초록 ▼

Superabsorbent polymeric compositions are prepared from monomer including acrylic acid and an effective amount of a second hydrophilic monomer, which can be a soluble salt of beta-acryloxypropionic acid. Preferably, the pH of the aqueous monomer solution is adjusted to substantially exclude free aci

Superabsorbent polymeric compositions are prepared from monomer including acrylic acid and an effective amount of a second hydrophilic monomer, which can be a soluble salt of beta-acryloxypropionic acid. Preferably, the pH of the aqueous monomer solution is adjusted to substantially exclude free acid, and the aqueous monomer solution is coated onto a heated surface to both polymerize the monomer and dry the resulting hydrogel. Free acid thermal degradation products are avoided and the superabsorbent product has greater absorption capacity than acrylate homopolymer.

대표청구항 ▼

A process for the preparation of a superabsorbent polymeric composition for absorbing and retaining aqueous fluids, the process comprising: (a) preparing a monomer mixture including at least one first hydrophilic monomer selected from the group consisting of acrylic acid and the water soluble salts

A process for the preparation of a superabsorbent polymeric composition for absorbing and retaining aqueous fluids, the process comprising: (a) preparing a monomer mixture including at least one first hydrophilic monomer selected from the group consisting of acrylic acid and the water soluble salts of acrylic acid, and an effective amount of at least one second hydrophilic monomer to at least reduce the extent of the phase separation of said mixture which would occur shortly after polymerization began in the absence of said second hydrophilic monomer; (b) adjusting the pH of said mixture prior to polymerization to substantially completely exclude the free acid forms of said first hydrophilic monomer and said second hydrophilic monomer: and (c) polymerizing said monomer mixture: wherein said second hydrophilic monomer is selected from beta-acryloxypropionic acid, the water-soluble salts of beta-acryloxypropionic acid, 2-hydroxyethyl methacrylate, the (C1-C4) alkoxy (C1-C4) alkyl (meth) acrylates, the (C1-C4) alkoxy (C1-C4) alkoxy (C1-C4)alkyl (meth) acrylates, the mono (meth) acrylate esters of HO(CH2CH2O)nH where n is a positive integer from 2 to about 10, and the (meth) acrylate esters of CH3O(CH2CH2O)xH where x is a positive integer from 2 to about 10.