RU2437908C1 - Paint composition with high scattering power for obtaining chemical coatings via cathodic electrodeposition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: compositions can be used to obtain chemical resistant coatings via cathodic electrodeposition on articles with a complex shape, e.g. oil pumps. The composition contains the following (g/l): epoxy-amine adduct modified with partially blocked toluylene diisocyanate 100; fluororubber latex SKF-264 V 48-52; pigment paste stabilised with said adduct 28-32; acetic acid 0.4; phenoxypropanol 4.5-5.1; butyl glycol 3.5-4.1; water - the rest.

EFFECT: invention enables to obtain thin, chemical-resistant coatings which are uniform on thickness on articles with a complex shape.

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Description

The invention relates to the creation of water-dispersing water compositions with high dispersing ability, used to obtain chemically resistant coatings by cathodic electrodeposition. The invention can be used when it is required to obtain a uniformly thick chemical-resistant coating on products of complex configuration.

Known aqueous compositions for producing chemical-resistant coatings by electrodeposition on the anode [ed. testimonial. SU 637746] and at the cathode [Russian patent 2221563] based on aqueous fluoroplastic dispersions with additives of carboxyl-containing (for electrodeposition on the anode) and amino-containing (for electrodeposition on the cathode) oligomeric electrolytes. The latter are stabilizers of fluoroplastic particles in an aqueous medium. Compositions are electrodeposited in accordance with the laws of the electrophoretic mechanism. The scattering power of these compositions is small. Therefore, they cannot be used to obtain coatings on products of complex configuration, in particular, for impellers of oil pumps.

Also known is an aqueous composition based on an epoxyamine adduct modified with an unsaturated diethyl malonate polyester and aqueous fluoroplastic dispersions (polytetrafluoroethylene or hexafluoroethylene) to produce hydrophobic anticorrosion coatings on a cathode [Russian patent 2222562]. Coatings are highly dispersible, but not chemically resistant.

The proposed paint composition is devoid of these disadvantages and allows to obtain uniform, thick, thin chemical-resistant coatings on products of complex configuration by the method of cathodic electrodeposition. It is based on the use of a certain ratio of components of the paint system, which includes: a binder - an epoxyamine adduct modified with partially blocked toluene diisocyanate, neutralized with acetic acid in the form of an aqueous emulsion with a concentration of 35-36% dry. ost. containing phenoxypropanol and butyl glycol additives; pigment paste (pigments can be any), stabilized by the indicated adduct, in the form of an aqueous dispersion of a concentration of 53-56% dry. ost .; as well as fluorine rubber latex SKF-264 B (TU2294-019-13693708-2004) (dry residue, 60-70%), acetic acid and water.

The composition is prepared as follows.

To the calculated amount of demineralized water, with stirring, add the corresponding amount of SCF-264B latex, previously acidified with acetic acid. Then, with vigorous stirring, the film former emulsion is introduced very slowly. In this case, an additional stabilization of the rubber particles by the adduct takes place, and the fluorine rubber particles acquire a positive charge. Stirring is continued for at least 2 hours. Then, while mixing, add a pigment paste and continue mixing for at least an hour. It turns out a working solution with the following parameters: dry matter content of 13-15% (mass.), PH 5.3-5.5, electrical conductivity - 1650-1750 μS.

The samples to be painted are degreased with white spirit. Coatings are obtained in an electrodeposition bath in which the samples to be coated serve as a cathode. The opposite electrode is a stainless steel plate. The electrodeposition is carried out in the following mode: voltage (V = const) = 160-250 V; duration = 120 seconds; temperature = 28-32 ° C. After painting, the coatings are washed with demineralized water and thermoset at 180 ° C for 30 minutes.

The prototype is the initial paint material without the addition of latex SKF-264 V.

Table 1 shows examples of the composition of the composition, table 2 shows the properties of the resulting coatings.

Table 1 The composition of the compositions (g / l) Name of components According to the invention Control sample 1 Control sample 2 Prototype one 2 3 four Film former one hundred one hundred one hundred one hundred Pigment paste (100%) 28-32 28-32 28-32 28-32 Latex SKF-264 (60-70%) 48-52 47 53-55 - Acetic acid (100%) 0.4 0.4 0.4 0.4 Butyl glycol 3.5-4.1 3.5-4.1 3.5-4.1 3.5-4.1 Phenoxypropanol 4,5-5,1 4,5-5,1 4,5-5,1 4,5-5,1 Water the rest is up to 1 liter the rest is up to 1 liter the rest is up to 1 l the rest is up to 1 liter

table 2 Coating Properties Sample No. from table 1 Thickness, microns GOSTR 51694 Adhesion, GOST 15 MO-78 score Impact resistance, cm, GOST 4765 Chemical resistance, hours in 10% hydrochloric acid solution at 80 ° C GOST 9.403 (method A) one 21-23 one fifty four 2 21-23 one fifty 3,7 3 The aggregate stability of the system decreases, therefore, coatings fail four 21-23 one fifty 0.2

The scattering ability of all compositions, determined according to TTM 1.94.1103-2205, clause 5.5, was at least 23 cm, which makes it possible to obtain a uniform coating in thickness on products of complex configuration.

Latex SKF-264V is a terpolymer of vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene and a modifier (soc. 60-70% wt .; pH 5-9).

Claims (1)

Composition for producing thin chemically resistant coatings by cathodic electrodeposition on products of complex configuration based on a paint and varnish system, comprising as a binder an epoxyamine adduct modified with partially blocked toluene-diisocyanate, a pigment paste stabilized by the indicated adduct, a neutralizer is 100% acetic acid, butyl phenoxypropanol and water, characterized in that it further comprises fluorine rubber latex SKF-264 B in the following ratio of components:
Name Concentration g / l Indicated adduct one hundred Pigment paste (100%) 28-32 Fluororubber latex SKF-264 V (60-70% s.o.) 48-52 Acetic acid (100%) 0.4 Butyl glycol 3.5-4.1 Phenoxypropanol 4,5-5,1 Water The rest is up to 1 liter