AU2012205262B2 - Pigment/auxiliary combination having improved colour properties - Google Patents

Abstract

Pigment/auxiliary combination having improved colour properties Abstract The present invention relates to a pigment/auxiliary combination having an improved chroma and/or relative colour strength, to its production and to its use.

Description

Australian Patents Act 1990 - Regulation 3.2A ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title "Pigment/auxiliary combination having improved colour properties" The following statement is a full description of this invention, including the best method of performing it known to us:- -*I Pigment/auxiliary combination having improved colour properties This application is a divisional application of Austalian Application No. 2006202780 the specification and drawings of which as originally filed are incorporated herein in their entirety by reference. 5 The present invention relates to a pigment/auxiliary combination having an improved chroma and/or relative colour strength, to its production and to its use. Inorganic pigments are encountered in numerous areas of everyday life. They are used for colouring building materials such as concrete and asphal, emulsion paints, other coating materials, plastis. and so on, Very often, however, the pigments are additionally coated 10 subsequently, after the actual synthesis. The purpose of such coaing is essentially to achieve. further improvement in the qualities of the pigments EP 0 199 975 Al describes red iron oxide pigments having improved colouristic qualities, the isoelectric point of the pigments being greater than 7, with particular preference greater tha 8. The pigments described in accordance with this teaching are required to have a coating, which 15 is composed of colourless compounds of one or more elements from the group Mg, Zn, Al, La, Y, Zr, Sn, or Ca. Compounds suitable for the coating are low-solibility compounds of Mg, cai, Al and/or Zn, and are applied to the pigment by spraying, painting and/or precipitation in aqueous phase. The process for producing these red iron oxide pigments is complex and necessitates continual monitoring of the isoelectric point 20 EP 0 634 991 Al describes surface-modified particles and also a process for producing them. The particles disclosed therein are similar to those from EP 0 199 975 Al. They differ only in a second coating with at least one dispersion promoter Examples given of such promoters include ligninsulphonates and polyacrylates The production of particles of this kind is always a multi-stage operation and is therefore extensive. 25 The present invention, therefore, aims to provide a pigment/auxiliary combination which has improved chroma and/or relative colour strength in the application medium and can be produced by a simple process in one step using commercially customary organic auxiliaries. Accordingly, the present invention provides pigment/auxiliary combination consisting essentially of one or more chromatic pigments selected frorn iron oxide pigments, chromium 30 oxide pigments, mixed-phase rutile pigments, and mixtures thereof, and one or more organic -1A auxiliaries selected from modified polycarboxylates, partly or fully hydrolyzed polyvinyl alcohols, alkyl sulphates, alkylsulphonates, alkyl phosphates, alkylphosphonates in the form of their alkali metal salts, and mixtures thereof and having * either a chroma difference ACbt measured in CIELAB units in accordance with DIN 5033 and DIN 6174 of > 15 anda relative colourstrength of>95 %, based on the pigment employed, without the auxiliaryijes used, in accordance with the building-material colour test; or * a relative colour strength of > 108%, based on the pigment employed, without the auxiliarylies used, in accordance with the building-maierial colourtest, 10 wherein the organic auxiliaries are added in an amount of 0.01% to 20% by weight, calculated in each case as active substance based on the organic pigment(s); the pigment/auxiliary combination is produced by a process selected from the group consisting of spray granulation, enlargement granulation and compacting granulation; 15 and said pigment/auxiliary combination is in granule form and is homogeneous.

The methods of measuring the colorimetric values and of calculating the chroma difference AC,* and the relative colour strength are specified in the examples. The pigmentiauxiliary combination employs, as inorganic pigments, chromatic pigments, iron oxide pigments. chromium oxide pigments, mixed-phase futile pigments, and mixtures thereof. 5 Also described are achromatic black pigments such as black iron oxide or carbon black (carbon pigments) or white pigments such as titanium dioxide or zinc oxide. The pigment/auxiliary combination comprises, as organic auxiliary, products from the neomere@TINT series from Chryso; i.e. modified polycarboxykes, partly or fully hydrolysed polyvinyl alcohols, alkyl sulphates, alkylsulphonates, alkyl phosphates and alkyphosphonates 10 in the form oftheir alkali metal salts, or mixtures thereof. Partly hydrolysed polyvinyl alcohols may be interpreted theoretically as a copolymer of vinyl alcohol with vinyl acetate In the pigment/auxiliary combination the organic auxiliaries are added in an amount of 0.01% to 20% by weight, more preferably of 0.1% to 5% by weight, calculated in each case as active substance, based on the inorganic pigment(s). Since the organic auxiliaries are often used not is in solid form but instead in the form of solutions, the above indicationis are understood to refer to the active substance. The pigment/auxiliary combination preferably comprises further auxiliaries Which promote processabilily Futher auxiliaries which promote processability are considered for the purposes of this invention to include emusifters, wetting agents, dispersing assistants, flow 2O assistants, disintegration assistants or granule binders The pigment/auxiliary combination preferably has a residual water content of below 4% by weight, preferably below 2% by weight, This can be achieved optionally by means of subsequent drying. The method of determining the residual water content is specified in the examples. 25 The pigment/auxiliary combination is in granule form. Granule in the context of the invention means any material whose average particle size has been enlarged as compared with the starting materials, by means of a treatment step. "Grule" therefore embraces not only spray granules and compacting granules but also, for example,roducts of wet or moist treatment with subsequent comminution, and products of dry or substantially dry processing steps, 30 examples being dry-prepared granules, briquettes and the like, -3 The pigment/auxiliary combination is preferably in the form of bead granules. At least 85% of the granulated pigment/auxiliary combination preferably has a particle size of between 60 pmand 3000 pm, more preferably between 80 piu and 1500 pni. The pigment/auxliary combination preferably further comprises preservatives, defoamers, S retention agents, rheology modifiers, antisettling agents and/or fragrances, The invention also encompasses a process for producing a pigment/auxiliary combination according to the invention, characterized in that conventionally prepared inorganic pigments are mixed with at least one organic auxiliary and the mixture is optionally dried and/or ground. It is an advantage of the production process of the invention that there can be no need for an 10 atertreatnent substance to be applied by precipitation, let alone for a multi-stage synthesis process for the aftertreatment, when preparing the pigment/auxiliary combination of the invention. The pigment/auxiliary combination of the invention can be produced either starting from the dry pigment or else in the wet phase (suspension or paste). 15 In the former case the conventionally prepared pigment is raixed with at least one organme auxiliary and the mixture is optionally ground. For the mixing of pigment and auxiliary it is possible to use all tixers known to the skilled person- Depending on the mixing assembly used it may also be advantageous in certain circumstance, during this procedure, to add on a mill, in order to obtain a complete and homogeneous pigmennauxiliary combination. 20 The conventionally prepared inorganic pigments in suspension or paste aire preferably mixed with at least one organic auxiliary and the mixture is dried and optionaly ground. In the case of preparation via the wet phase (suspension or paste) the auxiliary/ies can be added, after the actual pigment synthesis, at in principle any step in the process of working up and further-processing the pigment through to final conditioning; for example, water the filtration 25 and washing of the pigment and before its drying. The pigment suspension or paste is preferably a suspension from the pigment preparation operation. The addition of the. auxiliary in the wet phase is particularly preferred, since in the suspend sion it is easily possible to add and mix in the auxiliary/ies.

-4 The pigment suspension is preferably a redispersion of agglomerated particles. By redispersmng particles which have already undergone agglomeration it is possible, starting from the pigment powder, to produce, specifically, a pigment suspension for reaction with the organic auxiliary/ies. This is followed by drying. For the drying step the skilled person has a range of 5 assemblies available. Mention is made at this point only of duct dryers, belt dryers, platform dryers, cylinder dryers, drum dryers, tube dryers, paddle dryers, or else discontinuous chamber tray dryers. Drying takes place preferably by means of spray drying or fluidized-bed drying. Preference is given to using spray dryers (atomizing dryers) which operate with spraying discs or nozzles in a cocurrent or countercurrent process. 10 Depending on the drying assembly selected it may be necessary to include a subsequent grinding step. Grinding may be preceded or followed by an additional step of heat treatment as well. As the pigment/auxiliary combination is to be produced in granulated form, then the customary techniques are suitable for this purpose In accordance with the prior art, suitable 15 production processes for pigment granules include spray granulation (spray drying via dise or nozzle) in a cocurrent or countercurrent process, size-enlargement granulation (mixer, fluid-bed granulator, plate or drumn), compacting processes or extrusion processes. Combinations of these granulation processes are of course also conceivable. The selection of the appropriate granulation process depends on factors including that of whether the 20 auxiliary has been added actually to the wet phase (suspension or paste) or to the pigment which has already undergone drying. In the former case the spray drying or extrusion process is appropriate, in the latter case the compacting process. The pigment/auxiliary combination is preferably subjected in the dry and optionally ground state to a subsequent granulation operation as welt. 25 The invention also embraces the use of the pignit'auxiliary combination for coloring lime and/or cement-bound building materials, such as, for example coCrete, cement mortar, render, lime tuandstone or else for covering asphalt In principle, however, the pigment/auxiliary combination produced in accordance with the invention is also suliable for colouing coating materials, mclding emulsion paits, and plastics. 30 The pigment/auxiliary combination is preferably mixed with the building materials in an amount of 01 to 10% by weight, based on cement, or based on the entire mixed material in the case of asphalt.

The pigment/auxiliary combination is preferably first suspended in water and then mixed with the building materials. The subject matter of the present invention is apparent not only from the subject matter of the individual claims but also from the combination of the individual claims with one 5 another. Similar comments apply to all of the parameters disclosed in the description and to their arbitrary combinations. The examples which follow are used to illustrate the invention, without any intention by so doing that the invention should be restricted. The amounts given % by weight are based in each case on the pigment employed.

Examples I. Description of the measuring methods employed 1.1 Building-material colour test (BMCT) The colorimetric values in building materials were tested in cement mortar by colorimetric 5 measurement of prisms produced with white cement, the relevant data being as follows: Cement/quartz sand ratio 1:4, water/cement value 0.35, pigmentation level 1.2%, based on cement, mixer used from RK Toni Technik, Berlin, (DE), with 5 1 mixing bowl, model 1551, rotational speed 140 rpm, batch: 1200 g of quartz sand 0.1 to 1 mm, 600 g of quartz sand 1 to 2 mm, 200 g of fine limestone powder (< 5% sieve residue on 90 pm screen), 500 g of white 10 cement. The quartz sand fractions and the limestone powder are charged together to the mixing vessel. Then the pigment is added and the components are premixed for 10 s (mixer setting 1: slow). The water is then added to this mixture, ensuring that it is introduced in the middle of the mixture. After the water has seeped in, the cement is added and this composition is mixed (mixer setting 1: slow). After a mixing time of 100 s or 200 s a sample (600 g) is taken and 15 used to produce a specimen (10 x 10 x 2.5 cm) under pressure (pressing force 114 kN for 2 seconds). Curing of the specimens: 24 hours at 30*C and 95% relative humidity, with subsequent drying at 60*C for 4 hours. Colour data measurement via Dataflash 2000 Datacolor International, 4 measurement points per slab (measurement geometry d/8*, luminant C/2* with gloss inclusion). The average values obtained are compared with the values of a reference 20 sample. The parameters evaluated are the chroma difference ACab* and the relative colour strength (reference sample = 100%) (DIN 5033, DIN 6174). For the purposes of this specification the following colorimetric abbreviations and calculations are used, as known from the CIELAB system: * a* is the red/green axis, with Aa* = a* (sample) - a* (reference) 25 e b* is the yellow/blue axis, with Ab* = b* (sample) - b* (reference) e Cab* is the chroma, where (Cab*) 2 = (a*) 2 + (b*) 2 * ACab* is the chroma difference, with ACab* = Cab* (sample) - Cab* (reference) e L* is the luminance, with AL* = L* (sample) - L* (reference).

1.2 Relative colour strength The relative colour strength in % is subject to the following equations: (K/S)sample Relative colour strength in - 100 (K/S)rererence (1 - P*) 2 K/S = 2 -p* 5 Y/100 - ro 1 - ro - r 2 (1 - Y/100) where ro = 0.04 and r 2 = 0.6, and Y is the tristimulus value (luminance). Calculation takes place in general accordance with DIN 53 234. 10 1.3 Bulk density The bulk density was determined on ready-produced material without further treatment of the product, as the ratio of mass to volume. 1.4 Residual moisture content The residual moisture content was determined by gently drying the pigment/auxiliary 15 combination to constant weight. I.5 Compressive strength The compressive strength was determined in general accordance with DIN EN 196-1. The parameter tested is the compressive strength of pigmented cement mortar in comparison to an unpigmented sample, for which the deviations should not be greater than specified in 20 EN 12878 "Pigments for the colouring of building materials based on cement and/or lime" (a maximum of -8% for reinforced concrete).

1.6 Solidification behaviour The solidification behaviour was determined in general accordance with DIN EN 196-3. It involves comparison of the start and end of solidification of a cement paste with and without pigmentation,; the deviations should not be greater than as specified in EN 12878. 5 II. Example 1 10 kg of Bayferrox* 110 red iron oxide (commercial product of Lanxess Deutschland GmbH) were mixed intensely in a mixer with 2.5% by weight of neomere* TINT 317 (commercial product of Chryso, SAS) and the mixture was subsequently homogenized via a Bauermeister mill with a 3 mm screen insert. 10 The product obtained possessed a residual moisture content of 0.7% by weight and a bulk density of 0.40 g/cm 3 and was incorporated as described above in accordance with the BMCT with a mixing time of 100 s, colorimetry giving a Aa* = 1.0, Ab* = 1.4 - corresponding to a chroma difference ACab* = 1.7 - and a relative colour strength of I11%. The reference used was the Bayferrox@ 110 starting material, likewise ground via the Bauermeister mill with a 15 3 mm screen insert. The aftertreated sample is therefore substantially stronger in colour and substantially more saturated than the starting material. 111. Example 2 10 kg of Bayferrox* 110 red iron oxide were mixed intensely in a mixer with 2.0% by weight of Texapon* 842 (commercial product of Cognis Deutschland GmbH) and the mixture was 20 subsequently homogenized via a Bauermeister mill with a 3 mm screen insert. The product obtained possessed a residual moisture content of 0.5% by weight and a bulk density of 0.38 g/cm 3 and was incorporated as described above in accordance with the BMCT with a mixing time of 100 s, colorimetry giving a Aa* = 1.0, Ab* = 1.4 - corresponding to a chroma difference ACab* = 1.6 - and a relative colour strength of 108%. The reference used 25 was the Bayferrox@ 110 starting material, likewise ground via the Bauermeister mill with a 3 mm screen insert. The aftertreated sample is therefore substantially stronger in colour and substantially more saturated than the starting material.

IV. Example 3 25 kg of a brown mixture of red and black iron oxides were slurried with 25 kg of water, with addition of 2.5% by weight of neomere* TINT 317. The suspension had a solids content of 48.1% and a pH of 5.1 and was dried on a nozzle spray dryer. The granules obtained are free 5 flowing and possessed a residual moisture content of 0.5% by weight and a bulk density of 1.08 g/cm 3 . Studies on compressive strength in general accordance with DIN EN 196-1 and on the solidification behaviour in general accordance with DIN EN 196-3 show that the requirements of standard EN 12878 are met even for reinforced concrete. The granules were incorporated as described above in accordance with the BMCT, with a 10 mixing time of 200 s, colorimetry giving a Aa* =0.8, Ab* = 1.4 - corresponding to a chroma difference ACab* = 1.6 - and a relative colour strength of 110%. The reference used was the brown mixture without addition of an auxiliary. The granules with admixed auxiliary are therefore substantially stronger in colour and substantially more saturated than the starting material. A relative colour strength difference and a chroma difference of this magnitude 15 between reference and granules is visible even to the naked eye. V. Example 4 25 kg of Bayferrox* 920 yellow iron oxide (commercial product of Lanxess Deutschland GmbH) were suspended in 37.5 kg of water and 1.5% by weight of a 40% strength aqueous solution of an Na polyacrylate and with 0.5% by weight of a partly hydrolysed polyvinyl 20 alcohol of low molecular weight. The suspension had a solids content of 38.3% and a pH of 6.4 and was dried on a nozzle spray dryer. The granules obtained are free-flowing and possessed a residual moisture content of 0.7% by weight and a bulk density of 0.48 g/cm3. Studies on compressive strength in general accordance with DIN EN 196-1 and on the solidification behaviour in general accordance with DIN EN 196-3 show that the requirements 25 of standard EN 12878 are met even for reinforced concrete. The granules were incorporated as described above in accordance with the BMCT, with a mixing time of 200 s, colorimetry giving a Aa* = 0.0, Ab* = 2.3 - corresponding to a chroma difference ACab*= 2.2 - and a relative colour strength of 102%. The reference used was the Bayferrox* 920 powder used without additions. The granules with admixed auxiliary are 30 therefore substantially more chromatic than the starting material. A chroma difference of this magnitude between reference and granules is clearly visible.

VI. Example 5 25 kg of Bayferrox* 920 yellow iron oxide were suspended in 37.5 kg of water and 1.5% by weight of a 40% strength aqueous solution of the sodium salt of polyaspartic acid and with 1.0% by weight of a partly hydrolysed polyvinyl alcohol of relatively high molecular weight. 5 The suspension had a solids content of 38.6% and a pH of 5.9 and was dried on a nozzle spray dryer. The granules obtained are free-flowing and possessed a residual moisture content of 0.7% by weight and a bulk density of 0.49 g/cm 3 . Studies on compressive strength in general accordance with DIN EN 196-1 and on the solidification behaviour in general accordance with DIN EN 196-3 show that the requirements of standard EN 12878 are met even for reinforced 10 concrete. The granules were incorporated as described above in accordance with the BMCT, with a mixing time of 200 s, colorimetry giving a Aa* = 0.3, Ab* =3.8 - corresponding to a chroma difference ACab* = 3.8 - and a relative colour strength of 110%. The reference used was the Bayferrox* 920 powder used without additions. The granules with admixed auxiliary are 15 therefore substantially more chromatic and more strongly coloured than the starting material. A relative colour strength difference and a chroma difference of this magnitude between reference and granules is clearly visible. VI. Example 6 (Comparative example) 25 kg of Bayferrox* 920 yellow iron oxide were suspended in 37.5 kg of water and 1.5% by 20 weight of a 40% strength aqueous solution of the sodium salt of polyaspartic acid. The suspension had a solids content of 38.3% and a pH of 6.3 and was dried on a nozzle spray dryer. The granules obtained are free-flowing and possessed a residual moisture content of 0.7% by weight and a bulk density of 0.54 g/cm 3 . Studies on compressive strength in general accordance with DIN EN 196-1 and on the solidification behaviour in general accordance with 25 DIN EN 196-3 show that the requirements of standard EN 12878 are met even for reinforced concrete. The granules were incorporated as described above in accordance with the BMCT, with a mixing time of 200 s, colorimetry giving a Aa* = 0.2, Ab* = 0.9 - corresponding to a chroma difference ACab* = 0.9 - and a relative colour strength of 102%. The reference used was the 30 Bayferrox* 920 powder used without addition. The granules are therefore colouristically comparable with the starting material.

VII. Example 7 6 kg of Bayferrox* 960 yellow/red iron oxide mixture (commercial product of Lanxess Deutschland GmbH) were mixed intensely in a mixer with 1.5% by weight of neomere* TINT 305 (commercial product of Chryso, SAS) and with 1.5% by weight of a 20% strength 5; aqueous solution of a partly hydrolysed polyvinyl alcohol having a relatively high molecular weight and the mixture was subsequently homogenized via a Bauermeister mill with a 3 mm screen insert. The product obtained possessed a residual moisture content of 0.9% by weight and a bulk density of 0.26 g/cm 3 and was incorporated as described above in accordance with the BMCT 10 with a mixing time of 100 s, colorimetry giving a Aa* = 0.5, Ab* = 1.4 - corresponding to a chroma difference ACab* = 1.5 - and a relative colour strength of 108%. The reference used was the Bayferrox@ 960 starting material, likewise ground via the Bauenneister mill with a 3 mm screen insert. The aftertreated sample is therefore substantially stronger in colour and substantially more saturated than the starting material. 15 VII. Example 8 25 kg of Bayferrox* 110 red iron oxide were mixed intensely in a mixer with 1.5% by weight of neomere TINT 317 and with 2.0% by weight of a 25% strength aqueous solution of a partly hydrolysed polyvinyl alcohol of low molecular weight. The mixture was comminuted via a 200/50P compactor (Bepex, Leingarten (DE)) at approximately 10 kN (2 kN/cm) and 20 subsequently on a grinder (Frewitt, Fribourg, (CH)) with a screen having a mesh size of 1.25 mm. The comminuted product was sieved off via an Allgaier sieve with a mesh size of 250 Lm. The fraction of the granulated oversize was approximately 82%. The oversize obtained is free-flowing and possessed a residual moisture content of 1.0% by weight and a bulk density of 0.98 g/cm 3 . Investigations on the compressive strength in general 25 accordance with DIN EN 196-1 and on the solidification behaviour in general accordance with DIN EN 196-3 show that the requirements of standard EN 12878 are met even for reinforced concrete. The oversize was incorporated as described above in accordance with the BMCT, with a mixing time of 100 s. The slab produced was homogeneously coloured, colorimetry giving a Aa* = 0.7, Ab* = 1.8 - corresponding to a chroma difference ACab* = 1.7 - and a 30 relative colour strength of 103%. The reference used was the Bayferrox* 110 starting material. The granulated oversize is therefore substantially more saturated than the starting material.

- 14. VII. Example 9 20 kg of green chromium oxide GN (commercial product of Lanxess Deutschland GmbH) were suspended in 24.5 kg of water with 2.0% by weight of neomere@ TIT4 317 and 0.5% by weight of a partly hydrolysed polyvinyl alcohol of low molecular weight. The suspension had a solids content of 46.0% and a pH of 6.7 and was dried on a nozzle spray dryer. The granules obtained are free-flowing and possessed a residual moisture content of 0.5% by weight and a bulk density of 1.52 g/cm 3 . The granules were incorporated as described above in accordance with the BMCT, with a mixing time of 100 s and 200 s respectively. The slabs produced were homogeneously 10 coloured and, for a mixing time of 100 s, colorimetry gave a Aa* = -0.9, Ab* = 1.4 corresponding to a chroma difference ACab* = 1.7 - and a relative colour strength of 109%, while, for a mixing time of 200 s, colorimetry gave a Aa* = -1.3, Ab* = 1.6 - corresponding to a chroma difference ACab* = 2.1 - and a relative colour strength of 114%. The reference used was in each case the slab likewise homogeneously coloured with the green chromium oxide 15 GN powder used, without additions, with a mixing time of 100 s and 200 s respectively. The granules with admixed auxiliary are therefore substantially more chromatic and more strongly coloured then the starting material. A relative colour strength difference and a chroma difference of this magnitude between reference and granules is clearly visible. IX. Example 10 (Comparative example) 20 20 kg of green chromium oxide GN were suspended in 24.5 kg of water and 2.0% by weight of a 40% strength aqueous solution of sodium polyacrylate. The suspension had a solids content of 46.0% and a pH of 8.3 and was dried on a nozzle spray dryer. The granules obtained are free-flowing and possessed a residual moisture content of 0.5% by weight and a bulk density of 1.48 g/cm 3 . 25 The granules were incorporated as described above in accordance with the BMCT, with a mixing time of 100 s and 200 s respectively. The slabs produced were homogeneously coloured and, for a mixing time of 100 s, colorimetry gave a Aa* = + 0.0, Ab* = 0.2 corresponding to a chroma difference ACab* = 0.2 - and a relative colour strength of 103%, while, for a mixing time of 200 s, colorimetry gave a Aa* = 0.1, Ab* = 0.3 - corresponding to a 30 chroma difference ACab* = 0.3 - and a relative colour strength of 105%. The reference used was in each case the slab likewise homogeneously coloured with the green chromium oxide GN powder used, without additions, with a mixing time of 100 s and 200 s respectively. The granules are therefore colouristically comparable with the starting material. All results are summarized in Table 1.

N 00 *12 N 00 0 4 E E 0.) W) C) C) 0 0 0 0 0n 0 0f 0 ON o 0 o0 0 a. en 00 0- 0 o 0 0 e 00 N a -0 00 o 0 6S r cd ~ ~ - 00= = nV o 0 o A 0 - 14A Throughout this specification and the claims which follow, unless the context requires otherwise, the word 'comprise", and variations such as "coinprises" and "comprising', will be understood to imply the inclusion of a stated integer or step or group of integers or steps but 5 not the exclusion of any other integer or step or group of integers or steps. he reference in this speciication to any prior publication (or information derived fi-m it), or to any matter which is known is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter fors part of the common general knowledge in the field of endeavour to 10 which this specification relates.

Claims (20)

1. Pigment/auxiliary combination consisting essentially of one or more chromatic pigments selected from iron oxide pigments, chromium oxide pigments, mixed-phase rutile 5 pigments, and mixtures thereof, and one or more organic auxiliaries selected from modified polycarboxylates, partly or fully hydrolyzed polyvinyl alcohols, alkyl suIphates, alkylsulphonates, alkyl phosphates, alkylphosphonates, in the form of their alkali metal salts, and mixtures thereof, and having * a chroma difference ACb* measured in CIELAB units in accordance with 1 fDIN 5033 and DIN 614 of > 1.5 and a relative coour strength of' 95 %, based on the pigment employed, without the auxiliary/ies used, in accordance with the building-material colour test; or * a relative colour strength of lO10 based on the pigmat employed, without the auxiliary/ies used, in accordance with the building-material colour test, 15 wherein the organic auxiliaries are added in an amount of 0.01 % to 20% by Weight, calculated in each case as active substance based on the organic pigment(s); the pigment/auxiliary combination is produced by a process selected from the group consisting A spray granulation, enlargement granulation and compacting granulation; 20 and said pigment/auxiliary combination is in granule fon and is homogeneous,

2. Pigmentauxiliary combination according to Clain f, wherein the pigment/auxiliary combination has a chroma difference ACbt measured in CIELAB-units in accordance with DIN 5033 and DIN 6174, of> 1.8 and a relative colour strength of., 95 %, based 25 on the pigient used, without the auxiliary/ies used in accordance with the building material colour test.

3. Pigment/auxiliary combination according to Claim I or 2, wherein the pigment/auxiliary combination comprises further auxiliaries which promote processability.

4, Pigmentfauxiliary combination according to any one of Claims I to 3, wherein the pigment/auxiliary combination has a residual water content of below 4% by weight.

5. Pigment/auxiliary combination according to any one of Claims I to 4, wherein the pigment/auxiliary combination is in the form of bead granules. 5

6. Pigment/auxiliary combination according to Claim5, wherein at least 85% of the granulated pigment/auxihlary combination has a parties size of between 60 pm and 3000 pm.

7. Pigment/auxiliary combination according to any one of Claims I to 6, wherein the pigment/auxiliary combination further comprises preservatives, defoamers, retention 10 agents, theology modifiers, autisettling agents and/or figrances.

8. Pigment/auxiliary combination according to claim 1, substantially as hereinbefore described.

9. Process for producing a pigment/auxiliary combination according to any one of Claims 1 to 8, Whdrein conventionally prepared inorganic pigments are mixed with at 15 least one organic auxiliary and the mixture is optionally dried and/or ground.

10. Process for producing a pigment/auxiliary combination according to Claim 9, wherein conventionally prepared inorganic pigments are mixed in suspension or paste with at least one organic auxiliary and the mixture is dried and optionally ground.

11, Process for producing a pigment/auxiliary combination according to Chitn 10, wherein 20 the pigment suspension is a suspension or paste from the pigment preparation operation.

12, Process for producing a pigmentiauxiliary combination according to Claim 10, wherein the pigment suspension is a redispersion of agglomerated particles,

13. Process for producing a pigment'auxiliary combination according to anyone ofClaims 9 to 12, wherein the drying takes place by means of spray drying or fluidizedbed drying. 25

14. Process for producing a pigment/auxiliary combination according to Claim 9 or 10, wherein the pigment/auxiliary combination in the dry and optionally ground state is subsequently subjected additionally to a granulation operation.

15. Process according to claim 9, substantially as bereinbefore described.

16. Use of the pigment'auxiliary combination according to any one of Claims I to 8 or of the pigment/auxiliary combination produced by the process according to any one of Claims 9 to 15 for colouring lime- and/or cement-bound building materials. 5

17. Method of colouring building materials with pigment/auxitiary combination according to any one of Claims I to $ wherein the pigment/auxiliary combination is rixed with the building materials in an amount of 0.1% to 10% by weight, based on cement, or based on the entire mixed material in the case. of asphalt

18. Method of colouring building materials with pigmen/auxiliary combination according 10 to Claim 17, wherein the pigment/auxiliary combination is first suspended in water and then mixed with the building materials.

19. Use according to claim 16, substantially as hereinbefore described.

20. Method according to claim 17,substantially as hereinbefore described.