1. Field of the Invention
The present invention pertains to radiation-curable water-soluble combinations of polyester resins with high mass fraction of solids.
2. Description of the Related Art
From EP-A 0 574 775 self-emulsifying polymerizable binders are known which can be made by reacting pre-polymers containing (meth)acryloyl groups (A) and unsaturated polyesters (B) which are emulsifiable in water with multifunctional isocyanates. The preferred pre-polymers (A) containing (meth)acryloyl groups are polyester (meth)acrylates which are condensation products of aromatic and/or aliphatic dicarboxylic acids (A1), especially those of malonic, succinic, glutaric, adipic, sebacic, hexahydrophthalic, terephtalic, maleic, fumaric, citraconic and itaconic acids or their anhydrides, of polyols (A2), especially glycol, 1,2- and 1,3-propanediol, diglycol, dipropylene glycol, butanediol, etc., and .alpha., .beta.-unsaturated monocarboxylic acid derivatives (A3). The polyesters which are emulsifiable in water are the condensation products of the dicarboxylic acids referred to under (A1) and the polyols referred to under (A2) as well as of a polyether alcohol such polyethylene and polypropylene glycol and alcohols having, an allyl ether functionality. Using these polyesters, dispersions with a mass fraction of solids of approx. 50% can be produced.
From EP-A 0 425 974, water-soluble binders with at least one polymerizable double bond are known which may be produced by condensation of at least one polyoxy-alkylene glycol with a molar mass of from 300 to 800 g/mol, or optionally from one polyoxy-alkylene glycol with a molar mass of less than 300 g/mol, at least one alkoxylated trivalent alcohol, or optionally at least one alkoxylated tetra to hexavalent alcohol, at least one polycarboxylic acid or a derivative of a polycarboxylic acid and at least one monocarboxylic acid of a derivative thereof.
From DE-A 33 40 589, radiation-curable water-soluble polyesters containing acryloyl groups are known which contain co-condensed units of a dicarboxylic anhydride, a polyether alcohol, a bivalent alcohol and a trivalent alkoxylated alcohol and acrylic acid. Dispersions with a mass fraction of solids of approx. 50% can be produced using these polyesters.