MXPA99001206A - Coloring solid body coloring body brown coloring procedure for its manufacturing and its application - Google Patents

Abstract

The invention relates to new reddish brown burnt colored solid bodies for the coloration of ceramic masses. The colored solid bodies contain Fe2O3 and / or an iron compound that when burned produces Fe2O3 in a uniform distribution in a matrix in the form of powder based on oxides and / or silicates in a material at least 50% amorphous to the rays X with a specific surface area (BET) of at least 40 m2 / g and obtained by the intensive contact of the constituent parts. It is preferred that the matrix consist of 80 to 100% Si02 or SiO2-rich silicate with a BET surface area of 90 to 300 m2 / g and 0 to 20% auxiliary agent, such as silicone oil. The solid coloring bodies are manufactured by grinding in

Description

SOLID BODY COLORING BODIES COLOR BROWN BROWN PROCEDURE FOR ITS MANUFACTURE AND ITS APPLICATION DESCRIPTION OF THE INVENTION: The invention relates to reddish brown or burn colored colorant bodies containing iron (III) oxide < Fe203) and / or one or more iron compounds that burn form Fe203 as components produce color in a uniform distribution in a matrix made of powder with uniform distribution based on an oxidic and / or silicate material. The invention relates to a process for the manufacture of solid colored bodies as well as to their use for pigmenting ceramic masses. In the manufacture of the so-called Porcelain Stoneware, from a mass of fine vitrified clay for fast baking or burning, which in modern fluid production always gains new meaning, dye bodies containing iron are used to a large extent, to give to the dough after of the burned an attractive reddish brown color. Gres de Thiviers, a naturally occurring coloring body consisting of approximately 90% quartz and 10% goethite (FeOOH), is used to produce reddish-brown coloring tones. In this natural product is the iron oxyhydrate protected by a layer of quartz, before the chemical reaction with the constituent parts of the mass to be burned at a temperature of approximately 1100 to 1250 °.

REF. 29413 The disadvantages of this procedure are the variations of color tone, the relatively high concentration of the color donor material, which is necessary, to achieve the corresponding color tone, as well as the decline of the natural resources of this pigment. From here the search with great significance of synthetic products with properties equal or better than those of natural products follows. According to JP 02-263870 A violet coloring pigments have been reached when FeOOH, Si02 and K2C03 are mixed, milled and calcined. The reddish brown coloring tone is not obtained. According to EP-A-0 563 688, masses of ceramic gis or leaves are generated in a rapid calcination, if the clay is mixed with customary additives and an iron oxide pigment is molded and burned. The pigment used must contain less than 0.6% Si and less than 0.06% Mn and consist of alpha-FeOOH, ga ma-FeOOhh, alpha-Fe203 and / or Fe304. As the practice shows, the iron oxide pigments customary in the market and also those with the previously mentioned criterion of the content of Si and Mn, in a low concentration alone or in mixture with quartz, are not suitable for coloring, since Iron oxide dissolves widely in the masses. With a high concentration of iron oxide, it is precisely a coloring effect, but this is in any case an unattractive brown coloring tone. The cause for this result is considered to be that the iron oxide at an elevated temperature tends to a growth of crystals and the iron oxide in a coarse division leads in the ceramic mass to little bright colors. For the Chemie Europe 31-32 / 91, page 4, it is known that the crosslinking properties of the Bayer Pigments product Bayferrox (registered trademark) is improved with a subsequent treatment of aluminum oxide and for this red pigments of Fe203 are suitable for the critical link system. The type of the subsequent treatment, the amount of A1203 and its structure can not be known by that document. By tests of the inventor of the present application the red pigments called micronized are not suitable for use as coloring bodies in ceramic masses. When burning, a sintering of the Fe203 occurs and with this a variation of color from red to brown. In the book Ullmann's Enzyklopadie der technischen Chemie, 4 edition, volume 10, pages 437-438 the enamel compositions as well as the appropriate glass flow quantities are given. According to the definition given on page 438 for the inorganic coloring bodies, according to which the inorganic coloring pigments presented there do not vary with the burning, a mixture of burned glass and Fe203 is not any coloring body since the iron oxide during the burn it dissolves in the melt. For the production of coloring enamels, ground coloring bodies are added to the enamels. Nothing is said about the manufacture of the coloring body. The burned glass used in the enamels are precisely amorphous, the specific surface according to BET is usually around / below 1 m2 with a d-50 value of 1 μm. DE 32 ll 327 Al is directed to pigments of iron oxide with an iron oxide (II) content (page 10, line 11). The usual pigments containing FeO are black and have a BET surface of 12 to 18 m2 / g. Only for magnetic purposes are the products used, which may exceed 40 m / g.The present invention is directed, on the contrary, to reddish-brown, not black, calcined coloring bodies. The inventor of the present application tried to coat by a precipitation process iron oxide pigments with silicic acid, to obtain products with good properties of coloring bodies such as the Stoneware of Thiviere. In spite of a suitable method of coating itself, no products were reached, in which the thickness of the coating was sufficient, to resist the attack of the constituent parts of the ceramic mass. In addition, at high temperatures, grain growth was reached and with this a decrease in brilliance of color. In other tests, the common precipitation of silicic acid and iron hydroxide was sought from water glass or water glass and iron salt solutions. These precipitation products were again transformed due to the fine division of the iron hydroxide produced and their high reactivity at high temperature in a remarkable growth of the crystals, and thus unattractive shades of color were the result. In commerce there is obtainable a coloring body based on Fe2o3 in a matrix of Si02- CK 32055 of the Ferro Company. This dye body leads to the coloring of colored ceramic masses with a high part of blue (high b-value) and insufficient depths of color (high value L) determined in the CIELAB system in accordance with DIN 5033. A coloristically improved product it is obtainable commercially from Ithaka (JP) CP RE-18. This coloring body consists of about 10% by weight of Fe203 in a silicic acid matrix (SiO2), of which about 15% by weight is crystalline and 85% by weight is amorphous. In amorphous Si02 it is treated according to Trans Elektronen microscopy (TEM) of a spherical particle with a particle diameter of 40 nm. The specific surface of the coloring body, determined according to BET (N-.) And DIN 66131 was 36 m2 / g. It is the task of the present invention to prepare another coloring body for coloring ceramic masses, which is easily and inexpensively achievable and in an achievable form to establish an intense and bright reddish brown color in the ceramic melts. A reddish brown burned coloring body containing one or more iron compounds was found which forms a color-producing component in a uniform distribution in a matrix formed of powder based on oxides and / or silicate materials, which is characterized by burning. because the oxide and / or silicate material of the matrix has a specific surface according to BET (DIN 66131) equal to or greater than 40 m2 / g and at least 50% is amorphous to X-rays, the coloring body contains the component producing color in an amount of 25% by weight calculated as Fe203, and is obtained by bringing the color producing component into contact with the oxidic and / or silicatic material in intensive contact. The coloring bodies according to the invention are obtainable by a uniform distribution of the color-producing component in a matrix formed of powder based on an oxidic and / or silicate material, where the color-producing iron compound or compounds and the oxidic material and / or silicates of the matrix, optionally including auxiliary materials, mixed and / or milled together in a device for mixing and / or grinding intensively, that is, they are mixed with the application of an effective amount of mechanical energy. The intensive contact of the base material between the matrix and the dye binding components is important for the formation of a reddish brown color with a significant fraction of red of high brightness and intensity. A simple dry mixing of the constituent parts, as is sufficient in the production of customary metal oxide coloring bodies, is insufficient for the manufacture of the coloring bodies according to the present invention, because the red value a * and the chroma value C * too low and the L * value too high (Cielab system according to DIN 5033, part 3). An increase of the red value to *, decrease of the blue value b * as well as the value L * can be achieved by an intensive contact, approximately 0.1 to 10 hours of grinding in an intensive mixing-mixing device. This contact can be carried out dry or with humidity, where a dry contact is preferred, because with this the desired color values are obtained in a shorter time. By using an intensive mixing-mixing device, such as, in particular, a grinding mixer, an oscillating mill or a ball mill, the desired color values are obtained with a dry grinding-mixing treatment generally over a period of time of half an hour to 5 hours. He The technician will operate in such a way to the mixing-milling device that effective friction is achieved between the constituent parts in the shortest possible time. By the application of mechanical energy in the powder mixture the usual pigments or iron oxide sources when used, are effectively dispersed in the matrix. To obtain coloring bodies of good color values, a wide embedding or coating of the Fe source is necessary, especially an iron oxide of the Fe203 series, FeOOH and Fe304 in a silicic acid or a silicate rich in Si02, preferably completely amorphous . By the mechanical energy introduced into the powder mixture the iron oxide is deagglomerated and dispersed and distributed over the large surface of the carrier material (= matrix), which in turn disintegrates, and is largely coated by it. The growth of crystals that normally occurs at an elevated temperature, thus during burning, and the related variation of color tone toward blue and less red is diminished by the full effect of spatial separation of the iron oxide particles from each other . A large area of the carrier material is important for the quality of the pigment, whereby a sufficient spatial separation of the iron oxide crystallites is possible. It was surely determined, that by the joint use of an auxiliary compound of the oil series of silicone, as in particular, poly (dimethylsiloxane) as well as the alkoxysiloxane of the general formula (R0) 4-n SiR'n or lower condensation products of the same coloring bodies are obtained with improved coloring values. In the general formula R1 represents an organic radical bonded to the Si atom by means of a C atom, approximately an alkyl group with 8 carbon atoms, an omega-aminoalkyl group, an oxyalkyl methacryloyl group or a sulphate group, for example - (CH2) 3-S4- (CH2) 3-Si (0R) 3; R represents a lower alkyl moiety, such as methyl, ethyl n- and iso-propyl, n is a whole number 0, 1, 2 or 3. Usually other auxiliary materials are used in an amount of 0.1 to 10% by weight, especially 0.5. at 3% by weight each time in reference to the matrix, the application amount can also be raised, up to approximately 20% by weight in reference to the matrix, however no further improvement is obtained. With the joint use of the mentioned auxiliary materials it is possible under the same conditions of mixing and / or grinding to raise the value a * in some units, or the duration of the mixing-grinding can be reduced, in order to obtain the dye values sought. Preferred reddish brown burnt coloring bodies have a dyeing of a final vitrified clay mass (porcelain stoneware) with 4% by weight of coloring body or with a Fe203 content of about 10% after The following dye values were obtained as measured by Cielab (DIN 5033): L * less than 60, especially 50 to 57 a * greater than 10 especially 12 to 18 b * 10 to 18, especially 12 to 15. Essential characteristics of the invention are directed to the selection and material data of the base material of the matrix: the base material may be oxidic and / or silicic in nature. Suitable oxides are silicic acid (Si02), B203, A1203, Sn02, Bi203 and oxides of the secondary group elements 3 to 5, especially Ti02 and Zr02. Also mixed oxides such as spinel and Perowskite, which may contain, apart from the aforementioned oxides, also alkaline or alkaline metal oxides, are considered as base material. Especially preferred is the base material of SiO2 or SiO2, this is at least the main constituent part. Silicate base materials are preferably alkali metal silicates and alkaline earth silicates and mixtures thereof, where the aforementioned metals, preferably for the intended purpose, can also be present in sub-stearochimetric amounts. Si-2-rich silicates are thus preferred, as products with an SiO2 content of 80 to 95% by weight. Examples are the usual commercial products of Degussa AG, such as Extrusil (91% Si02, 6% CaO, 2% Na20 and Pasilex (82% Si02, 9.5% Al203, 8% CaO). The base material can be hydrophilic or hydrophobic, usually hydrophilic. The base material of the matrix that is used for the manufacture of the coloring body, in which it is a single substance or a mixture of substances, must be amorphous to the x-rays in at least 50%, preferably more than 90% and especially preferably over 99% and having a specific surface according to BET (DIN 66131 with N2 as measuring gas) equal to or greater than 40m2 / g preferably 90 to 300m2 / g and especially 100 to 200 m2. According to a preferred embodiment, the base material consists essentially of 90 to 100% Si02 and / or Si02-rich silicate rich in X-rays, each time with a BET surface in the range of 90 to 300 m2 / g. It shows that the amorphous is essential, because it would not be possible, to use a finely ground quartz powder instead of an amorphous silicic acid to obtain a usable coloring body. The size of the primary particles preferably of oxidic and silicatic materials of the matrix is preferably less than 30 nm, especially 20 nm; the shape of the primary particle is irregular. The oxidic and / or silicate materials which are found in the coloring bodies of a totally or predominantly amorphous structure and of the required BET surface can be obtained by precipitation or by hydrothermal synthesis. Also by a procedure pyrogen, by a known aerosil process or electric arc process, amorphous oxides are obtainable. For the low density of stamping, oxides prepared by pyrogen with the Aerosil process are preferred. Prepared by the precipitation processes, silicas and silicates are especially preferred. Examples of such substances can be taken from the factory leaflet "precipitated silicas und silicates" (2/88) from Degussa AG. As the color producing components, customary iron oxides or iron oxyhydrates, such as especially Fe203, alpha and gamma FeOOH and Fe304, which are contained in the coloring bodies can be used. Alternatively or additionally divalent and / or trivalent Fe compounds, such as sulfates, halides, carbonates, basic carbonates, nitrates and acetates, may be present. Preferably, the coloring bodies contain directly one of the aforementioned oxides or oxyhydrates, which are obtainable commercially as pigments. The average diameter of the source particles for Fe203 is preferably less than 2 μm, especially less than 0.2 μm; e- grain spectrum is preferably narrow. Preferably for the intended purpose the source of Fe of the coloring components, together an amount of 25% by weight especially 5 to 15% by weight, calculated as Fe203 and in reference to the coloring bodies, wherein this content .

As already indicated, the matrix may contain auxiliary materials apart from oxidic and silicatic materials, which modify the color and / or serve for an improved elaboration. Apart from the silicone oils and alkoxysilanes, it can be treated in auxiliary materials, for example grinding aids, other pigments, salts of fatty acids, and waxes. As long as auxiliary materials are contained in the matrix, their quantity remains in a margin greater than 0 to 20% by weight, especially in the range of 0.1 to 10% by weight, it is preferred that the matrix consists of 80 to 100% by weight. weight of an oxidic and / or silicatic material and from 0 to 20% by weight of auxiliary material. The coloring bodies according to the invention can be obtained, as shown, in a simple manner by an intensive contact of the constituent parts. The procedure is simple and with this achievable economically. Insofar as desired, a heat treatment of 500 to 800 ° C can be followed upon contact to cure or eliminate iron oxide crosslinking disorders that occurred during contact. Such treatment, however, acts weakly on the color value, so that it can usually be abandoned. Burnt reddish-brown coloring bodies are allowed to be applied for the coloring of ceramic masses, especially as masses of vitrified clay and clay fine vitrified, which usually contain 40 to 60% alumina, 20 to 40% pyroxene, 5 to 15% quarry stone or 0 to 5% lime. They are also suitable for the manufacture of decorative colors, as for a direct and indirect decoration, that is, they can be used on decals, ceramic substrates, such as glass, porcelain and ceramics. The coloring bodies of the invention are characterized by good color values, and simple accessibility. With the same content of Fe in the coloring body and the same amount of coloring body in a fine vitrified clay mass, brighter and more intensive colors are obtained than with the natural product so far used Gres de Thiviers. In contrast to a synthetic coloring body with crystalline Si02 in the matrix, the coloring bodies of the invention are characterized by a negligible blue (b *) value and a low L * value. The invention will be explained by means of examples and comparison examples. GENERAL INSTRUCTION FOR THE PREPARATION OF COLORING BODIES. The source for Fe203 and constituent parts of the matrix - as long as it is not otherwise indicated, is 10% by weight as Fe203 and 90% by weight of matrix in reference to the coloring body, they are contacted in a mixing device / ground. The mixture is heated by an intensive contact. The Contact duration in a ball mill makes contact duration of 2 hours. General instruction for the coloring body test: A ceramic mass of vitrified fine ceramic clay (Gres Porcellanato of the Cerdisa firm, Fiorano IT.) Was mixed with the coloring body - unless otherwise indicated, 4% by weight of body dye and 96 6% by weight of ceramic mass. After the homogenization of the dough, it is moistened with 4% water. In a laboratory press, it was molded into test bodies and after a previous drying for 60 minutes (cold-cold) it was burned at 1225 ° C. The color values of the vitrified clay article burned were determined according to Cielab (DIN 5033, part 3) by means of a commercially available color measuring apparatus (10 ° observer, normal light D 65) EXAMPLE B 1 and comparison EXAMPLES VB1 to VB 5. The coloring body FK / B 1 in accordance with The invention was prepared in accordance with the general instruction from 10 wt.% Fe203 pigment (L 2915 from the BASF) and 90 wt.% precipitated silica (FK 320 DS from Degussa AG) which was amorphous and had an BET surface area of 170 m2 / g, for a dry milling of 2 hours in a ball mill. The coloring body not belonging to the invention FK / VB 5 correspondingly was prepared with the same dye pigment and quartz plexus (-dso, 2 μm) The following tables give the color values (according to Cielab) of the coloring bodies of a d-e fine vitrified clay colored and burned with different coloring bodies.

The coloring body according to the invention FK / B l presents, in contrast to the commercial product of Ithaka, a red value higher than * and a higher brightness (higher chroma value C *). -The comparative example VB 3, whose coloring body contains a Si02 matrix, shows an insufficient depth of color and is bluish. The coloring body of comparison example VB 5 does not show any property of pigmentation. EXAMPLES B 2 to B4 The influence of the content of Fe203 on the coloring body is investigated. The matrix consists of precipitated silica FK 320 DS, Fe203 was used as a pigment. The preparation of the coloring body was for two hours of dry milling in a ball mill Test coloration with 4% coloring body.

By adjusting the content of Fe203, the coloring properties are influenced in a wide field by an increase in Fe203 content in the coloring body from 10 to 20% by weight, the L * value sinks, this is the color becomes more dark, however they simultaneously decrease the value a * (red) and the value chrome (brightness). EXAMPLES B5 to B8 The influx of the specific surface area of the precipitated silicic acid used for the matrix was investigated. The coloring bodies were produced in accordance with the general instruction, where a Fe203 pigment of Chinese origin was used in an amount of 10%. The tables show the results of dyeing of dough with 4% body coloring.

* The denominations are trade names of the Degusssa AG Firm. A silicic acid with a surface comparatively Low BET (45 mVg) led to a coloring body, which was clearly less red and less intense than one with the use of silicic acid with approximately 170 m2 / g. Also, a very high BET surface, for example 700 m2 / g of the matrix, leads to a decrease in the coloring properties. EXAMPLES B 9 a B 14 The influence of the quality of the iron oxide pigments in relation to the sources was investigated. The matrix consisted of the precipitation silica FK 320. The amount of pigment iron oxide, calculated as Fe203 in the mass was usually about 4%. The results are presented in the Table In the coloring bodies B 9 to -B-12 the Fe source is presented as Fe203, in B13 as FeOOH. The more finely divided the pigment the more red the color of the coloring body after burning, a primary particle size of the pigment um / below lOOnm is especially preferred. In another example, B 14 was used as the Fe compound forming iron (II) sulfate Fe203, an improvement of the color values is expected by the optimization of the Fe compound. COMPARATIVE EXAMPLE VB 6 and EXAMPLE B 16 investigated the influence of the intensity of the contacting on the color values of the coloring bodies - 90% by weight of the amorphous silica matrix FK 320 and 10% by weight of Fe203 (Chinese origin). The tables show the color values of the colored and burned ceramic mass.

EXAMPLES B17 and B 18 A coloring body of 10% by weight of Fe203 pigment and 90% of a matrix of 97.5% by weight of FK precipitation silicic acid was made (2 hours of dry milling in the ball mill). 320 and 2.5% by weight of silicone oil as auxiliary. The table shows the color values of the test bodies colored and burned in this example in comparison to the analogous coloring bodies of the same pigment and the same silicic acid, which was prepared in the absence of auxiliary medium (B 9).

EXAMPLE B 19 The influence of the subsequent tempering of the coloring body - 2 hours at 700 ° C - on the color values was investigated. The table shows the color values of the test body with the coloration with the coloring body FK / B l which served as the starting product as well as with the tempered product thereof produced FK / B 19.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (13)

1. CLAIMS Having described the invention as above, it is claimed as property contained in the following: 1.- Bodies colored tan burned reddish brown, containing Fe203 and / or one or more iron compounds that form when burning Fe203, as producing components of color in a uniform distribution in a matrix in the form of powder based on oxidic and / or eilactic materials characterized in that the oxidic and / or silicatic material of the matrix has a specific surface according to BET (DIN 66131) of equal or greater than 40. m2 / g and at least 50% is amorphous to X-rays, the color-producing components of the coloring body are contained in an amount of 25% by weight, in relation to Fe203 and the coloring body is obtained by placing intensive contact between the color producing components with the oxidic and / or silicatic material.
2. 2. Solid coloring bodies according to claim 1, characterized in that the oxidic and / or silicic material of the matrix is at least 90% and especially more than 99% amorphous to X-rays. dyeing solids according to claim 1 or 2, characterized in that the oxidic and / or silicatic material of the matrix consists of silicate rich in SiO2 amorphous to X-rays or amorphous Si02 alike. 4. - Solid colorants according to claim 3, characterized in that the oxidic and / or silicatic material of the matrix is produced by a precipitation process or a hydrothermal process. 5. Coloring solid bodies according to one of claims 1 to 4, characterized in that the specific surface (BET DIN 66131) of the oxidic and / or silicatic material of the matrix is 90 to 300 m2 / g, especially 100 to 200. mVg. 6. Coloring solid bodies according to claim 1 to 5, characterized in that the iron compounds which form the Fe203 burner are contained in an amount of 5 to 155 by weight, based on Fe203. 7. - Coloring solid bodies according to one of claims 1 to 6, characterized in that, as color producing components, they contain one or more iron compounds of the Fe20s, FeOOH and FßjO series, each time with a smaller particle diameter of 2 μm. 8. - Solid coloring bodies according to one of claims 1 to 7, characterized in that the matrix consists of 80 to 100% by weight of an oxide and / or silicatic material and from 0 to 20% by weight of one or more auxiliary agents for color modification and / or processing, especially a silicone oil or an alkoxysilane. 9. - Colorant solid bodies according to claim 8, characterized in that, the matrix consists of 90 to 99.9% by weight of an amorphous silicic acid and / or an amorphous Si02-rich silicate and 0.1 to 10% by weight of a silicone oil. 10. Coloring solid bodies according to claim 1, characterized in that, a mass of colored vitrified fine clay (Porcelain stoneware) with a coloring body containing 4% by weight of a 10% by weight Fe203, after burning in a CI-LAB system (DIN 5033, part 3) presented the following color values: L * less than 60, especially 50 to 57 a * greater than 10, especially 12 to 18 b * 10 to 18 ll.- Procedure for manufacturing of a burned coloring body of reddish brown color, comprising a uniform distribution of the color producing components made of Fe303 and / or of one or more iron compounds that form upon burning Fe203 in a matrix in powder form based on an oxidic and / or silicatic material, characterized in that an oxidic and / or silicatic material having as such a specific surface according to BET (DIN 66131) equal to or greater than 40 m2 / gm which is at least one 50% amorphous to the rays X, the color producing components are used in an amount of 1 to 25% by weight, in reference to the coloring body, and the color producing iron compounds and the matrix material, including if necessary auxiliary agents, are milled and / or mixed in a device for mixing and / or grinding and thus apply mechanical energy in an intensive manner. 12. Process according to claim 9, characterized in that the total constituent parts of the coloring body are mixed and / or milled, especially with the application of a mixer-shredder, an oscillating mill or a ball mill. 13. Use of a solid brown-reddish burnt coloring body according to one of claims 10, for the coloring of ceramic masses, especially masses of fine vitrified clay as well as for the manufacture of decoration colors and decals to decorate ceramic substrates, especially ceramics, porcelain and glass.