JPH0153691B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates in particular to a method for producing polyurethane polymers for electrodeposition coatings. Conventionally, when producing polyurethane polymers for electrodeposition coatings using blocked isocyanate compounds, high-temperature baking treatment has been necessary. Therefore, when painting a thin steel plate, problems such as deformation of the steel plate itself, melting of solder, and high energy consumption have arisen. In order to solve this difficulty, for example, as a dissociation catalyst for lowering the dissociation temperature of blocked isocyanate compounds,
No. 18877, JP-A No. 52-42528, JP-A No. 53-138434,
No. 53-138435 etc., tetrabutyl-1,
3-diacetoxydistanoxane, tetrabutyl-1,3-diphenoxydistanoxane, tetrabutyl-1,3-dibenzyloxydistanoxane, dibutyltin oxide, dibutyltin dilaurate, tetrabutyltin, etc. have been proposed. . However, even these compounds cannot be said to have sufficient catalytic effects, and even better catalysts are desired. In view of this, the present inventors have made extensive studies and found that at least one of the mono- or di-organotin compounds
It has been found that when the seeds are used in combination with a specific nitrogen-containing compound, a significantly better catalytic effect is exhibited than when the organotin compound is used alone. That is, the present invention combines a blocked isocyanate compound and an active hydrogen-containing compound with a dialkyltin compound,
At least one compound selected from the group consisting of diaryltin compounds, monoalkyltin compounds, and monoaryltin compounds, a morpholine compound, a piperidine compound, or the general formula (R) _3-o N(CH ₂ CH ₂ OH) _o ( ) [Wherein, R is hydrogen, alkyl having 1 to 4 carbon atoms (methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, etc.), phenyl group, or -
( _CH2 ) _{nNH2 group} (here, m is an integer of 1 to 8), and n is an integer of 1 to 3. Further, when n is an integer 1, R may be different from each other. ] This invention relates to a method for producing a polyurethane polymer for electrodeposition coatings, which is characterized by carrying out the reaction in the presence of an alkanolamine compound represented by the following. The blocking isocyanate compounds used in the present invention are the addition products of each stoichiometric amount of a polyisocyanate compound and an isocyanate blocking agent. The polyisocyanate compound mentioned herein may be of any type, and includes, for example, aromatic, alicyclic, and aliphatic polyesters such as tolylene diisocyanate, xylene diisocyanate, phenylene diisocyanate, bis(isocyanate methyl)cyclohexane, and tetramethylene diisocyanate. Examples include terminal isocyanate-containing compounds obtained by reacting isocyanate compounds and excess amounts of these polyisocyanate compounds with low-molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, trimethylolpropane, hexanetriol, and castor oil. Examples of isocyanate blocking agents include phenols such as phenol, m-cresol, xylenol, and thiophenol; alcohols such as methanol, ethanol, butanol, 2-ethylhexanol, cyclohexanol, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether; Examples include active hydrogen-containing compounds such as ethyl acetoacetate and diethyl malonate. On the other hand, the compound serving as the base of the polyurethane polymer is an active hydrogen-containing compound, such as polyether polyol, polyol, polyurethane polyol, and epoxy group-containing polyol. Next, as dialkyltin compounds, diaryltin compounds, monoalkyltin compounds and monoaryltin compounds used in the present invention, dimethyltin oxide, diethyltin oxide, dibutyltin oxide, dioctyltin oxide, diphenyltin oxide, dimethyltin oxide, etc. Sulfide, dipropyltin sulfide, dibutyltin sulfide, dioctyltin sulfide, dimethyltin diacetate, dimethyltin dibutyrate, dimethyltin dioctoate, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin distearate, tetrabutyl-
1,3-Diacetoxydistanoxane, Tetrabutyl-1,3-diphenoxydistanoxane, Tetrabutyl-1,3-dilauroyloxydistanoxane, Tetrabutyl-1,3-diacetoxythiodistannoxane, Tetra Methyl-1,3-di-2-ethylhexylcarbonylthiodistannoxane, dioctyltin diacetate, dioctyltin diacetate, dioctyltin dioctoate, dioctyltin dilaurate, diphenyltin diacetate, diphenyltin dilaurate, monomethyltin oxide, monobutyltin oxide, monooctyltin oxide, monophenyltin oxide,
Monomethyltin monoacetate, monomethyltin monooctoate, monobutyltin monoacetate, monobutyltin monooctoate, monobutyltin monolaurate, monooctyltin monoacetate, monooctyltin monolaurate, monophenyltin monoacetate, monomethyltin trilaurate, Examples include monobutyltin triacetate, monobutyltin trioctoate, monobutyltin trilaurate, monobutyltin tristearate, monooctyltin triacetate, monooctyltin trilaurate, monophenyltin triacetate, monophenyltin trioctoate, monophenyltin trilaurate, etc. It is not limited to these. Furthermore, these dialkyltin compounds, diaryltin compounds, morealkyltin compounds, and monoaryltin compounds may be used alone, but two or more types may be used in combination if necessary. Morpholine compounds used in combination with these organic tin compounds include morpholine, N-methylmorpholine, N-ethylmorpholine, morpholinoethanol, N-aminomorpholine, N-β-aminoethylmorpholine, N-phenylmorpholine, N-p
-acetoxyphenylmorpholine, N-o-acetoxyphenylmorpholine, N-p-aminophenylmorpholine, etc., but are not limited to these compounds. In addition, as piperidine compounds, N-ethyl-3-hydroxypiperidine, 2,2,6,6-
Tetramethyl-4-hydroxypiperidine, N-
β-hydroxyethylpiperidine, N-hydroxypiperidine, 4-phenylpiperidine, 4-
Amino-N-benzylpiperidine, N-aminoethylpiperidine, 4-amino-2,2,6,6-
Examples include, but are not limited to, tetramethylpiperidine and 4-benzylpiperidine. Examples of alkanolamine compounds of general formula () include ethanolamine, diethanolamine,
Triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, N,N-dibutylethanolamine, N-phenyldiethanolamine, N-phenyl-N-ethylethanolamine, N-phenylethanolamine, Examples include, but are not limited to, N-β-aminoethylethanolamine, N,N-diethylethanolamine, and N,N-dimethylethanolamine. Generally speaking, the ratio of these nitrogen-containing compounds alone or in combination of two or more as necessary for dialkyltin compounds, diaryltin compounds, monoalkyltin compounds, and monoaryltin compounds is as follows:
It is 0.5 to 20%, preferably 4 to 20%. The larger the amount of the tin compound as a catalyst used in the present invention, the more the reaction proceeds at a lower temperature and a polymer is obtained.
%, preferably 0.1-1%. Further, there is no problem in mixing antirust pigments, extender pigments, etc. necessary for the paint. The following examples illustrate the invention without limiting it thereto. Example 1 500 parts of a condensed epoxy resin of epichlorohydrin and bisphenol A having an epoxy equivalent of 500 (trade name Epon 1001, manufactured by Ciel Chemical Co., Ltd.) was completely dissolved in 100 parts of toluene at 80 to 100°C, and the mixture was stirred. While stirring, 73 parts of diethylamine was added at 80 to 100°C. After applying, the mixture was heated to 120°C while stirring.
Heat at ℃ for 2 hours. Thereafter, 280 parts of dehydrated castor oil fatty acid was added, heated under reflux at 200°C for 5 hours, and the resulting water was distilled off, and then the toluene was distilled off under reduced pressure.
Cool it to 100°C and add 300 parts of butyl acetate. Add tolylene diisocyanate (2,
4-Tolylene diisocyanate 80% and 2,6
-Tolylene diisocyanate mixture at 20℃) 174
264 parts of a partially blocked diisocyanate prepared by adding 90 parts of ethyl cellosolve dropwise under a nitrogen atmosphere at 60°C for 2 hours with stirring, and then holding at 60°C for 2 hours, was added at 100°C with stirring. After addition over a period of ~1.5 hours, the reaction mixture is held at 120° C. for 2 hours to react. This is then cooled to 50-60°C and 60 parts of acetic acid and 1365 parts of deionized water are added to obtain a 40% solids paint base for electrocoating. 40% paint base 100 manufactured by the above method
6 parts of Bengara, 6 parts of titanium white, and dialkyltin compounds and diaryltin compounds listed in Tables 1 to 3,
The monoalkyltin compound, monoaryltin compound and nitrogen-containing compound were added and kneaded in a ball mill for 20 minutes, then diluted with 288 parts of deionized water to remove the solid content.
A pigment dispersion composition of 13% and pH 5.5 to 6 is prepared. This product was electrodeposited on a degreased steel plate at 50V for 1 minute in an electrodeposition bath, washed with tap water, pre-dried (80℃, 10 minutes), and baked in an electric furnace at various temperatures for 20 minutes. are shown in Tables 1 to 3. In addition, the symbol ○ in the table means completely cured, × means uncured, and - means not tested.

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Claims (1)

[Scope of Claims] 1 A blocking isocyanate compound and an active hydrogen-containing compound are combined with at least one compound selected from the group consisting of dialkyltin compounds, diaryltin compounds, monoalkyltin compounds, and monoaryltin compounds, and morpholine. compound, piperidine compound or general formula (R) _3-o N(CH ₂ CH ₂ OH) _o [wherein R is hydrogen, an alkyl group having 1 to 4 carbon atoms, a phenyl group or -(CH ₂ ) _n NH ₂ groups (where m is an integer of 1 to 8), n is 1 to 8
Indicates an integer of 3. Also, when n is an integer 1,
R may be different from each other. ] A method for producing a polyurethane polymer for electrodeposition coatings, which comprises reacting in the presence of an alkanolamine compound represented by: