| 摘要 |
Aqueous based pressure sensitive adhesives having improved shear properties are prepared from a latex of a monomer composition selected from the group: (a) (i) from about 60 to 99.5 weight percent of an ester of acrylic or methacrylic acid; and (ii) from about 0.5 to about 40 weight percent of a C3-9 ethylenically unsaturated carboxylic acid; (b) (i) from about 40 to 99 weight percent of a C4-8 conjugated diolefin; (ii) optionally up to about 60 weight percent of a vinyl aromatic monomer; (iii) from about 0.5 to about 40 weight percent of a C3-9 ethylenically unsaturated carboxylic acid; and (c) (i) from about 1 to 40 weight percent of a C2-4 monoolefin; (ii) from about 60 to 99.5 weight percent of a vinyl ester; and (iii) from about 0.5 to 40 weight percent of a C3-9 ethylenically unsaturated carboxylic acid; said latex having been neutralized to a pH of equal to or greater than about 6 with an alkali metal hydroxide or salt. The polymer may optionally have a molecular weight distribution so that from about 20 to 55 weight percent of it has a molecular weight greater than 320,000. The adhesive may optionally include tackifiers. The resulting adhesives may be used in the manufacture of tapes and labels. |
