Styrene/acrylic-type polymers for use as surface sizing agents
Patent 5138004 Issued on August 11, 1992. Estimated Expiration Date: 
June 3, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
June 3, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2772252 2851448 3839308 InventorsApplicationNo. 709522 filed on 06/03/1991US Classes:526/293, Aromatic526/318.45, With hydrocarbon monomer526/318.6With hydrocarbon monomerExaminersPrimary: Schofer, Joseph L.Assistant: Nagumo, M. Attorney, Agent or FirmForeign Patent References
International ClassesC08F 220/18C08F 220/06 AbstractA process is disclosed for the preparation of styrene/acrylic type polymers which are useful in the sizing of paper. The process comprises polymerizing the monomers in an alcohol/water mixture at reflux temperature in the presence of a free-radical generating catalyst. The catalyst is added portion-wise over the course of the reaction and the resultant polymer is neutralized while substantially simulaneously separating the alcohol/water mixture and adding water to recover a product of less than 25% polymer solids. | |
