Title of Invention

"FLUORESCENT ELASTIC YARN AND METHOD FOR PRODUCING THE SAME"

Abstract There is provided a method for producing a covered fluorescent elastic yarn, comprising the step of covering a core yarn, wherein the core yam is the fluorescent elastic yarn comprising 0.0001 to 20% by weight of fluorescent brightener selected from the group consisting of a stilbene-based fluorescent brightener, a pyrazolone-based fluorescent brightener, an imidazole-based fluorescent brightener, an oxazole -based fluorescent brightener, a coumarin-based fluorescent brightener, a rhodamine-based fluorescent brightner and a fluorescein- based fluorescent brightener.
Full Text FLUORESCENT ELASTIC YARN AND METHOD FOR PRODUCING THE SAME
BACKGROUND OF THE INVENTION
1. Field of the invention
The present invention relates, in general, to a fluorescent elastic yarn and a method for producing the same and in particular, to a fluorescent elastic yarn which can fluoresce sufficiently to allow a thin elastic yarn to be ) seen by the naked eye when ultraviolet Light is irradiated to the fluorescent elastic yarn by adding a novel organic additive to a polymer or a spinf inish, and a method of producing the same.
2. Description of the Prior Art
An elastic yarn has been applied to various fields, and a process of knitting and weaving the elastic yarn covered with a natural fiber has been widely used In the art. Various types of elastic yarns, for example, a core spun yarn in which cotton or a rayon fiber is covered on the elastic yarn, and a covered yarn in which a synthetic fiber such as nylon and polyester is covered on the elastic yarn, are used to produce elastic textile fabrics or knitted goods requiring elasticity.
However, there is a problem during a covering process

of the elastic yarn in that a breakage of the elastic yarn cannot be discovered in good time, and so inferior products having only the covered yarn wound without the elastic yarn may be produced. . -. This problem causes a reduction in productivity of the covered elastic yarn and a waste of the covered yarns. Accordingly, there remains a need for the development of a novel method capable of finding a breakage of the elastic yarn in good time.
A conventional method of finding a breakage of the elastic yarn is based on a principle that titanium-based or magnesium-based inorganic additives added into the elastic yarn emit a dark violet ray when irradiated by ultraviolet light. However,, the inorganic additives are not only added into the elastic yarn in order to avoid the above problem, but also added into the elastic yarn so as to improve dulling effect and anti-blocking property, and so the problem cannot be overcame basically. Furthermore, the conventional method is disadvantageous in that when thickness of the elastic yarn is less than 40 deniers, or a small capacity device such as a portable UV radiator is used to discriminate breaking of the elastic yarn in a work place, it is almost impossible to find the breakage.
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Brief Statement of the Invention.
According to this invention there is provided a method for producing a covered fluorescent elastic yarn, comprising the step of covering a core yarn, wherein the core yarn is the fluorescent elastic yarn comprising 0.0001 to 20% by weight of fluorescent brightener selected from the group consisting of a stilbene-based fluorescent brightener, a pyrazolone-based fluorescent brightener, an imidazole-based fluorescent brightener, an oxazole based fluorescent brightener, a coumarin-based fluorescent brightener, a rhodamine-based fluorescent brightner and a fluorescein- based fluorescent brightener.
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Therefore, it is a feature of the present invention to provide a fluorescent elastic yarn which can be discriminated by fluorescence when ultraviolet light is irradiated to it.
It is another feature of the present invention to provide a method for producing the fluorescent elastic yarn.
It is the other feature of the present invention to provide a fluorescent elastic yarn covered with hard fiber.
In accordance with an aspect of the present invention, there is provided a fluorescent elastic yarn comprising 0.001 to 20 wt% of a fluorescent brightener.
In accordance with another aspect of the present invention, there is provided a method for producing a fluorescent elastic yarn comprising the step of spinning a polyurethane-urea copolymer, wherein a fluorescent brightener is mixed with the polyurethane-urea copolymer in an amount of 0.001 to 2.0 wt%.
In accordance with another aspect of the present invention, there is provided a method for producing a fluorescent elastic yarn comprising the step of spinning a polyurethane-urea copolymer, wherein aj^spinfinish having a fluorescent brightener dispersed therein is applied to a spun elastic yarn in such an amount that a content of the fluorescent brightener in the resulting elastic yarn ranges from 0.001 to 20 wt%.
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In accordance with the other aspect of the present invention, there is provided a method for producing a covered fluorescent elastic yarn, comprising the step of covering a core yarn, wherein the core yarn is the fluorescent elastic yarn.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
A segmented polyurethane-urea copolymer useful for production of a fluorescent elastic yarn of the present invention is produced by reacting organic diisocyanate with polydiol to produce a prepolymer, and then dissolving the prepolymer in an organic solvent and reacting with diamine and monoamine.
The organic diisocyanate used to produce the segmented polyurethane-urea copolymer includes, not limited to, diphenylmethane-4,4'-diisocyanate, hexamethylenediisocyanate, toluenediisocyanate, butylenediisocyanate, and hydrogenated P,P-methylenediisocyanate.
The polydiol used to produce the segmented polyurethane-urea copolymer includes, not limited to, polytetramethylene ether glycol, polypropylene glycol, and polycarbonate diol.
Furthermore, a diamine such as ethylene diamine, propylene diamine, and hydrazine can used as a chain
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extender, and a monoamine such as diethylamine, monoethanol amine, and dimethyl amine can be used as a chain termination agent.
Useful for covering the elastic yarn according to the present invention may be cotton, rayon, nylon, polyester, or cellulose.
A fluorescent brightener characteristically added to
an elastic yarn in the present invention may be mixed with a
polymer used as a raw material of the elastic yarn before
the elastic yarn is spun. Alternatively, the fluorescent
brightener may be added into a usual spinfinish,which is applied
to a spun elastic yarn after spinning. of the elastic yarn.
The fluorescent brightener is added to the elastic yarn in
such an amount that a fluorescent brightener content ranges
from 0.001 to 20 wt% in the resulting elastic yarn.
Aw *
When the fluorescent brightener content is less than
0.001 wt%, a fluorescent effect is poor. On the other hand, when the content is more than 20 wt%, dispersability of the fluorescent brightener in a polymer or spinfinish is poor and so the fluorescence of the fluorescent elastic yarn is non-uniform though the fluorescence is absolutely bright, and the fluorescent elastic yarn cannot be produced economically due to the heavy cost of brightener.
The fluorescent brightener used in the present invention include, not limited to, a stilbene-based
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fluorescent brightener, a pyrazolone-based fluorescent brightener, an imidazole-based fluorescent brightener, an oxazole-based fluorescent brightener, a coumarin-based fluorescent brightener, a rhodamine-based fluorescent brightener, and a fluorescein-based fluorescent brightener. Specific examples of each fluorescent brightener are as follows:
Stilbene-based fluorescent brightener: C.I.(Color Index) Fluorescent Brighteners No. 24, 77, 84, 85, 90, 97, 132, 151, 153, 154, and 166, which are kinds of ((Bis)triazinylaminostilbene)) or derivatives thereof;
Pyrazolone-based fluorescent brightener: C.I. Fluorescent Brighteners No. 54 and 124;
Imidazole-based fluorescent brightener: C.I. Fluorescent Brighteners No. 45, 133, 140, 150, 189, 228, and 2-isopropylimidazole (CAS{Chemical Abstract Society)# 36947-68-9);
Oxazole-based fluorescent brightener: C.I. Fluorescent Brighteners No. 170, 171, 219, 258, 259, and (2,2'-2,5-diophenydil)bis[5-(1,1-dimethylethyl)]-benzoxazol (usually referred to as xuvitex OB');
Coumarin-based fluorescent brightener: C.I. Fluorescent Brighteners No. 52, 69, 78, 91, 130, 152, 156, 162, Coumarin 1(CAS# 91-44-1, 7~diethylamino-4-methyl coumarin), and Coumarin 6(CAS# 38215-36-0, 3- (2-

Benzotiazofyl) - 7 - diethylamino coumarin);
Rhodamine - based fluorescent brightener: Rhodamine B (CAS# 81-88-9, N- [ 9- (2-carboxyphenyl) - 6- diethylamino -3H- xanthen -3- ylidene] -N-ethylethanammonium chloride), and Rhodamine isocyanate ( CAS# 36877 - 69 - 7); and
Fluorescein - based fluorescent brightener: Fiuorescein (CAS# 2321 - 07 -5 ), and Fluorescein isothiocyanate (CAS# 3326 - 32 -7 ).
It is preferable that the fluorescent brightener is dispersed in an organic solvent prior to being mixed with a polymer or spinfinish. The organic solvent includes, not limited to, methanol and hexylene glycol (CAS# 107 - 41 - 5, 2 - methyl - 2, 4 - pentandiol).
According to the present invention, wefl known activities such as a UV stabilizer, an antioxidant, a NOX gas yellowing resistance agent, an anti-blocking agent, a dye fastness improver, a chlorine-resisting agent, and a dulling agent may be added to the elastic yarn during dry spinning o the elastic yarn.
These can be for example as follows.
(1) UV STABILIZER : 9 HALS. 9 9 a BRAND NAME)
(2) ANTIOXIDANT; IRGANOX SERIES 9 A BRAND NAMEO
(3) NO GAS YELLOWING RESISTANCE AGENT; HN-50 9A BRAND NAMEO
(4) ANTI-BLOCKING AGENT; Mg- Stearate.
(5) DYE FASTNESS IMPROVER; POLYDOCIL
(6) CHLORINE-RESISTING AGENT;.ZhO.
(7) Dulling agent; ttlo2
When the fluorescent brightener is added to a dissolved polymer before spinning of the elastic yarn, the fluorescent brightener displays an eternal fluorescent effect under ultraviolet light, and so the fluorescent elastic yarn can be applied to clothes for a special use recognized by a UV radiator. Alternatively, when the
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fluorescent elastic yarn is produced using the spinfinish containing the fluorescent brightener, the fluorescent elastic yarn is advantageous in that the fluorescent elastic yarn is readily visually inspected because the fluorescent brightener is coated on the surface of the elastic yarn. Also, the knitted or woven fabric applied with the fluorescent elastic yarn mentioned above can be used for various purpose according to user's requirements, because the fluorescent brightener can be detached from the elastic yarn very easily under scoring and post processing of the fabric.
A better understanding of the present invention may be obtained by reading the following examples which are set forth to illustrate, but are not to be construed to limit the present invention.
EXAMPLE 1
518 g of diphenylmethane-4, 4' -diisocyanate was reacted with 2328 g of polytetramethylene ether glycol (molecular
weight: 1800) under a nitrogen gas atmosphere at 85°C for 90 min to produce a prepolymer containing isocyanate groups positioned at both terminations thereof. The prepolymer thus produced was cooled to room temperature, and 4643 g of

dimethylacetamide was added to the cooled prepolymer to produce a prepolymer solution.
After that, a solution, in which 54 g of propylene diamine "and 9.1 g .of diethylamine were dissolved in 1889 g of dimethylacetamide, was added to the prepolymer solution
at 10 °C or less to produce a segment polyurethane-urea copolymer solution.
Additives such as a UV stabilizer, an antioxidant, a yellowing resistance agent, a dye fastness improver, a magnesium-based anti-blocking agent, and a titanium-based dulling agent were added to the above segmented polyurethane-urea copolymer solution, and Coumarin 1 (CAS# 91-44-1, 7-diethyl amino-4-methylcoumarin) dispersed in hexylene glycol (CAS# 107-41-5, 2-methyl-2,4-pentanediol) in a weight ratio of 2:8 was added to the polymer solution in such an amount that a Coumarin 1 content was 5 wt% based on the resulting polymer solid. The resulting polymer was subjected to a defoaming process, drawn at a spinning temperature of 250°C by a dry spinning process, and wound to produce a polyurethane-urea elastic yarn with a thickness of 10 deniers. The elastic yarn was covered with a polyester false twist yarn with a thickness of 7 5 deniers with the use of conventional covering machines. Physical properties of the elastic yarn and the covered elastic yarn were evaluated, and results are described in Table 1.

EXAMPLES 2 TO 4
The procedure -of example 1 was repeated except that the resulting elastic yarns were 20, 40, and 140 deniers in thickness. Physical properties of the resulting elastic yarns are described in Table 1.
EXAMPLE 5
518 g of diphenylmethane-4, 4' -diisocyanate was reacted with 2328 g of polytetramethylenether glycol {molecular
weight: 1800) under a nitrogen gas atmosphere at 85°C for 90 min to produce a prepolymer containing isocyanate groups positioned at both terminations thereof. The prepolymer thus produced was cooled to room temperature, and 4 643 g of dimethylacetamide was added to the cooled prepolymer to produce a prepolymer solution.
After that, a solution, in which 54 g of propylene diamine and 9.1 g of diethylamine were dissolved in 188 9 g of dimethylacetamide, was added to the prepolymer solution at 10°C or less to produce a segmented polyurethane-urea copolymer solution.
Additives such as a UV stabilizer, an antioxidant, a yellowing resistance agent, a dye fastness improver, a
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magnesium-based anti-blocking agent, and a titanium-based dulling agent were added to the above segmented polyurethane-urea copolymer solution,. and the resulting polyurethane-urea copolymer solution was subjected to a defoaming process and drawn at a spinning temperature of 250°C by a dry spinning process. Coumarin 1 (CAS# 91-4 4-1, 7-diethyl amino-4-methylcoumarin) was dispersed in hexylene glycol (CAS# 107-41-5, 2-methyl-2,4-pentanediol) in a weight ratio of 2:8 to produce a dispersion liquid, and the dispersion liquid was added to the resulting polyurethane-urea copolymer polymer solution in such an amount that the dispersion liquid is 10 wt% based on a spinfinish generally used in winding the elastic yarn, for example, comprising polydimethylsiloxane and pure. 5wt% spinfinish based on the elastic yarn was applied to a surface of the elastic yarn to produce the resulting elastic yarn with a thickness of 10 deniers. The fluorescent brightener content in the resulting elastic yarn was 0.1 wt%. The resulting elastic yarn was covered with a polyester false twist yarn with a thickness of 75 deniers with the use of conventional covering machines. Physical properties of the elastic yarn and the covered elastic yarn were evaluated, and results are described in Table 1.
EXAMPLES 6 TO 8

The procedure of example 5 was repeated except that
the resulting elastic yarns were 20, 40, and 140 deniers in
thickness. Physical properties of the resulting elastic
yarns and covered elastic yarns were evaluated, and results
are described in Table 1.
COMPARATIVE EXAMPLES 1 TO 4
^ The procedure of example 1 was repeated to produce the resulting elastic yarns of 10, 20, 40, and 140 deniers except that a fluorescent dispersion liquid was not applied to the elastic yarn. Physical properties of the resulting elastic yarns and covered elastic yarns were evaluated, and
results are described in Table 1.
EXAMPLES 9 TO 10
The procedure of example 3 was repeated except that each Coumarin 1 added to a polymer solution was 0.001 and 20 wt% based on the resulting polymer solid.
COMPARATIVE; EXAMPLES 5 TO 6
The procedure of example 3 was repeated except that

each Coumarin 1 added to a polymer solution was 0.0001 and 25 wt% based on the resulting polymer solid.
EXAMPLE 11
The procedure of example 7 was repeated except that 0. wt% dispersion liquid having a fluorescent brightener dispersed therein based on a spinfinish was added to an elastic yarn, 5wt% spinfinish based on the elastic yarn was applied to a surface of the elastic yarn and the resulting mixture was wound to produce the resulting elastic yarn with a thickness of 4 0 deniers, and a fluorescent brightener content in the resulting elastic yarn was 0.001 wt%.
COMPARATIVE EXAMPLE 7
The procedure of example 7 was repeated except that 0.01 wt% dispersion liquid having a fluorescent brightener dispersed therein based on a spinfinish was added to an elastic yarn, 5wt% spinfinish based on the elastic yarn was attached to a surface of the elastic yarn and the resulting mixture was wound to produce the resulting elastic yarn with a thickness of 40 deniers, and a fluorescent brightener content in the resulting elastic yarn was 0.0001 wt%.

TABLE 1

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From the results of Table 1, it can be seen that a thin elastic yarn of 40 d or less without the fluorescent brightener is difficult to be visually inspected under UV,

and when a fluorescent brightener content based on the resulting polymer is 20 wt% or more as in the case of example 6, the elastic yarn has an excellent fluorescent effect, but has disadvantages of poor unwinding property of and poor dispersibility of a fluorescent substrate.
EXAMPLES 12 TO 18
The procedure of example 7 was repeated except that a fluorescent brightener and a dispersing agent are different from each other as shown in Table 2. Physical properties of the resulting elastic yarns and covered elastic yarns were evaluated, and results are described in Table 2.
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TABLE 2



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As described above, the present invention is advantageous in that a fluorescent elastic yarn of this invention can be visually inspected under UV even though the elastic yarn is covered with a polyester false twist yarn, and so it can be discriminated whether a thin elastic yarn of 10 deniers is present or not, thereby production of
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inferior covered yarn(No presence of elastic yarn) is minimized and productivity of the fluorescent elastic yarn is improved in a downstream process of producing the fluorescent elastic -yarn.
The present invention has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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We Claim;
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1. A method for producing a covered fluorescent elastic yam, comprising the step of covering a core
yarn, wherein the core yarn is the fluorescent elastic yarn comprising 0.0001 to 20% by weight of
fluorescent brightener selected from the group consisting of a stilbene-based fluorescent
brightener, a pyrazolone-based fluorescent brightener, an imidazole-based fluorescent
brightener, an oxazole -based fluorescent brightener, a coumarin-based fluorescent brightener, a
rhodamine-based fluorescent brightner and a fluorescein- based fluorescent brightener.
2. A method as claimed in Claim 1 wherein the fluorescent elastic yam is produced by the step of
spinning a polyurethane- urea copolymer.
3. A method for producing a fluorescent elastic yarn as clamed in claims 1 & 2 comprising the step
of spinning a polyurethane-urea copolymer, wherein a conventional spinfinish having a
fluorescent brightener dispersed therein is applied to a spun elastic yarn in such an amount that a
content of the fluorescent brightener in the resulting elastic yarn ranges from 0.001 to 20 wt.%.
4. A method as claimed I claims 1 to 3 wherein the fluorescent elastic yarn is covered with at least
one selected from the group consisting of cotton, rayon, nylon, polyester and cellulose.
5. A method for producing a covered fluorescent elastic yam substantially as herein described with
reference to the examples.
6. A covered fluorescent elastic yam wherein produced by the method of any of claims 1 to 5.

There is provided a method for producing a covered fluorescent elastic yarn, comprising the step of covering a core yarn, wherein the core yam is the fluorescent elastic yarn comprising 0.0001 to 20% by weight of fluorescent brightener selected from the group consisting of a stilbene-based fluorescent brightener, a pyrazolone-based fluorescent brightener, an imidazole-based fluorescent brightener, an oxazole -based fluorescent brightener, a coumarin-based fluorescent brightener, a rhodamine-based fluorescent brightner and a fluorescein- based fluorescent brightener.

Documents:

00532-cal-2002-abstract.pdf

00532-cal-2002-claims.pdf

00532-cal-2002-correspondence.pdf

00532-cal-2002-description(complete).pdf

00532-cal-2002-form-1.pdf

00532-cal-2002-form-18.pdf

00532-cal-2002-form-2.pdf

00532-cal-2002-form-3.pdf

00532-cal-2002-form-5.pdf

00532-cal-2002-letters patent.pdf

00532-cal-2002-p.a.pdf

00532-cal-2002-priority document others.pdf

00532-cal-2002-priority document.pdf

532-CAL-2002-FORM-27.pdf


Patent Number 206866
Indian Patent Application Number 532/CAL/2002
PG Journal Number 20/2007
Publication Date 18-May-2007
Grant Date 15-May-2007
Date of Filing 11-Sep-2002
Name of Patentee HYOSUNG CORPORATION
Applicant Address 450,KONGDUK-DONG, MAPO-GU,SEOUL ,121-020
Inventors:
# Inventor's Name Inventor's Address
1 YEON SOO KANG 105/108, WOOSUNG APPARTMENT, BAKDAL-DONG, MANAN-GU, ANYANG-SHI ,KYUNGKI-DO, 430-030
2 SO RA YOO OF 205/1210 MOKLYEON 2 DANJI HOGYE-DONG ,DONGAN-GU,ANYANG-SHI KYUNGKI-DO,431-080 KOREA
3 SEUNG WON SEO OF 991/2102 HANYANG APARTMENT SANBON-DONG GUNPO-SHI KYUNGKI-DO 435-040, KOREA
4 MIN SU PARK 1132-13 KEONGHWA 2-GA, JINHAE-SHI, KYUNGSANGNAM-DO, 645-801
PCT International Classification Number D 06 M 13/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2002-21159 2002-04-18 Republic of Korea