| 摘要 |
A gel forming preparation comprises an alkali metal (e.g. Na) carboxymethyl cellulose, a substantially water insoluble metal sulphide or oxide (e.g. Sb, Zn, Pb, Bi, Mn, Ni, Co, Sn, Fe, Cu or Co) and up to 8% by weight of an oxidising agent. The oxidising agent is alkali metal chromate, bichromate, permanganate, peroxide, or periodate, alkaline earth metal hypochlorite, chromium oxide, hydrogen peroxide, peracetic acid, periodic acid or nitric acid. The preparation may contain ammonium nitrate. The preparation may be prepared by mixing the components in dry form; by dispersing the cellulose derivative in an aqueous medium and then adding the sulphide or oxide and oxidising agent, or by dispersing a mixture of the cellulose derivative and the sulphide or oxide in an aqueous medium and then adding the oxidising agent.ALSO:A gel-forming preparation comprises a gum product, a substantially water-insoluble metal sulphide or oxide (e.g. Sb, Zn, Pb, Bi, Mn, Ni, Co, Sn, Fe, Cu or Co) and up to 8% by weight of an oxidizing agent. The gum product is galactomannan gum (e.g. guar, locust bean or tara), a glucomannan gum (e.g. Iles mannan gum), a glucoxylogalactan gum (e.g. tamarind gum), a xylogalactan gum (e.g. psyllium seed gum), waxy maize starch, an alkali metal (e.g. Na) alginate, an alkylene (e.g. propylene) glycol ester of alginic acid or an alkali metal (e.g. Na) carboxymethylcellulose. The oxidizing agent is alkali metal chromate, bichromate, permanganate, peroxide, or periodate, alkaline earth metal hypochlorite, chromium oxide, hydrogen peroxide, peracetic acid, periodic acid or nitric acid. The preparation may contain ammonium nitrate. The preparation may be prepared by mixing the components in dry form; by dispersing the gum in an aqueous medium and then adding the sulphide or oxide and oxidizing agent; or by dispersing a mixture of the gum and the sulphide or oxide in an aqueous medium and then adding the oxidizing agent.ALSO:Paper is coated with a gel-forming preparation comprising a gum product, a substantially water-insoluble metal sulphide or oxide (e.g. Sb, Zn, Pb, Bi, Mn, Ni, Co, Sn, Fe, Cu or Co) and up to 8% by weight of an oxidizing agent. The gum product is a galactomannan gum (e.g. guar, locust bean or tara), a glucomannan gum (e.g. Iles mannan gum), a glucoxylogalactan gum (e.g. tamarind gum), a xylogalactan gum (e.g. psyllium seed gum), waxy maize starch, an alkali metal (e.g. Na) alginate, an alkylene (e.g. propylene) glycol ester or alginic acid or an alkali metal (e.g. Na) carboxymethylcellulose. The oxidizing agent is alkali metal chromate, bichromate, permanganate, peroxide, or periodate, alkaline earth metal hypochlorite, chromium oxide, hydrogen peroxide, peracetic acid, per-iodic acid or nitric acid. The preparation may contain ammonium nitrate.
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