Fluid absorbent compositions and process for their preparation
AssigneeHoechst Celanese Corporation
InventorsYoji Fujiura, Takashi Sumiya
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Abstract
This invention relates to fluid absorbent polymer compositions having the ability to absorb aqueous ionic fluids and water rapidly and efficiently. These fluid absorbent polymer compositions are prepared from fine base polymer particles which are ionically surface crosslinked and agglomerated into larger particles by the use of high energy mixing conditions. The fluid absorbent compositions of the invention find application in the preparation of absorbent articles such as diapers, sanitary napkins and incontinent devices.
Claims21
A process for preparing a water absorbent polymer composition having an absorbency rate of 20 seconds or less comprising;
- (a) introducing a water absorbent base polymer having a free absorbency of at least 30 ml/gm and a particle size distribution such that 100 percent of said particles are 150 microns or less into a mixing zone;
- (b) uniformly contacting the surface of the absorbent base polymer with an aqueous crosslinker solution in an amount of from about 1 to about 20 percent by weight based upon the weight of said base polymer;
- said crosslinker solution containing from about 0.05 to about 10 percent by weight of a ionic crosslinker selected from an inorganic or an organic compound capable of providing an ionizable metal cation, an amino cation or an imino cation having a valence of at least two;
- and (c) subjecting the absorbent base polymer and crosslinking solution to a high intensity mixing to crosslink the surface of said base polymer particles and agglomerated said base polymer particles into particles of larger size.
A process according to claims 1, 4, 9, 12, 15, 18 or 21 comprising the further step of adding after crosslinking and agglomerating said base polymer particles from about 0.5 to about 20 percent of a inert inorganic, hydrophillic, water insoluble compound to said surface crosslinked and agglomerated base polymer and wherein said insert inorganic compound has an average particle size of 150 microns or less and an apparent density of less than about 0.5 g/ml.
Dependencies are inferred from the claim text.