PROCESS FOR MAKING AN ANTIMICROBIAL COMPOSITION

Abstract

The present invention relates to a composition and method for preparing a color stable and wash durable treated fabric with more even distribution of silver across the length of the treated textile.

Claims

1. A polymer bath composition comprising: a) a first polymer comprising: i) 60-90 wt % polymerized units of a monomer X selected from the group consisting of vinylimidazoles, vinylimidazolines, vinylpyridines, vinylpyrroles, derivatives thereof and combinations thereof; and ii) 10-40 wt % polymerized units of a monomer Y which is an ethylenically unsaturated compound; b) a second polymer comprising: i) polymerized units of a heterocyclic monomer X; and ii) polymerized units of monomer Y is a non-heterocyclic saturated compound selected from acrylic acid, (meth)acrylic acid, ethyl acrylate, and butyl acrylate and combinations thereof; and c) silver.

2. The composition of claim 1 wherein the silver is silver ion.

3. A treated article comprising: providing a fabric comprising the polymer bath composition of claim 1.

4. The treated article of claim 3 wherein the polymer bath composition when applied to the fabric has an average error less than 1.

5. The treated article of claim 3 wherein the polymer bath composition when applied to the fabric has an average error less than 0.8.

6. The treated article of claim 3 wherein the fabric is cotton.

7. The treated article of claim 3 wherein the fabric is a blend polyester and lycra.

8. The treated article of claim 3 wherein the fabric is polyester.

Description

EXAMPLES

Materials and Methods Used to Prepare a Treated Fabric

Materials:

[0031]

TABLE-US-00001 Polymer Formulation ID Description Example 1 QR-1719 45VI/40BA/15AA Example 2 QR-1831 75VI/25Pegma Example 3 KM5497 60VI/25BA/15AA Example 4 AR8923 30VI/70Pegma Example 5 AR8924 30VP/70Pegma

TABLE-US-00002 Fabrics ID Description WPUR Polyester TIC 730 SDL Atlas - Item # 400000: TIC 730 125% 100% Polyester Interlock Knit Cotton TIC 460 SDL Atlas - Item # 200789: TIC 460 80% 100% Cotton Interlock Knit Polyester- GU59913- Polyester-Lycra Blend - 4.4 oz Jersey 125% Lycra BLK Knit Black obtained from Guilford Mills, in PA Nylon TIC 300 SDL Atlas: TIC 300 100% Spun Nylon 55% 6.6 Plain Weave

Methods:

Fabric Treatment

[0032] A Lab scale padding machine from Werner Mathis AG (Model: CH-8155 VFM28888) was used to apply finishing chemicals to fabric samples.

[0033] First the wet-pick up rate (WPUR) is determined to calculate the concentration of antimicrobial formulation solution needed to achieve a target silver 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 reweighted to determine the increase in weight due to absorption of water. 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 typically will weigh around 27 grams after and 12 grams before for a calculated wet pick-up rate of (27-12)/12 or 125%. Cotton typically weighs 15 grams dried and 27 grams after the roller for a calculated wet pick-up rate of (27-15)/15 or 80%. If the wet pick-up rate does not match the desired value the pressure of the padding rollers is adjusted up or down to achieve the desired values. Polyester-Lycra blend fabric is very similar to standard Polyester fabric. Weights for polyester-lycra blend are typically around 27 grams after and 12 grams before for a calculated wet pick-up rate of (27-12)/12 or 125%. Weights for Nylon fabric are typically around 18.6 grams after and 12 grams before for a calculated wet pick-up rate of (18.6-12)/12 or 55%.

[0034] Second, the application bath solutions are prepared to treat each textile swatch. The concentration silver in the bath is calculated based on the initial concentrate solution and the wet pick-up rate. The calculation of bath concentration of an antimicrobial formulation is calculated by dividing the target silver 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 125% wet pick-up rate using an antimicrobial formulation with 1000 ppm of silver, would require 30 ppm Ag target/1000 ppm Ag in formulation/1.25 WPUR*100%, or 2.4 g antimicrobial formulation into 100 g. On cotton fabric with a 80% wet pick-up rate the calculation would be 30 ppm Ag target/1000 ppm Ag antimicrobial formulation/0.80 WPUR*100%, or 3.75 g antimicrobial formulation into 100 g.

[0035] The 30 ppm silver target fabric loading for polyester would be simply formulated by weighing out 2.4 grams of the antimicrobial formulation and mixing it into 97.6 grams of deionized water, and for cotton by weighing out 3.75 grams of antimicrobial formulation and mixing into 96.25 grams of deionized water.

[0036] 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.

POLYMER SYTHESIS EXAMPLES

[0037] Examples 1-5 describe preparation of the polymers used in later examples. Table I describes the monomer composition of each example.

Example 1

Preparation of Polymer Product 1

[0038] A polymer product was prepared using the following process: [0039] (a) 200 proof ethanol (2085 lbs.) was charged to a 2000 gallon jacketed reactor equipped with a 2-tiered pitch blade agitator and reflux condenser; [0040] (b) The contents were heated to reflux at 79-80 C. with agitation at atmospheric pressure using hot oil in the jacket of a temperature between 100 and 120 C.; [0041] (c) A mixture of butyl acrylate (1260 lbs.), 1-vinylimidazole (1418 lbs.), and glacial acrylic acid (472 lbs.) were added to the kettle over a period of 3 hours at a rate of 17.5 lb./min. Simultaneously, 1-amyl peroxypivilate (Trig 125-C-75) (54 lbs.) in 200 proof ethanol (1370 lbs.) was fed to the kettle at a rate of 7.91 lb./min for a period of 3 hours. The contents were maintained at 79-80 C. with agitation; [0042] (d) The monomer tank was rinsed with 200 proof ethanol (362 lbs.) and added to the product of (c); [0043] (e) The product of (d) was maintained at 79-80 C. with constant agitation for 30 minutes; [0044] (f) 1-amyl peroxypivilate (Trig 125-C-75) (80 lbs.) in 200 proof ethanol (270 lbs.) was added to the product of (e) at a rate of 11.7 lb./min; [0045] (g) The product of (f) was maintained at 79-80 C. with constant agitation for 30 minutes; [0046] (h) 1-amyl peroxypivilate (Trig 125-C-75) (80 lbs.) in 200 proof ethanol (270 lbs.) was added to the product of (g) at a rate of 11.7 lb./min; [0047] (i) The product of (h) was maintained at 79-80 C. with constant agitation for 30 minutes; [0048] (j) 200 proof ethanol (2090 lbs.) was added to the product of (i); [0049] (k) The heading source was removed and the product of (j) was allowed to cool to room temperature resulting in a polymer product with 45% 1-vinylimidazole.

Example 2

Preparation of Polymer Product 2

[0050] A polymer product was prepared using the following process: [0051] (a) DI water (140 g) was charged to a 1 liter reactor equipped with a stirrer, dropping funnel and a condenser set at 5 C.; [0052] (b) The contents were heated at 85 C. with agitation; [0053] (c) A mixture of DI water (78.1 g), 1-vinylimidazole (114.2 g), and PEGMA (38.1 g) were added to the kettle over a period of 2 hours at a rate of 1.83 mL/min Starting simultaneously, 2,2-Azobis(2-methylpropionitrile) (VAZO) (6.4 g) in DI water (133.7 g) and ammonium hydroxide (28% as ammonia) (7.6 grams) was fed to the kettle at a rate of 1.28 mL/min for a period of 3 hours. The contents were maintained at 85 C. with agitation; [0054] (d) The product of (c) was maintained at 85 C. with constant agitation for 200 minutes; [0055] (e) The heading source was removed and the product of (d) was allowed to cool to room temperature resulting in the polymer product with 75% 1-vinylimidazole.

Example 3

[0056] Preparation of example polymer 3 was carried out similarly to example polymer 1 but adjustments to the monomer ratios from 45% vinyl imidazole to 60% vinyl imidazole and from 40% butyl acrylate to 25% butyl acrylate with the remained as acrylic acid.

Example 4 and 5

[0057] Preparation of example polymers 4 and 5 were carried out similarly to example polymer 2. In example 4, vinyl imidazole was reduced from 75% to 30% with the remaining monomer as polyethylene glycol methyl ether methacrylate. In Example 5 75% vinyl imidazole was replaced with 30% 4-vinylpyridine with the remaining monomer as polyethylene glycol methyl ether methacrylate.

TABLE-US-00003 TABLE I Example Example Example Example Example Monomer Polymer Polymer Polymer Polymer Polymer Monomer Composition Acronym 1 2 3 4 5 1-vinylimidazole VI 45% 75% 60% 30% Poly(ethylene glycol) PEGMA methyl ether methacrylate (Mn ~400) 25% 70% 70% glacial acrylic acid AA 15% 15% butyl acrylate BA 40% 25% 4-vinylpyridine VP 30% % Polymer Solids 32% 30% 30% 30% 30%

Antimicrobial Formulations:

Examples 6-13

Composition of Antimicrobial Formulations

[0058] Examples 6-13 have compositions described below in Table II. Each of the antimicrobial formulation examples contains 1000 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-00004 TABLE II Antimicrobial Formulation Examples Component Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 DI Water 93.10 94.86 94.08 93.54 94.42 91.74 91.28 94.47 NH3 (28%) 1.70 1.70 1.70 1.70 1.70 1.70 1.70 1.70 Polymer Example 1 4.88 0.00 2.34 3.66 1.22 2.34 2.34 0.00 Polymer Example 2 0.00 3.12 1.56 0.78 2.34 0.00 0.00 1.56 Polymer Example 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.95 Polymer Example 4 0.00 0.00 0.00 0.00 0.00 3.90 0.00 0.00 Polymer Example 5 0.00 0.00 0.00 0.00 0.00 0.00 4.37 0.00 AgNO3 (50%) 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00

FABRIC TREATMENT EXAMPLES

[0059] Bath formulations using antimicrobial formulations in Examples 6 through 13 were generated by each Antimicrobial Formulation in Table II to the desired bath concentration in deionized water. For examples 14 through 21 on polyester fabric the bath dilution was set at 30 ppm Ag, or 3 grams into 97 grams of deionized water. The wet pickup rate for the polyester fabric is 1.25. Therefore the expected silver level is 30*1.25 or 38 ppm Ag on fabric. For examples 22 through 29 on cotton fabric the dilution level was 62 ppm Ag, or 6.2 grams into 93.8 grams of deionized water. The wet pickup rate for the cotton fabric is 0.8. Therefore the expected silver level for examples 22 through 29 on cotton is 62*0.8 or 50 ppm Ag. For examples 30 through 37 on polyester-lycra blend the bath dilution was set at 30 ppm Ag, or 3 grams into 97 grams of deionized water. The wet pickup rate for the polyester-lycra fabric is 1.25.

[0060] Therefore the expected silver level is 30*1.25 or 38 ppm. For examples 38 through 45 on Nylon fabric the bath dilution was set at 30 ppm Ag, or 3 grams into 97 grams of deionized water. The wet pickup rate for the nylon fabric is 0.55. Therefore the expected silver level is 30*0.55 or 17 ppm.

[0061] Finally, formulations were pH adjusted to 6 using dilute acetic acid, pad applied, and dried to fix the polymer complex. These baths were used to generate the treated fabric examples 14-45.

[0062] Comparative fabric examples 14 and 15 treated polyester fabric were utilized to demonstrate inconsistency of silver application across width and length. Fabric example 16 demonstrates the invention. Strips were cut from each fabric at 0, 5, 10, 15, and 20 ft. increments of padded fabric for metal analysis. The data is summarized in Tables III-VI for treated polyester examples 14-16. Metal concentration values at each increment are reported in parts per million for polyester fabric treated with Example formulations 6, 7, and 8 respectively.

TABLE-US-00005 TABLE III Example 14 - Formulation Example 6 on Polyester Measured Silver in mg Silver/kg fabric (ppm Ag) Width Width Length (ft.) Left Middle Right Averages StdDev. 1 50 60 56 55 4.73 5 45 47 46 46 0.91 10 43 45 43 44 1.28 15 46 46 47 46 0.30 20 44 44 43 44 0.64 Length Averages 46 48 47 Length Stdev. 2.8 6.4 5.4

TABLE-US-00006 TABLE IV Example 15 - Formulation Example 7 on Polyester Measured Silver in mg Silver/kg fabric (ppm Ag) Length Left Middle Right Average StdDev. 1 101 108 111 107 5.20 5 78 84 60 74 12.46 10 44 37 37 39 4.05 15 25 21 23 23 1.84 20 20 11 6 12 7.10 Average 54 52 47 Stdev. 35.2 41.8 41.0

TABLE-US-00007 TABLE V Example 16 - Formulation Example 8 on Polyester Measured Silver in mg Silver/kg fabric (ppm Ag) Length Left Middle Right Average StdDev. 1 49 52 51 50 1.58 5 46 47 47 47 0.36 10 47 47 48 47 0.86 15 48 47 50 48 1.45 20 40 42 44 42 2.21 Average 46 47 48 Stdev. 3.6 3.5 2.7

[0063] Examples 14-16 are summarized in Table VI. Averages and standard deviations have been calculated across both fabric width and length at several fabric points. Table VI demonstrates greater variability on early sections of treated polyester across length.

TABLE-US-00008 TABLE VI Width vs Length Deviations Measured Silver in mg Silver/kg fabric (ppm Ag) Example Example Example Calculation 14 15 16 Average 47 51 47 Stdev - 1.9 6.0 1.2 Width Stdev - 4.7 36.5 3.0 Length

[0064] To reduce preparation and measurement time, Fabric Examples 14-45 (Table VII-X) were compared using metal concentration across only the first 5 feet of fabric at the middle from width standpoint. Each example corresponds to a treated fabric using Antimicrobial Formulation Examples 6 through 13 on polyester fabric. Average error was used to articulate the measured differences of formulation (silver) uptake. The error is the absolute value between the measurement and the target treatment calculated value. All Application baths were prepared as described above.

TABLE-US-00009 TABLE VII Polyester Fabric Measured Silver in mg Silver/kg fabric (ppm Ag) - Target 38 ppm Ag Example Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Length: 1 ft 55 107 50 47 66 49 53 38 Length 5 ft 46 74 47 52 25 37 40 42 Ave. Error 0.33 1.38 0.27 0.29 0.53 0.16 0.22 0.06
Table VIII further provides average error for treated article Examples 22 through 29 using Example Formulations 6 through 13 on cotton fabric.

TABLE-US-00010 TABLE VIII Cotton Fabric Measured Silver in mg Silver/kg fabric (ppm Ag) - Target 50 ppm Ag Example Example 22 Example 23 Example 24 Example 25 Example 26 Example 27 Example 28 Example 29 Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Length: 1 ft 169 109 90 88 85 56 45 79 Length 5 ft 80 60 64 77 34 12 28 15 Ave. Error 1.49 0.69 0.54 0.64 0.50 0.44 0.27 0.64
Table IX further provides average error for treated article Examples 30 through 37. Formulations again are Examples 6 through 13 except on polyester-lycra blend.

TABLE-US-00011 TABLE IX Polyester-Lycra Blend Fabric Measured Silver in mg Silver/kg fabric (ppm Ag) - Target 38 ppm Ag Example Example 30 Example 31 Example 32 Example 33 Example 34 Example 35 Example 36 Example 37 Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Length: 1 ft 21 69 53 44 49 40 38 47 Length 5 ft 23 65 40 35 22 30 29 24 Ave. Error 0.42 0.76 0.22 0.12 0.36 0.13 0.12 0.30
Lastly, Table X provides average error for treated article Examples 38 through 45 using Examples 6 through 13 treated on nylon fabric.

TABLE-US-00012 TABLE X Nylon Fabric Measured Silver in mg Silver/kg fabric (ppm Ag) - Target 17 ppm Ag Example Example 38 Example 39 Example 40 Example 41 Example 42 Example 43 Example 44 Example 45 Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Length: 1 ft 32 35 22 16 10 14 9 38 Length 5 ft 9 27 10 19 14 14 6 16 Ave. Error 0.68 0.83 0.35 0.10 0.29 0.16 0.54 0.64

[0065] Table XI summarizes the four fabrics types treated using Example formulations 6 through 13. The error from each fabric was averaged together to further understand the combined impact of each formulation across all fabric types. A 95% confidence interval on the mean is calculated using the standard deviations. Example 6 and Example 7 formulations represent single polymer formulations. Formulation Examples 8 through 10 represent differing molar ratios of 1:1, 3:1, and 1:3 of N-vinylimidazole using both polymer examples 1 to 2. The confidence intervals on the average area for each of the three middle ratios (Example 8, 9, 10) are below the confidence intervals of Examples 6 and 7. This demonstrates statistically that the combination of Example Polymers 1 and 2 ranging in molar ratios of N-vinylimidazole from 25%/75% to 75%/25% results induced average error of the target treatment level compared to either polymer alone.

[0066] Furthermore, Formulation Examples 10, 11, and 12 evidence that alternate polymer combinations can be utilized to yield equal or improved average errors across fabrics when compared to individual Polymer Examples 6 and 7.

TABLE-US-00013 TABLE XI Summary of Average Errors for Silver Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Formulation Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Polyester 0.41 1.53 0.30 0.29 0.53 0.16 0.22 0.06 Cotton 1.49 0.69 0.54 0.64 0.50 0.44 0.27 0.64 Polyester-Lycra Blend 0.42 0.76 0.22 0.12 0.36 0.13 0.12 0.30 Nylon 0.68 0.83 0.35 0.10 0.29 0.16 0.54 0.64 Average 0.75 0.95 0.35 0.29 0.42 0.22 0.29 0.41 Stdev 0.51 0.39 0.13 0.25 0.12 0.15 0.18 0.28 Polymer 1 VI Mol/VI Mol Total 1.00 0.00 0.48 0.75 0.25 0.48 0.48 0.48 95% Confidence Interval 0.35 0.27 0.09 0.17 0.08 0.10 0.12 0.20 95% Lower Limit 0.57 0.82 0.31 0.20 0.38 0.17 0.22 0.31 95% Upper Limit 0.93 1.09 0.40 0.38 0.46 0.27 0.35 0.51