Thermoplastic polyurethane foam material

Abstract

The invention relates to a thermoplastic polyurethane foam material. The thermoplastic polyurethane foam material has the following characteristics: a) the density of the foam material is 0.06-0.15 g / cm < 3 >; b) the forming pressure range of the foaming material is 0.3-5 MPa, and the compression ratio is less than or equal to 12%; c) the rebound rate of the foaming material can reach 75%-85%; and d) the hardness of the thermoplastic polyurethane used for preparing the thermoplastic polyurethane foaming material is 50A-70D, and the softening point is 85-205 DEG C. The thermoplastic foaming material is low in density and high in foaming ratio, has excellent anti-attenuation performance due to a special structure, and meanwhile, surprisingly, the rebound resilience of the thermoplastic foaming material can reach 75%-85%.

Description

Technical Field

[0001] The invention belongs to the field of polymer material foaming, and in particular relates to a thermoplastic polyurethane foaming material and a preparation method thereof. Background Art

[0002] Foam materials are widely used in industry, agriculture, packaging, transportation, military, daily necessities and even aerospace due to their low density, high specific strength, excellent heat insulation and sound insulation and cushioning properties. At present, the method of preparing foam materials mainly uses physical or chemical methods to fill a large number of bubbles inside the plastic to expand the material to obtain foam materials. Commonly used foam materials are mostly plastics, mainly including polystyrene (PS) foam, polyethylene (PE) foam, polypropylene (PP) foam and polyurethane (PU) soft and hard foams, etc. Among them, PS plastic foam is prohibited from use because it cannot be degraded and will cause certain pollution to the ecological environment; PE and PP foam materials have poor temperature resistance, which limits their application range.

[0003] Thermoplastic polyurethane foam material-ETPU has been disclosed in patent documents WO2007082838A, WO2010136398A, and CN102229709A. The thermoplastic polyurethane foam material products in the relevant patents have high density and poor resilience, generally around 50-55%. Patent WO2020 / 136239A discloses the preparation of aliphatic isocyanate and aromatic isocyanate composition to prepare thermoplastic polyurethane foam material, and the product has a rebound rate of about 60%. Patent CN110183843A discloses a yellowing-resistant thermoplastic polyurethane foam material prepared from aliphatic isocyanate, and the product has a low rebound rate in the range of 55-60%; TPU is a linear crystalline polymer with high fluidity, and the melt foaming process can theoretically prepare a high-ratio foam material, but due to the low melt strength of linear polymers, bubble breaking and other phenomena are prone to occur during melt foaming, resulting in a decrease in the foaming rate, which is far from achieving the expected effect; and the structure of aliphatic isocyanate is more linear, and the viscosity is low during the foaming process, and a high-foaming-ratio foam cannot be obtained, and the mechanical strength of aliphatic TPU products is low, which cannot meet the requirements of lightweight and high performance of high-end daily necessities and manufacturing industries; especially in the field of shoe materials, with the increase of time, the decay of the product is obvious, and the rebound resilience and the like show a significant decrease, so the development of a slow-decaying thermoplastic polyurethane foam material is an urgent problem to be solved. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a thermoplastic polyurethane foam material and a preparation method thereof. The thermoplastic polyurethane foam material has excellent compression resistance, low and controllable foaming density, good resilience, excellent mechanical properties and slow decay.

[0005] The technical solution of the present invention to solve the above problems is as follows:

[0006] A thermoplastic polyurethane foam material is prepared from the following raw materials:

[0007] 1) Polyisocyanate: 15wt%-60wt%;

[0008] 2) Polyol: 25wt%-75wt%;

[0009] 3) Chain extender: 5wt%-15wt%;

[0010] 4) Antioxidant: 0.2wt%-4wt%;

[0011] 5) UV absorber: 0.2wt%-4wt%.

[0012] Further, the polyisocyanate includes one or more of aliphatic polyisocyanate, alicyclic polyisocyanate, and aromatic polyisocyanate; preferably diisocyanate, including 1,6-hexamethylene diisocyanate, 1,10-decane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate. , 2,4-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, m-xylylene diisocyanate, diphenylmethane-3,3'-dimethoxy-4,4'-diisocyanate, and one or more thereof, and more preferably 1,6-hexamethylene diisocyanate, 1,10-decane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-diphenylmethane diisocyanate, and 2,6-toluene diisocyanate.

[0013] Further, the polyol is one or more of polyether ester polyol, polyester polyol, polyether polyol, polycarbonate polyol, and polycaprolactone polyol; wherein the polyether ester polyol includes one or more of polyether-polyester polyol, polyether-polycaprolactone polyol, and polyether-polycarbonate polyol, and the schematic structural formulas thereof are as follows:

[0014] 1) Polyether-polyester polyols:

[0015]

[0016] 2) Polyether-polycaprolactone type polyol:

[0017]

[0018] 3) Polyether-polycarbonate polyols:

[0019]

[0020] Among them, R is a long-chain alkyl group with less than 12 carbon atoms; R1 is an alkyl group with less than 4 carbon atoms; R2 is a long-chain alkyl group with less than 12 carbon atoms or an alkyl group containing an aromatic ring.

[0021] As a preferred embodiment, the polyester polyol includes: a polyester polyol prepared from a dicarboxylic acid having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms, and a polyol, preferably one or more of polyethylene adipate, polybutylene adipate, polyhexylene adipate, polyethylene adipate 1,4-butylene adipate, and polybutylene adipate 1,4-hexylene adipate, and the number average molecular weight of the polyester polyol is 500 to 10000 g / mol, preferably 600 to 6000 g / mol, and more preferably 800-4000 g / mol.

[0022] As a preferred solution, the polyether polyol includes: one or more of polyethylene oxide glycol, polypropylene oxide glycol, polytetramethylene glycol with a number average molecular weight of 500-4000 g / mol, preferably polytetramethylene glycol with a number average molecular weight of 800-4000 g / mol.

[0023] As a preferred solution, the polycarbonate polyol is a macromolecular polymer having terminal hydroxyl groups at both ends of a long-chain molecule and repeating carbonate groups on the main chain, using a small molecule diol as an initiator and reacting with an aliphatic carbonate such as dimethyl carbonate, diethyl carbonate, and ethylene carbonate; commonly used initiators include 1,2-ethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, and the like, preferably 1,2-ethylene glycol, 1,4-butanediol, and neopentyl glycol; preferably, the number average molecular weight is 500-4000 g / mol, and more preferably 1000-4000 g / mol.

[0024] As a preferred solution, the polycaprolactone diol is prepared by ring-opening polymerization of ε-caprolactone in the presence of a catalyst and an initiator. Common initiators include ethylene glycol, diethylene glycol, neopentyl glycol, etc. The preferred number average molecular weight is 500-4000 g / mol, more preferably 800-4000 g / mol.

[0025] Further, the chain extender includes a combination of one or more of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol and a compound having a nitrogen heterocyclic structure, or the chain extender is a compound having a nitrogen heterocyclic structure.

[0026] As a preferred embodiment, the compound having a nitrogen heterocyclic structure is selected from one or more of 2,4-diaminopyridine, 2,4-diaminopyrimidine, ethyl 2,4-diamino-pyrimidine-5-carboxylic acid, 2,4-diamino-6-ethoxypyrimidine, 2,4-diamino-1,3,5-triazine, 6-nonyl-2,4-diamino-1,3,5-triazine, 6-methyl-2,4-diamino-1,3,5-triazine, 6-pentyl-2,4-diamino-1,3,5-triazine, 2-chloro-4,6-diamino-1,3,5-triazine, and 2,4-diamino-6-(4-methylphenyl)-1,3,5-triazine.

[0027] As a preferred solution, the addition amount of the compound having a nitrogen heterocyclic structure is 1.0 wt%-100 wt% of the chain extender.

[0028] Furthermore, the amount of the antioxidant is 0.1%-4% of the total mass of the thermoplastic polyurethane, and the antioxidant is mainly one or more of hindered phenol antioxidants, hindered amine antioxidants and phosphite antioxidants.

[0029] Furthermore, the UV absorber is a benzotriazole type UV absorber.

[0030] The present invention also provides a method for preparing a thermoplastic polyurethane for preparing a slow-decaying thermoplastic polyurethane foam material, comprising the following steps: adding an antioxidant and a UV absorber to a polyol, stirring for 10 to 60 minutes at 80 to 120° C. to allow the additive to be fully dissolved in the polyol, then using a casting machine to introduce polyisocyanate, polyol and chain extender into a twin-screw extruder, and pelletizing the melt obtained by the reaction underwater.

[0031] As a preferred solution, the extruder is heated in ten stages, with a temperature distribution range of 100°C-250°C. The extruder screw adopts a co-directional double-threaded meshing screw with a length-to-diameter ratio of 42:1-52:1, and the screw speed is 100-500RPM.

[0032] Furthermore, the present invention also provides a method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising the following steps:

[0033] The thermoplastic polyurethane is added into an autoclave, a blowing agent is added, and the mixture is stirred to allow the blowing agent to impregnate the thermoplastic polyurethane, and then the pressure in the autoclave is released.

[0034] Preferably, the process conditions of the preparation method of the slow-decaying thermoplastic polyurethane foam material include: the temperature of the autoclave is 90-180°C, more preferably 100-160°C; the surface pressure of the autoclave is 5-30MPa, more preferably 8-20MPa; the immersion time is 0.1-3 hours, more preferably 0.3-1 hour; the pressure release rate is 0.5-30MPa / s, more preferably 5-10MPa / s.

[0035] Preferably, the foaming agent includes: one or more of an organic liquid and an inorganic gas, wherein the organic liquid needs to be gaseous under the foaming conditions; the organic liquid includes halogenated or non-halogenated saturated or unsaturated aliphatic hydrocarbons, preferably non-halogenated saturated aliphatic hydrocarbons, such as one or more of methane, propane, butane, pentane, etc.; the inorganic gas mainly includes one or more of nitrogen, air, carbon dioxide, etc.

[0036] As another solution, the method for preparing the slow decay thermoplastic polyurethane foam material can also use an extrusion foaming process, comprising the following steps:

[0037] The thermoplastic polyurethane is put into a foaming extrusion device, and the material is melted and plasticized in the extrusion device to obtain a thermoplastic polyurethane melt; after the foaming agent is dissolved in the thermoplastic polyurethane melt, foaming is carried out through a die.

[0038] Preferably, the process conditions of the extrusion foaming process include: the surface pressure of the foaming agent is 10-30MPa, more preferably 15-25MPa; the mass of the foaming agent is 0.1-60% of the mass of the thermoplastic polyurethane melt, more preferably 5-40%; the die temperature is 100-180°C, more preferably 110-160°C; the die surface pressure is 10-30MPa, more preferably 15-25MPa.

[0039] The beneficial effects of the above technical solution are as follows: the introduction of nitrogen heterocycles can improve the rigidity of the molecular structure, improve the phase separation of the product, reduce energy dissipation, and provide better support and compression resistance for the foamed product to achieve a slow decay effect; with the introduction of the rigid group, the foaming effect unexpectedly becomes better, and the foaming ratio increases, which may be due to the presence of the rigid group to a certain extent. The viscosity of the material is increased, which helps to increase the foaming ratio and obtain a lightweight and highly resilient foamed product; the hardness range of the thermoplastic polyurethane material prepared by the present invention is 50A-70D, and the softening point is 85°C-205°C; the density of the foamed material obtained after the above thermoplastic polyurethane material is foamed is 0.06-0.15g / cm 3 , the molding pressure range is 0.3-5MPa; the cell rigidity of the foamed material is increased, the compression rate is reduced, ≤12%, and its rebound rate reaches 75%-85%, according to the DIN 53132 test.

[0040] The thermoplastic polyurethane foam material prepared by the above technical solution is particularly suitable for shoe materials, artificial leather, ground protection materials, children's entertainment venues, thermal insulation materials, sound insulation materials, high-end toys, mattresses, automotive parts, etc. DETAILED DESCRIPTION

[0041] The specific implementation methods and principles of the present invention are described below. The enumerated embodiments do not limit the scope of the present invention but are only used to better illustrate the present invention.

[0042] See Table 1 for raw materials.

[0043] Table 1

[0044]

[0045] Example 1

[0046] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 37.7 kg of hexamethylene diisocyanate, 12.3 kg of 1,4-butanediol, 0.2 kg of 2,4-diamino-1,3,5-triazine, 151.3 kg of polybutylene adipate diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder, reacting at 100° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 2% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 2% of the total amount;

[0047] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 115°C, the pressure is 15MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0048] Example 2

[0049] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 40.8 kg of hexamethylene diisocyanate, 8.7 kg of 1,4-butanediol, 0.2 kg of 2,4-diamino-1,3,5-triazine, 149.3 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 2.5% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 2.0% of the total amount;

[0050] The thermoplastic polyurethane foam material particles are added into an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 100°C, the pressure is 15MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0051] Example 3

[0052] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 36.8 kg of hexamethylene diisocyanate, 13.2 kg of 1,4-butanediol, 0.2 kg of 2,4-diamino-1,3,5-triazine, 148.6 kg of polycaprolactone diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 2.5% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 2.0% of the total amount;

[0053] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 110°C, the pressure is 16MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0054] Example 4

[0055] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 37.2 kg of hexamethylene diisocyanate, 12.8 kg of 1,4-butanediol, 0.2 kg of 2,4-diamino-1,3,5-triazine, 153.3 kg of polycarbonate polyol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 2.5% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 2.0% of the total amount;

[0056] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 115°C, the pressure is 17MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0057] Example 5

[0058] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 40.2 kg of hexamethylene diisocyanate, 8.7 kg of 1,4-butanediol, 1.2 kg of 2,4-diamino-1,3,5-triazine, 153.3 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder, and reacting at 100° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 2.5% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 2.0% of the total amount;

[0059] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 115°C, the pressure is 18MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0060] Example 6

[0061] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: adding 39.8 kg of hexamethylene diisocyanate, 6.5 kg of 1,4-butanediol, 2.4 kg of 2,4-diamino-1,3,5-triazine, 149.3 kg of polytetrahydrofuran diol, an antioxidant and a UV absorber into a twin-screw reaction extruder and reacting at 100° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 2.5% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 2.0% of the total amount;

[0062] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 105°C, the pressure is 15MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0063] Example 7

[0064] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 40.2 kg of hexamethylene diisocyanate, 3.7 kg of 1,4-butanediol, 6.0 kg of 2,4-diamino-1,3,5-triazine, 149.3 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder, and reacting at 100° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 2.5% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 2.0% of the total amount;

[0065] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 115°C, the pressure is 16MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0066] Example 8

[0067] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 38.7 kg of hexamethylene diisocyanate, 2.7 kg of 1,4-butanediol, 7.8 kg of 2,4-diamino-1,3,5-triazine, 149.3 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 2.5% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 2.0% of the total amount;

[0068] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 105°C, the pressure is 18MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0069] Example 9

[0070] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 39.0 kg of hexamethylene diisocyanate, 8.3 kg of 2,4-diamino-1,3,5-triazine, 150.3 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 3% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 0.3% of the total amount;

[0071] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 110°C, the pressure is 17MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0072] Example 10

[0073] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 73.8 kg of diphenylmethane diisocyanate, 8.0 kg of 1,4-butanediol, 16.2 kg of 2,4-diamino-1,3,5-triazine, 110.8 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 3% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 0.3% of the total amount;

[0074] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 110°C, the pressure is 17MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0075] Embodiment 11

[0076] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 108.8 kg of diphenylmethane diisocyanate, 2.0 kg of 1,4-butanediol, 24.2 kg of 2,4-diamino-1,3,5-triazine, 66.6 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 3% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 0.3% of the total amount;

[0077] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 135°C, the pressure is 20MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0078] Example 12

[0079] A method for preparing a slow-decaying thermoplastic polyurethane foam material, comprising: putting 30.8 kg of diphenylmethane diisocyanate, 6.6 kg of 1,4-butanediol, 6.1 kg of 2,4-diamino-1,3,5-triazine, 158.8 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 0.3% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 0.3% of the total amount of the thermoplastic polyurethane;

[0080] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 105°C, the pressure is 15MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0081] Embodiment 13

[0082] A method for preparing a slow-decaying thermoplastic polyurethane foam material comprises: putting 116.8 kg of diphenylmethane diisocyanate, 14.6 kg of 1,4-butanediol, 6.0 kg of 2,4-diamino-1,3,5-triazine, 68.2 kg of polytetrahydrofuran diol, an antioxidant, and a UV absorber into a twin-screw reaction extruder and reacting at 120° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 0.3% of the total amount of the thermoplastic polyurethane, and the amount of the UV absorber accounts for 0.3% of the total amount.

[0083] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 155°C, the pressure is 20MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0084] Comparative Example 1

[0085] 40.8 kg of hexamethylene diisocyanate, 7.7 kg of 1,4-butanediol, 149.3 kg of polytetrahydrofuran diol, an antioxidant and a UV absorber are put into a twin-screw reaction extruder and reacted at 120° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 3% of the total amount of the thermoplastic polyurethane and the amount of the UV absorber accounts for 0.3% of the total amount;

[0086] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 85°C, the pressure is 15MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0087] Comparative Example 2

[0088] 73.8 kg of diphenylmethane diisocyanate, 16.2 kg of 1,4-butanediol, 110.8 kg of polytetrahydrofuran diol, an antioxidant and a UV absorber are put into a twin-screw reaction extruder and reacted at 100° C.-200° C. to obtain a thermoplastic polyurethane elastomer, wherein the antioxidant accounts for 3% of the total amount of the thermoplastic polyurethane and the amount of the UV absorber accounts for 2.5% of the total amount;

[0089] The thermoplastic polyurethane foam material particles are added to an autoclave, and carbon dioxide is introduced to impregnate the TPU particles. The temperature of the autoclave is 90°C, the pressure is 15MPa, and the impregnation time is 3 hours. After impregnation, the material in the autoclave is discharged into the atmosphere at a pressure release rate of 10MPa / s to obtain foamed particles. The foamed particles are molded to prepare a 300mm*200mm*20mm foamed board, and the performance is tested for standby use.

[0090] The testing method of the thermoplastic polyurethane and its foamed material is as follows:

[0091] 1. Thermoplastic polyurethane hardness: using injection molded 6mm test pieces, tested according to ASTM D2240;

[0092] 2. Softening point of thermoplastic polyurethane: The viscosity is measured by CFT-500 rheometer to determine the softening point of the material;

[0093] 3. Density of the foam material, measured according to ASTM D792;

[0094] 4. After the foam material is formed by steam, the resilience of the foam material is tested according to DIN 53512;

[0095] 5. Compression deformation test of foam material after steam molding:

[0096] Test method: 50℃, 50% compression, maintain for 6 hours, then take out, and test the compression after returning to room temperature for 24 hours;

[0097] Performance parameters are shown in Table 2.

[0098] Table 2

[0099]

[0100]

[0101] The embodiments of the present invention have been described above, and the above description is an explanation of the present invention, not all of the present invention, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A thermoplastic polyurethane foam material, characterized in that: a) The density of the foaming material is 0.06-0.15g / cm 3 ; b) The foaming material molding pressure range is 0.3-5MPa, and the compression rate is ≤12%; c) The resilience of the foam material can reach 75%-85%; d) The thermoplastic polyurethane used to prepare the thermoplastic polyurethane foam material has a hardness of 50A-70D and a softening point of 85°C-205°C.

2. The thermoplastic polyurethane foam material according to claim 1, characterized in that: Including the following raw material preparation: 1) Polyisocyanate: 15wt%-60wt%; 2) Polyol: 25wt%-75wt%; 3) Chain extender: 5wt%-15wt%; 4) Antioxidant: 0.2wt%-4wt%; 5) UV absorber: 0.2wt%-4wt%.

3. The thermoplastic polyurethane foam material according to claim 1 or 2, characterized in that: The polyisocyanate includes one or more of aliphatic polyisocyanate, alicyclic polyisocyanate, and aromatic polyisocyanate; preferably 1,6-hexamethylene diisocyanate, 1,10-decane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane One or more of diisocyanate, isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,4-diphenylmethane isocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, meta-xylylene diisocyanate, and diphenylmethane-3,3'-dimethoxy-4,4'-diisocyanate.

4. The thermoplastic polyurethane foam material according to any one of claims 1 to 3, characterized in that: The polyol is one or more of polyether ester polyol, polyester polyol, polyether polyol, polycarbonate polyol and polycaprolactone polyol.

5. The thermoplastic polyurethane foam material according to any one of claims 1 to 4, characterized in that: The polyetherester polyol includes one or more of polyether-polyester polyol, polyether-polycaprolactone polyol, and polyether-polycarbonate polyol; 1) Polyether-polyester polyols: 2) Polyether-polycaprolactone type polyol: 3) Polyether-polycarbonate polyols: Among them, R is a long-chain alkyl group with less than 12 carbon atoms; R1 is an alkyl group with less than 4 carbon atoms; R2 is a long-chain alkyl group with less than 12 carbon atoms or an alkyl group containing an aromatic ring.

6. The thermoplastic polyurethane foam material according to any one of claims 1 to 5, characterized in that: The polyester polyol comprises: a polyester polyol prepared from a dicarboxylic acid having 2 to 12 carbon atoms, preferably 4 to 6 carbon atoms, and a polyol, preferably one or more of polyethylene adipate, polybutylene adipate, polyhexylene adipate, polyethylene adipate 1,4-butylene adipate, and polybutylene adipate 1,4-hexylene adipate, and the number average molecular weight of the polyester polyol is 500 to 10000 g / mol, preferably 600 to 6000 g / mol, and more preferably 800-4000 g / mol; The polyether polyol comprises: one or more of polyethylene oxide glycol, polypropylene oxide glycol, polytetramethylene glycol having a number average molecular weight of 500-4000 g / mol, preferably polytetramethylene glycol having a number average molecular weight of 800-4000 g / mol; The polycarbonate polyol is prepared by reacting 1,2-ethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol as initiators with dimethyl carbonate, diethyl carbonate, and ethylene carbonate, and has a number average molecular weight of 500-4000 g / mol, preferably 1000-4000 g / mol; The polycaprolactone diol is prepared by ring-opening polymerization of ε-caprolactone using ethylene glycol, diethylene glycol and neopentyl glycol as initiators, and has a number average molecular weight of 500-4000 g / mol, preferably 800-4000 g / mol.

7. The thermoplastic polyurethane foam material according to any one of claims 1 to 6, characterized in that: The chain extender includes a combination of one or more of ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, and diethylene glycol and a compound having a nitrogen heterocyclic structure, or the chain extender is a compound having a nitrogen heterocyclic structure.

8. The thermoplastic polyurethane foam material according to any one of claims 1 to 7, characterized in that: The compound having a nitrogen heterocyclic structure is selected from one or more of 2,4-diaminopyridine, 2,4-diaminopyrimidine, ethyl 2,4-diamino-pyrimidine-5-carboxylic acid, 2,4-diamino-6-ethoxypyrimidine, 2,4-diamino-1,3,5-triazine, 6-nonyl-2,4-diamino-1,3,5-triazine, 6-methyl-2,4-diamino-1,3,5-triazine, 6-pentyl-2,4-diamino-1,3,5-triazine, 2-chloro-4,6-diamino-1,3,5-triazine, and 2,4-diamino-6-(4-methylphenyl)-1,3,5-triazine.

9. The thermoplastic polyurethane foam material according to any one of claims 1 to 8, characterized in that: The addition amount of the compound having a nitrogen heterocyclic structure is 1.0 wt%-100 wt% of the chain extender.

10. The thermoplastic polyurethane foam material according to any one of claims 1 to 9, characterized in that: The method for preparing thermoplastic polyurethane for preparing thermoplastic polyurethane foaming material comprises the following steps: dissolving an antioxidant and a UV absorber in a polyol at 80-120° C., introducing the polyisocyanate and a chain extender into a twin-screw extruder, and pelletizing the obtained melt underwater.

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