Polyurethane resins, process for producing the same, and uses thereof

In a polyurethane resin having a number average molecular weight of 2,000-200,000 and molecular structure represented by the following general formula (1):

• T.sub.1 --(UP.sub.1 --E.sub.1)-- . . . --(UP.sub.n+1 --E.sub.n+1)--UP.sub.n+2 --T.sub.2 ( 1)
• wherein
• UP.sub.1, UP.sub.2 . . . Up.sub.n+2 is that part of a urethane prepolymer which excludes a terminated isoyanate group, said prepolymer being prepared by reacting an organic diisocyanate compound with a polymer diol compound, provided that n is an integer of 0-18 and that UP.sub.1, UP.sub.2 . . . Up.sub.n+2 have the same or different structures;
• E.sub.1, E.sub.2 . . . E.sub.n+1 is that part of a chain extender which excludes the functional groups reacted with the isocyanate group, said chain extender having at least two functional groups capable of reacting with the isocyanate group, provided that n is an integer of 0-18 and that E.sub.1, E.sub.2 . . . E.sub.n+1 have the same or different structures;
• T.sub.1 and T.sub.2 is a residue of a compound selected from the group consisting of hydrazines, alkylenedihydrazines, alkylenedihydrazides and polyaminohydrazines;
• and
• -- is the bond that has been formed by reaction between the isocyanate group and the functional group capable of reacting with said isocyanate group;
• wherein said polyurethane resin represented by general formula (1) is prepared by reacting an organic diisocyanate compound, a polymer diol compound, a chain extender, and at least one terminator, the improvement wherein said at least one terminator is at least one compound selected from the group consisting of hydrazines, alkylenedihydrazines, alkylenedihydrazides and polyaminohydrazides represented by the following general formula (2):
• ##STR4## wherein R.sub.1 is an alkylene group having 2-15 carbon atoms, that portion of an alicyclic or aromatic diamine having 6-15 carbon atoms which excludes the amino group, or that portion of a polyethylene polyamine having 3-5 nitrogen atoms which excludes a primary amino group;
• and
• R.sub.2 is hydrogen or a methyl group;
• such that at least one member selected from the group consisting of a hydrazine group, a hydrazide group, and a semicarbazide group is incorporated into said polyurethane resin.

A process for producing a polyurethane resin represented by the following formula (1):

• T.sub.1 --(UP.sub.1 --E.sub.1)-- . . . --(UP.sub.n+1 --E.sub.n+1)--UP.sub.n+2 --T.sub.2 ( 1)
• wherein
• UP.sub.1, UP.sub.2 . . . Up.sub.n+2 is that part of a urethane prepolymer which excludes a terminated isocyanate group, said prepolymer being prepared by reacting an organic diisocyanate compound with a polymer diol compound, provided that n is an integer of 0-18 and that UP.sub.1, UP.sub.2 . . . Up.sub.n+2 have the same or different structures;
• E.sub.1, E.sub.2 . . . E.sub.n+1 is that part of a chain extender which excludes the functional groups reacted with the isocyanate group, said chain extender having at least two functional groups capable of reacting with the isocyanate group, provided that n is an integer of 0-18 and that E.sub.1, E.sub.2 . . . E.sub.n+1 have the same or different structures;
• T.sub.1 and T.sub.2 is that part of a terminator which excludes the functional groups reacted with the isocyanate group, said terminator having at least one functional group capable of reacting with the isocyanate group, provided that T.sub.1 and T.sub.2 have the same or different structure;
• and
• -- is the bond that has been formed by reaction between the isocyanate group and the functional group capable of reacting with said isocyanate group;
• said process comprising the steps of:
• reacting an organic diisocyanate compound with a polymer diol compound at a molar ratio of diisocyanate/polymer diol of 1.3/1.0 to 3.0/1.0 to synthesize a urethane prepolymer, then chain extending the polymer using at least one chain extender in an amount 0.5-0.95 times the equivalent amount of residual isocyanate groups,
• wherein said at least one chain extender is polyaminohydrazide represented by the following general formula (2):
• ##STR5## wherein R.sub.1 is an alkylene group having 2-15 carbon atoms, that portion of an alicyclic or aromatic diamine having 6-15 carbon atoms which excludes the amino group, or that portion of a polyethylene polyamine having 3-5 nitrogen atoms which excludes a primary amino group;
• and
• R.sub.2 is hydrogen or a methyl group;
• so that at least one hydrazide group is incorporated into said polyurethane resin,
• and terminating the reaction of any residual isocyanate groups with a terminator,
• wherein the chain extender has at least one hydrazide group so as to incorporate at least one hydrazide group into said polyurethane resin.

A process for producing a polyurethane resin represented by the following formula (1):

• T.sub.1 --(UP.sub.1 --E.sub.1)-- . . . --(UP.sub.n+1 --E.sub.n+1)--UP.sub.n+2 --T.sub.2 ( 1)
• wherein
• UP.sub.1, UP.sub.2 . . . Up.sub.n+2 is that part of a urethane prepolymer which excludes a terminated isocyanate group, said prepolymer being prepared by reacting an organic diisocyanate compound with a polymer diol compound, provided that n is an integer of 0-18 and that UP.sub.1, UP.sub.2 . . . Up.sub.n+2 have the same or different structures;
• E.sub.1, E.sub.2 . . . E.sub.n+1 is that part of a chain extender which excludes the functional groups reacted with the isocyanate group, said chain extender having at least two functional groups capable of reacting with the isocyanate group, provided that n is an integer of 0-18 and that E.sub.1, E.sub.2 . . . E.sub.n+1 have the same or different structures;
• T.sub.1 and T.sub.2 is a residue of a compound selected from the group consisting of hydrazines, alkylenedihydrazines, alkylenedihydrazides and polyaminohydrazides;
• and
• -- is the bond that has been formed by reaction between the isocyanate group and the functional group capable of reacting with said isocyanate group;
• said process comprising the steps of:
• reacting an organic diisocyanate compound with a polymer diol compound at a molar ratio of diisocyanate/polymer diol of 1.3/1.0 to 3.0/1.0 to synthesize a urethane prepolymer, then
• chain extending the polymer using a chain extender in an amount 0.5-0.95 times the equivalent amount of residual isoycyanate groups, and
• terminating the reaction of any residual isocyanate groups with at least one terminator,
• wherein said at least one terminator is at least one compound selected from the group consisting of hydrazines, alkylene dihydrazines, alkylenedihydrazides and polyaminohydrazide, and is represented by the following general formula (2):
• ##STR6## wherein R.sub.1 is an alkylene group having 2-15 carbon atoms, that portion of an alicyclic or aromatic diamine having 6-15 carbon atoms which excludes the amino group, or that portion of a polyethylene polyamine having 3-5 nitrogen atoms which excludes a primary amino group;
• and
• R.sub.2 is hydrogen or a methyl group;
• so that at least one member selected from group consisting of a hydrazine group, a hydrazide group, and a semicarbazide group is incorporated into said polyurethane resin,
• wherein the terminator has at least one hydrazine group or hydrazide group so as to incorporate at least one hydrazine group, hydrazide group or semicarbazide group into said polyurethane resin.