COATED BUILDING BOARDS
The invention relates to a coated building board comprising a colour imaging layer for water-based ink and a method for the preparation of the coated building boards. The invention relates particularly to coated building boards, wherein the colour imaging layer contains a molecular sieve, particularly a microporous zeolite.
1 . A method for preparation of a coated building board comprising a colour imaging layer, comprising:
a) application of an aqueous coating composition comprising:
i) 20% to 80% by weight of the coating composition of an acrylic polymer emulsion, and
ii) 0.2% to 20% by weight of the coating composition of a molecular sieve on at least of a part of the surface of the building board; and
b) curing the coating composition.
2 . The method of claim 1 , wherein the molecular sieve is a microporous molecular sieve, preferably selected from the group consisting of zeolites.
3 . The method of claim 1 , wherein at least 90% of pores of the molecular sieve have pore diameters between 0.1 nm and 2 nm.
4 . The method of claim 1 , wherein the acrylic polymer emulsion 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.
5 . The method of 4 , wherein the acrylic monomer composition comprises at least 50% by weight acrylic monomers and less than 50% by weight of ethylenically unsaturated comonomers.
6 . The method of claim 1 , wherein the water content of the acrylic polymer emulsion is between 25% and 75% by weight.
7 . The method of claim 1 , wherein the aqueous coating composition comprises a film-former selected from the group consisting of glycol ethers or glycol esters or combinations thereof.
8 . The method of claim 1 , wherein the aqueous coating composition comprises up to 50% by weight of an additional polymer selected from the group of polyvinyl acetate, polyvinyl alcohol, and polyurethane.
9 . The method of claim 1 , wherein the aqueous coating composition comprises a dispersant, thickener, filler, defoamer, neutralizer, biocide, matting agent and/or pigment.
10 . A coated building board comprising a colour imaging layer of a cured coating composition of claim 1 on at least a part of the surface of the building board.
11 . A coated building board comprising a colour imaging layer on at least a part of its surface, wherein the colour imaging layer comprises 30% to 95% by weight of the layer of an acrylic polymer and 0.5% to 50% by weight of the layer of a molecular sieve.
12 . The coated building board of claim 11 , wherein the weight ratio of the molecular sieve to the acrylic polymer in the colour imaging layer is from 1:1 to 1:20.
13 . The coated building board of claim 11 , wherein the molecular sieve is a microporous sieve.
14 . The coated building board of claim 11 , wherein the building board is a cement plate, gypsum plate, ceramic plate, metal plate, wooden plate or polymer resin plate.
15 . Use of a building board of claim 11 as base material for inkjet printing with water-based ink.
16 . The coated building board of claim 13 , wherein the molecular sieve is a 3 Å, 4 Å, 5 Å zeolite or mixtures thereof.
17 . The method of claim 3 , wherein the molecular sieve is a 3 Å, 4 Å or 5 Å zeolite.