DE102010009134B3 - Fibrous sheet, useful as hygiene article, preferably as wet cloth or wet toilet paper, comprises a disintegration agent having pH-dependent swelling properties, comprising a swellable core provided with a coating, and/or a swelling agent - Google Patents

Abstract

Fibrous sheet comprises at least one disintegration agent having pH-value-dependent swelling properties, where the disintegration agent comprises a swellable core provided with at least one coating having a pH-value-dependent solubility and/or at least one swelling agent having pH-value-dependent swelling properties. An independent claim is included for producing a fibrous sheet, comprising (a) providing fibers, depositing the fibers on a receiving surface to obtain a fiber bed, (c) compacting the fiber bed to obtain a compressed fiber bed, where in steps (a), (b), (c) and/or between the steps (a)-(c) and/or after step (c), the disintegration agent is placed in the compressed fiber bed.

Description

• a.) einen quellfähigen Kern mit wenigstens einer eine pH-Wert-abhängige Löslichkeit aufweisenden Beschichtung umfasst und/oder
• b.) wenigstens ein Quellmittel mit pH-Wert-abhängiger Quellfähigkeit umfasst, sowie weiterhin ein Verfahren zur Herstellung des faserhaltigen Flächengebildes und seine Verwendung.

The present invention relates to a fibrous sheet in which at least one disintegrating agent with pH-dependent swelling capability is arranged, wherein the disintegrating agent

• a.) comprises a swellable core having at least one coating having a pH-dependent solubility and / or
• b.) comprises at least one swelling agent with pH-dependent swelling capacity, as well as a method for producing the fibrous sheet and its use.

Pre-moistened toilet tissue or skin wipes, short wet wipes, have long been known in the art and may be made from paper or paper products that have been treated to improve their wet strength. Therefore, after being introduced into water, for example, in the toilet, these products have a longer shelf life compared to dry comparative products which have not been increased in their wet strength. Due to the high wet strength wet wipes disintegrate after introduction into water in general only after a long time, so that they can contribute to the formation of pipe blockages and must be separated in the sewage treatment plant before the actual cleaning of the water.

Numerous approaches are known from the prior art to increase the disintegration ability of pre-moistened fiber wipers after introduction into water.

The U.S. Patent 5,629,081A describes a disintegratable wet wipe prewetted with a solution of 0.1-0.9 wt.% boric acid and 5-8 wt.% of an alkali metal bicarbonate, in which the fibers are bonded by a binder containing polyvinyl alcohol. Disadvantageously, the production of this product is very expensive.

From the U.S. Patent 5,384,189A is a water-breakable web is known in which the fibers are bound by a water-soluble binder based on unsaturated carboxylic acids and carboxylic acid esters. Some of the carboxylic acid contained in the binder is present as a salt, so that the binder is soluble in tap water, but not in an aqueous, at least 0.5 wt .-% solution of a neutral, monovalent inorganic salt. This process is complicated in the production.

The US Patent 4,755,421 A discloses a nonwoven fabric generated by waterjet needling of cellulosic fibers and regenerated cellulosic fibers which is to be broken up in the effluent by stirring or prolonged residence time. However, the nonwoven fabric has a low mechanical durability.

Another method for producing a water-breakable cloth is in US Patent 5,667,635 A described in which three layers of tissue paper are embossed together only at the corners and the two outer layers to control by additional local application of a wet agent, the disintegration of the cloth in an aqueous system. Disadvantageously, the production of this product is very expensive.

The DE 28 17 604 C2 discloses a premoistened wipe having high initial wet strength and lower wet strength upon immersion in a substantially neutral or alkaline liquid.

On the one hand, the known water-dissipative wet wipes have the disadvantage that they contain partially aggressive, food-problematic or even allergenic and inflammatory substances in order to achieve sufficient mechanical wet strength. On the other hand, however, the wet strength is sometimes so greatly reduced that, disadvantageously, the integrity of the wet wipe is already destroyed by low mechanical action, which may occur, for example, during use.

The object of the present invention is therefore to provide a fiber-containing fabric which, on the one hand, has sufficient mechanical wet strength in use and, on the other hand, should have sufficient water-decomposition capability after introduction into water, so that it does not block the toilet pipe or in the water Wastewater treatment plant must be removed before the actual purification of the wastewater.

Another object of the present invention is to provide a water-breakable fiber structure which is easy and inexpensive to manufacture.

• a.) einen quellfähigen Kern mit wenigstens einer eine pH-Wert-abhängige Löslichkeit aufweisenden Beschichtung umfasst und/oder
• b.) wenigstens ein Quellmittel mit pH-Wert-abhängiger Quellfähigkeit umfasst.

The object is achieved by the provision of a fibrous sheet in which at least one disintegrating agent with pH-dependent swelling capability is arranged, wherein the disintegrating agent

• a.) comprises a swellable core having at least one coating having a pH-dependent solubility and / or
• b.) comprises at least one swelling agent with pH-dependent swelling capacity.

• (a) Bereitstellen von Fasern,
• (b) Ablegen der Fasern auf einer Aufnahmefläche unter Erhalt eines Faserbetts,
• (c) Verdichten des Faserbetts, unter Erhalt eines verdichteten Faserbettes,

wobei in den Schritten (a), (b) und/oder (c) und/oder zwischen den Schritten (a), (b) und/oder (c) und/oder nach Schritt (c) wenigstens ein Desintegrationsmittel mit pH-Wert-abhängiger Quellfähigkeit in das verdichtete Faserbett eingebracht wird, wobei das Desintegrationsmittel a.) einen quellfähigen Kern mit wenigstens einer eine pH-Wert-abhängige Löslichkeit aufweisenden Beschichtung versehen ist und/oder b.) wenigstens ein Quellmittel mit pH-Wert-abhängiger Quellfähigkeit umfasst.Furthermore, the object is achieved by the provision of a method for producing a fibrous sheet, the method comprising the following steps:

• (a) providing fibers,
• (b) depositing the fibers on a receiving surface to obtain a fibrous bed,
• (c) compacting the fiber bed to obtain a compacted fiber bed,

wherein in steps (a), (b) and / or (c) and / or between steps (a), (b) and / or (c) and / or after step (c) at least one disintegrating agent with pH Value-dependent swelling capacity is introduced into the compacted fiber bed, the disintegrating agent a.) Providing a swellable core with at least one pH-dependent solubility coating and / or b.) At least one swelling agent with pH-dependent swelling capacity includes.

Furthermore, the object is achieved by the use of a fibrous sheet as a hygiene article, in particular as a wet wipe or moist toilet paper.

Preferred embodiments of the invention are specified in the subclaims.

Surprisingly, the inventors have found that by placing at least one disintegrant having pH dependent swellability in the fibrous web, it is possible to provide a fibrous web having, on the one hand, short term mechanical stress such as skin friction has sufficient mechanical wet strength and does not lose its integrity. On the other hand, the fibrous sheet according to the invention after introduction into water has sufficient Wasserzerfallfähigkeit, so that it can not lead to blockages after disposal via the toilet or must be removed in the sewage treatment plant before the actual purification of the wastewater. In addition, the fibrous sheet according to the invention has a sufficient dimensional stability even after prolonged storage.

• a.) einen quellfähigen Kern mit wenigstens einer eine pH-Wert-abhängige Löslichkeit aufweisenden Beschichtung und/oder
• b.) wenigstens ein Quellmittel mit pH-Wert-abhängiger Quellfähigkeit.

According to the invention, this comprises at least one disintegrating agent with pH-dependent swelling capacity

• a.) a swellable core having at least one pH-dependent solubility coating and / or
• b.) at least one swelling agent with pH-dependent swelling capacity.

Preferably, the at least one disintegrating agent with pH-dependent swelling capacity comprises or is a swellable core having at least one coating having a pH-dependent solubility.

After incorporation of the fibrous sheet in water having a pH at which the swellability of the disintegrant changes, swelling of the disintegrant which can weaken or destroy the structural integrity of the fibrous sheet by taking up water occurs.

In this case, the solubility behavior of the surrounding the swellable core coating and / or the degree of ionization of the swelling agent with pH-dependent swelling capacity may change, in case a.) The coating is dissolved or dissolved and the swellable core can absorb water below.

In the case b.), For example, by an increased electrostatic repulsion between groups of equal charge within the swelling agent subsequent swelling can be effected by absorbing water.

Ingestion of water in both cases a.) And b.) Leads to a swelling of the swellable core or the swelling agent with pH-dependent swelling capacity, wherein a Volume enlargement of the swellable core or the swelling agent occurs. By increasing the volume of the swellable core or the swelling agent, fiber structures and / or fiber connections can be widened, loosened, weakened, stretched and / or destroyed within the fibrous sheet structure. Due to mechanical influences, for example due to the flow influences occurring in wastewater, the structural integrity of the fibrous sheet can be weakened, preferably destroyed.

According to EC Directive 83/98 (CELEX No: 39810083) "On the quality of water intended for human consumption" (98/83 / EC) drinking water should have a pH in the range of 6.5 to 9.5 exhibit. For example, the pH of the wastewater used in biological wastewater treatment should be in the range of 6.0 to 8.0 so as not to hinder the purification process.

According to the invention, the coating, preferably coating, of the at least one swellable core has a pH-dependent solubility.

• (a) eine Zunahme der Löslichkeit in Wasser erfährt/erfahren; und/oder
• (b) eine Abnahme der Diffusionsdichte erfährt/erfahren; und/oder
• (c) eine Beschleunigung der Lösungskinetik erfährt/erfahren; und/oder
• (d) eine Abnahme der mechanischen Stabilität erfährt/erfahren.

The pH-dependent solubility of the coating of the swellable core leads, for example, to the fact that the coating or the materials forming the coating, when there is a change in the pH in the surrounding liquid to which the coating is exposed,

• (a) experiences an increase in solubility in water; and or
• (b) experiences a decrease in diffusion density; and or
• (c) experiences an acceleration of the solution kinetics; and or
• (d) experiences a decrease in mechanical stability.

In a preferred embodiment, the pH-dependent solubility coating completely envelopes or envelops the swellable core.

In a further preferred embodiment, the coating surrounds the swellable core not completely coherently but only partially.

The coating can be designed such that the at least one swellable core is directly coated. In such a case, the coating forms a shell surrounding the swellable core, wherein the swellable core and / or the coating can be present in all conceivable geometric shapes.

The at least one swelling agent with pH-dependent swelling capacity can also be present in all conceivable geometric forms.

Preferably, the swellable core or the at least one swelling agent with pH-dependent swelling capacity is in the form of a dimensionally stable shaped body in particulate form and / or as a fiber. The diameter of the particles and / or fibers or their size is subject to no particular restriction. Preferably, the swellable core or the at least one swelling agent with pH-dependent swelling capacity is in spherical, usually not exactly spherical, form.

Preferably, the swellable core and / or the swelling agent with pH-dependent swelling capacity has a particle diameter which is greater than 100 nm, but preferably 1.0 mm, advantageously does not exceed 0.75 mm, in particular the particle diameter is between 0, 01 mm and 1.0 mm, more preferably between 0.1 mm and 0.3 mm.

Preferably, the dimensions of the swellable core and / or the swelling agent with pH-dependent swellability are adapted to the desired thickness of the fibrous sheet. Preferably, the fibrous sheet has a thickness of from 0.1 to 2.0 mm, preferably from 0.2 mm to 1.4 mm, more preferably from 0.25 to 0.8 mm.

The term "dimensionally stable shaped article" is understood to mean shaped articles which, under normal conditions of manufacture, storage, transport and handling by the consumer, have a space shape which is stable in relation to breakage and / or pressure.

In the context of the invention, materials which are cohesive as a function of the pH can serve as the coating material. By changing the pH, it is preferable to lose cohesion due to mechanical stress, diffusion processes and / or chemical processes.

A "loss of cohesion" is understood in the context of the invention that the material of the coating either partially, so for example, to form cracks and / or holes and / or net-like structures optionally defined arrangement and / or size of the cracks and / or Holes and / or pores, and / or physically (eg, by melting, dissolving or dissolving) and / or chemically (eg, by chemical reaction). This preferably makes it possible to contact the aqueous environment with the previously coated, preferably coated, swellable core.

For example, the coating material forming the coating, preferably sheath, partially or completely dissolves as the pH increases above a critical point. This can happen, for example, when the fibrous sheet is thrown into the toilet. Upon contact with water, the at least one coating then partially or completely loses its cohesion and becomes penetrable for water. The pH in question at which the coating partially or completely dissolves may be adjusted so that, for example, the coating partially or completely loses its integrity as the pH increases above 5.5, for example, but remains substantially inert, as long as the pH is below 5.5.

In a preferred embodiment, the coating has a pH-dependent solubility in a range of from 4.0 to 8.0, preferably from 4.1 to 7.8, more preferably from 4.2 to 7.6, more preferably from 4, From 3 to 7.5, more preferably from 4.5 to 7.4, more preferably from 4.7 to 7.2, even more preferably from 4.9 to 7.1, more preferably from 5.0 to 7.0, more preferably from 5.3 to 6.9, more preferably from 5.5 to 6.8.

The term "inert" is understood according to the invention in the usual sense, ie in such a way that a physical or chemical reaction of the material of the coating with the swellable core contained therein, on the one hand and the liquid, preferably aqueous environment does not occur, but the material of Coating is physically and chemically resistant to the aqueous environment, so that the swellable core is substantially protected from contact with the liquid, preferably aqueous, environment.

Sufficient protection is provided when the swelling effect of the swellable core is substantially suppressed, or when the swelling effect of the swellable core is slowed down, preferably greatly slowed, as compared to an unjackled core.

The term "swelling" is understood according to the invention in the usual sense, ie as a physical uptake of liquid, preferably water, in a solid body, which is associated with an increase in volume of the solid.

For the purposes of the invention, the term "swelling capacity" is understood as meaning the liquid absorption capacity, preferably water absorption capacity, of the solid. The swelling capacity can be determined, for example, by determining the swelling number. Preferably, the swelling number indicates the volume in milliliters, which occupies 1 g of the solid after swelling in a liquid, preferably water, after a certain time, preferably 4 h.

Suitable methods for determining the swelling number are known in the art. Preferably, the swelling number is determined on the basis of the European Pharmacopoeia (Ph. Eur. 6, General Methods, 2.8.4) using demineralized water instead of the water-ethanol mixture.

In a preferred embodiment, the swellable core has a swelling number determined on the basis of Ph. Eur. 6 of at least 4, preferably at least 6, more preferably at least 9.

Alternatively, the swellability can be determined by determining the swelling ratio QZ. The solid is dried to constant mass (m ₀ ). Subsequently, the solid body for a certain time in a liquid, preferably water, in a decay tester, for example ZT3, Erweka Apparatebau GmbH (Offenbach, Germany) moves. Subsequently, the adhering water is removed and the solid for 15 min. stored over silica gel. The mass of the solid m ₁ is determined by means of an analytical balance and the swelling ratio QZ in% determined according to equation (i). QZ = [(m ₁ -m ₀ ) / m ₀ )] × 100 (i)

In a preferred embodiment, the swellable core at room temperature has a swelling ratio QZ of at least 10, preferably at least 20, more preferably at least 50.

Only after introduction of the fibrous sheet in wastewater, the coating loses all or part of its integrity and to such an extent that the coating provides the swellable core substantially no protection or sufficient protection against contact with water more. Preferably, it is sufficient if the coating has holes and / or cracks, so that a corresponding contacting of the swellable core with water is well possible.

Thereby, the coating may protect the swellable core disposed in the fibrous web of the present invention, depending on the pH, prior to ingestion of a liquid, preferably water.

In a preferred embodiment, the coating is designed such that it is in water, preferably at room temperature, at a pH of less than 6.5, preferably less than 6.2, preferably less than 6.0, in particular smaller as 5.5, is substantially inert.

In a further preferred embodiment, the at least one coating is designed so that these in water, preferably at a temperature of 25 ° C, at pH values above at least 5.5, preferably above at least 5.6, preferably above at least 5.8, more preferably above at least 6.0, more preferably above at least 6.5, their cohesion partially or completely loses.

In a further preferred embodiment, the coating may consist of several layers. Of course, the coating can also consist of only one layer. For example, these layers can lie directly on top of each other. For example, the coating enveloping the swellable core may consist of 2 or more layers. In a further preferred embodiment, the coating of the at least one swelling agent has 2, 3 or 4 layers.

Materials which can be used as coating material in the context of the invention are any inorganic and / or organic substances and / or mixtures, but in particular polymers, preferably homopolymers and / or copolymers, and / or polymeric composites having a pH-dependent solubility exhibit.

In a preferred embodiment, polymers, preferably homopolymers and / or copolymers which have film-forming properties and can preferably be used from aqueous dispersion, can be used as the coating material.

For example, for reasons of flammability and / or toxicity, organic solvents are disadvantageous in the preparation of coatings having a pH-dependent solubility. Aqueous dispersions are characterized, for example, by easy handling and the substantial avoidance of toxicologically problematic substances.

In a preferred embodiment, the coating comprises at least one plasticizer. Suitable plasticizers are generally all substances which reduce the glass transition temperature of the coating materials used, preferably homopolymers and / or copolymers, with a pH-dependent solubility. Preferably, the coating material can be applied at lower temperatures, possibly even at room temperature.

In a further preferred embodiment, the at least one plasticizer is citric acid ester (preferably tributyl citrate and / or triethyl citrate), phthalic acid ester (preferably dimethyl phthalate, diethyl phthalate and / or dibutyl phthalate), esters of organic polyalcohols (preferably glycerol triacetate), polyalcohols (preferably glycerol, propylene glycol ) and / or polyoxyethylene glycols (preferably polyethylene glycol). The plasticizer intervenes between the polymer chains, thereby increasing the mobility, reducing the interactions and avoiding abrasion and cracks in the film by reducing the brittleness. It is particularly advantageous if the coating material contains a polyacrylate and / or a derivative thereof and / or a corresponding copolymer based on acrylic esters and / or acrylic acids and other monomers. In particular, copolymers of acrylamide and acrylic acid and / or derivatives thereof are of advantage for the coating material of pH-dependent solubility used in the invention.

The principle of pH-dependent solubility is generally based on a protonation or deprotonation of functional groups of the polymer molecules, whereby their charge state accordingly changes. Preferably, the polymer has a stable charged state at a certain pH and is soluble in water. In contrast, the polymer precipitates in the uncharged state at a different pH.

In the context of the present invention, it is preferred that the coating material used according to the invention, preferably homopolymer and / or copolymer, at a lower pH, a lower water solubility than at higher pH values or even at a lower pH are water insoluble.

In a further preferred embodiment, the coating material used according to the invention is in water, preferably at a temperature of 25 ° C., at a pH above at least 5.5, preferably above at least 5.6, preferably above at least 5.8, more preferably above at least 6.0, more preferably above at least 6.5, partially or completely soluble.

In a further preferred embodiment, the coating material used according to the invention in water, preferably at a temperature of 25 ° C, at a pH below 6.5, preferably below 6.0, more preferably below 5.8, more preferred below 5.5, partially or completely insoluble.

Polymers with pH dependent solubility are known in the pharmaceutical arts. Here are z. B. acid-insoluble polymers used to give tablets an enteric coating, but soluble in the intestinal juice coating. Such acid-insoluble polymers are usually based on derivatives of polyacrylic acid, which is present in undissoziierter and thus insoluble form in the acidic region, but is neutralized in the alkaline range, for example at a pH of 8.0 and goes into solution as a polyanion.

Polymers of similar type, which have a pH-dependent solubility, are advantageous for the design of the coating. Preferably, this at least one layer is substantially inert in the acid, but partially or completely dissolves in the neutral to alkaline.

According to a preferred embodiment, the coating is such that it consists at least partially of polyacrylic acid and / or derivatives of polyacrylic acid which, at pH values above at least 5.5, preferably above at least 5.6, preferably above at least 5, 8, more preferably above at least 6.0, more preferably above at least 6.5, even more preferably above at least 7.0, even more preferably above at least 7.5, even more preferably above at least 8.0, is present as the polyanion and / or goes into solution.

Within the scope of the present invention, preferred substances are acidic, preferably film-forming polymers, preferably homopolymers and / or copolymers which contain carboxylic acid and / or sulfonic acid and / or sulfonamide and / or ester groups, more preferably carboxylic acid and / or sulfonic acid and / or or sulfonamide groups, more preferably carboxylic acid groups.

As monomers, for example, conventional acrylates, methacrylates, maleinates or derivatives of these compounds can be used. Suitable polymers are, for example, carboxyalkyl methacrylate copolymers, acrylic acid and / or methacrylic homo- and copolymers, polyvinyl acetate phthalates (PVAP), cellulose acetate phthalates (CAP), cellulose acetate trimellitates (CAT), cellulose acetate acetoacetates, hydroxypropylmethylcellulose phthalates (HPMCP ), Hydroxypropyl methylcellulose acetyl succinates (HPMCAS), shellac and mixtures thereof.

In a preferred embodiment, the coating comprises carboxyalkyl methacrylate copolymers, preferably methyl methacrylate and / or ethyl acrylate and / or methyl acrylate-methacrylic acid copolymers.

Particularly suitable carboxyalkyl methacrylate copolymers are sold by Evonik Industries AG (Essen, Germany) marketed and bear the trade name Eudragit ^®, for example, methacrylic acid-ethyl acrylate copolymers of the trade name Eudragit ^® L30 D-55 or 100-55 or methacrylic acid methyl methacrylate (50:50) copolymers of the trade name Eudragit ^® L100 or L12,5, or methacrylic acid-methyl methacrylate (30:70) copolymers of the trade name Eudragit ^® S100 or S12,5, or methacrylic acid-methyl acrylate-methyl methacrylate copolymers of trade name Eudragit ^® FS 30 D.

Other suitable carboxyalkyl methacrylate copolymers are, for example, by the company Colorcon (West Point, PA, USA) under the trade name Opadry ^® Enteric-94 series Methacrylic Acid Copolymer (methacrylic acid-methyl methacrylate (1: 1) copolymer) or Opadry ^® Enteric-95 series Methacrylic Acid Copolymer (methacrylic acid-methyl methacrylate (1: 2) copolymer).

Suitable polyvinyl acetate phthalates are sold for example by the company Colorcon under the tradename Sureteric ^®. For example, the FMC sells biopolymer (Philadelphia, PA, USA) suitable cellulose acetate phthalate under the trade name Aquacoat ^®. The company Eastman Chemical BV (Rotterdam, Netherlands) sells suitable cellulose acetate phthalate under the trade name Eastman CAP ^® or Aquateric ^®. Shin-Etsu Chemical Co., Ltd. (Tokyo, Japan) sells for example suitable hydroxypropyl methylcellulose phthalates under the name hypromellose phthalate HP-55 and HP-55S and appropriate Hydroxypropylmethylcelluloseacetyl-Succinate under the brand name AQOAT ^®. Suitable shellac is sold for example by Emerson Resources, Inc. (Norristown, PA, USA) under the trade name MarCoat ^®.

Other suitable polymers are marketed under the brand name Carbopol ^® from Lubrizol (Wickliffe, OH, United States). Preferably, these are Carbopol ^® 71 G, carbopol ^® 971P NF, Carbopol ^® 974 P NF, Carbopol ^® 934 P NF1, Carbopol ^® 5984 EP or Carbopol ^® 980 NF, where they are homopolymers of acrylic acid with Allyl succrose or allyl pentaerythritol are crosslinked.

The pH at which a polymer dissolves in water can be found by those skilled in the relevant product literature. For example, the polymers mentioned below dissolve at the indicated pH values: polymer PH value Eudragit ^® L30 D-55 or 100-55 ≥ 5.5 AQOAT ^® AS-LF ≥ 5.5 Cellulose acetate Trimellitate (CAT) ≥ 5.5 Hydroxypropylmethylcellulose acetyl succinate LF grade > 5.5 Eudragit ^® L100 or L12,5 ≥ 6.0 AQOAT ^® AS-MF ≥ 6.0 Hydroxypropylmethylcellulose acetyl succinate MF grade ≥ 6.0 Opadry ^® Enteric-94 series > 6.0 Eastman ^CAP® NF > 6.2 AQOAT ^® AS-HF ≥ 6.5 Hydroxypropylmethylcellulose acetyl succinate HF grade ≥ 6.8 Opadry ^® Enteric-95 series > 7.0 Eudragit ^® S100 or S12,5 ≥ 7.0 Eudragit ^® FS 30 D ≥ 7.0 MarCoat ^® 125 or 125N ≥ 7.0

Also, a coating at least partially of an ampholytic polymer, preferably a copolymer of basic monomers such as dialkylaminoalkyl (meth) acrylates with substituted and / or unsubstituted acrylic acids and / or (meth) acrylic acids and / or their esters with aliphatic C1-C8 alcohols , preferably methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, propanol, hexanol, heptanol or octanol, constitute a preferred embodiment of the invention.

In addition to the thermodynamic solubility, the dissolution kinetics of a liquid surrounded by a coating, preferably water, or the decrease in its mechanical stability may be important for the application. The solution kinetics of the coating materials used according to the invention can be pH-dependent down to the alkaline range.

In a further embodiment of the present invention, polymers are used whose water solubility is between the pH of 5.5 and the pH of 9.5, preferably from 5.8 to 9.0, preferably from 6.0 to 8, 5, more preferably from 6.5 to 7.5, and which are less soluble at lower pH than at higher pH. Suitable polymers preferably contain acidic groups, for example, carboxylic acid and / or sulfonic acid and / or sulfonamide and / or ester groups, preferably carboxylic acid and / or sulfonic acid and / or sulfonamide groups, more preferably carboxylic acid groups.

At lower pH values, the molecule is preferably in the uncharged state and is thus insoluble. As a rule, the transition takes place depending on the pKa value of the acidic groups and also depending on their density along the polymer chain. Suitable coating compositions therefore also include polymers in which the transition point is in a range between pH 5.5 and 8.5, preferably between pH 5.8 and 8.0, more preferably between pH 6.0 and 7.5.

This shift in the turnover point of a polymer suitable for the purposes of the present invention is dependent on the pKa value of the functional groups of the polymer, with only very little change in the state of charge of the polymer in solution in the region of higher pH values. Therefore, it is advantageous if the solubility of the polymer is critically affected with a small change in the state of charge of the polymer. The polymer preferably has such a hydrophilicity that it becomes insoluble in a completely uncharged state, but becomes soluble when already slightly charged, for example by protonation.

Copolymers of acidic monomers, water-insoluble monomers and, if desired, water-soluble monomers are very suitable according to the invention. Suitable acidic monomers are, for example, acrylic acid, methacrylic acid, phthalic acid or succinic acid. As the water-insoluble monomers esters of acrylic acid or methacrylic acid with alcohols having 1 to 8 carbon atoms, in particular the methyl esters, ethyl esters, butyl esters or 2-hexylethyl esters are used. Water-soluble monomers which are preferably used are substances such as acrylamide, methacrylamide, vinylpyrrolidone or hydroxyethyl acrylates or methacrylates.

Other suitable polymers include, for example, sulfonamide groups, wherein preferably monomeric sulfonamide derivatives are copolymerized with other monomers or directly coupled to polymers. Suitable monomeric sulfonamide derivatives are preferably selected from the group consisting of sulfamethizole, sulfathoxazole, sulfamethazine, sulfithomidine, sulfathetamide, sulfanylamide, sulfaphenazole, sulfamethoxazole, sulfadiazine, sulfamethoxydiazine, sulfamethoxypyridazine, sulfadoxine, sulfapyridine, sulfabenzamide, and mixtures thereof.

Suitable monomers that can be copolymerized with monomeric sulfonamide derivatives are preferably selected from the group consisting of acrylamide, N, N-dimethylacrylamide, acrylic acid, N-isopropylacrylamide, and mixtures thereof.

A suitable process for the preparation of polymers having pH-dependent solubility comprising sulfonamide groups is described, for example, in US Pat US 6,103,865 A described.

• – Copolymerisation eines Monomers mit basischer Funktion mit einem hydrophileren Monomer. Durch das Einbauverhältnis der jeweiligen Comonomeren wird der Umschlagspunkt beeinflusst.
• – Hydrophilierung des basische Gruppen tragenden Polymers durch eine polymeranaloge Umsetzung. Durch den Modifikationsgrad wird der Umschlagspunkt beeinflusst.

To adjust the hydrophilicity, the following measures can be taken:

• - Copolymerization of a monomer with a basic function with a hydrophilic monomer. The incorporation ratio of the respective comonomers influences the transition point.
• Hydrophilization of the basic group-bearing polymer by a polymer-analogous reaction. The degree of modification influences the turnover point.

According to the invention, in variant b.) The at least one swelling agent has a pH-dependent swelling capacity. A "pH-dependent swelling capacity" can be determined, for example, by determining the swelling number at different pH values on the basis of known methods.

Preferably, in variant b.), The swelling agent with pH-dependent swelling capacity determines a swelling number based on Ph. Eur. 6 at a pH of less than 5.5 of less than 3, preferably less than 2, more preferably less as 1, up.

In a further preferred embodiment in variant b.), The swelling agent with pH-dependent swelling capacity at room temperature and a pH of less than 5.5 has a swelling ratio QZ of less than 10, preferably less than 8, more preferably less than 5 , more preferably less than 3, on. In a further preferred embodiment, the swelling agent with a pH-dependent swelling capacity at room temperature and a pH of less than 5.5 has a swelling ratio QZ of 0.

In a further preferred embodiment in variant b.), The swelling agent with pH-dependent swelling capacity at room temperature and a pH of 6.8 has a swelling ratio QZ of at least 10, preferably of at least 20, more preferably of at least 50 ,

In a further preferred embodiment in variant b.), The swelling agent with pH-dependent swelling capacity at room temperature has a swelling ratio QZ of at least 10, preferably of at least 20, at a pH above at least 5.5, preferably above at least 5.6, preferably above at least 5.8, more preferably above at least 6.0, more preferably above at least 6.5 on.

Swelling agents with pH-dependent swelling capacity are known, for example, from pharmacy. Here are z. B. acid-insoluble polymers used to tablets from an enteric, but swellable in the intestinal juice matrix. manufacture. Such acid-insoluble polymers are usually based on derivatives of polyacrylic acid, which is present in undissoziierter and thus insoluble form in the acidic region. In the alkaline range, for example at a pH of 8.0, however, there is a dissociated form, wherein subsequent swelling by absorption of water is caused by electrostatic repulsion between the carboxylate groups within the swelling agent.

Polymers of similar type, which have a pH-dependent swelling capacity, are advantageous for the design of the swelling agent. Preferably, the at least one swelling agent with pH-dependent swelling capacity in the acidic is substantially inert, but swells in the neutral to alkaline partially or completely.

For example, the substances, preferably polymers, which are suitable for the coating with pH-dependent solubility, can also be used as swelling agent with pH-dependent swelling capacity.

According to a preferred embodiment, the swelling agent with pH-dependent swelling capacity is such that it comprises or at least partially consists of polyacrylic acid and / or derivatives of polyacrylic acid, which at pH values above at least 5.5, preferably above at least 5 , 6, preferably above at least 5.8, more preferably above at least 6.0, more preferably above at least 6.5, even more preferably above at least 7.0, even more preferably above at least 7.5, more preferably above of at least 8.0, as polyanion.

Preferred substances in the context of the present invention are acidic, preferably swelling polymers, preferably homopolymers and / or copolymers which contain carboxylic acid and / or sulfonic acid and / or sulfonamide and / or ester groups, more preferably carboxylic acid and / or sulfonic acid and / or or sulfonamide groups, more preferably carboxylic acid groups.

Examples of suitable substances are so-called hydrogels, which may comprise a water-containing, but water-insoluble polymer whose polymer chains are linked chemically, for example by covalent or ionic bonds, or physically, for example by looping the polymer chains, into a three-dimensional network. Built-in hydrophilic polymer components allow them to swell in water with considerable volume increase, but without losing their material cohesion.

The swellable core can be coated in a variety of ways, such as by phase separation techniques, mechanical-physical or polymerization techniques, such as suspension and emulsion polymerization, with phase separation techniques, also called coacervation, being preferred.

Coacervation means that a dissolved polymer in a polymer-rich, still solvent-containing phase by desolvation, z. B. by pH change, temperature change, salting out, change in ionic strength, addition of complexing agents (complex coacervation), addition of non-solvents, is transferred. The coacervate settles at the interface of the swellable core to be encapsulated to form a coherent capsule wall and is solidified by drying or polymerization.

Physical processes for the preparation of the coated swellable core are, for example, spray drying, fluidized bed processes, or extrusion processes (coextrusion), melt dripping (braze process), spray freeze drying.

In another preferred embodiment, the pH-dependent soluble polymer may be used not only as a coating but also as a matrix material in the swellable core.

It is not necessary for the polymer to completely dissolve at the pH conditions characteristic of the polymer. Rather, it is sufficient if, for example, the permeability of the polymer film changes and z. B. the penetration of water into the swellable core is made possible by the holes or pores formed. As a result, in a further preferred embodiment of the fibrous sheet according to the invention, a secondary effect, for. As a foaming or the activation of a disintegrant, which are known in particular from the pharmaceutical industry, provide for the complete release of the swellable core.

The layer thickness of the coating is preferably in the range of 5 microns to 50 microns, preferably from 20 microns to 40 microns. The molecular weight of the polymer should preferably be at least 1 kDa, more preferably in a range of at least 5 kDa to 6000 kDa, more preferably in a range of 12 kDa to 4000 kDa, and most preferably in a range of 40 kDa to 3500 kDa ,

In a further preferred embodiment, the at least one coating having a pH-dependent solubility has a content of from 0.1 to 20% by weight, preferably from 0.5 to 15% by weight, more preferably from 1% to 12% by weight, based in each case on the total weight of the swellable core. The swellable core is present in unswollen state.

In a further preferred embodiment, the coated swellable core is particulate and has a cumulative frequency distribution, determined by means of laser granulometry, with a D ₉₀ value of less than 1.4 mm, preferably less than 1.0 mm, preferably less than 0.6 mm , Under a D ₉₀ value of, for example, less than 1.0 mm is understood according to the invention that 90% of all coated swellable cores are less than or equal to 1.0 mm.

Preferably, the coated swellable core has an average particle size of from 0.2 to 1.4 mm, more preferably from 0.25 to 0.6 mm.

After introducing the fibrous sheet in wastewater, it is partially, preferably substantially completely, more preferably completely, for dissolution of the coating. This allows the swellable core by absorbing water to destroy the structural integrity of the fibrous sheet.

Suitable swellable cores are able to absorb a multiple of their own weight of liquid, preferably water, preferably. As a rule, expansion or swelling of the swellable core occurs. As a result, the structural integrity of the fibrous sheet is partially, preferably substantially completely, more preferably completely, destroyed.

In a preferred embodiment, the swellable core comprises one or more substances selected from the group consisting of superabsorbent polymers (SAP), starch, modified starch, guar gum, tara gum, locust bean gum, polyoxyethylene-polyoxypropylene co-polymers, polyacrylic and polymethacrylic Compounds, polyamines, polycarboxylic acids, polyoxyethylene polymers, polyethers such as polyethylene glycols, cellulosic polymers such as carboxymethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, methyl-ethylcellulose and / or mixtures thereof, or consists thereof. Locust bean gum and / or guar gum have proven to be very suitable.

Suitable superabsorbent polymers may be copolymers of acrylic acid and sodium acrylate, where the ratio of the two monomers may vary. Preferably, a so-called core crosslinker (core cross linker, CXL) is additionally added to the monomer solution, which connects the long-chain polymer molecules formed in places with one another by chemical bridges.

The fibrous sheet preferably comprises swellable cores coated according to the invention in an amount of 1 to 35% by weight, preferably 3 to 25% by weight, more preferably 5 to 20% by weight, based in each case on the total weight of the fibrous sheet ,

In a further preferred embodiment, the swellable core coated according to the invention comprises further constituents, such as disintegrants, fillers or dyes.

The fibrous sheet of the present invention preferably contains water-dispersible fibers. In a preferred embodiment, the fibers of the sheet have a length from a range of 0.2 mm to 6 mm, more preferably from 1 mm to 4 mm, more preferably from 1.1 to 3 mm.

In this case, both natural fibers and synthetic fibers and mixtures thereof can be used. In a preferred embodiment, pulp fibers are mainly used. In addition, for example, rayon, cotton, wool, acetate, or tencel fibers can be used. In another preferred embodiment, the fibrous web comprises from 40 to about 95% by weight, more preferably from 60 to 90% by weight, of pulp fibers, each based on the total weight of the dry fibrous web of the invention.

The pulp fibers used can be obtained by a chemical pulping of plant fibers or by using recycled fibers. Preferably, both wood fibers, fibers of annual plants such as straw, bagasse, kenaf or bamboo, and mixtures thereof may be used. In addition, for example, both softwood pulp and hardwood pulp may be used, the nature of the chemical pulping used per se is not critical.

The pulp fibers used may in a preferred embodiment be held together by at least one binder. The binder may preferably be used as a binder fiber and / or as an aqueous solution and / or as a binder foam.

In a preferred embodiment, the binder is water-insoluble after curing or crosslinking. In another preferred embodiment, the binder is selected from natural polysaccharides, polysaccharide derivatives and synthetic polymers. Examples of natural polysaccharides include sodium alginate, tragacanth, guar gum, xanthan gum, gum arabic, caragenan, galactomannan, gelatin, casein, algumine and pullulan. Examples of polysaccharide derivatives include carboxymethylcellulose, carboxyethylcellulose, carboxymethylated starch and its salts, starch, methylcellulose and ethylcellulose. Examples of synthetic polymers include polyvinyl alcohols, polyvinyl alcohol derivatives, styrene-butadiene or styrene-acrylate copolymers, ethylene-vinyl acetate copolymers, unsaturated carboxylic acids, polymer or copolymer salts, and salts of copolymers of unsaturated carboxylic acids and monomers copolymerizable with an unsaturated carboxylic acid , More preferably, the binder is an ethylene-vinyl acetate copolymer.

Preferably, the fibrous web comprises at least one binder in a proportion of 1 to 35 wt .-%, preferably from 3 to 25 wt .-%, more preferably from 5 to 20 wt .-%, each based on the total weight of the fibrous sheet.

In a preferred embodiment, the fibrous sheet has 1 to 4 layers, preferably 1 to 3 layers. More preferably, the fibrous sheet is single-ply.

In a further preferred embodiment, the fibrous sheet has multiple layers, preferably 2, 3 or 4 layers, none of these multiple layers being impermeable to aqueous media.

Preferably, the fibrous sheet according to the invention has a weight per unit area in the range from 40 g / m ² to 150 g / m ² , preferably from 45 g / m ² to 80 g / m ² .

In a further embodiment, the fibrous sheet is additionally provided with at least one coating having a pH-dependent solubility.

The fibrous sheet according to the invention is preferably present as nonwoven or nonwoven material. In a further preferred embodiment, the fibers are transferred into a fibrous web by carding, wet-laying, air laying, spunbonding or meltblowing. The fiber or nonwoven web is particularly preferably formed by the airlaid process, also referred to as airlaid process, in which substantially all, preferably all fibers are intimately mixed. Preferably, the airlaid web is then compressed or compacted.

• (a) Bereitstellen von Fasern,
• (b) Ablegen der Fasern auf einer Aufnahmefläche unter Erhalt eines Faserbetts,
• (c) Verdichten des Faserbetts unter Erhalt eines verdichteten Faserbettes,

wobei in den Schritten (a), (b) und/oder (c) und/oder zwischen den Schritten (a), (b) und/oder (c) und/oder nach Schritt (c) wenigstens ein Desintegrationsmittel mit pH-Wert-abhängiger Quellfähigkeit in das verdichtete Faserbett eingebracht wird.The fibrous sheet according to the invention is produced by a process comprising the following steps:

• (a) providing fibers,
• (b) depositing the fibers on a receiving surface to obtain a fibrous bed,
• (c) compacting the fiber bed to obtain a compacted fiber bed,

wherein in steps (a), (b) and / or (c) and / or between steps (a), (b) and / or (c) and / or after step (c) at least one disintegrating agent with pH Value-dependent swelling capacity is introduced into the compacted fiber bed.

The compacting of the fiber bed can take place by various methods known in the art, such as, for example, latex bonding, thermal bonding, hydrogen bonding or multi-bonding. Optionally, by calendering the thickness of the fibrous sheet can be adjusted. In a preferred embodiment, the fibrous sheet has superficial depressions and / or elevations, which may be produced by embossing, for example.

In a further preferred embodiment, at least one binder is added in step (a) and / or during steps (b) and / or (c), preferably in step (c).

More preferably, in step (a) and / or during steps (b) and / or (c), the at least one binder is added as an aqueous solution and / or as a binder foam and subsequently at a temperature of greater than 100 ° C., preferably greater solidified as 150 ° C.

In a further preferred embodiment, in step (a) and / or during steps (b) and / or (c) the at least one binder is added as binder fiber and subsequently at a temperature of greater than 100 ° C, preferably greater than 135 ° C melted. As a rule, the melting temperature does not exceed 160 ° C. In this preferred embodiment, the binder comprises or consists of at least two polymer components with different melting points, preferably polyethylene and / or polypropylene on the one hand and polyester on the other hand.

Preferably, the binder fiber has a length between 1.0 and 7.0 mm, preferably 2.0 and 6.0 mm, more preferably up to 3.0 mm.

In a further preferred embodiment, the fibrous sheet according to the invention consists of a pulp web, wherein the pulp web 50 to 90 wt .-% pulp, optionally 10 to 30 wt .-% of a synthetic fiber and / or 3 to 20 wt .-% of at least one binder includes.

Preferably, the fibrous sheet according to the invention has a wet strength, determined according to DIN 54540-8, from a range of 5 to 30%, preferably 8 to 20%, of the dry strength.

Surprisingly, the sheet according to the invention, in spite of its wet strength, has a sufficient ability to disintegrate water in order to disintegrate in the wastewater. It is preferred that the wet strength of the fibrous sheet, determined according to DIN 54540-8, by at least 50%, preferably of at least 60%, decreases, measured after one hour underwater storage at a temperature of 25 °.

In a preferred embodiment, the fibrous web is wet. More preferably, the fibrous sheet contains a lotion having a pH of less than 5.5. Preferably, the lotion has a pH in the range of 4.0 to 6.0, preferably 5.0 to 5.5, and is therefore pH neutral with respect to the pH of healthy skin.

In a further preferred embodiment, the lotion further comprises at least one preservative which can afford, for example, the protection of microorganisms in long-term storage. It is preferred that the preservative provide antimicrobial activity, including antibacterial activity, anti-fungal activity or anti-yeast activity, or a combination thereof. Preferably, the preservative is selected from the group consisting of formaldehyde and formaldehyde donors, glutaldehyde, quaternium 15, urea, PHB esters, chloroxylenol, chloromethyl, triclosan, zinc pyrithione, oxafin A, chaton, trimethylammonium bromide, benzalkonium chloride, or a combination thereof.

In a further preferred embodiment, the lotion further comprises skin-protecting and / or skin-healing and / or skin-care active substances which give the skin an advantage which goes beyond a mere sensory and / or cosmetic advantage.

For example, in a preferred embodiment, active skin care may be provided in the form of stimulating skin regeneration, promoting skin physiology, or strengthening the barrier function of the skin. The pH of the skin surface depends on the sweat secretion, bacterial flora and sebum composition. Depending on the skin region, the pH is between 4 and 7, with healthy skin in particular around 5.5.

Healthy human skin is characterized by the fact that its intact acid mantle provides adequate protection against microorganisms, germs and pathogens, that its buffering capacity and alkali neutralizing power are sufficient to ward off harmful influences of surrounding fluids, that there is a high degree of freedom from redness, and that there is freedom from skin damage such as cuts, abrasions and burns, irritation, inflammation and allergies, and that it is neither cracked nor dried out. In a preferred embodiment, at least one of the skin-healing and / or skin-protecting active substances contained in the lotion is antiseptic or contains at least one antiseptic substance, wherein the antiseptic substance is preferably an oil, in particular an essential oil.

This antiseptic oil is preferably an essential oil selected in particular from the group of Angelics fine - Angelica archangelica, Anis - Pimpinella anisum, Benzoin siam - Styrax tokinensis, Cabreuva - Myrocarpus fastigiatus, Cajeput - Melaleuca leucadendron, Cistrose - Cistrus ladaniferus, Copaiba balm - Copaifera reticulata, Costus root - Saussurea discolor, Edeltann needle - Abies alba, Elemi canarium luzonicum, Fennel - Foeniculum dulce Spruce needle - Picea abies, Geranium - Pelargonium graveolens, Ho leaves - Cinnamonum camphora, Immortelle (Strawflower) Helichrysum ang., Ginger extra - Zingiber off., St. John's wort - Hypericum perforatum, Jojoba, German chamomile - Matricaria recutita, Chamomile blue fine - Matricaria chamomilla, Chamomile rom. - Anthemis nobilis, Chamomile wild - Ormensis multicaulis, Carrot - Daucus carota, Mountain pine - Pinus mugho, Lavandin - Lavendula hybrida, Litsea Cubeba - (May Chang), Manuka - Leptospermum scoparium, Melissa - Melissa officinalis, Sea pine - Pinus pinaster, Myrrh - Commiphora molmol, Myrtle - Myrtus communis, Neem - Azadirachta, Niaouli - (MQV) Melaleuca quin. viridiflora, Palmarosa - Cymbopogom martini, Patchouli - Pogostemon patchouli, Peru balsam - Myroxylon balsamum var. pereirae, Raventsara aromatica, Rosewood - Aniba pink odora, Sage - Salvia officinalis, Horsetail - Equisetaceae, yarrow extra - Achilles millefolia, plantain lanceolate - Plantago lanceolata, Styrax - Liquidambar orientalis, Tagetes (Marigold) - Tagetes patula, Tea Tree - Melaleuca alternifolia, Tolu Balsam - Myroxylon Balsamum L., Virginia Cedar - Juniperus virginiana, Frankincense (Olibanum) - Boswellia carteri, Silver Fir - Abies alba.

In a preferred embodiment, the skin-protecting active ingredients contained in the lotion are a skin-protecting oil.

The skin-protecting substance is advantageously a skin-protecting oil, eg. B. also to a carrier oil, in particular selected from the group algae oil - Oleum Phaeophyceae, aloe vera oil - aloe vera brasiliana, apricot kernel oil - Prunus armeniaca, arnica oil - Arnica montana, avocado oil - Persea americana, borage oil - Borago officinalis, calendula oil - Calendula officinalis , Camellia oil - Camellia oleifera, Thistle oil - Carthamus tinctorius, Peanut oil - Arachis hypogaea, Hemp oil - Cannabis sativa, Hazelnut oil - Corylus avellana, St. John's wort oil - Hypericum perforatum, Jojoba oil - Simondsia chinensis, Carrot oil - Daucus carota, Coconut oil - Cocos nucifera, Pumpkin seed oil - Curcubita pepo , Kukui nut oil - Aleurites moluccana, Macadamia nut oil - Macadamia ternifolia, Almond oil - Prunus dulcis, Olive oil - Olea europaea, Peach kernel oil - Prunus persica, Rapeseed oil - Brassica oleifera, Castor oil - Ricinus communis, Black cumin oil - Nigella sativa, Sesame oil - Sesamium indicum, Sunflower oil - Helianthus a nnus, grapeseed oil - Vitis vinifera, walnut oil - Juglans regia, wheat germ oil - Triticum sativum, of which in particular borage oil, hemp oil and almond oil are advantageous.

According to another embodiment of the invention it is advantageous to combine different oils in the lotion, i. H. So to combine the antiseptic effective with the skin-protecting or even to combine the antiseptic and the skin-protecting one another.

In a preferred embodiment, the lotion additionally contains urea and / or lactic acid and / or citric acid and / or salts thereof.

Urea promotes skin health by providing anti-microbial, water-binding, anti-itching, dandruff-releasing, skin-smoothing, and inhibiting excessive cell growth. Furthermore, it can serve the skin as a moisturizing factor, i. H. it can help the skin to retain moisture.

Lactic acid and / or citric acid and / or salts thereof serve, inter alia, to support or renew the natural acid mantle or hydrolipid film of the skin. The hydrolipidic film of the skin is attacked or destroyed by alkaline influences, resulting in a loss of the barrier function of the skin, so that microorganisms or pollutants can more easily penetrate the skin. By the lactic and / or citric acid in the inventive compositions can be z. B. Remove residual alkali from clothing and adjust the pH of the textiles to a pH range around 5. The additional lactic acid acts; which is also part of the epidermis, additionally stabilizing the acidic pH of the skin (pH approx. 5.2) and serves as a moisturizing factor as it can improve the water-binding capacity of the skin.

In a further preferred embodiment, the lotion may contain further moisturizing factors, for example those selected from the following group: amino acids, chitosan or chitosan salts / derivatives, ethylene glycol, glucosamine, glycerol, diglycerol, triglycerol, uric acid, honey and hardened honey, creatinine, Cleavage products of collagen, lactitol, polyols and polyol derivatives (for example, butylene glycol, erythritol, propylene glycol, 1,2,6-hexane triol, polyethylene glycols such as PEG-4, PEG-6, PEG-7, PEG-8, PEG-9, PEG-10 , PEG-12, PEG-14, PEG-16, PEG-18, PEG-20), pyrrolidonecarboxylic acid, sugars and sugar derivatives (for example fructose, glucose, maltose, maltitol, mannitol, inositol, sorbitol, sorbitylsilanediol, sucrose, trehalose, Xylose, xylitol, glucuronic acid and its salts), ethoxylated sorbitol (sorbeth-6, sorbeth-20, sorbeth-30, sorbeth-40), hardened starch hydrolysates and mixtures of hardened wheat protein and PEG-20 acetate copolymer, especially panthenol.

Preferably, the fibrous sheet of the present invention is used as a sanitary article, particularly as a wet wipe or wet toilet paper.

A wet wipe can be used, for example, for personal care, such as a tissue or as a disinfectant wipe, or in the household as a wipe.

The invention will be illustrated by examples without, however, being limited thereto.

Noninventive Example 1 and Comparative Example 1:

Example 1:

In the pulp-material flow of approximately 60 g / m ² Total basis weight set airlaid pulp nonwoven fabric 20 have been wt .-% (corresponding to about 10 g / m ²⁾ of a dry carob flour with an average particle size of 75 microns (after sieving with a mesh size of 200 mesh) introduced.

The fiber / gum mixture was placed on the laying head system by vacuum on the underlying guided past Legesieb, pre-pressed and each of both sides with a 11% aqueous dispersion of a commercially available binder (VINNAPAS ^® EN 1020, Wacker Chemie AG, Burghausen, Germany) ethylene / Vinyl acetate base sprayed, wherein the binder content was adjusted to about 6 to 10 wt .-% of the total basis weight.

Comparative Example 1 was carried out as Example 1, but without the addition of the dry locust bean gum.

After drying and condensation of the binder, the fleece produced in each case in Example 1 and Comparative Example 1 was rolled up. Composition of the air-laid nonwoven webs component Example 1: Comparative Example 1 Pulp fiber 45 g / m ² 45 g / m ² Locust bean gum 10 g / m ² - binder 5 g / m ² 5 g / m ²

The measured basis weights, thicknesses and breaking loads in the dry or wet state of the nonwoven webs obtained in Example 1 and Comparative Example 1 are listed below. Example 1: Airlaid 60 g / m ² with 10 g / m ² locust bean gum Measurements: Test characteristics 1 2 3 4 5 6 7 8th Average 2 σ dev. Basis weight (M) conditioned g / m ² 59.2 58.8 56.5 60.2 58.7 59.3 61.8 56.6 58.9 3.5 g / m ² 60.3 58.2 61.0 57.7 59.3 60.9 60.3 56.2 59.2 3.4 Breaking loads dry longitudinally (M) conditioned N / 50 mm N / 50 mm 27.0 22.5 28.2 22.3 29.0 21.2 28.5 28.0 25.8 6.5 22.3 26.0 24.1 20.0 29.5 26.0 22.0 29.3 24.9 6.9 dry transversely (M) conditioned N / 50 mm N / 50 mm 20.2 24.8 22.5 25.0 19.8 24.5 20.2 27.0 23.0 5.4 22.2 19.9 27.3 21.1 20.9 21.8 26.0 23.0 22.8 5.2 wet longitudinally (M) conditioned N / 50 mm N / 50 mm 2.2 2.8 2.0 5.2 3.3 8.0 1.9 1.7 3.4 4.4 1.6 2.8 5.1 2.3 2.4 2.0 8.3 2.7 3.4 4.5 wet transverse (M) air-conditioned N / 50 mm N / 50 mm 1.2 2.0 3.0 2.2 6.8 2.1 1.7 2.1 2.6 3.5 1.5 1.3 2.2 6.9 2.6 1.8 2.2 3.0 2.7 3.6 Thickness (M) conditioned mm mm 0.39 0.37 0.40 0.36 0.35 0.40 0.38 0.36 0.38 0.04 0.37 0.38 0.37 0.35 0.41 0.38 0.40 0.34 0.38 0.05 Comparative Example 1: Airlaid 60 g / m ² without locust bean gum Measurements: Test characteristics 1 2 3 4 5 6 7 8th Average 2 σ dev. Basis weight (M) conditioned g / m ² 58.4 62.3 61.4 58.4 59.2 58.6 60.8 57.0 59.5 3.6 g / m ² 61.5 60.9 62.3 58.4 62.2 61.3 59.1 56.9 60.3 3.9 Breaking loads dry longitudinally (M) conditioned N / 50 mm N / 50 mm 23.6 27.9 26.5 25.5 25.3 25.8 26.9 28.8 26.3 3.2 27.0 24.5 26.6 27.2 28.6 26.3 26.1 26.8 26.6 2.3 dry transversely (M) conditioned N / 50 mm N / 50 mm 21.4 24.4 22.3 21.8 22.2 23.1 22.8 23.8 22.7 2.0 22.2 25.3 23.6 24.1 21.0 22.3 23.3 22.0 23.0 2.7 wet longitudinally (M) conditioned N / 50 mm N / 50 mm 11.0 13.4 14.0 14.1 12.2 11.9 14.9 13.3 13.1 2.6 10.6 11.3 13.2 12.4 13.8 12.9 13.3 13.0 12.6 2.2 wet transverse (M) air-conditioned N / 50 mm N / 50 mm 9.5 10.8 12.2 11.5 13.0 11.0 13.8 11.9 11.7 2.7 8.5 10.4 11.9 11.6 12.0 10.6 12.8 11.9 11.2 2.7 Thickness (M) conditioned mm mm 0.38 0.38 0.38 0.36 0.37 0.38 0.37 0.36 0.37 0.02 0.39 0.38 0.38 0.36 0.39 0.38 0.39 0.35 0.38 0.03

The test characteristics listed were determined on 10 × 10 cm sections immediately after receipt of the nonwoven (M) and after 1 h storage at 23 ° C. and 50% relative humidity (air-conditioned) in 8 independent measurements.

In order to check the effect of locust bean gum, the wet strength of the nonwoven fabric produced in Example 1 was compared with the wet strength of the airlaid nonwoven prepared in Comparative Example 1 according to DIN 54540-8 (1989).

In comparison with the airlaid nonwoven without locust bean gum obtained in Comparative Example 1, a significant reduction in the wet strengths of the nonwoven fabric produced in Example 1 was found. Wet strength was determined as the ratio of wet to wet transverse strength to dry transverse load fracture, using the average of 8 independent measurements to calculate wet strength. Table 1: Comparison of the strength ratios of the airlaid nonwovens prepared in Example 1 and Comparative Example 1 example 1 Comparative Example 1 binder application % 8.4 8.7 Strength ratio: - dry transverse / dry longitudinal (M) % 89.0 86.4 air-conditioned % 91.5 86.3 - wet across / dry across (M) % 11.5 51.5 air-conditioned % 11.8 48.8

The wet strength of about 50% present in comparative example 1 decreased to about 12% after addition of loci bean gum with 10 g / m ² . This corresponds to a value of commercially available untreated tissue products.

Inventive Example 2: Airlaid nonwoven with pH-dependent swellable disintegrating agent

1. Preparation of microencapsulated swellable cores

10 g of EUDRAGIT S-100 (5% by weight) were dissolved in 200 ml of ethanol. Subsequently, 10 g of locust bean gum were introduced with good stirring in small portions in the EUDRAGIT - solution and well homogenized. The suspension was tempered for 20 min. At 10 ° C.

800 ml thick liquid paraffin oil were heated to 10 ° C.

The EUDRAGIT / locust bean gum suspension was slowly added dropwise to the paraffin oil with stirring at about 2000 rpm.

When the addition was complete, the temperature was gradually brought to 50 ° C. with vigorous stirring (in each case 30 minutes at 20 ° C. to 50 ° C. in 5 ° C. steps) and the solvent was evaporated off. The resulting microcapsules were isolated on a Nutsche filter paper (Whatman Grade 4), washed several times with small portions of n-hexane and dried gently.

Several experimental approaches to microencapsulation were carried out for the following laying test. In total, about 100 g of encapsulated material was produced.

2. Airlaid fleece with microencapsulated swellable cores

Analogously to the experimental procedure in Example 1, the microencapsulated swellable cores were added to the pulp material flow of an airlaid pulp web set to about 60 g / m ² total basis weight and deposited on the laying sieve system by means of the laying head system.

After slight compression of the fiber composite by means of heated smooth rollers, both sides were sprayed in each case with an approximately 11% aqueous dispersion of a commercially available binder (VINNAPAS ^® EN 1020, Wacker Chemie AG, Burghausen, Germany) on ethylene / vinyl acetate-based, the binder content on about 6 to 10% by weight of the total basis weight was set.

After drying and condensation of the binder, the produced fleece was rolled up.

3. Test the resulting airlaid web for pH-dependent wet strength

Small, 10 × 10 cm large sections of the resulting web were at room temperature for 60 min. in a vessel with a 3M Na acetate buffer (pH 5.5) and then measured the wet strength in the tensile test according to DIN 54540-8.

Analogously, 10 × 10 cm sections were placed at room temperature in a vessel containing 0.1 M phosphate buffer (pH 6.8) and, after a reaction time of 60 minutes, the wet tensile strength according to DIN 54540-8 was measured. Airlaid 60 g / m ² with microencapsulated swelling body at pH = 5.5 Measurements: Test characteristics 1 2 3 4 5 6 7 8th medium 2 σ value Dev. Basis weight (M) conditioned g / m ² 57.2 61.8 60.2 58.3 60.5 57.8 61.3 55.1 59.0 4.6 g / m ² 56.9 60.3 62.8 60.5 61.0 59.6 60.8 56.2 59.8 4.4 Breaking loads dry longitudinally (M) conditioned N / 50 mm N / 50 mm 25.1 23.6 27.1 21.2 28.6 22.5 26.8 22.0 24.6 5.4 26.1 22.3 22.5 28.2 23.3 22.5 25.3 21.7 24.0 4.6 dry transversely (M) conditioned N / 50 mm N / 50 mm 20.1 19.5 24.0 20.2 20.5 22.6 19.3 19.6 20.7 3.4 19.2 22.1 24.0 19.6 23.1 20.5 21.7 18.5 21.1 3.9 wet longitudinally (M) conditioned N / 50 mm N / 50 mm 10.2 9.8 13.5 9.3 10.1 11.0 10.3 12.1 10.8 2.8 11.0 12.5 9.9 10.8 12.0 8.9 11.3 10.1 10.8 2.3 wet transverse (M) air conditioned N / 50 mm N / 50 mm 7.5 10.7 8.9 11.1 9.2 11.2 9.6 8.3 9.6 2.7 8.4 6.8 11.2 8.8 11.6 7.9 11.3 8.8 9.3 3.6 Thickness (M) conditioned mm mm 0.39 0.39 0.39 0.38 0.38 0.37 0.38 0.37 0.38 0.02 0.39 0.38 0.39 0.37 0.39 0.39 0.38 0.34 0.38 0.03 Airlaid 60 g / m ² with microencapsulated swelling body at pH = 6.8 Measurements: Test characteristics 1 2 3 4 5 6 7 8th Average 2 σ dev. Basis weight (M) conditioned g / m ² g / m ² 60.4 57.5 55.8 61.2 60.2 61.4 58.8 55.3 58.8 4.8 58.8 61.5 59.3 56.2 60.8 57.2 61.8 56.9 59.1 4.3 Breaking loads (M) dry longitudinally conditioned N / 50 mm N / 50 mm 26.3 21.8 25.5 19.7 26.3 22.5 28.5 22.5 24.1 5.9 21.8 24.9 20.2 26.9 22.5 27.1 21.3 24.5 23.7 5.2 dry transversely (M) conditioned N / 50 mm N / 50 mm 20.2 19.6 22.9 20.2 17.9 23.8 23.6 19.2 20.9 4.4 19.5 22.1 19.8 21.8 24.4 17.6 20.2 21.5 20.9 4.1 wet longitudinally (M) conditioned N / 50 mm N / 50 mm 3.3 3.8 6.4 2.9 6.6 3.3 3.6 2.9 4.1 3.0 2.7 2.6 3.2 5.6 3.9 3.5 7.6 2.7 4.0 3.5 wet transverse (M) air-conditioned N / 50 mm N / 50 mm 2.2 2.6 3.9 5.0 2.4 6.2 2.9 1.9 3.4 3.0 5.6 2.3 4.2 2.3 2.0 4.3 2.2 5.5 3.6 3.1 Thick air conditioned mm mm 0.39 0.37 0.40 0.36 0.35 0.40 0.38 0.36 0.38 0.04 0.37 0.38 0.37 0.35 0.41 0.38 0.40 0.34 0.38 0.05

Results:

Wet strength was determined as the ratio of wet to wet transverse strength to dry transverse load fracture, using the average of 8 independent measurements to calculate wet strength. The respective average values are shown in Table 2, for the sake of clarity, together with the results of the examples shown in Table 1.

The fleece retained most of its wet strength at pH 5.5. Table 2: Comparison of the strength ratios of the airlaid nonwoven fabric prepared in Example 2 with a microencapsulated swelling body Example 2 example 1 Comparative Example 1 at pH = 5.5 at pH = 6.8 binder application (%) 9.3 9.3 8.4 8.7 Strength ratio: - dry transverse / dry longitudinal (M) (%) 84.2 86.7 89.0 86.4 air-conditioned (%) 87.9 88.2 91.5 86.3 - wet across / dry across (M) (%) 46.1 16.2 11.5 51.5 air-conditioned (%) 44.3 17.0 11.8 48.8

At a pH of 6.8, there was a significant reduction in wet strengths. Here, too, the wet strength is slightly higher than that of the airlaid nonwoven fabric produced in Example 1 without microencapsulation of the swelling agent, which suggests an incomplete dissolution of the microencapsulation.

Claims (15)

Fiber-containing fabric, characterized in that in the fibrous sheet at least one disintegrating agent with pH-dependent swelling capability is arranged, the disintegrating agent a.) Is provided a swellable core having at least one pH-dependent solubility coating and / or b.) comprises at least one swelling agent with pH-dependent swelling capacity. Fiber-containing fabric according to claim 1, characterized in that the swellable core is coated with at least one pH-dependent solubility-containing coating. Fiber-containing fabric according to one of the preceding claims, characterized in that the fibrous fabric comprises binders. Fiber-containing fabric according to one of the preceding claims, characterized in that the fiber-containing fabric is moist. Fiber-containing fabric according to one of the preceding claims, characterized in that the coating with pH-dependent solubility from a pH of greater than 5.5, preferably greater than 5.8, is soluble and / or the swelling agent with pH Value dependent solubility from a pH greater than 5.5, preferably greater than 5.8, swells. Fiber-containing fabric according to one of the preceding claims, characterized in that the swellable core and / or the swelling agent having a pH-dependent swelling agent is present in particulate form and / or as a fiber. A fibrous web according to any one of the preceding claims, characterized in that the swellable core comprises one or more substances selected from the group consisting of superabsorbent polymers (SAP), starch, modified starch, guar gum, tara gum, locust bean gum, polyoxyethylene-polyoxypropylene copro Polymers, polyacrylic and polymethacrylic compounds, polyamines, polycarboxylic acids, polyoxyethylene polymers, polyethers such as polyethylene glycols, cellulosic polymers such as carboxymethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, methyl ethyl cellulose and / or mixtures thereof. A fiber-containing fabric according to any one of the preceding claims, characterized in that the coating having a pH-dependent solubility comprises one or more substances selected from the group consisting of carboxylalky methacrylate copolymers, acrylic acid and / or methacrylic acid homopolymers and copolymers, Polyvinyl acetate phthalates (PVAP), cellulose acetate phthalates (CAP), cellulose acetate trimellitates (CAT), cellulose acetate acetoacetates, hydroxypropyl methylcellulose phthalates (HPMCP), hydroxypropyl methylcellulose acetyl succinates (HPMCAS), shellac, and mixtures thereof. Fiber-containing fabric according to one of the preceding claims, characterized in that the fiber-containing fabric is a nonwoven fabric. Fiber-containing fabric according to one of the preceding claims, characterized in that the fiber-containing fabric is provided with at least one coating having a pH-dependent solubility. Fiber-containing fabric according to one of the preceding claims, characterized in that the fiber-containing fabric is single-layered. Fiber-containing fabric according to one of the preceding claims, characterized in that the fiber-containing fabric has a plurality of layers, none of these multiple layers being impermeable to aqueous media. A method of making a fibrous sheet according to any one of the preceding claims, comprising the steps of: (a) providing fibers, (b) depositing the fibers on a receiving surface to obtain a fibrous bed, (c) densifying the fibrous bed to obtain a consolidated one Faserbettes, characterized in that in steps (a) and / or (b) and / or (c) and / or between steps (a), (b) or (c) and / or after step (c) at least a disintegrating agent with pH-dependent swelling capacity is introduced into the compacted fiber bed, the disintegrating agent a.) having a swellable core with at least one coating having a pH-dependent solubility and / or b) at least one swelling agent having pH Value-dependent swelling capability. A method according to claim 13, characterized in that in step (c) at least one binder is added. Use of the fibrous sheet according to any one of claims 1 to 12 as a hygiene article, in particular as a wet wipe or moist toilet paper.