Cationic starch graft copolymers and novel process for the preparation of cationic starch graft copolymers
AssigneeKemira Oyj
InventorsBernd Hauschel, Bernd Thiele, Thomas Hubbe, Bernhard Jansen
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Abstract
Cationic starch graft copolymer composed of the monomers a) to d) a) 20-80% by weight of acrylamide, methacrylamide or mixtures thereof, b) 3-20% by weight of at least one basic or cationic vinyl monomer, c) 0.005-1.5% by weight of at least one bifunctional or higher-functional crosslinking agent, d) 0-10% by weight of at least one nonionic or anionic vinyl monomer which differs from the monomers mentioned under a) to c) and a grafting base e) e) 15-70% by weight of at least one starch or one starch derivative, the sum of a) to e) being 100% by weight.
Claims11
Cationic starch graft polymer composed of the monomers a) to d)
- a) 20-80% by weight of acrylamide, methacrylamide or mixtures thereof,
- b) 3-20% by weight of at least one basic or cationic vinyl monomer,
- c) 0.005-1.5% by weight of at least one bifunctional or higher-functional crosslinking agent,
- d) 0-10% by weight of at least one nonionic or anionic vinyl monomer which differs from the monomers mentioned under a) to c)
- and a grafting base e)
- e) 15-70% by weight of at least one starch or one starch derivative,
- the sum of a) to e) being 100% by weight.
Process for the preparation of a cationic starch graft polymer, characterized in that the monomers a) to d)
- a) 20-80% by weight of acrylamide, methacrylamide or mixtures thereof
- b) 3-20% by weight of at least one basic or cationic vinyl monomer
- c) 0-1.5% by weight of at least one bifunctional or higher-functional crosslinking agent
- d) 0-10% by weight of at least one nonionic or anionic vinyl monomer which differs from the monomers mentioned under a) to c)
- are subjected to free radical polymerization in the presence of
- e) 15-70% by weight of at least one starch or one starch derivative,
- wherein, in a first step, the component e), as the grafting base, is subjected to free radical polymerization in water with at least 30% by weight of the total amount of the component b) and then, in a second step, the other components a), c), d) and the remaining amount of b) are subjected to free radical polymerization in the presence of the reaction mixture formed in the first step, and the sum of a) to e) is 100% by weight.
Dependencies are inferred from the claim text.