Process for producing shaped articles from three-dimensional hydrophilic high polymers

• US 2,976,576 A
• Filed: 04/24/1956
• Issued: 03/28/1961
• Est. Priority Date: 04/24/1956
• Status: Expired due to Term

• Current Assignee: Drahoslav Lim, Otto Wichterle
• Original Assignee: Drahoslav Lim, Otto Wichterle
• Inventors: OTTO WICHTERLE, DRAHOSLAV LIM
• Application Number:
  US03/580,411
• Time in Patent Office: 1,799 Days
• US Class Current: 264/49
• CPC Class Codes: A61L 15/60 Liquid-swellable gel-forming materials, e.g. super-absorbents
• CPC Class Codes: B29C 39/00 Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor B29C41/00 takes precedence
• CPC Class Codes: C08F 220/12 of monohydric alcohols or phenols
• CPC Class Codes: C08L 33/14 of esters containing halogen, nitrogen, sulfur, or oxygen atoms in addition to the carboxy oxygen
• CPC Class Codes: G02B 1/043 Contact lenses
• CPC Class Codes: Y10S 425/012 Destructible mold and core
• CPC Class Codes: Y10S 425/808 Lens mold
• CPC Class Codes: Y10S 623/924 Material characteristic

Claims

7. A METHOD OF PREPARING A SPARINGLY CROSS-LINKED POLYMERIC HYDROGEL STRUCTURE, COMPRISING MIXING IN AQUEOUS SOLUTION A WATER SOLUBLE MONOESTER OF AN OLEFIN ACID SELECTED FROM THE GROUP CONSISTING OF ACRYLIC ACID AND METHACRYLIC ACID AND OF A BIFUNCTIONAL ALCOHOL HAVING AN ESTERIFIABLE HYDROXYL GROUP AND AT LEAST ONE ADDITIONAL HYDROPHILIC FUNCTIONAL GROUP, WITH A WATER-SOLUBLE DIESTER OF AN OLEFINIC ACID SELECTED FROM SAID GROUP AND OF AN ALCOHOL HAVING AT LEAST TWO ESTERIFIABLE HYDROXYL GROUPS, SAID DIESTER BEING PRESENT IN AN AMOUNT NOT TO EXCEED ONE MOL PERCENT OF SAID MONOESTER, IMMERSING AN ELONGATED INSERT IN THE AQUEOUS MIXTURE SO PRODUCED, CAUSING SAID MIXTURE TO REACT SO AS TO FORM A SHAPE-RETAINING BODY OF A CROSS-LINKED COPOLYMER OF SAID MONOESTER AND SAID DIESTER ABOUT SAID INSERT, SAID INSERT BEING COATED WITH A COATING OF SAID COPOLYMER PRIOR TO BEING IMMERSED IN SAID MIXTURE, AND REMOVING SAID INSERT SO AS TO FORM AN ELONGATED OPENING IN SAID BODY OF COPOLYMER.