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US 4,950,420 AGranted
Antifoam/defoamer composition
AssigneeNalco Chemical Company
InventorJames J. Svarz
Life of this patent
Estimating the term…
Abstract
An antifoam/defoamer composition a polyether surfactant and a polyhydric alcohol fatty acid ester. The polyether surfactant being admixed with the polyhydric alcohol fatty acid ester in a ratio in the range between 10:90 to 90:10% by weight.
Claims16
A method for controlling foam in a papermaking process comprising the steps of:
- adding to a pulp slurry and/or suspension an antifoam/defoamer composition consisting of:
- 10-90% by weight of a polyether surfactant, said polyether surfactant comprising at least one compound selected from the group consisting of polyoxyalkylated glycerol, polyoxyalkylated sorbitol or sorbitan, polyoxyalkylated sucrose, and isomers thereof;
- wherein said polyoxyalkylated glycerol, sorbitol, or sucrose contains ethylene oxide in the range between about 0-60 weight % and/or propylene oxide in the range between about 30-100 weight % and has a molecular weight in the range between about 1000-10,000;
- and
- 10-90% by weight of a polyhydric alcohol fatty acid ester, said polyhydric alcohol fatty acid ester comprising:
- a fatty acid mono and/or diester of polyethylene glycol and/or polypropylene glycol;
- whereby said antifoam/defoamer does not contain any oil, amides, hydrophobic silica or silicons, thereby avoiding deposition and felt filling caused by said oil, amides, hydrophobic silica or silicone.
4 more elements
Dependencies are inferred from the claim text.