摘要 |
<p>Glass fibres for use as reinforcement in cement products are coated with a composition containing a material to protect them against the alkaline environment, which comprises at least one dihydroxybenzoic acid, preferably 2,5 dihydroxybenzoic acid, and which may also comprise a partially-cured A-stage phenol-formaldehyde resin of the water-dilutable resole type. A further coating of an epoxy resin may be applied over this composition to protect it from abrasion during handling of the fibres and preparation of the cement products. The coating composition may be applied as a size to the individual filaments immediately after they have been drawn from a bushing, or it may be applied later after the filaments have been combined into a strand.</p> |