Polyurethane elastic foaming material and application

Abstract

The invention discloses a polyurethane elastic foam material and application thereof. The polyurethane elastic foaming material is prepared from a polyurethane elastomer through a supercritical foaming method. The hard segment content of the polyurethane elastomer is 15 to 55 weight percent, preferably 20 to 50 weight percent; the crosslinking density of the polyurethane elastomer is 3.5 * 10 <-5 >-2 * 10 <-4 > mol / g. According to the invention, the raw material end polyurethane elastomer is controlled to simultaneously meet the requirements of certain hard segment content and crosslinking density, the supercritical foaming polyurethane elastic foaming material with different hardness can be obtained, and meanwhile, the product has the advantages of low density, high resilience and high splitting layer tearing strength, and can be widely applied to the fields of shoe materials, furniture, automobiles and the like.

Description

Technical Field

[0001] The invention relates to a foaming material, in particular to a polyurethane elastic foaming material and application thereof. Background Art

[0002] Polyurethane elastic foam material is a polymer material with excellent elasticity and compression strength, which is widely used in the fields of shoes, furniture, automobiles, etc. At present, the commonly used foaming methods of polyurethane materials include chemical foaming method and physical foaming method, among which the physical foaming method has a wider application due to its typical advantages.

[0003] Based on the considerations of environmental friendliness, low cost and wide sources, inert gases such as CO2 and N2 can be used for supercritical foaming. Moreover, CO2 and N2 have higher solubility and diffusion coefficient in polymers when they are in a supercritical state. Compared with other foaming methods, the supercritical fluid physical foaming method can obtain low-density, high-performance, uniform-pore microporous materials. This method has been widely used in the foaming of thermoplastic elastomers, cross-linked polymers and other materials.

[0004] Most of the raw materials for preparing elastic foam materials by supercritical method are thermoplastic elastomers (TPE). Thermoplastic elastomers (TPE) can be divided into polyurethane elastomers such as TPU, polyolefin elastomers such as EVA, POE, OBC, EPDM, polyester elastomers such as TPEE, polyamide elastomers such as TAPE, polystyrene elastomers such as hydrogenated styrene-butadiene block copolymer (SEBS), etc.

[0005] For example, patent CN108047702A discloses a thermoplastic elastomer and its foaming material, which is prepared by melt blending Pebax, EVA, POE, and OBC, followed by extrusion of cross-linked particles or high-temperature vulcanization and cross-linking injection molding into sheets, and finally supercritical foaming of the elastomer particles or the molded material to obtain the foaming material.

[0006] However, when existing polyurethane elastomer materials are foamed using the supercritical process, they need to be melt-extruded and foamed, or melt-extruded / injection molded and then foamed, and the process is relatively complicated. In addition, it has been reported in the literature that the above-mentioned foaming process has the problem of high internal stress, which will cause the supercritical foaming material to have insufficient resilience and insufficient density.

[0007] Patent CN116461035A obtains a preformed material by evenly mixing the polyurethane raw material components and then pouring them into a mold, and then supercritically foaming the preformed material to obtain a supercritical foamed material with lower internal stress, good TPU resilience and low density. However, the product performance improvement is limited to resilience and density, and cannot meet the high requirements of high-end products in terms of comprehensive product indicators such as mechanical properties and mechanical properties.

[0008] Patent CN117881711A discloses a similar preparation process, in which polyurethane raw materials are mixed and poured to prepare polyurethane preforms, and then supercritical foaming is performed under certain conditions. The patent adjusts the process parameters to obtain a polyurethane elastomer foam that combines low density with good mechanical properties. However, comparative experiments show that if the hardness of the prepared polyurethane elastomer exceeds Shore A hardness 80, there will be defects such as poor foaming performance and uneven pores.

[0009] Therefore, it is necessary to develop a polyurethane elastomer foam that can be foamed to prepare polyurethane elastomer foam having low density, high resilience, good mechanical properties, mechanical properties and other comprehensive properties when using polyurethane elastomers of different hardness. Summary of the invention

[0010] In order to solve the above technical problems, the present invention provides a polyurethane elastic foam material and application thereof.

[0011] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0012] First, the present invention provides a polyurethane elastic foam material, which is obtained from a polyurethane elastomer through a supercritical foaming method;

[0013] The hard segment content of the polyurethane elastomer is 15-55wt%, preferably 20-50wt%;

[0014] The crosslinking density of the polyurethane elastomer is 3.5×10 -5 -2×10 -4 mol / g.

[0015] In the present invention, the hard segment content refers to the ratio of the mass of isocyanate and chain extender in the polyurethane to the total mass of the polymer; the crosslinking density refers to the ratio of the total molar amount of crosslinking bonds to the total mass of the polymer. Among them, crosslinking bonds refer to chemical bonds formed by the participation of other functional groups in the crosslinking reaction in the reactive raw materials of the polyurethane elastomer, except for two active functional groups used for linear reactions; the total molar amount of crosslinking bonds is the sum of the number of crosslinking bonds corresponding to a single molecule in each reactive raw material multiplied by the molar amount of the raw material. For one molecule of reactive raw material, the number of crosslinking bonds can be calculated by subtracting 2 from the functionality of the raw material. The types of reactive raw materials in polyurethane elastomers are well known to those in the field, and generally include polyols, chain extenders and isocyanate components.

[0016] The inventors have found in their continuous research on elastomers that the polyurethane elastic foam material prepared by a supercritical foaming process using a polyurethane elastomer that meets the above-mentioned hard segment content and cross-linking density requirements as a raw material not only has a lower density and high resilience, but also has a higher split tear strength. Moreover, the above performance improvements are not limited by the hardness of the polyurethane elastomer, and even when the hardness of the elastomer is higher, the comprehensive performance is significantly improved.

[0017] In some preferred examples of the present invention, the Shore A hardness of the polyurethane elastomer is 65-95.

[0018] In some preferred examples of the present invention, the supercritical foaming is selected from at least one of a supercritical CO2 foaming process, a supercritical N2 foaming process, a supercritical ethanol foaming process, a supercritical propane foaming process and a supercritical butane foaming process;

[0019] Preferably, the supercritical foaming is an intermittent foaming process.

[0020] In some preferred examples of the present invention, the supercritical foaming adopts a temperature-increasing foaming method or a pressure-reducing foaming method;

[0021] Preferably, the saturation temperature of the temperature-rising foaming method is 50-90°C, the saturation pressure is 2-50MPa gauge pressure, the saturation time is 12-48h, the foaming temperature is 100-160°C, and the foaming time is 1-10min; when the temperature-rising foaming method is used to prepare the foaming material, the polymer sample is first impregnated with a high-pressure fluid at room temperature or a relatively low temperature, and after diffusion equilibrium, pressure release of the autoclave, and sample transfer, a polymer sample impregnated with a high-pressure fluid is obtained, and then the polymer sample is heated and foamed by a high-temperature medium and then cooled with cold water to freeze the pore structure to obtain a foaming material.

[0022] Preferably, the saturation temperature of the pressure-reducing foaming method is 100-160°C, the saturation pressure is 5-50MPa gauge pressure, the saturation time is 5min-8h, the foaming temperature is 100-160°C, and the pressure reduction rate is 10-50MPa / s. When the pressure-reducing foaming method is used to prepare the foaming material, the polymer sample is immersed in the fluid at a relatively high temperature and a relatively high pressure (increasing the temperature will reduce the solubility of the high-pressure fluid in the polymer, while increasing the pressure can increase the solubility of the fluid). After the polymer sample is saturated with the high-pressure fluid, the pores will nucleate and grow after rapid pressure release. The autoclave body is opened, and the foaming sample is quickly taken out for cooling to obtain the polymer foaming material.

[0023] The polyurethane elastomer provided by the invention can not only be successfully foamed under supercritical process conditions, but also the foamed material has excellent performance.

[0024] In some preferred examples of the present invention, the polyurethane elastomer is prepared by injecting or pouring a mixture of isocyanate reactive component A and isocyanate component B into a mold for reaction; preferably, the number of moles of hydrogen atoms of active hydrogen in the isocyanate reactive component A is a, and the number of moles of isocyanate groups in the isocyanate component B is b, then the isocyanate index R of the raw material formula is 0.8-1.5, more preferably 0.9-1.2. It should be noted that the active hydrogen atoms refer to hydrogen atoms that can react with isocyanate groups.

[0025] In some preferred examples of the present invention, the isocyanate reactive component A comprises polyol A1 and chain extender A2;

[0026] Preferably, the polyol A1 is selected from one or more polyether polyols and polyester polyols having a functionality of no more than 4, preferably 2-3, preferably a polyol having a weight average molecular weight of 1000-5000;

[0027] The polyether polyol is a polymer obtained by the reaction of an initiator and an alkylene oxide polymerization monomer under catalysis. Available initiators include, but are not limited to, water, ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, pentanediol, hexanediol, diethylene glycol, triethylene glycol, dipropylene glycol, diethylene glycol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A, bisphenol S or mixtures thereof, preferably difunctional small molecule alcohols containing active hydrogen such as propylene glycol or dipropylene glycol, or trifunctional small molecule alcohols containing active hydrogen such as glycerol or trimethylolpropane; the catalytic effect can be provided by at least one of the following substances including, but not limited to, alkaline hydroxides, alkaline alcohol salts, antimony pentachloride and mixtures thereof; the polyether polyol of the present invention can also be a bio-based polyether polyol, including but not limited to polyether polyols prepared from castor oil, palm oil, olive oil, soybean oil, etc.

[0028] Specifically, the polyester polyol includes conventional polyester polyol, polycaprolactone polyol and polycarbonate polyol, etc. The conventional polyester polyol is usually formed by condensation (or transesterification) of organic dicarboxylic acid (anhydride or ester) and polyol or by polymerization of lactone and polyol. The dibasic acid includes but is not limited to one or more of phthalic acid or phthalic anhydride or its ester, halogenated phthalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, maleic acid and fumaric acid, and the polyol includes but is not limited to one or more of ethylene glycol, propylene glycol, diethylene glycol, trimethylolpropane, glycerol and pentaerythritol.

[0029] Preferably, the chain extender A2 is selected from a polyol or polyamine having a functionality of not more than 4, preferably 2-3, preferably selected from at least one of glycerol, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, diethylene glycol, dipropylene glycol, methylpropylene glycol, 1,4-butanediol, 1,3-butanediol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-cyclohexanol, 1,6-hexanediol, diethanolamine, triethanolamine, triisopropanolamine, and 3,5-diethyltoluenediamine. The amount of the chain extender A2 is generally 1-30wt%, preferably 3-20wt%, based on the total mass of the isocyanate reactive component A.

[0030] In some preferred examples of the present invention, the isocyanate-reactive component A also includes a catalyst A3; preferably, the catalyst A3 is selected from at least one of triethylenediamine, pentamethyldialkylenetriamine, tetramethyldialkylenediamine, bis(dimethylaminoethyl)ether, cyclohexylmethyl tertiary amine, stannous octoate, stannous oleate, tin laurate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dithiol, bismuth carboxylate, bismuth neodecanoate, and bismuth cycloalkaneate; the amount of catalyst A3 used is generally 0-2wt%, based on the total mass of the isocyanate-reactive component A.

[0031] Preferably, the isocyanate reactive component A further optionally comprises an auxiliary agent A4, wherein the auxiliary agent A4 comprises one or more of an antioxidant and a light stabilizer.

[0032] Preferably, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 168, and antioxidant 1520; if an antioxidant needs to be added, its amount is generally 0-5wt%, based on the total mass of the isocyanate-reactive component A.

[0033] Preferably, the light stabilizer is selected from one or more of Tinuvin 123, Tinuvin 770, Tinuvin 101, Tinuvin 213, Tinuvin 328, Tinuvin 571, Tinuvin 765, Tinuvin B75, Tinuvin B83, Tinuvin B88, UV-1, and UV292; if a light stabilizer needs to be added, its amount is generally 0-5wt%, based on the total mass of the isocyanate-reactive component A.

[0034] In some preferred examples of the present invention,

[0035] The isocyanate component B is selected from one or more of an organic isocyanate monomer, an isocyanate prepolymer, a polyisocyanate, and an isocyanate-modified product, preferably at least one polyol-modified isocyanate prepolymer, more preferably at least one polyol-modified isocyanate prepolymer having an NCO content of 5-35 wt %, preferably 10-26 wt %;

[0036] Preferably, the functionality of the isocyanate component B is 2-3.

[0037] In some preferred examples of the present invention, the isocyanate component B is selected from toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, 1,4-cyclohexane diisocyanate, xylene diisocyanate, cyclohexane diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, tetramethyl-m-xylene diisocyanate, norbornane diisocyanate, dimethyl biphenyl diisocyanate, methylcyclohexyl diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 2,4,6-trimethyl-1,3-phenylene diisocyanate, 4-chloro-6-methyl At least one of 1,3-phenylene diisocyanate, poly(tetrafluoroethylene oxide-co-difluoromethyleneoxy) α,ω-diisocyanate, 1,4-butane diisocyanate, 1,8-octane diisocyanate, 1,3-bis(1-isocyanato-1-methylethyl)benzene, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, naphthalene-1,5-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate or a mixture of these isomers, p-xylylene diisocyanate and their prepolymers, dimers, trimers, modified products, preferably one or more of the polyol-modified products of at least one of the above isocyanate types.

[0038] In some preferred examples of the present invention, the foam density of the polyurethane elastic foam material is 0.12-0.2 g / cm 3 The rebound rate is 70-80%, and the split tear strength is 3.1-4.1kN / m.

[0039] The key point of the present invention lies in the control of the hard segment content and crosslinking density of the polyurethane elastomer. On the one hand, when the hard segment content is controlled at 15-55wt%, preferably 20-50wt%, the hydrogen bonding effect between the molecular chains is stronger, the viscoelasticity of the polyurethane material is better and the storage modulus is higher, which is conducive to improving the matrix strength during the supercritical foaming process, thereby obtaining a foaming material with excellent cell performance. On the other hand, when the crosslinking density is controlled at 3.5×10 -5 -2×10-4 mol / g, the viscoelasticity and matrix strength of the polyurethane material will be further improved, the bubbles will not easily break during the supercritical foaming process, the bubble density and foaming ratio will increase, thus obtaining a foaming material with excellent comprehensive performance.

[0040] The present invention does not impose any restrictions on the control method of the hard segment content and crosslinking density of the polyurethane elastomer. Those skilled in the art can make comprehensive adjustments according to any known adjustment method. For example, the method of controlling the hard segment content includes but is not limited to the following means: (1) increasing the content of the chain extender to increase the hard segment content; (2) increasing the NCO content in the isocyanate component B to increase the hard segment content; (3) increasing the hard segment content by using a high isocyanate index R, that is, increasing the isocyanate content in the polyurethane. For the above specific adjustment methods, please refer to "Tian Yu, Zhang Jie, Wei Yongji. One-step preparation of high hardness polyurethane elastomer [J]. Polyurethane Industry, 2001, (01): 40-42." and so on.

[0041] For another example, the method of controlling the crosslink density includes but is not limited to the following means: (1) increasing the functionality or content of the chain extender in the polyurethane to increase the crosslink density; (2) increasing the proportion of polyol A1 in the polyurethane to increase the crosslink density; (3) increasing the functionality of the isocyanate component B in the polyurethane to increase the crosslink density; (4) increasing the content of polyisocyanate in the isocyanate component B to increase the crosslink density; (5) using polyurethane prepolymers with alkoxy, vinyl or other end-capping modifications to increase the crosslink density, etc. For the above specific adjustment means, please refer to "Jiang Faxing, Xie Zhihuan, Lin Fen, et al. Properties and influencing factors of polyurethane elastomers [J]. Rubber and Plastic Technology and Equipment, 2015, 41 (22): 24-25 + 30.", "Wang Shijie, Yang Pengfei, Li Tianduo. Research progress of post-crosslinking of polyurethane [J]. Polymer Bulletin, 2012, (02): 16-27.", etc.

[0042] The present invention also provides an application of the polyurethane elastic foam material described above in the fields of shoe materials, furniture and automobiles.

[0043] The present invention can obtain supercritical foaming polyurethane elastic foaming materials with different hardnesses by controlling the raw material end polyurethane elastomer to simultaneously meet certain hard segment content and crosslinking density requirements. At the same time, the product has the advantages of low density, high resilience and high split tear strength, and can be widely used in the fields of footwear, furniture, automobiles, etc. DETAILED DESCRIPTION

[0044] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0045] The main raw materials used in the following examples of the present invention are as follows. Unless otherwise specified, other raw materials and reagents can be purchased from commercially available products.

[0046] Polyether polyol PTMEG-3000, functionality 2, hydroxyl value 37mgKOH / g, weight average molecular weight 3000, BASF

[0047] Polyether polyol WH001, functionality 3, hydroxyl value 42mgKOH / g, weight average molecular weight 4000, Zhongshan Chemical

[0048] Polyester polyol CMA-44, functionality 2, hydroxyl value 56mgKOH / g, weight average molecular weight 2000, HuaDa Chemical

[0049] Chain extender: EG (ethylene glycol), Tianjin Zhonghe Shengtai Chemical Co., Ltd.; DPG (dipropylene glycol), SK picglobal; GL (glycerol), Fengyi Oil Technology Co., Ltd.

[0050] Catalyst DABCO 1027, Air Products and Chemicals, USA

[0051] Isocyanate component:

[0052] B1 is prepared by modifying diphenylmethane diisocyanate (MDI) with polyether polyol PTMEG-3000, wherein the NCO content is 24.8%.

[0053] B2 is prepared by modifying dicyclohexylmethane diisocyanate (HMDI) with polyether polyol PTMEG-3000, wherein the NCO content is 15.3%.

[0054] B3 is prepared from polyester polyol CMA-44 modified diphenylmethane diisocyanate (MDI), wherein the NCO content is 14.7%.

[0055] B4 is prepared from polyester polyol CMA-44 modified with hexamethylene diisocyanate (HDI), wherein the NCO content is 26.1%.

[0056] The calculation method of the hard segment content of the polyurethane elastomer in the present invention is:

[0057] Hard segment content = ratio of the mass of isocyanate and chain extender to the total mass of the polymer.

[0058] Among them, the mass of isocyanate is the mass of pure isocyanate, which does not include the mass of other non-isocyanate components in the modified isocyanate (such as polyol); the mass of the chain extender includes the sum of the mass of the chain extender in the isocyanate reactive component and the mass of the chain extender that may be used in the modified isocyanate.

[0059] The calculation method of the crosslinking density (P) of the polyurethane elastomer in the present invention is:

[0060] P = total molar amount of cross-linking bonds / total mass of polymer

[0061] Wherein, the functionality of the reactive raw material in the polyurethane elastomer is defined as G, and the molar weight is defined as N, then the total molar weight of the cross-linking bond = [(G A1 -2)*N A1 ]+[(G A2 -2)*N A2 ]+[(G B -2)*N B ]

[0062] The main test methods or standards involved in the following embodiments of the present invention are as follows:

[0063] Density: Tested in accordance with GB / T 24451-2009 standard;

[0064] Elastomer hardness: Tested in accordance with GB / T 531.1-2008;

[0065] Foam hardness: Tested according to GB / T 10807-1989;

[0066] Tensile strength: Tested in accordance with GB / T 6344-2008 standard;

[0067] Elongation at break: Tested in accordance with GB / T 6344-2008;

[0068] Resilience: Tested in accordance with GB / T 6670-2008 standard;

[0069] Split tear strength: Tested in accordance with standard GB / T 3903.29.

[0070] The following Examples 1-7 and Comparative Examples 1-6 prepare different polyurethane elastomers by casting method (refer to the formula in Table 1 and Table 2). The preparation method is: at 25°C, component A is pre-mixed evenly, and then components A and B are mixed and cast in a mold according to the corresponding isocyanate index R, and demolded after reaction for 20 minutes.

[0071] Table 1. Polyurethane elastomer formulations in Examples 1-7 (parts by mass)

[0072]

[0073]

[0074] Table 2, polyurethane elastomer formulations in comparative examples 1-6 (parts by mass)

[0075]

[0076]

Application examples

[0077] The polyurethane elastomers prepared in the examples and comparative examples were subjected to supercritical pressure reduction foaming to prepare polyurethane elastic foam materials:

[0078] The polyurethane elastomer is placed in a closed supercritical reactor, and a CO2 / N2 (volume ratio 1:1) mixed gas is introduced into the reactor, with a saturation pressure of 10-15MPa; at the same time, the temperature in the reactor is raised to 150-160°C, and the polyurethane elastomer is continuously immersed in the supercritical fluid for 1.5 hours, followed by rapid pressure relief at a rate of 15MPa / s, to ultimately obtain a polyurethane elastic foam material with good foaming properties. The test results of the material properties are shown in Table 3-4.

[0079] Table 3. Performance test results of polyurethane elastic foam material obtained in the examples

[0080]

[0081]

[0082] Table 4. Performance test results of polyurethane elastic foam material obtained in comparative example

[0083] Performance Testing Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 <![CDATA[Density (g / cm 3 )]]> 0.28 0.40 0.32 0.46 0.55 0.22 Shore C hardness 38 55 40 60 58 45 Tensile strength(MPa) 2.5 4.8 2.1 5.4 6.0 3.3 Elongation at break (%) 145 370 220 340 104 310 Resilience(%) 40 30 45 25 20 60 Split tearing force(kN / m) 3.1 4.3 2.8 4.5 5.1 3.5 Does the foam shrink? yes no yes no no no

[0084] From the test results in the above table, it can be seen that the hardness range of the polyurethane elastomers in Examples 1-7 is 65-95 Shore A, and the density can be obtained by supercritical process ≤ 0.2g / m 3 The polyurethane elastic foam material of Comparative Examples 1-5 has a large density and poor elasticity due to foam shrinkage or limited foaming ratio, and the polyurethane elastic foam material of Comparative Example 6 has good foaming and strength, but the elasticity is only 60%. Therefore, the polyurethane elastic foam material prepared by the method described in the present invention has low density, high elasticity and excellent mechanical properties.

[0085] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A polyurethane elastic foam material, characterized in that: It is obtained by supercritical foaming of polyurethane elastomer; The hard segment content of the polyurethane elastomer is 15-55wt%, preferably 20-50wt%; The crosslinking density of the polyurethane elastomer is 3.5×10 -5 -2×10 -4 mol / g.

2. The polyurethane elastic foam material according to claim 1, characterized in that: The Shore A hardness of the polyurethane elastomer is 65-95.

3. The polyurethane elastic foam material according to claim 1 or 2, characterized in that: The supercritical foaming is selected from at least one of a supercritical CO2 foaming process, a supercritical N2 foaming process, a supercritical ethanol foaming process, a supercritical propane foaming process and a supercritical butane foaming process; Preferably, the supercritical foaming is an intermittent foaming process.

4. The polyurethane elastic foam material according to claim 1 or 2, characterized in that: The supercritical foaming adopts a temperature-increasing foaming method or a pressure-reducing foaming method; Preferably, the saturation temperature of the temperature-raising foaming method is 50-90°C, the saturation pressure is 2-50 MPa gauge pressure, the saturation time is 12-48h, the foaming temperature is 100-160°C, and the foaming time is 1-10min; Preferably, the saturation temperature of the pressure reduction foaming method is 100-160° C., the saturation pressure is 5-50 MPa gauge pressure, the saturation time is 5 min-8 h, the foaming temperature is 100-160° C., and the pressure reduction rate is 10-50 MPa / s.

5. The polyurethane elastic foam material according to any one of claims 1 to 4, characterized in that: The polyurethane elastomer is prepared by injecting or pouring a mixture of isocyanate reactive component A and isocyanate component B into a mold for reaction; preferably, the isocyanate index R of the raw material formula is 0.8-1.5, more preferably 0.9-1.

2.

6. The polyurethane elastic foam material according to any one of claims 1 to 5, characterized in that: The isocyanate reactive component A comprises polyol A1 and chain extender A2; Preferably, the polyol A1 is selected from one or more polyether polyols and polyester polyols having a functionality of no more than 4, preferably 2-3, preferably a polyol having a weight average molecular weight of 1000-5000; Preferably, the chain extender A2 is selected from a polyol or polyamine having a functionality of no more than 4, preferably 2-3, preferably selected from at least one of glycerol, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, diethylene glycol, dipropylene glycol, methyl propanediol, 1,4-butanediol, 1,3-butanediol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-cyclohexanol, 1,6-hexanediol, diethanolamine, triethanolamine, triisopropanolamine, and 3,5-diethyltoluenediamine.

7. The polyurethane elastic foam material according to any one of claims 1 to 6, characterized in that: The isocyanate reactive component A further comprises a catalyst A3; preferably, the catalyst A3 is selected from at least one of triethylenediamine, pentamethyldialkylenetriamine, tetramethyldialkylenediamine, bis(dimethylaminoethyl)ether, cyclohexylmethyl tertiary amine, stannous octoate, stannous oleate, tin laurate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dithiolate, bismuth carboxylate, bismuth neodecanoate, and bismuth naphthenate; Preferably, the isocyanate-reactive component A further optionally includes an auxiliary agent A4, wherein the auxiliary agent A4 includes one or more of an antioxidant and a light stabilizer.

8. The polyurethane elastic foam material according to any one of claims 1 to 7, characterized in that: The isocyanate component B is selected from one or more of an organic isocyanate monomer, an isocyanate prepolymer, a polyisocyanate, and an isocyanate-modified product, preferably at least one polyol-modified isocyanate prepolymer, more preferably at least one polyol-modified isocyanate prepolymer having an NCO content of 5-35 wt %, preferably 10-26 wt %; Preferably, the functionality of the isocyanate component B is 2-3.

9. The polyurethane elastic foam material according to any one of claims 1 to 8, characterized in that: The isocyanate component B is selected from toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, 1,4-cyclohexane diisocyanate, xylylene diisocyanate, cyclohexane dimethylene diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, tetramethyl meta-xylylene diisocyanate, norbornane diisocyanate, dimethyl biphenyl diisocyanate, methylcyclohexyl diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 2,4,6-trimethyl-1,3-phenylene diisocyanate ester, 4-chloro-6-methyl-1,3-phenylene diisocyanate, poly(tetrafluoroethylene oxide-co-difluoromethyleneoxy) α,ω-diisocyanate, 1,4-butane diisocyanate, 1,8-octane diisocyanate, 1,3-bis(1-isocyanato-1-methylethyl)benzene, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, naphthalene-1,5-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate or a mixture of these isomers, p-xylylene diisocyanate and their prepolymers, dimers, trimers, modified products at least one.

10. Use of the polyurethane elastic foam material according to any one of claims 1 to 9 in the fields of footwear, furniture and automobiles.

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