| 摘要 |
Hard and abrasion resistant cast resin surfaces are made of a cured composition of an unsaturated polyester resin and at least 50% by weight of sand particles, the resin and particles being bonded by a bonding agent having at least two reactive groups one of which selectively reacts with the sand particles and the other with the resin. The particles may be treated with the bonding agent before compounding with the resin, will preferably have a slight moisture content before treatment and are subsequently dried before compounding. Specified bonding agents are alkenyl silanes and siloxanes, Werner-type methacrylato-chromic chloride complexes and allyl (or substituted allyl) silicates, numerous examples being given. The resin-sand compositions may contain the ingredients disclosed in Specifications 792,334 and 779,613. The Specification contains lists of suitable polyester components, comonomers, inhibitors, plasticizers (which may be used to replace part of the solvent comonomer), catalysts, accelerators and suspending agents. It is also desirable that the composition should contain an anti-foam agent. The compositions are used to coat cinder or cement masonry blocks by heating the composition in a mould to the gel stage, inserting the block in the mould and then heating in an oven to harden the coating on the block before removal from the mould.ALSO:Hard and abrasion resistant cast resin surfaces are made of a cured composition of an unsaturated polyester resin and at least 50% by weight of sand particles, the resin and particles being bonded by a bonding agent having at least two reactive groups one of which selectively reacts with the sand particles and the other with the resin. The particles may be treated with the bonding agent before compounding with the resin, will preferably have a slight moisture content before treatment and are subsequently dried before compounding. Specified bonding agents are alkenyl silanes and siloxanes, Werner-type methacrylatochromic chloride complexes and allyl (or substituted allyl) silicates, numerous examples being given. The resin-sand compositions may contain the ingredients disclosed in Specifications 792,334 and 779,613. The Specification contains lists of suitable polyester components, comonomers, inhibitors, plasticizers (which may be used to replace part of the solvent comonomer), catalysts, accelerators and suspending agents. It is also desirable that the composition should contain an anti-foam agent. The compositions are used to coat cinder or cement masonry blocks by heating the composition in a mould to the gel stage, inserting the block in the mould and then heating in an oven to harden the coating on the block before removal from the mould. |
