SU578273A1 - Enamel slip - Google Patents

Description

one

The invention relates to the production of slips for enameling metals.

An enamel slip for electrophoretic coating is known, comprising frit, bentonite, clay, sodium nitrite, sodium aluminate and water 1.

However, the known composition of the enamel slip is characterized by the formation of a loose sediment on the product due to electrolysis of the dispersion medium with the release of gases — oxygen, hydrogen, and others, which does not allow to obtain a high-quality coating.

The purpose of the invention is to improve the quality of coatings.

This is achieved by the fact that the enamel slip for electrophoretic coating also contains fluorspar, quartz sand and an alcohol solution of a phenol-formaldehyde resin at the next component ratio, wt. h .: Fritta100-200

Bentonite 5-10

Clay3-8

Sodium Nitrite 0.1-0.2

Sodium aluminate 0.2-0.5

Water40-80

Fluorspar3-6

Quartz iesok5-22

Alcohol solution of phenol formaldehyde resin 0.5-1.5

In this case, the frit may contain, by weight. %;

SiOa40,5-57

VgOz8-20,5

5KagO19-22

K200,5-3

TiOa0,5-3

A1203.2-7

Soo0,4-0,6

10NiO0.4-0,6

CaFs7-13

MgO 0.3-2

ZrOa0,2-3

ZnO0,2-0,8

15CaO0,5-3

In the described slurry, the dispersion medium is water, and the phenol-formaldehyde resin, dissolved in alcohols (a mixture of butyl and isopropyl alcohols), plays the role of a disperser phase particle charger, hardens the coating and expands the precipitation pH range.

The slip is prepared by wet grinding of frits, glyps, bentonite, sodium nitrite, 25 sodium aluminate, fluorspar n water in ball mills to a grinding fineness of 3-10% (according to Lysenko). A 3% solution of phenol-formaldehyde resin in a mixture of butyl and isopropyl alcohols is added to the obtained slip with occasional stirring and is kept for 3 to 24 hours. The viscosity of the proposed slip is from 17 to 55 s (TZ-4).

In tab. 1 shows specific examples of enamel shlpkerov, and table. 2 - nx properties.

with a moisture content from 12 to more dense packing of particles of the dispersed phase and, due to the electrically insulating effect, electric power lines are redistributed in the directions of surface areas with a smaller thickness, otherwise

The phenol-formaldehyde resin is pre-dissolved in a mixture of butyl and isopropyl alcohols in a ratio of 1: 2. Moreover, for the slip, a phenol-formaldehyde resin of low molecular weight (mol. Weight) is used, i.e. the initial stage of polymerization.

Using the following chemical composition of the original Frit, weight. %:

SiOa47,1

BsOs12,4

NasO21,9

K2O0,5

TiO20,7

ABO3.8

CoO0,5

NiO0.5

Sar28,4

MgO0.5

ZrOa0,7

ZnO0,4

CaO0,5

The introduction of a phenol-formaldehyde resin in a mixture of butyl and isopropyl alcohols makes it possible to obtain on the product x a dense electrophoretic precipitate, which is not washed off with water during repeated washing. Electrophoretic precipitate formation

yawning sediment. Alignment of sediment thickness on the product is detected by a sharp

0 current drop during sediment formation.

For example, if in the deposition current the current intensity is 16 A, then in 30-45 s it is 8-10 A, i.e. almost half of it decreases as a result

45 form a dense precipitate on the product. The intensity of sediment formation is from 150 to 500 micron / min.

Claims (2)

1. An enamel slip for electrophoretic coating containing frit, bentonite, clay, sodium nitrite, sodium aluminate and water, characterized in that, in order to improve the quality of coatings, it additionally contains fluorspar, quartz sand and an alcohol solution of phenol-formaldehyde resin with the following ratio of components, weight. including: Frit100-200 Bentonite 5-10 Clay3-8 Sodium Nitrite 0.1-0.2 Sodium aluminate 0.2-0.5 Voda40-80 5 Fluorspar 3-6 Quartz sand 5-22 Alcohol solution of phenol-formaldehyde resin 0.5-1.5 2. The slip according to claim 1, characterized in that 5 frit contains, weight. %: SiOj 40.5-57 B2O3 8-20.5 NajD 19-22 K2O 0.5-0.3 TiOg 0.5-310 2.5-7 CoO 0.4-0.6 NiO 0.4- 0.6 6 Sar2 7-13 MgO 0.3-2 ZrO2 0.2-3 ZnO 0.2-0.8 CaO 0.5-3 Sources of information taken into account during the examination 1. Posvolska L.V. and Razlivanova, V.Yo., on the application of enamels to steel surfaces by electrophoretic deposition. “Sanitary equipment. Sat Proceedings, No. 34, Sector of Scientific and Technical Information, M., 1970, p. 115-123.