Reticulated polyurethane foams and process for their production

• US 3,171,820 A
• Filed: 02/17/1964
• Issued: 03/02/1965
• Est. Priority Date: 02/17/1964
• Status: Expired due to Term

• Current Assignee: Robert A. Volz
• Original Assignee: Robert A. Volz
• Inventors: Volz, Robert A.
• Application Number:
  US04/345,352
• Time in Patent Office: 379 Days
• US Class Current: 521/61
• CPC Class Codes: B01D 39/1676 of synthetic origin
• CPC Class Codes: C08J 9/38 Destruction of cell membranes
• CPC Class Codes: Y10S 261/72 Packing elements
• CPC Class Codes: Y10S 273/08 Urethane
• CPC Class Codes: Y10S 297/01 Foam
• CPC Class Codes: Y10S 521/918 Physical aftertreatment of a cellular product
• CPC Class Codes: Y10S 55/13 Polyurethane filters
• CPC Class Codes: Y10S 55/42 Foam filter materials

Claims

1. A 3-DIMENSIONAL NETWORK OF INTERCONNECTING STRANDS OF POLYURETHANE RESIN FORMED BY THE REACTION OF AN ORGANIC POLYISOCYANATE WITH A POLYMER SELECTED FROM AT LEAST ONE MEMBER OF THE GROUP CONSISTING OF POLYALKYLENE ETHER GLYCOLS, POLYALKYLENE ETHER AMINES PRODUCED BY THE REACTION OF ALKYLENEOXIDES WITH POLYAMINES AND POLYESTERS PRODUCED BY THE REACTION OF POLYHYDRIC ALCOHOLS WITH POLYCARBOXYLIC ACIDS, SAID STRANDS BEING INTEGRALLY INTERCONNECTED BY THICKENED NEXUS AT SPACED APART POINTS SO AS TO FORM THE ISOTROPIC SKELETAL OUTLINE OF A MULTITUDE OF POLYHEDRONS WHOSE FACES ARE POLYGONAL, ARE COMMON TO A POLYHEDRON ADJACENT THERETO AND ARE OPEN AND FREE FROM MEMBRANEOUS POLYURETHANE RESIN, SAID NETWORK BEING SUBSTANTIALLY FREE FROM PERMEATOIDALLY DEGRADED STRANDS AND NEXUS.

7. THE METHOD OF MAKING A 3-DIMENSIONAL NETWORK OF INTERCONNECTING STRANDS OF POLYURETHANE RESIN WHICH COMPRISES SUBJECTING A FOAMED OPEN CELL CELLULAR STRUCTURE FORMED OF A HYDROLYZABLE POLYURETHANE RESIN TO THE HYDROLYTIC ACTION OF WATER IN THE PRESENCE OF AN ALKALI-METAL HYDROXIDE AS HYDROLYSIS CATALYST IN SUFFICIENT CONCENTRATION TO ACTIVATE HYDROLYSIS AT A TEMPERATURE OF AT LEAST 20*C. AND TO EFFECT IN THE FOAM A WEIGHT LOSS OF FROM 0.5% TO ABOUT 41.8%, AS THE RESULT OF THE REMOVAL OF A PORTION OF THE FOAM, PRIMARILY THE CELL FACES THEREOF, ARRESTING FURTHER HYDROLYTIC ACTION ON SAID FOAM, DRYING THE TREATED FOAM AND RECOVERING A SKELETAL NETWORK STRUCTURE.