Spandex containing a huntite and hydromagnesite additive
AssigneeE. I. Du Pont de Nemours and Company
InventorThomas E. Carney
Life of this patent
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Abstract
Spandex having dispersed within it particles of a mineral mixture of huntite and hydromagnesite has decreased tackiness, increased resistance to chlorine-induced degradation, satisfactory process continuity and little extraction of the mineral mixture in typical acid scouring and dyeing operations. The particles do not lead to excessive abrasiveness and are environmentally acceptable in effluent streams.
Claims6
A spandex containing particles of a mineral mixture of huntite and hydromagnesite dispersed within the spandex in an amount effective for decreasing the tackiness and increasing the chlorine-resistance of the spandex.
A process for dry spinning spandex from a solution of a polyurethane polymer in a solvent for the polyurethane, wherein the process comprises
- forming a concentrated slurry of particles of a mineral mixture of huntite and hydromagnesite in a solvent, and optionally other conventional particulate and non-particulate additives, the particles amounting to 10 to 40% of the total weight of the slurry and the weight percent of huntite in the huntite/hydromagnesite mixture being at least 35%,
- milling the concentrated slurry to break up particle aggregates and agglomerates and decrease the median particle size to less than 1 micron,
- incorporating the concentrated slurry into a polyurethane solution in an amount sufficient to provide a concentration of huntite/hydromagnesite particles amounting to 1.5 to 5% of the weight of the filaments to be spun, and
- dry spinning the solution into filaments.
Dependencies are inferred from the claim text.