| 摘要 |
Water-soluble polyvinyl alcohol/polyethyleneimine pressure sensitive adhesive compositions are stabilized by adding an acid, usually in an amount of at least 3-5 parts by weight per 100 parts by weight of polyethyleneimine. Monobasic and polybasic organic and inorganic acids are suitable; preferred acids are phosphoric, tartaric, citric, oxalic, fumaric and malonic acids. The compositions may also comprise humectants (e.g. glycerine, diethylene glycol and propylene glycol), and/or aliphatic alcohols (e.g. isopropanol and ethanol). Many examples of compositions are given, including comparative examples of compositions not containing an acid.ALSO:Polyvinyl alcohol/polyethyleneimine pressure sentitive water soluble adhesive coating compositions are stabilised by an acid, usually in an amount of at least 3.5 parts by weight per 100 parts by weight of polyethyleneimine. The acid may be mono- or polybasic, inorganic or organic. Suitable substrates are paper, paperboard, cloth, metal sheets and foils, fibreglass, foamed plastics, rubber, cellophane (Registered Trade Mark), wood, and plastic films and sheets derived from polyethylene, polypropylene, polyvinyl chloride, polyethylene glycol terephthalate, polystyrene and polyvinylidene chloride. The compositions may also comprise humectants, e.g. glycerine, diethylene glycol and propylene glycol; and aliphatic alcohols, e.g. ethanol, isopropanol, as anti-curling agents. |
