Gradient copolymers for use in automatic dishwashing systems
AssigneesDow Global Technologies LLC, Rohm and Haas Company
InventorsMarianne Creamer, Severine Ferrieux, Eric Wasserman
Life of this patent
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Abstract
A polymer comprising a first fraction and a second fraction, wherein the first fraction comprises from 90 to 100 wt % polymerized C3-C6 carboxylic acid monomer units; and the second fraction comprises from 30 to 80 wt % polymerized C3-C6 carboxylic acid monomer units and from 20 to 70 wt % polymerized sulfonic acid monomer units; wherein the first fraction is from 10 to 40 wt % of the polymer and the second fraction is from 60 to 90 wt % of the polymer; the polymer has Mw from 3,000 to 30,000; and monomers are randomly distributed within each fraction.
Claims11
A polymer comprising a first fraction and a second fraction, wherein the first fraction comprises from 90 to 100 wt % polymerized C3-C6 carboxylic acid monomer units;
- and the second fraction comprises from 30 to 80 wt % polymerized C3-C6 carboxylic acid monomer units and from 20 to 70 wt % polymerized sulfonic acid monomer units;
- wherein the first fraction is from 10 to 40 wt % of the polymer and the second fraction is from 60 to 90 wt % of the polymer;
- the polymer has weight-average molecular weight from 3,000 to 30,000 Daltons;
- and monomers are randomly distributed within each fraction.
A method for producing a polymer;
- said method comprising steps of:
- (a) polymerizing a first monomer composition comprising from 90 to 100 wt % C3-C6 carboxylic acid monomer in an initial polymerization phase;
- and (b) polymerizing a second monomer composition comprising from 30 to 80 wt % C3-C6 carboxylic acid monomer and from 20 to 70 wt % sulfonic acid monomer in a second polymerization phase;
- wherein a chain transfer agent is added during addition of the first and second monomer compositions.
Dependencies are inferred from the claim text.