RU2404216C2 - Silica-based inorganic pigment and preparation method thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to preparation of a silica-based inorganic pigment and can be used in production of enamel, glase, ceramic paints, polymer fillers, for volume and surface painting of building materials and articles. When preparing the pigment, a heteropoly compound which is molybdophosphate, tungstophosphate, molybdosilicate, tungstosilicate of one or more transition metals selected from iron, cobalt, nickel, manganese, chromium and copper is deposited on the surface of a base from 1-50% solutions of corresponding salts at temperature 30-60°C.The base used is marshalite minieral with particle size less than 10 mcm. Further, the suspension is filtered and the residue is dried. The obtained inorganic pigment contains 50-90 wt % marshalite and 10-50 wt % of the said heteropoly compound dyed with a cation of one or more transition metals.

EFFECT: invention simplifies preparation of silica-based pigment, with obtaining of intensely coloured pigments with a wide range of colours.

2 cl, 1 tbl, 3 ex

Description

The invention relates to the production of inorganic pigments and can be used for the manufacture of enamels, glazes, ceramic paints, polymer fillers, as well as for bulk and surface coloring of building materials and products.

A known inorganic pigment based on pyroxene and a method for its preparation by reacting a pyroxene mineral with a compound colored with a cation of an element of an iron triad — iron, cobalt or nickel molybdophosphate, synthesized and crystallized directly in solution at 30-60 ° C for 15-30 minutes (RU 2269553, 2005).

The molybdophosphates of the elements of the iron triad are precipitated during the synthesis on a dispersed pyroxene mineral (diopside or wollastonite), filtered and dried at a temperature of 120-180 ° C.

A disadvantage of the known method for producing an inorganic pigment is the need to grind the pyroxene mineral to particle sizes less than 10 microns, limited color gamut.

The closest technical solution is pigments based on silica (SiO ₂ ) and iron oxide (Fe ₂ O ₃ ) and a method for their production, in which highly dispersed siliceous dust obtained by condensation of gases released during the production of metallic silicon and / or its alloys is mixed with iron oxide (RU 2218371, 2003). The content of fine silica dust is 70-80 wt.%, Iron oxide is 2-30 wt.%. The mixture is agglomerated, fired for 1-24 hours at 800-1300 ° C. High-temperature firing of the initial mixture is carried out with the aim of interaction of silica with iron oxide acting as a chromophore. The calcined pigment is mixed, crushed, finally mixed and the color is controlled. The finished product is dosed and packaged. After agglomeration, further spraying and pre-firing can be carried out, followed by cooling. The pigments have a red-orange hue.

The disadvantages of the pigments of this composition are its high cost, due to significant energy costs when it is received, and limited color gamut.

The objective of the invention is to simplify the method and obtain intensely colored inorganic pigment in a wide range of colors.

The objective is achieved in that the inorganic pigment as a base contains a natural siliceous mineral - marshalite with a particle size of less than 10 microns, and as a compound colored by a transition metal cation adsorbed on the surface of the marshallite, a heteropoly compound is used - molybdenum, tungsten phosphates, molybdenum, tungsten silicates of one or more transition metals from the series: iron, cobalt, nickel, copper, manganese, chromium in the following ratio of components, wt.%:

marshalit 50-90 heteropoly compound dyed one or more transition metals from the series: iron, cobalt, nickel, manganese, chrome copper 10-50

The sorbed pigment is applied to marshalite (particle size less than 10 μm) in the following way: the heteropoly compounds of transition metals are deposited Me _n H _m [XY ₁₂ O ₄₀ ] · hH ₂ O, Me _n H _m [XY ₁₁ O ₃₉ ] · hH ₂ O, Me _n H _m [(PO ₄ ) ₂ Y ₅ O ₁₅ ] · hH ₂ O, Me _n H _m [XY ₆ O ₂₄ ] · hH ₂ O [where Me = Fe (II, III), Co (II), Ni (II), Cr (III), Mn (II), Cu (II); X = P, Si; Y = Mo, W; n, m≥1] from 1-50% solutions at temperatures of 30-60 ° C for 15-30 minutes. In acidic medium deposited Me _n H _m [XY ₁₂ O _40] · hH ₂ O, in a weakly acid - Me _n H _m [XY ₁₁ O _39] · hH ₂ O in neutral - Me _n H _m [(PO _{4) 2} Y ₅ O ₁₅ ] · hH ₂ O, Me _n H _m [XY ₆ O ₂₄ ] · hH ₂ O.

Anions with Dawson structure stable to pH ~ 6 can also exist in solutions. They are obtained by adding an excess of H ₃ XO ₄ to a solution of sodium molybdate (tungstate), have a structure of the general formula [X ₂ Y ₁₈ O ₆₂ ] ⁿ , formed from two parts, each of which is obtained from the structure of a 12-molybdo (tungsten) -heteropolyanion when removing three anions YO ₆ . With a further increase in pH, the anions decompose, forming a series of lacunar forms that have not yet been fully studied.

When the concentration of the solution is less than 1%, the amount of precipitated pigment is negligible and does not lead to a noticeable staining of the composition. At high concentrations (over 50%) and temperatures above 60 ° C, the impurity components of the aqueous solution crystallize. At temperatures less than 30 ° C, the intensity of the deposition process is low.

After precipitation, the suspension (precipitate) by known methods is filtered and dried at a temperature of 120-180 ° C.

Example 1. Tungsten oxide WO ₃ in an amount of 1.5 g is fused with 0.6 g of NaOH in a crucible. The resulting alloy is dissolved in 50 ml of H ₂ O, 10 ml of a 1% solution of sodium silicate Na ₂ SiO ₃ and 10 ml of a 5% solution of FeCl _{3 are} added to it. Using hydrochloric acid, the solution was adjusted to pH = 5-6 and heated to 40-60 ° C. Then add 5 g of finely dispersed marshallite, (dispersion less than 10 microns). The interaction of the components is carried out for 15 minutes After that, the suspension is filtered, the precipitate is transferred to a ceramic container and dried at 120-180 ° C.

An intensely colored yellow pigment is obtained on the basis of marshallite and iron tungsten silicate.

Example 2. Take 50 ml of a 5% solution of sodium molybdate Na ₂ MoO ₄ , pour to it 10 ml of a 1% solution of sodium hydrogen phosphate Na ₂ HPO ₄ and 10 ml of a 5% solution of chromium chloride CrCl ₃ . Using hydrochloric acid, the solution was adjusted to pH = 5-6 and heated to 40-60 ° C. Then add 5 g of finely dispersed marshallite (particle size less than 10 microns). The interaction of the components is carried out for 15 minutes After that, the suspension is filtered, the precipitate is transferred to a ceramic container and dried at 120-180 ° C. An intensely colored green pigment is obtained on the basis of marshallite and chromium molybdophosphate.

Example 3. Take 50 ml of a 5% solution of sodium molybdate Na ₂ MoO ₄ , pour to it 10 ml of a 1% solution of sodium hydrogen phosphate Na ₂ HPO ₄ , 10 ml of a 1% solution of potassium dichromate K ₂ Cr ₂ O ₇ , heated and maintained at a temperature of 40-60 ° C and pH ~ 2 for one hour (acidity is regulated with hydrochloric acid). Using alkali, the solution was adjusted to pH = 5-6, 10 ml of a 5% solution of copper chloride CuCl _{2 was} added. Then add 5 g of finely dispersed marshallite (particle size less than 10 microns). The interaction of the components is carried out for 15 minutes After that, the suspension is filtered, the precipitate is transferred to a ceramic container and dried at 120-180 ° C.

Examples 1-3 and others are shown in the table.

The use of an insignificant amount of chromophore, namely, a transition metal cation (iron, cobalt, nickel, copper, manganese, chromium) leads to intense staining of silica. Application and distribution of molybdophosphates, molybdosilicates, tungsten phosphates, transition metal tungsten silicates on silica significantly reduces the cost of pigment due to the low cost of the base.

The resulting pigments in a wide range of colors can also be used as water-based and oil-based paints, varnishes, and dry mixes. The presence of a field in the Novosibirsk region, 200 km from Tomsk, allows us to organize the production of the above products with low cost.

Table 1 Characterization of the pigment deposited on marshalite, depending on the composition and mode of synthesis Heteropolysilane, wt.% Marshalit, wt.% pH Color one 2 3 four iron molybdophosphate - 30 70 sour yellow iron molybdosilicate - 30 70 sour yellow iron tungsten phosphate - 30 70 sour yellow iron tungsten silicate - 30 70 sour yellow iron molybdophosphate - 20 80 neutral light beige cobalt molybdophosphate - 40 60 sour lilac cobalt tungsten phosphate - 40 60 sour pink cobalt molybdosilicate - 40 60 sour pink cobalt molybdosilicate - 40 60 neutral lilac cobalt tungsten silicate - 25 75 sour light pink cobalt tungsten silicate - 25 75 neutral light lilac nickel molybdophosphate - 10 90 sour light turquoise copper molybdophosphate - 50 fifty slightly acidic bright turquoise copper molybdosilicate - 30 70 slightly acidic turquoise copper tungsten silicate - 30 70 slightly acidic turquoise Manganese Molybdophosphate - 50 fifty slightly acidic chocolate chromium molybdophosphate - 30 70 slightly acidic green

one 2 3 four chromium molybdosilicate - 30 70 slightly acidic green chromium tungsten silicate - 30 70 slightly acidic green molybdochromophos
copper fat - 40 60 slightly acidic salad

Claims (2)

1. Inorganic silica-based pigment comprising a compound colored with a transition metal cation, characterized in that it contains marshalite as a base, and a heteropoly compound consisting of molybdophosphate, tungsten phosphate, molybdosilicate as a base colored with a cation of one or more transition metals tungsten silicate of one or more transition metals from the series iron, cobalt, nickel, manganese, chromium, copper, in the following ratio of components, wt.%:
marshalit 50-90 hetero compound 10-50 2. A method of producing an inorganic silica-based pigment, characterized in that a heteropolyside, which is a molybdophosphate, tungsten phosphate, molybdosilicate, tungsten silicate of one or more transition metals from the iron series, is deposited on the surface of the base, which is taken as marshalite with a particle size of less than 10 microns , cobalt, nickel, manganese, chromium, copper, from 1-50% solutions of the corresponding salts at a temperature of 30-60 ° C, after which the suspension is filtered, the resulting precipitate is dried.