Universal colouring compositions

Abstract: The present invention relates to universal colouring compositions comprising pigments, dispersants and solvents, which compositions are characterized in that the said dispersants are polymeric dispersants chosen from the group consisting of copolymers based on polyurethanes or polyacrylates functionalized with amine groups, and solutions thereof. These compositions are particularly suitable for mixing with a wide range of resinous paint bases, in the preparation of coloured paint products.

Description: In its most general aspect, the present invention relates to universal colouring compositions. The term "universal colouring compositions" is understood to refer to a series of colouring pastes comprising pigments, dispersants and solvents which can be mixed with a wide range of resinous paint bases in the preparation of coloured paint products. It is known that a coloured paint can be prepared by mixing, in a suitable mixer, a universal colouring composition with an opaque or transparent resinous paint base, both of which are chosen and mixed in predefined ratios as a function of the desired paint colour, selected from a suitable colour chart. Generally, it is possible to prepare paints in a wide variety of colours and colour gradations using a limited number (series) of universal colouring compositions and paint bases. It is also known that in order for a colouring composition to be considered "universal", the dispersants contained therein must be compatible with the most diverse paint base resins, such as, for example, acrylic, epoxy, alkyd, polyester, polyvinyl, etc. resins. These dispersants must also be soluble or dispersible in polar and apolar solvents, and capable of interacting with polar groups and functional groups of various organic and inorganic pigments so as to disperse the pigments effectively in the colouring composition, to stabilize its colour and gloss and to prevent flocculation of the pigments for a long time, both in the universal colouring compositions and in the final coloured paints. For these reasons, various low molecular weight surfactants such as, for example, certain sodium sulphosuccinates, have been used as dispersants. However, these dispersants are not entirely satisfactory, since some of them do not have the necessary compatibility with a wide range of pigments or resinous systems of paint bases, while others, although being compatible with various pigments and resinous systems, have a negative effect on the colouring properties of the final paints or increase their cost considerably. Moreover, in order to disperse the pigments effectively, the abovementioned dispersants are used in combination with small amounts of dispersion-coadjuvant compounds generally consisting of ethoxylated alkylphenols, in particular ethoxylated nonylphenols. These compounds have wetting and dispersing properties and lower the surface tension of most of the dispersants with which they are mixed, which thus helps them to interact with the functional groups of the pigments. However, along with these useful properties, ethoxylated alkylphenols have a number of major drawbacks associated with the highly negative effect they have on the environment. For this reason, the current trend in the paints industry is to remove ethoxylated alkylphenols from colouring compositions. The technical problem underlying the present invention is to provide universal colouring compositions which do not have the drawbacks mentioned above with reference to the universal colouring compositions of the prior art, i.e. universal colouring compositions which can be mixed with resinous paint bases, which are free of ethoxylated alkylphenols and in which the dispersant is both compatible with a wide range of resinous systems and capable of interacting effectively with a wide variety of organic and inorganic pigments. This problem is solved by universal colouring compositions as outlined in the appended claims. The pigments of the universal colouring compositions according to the invention are conventional organic or inorganic pigments that are suitable for the preparation of coloured paint products. The organic pigments can be chosen from the group comprising classes of coloured pigments which have the following international Colour Index classifications: P.B.7, P.B.15:2, P.B.15:4, P.G.7, P.R.19, P.R.122, P.R.168/112, P.V.23, P.Y.3, P.Y.74, P.Y.74/83 and P.Y.83. The inorganic pigments can be chosen from the group comprising classes of coloured pigments which have the following international Colour Index classifications: P.B.11, P.R.101, P.W.6 and P.Y.42. The solvents for the universal colouring compositions according to the invention are preferably chosen from the group comprising water and water-soluble organic solvents, and mixtures thereof. Water-soluble organic solvents which are particularly preferred are ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol. The solvents are added to the colouring compositions according to the invention in amounts such that the viscosity of the compositions is appropriately adjusted in the range 2.0-10.0 poises at 20°C, so as to make them easy to pump and meter using volumetric and/or gravimetric measuring equipment. Besides the abovementioned ingredients, the compositions according to the invention can also comprise up to 3% by weight, relative to the weight of the composition, of other conventional additives such as viscosity modifiers, wetting agents, antifoaming agents, biocides, diluents and surfactants, as long as these are, in all cases, free of ethoxylated alkylphenols. It has been found, surprisingly, that copolymers based on polyurethanes functionalized with amine groups can be used advantageously as dispersants in universal colouring compositions. These functionalized copolymers are known per se, however, they have never been used as dispersants in universal colouring compositions. Nevertheless, it has been found that the abovementioned copolymers are capable of effectively dispersing a wide variety of organic and inorganic pigments for a long time without the assistance of ethoxylated alkylphenols, and that they give the pigments colour stability and improved gloss. In addition, the universal colouring compositions which contain them can be effectively mixed with a large number of water-based or organic-based resinous paint products without resulting in any flocculation of the pigment or adverse changes in the colouring properties of the final paints. In the universal colouring compositions according to the invention, it is particularly preferred to use a polymer solution sold by the company BYK-Chemie GmbH under the trade name Disperbyk®-183 as dispersant. Among the resins of aqueous paint products which are compatible with the universal colouring compositions according to the invention, mention may be made, by way of non-limiting example, of various types of copolymers, such as vinyl versatate, acrylic/styrene/butadiene copolymers and modified alkyd emulsions. Among the resins of paint products in organic solvents which are compatible with the universal colouring compositions according to the invention, mention may be made, by way of example, of short-oil, medium-oil and long-oil alkyd resins and short-chain, medium-chain and long-chain acrylic and vinyl resins. The universal colouring compositions according to the invention can be prepared by conventional procedures. They can be prepared, for example, by grinding a mixture which comprises the pigment, the dispersant and the solvent in a ball mill, a sand mill or a colloidal mill or in a high-speed, high-shear mixer until a uniform dispersion is obtained. Preferably, the colouring compositions according to the invention are prepared by firstly premixing the dispersant with the solvent in a high-speed disperser, adding the pigment particles to the premix of the abovementioned components and grinding the whole in a ball mill for the time required to obtain a uniform dispersion of the pigments and the desired viscosity of the composition. The characteristics and advantages of the invention will emerge even more clearly from the following examples, given as non-limiting guides, for the preparation of two series of universal colouring compositions according to the invention. EXAMPLE 1 A series of twelve universal colouring compositions according to the invention were prepared, in which each composition of the series was obtained by firstly premixing, with stirring and in a disperser at high speed, a dispersant with a mixture of water and propylene glycol, adding the pigments to the premix of the abovementioned components and grinding the whole in a ball mill for the time required to obtain a uniform dispersion of the pigments and the desired viscosity of the composition. In each composition, the commercial product Disperbyk®-183 was used as dispersant and a mixture of water and propylene glycol was used as solvent. Table 1 gives the classes of the coloured pigments according to the international Colour Index classification and the weight ratios of the mixtures of water and propylene glycol used for each of the compositions of the series. Table 2, on the other hand, gives the weight percentages of the components and the viscosity for each composition. For each class, the organic or inorganic nature of the pigments belonging thereto is specified. Name Pigments Water/glycol weight ratio Type of pigments Mid-yellow P.Y. 74/83 1.5:1 Organic Red for Exterior use P.R. 168/112 1:1.7 Organic Red oxide P.R. 101 1:1.1 Inorganic Magenta P.R. 122 1:1.7 Organic Brown oxide P.R. 101; PB 11; P.Y. 42 1:1.5 Inorganic Phthalo green P.G. 7 1:1.65 Organic Phthalo blue P.B. 15:2 1:5.5 Organic Carbon black P.B. 7 1:2 Organic Titanium white P.W. 6 1:1.3 Inorganic Yellow oxide P.Y. 42 1:1 Inorganic Yellow for exterior use P.Y. 74 2.3:1 Organic Natural umber P.R. 101, PY 42; P.B. 7 1:1.5 Inorganic Name Pigments % by wt. Dispersant % by wt. Solvent % by wt. Viscosity poises Mid-yellow 25 2 73 8.0 Red for exterior use 10 8 82 6.8 Red oxide 65 7 28 9.6 Magenta 9 36 55 6.8 Brown oxide 46 14 40 5.3 Phthalo green 10 50 40 5.4 Phthalo blue 6 47 47 2.4 Carbon black 8 45 47 5.5 Titanium white 58 12 30 6.3 Yellow oxide 55 9 36 9.7 Yellow for exterior use 23 31 46 6.3 Natural umber 23 27 50 7.1 EXAMPLE 2 A second series of twelve universal colouring compositions according to the invention were prepared, in which each composition of the series was obtained by the process described for the preparation of the series of universal colouring compositions in Example 1. In each composition, the commercial product Disperbyk®-183 was used as dispersant and a mixture of water and propylene glycol was used as solvent. Table 3 gives the classes of the coloured pigments according to the international Colour Index classification and the weight ratios of the mixtures of water and propylene glycol used for each of the compositions of the series. Table 4, on the other hand, gives the weight percentages of the components and the viscosity for each composition. For each class, the organic or inorganic nature of the pigments belonging thereto is specified. Name Pigments Water/glycol weight ratio Type of pigments Titanium white P.W. 6 1:1.3 Inorganic Lemon P.Y. 3; 2.3:1 Organic P.Y. 74 Yellow P.Y. 83 1.5:1 Organic Yellow oxide P.Y. 42 1:1 Inorganic Light red P.R. 112 1:1.7 Organic Red P.R. 19 1:4 Organic Red oxide P.R. 101 1:1.1 Inorganic Phthalo green P.G. 7 1:1.65 Organic Phthalo blue P.B. 15:4 1:5.5 Organic Violet P.V. 23 1:2 Organic Carbon black P.B. 7 1:2 Organic Brown oxide P.Y. 42; PR 1:1.5 Inorganic 101; P.B. 7 Name Pigments % by wt. Dispersant % by wt. Solvents % by wt. Viscosity poises Titanium white 64 5 31 6.3 Lemon 42 12 46 6.3 Yellow 38 24 38 8.0 Yellow oxide 56 7 37 9.7 Light red 21 23 56 6.8 Red 16 21 63 2.1 Red oxide 55 14 31 9.6 Phthalo green 30 18 52 5.4 Phthalo blue 12 34 54 2.4 Violet 7 26 67 8.0 Carbon black 28 14 58 5.5 Brown oxide 53 17 30 5.3

Claims: Universal colouring compositions characterized in that they comprise 5-70% by weight of pigments, 1-50% by weight of Disperbyk®-183 and 20-80% by weight of solvents, and in which the pigments Disperbyk®-183 weight ratio ranges from 0.1:1 to 15:1, said pigments are of inorganic nature chosen from the group comprising classes of coloured pigments having the international Colour Index classifications P.B.11, P.R.101, P.W.6 and P.Y. 42, and of organic nature chosen from the group comprising classes of coloured pigments having the international Colour Index classifications: P.B.7, P.B.15:2, P.B.15:4, P.G.7, P.R.19, P.R.122, P.R.168/112, P.V.23, P.Y.3, P.Y.74, P.Y.74/83 and P.Y.83. Universal colouring compositions according to claim 1, in which the said solvents are chosen from the group comprising water and water-soluble organic solvents, and mixtures thereof. Universal colouring compositions according to Claim 2, in which the said water-soluble organic solvents are chosen from the group comprising ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol. Universal colouring compositions according to any one of the preceding claims, characterized in that they further comprise up to 3% by weight, relative to the weight of the composition, of additives chosen from the .group comprising viscosity modifiers, wetting agents, antifoaming agents, biocides, diluents and surfactants. Universal colouring compositions according to any one of the preceding claims, characterized in that they have a viscosity of 2.0-10.0 poises at 20°C. Universal colouring composition according to Claim 1, characterized in that it comprises 25% by weight of pigments P.Y. 74/83, 2% by weight of Disperbyk®-183 and 73% by weight of a mixture of water and propylene glycol in a 1.5:1 weight ratio. Universal colouring composition, characterized in that it comprises 10% by weight of pigments P.R. 168/112, 8% by weight of Disperbyk®-183 and 82% by weight of a mixture of water and propylene glycol in a 1:1.7 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 65% by weight of pigments P.R. 101, 7% by weight of Disperbyk®-183 and 28% by weight of a mixture of water and propylene glycol in a 1:1.1 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 9% by weight of pigments P.R. 122, 36% by weight of Disperbyk®-183 and 55% by weight of a mixture of water and propylene glycol in a 1:1.7 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 46% by weight of pigments P.R. 101, P.B. 11 and P.Y. 42, 14% by weight of Disperbyk®-183 and 40% by weight of a mixture of water and propylene glycol in a 1:1.5 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 10% by weight of pigments P.G. 7, 50% by weight of Disperbyk®-183 and 40% by weight of a mixture of water and propylene glycol in a 1:1.65 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 6% by weight of pigments P.B. 15:2, 47% by weight of Disperbyk®-183 and 47% by weight of a mixture of water and propylene glycol in a 1:5.5 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 8% by weight of pigments P.B. 7, 45% by weight of Disperbyk®-183 and 47% by weight of a mixture of water and propylene glycol in a 1:2 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 58% by weight of pigments P.W. 6, 12% by weight of Disperbyk®-183 and 30% by weight of a mixture of water and propylene glycol in a 1:1.3 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 55% by weight of pigments P.Y. 42, 9% by weight of Disperbyk®-183 and 36% by weight of a mixture of water and propylene glycol in a 1:1 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 23% by weight of pigments P.Y. 74, 31% by weight of Disperbyk®-183 and 46% by weight of a mixture of water and propylene glycol in a 2.3:1 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 23% by weight of pigments P.R. 101, P.Y. 42 and P.B. 7, 27% by weight of Disperbyk®-183 and 50% by weight of a mixture of water and propylene glycol in a 1:1.5 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 64% by weight of pigments P.W. 6, 5% by weight of Disperbyk®-183 and 31% by weight of a mixture of water and propylene glycol in a 1:1.3 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 42% by weight of pigments P.Y. 74 and P.Y. 3, 12% by weight of Disperbyk®-183 and 46% by weight of a mixture of water and propylene glycol in a 2.3:1 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 38% by weight of pigments P.Y. 83, 24% by weight of Disperbyk®-183 and 38% by weight of a mixture of water and propylene glycol in a 1.5:1 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 56% by weight of pigments P.Y. 42, 7% by weight of Disperbyk®-183 and 37% by weight of a mixture of water and propylene glycol in a 1:1 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 21% by weight of pigments P.R. 112, 23% by weight of Disperbyk®-183 and 56% by weight of a mixture of water and propylene glycol in a 1:1.7 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 16% by weight of pigments P.R. 19, 21% by weight of Disperbyk®-183 and 63% by weight of a mixture of water and propylene glycol in a 1:4 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 55% by weight of .pigments P.R. 101, 14% by weight of Disperbyk®-183 and 31% by weight of a mixture of water and propylene glycol in a 1:1.1 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 30% by weight of pigments P.G. 7, 18% by weight of Disperbyk®-183 and 52% by weight of a mixture of water and propylene glycol in a 1:1.65 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 12% by weight of pigments P.B. 15:4, 34% by weight of Disperbyk®-183 and 54% by weight of a mixture of water and propylene glycol in a 1:5.5 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 7% by weight of pigments P.V. 23, 26% by weight of Disperbyk®-183 and 67% by weight of a mixture of water and propylene glycol in a 1:2 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 28% by weight of pigments P.B. 7, 14% by weight of Disperbyk®-183 and 58% by weight of a mixture of water and propylene glycol in a 1:2 weight ratio. Universal colouring composition according to Claim 1, characterized in that it comprises 53% by weight of pigments P.Y. 42, P.R. 101 and P.B. 7, 17% by weight of Disperbyk®-183 and 30% by weight of a mixture of water and propylene glycol in a 1:1.5 weight ratio.

Inventors: GOEBEL JUNGHANNS CARLO, PAGNONI ANGELO, GOEBEL JUNGHANNS, CARLO, PAGNONI, ANGELO
Applicants: COLORS S P A J, J COLORS S.P.A.
Application year: 1998
Main classification: C09D17
IPC codes: C09D17, C09B67