Fibrous compositions

Claim 1

A wet-laid fibrous web having good formation comprising a dried composite containing (a) a paper-making grade of fiber having an anionic charge (b) from about 5 percent to about 2000 percent, solids basis calculated on the weight of the fiber, of a structured-particle latex having a non-ionic core of a copolymer of from about 20 percent to about 50 percent of an aliphatic, conjugated diene, from about 20 percent to about 80 percent of a monovinylidene aromatic compound, from 0 percent to about 5 percent of polar, non-ionic ethylenically unsaturated monomers and from 0 percent to about 25 percent of other ethylenically unsaturated, nonionic monomers which when in the form of homopolymers are water-insoluble; said non-ionic core being encapsulated by a thin layer of a water-insoluble organic copolymer having bound charges of pH independent cationic groups; said latex having from about 0.15 milliequivalent to about 0.6 milliequivalent of bound charge per gram of polymer in the latex and (c) from about 0.15 percent to about 160 percent, based on the weight of the fiber, of a co-additive which is a water-soluble anionic polymer of an acrylamide having a degree of polymerization of from about 3000 to about 10,000 and having an available charge of from about 0.3 milliequivalent to about 8 milliequivalents per gram of co-additive wherein the co-additive retains its water solubility in the presence of polyvalent metal ions at a pH from about 4 to about 7; said latex and said coadditive having been added before laying down of the web; all percentages being by weight.