With natural mineral pigment or inorganic compounds. Natural mineral pigments generally low purity, darker color, but the price is low. The synthesis of inorganic pigments varieties complete chromatography, bright color, pure, strong hiding power.
Inorganic pigments are widely used in coatings, plastics, synthetic fiber, rubber, building materials, cultural and educational supplies, paint, printing ink, paper, glass, enamel, ceramics and other industrial production department.
Inorganic pigments can be divided into two categories, color pigment and color pigment elimination. Decolorization pigments including a series of pigments from white, gray to black, they only show the amount of reflected light is different, the different brightness. Color pigment to certain wavelengths of light, to selectively absorb, put the rest of the wavelengths of light reflected in a variety of different colors.
Inorganic pigments in the early 80 s, the world's annual production capacity of 3.6 Mt, including: titanium white (74%), iron oxide series pigments accounted for 14.6%, 5.0% chrome yellow, antirust pigment accounted for 4.6%, 1% chrome oxide green, cadmium pigments accounted for 0.2%, other 0.6%. Novel compound pigment, annual production capacity has increased to 10 kt. Inorganic pigment production enterprises in China more than hundred, total output of over 200 kt.
White paint There are mainly titanium white, lithopone, zinc oxide and other varieties. Titanium white is currently the most widely used white paint. Its whiteness, covering capacity, tinting strength, weather resistance, chemical resistance character is superior to other white paint. The annual output is about 2.7 Mt. The performance of lithopone is a bit poor, and easy pulverization. Tinting strength, covering power of zinc oxide on both for the poor, coating with acid on the high side, breeds into zinc soap and now in addition to the used as antirust pigment, has less use.
Chemical composition of titanium white as titanium dioxide, there are two main crystal model has practical significance, namely the sharp titanium type and rutile type. Titanium dioxide particles, the use of aluminum, silicon, titanium and zirconium salts, surface treatment, a quick all kinds of titanium dioxide pigment. As titanium white pigment used mainly for the production of coatings.
lithopone Also known as lithopone. Made from barite chemical processing and barium sulphide solution, react with zinc sulfate solution to get a barium sulfate - zinc sulfide deposits, which again after roasting, grinding, drying, for a quick lithopone. After the surface treatment of lithopone, has good grinding wettability, suitable for coating, rubber and ink and other industrial use.
Have a direct method and indirect method zinc oxide, two kinds of production methods. More direct method zinc oxide with impurity, colour and lustre is dark and gray, but strong rust resistance. The indirect method zinc oxide colour and lustre is white, but the price is more expensive. Zinc oxide is mainly used in rubber, coating, metal soap, grease, feed and catalyst, soil additive manufacturing. High purity zinc oxide used in the manufacture of medical adhesive.
Black paint Second only to the importance of white pigment paint. Main varieties are black. The performance of carbon black pigment and rubber processing with different. The main quality index of pigment carbon black is black and hue.
Red pigment Inorganic pigments in the red pigment, mainly iron oxide red. Iron oxide has a variety of different colour and lustre, from yellow to red, brown and black. Iron oxide red is the most common form of iron oxide series pigments. Has good covering power and tinting strength, chemical resistance, color retention, dispersion, the price is relatively cheap. Iron oxide red used in the production floor paint, ship paint, due to a significant antirust performance, also is the main raw material production antirust paint and primer. Grinding particles of iron oxide red fine to 0.01 microns or less, the covering power of pigments in organic medium decreased significantly, the pigment is called transparent iron oxide, used to make transparent color paint or metallic paint, are better than using organic dye colour retention.
Yellow pigment Are mainly of lead chrome yellow, lead chromate, zinc chrome yellow (zinc chromate), cadmium yellow (cadmium sulphide) and iron yellow (hydrated ferric oxide), and other varieties. With most widely use of lead chrome yellow, production is the largest. The annual output of about 180 kt, annual production of about 10 kt in China. The covering power of lead chrome yellow is strong, bright color, easy to disperse, but variable dark under the sunlight. The covering power of zinc chrome yellow and tinting strength is difference of lead chrome yellow, but pale, light fastness is good. Cadmium yellow has good heat resistance, light fastness, bright color, but the tinting strength and hiding power than of lead chrome yellow, costs are high and restricted in application. Lead chromium yellow and cadmium Huang Jun containing heavy metals, cannot be used for children's toys, stationery and food packaging color. Iron yellow colour and lustre is dim, but durability, dispersion, covering power, heat resistance, chemical resistance, alkali resistance are good, and the price is low, so it is widely used in building materials of color.
Lead chromium yellow will lead nitrate or lead acetate and sodium dichromate or potassium bichromate, sodium hydroxide, aluminum sulfate and other raw materials, according to the different ratio, different reaction conditions, can produce all kinds of colour and lustre of lead chrome yellow.
Zinc chrome yellow Also called zinc yellow. The zno suspended in the water, then add the potassium dichromate and chromic acid, a quick potassium alkali type zinc chromate K2CrO4, 3 zncro4, zinc (OH) 2 is zinc chrome yellow pigment. Also useful replacing parts of the chromic acid, sulfuric acid or hydrochloric acid but produce potassium sulfate or potassium chloride, must be thoroughly washed before filtering and drying. Alkaline potassium chromate zinc can be used as citric yellow pigment, also can be made from iron oxide red primer. Another kind of zinc chrome yellow was made by using zinc oxide with chromic acid reaction, also known as the four base zinc chromate ZnCrO4 · 4 zinc (OH) 2, used in the manufacture of etch primer.
Cadmium cadmium Huang Youchun cadmium yellow and yellow with barium sulfate coprecipitation of cadmium yellow. To join in the aqueous solution of cadmium salt or sodium sulfide and sodium sulphide selenide, a mixture of sodium solution was deposited cadmium sulphide yellow or red, cadmium sulfide through washing, filtering, in turn kiln (see kiln) Canon 500 ~ 700 ° C roasting, quick from lemon yellow to orange red cadmium cadmium yellow or red pigment in different color.
Iron yellow, iron oxide yellow natural hydrated ferric oxide is a kind of various impurities, contains impurities, mainly silicate class. In the past, the preparation of iron oxide yellow with nitrobenzene reduction in aniline production scrap iron sludge as raw material. Another production method is in the presence of iron and oxygen, heat the ferrous sulfate hydrate, which generate iron oxide yellow. The thermal stability of iron oxide yellow, heated to above 180 ° C, namely into iron oxide red by dehydration.
Green paint There are mainly chrome oxide green and two kinds of lead chrome green. Chrome oxide green light resistance, heat resistance, excellent chemical resistance, but the darker color, poor tinting strength and hiding power. Lead, chromium oxide, such as durability, heat resistance were not as good as chrome oxide green, but bright color and good dispersibility, easy processing, because it contains toxic heavy metals, since the advent of phthalocyanine green, such as organic pigments, consumption has gradually reduced.
Chrome oxide green Also known as chromium trioxide to chromic anhydride and (or) ammonium potassium, sodium dichromate and carbon and sulfur by high temperature roasting, color from light green to dark green. Many used for metallurgical products, cement color. The grain hardness is higher, it could be optical materials and metal abrasive polishing agent; Spectral reflection characteristic of its very close to the chlorophyll, so can be used for military camouflage paint.
Lead chrome green is a mixture of iron chrome yellow and blue, in the wet blue chrome yellow to join in the process of producing iron slurry, and adjust the flow of iron blue add how much, can be obtained from the yellow light green (2% ~ 3% iron blue) to green (60% ~ 65% iron blue) of different colour and lustre of green paint. Lead chromium oxide can be used for general coatings. Another chrome yellow and phthalocyanine blue (see the organic pigment) also known as the mixture of lead chrome green, this paint bright color and other performance is better also.
Blue paint Mainly has the variety such as iron, cobalt blue, ultramarine blue. One group of larger output, ultramarine blue alkaline not acid, bright color, high temperature resistance. Iron blue acid alkali, not covering capacity, tinting strength higher than that of group of green, durability than a group of green. Since phthalocyanine blue into the market, because of its tinting strength is higher than iron blue twice and other performance, nice, and dosage of iron blue decline year by year. Cobalt blue high temperature resistance, good light fastness, but the tinting strength and hiding power is a bit poor, the price is high, the usage is restricted.
Iron blue by ferrous sulfate, yellow prussiate (potassium ferrocyanide), ammonium sulfate reaction generated white pulp, and then to chlorate oxidation. Green light blue iron called China blue (China blue), red iron blue called milo li blue (milori blue). Iron blue for hydrophilic paint, and grease, resin, such as medium low affinity, with surfactant treatment, can improve the oil wet, easy grinding performance, with dark blue paint made of iron blue, easy to produce copper light phenomenon after exposure to the surface. Mainly used in the manufacture of ink, and cultural and educational supplies.
Ultramarine blue by clay, sulphur, soda, glauber's salt, carbon black and silica powder, according to different formula and mixed loading in clay, calcined at high temperature, then through water such as refining process. Products are available from light blue to dark blue. After heat treatment, mixed with ammonium chloride can be made into pink, purple pigment. Used in paints, rubber, plastic, paint, etc. Ultramarine blue in calcium hydroxide to bleach, so cannot be used for the cement color.
The development trend New type of inorganic pigments in recent years, the research and development direction of mainly: (1) the development of compound pigment, such as the bright blue (CoO, Cr2O3, Al2O3), titanium yellow (TiO2, NiO, Sb2O3), etc. In nickel titanate, antimony, adding chromium, cobalt, iron, zinc oxide, yellow, green, blue, brown, etc can also be made of high temperature resistant, durable, resistant to chemicals low toxic and non-toxic paint, bright color, good performance, there is a requirement for high durability can be used in building materials, coating, engineering plastic coloring and preparation of paints, etc. (2) development of pigment particle surface treatment technology to inorganic compounds and organic compounds form a layer of color film in the surface of pigment particles, can change the properties of pigment particles and improve the light resistance, heat resistance, wetting characteristics, expand the application, improve the use value. (3) manufacturing pigments, users can be directly used, save a lot of grinding process.
