Patent GB-567338-A (GB)
Title: Improvements relating to rope and like materials comprising artificial fibres
IPC: D07B7/12
Filed: 1943-01-07
Abstract: A rope or the like having a basis of fibres (including filaments) of regenerated cellulose, is impregnated with a hot solution of a water-resistant organic derivative of cellulose in a non-aqueous liquid at a temperature of at least 120 DEG  C. and the liquid is then evaporated from the impregnated material.  Instead of regenerated cellulose, the rope may be composed of fibres of cellulose esters or ethers of relatively low water-resistance. Any moisture initially present in the materials is substantially removed by using such high impregnation temperatures, and adequate penetration by the impregnating solution is obtained.  Moisture may be removed by a previous treatment with a hot hydrophobe liquid. Ropes, cords and the like which are compact, have a desirable handle, can readily be spliced, and are of a high wet tenacity are obtained. The water-resistant esters or ethers of cellulose which are used are those which, when exposed dry to an atmosphere of 60 per cent relative humidity at 21 DEG  C., do not absorb more than 3.5 per cent of their weight of water.  Ethyl, propyl, benzyl, butyl, or hexyl ethers of cellulose, or cellulose propionate, butyrate, laurate, palmitate, or stearate may be used. The non-aqueous liquid is preferably a hydrophobe liquid such as a high-boiling liquid hydrocarbon.  Impregnation may be effected under pressure.  In addition to the impregnation with the cellulose derivative, the materials may be given other treatments, e.g. to improve wearing properties or resistance to attack by micro-organisms.  They may be treated with copper or zinc stearate or naphthenate, or aluminium stearate.  These salts may be used in solution in kerosene or other hydrophobic liquid.  They may be incorporated in the solution of the cellulose derivative.  Metal salts may be formed in situ on the materials by reaction between a sodium soap and a soluble metal salt. The materials may also be treated with linseed or other drying oil or with lubricants such as mineral oils and graphite.  Resistance to abrasion is improved by applying a composition containing an oil and rubber latex in a dispersion containing ammonium stearate.  In an example, a three-stranded rope made of high-tenacity regenerated cellulose yarn, obtained by saponifying cellulose acetate yarn which has been stretched in steam or hot water, is impregnated with a solution of ethyl cellulose in light grade coal tar solvent naphtha at 120-150 DEG  C.  After drying, the treated rope is impregnated with copper or zinc naphthenate in kerosene.  The rope may also be loaded with zinc or calcium stearate, palmitate or oleate.  Abrasion resistance may be improved by treating with an aqueous dispersion of zinc oxide, tannic acid, boiled linseed oil, castor oil and pyridine, or with a liquid comprising kerosene, boiled linseed oil, graphite and clay.  The twines, cords, ropes or the like materials may be composed of regenerated cellulose fibres in admixture with fibres of cotton, linen, jute, ramie, hemp, manilla, silk, wool, cellulose esters or ethers, polyvinyl compounds or polyamides.  Impregnation with the cellulose derivative solution may be carried out on the fibres, yarns, or strands from which the ropes are made.