BACTERICIDAL AND VIRUCIDAL FABRIC

Abstract

The present invention provides a bactericidal and virucidal fabric selected from cotton or non-woven fabric prepared by formulations and methods described herein. The formulations include a beta-cyclodextrin-containing compound associated with one or more metal ions including at least zinc ions and water for providing bactericidal and virucidal properties to the fabric dip-coated with the formulations according to various embodiments of the present invention. The as-prepared fabric has an increment in Grams per Square Meter (GSM) value of approximately 13.0 to 20.0 g/m.sup.2, an antibacterial activity value of at least 3.0, and/or antiviral activity value of at least 2.5.

Claims

1. A dip-coating, antibacterial and antiviral formulation for preparing a bactericidal and virucidal woven fabric, the formulation comprising: at least a beta-cyclodextrin-containing compound associated with zinc ions, and water to exert bactericidal and virucidal effect of the fabric on bacteria and/or viruses; at least one organic acid; and at least one metal salt, wherein the beta-cyclodextrin comprises at least one carboxylic ester unit and one carboxylic acid unit.

2. The formulation of claim 1, wherein a first organic acid of the at least one organic acids is ethylenediaminetetraacetic acid and is in a mole ratio of 4:1 to the beta-cyclodextrin.

3. The formulation of claim 2, wherein a second organic acid of the at least one organic acid is citric acid.

4. The formulation of claim 3, wherein the at least one metal salt comprises sodium dihydrogen phosphate, sodium hydrogen carbonate, zinc acetate and copper(II) acetate.

5. The formulation of claim 4, wherein the beta-cyclodextrin-containing compound associated with zinc ions, ethylenediaminetetraacetic acid, citric acid, and sodium dihydrogen phosphate are dissolved in water at approximately 60 degrees Celsius until thoroughly dissolved to form a first solution; sodium hydrogen carbonate is dissolved in water at room temperature or approximately 25 degrees Celsius until thoroughly dissolved to form a second solution; zinc acetate is dissolved in water at room temperature until thoroughly dissolved to form a third solution, wherein the woven fabric is dip-coated with the first, second and third solutions sequentially.

6. A method of preparing a bactericidal and virucidal woven fabric comprising: dip-coating the formulation of claim 5 to the woven fabric, said dip-coating comprising: preparing the first solution comprising dissolving a complex of beta-cyclodextrin-containing compound associated with zinc ions and water, ethylenediaminetetraacetic acid, citric acid, and sodium dihydrogen phosphate in a weight ratio of 11:50:15 in water at approximately 60 degrees Celsius until thoroughly dissolved; immersing the fabric into the first solution at approximately 60 degrees Celsius for about 5 minutes; padding the fabric and drying thereof at approximately 90 degrees Celsius for about 10 to 20 minutes; increasing the drying temperature to approximately 120 degrees Celsius to dry the fabric for another 20 minutes; rinsing the dried fabric with water and padded drying, immersing the dried fabric after said padded drying into the second solution comprising sodium hydrogen carbonate at 50 g/L in water at room temperature for about 15 to 20 minutes; rinsing the fabric with water, and padded drying thereof; immersing the dried fabric after being immersed into the second solution into the third solution comprising zinc acetate 60 g/L in water at room temperature for about 10 minutes; rinsing the fabric with water, padded drying thereof, followed by drying at 90 degrees Celsius for about 10 to 20 minutes.

7. A bactericidal and virucidal woven fabric prepared according to the method of claim 6, wherein the woven fabric comprises cotton fabric, and wherein the woven fabric has an increment in Grams per Square Meter (GSM) value of approximately 15.0 g/m.sup.2, an antibacterial activity value of at least 3.0.

8. The bactericidal and virucidal woven fabric of claim 7, wherein the woven fabric is capable of reducing bacterial growth and activity from bacteria comprising one or more of Staphylococcus aureus, Klebsiella pneumonia and Escherichia coli.

9. A dip-coating, antibacterial and antiviral formulation for preparing a bactericidal and virucidal non-woven fabric, the formulation comprising: at least a beta-cyclodextrin-containing compound associated with one or more metal ions including at least zinc ions, and water to exert bactericidal and virucidal effect of the fabric on bacteria and/or viruses; at least one organic acid; at least one metal salt; and a vinyl polymer; wherein the beta-cyclodextrin comprises at least one carboxylic ester unit and one carboxylic acid unit.

10. The formulation of claim 9, wherein the beta-cyclodextrin-containing compound, the at least one organic acid, the vinyl polymer and the at least one metal salt including at least zinc acetate are in a weight ratio of 2:2:2:1 dissolved in water at approximately 25 degrees Celsius followed by stirring at approximately 80 degrees Celsius until a thorough mixture is formed.

11. The formulation of claim 9, wherein the beta-cyclodextrin-containing compound is sodium (beta-cyclodextrin)propylsulphonate.

12. The formulation of claim 9, wherein one of the at least one organic acid is citric acid monohydrate.

13. The formulation of claim 10, wherein the at least one metal salt further includes copper(II) acetate.

14. A method of preparing a bactericidal and virucidal non-woven fabric comprising dip-coating the formulation of claim 13 to the non-woven fabric and drying the non-woven fabric at approximately 120 degrees Celsius for approximately 10 minutes in the absence of padding the non-woven fabric after said dip-coating the formulation to the non-woven fabric at 25 degrees Celsius for approximately 5 minutes.

15. A bactericidal and virucidal non-woven fabric prepared according to the method of claim 14, wherein the non-woven fabric comprises polypropylene, polyethylene, or any combination thereof, and wherein the non-woven fabric has an increment in Grams per Square Meter (GSM) value of approximately 13.0 to 20.0 g/m.sup.2, an antibacterial activity value of at least 3.0 and/or antiviral activity value of at least 2.5.

16. The bactericidal and virucidal non-woven fabric of claim 15, wherein the non-woven fabric is capable of reducing bacterial growth and activity from bacteria comprising one or more of Staphylococcus aureus, Klebsiella pneumonia and Escherichia coli, and/or is capable of reducing viral growth and activity from viruses comprising H1N1 and H3N2 strains, and coronavirus.

Description

DETAILED DESCRIPTION

[0038] The present invention will be described in detail through the following embodiments/examples. It should be understood that the specific embodiments are provided for an illustrative purpose only, and should not be interpreted in a limiting manner.

EXAMPLES

Example 1

[0039] Table 1 below provides the formulation for incorporating bactericide and virucide into non-woven fabric.

TABLE-US-00001 TABLE 1 Formulation on non-woven fabric: Materials Amount Sodium (beta-cyclodextrin)propyl- 25 g sulphonate Zinc acetate dihydrate 12.5 g Polyvinyl alcohol 25 g Citric acid monohydrate 25 g Distilled water 1162.5 g

[0040] Preparation Procedure:

1. Polyvinyl alcohol (2% wt against water) was first dissolved in water at 80 degrees Celsius with stirring until it was fully dissolved. The solution was then cooled down to 25 degrees Celsius and citric acid monohydrate (2% wt against water), sodium (beta-cyclodextrin)propylsulphonate (2% wt against water) and zine acetate dihydrate (1% wt against water) were added into the solution at 25 degrees Celsius. The mixture was then stirred at 25 degrees Celsius until all materials were dissolved;
2. Non-woven fabric (e.g., PE or PP) was dipped into the mixture obtained from 1 and completely immersed therein for 5 minutes at 25 degrees Celsius under stirring to make the fabric soaking wet;
3. The wet fabric was dried at 120 degrees Celsius for 10 minutes.
A coating GSM of about 13.0 to 20 g/m.sup.2 was resulted in the fabric after drying.

[0041] Below summarizes the bactericidal activity (Table 2) and virucidal activity (Table 3) of the non-woven fabric incorporated with the formulation 1 and the procedure described in this example, using the test standards ISO 20743 and ISO 18184, respectively, with methods that are known in the state-of-the-art

TABLE-US-00002 TABLE 2 Bactericidal Activity: Contact Bactericidal Test Strain Time Activity (Log.sub.10) Example 1 Staphylococcus 2 h >4.79 aureus Klebsiella >5.71 pneumonia

[0042] From Table 2, the bactericidal activity of the PP non-woven fabric of the Example 1 is reflected by the bactericidal activity (Log.sub.10) over a 24-hour test.

TABLE-US-00003 TABLE 3 Virucidal Performance: Virucidal Activity Test Strain Contact Time (Log.sub.10 TCID.sub.50/mL) Example 1 H1N1 A/PR8/34 5 min 3.73 2 h 6.56 H3N2 5 min 3.11 2 h 4.89 SARS-CoV-1 5 min 1.25

[0043] From Table 3, it shows that the PP non-woven fabric incorporated with the formulation 1 is effective in reducing the viral titer of different strains (herein include H1N1 A/PR8/34, H3N2 and SARS-CoV-1) within 2-hour test. When comparing the two viral strains, it seems that the PP non-woven fabric incorporated with formulation 1 is more effective in reducing the titer of H1N1 A/PR8/34 strain than that of H3N2, but it is not conclusive until more viral strains are tested. Overall, the fabric incorporated with the formulation 1 has virucidal activity against certain commonly known viruses, including coronavirus SARS-CoV-1.

Example 2

[0044] Table 4 below provides the formulation for incorporating bactericide and virucide into non-woven fabric.

TABLE-US-00004 TABLE 4 Formulation on non-woven fabric: Materials Amount Sodium (beta-cyclodextrin)propyl- 25 g sulphonate Zinc acetate dihydrate 12.5 g Copper(II) acetate hydrate 12.5 g Polyvinyl alcohol 25 g Citric acid monohydrate 25 g Distilled water 1150 g

[0045] Preparation Procedure: [0046] 1. Polyvinyl alcohol (2% wt against water) was first dissolved in water at 80 degrees Celsius with stirring until it was fully dissolved. The solution was then cooled down to 25 degrees Celsius and citric acid monohydrate (2% wt against water), sodium (beta-cyclodextrin)propylsulphonate (2% wt against water) and zine acetate dihydrate (1% wt against water) and copper(II) acetate hydrate (1% wt against water) were added into the solution at 25 degrees Celsius. The mixture was then stirred at 25 degrees Celsius until all materials were dissolved; [0047] 2. Non-woven fabric (e.g., PE or PP) was dipped into the mixture obtained from 1 and completely immersed therein for 5 minutes at 25 degrees Celsius under stirring to make the fabric soaking wet; [0048] 3. The wet fabric was dried at 120 degrees Celsius for 10 minutes.
A coating GSM of about 13.0 to 20 g/m.sup.2 was resulted in the fabric after drying.

[0049] Below summarizes the virucidal activity (Table 5) of the non-woven fabric incorporated with the formulation and the procedure described in this example against coronaviruses, using the test standards ISO 18184, respectively, with methods that are known in the state-of-the-art

TABLE-US-00005 TABLE 5 Virucidal Performance against Coronaviruses: Virucidal Activity Test Strain Contact Time (Log.sub.10 TCID.sub.50/mL) Example 2 HCoV-229E 5 min 2.50 SARS-CoV-1 5 min 2.73

[0050] From Table 5, it shows that the PP non-woven fabric incorporated with the formulation is effective in reducing the viral titer of different strains of coronaviruses HCoV-229E (Human Coronavirus) and of SARS-CoV-1 (responsible for the pandemic outbreak in Asia in 2003) within contact time of 5 minutes.

Example 3

[0051] Below illustrates the formulation and procedure in two parts for incorporating bactericide into a cotton woven fabric

TABLE-US-00006 TABLE 6 Formulation for Cotton Fabric - Part I: Materials Amount Beta-cyclodextrin-containing compound associated 22 g with zinc ions and ethylenediaminetetraacetic acid described in the third embodiment Citric acid 100 g Sodium dihydrogen phosphate 30 g Distilled water 1 L

[0052] Procedure I: [0053] 1. All of the solid reagents were dissolved in water at 60 degrees Celsius to obtain a first solution; [0054] 2. A piece of cotton fabric was dipped into the first solution for 5 minutes at 60 degrees Celsius; [0055] 3. The fabric was padded, and dried in an oven at 90 degrees Celsius for 10-20 minutes, then at 120 degrees Celsius for 20 minutes; [0056] 4. The dried fabric was rinsed with water, padded dry again.

TABLE-US-00007 TABLE 7 Formulation for Cotton Fabric - Part II: Materials Amount Sodium hydrogen carbonate 50 g Zinc acetate 60 g Distilled water 1 L

[0057] Procedure II

1. Sodium hydrogen carbonate was dissolved in 1 liter distilled water at room temperature to obtain a second solution;
2. Cotton fabric from Part I was immersed into the second solution for 15 to 20 minutes;
3. The wet fabric was rinsed with distilled water, padded dry;
4. Zinc acetate was dissolved in 1 liter distilled water in another container at room temperature to obtain a third solution;
5. Cotton fabric from step 3 was immersed into the third solution for 10 minutes;
6. The fabric was rinsed with water, padded dry again, and dried in oven at 90 degrees Celsius for 10-20 minutes;
A coating GSM of approximately 15 g/m.sup.2 was resulted from the cotton fabric incorporated with the formulation in Example 2.

[0058] Below (Table 6) illustrates the durability of the bactericidal performance of cotton fabric incorporated with the formulation described in Example 2 in terms of the difference in bacterial count reduction before and after 30 cycles of laundry washing and tumble dry, tested using the methods described in AATCC 100.

TABLE-US-00008 TABLE 8 Bactericidal Performance: Effective Bacterial Effective Count Reduction Bacterial After 30 Home Count Laundry Washing Contact Reduction and Tumble Test Strain Time (Log.sub.10) Dry Cycles (Log.sub.10) Staphylococcus 24 h 3.0 3.0 aureus Klebsiella 3.2 3.2 pneumonia Escherichia coli 3.3 3.3

[0059] From Table 8, it shows that the effective bacterial count reduction in three different bacterial strains after 30 cycles of home laundry washing and tumble dry remains unchanged. It can be concluded that the bactericidal activity of the woven fabric prepared according to the formulation and procedures in this example is durable even it is subjected to repeated washing and tumble dry, mimicking the situation of daily use of the products made of this kind of fabric.

INDUSTRIAL APPLICABILITY

[0060] The present invention is applicable in textile and disposable wearables including but not limited to specialized wearables and gears, medical device and equipment, which require antibacterial and/or antiviral functions.