摘要 |
<p>The surfaces of glass fibre filaments, during or after forming, yarns or strands, are treated with a water-soluble salt of an unsaturated polysiloxanol (see Group IV (a)). Preferably the glass fibres are freed from size and dipped, sprayed or flow-coated with a water solution of the polysiloxanate after adjustment of the pH value to between 5 and 8. The treated fibres may be washed before drying and heating, e.g. for 10 to 30 minutes at 200 DEG to 250 DEG F.ALSO:A composition for sizing glass fibres comprises an aqueous solution of a water-soluble unsaturated polysiloxanolate of the general formula <FORM:0729452/IV (a)/1> wherein M is sodium, potassium, lithium or ammonium, R is an unsaturated organic radical of less than 6 carbon atoms in a straight chain, e.g. allyl, methallyl, ethylallyl, vinyl, propenyl, butyne, crotenyl and allenyl, with or without halogen substituents, but may contain more than 6 carbon atoms if the chain also contains a cyclic group, e.g. styryl and chlorostyryl; further, one or more but not all of the R radicals may be hydrogen or a substituted or unsubstituted radical such as methyl, ethyl, propyl, butyl, tolyl, benzyl or furfuryl; and Z may be R or OM. The solutions are made by adding one or more unsaturated silanes to an ice-cold solution of an alkali or ammonium hydroxide to give a silane content of about 3 per cent by weight and a pH of 11 to 12. The pH is preferably adjusted to 5 to 8 before the solution is used for sizing. Polysiloxanolates specified are sodium diallyl-, sodium divinyl-, potassium diallyl-, sodium ethyl-allyl-, sodium methyl styryl-, sodium allyl-, potassium vinyl-, ammonium allyl-, potassium allyl-, sodium styryl-, sodium methallyl-, sodium methyl allyl- and mixed sodium ethyl methyl vinyl-polysiloxanolates.</p> |