Title of Invention

"A COMPO SITION SUITABLE FOR COLOURING CERAMIC ARTICLES A PROCESS FOR COLOURING CERAMIC ARTICLES USING THE SAID COMPOSITION AND VITRIFIED STONENARE TILES PREPREPARED BY THE SALD PROCESS"

Abstract A composition whereby ceramic manufactured articles , obtained by moulding a conventional ceramic mixture without added T1O2 . are coloured from yellow to orange , said composition consisting of an aqueous solution of inorganic compounds or organic complexes of titanium and chromium combined with antimony or tungsten or mixtures thereof, in quantities corresponding to (2 -6) % by wt Ti,3 to 12 % Sb ( or 4 to i4 % tungsten ) and 0,2 to 2.5 % chromium. A process for colouring ceramic manufactured articles obtained by moulding a standard ceramic mixture without added Ti02 using the said composition. Vitrified stoneware tiles obtained by the said colouring process.
Full Text Formulations based on water soluble compounds of titanium and chromium combined with antimony or tungsten or mixtures thereof suitable for colouring ceramic manufactured articles and relevant high temperature colouring process Field of the invention
The present invention relates to compositions suitable for colouring ceramic manufactured articles and the relevant colouring process.
In particular, the compositions of the invention consist of aqueous solutions of salts or organic complexes of titanium and chromium, combined with antimony or tungsten or mixtures thereof, which allow the obtainment of ceramic manufactured articles with shades ranging from light yellow to orange yellow to mustard. Furthermore, to obtain particular shades, said solutions may be mixed with solutions of other cations, State of the art
The use of coloured ceramic manufactured articles as well as the compositions and
procedures adopted to obtain the relevant colours have been known since long. One
of the methods most commonly used is based on the addition of powdered
pigments, in particular inorganic oxides and mineral colouring matters, to the
ceramic mixture (vitrified stoneware) before firing. The ceramic manufactured article
is thus coloured through its whole thickness, although with large consumption of
colouring matter, which is the most expensive component.
According to a used procedure, the surface of the ceramic material is caused to absorb, either after partial burning (as disclosed e.g. in German patent 2,012,304) or simply after press moulding and before burning (as disclosed e.g. in Swiss patent 575,894), an aqueous solution of inorganic salts or metal complexes (as disclosed
e.g. in Sprechsal, vol. 119, No. 10, 1986; in EP 0704411 and in patent PCT WO 97138952), which become stable colours at high temperature during the firing cycle of the ceramic manufactured article.
The aqueous solution is applied to the ceramic material, e.g. by immersion, spraying, disk techniques, and silk-screen techniques.

2
The aqueous solution is applied to the ceramic material before final firing. This
procedure is particularly advantageous because it allows the colouring of very thin
layers: therefore, it is widely used for flat manufactured articles (such as e.g. floor
and wall tiles).
Another problem to be solved when using colours in an aqueous solution is the
obtainable depth of colour penetration into the ceramic material. In fact, it was
experimentally found that the depth of penetration depends on several parameters,
such as the viscosity and surface tension of the colouring solution, the application
temperature, the quantity of water sprayed on the manufactured article once the
colouring solution has been applied, the application technique.
Of cardinal importance is the application technique: in particular, the quantity of
colouring solution that may be applied by disk and spraying techniques is as high as
400 to 600 g/m2; by silk-screen type techniques it usually amounts to 100 to 200
g/m2 and sometimes even to 400 g/m2, when thickened screens made of a small
number of threads are used.
Silk-screen type techniques are very much in demand, being the only techniques
allowing graphic decorations and drawings, and requiring lower quantities of
colouring matter. By using said techniques, the colouring solutions are to be
thickened with appropriate thickening agents, e.g. modified glucomannans, starch
and modified starch derivatives, cellulose and modified cellulose derivatives, or other
polymeric substances, soluble or dispersible in an aqueous solution.
The colour penetrates into the ceramic material before firing by using relatively high
quantities of water after application of the colouring solution. However, the resulting
colours are less intense than those obtained using other techniques.
Colour penetration into the material is particularly important in the case of
"smoothed" vitrified stoneware tiles.
The term "smoothed" means that the vitrified stoneware surface has been abraded
with diamond wheels by 0.8 to 1.5 mm, and subsequently smoothed or polished with
appropriate felt until obtaining a glassy surface.

3
It follows that colour penetration into stoneware articles to be smoothed after firing
must reach a depth of 1.6 mm min.
Other methods have been developed for smoothing very thin surface layers of the
manufactured article, in the order of 1 to 10 micron.
Technical problem
Considering that it is very simple to colour ceramic materials by disk techniques,
spraying and silk-screen techniques, the ceramic industry is highly interested in
finding new substances to be used therewith.
As concerns said new substances, the following technical problems are to be
solved. The substances must become stable colours at a high temperature; the
manufactured article has to be coloured in the desired shades, on its surface and to
a depth of 1.6 mm min from its surface, without too high consumption of colouring
matter
Unfortunately, very few are the colours available so far. In particular, the lack of
yellows and orange yellows, obtainable in the presence of other colours, is deeply
felt, especially by the industry of vitrified stoneware, which must propose ever new
aesthetic solutions.
In fact, as disclosed in patent application PCT WO 97/38952, the whole range of
yellows, oranges, orange beiges may be obtained using antimony/chromium,
zirconium/chromium, zinc/chromium, manganese/chromium solutions, exclusively on
supports modified by the addition of 0.5 to 10% by wt. titanium oxide,
preferably 1% by wt. min. However, titanium oxide heavily affects the development
of colours not included in the aforesaid range of yellows and oranges, which may be
obtained with the already known aqueous solutions of iron, cobalt, nickel, vanadium,
chromium, manganese, copper, ruthenium, palladium, zirconium, gold, and mixtures
thereof, especially when used in low concentrations, or by the silkscreen technique,
to obtain pale colours.
By way of example, Table 1 illustrates some tests carried out to prove the main
effects that titanium oxide addition to the ceramic mixture exerts on the development
of the (typical) colours of the aforesaid cations.

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All tests were performed according to the following procedure:
a) drying six 33x33 cm supports (two of mixture A, two of mixture B and two of mixture C) at 100°C to a water residue of 0.5% by wt. max.;
b) cooling said supports to room temperature;
c) letting fall an amount of mg 185 +/-15 of colouring solution in a single point, within an area of approx. 10 cm2, of each support;
d) equalizing the supports at room temperature for 2 h and in a thermo-ventilated oven at 60°C for 2 additional h to homogenize the solutions absorption;
e) kiln firing according to a standard ceramic cycle;
f) smoothing each support of mixtures A, B and C;
g) recording the support colour before and after smoothing.

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TABLE 1
Test Solution Mixture *Coiour before *Co!our after
No. {% as type smoothing smoothing
element) **CMYK values** **CMYK values**
***L*; a*; b* values ***L*; a*; b* values
1 0.4% Gold A Garnet Parma red
25-70-65-25 17-47-39-7
37,5; 14,6; 10,3 56,5; 13,5; 2,1
2 0.4% Gold B Reddish violet Cobalt violet
25-57-49-19 22-47-40-12
63,4; 8.3; 3,6
3 0.4% Gold C Violet Violet
30-64-57-27 27-49-40-18
41,9; 12; 4,8 51,4; 7,4; 0,6
4 8% Vanadium A Grey beige Lightgrey beige
30-31 -44-18 15-19-29-4
58,4; 2,2; 6,4 69,3; 2,9; 9,9
5 8% Vanadium B Ocher brown Dark beige
25-31-47-14 15-25-42-5
62,7; 3,9; 17,2
6 8% Vanadium C Pozzuoli red Ocher brown
30-50-69-27 19-45-68-15
45,1;8,1; 17,6 54,5; 9,1; 20,8
7 10% iron A Havana brown Burnt umber
29-57-22-25 22-46-64-18
39,7:13,8:15,5 46,8; 9,8; 21,1
8 10%1ron B Burntumber Raw sienna
29-53-61-26 15-54-85-22
48,6; 9,1; 26,9
9 10% Iron C Chocolate Tobacco brown
33-54-71-31 28-44-73-27
38,9; 8,4; 20,4 46,3; 5,8; 23,1
10 5,8% Cobalt A indigo Light ultramarine blue
62-67-22-25 59-13-9-7
34,7; -3,0; -20.9 42,9; -4,1; -27,4

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TABLE 1 (cont'd)
Test Solution Mixture 'Colour before *Colour after
No. (% as type smoothing smoothing
element) **C M Y K values** **CMYK values**
***L*; a*; b* ***L*; a*; b*
11 5.8% Cobalt C Manganese blue Turquoise blue
65-49-22-24 37-24-27-11
39,7; -8,3; -20 55,9; -6,3; -5,3
12 1.5% Cobalt A Light ultramarine blue Sky blue
60-43-20-18 39-22-10-4
41,2; -4,2; -23,2 60,6; -5; -13,9
13 1.5%Cobalt C Peacock blue Water green
53-38-23-18 23-17-23-6
46,8; -8,7; -14,5 69,5; -4,2; 2,7
14 6% Ru A Deep black Black
55-50-51-41 63-61 -62-55
23,6; -0,6; -0,7 14,5; -2; -0,3
15 6% Ru B black Matt black
43-41-46-29 61-84-68-59
20,8;-2,1; 2,6
16 6%Ru C Pinkish black Pinkish black
58-62-61 -53 59-60-62-54
21,3;-0,3; 2,6 20,6;-0,7; 2,2
17 1,5% Ru A Blackish grey Anthracite grey
53-50-50-41 47-35-49-2?
28,5;-1,5;-0,2 41,2;-4,1; 3,4
18 1.5%Ru C Pinkish dark grey Tobacco brown
48-48-55-38 36-42-58-28
31,4;-0,4;5,7 41,3; 2; 12,9
19 8.9%Cr A Cobalt green Olive green
42-52-80-24 46-31-65-27
43,9; -4,8; 10,3 43,1; -3,2; 12,4
20 6,9% Cr B Greyish green Dove grey
42-35-57-27 36-36-60-25
48,4;-0,8; 17,3

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TABLE 1 (cont'd)
Test Solution Mixture *Colour before *Colour after
No. {% as type smoothing smoothing
element) **C M Y K values** **CMYK values**
***L*; a*; b* ***L*; a*; b*
21 8.9% Cr C Greyish green Tobacco brown
44-38-58-29 24-39-70-21
42,8;-4,8; 8,8 49,1; 2,7; 23
22 2.2% Cr A Olive green Beige
34-34-60-24 13-18-35-3
49,8; 0,2; 14,0 68,9; 2,5; 14,5
23 2.2% Cr C Ocher brown Sand
24-42-67-20 13-20-50-3
54,5; 5,3; 24,4 71,1; 3,8; 28
*Cf. Colour Atlas, 2nd page of the cover; Italian-English dictionary; II Regazzini III edition; ed. Zanichelli; ISBN 88-08-09960-1
** Values of cyano, magenta, yellow, black primary colours, which constitute the colour of each test. The four colourimetric coordinates of each test were determined by a computing system consisting of scanner Saphir Linotype Hell, display Apple 21" with Color Profile Syns 2.1.2., RGB standard, power computing with operating system Apple System MAC OS 8, colour recording programme adobe Photoshop 4.0.
*** The reported values have been obtained by the instrument Spectra Pen of Dr. Lange. The instrument has been adjusted with a sample of white provided by the constructor and showing the following values x = 92.3; y = 97.4; z = 104.4. The sample of white provided by the constructor has been adjusted according to the norm DIN 55350 section 18, 4.1.2 through standard LZM 224 for Spectra Pen. Certificate number of the master standard "Opal BAM S1E 0504/A" (BAM = German

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Federal Bureau analysis and methods). ). For the measurement of the values the chromatic system L* a* b* has been adopted according to the norm DIN 6174 (Colorimetric evaluation of color differences of surface colours according to the CIELAB formula). The L*-axis indicates the lightness of a colour, the a*-axis the red-green share and the b*-axis the yellow-blue share. The L*values are always positive, with 0 for ideal black and 100 for idea! white colours. Red shades have positive a*-values, green shades negative ones. Yellow shades have positive b*-values, blue shades negative ones.
The compositions (% by weight) of the mixtures used in the tests are reported below.
A*) Si02 64.4%, AI203 21.8%, K20 3.8%, Na20 0.8%, CaO 0.6%, MgO 0.1%, Ti02 0.3%, Fe203 0.2%, ZrSi04 5%, H20 q.s. to 100%.
B) Si02 64.4%, A1203 21.8%, K20 3.8%, Na20 0.8%, CaO 0.6%, MgO 0.1%, Ti02 1.3%, Fe203 0.2%, ZrSi04 4%, H20 q.s. to 100%.
C) Si02 64.4%, AI203 21.8%, K20 3.8%, Na20 0.8%, CaO 0.6%, MgO 0.1%, Ti02 3.3%, Fe203 0.2%, ZrSi04 2%, H20 q.s. to 100%.
* The analysis of mixture A reports 0.3% Ti02. Actually, it is the Ti02
equivalent of the titanium present in the raw materials as titanium oxide and
other titanium derivatives.
The solutions used consist of vanadium glycolate, iron ammonium-2-hydroxy
propane-tricarboxylate, cobalt bisethanoate, ruthenium glycolate, chromium
trisethanoate.
As may be inferred from the results of Table 1. there is a deeply felt problem
concerning the obtainment of shades from yellow to orange on conventional ceramic
mixtures, which correctly develop, in the known manner, the colours deriving from
iron, cobalt, chromium, manganese, copper, ruthenium, palladium, zirconium, gold,
vanadium, nickel and mixtures thereof.
In fact, as may be inferred from the experimental results of Table 1, in the presence
of high quantities of titanium oxide in the ceramic mixture, the colours of the
aforesaid cations do not develop correctly, but are altered; only as example

9
compared tests 12 and 13, smoothed surface, colour based on Cobalt, the b* value is negative (-13,9) with standard support, therefore a blue colour, while on support with 3% of TiO2 b* is positive ( 2,7 ), therefore a shifting towards the yellow that gives a colour near the green.
It is an object of the present invention to provide a colouring formulation for ceramic products in the form of an aqueous solution, suitable for obtaining aesthetically excellent shades from yellow to orange on a ceramic material obtained from a conventional mixture without added Ti02 which, therefore, can be coloured in the traditional shades with the known metal cations mentioned above. This means that a single manufactured article can be coloured not only in the shades from yellow to orange using the formulation of the invention in some zones, but also, in different zones, with other traditional shades using formulations already known, in particular by the silk-screen technique.
A particular advantage of the invention is the possibility of obtaining a manufactured article coloured in shades from yellow to orange from a conventional ceramic mixture. Therefore, there is no need of using a different ceramic mixture added with Ti02, unsuitable for traditional colouring. The use of a single ceramic mixture to produce manufactured articles in different colours is a clear advantage for a plant running because it is not necessary to clean the apparatus for molding and drying the ceramic mixture as it occurs when in the manufacture of different articles different ceramic mixtures are used.
The Applicant, who has full-fledged experience in the production and sale of colouring matters for ceramic tiles, has now found that titanium and chromium inorganic salts or organic complexes in combination with inorganic salts or organic complexes of antimony or tungsten or mixtures thereof in water solutions or in water solutions mixed with alcohols or other water-miscible organic solvents, can be used to obtain - after firing - shades varying from orange yellow to orange, to orange beige, on manufactured articles consisting of a conventional ceramic mixture without added Ti02. The ceramic mixture considered herein may contain the Ti that is present in small quantities in the starting mineral materials (clay, kaolin) in various

10
forms (oxide, silicate) for a total amount generally of 0.5% by wt. max., expressed as Ti02, and in some cases up to 0.7% max.
The solutions object of the present invention contain from 2 to 8% by wt. of titanium as element; from 3 to 12% of antimony or from 4 to 14% of tungsten as elements; from 0.2 to 2.5% of chromium as element.
Particularly useful solutions contain from 5% to 12% Sb and from 6% to 10% by wt. of W.
The resulting shades depend on the titanium/antimony/chromium or titanium/tungsten/chromium ratio by wt. (as elements ) in the solution: by increasing the chromium concentration, colours gradually turn from orange-yellow to orange-beige.
The aqueous or hydroalcoholic solutions of the invention are particularly useful for colouring tiles of vitrified stoneware, also by silk-screen application techniques. It is, therefore, a fundamental feature of the present invention to use titanium and chromium inorganic salts or organic complexes in combination with antimony or tungsten or mixtures thereof in water solutions or water solutions mixed with organic solvents to treat, before firing, ceramic articles that, after firing, will be yellow, orange yellow, yellow ocher, orange beige coloured.
It is also possible to use ammonium or alkaline or alkaline-earth salts of chromic or tungstic or antimonic or sulfoantimonic acid.
Sulphuric, hydrochloric, hydrofluoric and nitric acid salts are particularly cheap and suitable for obtaining the desired colours, but suffer from the disadvantage of releasing corrosive vapours during the firing cycle. It follows that kilns are to be provided with exhaust gas neutralisation equipment. Therefore, whenever possible, it is preferable to use organic complexes that, during the firing cycle of the treated products, undergo thermal decomposition yielding water and carbon dioxide. Particularly useful are the salts of mono- or polycarboxylic organic acids, either aliphatic or aromatic, containing 1 to 18 carbon atoms, optionally with one to five hydroxylic or aminic or thiolic substituents in the aliphatic chain or in the aromatic nucleus.

11
The following compounds of Ti, Cr, Sb, W are reported by way of example, not of limitation, of the present invention: salts of acetic, formic, propionic, butyric, lactic, glycolic, tartaric, citric, oxalic, maleic, citraconic, ethyfenediaminetetraacetic, fumaric, gluconic, glycine, aminoadipic, aminobutyric, aminocaproic, aminocapryiic, 2-amino-1-hydroxy-butyric, amino isobutyric, aminolevulinic, thioglycolic, salicylic acids.
In particular the following compounds are suitable:
Antimony
Sb lactate, Sb/K citrate, K or Na exafluoroantimoniate, K or Na antimoniate, Sb/K
tartrate (C3H4K2012Sb2), Sb tartrate, Sb triacetate, sulfoantimoniates (obtained from
alcaline solution of Sb2S5), Sb/Na tartrate (C8H4Na2012Sb2), Sb dimercaptosuccinate,
sodium stibogluconate (C12H17Na012Sb2.9H20), Sb/Na thioglycolate
(C4H4Na04S2Sb), ammonium antimony tungsten oxide, antimony and sodium di-
hydroxy-succinate, Sb/K oxalate (C6K3Sb012), Sb sulfate.
Tungsten
Ammonium tetrathiotungstate, Na or K salt of tungstosilic acid, tungstophosphoric
acid, sodium/ammonium tungsten citrate.
Titanium
Titanium citrate neutralized or not neutralized with sodium or potassium or
ammonium, titanium oxalate neutralized or not neutralized with sodium or potassium
or ammonium, Titanium lactate neutralized or not neutralized with sodium or
potassium or ammonium.
Chromium
Chromium triacetate, chromium sodium citrate, chromium basic acetate, chromium
(III) potassium sulphate, potassium chromium (III) oxalate, alkaline chromates,
chromium 2-hydroxy-1,2,3-propanetricarboxylate, mixed citrates of Cr with K, Na or
NH4. Further inorganic compounds: CrCI3, CrCl2, Cr(N03)3.
According to a further feature of the invention, it is possible to mix
titanium/antimony/chromium and titanium/tungsten/chromium inorganic salts or
organic complexes in water solutions or water solution with organic solvents, with

12
other salts or organic complexes of metals known for coloring ceramic materials, to obtain colours or shades not yet available.
The typical process for applying colouring compositions of the invention consists of the following steps:
a) drying at 100°C of the moulded article to be coloured to a water residue of 0.5% by wt. max.;
b) optional pretreatment of the dried product with water up to a max. quantity of 300 g/m2 of the ceramic manufactured article;
c) treatment of the pretreated product with a colouring aqueous solution in a quantity of 30 to 600 g/m2 of the final coloured surface;
d) optional post-treatment of the treated product with water up to a max. quantity of absorbed water of 300 g/m2 of the treated product;
e) equalization of the post-treated product at room temperature for 8 h to homogenize the absorption of the solution;
f) kiln firing according to the usual ceramic cycle.
The colour penetration obtained with the process according to the invention reaches
a depth up to 2 mm. Consequently the coloured stoneware, for instance tiles, can be
subsequently smoothed and polished after a thin surface of 0.8 to 1.5 mm has been
abraded.
The following example is conveyed by way of indication, not of limitation, of the,
prospective embodiments of the invention.
Example 1
A series of tests was carried out using the ceramic mixture (% by wt.) indicated
below:
Si02 64.4%, A1203 21.8%, K20 3.8%, Na20 0.8%, CaO 0.6%, MgO 0.1%, Ti02.
0.5%, Fe203 0.2%, ZrSi04 5%, H20 q.s. to 100%.
The 0.5% Ti02 present in the mixture is entirely due to the titanium oxide or other
titanium derivatives present in the starting days.
The procedure adopted was as follows:

13
some 33 x 33 cm tiles were press moulded, dried at 100°C to a water residue of
0.1% (weight loss after 4 h at 120°C), allowed to cool to room temperature, sprayed
with 50 g/m2 distilled water (pretreatment). Then, an amount of mg. 185 +/- 15 of
colouring solution was let fall in a single point, within an area of approx. 10 cm2, of
each support.
The treated tiles were allowed to stand 8 h at room temperature (equalization) and
fired in a roll-type kiln according to a standard firing cycle of vitrified stoneware (T
1200°C max.).
After firing, a tile was divided into sections, and colour penetration was measured by
optical microscope. Another tile was smoothed with diamond wheels, with removal of
a 1.2 mm layer. At the end of said operation, the colour was recorded. The data
concerning the parameters used in the various tests are conveyed in Table 2.
Tests Nos 40 , 41 and 42(absence of Ti in the colouring solution) are indicated for
comparison.

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TABLE 2
(1) (2) Elements (% by wt.) (3) *Surface colour *Surface colour
in the solution used before smoothing after smoothing
Ti Sb Cr **CMYK values **CMYK values
***L*; a*. b* va|ues ***L*. a*; b* values
24 4 7 0.25 1,8 Slighty more intense Naples yellow
than after smoothing
13-21-44-3 10-15-36-2
74,6; 4,0; 23,9 75,5; 3,1; 21,0
25 4 7 0,5 1,8 Slighty more intense Deep cadmium yellow
than after smoothing
13-28-53-5 10-20-46-2
69,8; 7,1; 28,9 72,4; 4,9; 25,1
26 4 7 1 1,8 Slighty more intense Deep chrome yellow
than after smoothing
13-38-66-5 11-31-57-4
63,7; 10,2; 32,2 66,8; 8,0; 28,9
27 4 7 1,5 1,8 Slighty more intense Orange chromeyellow
than after smoothing
13-44-71-8 11-36-64-5
59,8; 11,5; 32,9 63,0; 9,6; 30,4
28 4 7 2 1,8 Slighty more intense Yellow ocher
than after smoothing
16-38-71-8 11-41-68-6
61,5; 9,1; 38,8 59,8; 10,6; 30,5
29 2 9 0.25 1,8 Naples yellow Light Naples yellow
12-18-41-3 10-13-31-2
75,1; 3,3; 21,4 76,8; 2,1; 18,1
30 2 9 1 1,8 Yellow ocher Sand
13-31-59-5 11-22-47-3
65,7; 7,7; 28,5 70,5; 4,7; 24,2
31 2 9 2 1,8 Ocher brown Deep sand
16-40-65-11 12-32-58-5
58,5; 9,3; 28,1 64,4; 7,2; 27,1
32 2 11 0.25 1,8 Naples yellow Light Naples yellow
13-19-42-3 41 -31 -58-6
74,3; 3,0; 20,8 76,6; 1,5; 16,5

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TABLE 2 (cont'd)
(1) (2) Elements (% by wt.) (3) *Surface colour *Surface colour
in the solution used before smoothing after smoothing
Ti Sb Cr **C M Y K values **C M Y K values
***L*; a*; b* values ***L*; a*; b* values
33 2 11 1 1,8 Light yellow ocher Light sand
14-31-58-6 12-17-42-3
66,8; 7,1; 28,0 72,2; 3,5; 21,1
34 3 7 0.25 1,8 Deep Naples yellow Naples yellow
13-20-45-4 10-14-34-2
74,3; 3,8; 23,1 76,3; 2,2; 19,4
35 3 7 1 1,8 Deep cadmium yellow Indian yellow
12-38-63-6 11 -29-53-4
63,7; 9,7; 31,2 67,6; 6,5; 26,9
36 3 7 2 1,8 Deep yellow ocher Deep yellow ocher
16-43-70-12 13-38-63-6
56,8; 10,9; 30,4 60,1; 8,7; 26,8
37 4 5 1 1,8 Deep chrome yellow Chrome yellow
13-37-64-7 12-29-56-5
63,8;10,2;31,5 67,1; 6,9; 27,8
38 5 5 0.5 1,8 Deep cadmium yellow Deep cadmium yellow
11-29-54-4 10-24-51 -3
69,8; 7,4; 29,5 71,3; 5,8; 26,6
39 5 5 1.5 1,8 Yellow ocher Orange chromeyellow
17-43-72-15 11 -35-65-5
60,4; 12,5; 34,7 60,8; 7,4; 23,0
40 0 7 0.5 1,8 Beige Beige
15-22-44-5 15-17-35-4
73,7; 2,3; 17,7 74,6; 2,3; 18,7
41 0 7 2 1,8 Deep sand Deep sand
18-34-53-10 15-23-42-5
62;4,9;22,5 68,0; 3,6; 21,7
42 0 5 1.5 1,8 Sand Sand
19-29-51-9 15-22-40-5
67,9; 3,6; 22,1 69,8; 3,2; 20,8

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TABLE 2 (cont'd)
(1) (2) Elements {% by wt.) (3) *Surface colour *Surface colour
in the solution used before smoothing after smoothing
Ti Sb cr **C M Y K values **C M Y K values
***L*; a*; b* values ***L*; a*; b* values
48 1 7 0(25 18 Very light sand Rattier uncolorless
76,0;2,8; 19,8 77,81; 1,85; 15,36
51 6 2 0,5 1,8 Yellow beige Light beige grey
73;14,6;28,1 72,l75;2,49;21,51
52 6 2 1,5 1,8 Light ocher brown Light tobacco brown
** **
65,2; 7,5; 28,4 65,18; 4,56; 25,74
53 2 12 0,25 1,8 Very light sand Very light sand
** **
76,3; 2,6; 19,1 76,25; 2,35:17,16
.55 5 5 0,1 1,8 Rather colourless Rather colourless
** **
78,6; 1,4; 18,6 77,52:1,52; 16,97
58 4 5 3 Tobacco brown Heavy beige
** **
56,3; 8,8; 26,7 55,95; 7,23; 24,49
Ti W Cr
43 4 8 0,8 1,8 Cadmium orange
16-39-61-10 17-32-57-9
59,3; 9,3; 25 64,0; 7,2; 26,0
44 4 8 0,4 1,8 Cadmium yellow
15-32-51-6 15-25-48-5
64,7; 7,0; 24,7 70,4; 3,9; 22,8
45 4 8 0,2 1,8 Naples yellow
14-25-47-5 14-19-40-4
69,2; 4,4; 23,7 73,7; 2,0; 19,3

17
TABLE 2 (cont'd)
(1) (2) Elements (% by wt.) (3) 'Surface colour *Surface colour
in the solution used before smoothing after smoothing
Ti W Cr **CMYK values **CMYK values
***L*; a*; b* values ***L*; a*; b* values
46 6 6 0,8 1,8 Indian yellow
16-33-53-7 16-27-51-6
63,0; 7,6; 25,3 66,5; 5,5; 24,7
47 6 6 0,4 1,8 Dull cadmium yellow
15-25-47-5 15-20-46-4
68,6; 4,2; 23,1 71,8; 2,9; 21,5
59 6 2 0,4 1,8 Beige grey Light beige grey
** **
71,4; 1,8; 20,1 72,04; 2,34; 18,94
60 6 2 0,8 1,8 Very light sepia Very light sepia
** **
66,9; 3,0; 21,3 68,07; 3,37; 20,03
61 3 10 0,1 1,8 Grey sand Light grey sand
** **
75,1; 1,4; 19,9 76,15; 1,06; 15,19
*;**;***; see pag. 7 and 8. (1 ) Test number
(2) Cations (% by wt.) in the solution used, expressed as elements. Antimony is used as antimony and sodium di-hydroxy-succinate; chromium, combined with antimony, is used as chromium hydroxybisethanoate; chromium, combined with tungsten, is used as chromium 2-hydroxy-1,2,3propanetricarboxylate; titanium is used as titanium-beta-hydroxypropanoate; Tungsten is used as sodium tung state.
(3) colour penetration (mm).
Tests 48-51-52-53-55-56-59-60 and 61, which cation concentrations are not in claimed ranges, are showed to demonstrate the concentration importance.

- 18-
We claim:
1. Composition for colouring ceramic articles, obtained from a standard ceramic mixture not modified through TI02. addition, wherein the articles are coloured, from yellow to orange at the surface and to a predetermined depth of at least 1mm, said composition consisting of an inorganic or an organic compound of titanium and chromium combined with inorganic or organic compounds of antimony or tungsten or mixtures thereof, in a water solution or in a water/hydrosoluble organic solvent mixture, in quantities of 2 to 6% by wt. titanium, 3 to 12% antimony (or 4 to 14% tungsten) and 0.2 to 2.5% chromium, said percent amounts being referred to the components expressed as elements.
2. The composition as claimed in clalm1, wherein titanium, chromium, antimony, and tungsten are present in quantities corresponding to 5 to 12% Sb, and 6 to 10% W, expressed as elements, by w.
3. The composition as claimed in claim 1, wherein the titanium, chromium, antimony and tungsten compounds are selected among the salts of mono-or polycarboxytic organic acids, either aliphatic or aromatic, containing 1 to 18 carbon atoms, optionally with one to five hydroxylic or aminic or thiolic substitutents, in the aliphatic chain or on the aromatic nucleus.
4. The composition as claimed in claim 1, wherein the tungsten compound is an alkaline or alkaline-earth or ammonic salt of tungstlc
acid.
5. The composition as claimed in claim 1, wherein the antimony
compound is an alkaline or alkaline-earth or ammonic salt of
antimonic acid.

6. process for colouring ceramic manufactured articles obtained by
moulding a standard ceramic mixture without added TI02, using the
composition as claimed in one of the preceding claims, consisting of
the following steps;
(a) drying at 100°C of the moulded article to be coloured to a water residue of 0.5% by wt.max.;
(b) optional pretreatment of the dried product with water up to a max. quantity of 300 g/m2 of the ceramic manufactured article;
(c) treatment of the optionally pretreated product with the colouring composition in a quantity of 30 to 600 g/m2 of the final coloured surface;
(d) optional post-treatment of the treated product with water up to a max. quantity of absorbed water of 300 g/m2 of the treated product;
(e) equalization of the post-treated product at room temperature for 8 h to homogenize the absorption of the solution;
(f) kiln firing according to the usual ceramic cycle,

7. The process as claimed in claim 6, wherein the colouring solution adequately added with thickening agents is applied to the ceramic manufactured article in step (c) by the silk-screen technique.
8. Process as claimed in claim 6, wherein the colour penetration reaches a depth up to 2mm.
9. Vitrified stoneware tiles obtained by the colouring process as claimed in any of claims 6 and 7.
10. Vitrified stoneware tiles obtained by the colouring process as claimed in any of claim .6 & 7, followed by smoothing for removal of a surface layer to a depth of 1.5 mm, and final polishing.
11. Vitrified stoneware tiles obtained by the colouring process as claimed in any of claims 6 & 7, following by removal of a 1 to 10µ surface layer and final polishing ,

12, The composition as claimed in claim 1, wherein the antimony compound is sodium and antimony di-hydroxy-succinate.
A composition whereby ceramic manufactured articles , obtained by moulding a conventional ceramic mixture without added T1O2 . are coloured from yellow to orange , said composition consisting of an aqueous solution of inorganic compounds or organic complexes of titanium and chromium combined with antimony or tungsten or mixtures thereof, in quantities corresponding to (2 -6) % by wt Ti,3 to 12 % Sb ( or 4 to i4 % tungsten ) and 0,2 to 2.5 % chromium. A process for colouring ceramic manufactured articles obtained by moulding a standard ceramic mixture without added Ti02 using the said composition. Vitrified stoneware tiles obtained by the said colouring process.

Documents:

00142-cal-1999 abstract.pdf

00142-cal-1999 claims.pdf

00142-cal-1999 correspondence.pdf

00142-cal-1999 description(complete).pdf

00142-cal-1999 form-1.pdf

00142-cal-1999 form-2.pdf

00142-cal-1999 form-3.pdf

00142-cal-1999 form-5.pdf

00142-cal-1999 letters patent.pdf

00142-cal-1999 p.a.pdf

00142-cal-1999 priority document others.pdf

00142-cal-1999 priority document.pdf

142-CAL-1999-FORM 27.pdf


Patent Number 201733
Indian Patent Application Number 142/CAL/1999
PG Journal Number 07/2007
Publication Date 16-Feb-2007
Grant Date 16-Feb-2007
Date of Filing 24-Feb-1999
Name of Patentee VIGNALI GRAZIANO
Applicant Address VIA DELLA ,PACE 2,40037 SASSO MARCONI,
Inventors:
# Inventor's Name Inventor's Address
1 VIGNALI GRAZIANO VIA DELLA ,PACE 2,40037 SASSO MARCONI,
PCT International Classification Number C04 B 41/50
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 MI98A000444 1998-03-05 Italy