Modified PU foam

Abstract

The present patent application relates to a PU foam comprising at least one secondary plant compound bound, preferably covalently bound, thereto, wherein the at least one secondary plant compound is partially or completely introduced in the form of wood particles.

Description

[Technical Field]

[0001] The present invention relates to polymers and their preparation and use. [Background technology]

[0002] Polymers such as polyurethane (PU) are used in a variety of applications and are often chemically modified to meet specific requirements. For example, polyurethanes are used as molding materials for compression molding, as casting resins (isocyanate resins), as elastic fiber materials (for textiles), as polyurethane lacquers, and as polyurethane adhesives. Flexible PU foams, in particular, are primarily used for upholstery (e.g., for furniture or car seats), mattress foams, carpet backings, textile laminates, cleaning sponges, and filter materials. The range of use for each material can be tailored by adding chemical additives. Therefore, it is common to modify PU foams with functional additives to produce a variety of applications. For example, the water absorption capacity of mattresses can be reversibly altered by incorporating additives into flexible polyurethane foam, which strongly supports the concept of mattresses. However, such additives are often toxic and non-biodegradable. Another example is the use of carcinogenic activated carbon black to absorb odorous substances.

[0003] Therefore, a fundamental drawback of typical modified PU foams is the presence of environmentally harmful functional chemicals, which can separate from the polymer and enter the environment (e.g., groundwater). Another drawback is related to the high amount of functional chemicals used, since the compounds incorporated into the polymer core often have no functional effect and are difficult to mobilize.

[0004] It is therefore an object of the present invention to provide sustainable PU foams with improved properties and high environmental compatibility. Summary of the Invention

[0005] The present invention therefore relates to a PU foam comprising at least one secondary plant compound bound, preferably covalently bound, thereto, wherein the at least one secondary plant compound is present partly or entirely in the form of wood particles.

[0006] Surprisingly, it has been shown that the properties of the PU foam of the present invention can be modified in a targeted manner by secondary plant compounds bound thereto, thereby increasing its environmental compatibility. Depending on the structure and properties of the secondary plant compounds, the properties of the material can be manipulated by covalently binding them to the fiber material without the use of toxic and / or environmentally harmful chemicals. The secondary plant compounds are natural components, found, for example, in daily nutrition, and therefore pose no risk to the environment or humans because they are products of biologically sustainable raw materials. The secondary plant compounds are present in the PU foam, partially or completely, in the form of wood particles. The wood particles are a biologically sustainable raw material, and the secondary plant compounds enhance or extend the properties of the resulting PU foam.

[0007] Another aspect of the present invention is a method for producing PU foam, comprising reacting at least one polyol component with at least one isocyanate component in the presence of a propellant and at least one catalyst for catalyzing the isocyanate-polyol reaction, wherein at least one secondary plant compound is incorporated during the reaction between the at least one polyol component and the at least one isocyanate component, the at least one secondary plant compound being present partially or completely in the form of wood particles. When producing the PU foam of the present invention, the starting materials are mixed, and linkage of the individual components is achieved by reaction of an isocyanate group (-N=C=O) of one molecule with a hydroxyl group (-OH) of another molecule to form a urethane group (-NH-CO-O). By incorporating at least one secondary plant compound into the reactants, the secondary plant compound can be covalently bonded to the PU foam, particularly in the isocyanate component. The method of the present invention allows for the production of environmentally friendly PU foam with modified properties, and the use products produced therefrom with modified properties have been shown to be ecologically safe.

[0008] Another aspect of the present invention relates to a PU foam obtainable by the process of the present invention.

[0009] Another aspect of the present invention relates to the use of PU foams for producing filters, upholstered products, mattresses, cushions, hygiene products, cleaning sponges and / or thermal insulation layers, preferably textiles, sound and heat insulation materials. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the present invention, the terms "PU foam", "PUR foam" and "polyurethane foam" particularly relate to products obtained by reacting polyisocyanates with polyols or compounds having isocyanate-reactive groups, and optionally with propellants. Preferred PU foams are flexible PU foams, rigid PU foams and PU integral foams. Particularly preferred herein are common flexible PU foams based on ether or ester polyols, high-resilience polyurethane cold foams, viscoelastic PU foams, PU ultra-flexible foams, semi-rigid PU foams and rigid PU foams, as well as PU foams with properties between these categories.

[0011] In the context of the present invention, the term "secondary plant compounds" refers to substances that are not produced in energy metabolism or in the construction (anabolic) or decomposition (catabolic) metabolism. They differ from primary plant materials in that they are produced in specific cell types of plants and are not directly important to the plant. The biosynthetic pathways that lead to the production of secondary plant compounds are summarized under the term "secondary metabolism." Secondary plant compounds are specific chemical metabolites, in contrast to the primary metabolites of plants. These metabolites are usually restricted to specific types or groups of plants and originate from primary metabolism. Depending on their chemical structure and functional properties, secondary plant compounds are divided into different groups, such as polyphenols, carotenoids, phytoestrogens, glucosinolates, sulfides, terpenes, terpenoids, saponins, protease inhibitors, phytosterols, and lectins. Secondary plant compounds, such as isoprenoids, resins, and terpenes, are also present, for example, in wood and its particles.

[0012] At least one secondary plant compound is bonded, preferably covalently bonded, to the PU foam. This means that the at least one secondary plant compound is bonded, preferably covalently bonded, to an isocyanate during the production of the PU foam, preferably by reaction of a polyol with the isocyanate. This means that the secondary plant compound, which may consist to some extent, i.e., partially or entirely, of wood particles, is thus integrated into the PU foam. This is particularly advantageous because it distributes the at least one secondary plant compound within the PU foam. Thus, the PU foam of the present invention contains at least one secondary plant compound in its internal structure and on its surface. Therefore, abrasion, cutting, and similar treatments to the PU foam do not cause the PU foam to lose its advantageous properties based on the at least one secondary plant compound, because the secondary plant compound is repeatedly "exposed" to the PU foam. As used herein, "covalently bound" means that at least 5 wt. %, preferably at least 10 wt. %, more preferably at least 20 wt. %, more preferably at least 40 wt. %, more preferably at least 50 wt. %, more preferably at least 60 wt. %, and more preferably at least 80 wt. % of the secondary plant compounds present in the PU foam of the present invention or used or added during the production of the PU foam of the present invention are actually covalently bound in the PU foam. The proportion of covalently bound secondary plant compounds can be determined by methods known to those skilled in the art. For example, an aqueous extract can be prepared based on the method described in DIN 53770, carried out at a pH value of 5.5, and the secondary plant compounds contained therein can be quantified and compared with the amount of secondary plant compounds originally used.

[0013] The PU foam of the present invention comprises at least one, preferably covalently bound, secondary plant compound. According to the present invention, the at least one secondary plant compound can be present partially or completely in the form of wood particles. "Completely" means that all secondary plant compounds in the PU foam of the present invention (i.e., 100% of the secondary plant compounds) are present in the form of wood particles. "Partially" means that at least 1% by weight, preferably at least 5% by weight, more preferably at least 10% by weight, more preferably at least 20% by weight, more preferably at least 30% by weight, more preferably at least 40% by weight, more preferably at least 50% by weight, more preferably at least 60% by weight, more preferably at least 70% by weight, more preferably at least 80% by weight, and more preferably at least 90% by weight of the secondary plant compounds are contained in the PU foam in the form of wood particles.

[0014] The effect of at least one secondary plant compound in a PU foam has been shown to be particularly pronounced at certain amounts. According to a preferred embodiment of the present invention, the PU foam comprises 0.1 to 10 wt. %, preferably 0.2 to 5 wt. %, and particularly preferably 0.3 to 3 wt. % of at least one secondary plant compound. As used herein, "wt. %" refers to the overall formulation of the PU foam.

[0015] The at least one secondary plant compound is preferably a terpenoid or a polyphenol, in order to impart to the PU foam of the present invention, for example, antistatic, abrasion resistant, absorbent, odor neutralizing, insecticidal, acaricidal, preferably antibacterial, or a combination thereof, properties.

[0016] Terpenes are compounds whose basic structure is based on an isoprene unit (C5 unit). Terpenoids are also based on isoprene units and feature additional functional groups, but terpenes contain only hydrocarbons. Terpenoids contain, among others, alcohols, ethers, aldehydes, ketones, carboxylic acids, esters, and glycoside groups. Polyphenols are compounds from the phenolic or hydroxyaromatic group. Polyphenols are typically found on the surface of fruits, vegetables, and grains. They contain several aromatic rings in their chemical structure and can contain color pigments, fragrances, and tannins, which typically protect plants from predators and attract insects for pollination. In some plants, polyphenols also protect the photosynthetic apparatus through their antioxidant properties and by filtering energy-rich UV-B radiation.

[0017] When classifying terpenoids, a distinction is usually made between acyclic, monocyclic, bicyclic, tricyclic, tetracyclic, pentacyclic, and polycyclic terpene structures, i.e., molecules with one, two, three, four, five, or several rings, and molecules without. Depending on the size of the molecule, terpenoids serve as fragrances (e.g., pheromones or repellents), adhesives, and preventatives against viral, bacterial, and fungal diseases. Terpenoids also constitute the majority of known essential oils. Essential oils are widely used as insect repellents. Many terpenoids also exhibit antibacterial activity. Terpenoids are active against bacteria, fungi, viruses, and protozoa.

[0018] Cyclic terpenoids, preferably bicyclic terpenoids, are often used as solvents in surface treatments, in household products (e.g., shoe polish, floor cleaning products), as fragrance additives in cosmetics, and are natural components of plant foods (e.g., oranges, lemons, carrots).

[0019] According to the present invention, terpenoids, preferably cyclic terpenoids, can be covalently bonded to the PU foam to modify its properties. This allows the properties of the terpenoid to be "integrated" into the PU foam. The PU foam modified in this way also has the properties exhibited by the terpenoid used.

[0020] According to a preferred embodiment of the present invention, the terpenoid is a monocyclic or polycyclic terpenoid, preferably a bicyclic, tricyclic, tetracyclic or pentacyclic terpenoid. According to another preferred embodiment of the present invention, the terpenoid is a monoterpenoid selected from the group consisting of pyrethrins, thymol, cineole, thuyanol, perillic acid, linalool, myrcenol, citral, citronellal, geranic acid, junionone, chrysanthemol, menthol, terpineol, verbenol, carveol, piperitone and camphor, preferably pyrethrins, thymol, cineole, thuyanol and / or perillic acid.

[0021] Monoterpenoids consist of two isoprene units, i.e., a basic structure with 10 C atoms. Monoterpenoids are mainly used as fragrances in the industry. By covalently bonding monoterpenoids to PU foam, it can provide foam that helps to avoid unpleasant odors, for example, in textile products, upholstery, etc.

[0022] According to another preferred embodiment of the present invention, the terpenoid is a sesquiterpenoid selected from the group consisting of farnesin, bisabolol, armirarin, merulidial, hirsutumic acid, nerolidol, zingiberene, germacrane, periplanone, elemol, guaiane, and cedrane, preferably farnesin, bisabolol, armirarin, merulidial, and / or hirsutumic acid.

[0023] Sesquiterpenoids contain a basic structure with three isoprene units, i.e., 15 C atoms. Sesquiterpenoids are primarily used as fragrances and aromas.

[0024] According to another preferred embodiment of the present invention, the terpenoid is a diterpenoid selected from the group consisting of agelasine, larixol, dehydroabietinol, abietic acid, boregrevirol, aframodial, phytol, retinol, primaran, nimbiol, forskolin, labdanolic acid, cassainic acid, gibberelan, isopimaric acid, dehydroabietinol, and abietic acid, preferably agelasine, larixol, dehydroabietinol, abietic acid, boregrevirol, and / or aframodial.

[0025] Diterpenoids are composed of four isoprene units (2-methylbutadiene) and can be subdivided into open-chain and cyclic compounds. Diterpenoids are present, for example, in many resins and often have anti-inflammatory properties.

[0026] According to another preferred embodiment of the present invention, the terpenoid is a sesterpenoid selected from the group consisting of ircinin, neomanoalide, cericerane, and dehydroircinin.

[0027] Sesterterpenoids consist of five isoprene units and are found mainly in lower plants, fungi, and potato leaves. Sesterpenoids are known, among other things, for their antibacterial activity (e.g., irusinin). Preferably, sesterpenoids can be covalently bonded to PU foam to provide a material with antibacterial properties.

[0028] According to another preferred embodiment of the present invention, the terpenoid is a triterpenoid selected from the group consisting of limonoids, lanosterol, fusidane, fusidic acid, euphane, dammarane, cucurbitane, cucurbitacin, betulin, and betulinic acid.

[0029] Triterpenoids contain a basic structure with six isoprene units, i.e., 30 C atoms. Tetracyclic triterpenoids (e.g., lanosterane type) include important groups of steroids and cucurbitacins. Pentacyclic compounds are subdivided into oleanane type, ursane type, and lupin type triterpenoids depending on their basic structure. They exist, for example, as triterpenoid alcohols and triterpenoid acids (resin acids and resinols) in resins, or as triterpenoid sapogenins (saponins). Many triterpenoids have important biological functions, for example, as hormones.

[0030] According to another preferred embodiment of the present invention, the terpenoid is a tetraterpenoid selected from the group consisting of carotene, crocetin, and lycopene.

[0031] Tetraterpenoids contain eight isoprene units, i.e., the basic structure contains 40 C atoms. Tetraterpenoids include fat-soluble pigments (lipochromes) in archaea, bacteria, plants, and animals. These include pure hydrocarbons such as carotenes and lycopene, as well as their oxygen-containing derivatives, xanthophylls. The attachment of tetraterpenoids to PU foams can, for example, cause coloring / discoloration of the foams.

[0032] According to another preferred embodiment of the present invention, the terpenoid is a polyterpenoid selected from the group consisting of betulaprenol, oleanolic acid, ubiquinone, dolochol, and betulaprenol, preferably betulaprenol, oleanolic acid, ubiquinone, and / or dolochol.

[0033] According to another preferred embodiment of the present invention, the polyphenol is a polyhydroxyphenol, preferably tannin, suberin, or lignin.

[0034] Tannins include polyhydroxyphenols with hydroxy groups in the ortho position, particularly derivatives (esters) of gallic acid (3,4,5-trihydroxybenzoic acid) with glucose and related sugars. Depending on the degree of condensation, tannins can be subdivided into gallotannins (e.g., glucogallin) and ellagitannins (e.g., pendunculagin). The free hydroxy groups allow cross-linking with polymers and proteins. Therefore, amino acids or proteins present on the surface of cells and viruses can be absorbed by the PU foams of the present invention. Gases such as oxygen, H2S, and ammonia can also be absorbed by the reactive groups of the bound polyphenols.

[0035] Suberin is a hydrophobic biopolymer deposited in the cell walls of plants. As a hydrophobic material, suberin has the natural function of sealing roots and preventing water penetration.

[0036] Lignin comprises a group of macromolecules with different monomeric building blocks (coumaryl alcohol, coniferyl alcohol, sinapyl alcohol, etc.). Lignin is characterized by its structure based on phenolic complexes (phenylpropanoids) with hydroxy, methoxy, and aryloxy substituents. Lignin is hydrophobic and has binding sites for polyvalent metal ions (Fe, Mn, Cr, etc.) and a special absorption capacity for some UV light with wavelengths in the 100-300 nm range.

[0037] By covalently bonding suberin and / or lignin in the PU foam, the material can become, for example, hydrophobic, absorbent and / or UV resistant or have these properties improved.

[0038] According to another preferred embodiment of the present invention, the tannin is a gallotannin or an ellagitannin.

[0039] According to another preferred embodiment of the present invention, the polyphenol is selected from the group consisting of phytoalexins, preferably resveratrol, flavonols, preferably taxifolen, catechins, flavonoids, anthocyans, proanthocyanidins, procyanidins, phlobaphenes, and isoflavones.

[0040] Phytoalexins are, for example, low molecular weight compounds with antibacterial and antioxidant properties that are produced by plants immediately after infection with microorganisms (e.g., bacteria or fungi) and can inhibit their spread, growth, or reproduction in the plant. Therefore, by attaching phytoalexins to PU foam, it is possible to impart antibacterial properties to the material.

[0041] According to another preferred embodiment of the invention, the at least one secondary plant compound is a tree resin, preferably colophony, mastic, or balsam.

[0042] Surprisingly, it has been shown that the antibiotic, and in particular antibacterial, action of the compounds is not only based in part on their different metabolic actions in microorganisms, but also on the adhesive properties of the solid resins (e.g. colophony).Since microorganisms attach to the resins by adhesive forces, the physical diffusion of microorganisms can be hindered or prevented by covalently bonding the tree resin to the PU foam.

[0043] PU foams can be subdivided, for example, into rigid PU foams with closed or partially closed cells and flexible PU foams with open or partially open cells. Rigid PU foams are primarily used as thermal insulation or for building insulation. Flexible PU foams are used in many technical applications in industry and the private sector, such as sound insulation, mattress production, or furniture upholstery. A particularly important market for different types of PU foams, such as traditional flexible foams based on ether or ester polyols, rigid foams, and foams with properties intermediate between these classifications, is the automotive industry. Here, rigid foams can be used, for example, as roof linings, as ester foams for interior door linings and die-cut sun visors, and as cold and flexible foams for seating systems. Another particularly important market relates to mattresses and seating systems, for example, for residential and office use. Regarding flexible foams, a distinction can also be made between low-temperature and high-temperature flexible foams.

[0044] According to another preferred embodiment of the present invention, the PU foam can be a rigid PU foam, a flexible PU foam, or a viscoelastic PU foam.

[0045] PU foams can be produced in a variety of ways. In principle, polyurethanes are produced by the polyaddition reaction of an isocyanate component and a polyol component, as described above. To foam the polyurethane produced during the reaction, a propellant (e.g., water) can be added to the mixture of the isocyanate component and the polyol component.

[0046] The isocyanate component used in the present invention is preferably one or more organic polyisocyanates having two or more isocyanate functional groups. Generally, any known aliphatic, cycloaliphatic, arylaliphatic, and preferably aromatic polyfunctional isocyanates can be used. Examples that may be mentioned here include alkylene diisocyanates having 4 to 12 carbon atoms in the alkylene residue, such as 1,12-dodecane diisocyanate, 2-ethyltetramethylene diisocyanate-1,4, 2-methylpentamethylene diisocyanate-1,5, tetramethylene diisocyanate-1,4, and preferably hexamethylene diisocyanate-1,6 (HMDI), cycloaliphatic diisocyanates, such as cyclohexane-1,3- and 1,4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3,35-trimethyl-5-isocyanatomethylcyclohexane, and the like. Examples of suitable isocyanates include hexane (isophorone diisocyanate, or IPDI for short), 2,4- and 2,6-hexahydrotoluylene diisocyanate and mixtures of the corresponding isomers, and preferably aromatic diisocyanates and polyisocyanates, such as 2,4- and 2,6-toluene diisocyanate (TDI) and mixtures of the corresponding isomers, methylene di(phenylisocyanate) (MDI), mixtures of 2,4'- and 2,2'-methylene di(phenylisocyanate), and polyphenylpolymethylene polyisocyanates (raw MDI), as well as mixtures of raw MDI and toluene diisocyanate (TDI). The organic diisocyanates and polyisocyanates can be used alone or in the form of mixtures. It is also possible to use modified isocyanates incorporating urethane, uretdione, isocyanurate, allophanate, and other groups, so-called modified isocyanates.Particularly suitable organic polyisocyanates which are particularly preferably used are therefore the various isomers of toluene diisocyanate (2,4- and 2,6-toluene diisocyanate (TDI), either in their pure form or as a mixture of isomers of different composition), 4,4'-methylenedi(phenylisocyanate), so-called "crude MDI" or "polymeric MDI" (which contains, in addition to the 4,4'- of MDI, also the 2,4'- and 2,2'-isomers and higher nuclear products), and binuclear products called "pure MDI", which consist mainly of a mixture of the 2,4'- and 4,4'-isomers or prepolymers thereof.

[0047] Polyols suitable as polyol components within the meaning of the present invention are any organic substances containing groups reactive with isocyanates, preferably OH groups. Preferred polyols are any polyether polyols and / or polyester polyols and / or hydroxyl-containing aliphatic polycarbonates, especially polyether polycarbonate polyols and / or polyols of natural origin, so-called "natural oil-based polyols" (NOPs), commonly used for producing polyurethane systems, especially PU foams. Suitable usable polyether polyols can be prepared by known methods, for example, by anionic polymerization of alkylene oxides in the presence of alkali hydroxides, alkyl alcoholates, or amines as catalysts, preferably with the addition of at least one starter molecule containing two or three bonded reactive hydrogen atoms, or by cationic polymerization of alkylene oxides in the presence of Lewis acids, such as antimony pentachloride or boron trifluoride etherate, or by double metal cyanide catalysis. Suitable alkylene oxides contain 2 to 4 carbon atoms in the alkylene residue. Examples are tetrahydrofuran, 1,3-propylene oxide, 1,2- or 2,3-butylene oxide, preferably ethylene oxide and 1,2-propylene oxide. The alkylene oxides can be used individually, cumulatively, in blocks, alternatingly, or as mixtures. The starter molecule can in particular be a compound having at least two, preferably 2 to 8, hydroxy groups in the molecule, or a compound having at least two primary amino groups.Usable starter molecules include, for example, water, di-, tri-, or tetrahydric alcohols such as ethylene glycol, propanediol-1,2 and 1,3, diethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythrit, castor oil, and higher polyfunctional polyols, especially sugar compounds such as glucose, sorbitol, mannitol, and sucrose, polyhydric phenols, resols such as oligomeric condensates of phenol with formaldehyde, and Mannich condensates of phenol, formaldehyde, and dialkanolamines, as well as melamine, or amines such as aniline, EDA, TDA, MDA, and PMDA, with TDA and PMDA being particularly preferred. The choice of suitable starter molecule depends on the respective application of the polyether polyol obtained during polyurethane production (for example, higher molecular weight triols are used for the production of flexible PU foams than for the production of rigid PU foams).

[0048] Preferred usable polyester polyols are based on esters of polyhydric aliphatic or aromatic carboxylic acids, preferably having 2 to 12 carbon atoms. Examples of aliphatic carboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, and fumaric acid. Examples of aromatic carboxylic acids are phthalic acid, isophthalic acid, terephthalic acid, and the isomeric naphthalenedicarboxylic acids. Polyester polyols can be obtained by condensing these polyhydric carboxylic acids with polyhydric alcohols, preferably with diols or triols having 2 to 12, particularly preferably 2 to 6, carbon atoms, and preferably with trimethylolpropane and glycerol.

[0049] Preferred usable polyether polycarbonate polyols are those containing carbon dioxide bound as the carbonate. Because carbon dioxide is a by-product of many processes in the chemical industry, the use of carbon dioxide as a comonomer in alkylene oxide polymerization is particularly interesting from a commercial standpoint. Partial replacement of alkylene oxide in polyols with carbon dioxide could significantly reduce the cost of polyol production. Furthermore, the use of CO2 as a comonomer is highly ecologically beneficial, since this reaction converts greenhouse gases into polymers. The production of polyether polycarbonate polyols by catalytically combining alkylene oxide and carbon dioxide with H-functional starting materials has long been known.

[0050] According to another preferred embodiment of the present invention, the PU foams are produced based on polyether and / or polyester polyols and toluene-2,4-diisocyanate and / or methylenedi(phenylisocyanate).

[0051] According to another preferred embodiment of the present invention, the PU foam has open or closed cells. In the context of the present invention, "open cell" means that the foam has high breathability (=porosity). The breathability of a foam can be determined by measuring the foam's dynamic pressure. This dynamic pressure measurement can be performed in accordance with EN 29053. When the measured dynamic pressure is provided in mm of water, open-cell PU foams, especially flexible PU foams, preferably have a dynamic pressure of less than 100 mm of water, preferably 50 mm or less, determined according to the described measurement method. In the present invention, "closed cell" refers to foams with nearly closed cells within the foam material, i.e., cells with only very small openings. Small openings allow air to re-enter slowly after compression, resulting in slow shape recovery. Closed-cell PU foams preferably have a dynamic pressure of at least 300 mm of water.

[0052] The at least one secondary plant compound is bonded or "integrated" to the PU foam by a covalent bond between the reactive group of the isocyanate component and the at least one secondary plant compound. In other words, this means that there is not only an adhesive or physical connection between the at least one secondary plant compound and the PU foam or its isocyanate component, but also a primarily chemical covalent bond. In addition to the secondary plant compound, the PU foam may contain additional substances that modify the material's properties. These substances can enhance or extend the properties of the PU foam obtained by the secondary plant compound. According to another preferred embodiment of the present invention, the PU foam thus contains light stabilizers, pigments, wood particles, biocides, miticides, and / or fungicides.

[0053] In another preferred embodiment of the present invention, the secondary plant compounds are introduced partially or completely in the form of comminuted plant parts, preferably comminuted wood parts or wood particles, or seeds. The comminuted plant parts can enhance or enhance the properties of the secondary plant compounds not introduced by the comminuted plant parts. Depending on their origin, the comminuted plant parts may contain a specific high proportion of secondary plant compounds. Therefore, for different applications, the comminuted plant parts can be introduced into the PU foam based on the natural composition of the secondary plant compounds. Preferably, the secondary plant compounds can be introduced in the form of wood particles together with other secondary plant compounds. In this way, for example, larch wood, which has a high content of diterpenoids, can be advantageously combined with the addition of isolated (e.g., extracted) oak tannin. The introduced comminuted plant parts can be of the same origin, or the mixture of comminuted plant parts can be of different origins. Preferably, the secondary plant compounds can be introduced partially or completely in the form of comminuted plant parts, preferably wood particles, of different origins. Thus, the different natural properties of the introduced secondary plant compounds can be utilized in combination. For example, pine wood particles and rock pine particles can be introduced to combine the secondary plant compounds naturally contained in wood. Preferably, the secondary plant compounds are introduced partially or completely in the form of finely divided wood parts or wood particles. The introduced finely divided wood parts or wood particles are preferably untreated finely divided wood parts or wood particles. The term "untreated finely divided wood parts or wood particles" refers to finely divided wood parts or wood particles that have not been treated by carbonization, charring, or firing.

[0054] According to a preferred embodiment of the present invention, the wood particles have a particle size of less than 50 μm, preferably less than 40 μm, more preferably less than 30 μm, more preferably less than 20 μm, more preferably between 0.1 μm and 20 μm, more preferably between 0.5 and 10 μm, more preferably between 1 and 5 μm. Such finely divided wood particles can be produced, for example, by cryogenic grinding, preferably by impact milling or colloid milling.

[0055] The size of the wood particles can be preferably determined by sieve analysis according to DIN 66165-1-2016-08 or DIN 66165-2. At least 70%, preferably at least 80%, more preferably at least 90%, more preferably at least 95%, more preferably at least 99%, and especially 100% of the wood particles used in the present invention have the above-mentioned particle size. The wood particles can have any shape.

[0056] Surprisingly, it has been shown that introducing wood particles with particle sizes less than 50 μm offers several advantages. Due to its biological structure, wood is structured with fibrils, thus exhibiting a distinct longitudinal orientation. This structure primarily serves to maintain the mechanical strength of trees and shrubs. Fibrils consist almost exclusively of cellulose chains embedded in a mixture of intercellular (non-oriented) substances (e.g., hemicellulose, lignin). According to the present invention, this specific structure is maintained during the production of wood particles, as described above. This is because the wood is preferably split longitudinally, which would otherwise result in undesirable fibrous longitudinal orientation in the ground material. Microscopic examination showed that the longitudinal structure of the fibrils is destroyed only when the wood particles are ground to a size less than the fibril diameter (approximately 0.5 mm to 0.1 mm, depending on the type of wood). This is important because introduced wood particles with particle sizes greater than 50 μm have corresponding fibril diameters and are therefore prone to accumulation / entanglement. This effect is particularly important when wood particles are incorporated into a highly viscous polyol component. Therefore, homogenization is only possible with great effort, which is incompatible with continuous foaming due to the "batch requirement." Such agglomerates can clog the high-pressure mixing chamber and its inlet, disproportionately hindering use. Surprisingly, it has been shown that agglomeration / entanglement of introduced wood particles can be prevented at particle sizes below 50 μm, preferably below 30 μm. Furthermore, it has been found that the desired release of secondary plant compounds into the polyol matrix occurs within an acceptable period only at particle sizes below 50 μm, and as a result, the time required for mixing with the isocyanate is sufficient to ensure the desired inventive covalent bonding of the secondary plant compounds to the PU foam. While such fine milling poses problems, especially with resilient softwoods, it has also been shown that cryogenic milling using liquid nitrogen or dry ice can produce satisfactory results. This milling variation also has the advantage of protecting the reactive secondary plant compounds from premature degradation, such as oxidation.Preferably, further additives such as colorants, light protectants, UV stabilizers, and even exogenous secondary plant compound extracts can be added during the milling procedure for optimal homogenization, during which process any solvents (and also water absorbed by the wood) evaporate and do not interfere with the subsequent PU foaming.

[0057] According to another preferred embodiment of the invention, the wood particles are selected from softwood particles, preferably spruce, fir, pine, stone pine, cedar, tsauga, yew or larch particles, hardwood particles, preferably beech, poplar, birch, oak or eucalyptus particles, or mixtures thereof.

[0058] It has been shown to be advantageous to adjust the ratio of secondary plant compounds to wood particles in order to further accentuate the desired effect.

[0059] A further aspect of the present invention relates to a method for producing the PU foam of the present invention.

[0060] In the inventive production of the PU foam of the present invention, preferably, at least one polyol component and at least one isocyanate component are reacted with each other, optionally in the presence of a propellant and a catalyst, together with an admixture of at least one secondary plant compound. Usable polyol and isocyanate components according to the present invention have already been described above. Depending on the chain length and number of branches of the polyol component, the mechanical properties of the PU foam may be affected. Of course, a person skilled in the art will select the amounts of each component required to produce different PU foam types, such as hot, cold, ester flexible PU foam, or rigid PU foam, to obtain the desired polyurethane type, particularly the PU foam type. The production of the PU foam of the present invention can be carried out according to any conventional method known to those skilled in the art. The inventive process may be carried out continuously or discontinuously.

[0061] The catalyst that can be used according to the present invention can be any catalyst for isocyanate-polyol (urethane formation) and / or isocyanate-water (amine and carbon dioxide formation) and / or isocyanate dimerization (uretdione formation), isocyanate trimerization (isocyanurate formation), isocyanate-isocyanate (carbodiimide formation) and / or isocyanate-amine (urea formation) with CO2 splitting and / or "secondary" crosslinking reactions, such as isocyanate-urethane (allophanate formation) and / or isocyanate-urea (biuret formation) and / or isocyanate-carbodiimide (uretonimine formation) reactions. The suitable amount of catalyst used will vary depending on the type of catalyst.

[0062] Suitable catalysts within the meaning of the present invention are, for example, substances that catalyze one of the aforementioned conversions, in particular the gel reaction (isocyanate-polyol), the drive reaction (isocyanate-water), and / or the dimerization or trimerization of isocyanates. Such catalysts are preferably nitrogen-containing compounds, in particular amines or ammonium salts, and / or metal-containing compounds. Within the meaning of the present invention, suitable nitrogen-containing compounds (hereinafter also referred to as nitrogen-containing catalysts) as catalysts are any nitrogen-containing compounds according to the state of the art that can catalyze one of the aforementioned isocyanate reactions and / or can be used to produce polyurethanes, in particular polyurethane foams. Suitable metal-containing compounds (hereinafter also referred to as metal-containing catalysts) within the meaning of the present invention are all metal-containing compounds according to the state of the art that can catalyze one of the aforementioned isocyanate reactions and / or can be used to produce polyurethanes, in particular polyurethane foams. For example, they can be selected from the group of metalloorganic or organometallic compounds, metalloorganic or organometallic salts, organometallic salts, inorganic metal salts, and from the group of charged or uncharged metal-containing coordination compounds, in particular metal chelate complexes.

[0063] Suitable propellants that can be used in the context of the present invention include gases, such as liquefied CO2, and highly volatile liquids, such as hydrocarbons with 4 or 5 carbon atoms, preferably cyclo-, iso-, and n-pentane; hydrofluorocarbons, preferably HFC245fa, HFC134a, and HFC365mfc, as long as they are not ozone-depleting; olefinic hydrofluorocarbons, such as HFO1233zd or HFO1336mzzZ; hydrochlorofluorocarbons, preferably HCFC141b; oxygen-containing compounds, such as methyl formate and dimethoxymethane. In addition to physical propellants, other chemical propellants that react with isocyanates to produce gases, such as formic acid, carbamates, or carbonates, can also be used. For open-cell flexible PU foams, water is preferably used as the propellant.

[0064] According to another preferred embodiment of the invention, the at least one secondary plant compound is incorporated in the form of an extract or eluate.

[0065] Secondary plant compounds can be obtained by methods such as steam distillation, extraction, or chromatography. For example, young plants usually provide terpenoid hydrocarbons, while older plants increasingly provide oxygen-containing derivatives such as alcohols, aldehydes, and ketones. Methods for obtaining secondary plant compounds are known from the state of the art. The term "extract" as used herein includes extracts of solid, liquid, and / or oily consistency from plants, particularly their fruits, roots, rhizomes, stems, shoots, leaves, seeds, or pits, obtained by extraction. The term "eluate" as used herein refers to solid, liquid, and / or oily substances separated or extracted from plants, particularly their fruits, roots, rhizomes, stems, shoots, leaves, seeds, or pits.

[0066] One advantage of the extracts and eluates that can be used is the natural composition of the secondary plant compound components that are contained. A particular advantage is that the bioavailability of the secondary plant compounds contained in the extracts can be higher than when synthetic compositions are used.

[0067] Another advantage of using an eluent is that, for example, the terpenoids are highly soluble in the polyol component at the preferred use amounts, which improves the distribution of the eluent in the polyol component. During the polyaddition with isocyanates, there is a particularly pronounced uniform distribution in the foam and thus also on the accessible cell surfaces.

[0068] According to a particularly preferred embodiment of the present invention, at least one secondary plant compound is incorporated into at least one polyol component.

[0069] The at least one secondary plant compound is capable of forming a covalent bond with a reactive group of the isocyanate component, and therefore is advantageously incorporated into the at least one polyol component to prevent premature reaction between the isocyanate component and the at least one secondary plant compound.

[0070] According to another preferred embodiment of the present invention, the PU foams are used to manufacture filters, upholstered products, mattresses, cushions, hygiene products, cleaning sponges, and / or thermal insulation layers, preferably in textiles, sound insulation and thermal insulation materials.

[0071] For example, the absorbency of foams plays an important role in many applications. Here, it is important that the foam exhibits high absorption capacity followed by rapid release of the absorbed moisture stored within the foam. The present invention enables the use of modified PU foams with improved absorbency to absorb body fluids such as sweat, blood, or urine. These properties make such PU foams suitable for use in wound dressings.

[0072] Another application is protection against microorganisms by absorbing and / or eliminating bacteria on filter materials, upholstered products, mattresses, cushions, hygiene products, medical products, cleaning products, or thermal insulation layers. Antimicrobial substances are widely used in everyday life, for example, in the healthcare sector, the food industry, agriculture, or general household products, to prevent the spread of microorganisms and microbial infections. However, a major problem arising from the large-scale use of such substances is the constant contamination of the environment with fungicidal and / or bactericidal substances. Such contamination can ultimately lead to the development of antibiotic-resistant microbial strains. The physical absorption of bacteria, viruses, molds, and / or their spores on PU foams is a major advantage, as it allows for the prevention of the use of physiologically and ecologically questionable fungicides and antibiotics. [Example]

[0073] In Examples 1 to 4, open-cell flexible foams were produced according to state-of-the-art technology using propylene oxide-polyether-polyol (functionality 3, MW 3500, OH number 50), isocyanate (toluene-2,4-diisocyanate (TDI) 80 / 20, NCO index 105) and propellant (water / TDI). The densities of the produced PU foams were 45-50 kg / m. 3 It was.

[0074] Example 1: Prior to foaming (mixing with isocyanate), 6 wt. % of micronized pine wood (fineness D50 = 15 μm), 0.7 wt. % of ellagitannin derived from French Limousin oak (Quercus robur), and 0.1 wt. % of perillic acid were uniformly added to the polyol batch (wt. % refers to the entire foam formulation).

[0075] The resulting yellow / orange flexible PU foam exhibited the following: a) Fungicidal properties (tested according to DIN EN 14119) b) Inhibits the reproduction of house dust mite eggs by over 95% c) Antiviral effect in in vitro tests according to ISO 18184.

[0076] Due to the properties found, this flexible PU foam is suitable for use as a filter, for use in oral-nasal masks or for use as upholstery (bedroom and / or living room).

[0077] Example 2: As in Example 1, in this example the polyol batch was supplemented with 3 wt. % of micronized larch wood (D50=5-10 μm), 1.5 wt. % of mastic, 0.5 wt. % of thyme oil as an extractant derived from thyme (containing, among others, carvacrol, thymol, cymene, geraniol, and polyphenols such as flavones and tannins), and 0.3 wt. % of HALS1 UV stabilizer (Lowilite 77) to avoid discoloration.

[0078] The resulting flexible PU foam exhibited the following: a) Bactericidal (DIN EN ISO 20743) b) Anti-inflammatory.

[0079] The properties found make this soft PU foam suitable for use as a wound pad, in dressings, and in mattresses.

[0080] Example 3: Similar to Example 1, in this example the polyol batch was supplemented with 2.5 wt% lignin, 0.5 wt% tannin (oak-derived ellagitannin), 1.5 wt% eluate from a 1:1 ratio of stone pine and eucalyptus, and 0.2 wt% perillic acid.

[0081] The resulting flexible PU foam exhibited the following: a) Bactericidal (DIN EN ISO 20743) b) Fungicidal (tested according to DIN EN 14119).

[0082] The properties found make this flexible PU foam suitable for use as a filter, in masks, wound dressings and in mattresses.

[0083] Example 4: Similar to Example 1, in this example the polyol batch was supplemented with 2 wt. % colophony from Nordic pine, 0.5 wt. % eluate from salvia, rosemary and ivy in a 2:1:1 ratio (also containing oleanolic acid), 0.3 wt. % cineole from eucalyptus oil, and 0.3 wt. % HALS1 UV stabilizer (Lowlite 77) to prevent discoloration.

[0084] The resulting flexible PU foam exhibited the following: a) Bactericidal (DIN EN ISO 20743) b) Fungicidal properties (tested according to DIN EN 14119) c) Acaricidal properties, especially physical adhesion effect against mites and their eggs.

[0085] The properties found make this flexible PU foam suitable for use in mattress and furniture upholstery, filters, especially fine particle filters for vacuum cleaners, and hygiene applications in general.

[0086] Example 5: In this example, a state-of-the-art closed-cell rigid foam was produced using propylene oxide-polyether-polyol (functionality 6, MW 450, OH number 50), isocyanate (methylenedi(phenylisocyanate) (MDI) 29% NCO, NCO index 110), and propellant (cyclopentane). The PU foam was produced at a yield of 35-40 kg / m. 3 The density was 1.02g.

[0087] To the polyol, 4 wt. % lignin, 2 wt. % tannin (oak-derived ellagitannin), 0.2 wt. % perillic acid, and 0.3 wt. % UV stabilizer HALS1 (Lowilite 77) were added prior to foaming (mixing with isocyanate).

[0088] Due to the addition of lignin, which acts as a pore nucleating agent, the resulting rigid PU foams had particularly fine pores. The foams exhibited excellent resistance to mold (Aspergillus niger) infestation, making them particularly suitable for use as insulation in residential buildings.

[0089] Example 6: Dissolution test In the dissolution test using distilled water (pH 7), the foams of Examples 1 to 5 showed no cleaning effect, which indicates that the additives are covalently bonded.

Claims

1. 1. A PU foam comprising at least one secondary plant compound bonded to the PU foam, wherein the at least one secondary plant compound is present partially or completely in the form of wood particles.

2. 2. The PU foam according to claim 1, wherein the PU foam comprises 0.1 to 10% by weight, preferably 0.2 to 5% by weight, particularly preferably 0.3 to 3% by weight of said at least one secondary plant compound.

3. 3. The PU foam according to claim 1, wherein the at least one secondary plant compound is a terpenoid or a polyphenol.

4. PU foam according to claim 3, characterized in that the terpenoid is a monocyclic or polycyclic terpenoid, preferably a bicyclic, tricyclic, tetracyclic, or pentacyclic terpenoid.

5. 5. PU foam according to claim 3 or 4, characterized in that the terpenoid is a monoterpenoid selected from the group consisting of pyrethrins, thymol, cineole, thuyanol, perillic acid, linalool, myrcenol, citral, citronellal, geranic acid, junionone, chrysanthemol, menthol, terpineol, verbenol, carveol, piperitone, and camphor, preferably pyrethrins, thymol, cineole, thuyanol, and / or perillic acid.

6. 5. The PU foam according to claim 3, wherein the terpenoid is a sesquiterpenoid selected from the group consisting of farnesin, bisabolol, armirarin, merlidial, hirsutumic acid, nerolidol, zingiberene, germacrane, periplanone, elemol, guaiane, and cedrane, preferably farnesin, bisabolol, armirarin, merlidial, and / or hirsutumic acid.

7. 5. The PU foam according to claim 3, wherein the terpenoid is a diterpenoid selected from the group consisting of agelasine, larixol, dehydroabietinol, abietic acid, boregrevirol, aframodial, phytol, retinol, primaran, nimbiol, forskolin, labdanolic acid, casaic acid, gibberellan, isopimaric acid, dehydroabietinol, and abietic acid, preferably agelasine, larixol, dehydroabietinol, abietic acid, boregrevirol, and / or aframodial.

8. PU foam according to claim 3 or 4, characterized in that the terpenoid is a sesterpenoid selected from the group consisting of irsinin, neomanoalide, sericeran, and dehydroirsinin.

9. 5. The PU foam of claim 3, wherein the terpenoid is a triterpenoid selected from the group consisting of limonoids, lanosterol, fusidane, fusidic acid, euphane, dammarane, cucurbitane, cucurbitacin, betulin, and betulinic acid.

10. 5. The PU foam according to claim 3, wherein the terpenoid is a tetraterpenoid selected from the group consisting of carotene, crocetin, and lycopene.

11. 5. PU foam according to claim 3 or 4, characterized in that the terpenoid is a polyterpenoid selected from the group consisting of betulaprenol, oleanolic acid, ubiquinone, dolocol, and betulaprenol, preferably betulaprenol, oleanolic acid, ubiquinone, and / or dolocol.

12. PU foam according to any one of claims 3 to 11, characterized in that the polyphenol is a polyhydroxyphenol, preferably tannin, suberin or lignin.

13. 13. The PU foam of claim 12, wherein the tannin is a gallotannin or an ellagitannin.

14. PU foam according to any one of claims 3 to 13, characterized in that the polyphenols are selected from the group consisting of phytoalexins, preferably resveratrol, flavonols, preferably taxifolene, catechins, flavonoids, anthocyans, proanthocyanidins, procyanidins, phlobaphenes, and isoflavones.

15. PU foam according to any one of claims 1 to 14, characterized in that the at least one secondary plant compound is a tree resin, preferably colophony, mastic or balsam.

16. PU foam according to any one of claims 1 to 15, characterized in that the PU foam is a rigid PU foam, a flexible PU foam or a viscoelastic PU foam.

17. PU foam according to any one of claims 1 to 16, characterized in that the PU foam is produced on the basis of polyether and / or polyester polyols and toluene-2,4-diisocyanate and / or methylenedi(phenylisocyanate).

18. PU foam according to any one of claims 1 to 17, characterized in that the PU foam has open or closed cells.

19. PU foam according to any one of claims 1 to 18, characterized in that the PU foam comprises light stabilizers, pigments, biocides, miticides and / or fungicides.

20. PU foam according to any one of the preceding claims, characterized in that the wood particles have a particle size of less than 50 μm, preferably less than 40 μm, more preferably less than 30 μm, more preferably less than 20 μm, more preferably between 0.1 μm and 20 μm.

21. 21. PU foam according to any one of claims 1 to 20, characterized in that the wood particles are selected from softwood particles, preferably spruce, fir, pine, stone pine, cedar, thuja, yew or larch wood particles, hardwood particles, preferably beech, poplar, birch, oak or eucalyptus wood particles, or mixtures thereof.

22. 22. A method for producing the PU foam of any one of claims 1 to 21, comprising reacting at least one polyol component with at least one isocyanate component in the presence of a propellant and at least one catalyst for catalyzing the isocyanate-polyol reaction, wherein at least one secondary plant compound is incorporated during the reaction of the at least one polyol component with the at least one isocyanate component, and wherein the at least one secondary plant compound is present partially or completely in the form of wood particles.

23. 23. The method according to claim 22, characterized in that when the at least one secondary plant compound is partially present in the form of wood particles, the at least one secondary plant compound is incorporated in the form of an extract or eluate.

24. 24. The method of claim 22 or 23, wherein the at least one secondary plant compound is incorporated into the at least one polyol component.

25. PU foam obtainable by the method according to any one of claims 22 to 24.

26. Use of the PU foams according to any one of claims 1 to 21 or 25 for producing filters, upholstered products, mattresses, cushions, hygiene products, cleaning sponges and / or thermal insulation layers, preferably textiles, sound and heat insulation materials.

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