JPS6337808B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyurethane polymers, especially for coatings. Conventionally, when producing a polyurethane polymer as a paint using a blocked isocyanate compound, a high-temperature baking treatment was required. Therefore, when painting a thin steel plate, problems such as deformation of the steel plate itself, melting of the solder, and high energy consumption occurred. In order to solve this problem, as a dissociation catalyst that lowers the dissociation temperature of the blocked isocyanate compound, for example, Japanese Patent Publication Nos. 18877-1987, 42528-1982, 138434-1983, 53-
138435 etc., tetra-n-butyl-1,
3-Diacetyloxydistanoxane, tetra-
n-Butyl-1,3-diphenoxydistanoxane, tetra-n-butyl-1,3-dibenzyloxydistanoxane, di-n-butyltin oxide, di-n-butyltin dilaurate, tetra- n
-Butyltin and the like 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 point, the present inventors have made intensive studies and found that in the presence of a compound selected from monoalkyltin oxide and monoaryltin oxide alone or in combination of two or more, or in the presence of the monoorganic tin oxide and a dialkyltin compound. We discovered that when the reaction is carried out in combination with a diaryltin compound and a diaryltin compound and in the presence of 1,10-phenanthroline or dipyridyl, a much better catalytic effect appears compared to the use of an organotin compound alone. This led to an invention. That is, the present invention combines a blocked isocyanate compound and an active hydrogen-containing compound in the presence of one or more compounds selected from monoalkyltin oxide and monoaryltin oxide, or in combination with these compounds and a dialkyltin compound and diaryltin oxide. The present invention relates to a method for producing a polyurethane polymer, characterized in that the reaction is carried out in combination with a tin compound and in the presence of 1,10-phenanthroline or dipyridyl. 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. 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, polyester polyol, polyurethane polyol, and epoxy group-containing polyol. Next, the monoalkyltin oxide and monoaryltin oxide used in the present invention generally include monomethyltin oxide, monoethyltin oxide, monopropyltin oxide, monobutyltin oxide, monooctyltin oxide, monophenyltin oxide, etc. However, it is not particularly limited to these. Further, dialkyltin compounds and diaryltin compounds that can be used in combination with these monoalkyltin oxides and monoaryltin oxides include dimethyltin oxide, dibutyltin oxide, dioctyltin oxide, diphenyltin oxide, dimethyltin sulfide, dibutyltin sulfide, Dioctyltin sulfide, dimethyltin diacetate, dimethyltin dibutyrate, dibutyltin acetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin distearate, tetrabutyl-1,3-diacetoxydistanoxane, tetrabutyl-1,3-diphenoxylate Cidistanoxane, Tetrabutyl-1,3-dilauryloxystanoxane, Tetrabutyl-1,3
-diacetoxythiodistanoxane, tetramethyl-1,3-di(2-ethylhexylcarboxy)thiodistannoxane, dioctyltin diacetate, dioctyltin dilaurate, etc., but are not limited thereto. The mixing ratio of monoalkyltin oxide or monoaryltin oxide and dialkyltin compound or diaryltin compound may be arbitrary. The mixture is not limited to two types, and two or more types may be mixed if necessary. The proportion of 1,10-phenanthroline or dipyridyl used together with these organic tin compounds is generally 0.5 to 20%, preferably 2 to 10%, and 1, 10-phenanthroline and dipyridyl may be used together in any ratio. 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%. Furthermore, there is no problem in mixing anti-rust pigments, extender pigments, etc. with the paint if necessary. 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 ,
73 of diethylamine at 80-100 °C with stirring.
Drip a portion. After addition, the mixture is heated at 120° C. for 2 hours with stirring. Thereafter, 280 parts of dehydrated castor oil fatty acid were added, and the mixture was heated under reflux at 200°C for 5 hours to distill off the produced water, followed by reducing the pressure and distilling off toluene. Cool it to 100°C and add 300 parts of butyl acetate. To this, 90 parts of ethyl cellosolve was added in advance to 174 parts of tolylene diisocyanate (a mixture of 80% 2,4-tolylene diisocyanate and 20% 2,6-tolylene diisocyanate) at 60°C with stirring under a nitrogen mist atmosphere. 60 hours after dripping
264 parts of a partially blocked diisocyanate prepared by holding at 100°C for 2 hours with stirring.
After addition over ~1.5 h, the reaction mixture was heated to 120 °C.
Hold for 2 hours to react. Next, heat this at 50-60℃
After cooling to , add 60 parts of acetic acid and 1365 parts of deionized water to obtain a 40% solids paint base for electrocoating. 6 parts of Bengara, 6 parts of titanium white, the organic tin compound listed in Table 1, and 1,10-phenanthroline were added to 100 parts of the 40% paint base produced by the above method, and the mixture was kneaded in a ball mill for 20 minutes. deionized water 288
1 part to obtain a pigment dispersion composition having a solid content of 13% and a pH of 5.5 to 6. Using this as an electrodeposition bath, electrodeposit on a degreased steel plate at 50V for 1 minute, then rinse with tap water.
Table 1 shows the results of pre-drying (80°C, 10 minutes) and baking at various temperatures in an electric furnace for 20 minutes. In addition, each symbol in the table indicates the following meaning. ×: Uncured △: Cured but sticky 〇: Completely cured -: Not tested

[Table] Example 2 Example 1 was repeated in the same manner except that 2,2'-dipyridyl was used instead of 1,10-phenanthroline. The results are shown in Table 2.

【table】

[Table] In addition, as a comparative example in the above example, 1,
No hardening occurred even when 0.004 parts, 0.008 parts, 0.012 parts, and further 2.0 parts of 10-phenanthroline or 2,2'-dipyridyl were added as catalysts and baked under the conditions listed in the table. .

Claims (1)

[Claims] 1. A blocked isocyanate compound and an active hydrogen-containing compound are combined in the presence of one or more compounds selected from monoalkyltin oxide and monoaryltin oxide, or in combination with these compounds and a dialkyltin compound and a diaryl compound. 1. A method for producing a polyurethane polymer, which is characterized in that the reaction is carried out in the presence of 1,10-phenanthroline or dipyridyl.