Superabsorbent Polymers Having Radiation Activatable Surface Cross-linkers And Method Of Making Them
Patent #: 7,166,356
Inventor(s): Andreas Flohr
Company: The Procter & Gamble Company
Patented are superabsorbent polymer particles comprising a water-absorbing resin that has been reacted with a radiation activatable surface crosslinker. The reaction product of the radiation activatable surface crosslinker and the water absorbing resin are present at surfaces of the superabsorbent polymer particles. The radiation activatable surface crosslinker comprises at least two radiation activatable groups R. The radiation activatable groups R are covalently bound to eachother or to at least one spacer group S. The spacer group S is selected from the group consisting of an organic group with a molecular weight of up to about Mw=10000 and a polymeric group with a molecular weight of up to about Mw=1000000. The radiation activatable groups R are the same or different and are selected from the group consisting of: a) acetophenone, benzophenone, anthraquinone, xanthone, thioxanthone, camphorquinone, terephthalophenone benzil, fluorenone, -ketocoumarin and acetophenone-, benzophenone-, anthraquinone-, xanthone-, thioxanthone-, camphorquinone-, terephthalophenone-, benzil-, fluorenone- and -ketocoumarin-derivatives. Acetophenone derivatives and benzophenone derivatives also comprise condensation products of acetophenone derivatives or benzophenone derivatives, comprising at least two acetophenone or benzophenone groups. Also included is a group consisting of methyl, benzyl, aryl, phenyl and substituted phenyl. A second group is selected from the group consisting of an aryl, an alkyl of 1 to 4 carbon atoms, cyclopropyl, cyclopentyl, cyclohexyl, -dialkoxyalkyl and -hydroxyalkyl. The first group is covalently bound to the second group via an additional carbonyl group. The second group is covalently bound to the spacer group S or to another radiation activatable group.
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