COLOR STABLE TREATED FABRIC AND METHOD OF MAKING THE SAME

Abstract

The present invention relates to a color stable treated fabric and the method for making the same.

Claims

1. A transition metal-polymer complex treated article comprising: a) a monomer X selected from the group consisting of vinylimidazole, vinylimidazoline, vinylpyridine, vinylpyrrole, derivatives thereof and combinations thereof; and b) a transition metal; further wherein the molar ratio of monomer X to transition metal is from 22:1 to 117:1.

2. The treated article of claim 1 is a fiber or fabric

3. The treated article of claim 1 wherein the molar ratio of monomer X to transition metal is from 31:1 to 117:1.

4. The treated article of claim 1 wherein monomer X is vinylimidazole.

5. The treated article of claim 1 wherein the transition metal is selected from copper, zinc, gold, silver, tin, and combinations thereof.

6. The treated article of claim 1 wherein the transition metal is silver.

7. The treated article of claim 5 wherein the transition metal is silver ion.

8. The treated article of claim 1 wherein the fabric is cotton, nylon, polyester, and combinations thereof.

9. A method for treating a fiber or fabric comprising: a) providing a fiber or fabric b) providing at least one transition metal polymer complex comprising: i) a monomer X selected from the group consisting of vinylimidazole, vinylimidazoline, vinylpyridine, vinylpyrrole, derivatives thereof and combinations thereof; and ii) a transition metal wherein the molar ratio of monomer X to transition metal is from 22:1 to 117:1; and c) contacting the fabric with the at least one polymer complex.

10. The method of claim 9 wherein the transition metal is silver ion.

11. The method of claim 10 wherein the molar ratio of monomer X to silver ion is from 31:1 to 117:1.

We claim:

1. A transition metal-polymer complex treated article comprising: a) a monomer X selected from the group consisting of vinylimidazole, vinylimidazoline, vinylpyridine, vinylpyrrole, derivatives thereof and combinations thereof; and b) a transition metal; further wherein the molar ratio of monomer transition metal is from 24:1 to 117:1.

2. The treated article of claim 1 is a fiber or fabric

3. The treated article of claim 1 wherein the molar ratio of monomer X to transition metal is from 31:1 to 117:1.

4. The treated article of claim 1 wherein monomer X is vinylimidazole.

5. The treated article of claim 1 wherein the transition metal is selected from copper, zinc, gold, silver, tin, and combinations thereof.

6. The treated article of claim 1 wherein the transition metal is silver.

7. The treated article of claim 5 wherein the transition metal is silver ion.

8. The treated article of claim 1 wherein the fabric is cotton, nylon, polyester, and combinations thereof.

9. A method for treating a fiber or fabric comprising: a) providing a fiber or fabric b) providing at least one transition metal polymer complex comprising: i) a monomer X selected from the group consisting of vinylimidazole, vinylimidazoline, vinylpyridine, vinylpyrrole, derivatives thereof and combinations thereof; and ii) a transition metal wherein the molar ratio of monomer X to transition metal is from 24:1 to 117:1; and c) contacting the fabric with the at least one polymer complex.

10. The method of claim 9 wherein the transition metal is silver ion.

11. The method of claim 10 wherein the molar ratio of monomer X to silver ion is from 31:1 to 117:1.

Description

EXAMPLES

[0025] Materials and Methods Used to Prepare a Treated Fabric

TABLE-US-00001 TABLE 1 Chemicals used for Producing Antimicrobial Concentrate Formulations Ingredient Source Description QR-1719 polymer The Dow Chemical Company 45VI/40BA/15AA (32% by weight) QR-1831 polymer The Dow Chemical Company 75VI/25PEGMA (30% by weight) Silver Nitrate Sigma Aldrich Reagent #209139 Ammonium EMD Millipore 105423 hydroxide (28%)

TABLE-US-00002 TABLE 2 Textiles/Fabrics used for Testing Fabrics Description WPUR Polyester SDL Atlas - Item # 400000: TIC 730 100% ~100% Polyester Interlock Knit Cotton SDL Atlas - Item # 200789: TIC 460 100% ~100% Cotton Interlock Knit Nylon SDL Atlas: TIC 300 100% Spun Nylon 6.6 ~125% Plain Weave

Methods:

Fabric Treatment

[0026] A Lab scale padding machine from Werner Mathis AG (Model: CH-8155 VFM28888) was used to apply the antimicrobial compositions to fabric samples.

[0027] First, as standard in the field, fabric wet-pick up rate (WPUR) is determined to calculate the concentration of silver ion-polymer complex solution needed to achieve a target silver ion loading on the dried textile. The roller pressure is set to 3 barg initially. Then a 12 by 16 swatch of fabric is weighed out. Most fabric swatches will weigh between 10 to 15 grams. Polyester is typically 12 grams and heavy cotton is typically 15 grams. The swatch is soaked in a deionized water bath for 3 to 8 seconds until it has fully absorbed the water Immediately after, the wet fabric is passed through the spinning rollers at the 3 barg pressure setting. The fabric is then reweighed to determine the weight increase due to water absorption. The WPUR is calculated by the difference in the weight of the wet fabric after going through the rollers and the dried fabric weight divided by the dried fabric weight. Polyester fabric used here typically weighed around 24 grams after and 12 grams before affording a wet pick-up rate of (24-12)/12 or 100%. Cotton typically weighs 15 grams dried and 30 grams after the roller for a calculated wet pick-up rate of (30-15)/15 or 100%. Nylon typically weighed 12 grams dried and 27 grams after the roller for a calculated wet pick-up rate of (27-12)/12 or 125%. If the wet pick-up rate does not match the desired value, the pressure of the padding rollers can be adjusted up or down to achieve the desired values. Fabric source and composition will directly impact the WPUR and should be determined in order to achieve the target silver ion fabric concentration.

[0028] Second, the application bath solutions are prepared to treat each textile swatch or fabric. The silver ion concentration in the bath is calculated based on the initial silver ion concentrate solution and the wet pick-up rate. The calculation of bath concentration of an antimicrobial formulation is calculated by dividing the target silver ion level by the active loading in the antimicrobial formulation and then dividing by the wet pick-up rate. For example, to target a theoretical 30 ppm of silver on polyester fabric with a 100% wet pick-up rate using an antimicrobial formulation with 1000 ppm of silver, one would divide 30 ppm Ag target/1000ppm Ag in formulation/(1.0 WPUR*100), which is equivalent to 3 g antimicrobial concentrate formulation in 97 g of water. For the purposes of this invention, cotton and polyester treatments across all antimicrobial concentrate formulations (Table 3, 1-13) distinguished by varying VI:Ag+ molar ratios, were utilized similarly due to similar WPUR. The exception was for nylon fabric samples which achieved approximately 125% wet pick-up rate, the calculation was 30 ppm Ag target/1000ppm Ag antimicrobial formulation/1.25 WPUR*100, or 2.4 g antimicrobial concentrate formulation in 97.6 g of water.

[0029] The 30 ppm silver target fabric loading for cotton and polyester would be simply formulated by weighing out 3 grams of the antimicrobial concentrate formulation and mixing it into 97 grams of deionized water, and for nylon by weighing out 2.4 grams of antimicrobial concentrate formulation and mixing into 97.6 grams of deionized water. Due to silver ion-polymer complex stronger affinity to nylon versus cotton and polyester, baths were prepared at 15 ppm silver (or 1.5 grams of antimicrobial concentrate formulation) instead of 24 ppm to match desired fabric concentrations of approximately 30 ppm silver ion. For all fabrics used as controls (without antimicrobial treatment), fabrics were processed using water alone and are designated so in subsequent tables.

[0030] Lastly, the treatment of each fabric was carried out in the padding machine using the pressure settings determined above to achieve the desired wet pick-up rate for each fabric swatch. Each silver solution was poured into the trough on the padding machine prior to treatment. Then fabric samples were dipped into silver solutions for 3 to 8 seconds until soaked Immediately, the wet fabric was then passed through the rollers to achieve the desired wet pick-up weights. Then fabrics were placed onto a device that stretches the fabric taught and dried in a convection oven at 150 C. for 2 minutes.

Antimicrobial Concentrate Formulations:

[0031] Antimicrobial concentrate formulations 1-10 supporting VI: Ag+ molar ratios from 4 to 117 are depicted in Table 3. Each of the antimicrobial formulation examples contains approximately 1000 ppm or approximately 200 ppm of silver ion which is added as a solution of 50% silver nitrate in water. Each of the formulations were prepared by combining the water and polymer(s) together and mixing thoroughly first. Then adding the ammonia, which is a 28% concentration of ammonia in water. Lastly, the silver nitrate solution is slowly mixed into the polymer solutions to achieve a clear single phase solution.

TABLE-US-00003 TABLE 3 1000 pm Silver Ion Concentrated Antimicrobial Formulations 1-10 Component 1 2 3 4 5 6 7 8 9 10 DI Water 95.67 93.72 90.01 88.14 85.33 83.46 78.7 74.02 69.34 52.57 NH3 1.70 1.70 1.70 1.70 1.70 1.70 1.70 1.70 1.70 1.70 (28%) QR-1719 2.32 2.32 2.32 2.32 2.32 2.32 2.32 2.32 2.32 2.32 (32%) QR-1831 0 1.95 5.66 7.53 10.34 12.21 16.97 21.65 26.33 43.1 (30%) AgNO3 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 (50%) Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100 100 ~VI:Ag+ 4 9 19 24 31 36 48 61 73 117

TABLE-US-00004 TABLE 4 200 pm Silver Ion Concentrated Antimicrobial Formulations 11-13 Component 11 12 13 DI Water 382.7 306.3 115.5 NH3 (28%) 1.7 1.7 1.7 QR-1719 (32%) 2.32 2.32 2.32 QR-1831 (30%) 113.0 189.3 380.2 AgNO3 (50%) 0.31 0.31 0.31 Total 500 500 500 ~VI:Ag+ 300 500 1000

Fabric Weathering

[0032] All fabrics were aged in a climate chamber (Model: KBWF 720 climate chamber, Binder Company) to accelerate color change. The 12 by 16 treated swatches of fabric were cut in half lengthwise to produce two strips of 6 by 16. One strip was used in the climate chamber by first covering half of the sample, or about 6 by 8, using a light-proof paper card on both sides and leaving the other have uncovered and exposed. Those strips were hung vertically inside the chamber. The chamber was then set to 30 C. and cycled humidity as follows: 30% relative humidity for 4 hours, 2 hour transition from 30% to 90%, hold at 90% for 4 hours, 2 hour transition from 90% to 30%, and repeated. This weathering cycle was repeated for 3 weeks. The light source was a LUMILUX Cool Daylight (OSRAM L36w/865 lighting bulb) which was kept on during the weathering process.

Color Measurement

[0033] The color of fabrics after weathering was measured using a Hunterlab

[0034] Spectrophotometer (Model: Labscan XE) with illumination from a pulsed xenon arc source, a 0 degree illumination angle and a 45 degree viewer angle with a 13 mm (0.5) measuring area. Measurements were performed on 2 layers of the experimental fabrics using standard white tile as the backing. The untreated standard cotton, polyester, or nylon were used as control fabric to which all experimental fabric samples were compared to evaluate total color change (E*ab) or by ISO Grey Scale interpretation. Larger E*ab corresponds with greater fabric color change. For ISO analysis, the scale is 1-5, with 5 representing minimal to no color change. ISO Grey Scale readings are an output of the spectrophotometer. The calculation of E*ab is based on the measurements of L, a, and b which describe the coordinate space of light/dark, red/green, and blue/yellow. The E*ab value is calculated as the square root of the sum of square differences between the measured sample values and the control sample.

E.sub.cb={square root over ((L.sub.iL.sub.0).sup.2+(a.sub.ia.sub.0).sup.2+(b.sub.ib.sub.0).sup.2)}

[0035] Where the subscript 0 represents the control sample values and i represents the individual sample measurement. Each fabric swatch was measured a three locations and averages of L, a, and b values were used on the E*ab calculations.

[0036] E*ab below approximately 1.3 or ISO Grey Scale readings equal to or greater than 4.5 are preferred.

Antimicrobial Performance Testing

[0037] The fabrics were cut into 0.4 g samples, and placed in sterile 50 mL conical tubes. The samples were inoculated with 200 l Escherichia coli ATCC 8739 inoculum. Samples were tested in triplicate, and one set of unpreserved samples was enumerated immediately after inoculation. The remainder of the bacterial samples were incubated at 37 C. and enumerated 24 hours post-inoculation. Bacteria were enumerated by adding 20 mL of Dey-Engley Neutralizing Broth to the samples and vortexing for 25 seconds. Aliquots of the cell suspensions were taken and enumerated using the Most Probable Number (MPN) method. (Modified ISO 20743 Antimicrobial Efficacy Test).

Qualitative Hand/Feel Test

[0038] Seven randomly selected panelists were given fabrics treated at various VI to Ag+ ratios using polymer and silver ion. Control fabrics were prepared using process water from tap without polymer or silver ion. Panelists were asked to compare hand feel changes relative to the process water treated polyester and nylon swatches or fabrics. The two categories of feedback were: 1) harder hand/feel than reference, 2) Same hand/feel as reference.

Experiments and Results

[0039]

TABLE-US-00005 TABLE 5 Comparative Example 1 Cotton, nylon and polyester fabric discoloration at molar ratios less than 22 moles VI/mol silver ion 3 Week Discoloration Fabric Molar Ratio Average Standard ISO Grey Type (VI:Ag+) dE* Deviation dE* Scale Cotton Process Water 0.85 0.01 5 (Control) Cotton 4:1 1.57 0.05 4 Polyester Process Water 0.89 0.089 4.5 (Control) Polyester 4:1 2.94 0.047 3.5 Polyester 9:1 2.65 0.036 3.5 Nylon Process Water 0.82 0.08 4.5 (Control) Nylon 9:1 5.16 0.41 2.5

[0040] Note: E*ab (Aged vs untreated) is a measurement of color stability by comparing the color difference for the treated fabrics against untreated fabric over time. Comparative example 1 demonstrates yellowing (discoloration) associated with compositional define treatments on polyester, nylon, and cotton.

TABLE-US-00006 TABLE 6 Inventive example 2 depicting discoloration performance at VI:Ag+ molar ratios greater than 4:1 for cotton. 3 week Discoloration Fabric Molar Ratio Average Standard ISO Grey Type (VI:Ag+) dE* Deviation dE* Scale Cotton Process Water 0.85 0.01 5 (Control) Cotton 9:1 0.61 0.02 4.5 Cotton 19:1 0.29 0.03 5 Cotton 24:1 0.24 0.03 5 Cotton 31:1 0.23 0.01 5

TABLE-US-00007 TABLE 7 Inventive Example 3 depicting discoloration performance at molar ratios greater than 4:1 for polyester. 3 week Discoloration Molar Silver Standard ISO Fabric Ratio Ion Average Deviation Grey Antimicrobial Same Type (VI:Ag+) (ppm) dE* dE* Scale Performance Hand/Feel Polyester Process 0.89 0.089 4.5 Water (Control) Polyester 9:1 29 2.65 0.036 3.5 >2.09 6/7 Polyester 19:1 33 2.21 0.105 3.5 >4.35 6/7 Polyester 24:1 32 1.69 0.107 4 >3.43 6/7 Polyester 31:1 34 1.24 0.035 4.5 >2.84 6/7 Polyester 36:1 34 1.32 0.015 4 >3.75 6/7 Polyester 48:1 35 0.95 0.017 4.5 4.15 6/7 Polyester 61:1 36 0.86 0.025 4.5 3.45 6/7

TABLE-US-00008 TABLE 8 Inventive example 3 depicting discoloration performance at molar ratios greater than 4:1 for nylon. 3 week Discoloration Molar Silver Standard ISO Fabric Ratio Ion Average Deviation Grey Antimicrobial Same Type (VI:Ag+) (ppm) dE* dE* Scale Performance Hand/Feel Nylon Process 0.82 0.08 4.5 Water (control) Nylon 9:1 33 5.16 0.41 2.5 2.91 6/7 Nylon 19:1 30 1.39 0.20 4 >4.56 6/7 Nylon 24:1 31 1.37 0.30 4 >3.64 6/7 Nylon 31:1 28 1.57 0.14 4 >3.05 6/7 Nylon 36:1 28 1.35 0.21 4 >3.96 6/7 Nylon 48:1 24 1.36 0.19 4.5 4.56 6/7 Nylon 61:1 27 1.26 0.19 4.5 3.86 6/7

TABLE-US-00009 TABLE 9 Inventive example depicting initial visible fabric color and hand/feel across VI/Ag+ molar ratios up to 1000:1. Hand feel Test* Hard hand Same hand Fabric Type VI/Ag+ ratio Initial Color feel feel Nylon Process Water (Control) 9:1 same 1/7 6/7 48:1 same 1/7 6/7 117:1 same 4/7 3/7 300:1 Yellower 7/7 0 500:1 Yellower 7/7 0 1000:1 Yellower 7/7 0 Polyester Process Water same (Control) 9:1 same 2/7 5/7 48:1 same 3/7 4/7 117:1 same 4/7 3/7 300:1 Yellower 7/7 0 500:1 Yellower 7/7 0 1000:1 Yellower 7/7 0