Water in oil dispersions of hydrophilic polymers based on acrylic acid partially or totally converted into the salt form with ammonia

Stable water in oil dispersions of hydrophilic polymers based on acrylic acid partially or totally converted into the salt form with ammonia, intended for the preparation of pastes for colour printing, characterized by the fact that they contain by weight:

• (a) 65 to 75% of an aqueous dispersed phase, 35 to 50% of the weight of the said aqueous dispersed phase being constituted by a hydrophilic polymer, having a molecular weight greater than 3,000,000 formed, in molar proportions, from:
• 0 to 50% acrylamide,
• 0.008 to 0.1% bisacrylamidoacetic acid partially or totally converted into the salt form with ammonia,
• made up to 100% with acrylic acid, of which 65 to 100% is in the form of ammonium acrylate,
• (b) 3 to 7% of an emulsifying system, having overall an HLB value greater than 7, constituted by a mixture of at least three surface active agents, of which more than 50% by weight is contributed by at least one surface active agent having an HLB between 3 and 5, and the complement to 100% being contributed by at least two surface active agents individually having an HLB between 11 and 14,
• (c) the complement to 100% is an oil phase constituted by one or a plurality of hydrocarbons which are liquid at ambient temperature, containing less than 20% by weight of aromatic hydrocarbons and having simultaneously a density, determined at 20.degree. C., greater than 0.8 g/cm.sup.3, a kinematic viscosity, determined at 20.degree. C., greater than 10 mm.sup.2 /s and a boiling point above 250.degree. C.