Laminating method and article using carboxylated latex adhesive

Claim 1

A LAMINATE COMPRISING AT LEAST FIRST AND SECOND SHEETS OF CELLULOSIC FIBROUS MATERIAL, THE FIRST SHEET BEING BONDED TO THE SECOND SHEET BY AN ADHESIVE COMPOSITION COMPRISING: (A) AN ADHESIVE SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF (A) WATER-SOLUBLE CARBOHYDRATE PAPER ADHESIVES; AND (B) WATER-SOLUBLE PROTEINACEOUS PAPER ADHESIVES; (B) A LATEX DISPERSION, COMPATIBLE WITH THE ADHESIVE, OF A RUBBERY COPOLYMER OF (I) BUTADIENE, (II) STYRENE, AND (III) ITACONIC ACID; AND (C) A CROSS-LINKING AGENT OPERATIVE TO CHEMICALLY LINK THE ADHESIVE TO THE COPOLYMER, SELECTED FROM THE GROUP CONSISTING OF (C) A WATER-SOLUBLE A-STATE UREA-FORMALDEHYDE CONDENSATE, (D) A WATER-SOLUBLE A-STAGE MELAMINE-FORMALDEHYDE CONDENSATE, AND (E) A WATER-SOLUBLE COMPLEX SALT OF A DI- OR TRIVALENT METAL, THE SAID CROSS-LINKING AGENT (C) BEING CHEMICALLY BOUND TO THE ADHESIVE SUBSTANCE (A) AND THE COPOLYMER OF THE LATEX (B), THE SAID FIBROUS MATERIAL BEING PAPER IMPREGNATED WITH ALUMINUM TRIFORMATE.