A nylon elastomer, a nylon elastomer foam material, and a preparation method and application thereof

Abstract

The present invention belongs to the technical field of polymer materials, and provides a nylon elastomer, a nylon elastomer foam material, and a preparation method and application thereof, wherein the characteristic viscosity of the nylon elastomer under the conditions of 150°C and 0.01 Hz is 200-50000 Pa·s; the characteristic temperature of the nylon elastomer is 120-170°C, and the characteristic temperature indicates the temperature at which the storage modulus and the loss modulus of the nylon elastomer are equal. Through the design of specific characteristic viscosity and characteristic temperature, the nylon elastomer has excellent foaming performance, and the nylon elastomer foam material obtained by foaming thereof has uniform pores, small pore diameter, stable properties, low shrinkage, high foaming ratio, high resilience and excellent mechanical properties, which greatly improves the comprehensive performance of the foam material and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a nylon elastomer, a nylon elastomer foaming material, and a preparation method and application thereof. Background Art

[0002] Nylon elastomer (Poly-Ether Block Amide, PEBA) is a linear block copolymer. It is lightweight and has excellent low-temperature resistance, elastic recovery, impact resistance and toughness. It is one of the most promising products among thermoplastic elastomers and is widely used in footwear, sporting goods, electronics and electrical, automotive industry, food packaging, medical products and other fields.

[0003] At present, the foaming process of PEBA foaming materials mainly includes bead foaming, sheet foaming, embryo mold foaming, mucell injection molding, etc. Supercritical fluid foaming technology is based on supercritical CO 2 , supercritical N 2 Compared with traditional physical foaming agents such as alkanes and freons, supercritical fluids have the advantages of wide sources, environmental friendliness, and non-flammability. 2 The particles after foaming have a serious shrinkage problem. This severe shrinkage not only significantly increases the density of the foamed material, but also causes obvious wrinkles and depressions on the surface of the foamed material, seriously affecting the subsequent use of the foamed material.

[0004] In order to improve the shrinkage problem of foaming materials, researchers have proposed a method of blending other polymers, dimensional stabilizers, nucleating agents and other additives. For example, CN108047702A discloses a thermoplastic elastomer and its foaming material, wherein the thermoplastic elastomer includes 50-95% of block polyetheramide elastomer, and also includes one or more of EVA, POE, and OBC, which accounts for 5-50% of the total mass fraction; the process for preparing the foaming material includes: after blending the components, cross-linking to obtain a thermoplastic elastomer material, and then supercritically foaming the material to obtain a foaming material with good resilience. CN117511184A discloses a low shrinkage thermoplastic polyamide elastomer foaming material, which is made by foaming a thermoplastic polyamide elastomer composition, and the thermoplastic polyamide elastomer composition includes the following components: 90-99 parts of thermoplastic polyamide elastomer, 0-10 parts of polyamide, 0.5-5 parts of inorganic filler, 1-2 parts of lubricant, 0.1-0.5 parts of antioxidant, 0-1.5 parts of chain extender; wherein, the interfacial tension between the inorganic filler and the thermoplastic polyamide elastomer is ≥2, so that the polyamide elastomer matrix phase and the inorganic filler dispersed phase have a lower nucleation barrier, which is conducive to the heterogeneous nucleation of gas at the two-phase interface; at the same time, the interaction between the two-phase interface is weak, which promotes the formation of an open-cell structure and avoids severe foam shrinkage caused by a large negative pressure. Although methods such as blending other polymers, dimensional stabilizers, and nucleating agents can solve the foam shrinkage problem to a certain extent, these methods will not only increase costs, but also reduce the foaming ratio.

[0005] Another method to improve shrinkage is to adjust the foaming equipment and process. For example, CN116323138A discloses a method and equipment for manufacturing foamed articles, which uses a solid foamable material and carbon dioxide to foam under conditions of heating and pressurization. The solid foamable material contains one or more thermoplastic elastomers. Carbon dioxide is injected into the solid foamable material and expanded without softening the solid material to form a foaming material with a low density, uniform porous foam structure and good performance. However, in this method, the process of heating and pressurization will change the state of the material, and a uniform pore structure cannot be obtained, which affects the uniformity and resilience of the foam.

[0006] Therefore, developing a foaming material with low shrinkage, high expansion ratio, low density and good resilience is an urgent problem to be solved in the field. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a nylon elastomer, a nylon elastomer foam material and a preparation method and application thereof. The nylon elastomer has a specific characteristic viscosity and characteristic temperature, and is used to prepare a nylon elastomer foam material, which can give the foam material a low shrinkage rate, a high foaming ratio and excellent rebound performance.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a nylon elastomer, wherein the characteristic viscosity of the nylon elastomer at 150°C and 0.01 Hz is 200-50000 Pa·s; the characteristic temperature of the nylon elastomer is 120-170°C, and the characteristic temperature indicates the temperature at which the storage modulus and loss modulus of the nylon elastomer are equal.

[0010] The nylon elastomer provided by the present invention has a specific characteristic viscosity and characteristic temperature, and has excellent foaming performance through parameter design. The nylon elastomer foam material prepared by foaming the nylon elastomer has uniform pores, small pore diameter, stable properties, low shrinkage rate, high foaming ratio and high resilience, and excellent mechanical properties.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] In the present invention, the intrinsic viscosity, storage modulus (G') and loss modulus (G'') of the nylon elastomer can be obtained by testing with a rotational rheometer.

[0013] Exemplarily, the method of testing using a rotational rheometer is as follows: using an instrument of model MCR 102e produced by Anton Paar, specifically at 150°C, the test frequency is set to 0.0001-200 Hz, and the 0.01-5 mm test piece is cut into a disc with a diameter of 15-25 mm for frequency scanning. The intrinsic viscosity is taken at 0.01 Hz and 150°C.

[0014] In the present invention, the intrinsic viscosity of the nylon elastomer at 150° C. and 0.01 Hz is 200-50000 Pa·s, for example, 300 Pa·s, 500 Pa·s, 1000 Pa·s, 2000 Pa·s, 5000 Pa·s, 8000 Pa·s, 10000 Pa·s, 12000 Pa·s, 15000 Pa·s, 18000 Pa·s, 20000 Pa·s, 22000 Pa·s, 25000 Pa·s, 28000 Pa·s, 30000 Pa·s, 32000 Pa·s, 35000 Pa·s, 38000 Pa·s, 40000 Pa·s, 42000 Pa·s, 45000 Pa·s or 48000 Pa·s. Pa·s, and specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, the present invention no longer exhaustively lists the specific point values ​​included in the range, preferably 800-45000 Pa·s, and further preferably 1000-30000 Pa·s.

[0015] The nylon elastomer of the present invention has an intrinsic viscosity of 200-50000 Pa·s at 150°C and 0.01 Hz, and can be foamed to obtain an elastomer foam product with low shrinkage, high foaming ratio and high resilience. If the intrinsic viscosity of the nylon elastomer is less than 200 Pa·s, the stability of the foamed product formed by foaming will be seriously lost, the pores will be easily broken, and the shrinkage will be large; if the intrinsic viscosity of the nylon elastomer is greater than 50000 Pa·s, the processing pressure required in the product molding process is high, and it is difficult to obtain a product with a high foaming ratio.

[0016] The characteristic temperature of the nylon elastomer is 120-170°C, for example, it can be 122°C, 125°C, 128°C, 130°C, 132°C, 135°C, 138°C, 140°C, 142°C, 145°C, 148°C, 150°C, 152°C, 155°C, 158°C, 160°C, 162°C, 165°C or 168°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0017] The storage modulus (G') and loss modulus (G'') of the nylon elastomer of the present invention have an intersection point within the temperature range of 120-170°C, that is, G' / G''=1, and the storage modulus G' is equal to the loss modulus G''.

[0018] Exemplarily, the test frequency of the storage modulus G', the loss modulus G'' and the characteristic temperature is 0.01 Hz.

[0019] The characteristic temperature of the nylon elastomer of the present invention is 120-170°C (0.01 Hz), and the nylon elastomer foam material with low shrinkage, high foaming ratio, low density, good rebound performance and excellent mechanical properties can be obtained by foaming. If the characteristic temperature is less than 120°C, the foam stability of the foam material will be reduced, resulting in reduced rebound performance; if the characteristic temperature is greater than 170°C, it is difficult to obtain a foam material with a high foaming ratio.

[0020] Preferably, the molecular structure of the nylon elastomer comprises a polyamide hard segment and a polyol soft segment.

[0021] Preferably, the polyamide hard segment is derived from any one of aliphatic polyamide and semi-aromatic polyamide, or a combination of at least two of them; the combination may be in the form of a mixture, a block copolymer, or a copolyamide.

[0022] Specifically, the polyamide (PA) in the polyamide hard segment includes any one or a combination of at least two of the condensation products of dicarboxylic acids and diamines, the condensation products of ω-amino acids, and the ring-opening polymerization products of cyclic lactams. Exemplarily, the dicarboxylic acids include any one or a combination of at least two of succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanediic acid, trihexadecanedioic acid, terephthalic acid. The diamine includes any one or a combination of at least two of pentamethylenediamine, hexamethylenediamine, decanedioamine, and dodecanedioamine. The cyclic lactam includes any one or a combination of at least two of caprolactam, capryllactam, undecane lactam, and lauryl lactam.

[0023] Preferably, the polyamide hard segment is derived from PA6, PA11, PA12, PA5.4, PA5.9, PA5.10, PA5.12, PA5.13, PA5.14, PA5.16, PA5.18, PA5.36, PA6.4, PA6.9, PA6.10, PA6.12, PA6.13, PA6.14, PA6.16, PA6.18, PA6.36, PA10.4, PA10.9, PA10.10, PA Any one of PA10.12, PA10.13, PA10.14, PA10.16, PA10.18, PA10.36, PA10.T, PA12.4, PA12.9, PA12.10, PA12.12, PA12.13, PA12.14, PA12.16, PA12.18, PA12.36, PA12.T, or a combination of at least two of them; the combination may be a mixture, or a block copolymer, or a copolyamide.

[0024] Preferably, the polyol soft segment is derived from any one or a combination of at least two of tetrahydrofuran polyether, propylene oxide polyether, polyethylene glycol, polypropylene glycol, polybutylene glycol, polycaprolactone diol, polyester diol, and polycarbonate diol, and is further preferably derived from any one or a combination of at least two of tetrahydrofuran polyether, propylene oxide polyether, polyethylene glycol, polypropylene glycol, and polybutylene glycol.

[0025] Preferably, the hardness of the nylon elastomer is 25D-50D, for example, it can be 30D, 35D, 40D, 45D, etc., and more preferably 30D-40D.

[0026] Preferably, the temperature of the melting peak of the nylon elastomer is 120-160°C, for example, it may be 122°C, 125°C, 128°C, 130°C, 132°C, 135°C, 138°C, 140°C, 142°C, 145°C, 148°C, 150°C, 152°C, 155°C or 158°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0027] Exemplarily, the melting temperature (melting peak temperature) of the nylon elastomer is obtained by differential scanning calorimetry (DSC) testing.

[0028] Illustratively, the method for preparing the nylon elastomer comprises: performing a polycondensation reaction of a double-terminated carboxyl polyamide and a polyol to obtain the nylon elastomer.

[0029] The double-terminal carboxyl polyamide constructs the polyamide hard segment of the nylon elastomer, and the polyol (diol) constructs the polyol soft segment of the nylon elastomer.

[0030] Preferably, the number average molecular weight (M n ) is 100-3000 g / mol, for example, it can be 200 g / mol, 400 g / mol, 500 g / mol, 600 g / mol, 800 g / mol, 1000 g / mol, 1200 g / mol, 1500 g / mol, 1800 g / mol, 2000 g / mol, 2200 g / mol, 2500 g / mol or 2800 g / mol, and specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and 300-2000 g / mol is further preferred.

[0031] Preferably, the number average molecular weight (M n) is 500-3500 g / mol, for example, it can be 600 g / mol, 800 g / mol, 1000 g / mol, 1200 g / mol, 1500 g / mol, 1800 g / mol, 2000 g / mol, 2200 g / mol, 2500 g / mol, 2800 g / mol, 3000 g / mol, 3200 g / mol or 3400 g / mol, and specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and further preferably 800-2500 g / mol.

[0032] Preferably, the molar ratio of the double-terminated carboxyl polyamide to the polyol is (0.95-1.05):1, for example, it can be 0.96:1, 0.97:1, 0.98:1, 0.99:1, 1:1, 1.01:1, 1.02:1, 1.03:1, 1.04:1, etc., further preferably (0.99-1.01):1, more preferably (0.995-1.005):1.

[0033] Preferably, the polycondensation reaction is carried out in the presence of a catalyst.

[0034] Preferably, the catalyst for the polycondensation reaction includes any one of zirconium n-propoxide, zirconium n-butoxide, and tetrabutyl titanate, or a combination of at least two thereof.

[0035] Preferably, based on the total mass of the double-terminal carboxyl polyamide and the polyol as 100%, the mass of the catalyst is 0.05-0.5%, for example, it can be 0.06%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25%, 0.28%, 0.3%, 0.32%, 0.35%, 0.38%, 0.4%, 0.42%, 0.45% or 0.48%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0036] Preferably, the polycondensation reaction is carried out in the presence of an antioxidant.

[0037] Preferably, based on the total mass of the double-terminated carboxyl polyamide and the polyol as 100%, the mass of the antioxidant is ≤1%, for example, it can be 0, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.6%, 0.7%, 0.8% or 0.9%, and specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 0-0.5% is further preferred.

[0038] Preferably, the antioxidant includes any one of a hindered amine antioxidant, a hindered phenol antioxidant, and a phosphite antioxidant, or a combination of at least two thereof.

[0039] Preferably, the polycondensation reaction is carried out in an inert atmosphere or a vacuum environment.

[0040] Preferably, the inert atmosphere includes any one of a nitrogen atmosphere, an argon atmosphere, and a helium atmosphere, or a combination of at least two of them.

[0041] Preferably, the temperature of the polycondensation reaction is 220-280°C, for example, it can be 225°C, 230°C, 235°C, 240°C, 245°C, 250°C, 255°C, 260°C, 265°C, 270°C or 275°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0042] Preferably, the polycondensation reaction time is 1-10 h, for example, it can be 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h or 9.5 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0043] Preferably, after the polycondensation reaction is completed, an extrusion granulation step is also included.

[0044] Preferably, the discharge port temperature of the extrusion granulation is 150-240°C, for example, it can be 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C, 225°C, 230°C or 235°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0045] In a second aspect, the present invention provides a nylon elastomer foam material, wherein the nylon elastomer foam material is obtained by foaming the nylon elastomer as described in the first aspect.

[0046] Preferably, the foaming method is a supercritical fluid foaming method.

[0047] In a third aspect, the present invention provides a method for preparing the nylon elastomer foam material as described in the second aspect, the preparation method comprising the following steps:

[0048] Using supercritical fluid as a foaming agent, the nylon elastomer described in the first aspect is foamed under pressure; after the foaming is completed, the pressure is released and the material is aged to obtain the nylon elastomer foam material;

[0049] The foaming comprises a first stage of foaming and a second stage of foaming which are performed sequentially, wherein the temperature of the first stage of foaming is T 1 The temperature of the second stage foaming is T 2 , 5℃≤T 2 -T 1 ≤20℃;

[0050] The aging temperature is T 3 , 5℃≤T 3 -T 1 ≤20℃.

[0051] The nylon elastomer foam material of the present invention adopts the specific nylon elastomer in the first aspect and is foamed by a supercritical fluid foaming method. On the basis of using the specific nylon elastomer, the preparation method further designs a two-stage foaming process. Through the process control of temperature, pressure relief and aging during the foaming process, a nylon elastomer foam material with high foaming ratio and low shrinkage can be obtained. The supercritical fluid foaming method of the present invention has a simple process and low energy consumption, which effectively improves the production efficiency and effectively solves the defects of the foaming method of thermoplastic elastomer in the prior art, which has a complex process and a large shrinkage rate. A nylon elastomer foam material with uniform pores, small pore diameter, high foaming ratio, small shrinkage rate, high resilience and excellent mechanical properties is prepared, which greatly improves the comprehensive performance of the foam material.

[0052] It should be noted that the material form of the nylon elastomer is not limited, for example, it can be beads, sheets or plates; specifically, it can be injection foaming, extrusion foaming, compression molding foaming, etc.

[0053] Preferably, the supercritical fluid comprises any one of supercritical carbon dioxide, supercritical nitrogen, supercritical helium, and supercritical argon, or a combination of at least two thereof, preferably supercritical carbon dioxide and / or supercritical nitrogen, more preferably supercritical carbon dioxide or a combination of supercritical carbon dioxide and supercritical nitrogen.

[0054] In a preferred technical solution, the material form of the nylon elastomer is beads, and the preparation method comprises: mixing the beads, a supercritical fluid and a solvent to obtain a suspension; foaming the suspension under pressure, and after the foaming is completed, releasing the pressure and aging to obtain the nylon elastomer foaming material (bead form).

[0055] Preferably, the solvent comprises water.

[0056] Preferably, the mass ratio of the solvent to the beads is (0.5-2):1, for example, it can be 0.6:1, 0.8:1, 1:1, 1.2:1, 1.5:1 or 1.8:1, etc.

[0057] In another preferred technical solution, the material form of the nylon elastomer is a sheet or a plate, and the preparation method comprises: placing the sheet or the plate in a foaming device, filling it with a supercritical fluid, and foaming it under pressure, and after the foaming is completed, releasing the pressure and ripening it to obtain the nylon elastomer foam material (sheet or plate).

[0058] Preferably, the melting temperature of the nylon elastomer is T m The temperature of the first stage of foaming is T 1 , then -40℃≤T 1 -T m ≤10℃, for example, T 1 -T m It can be -35°C, -30°C, -25°C, -20°C, -15°C, -10°C, -5°C, 0°C or 5°C, as well as specific values ​​between the above values. Due to space limitations and for the sake of simplicity, the present invention will no longer exhaustively list the specific values ​​included in the range. It is further preferred that -30°C ≤ T 1 -T m ≤0℃.

[0059] Preferably, the temperature of the first stage foaming is T 1 The temperature is 100-150°C, for example, it can be 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C or 145°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0060] Preferably, the temperature of the second stage foaming is T 2 The temperature of the first stage of foaming is T 1 , 5℃≤T 2 -T 1 ≤20℃, for example, T 2 -T 1It can be 6°C, 8°C, 10°C, 12°C, 14°C, 15°C, 16°C or 18°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0061] Preferably, the foaming pressure is 10-50 MPa, for example, it can be 15 MPa, 18 MPa, 20 MPa, 22 MPa, 25 MPa, 28 MPa, 30 MPa, 32 MPa, 35 MPa, 38 MPa, 40 MPa, 42 MPa, 45 MPa or 48 MPa, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0062] Preferably, the first foaming time is 0.1-24 h, for example, it can be 0.2 h, 0.5 h, 1 h, 2 h, 4 h, 5 h, 6 h, 8 h, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h, 22 h or 23 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific point values ​​included in the range, and 0.5-10 h is further preferred.

[0063] Preferably, the second foaming time is 0.05-5 h, for example, it can be 0.1 h, 0.2 h, 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h or 4.5 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 0.1-5 h is further preferred.

[0064] In the present invention, the "decompression" means releasing the pressure.

[0065] Preferably, the aging temperature is T 3 The temperature of the first stage of foaming is T 1 , 5℃≤T 3 -T 1 ≤20℃, for example, T 3 -T 1 It can be 6°C, 8°C, 10°C, 12°C, 14°C, 15°C, 16°C or 18°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0066] Preferably, the aging temperature T 3 The temperature of the second foaming stage is T 2 same.

[0067] Preferably, the aging time is 0.1-24 h, for example, it can be 0.2 h, 0.5 h, 1 h, 2 h, 4 h, 5 h, 6 h, 8 h, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h, 22 h or 23 h, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively enumerates the specific points included in the range, and 0.1-1 h is further preferred.

[0068] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0069] The beads of nylon elastomer, supercritical fluid and solvent are mixed to obtain a suspension; the suspension is subjected to a first stage of foaming and a second stage of foaming in sequence under a pressure of 10-50 MPa; the melting temperature of the nylon elastomer is T m The first stage of foaming time is 0.1-24 h, and the temperature is T 1 , -40℃≤T 1 -T m ≤10℃; the second stage foaming time is 0.05-5 h, the temperature is T 2 , 5℃≤T 2 -T 1 ≤20℃;

[0070] After the foaming is completed, the pressure is released, and then the temperature of the second stage of foaming is maintained for 0.1-3 hours to obtain the nylon elastomer foaming material (foaming beads).

[0071] Optionally, the nylon elastomer foam material (foamed beads) is placed in a mold and molded under heat treatment conditions to obtain a molded product (such as a plate).

[0072] Preferably, the heat treatment is performed by using water vapor for heat treatment molding.

[0073] Preferably, the pressure of the water vapor is 0.8-2.5 bar, for example, it can be 1 bar, 1.2 bar, 1.5 bar, 1.8 bar, 2 bar, 2.2 bar or 2.4 bar, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0074] As another preferred technical solution of the present invention, the preparation method comprises the following steps:

[0075] A sheet or plate-shaped nylon elastomer is placed in a foaming device, filled with a supercritical fluid, and then sequentially subjected to a first stage of foaming and a second stage of foaming under a pressure of 10-50 MPa; the melting temperature of the nylon elastomer is T m The first stage of foaming time is 0.1-24 h, and the temperature is T 1 , -40℃≤T 1 -T m ≤10℃; the second stage foaming time is 0.05-5 h, the temperature is T 2 , 5℃≤T 2 -T 1 ≤20℃;

[0076] After the foaming is completed, the pressure is released, and then the temperature of the second stage of foaming is maintained for 0.1-3 hours to obtain the nylon elastomer foam material (foamed sheet or foamed board).

[0077] Preferably, the density of the nylon elastomer foam material is 0.03-0.7 g / cm 3 , for example, it can be 0.04 g / cm 3 , 0.05 g / cm 3 , 0.08 g / cm 3 , 0.1 g / cm 3 , 0.12 g / cm 3 , 0.14 g / cm 3 , 0.15 g / cm 3 , 0.2 g / cm 3 , 0.25 g / cm 3 , 0.3 g / cm 3 , 0.35 g / cm 3 , 0.4 g / cm 3 , 0.45 g / cm 3 , 0.5 g / cm 3 , 0.55 g / cm 3 , 0.6g / cm 3 or 0.65 g / cm 3 , and specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and further preferably 0.04-0.15 g / cm 3 .

[0078] Preferably, the average cell diameter of the nylon elastomer foam material is ≤200 μm, more preferably ≤180 μm, and may be 80-180 μm.

[0079] Preferably, the shrinkage rate of the nylon elastomer foam material is ≤1%, more preferably ≤0.8%, more preferably ≤0.75%, and may be 0.25-0.73%.

[0080] Preferably, the ball rebound rate of the nylon elastomer foam material is greater than 70%, more preferably ≥ 75%, further preferably ≥ 80%, and may be 81-84%.

[0081] In a fourth aspect, the present invention provides an application of the nylon elastomer foam material as described in the second aspect in footwear materials, seat materials, tires, helmets, cushioning materials, thermal insulation materials, drag and noise reduction materials, decorative materials or sports equipment.

[0082] Preferably, the nylon elastomer foam material is applied to insoles, midsoles, saddles, tires, helmets, cushions, interior decorations or sports equipment.

[0083] Compared with the prior art, the present invention has the following beneficial effects:

[0084] The nylon elastomer provided by the present invention has excellent foaming performance through the design of specific characteristic viscosity and characteristic temperature. The nylon elastomer foam material prepared by foaming the nylon elastomer has uniform pores, small pore diameter, stable properties, low shrinkage rate, high foaming ratio, high resilience and excellent mechanical properties, which greatly improves the comprehensive performance of the foam material, can fully meet the performance requirements of the industry for high-performance foam materials, and has broad application prospects. DETAILED DESCRIPTION

[0085] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0086] As used herein, the terms "comprises," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0087] "Optionally" or "either" means that the subsequently described matter or event can or cannot occur, and that the description includes instances where the event occurs and instances where it does not.

[0088] In the following specific embodiments of the present invention, the materials for which the preparation methods are not provided are all commercially available chemicals, and the specific information of the materials is as follows:

[0089]

[0090] In the following specific embodiments of the present invention, the main testing methods for nylon elastomers and nylon elastomer foam materials are as follows:

[0091] (1) Intrinsic viscosity

[0092] The nylon elastomer to be tested was made into a disc with a diameter of 25 mm and a rotational rheometer (MCR 102e, Anton Paar) was used for frequency scanning. The frequency was set to 0.0001-200 Hz and the test temperature was 150°C. The intrinsic viscosity at 0.01 Hz and 150°C was recorded.

[0093] (2) Characteristic temperature

[0094] The nylon elastomer to be tested was made into a disc with a diameter of 25 mm, and a rotational rheometer (MCR 102e, Anton Paar) was used to perform frequency scanning with the frequency set to 0.0001-200 Hz. The test curves of the storage modulus G' and the loss modulus G'' were obtained respectively, and the temperature at the intersection of the storage modulus G' and the loss modulus G'' curves (i.e., the point where G' / G''=1) was recorded as the characteristic temperature.

[0095] (3) Hardness

[0096] The test was performed according to the method in standard ASTM D2240-15(2021).

[0097] (4) Shrinkage

[0098] The test was carried out according to the method in standard ISO 294-4, 2577.

[0099] (5) Ball rebound

[0100] The test was carried out according to the method in standard ASTM 2632.

[0101] (6) Density

[0102] The test was carried out according to the method in standard ASTM D792.

[0103] (7) Average cell diameter

[0104] The test was carried out according to the method in standard GB / T 16594-2008.

[0105] The nylon elastomer, nylon elastomer foam material and the preparation method thereof of the present invention will be described in detail below by taking a plurality of embodiments as examples, but the nylon elastomer, nylon elastomer foam material and the preparation method thereof of the present invention are not limited to these embodiments.

[0106] Example 1

[0107] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 12-500 and 1 mol of polybutylene glycol-1500 are melted in a nitrogen atmosphere, 0.1% of zirconium n-butoxide and 0.1% of antioxidant 168 accounting for the total mass of double-terminated carboxyl polyamide and polyol are added in sequence, reacted at 240° C. for 5 h, extruded and granulated through a 160° C. outlet to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0108] A nylon elastomer foam material and a preparation method thereof, the preparation method is as follows: 1 kg of the nylon elastomer provided in this embodiment and 1 kg of water are added to a 20 L autoclave, and 15 MPa supercritical carbon dioxide is charged to form a suspension; then the temperature is raised to 110°C, the pressure is maintained at 15 MPa, and constant temperature and pressure foaming is performed for 1.5 hours; then the temperature is raised to 120°C, and constant temperature and pressure foaming is performed for 20 minutes; then the gas in the pressure vessel is discharged into the atmosphere, and after the pressure is released, the material is aged at 120°C for 0.1 hour; the foam beads are obtained by drying, and the foam beads obtained above are filled into a mold of 300 mm in length, 200 mm in width, and 40 mm in thickness. Water vapor with a pressure of 1.2 bar is used to compress the particles by 15% along the thickness direction of the mold to bond and form the particles, and a molded foam product is obtained, and then the molded foam product is placed at room temperature for 48 hours for performance evaluation, and the data are shown in Table 1.

[0109] Example 2

[0110] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 12-500 and 1 mol of polybutylene glycol-2000 are melted in a nitrogen atmosphere, 0.25% of zirconium n-butoxide and 0.5% of antioxidant 168 accounting for the total mass of double-terminated carboxyl polyamide and polyol are added, reacted at 240° C. for 3 h, extruded and granulated through a 230° C. outlet to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0111] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in the present embodiment is screw-extruded into a 15 mm thick plate, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 105° C., the pressure is maintained at 20 MPa, and constant temperature and pressure foaming is performed for 1.5 h; then the temperature is raised to 120° C., and constant temperature and pressure foaming is performed for 30 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is aged at a constant temperature of 120° C. for 0.5 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0112] Example 3

[0113] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 12-1000 and 1 mol of polybutylene glycol-2000 are melted in a nitrogen atmosphere, 0.15% of zirconium n-butoxide accounting for the total mass of double-terminated carboxyl polyamide and polyol is added, reacted at 250° C. for 3 h, extruded and granulated through a 220° C. outlet to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0114] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in the present embodiment is screw-extruded into a 15 mm thick plate, the plate is placed in a foaming kettle, filled with 10 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen, and then the temperature is raised to 105°C, the pressure is maintained at 25 MPa, and foaming is performed at constant temperature and pressure for 1.5 h; then the temperature is raised to 120°C, and foaming is performed at constant temperature and pressure for 30 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is aged at a constant temperature of 120°C for 1 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0115] Example 4

[0116] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 612-1000 and 1 mol of polypropylene glycol-1000 are melted in a nitrogen atmosphere, 0.15% of tetrabutyl titanate and 0.3% of antioxidant 1098 accounting for the total mass of double-end carboxyl polyamide and polyol are added in sequence, reacted at 235° C. for 3 h, extruded and granulated through a 200° C. outlet to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0117] A nylon elastomer foam material and a preparation method thereof. The preparation method is as follows: the nylon elastomer (beads) provided in the present embodiment is injection molded into a small midsole embryo of a shoe material, and then placed in a foaming kettle for foaming, filled with 5 MPa supercritical carbon dioxide and 25 MPa supercritical nitrogen, and then heated to 115°C, maintained at a pressure of 30 MPa, and foamed at a constant temperature and pressure for 2 h; heated to 120°C, and foamed at a constant temperature and pressure for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the foamed shoe material embryo is matured at a constant temperature of 120°C for 24 h to obtain a large embryo, and its performance evaluation data is shown in Table 1.

[0118] Example 5

[0119] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 612-1000 and 1 mol of PTMEG-1000 are melted in a nitrogen atmosphere, 0.3% of tetrabutyl titanate accounting for the total mass of double-terminated carboxyl polyamide and polyol is added, reacted at 240° C. for 2 h, extruded and granulated through a 200° C. outlet to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0120] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in the present embodiment is injection molded into a plate, the plate is placed in a foaming kettle for foaming, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, the temperature is raised to 140°C, the pressure is maintained at 20 MPa, constant temperature and pressure foaming is performed for 5 h, and then the temperature is raised to 150°C, constant temperature and pressure foaming is performed for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, the pressure is released, and the plate is matured at a constant temperature of 150°C for 4 h to obtain an injection molded foam plate, and the performance evaluation data thereof are shown in Table 1.

[0121] Example 6

[0122] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 612-1000 and 1 mol of polypropylene glycol-1000 are melted in a nitrogen atmosphere, 0.2% of tetrabutyl titanate and 0.2% of antioxidant 1098 accounting for the total mass of double-end carboxyl polyamide and polyol are added, the mixture is reacted at 240° C. for 4 h, and granulated through an outlet at 180° C. to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0123] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in the present embodiment is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, filled with 10 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen, and then the temperature is raised to 115° C., the pressure is maintained at 25 MPa, and the foaming is carried out at a constant temperature for 10 h; then the temperature is raised to 130° C., and the foaming is carried out at a constant temperature for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 130° C. for 1 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0124] Example 7

[0125] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 1012-1000 and 1 mol of polycarbonate diol-1000 are melted in a nitrogen atmosphere, 0.2% of tetrabutyl titanate and 0.2% of antioxidant 1098 accounting for the total mass of double-terminal carboxyl polyamide and polyol are added, the mixture is reacted at 240° C. for 4 h, and granulated through an outlet at 180° C. to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0126] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in the present embodiment is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, filled with 10 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen, and then the temperature is raised to 115° C., the pressure is maintained at 25 MPa, and the foaming is carried out at a constant temperature for 10 h; then the temperature is raised to 130° C., and the foaming is carried out at a constant temperature for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 130° C. for 1 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0127] Example 8

[0128] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 6-1000 and 1 mol of polycaprolactone diol-1000 are melted in a nitrogen atmosphere, 0.2% of tetrabutyl titanate and 0.2% of antioxidant 1098 accounting for the total mass of double-end carboxyl polyamide and polyol are added, the mixture is reacted at 240° C. for 4 h, and granulated through an outlet at 180° C. to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0129] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in the present embodiment is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, filled with 10 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen, and then the temperature is raised to 115° C., the pressure is maintained at 25 MPa, and the foaming is carried out at a constant temperature for 10 h; then the temperature is raised to 130° C., and the foaming is carried out at a constant temperature for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 130° C. for 1 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0130] Example 9

[0131] A nylon elastomer and a preparation method thereof, wherein the materials and processes are the same as those in Example 2.

[0132] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in this embodiment is screw-extruded into a 15 mm thick plate, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 105° C., the pressure is maintained at 20 MPa, and constant temperature and pressure foaming is performed for 2 h; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 105° C. for 0.5 h to obtain a foamed plate, and its performance evaluation data are shown in Table 1.

[0133] Example 10

[0134] A nylon elastomer and a preparation method thereof, wherein the materials and processes are the same as those in Example 2.

[0135] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in the present embodiment is extruded into a 15 mm thick plate through a screw, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 120° C., the pressure is maintained at 20 MPa, and constant temperature and pressure foaming is performed for 2 h; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 120° C. for 0.5 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0136] Embodiment 11

[0137] A nylon elastomer and a preparation method thereof, wherein the materials and processes are the same as those in Example 2.

[0138] A nylon elastomer foam material and a preparation method thereof. The preparation method is as follows: the nylon elastomer (beads) provided in this embodiment is screw-extruded into a 15 mm thick plate, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 105° C., the pressure is maintained at 20 MPa, and constant temperature and pressure foaming is performed for 1.5 h; then the temperature is raised to 120° C., and constant temperature and pressure foaming is performed for 30 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0139] Comparative Example 1A

[0140] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 12-1500 and 1 mol of polybutylene glycol-500 are melted in a nitrogen environment, 0.2% of zirconium n-butoxide and 0.1% of antioxidant 168 accounting for the total mass of double-terminal carboxyl polyamide and polyol are added, vacuuming is performed, reacting at 240° C. for 4 h, and extruding and granulating through a 180° C. outlet to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0141] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in the comparative example is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, 10 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, the temperature is raised to 145°C, the pressure is maintained at 25 MPa, and constant temperature foaming is performed for 3 hours; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0142] Comparative Example 1B

[0143] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in comparative example 1A is screw-extruded into a 10 mm thick plate, the plate is placed in a foaming kettle, 10 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, the temperature is raised to 145°C, the pressure is maintained at 25 MPa, and the foaming is carried out at a constant temperature for 3 h, and then the temperature is raised to 155°C and the foaming is carried out at a constant temperature for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the foamed plate is matured at a constant temperature of 155°C for 1 h to obtain the foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0144] Comparative Example 2A

[0145] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 612-2000 and 1 mol of polypropylene glycol-500 are melted in a nitrogen atmosphere, 0.2% of tetrabutyl titanate and 0.2% of antioxidant 1098 accounting for the total mass of double-end carboxyl polyamide and polyol are added, the mixture is reacted at 240° C. for 4 h, and granulated through an outlet at 180° C. to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0146] A nylon elastomer foam material and a preparation method thereof. The preparation method is as follows: the nylon elastomer (beads) provided in this comparative example is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 115°C, the pressure is maintained at 20 MPa, and constant temperature foaming is performed for 10 hours, and the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere to obtain a foamed plate. The performance evaluation data of the foamed plate are shown in Table 1.

[0147] Comparative Example 2B

[0148] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in comparative example 2A is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 115° C., the pressure is maintained at 20 MPa, and the foaming is carried out at a constant temperature for 10 h; then the temperature is raised to 130° C., and the foaming is carried out at a constant temperature for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 130° C. for 1 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0149] Comparative Example 3A

[0150] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 612-500 and 1 mol of polypropylene glycol-2500 are melted in a nitrogen atmosphere, 0.2% of tetrabutyl titanate and 0.2% of antioxidant 1098 accounting for the total mass of double-end carboxyl polyamide and polyol are added, the mixture is reacted at 235° C. for 4 h, and granulated through an outlet at 180° C. to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0151] A nylon elastomer foam material and a preparation method thereof. The preparation method is as follows: the nylon elastomer (beads) provided in this comparative example is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 115°C, the pressure is maintained at 20 MPa, and constant temperature foaming is performed for 10 hours, and the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere to obtain a foamed plate. The performance evaluation data of the foamed plate are shown in Table 1.

[0152] Comparative Example 3B

[0153] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in comparative example 3A is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 115° C., the pressure is maintained at 20 MPa, and the foaming is carried out at a constant temperature for 10 h; then the temperature is raised to 130° C., and the foaming is carried out at a constant temperature for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 130° C. for 1 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0154] Comparative Example 4A

[0155] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 612-1500 and 0.998 mol of polypropylene glycol-500 are melted in a nitrogen atmosphere, 0.2% of tetrabutyl titanate and 0.2% of antioxidant 1098 accounting for the total mass of double-end carboxyl polyamide and polyol are added, the mixture is reacted at 235° C. for 4 h, and granulated through an outlet at 180° C. to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0156] A nylon elastomer foam material and a preparation method thereof. The preparation method is as follows: the nylon elastomer (beads) provided in this comparative example is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 115°C, the pressure is maintained at 20 MPa, and constant temperature foaming is performed for 10 hours, and the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere to obtain a foamed plate. The performance evaluation data of the foamed plate are shown in Table 1.

[0157] Comparative Example 4B

[0158] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in comparative example 4A is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, then the temperature is raised to 115° C., the pressure is maintained at 20 MPa, and the foaming is carried out at a constant temperature for 10 h, and then the temperature is raised to 130° C. and the foaming is carried out at a constant temperature for 15 min; the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 130° C. for 1 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0159] Comparative Example 5A

[0160] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 0.998 mol of polyamide 612-1500 and 1 mol of polypropylene glycol-500 are melted in a nitrogen atmosphere, 0.2% of tetrabutyl titanate and 0.2% of antioxidant 1098 accounting for the total mass of double-end carboxyl polyamide and polyol are added, the mixture is reacted at 235° C. for 4 h, and granulated through an outlet at 180° C. to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0161] A nylon elastomer foam material and a preparation method thereof. The preparation method is as follows: the nylon elastomer (beads) provided in this comparative example is extruded into a 10 mm thick plate through a screw, the plate is placed in a foaming kettle, 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen are filled, and then the temperature is raised to 115°C, the pressure is maintained at 20 MPa, and constant temperature foaming is performed for 10 hours, and the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere to obtain a foamed plate. The performance evaluation data of the foamed plate are shown in Table 1.

[0162] Comparative Example 5B

[0163] A nylon elastomer foam material and a preparation method thereof, the preparation method being as follows: the nylon elastomer (beads) provided in comparative example 5A is screw-extruded into a 10 mm thick plate, the plate is placed in a foaming kettle, filled with 5 MPa supercritical carbon dioxide and 15 MPa supercritical nitrogen, then the temperature is raised to 115°C, the pressure is maintained at 20 MPa, and the foaming is performed at a constant temperature for 10 h, and then the temperature is raised to 130°C, and the foaming is performed at a constant temperature for 15 min, and the carbon dioxide and nitrogen in the pressure vessel are discharged into the atmosphere, and after the pressure is released, the plate is matured at a constant temperature of 130°C for 1 h to obtain a foamed plate, and the performance evaluation data thereof are shown in Table 1.

[0164] Comparative Example 6A

[0165] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 1 mol of polyamide 12-500 and 0.998 mol of polybutylene glycol-1500 are melted in a nitrogen atmosphere, 0.02% of zirconium n-butoxide and 0.1% of antioxidant 168 accounting for the total mass of double-terminated carboxyl polyamide and polyol are added in sequence, the mixture is reacted at 220° C. for 5 h, and granulated through an outlet at 160° C. to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0166] A nylon elastomer foam material and a preparation method thereof, the preparation method is as follows: 1 kg of the nylon elastomer provided in this comparative example and 1 kg of water are added to a 20 L high-pressure reactor, and 16 MPa supercritical carbon dioxide is charged to form a suspension; then the temperature is raised to 110°C, the pressure is maintained at 16 MPa, and constant temperature and pressure foaming is performed for 1.5 hours; then the gas in the pressure vessel is discharged into the atmosphere; the foam beads are obtained by drying, and the foam beads obtained above are filled into a mold of 300 mm long × 200 mm wide × 40 mm thick. Water vapor with a pressure of 1.2 bar is used to compress the particles by 15% along the thickness direction of the mold to bond and form the particles, and then the molded foam product is placed at room temperature for 48 hours for performance evaluation, and the data are shown in Table 1.

[0167] Comparative Example 6B

[0168] A nylon elastomer foam material and a preparation method thereof, the preparation method is as follows: 1 kg of nylon elastomer and 1 kg of water provided by comparative example 6A are added to a 20 L autoclave, and 16 MPa supercritical carbon dioxide is charged to form a suspension; then the temperature is raised to 110°C, the pressure is maintained at 16 MPa, and constant temperature and pressure foaming is performed for 1.5 hours; then the temperature is raised to 120°C, and constant temperature and pressure foaming is performed for 20 minutes; then the gas in the pressure vessel is discharged into the atmosphere, and after the pressure is released, the material is aged at 120°C for 0.1 hour; the foam beads are obtained by drying, and the foam beads obtained above are filled into a mold of 300 mm in length, 200 mm in width, and 40 mm in thickness. Water vapor with a pressure of 1.2 bar is used to compress the particles by 15% along the thickness direction of the mold to form a bonding formation, and a molded foam product is obtained, and then the molded foam product is placed at room temperature for 48 hours for performance evaluation, and the data are shown in Table 1.

[0169] Comparative Example 7A

[0170] A nylon elastomer and a preparation method thereof. The preparation method is as follows: 0.9985 mol of polyamide 12-500 and 1 mol of polybutylene glycol-1500 are melted in a nitrogen atmosphere, 0.02% of zirconium n-butoxide and 0.1% of antioxidant 168 accounting for the total mass of double-terminal carboxyl polyamide and polyol are added in sequence, reacted at 220° C. for 5 h, extruded and granulated through a 160° C. discharge port to obtain a nylon elastomer, the parameters of which are shown in Table 1.

[0171] A nylon elastomer foam material and a preparation method thereof, the preparation method is as follows: 1 kg of the nylon elastomer provided in this comparative example and 1 kg of water are added to a 20 L high-pressure reactor, and 16 MPa supercritical carbon dioxide is charged to form a suspension; then the temperature is raised to 110°C, the pressure is maintained at 16 MPa, and constant temperature and pressure foaming is performed for 1.5 hours; the foam beads are obtained by drying, and the foam beads obtained above are filled into a mold of 300 mm in length×200 mm in width×40 mm in thickness. Water vapor with a pressure of 1.2 bar is used to compress the mold by 15% along the thickness direction of the mold to make the particles bond and form, to obtain a molded foam product, and then placed at room temperature for 48 hours, and the performance is evaluated, and the data are shown in Table 1.

[0172] Comparative Example 7B

[0173] A nylon elastomer foam material and a preparation method thereof, the preparation method is as follows: 1 kg of nylon elastomer provided in comparative example 7A and 1 kg of water are added to a 20 L autoclave, and 16 MPa supercritical carbon dioxide is charged to form a suspension; then the temperature is raised to 110°C, the pressure is maintained at 16 MPa, and constant temperature and pressure foaming is performed for 1.5 hours; then the temperature is raised to 120°C, and constant temperature and pressure foaming is performed for 20 minutes; then the gas in the pressure vessel is discharged into the atmosphere, and after the pressure is released, the material is aged at 120°C for 0.1 hour; the foam beads are obtained by drying, and the foam beads obtained above are filled into a mold of 300 mm in length, 200 mm in width, and 40 mm in thickness. Water vapor with a pressure of 1.2 bar is used to compress the particles by 15% along the thickness direction of the mold to bond and form the particles, and a molded foam product is obtained, and then the molded foam product is placed at room temperature for 48 hours for performance evaluation, and the data are shown in Table 1.

[0174] Table 1

[0175]

[0176] Combined with the data in Table 1, it can be seen that the nylon elastomer provided by the present invention has an intrinsic viscosity of 200-50000 Pa·s at 150°C and 0.01 Hz, and a characteristic temperature of 120-170°C, which gives it excellent foaming performance. The nylon elastomer foam material obtained by foaming has uniform pores and stable properties, so that the density of the foamed materials of Examples 1-8 is 0.045-0.12 g / cm 3 The average cell diameter is 80-180 μm, the shrinkage rate is 0.25-0.73%, and the ball rebound rate is 81-84%. It has low shrinkage, high foaming ratio, excellent rebound performance and mechanical properties.

[0177] Comparing Examples 1-8 with Examples 9-11, it can be seen that the present invention can further optimize the performance of the foaming material by controlling the temperature, pressure relief and aging process during the foaming process, and obtain a nylon elastomer foaming material with a high foaming ratio and low shrinkage. The one-stage foaming process used in Examples 9 and 10 resulted in difficulty in foaming, an increase in the density and shrinkage of the foam material, and a decrease in overall performance; and no aging was performed in Example 11, resulting in the shrinkage of the foaming material and the foaming density being lower than expected.

[0178] The characteristic viscosity and characteristic temperature of the nylon elastomer in Comparative Examples 1A-3B are not within the range defined by the present invention, resulting in poor foaming performance. Regardless of whether the conventional foaming process (Comparative Examples 1A, 2A, and 3A) or the preferred two-stage foaming and aging process of the present invention (Comparative Examples 1B, 2B, and 3B) is adopted, the obtained foamed materials have a low foaming ratio, a high shrinkage rate, and low resilience, and cannot meet the performance requirements of the industry for high-performance foam materials.

[0179] Only one of the characteristic viscosity and characteristic temperature of the nylon elastomer in Comparative Examples 4A-7B is within the limited range, resulting in poor foaming performance. The obtained foamed material has a low foaming ratio, a high density, a high shrinkage rate, and insufficient rebound performance, which cannot meet the industry's performance requirements for high-performance foam materials.

[0180] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the nylon elastomer, nylon elastomer foam material and the preparation method and application thereof, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A nylon elastomer foam material, characterized in that: The nylon elastomer foam material is obtained by foaming a nylon elastomer, and the intrinsic viscosity of the nylon elastomer at 150° C. and 0.01 Hz is 1000-10000 Pa·s; The characteristic temperature of the nylon elastomer is 120-162° C., and the characteristic temperature indicates the temperature at which the storage modulus and loss modulus of the nylon elastomer are equal. The test frequency of the storage modulus, loss modulus and characteristic temperature is 0.01 Hz.

2. The nylon elastomer foam material according to claim 1, characterized in that: The molecular structure of the nylon elastomer comprises a polyamide hard segment and a polyol soft segment; The polyamide hard segment is derived from any one of aliphatic polyamide and semi-aromatic polyamide or a combination of at least two thereof; The polyol soft segment is derived from any one of tetrahydrofuran polyether, propylene oxide polyether, polyethylene glycol, and polyester diol, or a combination of at least two of them.

3. The nylon elastomer foam material according to claim 2, characterized in that: The polyester diol includes polycaprolactone diol and / or polycarbonate diol.

4. The nylon elastomer foam material according to claim 1, characterized in that: The hardness of the nylon elastomer is 25D-50D.

5. A method for preparing a nylon elastomer foam material according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: Using supercritical fluid as a foaming agent to foam the nylon elastomer under pressure; after the foaming is completed, the pressure is released and the nylon elastomer is aged to obtain the nylon elastomer foam material; The foaming comprises a first stage of foaming and a second stage of foaming which are performed sequentially, the temperature of the first stage of foaming is T1, the temperature of the second stage of foaming is T2, and 5°C≤T2-T1≤20°C; The aging temperature is T3, 5°C≤T3-T1≤20°C.

6. The preparation method according to claim 5, characterized in that: The supercritical fluid includes any one of supercritical carbon dioxide, supercritical nitrogen, supercritical helium, and supercritical argon, or a combination of at least two of them.

7. The preparation method according to claim 5, characterized in that: The melting temperature of the nylon elastomer is T m , -40℃≤T1-T m ≤10℃; the foaming pressure is 10-50 MPa.

8. The preparation method according to claim 5, characterized in that: The first stage foaming time is 0.1-24 h, and the second stage foaming time is 0.05-5 h.

9. The preparation method according to claim 5, characterized in that: The aging time is 0.1-24 h.

10. Use of the nylon elastomer foam material according to any one of claims 1 to 4 in footwear materials, seat materials, tires, helmets, cushioning materials, thermal insulation materials, drag and noise reduction materials, decorative materials or sports equipment.

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