GB865380A - Sizes for glass fibres - Google Patents

Abstract

An aqueous emulsion for sizing glass fibres to be used for reinforcing plastics comprises (1) an adhesive agent which is either a chromium compound containing unsaturated organic groups, e.g. methacrylato chromic chloride, or an organic silicon compound containing hydrolyzable groups and organic groups capable of reacting with the plastic to be reinforced, or a hydrolysis product of such an organic silicon compound, for increasing the adhesion between the glass fibres and the plastic to be reinforced, and (2) a binding and lubricating composition containing (a) at least one unsaturated organic compound capable of reacting with the plastic to be reinforced and (b) at least one water-soluble organic hydroxy compound capable of forming a continuous film while drying in air. The organic silicon compound may be vinyl-triethoxy silane or vinyl-trichloro-silane and the unsaturated organic compound may be an unsaturated polyester resin, e.g. an unsaturated alkyd made from maleic acid, phthalic acid and ethylene glycol and/or an unsaturated monomeric ester, e.g. diallyl phthalate. Suitable water-soluble film-forming organic hydroxy compounds are watersoluble cellulose derivatives, e.g. ethyl hydroxyethyl cellulose and carboxymethyl cellulose, dextrin and polyvinyl alcohol. When the composition contains water-soluble organic hydroxy compounds and water-insoluble unsaturated organic compounds, the ratio by weight of the former to the latter is preferably between 0,2 and 0,5. The composition preferably contains also (1) an aldehyde, e.g. glyoxal, in a proportion not more than 20% of the weight of the water-soluble organic hydroxy compounds, (2) a peroxide catalyst, e.g. benzoyl peroxide, (3) a weak organic acid, e.g. formic or acetic acid, to adjust the pH value below 7, and (4) an emulsifier, e.g. a polyoxyethylene derivative, an ester of sorbitol or similar sugar alcohol or ammonium oleate. Specification 760,798 is referred to.ALSO:Glass fibres to be used for reinforcing plastics are sized with an aqueous emulsion, intended to serve simultaneously as a lubricant and as a binder for the fibres, comprising (1) an adhesive agent which is either a chromium compound containing unsaturated organic groups, e.g. methacrylato chromic chloride, or an organic silicon compound containing hydrolyzable groups and organic groups capable of reacting with the plastic to be reinforced, or a hydrolysis product of such an organic silicon compound, for increasing the adhesion between the glass fibres and the plastic to be reinforced, and (2) a binding and lubricating composition containing (a) at least one unsaturated organic compound capable of reacting with the plastic to be reinforced and (b) at least one water-soluble organic hydroxy compound capable of forming a continuous film while drying in air. The organic silicon compound may be vinyl-triethoxy silane or vinyl trichloro-silane and the unsaturated organic compound may be an unsaturated polyester resin, e.g. an unsaturated alkyd made from maleic acid, phthalic acid and ethylene glycol and/or an unsaturated monomeric ester, e.g. diallyl phthalate. Suitable water-soluble film-forming organic hydroxy compounds are water-soluble cellulose derivatives, e.g. ethyl hydroxyethyl cellulose and carboxymethyl cellulose, dextrin and poly-vinyl alcohol. When the composition contains water-soluble organic hydroxy compounds and water-insoluble unsaturated organic compounds, the ratio by weight of the former to the latter is preferably between 0,2 and 0,5. The composition preferably contains also (1) an aldehyde, e.g. glyoxal, in a proportion not more than 20% of the weight of the water-soluble organic hydroxy compounds, (2) a peroxide catalyst, e.g. benzoyl peroxide, (3) a weak organic acid, e.g. formic or acetic acid, to adjust the pH value below 7, and (4) an emulsifier, e.g. a polyoxyethylene derivative, an ester of sorbitol or similar sugar alcohol or ammonium oleate. After sizing, the glass fibres are preferably heat-treated either after twisting or after weaving and are then made up into laminates with, for example, styrene-modified polyester resins. Specification 760,798 is referred to.