HK1176385B - Spandex with high uniformity - Google Patents

Description

spandex with high uniformity

Background

Technical Field

The present invention relates to very uniform spandex (spandex) and a process for making the spandex. In more detail, the polyurethaneurea from which the spandex is prepared has both dialkylurea and cycloalkylurea ends, with the chain terminator composition including a dialkylamine such as diethylamine and a cycloalkylamine such as cyclohexylamine.

Description of the related Art

U.S. patent No. 6,503,996 discloses spandex compositions having high uniformity. The composition comprises alkyl carbamate ends derived from monoalcohol chain terminators and monoalkylurea chain terminators. Due to the relative reaction rates, the monol must be added to the polyol and isocyanate during the preparation of the capped glycol, rather than being added with the monoalkylurea chain terminator.

Summary of The Invention

Some aspects are spandex with high uniformity, which is particularly useful for warp knitting or high content weft knitting (including circular knitting). The present invention includes articles comprising at least one spandex fiber or yarn comprising a polyurethaneurea that is the reaction product of:

(a) a capped glycol comprising the reaction product of:

(i) a polyol selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, and combinations thereof; and

(ii) a diisocyanate;

(b) a chain extender comprising at least a first diamine and a second diamine; and

(c) a chain terminator composition comprising a monofunctional amine comprising cyclohexylamine;

wherein the polyurethaneurea comprises a first diamine and a second diamine in a molar ratio of about 75:25 to about 85: 15; and a cyclohexylurea terminus of from about 10meq/Kg to about 30 meq/Kg.

The present invention also provides a method of making spandex comprising:

(a) providing a polyol selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, and combinations thereof;

(b) providing a diisocyanate;

(c) contacting the polyol with the diisocyanate to form a capped glycol;

(d) providing a chain extender comprising at least a first diamine and a second diamine;

(e) providing a chain terminator composition comprising a monofunctional amine comprising cyclohexylamine;

(f) contacting the capped glycol, the chain extender, and the chain terminator composition in a solvent to form a polyurethaneurea in solution; and

(g) spinning the polyurethaneurea in solution to form the spandex,

wherein the polyurethaneurea comprises a first diamine and a second diamine in a ratio of about 75:25 to about 85: 15; and a cyclohexylurea terminus of from about 10meq/Kg to about 30 meq/Kg.

Detailed Description

Spandex with high fiber uniformity has been prepared with some aspects of the polyurethaneurea compositions. The polyurethaneurea composition comprises: a chain extender composition comprising a blend or mixture of two or more chain extenders, such as diamine chain extenders, and a chain terminator composition comprising cyclohexylamine.

The term "solution spinning" as used herein includes the preparation of fibers from solution, which may be a wet spinning or a dry spinning process, both of which are common techniques for fiber production.

Polyurethaneureas that have been terminated with aliphatic primary amine chains have monoalkylurea ends, e.g., cyclohexylamine as a chain terminator would provide cyclohexylurea ends. Termination with a (secondary) dialkylamine chain gives a dialkylurea end. The amine ends in the polyurethaneurea are derived from incompletely reacted diamine chain extenders. Spandex of some aspects may have diethylurea ends of about 10meq/Kg to about 60meq/Kg, including about 10meq/Kg to about 40meq/Kg, such as about 22meq/Kg to about 26 meq/Kg; (ii) a cyclohexylurea end of from about 10meq/Kg to about 30meq/Kg, such as from about 16meq/Kg to about 20 meq/Kg; and primary amine ends of about 12meq/Kg to about 24meq/Kg, such as about 16meq/Kg to about 20 meq/Kg. (all meq/Kg measurements are based on polymer solids).

Polyurethaneurea compositions useful for preparing fibers or long chain synthetic polymers comprise at least 85% by weight of a segmented polyurethane and are also known as spandex. Typically, these include polymeric diols that are reacted with diisocyanates to form NCO-terminated prepolymers ("capped diols") which are subsequently dissolved in suitable solvents such as dimethylacetamide, dimethylformamide or N-methylpyrrolidone and are secondly reacted with difunctional chain extenders. When the chain extender is a diol, a polyurethane is formed in a second step (and may be prepared without a solvent). When the chain extender is a diamine, a polyurethaneurea (a subclass of polyurethanes) is formed. In the preparation of a polyurethaneurea polymer spinnable into spandex, the diol is chain extended by sequential reaction of hydroxyl end groups with a diisocyanate and one or more diamines. In all cases, the diol must undergo chain extension to provide a polymer with the necessary properties including viscosity. If desired, dibutyl tin dilaurate, stannous octoate, mineral acids, tertiary amines (such as triethylamine, N' -dimethylpiperazine, and the like), and other known catalysts can be used to assist in the capping step.

Suitable polyol or polymeric diol components include polyether diols, polycarbonate diols, and polyester diols having number average molecular weights of about 600 to about 3,500, including about 1600 to about 2200 and about 1800. Mixtures or copolymers of two or more polymeric glycols may be included.

Examples of polyether diols that can be used include diols having two or more hydroxyl groups derived from the ring-opening polymerization and/or copolymerization of ethylene oxide, propylene oxide, oxetane, tetrahydrofuran, and 3-methyltetrahydrofuran, or from the polycondensation of polyols such as diols or diol mixtures (having less than 12 carbon atoms in each molecule, such as ethylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 2-dimethyl-1, 3-propanediol, 3-methyl-1, 5-pentanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol, and 1, 12-dodecanediol). Linear, difunctional polyether polyols are preferred, and poly (1, 4-butylene ether) glycols having a functionality of 2 and a molecular weight of from about 1,700 to about 2,100, such as Terathane 1800 (INVISTA of Wichita, KS) are one example of particularly suitable glycols. The copolymer may comprise poly (1, 4-butylene-co-ethyleneether) glycol.

Examples of the polyester polyol which can be used include ester diols having two or more hydroxyl groups produced by polycondensation reaction of a low molecular weight aliphatic polycarboxylic acid having not more than 12 carbon atoms in each molecule with a polyhydric alcohol or a mixture thereof. Examples of suitable polycarboxylic acids are malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid. Examples of suitable polyols for the preparation of the polyester polyols are ethylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 3-methyl-1, 5-pentanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol and 1, 12-dodecanediol. Linear difunctional polyester polyols having a melting temperature of from about 5 ℃ to about 50 ℃ are examples of specific polyester polyols.

Examples of the polycarbonate polyol that can be used include carbonate diols having two or more hydroxyl groups produced by polycondensation of phosgene, chloroformate, dialkyl carbonate or diallyl carbonate with low-molecular-weight aliphatic polyols having not more than 12 carbon atoms in each molecule or a mixture thereof. Examples of suitable polyols for the preparation of the polycarbonate polyols are diethylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 3-methyl-1, 5-pentanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol and 1, 12-dodecanediol. Linear difunctional polycarbonate polyols having a melting temperature of from about 5 ℃ to about 50 ℃ are examples of specific polycarbonate polyols.

Spandex yarns and fibers prepared from some aspects of the polyurethaneurea compositions can have a Coefficient of Denier Variation (CDV) lower than spandex including dialkyl urea and amine ends. This reduction in the denier variation coefficient is significant. The spandex CDV can vary depending on the denier of the fiber or yarn. For example, the CDV can be about 20 or less. The CDV may be about 18 for a yarn having a denier of 20, about 15 for a yarn having a denier of 30, and about 14 for a yarn having a denier of 40.

The method of some aspects includes contacting a polymeric diol with a diisocyanate to form a capped diol. The capped glycol is contacted with at least a first diamine chain extender and a second diamine chain extender, which may be provided from a blend or mixture, and a chain terminator composition comprising a monofunctional amine such as cyclohexylamine in a solvent, and the resulting polyurethaneurea solution is solution spun to form spandex.

The diisocyanate component may also include a single diisocyanate or a mixture of different diisocyanates, including isomeric mixtures of diphenylmethane diisocyanates (MDI) containing 4,4 '-methylene bis (phenyl isocyanate) and 2,4' -methylene bis (phenyl isocyanate). When an isomeric mixture of MDI is used, the ratio of the 4,4 'isomer to the 2,4' isomer may be from about 100:0 to about 50:50, including from about 98:2 to about 88:12, about 70:30 and about 60: 40. Any suitable aromatic or aliphatic diisocyanate may be included in combination with the 4,4 'isomer of MDI, with 4,4' -MDI being the major component. Examples of diisocyanates that can be used include, but are not limited to, 4 '-methylenebis (phenyl isocyanate), 2,4' -methylenebis (phenyl isocyanate), 4 '-methylenebis (cyclohexyl isocyanate), 1, 3-diisocyanato-4-methyl-benzene, 2' -toluene diisocyanate, 2,4 '-toluene diisocyanate, 5-isocyanato-1- (isocyanatomethyl) -1,3, 3-trimethylcyclohexane, 1, 6-diisocyanatohexane, 2-bis (4-isocyanatophenyl) -propane, 1' -methylenebis (4-isocyanatocyclohexane), 1, 4-diisocyanatocyclohexane, 1, 4-bis (4-isocyanato-alpha, alpha-dimethylbenzyl) benzene, 1-isocyanato-2- [ (4' -isocyanato-phenyl) methyl ] benzene and mixtures thereof. Examples of specific polyisocyanate components include Mondur ML (Bayer), Lupranate MI (BASF) and Isonate 50O, P' (Dow Chemical) and combinations thereof.

Generally, the NCO moiety content in the capped glycol can range from about 2 to about 6 weight percent, including from about 2.3 to about 3.0 weight percent, and from about 2.5 to about 2.7 weight percent.

For solution spinning, the capped glycol can be dissolved in a suitable solvent such as dimethylacetamide ("DMAc"), N-methylpyrrolidone, or dimethylformamide. The optional capping step may be carried out in a solvent such as dimethylacetamide containing less than about 50ppm water and less than about 2000ppm of a combination of formamide and amine, for example, based on the weight of the solvent.

The diamine chain extender composition comprises at least a first diamine and a second diamine, which may be blended or mixed together or added separately to contact the capped diol. Suitable diamines include diamines having 2 to 12 carbons such as ethylene diamine, 1, 3-butanediamine, 1, 4-butanediamine, 1, 3-diamino-2, 2-dimethylbutane, 1, 6-hexanediamine, 1, 2-propanediamine, 1, 3-propanediamine, N-methylaminobis (3-propylamine), 2-methyl-1, 5-pentanediamine, 1, 5-diaminopentane, 1, 3-diamino-4-methylcyclohexane, 1, 3-cyclohexanediamine, 1 '-methylenebis (4,4' -diaminohexane), 3-amino (mino) methyl-3, 5, 5-trimethylcyclohexane, 1, 3-diaminopentane, and mixtures thereof.

The weight ratio of the first diamine to the second diamine can be from about 75:25 to about 85:15, including about 80: 20.

In one aspect, the first diamine may be ethylene diamine and the second diamine such as 2-methyl-1, 5-pentanediamine (MPMD) or additional diamines may be considered "co-chain extenders".

The chain terminator composition comprises cyclohexylamine and may also be combined with other suitable chain terminators such as monoamine chain terminators having 5 to 12 carbons, such as 6 to 7 carbons, e.g., n-pentylamine, n-hexylamine, n-heptylamine, methylcyclohexylamines (e.g., 1-amino-3-methylcyclohexane, 1-amino-2-methylcyclohexane, and 1-amino-3, 3, 5-trimethylcyclohexane), n-dodecylamine, 2-aminonorbornane, 1-adamantylamine, Unsymmetrical Dimethylhydrazine (UDMH), and mixtures thereof. The monoamine may be used in an amount of at least about 2meq/kg and up to about 55meq/kg, based on the total weight of the polymer components.

The polyurethaneurea from which the spandex is prepared and in some aspects spun in the process can have an intrinsic viscosity of from about 0.90 to about 1.20dl/g, including from about 0.95 to about 1.10 dl/g.

Optionally, the polymeric glycol may contain an acid and an acid-producing compound, which may be added prior to the capping step, such as phosphoric acid, benzenesulfonic acid, p-toluenesulfonic acid, sulfuric acid, carboxylic acid chlorides and anhydrides, and phosphate esters, among others. The acid or acid-generating compound may be used in an amount of at least about 10 parts per million and at most about 125 parts per million ("ppm"), based on the weight of the polymeric glycol. Phosphoric acid can be used because of its low corrosiveness.

Various other additives may also be used in the spandex and methods of some aspects in any suitable amount to achieve desired properties. Examples include a matting agent, such as titanium dioxide, in any suitable amount, such as from about 0.05% to about 0.5%, based on the weight of the polymer; stabilizers such as hydrotalcite, mixtures of huntite and hydromagnesite (in any suitable amount, for example, 0.25% to 5.0% based on the weight of the polymer), barium sulfate, hindered amine light stabilizers, UV screeners, hindered phenols and zinc oxide; dyes and dye enhancers; and the like.

Optionally, diethylenetriamine may be used at low levels in the chain extension step to control solution viscosity. Suitable amounts when diethylenetriamine is included include from greater than 0 to about 500ppm or from greater than 0 to about 125ppm, from greater than 0 to about 250ppm, from about 50ppm to about 250ppm, including from about 50ppm to about 125ppm (based on the weight of the polymer).

The polyurethaneurea solution viscosity was determined according to the general method of ASTM D1343-69 with a falling ball viscometer model DV-8 (Duratech corp., Waynesboro, Va.) operating at 40 ℃ and recorded in poise. The highest solution viscosity that can be measured with this instrument is 35,000 poise.

To measure the denier variation coefficient ("CDV"), the first 50 meters of fiber on the surface of the wound spandex package were removed to avoid errors caused by shipping damage. The spandex was then removed from the package using a roller pull for 130 seconds and fed through a tensiometer that included piezo ceramic pins. The circumference of the pulling roll was 50% greater than the circumference of the feed roll and pulling roll were rotated at the same rpm so that the polyurethane fibers were drawn through the tensiometer at 50% elongation. As the spandex feed passes through these rolls, a tensiometer measures the tension. Since denier is directly proportional to tension, the standard deviation of tension is divided by the mean tension to give the coefficient of variation, which is recorded as CDV. CDV is independent of the linear density units used (denier vs. dtex), and low CDV indicates high fiber uniformity.

The total isocyanate moiety content (% by weight of NCO) of the capped glycol is measured by the method of "quantitative organic Analysis via Functional Group" by S. Siggia, third edition, Wiley & Sons, New York, p.559-561 (1963).

The strength and elasticity of spandex were measured according to the general methods of ASTM D2731-72. For each measurement, three filaments, a gauge length of 2-inches (5-cm), and an elongation cycle of 0-300% were used. Samples the samples were cycled 5 times using an Instron tensile tester at a constant elongation of 50 cm/min. The stress on spandex during initial elongation was measured at 200% elongation in the first cycle: load force (LoadPower) ("LP"). At the fifth stageThe Unload force (Unload Power) ("UP") was measured at 200% elongation during the load cycle. Elongation at break ("% ELO") and strength at break ("TEN") were measured at the sixth elongation. The breaking strength, load force and unload force were recorded in Centinewtons (CN). The set is also measured on samples subjected to 5 cycles of 0-300% elongation/relaxation. The set ("% S") was calculated as% S = 100 (L)_f- L_o)/L_oWherein L is_oAnd L_fRespectively, the length of the filament (yarn) when held straight without tension before and after 5 elongation/relaxation cycles.

The intrinsic viscosity ("IV") of the polyurethaneurea was determined according to ASTM D2515 in a standard kanen-Fenske viscometer tube at 25 ℃ by comparing the viscosity of a dilute solution of the polymer in DMAc with the viscosity of DMAc itself ("relative viscosity" method) and is reported as dl/g.

"Meq/kg" means milliequivalents of the component per kilogram of total components (i.e., polymer solids).

The yarn of some aspects may have the following properties:

Claims (14)

1. An article comprising at least one spandex fiber comprising a polyurethaneurea that is the reaction product of:

(a) a capped glycol consisting of the reaction product of:

(i) a polyol selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, and combinations thereof; and

(ii) a diisocyanate;

(b) a chain extender comprising at least a first diamine and a second diamine; and

(c) a chain terminator composition comprising cyclohexylamine and dialkylamine;

wherein the polyurethaneurea comprises the first diamine and the second diamine in a molar ratio of 75:25 to 85: 15; and 10meq/Kg to 30meq/Kg of cyclohexylurea ends.

2. The article of claim 1 wherein said dialkylamine is diethylamine and said polyurethaneurea comprises 10meq/Kg to 60meq/Kg of diethylurea ends.

3. The article of claim 1, wherein said polyurethaneurea comprises primary amine ends in the range of 12meq/Kg to 24 meq/Kg.

4. The article of claim 1, wherein said polyurethaneurea comprises a viscosity stabilizer.

5. The article of claim 4, wherein the viscosity stabilizer is present in an amount of 50ppm to 250 ppm.

6. The article of claim 1 wherein the first diamine comprises ethylenediamine and the second diamine comprises 2-methyl-1, 5-pentanediamine.

7. The article as defined in claim 1, wherein said polyol has a number average molecular weight of 1600-2200.

8. The article of claim 1, wherein the capped glycol has an% NCO of 2.3 to 3.0.

9. The article of claim 1 wherein said capped glycol has an% NCO of 2.5 to 2.7.

10. The article of claim 1, wherein the polyol comprises polytetramethylene ether glycol.

11. The article of claim 1 wherein said diisocyanate comprises diphenylmethane diisocyanate.

12. The article of claim 1, wherein the article is a knit.

13. The article of claim 12, wherein said knit goods are selected from the group consisting of warp knits and circular knits.

14. A method of making spandex comprising:

(a) providing a polyol selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, and combinations thereof; and

(b) providing a diisocyanate;

(c) contacting the polyol with the diisocyanate to form a capped glycol;

(d) providing a chain extender comprising at least a first diamine and a second diamine;

(e) providing a chain terminator composition comprising cyclohexylamine and dialkylamine;

(f) contacting the capped glycol, the chain extender, and the chain terminator composition in a solvent to form a polyurethaneurea in solution; and

(g) spinning the polyurethaneurea in solution to form the spandex,

wherein the polyurethaneurea comprises the first diamine and the second diamine in a molar ratio of 75:25 to 85: 15; and 10meq/Kg to 30meq/Kg of cyclohexylurea ends.