Moisture vapor permeable materials

• US 5,120,813 A
• Filed: 01/04/1991
• Issued: 06/09/1992
• Est. Priority Date: 02/29/1980
• Status: Expired due to Fees

• Current Assignee: Th. Goldschmidt AG (Rag-Stiftung)
• Original Assignee: Th. Goldschmidt AG (Rag-Stiftung)
• Inventors: Ward, Robert S. Jr.
• Primary Examiner(s): Bleutge, John C.
• Assistant Examiner(s): DEAN JR, RALPH H
• Application Number:
  US07/638,136
• Time in Patent Office: 522 Days
• Field of Search: 525/403, 525/453, 528/66, 528/28, 528/29
• US Class Current: 528/28
• CPC Class Codes: A61L 33/062 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 33/068 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L33/062 takes precedence
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/61 Polysiloxanes
• CPC Class Codes: C08G 77/455 containing polyamide, polyesteramide or polyimide sequences
• CPC Class Codes: C08G 77/458 containing polyurethane sequences
• CPC Class Codes: C08G 77/46 containing polyether sequences
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C08L 83/00 Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 83/12 containing polyether sequences

Abstract

Polymeric materials are provided characterized by hard segments and copolymer soft blocks comprising hydrophobic and hydrophilic components. The polymeric materials may be mixed with a base polymer and/or inorganic salts. The polymeric materials and mixtures containing same are characterized by improved moisture vapor transmission rates. The polymeric materials may be formed into films for use as wound dressings, burn dressings, surgical drapes, semipermeable membranes, and coatings for textiles.

Claims

1. A nonporous segmented block multipolymer film impermeable to liquid water and characterized by a high moisture vapor transmission rate comprising an essentially linear segmented copolymer chain characterized by

a) at least one hard segment, and

b) at least two soft segments,

a1) said hard segment being selected from the group consisting of reaction products of organic diisocyanates with

a11) a diamine, and

a12) a diol,

b1) said soft segments comprising

b11) at least one hydrophilic soft segment, and

b211) said hydrophilic soft segment,

b111) said hydrophilic soft segment consisting of ethylene oxide and up to at most 20% by weight of propylene oxide,

b211) said hydrophobic soft segment consisting of polytetramethylene oxide,

whereby the hydrophilic and the hydrophobic soft segments are separated from each other by hard segments.

2. A film according to claim 1, wherein said organic diisocyanate is selected from the group consisting of diphenylmethane diisocyanate and dicyclohexyl diisocyanate.

3. A film according to claim 1, which further comprises up to 2% by weight of a polydialkylsiloxane segment.

4. A film according to claim 1, comprising:

space="preserve" listing-type="tabular">______________________________________ 15-50% by weight of said hard segment 20-45% polyethylene oxide with a number average mol weight of between 1000-3000 25-65% polytetramethylene oxide 100% ______________________________________

5. A film according to claim 3, wherein the polydialkylsiloxane is polydimethylsiloxane.