Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2001-06-28
2002-06-11
Szekely, Peter (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S190000, C524S236000, C524S590000
Reexamination Certificate
active
06403682
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to spandex containing quaternary amine additives and, more specifically, to additives where quaternary amine groups are incorporated into a polyurethane oligomer or are part of a nonoligomeric structure.
2. Description of Background Art
Spandex and spandex-containing fabrics and garments are typically heat-set to provide the fiber or fabric with good dimensional stability and to shape the finished garment. Typical heat-setting temperatures used in commercial operations are 195° C. for fabrics containing spandex and 6,6-nylon, 190° C. when the fabric contains 6-nylon, and 180° C. when the fabric contains cotton. It is desirable to heat-set fabrics containing cotton and spandex, but if the spandex has adequate heat-set efficiency only at temperatures used for nylon-containing fabrics, the spandex cannot be properly heat-set in cotton-containing fabrics, which will be damaged by exposure to the required high temperatures. A variety of methods have been used to improve the heat-set efficiency of spandex and thereby lower the temperature at which the spandex can be heat-set. For example, U.S. Pat. No. 5,539,037 discloses the use of low concentrations of alkali metal carboxylates and thiocyanate in spandex to increase its heat-set efficiency. However, such salts are readily dissolved during fabric processing, and their effectiveness is thereby reduced. U.S. Pat. Nos. 5,948,875 and 5,981,686 disclose the use of high proportions of 2-methyl-1,5-pentanediamine and 1,3-diaminopentane chain extender, respectively, to increase the heat-set efficiency of spandex, but making such changes to the polymer can deleteriously affect the fiber properties, and the production flexibility possible with additives is lost.
According to U.S. Pat. No. 3,294,752, quaternary amine moieties can be chemically incorporated into the segmented polyurethane chain from which spandex is made, but there is no disclosure of such incorporation on the effect, if any, on heat-set efficiency and such spandex may suffer from the same deficiency as other polymer chains so modified, namely altered fiber properties and inflexible production and spandex product lines. The use of quaternary amines as additives in spandex is unknown.
A convenient, durable, and flexible means of improving the heat-set efficiency of spandex is still needed.
SUMMARY OF THE INVENTION
The present invention is a spandex containing about 3-100 meq of quaternary amine functionality/kg of spandex wherein the quaternary amine is an additive selected from the group consisting of:
(a) oligomers comprising the reaction product of at least one diisocyanate selected from the group consisting of 1-isocyanato-4-[(4-isocyanatophenyl)methyl]benzene, 1-isocyanato-2-[(4-isocyanatophenyl)methyl]benzene, 4-methyl-1,3-phenylene diisocyanate, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethyl-cyclohexane, 1,6-diisocyanatohexane and bis(4-isocyanatocyclohexyl)methane), and at least one quaternary amine selected from the group consisting of N,N-dialkyl-N,N-dialkanolammonium chlorides and N,N-dialkyl-N,N-dialkanolammonium alkylsulfates, wherein the alkanol grouping contains 2-4 carbon atoms;
(b) quaternary amines having the formula
wherein at least one of A, D and E is an alkyl or alkenyl group having about 10-22 carbon atoms, a mixture of such groups, or such groups including an
moiety, B is an alkyl group having up to three carbon atoms, D is selected from the group consisting of A, linear and branched alkyl and alkenyl groups having 1-9 carbon atoms, phenyl, benzyl, and —(CH
2
CH
2
O)
y
H groups wherein y is 1-10, and Y is either chloride or alkylsulfate ion; and
(c) quaternary amines having the formula
wherein A′ is an alkyl or alkenyl group having about 9-21 carbon atoms, B is an alkyl group having up to three carbon atoms, D is selected from the group consisting of A, linear and branched alkyl and alkenyl groups having 1-9 carbon atoms, phenyl, benzyl, and —(CH
2
CH
2
O)
y
H groups wherein y is 1-10, and Y is either chloride or alkylsulfate ion.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, “spandex” means a manufactured fiber in which the fiber-forming substance is a long-chain synthetic elastomer comprised of at least 85% by weight of a segmented polyurethane; “BDMSA” means N-benzyl-N,N-dimethyl-N-stearylammonium chloride; “fatty acid” means any of the saturated or unsaturated monocarboxylic acids, usually with an even number of carbon atoms, that occur naturally in fats and fatty oils.
It has now been found that certain quaternary amine additives in spandex result in surprising increases in the heat-set efficiency of the spandex. It is preferred that the normalized value of heat-set efficiency differences (as defined below) should be at least 0.1.
Spandex is conventionally made by first mixing a polyether, polyester, or polycarbonate glycol with a diisocyanate to form a mixture of isocyanate-terminated polymeric glycol and unreacted diisocyanate, which is also called a “capped glycol”. Examples of useful polyether glycols include poly(tetramethyleneether)glycol and poly(tetramethylene-co-2-methyltetramethyleneether)glycol. Examples of useful polyester glycols include those made from the polycondensation of low molecular weight diols, for example 2,2-dimethylpropanediol, ethylene glycol, butanediol, and mixtures thereof, with dicarboxylic acids such as adipic acid and dodecanedioic acid. Useful polycarbonates include poly(pentane-1,5-carbonate)diol and poly(hexane-1,6-carbonate)diol. The most widely used diisocyanate is 1-isocyanato-4-[(4-isocyanatophenyl)methyl]benzene, but other diisocyanates such as 1-isocyanato-2-[(4-isocyanatophenyl)methyl]benzene, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane, 4,4′-methylene-bis(cyclohexylisocyanate), and 4-methyl-1,3-phenylene diisocyanate can also be used, either alone or in mixtures. When a spandex is desired which comprises the polyurethaneurea sub-class of polyurethanes, the capped glycol is dissolved in a suitable solvent and chain-extended with a diamine to form a polymer solution. Suitable solvents include dimethylacetamide (DMAc), N-methylpyrrolidone, and dimethylformamide. Useful diamine chain extenders include ethylenediamine, 2-methyl-1,5-pentanediamine, 1,2-propanediamine, 1,3-pentanediamine, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-propanediamine and mixtures thereof. The molecular weight of the polyurethane can be controlled by the use of monofunctional chain terminators such as diethylamine.
The solution can then be dry-spun from a spinneret into a column supplied with hot gas to drive off the solvent and form the spandex, which is wound up into a package.
In one embodiment of the present invention, the spandex additives are polyurethane oligomers prepared from at least one diisocyanate selected from the group consisting of 1-isocyanato-4-[(4-isocyanatophenyl)methyl]benzene, 1-isocyanato-2-[(4-isocyanatophenyl)methyl]benzene, 4-methyl-1,3-phenylene diisocyanate, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane, 1,6-diisocyanatohexane, bis(4-isocyanatocyclohexyl)-methane) and at least one quaternary amine selected from the group consisting of N,N-dialkyl-N,N-dialkanolammonium chlorides and alkylsulfates, having 2-4 carbon atoms in the alkanol portion. These oligomers can further incorporate non-quaternized amines, for example N-alkyl-N,N-diethanolamines such as N-t-butyl-N,N-diethanolamine and N-methyl-N,N-diethanolamine. Spandex containing oligomeric additives based on N-t-butyl-N-methyldiethanolammonium- and N,N-dimethyldiethanolammonium ions are preferred due to the availability of the precursor amines. Alkylsulfate counterions are preferred because they are more effective at improving heat-set efficiency.
In another embodiment, the spandex additive is a non-polymeric quaternary amine represented by the general formula I:
wherein at least one of A, D and E is an alkyl or alkenyl group of about 10-22 carbo
Goodrich Charles William
Palmer, Jr. Charles Francis
Selling Gordon William
E. I. du Pont de Nemours and Company
Szekely Peter
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