Flexible sensing low-temperature-resistant back protection material, preparation method and sports back protection

Abstract

The invention discloses a flexible sensing low-temperature-resistant back protection material, a preparation method and a sports back protection. The flexible sensing low-temperature-resistant back protection material is prepared from the following raw materials in parts by weight: 90 to 110 parts of polyurethane prepolymer, 7 to 17 parts of chain extender, 1 to 3 parts of flexible sensing filler, 1 to 1.5 parts of foam stabilizer, 1 to 1.2 parts of cross-linking agent, 1 to 1.5 parts of catalyst and 1 to 1.5 parts of foaming agent. Two secondary valence bonds, namely an acylhydrazone bond and a disulfide bond, are introduced into the back protection material, and when the back protection material is impacted, the secondary valence bonds can absorb energy to be split and recombined, so that the impacted energy is consumed, the sports back protection material can still keep relatively good flexibility and damping and buffering capability in a cold environment, and reliable protection is provided for athletes; and meanwhile, the back protection material also has a flexible sensing function, so that the sports data and postures of the athletes can be better collected and sports habits can be collected and analyzed while comfort is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of sports back protectors, and in particular to a flexible sensing low-temperature resistant back protector material and a preparation method thereof, and a sports back protector. Background Art

[0002] Motorcycle / ski back protectors are an important part of related protective equipment. They are mainly used to protect the spine, prevent collisions from behind, and ensure the safety of skiers when sliding down at high speed or performing difficult movements. The design and material selection of motorcycle / ski back protectors are directly related to their protective performance and comfort. Therefore, choosing a suitable motorcycle / ski back protector is very important for motorcycle / ski enthusiasts.

[0003] The design standards for motorcycle / ski back protectors mainly include CE EN 1621-2, which is a safety standard for motorcycle / ski back protectors. It evaluates its protection ability by simulating objects of different weights and shapes hitting the back protector and measuring the residual force after passing through the back protector. According to this standard, ski back protectors are divided into different protection levels, among which those that meet the secondary armor standard (EN1621-2 Level 2) provide a higher level of protection because their residual force does not exceed 9kN. In contrast, the residual force of the first armor standard (EN 1621-2 Level 1) does not exceed 18kN. Therefore, from a safety perspective, the secondary armor standard provides better protection.

[0004] With the progress and development of society, people pay more and more attention to the quality of sports. The application of flexible sensors in sports back protectors can detect and feedback human activities in real time through internal sensors, evaluate the training effects such as muscle strength, speed, body coordination, monitor athlete fatigue, improve exercise quality, and prevent training injuries.

[0005] However, the shock absorption and energy absorption effects of traditional sports back protectors with flexible sensors are poor, especially in low-temperature environments, where the hardness increases and the flexibility decreases. They cannot provide reliable protection for athletes in high mountains and extremely cold environments, limiting their application in the field of sports protection. Traditional cushioning back protectors cannot detect the athlete's body shape and thus perform sports data analysis.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The purpose of the present invention is to provide a flexible sensing low-temperature resistant back protection material and a preparation method and a sports back protection. The present invention improves the low-temperature resistance of the back protection material by limiting the raw materials, and solves the problems of poor flexibility, high hardness and inability to provide reliable protection of the existing flexible sensing back protection in low-temperature environments.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0009] The first aspect of the present invention provides a flexible sensing low temperature resistant backing material, wherein the flexible sensing low temperature resistant backing material comprises the following raw materials in parts by weight:

[0010] 90-110 parts of polyurethane prepolymer, 7-17 parts of chain extender, 1-3 parts of flexible sensing filler, 1-1.5 parts of foam stabilizer, 1-1.2 parts of crosslinking agent, 1-1.5 parts of catalyst and 1-1.5 parts of foaming agent;

[0011] The chain extender consists of a disulfide bond chain extender and an acylhydrazone bond chain extender.

[0012] Preferably, the polyurethane prepolymer comprises a hard segment and a soft segment, and the mass ratio of the hard segment to the soft segment is 1:(0.2-0.25).

[0013] Preferably, the hard segment comprises toluene diisocyanate;

[0014] The soft segment comprises terminal hydroxyl polybutadiene-acrylonitrile and polyethylene glycol propylene glycol adipate in a mass ratio of 1: (0.8-1.2).

[0015] Preferably, the polyurethane prepolymer is prepared by the following method:

[0016] The terminal hydroxyl polybutadiene-acrylonitrile and polyethylene glycol propylene glycol adipate are mixed uniformly, water is removed, toluene diisocyanate is added, and then reacted at 80-85° C. to obtain the polyurethane prepolymer.

[0017] Preferably, the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is (2-4):(6-8).

[0018] Preferably, the disulfide bond extender is a polyol containing at least one disulfide bond;

[0019] The acylhydrazone bond chain extender is a polyol containing at least one acylhydrazone bond.

[0020] Preferably, the disulfide bond chain extender is prepared from isophorone diisocyanate and salicylaldehyde. Specifically, isophorone diisocyanate is dissolved and added dropwise to salicylaldehyde, and then a catalyst (a high-content organic bismuth catalyst, an organic tin catalyst, an organic zinc catalyst) is added, and then reacted in an inert gas environment to obtain a polyol containing a disulfide bond; further preferably, the mass ratio of isophorone diisocyanate to salicylaldehyde is 1:(2-3);

[0021] The acylhydrazone bond chain extender is prepared from adipic acid dihydrazide and salicylaldehyde. Specifically, ADH is dissolved in ethanol and then added dropwise to salicylaldehyde for reaction. After the reaction is completed, the mixture is dried to obtain a polyol containing an acylhydrazone bond. More preferably, the mass ratio of adipic acid dihydrazide to salicylaldehyde is 1:(1.5-2.5).

[0022] Preferably, the flexible sensing filler is graphene and / or carbon nanotubes.

[0023] Preferably, the foam stabilizer includes at least one of a polyurethane foam stabilizer, a rigid foam polyurethane foam leveling agent, a polyurethane rigid foam silicone oil AK-158, and a polyurethane oily release agent.

[0024] Preferably, the cross-linking agent includes at least one of polyols, alicyclic alcohols, aromatic alcohols, diamines, alcoholamines, and amines.

[0025] Preferably, the catalyst is at least one of a tertiary amine catalyst or an organic metal catalyst.

[0026] Preferably, the foaming agent is a carbon dioxide foaming agent.

[0027] The second aspect of the present invention provides a method for preparing the above-mentioned flexible sensing low-temperature resistant backing material, the preparation method comprising the following steps:

[0028] (a) adding a disulfide bond chain extender dropwise to a polyurethane prepolymer at 50 to 55° C. to perform a primary chain extension, and after the primary chain extension is completed, heating the prepolymer to 65 to 70° C., and then adding an acylhydrazone bond chain extender dropwise to perform a secondary chain extension;

[0029] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred at 20 to 30° C. to obtain the flexible sensing low-temperature resistant backing material.

[0030] A third aspect of the present invention provides a sports back protector, wherein the material of the sports back protector is the flexible sensing low-temperature resistant back protector material.

[0031] Compared with the prior art, the beneficial effects of the present invention include at least:

[0032] The present invention introduces two secondary bonds, an acylhydrazone bond and a disulfide bond, into the back protector material. When impacted, the secondary bonds can absorb energy to split and reorganize the secondary bonds, thereby consuming the received impact energy, so that the sports back protector can still maintain high flexibility and good shock absorption and buffering ability in a cold environment. Furthermore, the back protector material still has high flexibility and good shock absorption and buffering ability at low temperatures, and can provide reliable protection for athletes.

[0033] The present invention can play a reinforcing role and a conductive role by adding graphene and carbon nanotubes to the back protector material. When preparing the back protector, the graphene and carbon nanotubes are evenly distributed to form a conductive network. When the back protector is deformed, the resistance of the back protector material and the current passing through will change, thereby being able to reflect the movement state of the human body and facilitating the adjustment of the movement state. DETAILED DESCRIPTION

[0034] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0035] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0036] Sports back guards in the prior art usually absorb impact energy through pores and bubbles in the foam and spread them over the entire material, thereby reducing direct pressure on local areas, and at the same time use the elasticity of the elastic material itself to diffuse the local impact area, thereby reducing damage to the body; microscopically, existing sports back guards convert impact energy into frictional heat energy through internal friction of molecular chains in the material (such as dense methyl internal friction) and consume it, thereby achieving shock absorption; but for flexible sensing sports back guards, the addition of flexible sensing fillers will reduce the elasticity of the back guard material, thereby reducing the cushioning performance of the back guard, especially in cold environments, the movement of molecular chains slows down, the hardness of the back guard increases, and the internal friction decreases, resulting in the back guard being unable to effectively cushion the impact force, so that the flexible sensing sports back guard cannot provide reliable protection.

[0037] The embodiment of the present application provides a low-temperature resistant back protection material, whose raw materials include 90 to 110 parts of polyurethane prepolymer, 7 to 17 parts of chain extender, 1 to 3 parts of flexible sensing filler, 1 to 1.5 parts of foam stabilizer, 1 to 1.2 parts of cross-linking agent, 1 to 1.5 parts of catalyst and 1 to 1.5 parts of foaming agent.

[0038] As an optional embodiment, the chain extender is composed of a disulfide bond chain extender and an acylhydrazone bond chain extender. The present application introduces disulfide bonds and acylhydrazone bonds into the back protector material through disulfide bond chain extenders and acylhydrazone bond chain extenders. When impacted, the disulfide bonds and acylhydrazone bonds can absorb energy to split and reorganize, thereby consuming the impact energy received, so that the sports back protector can still maintain high flexibility and good shock absorption and buffering capabilities in a cold environment. Disulfide bond chain extenders and acylhydrazone bond chain extenders are compatible and do not interfere with each other in the same system, and the reaction conditions of disulfide bonds and acylhydrazone bonds are mild and have few side reactions. The processing performance of disulfide bonds is better, and acylhydrazone bonds can better improve the toughness of materials. Disulfide bonds and acylhydrazone bonds complement each other, and the synergistic effect of multiple dynamic bonds not only gives the material excellent mechanical properties, but also promotes the splitting and reorganization of disulfide bonds and acylhydrazone bonds, further improving the shock absorption and buffering performance of the material.

[0039] As an optional embodiment, the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is (2-4): (6-8). When the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is (2-4): (6-8), the synergistic effect of the acylhydrazone bond and the disulfide bond is more obvious, and the shock absorption performance of the prepared back protection material is better.

[0040] As an optional embodiment, the flexible sensing filler includes at least one of graphene or carbon nanotubes. Graphene and carbon nanotubes can play a reinforcing role as well as a conductive role. When preparing the back protector, the graphene and carbon nanotubes are evenly distributed to form a conductive network. When the back protector is deformed, the resistance of the back protector material and the current passing through will change, thereby being able to reflect the movement state of the human body and facilitate adjustment of the movement state.

[0041] The present application will be further described below through specific examples. The raw materials used in the following examples are as follows:

[0042] The polyurethane prepolymer is prepared by the following method:

[0043] 10 parts by weight of hydroxy-terminated polybutadiene-acrylonitrile and 10 parts by weight of polyethylene glycol propylene glycol adipate were uniformly mixed and then water was removed. Then 80 parts by weight of toluene diisocyanate were added and reacted at a temperature of 82° C. to obtain a polyurethane prepolymer.

[0044] The disulfide bond extender was prepared by the following method:

[0045] 12.4 g of isophorone diisocyanate was added to 30.5 g of salicylaldehyde, and an organic tin catalyst was added, and the mixture was reacted in an inert gas environment to obtain a polyol containing a disulfide bond.

[0046] The acylhydrazone bond extender is prepared by the following method:

[0047] 17.4 g of ADH was dissolved in 30 mL of ethanol and added dropwise to 30.5 g of salicylaldehyde. After reaction and drying, a polyol containing an acylhydrazone bond was obtained.

[0048] Example 1

[0049] This embodiment is a flexible sensing low temperature resistant backing material, and the flexible sensing low temperature resistant backing material comprises the following raw materials in parts by weight:

[0050] 90 parts of polyurethane prepolymer, 7 parts of chain extender, 3 parts of flexible sensing filler, 1 part of foam stabilizer, 1.2 parts of cross-linking agent, 1 part of catalyst and 1.5 parts of blowing agent;

[0051] The chain extender is composed of a disulfide bond chain extender and an acylhydrazone bond chain extender; the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is 2:8;

[0052] The flexible sensing filler is carbon nanotubes;

[0053] The foam stabilizer is a polyurethane foam stabilizer;

[0054] The cross-linking agent is a diamine cross-linking agent;

[0055] The catalyst is a tertiary amine catalyst;

[0056] The blowing agent is carbon dioxide.

[0057] The preparation method of the above-mentioned flexible sensing low-temperature resistant back protection material comprises the following steps:

[0058] (a) a disulfide bond chain extender is added dropwise to a polyurethane prepolymer at 52° C. for a primary chain extension for 1 h. After the primary chain extension is completed, the prepolymer is heated to 68° C. and an acylhydrazone bond chain extender is added dropwise for a secondary chain extension for 1.5 h.

[0059] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and rapidly stirred at 25° C., and after the reaction, defoaming and curing are performed to obtain the flexible sensing low-temperature resistant backing material.

[0060] Example 2

[0061] This embodiment is a flexible sensing low temperature resistant backing material, and the flexible sensing low temperature resistant backing material comprises the following raw materials in parts by weight:

[0062] 110 parts of polyurethane prepolymer, 17 parts of chain extender, 1 part of flexible sensing filler, 1.5 parts of foam stabilizer, 1 part of cross-linking agent, 1.5 parts of catalyst and 1 part of foaming agent;

[0063] The chain extender is composed of a disulfide bond chain extender and an acylhydrazone bond chain extender; the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is 4:6;

[0064] The flexible sensing filler is carbon nanotubes;

[0065] The foam stabilizer is a polyurethane foam stabilizer;

[0066] The cross-linking agent is a diamine cross-linking agent;

[0067] The catalyst is a tertiary amine catalyst;

[0068] The blowing agent is carbon dioxide.

[0069] The preparation method of the above-mentioned flexible sensing low-temperature resistant back protection material comprises the following steps:

[0070] (a) a disulfide bond chain extender is added dropwise to a polyurethane prepolymer at 52° C. for a primary chain extension for 1 h. After the primary chain extension is completed, the prepolymer is heated to 68° C., and an acylhydrazone bond chain extender is added dropwise for a secondary chain extension for 1.5 h.

[0071] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred to react at 25° C., and after the reaction, defoaming and curing are performed to obtain the flexible sensing low-temperature resistant backing material.

[0072] Example 3

[0073] This embodiment is a flexible sensing low temperature resistant backing material, and the flexible sensing low temperature resistant backing material comprises the following raw materials in parts by weight:

[0074] 100 parts of polyurethane prepolymer, 10 parts of chain extender, 2 parts of flexible sensing filler, 1.2 parts of foam stabilizer, 1.1 parts of cross-linking agent, 1.2 parts of catalyst and 1.2 parts of foaming agent;

[0075] The chain extender is composed of a disulfide bond chain extender and an acylhydrazone bond chain extender; the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is 3:7;

[0076] The flexible sensing filler is carbon nanotubes;

[0077] The foam stabilizer is a polyurethane foam stabilizer;

[0078] The cross-linking agent is a diamine cross-linking agent;

[0079] The catalyst is a tertiary amine catalyst;

[0080] The blowing agent is carbon dioxide.

[0081] The preparation method of the above-mentioned flexible sensing low-temperature resistant back protection material comprises the following steps:

[0082] (a) a disulfide bond chain extender is added dropwise to a polyurethane prepolymer at 52° C. for a primary chain extension for 1 h. After the primary chain extension is completed, the prepolymer is heated to 68° C., and an acylhydrazone bond chain extender is added dropwise for a secondary chain extension for 1.5 h.

[0083] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred to react at 25° C., and after the reaction, defoaming and curing are performed to obtain the flexible sensing low-temperature resistant backing material.

[0084] Example 4

[0085] This embodiment is a flexible sensing low temperature resistant backing material, and the flexible sensing low temperature resistant backing material comprises the following raw materials in parts by weight:

[0086] 100 parts of polyurethane prepolymer, 10 parts of chain extender, 2 parts of flexible sensing filler, 1.2 parts of foam stabilizer, 1.1 parts of cross-linking agent, 1.2 parts of catalyst and 1.2 parts of foaming agent;

[0087] The chain extender is composed of a disulfide bond chain extender and an acylhydrazone bond chain extender; the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is 4:6;

[0088] The flexible sensing filler is carbon nanotubes;

[0089] The foam stabilizer is a polyurethane foam stabilizer;

[0090] The cross-linking agent is a diamine cross-linking agent;

[0091] The catalyst is a tertiary amine catalyst;

[0092] The blowing agent is carbon dioxide.

[0093] The preparation method of the above-mentioned flexible sensing low-temperature resistant back protection material comprises the following steps:

[0094] (a) a disulfide bond chain extender is added dropwise to a polyurethane prepolymer at 52° C. for a primary chain extension for 1 h. After the primary chain extension is completed, the prepolymer is heated to 68° C., and an acylhydrazone bond chain extender is added dropwise for a secondary chain extension for 1.5 h.

[0095] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred to react at 25° C., and after the reaction, defoaming and curing are performed to obtain the flexible sensing low-temperature resistant backing material.

[0096] Example 5

[0097] This embodiment is a flexible sensing low temperature resistant backing material, and the flexible sensing low temperature resistant backing material comprises the following raw materials in parts by weight:

[0098] 100 parts of polyurethane prepolymer, 10 parts of chain extender, 2 parts of flexible sensing filler, 1.2 parts of foam stabilizer, 1.1 parts of cross-linking agent, 1.2 parts of catalyst and 1.2 parts of foaming agent;

[0099] The chain extender is composed of a disulfide bond chain extender and an acylhydrazone bond chain extender; the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is 2:8;

[0100] The flexible sensing filler is carbon nanotubes;

[0101] The foam stabilizer is a polyurethane foam stabilizer;

[0102] The cross-linking agent is a diamine cross-linking agent;

[0103] The catalyst is a tertiary amine catalyst;

[0104] The blowing agent is carbon dioxide.

[0105] The preparation method of the above-mentioned flexible sensing low-temperature resistant back protection material comprises the following steps:

[0106] (a) a disulfide bond chain extender is added dropwise to a polyurethane prepolymer at 52° C. for a primary chain extension for 1 h. After the primary chain extension is completed, the prepolymer is heated to 68° C., and an acylhydrazone bond chain extender is added dropwise for a secondary chain extension for 1.5 h.

[0107] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred to react at 25° C., and after the reaction, defoaming and curing are performed to obtain the flexible sensing low-temperature resistant backing material.

[0108] Example 6

[0109] This embodiment is a flexible sensing low temperature resistant backing material, and the flexible sensing low temperature resistant backing material comprises the following raw materials in parts by weight:

[0110] 100 parts of polyurethane prepolymer, 10 parts of chain extender, 2 parts of flexible sensing filler, 1.2 parts of foam stabilizer, 1.1 parts of cross-linking agent, 1.2 parts of catalyst and 1.2 parts of foaming agent;

[0111] The chain extender is composed of a disulfide bond chain extender and an acylhydrazone bond chain extender; the mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is 1:1;

[0112] The flexible sensing filler is carbon nanotubes;

[0113] The foam stabilizer is a polyurethane foam stabilizer;

[0114] The cross-linking agent is a diamine cross-linking agent;

[0115] The catalyst is a tertiary amine catalyst;

[0116] The blowing agent is carbon dioxide.

[0117] The preparation method of the above-mentioned flexible sensing low-temperature resistant back protection material comprises the following steps:

[0118] (a) a disulfide bond chain extender is added dropwise to a polyurethane prepolymer at 52° C. for a primary chain extension for 1 h. After the primary chain extension is completed, the prepolymer is heated to 68° C., and an acylhydrazone bond chain extender is added dropwise for a secondary chain extension for 1.5 h.

[0119] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred to react at 25° C., and after the reaction, defoaming and curing are performed to obtain the flexible sensing low-temperature resistant backing material.

[0120] Comparative Example 1

[0121] This comparative example is a back protector material, which is a conventional polyurethane back protector material.

[0122] Comparative Example 2

[0123] This comparative example is a flexible sensing low temperature resistant backing material, which comprises the following raw materials in parts by weight:

[0124] 100 parts of polyurethane prepolymer, 10 parts of chain extender, 2 parts of flexible sensing filler, 1.2 parts of foam stabilizer, 1.1 parts of cross-linking agent, 1.2 parts of catalyst and 1.2 parts of foaming agent;

[0125] Wherein, the chain extender is a disulfide bond chain extender;

[0126] The flexible sensing filler is carbon nanotubes;

[0127] The foam stabilizer is a polyurethane foam stabilizer;

[0128] The cross-linking agent is a diamine cross-linking agent;

[0129] The catalyst is a tertiary amine catalyst;

[0130] The blowing agent is carbon dioxide.

[0131] The preparation method of the above-mentioned flexible sensing low-temperature resistant back protection material comprises the following steps:

[0132] (a) a disulfide bond chain extender is added dropwise to a polyurethane prepolymer at 52° C. for a primary chain extension for 1 h. After the primary chain extension is completed, the prepolymer is heated to 68° C., and an acylhydrazone bond chain extender is added dropwise for a secondary chain extension for 1.5 h.

[0133] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred to react at 25° C., and after the reaction, defoaming and curing are performed to obtain the flexible sensing low-temperature resistant backing material.

[0134] Comparative Example 3

[0135] This comparative example is a flexible sensing low temperature resistant backing material, which comprises the following raw materials in parts by weight:

[0136] 100 parts of polyurethane prepolymer, 10 parts of chain extender, 2 parts of flexible sensing filler, 1.2 parts of foam stabilizer, 1.1 parts of cross-linking agent, 1.2 parts of catalyst and 1.2 parts of foaming agent;

[0137] Wherein, the chain extender is an acylhydrazone bond chain extender;

[0138] The flexible sensing filler is carbon nanotubes;

[0139] The foam stabilizer is a polyurethane foam stabilizer;

[0140] The cross-linking agent is a diamine cross-linking agent;

[0141] The catalyst is a tertiary amine catalyst;

[0142] The blowing agent is carbon dioxide.

[0143] The preparation method of the above-mentioned flexible sensing low-temperature resistant back protection material comprises the following steps:

[0144] (a) a disulfide bond chain extender is added dropwise to a polyurethane prepolymer at 52° C. for a primary chain extension for 1 h. After the primary chain extension is completed, the prepolymer is heated to 68° C., and an acylhydrazone bond chain extender is added dropwise for a secondary chain extension for 1.5 h.

[0145] (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred to react at 25° C., and after the reaction, defoaming and curing are performed to obtain the flexible sensing low-temperature resistant backing material.

[0146] Comparative Example 4

[0147] This comparative example is a commercially available NBR back protector with a thickness of 50 mm.

[0148] Comparative Example 5

[0149] This comparative example is a commercially available EVA back protector with a thickness of 50 mm.

[0150] Comparative Example 6

[0151] This comparative example is a commercially available XPE back protector with a thickness of 50 mm.

[0152] Comparative Example 7

[0153] This comparative example is a commercially available competitor back protector.

[0154] Comparative Example 8

[0155] This comparative example is a commercially available flexible sensing armor.

[0156] Experimental example

[0157] The back protection materials of Examples 1 to 6 and Comparative Examples 1 to 8 were obtained respectively;

[0158] Impact cushioning 1: The back protectors of Examples 1 to 6 and Comparative Examples 1 to 8 were respectively used to prepare back protectors of 420 mm*250 mm in size. The back protectors were subjected to impact tests in accordance with the reference standard EN1621-2, and the minimum thickness and weight required for each back protector to pass LEVEL 1 and LEVEL 2 in terms of cushioning performance were recorded.

[0159] Impact buffer 2: The back protectors of Examples 1 to 6 and Comparative Examples 1 to 8 were respectively used to prepare back protectors of 420 mm*250 mm in size. The buffering performance of each back protector at room temperature (23°C) and low temperature (-10°C) when passing LEVEL 1 was measured in reference to standard EN1621-2.

[0160] Hardness: The hardness of the protective gear or protective gear prepared by the back protection materials of Examples 1 to 6 and Comparative Examples 1 to 8 at room temperature (23°C) and low temperature (-10°C) was tested respectively.

[0161] Test Results

[0162] The performance test results of the back protectors prepared using the back protector materials of Examples 1 to 6 and Comparative Examples 1 to 8 are shown in Table 1 below.

[0163] Table 1: Performance Test

[0164]

[0165] According to the EN1621-2 test, to meet the LEVEL 1 (first-level armor standard), the impact must be less than or equal to 18kN, and to meet the LEVEL 2 (second-level armor standard), the impact must be less than or equal to 9kN. It can be seen from Table 1:

[0166] Compared with the comparative example and the commercially available back protectors, the back protectors prepared by the back protector materials of the embodiments of the present invention have more excellent mechanical properties. The back protectors prepared by the embodiments of the present invention have better performance than the back protectors of competing products, while the NBR, EVA and XPE back protectors sold on the market still cannot pass the performance test of EN1621-2 at 50mm. In addition, the back protectors prepared by the embodiments of the present invention have a flexible sensing function, while the commercially available competitive back protectors and NBR, EVA and XPE back protectors do not have flexible sensing capabilities. Comparative Example 8 is a commercially available flexible sensing armor, which has only one layer of pressure-sensing film and can only be used for data collection. It has no buffering and protection capabilities and cannot pass the performance test experiment. In summary, the back protector material in this application can meet the requirements of flexible sensing while having good shock-absorbing and cushioning performance.

[0167] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A flexible sensing low temperature resistant backing material, characterized in that: The flexible sensing low temperature resistant backing material comprises the following raw materials in parts by weight: 90-110 parts of polyurethane prepolymer, 7-17 parts of chain extender, 1-3 parts of flexible sensing filler, 1-1.5 parts of foam stabilizer, 1-1.2 parts of crosslinking agent, 1-1.5 parts of catalyst and 1-1.5 parts of foaming agent; The chain extender consists of a disulfide bond chain extender and an acylhydrazone bond chain extender.

2. The flexible sensing low temperature resistant backing material according to claim 1, characterized in that: The polyurethane prepolymer comprises a hard segment and a soft segment, and the mass ratio of the hard segment to the soft segment is 1:(0.2-0.25).

3. The flexible sensing low temperature resistant backing material according to claim 2 is characterized in that: The hard segment includes toluene diisocyanate; The soft segment comprises terminal hydroxyl polybutadiene-acrylonitrile and polyethylene glycol propylene glycol adipate in a mass ratio of 1: (0.8-1.2).

4. The flexible sensing low temperature resistant backing material according to claim 1, characterized in that: The polyurethane prepolymer is prepared by the following method: The terminal hydroxyl polybutadiene-acrylonitrile and polyethylene glycol propylene glycol adipate are mixed uniformly, water is removed, toluene diisocyanate is added, and then reacted at 80-85° C. to obtain the polyurethane prepolymer.

5. The flexible sensing low temperature resistant backing material according to claim 1, characterized in that: The mass ratio of the disulfide bond chain extender to the acylhydrazone bond chain extender is (2-4): (6-8).

6. The flexible sensing low temperature resistant backing material according to claim 5, characterized in that: The disulfide bond chain extender is a polyol containing at least one disulfide bond; The acylhydrazone bond chain extender is a polyol containing at least one acylhydrazone bond.

7. The flexible sensing low temperature resistant backing material according to claim 5, characterized in that: The disulfide bond chain extender is prepared from isophorone diisocyanate and salicylaldehyde; The acylhydrazone bond chain extender is prepared from adipic acid dihydrazide and salicylaldehyde.

8. The flexible sensing low temperature resistant backing material according to claim 1, characterized in that: The flexible sensing filler is graphene and / or carbon nanotubes.

9. The method for preparing the flexible sensing low temperature resistant backing material according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: (a) adding a disulfide bond chain extender dropwise to a polyurethane prepolymer at 50 to 55° C. to perform a primary chain extension, and after the primary chain extension is completed, heating the prepolymer to 65 to 70° C., and then adding an acylhydrazone bond chain extender dropwise to perform a secondary chain extension; (b) After the secondary chain extension is completed, a flexible sensing filler, a foam stabilizer, a cross-linking agent, a catalyst and a foaming agent are added and stirred at 20 to 30° C. to obtain the flexible sensing low-temperature resistant backing material.

10. A sports back protector, characterized in that: The material of the sports back protector is the flexible sensing low-temperature resistant back protector material as described in any one of claims 1 to 8.

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