Articles comprising aqueous dispersions of polyureaurethanes
View Patent ↗Polyurethane particles dispersed in water can be used to make articles of commerce with reduced chance of chemical and biological allergic reaction to skin, and which exhibit improved puncture and tear resistance when compared to gloves made with other materials.
1. An article made from a polyureaurethane aqueous dispersion; said dispersion comprising a water miscible organic solvent and a polyureaurethane comprising a THF copolymer soft segment comprising 25 to 60 percent by weight of ethylene glycol as a comonomer and an aromatic diisocyanate.
2. The article of claim 1 , wherein said article is selected from the group consisting of gloves, finger cots and condoms.
3. The article of claim 1 , having a tensile strength of greater than 2030 psi.
4. The article of claim 1 , having a puncture strength of at least 200 lb/in.
5. The article of claim 1 , having a tear strength per thickness of material of at least 20 Newtons/mm.
6. The article of claim 1 , having an improved resistance to solvent attack.
7. A process for producing an article made from a polyureaurethane aqueous dispersion; said dispersion comprising a water miscible organic solvent and a polyureaurethane comprising a THF copolymer soft segment comprising 25 to 60 percent by weight of ethylene glycol as a comonomer and an aromatic diisocyanate, comprising the steps:
a) dipping a mold into a coagulant solution and drying at an elevated temperature;
b) dipping the coagulant solution-coated mold into an aqueous polyureaurethane dispersion and drying;
c) subjecting the coated mold to a salt leaching bath; and
drying the coated mold at elevated temperature before stripping the article off of said mold.