It can be blended with various resins currently used as paints, coating agents, primers, and adhesives. For example, lacquer paints, acrylic lacquer paints, thermosetting acrylic paints, alkyd paints, melamine paints It can be used by mixing it with an epoxy paint or the like at an appropriate ratio, and the physical properties such as adhesion and weather resistance of these paints and coating agents can be improved. Hereinafter, the present invention will be described with reference to examples. Synthesis Example 1 Styrene 1 was added to 450 g of xylene heated to 110 ° C.
A mixture of 50 g, 300 g of butyl acrylate, 430 g of methyl methacrylate, 100 g of γ-methacryloxypropyltrimethoxysilane, 20 g of acrylamide, and 18 g of azobisisobutyronitrile was added dropwise under reflux for 5 hours. A mixed solution consisting of 1 g of butyronitrile and 90 g of xylene was added to 1
The mixture was added dropwise for 2 hours, followed by polymerization for 2 hours to obtain a solution having a solid content of 64%. The solution viscosity was 120 poise at 25 ° C.
The number average molecular weight of the obtained silyl group-containing compound measured by GPC was 10,000. Examples 1 to 5 and Comparative Example 1 100 parts by weight (in terms of solid content) of the silyl group-containing compound obtained in Synthesis Example 1 was diluted with xylene to a solid concentration of 35%, and then dioctyltin dimaleate 2 was added. 1 part by weight of a mercapto group-containing compound was added. The obtained curable coating composition is spray-coated on a polished mild steel plate which has been coated with lacquer plastic beforehand, set at 20 ° C. for 30 minutes, then cured at 60 ° C. and potted at 20 ° C. Physical properties such as life were measured. The results are shown in [Table 1]. As a comparative example, the case where no mercapto group-containing compound was used was also described. The physical properties were measured according to the following methods. A) Appearance: Judgment was made based on the state of the coated surface of the clear coating film on the lacquer plastic. …: Good paint surface condition, x: poor paint surface condition. B) Curability (masking property): After setting, a masking tape (paper adhesive tape No. 720 manufactured by Nitto Electric Industry Co., Ltd.) is applied to the coating at 60 ° C. every predetermined time, and the tape mark is formed. , Or the time until no tape traces remained. C) Pot life: 70 g of the prepared composition
In a 100cc Death Cup (Terraoka), 20 ℃
Was left standing in an open state, and adjusted with an Iwata cup, and the viscosity change for 2 hours was examined. D) Pencil hardness: Measured according to JIS-5400. [Table 1]

Claims (1)

(57) [Claims] (A) The following general formula: [Wherein, R ¹ and R ² are hydrogen or a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group, and an aralkyl group, X is a halogen, an alkoxy group, an acyloxy group, a ketoximate group, A group selected from an amide group, an acid amide group, an aminooxy group and a mercapto group, a =
At least one Yusuke ruby sulfonyl polymer silyl group represented by 0, 1 or 2 of the integer in the molecule (B) an organic tin compound (C) a mercapto group-containing compound above components (A) (B) ( A curable coating composition containing C) as an active ingredient, wherein component (B) is contained in an amount of 0.0001 to 50 parts by weight based on 100 parts by weight of component (A), and component (C) is contained. 0.1 weight ratio to component (B).
A composition for a curable coating, comprising from 0.5 to 20. 2. The curable coating composition according to claim 1, wherein the component (A) is a vinyl polymer having a molecular weight of 300 to 20,000. 3. The curable coating composition according to claim 1, wherein the mercapto group-containing compound as the component (C) is n-dodecyl mercaptan. 4. The curable coating composition according to any one of claims 1 to 3, wherein the mercapto group-containing compound as the component (C) is γ-mercaptopropyltrimethoxysilane.