PIGMENTED INK RECEIVING LAYER FOR DECORATIVE BUILDING BOARDS

1 . A method for the preparation of a coated building board comprising an ink receiving layer, the method comprising at least

i) application of an aqueous coating composition comprising

a) 5 to 40% by weight of the coating composition of an acrylic polymer,

b) 1 to 6% by weight of the coating composition of a molecular sieve, and

c) 1 to 30% by weight of the coating composition of a pigment,

on at least a part of the surface of the building board, and

ii) curing the coating composition.

2 . The method of claim 1 , wherein the surface of the building board on which the aqueous coating composition is applied does not contain a coloured primer layer.

3 . The method of claim 1 or 2 , wherein the surface of the building board on which the aqueous coating composition is applied contains a sealing layer.

4 . The method of any one of claims 1 to 3 , wherein the molecular sieve is a microporous molecular sieve, preferably selected from the group consisting of zeolites.

5 . The method of any one of claims 1 to 4 , wherein the at least 90% of the pores of the molecular sieve has pore diameters between 0.1 nm and 2 nm, preferably the molecular sieve is a 3 Å, 4 Å or 5 Å zeolite.

6 . The method of any one of claims 1 to 5 , wherein the acrylic polymer comprises an acrylic polymer obtainable by free radical polymerization of an acrylic monomer composition, wherein the acrylic monomers are selected from the group consisting of acrylate, methacrylate, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, epoxyalkyl acrylate, epoxyalkyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, acrylic acid and mixtures thereof and optionally ethylenically unsaturated comonomers.

7 . The method of any one of claims 1 to 6 , wherein the pigment is selected from the group consisting of titanium dioxide, zinc oxide, zinc sulphide, barium sulfate, lead white, antimony white, calcium carbonate and lithopone.

8 . The method of any one of claims 1 to 7 , wherein the aqueous coating composition comprises at least one additive selected from the group consisting of film-former, dispersants, thickeners, defoamer, neutralizer, biocides, matting agents and humectants.

9 . The method of any one of claims 1 to 8 , wherein the aqueous coating composition comprises a matting agent.

10 . The method of claim 9 , wherein the matting agent comprises at least one of silicon dioxide and wax powder.

11 . The method of any one of claims 1 to 10 , wherein the aqueous coating composition comprises a humectant.

12 . The method of any one of claims 1 to 11 , wherein the aqueous coating composition comprises a film former.

13 . An aqueous coating composition as defined in any one of claims 1 to 12 comprising

a) 5 to 40% by weight of an acrylic polymer,

b) 1 to 6% by weight of a molecular sieve, and

c) 1 to 30% by weight of a pigment.

14 . The aqueous coating composition of claim 13 comprising

a) 5 to 40% by weight of an acrylic polymer,

b) 1 to 6% by weight of a molecular sieve,

c) 1 to 30% by weight of a pigment,

d) optionally 0 to 2% by weight of a defoamer,

e) optionally 0 to 2% by weight of a dispersant or wetting agent,

f) optionally 0 to 15% by weight of a matting agent,

g) optionally 0 to 10% by weight of a film former,

h) optionally 0 to 2% by weight of a thickener,

i) optionally 0 to 1% by weight of a biocide,

j) optionally 0 to 1% by weight of a neutralizer, and

k) optionally 0 to 5% by weight of a humectant.

15 . The aqueous coating composition of claim 14 comprising

a) 10 to 35% by weight of an acrylic polymer,

b) 2 to 5.5% by weight of a molecular sieve,

c) 2.5 to 25% by weight of a pigment,

d) 0.1 to 2% by weight of a defoamer,

e) 0.1 to 2% by weight of a dispersant or wetting agent,

f) 0.1 to 15% by weight of a matting agent,

g) 0.1 to 10% by weight of a film former,

h) 0.1 to 2% by weight of a thickener,

i) 0.05 to 1% by weight of a biocide,

j) 0.05 to 1% by weight of a neutralizer, and

k) 0.1 to 5% by weight of a humectant.

16 . A coated building board comprising an ink receiving layer of a cured coating composition of one of claims 1 to 15 on at least a part of the surface of the building board.

17 . The coated building board of claim 16 , wherein the building board is a cement plate, gypsum plate, ceramic plate, metal plate, wooden plate, polymer resin plate, calcium silicate plate, diatomite plate and polystyrene plate.

18 . Use of a building board of any one of claims 16 and 17 as base material for inkjet printing with water-based ink.

19 . The use of an aqueous coating composition as defined in one of claims 1 to 15 for preparing an ink receiving layer on a building board used as base material for inkjet printing with water-based ink.

20 . The use of claim 19 , wherein the aqueous coating composition is applied to a surface of the building board that does not contain a coloured primer layer.