KR20130084977A - Dispersible wet wipes made using short cellulose fibers for enhanced dispersibility - Google Patents

Abstract

This publication relates generally to dispersible wet wipes. More particularly, the present disclosure relates to a dispersible wet wipe made from a wipe substrate containing a tissue web consisting of cellulose fibers and a binder composition for bonding the binder composition to the tissue web. The tissue web contains cellulose fibers having a fiber length of 3 mm or less. The structure of the dispersible wipe may allow a percent pass value calculated by a dispersible shake flask test of at least about 70% for increased dispersibility. More preferably, the dispersible single ply wet wipe may have a pass through percentage value of at least about 95%.

Description

DISPERSIBLE WET WIPES MADE USING SHORT CELLULOSE FIBERS FOR ENHANCED DISPERSIBILITY Manufactured Using Short Cellulose Fibers for Improved Dispersibility

Dispersible and flushable moist products should exhibit satisfactory in-use strength, but must disintegrate quickly in sewers or sewage purification systems. Existing flushable moist wipes do this by using a triggerable salt sensitive binder on a substrate comprising cellulose based fibers. The binder adheres to cellulose fibers to form a network of strength in use in a 2% salt solution (used as a moist wipe formulation), but swells and breaks in fresh water in toilets and sewer systems.

In addition, flushable moist wipes must easily pass through existing urban sewer systems. For many years, disposable issues have plagued the industry of providing disposable items such as diapers, wet wipes, incontinence garments and feminine hygiene products. Ideally, when a flushable disposable product is disposed of in a sewer or sewage treatment system, the product or a designated portion of the product “disperses” in water so as not to cause problems under conditions typically found in home or municipal sanitation systems. It must be sufficiently dissolved or disintegrated. Some products do not distribute properly. Many existing wipe manufacturers achieve acceptable strength in flushable moist wipes by using long fibers (> 10 mm) that intertwine with other fibers to develop a network of wet strength. However, these long fibers are undesirable because they tend to gather on the screen of the wastewater system and cause blockages and blockages.

As a result, there has been a movement by the city to define "flushable" through various regulations. Flushable moist wipes must meet these regulations, taking into account compatibility with household plumbing and drain lines, as well as disposal of products in single-family homes and municipal wastewater treatment systems. By following these regulations, manufacturers can ensure that, under normal conditions, products best disposed of by the wastewater system for public health and hygiene reasons do not clog toilets, drains, water transport and treatment systems, or have aesthetic problems in surface water or soil environments. Can be guaranteed.

One challenge for flushable moist wipes is that they take much longer to disintegrate when compared to dry toilet tissue, which can potentially cause problems in sewer or sewage purification systems. Existing dry toilet tissues quickly exhibit lower post-use strength when exposed to tap water, while existing flushable moist wipes take time and / or require stirring.

Achieving faster dispersing times with current binder technology requires lower in-use strengths that are considered unacceptable by current consumers. In addition, dispersibility can be improved by less curing / drying of the binder, while providing unacceptable strength in use.

Unfortunately, these approaches that address dispersibility issues provide unacceptable strength or provide products that do not disperse quickly enough. Thus, there is a need to provide wet wipes that provide adequate in-use strength for consumers but are distributed more similarly to toilet paper and defined as flushable products through various city regulations.

summary

This publication relates generally to dispersible wet wipes. More particularly, the present disclosure relates to a dispersible wet wipe made from a wipe substrate containing a tissue web consisting of cellulose fibers and a binder composition for bonding the binder composition to the tissue web. The tissue web contains cellulose fibers having a fiber length of 3 mm or less.

The structure of the dispersible wipes may allow for a pass through percentage value based on an INDA / EDANA dispersible shake flask test of at least about 70% for increased dispersibility. More preferably, the dispersible single ply wet wipe may have a pass through percentage value of at least about 95%. For purposes herein, the “pass percentage value” is equal to the amount of substrate that passes through a 3.18 mm perforated plate using the dispersible shake flask test described herein.

The amount of binder composition present in the single ply wipe substrate may preferably range from about 1 to about 15 weight percent based on the total weight of the single ply wipe substrate. More preferably, the binder composition may range from about 1 to about 8 weight percent based on the total weight of the single ply wipe substrate.

The amount of solids in the binder composition may preferably be less than about 18% by weight based on the total weight of the binder composition. More preferably, the amount of solids in the binder composition may be less than about 16 weight percent based on the total weight of the binder composition.

In a typical embodiment, the wipe substrate is made from a tissue web, which can be an uncreped, through-aired tissue web. In addition, the wipe substrate may be one layer.

Dispersible wet wipes should have the desired in-use strength. As disclosed herein, the dispersible wipe may have an in-use wet tensile strength of at least about 300 g / linear inch. The portions of the dispersible wet wipe that split when immersed in tap water after about 50 minutes or less and stirred in the slush box for about 10 minutes have a post-machine mechanical tensile strength of less than about 200 g / linear inch.

Preferably, the dispersible wet wipe has a ratio of mechanical tensile strength to lateral tensile strength of less than 2.2. In addition, dispersible wet wipes may have a geometric mean tensile strength of at least 300 g / linear inch. In addition, the dispersible wet wipe may have a formation value greater than 18.

This publication relates generally to dispersible wet wipes. More particularly, the disclosure relates to a dispersible wet wipe made from a wipe substrate containing a tissue web consisting of cellulose fibers and a binder composition for bonding the binder composition to the tissue web. The tissue web contains cellulose fibers having a fiber length of 3 mm or less to improve the dispersibility of the wipe.

Preferably, the dispersible wipe is made from a tissue web. Basesheets suitable for this purpose can be produced using any method that produces a high density resilient tissue structure. Such methods include uncreped through creped, creped and through dried, and modified wet press methods. Typical methods of making uncreped through-dried tissue are described in US Pat. No. 5,607,551, US Pat. No. 5,672,248, and US Pat. No. 5,593,545, US Pat. No. 6,083,346 and US Pat. All patents are incorporated herein by reference. Typically, the tissue web of the present disclosure defines a basis weight of about 60 to about 120 grams per square meter (grams per square meter), preferably about 60 gsm to about 90 gsm. Most preferably, the wipe of this disclosure defines a basis weight of about 65 to about 80 gsm.

For example, tissue webs can be made using a method of making uncreped through-aired tissue, in which a one-layer headbox deposits an aqueous suspension of papermaking fibers between forming wires. The freshly formed web is transferred from the forming wire to the slower moving transfer fabric using a vacuum box. The web is then transferred to a throughdrying fabric and passed over the tumble dryer to dry the web. After drying, the web is transferred from the throughdrying fabric to the reel fabric and inserted briefly between the fabrics. The dried web is still with the fabric until it is wound on the parent roll.

Preferably, the tissue web consists of fibers having a fiber length of less than 3 mm. By providing adequate cure to the dispersible binder with a fiber length of less than 3 mm, it will bring the fibers closer together and thus the dispersible binder can form an acceptable network in use, but still decomposes effectively into individual fibers. do. Thus, the degraded product will be able to pass through the smallest wastewater treatment screen or sieve as effectively as toilet paper. Optimization of the basesheet properties and process conditions allows the production of above-average strength in use while improving the flushability of the product and poses a risk to the wastewater treatment plant.

In order to provide a wipe substrate having the required strength, good formation of high basis weight tissue is beneficial. To produce a tissue web with a better formation, wide slice openings on the headbox can be used to allow more water passage and operate with higher equipment. Providing a good formation of the substrate provides the ability to provide strength with significantly less binder without requiring longer fibers.

Preferably, the wipe substrate of this disclosure has a formation value greater than 18. Provision of wipe substrates with formation values above 18 not only provides the strength required during use, but also permits wipe substrates to be dispersed in water.

The wipe substrate may be formed from a single layer or multiple layers. In the case of multiple layers, the layers are generally located in a juxtaposed or surface-surface relationship, and all or some of the layers may be joined to adjacent layers. In addition, the fibrous material may be formed from a plurality of individual fibrous materials, where each individual fibrous material may be formed from different kinds of fibers. If the fibrous material comprises multiple layers, the binder composition can be applied to the entire thickness of the fibrous material, or each individual layer can be treated separately and combined in parallel with the other layers to form the finished fibrous material. Can be. Preferably, the wipe may be formed from one layer or one layer.

As noted above, the wipe substrate comprises a binder composition. In one embodiment, the binder composition may comprise a triggerable polymer. In another embodiment, the binder composition may comprise a triggerable polymer and a cobinder polymer.

The amount of binder composition present in the single ply wipe substrate may preferably range from about 1 to about 15 weight percent based on the total weight of the single ply wipe substrate. More preferably, the binder composition may comprise about 1 to about 10 weight percent based on the total weight of the single ply wipe substrate. Even more preferably, the binder composition may comprise about 1 to about 8 weight percent based on the total weight of the single ply wipe substrate. Most preferably, the binder composition may comprise about 3 to about 8 weight percent based on the total weight of the single-ply wipe substrate. The amount of this binder composition is complete in use but provides a one-ply wipe substrate that disperses quickly when submerged in tap water.

The composition of tap water can vary greatly depending on the water source. In the case of dispersible wipes, the binder composition may lose sufficient strength to allow the wet wipe to disperse in tap water, which preferably covers the majority of the range of tap water compositions found throughout the United States (and throughout the world). Therefore, it is important to evaluate the dispersibility of the binder composition in an aqueous solution containing the major components of tap water in representative concentration ranges including most tap water sources in the United States. The predominant inorganic ions found in drinking water are sodium, calcium, magnesium, bicarbonate, sulphate and chloride. Based on a recent study conducted by the American Water Association (AWWA) in 1996, the majority of the US municipal water systems investigated (both groundwater and surface water sources) have a total dissolved solids of less than about 500 ppm of inorganic components. In addition, the 500 ppm total dissolved solids level represents the secondary drinking water quality standards set by the US Environmental Protection Agency. At this total dissolved solids level, the average water hardness representing calcium and magnesium concentrations in the tap water source was about 250 ppm (CaCo ₃ equivalents), which also includes the water hardness of the majority of municipal water systems investigated by AWWA. As defined by the US Geological Survey (USGS), a water hardness of 250 ppm CaCO ₃ equivalents will be considered "hard water". Likewise, the average bicarbonate concentration of the 500 ppm total dissolved solids reported in the study is 12 ppm, which also includes the majority of the bicarbonate or alkalinity of the irradiated municipal water system. USGS 'last study of 100 final treated water sources in large US cities suggests that about 100 ppm sulphate levels are sufficient to cover most of the final treated water sources. Likewise, sodium and chloride levels of at least 50 ppm each will be sufficient to cover most US final treated water sources. Thus, a binder composition that can lose strength in tap water compositions that meets these minimum requirements will increase strength in tap water compositions of lower total dissolved solids with various compositions of calcium, magnesium, bicarbonate, sulfate, sodium and chloride. You must lose. To ensure the dispersibility of the binder composition nationwide (and throughout the world), the binder composition may preferably be dissolved in water containing up to about 100 ppm total dissolved solids and up to about 55 ppm CaCO ₃ equivalent hardness. have. More preferably, the binder composition may be dissolved in water containing up to about 300 ppm total dissolved solids and up to about 150 ppm CaCO ₃ equivalent hardness. Even more preferably, the binder composition may be dissolved in water containing up to about 500 ppm total dissolved solids and up to about 250 ppm CaCO ₃ equivalent hardness.

In order to provide a wipe substrate with the required strength, good distribution of the binder is required throughout the sheet. Previous examples using similar basesheets had a cover using a single nozzle providing a poor distribution of the binder. Improving distribution is important for optimum strength generation and proper sheet handling.

In order to determine the proper distribution of the binder throughout the sheet, the ratio of the mechanical tensile strength to the transverse tensile strength can be measured. A more similar value between the mechanical and transverse tensile strengths indicates a better binder distribution throughout the sheet.

Preferably, the wipe substrate of the present disclosure has a ratio of mechanical tensile strength to lateral tensile strength of less than 2.25. Provision of a wipe substrate having a formation value of less than 2.25 not only provides the strength required during use but also allows it to be dispersed in water.

As previously disclosed, the binder composition may comprise a triggerable polymer and a cobinder. Various triggering polymers can be used. One type of triggerable polymer is a dilution triggerable polymer. Examples of dilution-inducing polymers include ion sensitive polymers, which can be used with wetting compositions where the insolubilizing agent is a salt. In addition, other dilution-inducing polymers may also be used, where such dilution-inducing polymers are used in combination with wetting agents using various insolubilizing agents such as organic or polymeric compounds.

The triggerable polymer may be selected from a variety of polymers including temperature sensitive polymers and pH sensitive polymers, but the triggerable polymer may preferably be a dilution triggerable polymer comprising an ion sensitive polymer. If the ion sensitive polymer is derived from one or more monomers at least one containing an anionic functional group, the ion sensitive polymer is called an anionic sensitive polymer. If the ion sensitive polymer is derived from one or more monomers where at least one contains a cationic functional group, the ion sensitive polymer is called a cation sensitive polymer. One typical anion sensitive polymer is described in US Pat. No. 6,423,804, which is incorporated herein by reference in its entirety.

Examples of cationic sensitive polymers are described in the following U.S. Patent Application Publications 2003/0026963, 2003/0027270, 2003/0032352, 2004/0030080, 2003/0055146, 2003/0022568, 2003 / No. 0045645, 2004/0058600, 2004/0058073, 2004/0063888, 2004/0055704, 2004/0058606, and 2004/0062791, which are inconsistent with the present application All publications of this application are hereby incorporated by reference in their entirety, except that the disclosure content or definition is considered to be governed by the disclosure content or definition herein.

Preferably, the ion sensitive polymer may be insoluble in the wetting composition comprising at least about 0.3% by weight of insolubilizing agent, which may consist of one or more inorganic and / or organic salts containing monovalent and / or divalent ions. More preferably, the ion sensitive polymer comprises from about 0.3% to about 3.5% by weight of insolubilizing agent, which may consist of one or more inorganic and / or organic salts containing monovalent and / or divalent ions. It may be insoluble. Even more preferably, the ion sensitive polymer comprises in a wetting composition comprising from about 0.5% to about 3.5% by weight of insolubilizer comprising one or more inorganic and / or organic salts containing monovalent and / or divalent ions. It may be insoluble. Particularly preferably, the ion sensitive polymer may be insoluble in the wetting composition comprising from about 1 to about 3 weight percent of an insolubilizer comprising one or more inorganic and / or organic salts containing monovalent and / or divalent ions. have. Suitable monovalent ions include Na ⁺ ions, K ⁺ ions, Li ⁺ ions, NH ₄ ⁺ ions, low molecular weight quaternary ammonium compounds (eg, compounds having less than 5 carbons in any side chain group), and combinations thereof Including but not limited to. Suitable divalent ions include, but are not limited to, Zn ²⁺ , Ca ²⁺ and Mg ²⁺ . These monovalent and divalent ions are derived from organic and inorganic salts including but not limited to NaCl, NaBr, KCl, NH ₄ Cl, Na ₂ SO ₄ , ZnCl ₂ , CaCl ₂ , MgCl ₂ , MgSO ₄ and combinations thereof. Can be. Typically, alkali metal halides are the most preferred monovalent or divalent ions because of cost, purity, low toxicity and availability. Preferred salt is NaCl.

In one preferred embodiment, the ion sensitive polymer may provide a wipe substrate with sufficient in-use strength (typically> 300 g / linear inch), preferably with the wetting composition containing sodium chloride. This wipe substrate may be dispersible in tap water and preferably loses most of its wet strength (<200 g / linear inch) within 1 hour or less.

In another preferred embodiment, the ion sensitive polymer comprises a cation sensitive polymer, wherein the cation sensitive polymer is a polymerization product of 96 mol% methyl acrylate and 4 mol% [2- (acryloxy) ethyl] trimethyl ammonium chloride Phosphorus cationic polyacrylate.

As previously discussed, the binder composition may comprise a triggerable polymer and / or a cobinder. When the binder composition comprises the triggerable polymer and the cobinder, the triggerable polymer and the cobinder are preferably compatible with each other in an aqueous solution to 1) allow easy application of the binder composition to the fibrous substrate in a continuous manner, and 2) It prevents disturbing the dispersibility of the binder composition. Thus, if the triggerable polymer is an anionic sensitive polymer, cobinders that are anionic, nonionic, or very weak cations may be preferred. If the triggerable polymer is a cation sensitive polymer, cobinders which are cationic, nonionic or very weak anions can be added. In addition, the cobinder preferably does not provide substantial cohesion with the wipe substrate by covalent bonds such that it interferes with the dispersibility of the wipe substrate.

The presence of cobinders can provide many desirable properties. For example, the cobinder may serve to reduce the shear viscosity of the triggerable polymer and thus the binder composition has improved sprayability over the triggerable binder alone. By using the term “sprayable” it is meant that this polymer can be applied to the fibrous material or substrate by spraying, allowing for a uniform distribution of the polymer throughout the surface of the substrate and penetration of this polymer into the substrate. . In addition, the cobinder may reduce the rigidity of the wipe substrate relative to the rigidity of the wipe substrate to which only the triggerable polymer is applied. Reduced stiffness can be achieved if the cobinder has a glass transition temperature Tg lower than the Tg of the triggerable polymer. In addition, the cobinder may be less expensive than the triggerable polymer and may serve to reduce the cost of the binder composition by reducing the amount of triggerable polymer required. Thus, it may be desirable to use the largest amount of cobinder possible in the binder composition so that the binder composition does not jeopardize the dispersibility and in-use strength properties of the wet wipe. In one preferred embodiment, the cobinder can replace a portion of the triggerable polymer in the binder composition to achieve a given level of strength such that the binder composition contains only the triggerable polymer in the binder composition while having substantially the same tensile strength. It provides at least one of lower stiffness, better tactile properties (eg lubricity or smoothness) or reduced cost compared to wet wipes.

In one embodiment, the cobinder present in the binder composition is about 10% or less, more preferably about 15% or less, more preferably 20% or less, more preferably 30% or less, further by weight of the binder composition Preferably about 45% or less. Typical ranges of cobinders relative to the solids mass of the binder composition may include about 1 to about 45%, about 25 to about 35%, about 1 to about 20%, and about 5 to about 25%.

The cobinder may be selected from a wide variety of polymers known in the art. For example, the cobinder may be poly (ethylene-vinyl acetate), poly (styrene-butadiene), poly (styrene-acrylic), vinyl acrylic terpolymer, polyester latex, acrylic emulsion latex, poly (vinyl chloride), ethylene -Vinyl chloride copolymer, carboxylated vinyl acetate latex, and the like. Various additional typical cobinder polymers are discussed in US Pat. No. 6,653,406 and US Patent Application Publication No. 2003/00326963, both of which are incorporated herein by reference in their entirety. Particularly preferred cobinders include Airflex® EZ123 and Airflex® 110.

To prepare the wipe substrates described herein, the binder composition can be applied to the fiber material by any known method. Suitable methods for applying the binder composition include, but are not limited to, printing, spraying, electrostatic spraying, using metered press rolls or impregnation. The amount of binder composition can be metered and distributed evenly on the fiber material or can be distributed unevenly on the fiber material.

Once the binder composition is applied to the fibrous material, drying can be accomplished by any conventional means, if necessary. Once dried, the wipe substrate may exhibit improved tensile strength as compared to the tensile strength of the untreated wet or dry fibrous material and, moreover, will have the ability to "break" or disintegrate quickly when placed in tap water.

For easy application to a fibrous substrate, the binder composition can be dissolved in water or a non-aqueous solvent such as methanol, ethanol, acetone and the like, with water being the preferred solvent. The amount of binder dissolved in the solvent can vary depending on the polymer used and the fabric application. Preferably, the binder solution contains less than about 18 weight percent binder composition solids. More preferably, the binder solution contains less than 16% by weight binder composition solids.

Unexpectedly, it has been found that a binder composition solids percentage of less than about 18%, preferably less than about 16%, ensures that the spray coating is optimized with an acrylate based binder. Unexpectedly, low solids spraying of the binder onto uncreped, through-aired tissues has yielded beneficial strength benefits in spite of the significantly higher attachment points per fiber volume (36000 contacts / dL) that should theoretically not require droplet size optimization. Provided. In addition, one skilled in the art would prefer not to lower the percentage of solids in the binder because lower binder additions make it difficult to spray at low solids because of dispersible binder nozzle tip requirements.

Effective spray coating will give the wipe better strength. “Geometric Mean Tensile Strength” (GMT) can be used to define effective spray coating by illustrating the strength throughout the wipe. Preferably, the dispersible wet wipe has a geometric mean tensile strength of at least 300 g / linear inch.

Many techniques are available for making wet wipes. In an embodiment, this technique can include the following steps:

1. Providing a fibrous material (eg, unbound airlaid, tissue web, carded web, fluff pulp, etc.).

2. Applying the binder composition to the fibrous material, typically in liquid, suspension or foam form, to provide a wipe substrate.

3. A step of allowing the wipe substrate to dry.

4. Applying the wetting composition to the wipe substrate to produce a wet wipe.

5. Packaging the product with the wet wipe in roll or stack.

In one embodiment, the binder composition applied in step 2 may comprise a triggerable polymer. In one further embodiment, the binder composition applied in step 2 may comprise a triggerable polymer and a cobinder.

The finished wet wipes may be individually packaged in a desiccant envelope, preferably folded, or may be packaged in a container holding the desired number of sheets in a waterproof packaging together with the wetting composition applied to the wipe. Some exemplary methods that can be used to make folded wet wipes are described in US Pat. Nos. 5,540,332 and 6,905,748, which are incorporated herein by reference. The finished wipe may also be packaged as a roll of detachable sheets in a moisture proof container that holds the desired number of sheets on the roll along with the wetting composition applied to the wipe. The roll may be free of cores and may be hollow or solid. Coreless rolls, including those with or without hollow centers, include SRP Industry, Inc. (San Jose, CA, USA) and Shimizu Manufacturing. And a known coreless roll winder and a device disclosed in US Pat. No. 4,667,890, including a coreless roll winder of Japan. In addition, US Pat. No. 6,651,924 provides an example of a method of making a coreless roll of wet wipes.

In addition to the wipe substrates, the wet wipes also contain the wetting compositions described herein. The liquid wetting composition may include any suitable ingredient that provides the desired wiping properties and may be any liquid that can be absorbed into the wet wipe basesheet. For example, the component can include water, emollients, surfactants, fragrances, preservatives, organic or inorganic acids, chelating agents, pH buffers or combinations thereof, as is well known to those skilled in the art. In addition, the liquid may also contain lotions, medications and / or antimicrobial agents.

The wetting composition is preferably from about 10 to about 600 weight percent of the substrate, more preferably from about 50 to about 500 weight percent of the substrate, even more preferably from about 100 to about 500 weight percent of the substrate, particularly more preferably Can be included in the wipe in an additional amount of about 200 to about 300 weight percent of the substrate.

In the case of dispersible wipes, the wetting composition for use with the wipe substrate preferably contains an insolubilizer that maintains the cohesiveness of the binder composition and thus maintains the wet wipe's in-use strength until the insoluble agent is diluted with tap water. Aqueous compositions. Thus, the wetting composition may contribute to the inducible properties of the inducible polymer and concomitantly the binder composition.

Insolubilizers in the wetting composition are for use with salts, such as ion sensitive polymers, to provide in-use and storage strengths in a binder composition, or blends of those previously disclosed, salts having both monovalent and polyvalent ions, When the binder composition transitions to a weaker state, it can be any other compound that can be diluted in water to enable dispersion of the wet wipe. The wetting composition may preferably contain greater than about 0.3 weight percent insolubilizing agent based on the total weight of the wetting composition. The wetting composition may preferably contain about 0.3 to about 10 weight percent insolubilizing agent based on the total weight of the wetting composition. More preferably, the wetting composition may contain from about 0.5 to about 5 weight percent insolubilizing agent based on the total weight of the wetting composition. More preferably, the wetting composition may contain about 1 to about 4 weight percent insolubilizing agent based on the total weight of the wetting composition. Even more desirably, the wetting composition may contain about 1 to about 2 weight percent of insolubilizing agent based on the total weight of the wetting composition.

The wetting composition may preferably be compatible with the triggerable polymer, the cobinder polymer, and any other component of the binder composition. In addition, the wetting composition preferably contributes to the ability of the wet wipe to maintain cohesion during use, storage and / or dispensing while still providing dispersibility in tap water.

In one example, the wetting composition may contain water. The wetting composition suitably contains water in an amount of about 0.1 to about 99.9 weight percent of the composition, more typically about 40 to about 99 weight percent of the composition, more preferably about 60 to about 99.9 weight percent of the composition. It may contain. For example, when the composition is used in connection with a wet wipe, the composition may suitably contain water in an amount of about 75 to about 99.9 weight percent of the composition.

The wetting composition may further contain additional agents that act to impart a beneficial effect to the skin or hair and / or further improve the aesthetics of the compositions and wipes described herein. Examples of suitable skin benefit agents include emollients, sterols or sterol derivatives, natural and synthetic fats or oils, viscosity enhancers, rheology modifiers, polyols, surfactants, alcohols, esters, silicones, clays, starches, celluloses, particulates, humectants, Film formers, slip modifiers, surface modifiers, skin protectants, hygroscopics, sunscreens and the like.

Thus, in one example, the moisturizing composition may optionally further comprise one or more emollients, which typically soften the skin, sooth the skin, and otherwise lubricate and / or moisturize the skin. give. Suitable emollients that may be included in the composition include oils such as petrolatum based oils, petrolatum, mineral oils, alkyl dimethicones, alkyl methicones, alkyldimethicone copolyols, phenyl silicones, alkyl trimethylsilanes, dimethicones, dimethicone crosspolymers ( crosspolymer), cyclomethicone, lanolin and derivatives thereof, glycerol esters and derivatives, propylene glycol esters and derivatives, alkoxylated carboxylic acids, alkoxylated alcohols, and combinations thereof.

In addition, ethers such as eucalyptol, cetearyl glucoside, dimethyl isosorbic polyglyceryl-3 cetyl ether, polyglyceryl-3 decyltetradecanol, propylene glycol myristyl ether, and combinations thereof are also suitable as emollients. Can be used.

Additionally, the wetting composition may comprise emollients in an amount from about 0.01 to about 20 weight percent of the composition, more preferably from about 0.05 to about 10 weight percent of the composition, more typically from about 0.1 to about 5 weight percent of the composition. It may include.

In addition, one or more viscosity enhancers can be added to the wetting composition to increase viscosity, help stabilize the composition, reduce migration of the composition, and improve delivery to the skin. Suitable viscosity enhancers include polyolefin resins, lipophilic / oil thickeners, polyethylene, silica, silica silylates, silica methyl silylate, colloidal silicon dioxide, cetyl hydroxy ethyl cellulose, other organic modified celluloses, PVP / decane copolymers, PVM / MA decadiene crosspolymer, PVP / eicosene copolymer, PVP / hexadecane copolymer, clay, starch, gum, water soluble acrylate, carbomer, acrylate based thickener, surfactant thickener and combinations thereof.

The wetting composition is preferably at least one in an amount of from about 0.01 to about 25 weight percent of the composition, more preferably from about 0.05 to about 10 weight percent of the composition, even more preferably from about 0.1 to about 5 weight percent of the composition. Viscosity improvers may be included.

The composition of the present disclosure may optionally further contain a hygroscopic agent. Examples of suitable humectants include glycerin, glycerin derivatives, sodium hyaluronate, betaine, amino acids, glycosaminoglycans, honey, sorbitol, glycols, polyols, sugars, hydrogenated starch hydrolysates, salts of PCA, lactic acid, lactates And urea. Particularly preferred moisture absorbents are glycerin. The composition of the present disclosure may suitably include one or more hygroscopic agents in an amount of about 0.05 to about 25 weight percent of the composition.

The composition of the present disclosure may optionally further contain a film former. Examples of suitable film formers include lanolin derivatives (e.g., acetylated lanolin), fatty fatty oils, cyclomethicones, cyclopentasiloxanes, dimethicones, synthetic and biological polymers, proteins, quaternary ammonium materials, starches, Gums, celluloses, polysaccharides, albumin, acrylate derivatives, IPDI derivatives and the like. The composition of the present disclosure may suitably include one or more film formers in an amount of about 0.01 to about 20 weight percent of the composition.

In addition, the wetting composition may further contain a skin protectant. Examples of suitable skin protectants include the ingredients mentioned in the SP monograph (21 CFR §347). Suitable skin protectants and amounts include those mentioned in the SP monograph (Subpart B-Active Ingredients §347.10): (a) allantoin, 0.5-2%, (b) aluminum hydroxide gel, 0.15-5%, (c) cal Amine, 1-25%, (d) cocoa butter, 50-100%, (e) cod liver oil, 5-13.56% (according to §347.20 (a) (1) or (a) (2), provided that Labeled on the product so that the amount used in time does not exceed 10000 USP unit vitamin A and 400 USP unit cholecalciferol), (f) colloidal oatmeal, at least 0.007%; According to §347.20 (a) (4), at least 0.003% with mineral oil, (g) dimethicone, 1 to 30%, (h) glycerin, 20 to 45%, (i) hard fat, 50 to 100% (j) kaolin, 4-20%, (k) lanolin, 12.5-50%, (l) mineral oil, 50-100%; According to §347.20 (a) (4), 30 to 35% with colloidal oatmeal, (m) petrolatum, 30 to 100%, (o) sodium bicarbonate, (q) topical starch, 10 to 98%, (r ) White petrolatum, 30-100%, (s) zinc acetate, 0.1-2%, (t) zinc carbonate, 0.2-2%, (u) zinc oxide, 1-25%.

The wetting composition may also further contain quaternary ammonium materials. Examples of suitable quaternary ammonium materials include polyquaternium-7, polyquaternium-10, benzalkonium chloride, behentrimonium methosulfate, cetrimonium chloride, cocamidopropyl pg-dimonium chloride, guar hydroxypropyl Trimonium chloride, isostearamidopropyl morpholine lactate, polyquaternium-33, polyquaternium-60, polyquaternium-79, quaternium-18 hectorite, quaternium-79 hydrolyzed silk, quaternium -79 Hydrolyzed Soy Protein, Rapeseed Amidopropyl Ethyldimonium Ethosulfate, Silicon Quaternium-7, Stearalkonium Chloride, Palmitamidopropyltrimonium Chloride, Butyl Glucoside, Hydroxypropyltrimonium Chloride , Laudimonium hydroxypropyl decylglucoside chloride, and the like. The composition of the present disclosure may suitably include one or more quaternary materials in an amount of about 0.01 to about 20 weight percent of the composition.

The wetting composition may optionally further contain a surfactant. Examples of suitable additional surfactants include, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, zwitterionic surfactants, nonionic surfactants, and combinations thereof. Specific examples of suitable surfactants are known in the art and include those suitable for inclusion in the wetting compositions and wipes. The composition of the present disclosure may suitably include one or more surfactants in an amount of about 0.01 to about 20 weight percent of the composition.

In addition to nonionic surfactants, the cleanser may also contain other types of surfactants. For example, in some embodiments, amphoteric surfactants such as zwitterionic surfactants may also be used. For example, one class of amphoteric surfactants that may be used in the present disclosure are derivatives of secondary and tertiary amines with aliphatic radicals that are straight or branched chains, wherein one of the aliphatic substituents is from about 8 to 18 Carbon atoms, and at least one of the aliphatic substituents contains an anionic water solubilizing group such as a carboxyl group, sulfonate group, or sulfate group. Some examples of amphoteric surfactants are sodium 3- (dodecylamino) propionate, sodium 3- (dodecylamino) propane-1-sulfonate, sodium 2- (dodecylamino) ethyl sulfate, sodium 2- (Dimethylamino) octadecanoate, disodium 3- (N-carboxymethyl-dodecylamino) propane-1-sulfonate, disodium octadecyliminodiacetate, sodium 1-carboxymethyl-2-undecylimida Sol, and sodium N, N-bis (2-hydroxyethyl) -2-sulfato-3-dodecoxypropylamine.

Additional classes of suitable amphoteric surfactants include phosphobetaines and phosphitanes. For example, some examples of such amphoteric surfactants are sodium coconut N-methyl taurate, sodium oleyl N-methyl taurate, sodium tall oil acid N-methyl taurate, sodium palmitoyl N-methyl taurate, coco Dimethylcarboxymethylbetaine, lauryldimethylcarboxymethylbetaine, lauryldimethylcarboxyethylbetaine, cetyldimethylcarboxymethylbetaine, lauryl-bis- (2-hydroxyethyl) carboxymethyl-betaine, oleyldimethyl Gammacarboxypropylbetaine, lauryl-bis- (2-hydroxypropyl) -carboxy-ethylbetaine, cocoamidodimethylpropylsultine, stearylamidodimethylpropylsultine, laurylamido-bis- (2 -Hydroxyethyl) propylsultine, di-sodium oleamide PEG-2 sulfosuccinate, TEA oleamido PEG-2 sulfosuccinate, disodium oleamide MEA sulfosuccinate, disodium oleamide MIPA sulfide Pour Succinate , Disodium ricinoleamide MEA sulfosuccinate, disodium undecyleneamide MEA sulfosuccinate, disodium lauryl sulfosuccinate, disodium wheat embryo amido MEA sulfosuccinate, disodium wheat embryo Ami PEG-2 sulfosuccinate, disodium isostearamideo MEA sulfosuccinate, cocoampoglycinate, cocoamphocarboxyglycinate, lauroamphoglycinate, lauroamphocarboxyglycinate, cap Liloampocarboxyglycinate, cocoampopropionate, cocoampocarboxypropionate, lauroampocarboxypropionate, capryloampocarboxypropionate, dihydroxyethyl tallow glycinate, cocoamido di Sodium 3-hydroxypropyl phosphobetaine, lauric myristic amido dishodium 3-hydroxypropyl phosphobetaine, lauric myristic amido glyceryl foam Sforbetaine, lauric myristic amido carboxy disodium 3-hydroxypropyl phosphobetaine, cocoamido propyl monosodium phosphitan, cocamidopropyl betaine, lauric myristic amido propyl monosodium phosphitane and Mixtures thereof, but are not limited thereto.

In some cases, it may also be desirable to use one or more anionic surfactants in the cleanser. Suitable anionic surfactants include alkyl sulfates, alkyl ether sulfates, alkyl ether sulfonates, sulfate esters of alkylphenoxy polyoxyethylene ethanol, alpha-olefin sulfonates, beta-alkoxy alkanes sulfonates, alkyllauryl sulfonates, Alkyl monoglyceride sulfates, alkyl monoglyceride sulfonates, alkyl carbonates, alkyl ether carboxylates, fatty acid salts, sulfosuccinates, sarcosinates, octoxynol or nonoxynol phosphates, taurates, fatty taurids , Fatty acid amide polyoxyethylene sulfate, isethionate or mixtures thereof.

Specific examples of some suitable anionic surfactants include C _8-18 alkyl sulfates, C _8-18 fatty acid salts, C _8-18 alkyl ether sulfates with 1 or 2 moles of ethoxylation, C _8-18 alkoyl sarcosy sulfonates, C _8-18 alkylsulfonyl acetate, C _8-18 sulfosuccinate, C _8-18 alkyl diphenyl oxide di-sulfonates, C _8-18 alkyl carbonate, C _8-18 alpha-olefin sulfonate, Methyl ester sulfonate and blends thereof, including but not limited to. The C _8-18 alkyl group can be straight chain (eg lauryl) or branched chain (eg 2-ethylhexyl). The cation of the anionic surfactant may be an alkali metal (eg sodium or potassium), ammonium, C _1-4 alkylammonium (eg mono-, di-, tri-) or C _1-3 alkanolammonium (eg For example, mono-, di-, tri-).

Specific examples of such anionic surfactants include lauryl sulfate, octyl sulfate, 2-ethylhexyl sulfate, decyl sulfate, tridecyl sulfate, cocoate, lauroyl sarcosinate, lauryl sulfosuccinate, Straight chain C ₁₀ diphenyl oxide disulfonate, lauryl sulfosuccinate, lauryl ether sulfate (1 and 2 mol ethylene oxide), myristyl sulfate, oleate, stearate, talate, ricinoleate , Cetyl sulfate, and similar surfactants.

In addition, cationic surfactants such as cetylpyridinium chloride and methylbenzethium chloride may also be used.

In addition, the wetting composition may further contain additional emulsifiers. As mentioned above, natural fatty acids, esters and alcohols and derivatives thereof and combinations thereof can act as emulsifiers in the composition. Optionally, the composition may contain additional emulsifiers other than natural fatty acids, esters and alcohols and derivatives thereof, and combinations thereof. Examples of suitable emulsifiers include polysorbate 20, polysorbate 80, anionic emulsifiers such as DEA phosphate, cationic emulsifiers such as behentrimonium methosulfate and the like. The composition of the present disclosure may suitably include one or more additional emulsifiers in an amount of about 0.01 to about 10 weight percent of the composition.

For example, nonionic surfactants can be used as emulsifiers. Nonionic surfactants typically have a hydrophilic chain comprising a hydrophobic base such as a long chain alkyl group or an alkylated aryl group, and a number of (eg, 1 to about 30) ethoxy and / or propoxy moieties. . Examples of some classes of nonionic surfactants that may be used are ethoxylated alkylphenols, ethoxylated and propoxylated fatty alcohols, polyethylene glycol ethers of methyl glucose, polyethylene glycol ethers of sorbitol, ethylene oxide-propylene oxide Block copolymers, ethoxylated esters of fatty (C _8-18 ) acids, condensation products of ethylene oxide and long chain amines or amides, condensation products of ethylene oxide and alcohols, and mixtures thereof .

Various specific examples of suitable nonionic surfactants include methyl glutet-10, PEG-20 methyl glucose distearate, PEG-20 methyl glucose _{sesquistearate} , C _11-15 pallet-20, cetet-8, cetet -12, dodoxinol-12, laureth-15, PEG-20 castor oil, polysorbate 20, stearette-20, polyoxyethylene-10 cetyl ether, polyoxyethylene-10 stearyl ether, polyoxyethylene -20 cetyl ether, polyoxyethylene-10 oleyl ether, polyoxyethylene-20 oleyl ether, ethoxylated nonylphenol, ethoxylated octylphenol, ethoxylated dodecylphenol, 3 to 20 ethylene oxide moieers Ethoxylated fatty (C _8-22 ) alcohols including tee, polyoxyethylene-20 isohexadecyl ether, polyoxyethylene-23 glycerol laurate, PEG 80 sorbitan laurate, polyoxy-ethylene-20 glyceryl Stearate, PPG-10 Methyl Written Lucose ether, PPG-20 methyl glucose ether, polyoxyethylene-20 sorbitan monoester, polyoxyethylene-80 castor oil, polyoxyethylene-15 tridecyl ether, polyoxy-ethylene-6 tridecyl ether, lauret -2, lauret-3, lauret-4, PEG-3 castor oil, PEG 600 dioleate, PEG 400 dioleate, and mixtures thereof.

In addition, the wetting composition may further contain a preservative. Suitable preservatives for use in the compositions include, for example, Kathon CG, which is a mixture of methylchloroisothiazolinone and methylisothiazolinone available from Rohm & Haas (Philadelphia, PA); Neolone 950®, methylisothiazolinone, available from Rohm and Haas (Philadelphia, PA); Glydant Plus, available from DMDM Hydantoin (eg, Lonza, Inc., Fairlon, NJ); iodopropynyl butylcarbamate, benzoic acid ester (paraben) Such as methylparaben, propylparaben, butylparaben, ethylparaben, isopropylparaben, isobutylparaben, benzylparaben, sodium methylparaben, and sodium propylparaben; 2-bromo-2-nitropropane-1,3-diol; Benzoic acid, imidazolidinyl urea, diazolidinyl urea, etc. In addition, other preservatives may be ethylhexylglycerine, phenoxyethanol caprylyl glycol, 1,2-hexanediol, caprylyl glycol, and tropolone Blends of phenoxy, and blends of phenoxyethanol and tropolone.

The wetting composition may further comprise adjunct ingredients commonly found in pharmaceutical compositions at levels established in the art in a manner established in the art. For example, the composition may contain additional compatible pharmaceutically active ingredients for combination therapy, such as antimicrobials, antioxidants, antiparasitic agents, antifungals, antifungals, preservatives, biologically active agents, astringents, keratinizing agents, local anesthetics. , Antistinging agents, anti-flushing agents, soothing agents, and combinations thereof. Other suitable additives that may be included in the compositions of this disclosure include colorants, deodorants, fragrances, perfumes, emulsifiers, antifoams, lubricants, natural moisturizers, skin conditioning agents, skin protectants and other skin benefit agents (e.g. extracts, Such as aloe vera, and anti-aging agents such as peptides), solvents, solubilizers, suspending agents, wetting agents, hygroscopic agents, pH adjusters, buffers, dyes and / or pigments, and combinations thereof.

As disclosed herein, wet wipes do not require organic solvents to maintain strength in use, and the wetting composition can be substantially free of organic solvents. Organic solvents can produce a sticky after-use feeling and can cause irritation in large amounts. However, small amounts of organic solvents may be included in the wetting compositions for different purposes in addition to maintaining wet strength during use. In one embodiment, small amounts of organic solvent (less than about 1%) may be used as the fragrance or preservative solubilizer to improve the processing and storage stability of the wetting composition. The wetting composition may preferably contain less than about 5% by weight of organic solvents such as propylene glycol and other glycols, polyhydroxy alcohols, and the like, based on the total weight of the wetting composition. More preferably, the wetting composition may contain less than about 3 weight percent organic solvent. Even more desirably, the wetting composition may contain less than about 1 weight percent organic solvent.

Preferably, the wet wipes disclosed herein can have sufficient tensile strength, intersheet adhesion, calculated stack thickness per layer, and flexibility.

Wet wipes can be made using a wipe substrate having a binder material and a fibrous material forming a nonwoven airlaid web. In addition, these wet wipes made from wipe substrates can be made available without breaking or tearing, can be made acceptable by the consumer, and once disposed of in a sanitary system, provide no problem disposal. Can be. In addition, wet wipes can be produced using a coform substrate as described above.

Wet wipes formed from the wipe substrate may preferably have a mechanical tensile strength in the range of at least about 300 to about 1000 g / linear inch. More preferably, the wet wipe may have a mechanical tensile strength in the range of at least about 300 to about 800 g / linear inch. Even more desirably, the wet wipe may have a mechanical tensile strength in the range of at least about 300 to about 600 g / linear inch. Most preferably, the wet wipe may have a mechanical tensile strength in the range of at least about 350 to about 550 g / linear inch.

Wet wipes can be configured to provide all desired physical properties by using single or multiple ply wet wipe products, and two or more ply substrates are joined together to form a multiply wipe by methods known in the art.

The total basis weight of the wipe substrate, consisting of one or multiple wipe substrates, in the final wet wipe product may range from at least about 25 to about 120 gsm. More preferably, the basis weight of the wipe substrate may be about 40 to 90 gsm. Even more desirably, the basis weight of the wipe substrate may be about 60 to 80 gsm. Especially more preferably, the basis weight of the wipe substrate may be about 70 to 75 gsm.

As mentioned previously, wet wipes formed from wipe substrates may be sufficiently dispersible to degrade and lose sufficient strength in tap water under conditions typically experienced in home or municipal sanitation systems. In addition, as previously mentioned, the tap water used to measure dispersibility should include the concentration range of most components typically found in the tap water composition encountered by the wet wipe at disposal. Previous methods of measuring the dispersibility of wipe substrates, whether dry or previously moist, such as measuring the time a material decomposes while being agitated by a mechanical mixer, are often systems exposed to shear while the material is in water. Relied on. This constant exposure to relatively high and unregulated shear gradients provides an unrealistic and overly optimistic test for products designed to flush in toilets with extremely weak or brief shear levels. For example, once the material enters the decay bath, the shear rate can be negligible. Thus, for a realistic assessment of wet wipe dispersibility, the test method should simulate the relatively low shear rate experienced once the product is flushed in the toilet.

For example, a static soak test will illustrate the dispersibility of the wet wipe after the wet wipe is completely submerged with water from the toilet and when the wet wipe experiences negligible shear, such as in a scavenger. Preferably, the wet wipe may have a tensile strength of less than about 200 g / linear inch after 1 hour when immersed in tap water.

As mentioned previously, wet wipes formed from single-ply wipe substrates may be sufficiently dispersible such that they lose sufficient strength in the tap water under conditions that they typically experience in home or municipal sanitation systems and degrade. In addition, as previously mentioned, the tap water used to measure dispersibility should include the concentration range of most of the components typically found in the tap water composition encountered by the wet wipe at disposal. Dispersible shake flask testing is intended to address the dispersibility or physical degradation of test products during the transportation of test products through building drains, sewage pumps, and sewers in the INDA / EDANA Guidance Document for evaluating the flushability of nonwoven consumer products. This is the first of two options to evaluate. It simulates the physical force that acts to disintegrate the product while passing through the sewage pump or through the sewer pipe. The intact product is placed in a flask containing tap water or untreated wastewater and mechanically shaken under the specified conditions. The contents of the flask can be passed through a series of screens of size 12, 6, 3 and 1.5 mm, and the fractions of various sizes retained on the screen can be weighed to determine the degree of disintegration. Under this test, if more than 95% of the product mass passes through a 3.18 mm sieve (porous plate) after stirring for 1 hour, the product is considered to be adequately dispersed during sewer transportation. For the purposes of the present application, the passthrough percentage value is equal to the amount of wipe passing through the 3 mm porous plate after stirring for 1 hour. Thus, the wipe will be smaller or smaller than necessary to allow the pieces to pass through the bar screens typically found in municipal sanitary sewer treatment facilities, causing no problems or blockages at home.

The dispersible shake flask test illustrates the dispersibility of the wet wipe when the wet wipe experiences representative force after it is sufficiently wet with water from the toilet and while it is transported through the sewage pump and municipal wastewater delivery system.

In one embodiment, the dispersible wet wipe has a pass through percentage value of at least 70%. More preferably, the dispersible wet wipe has a pass through percentage value of at least 90%. Even more preferably, the dispersible wet wipe has a pass through percentage value of at least 95%.

Preferably, the wet wipes disclosed herein may have an in-use wet tensile strength of at least about 300 g / linear inch and a tensile strength of less than about 200 g / linear inch after about 1 hour when immersed in tap water.

Most preferably, the wet wipes disclosed herein have a wet tensile strength of greater than about 300 g / linear inch when wet, and less than about 150 g / linear inch after use, preferably about 1 hour after soaking in tap water. It may have a tensile strength.

Wet wipes preferably retain the desired properties at times related to warehouse, transportation, retail display, and consumer storage. In one embodiment, shelf life may range from 2 months to 2 years.

Wet wipes disclosed herein are illustrated in the following examples, which should never be construed as limiting its scope. On the contrary, after reading the description herein, it should be clearly understood that various other embodiments, modifications, and equivalents may come to the mind of those skilled in the art without departing from the spirit and / or scope of the appended claims.

Test Methods

Wet wife The tensile strength  Measure

For the purposes of this application, the tensile strength is 1 inch jaw width (sample width after holding the sample at the same ambient conditions for 4 hours before testing the sample at ambient conditions of 23 ± 2 ° C. and 50 ± 5% relative humidity). ), 3 inch test interval (gauge length), and jaw separation rate 25.4 cm / min can be measured using a constant rate elongation (CRE) tensile tester. Wet wipes are JDC Precision Sample Cutter (Twing-Albert Instrument Company, Philadelphia, PA), from the center of the wipe to the specified machine direction (MD) or transverse machine direction (CD) orientation. Cut into 1-inch wide strips using model number JDC 3-10, serial number 37333). "MD tensile strength" is the peak load (in gram-force) per inch of sample width when the sample is pulled until it breaks in the machine direction. "CD tensile strength" is the peak load (in gram-force) per inch of sample width when the sample is pulled until it breaks transversely.

The instrument used to measure tensile strength is the MTS Systems Sinergy 200 model. The data acquisition software is MTS TestWorks® for Windows version 4.0 commercially available from MTS Systems Corp. (Eden Prairie, Minn.). The load cell is the MTS 50 Newton maximum load cell. The gauge length between jaws is 3 ± 0.04 inches. Upper and lower jaws are operated using pneumatic action up to 60 P.S.I. The breaking sensitivity is set at 40%. The data acquisition rate is set at 100 Hz (ie 100 samples per second). Place the sample centered in the vertical and horizontal directions on the instrument jaws. The test then begins and ends when the force drops to 40% of the peak. Record the peak load, expressed in gram-force, as the "MD tensile strength" of the sample. At least 12 representative samples are tested for each product and their average peak load is determined. As used herein, the “geometric average tensile strength” (GMT) is the square root of the product of the dry machine direction tensile strength and the dry transverse machine direction tensile strength, expressed in g per inch of sample width. These values are all for measuring tensile strength during use.

To provide a post-use tensile strength measurement, the tensile strength is measured after the sample is submerged in tap water for 1 hour.

Basis weight

The dry basis weight of the basesheet material forming the wet wipe can be obtained using ASTM activity standard D646-96 (2001), basis weight (mass per unit area) standard test method of paper and paperboard, or equivalent methods.

Dispersive shaking flask test

The percentage of mass loss of wet wipes can be obtained using the INDA / EDANA Guidance Document, Dispersible Shake Flask Test, for evaluating the flushability of nonwoven consumer products. For purposes herein, the samples are placed in tap water and tested after shaking on a flask shaker for 1 hour.

As used herein, the percent pass through value is equal to the percent mass loss, or the amount of substrate passing through the 3 mm porous plate.

This test is used to assess the dispersibility or physical degradation of flushable products during transport through sewage pumps (e.g. ejectors or grinder pumps) and municipal wastewater conveying systems (e.g. sewer pipes and pumping stations). Is used. This test assesses the rate and extent of disintegration of the test substance in the presence of tap water or untreated wastewater. The results from this test are used to predict the compatibility of flushable products with household sewage pumps and municipal collection systems.

Substances and Devices:

1. Glass culture flask (2800 mL) with Fernbach triplex.

2. Orbital bottom shaker with a 2 inch (5 cm) orbit capable of rotating at 150 rpm. The platform for the shaker requires a clamp that can accommodate a lower flask diameter of 205 mm.

3. USA standard test body # 18 (1 mm opening): 8 inches (20 cm) in diameter.

4. Perforated Screen Details

5. Drying oven capable of maintaining a temperature of 40 ± 3 ° C. for thermoplastic test materials and of 103 ± 3 ° C. for non-plastic test materials.

Exam start:

Each test product is tested three times, so three flasks are prepared for each of the two intended destructive sampling points. Each flask contains 1 L of prescreened wastewater or room temperature tap water and test product (see section 6.1 Summary of Test Methods for guidance in choosing a medium for test). Each test product shall be weighed three times in advance (based on dry weight) with an analytical balance measuring at least two decimal places and recorded in the laboratory notebook for later use in calculating the final disintegration percentage. In addition, a control flask with reference material is also tested to accommodate two disruptive sampling points. Each flask also contains 1 L of prescreened wastewater or tap water and a suitable reference material. If Whatman # 41 ashless filter paper is used, it should be folded into quarters, refolded and placed in a flask. In the case of pre-moistened products (eg, wet wipes), sample preconditioning that simulates product delivery to the sewer can be performed by flushing the product through a toilet and drain conduit. This should be recorded in the research record. Measure 1 liter of wastewater or tap water into each Pernbach flask and place it on a rotary shaker table. Add the test product to the flask (typically 1 to 3 g on a dry weight basis for one article, or toilet tissue). At least 1 g of test product should be used to ensure accurate measurement of disintegration loss. The flask is shaken at 150 rpm. For sewage pump evaluation, test and control products are observed after 30 and 60 minutes and then destructively sampled after 3 hours. For sewer transport evaluation, the test and control products are visually observed after one hour and destructively sampled after six hours. These tests are incubated at room temperature (22 ± 3 ° C.).

Exam end:

At the designated disruptive sampling point, remove the flask from each product set and control set tested and pour the contents through one set of nested screens arranged in the following order from top to bottom: 12 mm, 3 mm and 1.5 mm ( Diameter openings). Additional screens can be added to better understand the dispersibility characteristics of the sample. Handheld showerhead spray nozzles maintained at about 10-15 cm above the sieve, a flow rate of 4 L / min through the nested screens, taking care not to force the retained material through the next smaller screen Rinse the material gently for 2 minutes. After 2 minutes of rinsing, remove the top screen and continue rinsing the next smaller screen that is still superimposed for an additional 2 minutes using the same procedure as described above. The rinse process continues until all screens are rinsed. After the rinse is complete, the retained material is removed from each screen by using forceps or by backwashing with a smaller size sieve. Transfer the contents from each screen to weighed labeled individual aluminum weighing pans and dry overnight at 103 ± 3 ° C. The dried sample is cooled in a desiccator. After cooling, the material is weighed and the percentage of disintegration based on the initial starting weight of the test material is calculated.

Slush  Box test

This method uses a bench scale device to evaluate its disintegration or dispersibility when a flushable consumer product moves through a wastewater collection system. In this test method, the clear plastic tank is filled with product and tap water or untreated wastewater. The vessel is then moved up and down the cam system at a specified rotational speed to simulate the movement of wastewater in the collection system. Record the first disintegration point and the point at which the product disperses into 1 inch by 1 inch (25 mm by 25 mm) pieces. This 1 inch by 1 inch (25 mm by 25 mm) size is a parameter that is used because it reduces the likelihood of product recognition. The test can be extended until the product is fully dispersed. The various components of the product are then screened and weighed to determine the rate and level of disintegration.

Test parameters:

The slush box water transport simulator consists of a transparent flask tank mounted on a vibrating platform with a speed and holding time regulator. The inclination angle produced by the cam system produces water movement equivalent to 60 cm / s (2 ft / s), which is the minimum design standard of wastewater flow rate in a closed catchment system. The oscillation speed is mechanically controlled by the rotation of the cam and level system and should be measured periodically throughout the test. This cycle mimics the normal back and forth movement of wastewater as it flows through sewer pipes.

Exam start:

Room temperature tap water (softened and / or not softened) or untreated wastewater (2000 mL) is placed in a plastic container / tank. Set the timer for 6 hours (or longer) and set the cycle speed to 26 rpm. The preweighed product is placed in a tank and observed as it passes through the stirring period. In the case of toilet tissue, several sheets having a weight in the range of 1 to 3 g are added. All other products can be added with only one item intact per test. At least 1 g of test product is recommended to ensure sufficient loss measurements. Record the time to initial disassembly and complete dispersion in the laboratory notebook. Note that for pre-moistened products, it is recommended to flush the toilet and drain it down the toilet and drain conduit or rinse it by some other means before placing it in the slush box device. Other pre-rinse techniques should be described in the study record.

Exam end:

The test is terminated when the product reaches a scattering point or a designated destructive sampling point that has no pieces larger than 1 inch by 1 inch (25 mm by 25 mm) square. At the designated destructive sampling point, the clear plastic tank is removed from the vibrating platform. Pour the entire contents of the plastic tank through the nested screen arranged in the following order from top to bottom: 25.40 mm, 12.70 mm, 6.35 mm, 3.18 mm, 1.59 mm (diameter opening). Make sure the perforated screen is installed with the smooth side up. With a showerhead spray nozzle maintained at about 10 to 15 cm (4 to 6 inches) above the sieve, the material is passed through the nested screen for 2 minutes, taking care not to force the retained material to pass through the next small screen. Rinse gently at a flow rate of 4 L / min (1 gal / min). The flow rate can be assessed by measuring the time it takes to fill a 4 L beaker. The average of the three flow rates should be 60 ± 2 seconds. This procedure is similar to that used in the INDA / EDANA Spray Impact Test Method (WSP 80.3). Rinse for 2 minutes, then remove the top screen and continue to rinse the next smaller screen that is still overlaid for an additional 2 minutes. Again, be careful not to force the retained material to pass through the next small screen. After the rinse is complete, the retained material is removed from each screen using forceps and / or commercial paintbrush. The contents from each screen are transferred to individual labeled aluminum weighing pans. The pan is left overnight in a drying oven at 103 ± 3 ° C. (or any other suitable temperature, depending on the thermal stability of the test substance). Continue this procedure at each designated sampling point until all test products have been sampled. The dried sample is left to cool in the desiccator. After all samples are dried, the weight of material from each retained fraction is weighed and the percent disintegration is calculated based on the initial starting weight of the test material.

Fiber length

 Fiber length can be tested by TAPPI test method T 271 om-02 entitled "Fiber Length of Pulp and Paper by Automated Optical Analyzer Using Polarized Light". have. This test method is an automated method capable of measuring the fiber length distribution of pulp and paper in the range of 0.1 to 7.2 mm using polarized optics. The fiber length is measured according to the test method and calculated as the length weighted average fiber length.

Formation  value

Formation values were determined using Paper PerFect Formation Analyzer Code LPA07 from OPTEST Equipment Inc. (Hockesbury Tipper Street 900, Ontario, Canada). Test Samples are tested using the procedure outlined in Section 10.0 of the Paper Perfect Code LPA07 Operating Manual (LPA07_PPF_Operation_Manual_004.wpd 2009-05-20). The formation analyzer provides calculated PPF formation values for 10 size ranges from C1 for 0.5 to 0.7 mm to C10 for 31 to 60 mm. Small size is important for print transparency and large size is important for strength properties. For purposes herein, the strength measurements of the basesheets are generated using C9 PPF values for formation size ranges from 18.5 to 31 mm. PPF values are based on a 1000 point scale, with 1000 being completely uniform. The reported C9 PPF value for each sample is based on the average of 10 tests for 5 samples (2 tests per sample).

Example

Example 1

Basesheets were prepared using a non-crimped, through-aired tissue making method in which the headbox deposited an aqueous suspension of papermaking fibers between the forming wires. A vacuum box was used to transfer the freshly formed web from the forming wire to the slower moving transfer fabric. The web was then transferred to the throughdrying fabric and passed over the tumble dryer to dry the web. After drying, the web was transferred from the throughdrying fabric to the reel fabric and then briefly inserted between the fabrics. The dried web was still on the fabric until it was wound on the parent roll.

To form the tissue, a headbox was used, through which 100% softwood fibers and broke were pumped into a single layer. Fibers were diluted in the headbox to 0.19 to 0.29% consistency to ensure uniform formation. As a result, a single layer sheet structure was formed on the twin-wire suction roll. The speed of the forming fabric was 3304 fpm. The freshly formed web was then dewatered to a consistency of about 20-27% using vacuum suction from below the forming fabric before transferring to a transfer fabric traveling at 2800 fpm (18% rush transfer). The web was transferred to a transfer fabric using a vacuum shoe pulling about 9 to 10 inches of mercury vacuum. The web was transferred to t1207-12 throughdrying fabric made by Voice Fabrics Inc. using a second vacuum shoe pulling about 5 to 6 inches of mercury vacuum. The web was conveyed onto a pair of honeycomb trough dryers operating at a temperature of about 400 to 430 ° F. to dry to a final dryness of about 97 to 99% consistency. The dried cellulose web was rolled up to the core to form a parent roll of tissue.

The binder composition was fabricated on both sides of the fiber material using a series of Unijet® nozzles, nozzle type 800050 manufactured by Spraying Systems Co., Wheaton, Ill., Operating at about 70 to 120 psi. Sprayed on. Each binder composition was sprayed with about 15% binder solids with water as a carrier. The partially formed wet one-ply wipe substrate was conveyed at a rate of 350 fpm through a dryer operating at 350 to 400 ° F. to partially dry the one-ply wipe substrate. The partially dried wipe substrate was then wound around the core and then unwound and passed once again through a 350-400 ° F. dryer at a rate of 300-650 fpm to increase the temperature of the wipe substrate to 250-350 ° F. The total dry weight percentage of binder addition was 5% relative to the dry mass of the single ply wipe substrate. The basesheet was machined into parts of a 5.5 inch wide by 56 inch long continuous web with holes every 7 inches, these parts were glued and folded in a fan shape and the wetting composition applied in an additional amount of 235% A stack folded in the shape of a fan of wet wipes was created. In the conversion method of Example A, the wetting composition was added to KLEENEX® COTTONELLE FRESH® Folded Wipe (Kimberly-Clark Corporation), with the addition of 2% by weight sodium chloride. Used in commercially available wet wipes under the trade name Nina, Wisconsin. In the conversion method of Example B, the wetting composition was obtained commercially under the trade name Kleenex® Cotton El Fresh® Folded Wipe (Kimberly-Clark Corporation, Nina, Wisconsin) with the addition of 2% by weight sodium chloride and 2% organopolysiloxane. Used for possible wet wipes.

Typical dispersible wipes were tested under shake flask tests, each sample tested at screen sizes of 12.70 mm, 6.35 mm, 3.18 mm and 1.59 mm, and the mass was measured after wipe and tensile strength test to determine the Kleenex® Cotton El Fresh® plug Compared with shovel moist wipes and Natural Choice® flush moist wipes. Exemplary results are shown in Table 1 below.

As can be seen from this result, the use of a basesheet made of cellulose fibers less than 3.18 mm in length not only has the strength necessary for the consumer to use, but also passes more easily through smaller sieves. Typical wipes have a mass loss percentage value of greater than 95% at 3.18 mm, whereas the comparative examples do not. Thus, using small fibers significantly improves the percentage of passage of shaker flask tests compared to existing wipes on the market. The results show a clear advantage in the flush processability.

Example 2

In Example 2 a wipe substrate was prepared as described in Example A. Example C was prepared as a basesheet prepared without conversion and subsequent addition of the wetting composition. For comparison purposes, the basesheet of the airlaid nonwoven web was continuously formed into a commercial scale airlaid machine similar to a pilot scale machine. As the fiber material, Weyerhaeuser CF405 bleached softwood kraft fiber in the form of pulp sheets was used. This airlaid fiber material is densified to the desired level by a heated press roll and transferred to the oven wire, where 96 mol% methyl acrylate and 4 mol% [2- (acryloyloxy) on the top side of the fiber material The substrate-binder composition was sprayed by spraying a 70:30 ratio of the binder composition of cationic polyacrylate and Airflex® EZ123, the polymerization product of ethyl] trimethyl ammonium chloride. Comparative Example C was prepared by applying about half of the desired binder solids to the dry fiber material. Airlaid foundation sheets are commonly used with Kleenex® Cotton El Fresh® flushable moist wipes.

Example C and Comparative Example C were tested to find the formation values as described above. Example C has a formation value of about 20.36 and Comparative Example C has a formation value of about 16.90. Example C may have a better formation and provide wipes that disperse in the sewer system while providing the required strength.

Example  3

Example 3 illustrates the effect of the amount of binder solids present in the binder composition used for the wipe substrate. Except for changing the percentage of solids in the binder, a base sheet was prepared as described above for Example A to prepare Examples D, Comparative D, and Comparative E. To illustrate the effect of the amount of binder solids present in the binder composition, Examples D, Comparative D, and Comparative E were tested for tensile strength in use and are shown in Table 2.

Example tissue % Solids in binder Tensile strength during use
(MD)
(g / linear inch) Tensile Strength in Use (CD)
(g / linear inch) GMT in use
(g / linear inch) D UCTAD   15 716.7 179.7 358.8 Comparative Example D UCTAD   18 432.4 115.8 223.8 Comparative Example E UCTAD   21 404.8 132.8 231.8

As can be seen by the results illustrated in Table 2, low solids spraying of the binder significantly improved in-use strength by creating a better coating of the binder on the sheet. It has been found that a binder composition solids percentage of less than about 18%, preferably less than about 16%, ensures that the spray coating is optimized with an acrylate based binder. Unexpectedly, the low solids spray of binder on UCTAD provided a beneficial strength benefit despite a fairly high point of attachment per fiber volume (36000 contacts / dL) that should theoretically not require droplet size optimization. In addition, those skilled in the art would prefer not to lower the percentage of solids in the binder because lower binder additions make it difficult to spray at lower solids because of dispersible binder nozzle tip requirements. Better coatings of the binder provide better GMT in use. As can be seen in Table 2, lower amounts of binder solids increased GMT in use to about 300 g / linear inch.

Example  4

In addition, the use of better binder application on the wipe substrate resulted in better strength formation. The wipe substrate was prepared as described for Example A to produce Example E. For comparison purposes, a wipe substrate was prepared as described for Example A, except for changing the binder application method, the amount of plies, binder addition amount, and binder solids percentage to prepare Comparative Example F, Comparative Example G, and Comparative Example H. It was. Comparative Example F is a two-ply tissue with printed binder. Comparative Example G is a single ply tissue with printed binder. Comparative Example H is a single ply tissue with a binder sprayed using only a single nozzle. To illustrate the effects of these changes, Examples D, Comparative Examples D and E were tested for tensile strength in use, tensile strength ratio, and post tensile strength, and are shown in Table 3.

Example tissue % Binder addition amount % Solids in binder in use
The tensile strength
(MD)
(g / linear inch) in use
The tensile strength
(CD)
(g / linear inch) Tensile strength ratio
(MD / CD) after use
The tensile strength
(MD)
(g / linear inch) E UCTAD 5 15 568 272 2.08 108.2 Comparative Example F UCTAD 10 22 397.5 156.2 2.54 344 Comparative Example G UCTAD 9 21 467 283 2.54 285 Comparative Example H UCTAD 5 20 567 247 2.30 315

As illustrated in Table 3, applying the binder composition to a wipe substrate by printing or with a single nozzle provides a poor distribution of the binder. Improving the distribution is critical for optimum strength generation and proper sheet handling. This is shown by the data above for MD / CD personnel. The low tensile strength ratio of less than 2.25 for Example E indicated that improvements in binder application, binder addition amount, and percent solids in the binder composition allowed the present invention to reduce the binder content and cure to be more dispersible. To illustrate.

In addition, as can be seen by the post-use strengths in Table 3, the appropriate substrate application, addition percentages and percent solids in the binder are sufficiently strong during use but rapidly deteriorate in water to provide a dispersible product. To provide. Example E provides a sheet having a MD tensile strength of more than 300 g / linear inch while passing at least 95% of its weight through a 3.18 mm sieve in a shake flask assignment. Comparative Examples F, G and H do not pass through the 3.18 mm sieve.

 Persons of ordinary skill in the art may make other changes and changes to the appended claims without departing from the spirit and scope shown in the appended claims. It is understood that the features of the various examples may be interchanged both in whole or in part. The above description given by way of example to enable those skilled in the art to practice the claimed invention should not be construed as limiting the scope of the invention as defined by the claims and all equivalents thereof.

Claims (12)

A wipe substrate comprising a tissue web consisting of cellulose fibers having a fiber length of 3 mm or less, and a binder composition for bonding the binder composition to the tissue web, and
Wetting composition containing 0.4 to 3.5% salt
And wherein the binder composition is present at an addition rate of about 1% to about 15% based on the total weight of the wipe substrate, and wherein the binder composition comprises less than about 18% binder composition solids. The dispersible moist wipe set forth in claim 1 wherein said binder composition is present at an addition rate of about 1 to about 8% based on the total weight of the wipe substrate. The dispersible moist wipe set forth in claim 1 wherein the binder composition comprises less than about 16 wt% binder composition solids. The dispersible moist wipe set forth in claim 1 wherein the fibrous substrate comprises an uncreped through aired tissue web. 2. The dispersible wet wipe of Claim 1 wherein the wet wipe has a mechanical tensile strength in use of greater than 300 g / linear inch. The dispersible moist wipe set forth in claim 1 wherein the wet wipe has a mechanical tensile strength after use of less than 200 g / linear inch. The dispersible moist wipe set forth in claim 1 wherein the wet wipe has a ratio of mechanical tensile strength to lateral tensile strength of less than 2.25. The dispersible moist wipe set forth in claim 1 wherein the wet wipe has a geometric mean tensile strength of at least 300 g / linear inch. The dispersible moist wipe set forth in claim 1 wherein the wipe substrate comprises one layer. 2. The dispersible moist wipe set forth in claim 1 wherein said wipe substrate has a formation value greater than 20. 2. The dispersible wet wipe of Claim 1 wherein said dispersible wet wipe has a pass through percentage value of at least about 70%. 2. The dispersible wet wipe of Claim 1 wherein said dispersible wet wipe has a pass through percentage value of at least about 95%.