MXPA06004128A - Fibrous structures exhibiting improved wet strength properties - Google Patents

Abstract

Fibrous structures and/or sanitary tissue products comprising such fibrous structures, more particularly to fibrous structures and/or sanitary tissue products that exhibit improved wet strength properties, especially temporary wet strength properties, as compared to fibrous structures and/or sanitary tissue products that contain conventional wet strength additives.

Description

FIBROUS STRUCTURES THAT EXHIBIT IMPROVED PROPERTIES OF WET RESISTANCE FIELD OF THE INVENTION The present invention relates to fibrous structures and / or tissue paper hygienic products comprising these fibrous structures, more particularly to fibrous structures and / or tissue paper hygienic products that exhibit improved wet strength properties, especially strength properties. wet temporary, compared to fibrous structures and / or tissue paper hygienic products that contain conventional wet strength additives.

BACKGROUND OF THE INVENTION The wet strength properties are critical in certain fibrous structures, especially tissue paper hygiene products, in particular the napkin. Fibrous structures use wet strength additives to impart wet strength. An example of a commercially available wet strength additive is PAREZ® from Bayer Chemicals. Fibrous structures such as tissue paper hygiene products, in particular sanitary papers containing wet strength additives, especially temporary wet strength additives, exhibit wet strength properties such as wet total traction, percent decomposition, wetting speed, decomposition and / or% reduction of obstruction. These wet strength properties influence the ease with which these fibrous structures can be removed, for example in conventional toilets. Fibrous structures and / or tissue paper hygienic products of the prior art which comprise conventional dusts of wet strength show percentages of decomposition in 5 minutes of about 33% and / or decomposition percentages in about 30 minutes. of 64%. The need persists for fibrous structures comprising wet strength additives, especially temporary wet strength additives that exhibit improved wet strength properties, especially temporary wet strength properties, on fibrous structures containing conventional wet strength additives. in order to better meet the needs of consumers of fibrous structures. Accordingly, there is a need to develop fibrous structures comprising wet strength additives, especially temporary wet strength additives that exhibit improved wet strength properties compared to fibrous structures comprising conventional wet strength additives.

BRIEF DESCRIPTION OF THE INVENTION The present invention satisfies the needs identified above by providing fibrous structures, especially fibrous structures containing wet strength additives that exhibit improved wet strength properties, especially temporary wet strength properties, as compared to fibrous structures containing conventional wet strength additives. wet strength In one aspect of the present invention, a fibrous structure is provided which includes a wet strength additive, wherein the fibrous structure shows a decomposition percentage in 5 minutes greater than 45% and / or greater than 50% and at least about 55% and / or at least about 60% and / or at least about 75% (as illustrated for example in Figure 1) as determined by the Decomposition Rate Test Method described herein. In another aspect of the present invention, a fibrous structure including a wet strength additive is provided, wherein the fibrous structure shows a breakdown percentage in 30 minutes greater than 65% and / or greater than 70% and / or at least about 75% and / or at least about 80% and / or at least about 85% and / or at least about 90% (as shown for example in Figure 1) as determined by the Method of the decomposition percentage test described herein. In still another aspect of the present invention, a fibrous structure including a wet strength additive is provided, wherein the fibrous structure shows a slope of the decomposition rate (as shown for example by the slope of the lines in Figure 2) greater than about 13 and / or greater than about 14 and / or greater than about 15 and / or greater than about 16 and / or greater than about 17 and / or greater than about 18, as determined according to the Decomposition Rate Calculation described herein . In yet another aspect of the present invention, a fibrous structure including a wet strength additive is provided, wherein the fibrous structure shows a reduction in clogging percentage of at least about 1.5 times and / or at least about 2.0. times and / or at least about 2.5 times and / or at least about 3.0 times (as shown for example in Figure 3) as determined by the clogging percentage reduction test method described herein. In still another aspect of the present invention, there is provided a fibrous structure and / or the tissue paper hygienic product according to the present invention, wherein the fibrous structure and / or tissue paper hygienic product shows an improvement in softness greater than +0.20 panel rating units (PSU) and / or greater than +0.30 PSU and / or greater than +0.40 PSU and / or greater than +0.50 PSU (as shown for example in the Figure 4) as determined by the Softness Test Method described herein. Accordingly, the present invention provides a fibrous structure, especially a fibrous construction containing wet strength additive that exhibits improved wet strength properties as compared to fibrous structures comprising a conventional wet strength additive.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a decomposition percentage chart showing a fibrous / tissue product hygienic structure of the prior industry and fibrous tissue / tissue product embodiments according to the present invention; Figure 2 is a graph of the slope of the decomposition rate shown by a fibrous structure / tissue product of tissue from the prior art and embodiments of fibrous structures / tissue products of tissue according to the present invention; Figure 3 is a reduction chart in percentage of construction showing a fibrous structure / tissue product of the prior industry and embodiments of fibrous structures / tissue products of tissue according to the present invention; and Figure 4 is a picture of the softness showing a fibrous structure / tissue product of prior art tissue and embodiments of fibrous structures / tissue products of tissue according to the present invention. The fibrous structure / tissue paper hygienic product of the prior art comprises the best, or one of the best conventional wet strength additives commercially available and / or known at the time of submitting this application. Various embodiments of the fibrous structures and / or tissue paper hygiene products of the present invention are included in the figures. The embodiments of the present invention in one figure do not necessarily correspond to the embodiments in any of the other figures.

DETAILED DESCRIPTION OF THE INVENTION Definitions "Fibrous structure" as used herein means a substrate formed of non-woven fibers. The fibrous structure of the present invention can be manufactured by any suitable process such as wet laying, air laying, and consolidated filament processes. The fibrous structure may be in the form of one or more sheets suitable for incorporation into a tissue paper hygienic product and / or may be in the form of non-woven garments such as surgical garments including surgical covers for shoes, and / or op non-woven paper products such as surgical towels and wipes. "Fibrous structure comprising (containing) a wet strength additive" as used herein means that the fibrous structure comprises an agent that increases the wet strength of the fibrous structure as compared to the fibrous structure without the agent. In one embodiment, the agent increases the initial total wet tensile strength of the fibrous structure. "Fiber" as used herein means an elongated particle having an apparent length that far exceeds its apparent width, i.e., a length-to-diameter ratio of at least about 10. More specifically, as used in the present, "fiber" refers to fibers for the manufacture of paper. The present invention contemplates the use of a variety of paper fibers such as, for example, natural fibers or synthetic fibers, or any other suitable fibers, and any combination thereof. Papermaking fibers useful in the present invention include cellulosic fibers, known as wood pulp fibers. Some useful woodplasts herein are chemical pulps, for example Kraft, sulphite and sulfate pulps, as well as mechanical pulps including, for example, triiured wood, thermomechanical pulps and chemically modified thermomechanical pulps. Chemical pulps, however, may be preferred as they impart a superior tactile feel of softness to the sheets of tissue paper made therefrom. Pulps derived from deciduous trees can be used (hereinafter also referred to as "hardwood") and coniferous trees (hereafter also referred to as "softwood"). The hardwood and softwood fibers may be blended or alternatively may be deposited in layers to provide a coniferous, spiraled material. The countries of the USA num. 4, 300,981 and 3,994,771 are incorporated herein by reference for the purpose of exposing the stratified formation of hardwood and softwood fibers. Also useful are fibers derived from recycled paper that can contain one or all of the above mentioned fiber categories and other non-fibrous materials such as fillers and adhesives that facilitated the original papermaking process. In addition to the above, fibers and / or filaments made from polymers, specifically hydroxyl polymers, may be used in the present invention. Non-exhaustive examples of suitable hydroxyl polymers include polyvinyl alcohol, starch, starch derivatives, chiosanose, chi-gasan derivatives, cellulose derivatives, gums, arabinans, galacenens, and mixtures thereof. "Hygienic Paper Production", as used in the present, means a cleaning implement for cleaning after urination and after defecation (sanitary paper), for otorhinolaryngological discharges (facial tissue paper), and for absorbent uses and multifunctional cleaners (absorbent towels). "Leaf" and "leaves", as used in the present, signify an individual fibrous structure optionally to be placed in a face-to-face relationship with the same or other eyes forming a fibrous, multi-leaf structure. It is also contemplated that a single fibrous structure can efficiently form two "sheets" or multiple "sheets", for example by bending it on itself. "Base weight" as used in the present is the weight per unit area of a sample reported in pounds / 3000 ft2 or g / m2. The basis weight is measured by preparing one or more samples from a finished area (m2) and weighing the samples of a fibrous sheet according to the present invention or a paper product comprising that fibrous paper on a top loading scale with a Minimum resolution of 0.01 g. The balance is protected from drafts and other alterations by using a shield against air currents. The weights will be recorded when the readers in the balance are constant. The average weight (g) and the average area of the samples (m2) are calculated. The basis weight (g / m2) is calculated by dividing the average weight (g) by the average area of the samples (m2). If needed, the basis weight in units of g / m2 can be converted to pounds / 3000 ft2. "Caliber" as used herein means the macroscopic thickness of a sample. The size of a sample of fibrous structure according to the present invention is determined by cutting a sample of the fibrous structure so that it has a size greater than that of a loading foot surface where the circular surface of the loading foot a circular surface area of approximately 20.25 cm2 (3.14 inches2). The sample is confined between a flat horizontal surface and the loading surface of a loading foot. The loading surface of a loading foot applies a confining pressure to the sample of 11447 Pa (5.5 g / cm2 (approximately 0.21 psi)). The gauge is the space resulting from the flat surface and the loading surface of a loading foot. These measurements can be obtained with an electrosurgical thickness tester VIR Model II available from Thwing-Alberí Insírumení Company, Philadelphia, PA. The gauge is re-measured and recorded at least five (5) times to calculate the average gauge. The result was repeated in millimeters. "Density", as used in the present, means the basis weight of a sample divided by the caliber with the appropriate conversions incorporated therein. The bulk density that is used in the presence of units of g / cm3. "Weighted average molecular weight", as used in the present, means the weighted average molecular weight as determined by using gel permeation chroma- ography according to the protocol found in Colloids and Surfaces A. (Colloids and surfaces A.) Physico Chemical &; Engineering Aspecís (Physico-chemical and engineering aspects), Vol. 162, 2000, pages 107-121. Unless specified in any other way, all molecular weight values herein refer to the weight average molecular weight. "Machine address" or "DM", as used in the present, means the direction parallel to the flow of the fibrous process through the paper machine and / or the equipment to manufacture the product. "Transverse direction of the machine" or "DT", as used in the present, means the direction perpendicular to the machine direction in the same plane of the fibrous structure and / or the paper production comprising the fibrous structure. "Decomposition rate", as used in the respects, indicates the percentage of loss of the wet fraction as measured by the Decomposition Proof Testing Level described in the present. As the percentage of decomposition increases, the capacity of the fibrous process and / or the hygienic production of paper that includes the fibrous process of being flushed into the toilet without obstructing the drainage systems and / or the septic wells increases. The decomposition rate is usually measured in fixed-time points after the stringy fiber sample and / or hygienic paper product or portion of these have been immersed in water. The fixed time points are 5 minutiae and 30 minutiae. The portion of decomposition, as used in the present invention, does not take into account any wet strength that the pure fibrous process and / or the hygienic production of paper (without any wet strength additive) can inherently possess. "Decomposition rate", as used in the present, means the rate at which the loss of wet fraction of a fibrous structure and / or a hygienic paper product as measured according to the Decomposition Rate Calculation described above occurs. at the moment. The rate of decomposition is the gradient of a wet graph (g / 2.54 cm or g / inch) with time (seconds) for a sample of fibrous production and / or hygienic production of paper. The wet fraction of the fibrous material and / or the hygienic product of the paper is determined in 5 seconds (initial, humid initial fraction), 60 seconds (wet section in 1 minute), 300 seconds (wet fraction 5 minutes) and 1800 seconds (wet fraction in 30 minutes). The wet time graph for the fibrous materials and / or the hygienic paper products of the present invention show a dramatically higher rate of decomposition than a tissue paper hygienic structure / production of the prior industry. It includes a conventional wet strength additive such as Parez®, which is a temporary wet strength additive commercially available from Bayer Chemicals. The rate of decomposition of fibrous structures / hygienic paper products comprising a Parez® timeless wet strength additive was from about 6 to about 12.75, while in fibrous structures and / or tissue paper hygienic products. of the present invention, the slope was greater than 13 as shown in the graph of the slope of the decomposition speed of Figure 2. The actual calculated slope is negative because it is a reduction of wet traction, but for the purposes of the Present invention, the negative sign is set aside and the positive sign is expressed as the slope of the decomposition speed. "Obstruction portion" as used in the present, means the percentage of times a defined amount of fibrous structure and / or tissue paper hygienic product, especially a fibrous structure and / or hygienic paper product comprising an additive. of wet strength, does not pass through a domestic toilet (specifically a Kohier Portrait Lite toilet with a discharge volume of 6 L (1.6 gallon)) and the drainage pipe system. The percentage of obstruction is measured according to the percentage test of obstruction described in the present. "Reduction in percentage of obstruction", as used herein, means reduction (for example 1.5 times, 2 times, 2.5 times and / or 3 times, etc.) in percentage of obstruction that shows a fibrous appearance and / or hygienic paper production according to the present invention, compared to a fibrous structure / hygienic paper product comprising a conventional wet strength additive (for example, a commercially available wet strength additive available at the time of recording). application). "Weighted average molecular weight", as used in the present, means the weighted average molecular weight as determined by using gel permeation chromaeography according to the pro-isole found in Colloids and Surfaces A. (Colloids and surfaces A.) Physico Chemical &; Engineering Aspects (Physico-chemical and engineering aspects), Vol. 162, 2000, pages 107-121. Unless otherwise specified, all molecular weight values in the present refer to the weight average molecular weight.

The fibrous structure The fibrous structure of the present invention can be incorporated into a hygienic production of single-leaf or multi-leaf paper. The fibrous structures can be shortened as by crimping and / or microcontraction and / or rapid transfer, or unclipped as unriginated; crimped from a cylindrical dryer with a curling blade, reeled from a cylindrical dryer without the use of a curling blade, or processed without a cylindrical dryer. The fibrous materials of the present invention are useful in paper products, especially hygienic products of paper included, including, but not limited to: conventionally pressed paper with locker; densified iisú paper with paírón; and high-volume iris paper, non-compacted tissue paper. This paper can be homogeneous or multilayered and the products produced from it can be single sheets or multiple sheets. In one embodiment, the fibrous structure and / or tissue paper hygienic production of the present invention can be measured at a rate of approximately 10 g / m.sup.2 to approximately 120 g / m.sup.2, and a density of approximately 0.60 g / c.sup.c. or less. In another embodiment, the fibrous paper and / or tissue paper hygienic product of the present invention may show a basis weight below approximately 50% by weight. g / m2; and a density of approximately 0.30 g / cm3 or less. In another embodiment, the fibrous and / or hygienic paper production of the present invention may exhibit a density of about 0.04 g / cm 3 to about 0.20 g / cm 3. The fibrous structures can be chosen from the group comprising: fibrous structures dried by air circulation, fibrous structures of differential density, wet fibrous strands, conventional fibrous strands, fibrous strands of consolidated strands, fibrous strands of spinning by spraying and mixtures of these. . Fibrous structures can be made with a fibrous filler that produces a conical single-layer fibrous embryo or a fibrous filler that produces a multi-layered embryonic coniferous fibrous maternal. The fibrous structures of the present invention, and / or the hygienic paper products comprising them, can have a total dry traction of more than 150 g / 2.54 cm (150 g / inch) and / or of approximately 200 g / 2.54. cm (200 g / inch) to approximately 1000 g / 2.54 cm (1000 g / inch) and / or approximately 250 g / 2.54 cm (250 g / inch) to approximately 850 g / 2.54 cm (850 g / inch) as It is measured through the Dry-Uradic Testing Phase described in the Presence. The fibrous materials of the present invention, and / or the paper hygienic products comprising them, may have an initial wet initial ratio of at least about 25 g / 2.54 cm (25 g / inch) and / or at least about 40 g / 2.54 cm (25 g / inch) and / or at least about 40 g /. g / 2.54 cm (40 g / inch) and / or at least about 60 g / 2.54 cm (60 g / inch) and / or at least about 80 g / 2.54 cm (80 g / inch) and / or at least approximately 100 g / 2.54 cm (100 g / inch). It is desirable that the fibrous structures and / or hygienic paper products comprising them have an initial total wet tensile less than about 600 g / 2.54 cm (600 g / inch) and / or less than about 500 g / 2.54 cm ( 500 g / inch) and / or less than approximately 400 g / 2.54 cm (400 g / inch). The initial moist fraction of the fibrous striations and / or the hygienic p roducts exhibiting the same is true and sim pular f inatures through the trial period of the initial humid initial fraction described in the witness Initial wet traction may be inherently present in the fibrous process as a result of the materials forming the fibrous structure and / or the process used to fabricate the fibrous structure and / or may be provided by the presence of a strength additive in the process. wet in the fibrous structure. Wet strength additives are known in the industry.

Additives of the fibrous structure Any of the additives of fibrous materials / hygienic paper products, including wet strength additives, known to those experimented in the industry may be incorporated into fibrous materials and / or hygienic products of paper. The present invention provides that fibrous materials / hygienic paper products show improved wet strength properties as described herein, as compared to fibrous materials / hygienic paper products that include a conventional wet strength additive. . A non-exhaustive example of an additive of wet strength resistance suitable for use in the fibrous webs and / or tissue paper hygiene products of the present invention include the wet weathering additives disclosed herein.

Adjuvants of timeless wet strength Non-exhaustive examples of wet weathering additives suitable for use in the fibrous structures of the present invention generally have weight average molecular weights of from about 20,000 to about 400,000 and / or from about 50,000 to about 400,000 and / odeapproximately 70,000 to approximately 400,000 and / or from approximately 70,000 to approximately 300,000 and / or from approximately 100,000 to approximately 200,000. By forming the fibrous structures and / or the hygienic paper products of the present invention, the wet strength additives, if present, can be added as dilute aqueous solutions at any point in the papermaking process. where wet additives are usually added. These non-fibrous additions are described in Young, "Fiber Preparatio n and Approach Flow" (Preparing the fiber and flow of the raw material) Pulp and Paper Chemistry and Chemical Technology, Vol. 2, Vol. pages 881-882, which is incorporated as a reference. In one embodiment, the fibrous materials of the present invention comprise from about 0.005% to about 5% and / or from about 0.1% to about 2% and / or from about 0.1% to about 1% by weight of the fiber. The temporary wet strength additives of the present invention impart wet strength properties and wet breakdown properties to the fibrous materials and / or hygienic paper products of the present invention. It has been found that temporary wet strength additives with high weight average molecular weights (for example, those exceeding 300,000) can decompose unacceptably slowly for consumer purposes. They may not achieve a wet tensile decomposition rate greater than 35-45% after 5 minutes and / or greater than 50-65% after 30 minutes. In addition, it has been observed that the wet weathering additives with excreted low average weight molecular weights (for example, those less than 70,000) can have very low wet strength and may not be as temporary strength additives in wet for fibrous materials and / or hygienic paper products. The temporary wet strength additives according to the present invention have the formula: Structure where: A (the portion present in the monomeric unit of reciprocal crosslinking) independently is an electrophilic portion, non-exhaustive examples of which include the following: O O O II II ?? - C -X - (R,) -CH or - CH Z (the portion present in the monomeric homo-crosslinking unit) independently is a nucleophilic portion capable of forming an unstable covalent bond with the electrophilic portion, non-exhaustive examples of which include the following: O II - C -X - (Ra) -OH or -OH. and X independently is -O-, -NH-, or -NCH3-; and R1 and R2 independently are aliphatic groups susíiuuidos or unsubstituted; Y-i, Y2, and Y3 independently are -H, -CH3, or a halogen; Q is a cationic portion; and W is a non-nucleophilic portion or a nucleophilic portion that does not form a covalent bond with the electrophilic portion. Non-exhaustive examples of portions for W include heterocyclic portions of water-soluble nitrogen and / or water-soluble carboxylic acid portions. The mole percent of a varies from about 1% to about 47%, preferably from about 5% to about 30%, the mole percent of b ranges from about 0% to about 60%, preferably from about 0% to about 45%. %, the mole percent of c varies from about 10% to about 90%, preferably from about 30% to about 80%, and d ranges from about 1% to about 40%, preferably from about 2% to about 20%, more preferentially from approximately 5% to approximately 12%. Unless expressly specified otherwise, the values for a, b, c, and d will be values in mole per hundred based on the average number of monomer units in the polymeric backbone of the wet weathering additive of the present invention. . The monomeric units of the polymeric main chain of the wet weathering additive of the present invention are randomly distributed throughout the polymer in proportions corresponding to the mole percent ranges described herein. Each of the classes of monomer units may include a single monomer or may include combinations of two or more different monomers in that class. The mole percent of each monomeric unit in a class of monomer units can be chosen independently. to. Monomeric unit of reciprocal recrossing monomer The monomeric reciprocal crosslinking unit of the temporary wet strength additives of the present invention comprises an electrophilic portion and can be obtained from a monomer having the following structure: HE HAS H Yi where Yt and A are as defined earlier. If A is: O O II II - C-X- (R,) - CH R-i can be a branched or linear aliphatic group, susíiuuido or no susíiuuido. The aliphatic group preferably comprises a methylene or a C2-C8 chain, more preferably a methylene or a C2-C7 chain, even more preferably a methylene or a C2 chain. Preferably, if R-i is substituted, the substituent (s) will include a functionality of removal of elecronics in the alpha-methylene position relative to the aldehyde portion. Suitable electrostatic removal groups include, but are not limited to, halogens such as chlorine, fluorine and bromine; normal amides such as -NHCOR 'wherein each R' can be independently branched or linear aliphatic C? -C? 2 groups, susi? uid or non-susi? uid; hydroxyl groups, preferably with C C8 alkyl chains; cyano groups, eg -CN; and nitro groups, eg -NO2. The aldehyde functionality optionally can be chemically protected during polymerization by techniques well known in the industry. Non-exhaustive examples of suitable reciprocal cross-linking monomer units include N- (2,2-dimethoxy-ethyl) -N-methyl acrylamide, acrolein, meiacrolein, glyoxylated acrylamide, 3,3-dimethoxypropyl acrylamide, 3,3-diethoxypropyl acrylamide, 3,3- dimethyloxypropyl methacrylamide, 2,2-dimethioxy-1-methylethyl acrylate, 3,3-dimethyloxypropyl methacrylamide, 2- (acryloylamino) eianal dimethylacetal, 2- (methacryloylamino) propanaldimethyl acetal, 5- (acryloylamino) penanal dimethylacetal, 8- (acryloylamino) octanal dimefilacelal and 3- (N-acryloyl-N-methylamino) propanal dimethylar acetal. N- (2,2-dimethioxy-yl) -N-methyl acrylamide is more preferred. Other appropriate monomers are disclosed in the USA. no. No. 3,410,828 of Kekish filed on November 12, 1986 and US Pat. no. 3,317,370 of Kekish granted on May 2, 1967; Both patents are incorporated herein by reference. b_. Monomeric Homo-Crosslinking U The monomeric homo-crosslinking uof the wet time-resistive additives of the present invention comprises a nucleophilic portion capable of forming an unstable covalent bond with an electrophilic moiety (ie, the aldehyde moiety present in a monomeric monomer u. reciprocal cross-linking). As a consequence of this unstable covalent bond, the nucleophilic portion can cross-link to each other two or more wet time-resistive additives, at least one of which is a wet timeless additive of the present invention, via the covalent bond. unstable formed between the nucleophilic portion present in an additive of timeless wet strength and the electrophilic portion present in the wet additive epoxy. Thus, in other words, a mixture comprising only wet weathering additives of the present invention can be crosslinked to each other via the nucleophilic portion, as described above, or a mixture of wet weathering additives of the present invention. Invention with conventional additives of temporary wet strength can be cross-linked with each other via the nucleophilic portion present in the temporary wet strength additives of the present invention. A non-exhaustive example of an appropriate nucleophilic portion is a hydroxyl-containing portion. The monomeric uof homo-crosslinking of the temporary wet strength additives of the present invention, that is, the monomer u having a Z attached thereto in Formula I, can be obtained from a monomer which has the following structure: H H where Y3 and Z are as defined above. If Z is: R 2 can be a branched or linear aliphatic group, susíifuido or no susfiíuido. The preferred aliphatic group comprises a C2-C18 chain, more preferably a C2-C7 chain, even more preferably a C2-C4 chain. If Z is -OH, the hydroxyl group in the monomeric homo-crosslinking umust be chemically pro- tected during polymerization by means of techniques well known in the industry. Non-exhaustive examples of suitable homogenous cross-linking monomer u include the following: 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 4-hydroxybuyl acrylate, glyceryl mono-meiacrylate, glyceryl mono-acrylate, 2-hydroxypropyl acrylate 2-hydroxypropyl methacrylate, hydroxypropyl acrylate 4 -hydroxybutyl methacryloyl, diethylene glycol mono-methacrylate, sorbitol methacrylamide, 2-hydroxymethyl acrylate, 3-mefyl bufanol-2 methacrylate, 3,3-dimethylene butanol-2 methacrylate, ethyl 2- (hydroxymethyl) acrylate, N-2-hydroxyethyl meph acrylamide , N- (2-hydroxypropyl) methacrylamide, 2-acrylamidoglycolic acid, poly (ethylene glycol) acrylate and acrylamido-pyroxymethylmelanic acid. Other non-exhaustive examples of monomeric homo-crosslinking u include the poly (ethylene glycol) acrylate having the formula: wherein n is an integer from 2 to 100, preferably from 2 to 50, more preferably from 2 to 30, and a monomeric homocrine uhaving the formula: Cationic Monomeric U The cationic monomeric ucan be obtained from any polymerizable monomer that imparts a positive charge to the temporary wet strength additive of the present invention subsequent to polymerization. Cationic monomeric u can and do preferentially carry a positive electrodesic charge when dissolved in water. Suitable counterions may include chloride, fluoride, bromide, iodide, sulfate, methylsulfafo, phosphate and the like. Non-exhaustive examples of suitable cationic monomer u include 3- (methacryloylamino) propyltrimethylammonium chloride, 2-vinyl-N-methylpyridinium chloride, diallyldimethyl ammonium chloride, (p-vinylphenyl) -imethylammonium chloride, 2- (dimethylamino) ethylacrylate, 2-dimethylaminoethyl methacrylate, trimethyl (p-vinylbenzyl) ammonium chloride, p-dimethylaminoethylstyrene, dimethylaminopropylacrylamide, 2-rethylacryloxymethyltrimethylammonium meilylsulfafo, and 3-acrylamido-3-methylbutyltrimethylammonium chloride. Other non-exhaustive examples of suitable cationic monomeric units of the present invention include: d. Non-Nucleophilic and / or Nucleophilic Monomeric Units The non-nucleophilic and / or nucleophilic monomeric unit (the monomeric unit containing W) that does not form a stable covalent bond with the electrophilic portion (ie, the aldehyde portion present in a monomeric unit of reciprocal crosslinking) may optionally be incorporated into the temporary wet strength additive of the present invention. The non-nucleophilic monomeric unit can be obtained from a monomer having the following structure: wherein W and Y2 are as defined above, with Y2 preferably being H. Preferably W is hydrophilic. If W is a hydrophobic portion, the amount incorporated (b) must be below the levels that would result in a copolymer that is insoluble in water.

Non-exhaustive examples of suitable non-nucleophilic monomer units include monomer units containing a heterocyclic portion of nihologen, such as vinyl oxalidones, vinyl imidazoles, vinyl imidazolines, vinyl pyridines and vinyl pyrrolldones, such as N-vinyl pyrrolidone, 2-vinyl pyrrolidone, . Other useful nitrogen monomers useful as the initial monomer unit reagents include N-vinyl-5-methyl-2-oxazolidine, N-vinyl-2-oxazolidone, N-vinyl pyrrolidone, N-vinyl-midazole, N-vinyl-2. -methyl imidazole, 2-vinyl imidazole N-vinyl-3-morpholinone, N-vinyl caprolactam, etc. Vinyl pyrrolidones are preferred among these nitrogen heterocycles. Other non-exhaustive examples of non-nucleophilic hydrophilic monomer units are N, N-dimethyl acrylamide and methoxy poly (ethylene glycol) methacrylate. Non-exhaustive examples of non-nucleophilic hydrophobic monomer units include alkyl, especially C C4, esters and styrenes of acrylate and methacrylate. Non-exhaustive examples of suitable non-nucleophilic monomer units include methyl methacrylate, methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-propyl methacrylate, ethyl methacrylate, iso-propyl methacrylate, n-butyl acrylate, isobutyl acrylate, isobutyl methacrylate , n-butyl methacrylate, α-methyl styrene, benzyl acrylate and ethylhexyl acrylate. In one embodiment, the non-nucleophilic hydrophobic monomer unit includes a butyl acrylate. Non-exhaustive examples of nucleophilic monomer units that do not form stable covalent bonds with the electrophilic portion include carboxylic acids. Non-exhaustive examples of suitable carboxylic acids include C 1 monocarboxylic acids and C 1 dicarboxylic acids and may be selected from the group consisting of acrylic acid, meiacrylic acid, acetic acid acryloxypropionic acid, vinyl acetic acid, vinylpropionic acid, croonic acid, alpha acrylic acid, alpha acid -chloroacrylic, alpha-cyanoacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, melilenomalonic acid, its salts, and mixtures thereof. More preferably, the C3-8 monocarboxylic acids, C4-8 dicarboxylic acids, their salts and mixtures thereof, may be selected from the group comprising acrylic acid, meiacrylic acid, and maleic acid. It has surprisingly been found that fibrous structures and / or tissue paper hygiene products that include a wet strength additive, especially a wet weathering additive, more especially a wet weathering additive comprising a monomeric unit do not nucleophilic such as b util to crilaio and / or monomeric monomeric use of the crosslinking comprising a dep oli (ethylene glycol) to crilato for example minimizes the negative effect the curling on the wet traction of the fibrous structure and / or the tissue paper hygienic product and / or improves the softness of the fibrous structure and / or the tissue paper hygienic product as compared to a fibrous structure and / or the tissue paper hygienic product having a wet strength additive differentiate the which are described in the present. Without being limited by theory, it is believed that the wet strength additives of the present invention show a lower Tg than the conventional wet strength additives and thus as a result did not fracture during the curling process. By not fracturing during the curling process, the loss of wet traction in a fibrous structure and / or tissue paper hygienic product comprising wet wet adhesive is minimized or inhibited, in particular where the wet strength additive exhibits a Tg less than about 100 ° C.

The temporary wet strength additives of the present invention can be made from a wide variety of techniques, including mass, solution, emulsion, or suspension polymerization. Polymerization techniques and techniques are generally described in the Encyclopedia of Polimer Science and Technology, I níerscience Publishers (New York), Vol. 7, pages 361-431 (1967), and Kirk-Othmer Encyclopedia of Chemical Technology, Kirk-Othmer Chemical Encyclopedia, Volume 18, pages 740-744, John Wiley & amp;; Sons (New York), 1982; Both publications are incorporated herein by reference. See also Sorenson, WP and Campbell, TW, Preparative Methods of Polymer Chemistry, second edition, Interscience Publishers (New York), 1968, pages 248-251, incorporated as reference in the present, for the techniques reaction generals suitable for the present invention. Preferentially, the temporary wet strength additives are made by means of free radical copolymerization, using water soluble initiators. Suitable free radical initiators include, but are not limited to, thermal initiators, redox couples, and photochemical initiators. Preferred are redox and photochemical initiators for the polymerization processes initiated at temperatures below about 30 ° C (86 ° F). These initiators are generally described in Kirk-Oihmer Encyclopedia of Chemical Technology, third edition, John Wiley & Sons (New York), volume 13, pages 355-373 (1981), incorporated by reference in the present. Typical water-soluble initiators that can provide radicals at 30 ° C or less include the redox pairs, such as potassium persulfate / pyrimidine and ascorbic acid / hydrogen peroxide. A preferred method uses thermal initiators in polymerization processes performed above 40 ° C (104 ° F). Water-soluble initiators can be used that can provide radicals at 40 ° C (104 ° F) or higher temperatures. These include, but are not limited to, hydrogen peroxide, ammonium persulfate, and 2,2'-azobis (2-amidinopropane) dihydrochloride. In a particularly preferred method, the initial water-soluble monomers are polymerized in an aqueous solvent of alcohol at 60 ° C. (140 ° F) using 2,2'-azobis (2-amidinopropane) dihydrochloride as the initiator. The solvent usually must contain at least about 10% by volume of alcohol in order to avoid gelation of the polymerization reaction medium. Suitable alcohols for use in this reaction include low molecular weight alcohols such as, but not limited to, melanol, ethanol, isopropanol, and butanol. Another technical aspect is solution polymerization as described in the US. no. 3,317,370, Kekish, granted on May 2, 1967 and the USA payee. no. 3,410,828, Kekish, issued on November 12, 1968; Both patents are incorporated herein by reference. According to this process, the acrolein, or other aldehyde monomer, is copolymerized with a water-soluble, non-nucleophilic, water-soluble, nanophilic, and a redox initiator system. The copolymer is then rendered cationic by reacting the copolymer with a quaternary amine or amine soluble in water. The mines, including the quaternary amines, which are useful include, but are not limited to, primary, secondary, and tertiary amines, such as ethylene diamine, dieylene diamine, ethylene diamine, ethylene diamine, or the partial or partial quartz derivatives of any of the abovementioned amines. , the hydrazides and quaternaries of these, asbeiaine and betaine chloride hydrazide, NN-dimethylglycine hydrazide, dimethyl asymmetric hydrazides, polymers such as those formed by the reaction of urea and polyalkylene polyamine, guanidines, biguanides, guanilureas, mono and polyhydroxy polyamines and quaternaries thereof, eic. When the emulsion copolymerization technique is used, it will be necessary to control the molecular weight within the ranges provided herein. Appropriate methods for this are discussed later. Generally, as the weight average molecular weight of the wet weathering additive decreases, the wet strength is reduced and the decomposition of the wet strength is accelerated. The wet weathering additives of the present invention should have a molecular weight of at least about 20,000, preferably at least about 70,000. The upper limit for molecular weight will be limited by a combination of the additive's ability to impart the desired level of decomposition of strength, which is discussed below, and practical considerations such as a viscosity sufficiently low to apply to the pastes of pulp or pulp leaves and technical and economic concerns related to the formation of these high molecular weight additives. Generally, the molecular weight should be less than about 400,000, preferably less than about 300,000, and more preferably less than about 200,000. The molecular weight can be controlled by means of the methods known to persons with experience in the industry, such as varying the reaction temperature (increasing the temperature usually results in a reduction in molecular weight), varying the concentration of the initiator of free radical, and use chain transfer agents. Suitable chain transfer agents include, but are not limited to, beta-mercaptoethanol, thioglycolic acid, glycerol, acetone, and isopropanol. Other suitable chain transfer agents include, but are not limited to, those described in the Polymer Handbook, second edition, J. Brandrup and EH Immergut, editors, Wiley-lntersciences (New York), (1975) , pages II-57 hasía 11-104, incorporated as reference in the present.

Non-exhaustive examples of synthesis A non-exhaustive example of a suitable wet strength additive, in particular a temporary wet strength additive, for inclusion in a fibrous web and / or tissue paper hygienic product of the present invention, is as follows structure: it can be prepared as follows: N- (2,2-dimethoxy-ethyl) -N-methyl acrylamide (45.71 g, 0.2369 mol), 2-hydroxyethyl acrylate (214.55 g, 1.8477 mol), [3- (methacryloylamino) propyl chloride] trimethylammonium (58.27 g, 0.2640 mol), n-butyl acrylate (33.83 g, 0.2682 mol) dihydrochloride 2,2'-azobis (2-amidinopropane) (2.147 g, 7.917 mmol), 2-propanol (152 mL), acetone ( 650 mL) and water (1.48 L) are added to a three-necked 5 L round bottom flask, equipped with a mechanical stirrer, temperature probe and reflux condenser. This solution is irrigated with Ar for 30 minutes and then heated to ambient temperature at 55 ° C, with agilation under Ar, at which time the reaction is exothermic. The reaction time is usually from about 58 ° C to about 60 ° C until the reaction is no longer exothermic. The solution was heated at 60 ° C for an additional 20 hours. This polymer will have an acetyl protecting group. An analytical sample is reserved and characterized by protonic nuclear magnetic resonance and gel permeation chromatography. The 2-propanol and the ketone are removed in vacuo and then the viscous solution is transferred to a 12 L round bottom flask of neck necks with water (2.9 L) and then HCl (49 mL) is added, concentrated. The solution was heated at 40 ° C for 4 hours under nihologen to hydrolyze the protecting group. After cooling to ambient temperature, the solution was adjusted to pH 5 with NaOH. The weight average molecular weight of such polymer will usually be about 92,000, a, b, c and ordinarily will be from about 9% to about 11%, from about 9% to about 11%, from about 69% to about 71%, and from about about 9% to about 11%, respectively. The Tg for this typical polymer will be approximately 75 ° C.

Testing methods A Trial period of the decomposition percentage to. Preparation of the sample: hand towels If there is no fibrous sample structure, then a hand towel can be prepared to test the decomposition rate. Hand towels can be made from 100% Nordic Sofíwood Kraft (NSK) fibers not refined, mixtures of NSK and eucalyptus, or other fibers as desired. After dispersing the fibers of NSK or other fibers in water, a resin of temporary resistance in wet state is added to disintegrate the pulp and the watered pass is stirred during a fixed period of time varying from 1 to 60 minutes. The hand towels are manufactured essentially according to the TAPPI T205 standard with the following exceptions: (1) The sheet is formed on a polyester mesh forming fabric and drained by suction instead of pressed; (2) the embryonic continuous material is transferred by vacuum to a polyester mesh for papermaking; (3) The iron hole is made of steam on a rotary drum dryer. b. Test 1. Strips 11.33 cm (4.5 inches) wide by 10.16 cm (4 inches) long are prepared from the fibrous structure or the hygienic production of paper to be tested. Strips of 2.54 cm (1 inch) wide slice are cut from the fibrous structure or the tissue paper hygienic product. 2. In a conditioned enclosure where the temperature is 23 ± 3 ° C (73 ± 4 ° F) and the relative humidity of 50 ± 10% a sample line is mounted [2.54 cm (1 inch) in width] On an apparatus for testing of the fraction, a Tensile Tesfer model no. 1376-18 commercially available from Thwing Albert I nsírument Company. The equipment for testing works at a speed crosshead of 2.54 cm / minute (1 inch / minute). The indexing device is fixed to the lower clamp of the tensile tester such that the horizontal bar is parallel to the surfaces of the clamps and is otherwise located symmetrically with respect to the clamps. The position of the lower clamp was adjusted so that the horizontal axis of the bar is exactly 2.54 cm below the upper clamp. 3. A liquid container fills up to 0.3175 cm from the top of the container with running tap water, which contains 23 ppm of calcium ion, 7 ppm of magnesium ion and 67 ppm of sodium bicarbonate. The sample strip being measured is threaded under the bar in the wet traction device. The exfers of the strip of sample are placed together, the looseness is eliminated and the clamp is fixed. The sample strip is centrally located with respect to the horizontal bar and the upper clamp. The liquid container was lifted by dipping the loop end of the sample strip to a depth of at least 1.9. Exactly five seconds after the test apparatus has been lifted into place and the liquid container remains in place, the apparatus is coupled for testing. The load will be recorded. The wet fraction is expressed in units of g / inch (g / 2.54 cm).

Sum of maximum loads for the execution of tests Average wet traction (g / 2.54 cm) = - 2 x number of traction strips tested The wet fraction is calculated for the machine direction (MD) and the cross direction of the machine (CD). The wet total ratio (TWT) = Average wet traction (MD) + Average wet traction (CD) 4. A sample strip is then attached to the Intelecf 500 as described earlier in step 3. The liquid container it was lifted to its highest position by immersing the loop end of the specimen to a depth of at least 3/4"(1.9 cm) in tap tap water.The wet traction load is read again five minutes after the liquid container is lifted in place 5 Total wetting (TWT) 5 seconds soaking - Total wetting (TWT) 5 minutes soaking Decomposition rate = • x 100 Total wet traction (TWT) 5 seconds soak . Step 4 is repeated except that the sample line is submerged in tap water for 30 minutes instead of 5 minutes. The decomposition percentage is calculated as follows: Total wet traction (TWT) 5 seconds soaking - Total wet traction (TWT) 30 minutes soak -5 Percent decomposition = x 100 Total wet traction (TWT) 5 seconds soak B. Total dry fraction test method 1. Strips 11.33 cm (4.5 inches) wide by 10.16 cm (4 inches) in length of the fibrous structure or tissue product or hygienic paper to be tested are prepared. 2.54 cm (1 inch) wide sample strips are cut from the fibrous material or the tissue paper hygienic product. 2. In a conditioned room where the temperature is 23 ± 3 CC (73 ± 4 ° F) and the relative humidity is 5 50 + 10%, a sample strip of 2.54 cm is placed on an electronic device for testing This is an EJA Tensile Tesíer model no. 1376-18 commercially available from Thwing Albert Insírumenf Company. The elecronic apparatus for testing is operated according to the manufacturer's instructions at a crosshead speed of 5.08 cm / minute and a gauge length of 10.16 cm. Dry traction is expressed in units of g / inch (g / 2.54 cm).

Sum of maximum loads for the execution of tests Average dry traction (g inch) = - - Number of traction strips tested The total dry traction is the arithmetic total of the traction in the direction of the machine and in the cross direction of the machine of the sample strips.

O Test method for reducing the percentage of obstruction A fibrous and / or hygienic control tissue paper product comprising a wet strength additive having a basis weight of 34.18 g / m 2, an initial wet foraction fraction is obtained. of at least 40 g / 2.54 cm, preferably from about 60 g / 2.54 cm to about 70 g / 2.54 cm. Strips 71.12 cm long by 10.43 cm wide are obtained from the fibrous control structure and / or tissue paper hygienic product and from the fibrous structure and / or tissue paper hygienic product to be tested. Each line bends individually on itself to form a folded sample 10.16 cm long by 10.43 cm wide. In a conditioned room where the temperature is 23 ± 3 ° C and the relative humidity is 50 ± 10%, six of the folded conirol fibrous structures and / or tissue paper hygiene products are placed one at a time, with a 10-second interval in a Kohier Portrait Lite toilet with a discharge volume of 6 L. Each folded sample is weighed and placed in the toilet. The toilet was connected to a drain pipe of 100 mm internal diameter. The total length of the drainage pipe is 13.25 m-14 m. The drain pipe includes four curves made of two 45 ° elbows. The pressure of the water supply line is regulated to 138 ± 21 kPa. An individual "T" of 100 mm internal diameters is introduced into the junction between the toilet and the drain pipe to provide venililation. After all six bent control samples have been placed in the toilet, the toilet is discharged. The location of each toilet sample in the toilet and / or the drain line is recorded. If a sample fails to exit the toilet bowl or drain pipe, the test is recorded as an obstruction incident. If the water level in the toilet bowl is normal after discharge, but the samples did not leave the toilet bowl / drain line, an additional discharge action was performed followed by the application of a degasser if necessary to Remove samples from the toilet / drain pipe. Esío is reported as an incident of obstruction. If the water level in the toilet bowl is lower than normal after discharging and the samples did not come out of the toilet bowl / drain line on their own, the drainpipe is considered to be obstructed and the discharge to be discharged. it registers as a fault (an obstruction incident). The tissue paper is then removed from the drain line with the use of a plunger before proceeding with the next test. If the bowl of the toilet / drainpipe begins to get dark and the water level rises in the bowl of the toilet but then discharges on its own without any intervention. This is recorded as an obstruction incident. The test is performed by repeating the previous steps with a freshly cleaned toilet a total of ten times. The percentage of obstruction or the number of times of ten that an obstruction incident (failure) has occurred is calculated. The above steps are repeated with respect to the fibrous structures and / or the hygienic paper products to be tested. The reduction is calculated (for example, 1.5 times, 2 times, 2.5 times, 3 times, etc.) in percentage of obstruction, if any, dividing the obstruction percentage of the control by the percentage of obstruction of the sample to be tested.

D, Softness Test Method The "softness" of a fibrous structure and / or tissue paper hygienic production according to the present invention is determined as follows. After the softness test it is advisable to condition the samples to be tested in accordance with the method Tappi no. T4020M-88. In this method, the samples are preconditioned for 24 hours at a relative humidity level of 10 to 35% and within a temperature range of 22 ° C to 40 ° C. After this step of preconditioning, the samples should be conditioned for 24 hours at a relative humidity of 48% to 52% and at a temperature of 22 ° C to 24 ° C. Ideally, the softness panel test should be performed within ambient environmental humidity and humidity values. In case it is not feasible, all the samples, including those of conírol, must experience identical ambient exposure conditions. The softness test is performed as a pairwise comparison, ie in pairs in a similar way to that described in the "Manual on Sensory Testing Methods", ASTM Special Technical Publication 434, published by the American Society For Tesíing and Maíerials, 1968 and which is incorporated here as a reference. Softness is evaluated by a subjective test using what is called a paired difference test. The method uses an external reference to the test average. For the perceived tactile softness, two samples are presented so that the subject can not see the samples, and the subject is required to choose one of them based on the tactile smoothness. The result of the test is reported in what is called the Panel Rating Unit (PSU, by its English language). With regard to the softness test, to obtain the softness data reported here on the PSU, several softness panel tests are performed. In each of the tests, ten judges with practice in the softness qualification are asked to rate the relative softness of the pair paired sets. Each of the pairs of samples is judged one at a time by each judge: a sample of each pair is called C and Y is heard. Briefly, each sample X is scored against its paired sample Y as follows: 1. A sample is granted. degree of plus one if you consider that X could be a little softer than Y and a degree of minus one if you consider that Y could be a little softer than X; 2. a degree of plus two is granted if it is considered that X is surely a little softer than Y and a degree of minus two is granted if one considers that Y is surely a little softer than X; 3. a grade of more is granted if one considers that X is bastante softer than Y and a degree of minus three is granted if one considers that Y is quite softer than X and, finally, 4. a degree of more than one if X is considered to be much softer than Y and a degree of minus four is given if one considers that Y is much softer than X. The average of the ratings is calculated and the resulting value is in PSU. The resulting data is considered to be the results of a panel test. If more than one pair of samples is evaluated, then all pairs of samples are classified by category according to their ratings by paired statistical analysis. Then, the category moves up or down as required to give a PSU value of zero to any sample that is chosen to be the zero base reference. The other samples then have values more or less as determined by their relative ratings with respect to the zero-based reference. The number of panel tests performed and averaged is such that about 0.2 PSU represents a significant difference in the subjective perceived softness. The gross PSI rating is then corrected for lint and dry traction. For each fluff value +1 over 7.0 (the reference fluff value), the gross PSU score is reduced by 0.15 PSU. For every 100 g of the dry total traction value over 450 g / 2.54 cm (450 g / inch) (the total value of the reference dry traction), the gross PSU rating is reduced by 0.35 PSU. The fibrous webs and / or tissue paper hygienic products of the present invention are compared to a fibrous web and / or a tissue paper hygienic product that includes a commercially available and / or known wet strength additive at the time of presentation. request.

Claims (8)

1. A fibrous structure characterized in that it shows a 5 minute decomposition percentage greater than 45% and / or a 30 minute decomposition percentage greater than 65% as determined by the Decomposition Rate Test Method described herein.

2. The fibrous structure according to claim 1, further characterized in that the fibrous structure and / or the hygienic product of single or multi-sheet tissue paper comprising it exhibits an initial wet tofal traction of at least 30 g / l. 2.54 cm (30 g / inch).

3. The fibrous preparation according to any of the preceding claims, further characterized in that the fibrous structure comprises a wet strength additive, preferably wherein the wet strength additive has the following formula: wherein: A is an electrophilic portion independently selected from the group comprising: fl fl fl - C -X - (Rn) -CH or - CH Z is chosen independently from: fl - C -X - (R ^ -OH or -OH and X is independently chosen from -O-, -NH-, or -NCH3-, and R1 and R2 are each independently selected from substituted or unsubstituted aliphatic groups: Y1; Y2, and Y3 are independently selected from -H, -CH3, or a halogen; W is independently a non-nucleophilic portion or a nucleophilic portion that does not form a stable covalent bond with the electrophilic portion A; and Q is independently a cationic monomer unit, wherein the mole percent of a is from 1% to 47%, the mole percent of b is from 0% to 70%, the mole percent of c is 10% a 90%, and the mole percent of d is from 1% to 40%; and the temporary wet strength additive has a weight average molecular weight of at least 70,000.

4. The fibrous structure according to claim 3, further characterized in that the wet strength additive is present in the fibrous structure at a level of 0.005% to 5% by weight of the fiber.

5. The fibrous structure according to any of the preceding claims, further characterized in that the fibrous structure shows a slope of the decomposition rate greater than 13.

6. The fibrous structure according to any of the preceding claims, further characterized by the fact that a reduction in percentage of obstruction of more than 1.5 times as determined by the reduction test period in percentage of obstruction described in the present.

7. A tissue paper hygienic product comprising a fibrous structure according to any of the preceding claims.

8. A tissue paper hygienic product according to claim 7, further characterized in that it shows an improvement in softness of more than +0.20 PSU.