MXPA97007370A - Biodegradable and disposable water clothes, drenables, prehumedeci - Google Patents

Abstract

The present invention relates to a biodegradable, dispersible and pre-moistened wet cloth comprising: a) a non-woven fiber fabric and a binder selected from the group consisting of polyvinyl alcohol, a polymer emulsion stabilized with an aqueous polyvinyl alcohol, a mixture of polyvinyl alcohol and an aqueous polymer emulsion, and a combination thereof, b) an aqueous lotion comprising: from about 0.1 to about 0.9 percent by weight of the boric acid lotion, from about 5 to about about 8 percent by weight of the lotion of an alkali metal bicarbonate, and an effective condom to inhibit the microbial activity in said lotion, and c) said wet cleaner has a pH of between 7 and about 9 and a wet strength of between about 8 and about 20 ounces / flea

Description

WET TROUSERS BIODEGRADAB ES AND DISPOSABLE, DRENABLES, PREHUMEDECIDOS FIELD OF THE INVENTION This invention relates to wet cloths for cleaning, pre-moistened, for personal care that can be used and discarded discreetly and safely by throwing them in the toilet bowl.

BACKGROUND OF THE INVENTION The pre-moistened skin cleansing tissues are well known commercially and are mentioned as wet cleansers or wipes, wipes, and the like. These tissues can be prepared from paper or paper products which are treated in a manner such as to improve their wet strength. Such tis are generally designed so that they are useful for use as a wash cloth and can be packaged in closed containers. Alternatively, the tissues can be packaged individually.

Wet cleaning tissues are usually treated with an aqueous alcohol solution in order to maintain moisture. The tissues may also comprise a surfactant detergent, a humectant, and a perfuming agent or fragrance.

Numerous wet cleaner type materials have been described. U.S. Patent No. 3,808,165 describes a process for preparing a wet cleaner in which boric acid is added to polyvinyl alcohol (PVOH) rather than adding boric acid to the lotion at a later time. The fabric is dried, the heat of drying breaks down the organic acids present which raise the pH to stabilize the binder. Sodium bicarbonate is not used to raise the pH.

U.S. Patent No. 3,881,210 discloses a sanitary napkin or cloth comprising a PVOH core layer, wherein the multilayer structure is joined together by means of an engraving roll with a planar area of from 4 to 25 hundred. However, no stabilizing ingredients, percentages or resistance criteria are specified.

U.S. Patent No. 4,309,469 discloses a cleaner which is bonded with a three part adhesive binder consisting of PVOH and a self-degradable thermosetting polymer and a non-self-degradable terpene polymer. The complexing agent is alpha hydroxy and O-aromatic hydroxy acids rather than boric acid and sodium bicarbonate.

U.S. Patent No. 4,343,133 discloses a wipe impregnated with polyvinyl acetate latex, which uses a high percentage of boric acid, at least 3 percent, which is too rough for many applications. This wipe also does not comprise sodium bicarbonates.

U.S. Patent No. 5,256,417 discloses a water dispersible wipe which is impregnated with non-aqueous lotion formulas. The non-aqueous lotion composition of the organic compound stabilizes the PVOH binder but does not dissolve the PVOH.

U.S. Patent No. 3,689,314 uses a different process for preparing drainable wrappers for absorbent pads. The PVOH binder and chemical additives are added together and dried. The heat causes the chemicals to react and make the binder strong enough in the condition of use. The environment of the absorbent pad is a very small area of exposure of low level of saturation of body fluids.

Exposure time is also limited to a few hours, rather than months. In addition, heating is required for cross-linking after borax is formed. In addition, less than 0.5 percent sodium bicarbonate was used.

A major concern of many of these existing tissues which use a drainable binder system containing boric acid is that boric acid in a high dose can cause irritation of the toxic skin, particularly in individuals with compromised skin. Therefore there is a need to provide a soft lotion system containing low concentrations of boric acid. In addition, all wet cleaners currently on the market have an acidic pH. The most common range is from a pH of 4.0 to 5.5. The pH of the skin is around 5.5 in adults and babies, which is the pH that most manufacturers try to achieve when it develops in pH-balanced products.

U.S. Patent No. 5,252,332 discloses pre-moistened drainable wipes impregnated with polyvinyl alcohol containing binders.

A binder based on PVOH is applied to the non-woven fabric, which is locionized with a lotion containing boric acid and sodium bicarbonate. The range of sodium bicarbonate is declared as being 0.2 to 3 percent. In addition, the wipe contains an undesirably high amount of boric acid. The ratio of borate to bicarbonate is from 4: 1 to 1: 4, and is preferably from 2: 1 to 1: 2. In addition, the wipe is susceptible to the growth of microorganisms, especially mold and is therefore not suitable for long-term storage. In contrast, the applicants invention provides a ratio of borate to bicarbonate of 1: 8.5 to 1:12 and provides a much higher moisture resistance.

The applicant's invention provides a number of features which are desirable but not found in the prior art. First, the invention of the applicants provides an unexpectedly superior moisture resistance that is not obtained in other formulas with similar needs. Second, a high percentage of sodium bicarbonate is provided which improves cleaning and deodorization, while providing an alkaline pH suitable for babies and infants. Finally, the applicant's invention is surprisingly compatible with the existing Baby Fresh ™ lotion system by synergistically making a gentle and effective cleanser which is also drainable, dispersible and biodegradable. The Applicant's invention provides for the first time a locionized wet cleaner having an alkaline pH, a high moisture resistance, low boric acid concentrations that provide softness, and a preservative system that provides long-term storage. In addition, the applicants invention surprisingly provides a wet cloth or cleaner having an alkaline pH while simultaneously being soft and gentle.

The present invention provides a wet cleaner or cloth for pre-wet cleaning, for personal care comprising a binder containing PVOH in contact with an aqueous solution containing bicarbonate and borate ions. The wipe exhibits a desirable wet tensile strength but rapid disintegration in water. This material is used as a biodegradable and dispersible and drainable damp cloth for babies, children, adolescents and adults, both male and female of all ages. The wet cloth of the applicant can be discreetly disposed of by depositing it in the toilet bowl safely. The product also fills the existing aerobic and anaerobic biodegradation in drainage and septic systems. The applicant's invention further comprises a soft binder and a lotion system which allows the wet cleaner to disperse into very small fibrous components under conditions of volume and velocity of the water in which the cloth is placed.

SYNTHESIS OF THE INVENTION The present invention relates to a biodegradable, dispersible and pre-moistened wet cloth comprising a non-woven fabric of fibers placed in contact with a binder containing PVOH. The binder can be either a polyvinyl alcohol, an aqueous polyvinyl alcohol stabilized with a polymer emulsion, a polyvinyl alcohol blend or an aqueous polymer emulsion or a combination thereof. The fabric contacted with binder further comprises an aqueous lotion solution comprising from about 0.1 to about 0.9 percent by weight of the boric acid lotion and from about 5 to about 8 percent by weight of the lotion. the lotion of an alkaline metal bicarbonate. The resulting wet cloth has a pH of between 7 and about 9 and a wet strength of between about 8 and about 20 ounces / inch.

The present invention relates to a biodegradable, pre-moistened and dispersible wet cloth comprising a non-woven fabric of fibers contacted with a binder containing PVOH. The binder can be either a polyvinyl alcohol, a polymer emulsion stabilized with polyvinyl alcohol, a mixture of a polyvinyl alcohol or an aqueous polymer emulsion or a combination thereof. The wet cloth also comprises an aqueous lotion solution comprising from about 0.3 to about 0.7 weight percent of the boric acid solution and from about 6 to about 7 weight percent of the sodium bicarbonate lotion. , and further comprising propylene glycol, cocoamphodiacetate, polysorbate 20, methyl paraben, propyl paraben, and Suttocide A. The resulting wet cloth has a pH of between 7 and about 9 and a moisture resistance of between about 12 and about 16 ounces / inch.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the cross-directional tensioned voltage (CDLT) values versus time over a month at room temperature for wet cleaners comprising lotion compositions 1-12 having various concentrations of boric acid / sodium bicarbonate. The lotion compositions are shown in Table 1.

Figure 2 shows the CDLT values against time over a week at 52 degrees centigrade for wet cloths comprising the lotion compositions 7-12 having various concentrations of boric acid / sodium bicarbonate. The lotion compositions are shown in Table 1.

Figure 3 shows the CDLT values against the time over a week at room temperature for the wet cleaners comprising the lotion compositions 13-20 having various concentrations of boric acid / sodium bicarbonate. The lotion compositions are as follows (% boric acid /% sodium bicarbonate): 13 = 0.99% / 5.5%; 14 0.99% / 6.5%; 15 = 0.66% / 5.5%; 16 = 0.66% / 6.5%; 17 = 0.33% / 5.5%; 18 = 0.33% / 6.5%; 19 = 0.11% / 5.5%; and 20 = 0.11% / 6.5%.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention relates to a nonwoven wet cloth product that is safe to use and also drained and dispersed and finally biodegrades in the appropriate environments. This material is used as a drainable, dispersible and biodegradable wet cloth for both male and female babies, children, adolescents and adults of all ages. The wet cloth of the invention has an alkaline pH but still retains the softness and gentleness allowing its healthy applications for infants.

As used herein, the term "wet cloth" refers to a non-woven fabric of fibers that can be used for cleaning purposes. The damp cloth can also be mentioned as a wipe.

As used herein, the term "dispersible" is intended to refer to the breaking of the wet cloth in water or other liquid solutions.

As used herein, the term "percent by weight" is meant to refer to the amount by weight of a compound in the lotion of the wet cloth as a percentage of the weight of the lotion.

In its basic form, the wet cloth of the invention consists of a non-woven fibrous material, bound with a PVOH system and locionized with a non-irritating formula containing very low levels of boric acid and a moderate level of sodium bicarbonate. The wet cloth is composed primarily of cellulose from wood pulp fibers with an aggregate amount of textile fibers to improve wet and dry strength. It is preferred that the wood pulp fibers comprise about 75 percent to about 95 percent and the textile fibers comprise from about 5 percent to about 25 percent of the wet cloth. It is more preferable that the wood pulp fibers comprise from about 85 percent to about 90 percent and the textile fibers comprise about 10 percent to about 15 percent of the wet cloth. Preferred textile fibers include rayon, cotton, wool, acetate or tencel fibers.

Those skilled in the art will readily have the knowledge necessary to produce a fabric of fibers capable of being used as a wet cloth. Those skilled in the art of non-woven materials will readily appreciate that a fiber fabric can be formed by carding, by wet laying, by spinning, as well as by melt blowing. In addition, these processes can be combined to achieve unique results. The structure placed by homogeneous air that is preferred offers the most desirable and economical version for this application.

The non-woven fabric of the wet cloth is preferably formed by an air-laying process, wherein all the fibers are intimately mixed rather than being layered, to achieve a high degree of homogeneity of mixture as well as a high specific volume. . The fabric placed by air is compressed and can be engraved with a pattern. The engraving can produce wet cloth products having a variety of words, paints, or the like, such as, for example, animals, doll forms and the like. The fabric placed by air is sprayed on both sides with a PVOH binder so that a low level of aggregate solids of about 2 percent to about 20 percent is applied. It is preferred that an aggregate of solids be applied of about 5 percent to about 10 percent. The binder is typically in a 30 percent solids solution, premixed and ready to be diluted to a 10 percent solution that can be applied to about 100 percent wet pickup, to obtain an aggregate binder of 10 percent.

The fabric is air dried and rolled into a roll. The fabric is cut, folded, pre-moistened with lotion, cut and stacked in a small bucket or bucket. Saturation of lotions from about 100 percent to about 350 percent saturation. It is more preferable that the lotion saturation be about 250 percent to about 350 percent saturation. The base weight of the fabric (dry weight) is around 70 grams / square meter. The wet thickness of the product is around 20 to about 25 mils (1 mil = 1/1000 of an inch). The existing wet cloth products include Kid Fresh and Sofkins.

The PVOH-containing binders of the present invention include PVOH, a polymer emulsion stabilized with aqueous PVOH, a mixture of a PVOH and an aqueous polymer emulsion or a combination thereof. The binder preferred is Air Products A-911 PVOH.

The lotion formula comprises water, a low level of boric acid, preferably from about 0.1 to about 0.9 percent by weight of the lotion, and a moderate level of an alkali metal bicarbonate, preferably from about 5 to about of 8 percent by weight of the lotion, making it a very soft lotion. The lotion more preferably comprises from about 0.3 to about 0.7 percent by weight of the boric acid lotion and from about 6 to about 7 percent by weight of the lotion of an alkali metal bicarbonate. The alkali metal bicarbonate is preferably sodium bicarbonate. Boric acid and sodium bicarbonate are mixed in the lotion solution, rather than in the binder mixture.

The lotion formula also comprises a preservative system. The current commercial preservative systems are designed for acidic wet cleaners. Therefore, an alkaline lotion formula comprising a preservative system provides several advantages including protection against microorganisms and long-term storage. It is preferred that the condom provide an antimicrobial activity including the antibacterial activity, the antifungal activity or the activity against the yeast, or a combination thereof. It is also preferred that the condom provide the wet cloth of the invention with the ability to be stored for as long as three years. Preferred condoms include formaldehyde and formaldehyde donors, glutaraldehyde, quaternium-15, urea imidazolidinyl and diazolidinyl, parabens, chloroxylenol, chlorothimol, triclosan, propamidine, isethionate, dibromopropamidine, hexaminidine, isethionate, zinc pyrithione, oxadine A, cathion, alkyltrimethylammonium bromide, benzalkonium chloride, bezetonium chloride, piroctone olamine, glyceral monolaurate, or a combination thereof. The condom generally comprises from about 0.01 to about 1.5 percent by weight of the lotion.

The lotion formula can also comprise wetting agents and / or emollients, surfactants and / or emulsifiers and fragrances. Preferred humectants and emollients include polyols, proteins, plant derivatives, and water soluble barrier forming materials such as, for example, lanolins, fatty acids, alcohols, and the like, or a combination thereof. Moisturizers and emollients generally comprise from about 0.1 to about 10.0 percent by weight of the lotion. Fragrances include those that are currently available on the market which are chemically compatible with the lotion formula. Fragrances generally comprise from about 0.01 to about 2.0 percent by weight of the lotion. A preferred lotion is Baby Fresh foundation lotion. It is preferred that the pH of the lotion system be between about 7 and about 9 for use with infants and infants.

For an individual to use the cleaning cloth without disintegrating it in his hand, the cleaning cloth of the invention must have a sufficient wet strength. The wet strength of the cleaning cloth can be evaluated by the well-known CDLT strength test described in Example 2. The wet strength of the wet cloth is preferably examined in a one-month, three-month and one-month aging test. An acceptable cleaning cloth has a wet resistance that has passed a test of aging at room temperature and 50 degrees Celsius. After aging at room temperature and at 50 degrees centigrade, the cleaning cloth preferably retains significant transverse direction moist resistances of 8 to 20 ounces / inch. More preferably, the wet cleaner retains wet resistances in the transverse direction from 12 to 16 ounces / inch. A typical wet cloth CDLT test is present in Example 3 given here.

Properly designed, the damp cloth is also drainable in normal household toilet systems. The wet cloth of the invention disintegrates rapidly with agitation in a large volume of water. To analyze the dispersibility, which is a measure of drainability, the break test is preferred. A dispersibility time of less than three minutes is preferred. It is more preferred that the dispersibility time be less than two minutes.

The wet wipes of the present invention are preferably biodegradable. Wet cloths will also be soft so that they can be used for human use without inducing allergic responses or other similar phenomena. Wet cloths preferably pass the repeated insult patch test (RIPT) and other toxicity tests. The wet cloths of the invention are not toxic to humans.

It is surprising to find a total lotion system that fills the balanced requirements of softness and strength while retaining the ability to be dispersible. The present invention provides an alkaline wet cloth comprising a gentle lotion system containing low concentrations of boric acid and relatively high levels of sodium bicarbonate, while maintaining strength and dispersibility. This combination of properties is highly desirable.

E J E M P L O S EXAMPLE 1: Piece Break Test The piece break test can be used to determine the time required to break a single wet cloth product. Generally, a stir bar is placed in a beaker that is filled to a depth of six inches with water or a buffer of an appropriate pH. The beaker is placed on a magnetic stirrer and adjusted to the speed as desired. The solution is adjusted to the desired test temperature. The wet cloth sample to be tested is wrapped around a steel rod that is preferably 8 inches long, and an eighth of an inch in diameter, with a hooked end (folded for about a quarter of an inch at an angle of 110 degrees). The sample preferably does not extend beyond the bent end of the rod. The solution is stirred at a constant speed and the rod is placed on a handle attached to a ring support. The rod is located above the pointed vessel at a point midway between the center and the eyebrow tip of the vessel. The sample is gently lowered into the solution until the sample is completely submerged. The time is measured until the first sample of any size is broken from the wet cloth and until the sample is released from the steel rod.

EXAMPLE 2: CDLT test The wet strength of the wet cleaners of varying concentrations of boric acid and sodium bicarbonate was examined by CDLT at room temperature and the results are presented in Table 1. The CDLT of a wet sample cloth was preferably tested on an appropriate apparatus such as the Thwing-Albert Intelect II STD device according to the instructions set by the manufacturer. The test procedures for determining the dry tensile strength of a wet cloth sample are well known to those skilled in the art and are briefly stated herein. Five strips of samples were placed on the upper handle of the tensile strength apparatus. The handles are closed and one of the strips hangs from the upper handle and separates and the free end is placed in the bottom bracket.

A very light tension is applied to remove the loose and the bottom clamp is applied. The test is then started according to the instructions set by the manufacturer. After the test strip is broken, the test sequence is repeated with respect to the four remaining sample strips. For the tensile strength, five sample strips were tested. The two ends of the sample strip were placed together to form a curl in the center. The bent curl portion of the sample was placed inside the weighted beaker of either distilled water to test the wet wipes without lotion or inside a weeping beaker containing the lotion to test wet wipes with lotion. The curl of the wet center of the sample was gently touched with a towel to remove excess water or excess lotion and the sample was then inserted into the handles of the apparatus. The sequence of resistance to dry stress is then carried out. As can be seen in Table 1, a satisfactory CDLT with very low levels of boric acid concentrations can be achieved. Figures 1 and 2 show the CDLT values for solutions 1-12 over one month at room temperature (21 degrees Celsius) and 52 degrees Celsius, respectively. In addition, the variation of boric acid with bicarbonate is shown in Figure 3. In addition, Table 2 represents wet strength values for wet cloths having several lotion compositions after one week at room temperature. As can be seen, significant resistance can be achieved with wet cloths having boric acid lotion concentrations as low as 0.33 percent when sodium bicarbonate concentrations are high.

TABLE CDLT TO SEVERAL AWAY CONCENTRATIONS (OUNCE / INCH) W = H20; = Baby Fresh Lotion T A B L A CDLT A 7 DAYS AT AMBIENT TEMPERATURE (OUNCE / INCH) B I C A R B O N D O C D I C O% EXAMPLE 3: Lotion Compositions for Wet Wipes The following lotion solutions are preferred. 0. 5% Solution Water 91.22% Propylene Glycol 1.50% Cocoamfodiacetate 0.25% Polysorbate 20 0.20% Methyl Paraben 0.20% Propyl Paraben 0.03% Sodium Bicarbonate 6.00% Boric Acid 0.50% Suttocide 0.1% 0.6% Solution Water 91.12% Propylene Glycol 1.50% Cocoamfodiacetate 0.25% Polysorbate 20 0.20% Methyl Paraben 0.20% Propyl Paraben 0.03% Sodium Bicarbonate 6.00% Boric Acid 0.60% Suttocide 0.1% 0. 7% Solution Water 91.02% Propylene Glycol 1.50% Cocoamfodiacetate 0.25% Polysorbate 20 0.20% Methyl Paraben 0.20% Propyl Paraben 0.03% Sodium Bicarbonate 6.00% Boric acid 0.70% Suttocide 0.1%

Claims (10)

R E I V I N D I C A C I O N S

1. A biodegradable, dispersible and pre-wetted damp cloth comprising: a) a nonwoven fiber fabric and a binder selected from the group consisting of polyvinyl alcohol, a polymer emulsion stabilized with an aqueous polyvinyl alcohol, a mixture of polyvinyl alcohol and an aqueous polymer emulsion, and a combination thereof; b) an aqueous lotion comprising: from about 0.1 to about 0.9 percent by weight of the boric acid lotion; from about 5 to about 8 percent by weight of the lotion of an alkali metal bicarbonate; and an effective condom to inhibit the microbial activity in said lotion; Y c) said wet cleaner has a pH of between 7 and around 9 and a wet resistance from around 8 and about 20 ounces / inch.

2. The wet cloth as claimed in clause 1 characterized in that the amount of the aqueous lotion solution varies from 100 to 350 percent by weight of the fabric.

3. The wet cloth as claimed in clause 1 characterized in that the boric acid is from about 0.3 to about 0.7 percent by weight of the lotion.

4. The wet cloth as claimed in clause 1 characterized in that the alkali metal bicarbonate is from about 6 to about 7 weight percent of the lotion.

5. The wet cloth as claimed in clause 1 characterized in that the boric acid is from about 0.3 to about 0.7 percent by weight of the lotion and the alkali metal bicarbonate is from about 6 to about 7. percent by weight of the solution.

6. The wet cloth as claimed in clause 5 characterized in that the wet cloth has a wet strength of between about 12 and about 16 ounces / inch.

7. The wet cloth as claimed in clause 1 characterized in that the alkali metal bicarbonate is sodium bicarbonate.

8. The wet cloth as claimed in clause 1 characterized in that the aqueous lotion solution further comprises a humectant and a surfactant.

9. The wet cloth as claimed in clause 8 characterized in that the aqueous solution also comprises a fragrance.

10. A biodegradable, dispersible, prewet damp cloth comprising: a) a nonwoven fiber fabric and a binder selected from the group consisting of a polyvinyl alcohol, a polymer emulsion stabilized with an aqueous polyvinyl alcohol, a mixture of polyvinyl alcohol and an aqueous polymer emulsion and a combination thereof. b) an aqueous lotion comprising: from about 0.3 to about 0.7 percent by weight of the boric acid lotion; from about 6 to about 7 percent by weight of the sodium bicarbonate lotion; c) said lotion further comprises: propylene glycol, cocoamodiadetate, polysorbate 20, methyl paraben, propyl paraben, and Suttocide A, which is effective to inhibit microbial activity in said lotion; Y d) said wet cloth has a pH of between 7 and about 9 and a wet strength of between about 8 and about 20 ounces / inch. SUMMARY The present invention provides a pre-moistened, dispersible and biodegradable wet cloth comprising a non-woven fiber fabric contacted with a binder having PVOH. The fabric contacted with binder comprises an aqueous lotion solution comprising from about 0.1 to about 0.9 percent by weight of the boric acid lotion and from about 5 to about 8 percent by weight of the lotion. the lotion of an alkaline metal bicarbonate. The resulting wet cloth has a pH of between 7 and about 9 and a moisture resistance of between about 8 and about 20 ounces / inch.