The properties of alkali borotitanium-silicate glasses with different content of boron, titanium, and lithium oxides are investigated. It is indicated that glasses with a low content of B 2 O 3 (8 -10%) can be used to produce white glass-enamel coatings that have enhanced corrosion resistance and low leachability of the coating components in acetate solutions.Glass-enamel coatings represent the most common and reliable way to protect steel products, including kitchen utensils, from corrosion. The requirements on the quality of enameled kitchenware are becoming higher, regarding both their exterior appearance and corrosion resistance. The requirements on corrosion resistance of glass-enamel coatings have sharply grown after the adoption of the new Sanitary Regulations on migration of chemical elements from materials contacting food items (SanPiN 13-3 RB 01). The stricter requirements on migration of boron, nickel, and cobalt from a coating to acetate extracts, as well as the introduction of regulations on leaching of aluminum, titanium, and iron make it necessary to produce enamels with higher chemicals resistance.Silicate glasses for protective coatings are multicomponent, which makes it possible to vary their properties within wide ranges; however, the list of materials for the synthesis of white titanium enamels is limited. The compositions of white enamel have been refined over the past decades and a further improvement in their chemical resistance, while preserving other technological parameters, is hard to achieve. On the one hand, it is known [1 -3] that to increase the chemical resistance of glasses it is primarily necessary to increase their content of silicon and titanium oxides and to decrease their content of boron oxides and alkali metals oxides, which strengthens the silicon-oxygen skeleton and the glass structure, but, on the other hand, this has a negative effect on the technological and service properties of coatings.The present paper describes the study of alkaline borotitanium-silicate glasses with a higher content of silicon oxide compared to industrial compositions (GOST 24405-80) and a lower content of B 2 O 3 . Considering the valuable and actually indispensable role of boron oxide in enamel compositions responsible for decreasing viscosity and surface tension of melts, lowering the softening and firing temperature of coating, and facilitating the crystallization of anatase, it becomes obvious that B 2 O 3 cannot be completely eliminated from the composition. At the same time, the target of decreasing boron leachability from coatings motivates the search for compositions with a lower content of B 2 O 3 and methods for stronger fixation of boron in the glass structure. The undesirable phenomena related to the decreased content of boron oxide were compensated by additional introduction of lithium oxide, which has a favorable effect on acid resistance of glasses and decreasing the glass melt viscosity.We investigated the properties of four series of glasses that contain (%; here and elsewhere w...

The effect of the ratio of three alkali oxides on the physical and chemical properties of titanium-containing enamels has been investigated and their optimal concentrations have been determined. Acid resistant enamel for steel utensils has been developed.Titanium-containing glass enamels have an important place in the enameling industry and are widely used for enameling steel utensil and sanitary ware. The quality requirements for enameled utensils are becoming increasingly more stringent with respect to both the eutectic properties and corrosion resistance. Specifically, the requirements for the migration of harmful components from coatings into food solutions are becoming more and more stringent. The problem of increasing the chemical resistance of white utensil enamels is becoming more complicated because of the limited choice of the initial components for synthesizing glass frit.The objective of our investigations is to increase the chemical resistance of titanium enamels by introducing small quantities of lithium oxides and optimizing the ratio of the alkali oxides in them. Lithium oxide is known to increase the acid-resistance of glass substantially, and it is present in virtually all enamels used for chemical apparatus [1]. In this connection, the properties of glasses with different ratios of the alkali oxides (Na 2 O, K 2 O, Li 2 O) and constant content of all other components (SiO O 5 , F) were studied (the B 2 O 3 content was 10%). 2 The total content of the alkali oxides in the glasses studied was 16%. The Li 2 O content was varied in the range 0 -6%, Na 2 O in the range 6 -16%, and K 2 O in the range 0 -8% (Fig. 1).The present work is a continuation of the investigations of titanium-containing alkali glasses for white glass-enamel coatings [2, 3].Chemically pure reagents and OVS-015 quartz sand from the Novoselkovskoe deposit were used to synthesize the experimental glasses. The glasses were made in porcelain crucibles in an electric furnace with Silit heaters at temperature 1350°C with 30 min soaking.The glasses were completely made under the chosen conditions and were of good quality. Opalescence was observed in glasses containing 6% Li 2 O cast in the form of a small cake.For the titanium-containing glasses synthesized, where the ratio of the alkali metal oxides was varied, the CLTE, the softening onset temperature, the flowability, the acid-resis-

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