Latexes of encapsulated vinylidene chloride copolymer particles

An aqueous latex comprising heterogeneous polymer particles which on the average (A) comprise, from about 35 to about 75 weight percent of polymerized vinylidene chloride based upon the total particle weight and (B) are composed of:

• (1) from about 50 to about 95 parts by weight per 100 parts by weight of the polymer particle of a core of a soft interpolymer comprising, in polymerized form and based upon the weight of such core,
• (a) from about 40 to about 80 weight percent of vinylidene chloride;
• (b) from about 20 to about 60 weight percent of an aliphatic conjugated diene;
• and
• (c) from 0 to about 10 weight percent of a monoethylenically unsaturated carboxylic acid;
• and
• (2) from about 5 to about 50 parts by weight per 100 parts of the polymer particle of an encompassing polymeric shell consisting essentially of, in polymerized form and based upon the weight of such shell,
• (a) from about 60 to 100 weight percent of a monomer selected from the group consisting of aliphatic conjugated dienes, monovinylidene aromatic monomers and saturated aliphatic esters of monoethylenically unsaturated carboxylic acids;
• (b) from 0 to about 30 weight percent of vinylidene chloride;
• and
• (c) from 0 to about 10 weight percent of a monoethylenically unsaturated carboxylic acid.