Transparent cellulose hydrogel and production process thereof

• US 5,962,005 A
• Filed: 04/15/1998
• Issued: 10/05/1999
• Est. Priority Date: 04/17/1997
• Status: Expired due to Fees

• Current Assignee: Rengo Company Limited
• Original Assignee: Rengo Company Limited
• Inventors: Saga, Hiroshi, Saito, Hidenao
• Primary Examiner(s): Nutter, Nathan M.
• Application Number:
  US09/060,332
• Time in Patent Office: 538 Days
• Field of Search: 424/424, 424/426, 424/427, 424/428, 106/162.1, 106/162.6, 106/163.01, 106/166.01, 106/167.01, 523/105, 523/106, 210/500.1, 210/500.21, 210/500.27, 210/500.29, 351/159, 351/160 R, 351/160 H
• US Class Current: 424/424
• CPC Class Codes: A61F 2/14 Eye parts, e.g. lenses, corneal implants; Implanting instruments specially adapted therefor; Artificial eyes
• CPC Class Codes: A61F 2250/0091 transparent or translucent
• CPC Class Codes: B01J 13/0065 containing an organic phase
• CPC Class Codes: G02C 7/04 Contact lenses for the eyes disinfection or sterilisation of contact lenses A61L12/00

Abstract

A transparent cellulose hydrogel having a transmittance of visible light of not less than 70%/mm and a tensile strength of not less than 10 kg/cm², wherein the hydroxyl groups of cellulose constituting said hydrogel are not chemically crosslinked; and a process for producing a transparent cellulose hydrogel, comprising coagulation and regeneration of cellulose from a cellulose solution using an aqueous solution containing an organic solvent in a proportion of 20-95 wt %. The cellulose hydrogel of the present invention is useful as a raw material of an ophthalmic material, such as soft contact lens, artificial crystal lens, artificial cornea, artificial vitreous body and the like, a carrier of fragrance, and a base of gel and cream, and the like. In addition, the transparent cellulose hydrogel of the present invention has a densely packed and uniform structure, so that it can provide a material of a separation membrane having a small molecular cutoff and high pressure resistance.

Claims

1. A transparent cellulose hydrogel having a transmittance of visible light of not less than 70%/mm and a tensile strength of not less than 10 kg/cm², wherein all of the hydroxyl groups of cellulose constituting said hydrogel are not chemically crosslinked.

2. An ophthalmic material comprising the transparent cellulose hydrogel of claim 1 as a raw material.

3. The ophthalmic material of claim 2, which is a soft contact lens.

4. A separation membrane comprising the transparent cellulose hydrogel of claim 1.

5. A process for producing a transparent cellulose hydrogel, comprising coagulation and regeneration of cellulose from a cellulose solution using an aqueous solution containing at least one organic solvent selected from the group consisting of methanol, ethanol, acetonitrile, isopropyl alcohol, acetone, n-propyl alcohol and tetrahydrofuran, in a proportion of 30-90 wt % based on the weight of the aqueous solution.

6. A process for producing a transparent cellulose hydrogel, comprising coagulation and regeneration of cellulose from a viscose using an aqueous solution containing an organic solvent, which is a non-solvent for cellulose and is miscible with water, in a proportion of 50-95 wt % based on the weight of the aqueous solution, said aqueous solution containing a decomposition agent which decomposes cellulose xanthate into cellulose.