Sort by color
According to national standards, inorganic coloring pigments can be divided into 12 categories: red, orange, yellow, green, blue, purple, brown, black, white, metallic, luminescent pigments, and body pigments. They only show the difference in the amount of reflected light. That is, the difference in brightness. Color pigments can selectively absorb light of a certain wavelength, and reflect light of other wavelengths to present various colors.
1. Black pigment
An important pigment second only to white pigments. The main species is carbon black. The performance of carbon black for pigments is different from that for rubber processing. The main quality indicators of pigment carbon black are blackness and hue. Carbon black is an inorganic pigment colorant used in plastics second only to titanium dioxide. Carbon black is classified according to the processing method, and there are many varieties. It is generally called "pigment carbon black" when used as a pigment. Carbon black not only has coloring properties, but also has excellent weather resistance and thermal oxidation resistance.
2. Red pigment
The red pigment in the inorganic pigment is mainly iron oxide red. Iron oxide comes in a variety of shades, from yellow to red, brown to black. Iron oxide red is the most common iron oxide pigment. It has good hiding power and tinting power, chemical resistance, color retention, dispersibility, and the price is relatively cheap. Iron oxide red is used in the production of floor paint and ship paint. Due to its remarkable anti-rust performance, it is also the main raw material for making anti-rust paint and primer. When the particles of iron oxide red are ground to ≤0.01μm, the hiding power of the pigment in the organic medium is significantly reduced. This pigment is called transparent iron oxide, which is used to make transparent paint or metallic flash paint, which is more effective than using organic dyes. Better color retention.
3. Yellow pigment
There are mainly lead chrome yellow (lead chromate), zinc chrome yellow (zinc chromate), cadmium yellow (cadmium sulfide) and iron yellow (hydrated iron oxide) and other varieties. Among them, lead chrome yellow is the most widely used and the output is the largest. The world's annual output is about 180kt, and China's annual output is about 10kt. Lead chrome yellow has strong hiding power, bright color and easy to disperse, but it is easy to darken under sunlight. The hiding power and tinting power of zinc chrome yellow are worse than that of lead chrome yellow, but the color is light and the light fastness is good. Cadmium yellow has good heat resistance, light resistance, and bright color, but its tinting strength and hiding power are not as good as lead chrome yellow, and its cost is relatively high, so its application is limited. Both lead chrome yellow and cadmium yellow contain heavy metals and cannot be used for coloring children's toys, stationery and food packaging. Iron yellow has a darker luster, but it has good durability, dispersibility, hiding power, heat resistance, chemical resistance, and alkali resistance, and its price is low, so it is widely used in the coloring of building materials.
(1) Lead chrome yellow
Lead chrome yellow of various colors can be prepared by combining lead nitrate or lead acetate with sodium dichromate (or potassium dichromate), sodium hydroxide, aluminum sulfate and other raw materials according to different proportions and different reaction conditions.
(2) Zinc chrome yellow
Also known as zinc yellow. Suspend zinc oxide in water, then add potassium dichromate and chromic acid to obtain basic potassium zinc chromate K2CrO4·3ZnCrO4·Zn(OH)2, which is zinc chrome yellow pigment. Sulfuric acid or hydrochloric acid can also be used to replace part of chromic acid, but the generated potassium sulfate or potassium chloride must be thoroughly washed off before filtering and drying. Basic potassium zinc chromate can be used as a lemon yellow pigment, and can also be used with iron oxide red to make a primer. Another kind of zinc chrome yellow is made by reacting zinc oxide with chromic acid, also known as tetrabasic zinc chromate ZnCrO4·4Zn(OH)2, which is mostly used in the manufacture of phosphating primers.
(3) Cadmium yellow
There are two types of cadmium yellow: pure cadmium yellow and cadmium yellow co-precipitated with barium sulfate. Add sodium sulfide or a mixed solution of sodium sulfide and sodium selenide to the aqueous solution of cadmium salt, precipitate cadmium sulfide yellow or cadmium sulfide red, wash, filter, and roast at 500-700°C in a rotary kiln to obtain lemon sulfide. Pigment cadmium yellow or cadmium red in different shades from yellow to orange-red.
(4) Iron yellow
Natural iron oxide yellow is a kind of hydrated iron oxide containing various impurities, mainly silicates. In the past, iron oxide yellow was prepared from waste iron sludge during the reduction of nitrobenzene to produce aniline. Another production method is to heat ferrous sulfate for hydration in the presence of iron and oxygen to produce iron oxide yellow. Iron oxide yellow has poor thermal stability, and when heated above 180°C, it will be dehydrated and become iron oxide red.
4. Green pigment
There are mainly two kinds of chrome oxide green and lead chrome green. Chromium oxide green has excellent light resistance, heat resistance and chemical resistance, but its color is dark, and its tinting power and hiding power are poor. The durability and heat resistance of lead chrome green are not as good as chromium oxide green, but it has bright color, good dispersion and easy processing. Because it contains toxic heavy metals, since the advent of organic pigments such as phthalocyanine green, the amount has gradually decreased.
(1) Chrome oxide green
Also known as dichromium trioxide, it is made of chromic anhydride, sodium dichromate (or potassium, ammonium salt) and carbon or sulfur by high-temperature roasting, and its color ranges from bright green to dark green. It is mostly used in the coloring of metallurgical products and cement. Its particles have high hardness and can be used as a polishing agent for optical materials and metal grinding; its spectral reflection characteristics are very close to chlorophyll, so it can be used in military camouflage paint.
(2) Lead chrome green
It is a mixture of chrome yellow and iron blue. It is made by adding iron blue wet slurry during the production process of chrome yellow. Adjusting the amount of iron blue can be obtained from yellow light green (2% to 3% iron blue) to dark green ( 60% ~ 65% iron blue) green pigments of various colors. Lead chrome green can be used for general paint. There is another mixture of chrome yellow and phthalocyanine blue (see organic pigments), also known as lead chrome green, which has bright color and good other properties.
5. Blue paint
There are mainly iron blue, cobalt blue, ultramarine and other varieties. Among them, the output of ultramarine blue is relatively large. Ultramarine blue is alkali-resistant but not acid-resistant, bright and bright in color, and resistant to high temperatures. Iron blue is acid-resistant but not alkali-resistant, and its hiding power and tinting power are higher than ultramarine blue, but its durability is worse than ultramarine blue. Since phthalocyanine blue was put into the market, because its tinting strength is twice as high as that of iron blue and its other properties are better, the consumption of iron blue has decreased year by year. Cobalt blue has high temperature resistance and excellent light resistance, but its tinting strength and hiding power are slightly poor, its price is high, and its use is limited.
(1) Iron blue
White pulp is formed by reacting ferrous sulfate, yellow blood salt (potassium ferrocyanide) and ammonium sulfate, and then oxidized with chlorate. The blue iron blue is called China blue, and the red iron blue is called milori blue. Iron blue is a hydrophilic pigment, which has poor affinity with oils, resins and other media. It can be treated with surfactants to improve its lipophilicity and easy grinding performance. The dark blue paint made of iron blue, after exposure It is easy to produce copper light phenomenon. Mainly used in the manufacture of ink and stationery.
(2) Brown pigment
Iron oxide brown Iron oxide brown
a. Product overview: Molecular formula Fe2O3 nH2O, iron brown blended products have the characteristics of iron oxide red and iron oxide yellow. Iron brown also has the main characteristics of large color range and strong adaptability. Compared with iron oxide red and iron yellow The scope of application is wider and more suitable for users.
b. Specifications and models: 610/686/860/868.
c. Uses: Widely used in colored cement bricks, coatings, paints, building materials, rubber, plastics and other fields.
d. Storage and transportation conditions: store in a dry place, keep away from moisture, avoid high temperature, and keep away from acid and alkali. According to the above storage conditions, the effective storage period of the unopened product is three years.
Product Name: Iron Oxide Brown Model: 610/686/860/868.
Other categories
Ultramarine
It is made by mixing clay, sulfur, soda ash, Glauber's salt, carbon black and quartz powder according to different formulas, putting them in clay pots, roasting at high temperature, and then washing with water and other refining processes. Products are available from light blue to dark blue. After mixing with ammonium chloride and heat treatment, it can be made into pink and purple pigments. Used in paints, rubber, plastics, paints, etc. Ultramarine blue turns white when it encounters calcium hydroxide, so it cannot be used for cement coloring.
