Patent GB-607696-A (GB)
Title: Improvements in or relating to methods of treating textile fibres, and the improved textile fibres resulting therefrom
IPC: D06M11/79
Filed: 1945-07-16
Abstract: A colloidal solution of silica is applied to textile fibres prior to spinning to prevent slipping.  Penetration of the solution into the fibres may be assisted by adding a wetting agent.  The colloidal solution may be made by adding acid to a solution of a silicate, washing the resulting gel to remove electrolytes, covering the gel with a weak aqueous solution of a substance capable of forming hydroxyl ions, and after removing the gel from the solution, heating the gel while avoiding evaporation of water, until the gel is converted into a sol.  The sol may be used in neutral, slightly alkaline, or slightly acid state.  If desired, the sol may be obtained by adding a small amount of acid to a solution of silicate, and adding alcohol or cooling to precipitate electrolytes.  The sol may be obtained by treating an alkali silicate solution with an ion-exchanging material. Alternatively, an organosol of silica may be used.  The concentration of silica in the solution may range from 0.1 to 30 per cent.  A wetting agent such as sodium octyl benzene sulphonate, sodium lauryl sulphate, sodium salt of methyl stearamide ethionic acid, or dioctyl sodium sulphosuccinate may be added.  The silica sol may contain oil, fat, wax, fatty acid, or quaternary ammonium salts.  In an example, dilute sulphuric acid is added to a solution of sodium silicate and the gel formed is separated from liquor.  The gel is crushed, washed, and then covered with a very dilute solution of caustic soda.  After several hours the solution is drained off and the gel is heated under pressure in an autoclave until it is converted into a sol. This is diluted with water and a wetting agent is added. Hydrochloric acid may be used instead of sulphuric.ALSO:Textile fibres are treated to increase their resistance to slipping and prepare them for spinning by applying to them at a stage of their processing prior to spinning a colloidal solution of silica in an amount sufficient to supply from 0.1 to 5 per cent of silica based on the weight of the fibres, and allowing the treated fibres to dry.  The treated fibres may be readily spun into yarn of high-tensile strength.  Penetration of the solution of silica may be assisted by adding a wetting agent to the solution. The colloidal solution may be made by adding acid to a solution of a silicate, washing the resulting gel to remove electrolytes, covering the gel with a weak aqueous solution of a substance capable of forming hydroxyl ions, and after removing the gel from the solution, heating the gel while avoiding evaporation of water, until the gel is converted into a sol.  The sol may be used in neutral, slightly alkaline, or slightly acid state.  If desired, the sol may be prepared by adding a small amount of acid to a solution of a silicate, and adding alcohol or cooling to remove electrolytes.  Sols obtained by treating an alkali silicate solution with an ion-exchanging material, or anhydrous organosols of silica may be used.  The concentration of silica in the solution may range from 0.1 to 30 per cent.  The wetting agent may be sodium octyl benzene sulphonate, sodium lauryl sulphate, sodium salt of methyl stearamide ethionic acid, dioctyl sodium sulphosuccinate.  The solution of silica may contain a softening agent such as an emulsion of an oil, fat, wax, or fatty acid, or cetyl dimethyl benzyl ammonium chloride or the quaternary ammonium salts of diethyl aminoethyl oleyl amide hydroacetate.  The fibres treated may be of cotton, wool, regenerated cellulose, cellulose nitrate, cellulose acetate, silk, casein, nylon, polyvinyl compounds, or glass.  The silica sol may be applied to the raw stock or to the sliver.  The sol may be applied by spraying or by immersion.  In an example, dilute sulphuric acid is added to a solution of sodium silicate and the gel formed is separated from liquor.  The crushed gel is washed and then covered with a very dilute solution of caustic soda.  After several hours the solution is drained off and the gel is heated under pressure in an autoclave until it is converted into a sol.  The sol is diluted with water and a wetting agent is added.  Cotton sliver is treated with the silica sol, run through squeeze rolls and dried. In another example, hydrochloric acid is used instead of sulphuric.  In another example, a silica sol containing pine oil and an emulsifying agent is sprayed on to cut rayon staple fibre at the opener hopper, and the fibre is subsequently carded and spun.  In another example, wool raw stock at the opener picker is sprayed with a silica sol containing an emulsion of mineral oil and lard oil.