| 摘要 |
A flexible membrane having a valuable combination of desirable properties is composed of a generally heavy, dense supporting and reinforcing reticulated base fabric constituted of thick, generally loose bundles of multiple continuous filaments arranged in a mechanically interengated reticular array having an overall weight within the range of about 3-12 oz/yd2 the continuous filaments being of a synthetic polymer having good dimensional stability and high resistance to heat and light; and a solidified base coating composition completely impregnating the interstices of the base fabric and as forming a continuous coating along the opposite sides thereof, the composition having as essential ingredients a PVC resin and a plasticizer therefor in the amount of 35-75% of the resin of a trimellitate ester which exhibits high resistance to separation from the resin and imparts to the coating high flexibility at temperatures at least as low as about -35 DEG F., the amount of the coating composition being preferrably at least about equal in weight to the weight of the base fabric. Preferably, the coating composition exceeds the weight of the base fabric by a factor of two or more, at least one additional layer of such coating composition being applied to each of the opposite surfaces of the coated base fabric and fused into integral relation therewith so as to improve the abrasion resistance, waterproofness, UV resistance, heat resistance and like mechanical properties of the ultimate membrane. The coating composition can contain additional adjuvants of the several types known in the PVC coating field, including supplemental plasticizers, a fire retardant, UV resistance enhancing, opacifying pigment, fungicidal and like agents. In its optimum form, the present membrane exhibits special utility as a roofing fabric of exceptional durability.
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