Polyurethane elastic foamed material and application

Abstract

This invention discloses a polyurethane elastic foam material and its applications. The polyurethane elastic foam material is obtained from a polyurethane elastomer through a supercritical foaming method; the hard segment content of the polyurethane elastomer is 15-55 wt%, preferably 20-50 wt%; the crosslinking density of the polyurethane elastomer is 3.5 × 10⁻⁶. ‑5 -2×10 ‑ 4 mol / g. This invention, by controlling the polyurethane elastomer at the raw material end to simultaneously meet certain requirements for hard segment content and crosslinking density, can obtain supercritical polyurethane elastic foam materials with different hardness. The products also possess advantages such as low density, high resilience, and high plyometric tear strength, and can be widely used in footwear, furniture, automotive, and other fields.

Description

Technical Field

[0001] This invention relates to a foaming material, and more particularly to a polyurethane elastic foaming material and its applications. Background Technology

[0002] Polyurethane elastic foam is a polymer material with excellent elasticity and compressive strength, widely used in footwear, furniture, automobiles, and other fields. Currently, common foaming methods for polyurethane materials include chemical foaming and physical foaming, with physical foaming being more widely used due to its typical advantages.

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

[0004] Most elastic foam materials prepared using supercritical methods use thermoplastic elastomers (TPEs) as raw materials. TPEs can be categorized into polyurethane elastomers such as TPU, polyolefin elastomers such as EVA, POE, OBC, and EPDM, polyester elastomers such as TPEE, polyamide elastomers such as TAPE, and polystyrene elastomers such as hydrogenated styrene-butadiene block copolymer (SEBS).

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

[0006] However, existing polyurethane elastomer materials require melt extrusion foaming or melt, extrusion / injection molding followed by foaming when using supercritical foaming processes, which are relatively complex. In addition, literature has reported that the above foaming processes have the problem of high internal stress, which will result in insufficient resilience and insufficient density of supercritical foamed materials.

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

[0008] Patent CN117881711A discloses a similar preparation process, which involves mixing and casting polyurethane raw materials to prepare polyurethane preforms, followed by supercritical foaming under certain conditions. This patent achieves a polyurethane elastomer foam combining low density and good mechanical properties by adjusting process parameters. However, comparative experiments show that if the prepared polyurethane elastomer has a hardness exceeding Shore A 80, it exhibits defects such as poor foaming performance and uneven cell structure.

[0009] Therefore, it is necessary to develop polyurethane elastomer foams that can be foamed to produce low density, high resilience, and good mechanical properties when using polyurethane elastomers of different hardness. Summary of the Invention

[0010] To address the above technical problems, this invention proposes a polyurethane elastic foam material and its application.

[0011] To achieve the above objectives, 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 by supercritical foaming of polyurethane elastomer;

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

[0014] The crosslinking density of the polyurethane elastomer is 3.5 × 10⁻⁶. -5 -2×10 -4 mol / g.

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

[0016] Through continuous research on elastomers, the inventors discovered that polyurethane elastic foam materials prepared by supercritical foaming process using polyurethane elastomers that meet the above requirements for hard segment content and crosslinking density not only have lower density and higher resilience, but also higher plyometric tear strength. Furthermore, the improvement in these properties is not limited by the hardness of the polyurethane elastomer, and even at higher elastomer hardness, the overall performance is significantly improved.

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

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

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

[0020] In some preferred embodiments of the present invention, the supercritical foaming is performed by heating foaming or depressurization foaming.

[0021] Preferably, the saturation temperature of the heating foaming method is 50-90℃, the saturation pressure is 2-50MPa gauge pressure, the saturation time is 12-48h, the foaming temperature is 100-160℃, and the foaming time is 1-10min. When preparing foamed materials using the heating foaming method, the polymer sample is first impregnated with a high-pressure fluid at room temperature or a lower temperature. After diffusion equilibrium, pressure relief in the autoclave, and sample transfer, a polymer sample impregnated with high-pressure fluid is obtained. Then, the sample is heated and foamed by a high-temperature medium and the cell structure is frozen by cooling with cold water to obtain the foamed material.

[0022] Preferably, the saturation temperature of the pressure-reducing foaming method is 100-160℃, the saturation pressure is 5-50 MPa gauge pressure, the saturation time is 5 min-8 h, the foaming temperature is 100-160℃, and the pressure reduction rate is 10-50 MPa / s. When preparing foamed materials using the pressure-reducing foaming method, the polymer sample is impregnated with a fluid at a relatively high temperature and pressure (increasing the temperature reduces the solubility of the high-pressure fluid in the polymer, while increasing the pressure increases the solubility of the fluid). After the polymer sample is saturated with the high-pressure fluid, rapid pressure release causes cell nucleation and growth. The autoclave is then opened, and the foamed sample is quickly removed and cooled to obtain the polymer foamed material.

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

[0024] In some preferred embodiments of the present invention, the polyurethane elastomer is prepared by injection or casting a mixture of isocyanate reactive component A and isocyanate component B into a mold for reaction. Preferably, the number of molar hydrogen atoms of active hydrogen in the isocyanate reactive component A is 'a', and the number of molar isocyanate groups in the isocyanate component B is 'b', then the isocyanate index R of the raw material formulation is 0.8-1.5, more preferably 0.9-1.2. It should be noted that the active hydrogen atom refers to a hydrogen atom capable of reacting with the isocyanate group.

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

[0026] Preferably, the polyol A1 is selected from one or more polyether polyols and polyester polyols with a functionality of not more than 4, preferably 2-3, and preferably a polyol with a weight-average molecular weight of 1000-5000.

[0027] The polyether polyol is a polymer obtained by reacting an initiator and an epoxide monomer under catalysis. Suitable 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, neopentanediol, glycerol, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A, bisphenol S, or mixtures thereof. Preferably, it is a difunctional small-molecule alcohol containing active hydrogen, such as propylene glycol or dipropylene glycol, or a trifunctional small-molecule alcohol containing active hydrogen, such as glycerol or trimethylolpropane. The catalytic action can be provided by at least one of the following substances, including but not limited to: basic hydroxides, basic alkoxides, 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 polyols include conventional polyester polyols, polycaprolactone polyols, and polycarbonate polyols, etc. The conventional polyester polyols are typically formed by the condensation (or transesterification) of an organic dicarboxylic acid (anhydride or ester) with a polyol, or by the polymerization of a lactone with a polyol. The dicarboxylic acid includes, but is not limited to, one or more of phthalic acid or phthalic anhydride or its esters, halophthalic acid, succinic acid, glutaric acid, adipic acid, octanoic acid, maleic acid, and fumaric acid. The polyols include, but are 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 polyols or polyamines with a functionality of not more than 4, preferably 2-3, and is more 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-propanediol, 1,3-propanediol, 1,4-cyclohexanol, 1,6-hexanediol, diethanolamine, triethanolamine, triisopropanolamine, and 3,5-diethyltoluenediamine. The amount of chain extender A2 is generally 1-30 wt%, preferably 3-20 wt%, based on the total mass of the isocyanate reactive component A.

[0030] In some preferred embodiments of the present invention, the isocyanate reactive component A further includes catalyst A3; preferably, catalyst A3 is selected from at least one of triethylenediamine, pentamethyldialkyltriamine, tetramethylalkyldiamine, bis(dimethylaminoethyl) ether, cyclohexylmethyltertiary amine, stannous octoate, stannous oleate, stannous laurate, dimethyl dilaurate, dibutyl dilaurate, dibutyl dithiol tin, bismuth octoate, bismuth neodecanoate, and bismuth naphthenate; the amount of catalyst A3 is generally 0-2 wt%, based on the total mass of the isocyanate reactive component A.

[0031] Preferably, the isocyanate reactive component A may also optionally include an auxiliary agent A4, which includes one or more antioxidants and light stabilizers.

[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 is required, its dosage is generally 0-5 wt%, 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 is required, its dosage is generally 0-5 wt%, based on the total mass of the isocyanate reactive component A.

[0034] In some preferred embodiments of the present invention

[0035] The isocyanate component B is selected from one or more of organic isocyanate monomers, isocyanate prepolymers, polyisocyanates, and isocyanate modified products, preferably at least one polyol-modified isocyanate prepolymer, more preferably at least one polyol-modified isocyanate prepolymer with 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 embodiments 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, terephthalic diisocyanate, 1,4-cyclohexane diisocyanate, phenylenediamine diisocyanate, cyclohexane diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, tetramethyl-methylene diisocyanate, norbornene diisocyanate, dimethylbiphenyl diisocyanate, methylcyclohexyl diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 2,4,6-trimethyl-1,3-phenylenediamine diisocyanate, 4-chloro-6-methyl The polyol modified from at least one of the following isocyanates: 1,3-phenylene diisocyanate, poly(tetrafluoroethylene oxide-co-difluoromethyleneoxy)α,ω-diisocyanate, 1,4-butane diisocyanate, 1,8-octane diisocyanate, 1,3-bis(1-isocyanate-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 mixtures of these isomers, terephthalimide diisocyanate and their prepolymers, dimers, trimers, and modified products, preferably one or more of the following isocyanate types: terephthalimide diisocyanate and at least one of their prepolymers, dimers, trimers, and modified products.

[0038] In some preferred embodiments of the present invention, the foam density of the polyurethane elastic foam material is 0.12-0.2 g / cm³. 3 The resilience rate is 70-80%, and the tear strength is 3.1-4.1 kN / m.

[0039] The key to this invention lies in controlling the content of hard segments and the crosslinking density of the polyurethane elastomer. On one hand, when the hard segment content is controlled at 15-55 wt%, preferably 20-50 wt%, the hydrogen bonding between molecular chains is stronger, resulting in better viscoelasticity and a higher storage modulus of the polyurethane material. This is beneficial for improving the matrix strength during supercritical foaming, thereby producing a foamed material with excellent cell performance. On the other hand, the crosslinking density is controlled at 3.5 × 10⁻⁶. -5 -2×10-4 At a concentration of mol / g, the viscoelasticity and matrix strength of polyurethane materials are further improved. During the supercritical foaming process, the cells are less likely to break, and the cell density and foaming ratio will increase, thus obtaining a foamed material with excellent comprehensive performance.

[0040] This invention does not impose any restrictions on the methods for controlling the hard segment content and crosslinking density of the polyurethane elastomers described above. Those skilled in the art can make comprehensive adjustments based on any known adjustment methods. For example, methods for controlling the hard segment content include, but are not limited to, the following: (1) increasing the hard segment content by increasing the content of the chain extender; (2) increasing the hard segment content by increasing the NCO content in isocyanate component B; (3) increasing the hard segment content by using a high isocyanate index R, i.e., increasing the isocyanate content in the polyurethane, etc. For specific adjustment methods mentioned above, please refer to "Tian Yu, Zhang Jie, Wei Yongji. One-step preparation of high-hardness polyurethane elastomers [J]. Polyurethane Industry, 2001, (01): 40-42." etc.

[0041] For example, methods for controlling crosslinking density include, but are not limited to, the following: (1) increasing the crosslinking density by increasing the functionality or content of the chain extender in polyurethane; (2) increasing the crosslinking density by increasing the proportion of polyol A1 in polyurethane; (3) increasing the crosslinking density by increasing the functionality of isocyanate component B in polyurethane; (4) increasing the crosslinking density by increasing the content of polyisocyanate in isocyanate component B; (5) using polyurethane prepolymers with end-capping modifications such as alkoxy and vinyl groups to increase the crosslinking density. For specific adjustment methods mentioned above, please refer to "Jiang Faxing, Xie Zhihuan, Lin Fen, et al. Performance and influencing factors of polyurethane elastomers [J]. Rubber and Plastics Technology and Equipment, 2015, 41(22):24-25+30." and "Wang Shijie, Yang Pengfei, Li Tianduo. Research progress on 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 footwear, furniture, and automobiles.

[0043] This invention controls the polyurethane elastomer at the raw material end to simultaneously meet certain requirements for hard segment content and crosslinking density, thereby obtaining supercritical polyurethane elastic foam materials with different hardness. At the same time, the products have the advantages of low density, high resilience and high plyometric tear strength, and can be widely used in footwear, furniture, automobiles and other fields. Detailed Implementation

[0044] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

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

[0046] PTMEG-3000, a polyether polyol with a functionality of 2, a hydroxyl value of 37 mg KOH / g, and a weight-average molecular weight of 3000, is manufactured by BASF.

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

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

[0049] Chain extenders: EG (ethylene glycol), Tianjin Zhonghe Shengteng Chemical Co., Ltd.; DPG (dipropylene glycol), SK Picglobal; GL (glycerin), Wilmar Oils & Fats Technology Co., Ltd.

[0050] Catalyst DABCO 1027, Air Products, Inc.

[0051] Isocyanate component:

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

[0053] B2 is prepared from polyether polyol PTMEG-3000 modified dicyclohexylmethane diisocyanate (HMDI), 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 hexamethylene diisocyanate (HDI) modified with polyester polyol CMA-44, wherein the NCO content is 26.1%.

[0056] The method for calculating the hard segment content of polyurethane elastomer in this invention:

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

[0058] The mass of isocyanate refers to the mass of pure isocyanate, excluding the mass of other non-isocyanate components (such as polyols) in the modified isocyanate; the mass of chain extender includes the sum of the mass of the chain extender in the reactive component of the isocyanate and the mass of the chain extender that may be used in the modified isocyanate.

[0059] The method for calculating the crosslinking density (P) of polyurethane elastomers in this invention:

[0060] P = Total molar amount of crosslinking bonds / Total mass of polymer

[0061] Wherein, the functionality of the reactive raw materials in polyurethane elastomer is defined as G, and the molar amount is defined as N, then the total molar amount of crosslinking bonds = [(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 according to standard GB / T 24451-2009;

[0064] Elastomer hardness: Tested according to standard GB / T 531.1-2008;

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

[0066] Tensile strength: Tested according to standard GB / T 6344-2008;

[0067] Elongation at break: Tested according to standard GB / T 6344-2008;

[0068] Resilience: Tested according to standard GB / T 6670-2008;

[0069] Transverse tear strength: Tested according to standard GB / T 3903.29.

[0070] Examples 1-7 and Comparative Examples 1-6 below were prepared by casting method to prepare different polyurethane elastomers (refer to the formulations in Tables 1 and 2). The preparation method was as follows: at 25°C, component A was premixed evenly, and then components A and B were mixed according to the corresponding isocyanate index R and cast into the mold. After reacting for 20 minutes, the mixture was demolded.

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

[0072]

[0073]

[0074] Table 2. Polyurethane elastomer formulations (parts by weight) in Comparative Examples 1-6

[0075]

[0076]

Application Example

[0077] The polyurethane elastomers prepared in each embodiment and comparative example were subjected to supercritical depressurization foaming to prepare polyurethane elastic foam materials:

[0078] Polyurethane elastomer was placed in a sealed supercritical reactor, and a CO2 / N2 (volume ratio 1:1) mixed gas was introduced into the reactor at a saturation pressure of 10-15 MPa. At the same time, the reactor temperature was raised to 150-160℃, allowing the polyurethane elastomer to be continuously impregnated in the supercritical fluid for 1.5 h. Subsequently, the pressure was rapidly released at a rate of 15 MPa / s, and a polyurethane elastic foam material with good foaming properties was finally obtained. The test results of the various material properties are shown in Table 3-4.

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

[0080]

[0081]

[0082] Table 4. Performance test results of the polyurethane elastic foam materials obtained in the 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 Stratigraphic tear (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] As shown in the test results in the table above, the hardness range of the polyurethane elastomers in Examples 1-7 is Shore A 65-95, and a density ≤0.2g / m³ can be obtained through supercritical processing. 3 The foamed material prepared according to the method described in this invention exhibits excellent mechanical properties, with no foam shrinkage, and a balance between high resilience (70-80%) and high plyometric tear strength (3.1-4.1 kN / m). In contrast, the polyurethane elastic foamed materials in Comparative Examples 1-5 have higher densities due to foam shrinkage or limited expansion ratio, and also exhibit poorer elasticity; while the polyurethane elastic foamed material in Comparative Example 6 shows good foaming and strength, its resilience only reaches 60%. Therefore, the polyurethane elastic foamed material prepared according to the method described in this invention possesses low density, high elasticity, and excellent mechanical properties.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A polyurethane elastic foam material, characterized in that, It is obtained from polyurethane elastomer through a supercritical foaming method; The hard segment content of the polyurethane elastomer is 15-55 wt%; The crosslinking density of the polyurethane elastomer is 3.5 × 10⁻⁶. -5 -2×10 -4 mol / g; The polyurethane elastomer is prepared by adding a mixture of isocyanate reactive component A and isocyanate component B to a mold for reaction by injection or casting. The isocyanate reactive component A includes polyol A1 and chain extender A2; polyol A1 is selected from one or more of polyether polyols and polyester polyols with a functionality of no more than 4; chain extender A2 is selected from polyols or polyamines with a functionality of no more than 4. The isocyanate component B is selected from one or more of organic isocyanate monomers, isocyanate prepolymers, polyisocyanates, and isocyanate modified products, with a functionality of 2-3.

2. The polyurethane elastic foam material according to claim 1, characterized in that, The hard segment content of the polyurethane elastomer is 20-50 wt%.

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

4. The polyurethane elastic foam material according to any one of claims 1-3, characterized in that, The supercritical foaming process is selected from at least one of the following: supercritical CO2 foaming process, supercritical N2 foaming process, supercritical ethanol foaming process, supercritical propane foaming process, and supercritical butane foaming process.

5. The polyurethane elastic foam material according to claim 4, characterized in that, The supercritical foaming process is an intermittent foaming process.

6. The polyurethane elastic foam material according to any one of claims 1-3, characterized in that, The supercritical foaming process employs either a heating foaming method or a depressurization foaming method.

7. The polyurethane elastic foam material according to claim 6, characterized in that, The saturation temperature of the heating foaming method is 50-90℃, the saturation pressure is 2-50MPa gauge pressure, the saturation time is 12-48h, the foaming temperature is 100-160℃, and the foaming time is 1-10min.

8. The polyurethane elastic foam material according to claim 6, characterized in that, The saturation temperature of the pressure-reducing foaming method is 100-160℃, the saturation pressure is 5-50MPa gauge pressure, the saturation time is 5min-8h, the foaming temperature is 100-160℃, and the pressure reduction rate is 10-50MPa / s.

9. The polyurethane elastic foam material according to any one of claims 1-3, characterized in that, The isocyanate index R of the polyurethane elastomer raw material formulation is 0.8-1.

5.

10. The polyurethane elastic foam material according to claim 9, characterized in that, The isocyanate index R of the polyurethane elastomer raw material formulation is 0.9-1.

2.

11. The polyurethane elastic foam material according to any one of claims 1-3, characterized in that, The polyol A1 is selected from one or more polyether polyols and polyester polyols with a functionality of 2-3.

12. The polyurethane elastic foam material according to claim 11, characterized in that, The polyol A1 is selected from polyols with a weight average molecular weight of 1000-5000.

13. The polyurethane elastic foam material according to claim 11, characterized in that, The chain extender A2 is selected from polyols or polyamines with a functionality of 2-3.

14. The polyurethane elastic foam material according to claim 13, characterized in that, The chain extender A2 is selected from at least one of glycerol, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, diethylene glycol, dipropylene glycol, methylpropanediol, 1,4-butanediol, 1,3-butanediol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-cyclohexanol, 1,6-hexanediol, diethanolamine, triethanolamine, triisopropanolamine, and 3,5-diethyltoluenediamine.

15. The polyurethane elastic foam material according to any one of claims 1-3, characterized in that, The isocyanate reactive component A also includes catalyst A3.

16. The polyurethane elastic foam material according to claim 15, characterized in that, The catalyst A3 is selected from at least one of triethylenediamine, pentamethyldialkyltriamine, tetramethyldialkyltriamine, bis(dimethylaminoethyl) ether, cyclohexylmethyltertiary amine, stannous octoate, stannous oleate, stannous laurate, dimethyl stannous dilaurate, dibutyl stannous dilaurate, dibutyl dithiol stannous, bismuth octoate, bismuth neodecanoate, and bismuth naphthenate.

17. The polyurethane elastic foam material according to claim 15, characterized in that, The isocyanate reactive component A may also optionally include an auxiliary agent A4, which includes one or more antioxidants and light stabilizers.

18. The polyurethane elastic foam material according to any one of claims 1-3, characterized in that, The isocyanate component B is selected from at least one polyol-modified isocyanate prepolymer.

19. The polyurethane elastic foam material according to claim 18, characterized in that, The isocyanate component B is selected from at least one polyol-modified isocyanate prepolymer with an NCO content of 5-35 wt%.

20. The polyurethane elastic foam material according to claim 19, characterized in that, The isocyanate component B is selected from at least one polyol-modified isocyanate prepolymer with an NCO content of 10-26 wt%.

21. The application of a polyurethane elastic foam material according to any one of claims 1-20 in the fields of footwear, furniture, and automobiles.

Images