Cellulose functional molded bodies with controlled release of active ingredients, methods for their manufacture and their use

Abstract

Method for the production of cellulose molded bodies with controlled drug release comprising the following stages: a) Pulp is dispersed in an aqueous direct solvent for cellulose to form a cellulose slurry, b) In a separate process step, an organically modified nanoscale layered silicate or a nanoscale layered silicate pre-activated by ion exchange with potassium, calcium or aluminium ions is homogenized with an aqueous direct solvent for cellulose and partially or completely exfoliated by shear, added to the cellulose slurry and mixed with it, c) In a further separate process step, a composition of an active ingredient and a lipophilic matrix material for the active ingredient or an active ingredient-containing water-in-oil emulsion is stabilized by inorganic or organic thickeners and converted into a gel-like paste; this paste is also added to the cellulose slurry and mixed with it while stirring at temperatures up to 130 °C. d) Water is removed from the mixture until the cellulose is completely dissolved and e) The resulting spinning solution is formed into shaped bodies using a solution spinning process, then treated and dried.

Description

[0001] The invention relates to cellulose molded bodies with controlled release of active ingredient inclusions. The active ingredients are solid or liquid lipophilic active ingredients or water-in-oil emulsions. The process for their production results in the active ingredients being firmly bound within the molded body during its manufacture, but the release of the active ingredient can be controlled during use.

[0002] WO 2009 / 062 657 A2 already describes a process for incorporating nonpolar substances, such as phase change materials (PCMs) and / or nonpolar active ingredients, into cellulose molded bodies. The prior art described therein is a lyocell process. An emulsion of cellulose in an aqueous direct solvent and the nonpolar substance is produced. To stabilize this emulsion, nanoscale, hydrophobically modified pyrogenic silica is incorporated and / or flat and / or elongated nanoscale particles are added. This process achieves a very strong encapsulation of the nonpolar substances in the surrounding cellulose matrix, which largely prevents controlled release. An analogous procedure is described in DE 10 2006 046 358 A1. No teaching is provided for a controlled release rate of encapsulated active ingredients.

[0003] German patent DE 10 2015 105 309 A1 discloses cellulose molded bodies containing water-soluble layered silicates dispersed within them. These layered silicates can serve as carriers for active ingredients with cosmetic or therapeutic effects.

[0004] In WO 2012 / 034 679 A1, modified layered silicates are disclosed as functional additives in lyocell cellulose fibers.

[0005] The subject of DE 10 2007 054 702 A1 and US 2011 / 0 045 078 A1 is a wet-dry extrusion process for producing cellulosic molded bodies with inclusions of nonpolar organic compounds. Nonpolar compounds are generally compounds with a melting point of less than 100 °C, such as hydrocarbons, waxes, fatty acid esters, or long-chain alcohols. In the cellulose-containing spinning solution, the nonpolar organic compound is stabilized by the addition of a viscosity-increasing agent, for example, hydrophobized layered minerals (layered silicates) or hydrophobized, nanoscale, pyrogenic silicas.

[0006] German patent application DE 10 2006 046 358 B3 describes a process for producing functional cellulosic molded bodies with inclusions of nonpolar organic compounds. A hydrated amine oxide serves as the solvent for the cellulose. The nonpolar organic compounds form an emulsion with the cellulose solution in the spinning solution. The emulsion is stabilized by the addition of nanoscale, planar, hydrophobized particles, for example, hydrophobized bentonite.

[0007] The subject of US 2006 / 0128867A1 is a nano-composite comprising a polymer containing protecting groups, a layered silicate, and an activating agent capable of causing the removal of the protecting groups.

[0008] The direct incorporation of paraffin into meltable plastic matrices is also described in DE 10 2010 007 497 A1. In this process, the plasticized mixture of 40 to 75% paraffin and 60 to 25% polymeric carrier component, consisting of 5 to 20% of a thermoplasticizable polymer, 5 to 20% of a styrene block copolymer, and 0 to 20% of one or more additives, is extruded through a die opening at 130 to 220 °C and immediately quenched to a temperature of 10 to 80 °C after exiting the die. The main disadvantage of this approach is the low strength of the molded part, the enormous elongation of up to 500%, and the need for post-stretching by a factor of 2 to 12. Furthermore, this method for incorporating parts into melts is not transferable to methods for working with aqueous solutions, which typically have much lower viscosities.

[0009] Multi-component fibers with reversible thermal properties from Outlast Technologies Inc., which can also be manufactured from cellulose using solution spinning, are described in patents US 7,244,497 B2 and WO 2005 / 017247A2 and in utility model DE 20 2004 021259U1. Such fibers are obtained by using inclusion structures, typically capsules containing the PCM, or by core / sheath or island-in-the-sea structures in which the PCM material is tightly enclosed by non-PCM material. The aim is to achieve reversible thermal properties through the firm integration of the PCM materials into the composite body; therefore, they are unsuitable for the targeted release of active ingredients.Finally, US patent 5,153,066 A describes the incorporation of thermotropic dyes into a polymer matrix, in which the dye phase is embedded in inner and outer layers of the protective polymer matrix. Here, too, the inventive step is solely aimed at effectively preventing the release or premature degradation of the active ingredient by external influences. Furthermore, no teaching is provided on how such stabilized compositions or water-in-oil emulsions can be used for fiber production from a solution followed by extrusion, since these compositions or emulsions already constitute the final product.

[0010] Furthermore, the use of modified silicas for the mechanical stabilization of keratinous substances / emulsions or for the stabilization of W / O emulsions is known from DE 696 00 181 T2 or DE 10 2004 014 704 A1. The main reason for their use lies in enhancing the interactions of different mixture components and thus has no relation to the controlled release of active ingredients. Moreover, no instruction is given for incorporating these emulsions into fibers using the solution spinning process under the high temperatures and shear forces prevailing there.

[0011] The use of layered silicates with intercalated organic modifier molecules to control exfoliation in polymer mixtures or blends is known from the work of T. Fornes et al. (T. Fornes, P. Yoon, D. Hutter, H. Keskkula and D. Paul: Polymer 2002, 43, 5915). The structure of the intercalated modifiers alone can cause a number of structural changes in the polymer and / or blend structure (cf. T. Fornes, D. Hutter and D. Paul: Macromolecules 2004, 37, 1793). The degree of separation of the individual silica platelets can vary considerably with this approach. While microcomposites dominate at very low separation, intercalated or exfoliated structures are achieved by including molecule (chains) in the galleries of the silica platelets, whereby the complete release of individual silica platelets results in significant changes in the interaction at the phase boundaries of the polymer components.

[0012] Furthermore, Hasegawa et al. (N. Hasegawa, H. Okamoto, M. Kato, A. Usuki and N. Sato: Polymer 2003, 44, 2933) were able to demonstrate that unmodified or slightly modified nanolayer silicates, for example Na +Montmorillonite (NaMMT) can be exfoliated with water (vapor), resulting in polymer structures similar to those obtained with modified layered silicates. Water or steam can cause the NaMMT to swell, allowing molecular chains to intrude into the enlarged gallery spaces, similar to what occurs with organically modified layered silicates. N. Fedullo et al. (N. Fedullo, M. Sclavons, C. Bailly, J.-M. Lefebvre and J. Devaux: Macromol. Symp. 2006, 233, 235) also demonstrated that incorporated PA 6 molecular chains are sometimes highly resistant to washout, and that even multiple extractions with hexafluoroisopropanol (HFIP) could not completely remove the inclusions. Therefore, targeted control of the release behavior cannot be achieved through such methods.The use of these layered silicates for stabilizing lipophilic substances or even W / O emulsions during the production of cellulose molded bodies using the Lyocell process has not been described.

[0013] Based on the prior art described above, the invention aimed to develop a method for incorporating lipophilic active ingredient compositions in solid or molten state into cellulosic molded bodies during production, without the use of inclusion structures or carriers, or as water-in-oil emulsions. This ensures that the active ingredients are finely dispersed within the molded body and are not washed out during coagulation, which often takes place in aqueous media. Particular difficulties arise because the molded body production process from solutions often involves very high shear forces, which can cause phase separation. Furthermore, coagulation and solvent removal frequently occur in aqueous media, where the solvent is washed out, posing a risk of also washing out the active ingredient compositions.In the context of textile applications of the inventive cellulose molded bodies, active ingredients are to be released in a controlled manner, thus supplying the contained substances to an intended application without having to accept the technical and economic disadvantages described in the prior art. Furthermore, the invention was based on the objective of permanently storing lipophilic, but moisture-loving, active ingredients in dissolved or dispersed form and releasing them in a controlled manner into the molded body environment over an extended period. A further inventive objective was to be able to reload the functionalized molded bodies with highly volatile or thermo- or chemo-sensitive active ingredients during the use phase.

[0014] These problems are solved according to the invention by a method comprising the following stages: a) Pulp is dispersed in an aqueous direct solvent for cellulose to form a cellulose slurry, b) In a separate process step, an organically modified or pre-activated nanoscale layered silicate, obtained by ion exchange with potassium, calcium or aluminium ions, is homogenized with an aqueous direct solvent for cellulose and partially or completely exfoliated by shearing, added to the cellulose slurry and mixed with it. c) In a further separate process step, a composition of an active ingredient and a lipophilic matrix material for the active ingredient or an active ingredient-containing W / O emulsion is stabilized by inorganic or organic thickeners and converted into a gel-like paste; this paste is also added to the cellulose mash and mixed with it at temperatures up to 130 °C. d) Water is removed from the mixture until the cellulose is completely dissolved and e) the resulting spinning solution is formed into shaped bodies using a solution spinning process, then treated and dried.

[0015] The degree of exfoliation in stage b) can be adjusted by setting the shear rate (rotational speed) and shear duration. Stage e) produces, for example, staple fibers, filaments, films, or direct nonwovens.

[0016] A lipophilic substance containing an active ingredient is a mixture of an active ingredient and a lipophilic matrix material. Water-in-oil (W / O) emulsions containing active ingredients allow not only lipophilic but also hydrophilic active ingredients dissolved in water or hydrophilic solvents to be "packaged" in a lipophilic matrix. There are also processes in which a W / O emulsion is further "packaged" in a lipophilic matrix.

[0017] In solution spinning processes, a lyocell spinning process is preferred; it is therefore mostly a 'dry-wet spinning process'.

[0018] In the context of the present invention, the term nanoscale refers to substances or layered silicates which have a dimension of 100 nm or less in at least one dimension.

[0019] In step b), the layered silicate is pre-swollen, meaning that the distance between the individual lamellae (layers) of the layered silicate is increased by intercalation with, for example, ammonium salts of long-chain fatty amines, alkali metal, alkaline earth metal, or boron group cations from higher periods (3rd period or higher) of the periodic table, or water. This has a decisive influence on the degree of subsequent exfoliation in the spinning solution. Simultaneously, the viscosity of this dispersion increases. The degree of intercalation is influenced by the size of the intercalated compounds, the amount of intercalated water, and by a defined setting of shear duration and shear rate (see [reference]). Fig. ). The mixing in step c) preferably takes place in no more than 15 min, particularly preferably for about 10 min.

[0020] The inorganic or organic thickeners in step c) comprise nanoparticles based on pyrogenic silica, metal oxide ceramics, or solvent-compatible metal nanoparticles and / or aliphatic-aromatic block copolymers. The aspectless nanoparticles based on pyrogenic silica or metal oxide ceramics may be organically modified.

[0021] In addition to controlling the exfoliation of the layered silicates to control the release rates of the active ingredients, the layered silicates also play an important role as phase mediators in the system.

[0022] Surprisingly, it was found that, particularly through separate steps b) and c), the lipophilic active ingredient compositions or active ingredient-containing W / O emulsions could be stably incorporated into the spinning mass without the need for further stabilization of the mixtures or encapsulation of the active ingredients. They are ultimately present in the molded body in a finely dispersed form as domains, which are understood to be regions that are functionally and structurally (quasi-)independent of neighboring sections.

[0023] Equally astonishing, and in no way foreseeable for the person skilled in the art, is that by pre-swelling the layered silicate used in the separate process step b) even more so than by shearing the mixture of cellulose solution, active ingredient composition and layered silicate, the degree of exfoliation of the layered silicates and thus the release of the incorporated active ingredients or W / O emulsion can be controlled in time and intensity.

[0024] The layered silicates used in process step b) are preferably organically modified layered silicates containing organic molecules in the galleries of the layered silicate platelets. These molecules promote binding to the cellulose and simultaneously stabilize the fine distribution of the lipophilic substances (active ingredient compositions) or water-in-oil emulsions within the cellulose matrix. However, unmodified layered silicates, such as sodium montmorillonite, can also be used when more hydrophilic active ingredients, or particularly preferably water-in-oil emulsions, are to be incorporated into the cellulose fiber matrix and subsequently released. It has been found that the degree of intercalation / exfoliation of the layered silicates has a decisive influence on how firmly the lipophilic substances or active ingredient compositions are anchored within the cellulose matrix. This can be explained by the structure of the layered silicates as follows:As is known, layered silicates are composed of parallel stacked silicate platelets (single-cell lamellae), which in turn have a three-layer structure (approximately 1 nm layer thickness) of alternating tetrahedrally and octahedrally coordinated cation layers, which are connected by a common anion layer. Mobile cations required for charge balance (isomorphic cation exchange in the cation layers) are arranged in the interlamellar intermediate layers (galleries). These mobile cations can be very easily replaced by "organic cations," preferably ammonium or phosphonium cations with at least one longer, unbranched, saturated or unsaturated hydrocarbon residue having 14 or more carbon atoms, particularly preferably 14 to 20 carbon atoms, specifically 14, 16, or 18 carbon atoms. "Unsaturated hydrocarbon residues" are defined in particular as unbranched alkyl residues with 1, 2, or 3 double bonds.In particular, intercalation with the aforementioned organic cations, which possess alkyl and / or alkenyl groups, alters the interlamellar interactions, i.e., the cohesion of the individual lamellae. The alkyl or alkenyl groups can be substituted, especially by hydroxy or carboxyl groups. This, in turn, affects a more or less rapid splitting into individual lamellae (exfoliation). The same effect is achieved in inorganically modified layered silicates when, for example, the cations contained in the galleries, e.g., sodium ions, are replaced by equivalent cations from higher periods of the periodic table, e.g., potassium ions, or when the layered silicates are pre-swelled in polar solvents such as water.

[0025] Complete exfoliation (delamination), i.e., the complete splitting of the layered silicates into silicate platelets (single-cell lamellae), leads to a firm anchoring of the lipophilic substances or active ingredient compositions to the single lamellae and in the cellulose matrix, while weak exfoliation / intercalation leads to molded bodies that still contain active ingredients after the cellulose molded body production, but these are released again relatively quickly depending on the degree of exfoliation set.

[0026] Exfoliation can therefore - fundamentally due to the chemical structure and concentration of organic cations in the layered silicate, - by the size of the intercalated ions or the swelling degree of non-organically modified layered silicates, - in steps b) and c) by the temperature, the viscosity of the surrounding medium (dispersant used, moisture and hydrocarbons used in the stabilized active ingredient mixtures) as well as the intensity and duration of the mixing / shearing of the layered silicates and - in steps b) to d) are influenced by the rheological properties of the surrounding medium (insofar as also the completeness of the cellulose dissolution in the dissolution step), the temperature and also the shear intensity and duration.

[0027] For selected active ingredients (e.g. fragrances) that could not be directly incorporated into the cellulose functional mold body due to excessive volatility or thermal and / or chemical sensitivity in the fiber formation and processing process along the textile value chain, it was also possible to load / reload the functional mold bodies with active ingredients in quantities relevant to their effect.

[0028] For the production of the inventive, active ingredient-releasing fibers, all typical dissolving pulps such as hardwood and softwood pulps with high to very high α-cellulose contents (> 80%), high-alpha pulps (cotton linters) and pulps from annual plants with α contents greater than or equal to 90% can be used.

[0029] The solid or liquid active ingredient compositions according to the invention may preferably, but not exclusively, be cosmetic active ingredient compositions such as evening primrose, St. John's wort, jojoba, or avocado oil, fat-soluble vitamins and provitamins such as vitamin A, retinol, vitamin D or vitamin E, active ingredient-containing W / O emulsions or non-polar plant extracts in concentrations of 0.1 to 200 g per kilogram of cellulose.

[0030] Known direct solvents include, for example, NMMO, ionic liquids, and possibly mixtures of organic liquids with the aforementioned direct solvents or DMAc / LiCl.

[0031] The layered silicates used are natural and organically modified clay minerals such as talc, montmorillonite, bentonite, or kaolinite, or synthetic and organically modified silicates such as Nanofil®, Laponite®, or Hectorit®. The layered silicate content in the functional cellulose fiber is 0.5 to 20%, preferably 5 to 15%, based on the amount of cellulose used.

[0032] To stabilize the highly viscous mixtures of active ingredient-containing lipophilic substance, optionally in combination with hydrocarbons or the W / O emulsions in process step 1 c), nanoparticles based on pyrogenic silicas, metal oxide ceramics or solvent-compatible metal nanoparticles and / or aliphatic-aromatic block copolymers are used in concentrations of 0.1 to 10% based on the total amount of the mixture of active ingredient or active ingredient / hydrocarbon or W / O emulsion.

[0033] W / O emulsions are aqueous preparations of cosmetic active ingredients, such as urea, or aqueous extracts of plant constituents, each mixed with nonpolar hydrocarbons, fatty alcohols, fatty acids and fatty acid esters with more than 8 carbon atoms (in the case of fatty acid esters, more than 8 C atoms in the fatty acid part) and natural or synthetic emulsifiers, with the concentrations of the aqueous components ranging from 0.1 to 200 g per kilogram of nonpolar hydrocarbon.

[0034] The cellulose molded bodies with inclusions of mixtures of modified layered silicates, hydrocarbons and solid or liquid lipophilic active ingredients or W / O emulsions produced according to this process can be used as functional fibers in blended yarns with other natural or synthetic fibers, for example made of polyester, polyamide, polypropylene, viscose, cotton or wool, in knitted and woven textiles with added functional benefits, in functional nonwovens and nonwoven composites, in papers and paper composites, as well as in functional films and membranes.

[0035] The most important methods for characterizing the exfoliation of a layered silicate nanocomposite are, on the one hand, X-ray scattering (WAXS) and, on the other hand, transmission electron microscopy (TEM). However, both methods have only limited significance for a comparative assessment of the exfoliation of nanocomposite samples. In contrast, rheological investigations of nanocomposite dispersions offer at least two significant advantages: i) they query a macroscopic sample volume, but only require a few grams of the sample and ii) They are standard physicochemical methods and experimentally less expensive than WAXS or TEM.

[0036] The method is based on determining the shear thinning exponent n, which is a semi-quantitative measure of the delamination of a nanolayer silicate [R. Wagener et al.: “Rheological Characterization of Nanocomposites”, 8th Rudolstadt Plastics Day, May 21, 2003]. The measurements were performed in a Haake Mars 2 plate-plate rheometer at small deflections of less than 1%. Preliminary investigations verified that this shear amplitude did not lead to unwanted orientation of the plates in the measuring instrument. The viscosity of the respective samples was measured in the shear rate range between 0.1 and 100 Hz. A power equation was fitted to the resulting flow curve: η∗=A∗ω(n), with: η* = experimentally determined solution viscosity (or, in the case of thermoplastic polymers, melt viscosity) A = Prefactor ω = oscillation frequency of the rheometer (equivalent to the shear rate) n = shear thinning exponent

[0037] The shear thinning exponent n was determined from a double logarithmic plot of η* against ω by drawing a straight line along the linear portion of the graph at the lowest shear rates. The value of n is obtained as the slope of this line. Fig. shows the result of such a rheological investigation on cellulose solutions sheared to different degrees and / or lengths and modified with layered silicate nanocomposites.

[0038] Values ​​at or slightly below "0" indicate only a small change in exfoliation. Steeper downward slopes should be a measure of increasing exfoliation in the layered silicate nanocomposite and indicate increasingly greater shear thinning. However, this is not necessarily the result of differing exfoliation rates in the nanocomposites, but can also be caused by temperature effects.

[0039] Therefore, samples of the composite were subjected to a series of measurements at different temperatures in the interval 85 °C < T < 115 °C, analogous to Example 1. In the range of low oscillation frequencies ω < 2 Hz, practically no influence of temperature on the flow curve was observed. This behavior of nanocomposites, which is more typical for solids, is apparently determined by a comparatively regular, three-dimensional structure of silicate platelets with strong edge / surface interactions, as has also been shown in investigations of, for example, polycarbonate layered silicate nanocomposites [P. Pötschke et al., “Rheological behavior of multiwalled carbon nanotube / polycarbonate composites”; Polymer 43: 2002, 3247-3255].

[0040] Another object of the invention is cellulose molded bodies with organically modified nanoscale layered silicates or nanoscale layered silicates pre-activated by ion exchange with potassium, calcium or aluminium ions and domains of compositions of active ingredients and lipophilic matrix materials for the active ingredients or active ingredient-containing water-in-oil emulsions, which can be produced according to one of the aforementioned methods.

[0041] Using the described methodology, it has been possible to produce cellulose molded bodies and to evaluate them semi-quantitatively in a comparable manner, in which the release of the active ingredient can be controlled. Furthermore, this method makes it possible for the first time to incorporate even highly volatile or water-soluble active ingredients into the finished cellulose molded body and to control their release. The cellulose molded bodies according to the invention are used, for example, as functional fibers in blended yarns with polyester fibers, polyamide fibers, polypropylene fibers, viscose fibers, cotton fibers, or wool, in knitted and woven textiles, in nonwovens and nonwoven composites, in paper and paper composites, as well as in films and membranes. Examples

[0042] The following examples serve to illustrate the invention. They represent possible embodiments of the method according to the invention, without claiming exclusivity. Unless otherwise stated, percentages given are percentages by mass. Example 1

[0043] 2.265 kg of cotton linters pulp (DP: 618) and 114 g of propyl gallate are mixed with 21.000 kg of a 60% aqueous NMMO solution and fed into a stirred tank. Stirring is carried out for 50 minutes. -1 Approximately 5 liters of water are extracted from the mash under a vacuum of 40 mbar and a temperature of 50 °C. Simultaneously, the mash is sheared for 30 minutes using Ultra Turrax at 25,000 rpm. -12.242 kg of an 80% aqueous NMMO solution and 364.5 g of layered silicate (montmorillonite modified with methyl tallow bis-(2-hydroxyethyl)ammonium – the cations naturally present in the montmorillonite are replaced by these ammonium cations = Cloisite® 30 B Nanoclay from Southern Clay) are dispersed and added to the mash. The mash mixture is heated at 50 min. -1 The mixture was stirred at 100 °C and a vacuum of 20 mbar until a highly viscous mass was formed. A dispersion of 135 g evening primrose oil, 545 g n-octadecane, and 91.1 g pyrogenic silica (Aerosil® R 106), prepared separately under high shear using UltraTurrax, was then added to this highly viscous mass. The entire mixture was stirred at 100 °C and 20 mbar until all components were homogeneously distributed. The shear thinning exponent was determined to be -0.86 (curve d). Fig. After transferring the finished spinning mass, staple fibers with a fineness of 2.2 dtex and a cutting length of 60 mm are produced using a dry-wet spinning process (120 µm nozzle openings, 20 mm air gap).

[0044] 1,500 g of the staple fibers produced in this way are mixed with 3,500 g of cotton fibers, placed in a laboratory carding machine and, after cross-laying, formed into a nonwoven fabric with a basis weight of 150 g / m². 2 needled.

[0045] To measure the transfer of the active ingredient from the textile surface to a technical skin model at 25 °C and 60% relative humidity under mechanical stress, a wear simulation was performed using an abrasion tester in accordance with DIN EN ISO 105-X12 2002-12. The transferred active ingredient content was then detected by HPLC-MS after exhaustive extraction of toluene from the skin. The mean value of 5 parallel determinations was 0.073 mg / 100g evening primrose oil.

[0046] The determined, high negative shear dilution exponent of the spinning solution, which was set by a long shear time and a high shear rate, therefore correlates with a rather slow release of the incorporated evening primrose oil. Example 2

[0047] A mash prepared according to Example 1 was treated with a dispersion of 135 g evening primrose oil, 545 g n-dodecane and 91.1 g pyrogenic silica (Aerosil) using an otherwise analogous procedure. ® R 106) was added. The mixture, whose shear thinning exponent n = -0.56 (curve b) in Fig. ), is then processed and deformed analogously to Example 1. A nonwoven fabric of the same composition and basis weight as in Example 1 was formed from the resulting staple fibers.

[0048] When measuring the transfer of the active ingredient, an average value of 0.754 mg / 100g of evening primrose oil was determined.

[0049] By changing the active ingredient matrix composition, a lower negative shear thinning exponent is determined and a faster drug release is achieved. Example 3

[0050] A mash prepared according to Example 1 was mixed with a parallel dispersion consisting of 2.242 kg of an 80% aqueous NMMO solution and 364.5 g of layered silicate (Cloisite® 30 B), which had been dispersed using UltraTurrax for only 10 minutes. The mixture was then processed analogously to Example 1. The shear thinning exponent of the solution was -0.67 (curve c) in Fig. ).

[0051] The measurement of the active ingredient transfer revealed an average release of 0.522 mg / 100g evening primrose oil.

[0052] The significantly reduced shear duration compared to Example 1 leads to a decrease in the absolute value of the determinable shear dilution exponent and results in a significant increase in the amount of active ingredient released compared to Example 1. Example 4

[0053] A dispersion of 135 g α-tocopherol, 545 g palm kernel oil, and 91.1 g pyrogenic silica was added to the mash prepared according to Example 1, using otherwise analogous procedures. The mixture, whose shear thinning exponent was -0.13, was then further processed and deformed analogously to Example 1. A fleece of the same composition and basis weight as in Example 1 was formed from the resulting staple fibers.

[0054] When measuring the drug transfer, an average value of 1.290 mg / 100g α-tocopherol was determined.

[0055] In comparison to the examples already presented, a change in the composition of the active ingredient matrix, with otherwise comparable parameters, also causes a significant increase in the release rate here. Example 5

[0056] The mash prepared according to Example 1 was treated with a dispersion of 135 g W / O emulsion (urea, cocoa butter, wool wax alcohol), 545 g n-octadecane, and 91.1 g pyrogenic silica (HDK® N 20), following an otherwise analogous procedure. The shear dilution exponent was set to -0.04 (curve a) in Fig. The mixture is then processed and shaped analogously to Example 1. A yarn consisting of 30% functional fibers and 70% cotton was produced from the resulting staple fibers and further processed into a fine circular knitted piece.

[0057] When measuring the transfer of the active ingredient, an average value of 2.680 mg / 100g urea was determined.

[0058] W / O emulsions show a very sensitive influence of the shear dilution exponent on the active ingredient matrix composition with otherwise comparable treatment parameters, the lowest shear dilution exponents and comparatively high release rates.

Claims

Process for the production of cellulose molded bodies with controlled drug release comprising the following steps: a) Pulp is dispersed in an aqueous direct solvent for cellulose to form a cellulose slurry, b) in a separate process step, an organically modified nanoscale layered silicate or a nanoscale layered silicate pre-activated by ion exchange with potassium, calcium, or aluminum ions is homogenized with an aqueous direct solvent for cellulose and partially or completely exfoliated by shearing, added to the cellulose slurry, and mixed with it, c) in a further separate process step, a composition of an active ingredient and a lipophilic matrix material for the active ingredient or an active ingredient-containing water-in-oil emulsion is stabilized by inorganic or organic thickeners and converted into a gel-like paste.This paste is also added to the cellulose mash and mixed with it while stirring at temperatures up to 130 °C, d) water is removed from the mixture until the cellulose is completely dissolved, and e) the resulting spinning solution is formed into shapes using a solution spinning process, post-treated, and dried. The method according to claim 1, characterized in that the direct solvent for cellulose is an aqueous N-methylmorpholine N-oxide solution, an aqueous ionic liquid which may additionally contain organic solvents, or a solution of dimethylacetamide (DMAc) and lithium chloride. The method according to claim 1, characterized in that the organically modified layered silicates are synthetic layered silicates modified by ammonium cations with at least one long-chain, unbranched alkyl and / or alkenyl residue having 14 or more carbon atoms, preferably having 14 to 20 carbon atoms, wherein the alkyl or alkenyl residue may be substituted, in particular with one or more hydroxyl or carboxyl group(s). Method according to one or more of claims 1 to 3, characterized in that the proportion of organically modified layered silicate(s) in the cellulose molded bodies, which are preferably cellulose functional fibers, is 0.5 to 20 wt.%, preferably 5 to 15 wt.%, in each case based on the weight of the cellulose. Method according to one or more of claims 1 to 4, characterized in that the active ingredient is selected from the group of solid or liquid lipophilic active ingredients, wherein cosmetic active ingredients such as evening primrose oil, St. John's wort oil, jojoba oil, avocado oil, fat-soluble vitamins and provitamins, such as vitamin A, retinol, vitamin D or vitamin E, W / O emulsions or nonpolar or aqueous plant extracts are preferred. Method according to one or more of claims 1 to 5, characterized in that the lipophilic matrix material for the active ingredient is a hydrocarbon with more than 8 carbon atoms, preferably with 8 to 22 carbon atoms, a (C8-C22) fatty alcohol, a (C8-C22) fatty acid and / or a fatty acid ester with 8 to 22 carbon atoms in the fatty acid part. Method according to one or more of claims 1 to 6, characterized in that the inorganic thickeners are nanoparticles made of pyrogenic silica, metal oxide ceramic and / or metal. Method according to one or more of claims 1 to 7, characterized in that the organic thickeners are aliphatic-aromatic block copolymers. Method according to one or more of claims 1 to 8, characterized in that the composition of active ingredient and lipophilic material is used in concentrations of 0.1 to 200 g per kilogram of cellulose. The method according to claim 9, characterized in that the water-in-oil emulsion comprises a hydrophilic phase dispersed in an oily phase, preferably an aqueous preparation of cosmetic active ingredients or aqueous extracts of plant constituents, each mixed with nonpolar hydrocarbons, fatty alcohols, fatty acids and fatty acid esters with more than 8 carbon atoms and natural or synthetic emulsifiers, wherein the concentrations of the aqueous components are from 0.1 to 200 g per kilogram of liquid phase. A method according to one or more of claims 1 to 10, characterized in that the release of the active ingredients is controlled by the degree of exfoliation of the layered silicates, by the chemical structure and concentration of the organic cations in the layered silicate, by the size of the intercalated ions or the swelling degree of non-organically modified layered silicates, by the temperature during pre-swelling of the organically modified layered silicate and / or during the production of the paste from active ingredient and lipophilic material for the active ingredient, by the viscosity of the dispersing agent used, by the water content therein, by the type of lipophilic matrix material, and by the intensity and duration of the mixing / shearing of the organically modified layered silicates. Method according to one or more of claims 1 to 11, characterized in that the inorganic nanoparticles are used in a proportion of 0.1 to 10 wt.%, based on the total weight of the mixture of active ingredient and lipophilic material for the active ingredient. Method according to one or more of claims 1 to 12, characterized in that the shear thinning exponent n of the spinning solution is in the range of 0.0 to -1.2, preferably in the range of -0.1 to -1.

0. Cellulose molded bodies with organically modified nanoscale layered silicates or nanoscale layered silicates pre-activated by ion exchange with potassium, calcium or aluminium ions and domains of compositions of active ingredients and lipophilic matrix materials for the active ingredients or active ingredient-containing water-in-oil emulsions, produced according to a method according to one or more of claims 1 to 13. Cellulose molded bodies according to claim 14, characterized in that the organically modified layered silicates are modified by ammonium or phosphonium cations with at least one straight-chain hydrocarbon residue having 14 or more C atoms, preferably 14 - 20 C atoms. Cellulose molded bodies according to claim 14 or 15, characterized in that they are used in textile applications and can be reloaded with highly volatile, thermo- and / or chemosensitive active ingredients. Use of the cellulose molded bodies according to one or more of claims 14 to 16 as a functional fiber in blended yarns with polyester fibers, polyamide fibers, polypropylene fibers, viscose fibers, cotton fibers or wool, in knitted and woven textiles, in nonwovens and nonwoven composites, in paper and paper composites, as well as in films and membranes.

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