Abstract The present invention relates to a process of producing a polymer suitable for manufacturing spandex filament having remarkable elastic recovery rate and heat-setting efficiency wherein the process comprises: stirring a mixture of a glycol and a diisocyante, where the molar ratio of diisocyanate to glycol is 1.5 to 1.64, in a homogenizer at about 40° to about 50° C. and reacting said mixture to give a first polymer containing less than 4 mole % of unreacted diisocyanate; then, reacting said polymer with a chain-extender mixture containing ethylenediamine, 1,2-diaminopropane, and diethylenetriamine, preferably, about 74 to about 80 mole % of ethylenediamine, about 19 to about 25 mole % of 1,2-diaminopropane and about 0.2 to about 0.8 mole % of diethylenetriamine. Elastic polyurethaneurea-based spandex filament is produced by dry-spinning the polymer.
A process for producing a polymer suitable for manufacturing polyurethane-based filament comprising: stirring a mixture of a glycol and a diisocyante, where the molar ratio of diisocyanate to glycol is about 1.5 to about 1.64, in a homogenizer and reacting said mixture to give a first polymer containing less than 4 mole % of unreacted diisocyanate; then reacting said polymer with a chain-extender mixture containing ethylenediamine, 1,2-diaminopropane and diethylenetriamine.
Claim 2
Dependent Claim
69 words
A process for producing a polymer suitable for manufacturing polyurethane-based filament comprising: stirring a mixture of a glycol and a diisocyante, where the molar ratio of diisocyanate to glycol is about 1.5 to about 1.64, in a homogenizer and reacting said mixture to give a first polymer containing less than 4 mole % of unreacted diisocyanate; then reacting said polymer with a chain-extender mixture containing ethylenediamine, 1,2-diaminopropane and diethylenetriamine.
Claim 3
Dependent Claim
39 words
A process according to claim 1 wherein said chain-extender mixture comprises about 74 to about 80 mole % of ethylenediamine, about 19 to about 25 mole % of 1,2-diaminopropane and about 0.2 to about 0.8 mole % of diethylenetriamine.
Claim 4
Dependent Claim
20 words
A process according to claim 1 wherein polytetramethylene ether glycol (number average molecular weight: 1700-2000) is used as the glycol.
Claim 5
Dependent Claim
13 words
A process according to claim 1 wherein p,p'-methylenediphenyldiisocyanate is used as the diisocyanate.
Claim 6
Dependent Claim
25 words
A process according to claim 1 wherein the mixture of glycol and diisocyanate is stirred in a homogenizer at about 40° to about 50° C.
Claim 7
Dependent Claim
27 words
A process of manufacturing an elastic polyurethane-based spandex filament wherein the polymer produced by the process of claim 1 is dry spun at 220° to 280° C.
Claim 8
Dependent Claim
41 words
A process according to claim 6 wherein the elastic recovery rate of said elastic filament before heat-setting treatment is in the range of 19.5 to 24% and the elastic recovery rate after heat-setting treatment is in the range 13 to 18%.