Photocurable flexible orthopedic bandage

A method for producing a storage-stable flexible photocurable orthopedic material such as a bandage or splint for application to a body member, comprising a flexible fabric, a photosensitizer and a photocurable tacky composition containing at least one compound containing at least two carbon-carbon double bonds capable of being polymerized and crosslinked by light and being substantially free from free isocyanate groups, said method comprising the steps of:

• 1. a first step of reacting (A) at least one hydroxyalkyl acrylate or hydroxyalkyl methacrylate wherein said hydroxyalkyl portion contains 2 or 3 carbon atoms, with (B) 0.55 to 3 moles, per mole of the hydroxyalkyl acrylate or hydroxyalkyl methacrylate, of at least one diisocyanate of the formula
• OCN--NCO
• wherein R.sub.1 is (CH.sub.2).sub.6, ##STR5## to form a reaction product (D) containing remaining free isocyanate groups,
• 2. a second step of adding (C) at least one polyhydric alcohol of the following formula
• R.sub.2 (OH).sub.m
• wherein R.sub.2 represents a straight-chain or branched chain aliphatic hydrocarbon group containing 2 to 8 carbon atoms, a cycloaliphatic hydrocarbon group or the group ##STR6## in which n is a number of 1 to 4, and R.sub.3 is a hydrogen atom or a methyl group, and m is 2, wherein the amount of the polyhydric alcohol (C) is one which affords 1.05 to 1.5 equivalents, of hydroxyl groups based on the remaining isocyanate groups in the reaction product (D) of the first step,
• to form a reactive composition,
• 3. a third step of impregnating the flexible fabric with the reactive composition in the absence of a solvent,
• 4. adding photosensitizer either in the first, second or third step, and
• 5. a fourth step of completing the reacton of the free isocyanate groups in the impregnated composition with the polyhydric alcohol (C).

A method for producing a storage-stable flexible photocurable orthopedic material such as a bandage or splint for application to a body member, comprising a flexible fabric, a photosensitizer and a photocurable tacky composition containing at least one compound containing at least two carbon-carbon double bonds capable of being polymerized and crosslinked by light and being substantially free from free isocyanate groups, said method comprising the steps of:

• 1. a first step of reacting (A) at least one hydroxyalkyl acrylate or hydroxyalkyl methacrylate wherein said hydroxyalkyl portion contains 2 or 3 carbon atoms with (B) 0.55 to 3 moles, per mole of the hydroxyalkyl acrylate or methacrylate, of at least one diisocyanate of the formula
• OCN--R.sub.1 --NCO
• wherein R.sub.1 represents (CH.sub.2).sub.6, ##STR7## to form a reaction product (D) containing remaining free isocyanate groups,
• 2. a second step of adding (C) at least one polyhydric alcohol of the following formula
• R.sub.2 (OH).sub.m
• wherein R.sub.2 represents a straight-chain or branched chain aliphatic hydrocarbon group containing 2 to 8 carbon atoms, a cycloaliphatic hydrocarbon group, or the group ##STR8## in which n is a number of 1 to 4 and R.sub.3 is a hydrogen atom or a methyl group, and m is 2, wherein the amount of the polyhydric alcohol is one which affords 1.05 to 1.5 equivalents, of hydroxyl groups based on the isocyanate groups remaining in the reaction product (D) of the first step,
• to form a reaction product (D) containing substantially no free isocyanate groups,
• 3. a third step of impregnating the flexible fabric with a solution of the reaction product of the second step,
• 4. adding a photosensitizer and a solvent inert to the isocyanate groups either in the first, second or third step, and
• 5. volatilizing the solvent form the impregnated solution.