Problem description:
What is a constitution pigment?
In addition, what is the technical term for translating constitution varnish into Chinese?
Analysis:
Since this century, physique pigments (usually called fillers) have become more and more important. They include many compounds obtained from nature, directly manufactured or obtained as by-products. These substances are mainly salts of barium, calcium, magnesium or aluminum, oxides of silicon or aluminum, or mismatched double salts derived from the former two substances, which are widely used in the fields of coatings, ink, linoleum, plastic substances, paper and paper coatings, linoleum, putty, polishing and washing substances, rubber products, cement, plastics, pottery and so on. Their uses are now close to those of white opaque pigments, and the types and quantities of physique pigments and their applications in traditional industries will be further developed. These pigments have two general properties: the refractive index is lower than 1.75 (usually 1.45 ~ 1.70), and the color is white or almost white. Physique pigments differ greatly in other properties, such as relative density, capacity value, particle shape, particle size, particle size distribution, oil absorption and chemical activity. Since 1930, with the development of production technology, physical pigments have been greatly improved in color, uniformity, particle size, particle size distribution and surface treatment. Constitution pigments were originally obtained from nature, but at present, constitution pigments obtained from other chemical process by-products are gradually increasing, and many of them need special production. Commonly used physique pigments include calcium carbonate, magnesium silicate, aluminum silicate, calcium sulfate, crystalline silica, diatomite, barium sulfate and so on. Section 1 calcium carbonate calcium carbonate is mainly obtained from limestone ore, and can also be used as a by-product of some manufacturing processes, or directly prepared by reacting lime milk slurry with carbon dioxide. Natural calcium carbonate can be made by dry grinding or wet grinding. In the dry grinding method, the product after dry grinding is separated into oversized particles by an air separator, and then returned for re-grinding. Wet grinding can produce finer, brighter and better screened grades. Limestone is ground in the presence of water, and the ground products are continuously discharged from a conical or tubular grinder, separated by a centrifuge, and the oversized particles are sent back to be ground again together with the feed. Another important advantage of wet grinding is that the color and chemical purity of the product can be improved by further flotation. In the process of continuous grinding, various types of grinding machines can be used, but in principle, compressed air, high-temperature compressed air or superheated steam should be used as the liquid. Raw materials and liquid enter the grinder together, collide and rub with each other at high speed to produce grinding, and the grinding process of liquid and pigment is controlled so that fine particles and liquid flow out together. The general grinder has the functions of sorting and grinding at the same time. There are several mature processes for preparing precipitated calcium carbonate filler. Manufacturers can use different methods to make different grades of pigments, but the common point is that the precipitation method is to take natural calcium carbonate as raw material, calcine it to make calcium oxide (lime), and then hydrolyze it to get calcium hydroxide. In this process, there are many methods to remove almost all large-particle impurities and limestone that has not been decomposed into lime. 1. Calcium carbonate with different particle sizes can be obtained by controlling the reaction process of calcium hydroxide and carbon dioxide by calcium bicarbonate method, but for all precipitated calcium carbonate, the particle size of the powder is generally moderate. 2. By-product method This method uses the reaction of calcium hydroxide slurry and sodium carbonate solution to produce quite fine calcium carbonate particles. In this process, special attention should be paid to thoroughly cleaning all sodium hydroxide components, otherwise the calcium carbonate pigment is alkaline, which will lead to problems in coating application. 3. Calcium chloride method The reactants in this method are usually obtained from other chemical processes. For example, when ammonium chloride and calcium hydroxide are mixed to produce calcium chloride and ammonium hydroxide, a series of very fine calcium carbonate can be obtained by the reaction of calcium chloride and sodium carbonate, and the filler has high color purity and similar particle size distribution. Of course, all sodium chloride components need to be carefully washed away. Calcium carbonate obtained by calcium chloride method has calcite crystal structure, and its particle size is usually 8 ~ 10? M, the minimum range is 0.03 ~ 0.05? M the product obtained by lime milk method is aragonite, and the particle size is generally 0.2 ~ 2.0? M. There are many grades of calcium carbonate fillers, the relative density is between 2.70 and 2.77, the oil absorption is between 5 and 45g/1 00g, and the average particle size is less than1? M to very large, 200 mesh sieve residue (about 300? M) is usually 25 ~ 30%, and the colloid range (less than 0. 1? Products with particle size distribution. Calcium carbonate is insoluble in water and inert to most binders of oily resin coatings, but sensitive to dilute acids. This property is beneficial to the application of calcium carbonate in many indoor coatings, such as primer and semi-gloss paint. It is also used in high gloss paint, spray paint and many other industrial coatings. Typical characteristics of precipitated calcium carbonate are shown in Table 7- 1. Table 7- 1 Typical properties of precipitated calcium carbonate (without surface treatment) Calcite type (coarse grain) aragonite type (medium grain size) Calcite type (ultra fine grain size) Physical properties Appearance Pure white powder Cream powder Average grain size of pure white powder (? M) The particle size range of 3.00.40.06 is1.0 ~10.000.1~ 2.000 0.03 ~ 0.15325, when the moisture content (%) is 0.00/kl. 1, the relative density can be ignored.
Oil absorption (g/100g) 28 54 58 pH 9.4 9.8 10.4 chemical composition (%) calcium carbonate 99.3 98.5 98.9 magnesium carbonate 0.04 0.84 0. 04 silica 0. 0 1。 3 1。 0 1 fe2o 3 0。 004 0。 15 0。 At present, it is mainly used as calcium component in titanium dioxide-calcium composite pigment, and it is also used in a small amount in lithopone and zinc sulfide pigment. Gypsum is rarely used as a separate pigment, mainly because of its solubility in water and its sensitivity to water. Calcium sulfate exists in the form of gypsum in nature. After selection (color selection), it is crushed, wet-milled, separated from water, dried, screened or air-floated to become the finished product. Gypsum is completely dehydrated at about 650℃ and becomes anhydrous gypsum, also known as "fired" calcium sulfate, which is used in the above composite pigments. Calcium sulfate can also be prepared by the reaction of calcium ions and sulfuric acid ions, which becomes hydrated precipitate and then burns into anhydrous substances. The third magnesium pigment, magnesium silicate (h2mg 3(SiO 3)4), can be obtained from natural products, which contains talc, saponite and other components. There are two main particle forms, fiber or needle, flake or mica. Typical magnesium silicate products generally contain 7.0% CaO, and some special uses can reach as high as 15.0%. The relative density of magnesium silicate is 2.60 ~ 2.98, the oil absorption varies greatly from 20 ~ 89g/ 100g, the refractive index is about 1.59, and the particle size distribution is wide. Magnesium silicate is chemically inert to common coating substrates, unless the CaO content obviously exceeds 6.0%. Magnesium periodate is suitable for outdoor coatings because it has good durability and will not precipitate in ordinary oily adhesives. However, magnesium silicate can not be used in enamel because of its rough structure, but the newly developed fine particle size has expanded the application scope of magnesium silicate. The main purpose of magnesium silicate in exterior wall coatings is to increase the strength of paint film and prevent cracking. The main reason is that its fibrous or needle-like, flaky or mica-like particles inhibit the cracking of the coating film. In indoor flat paint, magnesium silicate is used to control luster or brightness, prevent sagging, and reduce flow and leveling. Magnesium carbonate, basic hydrated magnesium carbonate and magnesium oxide are three other magnesium compounds with different uses. Magnesium carbonate exists in the form of magnesite in nature, and its mining technology is the same as that of ordinary minerals, including crushing, grinding and classification. It is mainly used in cement, rubber products and paper making. Although some natural calcium carbonate (dolomite) with magnesium carbonate content as high as 45% has some applications in Europe, it is rarely directly used in coatings in North America. Alkaline hydrated magnesium carbonate (11mgco3.3mg (oh) 2.11H2O) is also called light magnesium carbonate. Calcining dolomite, suspending the remaining oxide in water after removing CO2, introducing CO2 to selectively precipitate calcium carbonate, dissolving magnesium hydroxide to obtain acidic carbonate, and heating the filtrate. CaCO3 MGC O3→CaO MgO+2 CO2 CaO MgO+2H2O→Ca（OH）2+Mg（OH）2 Ca（OH）2+Mg（OH）2+3 CO2→CaCO3+Mg（HCO 3）2+H2O 14 MGC O3→ 1 1 Mgco3.3mg (OH) 2.11H2O+65438+magnesium oxide (MgO) is calcined from alkaline hydrated magnesium carbonate or coarse dolomite ore, which is used in rubber and cement, but rarely used in coatings. Kaolin in the fourth section is usually called "porcelain clay", and its main component is aluminum silicate. Generally speaking, the content of A 12O3 is 37.5 ~ 44.5%, and the content of SiO2 is 44.8 ~ 53. 1%. It also contains a few oxides of iron, sodium, potassium, titanium, calcium and magnesium, and its refractive index is about 1.56. M, can the thicker one reach 70? M the color of kaolin varies greatly, from white to milky white or gray. Kaolin is widely used because of its inactive chemical properties, high filling rate and low price.
Apply. Applications in coatings include indoor flat paint, semi-gloss paint, primer, warehouse grid paint, truck paint and so on. Kaolin is also widely used in waterborne coatings, latex paints, paper industry and textile coatings because of its good dry hiding power. Kaolin with poor color performance is mostly used in linoleum, floor ingredients and tarpaulin. Kaolin usually needs post-treatment such as calcination to improve some of its properties. The Al2O3 content in calcined kaolin is 42. 1 ~ 45.3%, and the SiO2 content is 5 1.0~ 53. 1%. The loss on ignition is almost zero, and the oil absorption is slightly higher than that of calcined kaolin, usually 47 ~ 75 g/100 g. The function of calcination is to improve the gloss or brightness, and at the same time make the coating have better hiding power and bright brightness. The post-treatment of kaolin also includes adding dispersant and treating the particle surface with resin or hydrophobic organic substances. Finally, it is divided into various grades, and its particle size is relatively even and its distribution range is narrow. This grade of kaolin is mostly used for painting, enamel and flat paint. Section 5 Mica Mica is an orthosilicate of aluminum and potassium, and its chemical structural formula is K2O 3L2O3 6SiO2 2H2O. Pigment-grade mica is only obtained from muscovite or phlogopite, and has a flaky particle structure, which is the main reason why it can be used as a physique pigment. The main production process is to precipitate mica ore by dry grinding or wet grinding, recover suspended mica by centrifuge, and then dry and separate. The average particle size of super mica or micro mica is 5 ~ 10? M and 10 ~ 20? M, there is also a grade of surface treatment. The refractive index of mica is 1.58 ~ 1.606, the relative density is 2.5 ~ 2.83, the oil absorption is 30 ~ 74g/100g, and the residue of No.325 sieve is 3 ~ 30% except particle size. The flaky structure of mica particles and their opacity to ultraviolet rays can enhance the crack resistance and durability of outdoor building primers and final processing coatings. When the coating is exposed to air, the luminous characteristics of small particles sometimes affect the appearance of the coating. The shape and chemical stability of mica particles make it have a certain degree of application in porous surfaces and metal primer, latex paint, water-based paint, wallpaper and metal powder coatings (such as aluminum, bronze and gold foil). There are also the following aluminosilicate pigments. Pumice is a kind of volcanic ash or mixed silicate of aluminum, potassium and sodium. Because of its coarse particles, porosity and brittleness, pumice is widely used in flat paint, traffic sign paint and other processing paints. Typical grade pumice contains about 84% aluminum silicate, with a relative density of 2.22 and a particle size of 40-60 meshes. Expansive soil is a kind of colloidal soil, its expansibility can be effectively filled, and the mineral itself has pigment properties, so it has a small amount of application in water-based coatings or latex paints. The relative density of typical grade is 2.75, and the oil absorption is 23g/100g. Clay and bentonite are similar in composition, properties and uses, and their refractive index is 1. 63, and the relative density is 2. 9. The oil absorption capacity is 26g/100g. The sixth silica used as pigment in time is taken from the sandy skeleton sediments of quartzite or diatom and unicellular aquatic plants. Synthetic silica gel can also be used as pigment. Silica obtained from aquatic organisms is called diatomite or diatomite silica, which has a unique position in the application of modern pigments. They are different from animal or plant pigments. The latter is sometimes called "fossil" resin. Because there are too many kinds of primitive organic matter, it is of little value to ordinary pigments. Silica extracted from timely or diatomite is called amorphous silica. Although this term is not very accurate, it is usually used to distinguish it from diatomite. In time or after diatom mining, the first step is usually calcination and water quenching, which makes the subsequent crushing and grinding easier, and finally water separation, screening or air flotation. Silica pigments usually contain 99% pure silica. The refractive index of pigment-grade silica is 1.55, the specific gravity is 2.55-2.65, the oil absorption is15-47g/100g, and the residue of No.3253 sieve does not exceed 5%. Silica is very wear-resistant and difficult to grind or disperse in common coating binders, so it is rarely used as a filler for coatings. Diatoms are softer than quartzite, and their tissues are finer. Diatomite is a kind of fine powder, which will affect the sanitary conditions of the environment when used. If there is no optimized formula, it will quickly precipitate in the paint. Although it has such shortcomings, it still has many applications because of its inactive chemical properties and low price. Diatomite was used as outdoor building coating in the early days, but its application in this field gradually decreased because magnesium silicate and other fillers have better effects. However, diatomite can improve the paintability and enhance the adhesion of coatings, and it is still widely used as slurry wood filler, primer, flat paint, floor paint, ship paint and traffic sign paint. Most synthetic silica pigments are used as leveling agent or thickening coatings. There are two methods to synthesize silica: one is air sol method, in which air replaces the liquid in silica hydrosol; There is also a pyrometallurgical process in which silicon tetrachloride is hydrolyzed in the gas phase. The products obtained by these two methods have very fine particles and very high oil absorption, which also affects their use in coating formulations. Diatomite has many sedimentary minerals all over the world, but only a few of them are fine enough and have enough raw materials worth developing. Natural diatomite contains up to 60% free water, which can be reduced or removed by drying. The first method is heating, grinding and air flotation of dry matter. The second method is burning at about 540 ~ 1, 100℃ to remove free water, bound water and organic substances, and then grinding and air separation. The third method also includes grinding and combustion, but the difference is that it is burned with some chemicals at about 870 ~ 1, 100℃. These chemicals are used to bleach and convert impurities into synthetic silicates, and the products after combustion float through the air to obtain different grades. The main component of diatomite is silicon oxide, accounting for 83-89% or more. Other components are mainly Al2O3 and Fe2O3, and a small amount or trace of oxides such as sodium, potassium, calcium, magnesium and titanium. Diatomite has an open porous structure, and its physical properties vary greatly. Its refractive index is 1.4 ~ 1.5, its specific gravity is 2.0 ~ 2.30, and its average particle size is 1 ~ 60? M, the specific surface area is 7050 ~ 67000 cm2/g, and the oil absorption is 30 ~ 2 10g/ 100g. Pigment-grade diatomaceous earth was used in coatings from 1900, but gradually decreased from 1935. Because of the development of whiter and finer particles suitable for general coatings, its application has attracted attention again. Diatomite is inactive in chemical properties, low in gloss, high in filling rate and high in oil absorption rate, and has been widely used in flat wall coatings, primers, traffic sign paints, semi-gloss coatings, camouflage paints, surface paints, cement and mortar processing paints, house paints, flat varnishes and flat porcelain paints. In latex paints and other waterborne coatings, diatomite can not only be used as matting agent, but also provide hiding power for coatings. Because the structure and shape of diatomite are diverse, layered structure can also be produced in the coating film, which can be strengthened.
The strength of the coating improves the crack resistance. The open structure and irregular shape of diatomite particles will lead to considerable porosity of the coating film, which is extremely useful in some specific situations. If the surface coating needs the unique structure of diatomite, excessive grinding should be avoided, otherwise the diatomite particles will be destroyed, thus reducing the consistency of the coating, increasing the luster and reducing the porosity of the coating. Section 7 Barium Sulfate Barium sulfate used as pigment can be extracted from natural minerals, or prepared by the reaction of sodium sulfate and barium sulfide solution, or obtained from by-products of hydrogen peroxide production. Barium sulfate has a low refractive index and is the main component of lithopone. Barium sulfate is also a component of titanium dioxide-barium composite pigment, which is a coprecipitate of 25% anatase titanium dioxide and 75% barium sulfate. When lead white is used as the main pigment of outdoor building coatings, barium sulfate can sometimes be used as a blending agent. Because the paint is sold by weight, barium sulfate has become a common constitutional pigment because of its high relative density. Pigment-grade barium sulfate is obtained from mineral barite, and can also be prepared by precipitation of synthetic barium sulfate powder. Usually, minerals are ground, bleached, washed, dried and sorted by wet method. High-quality barium sulfate pigment or barite pigment contains at least 96% barium sulfate, the rest is mainly silica and gypsum, and a small amount of iron oxide. The refractive index of barite pigment is 1.64, the relative density is 4.30 ~ 4.46, the oil absorption is 5 ~ 12 g/ 100 g, and the average particle size is 2 ~ 5? M, the granularity range is 0. 1~ 30? M. The chemical properties of barite pigment are inactive. As a bulk pigment, the most important properties of barite pigment are its high density and low oil absorption, which are easy to be wetted by oil and coating binder and easy to grind. Barite pigment is very effective in high-acid or high-alkali coatings, because it is quite stable under acid and alkali conditions, but special attention should be paid to the adjustment of formula in application, because barite tends to precipitate faster than most other pigments. Other applications of barite include linoleum and floor composite coating. Barium sulfate powder was synthesized by the reaction of aqueous solution containing sulfate ions and aqueous solution containing barium ions. Its properties are similar to barite pigment, the relative density is 4. 18~ 4.40, and the oil absorption is13 ~ 30 g/100 g. Synthetic barium sulfate powder is a relatively expensive filler in coating application because of its low filling rate. Barium sulfate powder is as easy to precipitate as barite pigment, so it is necessary to pay attention to adjust the formula of the coating. As a filler of paint, it has little influence on the brightness of the final product, and also has certain applications in ink, linoleum, linoleum and rubber. Section 8 Other body pigments Some body pigments have unique properties and are widely used in coatings. These fillers include barium carbonate, aluminum hydroxide, bright white, satin white and silk white. Barium carbonate can be obtained from barium carbonate ore or by synthetic precipitation, and its use is similar to barium sulfate. "Aluminum hydroxide", also known as aluminum hydroxide or "light alumina hydrate", is usually prepared by adding excessive alkali to aluminum sulfate solution for precipitation. The main use of aluminum hydroxide is as a basic material for the precipitation of dyes and organic toners used in the production of printing ink. Aluminum hydroxide has high oil absorption, very active chemical properties and relatively expensive price, and has a certain degree of application in textiles and paper coatings and rubber fillers. Brilliant white is a composite pigment composed of 25% aluminum hydroxide and 75% barium sulfate powder, which has fine structure and corrosion resistance and is mainly used in printing ink. Satin white is a coprecipitate of aluminum hydroxide and calcium sulfate, which is mainly used for paper coating. Silk white is made by the reaction of calcium chloride and sodium silicate, and is mainly used for printing ink. In addition to the above-mentioned physical pigments, there is also a kind of glass beads used as fillers in special coatings (such as traffic sign coatings), which reflect incident light to a considerable extent. When the paint surface is worn, glass beads will be exposed and become tiny reflective balls, which greatly improves the visibility of traffic signs at night. The usual grades are 100% passing through No.70 sieve, 85~ 100% passing through No.80 sieve, 15 ~ 55% passing through No.440 sieve, 0 ~ 10% passing through No.230 sieve. Glass beads can also be used as fillers in coatings such as billboards, mailboxes and direction indicators.
I'm a layman, and the English meaning seems to be a gloss supplement.