Process for producing tissue paper by using a treating agent

0001The present invention relates to a method for the production of tissue paper and products made therefrom using a treatment agent and the use of a treatment agent.

0002Softness is an important property of tissue products such as handkerchiefs, facial tissues, toilet paper, napkins and also hand or kitchen towels and describes the feeling that the tissue paper creates when it touches the skin.

0003As described in the weekly paper for paper manufacture issue 11/12, 1988, on page 435 ff. In the article "Softness and Softening of Hygiene Tissue", the term softness is generally understandable, but extremely difficult to define because there is no physical method of determination and therefore there is no recognized industry standard as a standard for classifying different degrees of softness.

0004In order to really be able to grasp the softness, it must be determined by a subjective method, ie it is determined by a so-called panel test, in which several trained test persons give a comparative judgment.

0005Softness can be broken down into its main characteristics, surface softness and softness:

0006Surface softness describes the feeling you feel when you run your fingertips lightly over the surface of the tissue sheet.

0007Crumple softness is the sensory impression that a tissue squeezed with the hands creates during the process of squeezing.

0008The usual measures for producing or improving the softness of tissue paper can be divided into three main categories:<ul id="ul0001" list-style="none" compact="compact"><li>1. Selection of raw materials, especially pulp,</li><li>2nd mechanical measures (e.g. grinding, sheet formation, drying and creping, smoothing) and</li><li>3rd chemical additives.</li></ul>

0009Tissue papers require different properties depending on the intended use. For kitchen towels and even more so for towels, strength, in particular strength when wet and high suction power, are required in order to meet the demands of the consumer. For other products, such as handkerchiefs or facial tissues, softness of the surface and very good suppleness are outstanding properties that determine the practical value of these products in addition to strength. For toilet paper, a combination of dry strength, in addition to good softness and good thickness, determines suitability for use and consumer acceptance.

0010It is a particular challenge for papermakers to bring the various, often contradicting, influencing factors into a particular balance in order to use them to present the optimal combinations of properties required by the consumer for the end products sought.

0011It is now a sign of the times that across all product areas of hygiene articles, improving softness is one of the most important requirements for paper makers. Properties such as softness of a tissue product are determined in their basic formation by the manufacturing process and the selection of the raw and auxiliary materials, as previously discussed.

0012The tissue manufacturing process, regardless of its various variants, comprises the following procedural steps:

0013Suspending the fiber materials in water, possibly adding chemical auxiliaries to influence the product properties and process sequence, activating the fiber surfaces to open up the strength potential of the fiber raw materials by mechanical treatment such as grinding in a refiner, sheet formation by laying down the fibers, oriented or in a tangled position on one or between two endlessly rotating sieves of the paper machine with simultaneous removal of the main amount of dilution water to dry contents between 12 and 35%, drying of the primary nonwoven formed in one or more steps by mechanical and thermal means to a final dry content of around 93 to 97%. One of the most relevant steps for tissue production is the creping process, which dominates the properties of the finished tissue product in the conventional process. In today's dry crepe process, the creping is done on a drying cylinder, usually 4.5 to 6 m in diameter, the so-called Yankee cylinder, with the help of a crepe scraper at the aforementioned final dry content of the tissue paper. In older processes with lower demands on the tissue quality, the wet crepe process is also used, which is similar to the dry crepe process, but with lower dry contents below 80%, usually around 55 to 65% dry content, with subsequent drying on subsequent drying cylinders of a dryer section to the final dry content. In a subsequent step, the creped, finally dry raw tissue paper (raw tissue) is wound up on a supporting core to form a so-called drum or cut lengthways on sleeves to form mother rolls and is available in the form for further processing into finished products.

0014For the production of multi-layer tissue papers, such as. B. handkerchiefs, toilet paper, towels or kitchen towels, there is often an intermediate step with the so-called doubling, in which the raw cotton (raw tissue) is usually unwound in a drum number corresponding to the desired number of layers of the finished product and wound up into a common, multi-layer mother roll. In this processing step, smoothing or calibration in two- or multi-roll smoothing plants is often included. However, the smoothing (calibration) can also be carried out in the tissue production machine after drying and creping directly before the reeling.

0015The processing process, for example into folded products such as handkerchiefs or facial tissues, takes place in downstream, separate work steps in special processing machines designed for the task, the processes such as smoothing the tissue again, embossing the edges, sometimes combined with a flat and / or selective gluing to produce Layer adhesion of the individual layers to be brought together (raw tissue) as well as longitudinal section, folding, Cross-section, storage and merging of several individual tissues and their packaging in so-called tissue bags or special jewelry boxes as well as their merging into larger outer packaging or containers. Instead of the edge embossing, the layer adhesion generation can also be generated by knurling, as is the case, for. B. is common in cosmetic wipes.

0016In addition to the conventional tissue production process described, modified process technologies are used in particular in the USA, and increasingly also in Europe today, in which a special type of drying within the tissue machine improves the specific volume and, in this way, improves the softness of the tissue Tissues so produced is achieved. These processes, which exist in different subspecies, are referred to as TAD (Through Air Drying) processes. Its characteristic is that the "primary" nonwoven leaving the sheet formation is pre-dried to a dry content of about 80% on the Yankee cylinder before the final contact drying by blowing hot air through the nonwoven. The non-woven fabric is supported by an air-permeable sieve or belt and guided during its transport over the surface of an air-permeable, rotating cylinder drum. By structuring the support sieve or belt, any pattern of compressed and by deformation in the wet state can be generated on loosened zones, which lead to increased, medium, specific volumes and in connection with this an increase in softness, without the strength of the Nonwoven fabric drops below the level necessary for use. Another possibility of influencing the raw tissue production on softness and strength is the use of a layering in which the primary nonwoven to be formed is built up by a specially constructed headbox in the form of different layers of fibrous material, which are fed together as a stream of material for sheet formation. When using layering, nonwovens consisting of two, three or more layers belong to the prior art, for example DE-C 43 47 499. The surface softness can be significantly increased by suitable selection of raw materials in the channels of the headbox exit nozzle that determine the layering, for example the use of eucalyptus fibers on the nonwoven side facing the Yankee cylinder surface, which benefits the products made from the production of raw tissue.

0017In addition, the use of chemicals in the form of a lotion application to the raw tissue during the raw tissue production process, the doubling or the subsequent processing to improve the softness is known. The term "lotion" in cosmetic parlance includes, as is generally understood, aqueous or aqueous-alcoholic preparations with emulsifying active ingredients. In particular, the use of aqueous solutions or emulsions of polyhydroxy compounds such as glycol or polyethylene glycol or the use of polysiloxanes to improve the softness of tissue are described. However, it is not yet known that a significant increase in softness can be achieved as a synergy effect of a mixture of a polysiloxane with a polyethylene glycol in an aqueous emulsion.

0018The use of polysiloxanes as a treatment agent for improving the softness of tissue is described in the patent literature. However, it is not yet known that a significant increase in softness as a synergy effect of using a mixture of a polysiloxane with a polyhydroxy compound, such as. B. polyethylene glycol or glycerin in aqueous emulsion can be achieved as a treatment agent for tissue. For example, WO 90/09807 relates to a tissue product which contains at least one tissue layer, this tissue product containing 0.1 to 5% by weight of solids of a silicone compound. This is preferably an aqueous emulsion and / or solution of these silicone compounds. From this patent application the US patent 49 50 545 emerged.

0019EP-A-0 347 154 relates to tissue paper with a basis weight of 10 to 65 g / m² and a density of not more than 0.6 g / ml, this paper containing cellulosic fibers and a polysiloxane material, the amount being at least 0.004% polysiloxane based on the dry (fiber) weight of this nonwoven fabric. The subject of the US patent 50 59 282 which results from this is correspondingly restricted a tissue paper with a basis weight of 10 to 65 g / m² and a density of no more than 0.6 g / ml, said paper containing cellulosic fibers and an effective content of a polysiloxane material, said polysiloxane being applied uniformly to the outward surfaces of the tissue paper, said effective content of the polysiloxane being from 0.004% to 2% polysiloxane, based on the dry (fiber) weight of the tissue paper, said polysiloxane having a viscosity of 25 centistokes and more, and having an aging time of two weeks after its preparation, a wetting time of not more than 2 minutes. A manufacturing process for such paper is the subject of EP-A-347 153 or the corresponding US patent 52 15 626.

0020WO93 / 02252 relates to a production process for soft tissue paper with the step sequence of forming a sheet from aqueous suspension (wet laying) of cellulose fibers with formation of a nonwoven fabric (nonwoven fabric), drying the nonwoven fabric while increasing the temperature of the nonwoven fabric to at least 43 ° C., and creping the nonwoven fabric a temperature of at least 43 ° C, treatment of the nonwoven fabric at a temperature of at least 43 ° C with a sufficient amount of a polysiloxane, so that 0.004% to 0.75% of this polysiloxane based on the dry (fiber) weight of this tissue paper remains in this nonwoven fabric, this tissue paper having a basis weight of 10 to 65 g / m² and a density of less than 0.6 g / m³ having. According to a preferred embodiment, a water-soluble surfactant can be added at the same time as the polysiloxane. This subject is also described in US-A-50 59 282.

0021WO94 / 05857 relates to a method for applying a chemical papermaking additive to a dry tissue paper fleece (tissue paper fleece, raw tissue), this method being characterized in that it contains the following steps:

0022To provide a dry tissue paper nonwoven, to dilute a chemical paper making additive with a suitable solvent to form a dilute chemical solution, to apply this dilute chemical solution to a heated transfer surface, partially evaporating the solvent through the transfer surface to form a film containing this papermaking additive and transferring the film from the heated transfer surface to the surface of the tissue nonwoven such that a sufficient amount of the chemical papermaking additive is made such that 0.004 to 2% of this chemical papermaking additive , based on the dry (fiber) weight of this tissue nonwoven remains in this tissue nonwoven. This papermaking additive is preferably understood to mean plasticizers and mixtures thereof, preferably plasticizers selected from lubricants, plasticizers and mixtures thereof, these lubricants being polysiloxanes. If a chemical softening agent, which is primarily intended to serve as a plasticizer, is desired, it can be selected from a group of chemicals, including polyethylene glycol, for example polyethylene glycol with a molecular weight of 400. From this patent application the US-5 246 545 emerged.

0023DE-A-28 00 132 relates to a soft, pliable skin cleaning article with a nonwoven having a wiping surface and a low-density wiping zone, the wiping surface being a boundary of the low-density wiping zone, the low-density wiping zone being dirt-permeable and a multitude of in and under has cavities on the surface and the low-density wiping zone with about 10 to 150% lipophilic cleaning enamel, is treated based on the weight of the fleece. The term lipophilic cleaning enamel also includes silicone oils and nonionic surfactants.

0024DE-C 34 20 940 relates to an agent for cleaning and wiping the circuminal area, comprising at least one oil selected from the group of vegetable oils, animal oils and synthetic oils, characterized in that it comprises a silicone oil as a further component.

0025EP-A-0 459 501 relates to a method for reducing the static charge and the destruction during a wet printing process, which is characterized in that a silicone polymer emulsion, which has a particle size of less than 200 nm, a cationic surfactant and a nonionic surfactant is applied.

0026Furthermore, patents are known which describe the use of a mixture of polyethylene glycol with quaternary amines (cationic surfactants) as treatment agents, for example US Pat. No. 5,312,522.

0027For example, DE-C-34 47 499 relates to a non-drying cleaning cloth, which is characterized in that an emulsion is applied to a carrier material which consists of at least one moisture regulator, preferably polyethylene glycol and at least one further liquid substance.

0028Furthermore, it is known to use an anionic surfactant, nonionic surfactant or mixtures thereof as plasticizers in the production of soft tissue paper.

0029EP-A-03 47 177 relates to a method for producing soft tissue paper, which comprises the following steps:

0030Sheet formation from an aqueous suspension (wet laying) of cellulose fibers to form a fleece, application of a sufficient amount of a water-soluble non-cationic surfactant in such a way that 0.01 to 2% of this non-cationic surfactant, based on the dry (fiber) weight of this tissue paper through the fleece are withheld, this application being carried out with a fiber consistency of 10 to 80% and drying and creping of the fleece, this tissue paper has a basis weight of 10 to 65 g / m² and a density of less than 0.6 g / m³ having.

0031EP-A-0607796 relates to a non-woven fabric containing an organosilicon compound, the improvement being that the organosilicon compound contains 45 to 98% by weight of a water-soluble or water-dispersible polyether polysiloxane, the polyether groups being 30 to 100 mol % consist of oxyethylene units and oxypropylene units as the remainder and the polysiloxane block comprises 10 to 100 siloxane units, 1 up to 20% by weight of a water-soluble or water-dispersible organopolysiloxane with at least one ammonium group which is attached to the carbon atom and 1 to 20% by weight of water or a water-soluble alkylene glycol.

0032The pre-filed post-published EP-A-0688901 relates to tissue paper to which 3 to 30% by weight of an aqueous, softness-imparting composition has been added, said softening composition being 20 to 98% by weight glycerol and 0.2 to 5% by weight. % of at least one quaternary ammonium compound which is, inter alia, a special polysiloxane compound of the general formula (6) containing a quaternary ammonium compound, as defined below, can act. It is also described there that propylene glycol and / or polyethylene glycol are used instead of glycerol in amounts of 0.5 to 50% by weight, either 0.5 to 50% by weight, based on the main component.

0033The present invention has for its object to provide a method for producing tissue paper products using a polysiloxane-containing treatment agent to improve the softness, it being irrelevant according to which of the prescribed raw tissue production and processing methods the tissue product was produced. Such a treatment agent is obtained by a mixture of special amounts of at least one polyhydroxy compound, with the exception of natural or chemically modified natural polymers, in particular one at room temperature, ie at 20 ° C., liquid polyethylene glycol and / or glycerol as a further component, a portion of a polysiloxane and optionally up to 25 weight percent water. The application of such a mixture surprisingly leads to a significantly improved softness of tissue products compared to a pure polysiloxane application and compared to a pure polyethylene glycol or glycerol application (synergy effect).

0034The present invention thus relates to a process for the production of tissue paper products, characterized in that a polysiloxane-containing treatment agent which comprises 25 to 95 parts by weight, preferably 30 to 90 parts by weight of at least one polyhydroxy compound, in particular at least one polyethylene glycol and / or glycerol which is liquid at room temperature , 5 to 75 parts by weight, preferably 10 to 70 parts by weight of polysiloxane, and based on 100 parts by weight of this mixture, 0 to 35 parts by weight, preferably 1 to 30 parts by weight of water, with the exception of a treatment agent containing 5% by weight of a quaternary ammonium group-containing polysiloxane of the general formula<chemistry id="chem0001" num="0001"><img file="EP0803012B1_D0001.tif" /></chemistry>    in which<chemistry id="chem0002" num="0002"><img file="EP0803012B1_D0002.tif" /></chemistry> and R₁₉ a long chain C₁₂ - C₁₈-Alkylgruppe is applied to the nonwoven fabric or the "tissue web" within the wire / press section and / or dryer section, ie at a fiber density of 20 to 97%, based on the dry fiber weight of the web, in an amount of 0.01 to 15% and after the application, the fiber fleece undergoes post-smoothing and a process for the production of tissue paper products, characterized in that a treatment agent containing polysiloxane, which comprises 25 to 95 parts by weight, preferably 30 to 90 parts by weight of at least one polyhydroxy compound, in particular at least one polyethylene glycol and / or glycerine which is liquid at room temperature, 5 to 75 parts by weight, preferably 10 to 70 parts by weight of polysiloxane and, based on 100 parts by weight of this mixture, 0 to 35 parts by weight, preferably 1 contains up to 30 parts by weight of water, with the exception of a treatment agent, containing 5 wt .-% of a quaternary ammonium group-containing polysiloxane of the general formula<chemistry id="chem0003" num="0003"><img file="EP0803012B1_D0003.tif" /></chemistry>    in which<chemistry id="chem0004" num="0004"><img file="EP0803012B1_D0004.tif" /></chemistry> and R₁₉ a long chain C₁₂ - C₁₈-Alkylqruppe is applied to the nonwoven or the tissue web after the dryer section in the tissue paper machine and particularly preferably within the doubling machine or within the processing machine in an amount of 0.01 to 15% on the web and the web undergoes post-smoothing after application .

0035Preferred embodiments of the manufacturing method according to the invention are explained below.

0036The polyhydroxy compound in the sense of the type used in the process according to the invention means a low- and macromolecular organic compound which contain two or more hydroxy groups in the molecule. These polyhydroxy compounds, which are also called polyols, by definition include, in particular, polyhydric alcohols such as, for example, glycerol, polyethylene glycols, pentaerythritol, sugar alcohols, such as, for. B. Tetrides, pentites, hexites etc., in particular threit, erythritol, adonite, arabitol, xylitol, dulcitol, mannitol and sorbitol, carbohydrates, for example D (+) - glucose, D (+) - fructose, D (+) - galactose, D ( +) - Mannose, L-gulose, sucrose, galactose or maltose and synthetic polymers such as polyvinyl alcohol.

0037Any water-soluble and / or water-dispersible compound which is liquid, pasty or waxy at room temperature (20 ° C.) can be used as the polysiloxane component. This polysiloxane component includes polymeric, oligomeric, copolymeric and other polymonomeric siloxanes. In the following, the term polysiloxane should be understood to mean any polymeric, oligomeric or other multi-monomeric siloxane material. Furthermore, the polysiloxane material can have both a linear structure, a branched structure or a cyclic structure.

0038According to a preferred embodiment, the polysiloxane component has monomeric siloxane units of the following structure:<chemistry id="chem0005" num="0005"><img file="EP0803012B1_D0005.tif" /></chemistry> on, where R₁ and R₂ are the same or different for each monomeric siloxane unit and each is an alkyl, aryl, alkenyl, alkylaryl, arylalkyl, cycloalkyl, halogenated hydrocarbon or other group. Each of these groups can be substituted or unsubstituted. R₁ and R₂-Groups of each particular monomeric unit may differ from the corresponding functional groups of the next attached monomeric unit. Furthermore, these groups can be both straight-chain and branched or have a cyclic structure. The groups R₁ and R₂ can further and independently of one another be other silicone groups, but are not limited to siloxanes, polysiloxanes and polysilanes. The groups R₁ and R₂ can also contain a large number of organic functional groups, for example alcohol, carboxylic acid and amino-functional groups.

0039The degree of substitution and the type of substitution effect the relative degree of softness, silky feel and hydrophilicity imparted to the tissue paper structure. In general, the degree of softness and silky feel caused by the polysiloxane, among others, increases as the hydrophilicity of the substituted polysiloxane component decreases. Amino-functional polysiloxanes and polyether polysiloxanes are particularly preferred as the polysiloxane component in the treatment agent.

0040Preferred polysiloxanes include linear organopolysiloxane compounds of the following general formula,<chemistry id="chem0006" num="0006"><img file="EP0803012B1_D0006.tif" /></chemistry> where the R₁ to R₉Groups independently of one another C₁ to C₁₀ are unsubstituted alkyl or aryl groups and R₁₀ an arbitrarily substituted C₁ to C₁₀-Alkyl- or aryl radical. Each R is preferably₁ to R₉Group independently of one another a C₁ to C₁₀ unsubstituted alkyl group. It is known to those skilled in the art that it makes little difference whether, for example, R₉ or R₁₀ is the substituted group. The molar ratio of b to (a + b) is preferably between 0 and 20%, preferably between 0 and 10% and in particular between 1 and 5%.

0041According to a particularly preferred embodiment, R₁ to R₉Methyl groups, and R₁₀ is a substituted or unsubstituted alkyl, aryl or alkenyl group. Such materials are generally referred to here as polydimethylsiloxanes, which have a special functionality, as are used in the present case. Examples of such polydimethylsiloxanes can be: polydimethylsiloxanes such as Dow Corning® 200 Fluid, polydimethylcyclosiloxanes such as Dow Corning® 344 and 345, polydimethylsiloxane with an R₁₀-Alkyl hydrocarbon group and a polydimethylsiloxane with one or more amino, carboxyl, hydroxyl, ether, polyether, aldehyde, ketone, amide, ester, thiol and / or other R₁₀ functional groups, including alkyl and alkenyl analogs of such functional groups. For example, an amino functional alkyl group such as R₁₀ be an amino-functional or an aminoalkyl-functional polydimethylsiloxane. The exemplary listing of these polydimethylsiloxanes does not mean that others, not specifically mentioned here, are excluded from this.

0042The viscosity of the polysiloxanes used as a component in the process according to the invention can vary over a wide range, as long as the polysiloxane remains fluid and can be liquefied for use in the treatment agent according to the invention for application to the tissue paper. This means, for example, viscosities of 25 x 10^-6 m²/ s up to 20,000,000 x 10^-6 m²/ s or even higher. Viscosities of 15,000 × 10 are preferred here^-6 m²/ s up to 3,400,000 x 10^-6 m²/ s. Highly viscous polysiloxanes, which are not themselves flowable, can be applied as an ingredient of the treatment agent to tissue paper in an effective manner, for example by emulsifying the polysiloxane component according to the invention in PEG or glycerol or water or in a mixture thereof together with a surfactant or the polysiloxane, if it is not soluble in PEG or glycerol or water, by means of a solvent such as hexane. Special methods for applying the polysiloxane component to tissue paper are discussed below.

0043The aforementioned polysiloxane components are described, for example, in US-A-2826551, US-A-3964550, US-A-4364837, US-A-4395454, US-A-4950545, US-A-4921895 and British Patent 849433. Furthermore, the monograph "Silicon Compounds", pages 181-217, edited by Petrarch Systems, 1984, contains a detailed list and description of such polysiloxanes.

0044According to a further preferred embodiment, polyethersiloxanes of the general average formula can be used as polysiloxane component in the treatment agents,<chemistry id="chem0007" num="0007"><img file="EP0803012B1_D0007.tif" /></chemistry> in which R₁₂ are the same or different in the molecule and are an alkyl group having 1 to 12 carbon atoms or a polyether group - (C_nH_2nO)_x R₁₃, where R₁₃ Is hydrogen, hydroxyl, alkyl or an acyl group and n has a numerical value from 2 to 2.7 and x has a numerical value from 2 to 200, with the proviso that at least one of the R₁₂Groups in the average molecule is a polyether group; a has a numerical value from 0 to 98, b has a numerical value from 0 to 98 and a + b is 8 to 98. R₁₂ can be an alkyl group having 1 to 12 carbon atoms or a polyether group. However, the condition must be fulfilled that at least one R₁₂ is a polyether group in the average molecule. Preferably 2 to 5 are the R₁₂Groups polyether groups, and the remaining R₁₂Groups then have the meaning of an alkyl group, with the methyl group being particularly preferred. The alkyl group can also have up to 12 carbon atoms. In this way it is possible to vary the properties of the treatment agent and in this way to improve the handling on tissue paper products. The polyether groups correspond to the formula (C_nH_2nO)_xR₁₃. The index n has a numerical value from 2 to 2.7. In general, the ether group consists of a plurality of oxyethylenes and optionally oxypropylene groups. If the index n is 2, the polyether group consists exclusively of oxyethylene units. If the numerical value of n increases, the proportion of oxypropylene groups also increases. The numerical value of n = 2.7 means that 70% of the polyether groups are oxypropylene groups.

0045The index x means the number of oxyalkylene units. This value is an average numerical value since a mixture of products of different chain lengths is usually obtained in the synthesis of polyethers. The index x has a numerical value of 2 to 200 and is preferably 10 to 50. Polyether groups with an average molecular weight of 600 to 4,000 are preferred. The index a means the number of methylsiloxane units that the R₁₂-Group to be worn. The index b corresponds to the number of dimethylsiloxane units. While a and b can have a value from 0 to 98, the condition must be met that the sum of a + b has a value from 8 to 98. If a = 0, the polyether group or groups are terminally connected. The siloxanes with positive values ​​for a are replaced by the R₁₂-Side chains modified. Siloxanes in which the R₁₂Groups arranged in the side chain are preferred. The R₁₃Group can be hydrogen, hydroxyl, alkyl or also acyl. Preferably R is₁₃ a hydrogen atom. If R₁₃ is an alkyl group, lower alkyl groups having 1 to 4 carbon atoms are preferred. The acetyl group is the preferred acyl group.

0046According to a particularly preferred embodiment, the polysiloxane component has the following formula:<chemistry id="chem0008" num="0008"><img file="EP0803012B1_D0008.tif" /></chemistry> where R₁₄ a group of formula and<chemistry id="chem0009" num="0009"><img file="EP0803012B1_D0009.tif" /></chemistry> in which R₁₅ is a divalent hydrocarbon group whose carbon chain is interrupted by an oxygen atom, R₁₆, R₁₇, R₁₈ are identical or different and represent alkyl groups with 1 to 18 carbon atoms, one of which is R₁₆, R₁₇, R₁₈ one - (CH₂)₃ NHCOR₁₉Group is where R₁₉ is an alkyl group having 7 to 17 carbon atoms and X- is a monovalent anion and c is 5 to 100. R₁₅ is a divalent hydrocarbon group, for example the group of the formula -CH₂-C (OH) H-CH₂-O- (CH₂)₃-. The R₁₆-, R₁₇-, R₁₈-Groups can be the same or different and are alkyl groups with 1 to 18 carbon atoms. However, one of the aforementioned groups R₁₆, R₁₇, R₁₈ also the importance of a (CH₂)₃ NHCOR₁₉Group.

0047If R₁₆, R₁₇, R₁₈Groups are alkyl groups, they have 1 to 18 carbon atoms. R are particularly preferred₁₄Groups in which two of the aforementioned R₁₆-, R₁₇-, R₁₈-Groups have 1 to 4 carbon atoms and the third group has up to 18 carbon atoms. If one of the R₁₆-, R₁₇-, R₁₈-Groups one (CH₂)₃ NHCOR₁₉Group is, so is the R₁₉Group is an alkyl group having 7 to 17 carbon atoms. X^- is a monovalent anion, generally an acetate group. However, X can also be an inorganic group such as Cl^- be.

0048The index "c" indicates the number of dimethylsiloxy units in the linear siloxane and has a numerical value of 5 to 100 and preferably 10 to 80. Particularly preferred of the abovementioned siloxanes are those polydimethylsiloxanes and, for example, polyether, alkyl and quaternary or betaine Groups, in particular nitrogen groups, modified polydimethylsiloxanes.

0049Particularly preferred polysiloxanes are the organo-modified siloxanes sold under the name Tegopren® by Th. Goldschmidt AG with pronounced surface and interface activity in aqueous and organic systems.

0050These are polyether siloxanes as undated in the company publication "Tegopren® Informativ", the Th. Goldschmidt AG under the trade name Tegopren® 3012, Tegopren® 3020, Tegopren® 3021, Tegopren® 3022, Tegopren® 3070, Tegopren® 5830, Tegopren® 5840, Tegopren® 5842, Tegopren® 5843, Tegopren® 5847, Tegopren® 5851, ® 5852, Tegopren® 5863, Tegopren® 5873, Tegopren® 5878, Tegopren® 5884 and Tegopren® 7006 are sold and usually have medium cloud points in the range from below 25 ° C to 71 ° C as well as modified siloxanes in the form of teopren silicone Quats and betaines, as they are sold under the names Tegopren® 6920, Tegopren® 6922 and Tegopren® 6950.

0051The term tissue paper, or tissue for short, in the sense of the present invention is understood to mean all types of creped papers produced from aqueous dispersion with a basis weight range between 10 and 65 g / m 2². According to the invention, the term tissue papers covers both the entire area of ​​creped base papers, also called raw tissue, in particular the area of ​​dry-creped base tissue papers, regardless of whether single-layer or multilayer, as well as all end products made from these creped base papers, such as handkerchiefs , Facial and facial tissues, toilet paper, kitchen towels, hand towels and serviettes. The term tissue paper is still to be seen independently of the fiber raw material to be used, in particular regardless of whether the fiber raw material is produced exclusively or predominantly from native cellulose by the sulfate or sulfite process or is used in a mixture with chemo-thermomechanical wood pulps (CTMP), or whether the fiber raw material used originates from a secondary fiber preparation process and accordingly the fiber raw material required for tissue production consists entirely or partially of "recycled fibers". To differentiate it from so-called nonwovens, it should be noted that the predominant use of papermaking-disrupted, natural, that is to say vegetable pulp fibers, is characteristic for tissue paper production, a proportionate use by refinement of modified pulp fibers in a range of 10 to 50% or even a use of plastic fibers suitable for papermaking in a proportion of 10 to 30% falls under the aforementioned definition of tissue. An application of the treatment agent is possible beyond the area of ​​tissue production to corresponding areas of the non-woven area and the textile area in analog transmission.

0052According to a preferred embodiment of the present invention, the binary, polysiloxane-containing treatment agent can contain from 5 to 75 parts by weight (or% by weight) of at least one of the aforementioned polysiloxanes and 25 to 95 parts by weight (or% by weight) of the aforementioned polyethylene glycol. However, 10 to 70 parts by weight of polysiloxane, in particular 40 to 60 parts by weight of polysiloxane and, as a further component, 30 to 90 parts by weight, but in particular 40 to 60 parts by weight of the aforementioned liquid polyethylene glycol are preferred in this treatment agent.

0053According to a further preferred embodiment of the present invention, the treatment agent used in the process consists of 5 to 75 parts by weight (or% by weight) of at least one polysiloxane and 25 to 95 parts by weight (or% by weight) glycerol. In this case too, a treatment agent with 10 to 70 parts by weight, preferably 40 to 60 parts by weight of at least one polysiloxane and 30 to 90 parts by weight, in particular 40 to 60 parts by weight of glycerol is preferred.

0054Polyethylene glycol and glycerin can be exchanged in the treatment agent in any amount. However, mixtures of polyethylene glycol and glycerol can also be used in particular from an economic point of view, the mixing ratios preferably being 20 to 80% by weight or parts by weight, preferably 30 to 70% by weight or parts by weight of the aforementioned polyethylene glycol and 20 to 80 parts by weight. Make up% or parts by weight, preferably 30 to 70 wt .-% glycerol.

0055According to a preferred embodiment of the present invention, the treatment agent contains 30 to 90 parts by weight of at least one polyhydroxy compound, ie at 20 ° C., in particular at least one polyethylene glycol and / or glycerol which is liquid at room temperature, 10 to 70 parts by weight of polysiloxane and, based on 100 parts by weight of this Mixture, 1 to 30 parts by weight of water.

0056It is particularly preferred here that such a ternary treatment mixture comprises 20 to 70 parts by weight of at least one polyhydroxy compound, in particular at least one polyethylene glycol and / or glycerol which is liquid at room temperature, 30 to 70 parts by weight of polysiloxane and, based on 100 parts by weight of this mixture, 5 to 25 parts by weight Contains water.

0057According to a preferred embodiment, water is present as an additional component in addition to the two organic components. The treatment agents then consist of 5 to 75 parts by weight of at least one polysiloxane, 25 to 95 parts by weight of at least one polyhydroxy compound, in particular the aforementioned polyethylene glycol and, based on 100 parts by weight of the aforementioned mixture, 1 to 30 parts by weight of water.

0058In this ternary mixture with polyethylene glycol as one of the components, it is preferred to use a mixture of 30 to 90, but in particular 40 to 60 parts by weight of polyethylene glycol, 10 to 70 parts by weight, preferably 40 to 60 parts by weight of polysiloxane and, based on 100 parts by weight of the aforementioned two components, 1 to 30 parts by weight, preferably 5 to 25 parts by weight of water.

0059It is furthermore particularly preferred to use 15 to 24, preferably 17 to 22 parts by weight of water per 100 parts by weight of polyethylene glycol.

0060According to a further preferred embodiment with glycerol as one of the components, it is preferred to use an initially binary mixture of 30 to 90, but in particular 40 to 60 parts by weight of glycerol, 10 to 70 parts by weight, preferably 40 to 60 parts by weight of polysiloxane and, based on 100 parts by weight of the aforementioned two components, 1 to 30 parts by weight, preferably 5 to 25 parts by weight of water. It is furthermore particularly preferred to use 23 to 32 parts by weight, preferably 25 to 30 parts by weight of water per 100 parts by weight of glycerol.

0061In addition to these aforementioned components, the treatment agent can contain cosmetic agents with special properties and other customary auxiliaries as further agents. For example, skin active ingredients based on vitamins or plant extracts, such as extracts of horse chestnut seeds, birch, arnica, chamomile or bisabolol itself, St. John's wort, cucumber, aloe vera or witch hazel, are known in part because of their astringent and healing effects are.

0062Other active ingredients here are skin care products, for example sorbitan fatty acid esters and oxyethylated, homologous compounds of glycerol, esters of ethoxylated fatty alcohols, fatty alcohol alkanolamides, oxetylated fatty alcohols, ethoxylated wool fatty alcohols, glycerol monostearate, stearic acid, cetyl stearyl alcohol, vaseline and lasseline. In addition to lanolin itself, lanolin derivatives can also be used, such as lanolin alcohols or wool wax alcohols, which are sold under the name Amerchol® by Union Carbide Inc. in connection with mineral oils. The 400, BL, C, CAB, U9, L99, L111, L500 and RC series are known here, for example. Other lanolin derivatives are the acetylated lanolins and hydrophilic lanolin derivatives, for example lanolin-polyoxyethylene compounds. Hydrotropic solubilizers for fatty substances, such as, for example, polyalcohol ethers and ethoxylated fatty alcohols, can also be used as other additives in the treatment agent according to the invention.

0063Another group that can be used as an additional component in the treatment agents according to the invention are quaternary ammonium compounds, but especially quaternary ammonium salts, as described, for example, in US Patents 5312522, 5397435, 5405501, 5427696 and international patent applications WO 95/11344, WO95 / 11343 , WO 95/01478, WO 95/01479, WO94 / 29521, WO94 / 29520, WO94 / 16143 and WO94 / 19381.

0064In addition, fragrances of a conventional type can also be added, which are selected from natural, nature-identical or artificial fragrances, the corresponding fragrances being preferred. For example, agricultural oils such as lemon oil, bergamot oil, orange oil, petitgrain oil, softwood oils, foin coupe fragrance compositions or floral oils such as z. B. rose, jasmine, lilac, lavender, as well as synthetic fragrances based on menthol etc. An overview is given by Ullmann's Encyclopedia of Industrial Chemistry, 4th ed. 1981, volume 20, pp. 199-285.

0065In addition, appropriate inorganic pigments or organic dyes, as are customarily used in tissue paper production, can also be added together with the treatment agent used in the process according to the invention. Here, not least for ecological reasons, physiologically harmless and non-irritating dyes, in particular the corresponding natural dyes, are preferred. All of the aforementioned additives and auxiliaries used in the treatment agent according to the invention can be contained both individually and as a combination.

0066The treating agent for tissue paper products described above is applied in an application amount in the range of 0.01 to 15 weight percent, preferably 0.5 to 10 weight percent, most preferably 2 to 6 weight percent, based on the dry weight of the fibers.

0067A single or multi-layer, preferably at least two-layer and particularly preferably three or four-layer unembossed or embossed tissue paper is preferably used as the carrier material to which the treatment agent is to be applied. The individual paper webs can be mechanically connected to one another by embossing or knurling, glued flatly or selectively or else connected to one another in some other way. For the individual webs there is still a basis weight range of 10 to 40 g / m², preferably 14 to 30 g / m², in particular 15 to 25 g / m², most preferably from 15.5 to 17.5 g / m² proven. In special applications, however, heavier or lighter papers with basis weight ranges from 8 to 65 g / m can also be used² make sense.

0068According to a further preferred embodiment, the carrier material can also be solidified wet, the customary health-friendly wet strength agents, such as epichlorohydrin resins, urea-formaldehyde resins, melamine-formaldehyde resins and crosslinked cationic polyalkylene amines being used.

0069The treatment agent, which is in the form of an emulsion in a preferred embodiment, can be applied to the carrier material using any roller and spray application method or in an impregnation method. Care must always be taken to ensure that the emulsion cannot separate, ie that the components of the treatment agent must be thoroughly mixed during application in order to prevent separation. This is done, for example, by high shear forces, generated for example by high-speed stirrers, frequent pumping or by ultrasonic mixing.

0070The treatment agent, which can be used for a noticeably improved softness of tissue products, can be used in a wide variety of product areas. Its use on serviettes, toilet paper and hand and kitchen towels, handkerchiefs, facial tissues and facial tissues has proven to be particularly advantageous.

0071The above-mentioned composition of the treatment solution is dimensioned such that skin irritation (drying out due to the hygroscopic properties of polyethylene glycol or glycerol) cannot occur during the period of use by the consumer in the atmospheric humidities normally prevailing in the annual average due to the water content even when used continuously. Even water vapor-tight, resealable packaging is no longer necessary.

0072The treatment solution can be used both in the wet section of a tissue paper machine (wadding machine), at the end of the wire section, in front of or within the press section (mechanical dewatering), i.e. with solids contents between 20 and 50%, as well as in the drying section arranged after the press section with solids contents between 40 and 97 % Dry fiber weight can be added. State of the art are task locations on the transfer screen / belt, z. B. before the fleece transfer in the case of a TAD arrangement and the feeding onto the moist nonwoven fabric after its transfer to the transport (dry) felt in a conventional one- or two-felt tissue production machine. The state of the art is also the supply of treatment chemicals in a spray application onto the Yankee cylinder.

0073It is preferred to add the treatment agent in the tissue production machine by spraying it onto the Pope-Roller to produce a treatment agent film and then transfer it to the tissue web during the reeling process - usually the already creped "tissue web" as a result of the previous drying process on the Yankee cylinder has a residual temperature between 20 ° C and about 70 ° C, what is favorable for the distribution of the treatment agent and its penetration into the raw tissue - on the contact surface of the single-layer tissue web with the surface of the drum of the Pope-Roller. In addition to a spray application via a nozzle bar, the use of centrifugal rotors or brushing units and the indirect transfer of a treatment agent film via roller application units can also be considered. The order can also be placed directly on the tissue paper web. It is particularly preferred to add the treatment agent inside the doubling machine or within the processing machine to the outer layers of the multilayer doubled web before or during calibration / smoothing. Most preferred is the application of the treatment agent within the processing machine to the single or multi-layer web.

0074According to a preferred embodiment, the tissue paper products are obtained by applying a polysiloxane-containing treatment agent of the above type onto the tissue web or the nonwoven fabric after the dryer section in the tissue paper machine and particularly preferably inside the doubling machine or within the processing machine in an amount of 0.01 up to 15% applied to the web and after the application undergoes a smoothing. However, it is particularly preferred if the abovementioned polysiloxane-containing treatment agent is applied to the single-layer web in an amount of from 0.5 to 10%, based on the dry fiber weight of the single-layer web, at a fiber density of 35 to 97%. It is particularly preferred to use a multi-layer web as the tissue web and to apply the treatment agent at a fiber density of more than 90%, based on the dry fiber weight, to at least one of the outer layers of the multi-layer web in an amount of 1 to 7%. It is very particularly preferred to apply the treatment agent to the multilayer tissue web on both outer layers in an amount of 3 to 6%.

0075In the context of the aforementioned method, it is preferred that the smoothing is carried out by at least one passage of the tissue web through a nip of a pair of rollers, in which a roller with a steel surface and a counter roller with a steel, plastic, paper or rubber surface, but preferably one Plastic surface, is assigned.

0076This is preferably carried out in such a way that the smoothing is carried out by passing the tissue web twice through a nip of a pair of rollers, in which first a roller with a steel surface of a counter roller with a plastic surface and then a mirror image of a roller with a plastic surface of a counter roller with a steel surface assigned.

0077The smoothing of the tissue web after the application of the treatment agent is therefore usually carried out in such a way that the tissue webs sprayed on both sides are passed through a smoothing unit. This smoothing unit generally consists of two smooth rollers with steel surfaces (steel rollers), the surfaces of which are usually hard chrome-plated. These rollers are pressed together hydraulically or pneumatically or moved to a gap for calibration. This means that one of the two rollers is firmly positioned. The second or counter roller is pressed against a stop so that the two steel rollers cannot touch each other, but are at a certain, measurable and reproducible distance from one another. The tissue webs passed through this gap are compressed to the gap width and smoothed in the process. The structure of the surface is standardized, ie a uniform thickness is achieved. Smoothing is therefore carried out by leveling the surface in conjunction with an equalization of the thickness profile under the premise of as little loss of volume as possible.

0078The usual influencing factors on the smoothing are the line force, the surface temperature of the partially heated rollers, the nip width and the nip number (number of smoothing units). The articles in "apr Europe", 3 (1991), pages 121 to 123 and "JJA Rodal Tappi Journal", volume 76, no. 12, pages 63 to 74 provide an overview of this, as does the overview by E. Weißhun and H. Holik, in "Das Papier", Volume 38 (1984), No. 10A.

0079Instead of the two steel rollers that form the smoothing unit, a so-called soft smoothing unit can also be used. Here, a steel roller with a plastic surface is pressed against a smooth steel roller. Such a smoothing unit is supplied, for example, by Küsters Maschinen GmbH. These soft-smoothing calenders are known, among other things, as MAT-ON-Line smoothing uni ts. Another soft smoothing unit with steel roller and counter roller with plastic surface is the NIPCO-MAT smoothing unit from Edmund Küsters Maschinenfabrik, Krefeld, cf. Wochenblatt der Papierfabrikation 13/91, pp. 491 to 498. Such rollers are described in more detail in DE 3445890 and in EP 0273185.

0080Furthermore, instead of the two steel rollers which form the smoothing unit, a smoothing unit can also be used, a roller or counter-roller having a rubber or paper surface being used together with a steel roller or steel counter-roller.

0081An overview of the usual post-smoothing processes is given in German patent DE-A-1804418, German patent application DE-A-2455895, German patent DE-A-2528803, EP-A-0033559, US patent US-A-2179057 , US Patent US-A-3337388, British Patent GB-A-827735, and German Patents DE-C-822228 and DE-B-1045783.

0082Finally, the present invention relates to the use of the aforementioned polysiloxane-containing treatment agent for the softening of tissue paper products, in particular handkerchiefs, facial tissues, make-up wipes, serviettes, toilet paper, hand and kitchen towels.

0083The present invention is explained in more detail below by means of exemplary embodiments.

Example 1:

0084On a paper handkerchief (finished product) with a basis weight of about 4 x 15.5 g / m³ With a dry fiber content of 92 to 97% dry fiber weight, a treatment solution consisting of 32 weight percent polyethylene glycol, molecular weight 200, 60 weight percent of the polysiloxane Tegopren® 3021, a polyether siloxane with a cloud point of 38 ° C from Th. Goldschmidt AG and 8% water under good conditions in the laboratory Swirling in a quantity of 6% sprayed on the tissue and subjected to a smoothing. The application was carried out symmetrically on the outer surfaces of this fabric. The product thus obtained was referred to as A.

Example 2:

0085The application process according to Example 1 was repeated, but instead of a ternary mixture, a binary mixture of 50 percent by weight polyethylene glycol, molecular weight 200 and 50 percent by weight of the polysiloxane according to Example 1 was used. The sample thus obtained was named B.

Comparative experiment 1:

0086The process according to Example 1 was repeated, but instead of the ternary mixture according to the invention, the pure polysiloxane according to Example 1 was applied in an amount of 6% and the product thus obtained was designated C.

Comparative experiment 2:

0087The process according to Example 1 was repeated, but instead of the ternary mixture according to the invention, a pure polyethylene glycol with a molecular weight of 200 was applied in an amount of 6%. The product thus obtained was designated D. All of the cloths of Examples 1 and 2 and of Comparative Experiments 1 and 2 were reproducibly smoothed in a 2-roll (steel / plastic) smoothing unit under identical conditions (speed, temperature, contact pressure).

0088The haptic properties of the products A and B according to the invention were compared with the corresponding haptic results of the comparison products C (pure polysiloxane) and D (pure polyethylene glycol) (PEG) and these products were subjected to a so-called panel test (based on "Manual on Sensory Testing Methods, ASTM, Special Technical Publication 434, p. 22; Testform D-Ranking Methods-Rank Order, Elevents Printings February 1993). Here, the increasing softness, defined here as the sum of the surface softness and softness of a crumple softness of a group of 9 people was evaluated according to the following procedure:

0089The paper tissues to be tested were folded in half, so that the sample identification is not recognizable for the test person and in each case the same outside of the evaluation is presented. The cloths folded in this way were handed over to the test subjects with the instruction to check the folded cloths between thumb, ball of the thumb and fingers rubbing and crumpling with regard to their softness and surface softness and then to lay the cloths in line according to increasing subjective quality. The samples were ranked from 1, the best, to 4, the worst.

0090The test showed that products A and B according to the invention were described by 7 of the 9 test persons as very good in softness and in relation to the comparison products C and D as clearly softer. In contrast, only one of the 9 test persons found product D to be softer than product A according to the invention, and one of 9 test persons found comparative product C to be softer than products A and B according to the invention. The panel test also shows that products A and B according to the invention are significantly better in terms of crumple softness and surface softness than the comparative products C and D.

0091The results of this panel test are shown in the table below:<tables id="tabl0001" num="0001"><img file="EP0803012B1_D0010.tif" /></tables>

0092In addition to this first in-house panel test, a studio consumer test was also carried out with 160 people. Samples with a lotion composition of polyethylene glycol / polysiloxane / water in a ratio of 72/10/18 with a 3% application amount were judged to be significantly softer than a corresponding comparison sample with pure siloxane. Here again the polysiloxane described in Example 1 was used as the polysiloxane and the polyethylene glycol with a molecular weight of 200 described in Example 1 was used as the polyethylene glycol.