Bleaching and dyeing; fluid treatment and chemical modification – Dye or potential dye composition – additive – treatment,... – Azo – acridone – or quinone dye
Reexamination Certificate
1998-05-05
2001-03-27
Egwin, Kelechi C. (Department: 1774)
Bleaching and dyeing; fluid treatment and chemical modification
Dye or potential dye composition, additive, treatment,...
Azo, acridone, or quinone dye
C008S908000
Reexamination Certificate
active
06206936
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a dyed filament yarn exhibiting a bright and clear shade. The present invention relates in more detail to a dyed filament yarn appearing, as a whole, to have been uniformly dyed despite the fact that the individual filaments constituting the yarn have an uneven build-up of dye in the longitudinal direction, and exhibiting significantly improved brightness and clearness.
BACKGROUND ART
Synthetic fibers, particularly polyester fibers show poor color development when dyed, and various investigations have heretofore been carried out on this problem. For example, Japanese Unexamined Patent Publication (Kokai) No. 52-99400 and Japanese Examined Patent Publication (Kokoku) No. 60-37225 disclose an improvement in the deepness of the color of the fibers by imparting a fine unevenness on the surface of the fibers, by plasma etching, so that the absorption of light is increased. Although the method is effective in improving the deepness of black shade mainly caused by absorption of light, substantially no effect of improving the color developing property with respect to a chromatic color is observed.
On the other hand, a method of improving the degree of dyeing of polyester fibers by copolymerizing the polyester polymer constituting the polyester fibers with a third component has been widely known. For example, Japanese Unexamined Patent Publication (Kokai) No. 6-173114 discloses a polyethylene terephthalate yarn obtained by copolymerizing with an aliphatic dicarboxylic acid which has from 4 to 10 total carbon atoms and a glass transition temperature of up to 70° C. The patent publication also discloses that when the yarn is dyed, the yarn shows a high degree of dyeing compared with a conventional polyethylene terephthalate yarn, that is, the dyed yarn shows a low L* expressed in the L*a*b* color specification system recommended by International Illumination Commission (Commission Internationale de l'Eclairage (CIE)) and specified by JIS Z8729-1980.
However, the L* is an index showing the brightness of color, namely, the “deepness of color” of a dyed yarn,. Accordingly, the method is intended to dye a yarn “deeply”. In the intention, there is no recognition that the “chromaticness of color” represented by a C* in the L*a*b* color specification system of CIE, i.e., the brightness and clearness are improved.
Furthermore, as disclosed in the patent publication, when the polyethylene terephthalate yarn copolymerized with a third component such as an aliphatic dicarboxylic acid is dyed by a conventional method to merely increase the degree of dyeing (L* being decreased), there arises the problem that the color becomes dark and the brightness and clearness (C*) are rather decreased.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a dyed filament yarn which is not only dyed deeply but also dyed to exhibit significantly improved brightness and clearness, i.e., significantly improved “chromaticness of color.”
As a result of intensively carrying out investigations to achieve the object, the present inventors have discovered that the brightness and clearness of a filament yarn composed of an aromatic polyester copolymerized with an aliphatic dicarboxylic acid component and/or an aliphatic diol component are significantly improved when the individual filaments constituting the yarn have uneven build-up of dye in the longitudinal direction and the yarn as a whole exhibits a uniform dyed state. The present invention has thus been achieved.
That is, the present invention provides an aromatic polyester filament yarn dyed in a chromatic color and exhibiting a bright and clear shade, wherein (a) the filaments of the yarn are composed of an aromatic polyester polymer copolymerized with an aliphatic dicarboxylic acid component and/or an aliphatic diol component and having a glass transition temperature (Tg) of not higher than 65° C., (b) uneven build-up of dye exists in the individual filaments in the longitudinal direction, (c) the yarn appears as a whole to have been dyed visually uniformly despite the presence of the uneven build-up of dye as mentioned in (b), and (d) the yarn has a chromaticness C* of at least 36, as expressed in the L*a*b* color specification system, when dyed with an aqueous dispersion of 1% o.w.f. of a disperse dye based on C.I. Disperse Blue 56.
Best Mode for Carrying out the Invention
The aromatic polyester filament yarn used in the present invention is composed of an aromatic polyester polymer comprising an alkylene terephthalate, such as ethylene terephthalate, as main repeating unit, and an aliphatic dicarboxylic acid component and/or an aliphatic diol component copolymerized therewith, and having a glass transition temperature (Tg) of not higher than 650° C.
Although such an aromatic polyester polymer is a random copolymer, it shows a distinctive fiber structure in that the crystalline portions and the amorphous portions can be easily separated and that the specific gravity, the birefringence (&Dgr;n) and the dynamic viscoelasticity (tan &dgr;) are low.
Preferred examples of the aliphatic dicarboxylic acid component and the aliphatic diol component are aliphatic dicarboxylic acids having a total number of carbon atoms of 3 to 12, aliphatic diol components having a molecular weight of not more than 300 and their derivatives. Specific examples thereof include succinic acid, adipic acid, sebacic acid, propylene glycol, trimethylene glycol, diethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, 1,8-octanediol, 1,10-decanediol, tetraethylene glycol, and the derivatives of these compounds. Of these compounds, adipic acid and its derivatives are particularly preferred.
When the aliphatic dicarboxylic acid has less than 3 total carbon atoms, the aromatic polyester polymer is not likely to have a glass transition temperature (Tg) of not higher than 65° C. On the other hand, when the aliphatic dicarboxylic acid has a total number of carbon atoms greater than 12, or when the aliphatic diol has a molecular weight exceeding 300, the color fastness tends to decrease.
Moreover, the copolymerization amount of the aliphatic dicarboxylic acid component and/or aliphatic diol component may be arbitrarily selected so that the filaments have a glass transition temperature (Tg) of not higher than 65° C., preferably from 45° C. to 65° C. while the mechanical properties, dyeing properties, etc. are being taken into consideration. When adipic acid and its derivatives are used, they are preferably copolymerized in an amount of 10 to 15% by mole based on the total acid component.
When the glass transition temperature exceeds 65° C., the build-up amount of the dye becomes too small, and the effects of improving the brightness and clearness are difficult to manifest. On the other hand, when the glass transition temperature is too low, the difference in the deepness of color of the uneven build-up of dye present in the filaments in the longitudinal direction becomes too small to manifest the effects of improving the brightness and clearness, as described below, in addition to deterioration of the mechanical properties and a decrease in the color fastness. Accordingly, the glass transition temperature is preferably as low as 45° C.
Stabilizing agents, antioxidants, fire retardants, antistatics, optical brighteners, catalysts, inorganic particles such as titanium oxide, and the like may be added to the polyester filaments so long as the object of the present invention is not impaired.
The polyester filament yarn may naturally be used as a flat yarn. Furthermore, the polyester filament yarn may be used as various finished yarns such as a false-twisted textured yarn, a hard-twisted textured yarn and an air entangling treatment yarn, and yarns in various forms such as a thick and thin yarn and a spun yarn. Still furthermore, the polyester filament yarn may also be used in the form of woven or knitted fabrics, a nonwoven fabric, a raised fabric, and the like.
Moreover, the polyester filament yarn may opti
Aoyama Saori
Suzuki Togi
Egwin Kelechi C.
Sughrue Mion Zinn Macpeak & Seas, PLLC
Teijin Limited
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