Anti-compression master batch and preparation method thereof, and low-compression-deformation foaming material and preparation method thereof

Abstract

The invention provides an anti-compression master batch and a preparation method thereof as well as a low-compression-deformation foaming material and a preparation method thereof, and the anti-compression master batch is prepared by taking TPU (Thermoplastic Polyurethane) with carbon-carbon double bonds as a matrix, high-resilience rubber as a modifier and phenolic resin as an initiator through melt grafting reaction. The anti-compression master batch is added into a foaming material formula, the obtained foaming material is excellent in performance, the compression deformation resistance, the thermal shrinkage performance and the rebound resilience of the foaming material are greatly improved, and the foaming material has high application value.

Description

Technical Field

[0001] The present invention provides a compression-resistant masterbatch and a preparation method thereof, and a low-compression-set foamed material and a preparation method thereof, belonging to the field of shoe materials. Background Art

[0002] With the improvement of living standards, sports and fitness have become the consensus of people. Therefore, there are higher and higher requirements for the light weight, elasticity and comfort of shoe materials, especially the soles of sports shoes. Light weight and high elasticity are the main characteristics of sports shoe materials. In particular, professional sports such as basketball and running have very high requirements for the weight and resilience of the soles.

[0003] In recent years, by using the supercritical foaming process, high-performance thermoplastic elastomers such as polyamide elastomer (PEBA), thermoplastic polyurethane elastomer (TPU), and polyether ester elastomer (TPEE) are used. After foaming, a porous material with lighter weight and better elasticity is obtained, which can achieve excellent use performance when used in the midsole of shoes. For example, the midsole made of foamed thermoplastic polyurethane elastomer beads jointly developed by Adidas and BASF has a density of 0.22 - 0.26 g / cm3 and a rebound rate of more than 65%, becoming a revolutionary new shoe material.

[0004] In recent years, domestic and foreign sports brands such as Nike and Li-Ning have used the polyamide elastomer of Arkema company and prepared new high-performance midsole by using supercritical foaming technology. The density of the finished sole is as low as 0.10 - 0.18 g / cm 3 , and its rebound performance can reach more than 75%, becoming a new benchmark in the field of shoe materials. However, the above several materials need to use the supercritical foaming process for the forming process, and the process is relatively complex and the operation difficulty is relatively large.

[0005] For the light-weight and high-elastic midsole prepared by the general chemical foaming process, it is usually prepared by using ethylene-vinyl acetate resin (EVA) as the matrix and blending with one or more copolymers. However, the density is generally 0.20 - 0.26 g / cm 3 , the rebound is less than 65%, and the durability is not good. After wearing for a period of time, there are many wrinkles on the side wall of the sole, the foot feeling drops significantly, and the hardness increases significantly.

[0006] Therefore, developing a midsole material for shoes with a relatively simple process and having characteristics such as light weight, high elasticity, and low compression set rate has become the direction that needs to be broken through in sports shoe materials. Summary of the Invention

[0007] To solve the problem that the sole materials prepared by the chemical foaming process in the prior art often cannot achieve the characteristics of light weight, high elasticity, and low compression set rate at the same time, the present invention first provides an anti-compression masterbatch and its preparation method, which is obtained by cross-linking high-rebound rubber and TPU with phenolic resin and can be used to prepare compression deformation foaming materials.

[0008] The present invention also provides a low compression deformation foaming material and its preparation method. By using the above anti-compression masterbatch, high-rebound rubber capable of forming a cross-linked network structure with polyolefin is added to the TPU segment through the cross-linking action of phenolic resin, improving the melt strength of the polyolefin and TPU blend foaming material, and solving the problem of poor compatibility between the two during simple physical blending and serious deformation of the foaming material when the TPU dosage is ≥ 15%. In addition, due to the introduction of the anti-compression masterbatch, the increase in the dosage of TPU and high-rebound rubber can greatly improve the rebound performance and anti-compression permanent deformation performance of the product; the use of phenolic resin cross-linking agent can improve the heat resistance of the material and effectively improve the heat shrinkage performance of the foaming product.

[0009] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0010] The present invention provides an anti-compression masterbatch, which is prepared by a melt grafting reaction using TPU with carbon-carbon double bonds as the matrix, high-rebound rubber as the modifier, and phenolic resin as the initiator;

[0011] Preferably, the weight parts composition of each raw material of the anti-compression masterbatch includes: 60-80 parts of TPU with carbon-carbon double bonds, such as 60, 63, 66, 79, 72, 75, 78, 80 parts; 30-40 parts of high-rebound rubber, such as 30, 32, 34, 36, 38, 40 parts; 3-7 parts of phenolic resin, such as 3, 4, 5, 6, 7 parts.

[0012] In the present invention, the TPU with carbon-carbon double bonds is prepared by mixing and reacting diisocyanate with a chain extender, a polyester polyol, and a polyol with carbon-carbon double bonds;

[0013] Preferably, the weight parts composition of each raw material of the TPU with carbon-carbon double bonds includes: 10-45 parts of diisocyanate, such as 10, 15, 20, 25, 30, 35, 40, 45 parts; 3-20 parts of chain extender, such as 3, 6, 9, 12, 15, 18, 20 parts; 50-90 parts of polyester polyol, such as 50, 60, 70, 80, 90 parts; 10-20 parts of polyol with carbon-carbon double bonds, such as 10, 12, 14, 16, 18, 20 parts.

[0014] Preferably, the diisocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, 1,5-naphthalene diisocyanate, and more preferably at least one of hexamethylene diisocyanate and dicyclohexylmethane diisocyanate.

[0015] Preferably, the chain extender is a small molecule alcohol chain extender, preferably at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, and more preferably at least one of 1,3-butanediol and 1,4-butanediol.

[0016] Preferably, the polyester polyol is selected from at least one of polyethylene adipate glycol, polybutylene adipate glycol, and polycaprolactone glycol, and preferably at least one of polycaprolactone glycol and polybutylene adipate ethylene adipate.

[0017] Preferably, the polyol having a carbon-carbon double bond is selected from 1,5-hexadiene-3,4-diol, 2-methylidene-1,3-propanediol, cis-2-butene-1,4-diol, and 3-allyloxy-1,2-propanediol, and more preferably 2-methylidene-1,3-propanediol (MEPO).

[0018] Preferably, the TPU having a carbon-carbon double bond is prepared by the following method:

[0019] Mix the diisocyanate, chain extender, polyester polyol, and polyol having a carbon-carbon double bond in proportion in a mixer and stir at high speed to obtain a TPU homogeneous mixture, then place it in a twin-screw extruder, react at high temperature, extrude and pelletize, and dry to obtain a TPU having a carbon-carbon double bond;

[0020] The mixing, twin-screw extruder and subsequent operation processes are all well-known methods in the art, and the present invention does not make specific limitations; preferably, the temperature for reaction and extrusion at high temperature is 170-220 °C, such as 170, 180, 190, 200, 210, 220 °C.

[0021] In the present invention, the high resilience rubber is one or more of ethylene propylene diene monomer rubber, styrene butadiene rubber, butadiene rubber, and brominated butyl rubber.

[0022] In the present invention, the phenolic resin is selected from sulfurized phenolic resins, preferably at least one of tert-butyl phenolic sulfurized resin, octyl phenolic sulfurized resin, and brominated octyl phenolic sulfurized resin, and more preferably brominated octyl phenolic sulfurized resin.

[0023] The present invention also provides a method for preparing the above-mentioned anti-compression masterbatch, and the steps include:

[0024] Weigh TPU with carbon-carbon double bonds, high resilience rubber, and phenolic resin according to the ratio, add them to a high-speed mixer, stir and mix evenly, then place them in a twin-screw extruder for melt grafting reaction, and extrude and pelletize to obtain the anti-compression masterbatch.

[0025] In the present invention, the stirring speed in the high-speed mixer is 500 - 1000 r / min, such as 500, 600, 700, 800, 900, 1000 r / min, and the stirring time is 8 - 20 min, such as 8, 10, 12, 14, 16, 18, 20 min.

[0026] In the present invention, the temperature for the melt grafting reaction in the twin-screw extruder is 150 - 200 °C, such as 150, 160, 170, 180, 190, 200 °C.

[0027] The mixing, twin-screw extruder and subsequent operation processes involved in the above process are all well-known methods in the field, and the present invention does not make specific limitations; preferably, the temperatures of zones I to V of the barrel for extrusion granulation are controlled at 167 °C, 175 °C, 186 °C, 195 °C, 198 °C respectively, and the temperature of the die head is controlled at 190 - 200 °C, such as 190, 192, 194, 196, 198, 200 °C.

[0028] The present invention also provides the application of the above-mentioned anti-compression masterbatch in the field of polyolefin foaming, especially suitable for the midsole of shoes.

[0029] Preferably, the present invention provides a low compression set foaming material, which is prepared from the following raw materials in parts by mass:

[0030] Polyolefin elastomer 50 - 70 parts, such as 50, 53, 56, 59, 62, 65, 68, 70 parts;

[0031] Anti-compression masterbatch 30 - 50 parts, such as 30, 33, 36, 39, 42, 45, 48, 50 parts;

[0032] Crosslinking agent 1 - 4 parts, such as 1, 1.5, 2, 2.5, 3, 3.5, 4 parts;

[0033] Co-crosslinking agent 0 - 3 parts, such as 0, 0.1, 0.5, 1, 1.5, 2, 2.5, 3 parts;

[0034] Blowing agent 5 - 10 parts, such as 5, 6, 7, 8, 9, 10 parts;

[0035] Lubricant 1 - 5 parts, such as 1, 2, 3, 4, 5 parts.

[0036] Among them, the polyolefin elastomer is one or more of ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer.

[0037] Among them, the crosslinking agent is one or more of dicumyl peroxide (DCP), bis(tert-butylperoxyisopropyl)benzene (BIPB), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (bis-25), and tert-butyl peroxy-2-ethylhexyl carbonate (TBEC).

[0038] Among them, the co-crosslinking agent is one or more of trimethylolpropane trimethacrylate (TMPTMA) and triallyl isocyanurate (TAIC).

[0039] Among them, the foaming agent is one or more of azodicarbonamide (AC) and N,N'-dinitrosopentamethylenetetramine (H).

[0040] Among them, the lubricant is one or more of solid paraffin, polyethylene wax, stearic acid, organosiloxane, zinc oxide, and zinc stearate.

[0041] The present invention also provides a method for preparing the aforementioned low compression set foaming material, and the steps thereof are as follows:

[0042] S1: Prepare a polyolefin foaming masterbatch: Mix the polyolefin elastomer, lubricant, crosslinking agent, co-crosslinking agent, foaming agent, and compression-resistant masterbatch, knead them by a kneader and an open mill, and then extrude them through an extruder to obtain a polyolefin foaming masterbatch;

[0043] S2: Prepare a low compression set foaming material: Place the polyolefin foaming masterbatch in the heating barrel of an injection foaming machine to melt it, and then inject it into a mold to obtain a foamed product, i.e., a low compression set foaming material.

[0044] The mixing, kneading, and subsequent foaming operations involved in the above preparation process are all well-known methods in the field, and the present invention does not make specific limitations. For specific operating conditions, those skilled in the art can select them based on the prior art according to the actual situation.

[0045] It should be noted that the blending, extrusion granulation, etc. processes involved in the above method disclosed by the present invention are only for illustrative purposes and are all conventional operating methods in the field. The specific implementation process of the present invention and the following examples should not be limited by the steps and parameters in the above method. In the actual preparation process, those skilled in the art can select them based on the prior art according to actual needs.

[0046] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0047] The preparation method of the present invention has simple steps and an easy-to-control process. The anti-compression masterbatch therein is obtained by cross-linking high-elasticity rubber and TPU with phenolic resin, effectively solving the problems of uneven dispersion after physical blending of TPU and polyolefin elastomer and poor delamination and tearing performance of foamed products. Due to the support of the cross-linked structure, the problem of low melt strength of the TPU component under the conditions of chemical foaming process and serious deformation and poor cell uniformity of the products is effectively solved.

[0048] By introducing a large amount of TPU and high-elasticity rubber into the polyolefin chemical foaming formula, the present invention can significantly improve the rebound performance of foamed products, improve the anti-compression deformation, heat shrinkage and other properties of the products, and solve the problems of hardening of side wrinkles and decreased foot feeling after long-term wearing of current sports shoes. Detailed implementation manners

[0049] The following further elaborates on the present invention with reference to examples. The examples given are only for explaining the present invention and not for limiting the scope of the present invention.

[0050] The sources of the main raw materials in the examples and comparative examples of the present invention are as follows. Without special instructions, other raw materials and reagents are obtained through commercial channels in the market:

[0051] 1,3-Butanediol: Shandong Yaojia Chemical Co., Ltd.;

[0052] 1,4-Butanediol: Shandong Shengze Chemical Co., Ltd.;

[0053] Hexamethylene diisocyanate: Wanhua Chemical Group Co., Ltd., HT100;

[0054] Dicyclohexylmethane diisocyanate: Wanhua Chemical Group Co., Ltd.;

[0055] Polyethylene adipate glycol: Shanghai Hongzhuang Chemical Technology Co., Ltd.;

[0056] Poly(ε-caprolactone)diol: Beijing Innochem Science & Technology Co., Ltd., A81646

[0057] 2-Methylene-1,3-propanediol: TCI (Shanghai) Chemical Industry Development Co., Ltd., M2473;

[0058] EPDM (ethylene propylene diene monomer rubber): Sinopec Mitsui 3092PM;

[0059] SBR (styrene-butadiene rubber): Arlanxeo High Performance Elastomers Co., Ltd., 4525-0;

[0060] Brominated octylphenolic curing resin: Shanxi Research Institute of Chemical Industry Rubber and Plastic Auxiliary Factory, HY-2055;

[0061] Double-bond-free TPU: Wanhua Chemical Group Co., Ltd., A9063;

[0062] POE (ethylene-octene random copolymer): Dow Chemical 8150;

[0063] Crosslinking agent BIPB (di-tert-butyl peroxyisopropylbenzene): Akzo Nobel Perkadox 14S-fl;

[0064] Co-crosslinking agent TAIC (triallyl isocyanurate): Beijing Innochem Technology Co., Ltd. A59754;

[0065] Blowing agent AC3000: Shanghai Aladdin Biochemical Technology Co., Ltd. A302276;

[0066] Zinc stearate: Beijing Innochem Technology Co., Ltd. A34057.

[0067] Preparation Example 1

[0068] Preparation of TPU-1 with carbon-carbon double bonds:

[0069] 8 kg of 1,4-butanediol, 42 kg of hexamethylene diisocyanate, 80 kg of polyethylene glycol adipate diol, and 12 kg of 2-methyl-1,3-propanediol were subjected to high-speed stirring in a mixer to obtain a TPU homogeneous mixture, and then added to a twin-screw extruder. After reactive extrusion, underwater pelletization, and hopper drying, TPU-1 particles with carbon-carbon double bonds were obtained. The reaction temperature range of the twin-screw extruder was set at 185 °C, 190 °C, 195 °C, 195 °C, 190 °C, the die head temperature was 190 °C, the screw speed was 700 RPM, the granulation water temperature was 45 °C, the drying temperature was 60 °C, and the drying time was 2 h.

[0070] Preparation of TPU-2 with carbon-carbon double bonds:

[0071] 15 kg of 1,2-propanediol, 30 kg of dicyclohexylmethane diisocyanate, 60 kg of poly(ε-caprolactone) diol, and 16 kg of 2-methyl-1,3-propanediol were subjected to high-speed stirring in a mixer to obtain a TPU homogeneous mixture, and then added to a twin-screw extruder for mixing. After reactive extrusion, underwater pelletization, and hopper drying, TPU-2 particles containing carbon-carbon double bonds were obtained. The reaction temperature range of the twin-screw extruder was set at 170 °C, 185 °C, 190 °C, 200 °C, 200 °C, the die head temperature was 200 °C, the screw speed was 650 RPM, the granulation water temperature was 45 °C, the drying temperature was 60 °C, and the drying time was 2 h.

[0072] Preparation Example 2

[0073] Preparation of anti-compression masterbatch-1:

[0074] 65 kg of TPU-1 with carbon-carbon double bonds, 34 kg of EPDM 3092, and 4 kg of brominated octylphenol formaldehyde curing resin were added to a high-speed mixer and stirred at 700 r / min for 10 min to mix evenly. Then, they were placed in a twin-screw extruder for melt grafting reaction, extrusion, underwater pelletizing, and drying to obtain anti-compression masterbatch-1. The reaction temperature range of the twin-screw extruder was set at 167 °C, 175 °C, 186 °C, 195 °C, 198 °C, the die head temperature was 192 °C, the screw speed was 800 RPM, and the pelletizing water temperature was 45 °C.

[0075] Preparation of anti-compression masterbatch-2:

[0076] 78 kg of TPU-2 with carbon-carbon double bonds, 40 kg of SBR 4525-0, and 6 kg of brominated octylphenol formaldehyde curing resin were added to a high-speed mixer and stirred at 900 r / min for 15 min to mix evenly. Then, they were placed in a twin-screw extruder for melt grafting reaction, extrusion, underwater pelletizing, and drying to obtain anti-compression masterbatch-1. The reaction temperature range of the twin-screw extruder was set at 167 °C, 175 °C, 186 °C, 195 °C, 198 °C, the die head temperature was 196 °C, the screw speed was 700 RPM, and the pelletizing water temperature was 45 °C.

[0077] Comparative Preparation Example 1

[0078] Preparation of anti-compression masterbatch 3:

[0079] The TPU-1 with carbon-carbon double bonds was replaced with an equal mass of TPU-A9063 without carbon-carbon double bonds, and then anti-compression masterbatch 3 was prepared according to the same preparation method as anti-compression masterbatch-1.

[0080] Examples 1-4

[0081] Preparation of low compression set foamed material, steps:

[0082] S1: Preparation of polyolefin foamed masterbatch: Weigh each raw material according to the ratio in Table 1 below,

[0083] The polyolefin elastomer, anti-compression masterbatch, co-crosslinking agent (TAIC), and lubricant were added to a kneader for blending. The blending time was 10-12 min, and the blending temperature was set at 100-120 °C; then the crosslinking agent (BIPB) and blowing agent (AC3000) were added to the kneader and kneaded at 110 °C - 120 °C for 4-5 min to form a mixture;

[0084] The mixture was transferred to an open mill to roll out a thin sheet, thick passed 2 times, kneaded for 3 min, thin passed 2 times, and mixed for 2 min;

[0085] The flakes are added to a single-screw extruder for granulation to obtain polyolefin foaming masterbatch, at a temperature of 90 - 100 °C and an extruder rotation speed of 100 - 200 r / min.

[0086] S2: The polyolefin foaming masterbatch is placed in the heating barrel of an injection foaming machine for melting, and then injected into a mold to obtain a foamed product, which is a low compression set foaming material; the barrel temperature of the injection molding machine is controlled at 170 - 185 °C, and the holding pressure time is 200 s.

[0087] Comparative Examples 1 - 4

[0088] Weigh each raw material according to the ratio in Table 1 below, and then prepare the foaming material by the same method as in the examples.

[0089] Table 1 Components and ratios of each example (unit, Kg)

[0090]

[0091] The foaming materials prepared from Examples 1 - 4 and Comparative Examples 1 - 4 are made into sole samples through a mold during the above chemical foaming process, and performance measurements such as tensile strength, delamination tear, hardness, density, falling ball rebound rate, compression set rate, etc. are carried out. The measurement results are shown in Table 2.

[0092] The following test methods are adopted:

[0093] Tensile strength: GB / T 10654;

[0094] Delamination tear: GBT 10808 - 2006;

[0095] Hardness: HG / T 2489 - 2007;

[0096] Density: HG / T 2872 - 2009;

[0097] Falling ball rebound rate: GB / T 10652;

[0098] Compression set rate: GB / T 10653.

[0099] Table 2 Performance measurement results of each example and comparative example

[0100]

[0101] It can be seen from the data in Table 2 that the sole materials of the low compression set foaming materials provided by the present invention have a lower measured average density, higher tensile strength, higher rebound rate, and lower high-temperature compression set rate on the basis of ensuring hardness and tear strength; they have better properties of being actually lighter, highly elastic, low compression set rate, and excellent dynamic fatigue resistance.

[0102] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art of this patent, without departing from the scope of the technical solution of the present invention, can make some changes or modifications using the technical content prompted above to equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the present invention's solution.

Claims

1. An anti-compression masterbatch, characterized in that, The anti-compression masterbatch is prepared by a melt grafting reaction using TPU with carbon-carbon double bonds as the matrix, high resilience rubber as the modifier, and phenolic resin as the initiator; Preferably, the weight parts composition of each raw material of the anti-compression masterbatch includes: 60-80 parts of TPU with carbon-carbon double bonds, 30-40 parts of high resilience rubber, and 3-7 parts of phenolic resin.

2. The anti-compression masterbatch according to claim 1, characterized in that, The TPU with carbon-carbon double bonds is prepared by mixing and reacting a diisocyanate with a chain extender, a polyester polyol, and a polyol with carbon-carbon double bonds; Preferably, the weight parts composition of each raw material of the TPU with carbon-carbon double bonds includes: 10-45 parts of diisocyanate, 3-20 parts of chain extender, 50-90 parts of polyester polyol, and 10-20 parts of polyol with carbon-carbon double bonds.

3. The anti-compression masterbatch according to claim 2, characterized in that, The diisocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, 1,5-naphthalene diisocyanate, preferably at least one of hexamethylene diisocyanate and dicyclohexylmethane diisocyanate; and / or The chain extender is a small molecule alcohol chain extender, preferably at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, more preferably at least one of 1,3-butanediol and 1,4-butanediol; and / or The polyester polyol is selected from at least one of polyethylene adipate glycol, polybutylene adipate glycol, and poly(ε-caprolactone) glycol, preferably at least one of poly(ε-caprolactone) glycol and polyethylene adipate glycol; and / or The polyol with carbon-carbon double bonds is selected from 1,5-hexadiene-3,4-diol, 2-methylidene-1,3-propanediol, cis-2-butene-1,4-diol, and 3-allyloxy-1,2-propanediol, preferably 2-methylidene-1,3-propanediol; and / or The TPU with carbon-carbon double bonds is prepared by the following method: According to the ratio, the diisocyanate, the chain extender, the polyester polyol, and the polyol with carbon-carbon double bonds are subjected to high-speed stirring in a mixer to obtain a TPU homogeneous mixture, and then placed in a twin-screw extruder, reacted at a high temperature, extruded and pelletized, and dried to obtain the TPU with carbon-carbon double bonds; Preferably, the temperature for reaction and extrusion at a high temperature is 170-220 °C.

4. The anti-compression masterbatch according to claim 1, characterized in that, The high resilience rubber is one or more of ethylene propylene diene monomer rubber, styrene-butadiene rubber, butadiene rubber, and bromobutyl rubber; and / or The phenolic resin is selected from sulfurized phenolic resins, preferably at least one of tert-butylphenol sulfide resin, octylphenol sulfide resin, and brominated octylphenol sulfide resin, more preferably brominated octylphenol sulfide resin.

5. A preparation method of the anti-compression masterbatch according to any one of claims 1-4, characterized in that the steps Including: Weigh the TPU with carbon-carbon double bonds, high resilience rubber, and phenolic resin according to the ratio, add them to a high-speed mixer, stir and mix evenly, then place them in a twin-screw extruder for melt grafting reaction, and extrude and pelletize to obtain the anti-compression masterbatch.

6. The preparation method according to claim 5, characterized in that, The stirring speed in the high-speed mixer is 500 - 1000 r / min, and the stirring time is 8 - 20 min; and / or The temperature for the melt grafting reaction in the twin-screw extruder is 150 - 200 °C.

7. The application of the anti-compression masterbatch according to any one of claims 1-4 or the anti-compression masterbatch prepared by the method according to claim 5 or 6 in the field of polyolefin foaming, especially suitable for the midsole material of shoes.

8. A low compression set foaming material, characterized in that, The raw materials include the anti-compression masterbatch described in any one of claims 1 - 4 or the anti-compression masterbatch prepared by the method described in claim 5 or 6, and are specifically prepared from the following raw materials in parts by mass:

9. The low compression set foaming material according to claim 8, characterized in that, The polyolefin elastomer is one or more of ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer; and / or The crosslinking agent is one or more of dicumyl peroxide (DCP), bis(tert-butylperoxyisopropyl)benzene (BIPB), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (bis-25), and tert-butyl peroxy-2-ethylhexyl carbonate (TBEC); and / or The co-crosslinking agent is one or more of trimethylolpropane trimethacrylate (TMPTMA) and triallyl isocyanurate (TAIC); and / or The foaming agent is one or more of azodicarbonamide (AC) and N,N'-dinitrosopentamethylenetetramine (H); and / or The lubricant is one or more of solid paraffin, polyethylene wax, stearic acid, silicone oxide, zinc oxide, and zinc stearate.

10. A preparation method of the low compression set foaming material according to claim 8 or 9, characterized in that, It includes the following steps: S1: Prepare the polyolefin foaming masterbatch: Mix the polyolefin elastomer, lubricant, crosslinking agent, co-crosslinking agent, foaming agent, and anti-compression masterbatch, knead them by a kneader and an open mill, and then extrude them through an extruder to obtain the polyolefin foaming masterbatch; S2: Prepare the low compression set foaming material: Melt the polyolefin foaming masterbatch in the heating barrel of an injection foaming machine, and then inject it into a mold to obtain a foamed product, i.e., the low compression set foaming material.

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