Non-crosslinked, crosslinkable polyurethane
A non-crosslinked, crosslinkable polyurethane has an acid number of 20-40 and a glass transition temperature of up to and including 40° C. It can be derived from an aromatic diisocyanate; and a diol mixture of at least D 1 , D 2 , D 3 , and D 4 diols. D 1 has a C 3 to C 7 aliphatic group and at least one pendant carboxy group or pendant neutralized carboxy group. D 2 has a chain of repeating C 2 to C 6 alkylene oxide groups and a molecular weight of 250-3000. D 3 is an alkoxylated bisphenol A or aliphatic cyclic diol present in an amount of at least 5 mol %. D 4 is a hydroxy-terminated polybutadiene having a molecular weight of at least 1000, and is present in an amount of at least 0.1-5 mol %.
1. A non-crosslinked, crosslinkable polyurethane having an acid number of at least 20 and up to and including 40, and a glass transition temperature (T g ) of up to and including 40° C.,
the non-crosslinked, crosslinkable polyurethane derived from:
1) an aromatic diisocyanate; and
2) a diol mixture of at least D 1 , D 2 , D 3 , and D 4 diols,
wherein:
the D 1 diol comprises a C 3 to C 7 aliphatic group between two hydroxy groups, and at least one pendant carboxy group or pendant neutralized carboxy group,
the D 2 dial comprises a chain of one or more repeating C 2 to C 6 alkylene oxide groups and has a molecular weight of at least 250 and up to and including 3,000,
the D 3 diol is an alkoxylated bisphenol A or an aliphatic cyclic diol that is present in an amount of at least 5 mol %, based on the total molar amount of the at least D 1 through D 4 diols in the diol mixture, and
the D 4 diol is a hydroxy-terminated polybutadiene having a molecular weight of at least 1000, and is present in an amount of at least 0.1 mol % and up to and including 5 mol %, based on the total molar amount of the at least D 1 through D 4 diols in the diol mixture.
2. The non-crosslinked, crosslinkable polyurethane of claim 1 , having an acid number of at least 20 and up to and including 35.
3. The non-crosslinked, crosslinkable polyurethane of claim 1 , having a glass transition temperature (T g ) of at least 10° C. up to and including 40° C.
4. The non-crosslinked, crosslinkable polyurethane of claim 1 , having a weight average molecular weight (M w ) of at least 20,000 and up to and including 150,000.
5. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 1 diol comprises a C 3 to C 5 aliphatic group between the two hydroxy groups.
6. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 2 diol comprises a chain of repeating C 3 or C 4 alkylene oxide groups and has a molecular weight of at least 250 and up to and including 1,000.
7. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 3 diol comprises an alkoxylated bisphenol A.
8. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 3 diol is present in an amount of at least 5 mol % and up to and including 30 mol %, based on the total molar amount of the at least D 1 through D 4 diols in the diol mixture.
9. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 3 diol is present in an amount of at least 8 mol % and up to and including 25 mol %, based on the total molar amount of the at least D 1 through D 4 diols in the diol mixture.
10. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 4 diol has a molecular weight of at least 1,000 and up to and including 7,000.
11. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 4 diol is present in an amount of at least 0.2 mol % and up to and including 2 mol %, based on the total molar amount of the D 1 through D 4 diols in the dial mixture.
12. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 1 diol is present in an amount of at least 25 mol % and up to and including 40 mol %, the D 2 diol is present in an amount of at least 30 mol % and up to and including 75 mol %, the D 3 diol is present in an amount of at least 8 mol % and up to and including 25 mol %, and the D 4 diol is present in an amount of at least 0.3 mol % and up to and including 1.5 mol %, all based on the total molar amount of the at least D 1 through D 4 diols in the diol mixture.
13. The non-crosslinked, crosslinkable polyurethane of claim 1 , having an acid number of at least 25 and up to and including 35 and a glass transition temperature (T g ) of at least 10° C. up to and including 40° C., and wherein the aromatic diisocyanate is 4,4′-methylenebis(phenylisocyanate), the D 1 diol is 2,2′-bis(hydroxymethyl)propionic acid or a neutralized form thereof, the D 2 diol is poly(tetramethylene glycol) (M n of 650), the D 3 diol is bisphenol A bis(2-hydroxypropyl) ether, and the D 4 diol is hydroxyl terminated poly(butadiene).
14. The non-crosslinked, crosslinkable polyurethane of claim 1 , having a weight average molecular weight (M w ) of at least 35,000 and up to and including 120,000.
15. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 1 diol has an acyclic aliphatic group and a carboxy group that is attached to the acyclic aliphatic group at least one carbon atom removed from each hydroxy group.
16. The non-crosslinked, crosslinkable polyurethane of claim 1 , wherein the D 1 diol is at least partially neutralized using ammonium hydroxide, dimethylaminoethanol, or potassium hydroxide.