Storage-stable coated particles and their preparation

Abstract

The present invention relates to a method for preparing storage-stable coated particles for storage-stable coated particles and molded articles containing coated particles, and moldable thermoplastic particle foams, comprising: a1) a step of contacting particles with an aqueous polyurethane dispersion, such that the polyurethane has a K value greater than 50 and less than 100, preferably in the range of 55 to 95, according to DIN EN ISO 1628-1 2021, and at least partially coated particles as a result; and a2) a step of drying the coated particles. The present invention also relates to a method for preparing a molded article and a method for treating a molded article, comprising the above method as a first step.

Description

[Technical Field]

[0001] The present invention relates to a method for preparing storage-stable coated particles for storage-stable coated particles and molded articles containing said coated particles, and moldable thermoplastic particle foams, comprising: a1) a step of contacting particles with an aqueous polyurethane dispersion, such that the polyurethane has a K value greater than 50 and less than 100, preferably in the range of 55 to 95, according to DIN EN ISO 1628-1 2021, and at least partially coated particles; and a2) a step of drying said coated particles. The present invention also relates to a method for preparing a molded article and a method for treating said molded article, comprising the above method as a first step.

[0002] Moldable thermoplastic particle foams are used, for example, for the production of any solid foam body, such as sports mats, body protectors, lining elements in automotive components, sound and vibration dampers, packaging, or shoe soles.

[0003] Conventionally, a mold is filled with foam particles, and then the surface of each individual foam particle is melted by heat, bonding them together to form a granular foam. In this way, in addition to simple products, complex semi-finished products or molded parts with undercuts can be produced.

[0004] Moldable thermoplastic particle foams are known in the art and are described, for example, in Robin Britton (Author), Update on Moldable Particle Foam Technology, Rapra Technology Ltd, 2009. Expandable thermoplastic elastomers, in particular expandable thermoplastic polyurethanes (E-TPUs), represent certain types of moldable thermoplastic particle foams.

[0005] Expandable thermoplastic elastomers are known in the art. For example, International Publication No. 2018 / 082984 describes a particulate foam based on an expandable thermoplastic elastomer. International Publication No. 2008 / 087078 describes a hybrid system consisting of an expanded thermoplastic elastomer and polyurethane.

[0006] An exemplary thermoplastic polymer is expanded thermoplastic polyurethane (E-TPU). It is commercially available, for example, sold by BASF under the name Infinergy®. E-TPU particles primarily represent completely closed-cell foam particles. Thermoplastic polyurethane (e.g., Elastollan®) expands, resulting in foam particles that can be processed with standard molding machines. Thanks to its closed particle surface and the chemical properties of the TPU used, standard E-TPU grades also absorb only small amounts of water. Like its underlying TPU, it can also be characterized by high fracture elongation, tensile strength, and abrasion resistance, along with good chemical resistance.

[0007] Rapid prototyping of 3D objects fabricated from expandable thermoplastic elastomers is not easily achieved today. Typically, isocyanate-containing binders are used for particle bonding or for suitable machinery such as steam and steam chest molding machines. Neither approach is easily accessible due to health and safety reasons, energy costs, or lack of access to suitable machinery (steam chest molding machines). Furthermore, while the use of steam only allows for the molding of particles of the same type, coating on E-TPU particles or the use of water-based binders can allow for the bonding of E-TPU particles of different types (glass transition temperature, melting point) and sizes, but can also allow for the bonding of different TPUs or even different particle foams, such as different mixtures of E-TPS, E-PS, E-PP, E-TPA, E-TPC, E-TPO, etc. The application of coatings also allows for the adjustment of mechanical properties and applicability by directly incorporating additives such as pigments or dyes, flame retardants or antistatic agents onto the particle surface. Fillers, for example, allow for increased rigidity of the final part, while the use of additives that can be excited by, for example, an electromagnetic field, enables the moldability of the coating, thereby reducing the energy required for molding.

[0008] Additives that can be used include pigments, dyes, fragrances, fillers, bio-based and / or biodegradable additives, UV stabilizers, heat stabilizers, flame retardants such as expandable graphite, additives that provide antistatic properties and electrical conductivity, additives that reduce dirt incorporation, antimicrobial additives, waxes, crosslinking agents, surface functionalizing fillers, foaming additives such as Expansionll, and additives that can be irradiated with electromagnetic fields and / or high frequencies and / or microwaves.

[0009] International Publication No. 2022 / 223438 describes different aqueous binders for coating particles that can be shaped into the aforementioned 3D parts.

[0010] U.S. Patent No. 6,616,797 describes the formation of adhesive bonds by a process comprising applying a dispersion containing a polyurethane having structural units of formula (I) to a surface. First, the dispersion is coated onto the surface to form a coating. The coating is dried to give an essentially anhydrous coating. The dried coating is then subjected to thermal activation. Adhesive bonds are formed by bonding the thermally activated coating to itself or to another surface. However, particulate coatings are not described.

[0011] International Publication No. 2012 / 13506 describes the use of an aqueous polyurethane dispersion adhesive for producing a biodegradable composite film in which at least two substrates are bonded to each other using a polyurethane dispersion adhesive, and at least one of the substrates is a biodegradable polymer film. At least 60% by weight of the polyurethane consists of a diisocyanate, a polyester diol, and at least one bifunctional carboxylic acid selected from dihydroxycarboxylic acids and diaminocarboxylic acids.

[0012] International Publication No. 2005 / 003247 relates to a method for bonding substrates having different surface energies. The adhesive used for bonding consists of at least 15% by weight of polyurethane (without water or other organic solvents having a boiling point less than 150°C at 1 bar), the adhesive is applied to a substrate having a lower surface energy, and the resulting adhesive-coated substrate is bonded to a substrate having a higher surface energy.

[0013] International Publication No. 2021 / 7249749 describes the recycling of bonded articles containing a TPU foam substrate by using an aqueous polyurethane dispersion of the specified molecular weight as an adhesive. It does not mention the coating of the foam particles.

[0014] Different binders that are generally useful for binding particles are described, but there is a need for the preparation of storage-stable coated particles that prevent aggregation of the stored particles. This includes particles that are more fluid, have less electrostatic charging due to friction, and enable much easier realization of 3D parts by using an easy molding process (e.g., a standard convection oven or a hot press).

[0015] Therefore, there is a need for a material that combines the following advantages: a) Reduction in the amount of binder by generating only a thin layer of the solid surface b) Storage stability of beads without aggregation c) Easy and diverse processability d) Performance adjustability.

[0016] While the adhesive-particle mixture exhibits a certain viscosity, the solid coating of the particles allows for easier filling during processing, e.g., into a mold or cavity, due to better fluidity and less electrostatic charging by friction.

[0017] Also, the particles can be processed in different ways, e.g., by a standard convection oven or a hot press, and even by an electromagnetic field. Thereby, the beads can be filled into gaps, for example, and adhered by a trigger.

[0018] Therefore, an object of the present invention is to provide a method for the preparation of storage-stable coated particles.

[0019] This object is a method for the preparation of storage-stable coated particles of a moldable thermoplastic particle foam, a1) a step of contacting the particles with an aqueous polyurethane dispersion, wherein the polyurethane has a K value of more than 50 and less than 100, preferably in the range of 55 to 95, according to DIN EN ISO 1628-1 2021, resulting in at least partially coated coated particles; a2) a step of drying the coated particles This is achieved by methods including,

[0020] Another aspect of the present invention is a storage-stable, at least partially coated particle (at least partially coated particle) of a moldable thermoplastic particle foam having a K value greater than 50 and less than 100, preferably in the range of 55 to 95, according to DIN EN ISO 1628-1 2021. Preferred at least partially coated particles of a moldable thermoplastic particle foam according to the present invention can be obtained from a coating method according to the present invention.

[0021] Another aspect of the present invention is a molded article comprising at least partially coated particles with storage stability according to the present invention. A preferred molded article of the present invention can be obtained by a method for preparing a molded article according to the present invention.

[0022] Surprisingly, it was found that polyurethane in aqueous dispersions having the above K value can be used to realize 3D parts without the need for steam. The coating enables the realization of 3D parts with excellent mechanical values ​​by hot pressing, which are equivalent to, and even superior to, 3D parts produced using standard steam chest molding processes.

[0023] In particular, the preferred dispersion used for the method of the present invention may have a high solid content (>40%) but still exhibit low viscosity. This allows for easy application of the dispersion to the particles. The particles are homogeneously coated with a transparent coating and are non-stick at room temperature. On the other hand, when the particles are heated under compression, such as in a hot-pressing process, the coating melts, allowing for bead bridging upon cooling. Only moderate heating is required.

[0024] Furthermore, the coated particles exhibit surprisingly improved flow behavior in addition to very interesting antistatic properties. This is a crucial factor when the particles are stored for extended periods, such as in Octavins, because particle clogging during storage can cause unpleasant problems at customer sites.

[0025] -The surface coating of the particles has the following additional advantages: Since the adhesive properties originate from the coating and not from the melting of the particle walls, particles of different sizes and chemical properties (e.g., E-TPU, E-TPS, E-PS, E-TPO, E-PP, E-TPA, E-TPC) can bond to each other. This has the advantage that even particles with high melting points can be processed into 3D parts in a steamless process at temperatures such as 100°C. - A hot press can be used, which has the advantage of avoiding the use of steam and allowing the use of low-temperature molds. This results in energy savings and reduced complexity. - Additives can be mixed with the coating and placed directly on the bead surface (surface modification). Interesting additives include thermally conductive particles, antistatic particles, flame retardants, dyes, UV stabilizers, ferromagnetic particles, and anticaking agents.

[0026] In 3D parts (molded bodies), the coating particles of the polyurethane dispersion described herein can be decomposed, for example, by exposing the 3D part to alkaline conditions under agitation, when a dispersion that can be redispersed in water is used.

[0027] In realizing 3D parts, other materials (e.g., textiles, leather, thermoplastic films, metal parts) can be bonded to particles in a single step. This enables the realization of various hybrid materials for a wide range of applications (sports (shoes) and leisure, automotive interiors, electronics applications, flooring sheets, etc.).

[0028] Although not preferred, the coated particles can still be processed using a standard steam chest mold process or other heating processes that use high-energy radiation to raise the coating temperature, as described in European Patent No. 3338984 relating to expansion beads, and therefore it is compatible with existing customer equipment.

[0029] This process enables the creation of 3D parts with extremely complex geometric shapes. The 3D parts can still have gaps between particles (allowing water to penetrate) or gaps between beads, which is highly desirable for the production of shoe soles.

[0030] The present invention relates to the preparation of coated particles for a moldable thermoplastic particle foam. Such foams are known in the art (see, for example, Robin Britton (Author), Update on Mouldable Particle Foam Technology, Rapra Technology Ltd, 2009). Preferably, the moldable thermoplastic particle foam is an expandable thermoplastic elastomer.

[0031] Expandable thermoplastic elastomer particles are known in the art. Suitable thermoplastic elastomers include, for example, thermoplastic polyurethane (TPU), thermoplastic polyester elastomer (e.g., polyether esters and polyester esters) (TPC), thermoplastic copolyamide (e.g., polyether copolyamide) (TPA), thermoplastic polyolefin (TPO), or thermoplastic styrene-butadiene block copolymer (TPS). Foam particles based on thermoplastic polyurethane (TPU) are particularly preferred. Therefore, the expandable thermoplastic elastomer is preferably E-TPU.

[0032] Examples of methods for preparing expandable thermoplastic elastomer particles are described in International Publication No. 2008 / 087078, International Publication No. 2018 / 082984, U.S. Patent No. 10005218, and International Publication No. 2007 / 082838.

[0033] Preferably, the aqueous polymer dispersion used in the method of the present invention has a solid content of at least 40% by weight, and more preferably 45% to 60% by weight, based on the total weight of the dispersion.

[0034] Preferably, the polyurethane in the aqueous polymer dispersion contained in the at least partially coated particles and molded article according to the present invention is subjected to 23°C and 250s. -1 It has a viscosity of less than 300 mPas at 23°C, preferably less than 200 mPas at 23°C, as measured according to DIN EN ISO 3219-2:2021 at a shear rate.

[0035] Preferably, the polyurethane in the aqueous polyurethane dispersion contained in at least partially coated particles and molded articles according to the present invention has a glass transition temperature T of less than 0°C, more preferably -10°C to -80°C, even more preferably -20°C to -75°C, even more preferably -30°C to -70°C, even more preferably -40°C to -65°C, and even more preferably -45°C to -60°C. g It has.

[0036] The glass transition temperature can be determined as the so-called midpoint temperature by differential scanning calorimetry according to DIN EN ISO 11357-2 (2014). The glass transition temperature of the polymer in the polymer dispersion is the glass transition temperature obtained when evaluating the second heating curve (heating rate 20°C / min).

[0037] In a preferred embodiment of the present invention, the polyurethane has at least a first glass transition temperature T g1 and the second glass transition temperature T g2 It has T g1 It is below 0℃, T g2is above 25°C. More preferably, T g2 is above 40°C, even more preferably above 50°C, even more preferably above 60°C. Typically, the polyurethane of the aqueous polyurethane dispersion has a T g1 of from -10°C to -60°C and a T g2 of from 60°C to 90°C. Preferably, the polyurethane has exactly two T g .

[0038] Preferably, the polyurethane of the aqueous polyurethane dispersion comprised in at least partially coated particles and shaped bodies according to the invention has a melting temperature T m in the range from 30°C to 100°C, preferably from 40°C to 80°C.

[0039] The melting point and the enthalpy of fusion are determined in accordance with DIN EN ISO 11357-3 (2018) by heating at 20 K / min after cooling to -80°C (melting point = peak temperature); the second enthalpy of fusion (delta H2), on the other hand, is calculated from the area of only the second melting.

[0040] The T g and T m of the aqueous polyurethane dispersion means, according to the invention, that the polyurethane comprised in the aqueous polyurethane dispersion has these T g values and T m values.

[0041] Generally, the aqueous polyurethane dispersions used in the process according to the invention can be prepared by methods known in the art. Exemplary methods are described in WO 2021 / 249749.

[0042] Therefore, the aqueous polyurethane dispersion comprises at least one polyurethane as a polymeric binder dispersed in water, and optionally additives. Preferred additives are selected from the group consisting of ionic surfactants, nonionic surfactants, rheology modifiers (including thickeners), anti-blocking additives, other aqueous dispersions, crosslinking agents, plasticizers, hydrolysis stabilizers, biocides, fillers, and anti-foaming agents. The polymeric binder preferably takes the form of a dispersion in water, or otherwise a dispersion in a mixture of most water and a water-soluble organic solvent having a boiling point of preferably less than 150°C (1 bar). Water is particularly preferred as the sole solvent.

[0043] The polyurethane dispersion used in the method of the present invention and contained in at least the partially coated particles and molded articles according to the present invention comprises at least one polyurethane. A suitable polyurethane can, in principle, be obtained through the reaction of at least one polyisocyanate with at least one compound having at least two groups reactive to the isocyanate group. The polyurethane also includes so-called polyurethane-polyurea, which further has urea groups in addition to polyurethane groups.

[0044] The polyurethane dispersion, at least partially coated particles, and molded articles according to the present invention preferably comprise at least one polyurethane comprising at least one polyisocyanate and at least one polyol in copolymer form. The polyurethane dispersion, at least partially coated particles, and molded articles according to the present invention preferably comprise at least one polyurethane comprising at least one polyisocyanate and a diol component in copolymer form, of which a) 10 to 100 mol% based on the total amount of diol has a molecular weight of 500 to 5000 g / mol, and b) 0 to 90 mol% based on the total amount of diol has a molecular weight of less than 60 to 500 g / mol. Polymerizable polyols are preferred. Suitable polymerizable polyols are preferably selected from polyester diols, polyether diols, and mixtures thereof. The polymerizable polyols preferably have a number-average molecular weight in the range of about 500 to 5000 g / mol.

[0045] Polyurethanes are preferably synthesized from at least 40% by weight, more preferably at least 60% by weight, and very preferably at least 80% by weight of at least one diisocyanate and at least one polyetherdiol and / or polyesterdiol, based on the total weight of monomers used in the preparation of the polyurethane. Up to 100% by weight of suitable further synthetic components are, for example, the following polyisocyanates having at least three NCO groups, and compounds that, unlike polymeric polyols, have at least two groups reactive to the isocyanate group. These include, for example, nonpolymeric diols; diamines; polymers that, unlike polymeric polyols, have at least two active hydrogen atoms per molecule; compounds having two active hydrogen atoms per molecule and at least one ionogenic or ionic group; and mixtures thereof.

[0046] The polyurethane in aqueous polyurethane dispersion adhesives is preferably crystalline.

[0047] Preferred polyurethanes are a) At least one monomer diisocyanate, b) At least one diol component (b) comprising at least one diol having a number-average molecular weight in the range of 500 to 5000 g / mol, c) Unlike monomers (a) and (b), at least one monomer having at least one isocyanate group, or at least one group reactive to an isocyanate group, and additionally having at least one hydrophilic group or a latent hydrophilic group, d) Optionally, at least one further compound having at least two reactive groups selected from an alcoholic hydroxyl group, a primary or secondary amino group, or an isocyanate group, which differ from monomers (a) to (c), and e) Optionally, at least one monofunctional compound having a reactive group that differs from monomers (a) to (d), which is an alcoholic hydroxyl group, a primary or secondary amino group, or an isocyanate group. It is synthesized from.

[0048] Preferably, the polyurethane dispersion is an anionic polyurethane dispersion prepared using a small amount of aromatic diisocyanate, for example less than 60 mol%, based on the total of all organic diisocyanates a), or without aromatic diisocyanate. The anionic group of the anionic polyurethane is preferably selected from carboxylic acid groups and sulfonic acid groups. The same applies to the polyurethane contained in at least the partially coated particles and molded articles according to the present invention.

[0049] Component b) is preferably, b1) Based on the total amount of component b), a diol having a molecular weight of 500 to 5000 g / mol, in an amount of 10 to 100 mol%. b2) Diols having a molecular weight of less than 60-500 g / mol, with a total amount of 0-90 mol% based on the total amount of component b). It consists of.

[0050] The molar ratio of diol b1) to monomer b2) is more preferably 1:5 to 5:1, and more preferably 1:2 to 2:1. More preferably, b2) is not used. In particular, diol b) is selected from polytetrahydrofuran, polypropylene oxide, polyester diols selected from reaction products of dihydric alcohols and dibasic carboxylic acids, and lactone-based polyester diols.

[0051] In particular, diisocyanate X(NCO)2 [wherein X is an acyclic aliphatic hydrocarbon group having 4 to 15 carbon atoms, a cyclic aliphatic or aromatic hydrocarbon group having 6 to 15 carbon atoms, or an aromatic aliphatic hydrocarbon group having 7 to 15 carbon atoms] can be cited as monomer (a). Examples of such diisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1-isocyanato-3,5,5-trimethyl-3-isocyanatomethylcyclohexane (IPDI), 2,2-bis(4-isocyanatocyclohexyl)-propane, trimethylhexane diisocyanate, 1,4-diisocyanatobenzene, and 2,4-diiso This includes isomers of bis(4-isocyanatocyclohexyl)methane (HMDI), such as cyanatotoluene, 2,6-diisocyanatotoluene (TDI), 4,4'-diisocyanato-diphenylmethane, 2,4'-diisocyanatodiphenylmethane, p-xylylenediisocyanate, tetramethylxylylenediisocyanate (TMXDI), trans / trans, cis / cis, and cis / trans isomers, as well as mixtures of these compounds. This type of diisocyanate is commercially available. Particularly preferred are diisocyanates selected from the group consisting of hexamethylene diisocyanate, 1-isocyanato-3,5,5-trimethyl-3-isocyanato-methylcyclohexane, 2,6-diisocyanatotoluene, and tetramethylxylylenediisocyanate, or mixtures thereof. A particularly important mixture of these isocyanates is a mixture of structural isomers of diisocyanatotoluene and diisocyanatodiphenylmethane; a mixture of 80 mol% 2,4-diisocyanatotoluene and 20 mol% 2,6-diisocyanatotoluene is especially suitable.Similarly, particularly advantageous are mixtures of aromatic isocyanates such as 2,4-diisocyanatotoluene and / or 2,6-diisocyanatotoluene with aliphatic or cyclic aliphatic isocyanates such as hexamethylene diisocyanate or IPDI, in which case the preferred molar ratio of aliphatic to aromatic isocyanate is 1:9 to 9:1, and especially 4:1 to 1:4. It is also preferable that only aliphatic isocyanates be used.

[0052] The diol (b1) may be a polyester polyol, which is known, for example, from Ullmanns Enzyklopadie der technischen Chemie, 4th edition, volume 19, pp. 62 to 65. It is preferable to use a polyester polyol obtained by reacting a dihydric alcohol with a dibasic carboxylic acid. Polyester polyols can also be prepared using the corresponding polycarboxylic acid anhydride or the corresponding polycarboxylic acid ester of a lower alcohol or a mixture thereof instead of a free polycarboxylic acid. The polycarboxylic acid may be aliphatic, cyclic aliphatic, aromatic aliphatic, aromatic or heterocyclic, and may optionally be substituted with, for example, a halogen atom, and / or unsaturated. Examples include: suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, and dimer fatty acids. Preferred dicarboxylic acids are those with the general formula HOOC-(CH2) y-COOH [wherein y is a number from 1 to 20, preferably an even number from 2 to 20], examples of which are succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid. Suitable examples of dihydric alcohols include ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butene-1,4-diol, butyn-1,4-diol, pentane-1,5-diol, neopentyl glycol, bis(hydroxymethyl)cyclohexane such as 1,4-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1,3-diol, methylpentanediol, as well as diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, and dibutylene glycol and polybutylene glycol. Preferred alcohols for obtaining crystallinity are those with the general formula HO-(CH2) x -OH [wherein x is a number from 1 to 20, preferably an even number from 2 to 20]. Examples of such alcohols are ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol, and dodecane-1,12-diol.

[0053] The diol (b1) may be a polycarbonate diol, for example, obtained by reacting an excess of low molecular weight alcohol, as described as a synthetic component for polyester polyols, with phosgene.

[0054] The diol (b1) may also be a lactone-based polyester diol, which is a homopolymer or copolymer of lactone, preferably a hydroxyl-terminated adduct of lactone with a suitable bifunctional starter molecule.

[0055] To obtain crystallinity, the preferred lactone is of the general formula HO-(CH2) zThese are derived from compounds of the form -COOH [wherein z is a number from 1 to 20, and one or more H atoms of the methylene unit may be substituted with C1-C4 alkyl groups]. Examples include ε-caprolactone, β-propiolactone, γ-butyrolactone and / or methyl-γ-caprolactone, as well as mixtures thereof. Examples of suitable starter components are the low molecular weight dihydric alcohols described above as synthetic components for polyester polyols. The corresponding polymer of ε-caprolactone is particularly preferred. Lower polyester diols or polyether diols can also be used as starters for preparing lactone polymers. Instead of the lactone polymer, it is also possible to use the corresponding chemically equivalent polycondensates of the hydroxycarboxylic acid corresponding to the lactone.

[0056] The diol (b1) may also be a polyetherdiol. Polyetherdiols can be obtained particularly by polymerizing ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide, or epichlorohydrin with themselves, for example, in the presence of BF3, or by optionally adding these compounds in a mixture or successively to a starter component containing a reactive hydrogen atom, such as an alcohol or amine (e.g., water, ethylene glycol, propane-1,2-diol, propane-1,3-diol, 2,2-bis(4-hydroxyphenyl)propane, and aniline). Polyetherdiols having a molecular weight of 500 to 5000, particularly 600 to 4500, are especially preferred. A particularly preferred polyetherdiol is polytetrahydrofuran. Suitable polytetrahydrofurans can be prepared by cationic polymerization of tetrahydrofuran in the presence of an acidic catalyst, such as sulfuric acid or fluorosulfuric acid. This type of preparation process is known to those skilled in the art.

[0057] The compounds included in b1) consist only of polyetherdiols composed of less than 20% by weight of ethylene oxide based on their total weight. Polyetherdiols incorporating at least 20% by weight of ethylene oxide units are hydrophilic polyetherdiols, and these are included as monomer c).

[0058] As monomer bi), polyhydroxyolefins, preferably those having two terminal hydroxyl groups, such as α,ω-dihydroxypolybutadiene, α,ω-dihydroxypolymethacrylate, or α,ω-dihydroxypolyacrylic acid ester may also be used. Such compounds are known, for example, in European Patent Application Publication No. 622378. Further suitable polyols are polyacetals, polysiloxanes, and alkyd resins.

[0059] The hardness and modulus of elasticity of polyurethane can be increased not only by using diol (b1) as diol (b), but also by using low molecular weight diol (b2) having a molecular weight of about 60 to less than 500, preferably 62 to 200 g / mol.

[0060] The monomer (b2) used is, in particular, a synthetic component of the short-chain alkanediol described for preparing polyester polyols, and unbranched diols having 2 to 12 carbon atoms and an even number of carbon atoms are preferred, and pentane-1,5-diol and neopentyl glycol are also preferred. Examples of suitable diols (b2) include ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butene-1,4-diol, butyne-1,4-diol, pentane-1,5-diol, neopentyl glycol, bis(hydroxymethyl)cyclohexane such as 1,4-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1,3-diol, methylpentanediol, and additionally diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, and polybutylene glycol. To obtain crystallinity, the general formula HO-(CH2) x Alcohols of the -OH type [wherein x is a number from 1 to 20, preferably an even number from 2 to 20] are preferred. Examples include ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol, and dodecane-1,12-diol.

[0061] To produce a polyurethane that is dispersible in water, it comprises monomer (c) as a synthetic component, which has at least one isocyanate group, or at least one group reactive to an isocyanate group, and furthermore, at least one hydrophilic group or a group that can be converted to a hydrophilic group. In the following specification, the term “hydrophilic group or potential hydrophilic group” is abbreviated as “(potential) hydrophilic group”. A (potential) hydrophilic group reacts with the isocyanate at a substantially slower rate than the functional groups of the monomer used to synthesize the polymer backbone react. The proportion of components having a (potential) hydrophilic group out of the total amount of components (a) to (e) is generally such that the molar amount of the (potential) hydrophilic group based on the weight of all monomers (a) to (e) is 30 to 1000, preferably 50 to 500, more preferably 80 to 300 mmol / kg. The (potential) hydrophilic group may be nonionic, or preferably, a (potential) ionic hydrophilic group.

[0062] Particularly suitable nonionic hydrophilic groups are polyethylene glycol ethers, preferably composed of 5 to 100, more preferably 10 to 80 repeating ethylene oxide units. The amount of polyethylene oxide units is generally 0 to 10% by weight, preferably 0 to 6% by weight, based on the weight of all monomers (a) to (e). Preferred monomers containing nonionic hydrophilic groups are polyethylene oxide diols, polyethylene oxide monools, and reaction products of polyethylene glycol and diisocyanates having terminally etherified polyethylene glycol groups, each containing at least 20% by weight of ethylene oxide. These types of diisocyanates and processes for preparing them are described in U.S. Patent Nos. 3,905,929 and 3,920,598.

[0063] Ionic hydrophilic groups are, in particular, anionic groups such as sulfonic acid groups, carboxylic acid groups, and phosphate groups in the form of alkali metal salts or ammonium salts, as well as cationic groups such as ammonium groups, especially protonated tertiary amino groups or quaternary ammonium groups. Potential ionic hydrophilic groups are, in particular, those that can be converted to the aforementioned ionic hydrophilic groups by simple neutralization, hydrolysis, or quaternization reactions, in other words, carboxylic acid groups or tertiary amino groups. (Potential) ionic monomers (c) are described in detail, for example, Ullmanns Enzyklopadie der technischen Chemie, 4th edition, volume 19, pp. 311-313 and, for example, West German Patent Application Publication No. 1495745. The acidic groups of polyurethane are neutralized with a suitable neutralizing agent, preferably at least 10 mol%, more preferably at least 40 mol%, more preferably at least 70 mol%, and very preferably at least 90 mol%, and especially completely (100 mol%), and thus exist in the form of a salt in which the acidic group is anion and the neutralizing agent is a cation. The neutralizing agents are, for example, ammonia, alkali metal hydroxides such as NaOH or KOH, or alkanolamines. Particularly important as (potential) cationic monomers (c) are monomers containing a tertiary amino group, examples of which are tris(hydroxyalkyl)amine, N,N'-bis(hydroxyalkyl)alkylamine, N-hydroxyalkyldialkylamine, tris(aminoalkyl)amine, N,N'-bis(aminoalkyl)alkylamine, and N-aminoalkyldialkylamine, where the alkyl and alkanediyl units of these tertiary amines consist of 1 to 6 carbon atoms independently of each other. Equally suitable are polyethers containing a tertiary nitrogen atom and preferably two terminal hydroxyl groups, which can be obtained by conventional methods, for example, by alkoxyling an amine containing two hydrogen atoms bonded to an amine nitrogen, such as methylamine, aniline, or N,N'-dimethylhydrazine. This type of polyether generally has a molar weight of 500 to 6000 g / mol.These tertiary amines are converted to ammonium salts by using an acid, preferably a strong mineral acid such as phosphoric acid, sulfuric acid, or hydrohalic acid, or a strong organic acid, or by reaction with a suitable quaternizing agent such as a C1-C6 alkyl halide or benzyl halide, for example, a bromide or chloride.

[0064] Suitable monomers having (potential) anionic groups typically include aliphatic, cyclic aliphatic, aromatic aliphatic, or aromatic carboxylic acids and sulfonic acids having at least one alcoholic hydroxyl group or at least one primary or secondary amino group. Dihydroxyalkyl carboxylic acids, particularly those having 3 to 10 carbon atoms, as described in U.S. Patent No. 3,412,054, are preferred. General formula (c1) [ka] [In the formula, R 1 and R 2 These are C1-C4 alkanediyl (units), and R 3 Compounds of which are C1-C4 alkyl (units) are particularly preferred, and dimethylolpropionic acid (DMPA) is particularly preferred. Similarly suitable are dihydroxyphosphonic acids such as the corresponding dihydroxysulfonic acid and 2,3-dihydroxypropanephosphonic acid. Other suitable are dihydroxyl compounds having a molecular weight greater than 500-10000 g / mol and at least two carboxylic acid groups, which are known from West German Patent Application Publication No. 3911827. These can be obtained by reacting the dihydroxyl compound with a tetracarboxylic dianhydride such as pyromellitic acid dianhydride or cyclopentanetetracarboxylic dianhydride in a molar ratio of 2:1-1.05:1 in a polyaddition reaction. Particularly suitable dihydroxyl compounds are monomers (b2) and diols (b1), which are listed as chain extenders.

[0065] Suitable monomers (c) containing an amino group reactive with isocyanate include aminocarboxylic acids such as lysine and β-alanine, or adducts of aliphatic diprimer diamines with α,β-unsaturated carboxylic acids or sulfonic acids, as described in West German Patent Application Publication No. 2034479. Such compounds are, for example, of formula (c2) H2N-R 4 -NH-R 5 -X (c2) [In the formula, R 4 and R 5 The formula follows the order [where C1-C6 alkanediyl units are independently of each other, preferably ethylene, and X is COOH or SO3H]. Particularly preferred compounds of formula (c2) are N-(2-aminoethyl)-2-aminoethanecarboxylic acid and N-(2-aminoethyl)-2-aminoethanesulfonic acid and their corresponding alkali metal salts, with Na being a particularly preferred counterion.

[0066] Similarly, particularly preferred are adducts of the above-mentioned aliphatic diprimer and 2-acrylamido-2-methylpropanesulfonic acid, such as those described in West German Patent Application Publication No. 1954090.

[0067] When monomers with latent ionic groups are used, the ionic monomers often do not dissolve well in the reaction mixture, so their conversion to the ionic form may be carried out before, during, or preferably after the isocyanate polyaddition. Examples of neutralizing agents include ammonia, NaOH, triethanolamine (TEA), triisopropylamine (TIPA), or morpholine, or their derivatives. The sulfonic acid group or carboxylic acid group is more preferably in the form of their salts having an alkali metal ion or ammonium ion as a counterion.

[0068] Unlike monomers (a) to (c), monomer (d), which may also be a component of polyurethane, can be useful for crosslinking or chain extension. These may include nonphenolic alcohols having a functional value greater than 2, amines having two or more primary and / or secondary amino groups, and compounds having one or more primary and / or secondary amino groups as well as one or more alcoholic hydroxyl groups. Alcohols having a functional value greater than 2 that can be used to provide some degree of branching or crosslinking include, for example, trimethylolpropane, glycerol, or sugars. Another suitable compound (d) is an α,ω-diaminopolyether, which can be prepared by amination of a polyalkylene oxide with ammonia. Compound (d) may also be, for example, an isocyanate, which further has masked isocyanate groups, such as a uretdione group or a carbodiimide group, as well as a free isocyanate group.

[0069] Equally suitable are monoalcohols having one or more primary and / or secondary amino groups, such as monoethanolamine, which have not only hydroxyl groups but also additional isocyanate-reactive groups. Since amines generally react with isocyanates more rapidly than alcohols or water, polyamines having two or more primary and / or secondary amino groups are used, especially when chain extension and / or crosslinking are carried out in the presence of water. This is often necessary when the requirement is for crosslinked polyurethanes or aqueous dispersions of polyurethanes with a large molar weight. In such cases, the approach taken is to prepare prepolymers having isocyanate groups, rapidly disperse them in water, and then extend or crosslink them by adding compounds having two or more isocyanate-reactive amino groups.

[0070] Amines suitable for this purpose are generally polyfunctional amines in a molar weight range of 32 to 500 g / mol, preferably 60 to 300 g / mol, containing at least two amino groups selected from the group consisting of primary and secondary amino groups. Examples of such amines are diamines such as diaminoethane, diaminopropane, diaminobutane, diaminohexane, piperazine, 2,5-dimethylpiperazine, amino-3-aminomethyl-3,5,5-trimethylcyclohexane (isophoronediamine, IPDA), 4,4'-diaminodicyclohexylmethane, 1,4-diaminocyclohexane, aminoethylethanolamine, hydrazine, hydrazine hydrate, or triamines such as diethylenetriamine or 1,8-diamino-4-aminoethyloctane. The amines can also be used in blocked form, for example, in the form of the corresponding ketimine (see, for example, Canadian Patent Application Publication No. 1129128), ketazine (see, for example, U.S. Patent No. 4,269,748), or amine salt (see U.S. Patent No. 4,292,226). Oxazolidines, such as those used in, for example, U.S. Patent No. 4,192,937, also represent blocked polyamines that can be used for chain extension of the prepolymer and for the preparation of the polyurethanes of the present invention. When this type of blocked polyamine is used, they are generally mixed with the prepolymer in the absence of water, and then this mixture is mixed with dispersed water or a portion of dispersed water, so that the corresponding polyamine is released by hydrolysis. It is preferable to use a mixture of diamine and triamine, more preferably a mixture of isophorone diamine (IPDA) and diethylenetriamine (DETA).

[0071] The polyurethane contains a polyamine in an amount of preferably 1 to 30 mol%, more preferably 4 to 25 mol%, based on the total amount of components (b) and (d), which has at least two isocyanate-reactive amino groups as monomer (d).

[0072] For the same purpose, it is also possible to use an isocyanate having a functional value greater than 2 as monomer(d). Examples of standard commercially available compounds are biuret of isocyanurate or hexamethylene diisocyanate.

[0073] The monomers (e) used of option are monoisocyanates, monoalcohols, and monoprimary and monosecondary amines. Their proportions generally do not exceed 10 mol% based on the total molar amount of monomers. These monofunctional compounds typically have further functional groups such as olefin or carbonyl groups and serve to introduce functional groups into the polyurethane, which facilitates the dispersion and / or crosslinking or further polymer-like reactions of the polyurethane. Monomers suitable for this purpose include isopropenyl-α,α'-dimethylbenzyl isocyanate (TMI) and esters of acrylic or methacrylic acids such as hydroxyethyl acrylate or hydroxyethyl methacrylate.

[0074] At least the first glass transition temperature T g1 and the second glass transition temperature T g2 The polyurethane in the aqueous polyurethane dispersion having is a) at least one organic diisocyanate selected from diisocyanates of formula X(NCO)2 [wherein X is an acyclic aliphatic hydrocarbon group having 4 to 15 carbon atoms, a cyclic aliphatic hydrocarbon group having 6 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 15 carbon atoms, or an aromatic aliphatic hydrocarbon group having 7 to 15 carbon atoms], wherein the amount of aromatic diisocyanate is less than 60 mol% based on the total of all organic diisocyanates a); b1) A compound having a molecular weight of 500 g / mol to 5000 g / mol, and comprising at least one dihydroxy compound selected from the group consisting of polyesterdiols, polyetherols, and polytetrahydrofurans; b2) A dihydroxy compound selected from the group consisting of branched or unbranched acyclic diols having 2 to 8 carbon atoms and cyclic diols having 3 to 8 carbon atoms, preferably having a molecular weight of 62 g / mol to 200 g / mol; c) At least one compound having at least one group reactive to an isocyanate group, and additionally having at least one ionic group or one group that can be converted to an ionic group, preferably comprising a group selected from a carboxylic acid group and a sulfonic acid group, d) Select any further compounds different from a) to c) It can be prepared from.

[0075] Preferred polyurethanes are a) At least one monomer diisocyanate, b) at least diols b1) and b2), c) Unlike monomers (a) and (b), at least one monomer having at least one isocyanate group, or at least one group reactive to an isocyanate group, and additionally having at least one hydrophilic group or a latent hydrophilic group, d) Optionally, at least one further compound having at least two reactive groups selected from an alcoholic hydroxyl group, a primary or secondary amino group, or an isocyanate group, which differ from monomers (a) to (c), and e) Optionally, at least one monofunctional compound having a reactive group that differs from monomers (a) to (d), which is an alcoholic hydroxyl group, a primary or secondary amino group, or an isocyanate group. It is synthesized from.

[0076] Preferably, the polyurethane dispersion is an anionic polyurethane dispersion prepared using a small amount of aromatic diisocyanate, for example less than 60 mol%, based on the total of all organic diisocyanates a), or without aromatic diisocyanate. The anionic group of the anionic polyurethane is preferably selected from carboxylic acid groups and sulfonic acid groups. The same applies to the polyurethane contained in at least partially coated particles and molded articles according to the present invention.

[0077] Component b) is preferably, b1) Based on the total amount of constituent component b), 10-90 mol% of diol b1), b2) Based on the total amount of component b), 10-90 mol% of diol b2) It consists of.

[0078] The molar ratio of diol b1) to monomer b2) is more preferably 1:5 to 5:1, and more preferably 1:2 to 2:1.

[0079] In particular, diisocyanate X(NCO)2 [wherein X is an acyclic aliphatic hydrocarbon group having 4 to 15 carbon atoms, a cyclic aliphatic or aromatic hydrocarbon group having 6 to 15 carbon atoms, or an aromatic aliphatic hydrocarbon group having 7 to 15 carbon atoms] can be cited as monomer (a). Examples of such diisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1-isocyanato-3,5,5-trimethyl-3-isocyanatomethylcyclohexane (IPDI), 2,2-bis(4-isocyanatocyclohexyl)-propane, trimethylhexane diisocyanate, 1,4-diisocyanatobenzene, and 2,4-diiso This includes isomers of bis(4-isocyanatocyclohexyl)methane (HMDI), such as cyanatotoluene, 2,6-diisocyanatotoluene (TDI), 4,4'-diisocyanato-diphenylmethane, 2,4'-diisocyanatodiphenylmethane, p-xylylenediisocyanate, tetramethylxylylenediisocyanate (TMXDI), trans / trans, cis / cis, and cis / trans isomers, as well as mixtures of these compounds. This type of diisocyanate is commercially available. Particularly preferred are diisocyanates selected from the group consisting of hexamethylene diisocyanate, 1-isocyanato-3,5,5-trimethyl-3-isocyanato-methylcyclohexane, 2,6-diisocyanatotoluene, and tetramethylxylylenediisocyanate, or mixtures thereof. A particularly important mixture of these isocyanates is a mixture of structural isomers of diisocyanatotoluene and diisocyanatodiphenylmethane; a mixture of 80 mol% 2,4-diisocyanatotoluene and 20 mol% 2,6-diisocyanatotoluene is especially suitable.Similarly, particularly advantageous are mixtures of aromatic isocyanates such as 2,4-diisocyanatotoluene and / or 2,6-diisocyanatotoluene with aliphatic or cyclic aliphatic isocyanates such as hexamethylene diisocyanate or IPDI, in which case the preferred molar ratio of aliphatic to aromatic isocyanate is 1:9 to 9:1, and especially 4:1 to 1:4. It is also preferable that only aliphatic isocyanates be used.

[0080] The diol (b1) may be a polyester polyol, which is known, for example, from Ullmanns Enzyklopadie der technischen Chemie, 4th edition, volume 19, pp. 62 to 65. It is preferable to use a polyester polyol obtained by reacting a dihydric alcohol with a dibasic carboxylic acid. Polyester polyols can also be prepared using the corresponding polycarboxylic acid anhydride or the corresponding polycarboxylic acid ester of a lower alcohol or a mixture thereof instead of a free polycarboxylic acid. The polycarboxylic acid may be aliphatic, cyclic aliphatic, aromatic aliphatic, aromatic or heterocyclic, and may optionally be substituted with, for example, a halogen atom and / or unsaturated. Examples include: suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, and dimer fatty acids. Preferred dicarboxylic acids are those with the general formula HOOC-(CH2) y-COOH [wherein y is a number from 1 to 20, preferably an even number from 2 to 20], examples of which are succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid. Suitable examples of dihydric alcohols include ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butene-1,4-diol, butyn-1,4-diol, pentane-1,5-diol, neopentyl glycol, bis(hydroxymethyl)cyclohexane such as 1,4-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1,3-diol, methylpentanediol, as well as diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, and dibutylene glycol and polybutylene glycol. Preferred alcohols for obtaining crystallinity are those with the general formula HO-(CH2) x -OH [wherein x is a number from 1 to 20, preferably an even number from 2 to 20]. Examples of such alcohols are ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol, and dodecane-1,12-diol.

[0081] The diol (b1) may also be polytetrahydrofuran. A suitable polytetrahydrofuran can be prepared by cationic polymerization of tetrahydrofuran in the presence of an acidic catalyst, such as sulfuric acid or fluorosulfuric acid. This type of preparation process is known to those skilled in the art.

[0082] The diol (b1) may also be a polyetherdiol. Polyetherdiols can be obtained particularly by polymerizing ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide, or epichlorohydrin with themselves, for example, in the presence of BF3, or by optionally adding these compounds in a mixture or successively to a starter component containing reactive hydrogen atoms, such as an alcohol or amine (e.g., water, ethylene glycol, propane-1,2-diol, propane-1,3-diol, 2,2-bis(4-hydroxyphenyl)propane, and aniline). Polyetherdiols having a molecular weight of 500 to 5000, particularly 600 to 4500, are especially preferred.

[0083] The polyurethane in the aqueous polyurethane dispersion contained in the at least partially coated particles and molded article according to the present invention has a K value greater than 50 and less than 100, preferably 55 to 95.

[0084] The K value is the relative viscosity number, which is determined at 25°C according to DIN EN ISO 1628-1 2021. It consists of the flow rate of a 1 wt-% strength solution of polyurethane in DMF as opposed to the flow rate of pure DMF, and characterizes the average molecular weight of the polyurethane.

[0085] In the field of polyurethane chemistry, it is common knowledge how the molecular weight (and therefore the K value) of polyurethane can be adjusted by selecting the arithmetic mean of the ratio of monomers that are reactive with each other and the number of reactive functional groups per molecule. The constituent components (a) to (e) and their respective molar amounts are given by a ratio A:B, A) is the molar amount of isocyanate groups, B) is the sum of the molar amounts of hydroxyl groups and the molar amounts of functional groups that can react with the isocyanate in the addition reaction, and is 0.5:1 to 2:1, preferably 0.8:1 to 1.5:1, and more preferably 0.9:1 to 1.2:1. This is how it is usually chosen. Very preferably, the ratio A:B is as close to 1:1 as possible.

[0086] The monomers (a) to (e) used typically have, on average, 1.5 to 2.5 isocyanate groups, preferably 1.9 to 2.1, and more preferably 2.0 isocyanate groups and / or functional groups that can react with isocyanates in addition reactions. Very high K values ​​are achieved by using monomers (a) to (e) with small amounts of functional value >2.5 or monomers with additional crosslinking groups such as carbodiimide, silane, and aziridine.

[0087] The polyaddition of components (a) to (e) for the preparation of polyurethane occurs under atmospheric pressure or autogenous pressure, preferably at a reaction temperature of up to 180°C, more preferably up to 150°C, for example, 20 to 180°C, preferably 70 to 150°C. The preparation of polyurethane and aqueous polyurethane dispersions is known to those skilled in the art. The polyaddition of synthetic components for the preparation of polyurethane can be catalyzed using organic or organometallic compounds. Suitable catalysts include dibutyltin dilaurate (DBTL), tin(II) octoate, tetrabutoxytitanium (TBOT), or diazabicyclo[2.2.2]octane. Other suitable catalysts are cesium salts, in particular cesium carboxylates such as cesium formate, acetate, propionate, hexanoate, or 2-ethylhexanoate.

[0088] The aqueous polyurethane dispersion for the purposes of the present invention is a dispersion having an aqueous solvent as a continuous phase. Suitable aqueous solvents are water and mixtures of water and water-miscible solvents, examples of which are alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-hexanol and cyclohexanol; glycols such as ethylene glycol, propylene glycol and butylene glycol; methyl or ethyl ethers of dihydric alcohols, diethylene glycol, triethylene glycol, polyethylene glycol having a number average molecular weight of up to about 3000, glycerol and dioxane, and especially ketones such as acetone. Preferably, the polyurethane dispersion is substantially free of organic solvents. Here, "substantially free of organic solvents" means that the proportion of organic solvents does not exceed 5% by weight, more preferably 1% by weight, and especially 0.1% by weight, based on the total weight of the solvent.

[0089] Preferably, the polyurethane is prepared in the presence of at least one organic solvent. Preferred organic solvents for preparing the polyurethane are acetone and ketones such as methyl ethyl ketone, as well as N-methylpyrrolidone. Acetone is particularly preferred. When at least partially water-miscible solvents are used to prepare the polyurethane, the polyurethane dispersion of the present invention may contain, in addition to water, the organic solvent used for preparation. It should be understood that the polyurethane dispersion of the present invention can be prepared in the presence of at least one organic solvent, which is later replaced whole or partially with water.

[0090] Polyurethane dispersions may be prepared by, for example, one of the following processes: According to the "acetone process," an ionic polyurethane is prepared from synthetic components in a solvent miscible with water and boiling below 100°C at atmospheric pressure. Sufficient water is added to produce a dispersion in which water represents the coherent phase. The "prepolymer mixing process" differs from the acetone process in that a prepolymer with isocyanate groups is prepared first, rather than a fully reacted (potentially) ionic polyurethane. In this case, the components are selected such that the defined ratio A:B is greater than 1.0, at most 3, preferably 1.05 to 1.5. The prepolymer is first dispersed in water and then, optionally, crosslinked by the reaction of an amine with more than two isocyanate-reactive amino groups with an isocyanate group, or chain-extended by the reaction of an amine with two isocyanate-reactive amino groups with an isocyanate group. Chain extension may also occur without the addition of an amine. In that case, the isocyanate group is hydrolyzed to an amino group, which is consumed by reaction with the remaining isocyanate groups in the prepolymer as the chain lengthens. Typically, if a solvent is also used during the preparation of the polyurethane, most of the solvent is removed from the dispersion by distillation under reduced pressure, and the dispersion preferably has a solvent content of less than 10% by weight, and particularly preferably is solvent-free. The term "solvent" is understood to mean an organic solvent.

[0091] Preferably, the polyurethane in the aqueous polyurethane dispersion contained in the at least partially coated particles (at least partially coated particles) and the molded article according to the present invention is a) At least one organic diisocyanate selected from diisocyanates of formula X(NCO)2 [wherein X is an acyclic aliphatic hydrocarbon group having 4 to 15 carbon atoms, a cyclic aliphatic hydrocarbon group having 6 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 15 carbon atoms, or an aromatic aliphatic hydrocarbon group having 7 to 15 carbon atoms], wherein the amount of aromatic diisocyanate is less than 60 mol% based on the total of all organic diisocyanates a), b) At least one dihydroxy compound selected from the group consisting of polyester diols and polytetrahydrofurans, c) at least one compound c) having at least one group reactive to an isocyanate group, and additionally having at least one ionic group or one group that can be converted to an ionic group, preferably comprising a group selected from a carboxylic acid group and a sulfonic acid group, d) Select any further compounds different from a) to c) It is prepared from.

[0092] In the first step a1) of the method of the present invention, the particles are brought into contact with an aqueous polyurethane dispersion, the polyurethane having a K value of more than 50 and less than 100, preferably in the range of 55 to 95, according to DIN EN ISO 1628-1 2021, resulting in at least partially coated particles.

[0093] Preferably, in step a1), contact is achieved by mixing the foam beads and dispersion using a kitchen or cement mixer or spray, as if mixing with a Vollrath mixer or spray drying. The amount of liquid / suspension relative to the weight of the product may be in the range of 1 ml / kg / min to 1000 ml / g / min. The droplet size may vary in diameter from 1 mm to 1000 mm. Suitable nozzles would be empty cone nozzles, full cone nozzles or flat jet nozzles, as well as spray discs that generate droplets through rotational motion and centrifugal force. A suitable mixer that can be used is the EMT 30 L. The EMT L 30 is a discontinuous paddle mixer. It is suitable for mixing, agglomeration, and coating experiments. It consists of a rigid container with a rotatable mixing tool. There are various attachable nozzles available depending on the application field. The mixer is heatable due to its double jacket. The rotation speed is adjustable via a mechanical variator. Melting containers and pressure vessels are used for adding liquid.

[0094] In general, common methods for coating can be used, such as spray coating, as described, for example, in European Patent Application Publication No. 0009727. In a preferred embodiment of coating, particles are spray coated while being kept in motion by blowing, for example, air or a mixture of different gases onto them.

[0095] At least partially coated particles are coated with an amount of 0.1% to 40% by weight, preferably 5% to 25% by weight, based on the total weight of the particle and coating. Preferably, at least partially coated particles are coated with an amount of at least 90%, preferably at least 95%, more preferably at least 99%, based on the total surface of the particle, and more preferably completely coated.

[0096] Step a2) concerns drying the coated particles. In principle, all suitable methods such as convection drying, contact drying, infrared drying, and microwave technology are possible.

[0097] In contact drying, the temperature difference between the product and the wall should be limited to 1-100K, and in convection drying, the gas composition may be N2 or air. The gas flow rate is preferably 1-1000 liters / minute per kg of product, and the product temperature in the mixer should be 1°C-100°C, preferably 10°C-60°C.

[0098] Preferably, during step a2), the coated particles are kept moving at least partially. This prevents the particles from agglomerating.

[0099] Preferably, after step a1) but before step a2), the particles are separated from each other. This can be achieved, for example, by using a vibrating belt. Similarly, this option prevents particle aggregation.

[0100] Another aspect of the present invention is, b1) A step of coating particles of expandable thermoplastic elastomer by the method of the present invention, b2) A step of shaping the particles obtained from step b1) This is a method for preparing a molded article, including [the specified element].

[0101] Preferably, the molding in step b2) is carried out by a steamless thermopress.

[0102] Preferably, the thermopress (also called hot press or thermal press) is performed at a temperature of 60°C to 160°C, more preferably 80°C to 160°C, even more preferably 90°C to 140°C, and even more preferably 90°C to 130°C.

[0103] Preferably, after molding by thermopressing, the resulting molded body is cooled to room temperature, thereby improving its mechanical properties.

[0104] In one embodiment of the present invention, the molding process can be carried out by using an electromagnetic field to generate the required heat completely or partially. The electromagnetic field is preferably in the range of 30 kHz to 1 GHz (corresponding to radio frequency (RF) and microwave molding), more preferably 30 kHz to 300 MHz (corresponding to RF molding).

[0105] Therefore, in a preferred embodiment, the molding is carried out by heat, which is partially or completely generated by an electromagnetic field in the range of 30 kHz to 1 GHz, preferably in the high frequency range (30 kHz to 300 MHz).

[0106] Energy radiation shaping is generally performed within the microwave frequency range of 300 MHz to 300 GHz or the high-frequency range of 30 kHz to 300 MHz. Microwaves are preferably applied within the frequency range of 0.5 to 100 GHz, and particularly preferably within the range of 0.8 to 10 GHz, with irradiation times of 0.1 to 15 minutes. Radio waves are preferably applied within the frequency range of 500 kHz to 100 MHz, and particularly preferably within the range of 1 MHz to 80 MHz, with irradiation times of 0.1 to 30 minutes.

[0107] Preferably, the molded article is a particle composite material with other materials such as textiles, leather, thermoplastic films, or metal components.

[0108] Another aspect of the present invention is, c1) The step of preparing a molded article according to the method of the present invention; c2) A step of decomposing particles by exposing the molded body to an alkaline aqueous fluid which may contain a surfactant. The present invention relates to a method for treating a molded body, including the present invention.

[0109] At least the partial coating particles according to the present invention can be used in their pure form, as a mixture with various particles and / or other materials to obtain 3D parts for industrial, consumer, transport, and construction applications, used alone or as components for sealing, insulation for houses, pipelines or gas tanks, shoe parts, shoe midsoles, shoe inserts, shoe combination soles, bicycle saddles, bicycle tires, damping elements, impact protection, sound and vibration dampers, decoration, furniture, upholstery, mattresses, yoga mats, underlays, railway pads, handles, protective sheets, packaging, drop protection, automotive interiors and exteriors, headliners, armrests, door linings, seats, battery housings, sporting goods, balls, tennis rackets, baseball clubs, treadmills, toys, flooring, running tracks, artificial turf, playgrounds, sports halls, and sidewalks. [Examples]

[0110] 23℃ and 250s -1 The viscosity was measured at the shear rate according to DIN EN ISO 3219-2:2021.

[0111] The dispersion was dried in a mold at 40°C for 3 days, followed by 23°C for 7 days. Thermal properties were measured by differential scanning calorimetry.

[0112] The glass transition temperature was determined as the so-called midpoint temperature according to DIN EN ISO 11357-2 (2014). The glass transition temperature of the polymer in the polymer dispersion is the glass transition temperature obtained when evaluating the second heating curve (heating rate 20°C / min). The melting point and enthalpy of melting were determined according to DIN ISO 11357-3 (2018) by cooling to -80°C and then heating at 20 K / min (melting point = peak temperature); on the other hand, the second enthalpy of melting (delta H2) is calculated from the area of ​​the second melt only; a) From the untreated (dried) film → Tm1, Delta H1 b) After heating the polyurethane film to 130°C, cool it to -80°C at 20K / min; reheat at 20K / min → Tm2 Delta H2

[0113] Example 1: PUD according to Example 1 of International Publication No. 2012 / 13506 The example was repeated: sc40%. K value: 55. Viscosity: 48 mPas. Tg: -46℃ [Table 1]

[0114] Example 2: 676 g of polyester diol (OH value 45) derived from adipic acid and 1,4-butanediol was reacted with 0.11 g of titanium tetrabutyrate, 40 g of IPDI, and 0.77 g of NCO-terminated polycarbodiimide (Elastostab H02, BASF) in 153 g of dry acetone at 60°C for 60 minutes. Then, 37.8 g of HDI was added and the temperature was raised to 74°C. The reaction was continued until the NCO value was less than 1.25%. The mixture was diluted with 539 g of acetone and cooled to 35-40°C. Then, 22.4 g of sodium aminoethylaminoethanesulfonate (50% in water), diluted with 22 g of demineralized water, was added over 3 minutes, followed by 4.6 g of isophoronediamine, diluted with 23 g of demineralized water, also over 3 minutes. Before dispersion, 38.7 g of a 20% aq. solution of Lutensol AT18 (BASF) was added, followed by dispersion in 463 g of demineralized water for 15 minutes. Immediately after adding water, 4 g of N-(2-aminoethyl)ethanolamine in 30 g of water was added along with an additional 200 g of demineralized water for 15 minutes. Acetone was removed by vacuum distillation with the help of 2 drops of an antifoaming agent (modified polyalkylene glycol, FoamStar PB 2724, BASF) to adjust the solids content to 50%. K value: 60 Viscosity: 169 mPas Tg: -55℃ [Table 2]

[0115] Example 3: 541 g of polyester diols (OH value 56) derived from adipic acid, 1,6-hexanediol, and 1,4-butanediol were reacted with 0.11 g of titanium tetrabutyrate, 40 g of IPDI, and 0.9 g of NCO-terminated polycarbodiimide (Elastostab H02, BASF) in 153 g of dry acetone at 60°C for 60 minutes. Then, 37.8 g of HDI was added and the temperature was raised to 74°C. The reaction was continued until the NCO value was lower than 1.47%. The mixture was diluted with 539 g of acetone and cooled to 35-40°C. Then, 21.9 g of sodium aminoethylaminoethanesulfonate (50% in water), diluted with 22 g of demineralized water, was added over 3 minutes, followed by 4.6 g of isophoronediamine, diluted with 23 g of demineralized water, also over 3 minutes. Before dispersion, 31.8 g of a 20% aq. solution of Lutensol AT18 (BASF) was added, followed by dispersion in 361 g of demineralized water for 15 minutes. Immediately after adding water, 4 g of N-(2-aminoethyl)ethanolamine in 30 g of water was added along with an additional 200 g of demineralized water for 15 minutes. Acetone was removed by vacuum distillation with the help of 2 drops of an antifoaming agent (modified polyalkylene glycol, FoamStar PB 2724, BASF) to adjust the solids content to 50%. K value: 66.5 Viscosity: 51 mPas Tg: -57℃ [Table 3]

[0116] Example 4: With the help of 0.2 g of tetrabutyl titanate as a catalyst, 748 g of polyester diol (OH value 45) from adipic acid and 1,4-butanediol was reacted with 13.5 g of 1,4-butanediol and 49.8 g of toluene diisocyanate (80 / 20 mixture of isomers) in 309 g of dry acetone at 65°C until the NCO value reached 0.2%, then 48 g of hexamethylene diisocyanate was added, followed by rinsing with 58 g of dry acetone. The reaction was continued until the NCO value reached 0.95%. The mixture was diluted with 684 g of acetone and cooled to 40°C. Chain extension was performed for 10 minutes with 43.4 g of a 50% sc aqueous solution of sodium aminoethylaminoethanesulfonate. Then, 4.4 g of Lutensol TO5 (ethoxylated, iso-C13 alcohol, BASF) dissolved in 12 g of water was added, followed by 726 g of deionized water. Acetone was removed by vacuum distillation, and to control foaming, the defoaming agent Foamstar PB 2724 (modified polyalkylene glycol) had to be added in two portions (2 × 0.1 g) during distillation. The solids content was adjusted to 45%. K value: 56, Viscosity: 19 mPas, Tg: -54℃ [Table 4]

[0117] Example 5: 745 g (0.30 mol) of polyester diol (based on 1,4-butanediol / adipic acid) with an OH value of 45.2, 13.4 g (0.10 mol) of dimethylolpropionic acid, 1.0 g of tetrabutyl orthotitanate (10% foam), and 100 g of acetone were added as initial additions. These were mixed with 112.3 g (0.505 mol) of isophorone diisocyanate at 60°C and stirred at 90°C for 4 hours. Next, 900 g of acetone, 20.25 g of triisopropanolamine (0.09 mol), 5 g of carbodiimide (1,3-bis(1-isocyanato-1-methylethyl)benzene, a polymer based on isocyanate terminal groups) in 5 g of acetone (0.005 mol), 0.97 g of aminopropyltrimethoxysilane (0.005 mol), 31.35 g of sodium aminoethylaminoethanesulfonate (0.075 mol), and 40 g of water were weighed in, and the reaction mixture was stirred for a further 20 minutes. It was then dispersed with 1300 g of water; after which the acetone was removed by distillation under reduced pressure, and the solids content was adjusted to approximately 40%. K value: 94 Viscosity: 120 mPas Tg: -53℃ [Table 5]

[0118] Example 6: 726 g of polyester diol (OH value 45) from adipic acid and 1,4-butanediol was reacted at 90°C with 8.05 g of dimethylolpropionic acid (DMPA) and 67.3 g of hexamethylene diisocyanate in 80 g of anhydrous acetone until the NCO content reached 0.52-0.47%. The mixture was then diluted with 600 g of acetone and cooled to 35°C. The mixture was neutralized with 5.8 g of triethylamine, and the chain was stopped with 3.15 g of diethanolamine in 25 g of deionized water. After 10 minutes, the mixture was dispersed using 785 g of deionized water and stabilized by adding 40 g of a 20% solution of Lutensol AT 18 (ethoxylated C16 / C18 alcohol, BASF). The acetone was removed by distillation under vacuum, and the solids content was adjusted to 50%. K value: 55 Viscosity: 63 mPas Tg: -53℃ [Table 6] A latent reactive dispersion was obtained by combining 79.5 g of the dispersion with 0.1 g of Lumiten I-SC (solution of sodium sulfosuccinate and ethoxylated isotridecanol in water, BASF) and 6 g of Aqualink U (dispersion of blocked TDI dimers, Aquaspersion Co., UK).

[0119] Example 7: 563 g of polyester diol (OH value 45) from adipic acid and 1,4-butanediol and 0.17 g of Borchikat 315 (tin-free catalyst, bismuth neodecanoate, Borchers) were reacted in 67.9 g of IPDI and 90 g of dry acetone at 60°C to 65°C until the NCO value reached 0.9%. The mixture was diluted with 630 g of acetone and cooled to 50°C. Then, 21.8 g of sodium aminoethyl-aminoethane-sulfonate (50% in water), diluted with 22 g of deionized water, was added over 3 minutes. After 10 minutes, dispersion was continued with 927 g of deionized water. Acetone was removed by vacuum distillation with the help of 2 drops of defoaming agent (modified polyalkylene glycol, FoamStar PB 2724, BASF) to adjust the solids content to 40%. K value: 60, Viscosity: 121 mPas, Tg: -53℃ [Table 7]

[0120] Example 8: 563 g of polyester diol (OH value 45) from adipic acid and 1,4-butanediol was reacted with 0.08 g of Borchikat 315 (tin-free catalyst, bismuth neodecanoate, Borchers), 51.4 g of HDI, and 90 g of dry acetone at 60°C to 65°C until the NCO value reached 0.96%. The mixture was diluted with 630 g of acetone and cooled to 50°C. Then, 21.8 g of sodium aminoethyl-aminoethane-sulfonate (50% in water), diluted with 22 g of deionized water, was added over 3 minutes. After 10 minutes, dispersion was continued with 907 g of deionized water. Acetone was removed by vacuum distillation with the help of 2 drops of defoaming agent (modified polyalkylene glycol, FoamStar PB 2724, BASF) to adjust the solids content to 40%. K value 65, viscosity 50 mPas, Tg: -54℃ [Table 8]

[0121] Example 9: 332 g of polyester diol (OH value 45) derived from adipic acid and 1,4-butanediol, and 271 g of poly-THF 2000 (OH value = 56 mg KOH / g) were reacted with 27.8 g of IPDI and 41.4 g of HDI in 60 g of dry acetone at 100°C for 6 hours. The mixture was diluted with 804 g of acetone and cooled to 40°C. The chain reaction was stopped by adding a mixture of 3.55 g of diethanolamine, 0.82 g of N-(2-aminoethyl)ethanolamine, and 16 deionized water. Then, 18.7 g of sodium aminoethyl-aminoethane-sulfonate (50% in water), diluted with 17 g of deionized water, was added over 3 minutes. After 10 minutes, the dispersion was continued with 657 g of deionized water for 30 minutes. The acetone was removed by vacuum distillation with the help of 2 drops of defoaming agent (modified polyalkylene glycol, FoamStar PB 2724, BASF). To stabilize the dispersion, 68.6 g of a 20% solution of Lutensol AT 18 (ethoxylated C16 / C18 alcohol, BASF) was added to adjust the solid content to 48%. K value: 57, Viscosity: 210 mPas, Tg: -57℃ [Table 9]

[0122] Example 10: 543 g of polyester diol (OH value 56) from adipic acid, 1,6-hexanediol, and 1,4-butanediol was reacted at 95°C with 27.12 g of IPDI and 40.4 g of HDI in 60 g of dry acetone until the NCO value reached 1.14% to 1.0%. The mixture was diluted with 804 g of acetone and cooled to 40°C. The chain reaction was stopped by adding a mixture of 3.55 g of diethanolamine, 0.83 g of N-(2-aminoethyl)ethanolamine, and 16-deionized water. Then, 14.1 g of sodium aminoethyl-aminoethane-sulfonate (50% in water), diluted with 17 g of deionized water, was added over 3 minutes. After 10 minutes, the dispersion was continued with 594 g of deionized water for 30 minutes. The acetone was removed by vacuum distillation with the help of 2 drops of defoaming agent (modified polyalkylene glycol, FoamStar PB 2724, BASF). To stabilize the dispersion, 62 g of a 20% solution of Lutensol AT 18 (ethoxylated C16 / C18 alcohol, BASF) was added to adjust the solid content to 50%. K value: 57 Viscosity: 59 mPas Tg: -57℃ [Table 10]

[0123] Example 11: 1039 g of polyester diol (molecular weight 2000 g / mol) from adipic acid and isophthalic acid (molar 1:1) and 1,6-hexanediol, 104.6 g of dimethylolpropionic acid (DMPA), and 186.8 g of butanediol-1,4 were reacted in a pressurized reactor with 900 g of IPDI in 530 g of dry acetone; starting at 50°C, the temperature was raised to 90°C in 30 minutes, then to 2.9 bar and 90°C for 8 hours. The mixture was diluted with 1852 g of acetone, cooled to 40°C, and expanded to atmospheric pressure. The NCO value was determined to be 1.2%. Then, 10.2 g of isophoronediamine was added in one addition, followed by 81 g of diethylethanolamine (neutralizing agent) over 5 minutes. After stirring for 5 minutes, the dispersion step was continued at 30°C for 37 minutes with 3567 g of deionized water, followed by the addition of 19,8-diethylenetriamine in 340 g of deionized water over 30 minutes. Acetone was removed by vacuum distillation with the help of 0.23 g of an antifoaming agent (FoamStar PB 2724, BASF), and the solids content was 37.4%. Dispersion Example 11 K value 63 Viscosity 31mPas Tg1 -20℃ Tg2 69℃

[0124] Example 12: 1024 g of polyester diol (molecular weight 2000 g / mol) from adipic acid and isophthalic acid (molar 1:1) and 1,6-hexanediol, 104.6 g of dimethylolpropionic acid (DMPA), 187 g of butanediol-1,4, and 72.8 g of side-chain polyethylene glycol, Ymer N 120 (Perstorp) were reacted with 686.3 g of IPDI in a pressurized reactor in 550 g of dry acetone; starting at 55°C, IPDI was supplied, the temperature was raised to 75°C in 30 minutes, then to 2.4 bar, 75°C for 1.5 hours. Then, the second portion of 228.8 g of IPDI and 18 g of acetone were added, and the reaction was continued until the NCO value was 2.2%. The mixture was diluted with 1574 g of acetone, cooled to 40°C, and expanded to atmospheric pressure. The NCO value was determined to be 1.39%. Next, the mixture was further diluted with 366 g of acetone, and 10.5 g of isophoronediamine was added in one addition, followed by 82.2 g of diethylethanolamine (neutralizing agent) over 5 minutes. After stirring for 10 minutes, the dispersion step was continued with 3294 g of deionized water at 39°C for 37 minutes, followed by the addition of 19,8-diethylenetriamine in 346 g of deionized water over 30 minutes. Acetone was removed by vacuum distillation with the help of 0.58 g of an antifoaming agent (FoamStar PB 2724, BASF), and the solids content was 37%. Dispersion Example 12 K value 57 Viscosity 173mPas Tg1 -22℃ Tg2 75℃

[0125] Comparative Example C1: Amorphous dispersion 706 g of polypropylene oxide diol (OH value = 57.2 mg KOH / g) and 57.9 g of dimethylolpropionic acid (DMPA) were reacted with 137.9 g of toluene diisocyanate (80 / 20 isomer mixture) in 63 g of anhydrous acetone at 110°C until the NCO content was <0.1%. The mixture was then diluted with 720 g of acetone and cooled to 25°C. The mixture was neutralized with 48.9 g of aqueous NaOH solution (8 wt%) and dispersed using 710 g of deionized water. Acetone was removed by distillation under vacuum with the help of 3 drops of the defoaming agent Foam Star PB2724 (modified polyalkylene glycol, BASF). The solids content was adjusted to 50%. K value 43; melting point or crystalline portion could not be detected.

[0126] Comparative Example C2: Amorphous dispersion 801.4 g of polypropylene oxide diol (OH value = 56 mg KOH / g) and 64.4 g of dimethylolpropionic acid (DMPA) were reacted with 153.3 g of toluene diisocyanate (80 / 20 isomer mixture) in 100 g of anhydrous acetone at 100-110°C until the NCO content was <0.1%. The mixture was then diluted with 800 g of acetone and cooled to 50°C. The mixture was neutralized with 19.4 g of triethylamine and dispersed using 1580 g of deionized water. The acetone was removed by distillation under vacuum. The solids content was adjusted to 40%. The K value was 43, and neither the melting point nor the crystalline portion could be detected.

[0127] Example 13: Coated e-TPU beads using a Vollrath dissolving machine Using a Vollrath dissolving machine, the polyurethane dispersion described in Example 2 was mixed with E-TPU beads (particles) (Infinergy 230, BASF SE, based on diisocyanate 4, BDO, and polyol 1) prepared according to International Publication No. 2013 / 153190, Example 1, at room temperature for 60 seconds. The beads were then dried on Teflon foil using RT, taking care to separate them from each other. After approximately 10 minutes, the beads were collected. The beads were non-stick and had storage stability. Different coating levels were achieved. 5% to 20% w / w dispersion relative to the beads. For example, to obtain Sample 1 (coated with a 5% dispersion), 5 g of the coating was mixed with 95 g of E-TPU beads. Sample 1: E-TPU beads coated with a 5% dispersion. Sample 2: E-TPU beads coated with a 10% dispersion. Sample 3: E-TPU beads coated with a 15% dispersion. Sample 4: E-TPU beads coated with a 20% dispersion.

[0128] Example 14: Coating e-TPU beads using a kitchen mixer The polyurethane dispersion described in Example 2 was mixed with E-TPU beads (Infinergy 230, BASF SE, based on diisocyanate 4, BDO, and polyol 1) having a bulk density of 130 g / l and a particle weight of 27 mg, prepared according to Example 1 of International Publication No. 2013 / 153190. The beads were mixed until the water evaporated. For 100 g of product, approximately 15 minutes were allowed for particle drying. This process leads to coated beads that are non-stick and storage stable.

[0129] Example 15: Coating e-TPU beads using a kitchen mixer Using a Vollrath dissolving machine, the polyurethane dispersion described in Example 11 was mixed with E-TPU beads (particles) (Infinergy 230, BASF SE, based on diisocyanate 4, BDO, and polyol 1) prepared according to International Publication No. 2013 / 153190, Example 1, at room temperature for 60 seconds. The beads were then dried on Teflon foil using RT, taking care to separate them from each other. After approximately 10 minutes, the beads were collected. The beads were non-stick and had storage stability. Different coating levels were achieved. 5% to 20% w / w dispersion relative to the beads. For example, to obtain Sample 1 (coated with a 5% dispersion), 5 g of the coating was mixed with 95 g of E-TPU beads. Sample 1: E-TPU beads coated with a 5% dispersion. Sample 2: E-TPU beads coated with a 10% dispersion. Sample 3: E-TPU beads coated with a 15% dispersion. Sample 4: E-TPU beads coated with a 20% dispersion.

[0130] Example 16: Coating e-TPU beads using a cement mixer equipped with a sieve drum 2.75 kg of E-TPU beads (Infinergy 230, BASF SE, based on diisocyanate 4, BDO, and polyol 1), prepared according to International Publication No. 2013 / 153190, Example 1, with a bulk density of 130 g / l and a particle weight of 27 mg, were placed in a Scheppach cement mixer, model mix 140, equipped with a sieve drum. 481 g of the dispersion from Example 2, containing 1% blue dye, was slowly added to the cement mixer under rotation. The beads were completely coated within 90 seconds. The beads were then allowed to reach the sieve drum, which allowed for the separation of coated individual beads and collection on the Teflon belt below. Within 10 minutes after coating, the beads became non-stick and could be collected and stored.

[0131] Example 17: Coated beads using a spray drying machine 1.4 kg of E-TPU beads (Infinergy 230, BASF SE, based on diisocyanate 4, BDO, and polyol 1, with a bulk density of 130 g / l and a particle weight of 27 mg, prepared according to International Publication No. 2013 / 153190, Example 1) were placed in a 30-liter paddle mixer from EMT GmbH (manufactured in 2013), where they were mixed at 100 rpm using a Becker blade. 150 g of the dispersion described in Example 2 was delivered via a gear pump at 3 bar to a 1.0 mm diameter nozzle (manufacturer: Spraying Systems), where the dispersion was sprayed onto moving E-TPU beads. The throughput was controlled to a flow rate of 75 g / min. The mixture was mixed at 100 rpm and 20°C for 2 minutes while coating the E-TPU beads. After coating the E-TPU beads, 1.0 kg / h of nitrogen at 20°C was flushed into the mixer chamber through separate tubes with an inner diameter of 4 mm to increase the drying intensity by convection drying. After drying for 7 hours, the pourable E-TPU beads were filled into plastic bags via the flap at the bottom of the mixer at a constant mixing speed of 100 rpm.

[0132] Example 18: Hot pressing experiment for realizing 3D parts using coated beads 65g of coated beads (Sample 3) from Experiment 13, pre-sprayed with Indrosil 2000 as a silicone-based release agent, measuring (16.3 × 9.6 × 3.3) cm. 3 The 3D part was placed in a preheated mold of (length, brightness, depth). The filled mold was covered with a mold lid (which was also sprayed with Indrosil 2000), which allowed for 50% compression / consolidation. The time spent in the heated press and the remaining time to cool the 3D part before demolding are summarized in the table below. Furthermore, tensile strength and elongation were measured according to ASTM D 5035:2011, where (150 × 25.4 × 1.6) mm³ e-TPU pieces were used instead of fabric pieces. The rebound measured according to DIN 53512:2000-4 and the density of the obtained 3D parts measured according to DIN EN ISO 845:2009-10 are also reported below. For reference, see International Publication No. 2013 / 153190, Example 1, which describes 65 g of E-TPU beads with a bulk density of 130 g / l and a particle weight of 27 mg, measured in (16.3 × 9.6 × 3.3) cm. 3 It was placed in a preheated mold (length, width, depth). The filled mold was covered with the mold lid. This allows for 50% compression / consolidation. This results in the following dimensions: (16 × 9.5 × 1.6) cm 3 We report on hot-press molded 3D parts that can be obtained by producing plates with coated E-TPU beads, respectively. [Table 11]

[0133] Example 19: 65g of coated beads (Sample 1) from Experiment 15, pre-sprayed with Indrosil 2000 as a silicone-based release agent, measuring (16.3 × 9.6 × 3.3) cm. 3 The 3D part was placed in a preheated mold of (length, brightness, depth). The filled mold was covered with a mold lid (which was also sprayed with Indrosil 2000), which allowed for 50% compression / consolidation. The time spent in the heated press and the remaining time to cool the 3D part before demolding are summarized in the table below. Furthermore, tensile strength and elongation were measured according to ASTM D 5035:2011, where (150 × 25.4 × 1.6) mm³ e-TPU pieces were used instead of fabric pieces. The rebound measured according to DIN 53512:2000-4 and the density of the obtained 3D parts measured according to DIN EN ISO 845:2009-10 are also reported below. For reference, see International Publication No. 2013 / 153190, Example 1, which describes 65 g of E-TPU beads with a bulk density of 130 g / l and a particle weight of 27 mg, measured in (16.3 × 9.6 × 3.3) cm. 3 It was placed in a preheated mold (length, width, depth). The filled mold was covered with the mold lid. This allows for 50% compression / consolidation. This results in the following dimensions: (16 × 9.5 × 1.6) cm 3 We report on hot-press molded 3D parts that can be obtained by producing plates with coated E-TPU beads, respectively. [Table 12]

[0134] Example 20: 170 g of E-TPU beads (Infinergy 230, BASF SE, based on diisocyanate 4, BDO, and polyol 1), having a bulk density of 130 g / l and a particle weight of 27 mg, according to International Publication No. 2013 / 153190, Example 1, coated with a 10 w / w% dispersion of Example 2, were placed in a cylinder 15 cm high and 11 cm in diameter. An 800 g heavy lid was placed on top of the filled cylinder, and it was stored at room temperature. After 10 days, the lid was removed and the coated particles were released. No aggregation or caking was observed. The same experimental setup was used to evaluate the aggregation behavior of coated beads over a three-month period. The coated beads were able to flow out without agglomerating even after three months of storage. For reference, 170 g of E-TPU beads (Infinergy 230, BASF SE, based on diisocyanate 4, BDO, and polyol 1) according to International Publication No. 2013 / 153190 was placed in a cylinder 15 cm high and 11 cm in diameter. An 800 g heavy lid was placed on top of the filled cylinder, and it was stored at room temperature for 10 days. When the lid was removed, the beads did not flow out of the cylinder, and mechanical stirring was required to break up the aggregates. Therefore, the coated beads exhibit a positive phenomenon of avoiding aggregation when stored under defined pressure.

[0135] Example 21: 50 g of E-TPU beads (Infinergy 230, BASF SE, based on diisocyanate 4, BDO, and polyol 1) according to International Publication No. 2013 / 153190, Example 1, coated with a 15 w / w% dispersion of Example 2, were placed in contact with a Teflon foil. The coated beads were shaken for 2 minutes to electrostatically charge them. The coated beads were then allowed to flow off the Teflon foil and collected in a jar. No electrostatic charge was observed on the beads, and the coated beads could be easily removed from the Teflon support. For reference, 50g of E-TPU beads, according to International Publication No. 2013 / 153190, were placed in contact with Teflon foil. The coated beads were shaken for 2 minutes to electrostatically charge them. The E-TPU beads exhibited strong electrostatic charge and were unable to flow off the Teflon foil, instead adhering to it without flowing away. Therefore, coated beads offer the advantage of avoiding electrostatic charge and can be used in applications where antistatic properties are not required.

[0136] Example 22: 60 g of the dispersion from Experiment 2 was mixed with 20 g of Exolit AP 422 (Clariant). 200 g of E-TPU beads according to International Publication No. 2013 / 153190, Example 1 were placed in a kitchen mixer (Bosch) equipped with a dough hook. The beads and the dispersion containing Exolit AP 422 were mixed for 10 minutes until the water had completely evaporated. 65g of the obtained coated beads were pre-sprayed with Indrosil 2000 as a release agent, resulting in a size of (16.3 × 9.6 × 3.3) cm. 3 The 3D part was placed in a preheated mold of (length, brightness, depth). The filled mold was covered with a mold lid (which was also sprayed with Indrosil 2000), which allowed for 50% compression / consolidation. The time spent in the heated press and the remaining time to cool the 3D part before demolding are summarized in the table below. [Table 13] This experiment demonstrates that it is possible to incorporate flame retardants into coatings, and that this can result in 3D parts with good mechanical stability.

Claims

1. A method for preparing moldable thermoplastic particle foams with storage stability coated particles, a １ ) A step of bringing particles into contact with an aqueous polyurethane dispersion, wherein the polyurethane has a K value of more than 50 and less than 100, preferably in the range of 55 to 95, according to DIN EN ISO 1628-1 2021, and resulting in coated particles that are at least partially coated; a ２ ) A step of drying the coated particles Methods that include...

2. The method according to claim 1, wherein the moldable thermoplastic particle foam is an expandable thermoplastic elastomer.

3. The method according to claim 2, wherein the expandable thermoplastic elastomer is expandable thermoplastic polyurethane.

4. The method according to any one of claims 1 to 3, wherein the aqueous polyurethane dispersion has a solid content of at least 40% by weight, preferably in the range of 45% to 60% by weight, based on the total weight of the dispersion.

5. The aqueous polyurethane dispersion was heated to 23°C for 250 seconds. －１ The method according to any one of claims 1 to 4, having a viscosity of less than 300 mPa, preferably less than 200 mPa, at 23°C as measured according to DIN EN ISO 3219-2:2021 at a shear rate of .

6. The polyurethane in the aqueous polyurethane dispersion has a glass transition temperature T of less than 0°C, preferably -10°C to -80°C, more preferably -20°C to -75°C, even more preferably -30°C to -70°C, even more preferably -40°C to -65°C, and even more preferably -45°C to -60°C, according to DIN EN ISO 11357-2 (2014). ｇ The method according to any one of claims 1 to 5, comprising:

7. The polyurethane has at least a first glass transition temperature T ｇ１ and the second glass transition temperature T ｇ２ It has T ｇ１ The temperature is below 0°C, ｇ２ The method according to any one of claims 1 to 6, wherein the temperature is greater than 25°C.

8. The polyurethane of the aqueous polyurethane dispersion has a melting temperature T within the range of 30°C to 100°C, preferably 40°C to 80°C, according to DIN EN ISO 11357-3 (2018). ｍ The method according to any one of claims 1 to 7, having ｍ .

9. The polyurethane in the aqueous polyurethane dispersion is a) Formula X (NCO) ２ At least one organic diisocyanate selected from diisocyanates of the formula [wherein X is an acyclic aliphatic hydrocarbon group having 4 to 15 carbon atoms, a cyclic aliphatic hydrocarbon group having 6 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 15 carbon atoms, or an aromatic aliphatic hydrocarbon group having 7 to 15 carbon atoms], wherein the amount of aromatic diisocyanate is less than 60 mol% based on the total of all organic diisocyanates a), b) At least one dihydroxy compound selected from the group consisting of polyester diols and polytetrahydrofurans, c) At least one compound having at least one group reactive to an isocyanate group, additionally having at least one ionic group or one group that can be converted to an ionic group, preferably comprising a group selected from a carboxylic acid group and a sulfonic acid group, d) Optionally, further compounds different from a) to c) A method according to any one of claims 1 to 8, prepared from.

10. The method according to claim 9, wherein the aqueous polyurethane dispersion contains at least one additive selected from the group consisting of ionic surfactants, nonionic surfactants, rheology modifiers, fillers, anti-blocking additives, other aqueous dispersions, crosslinking agents, plasticizers, hydrolysis stabilizers, foaming inhibitors, and biocides.

11. Step a １ The method according to any one of claims 1 to 10, wherein contact is achieved by mixing or spraying.

12. The method according to any one of claims 1 to 11, wherein the at least partially coated coated particles are coated in an amount of 0.1% to 40% by weight based on the total weight of the particles and the coating.

13. Step a ２ The method according to any one of claims 1 to 12, wherein the at least partially coated coated particles are kept moving during the process.

14. Step a １ ) after step a ２ The method according to any one of claims 1 to 13, wherein the particles are separated from each other before ) in order to prevent aggregation of the particles.

15. b １ ) a step of coating particles of an expandable thermoplastic elastomer by the method according to any one of claims 1 to 14; b ２ ) Step b １ The steps of molding the particles obtained from ) A method for preparing a molded body, including the preparation of a molded body.

16. Step b ２ The method according to claim 15, wherein the molding in ) is performed by a steamless thermopress.

17. The method according to claim 16, wherein the thermopress is performed at a temperature of 60°C to 160°C, preferably 80°C to 160°C, more preferably 90°C to 140°C, and even more preferably 90°C to 130°C.

18. The method according to any one of claims 15 to 17, wherein the molding is performed by heat, and the heat is partially or completely generated by an electromagnetic field in the range of 30 kHz to 300 MHz.

19. The method according to any one of claims 15 to 17, wherein the molded article is a composite material of the particles with other materials such as textiles, leather, thermoplastic films, or metal components.

20. c １ ) a step of preparing a molded article according to any one of claims 15 to 19; c ２ ) A step of decomposing the particles by exposing the molded body to an alkaline aqueous fluid. A method for treating a molded body, including the treatment of a molded body.

21. Storage-stable, at least partially coated particles of a moldable thermoplastic particle foam, wherein the coating is a dried aqueous polyurethane dispersion, and the polyurethane has a K value of more than 50 and less than 100, preferably in the range of 55 to 95, according to DIN EN ISO 1628-1 2021.

22. A molded article comprising at least partially coated particles having storage stability as described in claim 21.

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