Patent GB-625937-A (GB)
Title: Improvements in or relating to resin bonded cellulosic fibrous materials particularly cords
IPC: B29D30/40
Filed: 1947-01-23
Abstract: Alkali metal rosinate is mixed with a phenolformaldehyde condensation product in the water-soluble or "A" stage.  The composition may be rendered insoluble by heating.  A phenol is heated with a molecular excess of formaldehyde in the pressure of an alkaline catalyst for a short time, e.g. 50 minutes at 90 DEG  C. Sodium or potassium rosinate may be used in a proportion of 25-400 parts per 100 parts by weight of the condensation product.  A wetting agent such as a polyether-alcohol and a small proportion of caustic soda may be included in the solution.  The solution is used for bonding cellulosic fibres, particularly in the form of yarns or cords. Heating to insolubilize the resin is effected subsequent to application to the fibres.  The temperature of hardening may be 300-600 DEG  F.  When the cords are embedded in rubber, as in the production of tyres, the heat treatment to harden the resin may be effected at the same time as vulcanization of the rubber.ALSO:Cellulosic fibres, particularly in the form of yarns or cords, are bonded together by applying an adhesive comprising a mixture of a phenolformaldehyde condensation product in the water-soluble stage of condensation and an alkali metal rosinate, and heating to thermoset the adhesive.  Sodium or potassium rosinate may be used in a proportion of 25-400 parts per 100 parts by weight of the condensation product.  A wetting agent such as a polyether-alcohol, and a small proportion of caustic soda may be included in the adhesive solution.  The fibres may be treated in sliver, roving, yarn, or cord form, during processes of sliving, roving, plying, cabling, or stretching.  Cords suitable for use in tyre construction or in the production of other rubber articles may be obtained.  After application of the adhesive by dipping or by means of moistened rollers, the fibres or cords may be stretched and then heated to thermoset the resin.  The degree of hardening is dependent on the temperature which may be 300-600 DEG  F., and on the time of treatment.  If desired, the thermosetting treatment may be carried out after the cords have been embedded in rubber in the manufacture of tyres or other articles.  When shaping the tyres, the cords may be stretched and when the tyres are vulcanized the resin may be thermoset by the heat of vulcanization.  Cotton tyre cords may be dipped in the adhesive, partially thermoset while in relaxed condition, dipped a second time in the adhesive, and finally thermoset while under a tension in the region of the breaking point. Specification 597,941, [Group XIX], is referred to.ALSO:Cellulose fibres, particularly in the form of yarns or cords, are bonded together by applying an adhesive comprising a mixture of water-soluble phenol-formaldehyde condensation product and an alkali metal rosinate, and heating to thermoset the adhesive.  A wetting agent such as a polyether-alcohol and a small proportion of caustic soda may be included in the adhesive solution.  The fibres, yarns or cords are used in the production of rubber articles such as tyres. The yarns or cords may be in stretched condition during the heat-setting treatment which may be effected at 300 DEG  - 600 DEG F. and carried out after they have been embedded in rubber.  When shaping tyres, the cords may be stretched and the resin may be heat hardened during the vulcanization of the rubber. Specification 597,941, [Group XIX], is referred to.