Spandex fiber for reduced visibility

Abstract

Spandex fiber compositions are provided that have reduced grain peeling effects. Methods for making and using these compositions are also provided.

Description

[Technical Field]

[0001] The present disclosure relates to spandex fiber compositions containing carbon black pigment, a white opacifying enhancer, and an inorganic pigment or acid dye acceptor, which exhibit reduced grain peeling effects in stretch fabrics, and methods for their manufacture and use. [Background technology]

[0002] Fabrics containing spandex are often combined with other companion yarns, such as cotton, nylon, polyester, wool, or acrylic. These fabrics are typically colored with dyes whose chemical structure is specifically designed to match that particular companion yarn.

[0003] In some cases, spandex fibers are knitted or plated with companion yarns before dyeing, or fabrics are woven into them, and thus are also subjected to this dyeing process. However, dye chemistries are not intentionally formulated for spandex fibers that differ in chemistry and linear density or decitex from the companion yarns, so the resulting shade of the spandex fiber may differ from that of the companion yarn.

[0004] In other cases, the companion yarns are dyed before making the fabric, and the spandex fibers are not involved in the dyeing process at all. Again, in these cases, the spandex will be a different color than the companion yarns in the fabric.

[0005] When a knit fabric containing spandex is stretched, the structure opens up, making the spandex more visible. When this happens, if the spandex is of a different hue or sheen, the fabric will have a very different, often undesirable, appearance compared to the fabric in its relaxed state. This effect is known in the art as "grain peeling."

[0006] Spandex fiber manufacturers have made various attempts to reduce the grain effect.

[0007] For example, attempts have been made to make spandex more compatible with the dyes used in the companion yarn. These "dyeable" spandex fibers are disclosed, for example, in published U.S. patent applications US2005 / 0165200, WO2009 / 084815, and EP 2157215A1. However, these are limited to improving the dyeability of nylon with acid dyes, and matching the shade of dyed spandex to dyed nylon can be difficult due to the different decitex and luster levels of each fiber.

[0008] A second commercially used method is to add black pigment to spandex fibers to make them less visible in fabrics. See, for example, US 2006 / 0210794. This method is limited to fabrics intended for dark shades and can have an undesirable graining effect when stretched.

[0009] Fiber manufacturers have also attempted to minimize the glossy or shiny aspect of grain by using fiber opacifying enhancers such as titanium dioxide, which are effective in increasing the opacity of spandex fibers and increasing the degree to which the fibers appear white, but samples in fabrics still exhibit the undesirable grain effect in practical applications.

[0010] There is a need for spandex fibers that significantly reduce or eliminate the grain-peeling effect in stretch fabrics. Summary of the Invention

[0011] The present disclosure relates to spandex fibers that exhibit significantly reduced grain effect in stretch fabrics, and methods for their manufacture and use.

[0012] Accordingly, one aspect of the present invention relates to a spandex fiber composition comprising spandex, a carbon black pigment, a white opacifying enhancer, and an inorganic pigment and / or an acid dye acceptor.

[0013] Another aspect of the present invention relates to filaments and fibers for producing stretch fabrics with reduced grain, the fibers being made from a spandex fiber composition comprising spandex, carbon black pigment, a white opacifying enhancer, and an inorganic pigment and / or acid dye acceptor.

[0014] Another aspect of the present invention relates to a method for reducing the graining effect of spandex in stretch fabrics, in which a carbon black pigment, a white opacifying enhancer, and an inorganic pigment and / or an acid dye acceptor are added to a spandex fiber composition.

[0015] Yet another aspect of the present invention relates to an article of manufacture, at least a portion of which comprises a composition or fiber comprising spandex, a carbon black pigment, a white opacifying enhancer, and an inorganic pigment and / or an acid dye acceptor.

[0016] The present invention relates to spandex fiber compositions that have reduced grain in stretch fabrics, and methods for making these compositions and using these compositions in fiber and filament production and articles of manufacture.

[0017] The spandex fiber composition of the present invention comprises spandex, a carbon black pigment, a white opacifying enhancer, and an inorganic pigment or acid dye acceptor.

[0018] The term "spandex" is used herein in its general sense to refer to a manufactured fiber in which the fiber-forming substance is a long-chain synthetic polymer composed of segmented polyurethanes and / or polyurethaneureas. Spandex compositions are well known in the art and may include many variations, such as those disclosed in Monroe Couper, Handbook of Fiber Science and Technology: Volume III, High Technology Fibers Part A. Marcel Dekker, INC.: 1985, pages 51-85.

[0019] The spandex is loaded with carbon black pigment. In one non-limiting embodiment, low levels of carbon black pigment are loaded. As used herein, "low levels" refers to about 25 ppm to about 200 ppm of carbon black pigment.

[0020] A white opacifying enhancer is also added to the spandex. In one non-limiting embodiment, the white opacifying enhancer is titanium dioxide. In one non-limiting embodiment, about 0.01 to about 1 weight percent of the white opacifying enhancer is added. The opacifying enhancer is titanium dioxide or other material having a refractive index greater than 1.8 at 632.8 nanometers. In one non-limiting embodiment, about 0.01 to about 1 percent of titanium dioxide is added.

[0021] In one non-limiting embodiment, the spandex fiber composition further comprises an inorganic pigment. Non-limiting examples of inorganic pigments that can be used include hydrotalcite, huntite, hydromagnesite, magnesium carbonate, calcium carbonate, magnesium oxide, magnesium hydroxide, and combinations thereof. In one non-limiting embodiment, about 1 to about 10 wt. % of the inorganic pigment is added.

[0022] In one non-limiting embodiment, the spandex fiber composition further comprises an acid dye receptor. In one non-limiting embodiment, the acid dye receptor is from the tertiary and quaternary ammonium salt family or a combination thereof. In one non-limiting embodiment, the acid dye receptor is present in an amount of about 10 to about 50 milligram equivalents of active N / kg fiber.

[0023] Also provided by the present invention are filaments and fibers produced from these spandex fiber compositions that have reduced grain peeling effects. Methods for producing such filaments and fibers are well known in the art and need not be described in detail herein.

[0024] The present invention further provides an article of manufacture, at least a portion of which comprises the composition, filament or fiber of the present invention.

[0025] In one non-limiting embodiment, the article of manufacture is a fabric. In one non-limiting embodiment, the fabric is a stretch fabric.

[0026] The spandex-containing fabrics of the present invention may have a spandex content of about 0.5 weight percent (wt%) to about 40 wt%, based on the weight of the fabric. For example, circular knits containing spandex may contain about 2 wt% to about 25 wt% spandex, legwear containing spandex may contain about 1 wt% to about 40 wt% spandex, Raschel fabrics containing spandex may contain about 10 wt% to about 40 wt% spandex, and warp knit tricots containing spandex may contain about 14 wt% to about 22 wt% spandex.

[0027] The fabric of the present invention may further comprise a companion fabric. Non-limiting examples of the companion fabric include cotton, nylon, polyester, wool, or acrylic. The spandex fiber of the present invention can be produced by dry spinning, wet spinning, or melt spinning. The properties of the fiber are not limited to circular knitting fabric processes. Any fabric manufacturing route, such as warp knitting, seamless knitting, stockinette knitting, hosiery knitting, and weaving processes, are suitable for the fiber of the present invention.

[0028] Also provided by the present invention is a method for reducing the grain effect of spandex-containing fabrics using the spandex fiber composition.

[0029] As shown herein, these spandex fiber compositions impart a dull luster and gray hue to the spandex fiber, resulting in a significantly reduced or eliminated grain effect. Furthermore, in combination with dye additives, grain could be further reduced without adversely affecting light to dark colors.

[0030] While not wishing to be bound by theory, it is believed that the gray hue produced by low levels of carbon black serves to dilute the visual contrast of companion yarn dyes absorbed or bound to the spandex relative to the color depth they would exhibit if dispersed in standard, unaltered-color spandex fiber. Furthermore, the addition of certain amounts of white opacifying enhancers is believed to help reduce color shifts caused by oxidative yellowing of the fiber, despite the white color of these additives contrasting with the intended effect of carbon black pigments. Furthermore, inorganic pigments are believed to specifically reduce fiber luster, which is related to the shine of the fiber when exposed to an observer during stretching of a fabric containing spandex fiber, while acid dye receptors are believed to enhance the color of the spandex, providing richer, deeper shades.

[0031] All patents, patent applications, test procedures, priority documents, papers, publications, manuals, and other documents cited herein are incorporated by reference in their entirety to the extent such disclosure is not inconsistent with the present invention and for all jurisdictions where such incorporation is permitted.

[0032] The following examples demonstrate the present invention and its usability. The invention is capable of other and different embodiments, and its several details can be modified and / or substituted in various obvious respects without departing from the spirit and scope of the invention. Accordingly, the examples should be considered as illustrative in nature and not limiting. Example

[0033] The knit fabrics listed in Table 1 were manufactured in the form of circular knit tubes on a Lawson Knitting Unit (Lawson-Hemphill Company), model "FAK." For items 1-21, one feed of 40 denier spandex was knitted to form a 100% spandex fabric. For items 22-27, one end of 40 / 34 flat nylon was knitted with one end of 40 denier spandex to form a knitted fabric. Lawson tube samples were scoured at 80°C for 30 minutes using 1 g / L soda ash and 1 g / L Domoscour LFE-810. [Table 1]

[0034] Table 2 shows the color depth of various knit fabrics made with 100% spandex with the additive formulations listed in columns 2, 3, and 4. L* is an internationally recognized scale of color depth ranging from 0 to 100. The lower the L value, the darker the color. As the carbon black loading increased, the L* value of the spandex items decreased. This was also true in the presence of inorganic pigments and white opacifying enhancers. As shown, as the TiO2 loading increased, the L* value also increased. See Table 2. [Table 2]

[0035] Knit fabrics made from 100% spandex with the additive formulations listed in columns 2, 3, and 4 of Table 3 were optically whitened using Phorwite CLE (1.5%) at pH 5 and 98°C for 40 minutes. The optically whitened fabrics were exposed to combustion gas fumes under AATCC test conditions. The ΔCIE values ​​are the change in CIE brightness value after exposure to combustion gas fumes under AATCC test conditions. The smaller the change, the less impact the combustion gases have on producing color change (e.g., less yellowing seen in the L100 item versus CC or C100 values). The presence of carbon black reduces the initial CIE brightness and significantly reduces the ΔCIE between initial and final brightness. See Table 3. [Table 3]

[0036] Knit fabrics made from 40 / 34 flat nylon and 40 denier spandex with the additive formulations listed in columns 2, 3, and 4 of Table 4 were optically whitened using Phorwite CLE (1.5%) at pH 5 and 98°C for 40 minutes. The optically whitened fabrics were exposed to combustion gas fumes under AATCC test conditions. The ΔCIE values ​​are the change in CIE whiteness value after exposure to combustion gas fumes under AATCC test conditions. A similar trend to the 100% spandex fabrics was also observed in the optically whitened nylon / spandex fabric blends. See Table 4. [Table 4]

Claims

1. A composition for spandex fibers comprising a long-chain synthetic polymer composed of segmented polyurethane and / or polyurethane urea, a carbon black pigment in the range of 60 to 100 ppm, 0.01 to 1 wt. % titanium dioxide, and 1 to 10 wt. % inorganic pigment selected from hydrotalcite, huntite, hydromagnesite, magnesium carbonate, calcium carbonate, magnesium oxide, magnesium hydroxide, and combinations thereof.

2. A filament or fiber comprising the composition of claim 1.

3. 10. An article of manufacture, at least a portion of which comprises the composition of claim 1 or the filament or fiber of claim 2.

4. 4. The article of manufacture of claim 3, which is a fabric.

5. 5. The article of manufacture of claim 4, which is a stretch fabric.

6. 6. The article of manufacture of claim 4 or 5, wherein the fabric further comprises a companion yarn.

7. 7. The article of manufacture of claim 6, wherein the companion yarn is selected from cotton, nylon, polyester, wool, or acrylic, or any combination thereof.

8. A process comprising producing filaments or fibers from the spandex fiber composition of claim 1.

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