Loading patent…
OwnerHugh Semple Munro, Michael Joseph Donnelly +1inventors
InventorsHugh Semple Munro, Michael Joseph Donnelly, Alison Page
Estimating the term…
The present invention provides a process for the manufacture of a high water content (greater than about 40% by weight of water) cross-linked hydrogel composition which has an acceptable non-greasy “feel”, sufficient structural integrity and low brittleness, as well as good processing properties. In the process, a photopolymerisable monomer is photopolymerised, in the presence of water, low levels of a multifunctional photopolymerisable cross-limiting agent (less than about 0.5% by weight of the total polymerisation reaction mixture) and low levels of a photoinitiator (between about 0.002% and about 0.05% by weight of the total polymerisation reaction mixture).
A process for the manufacture of a high water content cross-linked hydrogel composition, comprising:
A process according to any one of the preceding claim, wherein the mixture prepared in step (i) further comprises one or more electrolyte.
A process according to any one of the preceding claims, wherein the mixture prepared in step (i) further comprises one or more organic plasticiser.
A process according to any one of the preceding claims, wherein the mixture prepared in step (i) further comprises one or more surfactant.
A process according to any one of the preceding claims, when carried out in a continuous manner for the production of a continuous hydrogel sheet.
A process according to any one of the preceding claims, wherein the one or more monomer comprises 2-acrylamido-2-methylpropane sulphonic acid, acrylic acid, acrylic acid (3-sulphopropyl) ester, a substituted derivative thereof, or a salt thereof.
A process according to any one of the preceding claims, wherein the one or more monomer comprises at least one of acrylamide or a mono- or di-N-alkylacrylamide or an analogue thereof containing an alkyl or substituted alkyl group linked to a carbon-carbon double bond via an amido or alkylamido function.
A process according to any one of the, preceding claims, wherein the photoinitiator (2) is present in the mixture in step (i) in an amount of from about 0.003% to about 0.05% by weight of the total polymerisation reaction mixture.
A process according to any one of the preceding claim, wherein the photoinitiator comprises a compound of the following general formula:
A process according to any one of the preceding claims, wherein the one or more cross-linking agent (3) is present in the mixture in step (i) in an amount of from about 0.01% to about 0.5% by weight of the total polymerisation reaction mixture.
A process according to any one of the preceding claims, wherein the cross-linking agent comprises tripropylene glycol diacrylate, ethylene glycol dimethacrylate, triacrylate, polyethylene glycol diacrylate or methylene bis acrylamide.
Use of a controlled amount of one or more free radical photoinitiator in the range between about 0.002% and about 0.05% by weight of the total mixture and a controlled amount of one or more multifunctional unsaturated free radically photo-polymerisable cross-linking agent in the range less than about 0.5% by weight of the total mixture, in a pre-photopolymerisation mixture comprising also water and one or more unsaturated free radically photo-polymerisable monomer in a process for the manufacture of a high water content cross-linked hydrogel composition having a desired predetermined combination of two or more of:
Dependencies are inferred from the claim text.