A method of making polyurethane or polyurethane urea strands containing siloxane in the polyurethane or polyurethane urea backbone including the steps of: (a) reacting a macroglycol with a diisocyanate to form a prepolymer; (b) reacting the prepolymer with a diamine to form a spinning solution; (c) spinning the spinning solution to form polyurethane or polyurethane urea strands, wherein: i. a diol-polydimethylsiloxane is reacted with the macroglycol and the diisocyanate in step (a); ii. a diamine-polydimethylsiloxane is reacted with the prepolymer prior to the reaction of the prepolymer with the diamine in step (b); or iii. a diamine-polydimethylsiloxane is reacted at the same time as the prepolymer and diamine in step (b), and wherein the polyurethane or polyurethane urea strands comprise less than or equal to 6% of siloxane by weight based on the weight of the polyurethane or polyurethane urea strands and elastic fibers made thereby. An elastic fiber including two or more polyurethane or polyurethane urea strands including siloxane in the polyurethane or polyurethane urea backbone that are bundled together, wherein the siloxane is present in an amount of greater than or equal to 0.01% and less than or equal to 4.0% by weight based on the weight of the fiber. In some aspects, the siloxane is free of urethane radicals.

A method of making polyurethane or polyurethane urea strands containing siloxane in the polyurethane or polyurethane urea backbone including the steps of: (a) reacting a macroglycol with a diisocyanate to form a prepolymer; (b) reacting the prepolymer with a diamine to form a spinning solution; (c) spinning the spinning solution to form polyurethane or polyurethane urea strands, wherein: i. a diol-polydimethylsiloxane is reacted with the macroglycol and the diisocyanate in step (a); ii. a diamine-polydimethylsiloxane is reacted with the prepolymer prior to the reaction of the prepolymer with the diamine in step (b); or iii. a diamine-polydimethylsiloxane is reacted at the same time as the prepolymer and diamine in step (b), and wherein the polyurethane or polyurethane urea strands comprise less than or equal to 6% of siloxane by weight based on the weight of the polyurethane or polyurethane urea strands and elastic fibers made thereby. An elastic fiber including two or more polyurethane or polyurethane urea strands including siloxane in the polyurethane or polyurethane urea backbone that are bundled together, wherein the siloxane is present in an amount of greater than or equal to 0.01% and less than or equal to 4.0% by weight based on the weight of the fiber. In some aspects, the siloxane is free of urethane radicals.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope. ##STR00001##
In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope. ##STR00001##
In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.

A dye composition and a dyeing method for an elastic fabric are provided. The dyeing method includes: (a) providing an elastic fabric which includes an elastic fiber; and (b) immersing the elastic fabric in a dye composition. The dye composition includes an ion modifier and a dye. The elastic fiber of the elastic fabric has a first ion by contacting the ion modifier, and the first ion has a first charge; the dye has a second ion, and the second ion has a second charge opposite to the first charge. The first ion of the elastic fiber and the second ion of the dye together form an ionic bonding.

A dye composition and a dyeing method for an elastic fabric are provided. The dyeing method includes: (a) providing an elastic fabric which includes an elastic fiber; and (b) immersing the elastic fabric in a dye composition. The dye composition includes an ion modifier and a dye. The elastic fiber of the elastic fabric has a first ion by contacting the ion modifier, and the first ion has a first charge; the dye has a second ion, and the second ion has a second charge opposite to the first charge. The first ion of the elastic fiber and the second ion of the dye together form an ionic bonding.

The present invention is directed to a reactive dye-dyeable polyurethane-urea elastic yarn including a reaction product of at least two polyols, a diisocyanate compound, a diamine chain extender, an amine chain terminator, and a diethylenetriamine compound, wherein one of the polyols is polyethylene glycol, which is included in an amount of 20 to 30.0 mol % based on the total amount of the polyols, a polyurethane-urea polymer includes 10 meq/kg to 45 meq/kg of primary amine ends, and the capping ratio (CR) of the diisocyanate to the polyols is 1.8 to 2.0.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope.

##STR00001##

In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope.

##STR00001##

In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope. ##STR00001##
In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, l, m and n is 0 or a positive number.