摘要 |
<p>Polymer and process of polymerizing a monomer charge containing at least 85% of an olefinically unsaturated carboxyl monomer of 3 to 5 carbon atoms at up to 15% of a copolymerizable comonomer, in the presence of a mixed reaction medium containing an organic solvent and a hydrocarbon solvent in respective weight ratio of 95/5 to 1/99, said organic solvent is selected from ketones, esters, ethers, and alcohols having solubility parameter in the range of 8 to 15 and said hydrocarbon solvent is selected from aliphatic and cyclic aliphatic alkanes containing 4 to 12 carbon atoms and non-benzene aromatics of 7 to 9 carbon atoms. Said organic solvent and said hydrocarbon solvent are preferably liquid at room temperature. Viscosity of the 0.2% by weight polymer is in excess of 15,000 cps, preferably in excess of 20,000 cps, and its clarity is at least 80%, preferably 85% transmittance. Viscosity of 1% mucilages containing 1% sodium chloride salt is greater than 5,000 cps, preferably greater than 8,000 cps.</p> |