Quantitative detection of non-fluorine anti-soil using a fluorescent trace indicator

Abstract

A method for quantitatively and indirectly measuring non-fluorine anti-soil chemistry in carpet applications, is based on a known amount of FI trace to be added along with anti-soil chemistry in formulation prior to application to a carpet surface. The anti-soil chemistry with the trace amount of FI is then applied to the carpet through a topical foam or spray applicator during a precoating process. After completion of the precoat process, a carpet sample is collected, carpet face fiber is shaved, and FI is extracted using water. The extracted water solution is used to measure the fluorescence intensity (in counts per second or “CPS”) using a Fluorimeter.

Claims

1. A method for quantitatively measuring an amount of a non-fluorine anti-soil treatment composition present on a textile substrate, the method comprising the following steps, in order: (a) adding a predetermined amount of a fluorescent indicator (FI) of 1,5 naphthalenedisulfonic acid disodium salt to the non-fluorine anti-soil treatment composition; (b) applying the non-fluorine anti-soil treatment composition obtained from (a) to a surface of the textile substrate; (c) collecting a sample from the surface of the textile substrate; (d) extracting the FI from a portion of the collected sample to obtain a solution containing the extracted FI; (e) measuring a fluorescence emission intensity in the solution containing the extracted FI, and (f) comparing the measured fluorescence emission intensity to a predetermined baseline determine a concentration of FI indicative of a degree of application of the non-fluorine anti-soil treatment composition to the portion of the collected sample.

2. The method of claim 1, wherein (c) further comprises isolating the sample of the textile substrate and removing the portion of the surface from the sample.

3. The method of claim 1, wherein the textile substrate is a carpet.

4. The method of claim 1, wherein the textile substrate has an uneven and/or irregular surface onto which the treatment composition is applied.

5. The method of claim 1, wherein the predetermined amount of the FI in (a) is between 5-100 ppm of FI.

6. The method of claim 1, wherein, in (b), the non-fluorine anti-soil treatment composition is applied using a topical foam applicator.

7. A method for quantitatively measuring an amount of a non-fluorine anti-soil treatment composition present on a textile substrate, the method comprising the following steps, in order: (a) adding a predetermined amount of a fluorescent indicator (FI) of 1,5 naphthalenedisulfonic acid disodium salt to the non-fluorine anti-soil treatment composition; (b) applying the non-fluorine anti-soil treatment composition obtained from (a) to a surface of the textile substrate; (c) collecting a sample from the surface of the textile substrate, wherein the collected sample comprises at least one face fiber; (d) isolating the at least one face fiber from the collected sample; (e) extracting the FI from the isolated at least one face fiber to obtain a solution containing the extracted FI; (f) measuring the fluorescence emission intensity in the solution containing the extracted FI; (g) comparing the measured fluorescence emission intensity to a predetermined baseline to determine a first degree of application of the non-fluorine anti-soil treatment composition to the isolated at least one face fiber; and (h) adjusting one or more parameters of an application or manufacturing process based on the determined first degree of application such that a second degree of the non-fluorine anti-soil treatment composition is applicable to another textile substrate via the adjusted one or more parameters of the application or manufacturing process, wherein the determined first degree of application is a greater degree of application or lesser degree of application than the second degree of application.

8. The method of claim 1, wherein the one or more parameters comprise at least one of speed, pressure, temperature, application mechanism, and concentration.

9. A method for quantitatively measuring an amount of a non-fluorine anti-soil treatment composition present on a textile substrate, the method comprising the following steps, in order: (a) adding a predetermined amount of a fluorescent indicator (FI) to the non-fluorine anti-soil treatment composition; (b) applying the non-fluorine anti-soil treatment composition obtained from (a) to a surface of the textile substrate; (c) collecting a sample of the surface; (d) extracting the FI from a fiber portion of the collected sample to obtain a solution containing extracted FI; (e) measuring the fluorescence emission intensity in the solution containing extracted FI; and (f) comparing the measured fluorescence emission to a predetermined baseline to determine a concentration of FI with respect to the fiber portion of the collected sample, wherein the FI comprises a naphthalic, pyrene, or phenyl moiety having the chemical structure: ##STR00002## wherein R is an amino (—NH2), hydroxyl (—OH) group, aliphatic, aromatic, alicyclic, alkyl (straight or branched chain), phenyl, halogen, or heteroaromatic moiety at any position of naphthalene ring, X is sulfonic acid or its salt with an integer from 0-3 attached at any position of naphthalene moiety, and M is sodium, potassium, or lithium metal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1 and 2: show Fluorescence Emission Spectra of Pure and Extracted Samples in Example 1. FIG. 1 shows pure fluorescent indicator (FI) (10 ppm) at 1 nm slit; FIG. 2 shows emission of water sample extracted from carpet sample treated with 25 ppm FI, which is further diluted to 0.75 ppm by dissolving 1 gram of shaved fiber in 20 mL water.

(2) FIG. 3: shows Emission Spectra at Various extraction in Example 1.

(3) FIGS. 4 and 5 show pure FI at various concentrations to determine the emission baseline.

DETAILED DESCRIPTION

(4) As used herein, a “trace amount” refers to an average concentration of less than or equal to 100 parts per million (ppm) of anti-soil coating solution, preferably about 5-100 ppm.

(5) The inventors have developed a novel, cost-effective, quantitative, test method that can be used to measure non-fluorine anti-soil chemistry in carpet applications. This method will help manufacturing detect and monitor anti-soil application rate with more consistency and provide better quality control. In addition, this method can be used beyond anti-soil application and testing. For example, the method can be used with a manufacturing process, such as in material coating or compounding, where the material application rate cannot otherwise be measured and monitored directly using the processing materials. In particular, the method is particularly directed toward surfaces having an irregular and/or three-dimensional surface, such as woven textile, and particularly carpeting. In addition to the irregularity of a carpet surface, the nature of the carpet face fiber design makes it inherently difficult to measure the degree of application of a chemical layer applied thereto.

(6) The method requires a known amount of FI trace be added along with anti-soil chemistry in formulation, which is then applied to the carpet (in one embodiment, by way of a known topical foam applicator) during a topical/spray treatment process. After completion of the topical/spray process, a carpet sample is collected, carpet face fiber is isolated and removed (e.g. by shaving), and FI is extracted using water at alkaline pH of about 8.5-9.5, preferably of about 9 More specifically, in one embodiment, one gram of shaved fiber is added to 19 mL of de-ionized water along with 1 mL of 1% sodium carbonate, followed by agitation for 30 minutes. The extraction process, amounts and timing may be adjusted according to the knowledge of one skilled in the art. The extracted water solution is filtered and used to measure the emission intensity using a Fluorimeter. The fluorescence emission intensity is directly proportional to the concentration of FI on the carpet fiber. Hence, the concentration of anti-soil is measured indirectly. The general principle is that the FI absorbs light at a lower UV-region (228 nm) and emits light in the higher UV-region (334 nm). The fluorescence emission intensity is measured to quantify the amount of FI trace, i.e., indirectly providing the concentration of anti-soil compound as applied to the carpet face. Remarkably, the FI provides emission in the non-visible UV-region and will not impact the carpet color aesthetics.

(7) The Fluorescent Indicator (FI)

(8) The Fluorescent compounds may generally comprise a naphthalic, pyrene or phenyl moiety having the following general chemical structure:

(9) ##STR00001##
where R is an amino (—NH2), hydroxyl (—OH) group, aliphatic, aromatic, alicyclic, alkyl (straight or branched chain), phenyl, halogen, heteroaromatic moiety at any position of naphthalene ring; similarly X is sulfonic acid or its salt with an integer from 0-3 may be attached at any position of naphthalene moiety; and M is sodium, potassium or lithium metal. Examples of FI that may be suitable include, but are not limited to 1,5-Naphthalenedisulfonic acid disodium salt; 1,5-Naphthalenedisulfonic acid tetrahydrate; 2,6-Naphthalenedisulfonic acid disodium salt; 1-Naphthol-4-sulfonic acid sodium salt; 6-Hydroxy-2-naphthalenesulfonic acid sodium salt hydrate; 2-naphthol-6-sulfonic acid potassium salt; 2-Naphthol-3,6-disulfonic acid disodium salt; 4-Hydroxy-2,7-naphthalenedisulfonic acid disodium salt; 4-Amino-5-hydroxynaphthalene-2,7-disulfonic acid monosodium salt hydrate; Tetrasodium 1,3,6,8-pyrenetetrasulfonate hydrate; 1-Pyrenesulfonic acid sodium salt and 8-Hydroxypyrene-1,3,6-trisulfonic acid trisodium salt. In a particular embodiment, the FI is 1,5-Naphthalenedisulfonic acid disodium salt (CAS Number 1655-29-4).
Anti-Soil Composition

(10) The inventive test method can be used to measure the effective application level of any coating material to a textile surface. In one embodiment, the method is used to measure the effective application of anti-soil materials such as fluorochemicals, acrylics, silicones and waxes materials on a textile and/or carpet surface, which may be woven, tufted or non-woven.

(11) Coatings Systems

(12) The inventive test method can be used with any polymer/material coating systems where the polymer/material application rate needs to quantify. Examples of coating systems that may be suitable include, but are not limited to, carpet anti-soil coatings, textile water-repellant coatings and textile softening coatings.

(13) Alternatives

(14) A rare metal trace can be used as an indicator, but it may be less desirable because of its associated lower solubility and stability.

(15) Finally, it should be clear to those skilled in the art that each embodiment disclosed herein can be and is contemplated as being applicable to each of the other disclosed embodiments. Accordingly, all combinations of the various elements described herein are within the scope of the invention.

EXPERIMENTAL DETAILS

Example 1

(16) The objective of this experiment is to develop a cost-effective, quantitative test method to measure non-fluorine anti-soil chemistry application rate in a topical/spray using a FI. This experiment involves screening and evaluating fluorescent trace agents that can be used as an indicator to monitor the anti-soil application rate using a Fluorimeter, in carpet topical/spray application.

(17) Fluorescent Indicator (FI) Application Rate

(18) Preparation of 1000 ppm FI Stock Solution

(19) Fluorescent Indicator (FI)=0.100 grams (1,5-Naphthalenedisulfonic acid disodium salt (CAS Number 1655-29-4)) Eco-Ensure (Anti-soil mix/Solution)=100 mL

(20) TABLE-US-00001 TABLE 1 Preparation of Eco-Ensure and Fluorescent Indicator solution (mix) and application rate to four carpet samples (based on dilution with additional Eco-Ensure solution) Carpet Calculated Actual Eco- FI, sample Eco-Ensure mix Ensure mix Concentration weight application rate application rate* Sample (PPM) (grams) (grams) (grams) Blank 0 50 11 12.0 A 25 50 11 11.9 B 25 50 11 11.7 C 25 50 11 11.3 *The amount of Eco-Ensure mix is calculated and used based on 22% wet pick-up and 2% Eco-Ensure add-on (target) on the weight of carpet face fiber.

(21) TABLE-US-00002 TABLE 2 Fluorescent Indicator (FI) Extraction Method from Carpet Samples Fiber wt. 1 gram Water 19 mL Sodium Carbonate (1%) 1 mL pH 9 ± 0.5 Agitation 30 minutes

(22) TABLE-US-00003 TABLE 3 Fluorescence Emission Measurement to effectiveness of FI extrusion process. Concen- Fiber Excita- Emis- Emission tration wt. tion λ sion λ Intensity Sample (PPM) (grams) (nm) (nm) (CPS) Blank sample 0 1.0036 280 334 No peak 1st extraction, 25 1.0054 280 334 632710 sample A 1st extraction, 25 1.0065 280 334 711760 sample B 1st extraction, 25 1.0087 280 334 644540 sample C 2nd extraction, NA 1.0054 280 334 103500 sample A 2nd extraction, NA 1.0065 280 334 109740 sample B 2nd extraction, NA 1.0087 280 334 110440 sample C 3rd extraction, NA 1.0054 280 334 28370 sample A 3rd extraction, NA 1.0065 280 334 23420 sample B 3rd extraction, NA 1.0087 280 334 21350 sample C Measurement conditions: slit = 2 nm; increment = 1 nm and filtered Ext. Solu. = PA, 0.45 μm.

(23) Emission spectra of pure FI in de-ionized water at 10 ppm concentrations are shown in FIG. 1 Fluorescence emission intensity of pure FI after extraction from carpet fiber treated with a 25 ppm solution of FI is shown in FIG. 2. Emission spectrum of fluorescent trace indictor sample extracted from carpet fiber is measured in deionized water. The carpet sample was treated with 25 ppm fluorescent indicator and Eco-Ensure mix using a foam applicator at a wet-pickup of 22%.

(24) Fluorescence Emission Spectra of FI extracted from carpet fiber samples are shown in FIG. 3. The 25 ppm trace amount of FI along with Eco-Ensure anti-soil is applied to the carpet through a topical foam applicator during a precoat process, carpet face fiber is isolated by shaving, using 1 g fiber from each of three samples A-C and FI is extracted using a 20 mL water extraction process. The extraction process is repeated three times for each sample and emission is measured each time (in counts per second or “CPS”) using a Fluorimeter) to evaluate effectiveness of the extrusion process. The extraction result showed that the FI indicator is rapidly soluble in water and effectively removed from the fiber in first extrusion. The residual FI in second extrusion is very minimum and in third extrusion it is completely removed.

(25) In order to have a comparative baseline measurement for presence of FI indicator, emission intensity was measured for the FI indicator in pure water solution based on varying amounts of FI indicator. The results are set out in Table 5 below where a direct correlation between amount of FI and measured intensity is seen. FIG. 4 shows the corresponding emission spectra and FIG. 5 depicts the baseline graphically.

(26) TABLE-US-00004 TABLE 4 Fluorescent Indicator concentration in pure water solution and their emission intensity for baseline measurements Fluorescent Indicator Excita- Emis- Emission Sample Concentration tion λ sion λ Intensity # (ppm) (nm) (nm) (CPS) 1 Blank 280 334 570 2 0.05 280 334 35500 3 0.1 280 334 67060 4 0.2 280 334 129910 5 0.3 280 334 203960 6 0.4 280 334 261080 7 0.5 280 334 349000 8 0.6 280 334 444520 9 0.7 280 334 497210

(27) A preferred ratio of Fluorescent Indicator and Eco-Ensure anti-soil was used in testing formulation in connection with Table 5 to prepare the topical anti-soil treatment solution, which is employed to carpet face fiber using a foam applicator during precoat process.

(28) TABLE-US-00005 TABLE 5 Preoaration of Eco-Ensure and Fluorescent Indicator solution and their weight ratio weight ratio Anti-soil treatment Concentration Concentration (Eco-Ensure/ chemical formulation (wt %) (ppm) Indicator) Eco-Ensure 9 90000 1800 Fluorescent Indicator 0.01 50

(29) TABLE-US-00006 TABLE 6A The Eco-Ensure and FI treat carpet fiber weight and emission intensity test results Shaved fiber Deionized Excita- Emis- Emission Sample weight water tion λ sion λ Intensity # (g) (dilution) mL (nm) (nm) (CPS) 1 1.014 20 280 334 493540 2 1.014 20 280 334 466600 3 1.024 20 280 334 528590 4 1.020 20 280 334 462080 5 1.015 20 280 334 436200 6 1.030 20 280 334 462770 7 1.025 20 280 334 410810 8 1.029 20 280 334 482370 9 1.024 20 280 334 481050 10 1.025 20 280 334 491460 11 1.027 20 280 334 504780 12 1.027 20 280 334 446450 13 1.023 20 280 334 446180 14 1.030 20 280 334 477960 15 1.026 20 280 334 448540 16 1.030 20 280 334 487380 17 1.034 20 280 334 503070 18 1.032 20 280 334 521460 19 1.029 20 280 334 483120 20 1.027 20 280 334 496880 21 1.024 20 280 334 440860

(30) TABLE-US-00007 TABLE 6B Estimation of % Eco-Ensure amount on carpet fiber using FI emission test results ppm, F. % Eco- Indicator Ratio ppm, Eco- Ensure on Emission (y = (Eco- Ensure weight of Sample Intensity 719465x − Ensure/ (ppm-Ind. × carpet # (CPS) 6915.1) Indicator) 1800 × 20@) fiber 1 493540 0.611 1800 21985.54 2.20 2 466600 0.578 1800 20802.04 2.08 3 528590 0.653 1800 23525.33 2.35 4 462080 0.572 1800 20603.47 2.06 5 436200 0.541 1800 19466.53 1.95 6 462770 0.573 1800 20633.78 2.06 7 410810 0.51 1800 18351.12 1.84 8 482370 0.597 1800 21494.83 2.15 9 481050 0.595 1800 21436.84 2.14 10 491460 0.608 1800 21894.17 2.19 11 504780 0.624 1800 22479.33 2.25 12 446450 0.553 1800 19916.83 1.99 13 446180 0.553 1800 19904.97 1.99 14 477960 0.592 1800 21301.1 2.13 15 448540 0.556 1800 20008.64 2.00 16 487380 0.603 1800 21714.93 2.17 17 503070 0.622 1800 22404.21 2.24 18 521460 0.645 1800 23212.1 2.32 19 483120 0.598 1800 21527.78 2.15 20 496880 0.615 1800 22132.27 2.21 @= Dilution Factor, one gram of shaved fiber is added to 20 mL of de-ionized water to extract fluorescent indicator

(31) The confirmation data as set forth in Table 6 above shows that the test measurement provides verifiable confirmation of the degree of anti-soil application on carpet fibers, in this case in reference to a desired application rate of 2% Eco-Ensure. The results indicate a mean rate of application at 2.11%+/−0.13.