1. Field of the Invention
The present invention relates to aqueous overfinish compositions, yarns treated therewith and methods of producing wet abrasion resistant cordage from the yarn. More specifically, the present invention relates to aqueous overfinishes for application to yarns of polyamide, polyester or polyolefin to improve wet and dry abrasion resistance thereof as well as that of cordage made therefrom.
2. Description of the Prior Art
Cordage products designed for prolonged contact with water need to have wet abrasion resistance. This invention is directed to enhancing wet abrasion resistance for cordage made from natural and/or synthetic fibers. The general term yarn is used herein to include mono- and multifilaments, fiber, thread, yarn or other similar forms. Preferred are synthetic continuous filaments.
Cords or ropes fabricated of the yarns treated in accordance with the teachings of U.S. Pat. No. 3,103,448 to Ross are more resistant to wet and dry chafing abrasion. Drawn or undrawn synthetic continuous filament yarns, especially nylon, are treated with an aqueous emulsion of an oxidized polyethylene (See U.S. Pat. No. 3,060,163 to Erchak, Jr.). Further, the coatings of oxidized polyethylene may be applied alone or with other finish additives, e.g. silicones (column 3, lines 9-31).
Spin finishes for polyamide yarn which include an oxidized polyethylene are disclosed in U.S. Pat. Nos. 3,917,893, 4,129,507, 4,293,460 and 4,371,658, all to Marshall et al. An overfinish for polyester yarn which includes an oxidized polyethylene is disclosed in U.S. Pat. No. 3,850,658 to Gomez et al.
Enhanced adhesion and fatigue resistance for polyester and polyamide tire and industrial yarns are achieved according to U.S. Pat. No. 3,853,607 to Iyengar et al. via treatment with a lubricating finish composed of a polyorganosiloxane oil and a polyalkylene wax or a microcrystalline wax dispersed in a dialkylphthalate oil. Known dressing agents (lubricants) for sewing threads are polydiorganosiloxane oils or a mixture of these oils and polyethylene waxes, according to U.S. Pat. No. 3,844,826 to Buchner et al., and U.S. Pat. No. 4,394,518 to Huber et al. states (column 3) that organosilicone compounds of that invention can be applied in admixture with other substances previously used to improve slipping or gliding properties of organic fiber, e.g. paraffin and/or polyethylene waxes. Similarly, U.S. Pat. No. 3,983,272 to Huber et al. teaches improved lubricity or gliding ability of fibers by coating with a composition containing a diorganopolysiloxane, a phosphorus compound and paraffin waxes. All of the prior art patents mentioned above are hereby incorporated by reference.
None of the prior art teaches the required combination of ingredients to achieve the specific beneficial results of the finishes of this invention. More specifically, although it is known to use coatings of oxidized polyethylene on yarn to improve wet and dry chafing abrasion, solids retention on the yarn (an indicator of durability of the coating) after prolonged exposure to water has been unsatisfactory with some of these coatings, and the wet abrasion resistance has not always translated to rope made of the yarn.