Hydrophilic polyurethane polymers derived from a mdi-based isocyanate-terminated prepolymer
OwnerVerena Thiede, Luigi Pellacani +2inventors
InventorsVerena Thiede, Luigi Pellacani, Netza Lopez, Franklin Parks
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Abstract
The present invention relates an MDI-based isocyanate-terminated prepolymer suitable for preparing a hydrophilic polyurethane polymer. The MDI-based composition comprises a prepolymer obtained by reacting isocyanate mixture comprising 2,4′-methylene diphenylisocyanate (MDI) and 4,4′-methylene diphenylisocyanate in a molar ratio of from 25:75 to 80:20 with a polyether polyol having an oxyethylene content of at least 30 percent by weight.
Claims12
1) A hydrophilic polyurethane polymer prepared by bringing together water and an isocyanate-terminated prepolymer wherein the prepolymer is the reaction product of:
- a) a polyether polyol composition having a nominal hydroxyl functionality of from 1.6 to 8, a molecular weight of from 1000 to 12000 and having at least 30 percent by weight of oxyethylene groups,
- b) with an isocyanate mixture that contains methylene diphenylisocyanate (MDI) in at least about 60 weight percent of the total isocyanate present and wherein the MDI comprises the 2,4′- and 4,4′-methylene diphenylisocyanate isomer in a molar ratio of from 25:75 to 80:20;
- the prepolymer having a free NCO content of from 1 to less than 15 percent by weight.
8) An isocyanate-terminated prepolymer composition that has an isocyanate content of less than 15 weight percent and is the reaction product of:
- a) a polyether polyol composition having a nominal hydroxyl functionality of from 1.6 to 8, a molecular weight of from 1000 to 12000 and having at least 30 percent by weight of oxyethylene groups;
- b) with a stoichiometric excess of an isocyanate mixture that contains methylene diphenylisocyanate (MDI) in at least about 60 weight percent of the total isocyanate present and wherein the MDI comprises the 2,4′- and 4,4′-methylene diphenylisocyanate isomer in a molar ratio of from 25:75 to 80:20.
9) An isocyanate-terminated prepolymer composition that has an isocyanate content of from 2 to 12 weight percent and is the reaction product of:
- a) a polyether polyol having a nominal hydroxyl functionality of from 1.6 to 4, a molecular weight of from 1000 to 5000 and having at least 65 percent by weight of oxyethylene groups;
- with a stoichiometric excess of
- b) an isocyanate mixture that consists essentially of methylene diphenylisocyanate (MDI) wherein the MDI comprises the 2,4′- and 4,4′-methylene diphenylisocyanate isomer in a molar ratio of from 40:60 to 60:40.
10) A process for making a hydrophilic polyurethane foam comprising mixing together an aqueous phase with an isocyanate-terminated prepolymer composition that is the reaction product of:
- a) a polyether polyol composition having a nominal hydroxyl functionality of from 1.6 to 8, a molecular weight of from 1000 to 12000 and having at least 30 percent by weight of oxyethylene groups;
- with a stoichiometric excess of
- b) an isocyanate mixture that contains methylene diphenylisocyanate (MDI) in at least about 60 weight percent of total isocyanate present and wherein the MDI comprises the 2,4′- and 4,4′-methylene diphenylisocyanate isomer in a molar ratio of from 25:75 to 80:20, wherein the isocyanate-terminated prepolymer composition and aqueous phase are present in a parts by weight ratio of from 100:10 to 100:500 and the proviso that the free NCO content of the prepolymer is less than 15 weight percent.
12) A process for making a hydrophilic polyurethane gel comprising mixing together an aqueous phase with an isocyanate-terminated prepolymer composition that is the reaction product of:
- a) a polyether polyol composition having a nominal hydroxyl functionality of from 1.6 to 8, a molecular weight of from 1000 to 12000 and having at least 30 percent by weight of oxyethylene groups;
- with a stoichiometric excess of
- b) an isocyanate mixture that contains methylene diphenylisocyanate (MDI) in at least about 60 weight percent of total isocyanate present and wherein the MDI comprises the 2,4′- and 4,4′-methylene diphenylisocyanate isomer in a molar ratio of from 25:75 to 80:20,
- wherein the isocyanate-terminated prepolymer composition and aqueous phase are present in a parts by weight ratio of from 100:900 to 100:5000 and the proviso that the free NCO content of the prepolymer is less than 15 weight percent.
Dependencies are inferred from the claim text.