High-elasticity thermoplastic polyurethanes and uses thereof

Abstract

The present disclosure relates to a thermoplastic polyurethane (TPU) composition comprising the TPU reaction product of: a polyisocyanate comprising a linear aliphatic diisocyanate having from 3 to 12 carbon atoms; a polyisocyanate comprising a linear aliphatic diisocyanate having from 3 to 12 carbon atoms; a polyol selected from the group consisting of polycaprolactone and polyester; and a linear or branched chain extender having a major backbone of from 4 to 16 carbon atoms and a hydroxyl group separated by at least two carbon atoms. The TPU of the present disclosure has a hard segment from 15% to 50% and an average vertical elasticity of at least 50% as measured according to ASTM D2632. The TPU of the present disclosure exhibits improved vertical elasticity and powder melting time, and has particular uses in the printing of three-dimensional (3D) articles.

Description

Technical Field

[0001] The present disclosure relates to a thermoplastic polyurethane (TPU) composition comprising a TPU reaction product of: a polyisocyanate comprising a linear aliphatic diisocyanate having 3 to 12 carbon atoms; a polyol selected from polycaprolactone and polyester; and a linear or branched chain extender having a main backbone of 4 to 16 carbon atoms and hydroxyl groups separated by at least two carbon atoms. The TPU of the present disclosure has 15% to 50% hard segments and at least 50% average vertical elasticity as measured by ASTM D2632. The TPU of the present disclosure can exhibit improved vertical elasticity and powder melt time and has a particular use in the printing of three-dimensional (3D) articles. Background Art

[0002] The present disclosure relates to a TPU composition having one or more of improved vertical elasticity and recovery properties while having a reduced 3D printing speed when used to print 3D articles.

[0003] The determination of the recovery properties of a polymer and / or whether a particular polymer has a "quick recovery" property is based on the time it takes for an article made from the polymer to return to its original shape after deformation. For example, the time it takes for a sole made from the polymer under consideration to return to its original shape once the force is released when it is flexed and / or bent by the application of a force. For many applications, including sole applications, the faster the recovery, the better, i.e., the faster the article returns to its original shape, the better. Thus, materials with quick recovery properties are more suitable for such applications.

[0004] Resilience is an indication of hysteresis energy loss, which can also be defined by the relationship between the storage modulus and the loss modulus. The measured percentage of resilience is inversely proportional to the hysteresis loss. The percentage of elasticity or resilience is commonly used in quality control tests for polymers and compounded chemicals. Resilience can be determined by a free-falling pendulum and / or ball that falls from a given height, thereby hitting a test sample and imparting a certain amount of energy to it. A portion of this energy is returned by the specimen to the pendulum and can be measured by the degree of pendulum rebound, whereby the restoring force is determined by gravity. 3D printed articles with high resilience or energy return may be advantageous for sports footwear applications. The synergistic effect of customizable 3D printed sole components and high resilience can maximize the performance of athletes.

[0005] In existing compositions, it seems difficult to provide a thermoplastic polyurethane composition having a combination of improved vertical elasticity and recovery while reducing the speed of printing 3D articles. Generally, efforts to improve the recovery properties and / or resilience result in an increase or insufficiency in the printing speed of the TPU.

[0006] Accordingly, there is a general need in the art for TPU compositions that can be used to reduce 3D printing times while providing sufficient or improved vertical resilience and / or recovery. SUMMARY OF THE INVENTION

[0007] The present disclosure relates to a thermoplastic polyurethane (also referred to herein as "TPU") composition comprising a TPU having 15 wt% to 50 wt% hard segments and an average vertical resilience of at least 50% as measured by ASTM D2632. The TPU is formed from the reaction product of: a polyisocyanate component comprising a linear aliphatic diisocyanate having 3 to 12 carbon atoms; a polyol component selected from polycaprolactone and polyester; and a linear or branched chain extender component having a main backbone of 4 to 16 carbon atoms, wherein the methanol groups are separated by at least two carbon atoms.

[0008] In one embodiment of the present disclosure, the TPU composition comprises a TPU formed from the reaction product of: a polyisocyanate component comprising a linear aliphatic diisocyanate selected from 1,6 - hexamethylene diisocyanate and pentamethylene diisocyanate; a polycaprolactone polyol component; and a chain extender component selected from 1,12 - dodecanediol, 1,6 - hexanediol, and 1,4 - butanediol. In such embodiments, the TPU has 20 wt% to 45 wt% hard segments, 20 wt% to 45 wt% average vertical resilience as measured by ASTM D2632, and a tanδ (measured according to D5279) of less than 0.0035 at 1.0 Hz.

[0009] In one embodiment, the TPU composition can be formed into a powder having a melt time of less than 30 seconds. In another embodiment, the particle size (D90) of the TPU powder can be less than 140 microns.

[0010] Another aspect of the present disclosure relates to 3D articles or components printed from the TPU compositions of the present disclosure. In another embodiment, the 3D article or component has a resilience elasticity greater than 50 as measured by ASTM D7121.

[0011] In another aspect of the present disclosure, the 3D article or component can be selected from footwear, prosthetics, orthopedic supplies, electronic components, consumer goods, sporting goods, and toys.

[0012] The following embodiments of the subject matter are contemplated:

[0013] 1. A thermoplastic polyurethane (TPU) composition, the thermoplastic polyurethane (TPU) composition comprising: TPU, the TPU having 15% to 50% hard segments and at least 50% average vertical elasticity measured according to ASTM D2632, the TPU being formed from the reaction product of: a polyisocyanate component comprising a straight-chain aliphatic diisocyanate having 3 to 12 carbon atoms; a polyol component selected from polycaprolactone polyols and polyester polyols; and a straight-chain or branched-chain chain extender component, the straight-chain or branched-chain chain extender component having a main backbone of 4 to 16 carbon atoms and at least two hydroxyl groups, wherein the methanol groups are separated by at least two carbon atoms.

[0014] 2. The composition according to embodiment 1, wherein the straight-chain aliphatic diisocyanate component is selected from 1,6-hexamethylene diisocyanate and pentamethylene diisocyanate, preferably 1,6-hexamethylene diisocyanate.

[0015] 3. The composition according to any one of the foregoing embodiments, wherein the polyisocyanate component is present in an amount of 10% to 30% by weight of the TPU.

[0016] 4. The composition according to any one of the foregoing embodiments, wherein the polyisocyanate component is present in an amount of 10% to 25% by weight of the TPU.

[0017] 5. The composition according to any one of the foregoing embodiments, wherein the polyol component is polycaprolactone.

[0018] 6. The composition according to any one of the foregoing embodiments, wherein the polyol component has a molecular weight (M w ) of 1,000 to 3,500.

[0019] 7. The composition according to embodiment 6, wherein the molecular weight is 1,500 to 3,250 or 1,850 to 3,250.

[0020] 8. The composition according to any one of the foregoing embodiments, wherein the polyol component is present in an amount of 40% to 80% by weight of the TPU.

[0021] 9. The composition according to any one of the foregoing embodiments, wherein the polyol component is present in an amount of 50% to 80% by weight of the TPU.

[0022] 10. The composition according to any one of the foregoing embodiments, wherein the polyol component is present in an amount of 55% to 78% by weight of the TPU.

[0023] 11. The composition according to any one of the foregoing embodiments, wherein the chain extender component is selected from 1,12-dodecanediol, 1,6-hexanediol, and 1,4-butanediol.

[0024] 12. The composition according to any one of the foregoing embodiments, wherein the chain extender component is 1,12-dodecanediol.

[0025] 13. The composition according to any one of the foregoing embodiments, wherein the chain extender is present in an amount of 5% to 30% by weight of the TPU.

[0026] 14. The composition according to any one of the foregoing embodiments, wherein the chain extender component is present in an amount of 7% to 25% by weight of the TPU.

[0027] 15. The composition according to any one of the foregoing embodiments, wherein the chain extender component is present in an amount of 8% to 22% by weight of the TPU.

[0028] 16. The composition according to any one of the foregoing embodiments, wherein the TPU has 20% to 45% hard segments.

[0029] 17. The composition according to any one of the foregoing embodiments, wherein the TPU has 22% to 42% hard segments.

[0030] 18. The composition according to any one of the foregoing embodiments, wherein the TPU has 24% to 41% hard segments.

[0031] 19. The composition according to any one of the foregoing embodiments, wherein the TPU composition further comprises a plasticizer component.

[0032] 20. The composition according to embodiment 19, wherein the plasticizer component is a dialkyl glutarate.

[0033] 21. The composition according to embodiment 19, wherein the plasticizer component is present in an amount of at most 7% by weight of the TPU composition.

[0034] 22. The composition according to embodiment 19, wherein the plasticizer component is present in an amount of at most 6.5% by weight of the TPU composition.

[0035] 23. The composition according to embodiment 19, wherein the plasticizer component is present in an amount of at most 5.5% by weight of the TPU composition.

[0036] 24. The composition according to embodiment 19, wherein the plasticizer component is present in an amount of 0.5 wt% to 10 wt% of the TPU composition.

[0037] 25. The composition according to embodiment 19, wherein the plasticizer component is present in an amount of 1 wt% to 7 wt% of the TPU composition.

[0038] 26. The composition according to any one of the preceding embodiments, wherein the vertical elasticity of the TPU is at least 54%.

[0039] 27. The composition according to any one of the preceding embodiments, wherein the TPU has a tanδ (measured according to ASTM D5279) of less than 0.0035 at 1.0 Hz.

[0040] 28. The composition according to embodiment 27, wherein the tanδ is less than 0.0032.

[0041] 29. The composition according to embodiment 27, wherein the tanδ is less than 0.0030.

[0042] 30. The composition according to any one of the preceding embodiments, wherein the TPU composition is formed into a powder having a particle size (D90) of less than 140 microns.

[0043] 31. The composition according to any one of the preceding embodiments, wherein the particle size is less than 135 microns.

[0044] 32. The composition according to any one of the preceding embodiments, wherein the particle size is less than 132 microns.

[0045] 33. The composition according to any one of the preceding embodiments, wherein the TPU composition is formed into a powder having a powder melting time of less than 30 seconds.

[0046] 34. The composition according to embodiment 30, wherein the powder melting time is less than 25 seconds.

[0047] 35. A 3D printed part prepared from the TPU composition according to any one of the preceding embodiments.

[0048] 36. The 3D printed part according to embodiment 35, wherein the 3D printed part has a resilience elasticity greater than 50 measured according to ASTM D7121.

[0049] 37. The 3D printed part according to embodiment 35, wherein the 3D printed part has a resilience elasticity greater than 55.

[0050] 38. The 3D printed part according to embodiment 35, wherein the 3D printed part has a resilience elasticity greater than 58.

[0051] 39. The 3D printed part according to any one of embodiments 35 to 38, wherein the 3D printed part is selected from footwear midsole, prosthesis, orthopedic supplies, electronic components, consumer goods, sports goods and toys. Detailed Description

[0052] The present disclosure describes a thermoplastic polyurethane composition, which comprises a TPU having 15 wt% to 50 wt% of hard segments and an average vertical elasticity of at least 50% measured according to ASTM D2632. The TPU is formed from the reaction product of: a polyisocyanate component comprising a straight-chain aliphatic diisocyanate component having 3 to 12 carbon atoms; a polyol component selected from polycaprolactone and polyester; and a straight-chain or branched-chain chain extender component having a main backbone of 4 to 16 carbon atoms, wherein the methanol groups are separated by at least two carbon atoms.

[0053] Polyisocyanate component :

[0054] The TPU reaction product of the composition of the present disclosure is prepared using a polyisocyanate component comprising a straight-chain aliphatic diisocyanate having 3 to 12 carbon atoms. Examples of suitable diisocyanates include, but are not limited to, 1,6-hexamethylene diisocyanate (HDI), 1,4-butane diisocyanate, pentamethylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, and combinations thereof. In one embodiment, the diisocyanate is 1,6-hexamethylene diisocyanate.

[0055] In some embodiments, the polyisocyanate component may comprise one or more additional polyisocyanates, which are generally diisocyanates.

[0056] Suitable polyisocyanates that can be used in combination with the above straight-chain aliphatic diisocyanates may include straight-chain or branched-chain aromatic diisocyanates, branched-chain aliphatic diisocyanates, or combinations thereof. In some embodiments, the polyisocyanate component comprises one or more aromatic diisocyanates. In other embodiments, the polyisocyanate component is substantially free or even completely free of aromatic diisocyanates.

[0057] The additional polyisocyanate component may comprise one or more aromatic diisocyanates. Examples of suitable aromatic polyisocyanates include, but are not limited to, 4,4'-methylenebis(phenyl isocyanate) (MDI), m-xylene diisocyanate (XDI), phenylene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, and toluene diisocyanate (TDI); and aliphatic diisocyanates such as isophorone diisocyanate (IPDI), 1,4-cyclohexyl diisocyanate (CHDI), decane-1,10-diisocyanate, lysine diisocyanate (LDI), 1,4-butane diisocyanate (BDI), isophorone diisocyanate (IPDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), and dicyclohexylmethane-4,4-diisocyanate (H12MDI). Mixtures of two or more polyisocyanates may be used. In some embodiments, the polyisocyanate is MDI and / or H12MDI. In some embodiments, the polyisocyanate comprises MDI. In some embodiments, the polyisocyanate comprises H12MDI.

[0058] In other embodiments, in addition to the above aromatic polyisocyanates and linear aliphatic diisocyanates, the polyisocyanate component may further comprise one or more additional aliphatic diisocyanates. Suitable aliphatic diisocyanates include isophorone diisocyanate (IPDI), 1,6-hexamethylene diisocyanate (HDI), 1,4-cyclohexyl diisocyanate (CHDI), decane-1,10-diisocyanate, lysine diisocyanate (LDI), 1,4-butane diisocyanate (BDI), and dicyclohexylmethane-4,4'-diisocyanate (H12MDI). In some embodiments, mixtures of two or more polyisocyanates may be used.

[0059] The polyisocyanate component of the TPU composition of the present disclosure may be present in the TPU in an amount of 10 wt% to 30 wt% of the TPU. In another embodiment, the polyisocyanate component may be present in the TPU in an amount of 10 wt% to 25 wt% of the TPU.

[0060] Polyol component :

[0061] The TPU reaction product of the composition of the present disclosure is further formed from a polyol or a diol. The polyol for forming the TPU of the TPU composition of the present disclosure is selected from one or more of polyester polyols and polycaprolactones. In one embodiment, the polyol is polycaprolactone. In another embodiment, the polyol is a polyester polyol.

[0062] The average molecular weight (M w)It can be from 1,000 to 3,500. In one embodiment, the average molecular weight of the polyol component is from 1,500 to 3,250. In another embodiment, the average molecular weight of the polyol component is from 1,850 to 3,250.

[0063] The average molecular weight of the polyol can be determined by calculation using the following equation:

[0064]

[0065] Functionality: The functionality of the polyol. If it is a diol, the functionality is 2;

[0066] OH value: The weight of KOH in milligrams that neutralizes the acetic anhydride capable of reacting with 1 gram of the polyol by acetylation.

[0067] The polycaprolactone polyol useful for preparing the TPU compositions described herein comprises a polyester diol derived from caprolactone monomers (i.e., polycaprolactone). The polycaprolactone polyol is terminated by a primary hydroxyl group. Suitable polycaprolactone polyols can be made from ε-caprolactone and a difunctional initiator such as diethylene glycol, 1,4-butanediol or any other diol listed herein. In some embodiments, the polycaprolactone polyol is a linear polyester diol derived from caprolactone monomers.

[0068] Available examples include CAPA TM 2202A, which is a linear diol with a number average molecular weight (Mn) of 2,000; and CAPA TM 2302A, which is a linear diol with a Mn of 3,000, both of which are commercially available from Perstorp Polyols Inc. These materials can also be described as polymers of 2-oxepanone and 1,4-butanediol.

[0069] The polycaprolactone polyol can be made from 2-oxepanone and a diol, where the diol can be 1,4-butanediol, diethylene glycol, monoethylene glycol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol or any combination thereof. In some embodiments, the diol used to prepare the polycaprolactone polyol is linear. In some embodiments, the polycaprolactone polyol is prepared from 1,4-butanediol.

[0070] In addition to the polycaprolactone polyol, polyester polyols can also be employed to form the TPU of the TPU composition.

[0071] Suitable polyester polyols typically have an acid value of less than 1.3. In some embodiments, the polyester polyol has an acid value of less than 0.5. The polyester polyol including the intermediate can be produced by: (1) the esterification reaction of one or more diols with one or more dicarboxylic acids or acid anhydrides or (2) the transesterification reaction, i.e., the reaction of one or more diols with a dicarboxylic acid ester. To obtain a straight chain with a predominance of terminal hydroxyl groups, it is generally preferred that the molar ratio of diol to acid exceeds one mole. Suitable polyester intermediates also include the dicarboxylic acids of the desired polyester, and the dicarboxylic acids of the desired polyester can be aliphatic, alicyclic, aromatic, or a combination thereof. Suitable dicarboxylic acids that can be used alone or in a mixture typically have a total of 4 to 15 carbon atoms and include: succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, etc. Acid anhydrides of the above dicarboxylic acids can also be used, such as phthalic anhydride, tetrahydrophthalic anhydride, etc. Adipic acid is the preferred acid. The diols that react to form the desired polyester intermediate can be aliphatic, aromatic, or a combination thereof, which include any of the diols in the above chain extender segments and have a total of 2 to 20 or 2 to 12 carbon atoms. Suitable examples include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, dodecamethylene glycol, and mixtures thereof.

[0072] The polyol component can be present in the TPU in an amount of 40 wt% to 80 wt%, or 50 wt% to 80 wt%, or 55 wt% to 78 wt% of the TPU.

[0073] The TPU composition can also contain additional polyols other than the above-mentioned polycaprolactone and / or polyester polyol. When present, the additional polyols can include one or more hydroxyl-terminated polyethers, one or more hydroxyl-terminated polycarbonates, one or more hydroxyl-terminated polysiloxanes, or mixtures thereof.

[0074] Suitable hydroxyl-terminated polyether intermediates include polyether polyols derived from diols or polyols having a total of 2 to 15 carbon atoms, and in some embodiments, are alkyl diols reacted with ethers comprising alkylene oxides having 2 to 6 carbon atoms (typically ethylene oxide or propylene oxide or mixtures thereof). For example, a hydroxyl-functional polyether can be prepared by first reacting propylene glycol with propylene oxide and then with ethylene oxide. The primary hydroxyl groups produced by ethylene oxide are more reactive than secondary hydroxyl groups and are thus preferred. Commercially available polyether polyols include poly(ethylene glycol) comprising ethylene oxide reacted with ethylene glycol, poly(propylene glycol) comprising propylene oxide reacted with propylene glycol, poly(tetramethylene ether glycol) comprising water reacted with tetrahydrofuran, which can also be described as polytetrahydrofuran and is commonly referred to as PTMEG. In some embodiments, the polyether intermediate comprises PTMEG. Suitable polyether polyols also include polyamide adducts of alkylene oxides and can include, for example, an ethylenediamine adduct comprising the reaction product of ethylenediamine and propylene oxide, a diethylenetriamine adduct comprising the reaction product of diethylenetriamine and propylene oxide, and similar polyamide-type polyether polyols. Copolyethers can also be used in the compositions. Typical copolyethers include the reaction products of THF and ethylene oxide or THF and propylene oxide. These can be block copolymers B and random copolymers R are purchased from BASF. The various polyether intermediates typically have a number average molecular weight (Mn) determined by measuring the terminal functional groups, with an average molecular weight greater than about 700, such as about 700 to about 10,000, about 1,000 to about 5,000, or about 1,000 to about 2,500. In some embodiments, the polyether intermediate comprises a blend of two or more different molecular weight polyethers, such as a blend of 2,000M n and 1,000M n PTMEG.

[0075] Suitable hydroxyl-terminated polycarbonates include those prepared by reacting a diol with a carbonate. U.S. Patent No. 4,131,731 is incorporated herein by reference for its disclosure of hydroxyl-terminated polycarbonates and their preparation. Such polycarbonates are linear and have terminal hydroxyl groups that are substantially free of other end groups. The basic reactants are a diol and a carbonate. Suitable diols are selected from alicyclic and aliphatic diols containing 4 to 40, and or even 4 to 12 carbon atoms, and polyalkylene glycols containing 2 to 20 alkoxy groups per molecule and 2 to 4 carbon atoms per alkoxy group. Suitable diols include aliphatic diols containing 4 to 12 carbon atoms, such as 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,10-decanediol, hydrogenated dilinoleyl glycol, hydrogenated dioleyl glycol, 3-methyl-1,5-pentanediol; and alicyclic diols, such as 1,3-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclohexanedimethanol, 1,4-endomethylene-2-hydroxy-5-hydroxymethylcyclohexane and polyalkylene glycols. The diol used in the reaction can be a single diol or a mixture of diols, depending on the properties desired in the finished product. Hydroxyl-terminated polycarbonate intermediates are generally those known in the art and in the literature. Suitable carbonates are selected from alkylene carbonates consisting of 5- to 7-membered rings. Suitable carbonates used herein include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-vinyl carbonate, 1,3-pentylene carbonate, 1,4-pentylene carbonate, 2,3-pentylene carbonate and 2,4-pentylene carbonate. In addition, suitable herein are dialkyl carbonates, cycloaliphatic carbonates and diaryl carbonates. The dialkyl carbonate can contain 2 to 5 carbon atoms in each alkyl group, and specific examples thereof are diethyl carbonate and dipropyl carbonate. Cycloaliphatic carbonates, especially bicycloaliphatic carbonates, can contain 4 to 7 carbon atoms in each ring structure and can have 1 or 2 such structures. When one group is cycloaliphatic, the other group can be alkyl or aryl. On the other hand, if one group is aryl, the other can be alkyl or cycloaliphatic. Examples of suitable diaryl carbonates are diphenyl carbonate, dimethylxylene carbonate and dinaphthyl carbonate, which can contain 6 to 20 carbon atoms in each aryl group. In particular, the hydroxyl-terminated polycarbonate can be polyhexamethylene carbonate diol, polytetramethylene carbonate diol or polycarbonate copolymer diol. More particularly, the hydroxyl-terminated polycarbonate is polyhexamethylene carbonate diol.

[0076] Suitable polysiloxane polyols include α,ω-hydroxy or amine or carboxylic acid or thiol or epoxy group-terminated polysiloxanes. Examples include poly(dimethylsiloxane) terminated with a hydroxyl or amine or carboxylic acid or mercapto or epoxy group. In some embodiments, the polysiloxane polyol is a hydroxyl-terminated polysiloxane. In some embodiments, the polysiloxane polyol has a number average molecular weight in the range of 300 to 5,000 or 400 to 3,000.

[0077] The polysiloxane polyol can be obtained by a dehydrogenation reaction between a polysiloxane hydride and an aliphatic polyol or a polyoxyalkylene alcohol to introduce an alcohol hydroxyl group onto the polysiloxane backbone.

[0078] In some embodiments, the polysiloxane can be represented by one or more compounds having the following formula:

[0079]

[0080] wherein: each R 1 and R 2 are independently an alkyl group of 1 to 4 carbon atoms, a benzyl group or a phenyl group; each E is OH or NHR 3 , wherein R 3 is hydrogen, an alkyl group of 1 to 6 carbon atoms or a cycloalkyl group of 5 to 8 carbon atoms; a and b are each independently an integer from 2 to 8; p is an integer between 3 and 50. In the polysiloxane containing an amino group, at least one E group is NHR 3 . In the polysiloxane containing a hydroxyl group, at least one E group is OH. In some embodiments, both R 1 and R 2 are methyl groups.

[0081] Suitable examples include α,ω-hydroxypropyl-terminated poly(dimethylsiloxane) and α,ω-aminopropyl-terminated poly(dimethylsiloxane), both of which are commercially available materials. Further examples include copolymers of poly(dimethylsiloxane) materials and poly(alkylene oxides).

[0082] Additional polyol components (if present) may include poly(ethylene glycol), poly(tetramethylene ether glycol), poly(trioxane), ethylene oxide-terminated poly(propylene glycol), poly(butylene adipate), poly(ethylene adipate), poly(hexylene adipate), poly(tetramethylene-co-hexylene adipate), poly(3-methyl-1,5-pentamethylene adipate), polycaprolactone diol, poly(hexylene carbonate) diol, poly(pentamethylene carbonate) diol, poly(trimethylene carbonate) diol, dimer fatty acid polyester polyols, vegetable oil polyols or any combination thereof.

[0083] Examples of dimer fatty acids that can be used to prepare suitable polyester polyols include Priplast, commercially available from Croda TM polyester diols / polyols and those commercially available from Oleon polyester diols.

[0084] In some embodiments, the polyol component does not contain or is substantially free of additional polyols other than polycaprolactone or polyester polyols. In one embodiment, the TPU does not contain or is substantially free of polyols other than the aforementioned polycaprolactone or polyester polyols. In one embodiment, the TPU composition comprises polycaprolactone polyol and does not contain any additional polyols.

[0085] In some embodiments, the polyol component includes ethylene oxide, propylene oxide, butylene oxide, styrene oxide, poly(tetramethylene ether glycol), poly(propylene glycol), poly(ethylene glycol), copolymers of poly(ethylene glycol) and poly(propylene glycol), epichlorohydrin, etc., or combinations thereof. In some embodiments, the polyol component includes poly(tetramethylene ether glycol).

[0086] Chain extender component :

[0087] The TPU reaction product of the compositions of the present disclosure is further formed from a chain extender component. The chain extender component comprises a straight-chain or branched-chain chain extender having a main backbone of 4 to 16 carbon atoms and having at least two hydroxyl groups, wherein the methanol groups are separated by at least two carbon atoms. As used herein, "main backbone" refers to the longest carbon-carbon chain in the chain extender component. Further, "methanol group" refers to the -C(OH)- moiety.

[0088] Suitable chain extenders include relatively small polyhydroxy compounds, such as lower aliphatic or short-chain diols having 4 to 16, or 4 to 12, or 4 to 10 carbon atoms. Suitable examples include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol (BDO), 1,6-hexanediol (HDO), 1,3-butanediol, 1,5-pentanediol, neopentyl glycol, hexamethylene glycol, heptanediol, nonanediol, dodecanediol, 3-methyl-1,5-pentanediol, etc. and mixtures thereof. In some embodiments, the chain extender includes BDO, HDO, 3-methyl-1,5-pentanediol, or combinations thereof. In some embodiments, the chain extender includes BDO. Other diols can be used, but in some embodiments, the TPU compositions described herein are substantially free of or even completely free of such substances.

[0089] In some embodiments, the chain extender component includes 1,4-butanediol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, dimethanol, 3-methyl-1,5-pentanediol, or a combination thereof. In some embodiments, the chain extender component includes 1,4-butanediol, 3-methyl-1,5-pentanediol, or a combination thereof. In some embodiments, the chain extender component includes one or more of 1,12-dodecanediol, 1,6-hexanediol, and 1,4-butanediol. In another embodiment, the chain extender component is 1,12-dodecanediol.

[0090] In some embodiments, the molar ratio of the chain extender is present in an amount of 5 wt% to 30 wt%, or 7 wt% to 25 wt%, or 8 wt% to 22 wt% of the TPU. In one embodiment, the chain extender component is present in an amount of 8 wt% to 22 wt% of the TPU.

[0091] The thermoplastic polyurethane composition of the present disclosure includes hard segments and soft segments. The hard segments are derived from the reaction of a diisocyanate component and a chain extender component. The hard segments may also be referred to herein as "hard blocks". The soft segments, also referred to as "soft blocks", are derived from the reaction of a diol and a diisocyanate, and their properties depend on the type of diol. In one embodiment, the hard segment content of the TPU is at least 15 wt% or at least 20 wt% based on the total weight of the TPU. In another embodiment, the hard segment content of the TPU is at least 22 wt% based on the total weight of the TPU. In one embodiment, the hard segment content of the TPU is at least 24 wt% based on the total weight of the TPU. The TPU may have a hard segment content of 15 wt% to 50 wt% of the TPU. In one embodiment, the hard segment content is 20 wt% to 45 wt% of the TPU. In another embodiment, the hard segment content is 22 wt% to 42 wt% of the TPU. In one embodiment, the hard segment content is 24 wt% to 41 wt% of the TPU. In one embodiment, the hard segment content is 24 wt% to 32 wt%, or 22 wt% to 26 wt%, or 30 wt% to 34 wt% of the TPU.

[0092] The TPU composition may have a TPU having 15% to 50% hard segments and at least 50% average vertical elasticity measured according to ASTM D2632, and the TPU is formed from the reaction product of 1,6-hexamethylene diisocyanate, polycaprolactone, and 1,12-dodecanediol. Specifically, the hard segments may account for 24 wt% to 41 wt%, or 24 wt% to 32 wt%, or 22 wt% to 26 wt%, or 30 wt% to 34 wt% of the TPU.

[0093] The TPU composition as described herein can be prepared by reacting: a) the above-mentioned polyisocyanate component; b) the above-mentioned polyol component; c) the above-mentioned chain extender component, wherein the reaction can be carried out in the presence of a catalyst. The reaction can be carried out by a batch or continuous method.

[0094] The TPU composition as described herein can also be characterized by having recovery properties indicated by dynamic mechanical analysis ("DMA") values. These values are measured by performing a dynamic frequency sweep on a rectangular torsion mode sample of 20 mm × 12.7 mm × 2.0 mm using a Rheometrics ARES system at a temperature of 23 °C, a strain of 0.1%, and a frequency from 0.1 Hz to 100 Hz. The resulting values give an indication of the recovery properties of the sample, where a smaller tanδ value at a given frequency indicates better recovery. In one embodiment, the TPU composition has a tanδ (measured according to ASTM D5279) of less than 0.0035 at 1.0 Hz. In another embodiment, the tanδ is less than 0.0032. In yet another embodiment, the tanδ is less than 0.0030.

[0095] The TPU composition as described herein can also be characterized by its resilience in vertical rebound measured by ASTM D2632. ASTM D2362 is a standard test for evaluating the resilience of TPU, and resilience is a key parameter in, for example, sports footwear applications. In one embodiment, the vertical resilience of the TPU composition is at least 50%. In another embodiment, the vertical resilience of the TPU composition is at least 54%.

[0096] The TPU composition as described herein can have a melt time when formed into a powder. The melt time is measured by spreading a 0.2 mm thick TPU powder on a steel plate and heating the TPU using an electric heater until it exhibits melting. Melting can be observed by recording a video of the melting process using a high-speed camera. The recorded film is converted into frames at one image per second, and these frames are analyzed to determine the time when the TPU sample is completely melted. The time when the TPU is completely melted is reported as the "powder melt time" for the sample. In some embodiments, the TPU composition as described herein has a powder melt time of less than 30 seconds. In another embodiment, the powder melt time is less than 25 seconds. Specifically, the melt time is less than 20.

[0097] The TPU powder melt time is an important characteristic of TPU powder for 3D printing applications.

[0098] The TPU composition of the present disclosure can be further formed into TPU powder having a suitable particle size. The TPU powder can be formed by conventional means such as cryogenic grinding. In one embodiment, the particle size (D90) is less than 140 microns, which is the size value to which 90% of the volume particle population belongs when measured according to ISO-13320. In another embodiment, the particle size is less than 135 microns. In one embodiment, the particle size is less than 132 microns.

[0099] The method for producing the TPU polymer of the present invention can utilize conventional and hereinafter developed TPU manufacturing equipment and known or hereinafter developed methods. The TPU can be produced by casting, extrusion or any other method known to those skilled in the art in a so-called one-shot, semi-prepolymer or prepolymer method. In one embodiment, the method is a so-called "one-shot" process in which all three reactants are added to an extruder reactor and reacted.

[0100] The TPU composition of the present disclosure is particularly useful for 3D printing applications. For 3D printing, the TPU composition is dispensed from a dispensing head having a set of nozzles to deposit a layer of the TPU composition on a support structure. These layers can then be cured to ultimately form a 3D printed article. The 3D composition disclosed herein is characterized by a reduced powder melting time, which allows for faster printing of 3D articles. Further, the articles formed from the TPU composition of the present disclosure exhibit similar good vertical resilience and elasticity (as described above) compared to currently available 3D printing materials of similar composition. In some embodiments, the 3D printed article can have a resilience elasticity greater than 55 or greater than 58 or greater than 60.

[0101] Articles formed from the TPU compositions disclosed herein may include footwear midsole, prosthetics, orthopedic supplies, electronic components, consumer goods, sporting goods, and toys. The types of articles that can be 3D printed using the TPU compositions of the present disclosure are not limited, and more specific examples of 3D printed articles may include cooking and storage utensils, furniture, automotive components, toys, sportswear, medical devices, personalized medical articles, replicated medical implants, dental articles, sterilization containers, curtains, surgical gowns, filters, hygiene products, diapers, films, sheets, tubes, pipes, wire sheaths, cable sheaths, agricultural films, geomembranes, sports equipment, cast films, blown films, profiles, boat and watercraft components, crates, containers, packaging, laboratory utensils, office floor mats, instrument sample racks, liquid storage containers, packaging materials, medical tubes and valves, footwear components, sheets, tapes, carpets, adhesives, wire jackets, cables, protective clothing, automotive parts, coatings, foam laminates, overmolded articles, automotive skins, awnings, tarps, leather goods, roofing articles, steering wheels, powder coatings, powder slush molding, durable consumer goods, grips, handles, hoses, hose linings, pipes, pipe linings, casters, roller skate wheels, computer components, belts, decals, footwear components, conveyor belts or timing belts, gloves, fibers, fabrics or garments.

[0102] Additional articles that can be 3D printed with the TPU compositions of the present disclosure include jewelry, custom shakers and / or collectibles, such as, but not limited to, commemorative coins, badges, picture frames and photo frames, eyeglass frames, keys, cups, mugs, miniatures and models, wristbands, personalized action figures, etc.

[0103] Other additives :

[0104] In addition to the TPU reaction product, the TPU compositions disclosed herein may also contain other optional components.

[0105] Optional additive components may be present during the reaction and / or optional additive components may be incorporated into the above TPU reaction product to improve processing and other properties. These additives include, but are not limited to, antioxidants, organic phosphites, phosphines and phosphonates, hindered amines, organic amines, organic sulfur compounds, lactones and hydroxylamine compounds, biocides, fungicides, antimicrobials, compatibilizers, electrical dissipation or antistatic additives, fillers and reinforcing agents (such as titanium dioxide, alumina, clay and carbon black), flame retardants (such as phosphate esters, halogenated materials and metal salts of alkylbenzenesulfonic acid), impact modifiers (such as methyl methacrylate-butadiene-styrene (“MBS”) and methyl methacrylate-butyl acrylate (“MBA”)), release agents (such as waxes, greases), pigments and colorants, plasticizers, polymers, rheology modifiers (such as monoamines, polyamide waxes, silicones and polysiloxanes), slip additives (such as paraffin wax, hydrocarbon polyolefins and / or fluorinated polyolefins), and UV stabilizers (which may be of the hindered amine light stabilizer (HALS) and / or UV light absorber (UVA) type). Other additives may also be used to enhance the performance of the TPU composition or blend product. All of the above additives may be used in effective amounts commonly used for these substances. In some embodiments, the additives may be used in the TPU composition in an amount of up to and including 1.0 wt% of the TPU composition.

[0106] These additional additives may be incorporated into the components used to prepare the TPU reaction product or into the reaction mixture used to prepare the TPU reaction product, or may be incorporated into the TPU composition after the TPU reaction product has been prepared. In another method, all of the materials may be mixed with the TPU reaction product and then melted, or they may be directly incorporated into the melt of the TPU reaction product.

[0107] In one embodiment, the TPU compositions described herein further comprise a plasticizer. The type of plasticizer used can be any of the known plasticizers for TPU. The most commonly used type of plasticizer is phthalate, and butyl benzyl phthalate is most preferred. The plasticizers used in the present invention may include phthalate-based plasticizers such as dibutyl phthalate, di-2-ethylhexyl phthalate (DOP), di-n-octyl phthalate, diisodecyl phthalate, diisooctyl phthalate, octyl decyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl isophthalate phosphate; aliphatic ester-based plasticizers such as di-2-ethylhexyl adipate (DOA), di-n-decyl adipate, diisodecyl adipate, dibutyl sebacate, and di-2-ethylhexyl sebacate; pyromellitate-based plasticizers such as trioctyl trimellitate, tridecyl trimellitate; phosphate-based plasticizers such as tributyl phosphate, tri-2-ethylhexyl phosphate, 2-ethylhexyl diphenyl phosphate, and tricresyl phosphate; epoxy resin-based plasticizers such as epoxy resin-based soybean oil; and polyester-based polymeric plasticizers. For applications that are sensitive from a toxicological perspective, such as children's toys and food contact, diisononyl-cyclohexane-1,2-dicarboxylate (obtained from BASF ) can be used as a plasticizer. A single plasticizer can be used, or a combination of two or more plasticizers can be used. It is expected that the choice of plasticizer will depend on the end-use application of the TPU polymer, as will be well understood by those skilled in the art of formulating TPU.

[0108] In one embodiment, the plasticizer is a dialkyl ether ester of glutaric acid. The plasticizer component can be present in the TPU composition in an amount of up to 7 wt% of the TPU composition. In another embodiment, the plasticizer component can be present in the TPU composition in an amount of up to 6.5 wt% of the TPU composition. In one embodiment, the plasticizer component can be present in the TPU composition in an amount of up to 5.5 wt% of the TPU composition. In one embodiment, the plasticizer can be present in the TPU composition in an amount of 0.5 wt% to 10 wt% of the TPU composition. In another embodiment, the plasticizer can be present in the TPU composition in an amount of 1 wt% to 7 wt% of the TPU composition, more specifically, 4 wt% to 6 wt% of the TPU composition of the plasticizer.

[0109] The TPU composition may have a TPU having 15% to 50% hard segments and at least 50% average vertical elasticity measured according to ASTM D2632. The TPU is formed from the reaction product of 1,6 - hexamethylene diisocyanate, polycaprolactone, and 1,12 - dodecanediol and a plasticizer in an amount of 1 wt% to 7 wt% of the TPU composition. Specifically, the amount of the plasticizer is 4 wt% to 6 wt% of the TPU composition.

[0110] The TPU composition may have a TPU having 20% to 45% hard segments and at least 50% average vertical elasticity measured according to ASTM D2632. The TPU is formed from the reaction product of 1,6 - hexamethylene diisocyanate, polycaprolactone, and 1,12 - dodecanediol and a plasticizer in an amount of 1 wt% to 7 wt% of the TPU composition. Specifically, the amount of the plasticizer is 4 wt% to 6 wt% of the TPU composition.

[0111] It is generally preferred to incorporate one or more antioxidants into the above - mentioned TPU reaction product and / or TPU composition. These can be added during the reaction to form the TPU reaction product, blended into the previously formed polymer mentioned above, or added to the TPU composition. Suitable antioxidants include phenols, organic phosphites, phosphines and phosphonites, hindered amines, organic amines, organic sulfur compounds, lactones, and hydroxylamine compounds. For applications where transparency is required, the antioxidant is preferably soluble in the above - mentioned TPU reaction product or dispersed therein as very fine droplets or particles. Many suitable antioxidant materials are commercially available. These include Irganox TM 1010, Irganox TM MD1024, Irgaphos TM 168, Irgaphos TM 126 (all available from BASF Specialty Chemicals), etc. The antioxidant can be used in a conventional amount, such as 0.1 wt% to 3 wt%, or 0.2 wt% to 2 wt%, or 0.3 wt% to 1.1 wt% in the TPU composition.

[0112] The TPU composition of the present disclosure may further comprise from about 0.10 wt% to about 10.0 wt% of an antimicrobial material and / or a biocide material. In an alternative embodiment of the present invention, the composition may comprise from about 1 wt% to about 6 wt% of an antimicrobial and / or biocide material, from about 2 wt% to about 4 wt% of an antimicrobial material and / or a biocide material, and many percentages therebetween. In the context of this formulation, the terms "antimicrobial agent" and / or "biocide" are intended to include, but are not limited to, fungicides, herbicides, insecticides, antimicrobial agents, which include all forms of carbonates, silicates, sulfates, halides, and borates of sodium, potassium, calcium, zinc, copper, and barium; zinc carboxylates; boric acid; sodium dichromate; copper chromated arsenate (CCA); copper chromated borate (CBC); ammoniacal copper arsenate (ACA); ammoniacal copper zinc arsenate (ACZA); copper chromated fluoride (CFK); copper chromated fluoborate (CCFB); copper chromated phosphate (CCP); propiconazole tebuconazole; organic chlorides such as pentachlorophenol (PCP); quaternary ammonium compounds (MC); copper 8-hydroxyquinoline or potassium peroxymonosulfate copper; tributyltin oxide (TBTO); tributyltin naphthenate (TBTN); didodecyldimethylammonium bromide (DDAB); didodecyldimethylammonium chloride (DDAC); silver ions, mercury ions, carbamates, isothiazolinones, chlorophenoxy, and polyhexamethylene biguanide hydrochloride, barium metaborate monohydrate, borates, and mixtures thereof. A preferred composition of the present invention is water-insoluble and comprises an inorganic biocide.

[0113] The TPU composition disclosed herein may also comprise a compatibilizer. Useful compatibilizers include maleated thermoplastics, thermoplastic elastomer block copolymers, crystalline copolymers of propylene with ethylene or other higher alpha-olefins, chlorinated thermoplastics, ionomers, maleated elastomeric copolymers, and mixtures thereof.

[0114] Suitable compatibilizers may also include modified polyolefins, which include modified thermoplastics and modified rubbers. In one or more embodiments, these modified polyolefins contain at least one functional group attached thereto. In one or more embodiments, these functional groups may include carboxylic acids; C1-C8 carboxylic acid esters such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl, heptyloxycarbonyl, octyloxycarbonyl and their isomeric forms; carboxylic anhydrides; carboxylates formed by neutralizing carboxylic acid groups with metal ions of Groups I, II, III, IV-A and VII of the periodic table, exemplarily including sodium ions, potassium ions, lithium ions, magnesium ions, calcium ions, iron ions, nickel ions, zinc ions and aluminum ions and mixtures thereof; amides; epoxy resins; hydroxyl groups; amino groups; and C2-C6 acyloxy groups, such as acetoxy, propionyloxy or butyryloxy. In one or more embodiments, these functional groups may be part of an unsaturated monomer precursor that can be copolymerized with an olefin monomer or grafted onto a polyolefin to form a modified polyolefin.

[0115] Functionalized monomers or reagents include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, acrylamide, methacrylamide, glycidyl acrylate, glycidyl methacrylate, vinyl acetate, vinyl butyrate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, sodium acrylate, zinc acrylate, ionic hydrocarbon polymers from the polymerization of alpha-olefins and alpha,beta-ethylenically unsaturated carboxylic acids.

[0116] Suitable modified polyolefins include those disclosed in U.S. Pat. Nos. 6,001,484, 6,072,003, 3,264,272 and 3,939,242, which are incorporated herein by reference.

[0117] In one or more embodiments, the link units of the polyolefin containing functional groups may be present in the polyolefin in an amount of about 0.05 mol% to about 5 mol%. For example, in the case of maleated polyethylene, about 0.005 mol% to about 5 mol% of the link units contain maleic acid residues side-attached to the main chain.

[0118] In one or more embodiments, useful modified polyolefins may be obtained under the trade names OPTEMA TM TC120 and TC220 (ExxonMobil), which are ethyl methacrylate copolymers, and under the trade names POLYBOND TM (Chemtura) or FUSABOND TM (DuPont), which are maleated polypropylenes.

[0119] The maleated elastomeric copolymer comprises a copolymer of ethylene, an α-olefin and one or more dienes, wherein the copolymer is reacted with maleic anhydride to provide further functionality. These copolymers are commercially available under the trade name EXXELOR (ExxonMobil). The compatibilizers as disclosed herein can be used in the TPU composition in conventional amounts such as 0.1 wt% to 50 wt%, or 0.3 wt% to 30 wt%, or 0.5 wt% to 20 wt%.

[0120] The TPU composition disclosed herein may further comprise an antistatic agent. Many antistatic agents are known in the art. Sometimes, the antistatic agent is applied to the surface of the polymer article made of the TPU composition by spraying or dip coating.

[0121] Low molecular weight antistatic agents are sometimes blended with the above TPU composition instead of being coated on the surface. Such low molecular weight antistatic agents include: ethoxylated fatty amines, esters or amides, such as those described in: U.S. Pat. Nos. 3,631,162; 3,591,563; 3,575,903; 3,441,552; 3,441,552; and 3,270,650; 3,468,702; 3,454,494; 3,365,437; 3,223,545; and 3,206,429; quaternary ammonium salts, such as those described in: U.S. Pat. Nos. 3,933,871; 3,862,045; 3,850,818; 3,395,100; 3,324,091; and 3,272,648; or alkyl sulfonates, sulfates or phosphates, such as those described in: U.S. Pat. Nos. 3,475,203 and 3,446,651 and Japanese Pat. Nos. 82-30,756; 82-202,338; and 73-14,651.

[0122] The low molecular weight antistatic agent blended into the above TPU composition is generally an organic compound comprising a hydrophobic component and a hydrophilic component. The hydrophobic component generally provides compatibility with the polymer, thus joining the two materials together. The hydrophilic component generally absorbs moisture and distributes water evenly on the surface of a specific polymer. This water film formed on the surface increases the surface conductivity through an ion conduction process, thereby increasing the static charge dissipation rate. Therefore, conventional low molecular weight internal antistatic agents generally do not improve the volume conductivity of the polymer and are generally sensitive to atmospheric humidity, usually providing poor performance at low humidity.

[0123] Internal low molecular weight antistatic agents are typically designed to migrate from the interior of the above TPU composition to the surface during or after molding. Gradual surface migration can be advantageous as it can replace any antistatic agent at the surface that is lost due to evaporation, cleaning, or abrasion. However, the migration must occur at an appropriate rate. If it is too fast, the migration can lead to blooming, surface streaking, and molding difficulties; if it is too slow, the antistatic properties will be unstable as any lost antistatic agent cannot be replaced in a timely manner. Slow migration is a common problem in polymers with high crystallinity such as polypropylene, and migration after molding may take up to about a month to reach maximum antistatic performance.

[0124] Additional representative antistatic agents that can be included in the mixture include quaternary ammonium compounds such as those disclosed in U.S. Patent No. 5,933,693, including but not limited to quaternary ammonium salts of alkyl sulfates and carboxylic acids; metal salts of lithium, sodium, potassium, ammonium, calcium, and barium; complexes of metal salts with polyols and their derivatives such as 1,4-butanediol, ethylene glycol, propylene glycol, and polyethylene glycol, and complexes of metal salts with monohydric alcohols such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; hexahalogenated ionic compounds such as those disclosed in U.S. Patent No. 5,677,357, including hexahalogenated phosphate compounds such as potassium hexafluorophosphate, sodium hexafluorophosphate, and ammonium hexafluorophosphate.

[0125] Metal salt antistatic additives can be used in the composition, such as metal salts carried by diethylene glycol dimethyl ether (2-methoxyethyl ether) and triols, polyethers, or butanediol.

[0126] Some antistatic agents (such as quaternary ammonium salts) cannot withstand the processing temperatures required in the conventional manufacturing or molding steps of some polymers. Additionally, conventional low molecular weight antistatic agents tend to lose their antistatic effect due to evaporation, or they cause undesirable odors or promote cracking or crazing.

[0127] The TPU compositions disclosed herein may also include fillers or reinforcing agents. Fillers include a wide range of particulate materials, which include talc, marble, granite, carbon black, graphite, aromatic polyamide, silica-alumina, zirconia, bentonite, antimony trioxide, coal-based fly ash, clay, feldspar, nepheline, pyrogenic silica, alumina, magnesia, zinc oxide, barium sulfate, aluminum silicate, calcium silicate, titanium dioxide, titanate, chalk, ground glass, silica or glass, glass microspheres, glass beads, or glass fibers. The glass fibers used can be made of E, A, or C glass and preferably have a size and coupling agent. Their diameter is typically from 6 μm to 20 μm. Continuous filament fibers (roving) or chopped glass fibers (chopped strand) with lengths from 1 mm to 10 mm, preferably 3 mm to 6 mm, can be used.

[0128] The filler can also be a metal hydroxide, such as magnesium hydroxide, potassium hydroxide, and aluminum hydroxide; a metal carbonate, such as magnesium carbonate and calcium carbonate; a metal sulfide and sulfate such as molybdenum disulfide and barium sulfate; a metal borate, such as barium borate, metaborate barium, zinc borate, metaborate zinc; a metal anhydride, such as aluminum anhydride; or aluminum trihydrate.

[0129] Boron nitride and various recycled and reground thermosetting polyurethane and / or polyurea polymers can also be used.

[0130] Representative fillers include, but are not limited to, clays such as diatomaceous earth, kaolin, and montmorillonite; dolomite; diatomaceous earth; asbestos; ground minerals; and lithopone. These fillers are typically used in conventional ways and in conventional amounts, such as 5 wt% or less to 50 wt% or more based on the weight of the composition.

[0131] Reinforcing materials include high aspect ratio materials such as flakes and fibers, which can be flakes and fibers of glass, aramid, various other polymers, etc. Additional materials that can be used include mineral fibers, whiskers, alumina fibers, mica, powdered quartz, metal fibers, carbon fibers, and wollastonite. The reinforcing agent is typically used in an amount of 5 wt% to 50 wt% based on the entire layer or composition.

[0132] Fillers that can be used in some formulations include flame retardant fillers, which can include antimony oxide, decabromodiphenyl oxide, aluminum trihydrate, magnesium hydroxide, borates, and halogenated compounds.

[0133] In addition, metal flakes (e.g., aluminum flakes from Transmet Corp.), metal powders, metal fibers, metal-coated fillers (e.g., nickel-coated glass fibers), and still other additives for shielding electromagnetic waves can be added. Aluminum flakes (K-102 from Transmet) are particularly suitable for EMI (electromagnetic interference) purposes. The composition can also be mixed with additional carbon fibers, carbon black, especially conductive carbon black, or nickel-coated carbon fibers.

[0134] Various other fillers include wood fiber / flour / chips, rubber powder, cotton, starch, clay, synthetic fibers (e.g., polyolefin fibers), and carbon fibers.

[0135] The content of the filler depends on the filler density; the higher the filler density, the more filler can be added to the formulation without significantly affecting the volume fraction of the filler. Thus, the content of the filler is discussed herein as a weight percentage of the filler based on the total weight of the formulation. In the formulations disclosed herein, the filler content is in the range of about 0.1% to about 80%, preferably about 5% to about 50% (except for carbon black, which is typically used in an amount of about 0.1% to about 5%), more preferably about 5% to about 40%, especially about 8% to about 30%.

[0136] The TPU composition disclosed herein may also include a flame retardant. The flame retardant may or may not be an intumescent material. Examples include phenyl bis(dodecyl phosphate), phenyl bis(neopentyl phosphate), phenyl ethylidene hydrogen phosphate, phenyl-bis-3,5,5'-trimethylhexyl phosphate), ethyl diphenyl phosphate, 2-ethylhexyl di(p-tolyl) phosphate, diphenyl hydrogen phosphate, bis(2-ethylhexyl) p-tolyl phosphate, tricresyl phosphate, bis(2-ethylhexyl)-phenyl phosphate, tris(nonylphenyl) phosphate, phenyl methyl hydrogen phosphate, di(dodecyl) p-tolyl phosphate, tricresyl phosphate, triphenyl phosphate, dibutylphenyl phosphate, p-tolyl bis(2,5,5'-trimethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, and diphenyl hydrogen phosphate. Preferred flame retardants are bisphenol-A bis(diphenyl phosphate), resorcinol bis(diphenyl phosphate), and cresol bis(diphenyl phosphate).

[0137] Other examples of flame retardants include brominated organic compounds, such as brominated glycols. They may contain 5 to 20 carbon atoms, and in some embodiments, 5 to 10 or even 5 carbon atoms, and may contain quaternary carbon atoms. The additive may be present in an amount sufficient to provide the desired flame retardancy, and in other embodiments, may be present in an amount of 0% to 15% by weight of the total composition, or even 0% to 10%, 0.1% to 7%, or 0.2% to 5% by weight of the total composition.

[0138] Other examples include brominated organic compounds. Suitable examples include brominated glycols, brominated monohydric alcohols, brominated ethers, brominated esters, brominated phosphates, and combinations thereof. Suitable brominated organic compounds may include tetrabromobisphenol-A, hexabromocyclododecane, poly(pentabromobenzyl acrylate), pentabromobenzyl acrylate, tetrabromobisphenol A-bis(2,3-dibromopropyl ether), tribromophenol, dibromoneopentyl glycol, tribromoneopentyl glycol, tris(tribromoneopentyl) phosphate, and 4,4'-isopropylidene bis[2-(2,6-dibromophenoxy)ethanol].

[0139] In some embodiments, the flame retardant additive includes a metal salt of a halogen borate, a metal salt of a halogen phosphate, or a combination thereof. In some embodiments, a combination of flame retardants is used. Additional examples of flame retardant additives include metal salts of organic sulfonates, such as sodium alkylbenzene sulfonates, and in some embodiments, the flame retardant additive includes nitrogen-containing compounds. The flame retardant can be added to the TPU composition in a conventional amount. In certain embodiments, the flame retardant can be present in the TPU composition in an amount of 0 wt% to 30 wt% based on the total weight of the TPU composition. In another embodiment, the flame retardant can be present in the TPU composition in an amount of 0.1 wt% to 20 wt% based on the total weight of the TPU composition. In one embodiment, the flame retardant can be present in the TPU composition in an amount of 0.5 wt% to 15 wt% based on the total weight of the TPU composition.

[0140] Examples

[0141] Examples 1 to 11

[0142] As shown in Table 1, a series of thermoplastic polymers were prepared, including those of the technology disclosed in the present disclosure.

[0143] Table 1

[0144]

[0145] Abbreviations: HDI, hexamethylene diisocyanate; MDI, 4,4'-methylenebis(phenyl isocyanate); UVp, UV protectant; AO, antioxidant; HS, hard segment.

[0146] * Comparative example.

[0147] UVp is a chemical based on oxanilide, and AO is a chemical based on phenol and phosphite.

[0148] The plasticizer used was dialkyl glutarate.

[0149] Example 12 - Material properties

[0150] Test samples were prepared by reacting the components disclosed in Table 1 and forming samples by molding.

[0151] The following properties were determined:

[0152] - Average vertical elastic resilience (%) according to ASTM D2632.

[0153] - Recovery characteristics indicated by dynamic mechanical analysis ("DMA") values. These values are measured by performing a dynamic frequency sweep on a 20 mm x 12.7 mm x 2.0 mm rectangular torsion mode sample using a Rheometrics ARES system at a temperature of 23 °C, a strain of 0.1%, and frequencies from 0.1 Hz to 100 Hz. tanδ is measured according to ASTM D5279.

[0154] Table 2

[0155]

[0156] When measured at various frequency settings, embodiments of the present invention exhibit significantly higher resilience elasticity and lower tanδ values. These properties indicate that embodiments of the present invention can provide very high energy return when used as 3D printed objects.

[0157] Example 13 – Properties of TPU powder

[0158] The powder is prepared by reacting the components disclosed in Table 1 and performing cryogenic grinding via a needle mill and air classification.

[0159] The particle size D90 is determined according to ISO 13320 using a particle size analyzer (Particle Size Analyzer LS230 from Beckman Coulter). Less than 2 g of the powder is mixed with a reference oil at 23 °C and loaded into the particle size analyzer. Then, the particle size analyzer measures the particle size by polarization intensity difference light scattering technology. After analysis, the particle size analyzer provides the volume distribution of the particles, and D90 is the size value to which 90% of the particle population belongs.

[0160] The melting time is measured by spreading 0.2 mm thick TPU powder on a steel plate and heating the TPU using an electric heater until it exhibits melting. Melting can be observed by recording a video of the melting process using a high-speed camera. The recorded film is converted into frames at one image per second, and these frames are analyzed to determine the time when the TPU sample is completely melted. The time when the TPU is completely melted is reported as the "powder melting time" for the sample.

[0161] Table 3

[0162] Example number D90 [μm] Powder melting time [seconds] 1 133 47 2 129 87 3 130 22.5 4 121 16 5 128 17 6 130 23 7 122 16.5 8 123 10 9 124 20 10 115 62.5 11 125 33.75

[0163] Preferred embodiments provide a powder melting time significantly shorter than 30 seconds. This indicates that the preferred embodiments have more efficient melting and coalescence behavior, which ultimately results in shorter printing times and higher throughput.

[0164] Example 14 – Properties of 3D printed parts

[0165] A 3D printed part is prepared by using a Multi Jet Fusion 3D printing machine from Hewlett Packard.

[0166] The resilience elasticity is determined according to ASTM D7121.

[0167] The UTS is the ultimate tensile strength, which is measured according to ASTM D2632, and the EAB is the elongation at break, which is also measured according to ASTM D2632. To evaluate the isotropic properties of the 3D printed object, tensile specimens are printed parallel to the horizontal and vertical axes of the printing bed and tested according to ASTM D2632. Then, the corresponding ratios (UTS - ISOTRO% and EAB - ISOTRO%) between the vertical and horizontal axis properties are calculated to represent the isotropic properties of the 3D printed object.

[0168] Table 4

[0169] Example number UTS-ISOTRO% EAB-ISOTRO% Rebound elasticity [%] 1 46.2％ 49.4％ 56 2 76.9％ 88.7％ 58 3 65.9％ 24.0％ 60 4 77.0％ 43.8％ 61 5 56.4％ 44.8％ 60 6 76.4％ 77.8％ 62 7 53.9％ 27.3％ 62 8 26.7％ 7.7％ 61 9 72.8％ 63.6％ 64 10 47.1％ 22.5％ 41 11 43.8％ 23.3％ 45

[0170] Due to the layer - by - layer construction of 3D printing technology, it is generally challenging to obtain isotropic behavior in 3D printed objects. Examples 4, 6, and 9 show significantly enhanced isotropic tensile properties compared to the remaining examples in the embodiment. In other words, regardless of the printing orientation, the 3D printed objects printed with Examples 4, 6, and 9 have uniform and consistent mechanical and physical properties. In addition, these examples exhibit high resilience elasticity, which is a preferred property for footwear components.

[0171] The embodiments will be further illustrated by the following examples, which illustrate particularly advantageous embodiments. While the examples are provided to illustrate certain embodiments, they are not intended to be limiting.

[0172] Unless otherwise specified herein, references to the treatment rate or amount of a component present in the lubricating compositions disclosed herein are on an oil - free basis, i.e., the amount of the active substance. Additionally, unless otherwise specified, "weight %" as used herein shall refer to the weight percentage based on the total weight of the composition on an oil - free basis.

[0173] The present disclosure is not limited to the specific embodiments described in this application, which are intended to illustrate various aspects. Many modifications and variations can be made without departing from the spirit and scope of the invention, which will be apparent to those skilled in the art. In addition to those enumerated herein, functionally equivalent methods and components within the scope of the present disclosure will be apparent to those skilled in the art based on the foregoing description. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is limited only by the terms of the appended claims and the full scope of equivalents thereof. It should be understood that the present disclosure is not limited to a particular method, reagent, compound, or composition, which can of course vary. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0174] While various compositions, methods, and devices are described as "comprising" various components or steps (interpreted to mean "including, but not limited to"), the compositions, methods, and devices may also "consist essentially of" or "consist of" the various components and steps, and such terms should be interpreted to define substantially closed groups of members.

[0175] Regarding the use of substantially any plural and / or singular terms herein, those skilled in the art can appropriately convert from plural to singular and / or from singular to plural according to the context and / or application. For clarity, various singular / plural permutations may be set forth explicitly herein.

[0176] Those skilled in the art should understand that, generally speaking, the terms used herein and especially those used in the appended claims (e.g., the subject matter of the appended claims) are generally intended to be "open" terms (e.g., the term "comprising" should be interpreted as "comprising, but not limited to", the term "having" should be interpreted as "having at least", the term "including" should be interpreted as "including, but not limited to", etc.). Those skilled in the art will further understand that if an intention is to introduce a specific number of claim limitations, such intention will be expressly recited in the claim, and in the absence of such recitation, no such intention exists. For example, for purposes of illustration, the following appended claims may contain the use of introductory phrases "at least one" and "one or more" to introduce claim limitations. However, the use of such phrases should not be construed as implying that the introduction of a claim limitation by the indefinite article "a" or "an" will limit any particular claim containing such introduced claim limitation to an embodiment containing only one such limitation, even when the same claim includes an introductory phrase "one or more" or "at least one" as well as an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim limitations. Further, even if a specific number of introduced claim limitations is expressly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the unadorned recitation of "two limitations", without other modifiers, means at least two limitations or two or more limitations). Additionally, in those instances where a convention such as "at least one of A, B, and C, etc." is used, generally speaking, such a construction is intended to have the meaning that those skilled in the art will understand the convention to have (e.g., a system having at least one of A, B, and C will include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). In those instances where a convention such as "at least one of A, B, or C, etc." is used, generally speaking, such a construction is intended to have the meaning that those skilled in the art will understand the convention to have (e.g., a system having at least one of A, B, or C will include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). Those skilled in the art will further understand that, in fact, any disjunctive word and / or phrase presenting two or more alternative terms, whether in the specification, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, any one of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B".

[0177] In addition, when features or aspects of the present disclosure can be described in terms of a Markush group, those skilled in the art will recognize that the present disclosure is also thereby described in terms of any single member or subgroup of members of the Markush group.

[0178] As will be understood by those skilled in the art, for any and all purposes, such as in providing a written description, all ranges disclosed herein also cover any and all possible sub-ranges and combinations of sub-ranges thereof. Any recited range can be readily viewed as being sufficiently described and enabling the same range to be broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. By way of non-limiting example, each range discussed herein can be readily broken down into a lower third, a middle third, and an upper third, etc. As will also be understood by those skilled in the art, all language such as "at most," "at least," etc. includes the recited number and refers to ranges that can then be broken down into the sub-ranges as described above. Finally, as will be understood by those skilled in the art, a range includes each individual member. Thus, for example, a group having from 1 wt% to 3 wt% means a group having 1 wt%, 2 wt%, or 3 wt%. Similarly, a group having from 1 wt% to 5 wt% means a group having 1 wt%, 2 wt%, 3 wt%, 4 wt%, or 5 wt%, etc., including all points therebetween.

[0179] In addition, when a recited range is provided for a processing rate, it is contemplated that the range should include the processing rates for the individual components and / or mixtures of components. Thus, for example, a range of 1 wt% to 3 wt% contemplates that a given component can be present in the range of 1 wt% to 3 wt% or that a mixture of similar components can be present in the range of 1 wt% to 3 wt%.

[0180] Although the invention has been explained with reference to its preferred embodiments, it should be understood that various modifications thereof will become apparent to those skilled in the art upon reading this specification. Accordingly, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.

Claims

1. A thermoplastic polyurethane (TPU) composition, the thermoplastic polyurethane (TPU) composition comprising: TPU, the TPU having 15% to 50% hard segments and at least 50% average vertical elasticity measured according to ASTM D2632, the TPU being formed from the reaction product of: A polyisocyanate component comprising a straight-chain aliphatic diisocyanate having 3 to 12 carbon atoms; A polyol component selected from polycaprolactone polyols and polyester polyols; and A straight-chain or branched-chain chain extender component having a main backbone of 4 to 16 carbon atoms and at least two hydroxyl groups, wherein the methanol groups are separated by at least two carbon atoms.

2. The composition according to claim 1, wherein the straight-chain aliphatic diisocyanate component is selected from 1,6-hexamethylene diisocyanate and pentamethylene diisocyanate, preferably 1,6-hexamethylene diisocyanate.

3. The composition according to claim 1 or claim 2, wherein the polyisocyanate component is present in an amount of 10% to 30% by weight of the TPU.

4. The composition according to any one of claims 1 to 3, wherein the polyol component is polycaprolactone.

5. The composition according to any one of claims 1 to 4, wherein the polyol component has a molecular weight (M w ) of from 1,000 to 3,500.

6. The composition according to any one of claims 1 to 5, wherein the polyol component is present in an amount of 40% to 80% by weight of the TPU.

7. The composition according to any one of claims 1 to 6, wherein the chain extender component is selected from 1,12-dodecanediol, 1,6-hexanediol, and 1,4-butanediol.

8. The composition according to any one of claims 1 to 7, wherein the chain extender component is present in an amount of 5% to 30% by weight of the TPU.

9. The composition according to any one of claims 1 to 8, wherein the TPU composition further comprises a plasticizer component.

10. The composition according to claim 9, wherein the plasticizer component is a dialkyl glutarate ester.

11. The composition according to claim 9 or claim 10, wherein the plasticizer component is present in an amount of at most 7% by weight of the TPU composition.

12. The composition according to any one of claims 1 to 11, wherein the vertical elasticity of the TPU is at least 54%.

13. The composition according to any one of claims 1 to 12, wherein the TPU has a tanδ (measured according to ASTM D5279) of less than 0.0035 at 1.0 Hz.

14. The composition according to any one of claims 1 to 13, wherein the TPU composition is formed into a powder having a particle size (D90) of less than 140 microns.

15. The composition according to any one of claims 1 to 15, wherein the TPU composition is formed into a powder having a powder melting time of less than 30 seconds.

16. A 3D printed part, the 3D printed part being prepared from the TPU composition according to any one of claims 1 to 15.

17. The 3D printed part according to claim 16, wherein the 3D printed part has a resilience elasticity greater than 50 measured according to ASTM D7121.

18. The 3D printed part according to claim 16 or claim 17, wherein the 3D printed part is selected from footwear midsole, prosthesis, orthopedic supplies, electronic components, consumer goods, sports goods and toys.

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