Cross-linked membranes of polyvinyl alcohol

• US 3,232,916 A
• Filed: 04/17/1962
• Issued: 02/01/1966
• Est. Priority Date: 04/17/1962
• Status: Expired due to Term

• Current Assignee: Allied Corp. (Honeywell International Inc.)
• Original Assignee: Merlyn W. Fogle
• Inventors: Fogle, Merlyn W.
• Application Number:
  US04/188,246
• Time in Patent Office: 1,386 Days
• US Class Current: 525/56
• CPC Class Codes: B01D 71/381 Polyvinylalcohol
• CPC Class Codes: B01D 71/383 Polyvinylacetates
• CPC Class Codes: C08F 16/06 Polyvinyl alcohol ; Vinyl alcohol
• CPC Class Codes: C08F 2810/20 leading to a crosslinking, either explicitly or inherently
• CPC Class Codes: C08F 8/00 Chemical modification by after-treatment graft polymers, block polymers, crosslinking with unsaturated monomers or with polymers C08F251/00 - C08F299/00; of conjugated diene rubbers C08C
• CPC Class Codes: C08K 3/38 Boron-containing compounds
• CPC Class Codes: C08K 5/1515 Three-membered rings
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids

Claims

1. THE PROCESS OF MAKING WATER INSOLUBLE FILMS COMPRISING DISSOLVING PARTIALLY SAPONIFIED POLYVINYL ACETATE BEING IN A WATER-ALCHOL SOLUTION, SAID POLYVINYL ACETATE BEING SAPONIFIED TO THE EXTENT THAT IT IS SOLUBLE IN THE WATERALCOHOL SOLUTION, ADDING THERETO DIGLYCIDYL ETHER OF GLYCERINE AND FLUOROBORIC ACID,FORMING THE FILM FROM THE SOLUTION, DRYING THE FILM, CURING THE FILM AT AN ELEVATED TEMPERATURE, AND THEREAFTER REMOVING THE ACETATE FROM THE FILM BY IMMERSION THE FILM IN A SOLUTION OF SODIUM HYDROXIDE AND WATER.

6. A FILM OF POLYVINYL ALCOHOL WHICH IS INSOLUBLE IN ACIDIC AND BASIC AQUEOUS SOLUTIONS OF ELECTROLYTES, HAVING CROSS-LINKING GROUPS BETWEEN THE POLYMER MOLECULES, FORMED WHEN A COMPOUND OF DIGLYCIDYL ETHER OF BIS (4,4'"'"''"'"' HYDROXY PHENOL) METHANE REACTS IN THE PRESENCE OF A FLUOBORIC ACID CATALYST WITH THE POLYMER MOLECULES TO FORM ETHER-TYPE BONDS WHICH ARE STABLE TOWARD BOTH ACIDIC AND BASIC AQUEOUS SOLUTIONS.