PRESSURE SENSITIVE ADHESIVES

摘要

PSAs having enhanced resistance to water-whitening and high shear stability are disclosed. The PSAs are obtained from an aqueous dispersion comprising an effective amount of surfactant mixture comprising at least one ionic surfactant comprising a plurality, preferably at least three, aromatic rings, at least one electronegative substituent selected from a mono valent oxy substituted sulfo anion, and/or a mono valent oxy substituted phospho anion, and at least one substituent comprising one or more repeating alkoxy units (e.g. Soprophor 4D 384), and at least one non-ionic surfactant (e.g. Abex 2535) and a further non aromatic ionic surfactant (e.g. Aerosol OT 75); and a monomer composition comprising: at least one hydrophobic monomer (Component I), at least one hydrophilic monomer (Component II) at least one partially hydrophilic monomer (Component III) and optionally at least one a ureido monomer (e.g. Norsocryl 102) (Component IV). The dispersion has an average particle size of from about 100 nm to about 400 nm and a pH of from about 5.5 to about 9.0. The latex forms PSAs which have good water whitening resistance and is sufficiently stable under high shear to be curtain coatable.