Polyurethane pressure-sensitive adhesives
AssigneeE. R. Squibb & Sons, Inc.
InventorsAgis Kydonieus, Ladislav Bastar, Kishore Shah, Khosrow Jamshidi, Tak-lung Chang, Sheng-hung Kuo
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AssigneeE. R. Squibb & Sons, Inc.
InventorsAgis Kydonieus, Ladislav Bastar, Kishore Shah, Khosrow Jamshidi, Tak-lung Chang, Sheng-hung Kuo
Estimating the term…
Pressure-sensitive adhesives which possess absorptivity and/or permeability properties to remove transepidermal water loss and/or other bodily fluids that come into contact with the adhesive, in combination with a fine balance of cohesion and adhesion properties, can be formulated by controlling the crosslinking of a polyurethane polymer having excess hydroxyl functionality, a glass transition temperature of less than about 0.degree. C., a moisture absorption of at least about 20% of its weight and/or a moisture vapor transmission rate of at least about 300 grams/meter.sup.2 /24 hours measured at 37.degree. C. and a 90% relative humidity gradient. Adhesives of these polymers possess a peel adhesion to human skin of between about 0.3 and 4 newtons/cm width of the polymer or adhesive.
A pressure-sensitive adhesive comprising a polyurethane polymer formed by the reaction of an isocyanate component and a polyol component having a molecular weight between about 1,000 and 10,000, said components being reacted at a molar ratio of isocyanate moieties to hydroxyl moieties of less than one, said polymer being free from any added tackifying and plasticizing agents, said polymer having a glass transition temperature of less than about 0.degree. C., a moisture absorption at equilibrium of at least 20% of its weight, and a peel adhesion to human skin of between about 0.3 and 4 newtons/cm width of the polymer, wherein said isocyanate and said polyol components each have a functionality of at least two and wherein at least one of said components has a functionality that is greater than 2, and further wherein said polyurethane polymer is crosslinked to a crosslink density .alpha. of between about 10.sup.-4 and 10.sup.-3 wherein .alpha. is defined by the equation ##EQU5## where i=1 to n where n is the number of the reactant components;
A method for making a pressure-sensitive adhesive for application to skin which comprises:
Dependencies are inferred from the claim text.