Manufacture of vesiculated polymer granules
Patent 3979342 Issued on September 7, 1976. Estimated Expiration Date: 
September 7, 1993. 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.
September 7, 1993. 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 3255127 3740255 InventorsAssigneeApplicationNo. 05/507550 filed on 09/19/1974US Classes:521/162, N=C=X reactant contains atoms other than carbon and hydrogen and other than nitrogen and chalcogen as part of the N=C=X group521/138, At least one polymer is derived from a polycarboxylic acid or derivative and a polyol or wherein the polymer-forming system containing the same type of reactants521/64Removing a liquid to form a cellular productExaminersPrimary: Foelak, MortonInternational ClassesC08F 299/00 (20060101)C08F 299/04 (20060101) C08J 9/00 (20060101) C08J 9/28 (20060101) AbstractThe invention relates to a process for preparing vesiculated cross-linked polyester resin granules by polymerizing a water-in-oil-in-water emulsion formed from a polymerizable water-immiscible oil phase, composed of an ethylenically unsaturated monomer and a polyester condensation product and an aqueous phase. The polymerization is effected essentially instantaneously and substantially immediately following the formation of the emulsion by contacting the water-immiscible oil phase at a temperature from 10° to 40°C. with an aqueous phase containing a strong base and having a temperature from 65° to 95°C. Polymerization is thereby effected while the size of the oil phase globules of the water-in-oil emulsion is at a minimum and before appreciable agglomeration can take place, resulting in a reduction in particle size and particle size distribution. The product is especially useful as an opacifying pigment for latex paints and the like, wherein it contributes improved hiding power. | |
