HK1188553B - Flushable article including polyurethane binder and method of using the same - Google Patents

Description

Flushable article including polyurethane adhesive and method of using same

Cross reference to related patent applications

This application claims priority from U.S. provisional application No.61/421,895, filed on 10/12/2010 and incorporated herein.

Background

The present invention relates to disintegrating substrates, such as wipes.

Efforts have been made to develop disposable products such as diapers and personal care products that can be discarded by flushing into a toilet. One area of focus for this effort is: a binder for binding together fibers used in disposable products. The binder must have sufficient strength to hold the fibers together during storage and use, but loses strength when placed in water.

The binders proposed for this purpose have been formulated with polymers that are soluble in cold water (e.g., water in a toilet) but insoluble in warm water. Other binders have also been formulated with ion-sensitive polymers. The ion-sensitive polymer is sensitive to changes in the concentration of ions in an aqueous medium when placed in the aqueous medium. Some ion-sensitive polymers are insoluble in aqueous solutions having high concentrations of salts but soluble in aqueous solutions having low concentrations of salts. Theoretically, if a polymer is soluble in a solution having a low concentration of salt, such as water, the polymer will dissolve upon contact with water. If the adhesive dissolves, it will no longer be able to function as an adhesive and will lose its "adhesive" properties. Thus, articles constructed with such adhesives may be dispersed when placed in toilet water and flushed from the toilet.

Disclosure of Invention

In one aspect, the invention features a flushable article that includes a substrate including fibers and a dry binder composition in contact with the fibers, the article being insoluble in water having a pH of no greater than 6 and disintegrating in water having a pH of at least 6.5. In some embodiments, the article is in the form of a flushable wipe comprising a substrate comprising fibers and a dry binder composition in contact with the fibers, the wipe being insoluble in water having a pH of no greater than 6 and disintegrating in water having a pH of at least 6.5.

In some embodiments, the dried binder composition is insoluble in water having a pH of no greater than 6 and disintegrates in water having a pH of at least 6.5. In other embodiments, the dry binder composition exhibits a loss of integrity relative to its initial state, a decrease in cohesive strength relative to its initial state, or a combination thereof in water having a pH of at least 6.5. In one embodiment, the dry binder composition is insoluble in water having a pH of no greater than 5.5. In another embodiment, the dry binder composition is insoluble in water having a pH of no greater than 5. In some embodiments, the dry binder composition decomposes in water having a pH of at least 7.

In other embodiments, the substrate is saturated with the binder composition such that a dry binder composition is present on the fibers and in the interstices between the fibers.

In one embodiment, the wipe further comprises an aqueous medium in contact with the substrate, the medium having a pH of no greater than 6. In other embodiments, the medium comprises an emulsion. In some embodiments, the fibers comprise at least one of: wood pulp, cellulose, polyethylene, polypropylene, polyester, polyamide and polylactic acid.

In some embodiments, the substrate comprises multiple layers. In one embodiment, the substrate includes a first layer comprising fibers oriented in a first direction and a second layer comprising fibers oriented in a second direction different from the first direction.

In another embodiment, the wipe comprises at least 5 wt% of the dry adhesive composition, based on the weight of the adhesive and the substrate. In other embodiments, the wipe comprises from about 10% to about 25% by weight of the dry adhesive composition, based on the weight of the adhesive and substrate.

In some embodiments, the dry binder composition is insoluble in water having a pH of no greater than 5.5.

In one embodiment, the dry adhesive composition is derived from an anionic polyurethane dispersion. In one embodiment, the dry adhesive composition includes a polyurethane that includes the reaction product of: a polyurethane prepolymer, a chain extender comprising a polyamine, and a chain terminator comprising a monoamine. In other embodiments, the dry adhesive composition includes a polyurethane that includes the reaction product of: an acid functional polyurethane prepolymer, a chain extender comprising a polyamine, and a chain terminator comprising a monoamine.

In another embodiment, the dry adhesive composition includes a polyurethane that includes the reaction product of: an acid functional polyurethane prepolymer, at least a portion of which is in a form selected from the group consisting of alkali metal salts, tertiary amine salts, ammonium salts, and combinations thereof; a chain extender comprising a polyamine; and a chain terminator comprising a monoamine.

In another embodiment, the dry adhesive composition includes a polyurethane that includes the reaction product of: a polyurethane prepolymer, an alkylene polyamine, and an alkanolamine. In other embodiments, the dry adhesive composition includes a polyurethane that includes the reaction product of: polyurethane prepolymers, polyamines, monoamines and tertiary amines. In some embodiments, the polyurethane prepolymer includes the reaction product of a polymer polyol, a dihydroxy acid, and a polyisocyanate. In other embodiments, the dihydroxy acid comprises dimethylolpropionic acid and the polyisocyanate comprises isophorone diisocyanate. In another embodiment, the dihydroxy acid comprises the reaction product of a trifunctional polyol and phthalic anhydride.

In one embodiment, the polyurethane prepolymer has an acid number of at least 10.

In another embodiment, the residual isocyanate functionality of the polyurethane prepolymer is from 2 to 6 weight percent and the dry binder composition is formed from a monoamine in an amount such that the ratio of amine groups in the monoamine to isocyanate groups in the polyurethane prepolymer is from 0.01:1 to 0.8:1.

In other aspects, the invention features a flushable wipe that includes a substrate including fibers and a dry binder composition in contact with the fibers, the dry binder composition including a polyurethane polymer, the wipe being insoluble in water having a pH of greater than 6.5 and disintegrating when tested according to a wipe disintegration method. In one embodiment, the polyurethane polymer is an anionic polyurethane polymer. In some embodiments, the anionic polyurethane polymer is insoluble in water having a pH of less than 6 when dried and decomposes in water having a pH of at least 6.5.

In another aspect, the invention features a packaged article that includes: a container, an aqueous medium disposed in the container, and a wipe as described herein disposed in the container and saturated with the aqueous medium.

In other aspects, the invention features a method of making a flushable article, the method including: applying an aqueous binder composition disclosed herein to at least one of the fibers and a substrate comprising the fibers, the binder composition being insoluble in water having a pH of no greater than 6 when dried and disintegrating in water having a pH of greater than 6.5; forming a substrate from the fibers if the fibers are not in the form of a substrate; and drying the adhesive composition. In one embodiment, the article disintegrates in tap water when tested according to the substrate integrity test method. In another embodiment, the method further comprises contacting the substrate with an aqueous medium having a pH of no greater than 6. In one embodiment, the aqueous binder composition includes a first anionic polyurethane dispersion including the reaction product of a polyurethane prepolymer, a polyamine, and a monoamine. In other embodiments, the aqueous binder composition further comprises a second anionic polyurethane dispersion comprising an alkali metal salt of a sulfonic acid. In some embodiments, the article is a wipe and the substrate is a sheet.

In one embodiment, the method is a method of making a flushable wipe, the method comprising: applying the aqueous binder composition disclosed herein to at least one of the fibers and a substrate comprising the fibers, the binder composition being insoluble in water having a pH of no greater than 6 when dried and disintegrating in water having a pH of greater than 6.5, and if the binder is applied to the fibers, the method further comprises forming the fibers into a substrate. In some embodiments, the method further comprises applying the aqueous adhesive composition to a substrate. In another embodiment, the method further comprises drying the adhesive composition. In other embodiments, the fibers are in the form of a substrate prior to application of the aqueous binder composition. In one embodiment of the method, the aqueous binder composition comprises a polyurethane as disclosed herein. In another embodiment, the method further comprises contacting the substrate with a medium having a pH of no greater than 6. In some embodiments, the medium comprises an aqueous liquid.

In another aspect, the invention features a flushable article that includes a substrate including fibers and a dry binder composition in contact with the fibers, the dry binder composition being insoluble in water having a pH of no greater than 6 and disintegrating in water having a pH of at least 6.5. In one embodiment, the dried binder is insoluble in water having a pH of no greater than 5.5. In other embodiments, the dry binder decomposes in water having a pH of at least 7.

In one embodiment, the article is a multi-component article comprising the article described herein, and is in the form of: a diaper, a sanitary napkin, a sheet material, a training pant, an incontinence article, a container, a filter, an ostomy bag, a garment, a surgical gown, a face mask, an inner pad of an absorbent article, an insole, an antiperspirant sheet, a breast pad, a helmet liner, a wound dressing, a sterile package, a car cover, a floor covering, a blanket, a tablecloth, or a combination thereof.

In another aspect, the invention features a flushable article that includes a substrate including fibers and a dry binder composition in contact with the fibers, the dry binder composition being insoluble in water having a pH of no greater than 6 and disintegrating, losing its integrity relative to its initial state, decreasing its cohesive strength relative to its initial state, or a combination thereof when tested in tap water according to dry binder integrity test method I.

In other aspects, the invention features a dry adhesive composition that includes the reaction product of: a polyurethane prepolymer, a chain extender comprising a polyamine, and a chain terminator comprising a monoamine, the dry binder composition being in a form selected from the group consisting of fibers, filaments, granules, particles, powders, or combinations thereof, and being insoluble in water having a pH of no greater than 6 and decomposing in water having a pH of at least 6.5.

The invention features a wipe that maintains its integrity during storage and use and disintegrates when placed in water having a pH of at least 6.5. The invention also features an article that maintains its integrity in water having a pH of no greater than 6 and disintegrates when placed in water having a pH of at least 6.5.

Other features and advantages will be apparent from the following description of the preferred embodiments, and from the claims.

Glossary

In connection with the present invention, these terms have the following meanings:

the term "disintegration" refers to the dispersion.

The term "flushable" refers to an article that disintegrates, breaks, exhibits a loss of integrity, or a combination thereof when tested according to the "tap water wipe integrity test method" or the "tap water substrate integrity test method".

The term "water having a pH of no greater than …" refers to an aqueous solution formulated by adding citric acid and sodium citrate to deionized water in an amount sufficient to form a buffer solution having a pH of no greater than the stated value.

Detailed Description

Flushable articles (e.g., wipes) include a substrate (e.g., a sheet) comprising fibers and a dry binder composition in contact with the fibers. The flushable article retains its integrity and strength (e.g., does not disintegrate) when stored in water having a pH of no greater than 6 but disintegrates in water having a pH of greater than 6.5. Substrates that decompose at a pH greater than 6.5 may not decompose at a pH of 6.6, but may decompose at a pH of about 7, at least 7.5, or even at least 8. One method of determining whether a substrate retains its integrity in water having a pH of no greater than 6 and disintegrates in water having a pH of greater than 6.5 is the substrate integrity test method described herein.

For ease of reference, the article will hereinafter be referred to as a wipe; however, it should be understood that the description with respect to the wipe applies equally to the article. Flushable wipes also retain their integrity and strength (e.g., do not disintegrate) when stored in water having a pH of no greater than 6 and disintegrate in water having a pH of greater than 6.5. Wipes that decompose at a pH greater than 6.5 may not decompose at a pH of 6.6, but may decompose at a pH of about 7, at least 7.5, or even at least 8. One method of determining whether a wipe retains its integrity in water having a pH of no greater than 6 and disintegrates in water having a pH of greater than 6.5 is the wipe integrity test method described herein. The wipes are optionally stored in a storage medium which can help maintain the integrity of the wipes until the wipes are discarded.

The substrate is formed from fibers derived from a variety of sources including, for example, wood pulp, cotton, flax, jute, hemp, wool, cellulose acetate, viscose rayon, polyolefins (e.g., polyethylene and polypropylene), polyesters, polyamides, polyacrylics, polylactic acid, and combinations thereof. The fibers may be formed by a variety of processes including, for example, extrusion, carding, melt blowing, spunbonding, staple fiber carding, film punching, pulping, and combinations thereof. The fibers can have any dimension including, for example, staple fibers, filaments, and combinations thereof having a length of no greater than 30 millimeters.

The fibers can be formed into various forms of substrates including, for example, sheets, rolls, felts (e.g., airfelt and wetlaid felts), mats, tissues (e.g., creped and uncreped), nonwoven webs, coform products, hydroentangled webs, and combinations and composites thereof. The substrate may be formed using any suitable process including, for example, air-laid processes, wet-laid processes, staple fiber carding, hydroentangling processes, staple fiber bonding, and solution spinning.

The substrate may be in the form of a single layer or multiple layers and have any suitable density. The fibers in the substrate can be oriented in a variety of configurations, including, for example, in one direction, in multiple directions, randomly, and combinations thereof, and if multiple layers are present, the layers can include a variety of configurations, including, for example, a layer including fibers oriented in a first direction, a layer including fibers oriented in a second direction, a layer including fibers oriented in a third direction, a layer including randomly oriented fibers, and combinations thereof. The substrate may also include texture, such as embossed texture (e.g., waves and lines (e.g., straight and curved)), sanding, quilting, wrinkling, and combinations thereof.

The dry binder composition of the wipe comprises the reaction product of a polyurethane prepolymer and optionally a monoamine chain terminator, a polyamine chain extender and combinations thereof. The dry binder composition is formed from an aqueous polyurethane dispersion (i.e., an aqueous binder composition) that is applied to the substrate fibers, the substrate, or a combination thereof and dried. The dry adhesive composition holds the fibers in the substrate of the wipe in a fixed relationship to each other. The integrity of the dried binder composition changes in response to changes in pH. The dried binder composition is insoluble in water having a pH of no greater than 6. In water having a pH of at least 6.5, the dried binder composition may exhibit a variety of properties including, for example, disintegration, loss of its integrity relative to its initial state, exhibiting a decrease in cohesive strength relative to its initial state, and combinations thereof. Two methods of determining whether a dried binder composition is insoluble in water at a pH of no greater than 6 and decomposes in water at a pH of greater than 6.5 are the "dried binder integrity test methods I and II" described herein.

The amount of dry adhesive composition present in the wipe (i.e., "add-on") can be any suitable amount. Useful amounts of dry binder added result in a wipe that includes at least 5 wt.%, at least 10 wt.%, at least 20 wt.%, or even from about 10 wt.% to about 25 wt.% dry binder, based on the total dry weight of the wipe.

The aqueous binder composition from which the dry binder composition is derived includes an anionic polyurethane dispersion that includes the reaction product of an acid-functional polyurethane prepolymer, a monoamine chain terminator and a polyamine chain extender. The aqueous binder composition has a pH of from about 7 to about 8.7, or even from about 7.1 to about 8.2, and can be formulated to exhibit any desired viscosity, including, for example, a viscosity suitable for spraying. Useful aqueous adhesive compositions have a viscosity of no greater than 1000 centipoise (cP), no greater than 500cP, no greater than 250cP, no greater than 100cP, or even no greater than 50cP when measured at room temperature, i.e., 77 ° f (25 ℃). The aqueous binder composition includes at least 20 wt% solids, no greater than about 65 wt% solids, from about 25 wt% solids to about 60 wt% solids, from about 30 wt% solids to about 55 wt% solids, or even from about 30 wt% solids to about 50 wt% solids. The aqueous adhesive composition preferably comprises at least 60 wt.%, at least 65 wt.%, at least 70 wt.%, at least 75 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.% or even at least 100 wt.% of the anionic polyurethane dispersion.

The acid functional polyurethane prepolymers suitable for use in the polyurethane dispersion of the aqueous binder composition are water dispersible and have an average isocyanate functionality (i.e., average number of functional groups) of at least about 1.8, at least about 2.0, or even no greater than about 3.0. The polyurethane prepolymer has an isocyanate content of from about 2 wt% to about 6 wt%, from about 2 wt% to about 5.5 wt%, or even from about 2.25 wt% to about 5 wt%, and an acid number of less than 30, from about 10 to less than 30, from about 15 to about 27, or even from about 15 to about 25 as determined by ASTM D-1639-90. The acid functional polyurethane prepolymer is the reaction product of an acid functional component, a polymer polyol, a polyisocyanate, and optionally a neutralizing agent, a catalyst, or a combination thereof.

The acid functional component and the polymer polyol may be present on the same compound (i.e., the polyol may have acid functionality); alternatively or additionally, the polyol and the acid functional component may be two separate compounds. The acid functional component includes at least one acid group, such as carboxylic acids, sulfonic acids, and combinations thereof. Examples of useful acids include dihydroxy carboxylic acids, dihydroxy sulfonic acids, diamino carboxylic and sulfonic acids, dimethylol propionic acid, glycolic acid, thioglycolic acid, lactic acid, malic acid, dihydroxy malic acid, tartaric acid, dihydroxy tartaric acid, 2, 6-dihydroxybenzoic acid, oxaloic acid, anilidoacetic acid, glycine, alpha-alanine, 6-aminocaproic acid, the reaction product of ethanolamine and acrylic acid, hydroxyethyl propionic acid, 2-hydroxyethyl sulfonic acid, sulfanilic acid, and combinations thereof.

The acid-functional component is optionally provided in the form of an alkali metal salt (e.g., sodium and potassium), useful examples of which include alkali metal salts of sulfonic acids, alkali metal salts of carboxylic acids, and combinations thereof.

The acid-functional component optionally includes at least one functional group (or even at least two functional groups) that reacts with an isocyanate group, examples of which include hydroxyl groups, amine groups, thiol groups, and combinations thereof. Suitable acid functional components that include additional functional groups include, for example, hydroxycarboxylic acids, mercaptocarboxylic acids, aminocarboxylic acids, aminohydroxycarboxylic acids, hydroxysulfonic acids, sulfamic acids, aminohydroxysulfonic acids, and combinations thereof.

Useful acid functional polyols have at least two hydroxyl functional groups and at least one acid functional group. A variety of acid-functional polyols are suitable, including, for example, acid-grafted polyols (e.g., acid-grafted polyether polyols (e.g., polyether glycols and triols derived from ethylene oxide polymers, propylene oxide polymers, and combinations thereof grafted with acids such as maleic acid and fumaric acid)), polyether polyols formed from trifunctional polyether polyols and phthalic anhydride, polyester polyols formed from mixtures of compounds including at least two acid functional groups (e.g., di-and triacids (e.g., dicarboxylic acids)) and at least two hydroxyl groups such that the resulting polyester polyol has residual acid functional groups and at least two hydroxyl groups, and combinations thereof.

Polymer polyols useful in forming the polyurethane prepolymer include, for example, polyester polyols, polyether polyols, polycarbonate polyols, polyurethane polyols, polyacetal polyols, polyacrylate polyols, polycaprolactone polyols, polyester ether polyols, amide-containing polyols, and anionic polymer polyols described in U.S. Pat. No.5,334,690 to Hoechst Aktiengesellschaft, Fed. (Germany), of Herster, Germany. Suitable polymer polyols have an average of at least two, at least three, at least four, or even at least five hydroxyl groups per molecule (e.g., diols, triols, tetraols, and pentaols), a molecular weight of from about 500 to about 12,000, or even from about 1,000 to about 2,000, and an average hydroxyl number of from about 10 to about 2000, from about 20 to 1500, or even from about 25 to about 500. As described above in the discussion regarding the acid component, the polymer polyol can include a plurality of functional groups including, for example, acid, hydroxyl, amine, and thiol groups, and combinations thereof.

Particularly useful polymeric polyols include, for example, polyalkylene ether polyols (e.g., thioethers, poly (oxytetramethylene) glycols, poly (oxyethylene) glycols, polypropylene glycols, and reaction products of ethylene glycol with mixtures of propylene oxide and ethylene oxide), polyester polyols (e.g., polyhydroxy polyesteramides and hydroxyl-containing polycaprolactones), hydroxyl-containing acrylic interpolymers, and combinations thereof.

Useful polymeric polyether polyols include polyether polyols formed from the alkoxylation of various polyols including, for example, glycols (e.g., ethylene glycol, butylene glycol, 1, 6-hexanediol, and neopentyl glycol), bisphenol a, hydroxyalkylated bisphenols, cyclohexane diol, cyclohexane dimethanol, caprolactone diols (e.g., the reaction product of caprolactone and ethylene glycol), higher functionality polyols (e.g., trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, and polyols made from the alkoxylation of compounds such as sorbitol and sucrose), and combinations thereof. One common alkoxylation process involves reacting a polyol with an alkylene oxide (e.g., propylene oxide, or propylene oxide followed by ethylene oxide) in the presence of a catalyst.

Useful polymeric polythioethers include, for example, the condensation products of thioglycol and the reaction products of polyols.

Useful polymeric polyester polyols are prepared by polyesterification of organic polycarboxylic acids (or anhydrides thereof) with organic polyols. Polycarboxylic acids that can be used to form the polyester polyols include aliphatic and aromatic dibasic acids. Polyols useful in forming polyester polyols include glycols and higher functionality polyols (useful examples of both of which are described above). Additional examples of glycols suitable for use in preparing the polyester polyols include, for example, glycols, alkylene glycols (e.g., ethylene glycol, butylene glycol, and neopentyl glycol), hydrogenated bisphenol a, cyclohexanediol, cyclohexanedimethanol, caprolactone glycol (e.g., the reaction product of caprolactone and ethylene glycol), hydroxyalkylated bisphenols, polyether glycols (e.g., poly (oxytetramethylene) glycol), and combinations thereof. Higher functionality polyols suitable for use in forming the polyester polyols include, for example, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, polyols prepared by alkoxylation of low molecular weight polyols (e.g., the reaction product of 20 moles of ethylene oxide per mole of trimethylolpropane), and combinations thereof.

The polyurethane prepolymer may also be made from a small amount of aliphatic polyol in addition to the polymer polyol. Such aliphatic polyols include, for example, alkylene polyols having 2 to 18 carbon atoms (e.g., diols, triols, and tetraols). Useful alkylene glycols have a hydroxyl number of from about 100 to about 1250, or even from about 950 to about 1250. Examples of useful glycols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, alkoxylated glycerin, 1, 4-butanediol, 1, 6-hexanediol, cycloaliphatic polyols (e.g., 1, 2-cyclohexanediol and cyclohexanedimethanol), furandimethanol, glycerin, bis (dihydroxyethyl) lauramide, polyethylene ether glycols, poly-1, 2-propylene ether glycols, polytetramethylene ether glycols, poly-1, 2-dimethylethylene ether, and combinations thereof. Useful triols and higher order polyols include, for example, trimethylolethane, trimethylolpropane, glycerol and pentaerythritol.

The prepolymer can be made from 0 wt% to about 5.0 wt%, 0.1 wt% to about 5.0 wt%, or even from about 1.0 wt% to about 4.0 wt% of the optional aliphatic polyol, based on the weight of the polyurethane prepolymer.

Useful polyisocyanates include, for example, monomeric diisocyanates, homologs of monomeric diisocyanates, modified diisocyanates (e.g., carbodiimide-modified isocyanates, allophanate-modified isocyanates, biuret-modified isocyanates, and isocyanurates), and higher-order isocyanates (including triisocyanates), and combinations thereof. Useful classes of isocyanates include, for example, linear aliphatic, cycloaliphatic, araliphatic, and aromatic diisocyanates and combinations thereof. Examples of suitable diisocyanates include hexane diisocyanate, 2,4, 4-trimethylhexamethylene diisocyanate, 2, 4-trimethylhexamethylene diisocyanate, 4,4' -methylenebis (cyclohexyl isocyanate), 2' -methylenebis (cyclohexyl isocyanate), 4,4' -diphenylmethane diisocyanate, 2,4 '-diphenylmethane diisocyanate, 2' -diphenylmethane diisocyanate, 2,4 '-toluene diisocyanate, 2, 6' -toluene diisocyanate, isophorone diisocyanate, 1, 3-tetramethylxylylene diisocyanate, 1, 4-tetramethylxylylene diisocyanate, and mixtures thereof.

The components used to form the polyurethane prepolymer optionally include a neutralizing agent. The neutralizing agent neutralizes the acid groups of the acid component used to form the polyurethane prepolymer. The neutralizing agent is any suitable tertiary amine. Neutralization of the acid groups to ionic groups (i.e., salts) can occur at any point during the preparation of the polyurethane prepolymer or polyurethane dispersion, including, for example, prior to the condensation reaction to form the polyurethane prepolymer, immediately prior to dispersing the polyurethane prepolymer in water, after dispersing the polyurethane prepolymer in water, and combinations thereof. When the acid groups are neutralized after dispersing the prepolymer in water, the neutralizing agent may be a tertiary amine, ammonia, and combinations thereof. Useful tertiary amines include, for example, trimethylamine, triethylamine, tri-N-propylamine, tri-N-butylamine, N-methylpiperidine, N-ethylpiperidine, N-methylpyrrolidine, methyldiethylamine, dimethylethylamine, ethyldipropylamine, and combinations thereof.

The tertiary amine may be present in an amount sufficient to neutralize at least 50% of the acid groups, from about 85% to 100% of the acid groups, from about 85% to 95% of the acid groups, or even from about 90% to about 95% of the acid groups.

Additionally or alternatively, a neutralizing agent may optionally be added to the aqueous mixture used to form the binder composition. Examples of neutralizing agents suitable for addition to the aqueous mixture used to form the adhesive composition include ammonia, alkali metal hydroxides (e.g., sodium hydroxide and potassium hydroxide), and the neutralizing agents discussed above with respect to forming the polyurethane prepolymer, i.e., tertiary amines. When ammonia or an alkali metal hydroxide is used as the neutralizing agent, it may be present in the mixture used to form the binder composition in an amount sufficient to neutralize at least 50% to 100% of the acid groups, from about 60% to about 95% of the acid groups, or even from about 70% to about 95% of the acid groups of the polyurethane prepolymer.

Neutralizing agents (such as those described above) may also be added to the adhesive composition, the mixture used to form the polyurethane prepolymer, or both, to adjust the pH of the resulting adhesive composition. Suitable amounts of neutralizing agent are amounts sufficient to change the pH of the adhesive composition to a pH of from about 7 to about 8.7 or even from about 7.1 to about 8.2.

The reaction mixture used to form the polyurethane prepolymer optionally includes a catalyst. Useful catalysts include, for example, organotin (e.g., dibutyltin dilaurate and tin octoate) and tertiary amines.

The chain terminator of the aqueous binder composition is water soluble. Useful water-soluble chain terminators include monoamines, including, for example, aliphatic monoamines, aromatic monoamines, and mixtures thereof. Useful monoamines include, for example, alkanolamines (e.g., monoethanolamine, monomethanolamine, dimethanolamine, and diethanolamine). The chain terminator is present in the aqueous binder composition at an amine active hydrogen to isocyanate equivalent ratio of from about 0.01:1.0 to about 0.8:1.0 or even from about 0.05:1.0 to about 0.5: 1.0.

Suitable chain extenders for the aqueous adhesive composition are polyamines. Suitable classes of polyamines include, for example, diamines, triamines, tetraamines, and combinations thereof. Examples of useful polyamines include hydrazine, substituted hydrazines, ethylenediamine, propylenediamine, butylenediamine, hexylenediamine, cyclohexyldiamine, piperazine, 2-methylpiperazine, phenylenediamine, tolylenediamine, xylyldiamine, tris (2-aminoethyl) amine, dialkylenetriamines such as dimethylenetriamine and diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and combinations thereof. The chain extender is present in the aqueous binder composition at an amine active hydrogen to isocyanate equivalent ratio of about 0.1:1.0 to about 0.9:1.0 and about 0.4:1.0 to about 0.8: 1.0.

The aqueous binder composition optionally includes a variety of other additives including, for example, additional polymers, preservatives, colorants, surfactants, defoamers, fungicides, bactericides, thickeners, and combinations thereof.

Examples of additional polymers that may be used include additional anionic polyurethane dispersions (e.g., a second anionic polyurethane dispersion different from the first polyurethane dispersion), polyacrylates, polyacrylamides, copolymers of acrylamide and acrylic acid, polyvinyl alcohol, polyvinyl acetate, partially de-esterified polyvinyl acetate, sulfonated polyesters, phosphonated polyesters, and combinations thereof. The additional polymer, when present, is preferably present in an amount of less than 50% by weight of the aqueous binder composition.

One example of a useful class of second polyurethanes includes anionic polyester polyurethane dispersions that include alkali metal salts of acids in the backbone of the polyurethane, including alkali metal salts of sulfonic acids, alkali metal salts of carboxylic acids, and combinations thereof. Suitable alkali metal salts include, for example, sodium and potassium. Examples of useful anionic polyester polyurethane dispersions include sodium salts of sulfonic acid anionic polyester polyurethane dispersions, potassium salts of sulfonic acid anionic polyester polyurethane dispersions, sodium salts of carboxylic acid anionic polyester polyurethane dispersions, potassium salts of carboxylic acid anionic polyester polyurethane dispersions, and combinations thereof. One example of a commercially available anionic polyester polyurethane dispersion that may be used is BAYBONDPU330 from Pittsburgh Bayer materials technology, pa (Bayer Material Sciences, Pittsburgh, Pennsylvania).

When present, the at least one second anionic polyurethane dispersion is preferably present in the aqueous binder composition in an amount of less than 45 wt.%, less than 40 wt.%, no greater than 35 wt.%, no greater than 30 wt.%, at least 0.5 wt.%, at least 2.5 wt.%, at least about 5 wt.%, at least about 10 wt.%, or even from about 5 wt.% to about 30 wt.%.

Examples of useful preservatives include formaldehyde, 1, 2-benzisothiazol-3 (2H) -one, 1- [ (diiodomethyl) sulfonyl ] -4-toluene, 5-chloro-2-methyl-3 (2H) -isothiazolinone, and combinations thereof.

The wipe can be made using any suitable technique, including, for example, contacting the fibers or fibrous substrate with an aqueous binder composition, optionally forming the fibers into a substrate when the fibers are not in the form of a substrate, and drying the binder composition. Processes that can be used to apply the aqueous binder composition to the fibers or fibrous substrate include, for example, printing, brushing, spraying, electrostatic spraying, coating, dipping, submerging (e.g., saturating), roll coating (e.g., metering rolls and immersion coating), and combinations thereof. The binder composition can be present on the wipe in a variety of configurations, including, for example, on at least one surface of the substrate, throughout the fibrous substrate (e.g., impregnated into the substrate such that the binder is present on the fibers and in the interstitial spaces between the fibers (e.g., saturating the substrate with the binder composition)), and combinations thereof, uniformly, non-uniformly, as a continuous coating, as a discontinuous coating, and combinations thereof. The adhesive composition may be dried using any suitable process, including, for example, air drying, drying at an elevated temperature (e.g., at least about 120 ℃, at least about 130 ℃, or even at least about 150 ℃), drying at an elevated temperature in a controlled environment, and combinations thereof.

The wipe optionally includes a storage medium that remains within the fibrous substrate until the wipe is used by a user. The pH of the storage medium is no greater than 6, no greater than 5.5, no greater than 5, from about 3.5 to about 6, or even from about 3.5 to 5.5. The storage medium may take a variety of forms including, for example, liquid and slurry. The fibrous base material may be saturated with the medium such that the medium penetrates the fibers and interstitial spaces between the fibers. The storage medium is selected such that the integrity of the dry adhesive will be maintained such that the wipe will not disintegrate. The dried binder is insoluble in the storage medium.

The media can be associated with the substrate in a variety of ways including, for example, as a coating on at least one surface of the substrate, impregnated into the substrate such that the media is present on and in the interstitial spaces between the fibers (e.g., saturating the substrate with the media), and combinations thereof. The wipe can be contacted with the medium using a variety of processes including, for example, dipping, immersing, brushing, printing, rolling, spraying, and combinations thereof. The medium can provide a variety of functions including a storage medium such as a wipe, an active agent to be coated from the wipe when the wipe is used by a user, and combinations thereof.

Various components may be included in the medium including, for example, water, isopropanol, emulsions (including, for example, simethicone, surfactants, soap, stearic acid, cetyl alcohol, lanolin, triethanolamine, glycerin, propylene glycol, aloe vera leaf juice, tocopherol acetate, PEG75 polyethylene glycol, lanolin, disodium cocoamphodiacetate, polysorbate 20, methylisothiazolinone, 2-bromo-2-nitro-1, 3-propanediol, and iodopropynyl butylcarbamate, and emulsions of combinations thereof), emollients, acids (such as boric acid and citric acid), salt solutions (such as potassium chloride, sodium chloride, zinc sulfate, and sodium borate), antibacterial agents, anti-acne agents, fragrances, preservatives, emollients, humectants, cleansing agents, soaps, antiviral agents, antimicrobial agents, disinfectants, antifungal agents, and combinations thereof. The medium can include a variety of additives including, for example, skin care additives, odor control additives, detackifiers, microparticles, delivery vehicles ((e.g., including microcapsules) for providing a variety of substances to the skin of a user, including, for example, skin care agents, medicaments, comfort enhancers (e.g., eucalyptus oil, camphor oil, and aloe vera extract), perfumes, odor control additives, vitamins, powders, and other components), preservatives, antimicrobials, humectants (e.g., surfactants), cleansing agents, aqueous microemulsions of silicone particles, emollients, surface feel modifiers for improving the feel (e.g., lubricity) experienced by the skin during use of the product, fragrances, solubilizers, opacifiers, and combinations thereof.

Useful skin care additives that may be included in the medium include, for example, enzyme inhibitors, chelating agents, antimicrobial agents, sunscreens, ultraviolet absorbers, acne treatment agents, drugs, baking powders (including encapsulated forms thereof), vitamins and derivatives thereof (e.g., vitamins a and E), botanicals (e.g., witch hazel extract and aloe vera), allantoin, emollients, disinfectants, hydroxy acids for anti-wrinkle or anti-aging effects, sunscreens, tanning enhancers, skin lightening agents, deodorants, antiperspirants, ceramides, astringents, moisturizers, nail polish rinses, insect repellents, antioxidants, preservatives, anti-inflammatory agents, and combinations thereof.

The medium optionally includes a pH control agent. Suitable pH control agents include, for example, malic acid, citric acid, hydrochloric acid, acetic acid, sodium hydroxide, potassium hydroxide, and combinations thereof. If the wipe is to be used in an application where pH sensitivity may be present, the pH of the medium may be selected to minimize or increase sensitivity depending on the purpose of the wipe, e.g., for skin applications, the pH may be selected to minimize the amount of skin irritation caused by the wetting composition contacting the skin. Useful media have a pH of less than 6.5, less than 6, no greater than about 5, from about 3.6 to about 5, or even from about 4 to about 5.

Wipes are suitable for a variety of uses and purposes, including, for example, personal hygiene (e.g., cleaning and treating skin, removing makeup, nail polish), medical uses (e.g., cleaning and treating wounds and incisions and relieving pain), pet care (e.g., eye, ear, and tooth cleaning), household uses, including, for example, cleaning surfaces (e.g., bathroom surfaces, kitchen surfaces, laundry surfaces, garage surfaces, and automobile surfaces, and sink surfaces).

The invention will now be described by way of the following examples. All parts, ratios, percentages, and amounts described in the examples are by weight unless otherwise indicated.

Examples of the invention

Test program

The test procedures used for the examples include the following. All ratios and percentages are by weight unless otherwise indicated.

Acid value

Acid numbers were determined according to ASTM D1639-90(1996) e1 entitled "Test Method for Acid Value of Organic coating materials".

Weight percent of isocyanate groups

The weight percent of Isocyanate Groups present on the polyurethane prepolymer is determined in accordance with ASTM D2572-97(2003) e1 entitled "Standard test Method for Isocyanate Groups in Urethane Materials or Prepolymers".

10mM of a buffer solution having a pH of 4.3 to 4.5 was prepared

One liter of a 10 millimolar (mM) buffer solution having a pH of about 4.4 is prepared by: 1.1g of citric acid and 1.4g of sodium citrate were placed in a flask. A volume of 500mL of tap water was added to the flask and the contents were gently stirred to dissolve all solid particles. The liquid volume was then adjusted to 1 liter scale by adding tap water. The solution was gently shaken to homogenize the solution. The pH of the solution was measured using a calibrated pH meter. The pH of the resulting buffer solution was 4.3 to 4.5.

Preparation of the test emulsion

The test emulsion was an aqueous liquid present in a container of PARENT' S choicee odorless baby wipes (Walmart Stores inc, Bentonville, Arkansas, usa) and comprised 99% water and a mixture of 1% of the following ingredients: propylene glycol, aloe vera leaf juice, tocopheryl acetate, PEG75 polyethylene glycol, lanolin, disodium cocoamphodiacetate, polysorbate 20, citric acid, disodium phosphate, disodium EDTA (ethylenediaminetetraacetic acid), methylisothiazolinone, 2-bromo-2-nitro-1, 3-propanediol, and iodopropynyl butylcarbamate, and has a pH of 4.5 to 5.

Dry adhesive integrity test method I

A sufficient amount of the adhesive composition was poured onto a non-stick pan and allowed to dry at room temperature to give about 1.0g of a film having a thickness of about 1 mm. This process is repeated multiple times to form multiple samples. The samples were divided into two groups.

Tap water drying adhesive integrity test method I

In the first set, each dry film sample was transferred to a 1 liter jar containing about 700g of tap water having a pH of 7 and immersed in water. The jar was then sealed and the sample allowed to soak for two hours.

Buffer dried adhesive integrity test method I

In the second group, each dried film sample was transferred to a 1-liter jar containing the above 10mM buffer solution with pH 4.3 to 4.5 and immersed in the solution. The jar was then sealed and the sample allowed to soak for two hours.

The jar was then placed on a laboratory shaker (Eberbach Corporation, Ann Arbor, Michigan, usa). The shaker shakes the jar for 10 minutes at a frequency of 150 cycles/min. The jar was then removed from the machine and opened. The contents of the jar were visually evaluated. The film or portion thereof was removed from each jar and evaluated. The observations of the film or portions thereof were recorded.

If the film appearance did not change from its initial state, it was recorded as insoluble.

If the film is dispersed, it is recorded as having broken down and lost integrity.

The films were also evaluated to determine if their integrity and cohesive strength changed from their initial state. The film is recorded as losing integrity if it breaks apart or crumbles when it is removed from the jar, if it becomes brittle and lacks cohesive strength compared to its initial state, or cannot be removed from the jar because of its lack of cohesive strength.

Dry adhesive integrity test method II

An amount of adhesive composition sufficient to form a dry film having a thickness of about 1mm is poured onto the non-stick surface and allowed to dry at room temperature for a minimum of 16 hours. The resulting film was then evaluated in this form or further treated by heating in a convection oven at 150 ℃ for 1 minute and then evaluated again.

The dried films were evaluated in the following four test liquids: 1) the above 10mM buffer solution having a pH of 4.3 to 4.5, 2) the above test emulsion, 3) deionized water, and 4) tap water having a pH of 6.5 to 9.0.

About 0.2g of the dried film was placed in a screw-top glass jar containing about 20g of the test solution. The jar was then sealed and the sample allowed to soak for a minimum of 16 hours (overnight).

After soaking in the test solution, the contents of the jar were visually evaluated. Observations of the contents were recorded. The film or portion thereof was removed from each jar and evaluated. The observations of the film or portions thereof were recorded.

If the film appearance did not change from its initial state, it was recorded as insoluble.

If the film is dispersed, it is recorded as having broken down and lost integrity.

The films were also evaluated to determine if their integrity and cohesive strength changed from their initial state. The film is recorded as losing integrity if it breaks apart or crumbles when it is removed from the jar, if it becomes brittle and lacks cohesive strength compared to its initial state, or cannot be removed from the jar because of its lack of cohesive strength.

Wipe integrity test method

A plurality of samples in the form of wipes or portions of wipes are obtained. When the wipes were too large to be easily immersed in 700 grams of tap water or buffer solution, samples were cut from each wipe. The weight of the sample is at least 1g to no greater than 3 g. If the weight of the wipe is less than 1g, multiple wipes may be used to make up the sample.

The samples were divided into two groups.

Integrity test method for tap water wipe

In the first group, each sample was placed in a 1 liter jar containing 700g of tap water having a pH of 6.5 to 9 and immersed in water. The jar was then sealed and placed on a laboratory shaker (Eberbach Corporation, Ann Arbor, Michigan, usa).

Method for testing integrity of wipe containing aqueous buffer

In the second group, each sample was placed in a 1 liter jar containing 700g of the above 10mM buffer solution having a pH of 4.3 to 4.5, and immersed in the solution.

The jar was then sealed and placed on a laboratory shaker. The shaker shakes the jar for 10 minutes at a frequency of 150 cycles/min. After ten minutes, the jar was removed from the shaker and opened and the contents of the jar were evaluated. Observations of the contents were recorded.

If the wipe appearance is unchanged from its initial state, it is recorded as insoluble.

If the wipe is spread, the wipe is recorded as broken down and losing integrity.

If the wipe is intact or partially intact, the wipe is removed from the jar and rubbed between the fingers and thumb. If the wipe breaks up and disperses in the rubbing action, the wipe is recorded as breaking down and losing integrity. Observations of the rubbing results were recorded.

Method for testing integrity of substrate

A plurality of sample substrates were obtained. When the substrates were too large to be easily immersed in 700 grams of tap water or buffer solution at a pH of 6.5 to 9, samples were cut from each substrate. The weight of the sample is at least 1g to no greater than 3 g. If the weight of the substrate is less than 1g, multiple substrates may be used to make up the sample.

The samples were divided into two groups.

Running water base material integrity test method

In the first group, each sample was placed in a 1 liter jar containing 700g of tap water and immersed in water. The jar was then sealed and placed on a laboratory shaker (Eberbach Corporation, Ann Arbor, Michigan, usa).

Method for testing integrity of substrate containing aqueous buffer

In the second group, each sample was placed in a 1 liter jar containing 700g of the above 10mM buffer solution having a pH of 4.3 to 4.5, and immersed in the solution. The jar was then sealed and placed on a laboratory shaker. The shaker shakes the jar for 10 minutes at a frequency of 150 cycles/min. After ten minutes, the jar was removed from the shaker and opened and the contents of the jar were evaluated. Observations of the contents were recorded.

If the substrate appearance is unchanged from its initial state, it is recorded as insoluble.

If the substrate is scattered, the substrate is recorded as decomposed and losing integrity.

If the substrate is intact or partially intact, the substrate is removed from the jar and rubbed between the fingers and thumb. If the substrate breaks up and disperses in the kneading action, the substrate is recorded as decomposing and losing integrity. Observations of the rubbing results were recorded.

Control

A control was prepared in the manner described under the heading "wipe preparation" in example 1 above, except that a sheet of the fibers was sprayed with water instead of the adhesive composition.

The resulting sheet was tested according to the wipe integrity test method. The sheet breaks down into individual fibers in the buffer solution without integrity (i.e., intact and tough), and breaks down into individual fibers in tap water without integrity.

Example 1

Preparation of polyurethane prepolymer I

The polyurethane prepolymer was prepared by: 11.45% by weight of isophorone diisocyanate, 1.68% by weight of dimethylolpropionic acid, 20.69% by weight of DESMOPHENS-102-one polyol (Bayer, Pittsburgh, Pennsylvania) and 1.2% by weight of triethylamine were mixed under stirring, the mixture was heated to 80 ℃ and the components were allowed to react at 80 ℃ for one to four hours. (weight percent based on the total weight of the adhesive composition of example 1.) the resulting polyurethane prepolymer had 4.5 weight percent isocyanate groups and an acid number of 20.

Preparation of adhesive composition

The adhesive composition was prepared as follows: the polyurethane prepolymer I was mixed with water and the mixture was then transferred to a stirred dispersion tank. A mixture of monoethanolamine and water is then added to the dispersion tank. A mixture of diethylenetriamine and water is then added to the dispersion tank. A mixture of ethylenediamine and water was then added to the dispersion tank. Allowing the resulting mixture to react for 30 minutes to form a polyurethane dispersion comprising, by total weight of the resulting adhesive composition: 63.59% by weight of water, and the reaction product of 35.02% by weight of a polyurethane prepolymer, 0.41% by weight of diethylenetriamine, 0.56% by weight of ethylenediamine and 0.21% by weight of monoethanolamine. A 37 wt% aqueous formaldehyde solution is then added to the polyurethane dispersion in an amount such that the resulting adhesive composition includes 0.26 wt% of the 37 wt% formaldehyde solution.

The resulting adhesive composition has a pH of about 8 and a viscosity of about 25 centipoise at 77 ° f (25 ℃).

The adhesive compositions were tested according to adhesive integrity test method I. The sample turned white, sandy in tap water and became brittle and dispersed. After storage of the sample film in tap water for several weeks, the water in the container appeared milk-like.

The samples in the buffer solution were intact and tough. After several weeks of storage of the sample film in the buffer solution, the water in the container appeared clear.

Preparation of wipes

The adhesive composition of example 1 was sprayed onto a 1g wood pulp fiber sheet in the form of a 4.5 inch x 9.0 inch area fiber mat. The sheet was dried in an oven at 125 ℃ to 130 ℃ for 2 minutes and then allowed to cool. The resulting wipe includes about 45 wt.% to 50 wt.% dry adhesive.

The wipes were tested according to the wipe integrity test method. The wipe retains its integrity (i.e., is intact and tough) in the buffer solution and loses integrity, disintegrates and breaks in tap water.

Example 2

Preparation of polyurethane prepolymer II

The polyurethane prepolymer was prepared by: 7.67% by weight of isophorone diisocyanate, 0.67% by weight of dimethylolpropionic acid, 9.09% of RM0294 acid-functional polyol (H.B. Fuller Company, Vadnais Heights, Minnesota), 1 mole of VORANOL230-238 (the reaction product of Dow Chemical, Midland, Michigan, Mich.) with 1 mole of phthalic anhydride), 16.85% by weight of VOOL RAN220-056 (Dow Chemical, Midland, Michigan), 0.01% by weight of triethylamine, and 0.01% by weight of dibutyltin dilaurate were mixed with stirring, the mixture was heated to 80 deg.C, and then the mixture was allowed to react at 80 deg.C for 1 to 4 hours. (weight percents are based on the total weight of the adhesive composition of example 2.)

Preparation of adhesive composition

An adhesive composition was prepared by: dispersing polyurethane prepolymer II in water containing ammonia with stirring, transferring the mixture to a stirred dispersion tank with stirring, adding a mixture of monoethanolamine and water to the dispersion tank with stirring, adding a mixture of diethylenetriamine and water to the dispersion tank with stirring, adding a mixture of ethylenediamine and water to the dispersion tank with stirring, and allowing the resulting mixture to react for 30 minutes to form a polyurethane dispersion comprising, based on the total weight of the resulting adhesive composition: 63.71 wt% water, and the reaction product of 34.3 wt% polyurethane prepolymer II, 0.22 wt% monoethanolamine, 0.19 wt% diethylenetriamine, 0.28 wt% ethylenediamine, and 1.04 wt% 25.6 wt% aqueous ammonia mixture. Then, a 0.26 wt% 37 wt% aqueous formaldehyde solution was added to the polyurethane dispersion to form a binder composition.

The resulting adhesive composition has a pH of about 8 and a viscosity of about 25 centipoise at 77 ° f (25 ℃).

The adhesive compositions were tested according to "dry adhesive integrity test method I". The sample turned white, sandy in tap water and became brittle and dispersed. After storage of the sample film in tap water for several weeks, the water in the container appeared milk-like.

The samples in the buffer solution were intact and tough. After several weeks of storage of the sample film in the buffer solution, the water in the container was clear.

Preparation of wipes

The adhesive composition of example 2 was sprayed onto a 1g wood pulp fiber sheet in the form of a 4.5 inch x 9.0 inch area fiber mat. The sheet was dried in an oven at 125 ℃ to 130 ℃ for 2 minutes and then allowed to cool. The resulting wipe includes about 45 wt.% to 50 wt.% dry adhesive.

The wipes were tested according to the wipe integrity test method. The wipe retains its integrity (i.e., is intact and tough) in the buffer solution and loses integrity, disintegrates and breaks in tap water.

Examples 3-11 and controls 2-3

Adhesive compositions were prepared by mixing the adhesive composition of example 1 with a BAYBOND PU330 polyurethane dispersion (Pittsburgh Bayer, Pittsburgh, PA) in the ratios shown in table 1. The adhesive compositions of examples 3-11 and controls 2-3 were then tested according to "Dry adhesive integrity test method II" and the results and observations for the test samples are shown in Table 1.

All patents and references mentioned herein are incorporated herein.

Other embodiments are within the claims. In one embodiment, for example, the wipes are packaged in a container that stores the wipe or wipes (e.g., a roll or stack of wipes) until use. A storage medium is optionally present in the container, and the wipe is optionally saturated with the storage medium.

The wipes may be of any size and any shape, including, for example, rectangular, square, circular, and oval.

Further, while the substrate comprising the fiber and adhesive composition has been described above in the form of a wipe, the substrate may be in the form of, and may be a component of, a variety of articles including, for example, woven webs, nonwoven webs, pads, sanitary napkins, diapers, training pants, incontinence articles, containers (e.g., boxes, bags, and envelopes, and combinations thereof), filters (air, oil, and gasoline filters), ostomy bags, disposable garments, disposable gowns, masks, inner pads of absorbent articles, shoe pads, antiperspirant sheets, breast pads, helmet liners, wound dressings, sterile packaging, car covers, disposable floor coverings, bed sheets, tablecloths (e.g., surgical, physical examination, and mortuary sheets), and combinations thereof.

The dried binder can also be provided in a variety of forms including, for example, films, particles (e.g., granules and powders), fibers, webs (e.g., woven and nonwoven webs), and composites and combinations thereof, and optionally combined with other components to form films, fibers, webs (e.g., woven and nonwoven webs), composites and combinations thereof. Other components that may be combined with the binder may be in a variety of forms including, for example, fibers, pellets, granules, powders, and made from a variety of materials including, for example, polymers (e.g., synthetic (such as thermoplastic polymers, superabsorbent polymers, and combinations thereof) and natural), cellulose, polylactic acid polymers, biodegradable materials, metals, soils, and combinations thereof.

Claims (12)

1. A flushable article comprising:

a fibrous substrate; and

a dry binder composition in contact with said fibers, said dry binder composition derived from an aqueous anionic polyurethane dispersion comprising a polyurethane comprising the reaction product of:

an acid-functional polyurethane prepolymer comprising a mixture of an acid-functional polyurethane prepolymer,

a chain extender comprising a polyamine, and

a chain terminator comprising a monoamine,

the article is insoluble in water having a pH of no greater than 6 and disintegrates in water having a pH of at least 6.5.

2. The article of claim 1, wherein the substrate is in the form of a wipe.

3. The article of claim 1, further comprising an aqueous medium in contact with the substrate, the medium having a pH of no greater than 6.

4. The article of claim 3, wherein the medium comprises an emulsion.

5. The article of claim 1, wherein the fibers comprise at least one of wood pulp, cellulose, polyethylene, polypropylene, polyester, polyamide, and polylactic acid.

6. The article of claim 1, wherein the article comprises at least 5 wt% adhesive, based on the weight of the adhesive and the substrate.

7. The article of claim 1, wherein the dry binder composition is insoluble in water having a pH of no greater than 5.5.

8. The article of claim 1 wherein at least a portion of the acid functional polyurethane prepolymer comprises a form selected from the group consisting of alkali metal salts, tertiary amine salts, ammonium salts, and combinations thereof.

9. The article of claim 1, wherein the polyurethane comprises the reaction product of:

a polyurethane prepolymer,

Polyamine, and a process for producing the same,

A monoamine, and

a tertiary amine.

10. A packaged article comprising:

a container;

an aqueous medium disposed in the container; and

the article of claim 1 placed in the container and saturated with the aqueous medium.

11. The article of claim 1 wherein the dry adhesive composition has been further derived from a second anionic polyurethane dispersion comprising an alkali metal salt of a sulfonic acid.

12. The article of any of claims 3-9 and 11, wherein the substrate is in the form of a wipe.