Hot Melt Adhesives Based On Graft Copolymers
Patent #: 7,166,341
Inventor(s): Marcus Heemann, Thomas Moeller, Ingo Gensch and Wolfgang Klingberg
Company: Henkel Kommanditgesellschaft auf Aktien (Henkel KGAA)
A water-soluble or water-dispersible hotmelt adhesive has been patented. The adhesive comprises 20-80% by weight of at least one component; 1-70% by weight of at least one polymer selected from the group consisting of polyesters, polyurethanes, alkyl poly(meth)acrylates, acrylic acid homopolymers, acrylic acid copolymers and vinyl polymers; 10-70% by weight of at least one resin that is different from at least one polymer from the above group. The resin comprises styrene/acrylic acid copolymer; 0-30% by weight of at least one plasticizer and 0-3% by weight of at least one additive as component. The sum total of the above components is 100% by weight. A graft copolymer contains 30-90% by weight of olefinically unsaturated monomer. The olefinically unsaturated monomer corresponds to one or more monomers selected from at least one olefinically unsaturated monomer selected from the group consisting of: a) mono- and di-esters of crotonic acid, cinnamic acid, fumaric acid, maleic acid, citraconic acid, and itaconic acid; b) carboxyfunctional monomers; c) N-vinyl caprolactam, vinyl phosphonates, N-vinyl formamides, N-vinyl acetamides, hydroxypropyl acrylates and methacrylates, monoacrylates and monomethacrylates of polyalkylene glycols, acrylates, methacrylates, acrylic acid and methacrylic acid amides containing amine groups; d) vinyl esters corresponding to general formula (I) CH2xCH——O——C(O)——R1, with R1=C11-21. At least one olefinically unsaturated monomer of group (a), (b), (c) or (d) is present in the graft copolymer in a quantity of up to 50% by weight or (i-b) a mixture of olefinically unsaturated monomers of vinyl acetate and, based on the graft copolymer, up to 50% by weight of at least one olefinically unsaturated monomer selected from the group consisting of stearyl acrylate, vinyl laurate, vinyl versatate, lauryl acrylate, lauryl methacrylate, dibutyl maleate, dibutyl itaconate, dibutyl fumarate and acrylates and methacrylates corresponding to general formula (II): CH2xCR2——C(O)——O——R3 with R2=H or CH3 and R3=C12-22; or at least one monomer selected from the group consisting of vinyl acetate and vinyl propionate; and ii) 10 to 70% by weight of polyalkylene oxide where the ethylene oxide content of the polyalkylene oxide is at least 50% by weight.
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