Treating leather with silicone - (meth)acrylate copolymer emulsion to impart stain resistance and oil repellency

A method for treating leather comprises:

• I) applying to a surface of a leather substrate, a leather treatment composition comprising
• (F) a silicone-(meth)acrylate copolymer comprising unit formula:
• wherein
• each R1 is an independently selected monovalent hydrocarbon group of 1 to 12 carbon atoms;
• each D2 is an independently selected divalent hydrocarbon group of 2 to 12 carbon atoms;
• each R2 is independently selected from the group consisting of H and methyl;
• each R3 is a group of formula OSi(R4)3;
• wherein
• each R4 is independently selected from the group consisting of R and DSi(R5)3, wherein
• each R is an independently selected monovalent hydrocarbon group of 1 to 12 carbon atoms, and
• each D is independently selected from the group consisting of an oxygen atom, a (poly)alkylene oxide group of 1 to 12 units, and a divalent hydrocarbon group of 2 to 4 carbon atoms;
• each R5 is independently selected from the group consisting of R and DSi(R6)3;
• each R6 is independently selected from the group consisting of R and DSiR3;
• with the proviso that R4, R5, and R6 are selected such that the silicone-(meth)acrylate co-macromonomer unit with subscript b2 has at least 5 silicon atoms;
• subscripts a, b1, and b2 represent weight fractions of units in the copolymer, and
• subscripts a, b1, and b2 have values such that 0.25<a≤1;
• and 0≤(b1+b2)<0.75, and (a+b1+b2)=1, with the proviso that the silicone-(meth)acrylate copolymer further comprises a terminal moiety;
• and where (F) the silicone—(meth)acrylate copolymer is a reaction product of starting materials consisting essentially of (A) a silicone-(meth)acrylate macromonomer and (C) an initiator, and when present (B) a silicone-(meth)acrylate co-macromonomer and/or (H) a chain transfer agent;
• (D) a nonionic surfactant;
• (E) water;
• and
• II) drying the substrate.