阅读说明：本技术 用阳离子粘合剂粘合的抗微生物非织造湿纸巾 (Antimicrobial nonwoven wet wipes bonded with cationic binder ) 是由 约翰·博伊兰 丹尼斯·萨格 于 2018-12-14 设计创作，主要内容包括：一种抗微生物非织造湿纸巾包括：i)用由来自阳离子乙烯醇-N-乙烯基胺共聚物的组中的一种或多种阳离子保护胶体稳定的可交联VAE分散体粘合的纤维非织造基材,和ii)吸附于所述非织造基材中的包括一种或多种阳离子消毒剂的水性洗剂。所述抗微生物非织造湿纸巾中不存在阴离子表面活性剂。一种生产抗微生物非织造湿纸巾的方法包括：a)向非织造基材涂施包含由来自阳离子乙烯醇-N-乙烯基胺共聚物的组中的一种或多种阳离子保护胶体稳定的可交联VAE分散体的第一水性组合物；b)干燥所述组合物；和c)将第二水性组合物涂施于步骤b)的产物上。所述第一和第二水性组合物中的至少一种包括一种或多种阳离子消毒剂。(An antimicrobial nonwoven wet wipe comprising: i) a fibrous nonwoven substrate bonded with a crosslinkable VAE dispersion stabilized by one or more cationic protective colloids from the group of cationic vinyl alcohol-N-vinylamine copolymers, and ii) an aqueous lotion comprising one or more cationic disinfectants adsorbed in the nonwoven substrate. The antimicrobial nonwoven wet wipe is free of anionic surfactants. A method of producing an antimicrobial nonwoven wet wipe comprising: a) applying to a nonwoven substrate a first aqueous composition comprising a crosslinkable VAE dispersion stabilized by one or more cationic protective colloids from the group of cationic vinyl alcohol-N-vinylamine copolymers; b) drying the composition; and c) applying a second aqueous composition to the product of step b). At least one of the first and second aqueous compositions includes one or more cationic disinfecting agents.)

1. An antimicrobial nonwoven wet wipe comprising

i) A fibrous nonwoven substrate bonded with a crosslinkable VAE dispersion stabilized by one or more cationic protective colloids from the group of cationic vinyl alcohol-N-vinylamine copolymers, and

ii) an aqueous lotion adsorbed in the nonwoven substrate comprising one or more cationic disinfectants,

wherein anionic surfactant is not present in the antimicrobial nonwoven wet wipe.

2. The antimicrobial wet nonwoven wipe of claim 1 wherein the crosslinkable VAE dispersion is additionally stabilized with one or more nonionic protective colloids.

3. The antimicrobial wet nonwoven wipe of claim 1, wherein the crosslinkable VAE dispersion is additionally stabilized with one or more nonionic surfactants.

4. The antimicrobial nonwoven wet wipe of any one of the preceding claims, wherein the vinyl alcohol-N-vinylamine copolymer is comprised of 50 mol% to 99 mol% of vinyl alcohol units, 0 to 10 mol% of vinylformamide units, and 1 mol% to 25 mol% of vinylamine units.

5. The antimicrobial wet nonwoven wipe of any one of the preceding claims, wherein the one or more cationic disinfectants comprises a quaternary ammonium disinfectant.

6. The antimicrobial nonwoven wet wipe of any one of the preceding claims, wherein the one or more cationic disinfectants comprises benzalkonium chloride.

7. A method of producing the antimicrobial nonwoven wet wipe of any of the preceding claims, comprising:

a) applying a first aqueous composition comprising a crosslinkable VAE dispersion stabilized with one or more cationic protective colloids from the group of cationic vinyl alcohol-N-vinylamine copolymers onto a nonwoven substrate;

b) drying the composition; and

c) applying a second aqueous composition to the product of step b);

wherein at least one of the first and second aqueous compositions comprises one or more cationic disinfecting agents.

8. The method of claim 7, wherein the first aqueous composition comprises one or more of the cationic disinfecting agents.

9. The method of claim 7, wherein the second aqueous composition comprises one or more of the cationic disinfecting agents.

10. The method of claim 7 wherein the antimicrobial wet nonwoven tissue bonded with the vinyl acetate-ethylene dispersion colloidally stabilized with cationic vinyl alcohol-N-vinylamine copolymer added dry to dry nonwoven in an amount of 1.0% to 25% provides a dry nonwoven tensile strength of 250 grams force per 5cm width to 5000 grams per 5cm width and a wet tensile strength of 250 grams per 5cm width to 3000 grams per 5cm width as determined on an Instron tensile tester using ASTM method D5035-95.

Technical Field

The present invention relates to a nonwoven wet wipe (nonwoven wet wipe) comprising a nonwoven substrate and an aqueous antimicrobial lotion, wherein the nonwoven substrate is bonded with a cationic binder.

Background

Self-crosslinking dispersion adhesives suitable for use in the air laid (airlad) nonwoven industry are typically stabilized with certain amounts of anionic surfactants. US 5,109,063 a discloses a method of preparing vinyl acetate ethylene N-methylol acrylamide (NMA) copolymer emulsions for nonwoven adhesive applications. The emulsifying system consists of a salt of alkyleneoxy poly (ethyleneoxy) sulfate. This type of binder is commonly used in lotioned wet wipe (lotioned wet wipe) applications where the lotion is compatible with the anionic properties of the self-crosslinking binder used to provide integrity to the nonwoven article.

However, if the lotion contains a charged cationic compound, as is the case with quaternary ammonium disinfectants, commonly referred to as quaternary ammonium based disinfectants (quats), such as benzalkonium chloride, the anionic nature of the surfactant tends to neutralize the efficacy of the quaternary ammonium disinfectant, thereby reducing the biocidal efficacy of the disinfectant. Thus, the nonwoven articles need to be bonded with a nonionic or cationic stable dispersion. US 2004/0137815 Al claims a nonwoven antimicrobial tissue comprising a fibrous nonwoven substrate bonded with a nonionic binder and containing a cationic disinfectant. US 2002/0183233 a1 discloses the improvement of antimicrobial nonwoven tissues by the addition of a salt (cationic release agent) to the lotion, which improves the release of the cationic disinfectant. The cationic release agent competes with the cationic quaternary ammonium salt for anionic sites in the tissue substrate. No nonionic or cationic binder is used. US 2005/0025668 a1 describes wet wipes impregnated with a disinfectant. The nonwoven substrate is free of latex binder and the aqueous hypohalite-releasing composition is applied to the substrate. US 2002/0031486 a1 discloses a wipe consisting of a water-insoluble nonwoven substrate and an aqueous antimicrobial cleansing composition comprising a cationic disinfecting agent and a nonionic surfactant. US 5,326,809 describes poly (vinyl alcohol) -co- (vinylamine) as protective colloid in aqueous emulsion polymerization. There is no disclosure of its use for antimicrobial nonwoven wet wipes.

There remains a need for a simple and cost effective means for improving the efficacy of cationic disinfectants in wet wipe compositions.

Disclosure of Invention

The present invention provides an antimicrobial nonwoven wet wipe comprising: i) a fibrous nonwoven substrate bonded with a crosslinkable Vinyl Acetate Ethylene (VAE) dispersion stabilized with one or more cationic vinyl alcohol-N-vinylamine copolymers and optionally one or more nonionic surfactants or nonionic protective colloids, and ii) an aqueous lotion comprising one or more cationic disinfectants adsorbed within the nonwoven substrate. The antimicrobial nonwoven wet wipe is free of anionic surfactants.

A method of producing an antimicrobial nonwoven wet wipe comprising: a) applying a first aqueous composition comprising a crosslinkable VAE dispersion stabilized with one or more cationic protective colloids of the group of cationic vinyl alcohol-N-vinylamine copolymers and optionally one or more nonionic surfactants or nonionic protective colloids onto a nonwoven substrate; b) drying the composition; and c) applying a second aqueous composition to the product of step b). At least one of the first and second aqueous compositions includes one or more cationic disinfecting agents.

Detailed Description

The inventors have found that if anionic surfactants are present in the wet nonwoven wipe, the release and hence the efficacy of cationic disinfectants, such as quaternary ammonium disinfectants, is reduced. Anionic surfactants are commonly used to stabilize vinyl acetate ethylene copolymer (VAE) dispersions for use as nonwoven substrate binders. However, the inventors have found that dispersions of VAE that are cationically stabilized by one or more cationic protective colloids of the group of vinyl alcohol-N-vinylamine copolymers provide improved efficacy of cationic disinfectants in the wet wipe composition compared to anionically stabilized or non-ionically stabilized VAE binder dispersions. The adhesive composition according to the invention, and the wet wipes produced therefrom, are free, or substantially free, of anionic surfactants, thereby avoiding interference with the activity of the cationic disinfectant.

The components and methods for making an antimicrobial nonwoven wet wipe bonded with a nonionic VAE binder according to the present invention will now be discussed in detail. Percentages of materials recited herein are by weight unless the context indicates otherwise.

VAE copolymers

Unless otherwise indicated, the weight percentages of monomers referred to herein are based on the total weight of all monomers in the polymerization reaction used to make the VAE copolymer, with the weight percentages of monomers in each case totaling 100%.

The VAE copolymers used as adhesives according to the present invention comprise polymerized units of vinyl acetate, ethylene, N-methylol functional monomer and (meth) acrylamide, i.e., acrylamide and/or methacrylamide. Vinyl acetate is typically copolymerized in an amount of at least 65 wt%, or at least 70%, and up to 94.5 wt%, or up to 85%. Ethylene is usually copolymerized in an amount of at least 5% by weight, or at least 10% by weight, and at most 30% by weight or at most 20% by weight.

The fraction of N-methylol functional monomer in the copolymer is typically at least 0.1 weight percent, or at least 0.5%, 1% or 2 weight percent, and typically at most 10.0 weight percent, or at most 8 weight percent or 5 weight percent, in each case based on the total weight of monomers used in the polymerization. The N-methylol functional monomer is suitably used in an amount of at least 25 wt%, or at least 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt% or 55 wt% relative to the total amount of N-methylol functional monomer plus (meth) acrylamide. The amount is at most 85 wt%, or at most 80 wt%, 75 wt%, 70 wt%, 65 wt% or 60 wt%. The total amount of N-methylol functional monomer plus (meth) acrylamide present in the copolymer is at least 0.2 wt%, or at least 0.5 wt%, 1 wt%, 3 wt%, or 5 wt%, and up to 5.0 wt%, or up to 8 wt%, 10 wt%, or 15 wt%.

Suitable exemplary N-methylol functional monomers for preparing the copolymer include N-methylolacrylamide (NMA), N-methylolmethacrylamide, allyl N-methylolcarbamate, and esters of N-methylolacrylamide, N-methylolmethacrylamide, or allyl N-methylolcarbamate. N-methylol-acrylamide and N-methylol-methacrylamide are particularly preferred. The N-methylol functional monomer is used in combination with acrylamide and/or methacrylamide, preferably acrylamide. Most preferred are blends of N-methylolacrylamide and acrylamide. Such blends are commercially available, for example, as a 48 wt% aqueous solution of NMA and acrylamide in a 1:1 molar ratio, and can be sold under the trade nameNMA-LF MONOMER (Cytec Industries, Woodland Park, NJ) is commercially available, or contains an aqueous solution of 28 wt% N-methylolacrylamide and 20 wt% acrylamide, and can be sold under the trade name

NMA 2820(SNF Floerger, Andrezieux, France) is commercially available. Alternatively, NMA and acrylamide may be added separately to the polymerization feed.

In addition to NMA, other N- (C) s may be included in the VAE copolymer_1-4) Hydroxyalkyl (meth) acrylamides. Ethylenically unsaturated monomers containing cellulose reactive moieties, such as those containing aldehyde, protected aldehyde and glycolic acid moieties, may also be included. Examples include isobutoxymethacrylamide, acrylamidoglycolic acid, acrylamidobutyraldehyde, and the dialkyl acetals of acrylamidobutyraldehyde, wherein the alkyl groups each independently have from 1 to 4 carbon atoms.

Alternatively, the range of useful properties of the copolymer in the dispersion can be extended by including additional monomers in the VAE copolymer. Generally, suitable comonomers are monomers having a single polymerizable olefinic group. Examples of such comonomers are vinyl esters of carboxylic acids having from 3 to 18 carbon atoms. Preferred vinyl esters are vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methylvinyl acetate, vinyl pivalate and vinyl esters of alpha-branched monocarboxylic acids having 9 to 11C atoms, examples being VEOVA9^TMOr VEOVA10^TMEsters (commercially available from momentive specialty Chemicals, Houston, TX). Other suitable comonomers include esters of acrylic or methacrylic acid with linear or branched alcohols having 1 to 15C atoms. Exemplary methacrylates or acrylates include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, and norbornyl acrylate. Other suitable comonomers include vinyl halides, such as vinyl chloride, or olefins, such as propylene. Generally, the other comonomers are copolymerized in an amount of 0.5 to 30% by weight, preferably 0.5 to 20% by weight, based on the total weight of the monomers used for the polymerization.

Optionally, from 0.05% to 10% by weight, based on the total weight of the monomers used for the polymerization, of other monomers (auxiliary monomers) may additionally be copolymerized to form the dispersion. The auxiliary monomer includes a polymerizable alkenyl group and at least one additional functional group. Examples of auxiliary monomers include acrylonitrile and diesters of fumaric and maleic acids, e.g., diethyl and diisopropyl esters. Typically, there is only one polymerizable alkenyl group in each monomer used to prepare the VAE copolymer, although in some cases there may be more polymerizable alkenyl groups.

On the other hand, when used for manufacturing wet wipes according to the present invention, ethylenically unsaturated monomers containing carboxylic, sulfonic or phosphoric acid or phosphonic acid groups, salts thereof or groups hydrolyzed to them are generally excluded from the VAE copolymer used as a binder for making wipes. Specific examples include acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, vinylsulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid.

The choice of monomers or the choice of the monomer weight ratio is preferably made in such a way that the copolymer generally has a suitable glass transition temperature (Tg). Typically, the Tg is at least-10 deg.C, or at least-5 deg.C, or at least 0 deg.C, and at most +20 deg.C, or at most +15 deg.C, or at most +10 deg.C. The glass transition temperature Tg of the copolymers can be determined by Differential Scanning Calorimetry (DSC) in a known manner according to ASTM D3418-82 as starting temperature at a heating rate of 10 ℃ per minute. Tg can also be approximately pre-calculated by the Fox equation. According to Fox t.g., bull.am. physics soc.1,3, page 123 (1956): 1/Tg ═ xl/Tg1+ x2/Tg2+ … + xn/Tgn, where xn is the mass fraction of monomer n (wt%/100) and Tgn is the Kelvin glass transition temperature of the homopolymer of monomer n. The Tg values for homopolymers are provided in Polymer Handbook, second Edition, J.Wiley & Sons, New York (1975) (the Polymer Handbook 2nd Edition, J.Wiley & Sons, New York (1975)).

Cationic protective colloids

Suitable cationic protective colloids are cationic vinyl alcohol-N-vinylamine copolymers, also referred to herein as cationic poly (vinyl alcohol) -co- (vinylamine). Vinyl alcohol-N-vinylamine copolymers are commercially available from Sekisui. The synthesis of these copolymers is well known in the art and is described, for example, in EP 0339371 a2 or WO 2006/082157a 1. In the first step of the preparation, vinyl acetate and N-vinylformamide are copolymerized to give a vinyl acetate-N-vinylformamide copolymer. In a second step, the vinyl acetate-N-vinylformamide copolymer is saponified by acid or base catalysis to give a vinyl alcohol-N-vinylamine copolymer. In the third step, the vinyl alcohol-N-vinylformamide copolymer is hydrolyzed to a vinyl alcohol-N-vinylformamide copolymer with acid or base catalysis. After hydrolysis, the vinyl alcohol-N-vinylamine copolymers preferably consist of 0 to 15 mol% of vinyl acetate units, 50 mol% to 99 mol% of vinyl alcohol units, 0 to 10 mol% of vinylformamide units and 1 mol% to 25 mol% of vinylamine units, and the data in mol% amounts to 100 mol% in each case. In general, the weight average molecular weight Mw of the vinyl alcohol-N-vinylamine copolymer is 10,000-200,000, preferably Mw is 15,000-130,000. In general, the vinyl alcohol-N-vinylamine copolymers have a viscosity of 1 to 30mPas (Hoeppler viscosity, determined at 20 ℃ according to DIN 53015) in a 4% strength aqueous solution. Generally, the cationic charge of the vinyl alcohol-N-vinylamine copolymer is introduced during the emulsion polymerization of the VAE copolymer, which is typically performed at a pH below 6.

In addition, one or more nonionic protective colloids can be used to stabilize the VAE dispersion during and after the emulsion polymerization. Suitable nonionic protective colloids include polyvinyl alcohol (PVOH) and nonionic cellulose derivatives, for example, hydroxyethyl cellulose. Other examples include polyvinylpyrrolidone, PVOH with ethylene oxide or polyethylene oxide substituents, and acetoacetylated PVOH. Additionally, copolymers of PVOH may be used. Examples include ethylene and/or N-vinylpyrrolidone copolymers of vinyl alcohol. Polyvinyl alcohol is particularly useful. Suitable PVOH include partially hydrolyzed polyvinyl alcohols having a degree of hydrolysis of 80 mol% to 99 mol%, preferably 85 mol% to 99 mol%, and a viscosity in 4% strength aqueous solution of 1 to 30mPas, preferably 3 to 6mPas (hoppler viscosity, determined according to DIN 53015 at 20 ℃). Such PVOH can be obtained commercially or can be obtained by methods known to the skilled person.

The cationic vinyl alcohol-N-vinylamine copolymer, and optionally other protective colloids, e.g., polyvinyl alcohol, will typically be present at a level of at least 0.1 wt%, or at least 0.2 wt% or 0.5 wt%. Typically, this level is at most 10 wt%, or at most 5 wt% or 1 wt%. These percentages represent the content of protective colloid relative to the total weight of all monomers used for the polymerization.

In addition to the cationic vinyl alcohol-N-vinylamine copolymer, nonionic surfactants (emulsifiers) can optionally be present in the crosslinkable VAE dispersions. Preferred nonionic surfactants are ethoxylated branched or unbranched aliphatic alcohols, especially having 3 to 80 ethylene oxide units and C₅-C₃₆Degree of ethoxylation of the alkyl group. Preferred nonionic surfactants also include C having a degree of ethoxylation of from 3 to 30 ethylene oxide units₁₃-C₁₅Carbonylated alcohol ethoxylate (C)₁₃-C₁₅oxo-process alcohol ethoxylate), and C having a degree of ethoxylation of from 11 to 80 ethylene oxide units₁₆-C₁₈An aliphatic alcohol ethoxylate. Particularly preferred are C's having a degree of ethoxylation of from 3 to 30 ethylene oxide units₁₂-C₁₄Aliphatic alcohol ethoxylates, and copolymers of ethylene oxide and propylene oxide having a minimum content of at least 10 wt% ethylene oxide. These surfactants preferably do not contain alkylphenol ethoxylate structures.

The total amount of surfactants is generally from 0.5% to 5% by weight, preferably from 1% to 3% by weight, based in each case on the total weight of the monomers.

Emulsion polymerization protocol

During the polymerization of the VAE copolymer, the polymerization mixture is stabilized with one or more vinyl alcohol-N-vinylamine copolymers and optionally one or more nonionic surfactants or nonionic protective colloids. The VAE dispersion may be prepared by emulsion polymerisation, typically at a temperature of from 40 ℃ to 100 ℃, more typically from 50 ℃ to 90 ℃, most typically from 60 ℃ to 80 ℃. The polymerization pressure is generally from 10 to 100bar, more generally from 25 to 90bar, and in particular from 45 to 85bar, depending on the ethylene feed. The pH of the polymerization mixture is adjusted to a pH < 5, preferably to a pH of 3 to 5.

The polymerization is initiated using a redox initiator combination, such as a combination conventionally used in emulsion polymerization. Redox initiator systems may be used to prepare VAE dispersions suitable for use in the present invention. The initiator may be a formaldehyde generating redox initiation system such as sodium formaldehyde sulfoxylate. However, in certain embodiments, it is desirable to minimize the formaldehyde level in the dispersion. In such cases, it is desirable to use a redox initiation system that does not generate formaldehyde. In general, suitable non-formaldehyde-generating reducing agents for use in redox couples include, as non-limiting examples, those based on ascorbic acid known in the artThose of acid, bisulfite, erythorbate or tartaric acid chemicals, and those manufactured by Bruggeman Chemical, Haerbulon, Germany (Heilbronn)FF 6M. Non-redox initiators may also be used, such as peroxides and azo-type initiators, all of which are well known in the art.

All of the monomers may constitute the initial charge, or all of the monomers may form the charge, or a portion of the monomers may form the initial charge, while the remainder may form the charge after initiation of polymerization. The feeds may be separate (spatially and temporally) or all or part of the components may be fed after pre-emulsification. Once the polymerization process is complete, post-polymerization (post-polymerization) to remove residual monomers can be carried out using known methods, one example of a suitable method being post-polymerization initiated by a redox catalyst. Volatile residual monomers can also be removed by distillation, preferably at subatmospheric pressure, and, where appropriate, by passing an inert entraining gas, such as air, nitrogen or water vapor, through or over the material.

Suitable VAE copolymer dispersions are prepared which typically have a solids content in the range of 45% to 75% by weight. If diluted to a solids level of 25%, the dispersions typically have a viscosity of at least 5mPas or at least 10, 20 or 30 mPas. The viscosity is typically at most 800mPas, or at most 700, 600 or 500 mPas. The viscosity was measured using a Brookfield viscometer model LVD with spindle #3 at 60rpm and 25 ℃.

Fibrous nonwoven substrate

The fibrous nonwoven substrate may be natural fibers such as, but not limited to, cellulosic fibers or wood pulp, or synthetic fibers including, but not limited to, polyester, polyethylene, polypropylene, and polyvinyl alcohol or viscose fibers or a combination of any of these treated by dry (air laid), carded (carded), rando (rando) or wet laid (wet laid) processes. In use with cationic adhesiveThe fibrous nonwoven substrate typically has a basis weight of at least 10g/m prior to treatment with the composition²Or at least 45g/m²And usually at most 150g/m²Or at most 120g/m²。

Aqueous disinfectant lotion

The aqueous lotion absorbed in the bonded nonwoven substrate comprises one or more cationic disinfectants. These are typically quaternary ammonium disinfectant compounds. Benzalkonium chloride (Benzalkonium chloride) is a specific example, although any other cationic disinfectant known in the art may be used instead or in addition. Some cationic disinfectants may dissolve in the aqueous phase of the lotion while others adsorb onto the fiber surfaces of the nonwoven substrate. Preferably the cationic disinfecting agent comprises only one cationic moiety per molecule.

The aqueous lotion can also optionally contain a salt that is not a cationic disinfectant. Any type of salt may be included, for example, organic salts, inorganic salts, and salts containing organic anions and metals, non-disinfectant quaternary ammonium cations, or non-quaternary ammonium cations, i.e., NH₄ ⁺Or salts of protonated primary, secondary, or tertiary amines. Non-limiting examples include acetate, acetylide, ammonium salts (excluding quaternary ammonium salts), arsenate, astatide, azide, bis-halide, bicarbonate, bis-sulfide, boride, borohydride, borohalide, carbonate, citrate, cyanate, cyanide, formate, germanate, glycinate, halate, halide, hydride, hydrogen selenate, hydrosulfide, hydroxide, imide, metaniobate, metatantalate, metavanadate, nitrate, nitride, nitrite, oxide, perchlorate, phosphate, phosphonium, selenide, selenite, selenate, sulfide, sulfate, tribasic, non-disinfectant tetraalkylammonium salts, telluride, thiocyanate, and/or vanadate. Specific examples include potassium citrate, sodium tartrate, potassium lactate, sodium and/or potassium salicylate, magnesium sulfate, sodium chloride, ammonium chloride and/or potassium chloride. However, it is possible to exclude other than cationic disinfectantsAny one or more or all of the above salts.

The aqueous lotion can also comprise an organic solvent, which if present, will typically comprise up to 10 wt%, or up to 5 wt%, 2 wt%, or 1 wt% of the lotion composition. Examples include C_1-6Alkanol, C_1-6Diol, C of alkylene glycol_1-10Alkyl ethers, C_3-24Alkylene glycol ethers and/or polyalkylene glycols. Specific types of solvents include alkanols such as methanol, ethanol, n-propanol, isopropanol, butanol, pentanol and/or hexanol and various positional isomers thereof; acetone; and glycol ethers such as ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, propylene glycol n-propyl ether, propylene glycol monobutyl ether, propylene glycol tert-butyl ether, diethylene glycol monoethyl or monopropyl or monobutyl ether, methyl or ethyl or propyl or butyl ether of di-or tripropylene glycol, acetates and/or propionates of glycol ethers. However, any one or more of the above solvents, or all solvents, may be excluded.

Making antimicrobial nonwoven wet wipes

The cationic VAE adhesive composition is typically applied to the nonwoven substrate by spraying, saturating, gravure printing, or foaming. The binder composition may optionally comprise a catalyst, for example, an acidic compound or an ammonium salt thereof. One example is ammonium chloride.

Wetting additives may be included in the adhesive composition to aid in wetting not only the formulated adhesive on the substrate, but also the subsequent finished fibrous nonwoven substrate. The wetting additive should be a nonionic or cationic wetting surfactant to avoid reducing the efficacy of the cationic disinfectant added as a lotion to the bonded nonwoven substrate. An example is

This is a nonionic ethoxylated acetylenic diol (nonionics ethoxylated acetylenic diol) sold by Air Products. The humectant may be included in the adhesive composition at a level of from 0.1 to 3 dry parts (dry parts), but more typically is included, based on the weight of dry polymerThe amount of the compound is 0.5-2 parts.

The composition is typically applied at a solids content of 0.5 wt% to 30 wt%, depending on the desired loading on the substrate. Generally, the amount of binder will be at least 5 wt%, or at least 10% or 15% by dry weight based on the weight of the untreated substrate. It is generally at most 50% by weight, or at most 40% or 30%.

After the adhesive composition is applied to a substrate, the substrate is dried. Typically in the temperature range of 120 ℃ to 160 ℃, although higher or lower temperatures may be used. Thereafter, an aqueous lotion containing a cationic disinfectant can be applied.

Alternatively, the cationic disinfectant may be included in the VAE adhesive composition, rather than being added separately to the lotion as described above. In that case, water and any other lotion components, e.g., solvents, may be added to the substrate after the adhesive composition has been applied and dried, and it should be understood that some or all of the cationic disinfecting agent may be dissolved in the water. Alternatively, two ways of adding the cationic disinfectant may be used. In either of these ways, the aqueous lotion will generally be present in an amount of at least 50 parts lotion (wet basis) or at least 150, 200, or 250 parts per 100 parts of bonded substrate (dry basis). The amount of lotion is generally up to 500 parts, or up to 400 or 350 parts per 100 parts of substrate. In all cases, the wet wipes obtained can be packaged in any manner effective to minimize or avoid drying out.