| 摘要 |
There is described a pressure sensitive adhesive (PSA) composition that is sufficiently stable under high shear to be curtain coatable, and also exhibits acceptable, optionally enhanced, water whitening resistance, the composition comprising: a) a latex emulsion obtained and/or obtainable by emulsion polymerisation in the presence of a polymerisable surfactant of a monomer mixture comprising: i) at least one C4-12alkyl(meth)acrylate; ii) at least one ethylenically unsaturated C3-6carboxylic acid and/or anhydride; ii) optionally at least one styrenic monomer; and iv) optionally at least one C2-3 alkyl(meth)acrylate b) a rheology modifier preferably selected from: at least one mixture of a polyether polyol and an alkyl(alkoxy)alcohol; at least one alkylene glycol arylate; at least one alkylene glycol alkylate; at least one polyacrylic thickener and/or at least one polyurethane derived thickener and where the PSA composition has a dynamic viscosity (optionally measured at a shear rate of 1,000 s-1) of > 500 mPa.s. Preferred rheological properties are a dynamic viscosity > 100 mPa.s, an elasticity from 1.3 mm to 38 mm (0.5 to 1.5 in), a stretch of less than 3.0 x 10-2 N / m (< 30 dynes / cm) more preferably the lower the better and/or a surface energy (SEA) of greater than about 40 JI-1. Preferably the monomer mixture consists essentially of components i), ii), iii) and optionally iv) and no others. Label facestock coated with the PSA and a method of curtain coating using the PSA are also described. |
