UA115634C2 - ENAMEL - Google Patents

Abstract

The invention relates to the chemical industry, namely the production of soilless silicate enamels, which are used as anti-corrosion protective coatings for steel pipes in hot water systems. The enamel to obtain the soil coatings contains, wt. %: 54.9-57.6 SiO2; 16.9-19.22 Na2O; 4.9-6.5 K2O; 6.3-8.73 B2O3; 3.0-3.8 CaO; 0.40-0.46 CoO; 2.1-3.6 ZrO2; 0.8-1.3 MnO2; 3.52-5.3 TiO2; 2.0-2.5 F '. EFFECT: application of the invention provides the obtaining of soil-free enamel with high heat resistance, alkali and water resistance, with enamel coatings having increased adhesion to the base.

Description

The proposed invention belongs to the chemical branch of industry, namely the production of soilless silicate enamels, which can be used as anti-corrosion protective glass coatings when enameling steel pipes used in hot water supply systems. d,

The glass-enamel coating improves the hydraulic characteristics of the pipeline and prevents the deposition of various substances on the walls. In addition, the enameled surface of the pipes allows you to collect clean water and other transported products.

Primerless enamels are most often used as protective coatings, which combine the properties of both the primer and the coating layer of enamel. These enamels are distinguished by increased chemical resistance to aggressive environments, gas tightness, mechanical strength and wear resistance, as well as high hygiene.

Known frit for soilless enamel coating to protect ferrous metals from corrosion by acidic aggressive environments at elevated temperatures (A.s. 920015 USSR, MPKU

SsoZS 7/04, SSOZS 7/06, Fritta for soilless bituminous coating. / Nikitina R.I., Valbe

NA., Ignatova R.M., statement 03.25.80, Mo. 2885841/29-33, publ. 15.04.82 Bul.Me14|. This enamel includes oxides of silicon, aluminum, calcium, boron, potassium, lithium, sodium, titanium, cobalt, nickel, copper, lead and fluorine in the following ratio of components, wt. 90: 57-59 5102; 1.2-1.6

AI26 Oz; 5-6,1 Sabo; 7.8-8.5 V2Oz; 1.5-2.5 K2gO; 2.5-3.5 120; 15-17 MagO; 1-2.5 TO"; 0.6-0.8 So; 0.6-0.8 MiO; 0.1-0.93 Sy; 1.2-1.8 RBO, 1-1.1 E.

The disadvantages of the above-mentioned enamel are that it contains toxic RBO, it contains a significant amount of expensive cobalt oxide (up to 0.8 wt. 95), and coatings based on it have insufficient adhesion strength.

Enamel for primerless enameling of steel products, in particular hot water pipelines, is also known (Patent Mo 10991 Ukraine, IPKZ SOZS 8/06, Zmal. /

Pylypenko M.F., Opymakh E.N., Malinsky L.N., Guba N.Y., Kaplyuchenko M.S., application. 04/13/94,

Mo. 94041903, publ. 25.12.96 Y1. This enamel includes oxides in the following ratio, by weight. to: 52-58 5102; 0.5-6.0 2715104, 2-6 B2Oz; 12-18 MagO; 2-6 K2O; 0.2-0.7 SogOz; 1-6 Sabo; 1.0-2.5

MPO"; 5-8 Sugg; 1-5 TiO»2; 2-6 AI2Oz.

The disadvantages of the above-mentioned enamel are that it contains a significant amount

From expensive cobalt oxide (up to 0.7 wt. 95), low indicators of alkali resistance, water resistance and adhesion strength of coatings.

The closest to the claimed invention, in terms of technical essence and the result achieved, is enamel, which is currently used in the enameling of steel pipes for various purposes at PJSC "Emalkhimprom" (Kremenchuk, Poltava Region) and KP "Santekhmontazh" ( Dnipropetrovsk) and includes the following components in the ratio, wt. 9o: 58.08 5102; 4.40 V2Oz; 13.31 MagO; 2.70 KgO; 3.90 1 20; 2.40 Sa; 4.15 Sag"; 2.65 AI2Oz; 2.10 TiO"; 0.71 Co2Oz; 0.74 Mi2Oz; 1.50 510; 3.26 Mag5biv. Kozlova A.P. Comparative tests of groundless primers for pipes |Hext| / A.P. Kozlova, N.I. Guba, I.A. Drobot // Glass and ceramics. - 2001. - Mo 2. - E. 33-35) - (closest analogue).

The disadvantages of the closest analogue are: high temperature of cooking enamels (1250-1350 C) and firing of coatings (880-920 C); insufficient adhesion strength of enamel to metal (2.0 J); low indicators of physical and chemical properties of soilless coatings (heat resistance, alkali resistance); unsatisfactory quality of the glass layer (insufficient density and burns).

The invention is based on the task of developing a primerless enamel composition with improved physico-chemical (heat resistance, alkali and water resistance) and operational properties of enamel coatings (adhesion strength), which are used in the enameling of steel pipes for various purposes, in particular for hot water supply pipes by adjusting the quantitative ratio components in the composition of the frit, as well as in the composition of the enamel glaze.

The task is solved by the fact that the enamel for obtaining: soilless coatings is known, which includes oxides of silicon, sodium, potassium, boron, calcium, cobalt, zirconium, manganese, titanium and, according to the invention, contains in its composition the above-mentioned components with the following ratios, mass for: 54.9-57.6 5iO»2; 16.9-19.22 MagO; 4.9-6.5 KO; 6.3-8.73

B2Oz; 3.0-3.8 Sa; 0.40-0.46 So; 2.1-3.6 277052; 0.8-1.3 MPO"; 3.52-5.3 TiO"; 2.0-2.5 E".

Table 1 shows the chemical compositions of the proposed primerless enamels.

The following raw materials are used to produce enamel frits: quartz sand, sodium and potassium nitrate, borax, chalk, cobalt oxide, zircon concentrate, manganese ore, titanium dioxide and fluorspar. Boiling of enamel is carried out at a temperature of 1260-1280 "C for 65-67 minutes, followed by granulation of the melt into water.

Enamel schlickers are prepared according to the generally accepted technology with the addition of 100.0 wt.h. for frits of refractory clay, electrolytes, quartz sand and water. Slickers are applied to a previously prepared metal surface by the watering method; after drying, glass-enamel coatings are fired at the following temperatures: metal samples at 860 "C for 4 minutes, pipe elements at 860 "C for 6 minutes.

The properties of the developed enamels were determined in accordance with the standards (GOST 10134. 1-82;

GOST 24788-2001; TU 1396-002-17213088-06), which are presented in table 2.

Compared to the prototype, the proposed enamels have the following advantages: - the cooking of the developed enamels and firing of the coatings is carried out at a lower temperature (1260-1280 and 860 "С, respectively), which will help save energy costs; - all enamels belong to the 1st hydrolytic class; alkali resistance is 0.12-0.21 mg/cm-h, which is significantly higher than in the prototype; - enamel coatings have a higher bond strength between enamel and metal (4.0-5.0 J); - glass coatings, based on the developed enamel, is characterized by a dense, smooth, shiny glass layer and has better heat resistance (340-360 "C) compared to the prototype (16079).

The use of the invention, in which primerless enamel is proposed, ensures obtaining high-quality single-layer enamel coatings for steel pipes of water, gas pipelines and pipes operating at elevated temperatures, reducing the cost of enameled pipes due to the reduction of energy consumption during cooking of the enamels themselves and firing of the coatings, and improves the properties of enameled pipes and increases their service life.

Table 1

Chemical composition of the proposed enamels, wt. 9Uo

The closest name

Ts bug Y717768 Her 11111111 1 -

Agoz 1717891 HER

MPBG 17717 HER 713 | 109 | 170 | 08

EE A1111201 11125 | 21 | 23

Table 2

Properties of frits and coatings (Enamel 25C)

Water resistance of the frit for pizheyatanachen ze |zer|»| with boiling at 20 Fo-i NSI for 1.32 34 | 32 | 3.5 3.6 2 hours, to

SS/min) h. boiling in dist. water,

Table 2

Properties of frits and coatings of the GG slag

Alkali resistance of the coating after 4 hours. boiling in 4 U5th Mahon, 02110121 013 012 mg/sme-h.

Acid resistance of the coating after 4 hours. boiling in 20 9b5th NOSE, 0.52 0.56 | 0.48 | 0.51 0.47 mg/sme-h.

Grip strength upon impact, D

Claims (1)

FORMULA OF THE INVENTION Enamel for obtaining soilless coatings, which includes oxides of silicon, sodium, potassium, boron, calcium, cobalt, zirconium, manganese, titanium and fluorine, which is distinguished by the fact that it contains the above components in the following ratio, by weight. Us: 54.9-57.6 BIO"; 16.9-19.22 MagO; 4.9-6.5 K2O; 6.3-8.73 B2Oz; 3.0-3.8 Sa; 0.40-0.46 So; 2.1-3.6 2102; 0.8- 1.3 Mpo"; 3.52-5.3 TO"; 2.0-2.5 R.