Aqueous casting solutions for the production of light-polarizing sheets or films based on polyvinyl alcohol

US5093401A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Uwe Claussen · Leverkusen, DE
• Friedrich W. Krock · Odenthal, DE

Key dates

• Filing date: Dec 11, 1989
• Grant date: Mar 3, 1992
• Expiry date: Dec 11, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08K5/053
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Casting solutions for the production of light-polarizing films or sheets contain, relative to the sum of weights (A)+(B)+(C)+(D)=100% by weight, (A) 30-95% by weight, preferably 40-75% by weight, of water, (B) 1-40% by weight, preferably 4-30% by weight, of vinyl, alcohol polymer, (C) 0.01-5% by weight, preferably 0.02-2% by weight, of the dichroic dyestuff, (D) 0.1-75% by weight, preferably 0.5-50% by weight, of one or several organic compounds from the group consisting of aliphatic polyols having 2-6 C atoms, aliphatic ether polyols having 2-6 C atoms, C.sub.1 -C.sub.4 -alkyl ethers of aliphatic polyols having 2-6 C atoms, aliphatic aminoalcohols having 2-4 C atoms, amides of aliphatic C.sub.1 -C.sub.4 -carboxylic acids, and, if desired, a C.sub.1 -C.sub.4 -monoalcohol, and, if desired (E) further additives customary for casting solutions, for example stabilizers, and wherein if using glycerol solely, the weight ratio of glycerol: vinylalcohol polymer is about 0.2-1:1, preferably 0.3-0.5:1.