DESC:FIELD OF INVENTION :
This invention relates to textile fabrics its extensions & application areas and articles that possesses antiviral antimicrobial/properties and a method for their preparation.

PRIOR ART :
Textiles fabrics/articles are treated so that after treatment it renders a safety against microbicidal microorganisms coming in contact with the article so that fabrics/textiles can be used in environment where there is a possibility and / or fear of microorganisms infested conditions.

Many methods and textiles fabrics are known in prior art and most of them suffer severe diminishment of antimicrobial properties after few hours of laundering and some suffer UV unstability over duration of exposure.

As until date no attention was given to antivirus fabrics/textiles, since this suffering was unknown to the world.

Typically all prior art teach the method for preparing nano silver containing antibacterial fabric with impregnation technology which comprises of impregnating the fabric with dopamine solution at control temperature and then treated with silver nitrate solution subsequently and as final step of the treatment. This is a two steps process.

Some prior art teach a nano-silver colloidal solution prepared in one step by mixing AgNO3 aqueous solution and an amino-terminated hyperbranched polymer (HBP-NH2) aqueous solution under vigorous stirring at room temperature. The cotton fabric is treated with nanosilver colloid by an impregnation method to provide the cotton fabric with antibacterial properties and it was found that silver nano particles got fixed and well dispersed on fabric surface and major state of the silver present on the surface was Ag2O.

Both of these suffer certain disadvantages of not possessing antiviral activity which is a great disadvantage in current scenario wherein a large number of virus variants are attacking human races globally for years at a stretch.

Accordingly all the prior art are relating only to antimicrobial possessing properties to be incorporated in the textile fabric/article.

OBJECTS OF THE INVENTION :
There are many views of using silver in textile industry and silver compounds are used for the chemical modification of textile fibers, including colloidal Ag, Ag salts, and Ag powder. Further the mechanism of antimicrobial activity of Ag when incorporated into textile fibers are very interesting in the scenario of polluted environment and the invention also worked on improving the prior art and to obtain a treated textile fabric/article which exhibited antiviral properties and the invention also discloses not only the textile fabric/article but also discloses the method of incorporating the unique novel antiviral feature into textile fabric/article.

Textiles are excellent substrates for bacterial growth and microbial/viral proliferation under appropriate moisture, nutrients and temperature conditions. In a polluted environment, textiles can be an important source of bacteria, viruses and fungi that may contaminate the wearer and all persons in proximity to the wearer, due to the dispersal of pathogens in the air, which then fall down and infect the immediate and non-immediate environments.

Hence textile containing nano-particles such as silver is used to impart antiviral properties to the textile. Silver in its metallic state is inert but it reacts with the moisture and gets to ionize. The ionised silver is exploited advantageously to achieve the objective of the present invention.

Silver and its inherent reactive nature is exploitedly advantageously in the process:
Silver is generally an inert metal but Silver is highly reactive, as it binds to tissue proteins and brings structural changes in the bacterial cell wall and nuclear membrane leading to cell distortion and death. Silver ions also bind to bacterial DNA and RNA by denaturing and inhibiting bacterial replication.

It is identified and known that antimicrobial properties of silver are dependent on the size and shape of particles, which resulted from the “preparation route”.

So the object of the invention is to overcome the scientific challenge in producing an antiviral textiles/article, which is easy and cheap way of manufacturing and thereby enabling simple mass production and availability in abundance, a treated textile fabric/article which exhibits antiviral properties.

Colloidal solution is exploited advantageously in the process :
The invention focused on the suffering of prior art, so the inventors obtained and characterised a novel method of using colloidal solution to impregnate fabrics that will exhibit antibacterial and antiviral properties. Hence invention teaches the method of preparing this colloidal solution also.

Silver has a strong cytotoxity towards a broad range of microorganisms and viruses, low toxicity to human cells, high selectivity, long term durability, increased dyeability and bio compatibility and due to these unique properties ‘silver’ is used for production of textile surfaces with novel properties such as acronyms protection, virus protection, UV protection and water resistance, etc. This invention has exploited utilising silver to create a novel treated textile fabric/article through a novel process of treatment, which treated article exhibit as ‘antiviral’ properties and thereby can be used in polluted environment by creating garments, footwear, clothing, masks, filter media, filter bags, curtains, blankets, bed spreads, bandage clothes and all areas that need purified ambience without any limitation.

SUMMARY OF THE INVENTION :
Currently in the recent past few years due to suffering of SARS and the most recent COVID 19 suffering in the year 2020, there is an urgent need for antiviral properties to be incorporated into medicated textile fabrics/articles.

The invention provides a fibrous textile article containing an antiviral and an antimicrobial agent interstially deposited on the surface and also within said fibrous textile/article, said agent present in said fibrous textile/article in an amount sufficient to impart antiviral and to impart antimicrobial properties to said treated articles and fabrics.

DESCRIPTION OF INVENTION :
Imparting antiviral and antimicrobial properties to fibrous textile/articles and related filter media, is achieved in the instant invention by surface deposition and interstitial deposition of molecular compound Ag ions on the textiles/article and into the textile/article.

For antimicrobial/antiviral application, Ag ions may be deposited within the interstices of fibrous articles by simply soaking the article in an aqueous dispersion of the crystals or by combining the crystals with a carrier medium into which the article can be soaked. This method of physical incorporation of crystals is useful where the article is composed of low density or loosely associated fibres such as bandage pads, gauze and all loosely non-woven products. However physical incorporation of the crystals is less effective where the treated article is a fibre or yarn or a higher density woven or non-woven fabric, since the pre-formed crystals cannot sufficiently penetrate into the interstices of such articles. In such cases deposition of Ag ions via interstial precipitation is preferred. In this invention interstitial precipitation of Ag ions is accomplished by providing an aqueous solution of water soluble silver salt such as mix of silver nitrate and sodium acetate. The article to be treated fabric is thoroughly wetted with this salt solution such that the article absorbs solution on fibre surfaces as well as at one or more interstices between fibrils forming the fiber, between fibers forming the yarn, or non-woven fabric or between the weft and warp yarns present in woven fabrics. The preferred method is by dipping and soaking the article in a bath of silver salt solution for a period of time sufficient for the article to absorb the requisite amount of silver salt solution. The most preferred duration is atleast 30 minutes as per this invention.

Next the wetted article is squeezed to remove the excess silver salt solution and then immersed in heated bath containing a second aqueous solution comprising a strong alkali, a water soluble oxidising agent and heated for a period of time sufficient to cause reaction leading to the interstitial precipitation of silver oxide material in the interstices of the fibrous article. Most preferred alkali is 4% potassium hydroxide. Reaction in the bath is accomplished by heating at the temperature of 70°C - 90°C for a period of time sufficient to maximize yield of Ag ions, generally around 30 minutes. After the reaction is completed, the treated article is removed from the bath and is washed with demineralised water one or more times to remove soluble impurities or unreacted reagents and to neutralise the pH. The wet treated article is then dried at room temperature or in an air circulating chamber with ambient temperature not exceeding 60°C.

The quantity of Ag ions present in the resulting treated article will generally be a function of the quantity of silver salt absorbed by the treated article, which can be varied depending on the nature of the article eg., loose or closely knit fabrics, or whether the fabric is natural or synthetic, woven or non-woven and so on ,the former being more absorptive of the silver salt solution.

In general the quantity of alkali present in the second bath should be sufficient to maintain a strong basic pH of around 12+, and providing a slight molar excess of silver salt over the oxidising agent more suitable to complete the reaction. Thus the content of silver oxide interstially precipitated within any given fibrous article may be controlled by varying the concentration of the silver salt in the solution used to first wet the article and appropriately adjusting the amount and concentration of alkali and its ability to oxidise the material present in the immersion solution, at approximately stoichiometric levels.

PROCESS STEPS :
The invention also provides a process for imparting antiviral and antimicrobial properties to a fibrous textile/article and all the other related media but not limited to, comprises of:

a. Preparing a preparatory wash solution which is 5% V/V linear alkyl benzene sulphonate sodium salt solution,
b. Preparing a first salt mixture which is a colloidal/ionic silver suspension solution of silver nitrate and sodium acetate in weight ratio of 5:1 to 1:5 in demineralized water preferably 1:1, the prepared solutionis heated to a temperature of atleast 90°C for a duration of 10-30 minutes,
c. Preparing a second potassium hydroxide solution which is a 4% W/V solution and heated to a temperature in the range 70°C - 90°C,
d. Washing the selected fibrous textile/article using the said preparatory wash solution of step (a) atleast two times to neutralise the pH and thereafter allowing the washed article to dry at room temperature,
e. Soaking the washed article/textile of step (d) in said first salt solution for a duration of atleast 30 minutes and thereafter draining the excess solution from the soaked article/textile with a poly propylene roller,
f. Immersing the said soaked article/textile of step (e) in said second potassium hydroxide solution for atleast 30 minutes maintained at a temperature of 70°C - 90°C, and
g. Washing the textile/article of step (f) with demineralised water to neutralise the pH and thereafter allowing the treated textile/article to dry at room temperature.

Details of step (b) of the process steps – preparation of salt mixture

Mixing of Silver Nitrate and Sodium Acetate : The sodium acetate is represented by molecular formula of CH3COONa and the molecular formula of silver nitrate is represented by AgNO3 so the molecular equation is shown below :

AgNO3(aq) + CH3COONa(aq) ---->CH3COOAg (colloid) + NaNO3(aq)

Since sodium acetate and silver nitrate are ionic in nature, so they exist as ions in the solution. So its total ionic equation becomes :

Ag+(aq) + NO3- (aq) + Na+ (aq) + CH3COO-(aq) ---->CH3COOAg (aq) + Na+ (aq) + NO3- (aq)
Silver acetate is formed which makes a colloidal state. In the total ionic equation, the sodium cation and nitrate anion are present on both sides. So they cancel each other. The net ionic equation becomes :

Ag+(aq) + CH3COO-(aq) ---->CH3COOAg (colloid)

As such ‘ions’ in these solutions react with each other to form a colloidal dispersion due to double displacement reaction and so the two aqueous solutions react forming,

One aqueous compound and one solid and that solid is the colloid. As such a colloidal reaction occurs (silver nitrate and sodium acetate) are combined in this invention to prepare the solution for the process.

Hence “silver acetate” is formed as end result in the mixing.

As detailed above the prepared silver acetate is an covalent/ionic compound with empirical formula CH3CO2Ag, which is a photosensitive is a source of silver ions lacking an oxidising anion-site.

Details of step (e) and step (f) in the process steps
Balanced Chemical equation of Silver acetate and KOH :

KOH + AgCH3COO ---? KCH3CO2 + AgOH
2 AgOH =Ag2O+ H2O

Potassium Hydroxide + Silver Acetate = Potassium Acetate + Silver Hydroxide
Silver Hydroxide = Silver Oxide + Water

This is a precipitation reaction Ag2O is formed as precipitate.

The antiviral properties are evaluated in accordance with this invention using test methods such as Antibacterial evaluation (Quantitative) ASTME 2149-13a. Standard Test method for determining the antimicrobial activity of antimicrobial agents under dynamic contact condition,which is used primarily to evaluate the viral static activity of laundry additive disinfectants.

Hence the invention is disclosing in one aspect a method for producing a textile and its equivalent article having antiviral properties comprising contacting the article with a first solution, the first solution comprising silver, and contacting the article with a second solution, the second solution comprising an amount of oxidising agent sufficient to deposit an antiviral active amount of silver ions within the article.

In another aspect, the invention discloses that the said silver comprises silver nitrate.

In another aspect, the second solution comprises an amount of alkali sufficient to provide a pH of atleast about to 12.

In another aspect, the said oxidising agent is potassium hydroxide.

In another aspect, the silver ions crystals are interstitially deposited by interstitial precipitation.

In another aspect, the contacting bath of first solution comprising silver is heated to a temperature of around 90°C.

In another aspect the contacting bath of second solution of oxidising agent of KOH is heated to a temperature of 70°C - 90°C.

In another aspect, the said treated article contains 0.72% w/w of silver content and 2.82% w/w of water content after use.

In another aspect, the invention is for a fibrous textile and or its equivalent article containing antiviral agent such as silver ions is interstitially deposited within said article, said agent present in said article is an amount sufficient to impart antiviral properties to said article.
In another aspect, the said treated article capable of withstanding atleast 45 days of laundering without significant loss of antiviral efficacy.

In another aspect, the said treated article is capable of withstanding atleast 45 days of exposure to ultraviolet lights without significant loss of antiviral efficacy.

Textile fabrics treated in accordance with this invention hold promise for many antiviral applications, as currently many virus of different nature and different families are invading globally. Hence it has an extraordinary commercial value alongwith protecting the humans with a simple article, which can be made available in large quantity at low cost.

The invention has been described as detailed above but various embodiments and variations are possible beyond the preferred embodiments disclosed in this document. All such variations and modifications as obvious to the skilled person is within the scope of this invention.

The applicant relies upon the provisional specification filed in this application and shall be considered as part and parcel of complete specification.
,CLAIMS:WE CLAIM :-

1. A process for imparting antiviral and antimicrobial properties to a fibrous textile and/or equivalent article comprising of :
a. Preparing a preparatory wash solution which is 5% linear alkyl benzene sulphonate sodium salt solution,
b. Preparing a first salt mixture which is a colloidal/ionic silver suspension solution which is a mix of silver nitrate and sodium acetate in weight ratio of 5:1 to 1:5 in demineralized water and which mix is heated to a temperature of atleast 90°C for a duration of 10-30 minutes,
c. Preparing a second potassium hydroxide solution which is a 4% W/V solution and heated to a temperature in the range 70°C - 90°C,
d. Washing the selected fibrous textile/article using the said preparatory wash solution of step (a) atleast two times and thereafter allowing the washed article to dry at room temperature,
e. Soaking the washed article/textile of step (d) in said first salt mixture (b) for a duration of atleast 30 minutes and thereafter draining the excess solution from the soaked article/textile with a poly propylene roller,
f. Immersing the said soaked article/textile of step (e) in said second potassium hydroxide solution for atleast 30 minutes maintained at a temperature of 70°C - 90°C, and
g. Washing the textile/article of step (f) with demineralised water to neutralise the pH and thereafter allowing the treated textile/article to dry at room temperature.

the said process characterised in that ions in the solutions react with each other to form insoluble precipitate due to double displacement reaction, such that two aqueous solutions forming one aqueous compound and one solid, wherein the solid portion is the precipitate.

2. The process as claimed in claim 1(b), wherein weight ratio of silver nitrate and sodium acetate is most preferred as 1:1.

3. A textile material treated with a process as claimed in claim 1 which treated material containing antiviral agent such as silver ions interstitially deposited within said material.