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US 7,803,247 B2Granted
Papers containing floc derived from diamino diphenyl sulfone
AssigneeE.I. du Pont de Nemours and Company
InventorsMikhail R. Levit, Vlodek Gabara, Gary Lee Hendren
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Abstract
This invention relates to papers made with floc containing a polymer or copolymer derived from a monomer selected from the group consisting of 4,4′diaminodiphenyl sulfone, 3,3′diaminodiphenyl sulfone, and mixtures thereof. Such papers have higher elongation-at-break and work-to-break (toughness) properties and exhibit less shrinkage at high temperatures than papers made with solely with poly (metaphenylene isophthalamide) floc.
Claims11
A paper useful for electrical insulation, comprising:
- a) at least 20 weight percent floc containing a polymer or copolymer derived from an amine monomer selected from the group consisting of 4,4′diaminodiphenyl sulfone, 3,3′diaminodiphenyl sulfone, and mixtures thereof, the floc having a length of from 2 to 25 mm;
- and
- b) non-granular, fibrous or film-like polymer fibrids, the fibrids containing a polymer or copolymer derived from metaphenylene diamine, the fibrids having an average maximum dimension of 0.1 to 1 mm, a ratio of maximum to minimum dimension of 5:1 to 10:1, and a thickness of no more than 2 microns,
- wherein the papers have at least a 50% improvement in work-to-break values over papers made solely with poly(metaphenylene isophthalamide) floc.
1 more element
Dependencies are inferred from the claim text.