Classification and properties of ceramic pigments
Classification and performance of ceramic pigments Ceramic pigments are divided into glazed pigments and underglaze yan family. In up to two rice, there is a difference between liquid pigments and solid pigments. Glaze pigments are mainly made up of Consisting of a pigment and a flux. We are the leading ceramic pigments manufacturer.
The pigment includes colored metal oxides (consisting of two or more oxides of simple government fine and fast with coloring silicate, aluminosilicate, pot salt, acid pot, ferrite, etc.). In the whites + ceramic pigments, ~ solid solutions or suspensions (such as femoral gold in a metastynic acid solution are detected Purple gold one by one glaze on the color base of agate red). The flux is a lynx with a lower melting temperature, and its composition is closely related to the color of the pigment. The flux is divided into three categories: acidic magnetic and neutral, and its composition is divided into potassium-rich potassium, sodium, bell, silicon, Boric acid police
Underglaze pigments, consisting of pigments and parent minerals (or other additives). Whether it is an overglaze pigment or an underglaze pigment, the primary requirement is to withstand high or low temperature burning. After firing at a certain temperature, the required colors are produced. The firing temperature of the glazed pigment is between about 600 and 850%C. Underglaze pigments, generally must reach more than 1300C
The above-mentioned overglaze and underglaze pigments are all solid pigments. Liquid pigments, mainly electro-light water. It is divided into peach water, blue water, green water, yellow water, white water (known in Japan as white pearl), tea water (i.e., golden tea) silver water and gold water, etc. The electro-optical water is a resinic acid metal salt combined with a vulcanized balm, and then dissolved in volatile oils and organic solvents to become a thick colloidal oily liquid. The electric water should be fired at the same temperature as the glazed pigment, and the different pearls of The Fata Valley shine.
Other underglaze pigment water is made by dissolving soluble non-ferrous metal salts or a mixture of two or more jinyu salts in water. In order to dry the painting decoration, it is necessary to add dextrin, sun oil, syrup, etc. to increase its viscosity so that it becomes a viscous liquid, which is painted after painting
The pigment water is inhaled between the very fine chin particles of the body, and then the glaze is applied on the outside, and after firing, the desired underglaze color is produced.
According to the firing range of ceramic pigments, the glaze pigments have more colored metal oxides due to the lower firing temperature, so the pigment color types are also more. The color under the glaze of porcelain generally needs to be fired at a high temperature of more than 1300C at the same time as the porcelain, and the composition of the glaze and the melting function of the glaze are required not to affect the color of the pigment Therefore, there are few colored metal oxides suitable for this condition, so the color of porcelain underglaze pigments is currently limited.
Feldspar white pottery made in England (forked as white tableware), fine pottery in France, steel pottery in Japan, its glaze firing temperature is between about 1000 and 1100C. Because the glaze firing temperature is low, the color of the colored metal oxide is stable, so there are many types of underglaze pigments used. China has not yet developed a lot of fine pottery, so at present, the underglaze pigment of pottery does not need much. In order to meet the needs of China’s porcelain production, it is necessary to increase new varieties of porcelain pigments on the existing basis and expand the color range. Using scientific methods, an appropriate number of special compounds can be added to the low-temperature underglaze pigments of foreign pottery to improve heat resistance and color stability. Or in pigments with a higher melting point, an appropriate flux or mineralizing agent is added to reduce the melting point, protect the stability of its color and increase its chemical resistance. It is a new direction for the development of overglaze pigments.
There are still many new research topics in underglaze pigments, such as the problem of underglaze yellow. Previously, underglaze uranium yellow was used, because uranium is a radioactive element, and there are other important uses. Now it is proposed that new pigments such as titanium, titanium, titanium, and titanium are proposed, all of which can withstand the high temperature of 1300C and do not change color. Lead oxylate (2PbO· Sb.O,) compound, which is the most distinctive pigment of yellow, is extremely suitable for use on glazes, but its melting point is too low It is too fluid to be used under high-temperature porcelain glaze. Now, after many studies, the use of gray cassiterite (CaO· SnO2) With the solid solution to improve its heat resistance, unfortunately has not yet reached the ideal requirements. Others such as zinc green (Victoria green), titanium green, titanium aluminum red, titanium aluminum zinc red, titanium tin red, gold red, iron red, mantle red, titanium red, etc., are the objects of current research on underglaze pigments, and have achieved considerable results, but they must be gradually improved.