| 摘要 |
1521197 Laminates AMERICAN COLLOID CO 14 July 1976 [28 Oct 1975] 29364/76 Heading B5N A panel for providing a water barrier, comprises two opposing spaced sheets having between them a sealant composition comprising bentonite, a water-soluble dispersing agent selected from water-soluble salts of acetic acid, water-soluble salts of phosphoric acid and watersoluble salts of boric acid, and a water-soluble polymer selected from polyacrylic acid, watersoluble salts of polyacrylic acid, hydrolysed polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, copolymers of the foregoing and copolymers of acrylic acid and maleic anhydride, the amount of water-soluble polymer in said sealant composition being from 0À1% to 3À0%, by weight, and the amount of water-soluble dispersant in said sealant composition being from 0.1% to 3.0%, by weight, the weight ratio of water-soluble dispersant to water-soluble polymer being from 6 : 1 to 1 : 6. The bentonite may be a sodium or calcium bentonite; the dispersant a phosphate, borate or acetate of sodium, potassium or lithium; the polymer may be polyacrylic acid or a salt thereof. or hydrolysed polyacrylonitrile, or polyvinyl alcohol or polyvinyl acetate; copolymers may also be used. In a preferred embodiment the panel consists of a double-faced corrugated paperboard having the said spaces filled with the said composition; the edges may be sealed with wax, tape or watersoluble gum to avoid loss during transportation. |
