EP3781616A1

EP3781616A1 - Foams based on thermoplastic elastomers

Info

Publication number: EP3781616A1
Application number: EP19717942.7A
Authority: EP
Inventors: Elmar Poeselt; Peter Gutmann; Florian Tobias RAPP; Frank Prissok
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2018-04-20
Filing date: 2019-04-18
Publication date: 2021-02-24
Also published as: US20210189087A1; CN112004870A; WO2019202098A1

Abstract

The present invention relates to particle foams of thermoplastic polyurethane and polypropylene, molded parts produced therefrom, to methods for producing the particle foams and molded parts, and to the use of the molded parts for shoe midsoles, shoe insoles, combined soles, cushioning elements for shoes, bicycle saddles, bicycle tires, damping elements, upholstery, mattresses, supports, handles, protective films, in components in automobile interiors and automobile exteriors, in balls and sport devices or as a floor covering.

Description

Foams based on thermoplastic elastomers

description

Particle foams (or particle foams, particle foam) and shaped articles based thereon on the basis of thermoplastic polyurethane or other elastomers are known (for example WO 94/20568, WO 2007/082838 A1, WO2017030835, WO 2013/153190 A1

WO2010010010) and can be used in a variety of ways.

Particle foam or particle foam in the sense of the present invention denotes a foam in the form of a particle, wherein the average diameter of the particle foam is between 0.2 to 20, preferably 0.5 to 15 and in particular between 1 to 12 mm. For non-spherical, e.g. elongated or cylindrical particle foam is meant by diameter the longest dimension.

Basically there is a need for particle foams with improved processability to the corresponding moldings at the lowest possible temperatures while preserving advantageous mechanical properties. This is particularly relevant in the currently common methods for welding, in which the energy input for welding the Parti kelschäume by an auxiliary medium such as water vapor enter, as here a better bonding is achieved and at the same time damage the material or the

Foam structure is reduced.

Sufficient bonding or welding of the particle foams is essential in order to obtain advantageous mechanical properties of the molded part produced from the particle foam. In the case of inadequate bonding or welding of the foam particles, its properties can not be used to their full extent, as a result of which the overall mechanical properties of the molded part obtained are adversely affected. The same applies to a weakening of the molding. Here, the mechanical properties at the weakened sites are unfavorable with the same result as mentioned above.

Advantageous mechanical properties are to be understood with regard to the imaginary applications. The application which is of primary importance for the subject of the present invention is the use in the shoe sector, wherein the particle foams can be used for shaped bodies for components of the shoe in which cushioning and / or padding is relevant, such as e.g. Midsoles and inserts.

Thus, for the abovementioned applications in the shoe or sports shoe sector, there is a need not only to obtain advantageous tensile and flexural properties of the shaped bodies produced from the particle foams, but also to be able to produce shaped bodies which have the advantageous resilience and compression properties in a possible application. As low as possible. Density and compression properties are Conversely, because the compression property is a measure of the minimum achievable density in a molded part around the requirements of the application.

Thus, a shaped particle of foam with low compression properties fundamentally a higher density and thus more material than a molded body of foam particles with high compression properties in order to genrieren at the end similar properties. The applicability of a particle foam for specific applications is also given by this connection. For applications in the shoe sector, in particular particle foams are advantageous in which the compression properties of the molded articles produced from the particle foams are rather low with little force, and in the region in which the shoe is worn have a deformation which is sufficient for the wearer.

A further problem is that in the case of large-scale production of particle foam via extrusion, the highest possible throughput of material is desirable in order to produce the required quantities in as short a time as possible. However, too fast processing of the material into inferior material leads to instability and / or collapse of the obtained particle foams. Accordingly, there is still a need to provide particle foams in which the production time is as low as possible.

It was therefore an object of the present invention to provide correspondingly suitable particle foams.

The object was achieved by the provision of particle foam comprising a composition (Z) comprising

a) 60-90% by weight of thermoplastic polyurethane as component I.

b) 10 to 40% by weight of polypropylene as components II,

wherein the sum of components I and II is 100% by weight.

The thermoplastic polyurethanes used as component I are well known. The preparation is carried out by reacting (a) isocyanates with (b) isocyanate-reactive compounds, for example polyols, having a number-average molecular weight of 500 g / mol to 100,000 g / mol (b1) and optionally chain extenders having a molecular weight of 50 g / mol to 499 g / mol (b2), if appropriate in the presence of (c) catalysts and / or (d) customary auxiliaries and / or additives.

For the purposes of the present invention, thermoplastic polyurethanes are obtainable by reacting (a) isocyanates with (b) compounds which are reactive towards isocyanates, for example polyols (b1) having a number-average molecular weight of from 500 g / mol to 100,000 g / mol and one Chain extender (b2) having a molecular weight of from 50 g / mol to 499 g / mol, if appropriate in the presence of (c) catalysts and / or (d) customary auxiliaries and / or additives. The components (a) isocyanate, (b) compounds which are reactive toward isocyanates, for example polyols (b1), and optionally chain extenders (b2) are also mentioned individually or together as synthesis components. The synthesis components, including the catalyst and / or the customary auxiliaries and / or additives, are also called starting materials.

To adjust the hardness and melt index of the thermoplastic polyurethanes, the amounts used of the synthesis components (b) can be varied in their molar ratios, the hardness and the melt viscosity increasing with increasing content of chain extender in the component (b), while Melt index decreases with a constant molecular weight of the TPU.

To prepare the thermoplastic polyurethanes, the synthesis components (a), (b), where (b) in a preferred embodiment also contains chain extenders, in the presence of a catalyst (c) and optionally auxiliaries and / or additives in such quantities Reaction brought that the equivalence ratio of NCO groups of the diisocyanates (a) to the sum of the hydroxyl groups of component b) in the range of 1 to 0.8 to 1 to 1.3.

Another size that describes this ratio is the metric. The index is defined by the ratio of the total of the isocyanate groups used in the reaction to the isocyanate-reactive groups, ie in particular the reactive groups of the polyol component and the chain extender. With a figure of 1000, an isocyanate group has an active hydrogen atom. For ratios above 1000, more isocyanate groups exist than isocyanate-reactive groups.

Here, an equivalence ratio of 1 to 0.8 corresponds to a ratio of 1250 (KZ 1000 = 1 to 1) and a ratio of 1 to 1, 3 of a ratio of 770.

In a preferred embodiment, the ratio in the reaction of the abovementioned components is in the range from 965 to 1110, preferably in the range from 970 to 110, more preferably in the range from 980 to 1030 and very particularly preferably in the range from 985 to 1010 particularly preferred.

According to the invention, thermoplastic polyurethanes are preferably prepared in which the thermoplastic polyurethane has a weight-average molecular weight (M _w ) of at least 60,000 g / mol, preferably of at least 80,000 g / mol and in particular greater than 100,000 g / mol. The upper limit for the weight-average molecular weight of the thermoplastic polyurethanes is generally determined by the processability as well as the desired property spectrum. The number-average molecular weight of the thermoplastic polyurethanes is preferably between 80,000 and 300,000 g / mol. The average molecular weights stated above for the thermoplastic polyurethane as well as for the synthesis components (a) and (b) are the weight average determined by means of gel permeation chromatography (eg according to DIN 55672-1, March 2016 or analogous). As organic isocyanates (a) it is possible to use aliphatic, cycloaliphatic, araliphatic and / or aromatic isocyanates.

The aliphatic diisocyanates used are customary aliphatic and / or cycloaliphatic diisocyanates, for example tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene-1,5-diisocyanate, 2-ethyltetramethylene 1, 4-diisocyanate, hexamethylene-1,6-diisocyanate (HDI), pentamethylene-1,5-diisocyanate, butylene-1,4-diisocyanate, trimethylhexamethylene-1,6-diisocyanate, 1-isocyanato 3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1, 4- and / or 1, 3-bis (isocyanatomethyl) cyclohexane (HXDI), 1, 4-cyclohexane diisocyanate, 1-methyl 2,4-and / or 1-methyl-2,6-cyclohexane diisocyanate, 4,4'-, 2,4'- and / or 2,2'-methylenedicyclohexyl diisocyanate (H12MDI).

Suitable aromatic diisocyanates are, in particular, 1,5-naphthylene diisocyanate (NDI), 2,4- and / or 2,6-toluene diisocyanate (TDI), 3,3'-dimethyl-4,4'-diisocyanato-diphenyl (TODI), p-phenylene diisocyanate (PDI), diphenylethane-4,4'-diisoyanate (EDI), methylene diphenyl diisocyanate (MDI), where the term MDI denotes 2,2'-, 2,4'- and / or 4,4'-diphenylmethane diisocyanate. 3,3'-dimethyl-diphenyl-diisocyanate, 1, 2-diphenylethane diisocyanate and / or phenyl diisocyanate or H12MDI (4,4'-methylene dicyclohexyl diisocyanate).

In principle, mixtures can also be used. Examples of mixtures are mixtures which contain, in addition to 4,4'-methylene diphenyl diisocyanate and at least one further methylene diphenyl diisocyanate. Here, the term methylene diphenyl diisocyanate denotes 2,2'-, 2,4'- and / or 4,4'-diphenylmethane diisocyanate or a mixture of two or three isomers. Thus, e.g. be used as a further isocyanate 2,2'- or 2,4'-diphenylmethane diisocyanate or a mixture of two or three isomers. In this embodiment, the polyisocyanate composition may also contain further, the above-mentioned polyisocyanates.

Further examples of mixtures are containing polyisocyanate compositions

4,4-MDI and 2,4-MDI, or

4,4'-MDI and 3,3'-dimethyl-4,4'-diisocyanato-diphenyl (TODI) or

4,4'-MDI and H12MDI (4,4'-methylene dicyclohexyl diisocyanate or

4,4'-MDI and TDI; or

4,4'-MDI and 1,5-naphthylene diisocyanate (NDI).

According to the invention, it is also possible to use three or more isocyanates. Usually, the polyisocyanate composition contains 4,4'-MDI in an amount of 2 to 50% based on the total polyisocyanate composition and the other isocyanate in an amount of 3 to 20% based on the total polyisocyanate composition.

It is also possible to use crosslinkers, for example the above-mentioned higher-functional polyisocyanates or polyols, or also other higher-functional molecules having a plurality of isocyanate-reactive functional groups. Likewise, it is possible in the context of the present invention, a cross-linking of the products by an excess of used isocyanate groups relative to the hydroxyl groups. Examples of higher functionality isocyanates are triisocyanates, e.g. B. triphenylmethane-4,4 ', 4 "-triisocyant and isocyanurates, furthermore the cyanurates of the aforementioned diisocyanates, as well as the oligomers obtainable by partial reaction of diisocyanates with water, for example the biurets of the abovementioned diisocyanates, furthermore oligomers obtained by targeted implementation of semiblocked diisocyanates with polyols having an average of more than two and preferably three or more hydroxy groups are available.

Here, the amount of crosslinker, i. higher-functionality isocyanates and higher-functional polyols (b) not exceeding 3% by weight, preferably 1% by weight, based on the total mixture of components (a) to (d).

Furthermore, the polyisocyanate composition may also contain one or more solvents. Suitable solvents are known to the person skilled in the art. Suitable examples are non-reactive solvents such as ethyl acetate, methyl ethyl ketone and hydrocarbons.

Preferred isocyanate-reactive compounds (b1) are those having a molecular weight between 500 g / mol and 8000 g / mol, more preferably 500 g / mol to 5000 g / mol, in particular 500 g / mol to 3000 g / mol.

The isocyanate-reactive compound (b) has on statistical average at least 1, 8 and at most 2.2, preferably 2, Zerewitinow active hydrogen atoms, this number is also referred to as functionality of the isocyanate-reactive compound (b) and gives the amount of a substance theoretically reduced to a molecule amount of the isocyanate-reactive groups of the molecule.

The isocyanate-reactive compound is preferably substantially linear and is an isocyanate-reactive substance or a mixture of various substances, in which case the mixture satisfies the said requirement.

The ratio of components b1) and b2) is varied so that the desired hard segment content is obtained, which can be calculated according to the formula disclosed in PCT / EP2017 / 079049.

In this case, a hard segment content of less than 60%, preferably less than 40%, particularly preferably less than 25% is suitable.

The isocyanate-reactive compound (b1) preferably has a reactive group selected from the hydroxyl group, the amino group, the mercapto group or the carboxylic acid group. It is preferably the hydroxyl group and very particularly preferably primary hydroxyl groups. The isocyanate-reactive compound (b) is particularly preferably selected from the group of the polyester oil, the polyether oil or the polycarbonate diols, which are also combined under the term "polyols". According to the invention, homopolymers such as, for example, polyether oil are suitable, polyester oxide, polycarbonate (diol) s, polysiloxane diols, polybutadiene diols, but also block copolymers and hybrid polyols such as poly (ester / amide). According to the invention, preferred polyetheroils are polyethylene glycols, polypropylene glycols, polytetramethylene glycol (PTHF), polytrimethylene glycol. Preferred polyester polyols are polyadipates, polysuccinic acid esters and polycaprolactones.

According to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the polyol composition contains a polyol selected from the group consisting of polyether oils, polyester oils, polycaprolactones and polycarbonates.

Suitable block copolymers are, for example, those which have ethers and ester blocks, for example polycaprolactone with polyethylene oxide or polypropylene oxide end blocks or polyethers with polycaprolactone end blocks. Polyetheroic preferred are polyethyleneglycols according to the invention, polypropylene glycols, polytetramethylene glycol (PTHF) and Polytri methylenglykol. Further preferred is polycaprolactone.

According to a particularly preferred embodiment, the polyol used has a molecular weight Mn in the range from 500 g / mol to 4000 g / mol, preferably in the range from 500 g / mol to 3000 g / mol.

Accordingly, according to another embodiment, the present invention relates to a thermoplastic polyurethane as described above, wherein at least one polyol contained in the polyol composition has a molecular weight Mn in the range of 500 g / mol to 4000 g / mol.

According to the invention, it is also possible to use mixtures of different polyols.

According to one embodiment of the present invention, at least one polyol composition containing at least polytetrahydrofuran is used to prepare the thermoplastic polyurethane. According to the invention, the polyol composition in addition to polytetrahydrofuran also contain other polyols.

According to the invention, for example, polyethers are suitable as further polyols, but also polyesters, block copolymers and hybrid polyols, such as, for example, polyesters. Poly (ester / amide). Suitable block copolymers are, for example, those which have ethers and ester blocks, for example polycaprolactone with polyethylene oxide or polypropylene oxide end blocks or also polyethers with polycaprolactone end blocks. Preferred polyetheroie are according to the invention polyethylene eneglycols, polypropylene glycols. Further preferred polycaprolactone is another polyol.

Suitable polyols are, for example, polyethers, such as polytrimethylene oxide or polytetramethylene oxide. Accordingly, the present invention according to another embodiment relates to a thermoplastic polyurethane as described above, wherein the polyol composition at least one polytetrahydrofuran and at least one further polyol selected from the group consisting of a further polytetramethylene oxide (PTHF), polyethylene glycol, polypropylene glycol and Contains polycaprolactone.

According to a particularly preferred embodiment, the polytetrahydrofuran has a number average molecular weight Mn in the range of 500 g / mol to 5000 g / mol, more preferably in the range of 550 to 2500 g / mol, particularly preferably in the range of 650 to 2000 g / mol and most preferably in the range of 650 to 1400 g / mol.

The composition of the polyol composition can vary widely within the scope of the present invention. For example, the content of the first polyol, preferably polytetrahydrofuran, can be in the range of 15% to 85%, preferably in the range of 20% to 80%, more preferably in the range of 25% to 75%.

According to the invention, the polyol composition may also contain a solvent. Suitable solvents are known per se to the person skilled in the art.

If polytetrahydrofuran is used, the number average molecular weight Mn of the polytetrahydrofuran is, for example, in the range from 500 g / mol to 5000 g / mol, preferably in the range from 500 to 3000 g / mol. More preferably, the number average molecular weight Mn of the polytetrahydrofuran is in the range of 500 to 1400 g / mol.

In this case, the number-average molecular weight Mn can be determined via gel permeation chromatography as mentioned above.

According to a further embodiment, the present invention also relates to a thermoplastic polyurethane as described above, wherein the polyol composition selected from the group consisting of polytetrahydrofurans having a number average molecular weight Mn in the range of 500 g / mol to 5000 g / contains mol.

It is also possible according to the invention to use mixtures of different polytetrahydrofurans, i. Mixtures of polytetrahydrofurans with different molecular weights.

The chain extenders (b2) used are preferably aliphatic, araliphatic, aromatic and / or cycloaliphatic compounds having a molecular weight of from 50 g / mol to 499 g / mol, preferably with 2 isocyanate-reactive compounds, which are also referred to as functional groups. Preferred chain extenders are diamines and / or alkanediols, more preferably alkanediols having 2 to 10 carbon atoms, preferably 3 to

8 carbon atoms in the alkylene radical, which more preferably have only primary hydroxyl groups. In preferred embodiments, chain extenders (c) are used, these are preferably aliphatic, araliphatic, aromatic and / or cycloaliphatic compounds having a molecular weight of 50 g / mol to 499 g / mol, preferably with 2 isocyanate-reactive groups, which are also functional groups be designated. The chain extender is preferably at least one chain extender selected from the group consisting of 1, 2-ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 4-butanediol, 2,3-butanediol, 1, 5-pentanediol , 1, 6-hexanediol, diethylene glycol, dipropylene glycol, 1, 4-cyclohexanediol, 1, 4-dimethanolcyclohexane, neopentyl glycol and hydroquinone bis (beta-hydroxyethyl) ether (HQEE). Particularly suitable are chain extenders selected from the group consisting of 1, 2-ethanediol, 1, 3-propanediol, 1, 4-butanediol and 1, 6-hexanediol and mixtures of the above-mentioned chain extenders. Examples of specific chain extenders and mixtures are disclosed, inter alia, in PCT / EP2017 / 079049

In preferred embodiments, catalysts (c) are used with the synthesis components. These are in particular catalysts which accelerate the reaction between the NCO groups of the isocyanates (a) and the hydroxyl groups of the isocyanate-reactive compound (b) and, when used, the chain extender.

Further suitable catalysts are, for example, organic metal compounds selected from the group consisting of tin, titanium, zirconium, hafnium, bismuth, zinc, aluminum and iron organyls, such as tin organyl compounds, preferably tin dialkyls such as dimethyltin or diethyltin or tin organyl compounds of aliphatic carboxylic acids, preferably tin diacetate, tin dilaurate, dibutyltin diacetate, dibutyltin dilaurate, bismuth compounds such as bismuth-alkyl compounds or the like, or iron compounds, preferably iron (MI) acetylacetonate or the metal salts of the carboxylic acids such as Tin isooctoate, tin dioctoate, titanic acid ester or bismuth (III) neodecanoate. Particularly preferred catalysts are tin dioctoate, bismuth decanoate and titanic acid esters. The catalyst (d) is preferably used in amounts of from 0.0001 to 0.1 parts by weight per 100 parts by weight of the isocyanate-reactive compound (b). In addition to catalysts (c), conventional auxiliaries (d) can also be added to the synthesis components (a) to (b). Mention may be made, for example, of surface-active substances, fillers, flame retardants, nucleating agents, oxidation stabilizers, lubricants and mold release agents, dyes and pigments, optionally stabilizers, preferably against hydrolysis, light, heat or discoloration, inorganic and / or organic fillers, reinforcing agents and / or plasticizer.

Suitable dyes and pigments are listed below.

Stabilizers in the context of the present invention are additives which protect a plastic or a plastic mixture against harmful environmental influences. Examples include primary and secondary antioxidants, hindered phenols, hindered amine light stabilizers, UV absorbers, hydrolysis inhibitors, quenchers and flame retardants. Examples of commercial stabilizers are given in Plastics Additives Handbook, 5th Edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001 ([1]), p.98-S136. The preparation of the thermoplastic polyurethanes can be carried out according to the known methods dis- continuously or continuously, for example with reaction extruders or the tape method according to the "one-shot" - or the prepolymer process, preferably by the "one-shot" - method. In the "one-shot" process, the components (a), (b) reacting, in preferred embodiments, also the chain extender in component (b), (c) and / or (d) successively or simultaneously mixed together, the polymerization reaction starts immediately. The TPU can then be directly granulated or convoluted by extrusion into lens granules. In this step, it is possible to include further additives or other polymers.

In the extruder process, the synthesis components (a), (b) and, in preferred embodiments, also (c), (d) and / or (e) are introduced into the extruder individually or as a mixture and, preferably, at temperatures of from 100.degree 280 ° C, preferably 140 ° C to 250 ° C, reacted. The resulting polyurethane is extruded, cooled and granulated or granulated directly via an underwater granulation as lens granules.

In a preferred process, a thermoplastic polyurethane is prepared in a first step from the synthesis components isocanate (a), isocyanate-reactive compound (b) including chain extenders and in preferred embodiments the other starting materials (c) and / or (d) and in a second Extrusion step incorporated the additives or excipients.

Preferably, a twin-screw extruder is used, since the twin-screw extruder works positively conveying and so a more precise adjustment of the temperature and discharge rate is possible on the extruder. Furthermore, the production and expansion of a TPU can be carried out in a reaction extruder in one step or via a tandem extruder according to methods known to the person skilled in the art.

By the polyolefins mentioned as component II is meant homopolypropylene.

Suitable are polyolefins prepared both with Ziegler and with metallocene catalysts.

The crystallite melting point (DIN EN ISO 1 1357-1 / 3, February 2017 / April 2013, W peak melting temperature) of the polyolefins which can be used according to the invention is generally between 90 and 170.degree.

According to the invention, conventional products can also be used, such as moplen

HP400H, Moplen HP2636, Moplen HP2619, Moplen HP501L, Daploy WB135HMS, Daploy WB140HMS or SABIC® PP48M10.

As stated above, the composition comprises Z

10 to 40% by weight of polypropylene as components II,

wherein the sum of components I and II is 100% by weight. Preferably, the composition comprises Z

65-80% by weight of thermoplastic polyurethane as component I

20-35% by weight of polypropylene as components II,

wherein the sum of components I and II is 100% by weight.

Most preferably, the composition comprises Z

70-80% by weight of thermoplastic polyurethane as component I

20-30% by weight of polypropylene as components II,

wherein the sum of components I and II is 100% by weight.

The non-expanded starting material, the composition Z, required for the production of the particle foam is prepared in a manner known per se from the individual thermoplastic elastomers (TPE-1) and (TPE-2) and optionally further components. Suitable methods are, for example, customary mixing methods in a kneader or an extruder.

The unexpanded polymer mixture of composition Z required for the preparation of the particle foam is prepared in a known manner from the individual components and, if appropriate, other components such as processing aids, stabilizers, compatibilizers or pigments. Suitable processes are, for example, customary mixing processes with the aid of a kneader, continuous or discontinuous, or an extruder, such as a co-rotating twin-screw extruder.

In the case of compatibilizers or auxiliaries such as stabilizers, these can also be incorporated in the preparation of the components in this already. Usually, the individual components are combined before the mixing process or metered into the apparatus which takes over the mixing. In the case of an extruder, the components are all dosed into the feeder and conveyed together into the extruder or individual components added via a side dosing (usually not for foams as this part of the extruder is not tight).

Processing takes place at a temperature at which the components are in a plasticized state. The temperature depends on the softening or melting ranges of the components, but must be below the decomposition temperature of each component. Additives such as pigments or fillers or further of the abovementioned customary auxiliaries (d) are not melted, but incorporated in the solid state.

In this case, further embodiments are possible by conventional methods, wherein the processes used in the preparation of the starting materials can be included directly in the production. For example, in the case of the belt process, directly at the end of the belt, where the material is fed into an extruder to obtain lens granules, it would be possible to incorporate the second elastomer (TPE-2) and fillers or dyes. In this step, some of the above conventional additives (d) may be added to the mixture.

The particle foams according to the invention generally have a bulk density of from 50 g / l to 200 g / l, preferably from 60 g / l to 180 g / l, particularly preferably from 80 g / l to 150 g / l. The bulk density is measured analogously to DIN ISO 697, whereby a vessel with 10 l volume is used instead of a vessel with 0.5 l volume in the determination of the above values, in contrast to the standard, since especially for the foam particles with lower Dense and large mass a measurement with only 0.5 l volume is too inaccurate.

As stated above, the diameter of the particle foams is between 0.5 to 30; preferably 1 to 15 and especially between 3 to 12 mm. For non-spherical, e.g. elongated or cylindrical particle foam is meant by diameter the longest dimension:

The production of the particle foams can be carried out by the usual methods known in the prior art

i. Providing a composition (Z) according to the invention;

ii. Impregnating the composition with a propellant under pressure;

iii. Expand the composition by means of pressure drop.

The amount of blowing agent is preferably 0.1 to 40, in particular 0.5 to 35 and particularly preferably 1 to 30 parts by weight, based on 100 parts by weight of the amount of the composition (Z) used.

An embodiment of the above method comprises

i. Providing a composition (Z) according to the invention in the form of a granule;

ii. Impregnation of the granules with a propellant under pressure;

iii. Expand the granules by means of pressure drop.

Another embodiment of the above method comprises a further step: i. Providing a composition (Z) according to the invention in the form of a granule;

ii. Impregnation of the granules with a propellant under pressure;

iii. Reducing the pressure to normal pressure without foaming the granules, if necessary by prior reduction of the temperature

iv. Foaming of the granules by a temperature increase.

In this case, the granulate preferably has an average minimum diameter of 0.2-10 mm (determined via 3D evaluation of the granulate, for example via dynamic image analysis with the use of an optical measuring apparatus named PartAn 3D from Microtrac).

The individual granules generally have an average mass in the range from 0.1 to 50 mg, preferably in the range from 4 to 40 mg and more preferably in the range from 7 to 32 mg. This average mass of the granules (particle weight) is determined as an arithmetic mean by weighing 3 times each of 10 granular particles.

An embodiment of the above method comprises impregnating the granules with a propellant under pressure and then expanding the granules in step (ii) and (iii): ii. Impregnation of the granules in the presence of a propellant under pressure at elevated temperatures in a suitable closed reaction vessel (for example autoclave)

iii. sudden relaxation without cooling.

In this case, the impregnation in step ii) can be carried out in the presence in the presence of water and optional suspension aids or only in the presence of the blowing agent and the absence of water.

Suitable suspension aids are e.g. water-insoluble inorganic stabilizers, such as tricalcium phosphate, magnesium pyrophosphate, metal carbonates; also polyvinyl alcohol and surfactants such as sodium dodecylarylsulfonate. They are usually used in amounts of 0.05 to 10 wt .-%, based on the composition of the invention.

The impregnation temperatures are in the range of 100-200 ° C., depending on the selected pressure, the pressure in the reaction vessel being between 2 and 150 bar, preferably between 5 and 100 bar, particularly preferably between 20 and 60 bar, the duration of impregnation. generally takes 0.5 to 10 hours.

The performance of the process in suspension is known to those skilled in the art and e.g. described in detail in W02007 / 082838.

When carrying out the process in the absence of the blowing agent, it must be ensured that the aggregation of the polymer granulate is avoided.

Suitable propellants for carrying out the process in a suitable closed reaction vessel are e.g. organic liquids and gases which are in a gaseous state in the processing conditions, such as hydrocarbons or inorganic gases, or mixtures of organic liquids or gases and inorganic gases, which may also be combined.

Suitable hydrocarbons are, for example, halogenated or non-halogenated, saturated or unsaturated aliphatic hydrocarbons, preferably non-halogenated, saturated or unsaturated aliphatic hydrocarbons. Preferred organic blowing agents are saturated, aliphatic hydrocarbons, especially those having 3 to 8 carbon atoms, such as butane or pentane. Suitable inorganic gases are nitrogen, air, ammonia or carbon dioxide, preferably nitrogen or carbon dioxide or mixtures of the abovementioned gases.

In a further embodiment, the impregnation of the granules with a blowing agent under pressure comprises processes and subsequent expansion of the granules in step (ii) and (iii):

ii. Impregnation of the granules in the presence of a blowing agent under pressure at elevated temperatures in an extruder

iii. Granulation of the mass exiting the extruder under conditions which prevent uncontrolled foaming:

Suitable blowing agents in this process variant are volatile organic compounds having a boiling point at atmospheric pressure of 1013 mbar 35 from -25 to 150, in particular -10 to 125 ° C. Very suitable are hydrocarbons (preferably halogen-free), in particular C 4 -C 10 -alkanes, for example the isomers of butane, pentane, hexane, heptane and octane, particularly preferably iso-pentane. Further possible blowing agents are also sterically more demanding compounds such as alcohols, ketones, esters, ethers and organic carbonates.

Here, the composition in step (ii) is melt-blended in an extruder with the blowing agent under pressure, which is fed to the extruder. The propellant-containing mixture is squeezed out under pressure, preferably with moderately controlled back pressure (for example, underwater granulation) and granulated. In this case, the melt strand foams and granules give the particle foams.

The implementation of the process via extrusion is known to the person skilled in the art and e.g. described in detail in WO02007 / 082838 and WO 2013/153190 A1.

Suitable extruders are all conventional screw machines, in particular single-screw and twin-screw extruders (eg type ZSK from Werner & Pfleiderer), co-kneaders, Kombiplast machines, MPC kneading mixers, FCM mixers, KEX kneading screw extruders and shear roller extruders, as they eg in Saechtling (ed.), plastic paperback, 27th edition, Hanser-Verlag Munich 1998, chap. 3.2.1 and 3.2.4 are described. The extruder is usually operated at a temperature at which the composition (Z1) is in the form of a melt, for example at 120 ° C. to 250 ° C., in particular 150 to 210 ° C. and a pressure after the addition of the blowing agent of 40 to 200 bar, preferably 60 to 150 bar, more preferably 80 to 120 bar to ensure homogenization of the blowing agent with the melt.

Here, the implementation can be carried out in an extruder or an arrangement of one or more extruders. For example, in a first extruder, the components can be melted and blended, and a propellant injected. In the second extruder, the impregnated melt is homogenized and the temperature and / or the pressure are adjusted. For example, if three extruders are combined with each other, the see the components and the injection of the propellant are divided into two different process parts. If, as preferred, only one extruder is used, then all process steps, melting, mixing, injection of the blowing agent, homogenization and adjustment of the temperature and / or the pressure in an extruder are carried out.

Alternatively, according to the methods described in WO2014150122 or WO2014150124 A1, the corresponding, possibly even already colored, particle foam can be produced directly by impregnating the corresponding granulate with a supercritical fluid, from which the supercritical fluid is removed from

(i) immersing the article in a heated fluid or

(ii) irradiating the article with energetic radiation (e.g., infrared or microwave irradiation).

Suitable supercritical fluids are e.g. those described in WO2014150122 or described e.g. Carbon dioxide, nitrogen dioxide, ethane, ethylene, oxygen or nitrogen, preferably carbon dioxide or nitrogen.

The supercritical fluid may also contain a polar fluid having a Hildebrand solubility parameter equal to or greater than 9 MPa-1/2.

Here, the supercritical fluid or the heated fluid may also contain a dye, whereby a dyed, foamed article is obtained.

Another object of the present invention is a molded article produced from the particle foams according to the invention.

The corresponding shaped bodies can be produced by methods known to the person skilled in the art.

A preferred method for producing a foam molding comprises the following steps:

(i) introducing the particle foams according to the invention in a corresponding form,

(ii) fusing the particle foams of step (i) according to the invention.

The fusion in step (ii) is preferably carried out in a closed form, wherein the fusion can be effected by steam, hot air (as described for example in EP1979401 B1) or energetic radiation (microwaves or radio waves).

The temperature at the fusing of the particle foam is preferably below or close to the melting temperature of the polymer from which the particle foam was made. Accordingly, the temperature for fusing the particle foam is between 100 ° C. and 180 ° C., preferably between 120 and 150 ° C., for the customary polymers. In this case, temperature profiles / residence times can be determined individually, for example in analogy to the methods described in US20150337102 or EP2872309B1.

The welding via energetic radiation generally takes place in the frequency range of microwaves or radio waves, if appropriate in the presence of water or other polar liquids, such as e.g. polar group-containing microwave-absorbing hydrocarbons (such as esters of carboxylic acids and diols or triols or glycols and liquid polyethylene eneglycols) and can be carried out in analogy to the processes described in EP3053732A or WO16146537.

For welding with high-frequency electromagnetic radiation, the particle foams can preferably be wetted with a polar liquid which is suitable for absorbing the radiation, for example in proportions of from 0.1 to 10% by weight, preferably in fractions of from 1 to 6 wt .-%, based on the particle foams used. The welding with high-frequency electromagnetic radiation of the particle foams can also be achieved in the context of the present invention without the use of a polar liquid. The thermal bonding of the foam particles takes place, for example, in a mold by means of high-frequency electromagnetic radiation, in particular by means of microwaves. High-frequency is understood to mean electromagnetic radiation with frequencies of at least 20 MHz, for example of at least 100 MHz. As a rule, electromagnetic radiation is used in the frequency range between 20 MHz and 300 GHz, for example between 100 MHz and 300 GHz. Preference is given to using microwaves in the frequency range between 0.5 and 100 GHz, more preferably 0.8 to 10 GHz, and irradiation times of between 0.1 to 15 minutes. Preferably, the frequency range of the microwave is adapted to the absorption behavior of the polar liquid or, conversely, the polar liquid is selected on the basis of the absorption behavior in accordance with the frequency range of the microwave device used. Suitable methods are described, for example, in WO 2016 / 146537A1.

As stated above, the particle foam may also contain dyes. In this case, the addition of dyes can take place via different routes.

In one embodiment, the produced particle foams can be colored after production. In this case, the corresponding particle foams are contacted with a carrier liquid containing a dye, the carrier liquid (TF) having a polarity which is suitable for sorption of the carrier liquid into the particle foam. The procedure can be carried out in analogy to the methods described in the EP application with the application number 17198591.4.

Suitable dyes are, for example, inorganic or organic pigments. Suitable natural or synthetic inorganic pigments are, for example, carbon black, graphite, titanium oxides, iron oxides, zirconium oxides, cobalt oxide compounds, chromium oxide compounds, copper oxide compounds. Suitable organic pigments are, for example, azo pigments and polycyclic pigments. In a further embodiment, the color may be added in the production of the particle foam. For example, in the production of the particulate foam, the dye may be added to the extruder via extrusion.

Alternatively, already dyed material can be used as the starting material for the production of the particle foam, which is extruded or expanded in a closed vessel according to the above-mentioned method.

Further, in the method described in WO2014150122, the supercritical fluid or the heated fluid may contain a dye.

As stated above, the molded parts according to the invention have advantageous properties for the abovementioned applications in the shoe or sports shoe sector.

Here, the tensile and compression properties of the moldings produced from the particle foams are characterized in that the tensile strength is above 600 kPa (DIN EN ISO 1798, April 2008), the elongation at break is above 100% (DIN EN ISO 1798, April 2008 ) and the compressive stress is above 15 kPa at 10% compression (analogous to DIN EN ISO 844, November 2014, the deviation from the standard is the height of the sample at 20 mm instead of 50 mm and thus the adaptation of the test speed to 2 mm / min).

The rebound resilience of the moldings produced from the particle foams is above 55% (analogous to DIN 53512, April 2000, the deviation from the standard is the test piece height, which should be 12 mm, but in this test is carried out at 20 mm). beat "the sample and avoid measuring the ground).

As stated above, the density and compression properties of the molded bodies produced are related. Advantageously, the density of the molded parts produced is between 75 and 375 kg / m ³ , preferably between 100 and 300 kg / m ³ , particularly preferably between 150 and 200 kg / m ³ (DIN EN ISO 845, October 2009).

The ratio of the density of the molding to the bulk density of the particle foams of the invention is generally between 1, 5 and 2.5, preferably from 1.8 to 2.0.

The invention furthermore relates to the use of a particle foam according to the invention for the production of a shaped body for shoe midsoles, shoe insoles, shoe combination soles, bicycle saddles, bicycle tires, damping elements, upholstery, mattresses, underlays, handles, protective films, in components in the automotive interior and exterior, in balls and sports equipment or as a floor covering, in particular for sports surfaces, athletics tracks, sports halls, children's playgrounds and sidewalks. Preference is given to the use of a particle foam according to the invention for the production of a shaped body for shoe midsoles, shoe insoles, shoe combination soles or upholstery element for shoes. Here, the shoe is preferably a street shoe, sports shoe, sandal, boots or safety shoe, particularly preferably a sports shoe.

A further subject matter of the present invention is therefore also a molded article, wherein the molded article is a shoe combination sole for shoes, preferably for street shoes, sports shoes, sandals, boots or safety shoes, particularly preferably sports shoes.

Another object of the present invention is therefore also a molded article, wherein the molded article is a midsole for shoes, preferably for street shoes, sports shoes, sandal, boots or safety shoes, particularly preferably sports shoes.

Accordingly, a further subject matter of the present invention is also a shaped body, wherein the shaped body is an insert for shoes, preferably for street shoes, sports shoes, sandals, boots or safety shoes, particularly preferably sports shoes.

Accordingly, a further subject matter of the present invention is also a shaped body, wherein the shaped body is a padding element for shoes, preferably for street shoes, sports shoes, sandals, boots or safety shoes, particularly preferably sports shoes.

Here, the cushioning element may be e.g. Heel area or forefoot area can be used. A further subject of the present invention is therefore also a shoe in which the shaped article according to the invention is used as midsole, midsole or padding in the e.g. Heel area, forefoot area is used, wherein the shoe is preferably a street shoe, sports shoe, sandal, boots or safety shoe, particularly preferably a sports shoe.

Listed below are exemplary embodiments of the present invention, which are not limitative of the present invention. In particular, the present invention also encompasses those embodiments which result from the back references given below and thus combinations:

1. Particle foam comprising a composition (Z) comprising

a) 60-90% by weight of thermoplastic polyurethane as component I.

b) 10 to 40% by weight of polypropylene as components II,

wherein the sum of components I and II is 100% by weight.

2. Particle foam according to claim 1, comprising

a) 65-80% by weight of thermoplastic polyurethane as component I

b) 20-35% by weight of polypropylene as components II,

wherein the sum of components I and II is 100% by weight.

3. Particle foam according to embodiment 1, comprising a) 70-80% by weight of thermoplastic polyurethane as component I b) 20-30% by weight of polypropylene as component II,

wherein the sum of components I and II is 100% by weight.

4. Particle foam according to one of embodiments 1 to 3, wherein the average diameter of the particle foams is 0.2 to 20.

5. Particle foam according to one of embodiments 1 to 3, wherein the average diameter of the particle foams is between 0.5 to 15 mm.

6. Particle foam according to one of embodiments 1 to 3, wherein the average diameter of the particle foams is between 1 to 12 mm.

7. A method for producing a shaped body of particle foams according to one of the embodiments 1 to 6, comprising

i. Providing a composition (Z) according to the invention;

ii. Impregnating the composition with a propellant under pressure;

iii. Expand the composition by means of pressure drop.

8. Moldings of particle foam according to one of the embodiments 1 to 6.

9. molded body made of particle foam according to one of the embodiments 1 to 6, characterized in that the tensile strength of the molding is above 600 kPa.

10. Shaped body according to embodiment 8 or 9, characterized in that the elongation at break is more than 100%.

1 1. Shaped body according to embodiment 8, 9 or 10, characterized in that the

Compressive stress at 10% compression above 15 kPa.

12. Shaped body according to one of the embodiments 8 to 1 1, characterized in that the density of the shaped body is between 75 to 375 kg / m ³ .

13. Shaped body according to one of embodiments 8 to 12, characterized in that the density of the shaped body is between 100 to 300 kg / m ³ .

14. Shaped body according to one of embodiments 8 to 13, characterized in that the density of the shaped body is between 150 to 200 kg / m ³ .

15. Shaped body according to one of the embodiments 8 to 14, characterized in that the rebound resilience of the shaped body is above 55%. 16. Shaped body according to one of the embodiments 8 to 15, characterized in that the ratio of the density of the molded part to the bulk density of the particle showers is between 1, 5 and 2.5.

17 molded particle foam body according to one of the embodiments 8 to 16, characterized in that the ratio of the density of the molding to the bulk density of the particle showers is between 1.8 to 2.0.

18. Shaped body according to one of the embodiments 8 to 17, wherein the molded body is a midsole for shoes.

19. Shaped body according to one of the embodiments 8 to 17, wherein the shaped body is an insert for shoes.

20. Shaped body according to one of the embodiments 8 to 17, wherein the shaped body is a padding element for shoes.

21. A mold body according to any one of embodiments 8 to 17, wherein the shoe is a road shoe, sports shoe, sandal, boots or safety shoe.

22. Shaped body according to one of the embodiments 8 to 17, wherein the shoe is a sports shoe.

23. A method for producing a shaped article according to one of the embodiments 8 to 17 comprising

(i) introducing the particle foams into a corresponding shape,

(ii) fusing the particle foams from step (i).

24. The method according to claim 23, characterized in that the fusion in step (ii) takes place in a closed form.

25. The method according to claim 23 or 24, characterized in that the fusion in step (ii) takes place by means of steam, hot air or energy radiation.

26. Shoe comprising a shaped body according to one of the embodiments 8 to 17.

27. Shoe according to embodiment 26, characterized in that the shoe is a street shoe, sports shoe, sandal, boots or safety shoe.

28. Shoe according to embodiment 26, characterized in that the shoe is a sports shoe. Use of a particle foam according to one of embodiments 1 to 6 for the production of a molded article according to one of embodiments 8 to 17 for shoe insoles, shoe insoles, shoe combination soles, upholstery elements for shoes, bicycle saddles, bicycle tires, damping elements, upholstery, mattresses, pads, handles , Protective films, in automotive interior and exterior components, in balls and sports equipment or as a floor covering. Use according to embodiment 29 for shoe midsoles, shoe insoles, shoe combination soles, upholstery elements for shoes.

Use according to embodiment 30, wherein the shoe is a sports shoe.

Quoted literature

WO 94/20568 A1

WO 2007/082838 A1,

W02 017/030835 A1

WO 2013/153190 A1

WO 2010/010010 A1

PCT / EP2017 / 079049

Plastics Additives Handbook, 5th Edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001 ([1]), p.98-S136

Plastics Handbook Vol. 4, "Polystyrene", Becker / Braun (1996)

Saechtling (ed.), Plastic paperback, 27th edition, Hanser-Verlag Munich 1998, chapter 3.2.1 and 3.2.4

WO 2014/150122 A1

WO 2014/150124 A1

EP 1979401 B1

US 2015/0337102 A1

EP 2872309 B1

EP 3053732 A

WO 2016/146537 A1

Claims

claims

1. Particle foam comprising a composition (Z) comprising

a) 60-90% by weight of thermoplastic polyurethane as component I.

b) 10 to 40% by weight of polypropylene as components II,

wherein the sum of components I and II is 100% by weight.

2. Particle foam according to claim 1, comprising

a) 65-80% by weight of thermoplastic polyurethane as component I

b) 20-35% by weight of polypropylene as components II,

wherein the sum of components I and II is 100% by weight.

3. Particle foam according to one of claims 1 to 2, wherein the average diameter of the particle foams is between 0.2 and 20 mm.

4. A process for the production of a shaped body of particle foams according to one of claims 1 to 3, comprising

i. Providing a composition (Z) according to the invention;

ii. Impregnating the composition with a propellant under pressure;

iii. Expand the composition by means of pressure drop.

5. molded particle foam body according to one of claims 1 to 4.

6. Moldings of particle foam according to one of claims 1 to 4, characterized in that the tensile strength of the molding is above 600 kPa.

7. Shaped body according to claim 5 or 6, characterized in that the elongation at break is greater than 100%.

8. Shaped body according to claim 5, 6 or 7, characterized in that the compressive stress at 10% compression is above 15 kPa.

9. Shaped body according to one of claims 5 to 8, characterized in that the density of the shaped body is between 75 and 375 kg / m ³ .

10. Shaped body according to one of claims 5 to 9, characterized in that the rebound resilience of the shaped body is above 55%.

1 1. Shaped body according to one of claims 5 to 9, wherein the shaped body is an insole, a depositor or a padding element for shoes, wherein the shoe is a street shoe, sports shoe, sandal, boots or safety shoe.

12. A method for producing a shaped article according to one of claims 5 to 9 comprehensive send

(i) introducing the particle foams into a corresponding shape,

(ii) fusing the particle foams from step (i).

13. Shoe comprising a shaped body according to one of claims 5 to 9.

14. Use of a particle foam according to one of claims 1 to 3 or a Parti kelschaums obtained according to a method according to claim 4, for the manufacture of a molded article according to one of claims 5 to 9 for shoe midsoles, shoe insoles, shoe combination soles, upholstery elements for shoes , Bicycle saddles, bicycle tires, damping elements, upholstery, mattresses, underlays, handles, protective films, in automotive interior and exterior components, in balls and sports equipment or as a floor covering.

15. Use according to claim 14 for shoe midsoles, shoe insoles, shoe combination soles, upholstery elements for shoes.