JP2013543936A - Antifouling formulations for spraying on fibers, carpets and fabrics - Google Patents

Abstract

  An antifouling formulation for spraying and a method for treating fibers, carpets and fabrics are disclosed. The antifouling formulation comprises a synergistic mixture of one antifouling component and one fouling blocker component adapted to be sprayed onto a fiber, carpet or fabric instead of a known discharge application. It becomes. The antifouling component can be either fluorochemical or non-fluorochemical based, while the contamination blocker can comprise any chemical that blocks positively charged dye sites. Fibers, carpets and fabrics treated with antifouling formulations exhibit excellent antifouling characteristics compared to sprayed fluorochemicals and similar antifouling characteristics compared to known discharge applications .

Description

  The present invention relates to spraying antifouling formulations for all fibers, and in particular to spraying antifouling formulations for polyester and olefin fibers, carpets and fabrics. The antifouling formulation comprises a synergistic mixture of an antifouling component and a contamination blocker component. Also disclosed are soil-repellent fibers, carpets and fabrics with improved anti-stain properties. Further disclosed herein are methods for making soil-repellent fibers, carpets and fabrics.

  Carpets are recently treated with topical chemicals for improved stain and / or soil resistance. Traditionally, for nylon carpets, both fouling blockers (eg, acid dye blockers) and antifouling agents including fluorochemicals are used. For polyester carpets such as 2GT and 3GT carpets and polypropylene carpets, no topical chemicals are applied or only antifouling agents are applied topically. Polyester and polypropylene carpets typically do not require local treatment of the stain blocker due to the inherent stain resistance and lack of amine end groups that serve as dye sites.

  Topical application is known to be an improved method compared to spray application at 10-20% by weight impregnation of antifouling agent, an exhaust application form [ie high (300-400% by weight) impregnation. Flex-nip method in rate. Emission applications typically consume more water and energy to dry and cure the carpet. Fluorochemical products for spraying consume less water and energy than discharge applications, but do not provide satisfactory antifouling properties.

  The carpet industry uses various methods for dyeing and finishing carpets, some large and some small, but most wide loom carpets manufactured today are continuous dyeing. It is dyed and finished on the range. This is mainly carried out in one of two ways: in one case a two-stage method is used, in which the carpet is first steamed, dyed, steamed, rinsed and excess water. , Then apply a stain blocker (SB), steam again the carpet, wash, and then apply fluorochemical (FC) in the form of a foam or liquid spray and finally dry the carpet (For example, see Patent Documents 1, 2, and 3). In a slightly improved case, called the second, simultaneous application method, the carpet is also first steamed, dyed, steamed again, rinsed and dehydrated, then the blend of SB and FC. It is applied together at a high impregnation rate, after which the carpet and chemicals are again exposed to steam to fix the treatment and then dry (see, for example, US Pat.

US Pat. No. 5,853,814 US Pat. No. 5,948,480 International Publication No. 2000/000691 Pamphlet US Pat. No. 6,197,378 US Pat. No. 5,520,962

  For environmental and economic reasons, there is a desire to reduce the overall use of topical antifouling formulations, particularly those containing fluorochemicals. Therefore, there is a need for antifouling compositions that can be applied by spray application equipment because the spraying method consumes a smaller amount of water and energy to dry than the discharge application. However, current spray compositions do not give satisfactory antifouling properties at the low impregnation required when applied.

  Accordingly, it is desirable to develop an antifouling composition that can be applied by spraying at low impregnation rates. Such a composition appears to be ideal for carpets made from dyed fibers that do not need to be further exposed to the discharge method. In addition, rug factories that do not have facilities for applying antifouling compositions by discharge methods would benefit from such spray compositions.

  The invention disclosed herein provides an antifouling composition for spraying comprising an antifouling component and a fouling blocker component. Spray antifouling compositions can be used with a variety of fibers, carpets and fabrics, such as those made with olefin and polyester polymer components. Such compositions are counter-intuitive because certain olefin and polyester fibers, carpets and fabrics do not require a stain blocker because they are inherently stain resistant. Thus, there is a surprising synergistic effect with a composition comprising both an antifouling component and a contamination blocker component. The antifouling component may be either fluorochemical or non-fluorochemical based. Polyester and olefin carpets treated with the disclosed compositions exhibit superior antifouling properties compared to similar carpets treated with known fluorochemical antifouling compositions. Further disclosed are methods of making soil-repellent fibers, carpets and fabrics.

  In one embodiment, an antifouling composition comprising an antifouling component and a fouling blocker component is disclosed. The antifouling composition is adapted to be sprayed onto the fibers at an impregnation rate of about 8% and about 40%. Antifouling compositions are high specific surface energy chemicals or other materials such as fluorochemicals that give high specific surface energy properties such as high contact angles for water and oil, or non-fluorochemical particulates with similar properties. Substances can also be included. Contamination blockers can be used to bind any acidic fiber coating chemicals, such as contamination blocker chemicals that are designed to make acid dyes resistant to contamination by binding to positively charged dye sites such as amine end groups. Can be included.

  In another aspect, a fiber comprising a spray surface treatment comprising an effective amount of a contamination blocker is disclosed. Contamination blockers are present at about 500 ppm to about 4% based on fiber weight. The fibers can have a polypropylene or polyester polymer component. The fibers can be processed into carpets or fabrics. The surface treatment agent can further contain an antifouling component.

  In a further aspect, a carpet treated with the disclosed antifouling composition having a Delta E stain resistance rating of less than about 10 in a 15,000-step cycle is disclosed. The carpet has an initial L value in the range of about 58 to about 62.

  In yet another aspect, a carpet treated with the disclosed antifouling composition having a Delta E stain resistance rating of less than about 4 after a 15,000-step cycle and after one hot water dewatering is disclosed. The The carpet has an initial L value in the range of about 58 to about 62.

In yet a further embodiment, (a) contacting the fiber with an antifouling composition comprising an antifouling component and a fouling blocker component at an impregnation rate of about 10-20% by weight; and (b) the fiber A method of treating fibers comprising the step of drying is disclosed. The contacting step can be carried out by spraying. Contamination blockers are present at about 500 ppm to about 4% based on fiber weight after drying. The fibers can include a polyester or polypropylene polymer component.

Definitions Although most of those skilled in the art are familiar, the following definitions are provided for clarity.
OWF [On weight of fiber] : The amount of chemical applied as a percentage of the weight of the fiber.
WPU [Wet pick-up] : The amount of water and solvent applied to the carpet prior to drying the carpet, expressed as a percentage of the weight of the fiber.

DETAILED DESCRIPTION OF THE INVENTION An antifouling composition comprising an antifouling component and a fouling blocker component is disclosed. The composition is adapted to be sprayed onto fibers, carpets or fabrics with an impregnation rate between about 8% and about 40% by weight. Antifouling compositions for use in the disclosed antifouling compositions have a high contact angle for water and oil (eg, water and oil “bead-up” on the surface treated thereby). High specific surface energy characteristics such as The antifouling component can comprise a fluorochemical dispersion, the dispersion comprising fluorochemical allophanate, fluorochemical polyacrylate, fluorochemical urethane, fluorochemical carbodiimide, and fluorochemical guanidine. Including those selected from the group and can be either primarily cationic or anionic. Alternatively, the fluorochemical can have no more than 8 fluorinated carbons, including no more than 6 fluorinated carbons. Exemplary fluorochemical antifouling components include DuPont TLF 10816 and 10894; Daikin TG 2511 and DuPont Capstone RCP: Non-fluorinated antifouling ingredients include silicones, silsesquioxanes and fluorosilanized and fluoroalkylated granules, anionic non-fluorinated surfactants and anionic hydrophobic non-fluorinated surfactants (sulfonates, sulfates, phosphates). And carboxylate): (see US Pat. No. 6,824,854, which is hereby incorporated by reference).

  Contamination blocker compositions for use in the disclosed antifouling compositions comprise acidic groups that bind to the amine end groups of the polymer and protect them from contamination due to acid dye contamination. A general class of chemicals suitable for the method of the present invention can comprise any chemical that blocks positively charged dye sites. Contamination blockers are available in various forms such as syntans, sulfonated novolaks, or sulfonated aromatic aldehyde condensation products (SAC). They are usually produced by reacting formaldehyde, phenol, polymethacrylic acid, maleic anhydride and sulfonic acid, depending on the specific chemical structure. In addition, fouling blockers are typically water-soluble and generally penetrate the fiber, while anti-fouling agents, usually fluorochemicals, are water-insoluble dispersions that coat the surface of the fiber.

Examples of contamination blockers include, but are not limited to, phenol formaldehyde polymers or copolymers such as CEASESTAIN and STAINAWAY (from American Emulsions Company, Inc., Dalton, Ga.), MESITOL (Bayer Corporation, Rock Hill, N. From C.), ERIONAL (from Ciba Corporation, Greensboro, NC), INTRATEX (from Crompton & Knowles Colors, Inc., Charlotte, NC), STAINKLEER (Dy)
etech, Inc. Dalton, Ga. ), LANOSTAIN (from Lemar Chemical Corporation, Dalton, Ga.) And SR-300, SR-400 and SR-500 (from EI du Pont de Nemours and Company, Wilmington, Del.); Cohesives such as SCOTCHGARD FX series carpet protectants (from 3M Company, St. Paul Minn.); Sulfonated fatty acids (from Rockland React-Rite, Inc., Rockmart, Ga); and soil resistance chemistry from ArrowStar LLC, Dalton Chemicals and Tri-Tex (Canada):

  The antifouling composition comprises from about 500 ppm to about 4 wherein the soil blocker comprises from about 1000 ppm to about 3%, from about 0.5% to about 2%, and from about 0.5% to about 1%, based on the weight of the fiber. % And the fluorine-based antifouling component based on the weight of the fiber is sprayed to be about 50 ppm to about 800 ppm fluorine, including about 100 to about 500 ppm fluorine, and about 100 ppm to about 300 ppm. Fiber, carpet and fabric. The impregnation rate of the composition is between 8 and 40 wt%, including about 10 to 20 wt%, about 10 to 15 wt% and about 10 to 12 wt%.

  Conventional fouling blockers use sulfonated groups as part of the chemical structure, which results in the presence of sulfur on the treated fiber. The sulfur content can range from about 50 ppm with a 5% fouling blocker to about 1 ppm with a 0.1% fouling blocker, based on the weight of the fiber. Thus, based on the contamination blocker concentration, the sulfur content based on the weight of the fiber is in the range of about 0.5 ppm to about 40 ppm, including about 1 ppm to about 30 ppm, about 5 ppm to about 20 ppm, and about 5 ppm to about 10 ppm. There will be. The sulfur content can be determined by x-ray diffraction or other methods.

  Carpets treated with the disclosed antifouling compositions of various embodiments exhibit a Delta E stain resistance rating of less than about 10, including less than about 9 and less than about 8, in a 15,000-step cycle. Note that Delta E is a function of the original color of the carpet. The above results relate to carpet colors in the L value range of about 58 to about 68. Furthermore, carpets treated with the various disclosed antifouling compositions exhibit improved Delta E stain resistance after warm water dewatering compared to carpets treated with fluorochemical alone. If the carpet is a darker color, or if the L value is less than this specified range, the stain resistance Delta E will also be smaller (ie, the color change of the darker carpet It will be more difficult to see). Contamination blockers from the antifouling composition comprise about 500 ppm to about 4 including about 1000 ppm to about 3%, about 0.5% to about 2%, and about 0.5% to about 1%, based on the weight of the fiber. % Present on the carpet.

  Further disclosed is a fiber comprising a sprayed surface treatment comprising an effective amount of a contamination blocker. The contamination blocker can be any of the ingredients described above. Contamination blockers are on the fiber at about 500 ppm to about 4%, including about 1000 ppm to about 3%, about 0.5% to about 2%, and about 0.5% to about 1%, based on the weight of the fiber. Exists. The surface treatment agent can further comprise any of the aforementioned antifouling ingredients. The surface treatment agent prior to drying the fiber is present at an impregnation rate of from about 10 to about 20 weight percent, including from about 10 to about 15 weight percent, and from about 10 to about 12 weight percent. The fibers can be processed into carpets or fabrics themselves or mixed with untreated fibers. The fibers can include a polymeric component of polyester (eg, PET or PPT) or olefin (eg, polypropylene). An effective amount of spray surface treatment provides a soil-preventing feature that is approximately equivalent to or better than the same fiber treated by the discharge method.

  Further disclosed is a method for treating fibers. The method comprises the steps of: (a) contacting the fiber with a stain prevention composition comprising a stain prevention component and a stain blocker component at an impregnation rate of between about 10 and 20% by weight; and (b) the fiber. Comprising the step of drying. The antifouling component and the contamination blocker component can be any of the chemicals disclosed above. The contacting step can be carried out by spray application at a low impregnation rate. The drying process can be carried out using any type of oven, normal dryer or forced hot air application. Drying temperatures can range from about 230 ° F. (110 ° C.) to about 280 ° F. (138 ° C.), including from about 245 ° F. (118 ° C.) to about 260 ° F. (127 ° C.). The drying period can range from about 1 to about 4 minutes, including from about 1 to about 3 minutes. The impregnation rate can also range from about 10 to about 15% by weight, including from about 10 to about 12% by weight. After drying, the soil blocker is present at about 500 ppm to about 4%, including about 1000 ppm to about 3%, about 0.5% to about 2%, and about 0.5% to about 1%, based on the weight of the fiber. . When a fluorine-based antifouling component is used, the fluorine-based antifouling component based on the weight of the fiber includes from about 100 to about 500 ppm fluorine, and from about 100 ppm to about 300 ppm, from about 50 ppm to about 800 ppm. Fluorine. The fibers can include a polyester or polypropylene polymer component.

  The fibers can be processed into carpets or fabrics themselves or blended with untreated fibers. Furthermore, the disclosed method can be used to treat carpets or fabrics rather than fibers. Furthermore, the disclosed method can be used not only for dyed fibers, but also for pigmented fibers (also known as solution dyeing). This would include carpets made from polyester. Polypropylene is usually solution dyed. The antifouling composition may or may not contain a fluorochemical. Fluorochemical compositions may be cationic or anionic in these formulations, and the disclosed antifouling compositions can use both.

  The combination of antifouling agent and stain blocker provides a surprisingly synergistic antifouling composition that is more effective in improving the stain resistance of carpets. This is surprising because the stain blocking agent itself does not give the fibers any antifouling features. In addition, polymers of polyesters (eg, PET and PPT) and olefins (eg, polypropylene) serve as sites for acid dyes, and are free of amine end groups that are inherently resistant to contamination, thereby causing contamination blocking agents. Are typically not required for these fibers. The combination of antifouling and fouling block components for olefins and polyesters is synergistic because surprisingly low levels of dosage can be effective. Those of ordinary skill in the art will obtain chemicals with other closely related properties (sulfonated low molecular weights) that are not specifically used as contamination blockers to blend with antifouling formulations to obtain the disclosed improvements. Polymers, polymer binders, soft coatings, etc.) can be selected. These modifications are also considered part of the invention. Furthermore, the antifouling composition can be applied to fibers, carpets or fabrics by spray application instead of discharge application, while still maintaining excellent antifouling properties due to the synergistic effect.

  The following are examples of polyester and polypropylene rugs treated with the antifouling compositions disclosed above as compared to standard antifouling fluorochemical treated rugs and untreated rugs. The choice of alternative antifouling components and fouling blocker components, fibers and fabrics with different surface chemical structures will require minor adjustments to the variables described herein.

Test method
Walking test : The description of the walking test is as follows:
1. Pedestrian selection : Select the pedestrian with the maximum possible traffic. Samples should be placed 20-30 feet (6m-9m) from the outside entrance. Always use a withdrawal area (eg: a small carpet) on both ends of the test that spans at least 6-8 feet (1.8 m-2.4 m). Measure traffic numbers with an electro-visual counter or pad counter. This method will not succeed if a large number of groups enter the room at the same time.

2. Measure corridor size for sample preparation and installation walk test. The length of the corridor will determine the sample number and sample size. A minimum width (minimum width) of 12 "(30.5 cm) to a width of 24" (61 cm) can be used.

Contamination Resistance Method A set of sample carpets or multiple sets of samples can be installed. Measure the first L, a, b of the sample (using a Minolta spectrophotometer). As the contamination progresses, L, a, b readings are collected and delta E is calculated. This Delta E represents the change in color of the sample when compared to the same carpet sample before contamination. When Delta E reaches a high value, it will be time to warm water dehydrate (HWE) and measure Delta E after washing. This method can be repeated to collect data for multiple cleaning and traffic cycles.

  In this test, a beige, 37 Oz (1.05 kg) PET rug with an L value of about 65 was sprayed with various fluorochemical chemicals to a fluorine level of about 300 ppm on the rug. Fluorochemical chemicals were from DuPont and Daikin. Table 1 shows the composition of antifouling chemicals. These carpet sections were installed for walking tests and Delta E was measured using a Minolta spectrophotometer at various periods of traffic. L, a, b measurements were taken for 5,000, 10,000, 15,000 and 17,5000 cycles of traffic and Delta E was calculated. The carpet was dehydrated with warm water in a 17,5000 cycle traffic. After washing, L, a, b values were recorded again and Delta E was calculated. The data in Table 1 shows that the contamination is very high (greater than 16 Delta E) and has a high Delta E greater than 9 even after cleaning. Therefore, such chemical spray application does not provide improved anti-contamination performance.

  In this test, various fluorochemical chemicals were sprayed onto PET rugs with a beige color of 30 Oz (894 g) having an L value of about 58 to a fluorine level of about 300 ppm on the carpet. Fluorochemical chemicals were from DuPont and Daikin and included a contamination blocker S-801 manufactured by INVISTA. Table 2 shows the composition of antifouling chemicals. These carpet sections were installed for walking tests and Delta E was measured using a Minolta spectrophotometer at various periods of traffic. Measured L, a, b of traffic of 5000, 10,000, 15,000 cycles and calculated Delta E. In 15,000 cycles of traffic, the carpet was dehydrated with warm water with detergent. After washing, L, a, b values were recorded again and Delta E was calculated. The data in Table 2 is 15 for samples 6 and 7 based on the disclosed antifouling compositions, compared to sample 4 which is a sample of untreated carpet and sample 5 which was treated by conventional application. It shows that the stain resistance is much improved (lower Delta E) at 1,000 cycles (lower Delta E). Sample 7 in Table 2 uses a fluorochemical similar to that used in Sample 3 in Table 1, but shows much better performance in stain resistance due to the use of blends in the context of the present invention. Furthermore, when the samples were washed after 15,000 cycles, samples 6 and 7 showed a Delta E improvement of 64% to 70%, while Samples 4 and 5 showed a Delta E improvement of only about 50%. . The Delta E results for samples 6-7 after washing are low enough that they are commercially acceptable. Carpets treated with the disclosed antifouling compositions respond better to carpet cleaning than traditionally treated carpets and have superior stain resistance results throughout the walking test, including after cleaning.

The test was carried out on a polypropylene carpet with a floral carpet design. Table 3 lists various polypropylene carpet products and their processing methods. The chemicals used were Daikin TG 2511, DuPont TLF 10816, TLF 10894 and Capstone RCP. All samples were 35 oz (991 g) rug carpets and the fluorochemical application level was about 300 ppm fluorine.

  Due to the floral design, measurement of the Delta E walking cycle test was not possible. However, visual observations showed that sample 10 followed, but sample 13 showed better stain resistance than the remaining samples. This improvement was also seen after washing. These samples with excellent antifouling performance were prepared by the disclosed methods of various embodiments.

  It should be noted that Daikin TG 2511 is a cationic formulation and DuPont's chemical is an anionic formulation. This shows that the method of the present invention is effective for different types of formulations of fluorochemical chemicals.

  The present invention has been described above in connection with various aspects of the disclosed antifouling compositions, treated fibers, carpets, fabrics and methods of making them. Upon reading and understanding the detailed description of the procedure, modifications and changes that will be apparent to other persons skilled in the art will occur. The present invention is intended to be construed to include all such modifications and variations as long as they are within the scope of the claims.

Claims (38)

  An antifouling composition comprising an antifouling component and a fouling blocker component, wherein the composition is sprayed onto the fibers at an impregnation rate of about 8 wt% and about 40 wt%.   The antifouling composition of claim 1 comprising a fluorochemical.   Antifouling composition according to claim 1 or 2, wherein the fibers are colored or solution dyed.   The antifouling composition according to claim 1, wherein the fiber has a polymer component selected from the group consisting of polyester and polypropylene.   The group consisting of fluorochemicals incorporating fluorochemical allophanates, fluorochemical polyacrylates, fluorochemical urethanes, fluorochemical carbodiimides, fluorochemical quinidines and C-2 to C-8 chemicals The antifouling composition of claim 2 selected from.   The antifouling composition of claim 2, wherein the fluorochemical has 6 or fewer fluorinated carbons.   The antifouling composition of claim 2, wherein the fluorochemical is a fluorochemical urethane.   The fouling blocker is selected from the group consisting of syntans, sulfonated novolaks, sulfonated aromatic aldehyde condensation products (SAC) and / or reaction products of formaldehyde, phenol, polymethacrylic acid, maleic anhydride and sulfonic acid The antifouling composition according to claim 1.   A fiber comprising a spray surface treatment comprising an effective amount of a contamination blocker.   The fiber of claim 9, wherein the fiber has a polymer component selected from the group consisting of polyester and polypropylene.   11. The fiber of claim 9 or 10, wherein the contamination blocker is present at about 500 ppm to about 4% based on fiber weight.   11. The fiber of claim 9 or 10, wherein the contamination blocker is present at about 1000 ppm to about 3% based on fiber weight.   11. The fiber of claim 9 or 10, the product of claim 10, wherein the soil blocker is present from about 0.5% to about 2% based on fiber weight.   11. The fiber of claim 9 or 10, wherein the surface treatment further comprises an antifouling component.   15. The fiber of claim 14, wherein the antifouling component comprises a fluorochemical. 16. The fiber of claim 15, wherein the fluorochemical is selected from the group consisting of fluorochemical allophanate, fluorochemical polyacrylate, fluorochemical urethane, fluorochemical carbodiimide, and fluorochemical guanidine.   16. The fiber of claim 15, wherein the fluorochemical has 6 or fewer fluorinated carbons.   The fiber of claim 15, wherein the fluorochemical is a fluorochemical urethane.   19. The fiber of any one of claims 15-18, wherein the fluorine in the antifouling component is present at about 50 ppm to about 800 ppm based on fiber weight.   The fouling blocker is selected from the group consisting of: syntans, sulfonated novolaks, sulfonated aromatic aldehyde condensation products (SAC), reaction products of formaldehyde, phenol, polymethacrylic acid, maleic anhydride and sulfonic acid: The fiber according to claim 9 or 10.   11. The fiber of claim 9 or 10, comprising from about 0.5 ppm to about 40 ppm sulfur based on fiber weight.   11. The fiber of claim 9 or 10, wherein a surface treatment agent is present at an impregnation rate of between about 10-20% by weight before the fiber is dried.   A carpet or fabric made from a plurality of fibers from one of claims 9-22.   9. An initial L value in the range of about 58 to about 62 comprising an atomized surface treatment comprising the antifouling composition of claim 1 and 15,000 steps. Carpet having a Delta E stain resistance rating of less than about 10 in a cycle of   9. An initial L value in the range of about 58 to about 62 comprising an atomized surface treatment comprising the antifouling composition of claim 1 and 15,000 steps. Carpet having a Delta E stain resistance rating of less than about 4 after a total of cycles and after one hot water dehydration.   25. The carpet of claim 24, wherein the contamination blocker is present at about 500 ppm to about 4% based on fiber weight.   25. The carpet of claim 24, wherein the soil blocker is present at about 1000 ppm to about 3% based on fiber weight.   25. The carpet of claim 24, wherein the soil blocker is present at about 0.5% to about 2% based on fiber weight.   25. The carpet of claim 24, wherein the Delta E stain resistance is less than about 9 in a 15,000-step cycle.   25. The carpet of claim 24, wherein the Delta E stain resistance is less than about 8 in a 15,000-step cycle.   26. The carpet of claim 24 or 25, wherein the carpet comprises polyester fibers.   (A) bringing the fiber into contact with a stain prevention composition comprising a stain prevention component and a stain blocker component at an impregnation rate of about 10 to 20% by weight; and (b) drying the fiber. A method for treating a fiber comprising:   35. The method of claim 32, wherein the soil blocker is present at about 500 ppm to about 4% based on fiber weight after drying.   36. The method of claim 32, wherein the contacting step comprises spraying the composition onto the fibers.   35. The method of claim 32, wherein the drying step is performed at a temperature of from about 230 <0> F (110 <0> C) to about 280 <0> F (138 <0> C).   35. The method of claim 32, wherein a contaminating blocker component is present from about 500 ppm to about 4% based on fiber weight after the drying step.   35. The method of claim 32, wherein the antifouling component is a fluorochemical and fluorine is present at about 50 ppm to 800 ppm based on fiber weight.   38. The method of one of claims 31 to 37, wherein the fiber comprises a polymer component selected from the group consisting of polypropylene and polyester.