Rubber material for the soles of paratrooper boots and method for its preparation

Abstract

The application relates to the rubber field and particularly discloses a rubber material for paratrooper boot soles and a preparation method thereof. The rubber material for paratrooper boot soles comprises the following components in parts by weight: 70-160 parts of polyurethane rubber, 10-18 parts of functionalized modified carbon black / white carbon black intersecting particles, 3-5 parts of stearic acid, 1.5-4 parts of zinc oxide, 3-5 parts of anti-aging agent, 1-3 parts of accelerator and 2-3 parts of vulcanizing agent; and the preparation method comprises the following steps: S1, opening and kneading, S2, closed kneading and S3, vulcanization. When the rubber material for paratrooper boot soles is coated and formed in an arch area, the strength of the arch area can be improved, thereby meeting the requirements of multiple rope descending of paratroopers.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rubber, in particular to a rubber material for the sole of paratrooper boots and a preparation method thereof. BACKGROUND

[0002] Parachuting is a common extreme sport, which refers to a sport that parachutists jump from an aircraft, balloon or other aerial equipment to a high altitude, and complete various specified actions before and after the parachute opens by air power and the parachute, and land safely in a designated area by using the parachute to slow down the descent speed. Paratroopers need to wear special paratrooper boots when parachuting to reduce the impact force when landing, so as to reduce the impact force on the legs and prevent injuries to the ankles.

[0003] In related technologies, a common paratrooper boot sole includes a forefoot area corresponding to the forefoot, a heel area corresponding to the hind foot, and an arch area between the forefoot area and the heel area. Paratroopers usually use the "parallel leg rope clamping" method for rope descent, that is, the arch area is used to rub the rope to control the speed of descent.

[0004] For the related technologies in the above, the inventors believe that in order to meet the needs of paratroopers' rope descent, a layer of high-hardness rubber needs to be covered on the arch area, so that the arch area has high strength and excellent wear resistance. If it is an ordinary rubber sole, it may be scrapped after one rope descent, and it is difficult to achieve multiple uses, and therefore needs to be improved. SUMMARY

[0005] In order to improve the strength of the arch area, the present application provides a rubber material for the sole of paratrooper boots and a preparation method thereof.

[0006] The rubber material for the sole of paratrooper boots and the preparation method thereof provided by the present application adopt the following technical solutions:

[0007] In a first aspect, the present application provides a rubber material for the sole of paratrooper boots, which adopts the following technical solutions:

[0008] A rubber material for the sole of paratrooper boots includes the following raw materials by weight:

[0009] Polyurethane rubber 70-160 parts;

[0010] Functionalized modified carbon black / white carbon black intersection particles 10-18 parts;

[0011] Stearic acid 3-5 parts;

[0012] Zinc oxide 1.5-4 parts;

[0013] Antioxidant 3-5 parts;

[0014] Accelerator 1-3 parts;

[0015] Vulcanizing agent 2-3 parts.

[0016] By adopting the above technical solutions, on the one hand, polyurethane rubber itself possesses high hardness. The functionalized modified carbon black / silica cross-linked particles not only have numerous active groups on their surface, which can chemically react with polyurethane rubber, causing cross-linking of carbon black, silica, and polyurethane rubber, thereby improving the hardness, mechanical properties, and tear strength of the rubber material used for paratrooper boot soles; moreover, the functionalized modified carbon black / silica cross-linked particles can reduce their own agglomeration in polyurethane rubber, helping to improve their dispersion within the polyurethane rubber, thus enhancing the hardness and mechanical properties of the rubber material used for paratrooper boot soles. Furthermore, by incorporating silica into the carbon black reinforcing system, the rolling resistance of the composite material can be reduced, and the tensile strength can be improved.

[0017] On the other hand, zinc oxide can not only act as a reinforcing agent for polyurethane rubber, improving its hardness, but also form zinc soaps with stearic acid, increasing the solubility of zinc oxide in the rubber compound. It also forms an active complex with accelerators, which helps to enhance the activity of accelerators and reduce the amount of accelerators used.

[0018] Preferably, the preparation process of the functionalized modified carbon black / fumed silica interlaced particles is as follows: 180-200 parts by weight of a 0.14-0.16 mol / L sodium silicate solution adjusted to pH 7-8 with hydrochloric acid are added to 30-50 parts by weight of silica gel. The mixture is stirred and reacted at 60-70°C for 10-16 minutes to obtain a first mixture. The pH of the first mixture is then adjusted to 7-8, and 5-6 parts by weight of a cationic surfactant are added to the first mixture to obtain the second mixture. Two mixtures are prepared; 3-5 parts of silica and 15-25 parts of carbon black are added to the second mixture, and the mixture is stirred and reacted at 70-90℃ for 20-24 min to obtain a suspension. The prepared suspension is centrifuged at 1500-2000 r / min for 10-20 min and washed with deionized water to obtain a precipitate. Finally, the precipitate is vacuum dried at a constant temperature of 40-50℃ to obtain functionalized modified carbon black / silica interphase particles.

[0019] By adopting the above technical solution, the modified functionalized carbon black / silica interlaced particles can weaken the interaction between carbon black and silica, and enhance the interaction between carbon black, silica and polyurethane rubber, thereby reducing their agglomeration in polyurethane rubber.

[0020] Preferably, it also includes 2-4 parts by weight of lignin.

[0021] By adopting the above technical solutions, lignin can introduce rigid benzene rings into polyurethane rubber, which helps to improve the hardness and wear resistance of polyurethane rubber; moreover, lignin is a widely available natural green material, which is conducive to the sustainable and green development of the rubber industry.

[0022] Preferably, the lignin is modified, and the modification process is as follows:

[0023] By weight, 10-20 parts of lignin are first dispersed in 120-150 parts of 0.18-0.2 mol / L sodium hydroxide solution and heated in a constant temperature water bath at 70-80℃ for 4-6 hours. Then, the mixture is washed with deionized water and centrifuged at 1000-1500 r / min for 10-20 minutes to obtain a precipitate. Finally, the precipitate is vacuum dried at a constant temperature of 35-55℃ for 5-6 hours and then crushed to obtain pretreated lignin.

[0024] The pretreated lignin and 4-6 parts of titanate coupling agent are dispersed in 150-200 parts of ethyl acetate solvent and heated in a constant temperature water bath at 60-70℃ for 4-6 hours. Then, the mixture is washed with deionized water and centrifuged at 1500-2000 r / min for 10-20 minutes to obtain a mixture. Finally, the mixture is vacuum dried at a constant temperature of 40-50℃ for 4-6 hours to obtain modified lignin.

[0025] By adopting the above technical solution, the modified lignin has a large number of reactive sites on its surface, which can effectively combine with the polyurethane rubber matrix. This helps to improve the crosslinking density and hardness, increase the dispersion of reinforcing fillers in polyurethane rubber, reduce the rolling resistance of polyurethane rubber, improve the tear resistance of polyurethane rubber, and reduce the production cost of rubber materials for paratrooper boot soles.

[0026] Preferably, it also includes 1-2 parts by weight of graphene oxide.

[0027] By adopting the above technical solutions, graphene oxide can not only improve the mechanical properties of polyurethane rubber, but also the modified lignin can reduce the aggregation of graphene oxide in the polyurethane rubber matrix, thereby improving the dispersibility and compatibility of graphene oxide in polyurethane rubber, which helps to improve the hardness and vulcanization performance of polyurethane rubber.

[0028] Preferably, it also includes 2-3 parts by weight of unsaturated carboxylate.

[0029] By adopting the above technical solution, unsaturated carboxylates can not only improve the vulcanization speed of rubber and increase the crosslinking density and tear strength of the vulcanized polyurethane rubber, but also promote the dispersion of functionalized modified carbon black / fumed silica interlaced particles in polyurethane rubber, thereby improving interfacial interactions; and also form a crosslinking network structure with functionalized modified carbon black / fumed silica interlaced particles during vulcanization, which increases the crosslinking density and maintains a stable crosslinking density, thus helping to improve the wear resistance of polyurethane rubber.

[0030] Preferably, it also includes 1-2 parts by weight of Scutellaria baicalensis root extract.

[0031] By adopting the above technical solution, the root extract of Scutellaria baicalensis can not only introduce rigid benzene rings into polyurethane rubber, which helps to improve the hardness and wear resistance of polyurethane rubber; but also the covalent cross-linking of the molecular chain of Scutellaria baicalensis root extract with polyurethane rubber helps to improve the mechanical properties, tear strength and tensile strength of polyurethane rubber.

[0032] Preferably, the accelerator is any one of accelerator TMTD, accelerator TETD, and accelerator TBTD.

[0033] By adopting the above technical solutions, accelerators TMTD, TETD, and TBTD not only activate the vulcanizing agent, accelerating the crosslinking reaction between the vulcanizing agent and rubber molecules and shortening the vulcanization time, but also, due to the presence of sulfur-containing side groups, when zinc oxide reacts with stearic acid to produce zinc salt, the zinc salt can chelate with these side groups, stabilizing the weak bonds. This results in shorter crosslinking bonds being generated during rubber vulcanization, increasing the number of new crosslinking bonds, improving the crosslinking density, and thus helping to improve the mechanical properties and tensile strength of polyurethane rubber.

[0034] Secondly, this application provides a method for preparing a rubber material for the sole of paratrooper boots, employing the following technical solution:

[0035] A method for preparing a rubber material for the sole of paratrooper boots includes the following steps:

[0036] S1 Open Mixing: According to the weight parts specified in the formula, the polyurethane rubber is plasticized at a temperature of 60-70℃ for 10-20 minutes, and passed through a thin tube 1-3 times to obtain the preformed rubber.

[0037] S2 Intensive Mixing: According to the required weight parts of the formula, zinc oxide, stearic acid, antioxidant, accelerator, and functionalized modified carbon black / fumed silica interlaced particles are added sequentially to the preformed rubber of S1 open mixing and intensive mixing. The intensive mixing temperature is 100-120℃, the intensive mixing time is 15-25min, and it is allowed to stand and cool for 20-26h to obtain the compounded rubber.

[0038] S3 vulcanization: Add vulcanizing agent to the compound obtained by S2 internal mixing according to the required weight parts of the formula, mix evenly and then vulcanize. The vulcanization temperature is 160-170℃ and the vulcanization time is 12-16min to obtain the rubber material for paratrooper boot soles.

[0039] By adopting the above technical solutions, the preparation method of rubber materials for paratrooper boot soles is mature and suitable for widespread application.

[0040] Preferably, in S2 above, zinc oxide, stearic acid, antioxidant, accelerator, functionalized modified carbon black / white carbon black cross-linked particles, modified lignin, graphene oxide, and Scutellaria baicalensis root extract are added sequentially to the preformed rubber prepared in S1 according to the required weight parts of the formula. The mixture is then thoroughly mixed and internally kneaded at a temperature of 100-120℃ for 15-25 minutes, and allowed to stand and cool for 20-26 hours to obtain the compounded rubber.

[0041] In S3 above, according to the required weight parts of the formula, vulcanizing agent and unsaturated carboxylate are added to the compound obtained by S2 internal mixing, mixed evenly and then vulcanized. The vulcanization temperature is 160-170℃ and the vulcanization time is 12-16min to obtain the rubber material for paratrooper boot soles.

[0042] In summary, this application has the following beneficial effects:

[0043] 1. Functionalized modified carbon black / silica interphase particles have many active groups on their surface, which enables carbon black, silica and polyurethane rubber to cross-link, thereby improving the hardness, mechanical properties and tear strength of the rubber material used for paratrooper boot soles; by introducing silica into the carbon black reinforcing system, the rolling resistance of the composite material can be reduced and the tensile strength can be improved.

[0044] 2. Modified lignin can not only introduce rigid benzene rings into polyurethane rubber, which helps to improve the hardness and wear resistance of polyurethane rubber; but also has a large number of reactive sites on its surface, which can effectively combine with the matrix of polyurethane rubber, helping to improve the crosslinking density and hardness.

[0045] 3. The root extract of Scutellaria baicalensis can not only improve the strength and wear resistance of polyurethane rubber, but also covalently crosslink with the molecular chain of polyurethane rubber, which helps to improve the mechanical properties and tensile strength of polyurethane rubber. Detailed Implementation

[0046] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources.

[0047] The embodiments of this application use the following raw materials:

[0048] The thermoplastic polyurethane rubber, model 1185A, was purchased from Shanghai Xinhesheng Plastics Co., Ltd.; the molecular formula of stearic acid is C1185A. 18 H 36 O2, molecular weight 284.48; zinc oxide, grade 1, purchased from Shandong Ruiqi Chemical Co., Ltd.; antioxidant 0410, product number 032563, purchased from Hubei Shiteng Chemical Technology Co., Ltd.; sulfur, chemical formula S, molecular weight 32.06; silica gel, product number 001, purchased from Hubei Chengfeng Chemical Co., Ltd.; hexadecyltrimethylammonium bromide, product number 1631 (bromine type), purchased from Shanghai Jinshan Jingwei Chemical Co., Ltd.; precipitated silica, purity 99%, purchased from Anhui Aiyota Silicon Oil Co., Ltd.; carbon black, industrial grade, purchased from Wuhan Huamei New Material Technology Co., Ltd.; lignin, product number N129, purchased from Hubei Hanwei Chemical Co., Ltd.; titanate coupling agent NDZ-201, molecular formula C 51 H 112 O 22 P6Ti, molecular weight 1311.13; ethyl acetate, molecular formula C4H8O2, molecular weight 88.11; graphene oxide, model DZ-668, purchased from Dazhan Nano (Guangdong) Co., Ltd.; methacrylic acid, molecular weight C4H6O2, purchased from Jinan Century Tongda Chemical Co., Ltd.; accelerator TMTD, standard grade 1, purchased from Wuhan Nengren Pharmaceutical Chemical Co., Ltd.; accelerator TETD, catalog number 7147670, purchased from Shanghai Koraman Reagent Co., Ltd.; accelerator TBTD, model TBTD-40, purchased from Ningbo Aikem New Materials Co., Ltd.

[0049] Preparation Example 1

[0050] The preparation process of Scutellaria baicalensis root extract is as follows: First, fresh and clean Scutellaria baicalensis root is washed and cut into shreds. Then, the Scutellaria baicalensis root shreds are dried at 60℃ for 4 hours, then pulverized and filtered through a 60-mesh sieve to obtain dried Scutellaria baicalensis root shred powder. The Scutellaria baicalensis root shred powder is then refluxed with 80% ethanol at a ratio of 1:20 g / mL three times. The extraction temperature is 75℃ and the extraction time is 3 hours. During the extraction process, the raw material is stirred once every 20 minutes for 3 minutes each time. The filtrate of the extraction is collected to obtain the extract. The extract is then vacuum rotary evaporated at 40℃ and freeze-dried to obtain Scutellaria baicalensis root extract.

[0051] Preparation Example 2

[0052] The preparation method of functionalized modified carbon black / silica interleaved particles is as follows:

[0053] 30 kg of silica gel was added to 180 kg of a 0.14 mol / L sodium silicate solution adjusted to pH 7 with hydrochloric acid. After stirring at 60 °C for 10 min, a first mixture was obtained. The pH of the first mixture was then adjusted to 7, and 5 kg of hexadecyltrimethylammonium bromide was added to the first mixture to obtain a second mixture. 3 kg of silica and 15 kg of carbon black were added to the second mixture, and after stirring at 70 °C for 20 min, a suspension was obtained. The suspension was centrifuged at 1500 r / min for 10 min and washed with deionized water to obtain a precipitate. Finally, the precipitate was vacuum dried at a constant temperature of 40 °C to obtain functionalized modified carbon black / silica interleaved particles.

[0054] Preparation Example 3

[0055] The preparation method of functionalized modified carbon black / silica interleaved particles is as follows:

[0056] 50 kg of silica gel was added to 200 kg of a 0.16 mol / L sodium silicate solution adjusted to pH 8 with hydrochloric acid. After stirring at 70 °C for 16 min, a first mixture was obtained. The pH of the first mixture was then adjusted to 8, and 6 kg of hexadecyltrimethylammonium bromide was added to the first mixture to obtain a second mixture. 5 kg of silica and 25 kg of carbon black were added to the second mixture, and after stirring at 90 °C for 24 min, a suspension was obtained. The suspension was centrifuged at 2000 r / min for 20 min and washed with deionized water to obtain a precipitate. Finally, the precipitate was vacuum dried at a constant temperature of 50 °C to obtain functionalized modified carbon black / silica interphase particles.

[0057] Preparation Example 4

[0058] The preparation method of functionalized modified carbon black / silica interleaved particles is as follows:

[0059] 190 kg of a 0.15 mol / L sodium silicate solution, adjusted to pH 7.5 with hydrochloric acid, was mixed with 40 kg of silica gel. The mixture was stirred at 65 °C for 13 min to obtain a first mixture. The pH of the first mixture was then adjusted to 7.5, and 5.5 kg of hexadecyltrimethylammonium bromide was added to obtain a second mixture. 4 kg of silica and 20 kg of carbon black were added to the second mixture, and the mixture was stirred at 80 °C for 22 min to obtain a suspension. The suspension was centrifuged at 1750 r / min for 15 min and washed with deionized water to obtain a precipitate. Finally, the precipitate was vacuum dried at a constant temperature of 30 °C to obtain functionalized modified carbon black / silica interleaved particles.

[0060] Preparation Example 5

[0061] The preparation method of modified lignin is as follows:

[0062] First, 10 kg of lignin was dispersed in 120 kg of 0.18 mol / L sodium hydroxide solution and heated in a constant temperature water bath at 70 °C for 4 h. Then, it was washed with deionized water and centrifuged at 1000 r / min for 10 min to obtain a precipitate. Finally, the precipitate was vacuum dried at 35 °C for 5 h and crushed to obtain pretreated lignin.

[0063] The pretreated lignin and 4 kg of titanate coupling agent NDZ-201 were dispersed in 150 kg of ethyl acetate solvent and heated in a constant temperature water bath at 60 °C for 4 h. Then, the mixture was washed with deionized water and centrifuged at 1500 r / min for 10 min to obtain a mixture. Finally, the mixture was vacuum dried at 40 °C for 4 h to obtain modified lignin.

[0064] Preparation Example 6

[0065] The preparation method of modified lignin is as follows:

[0066] First, 20 kg of lignin was dispersed in 150 kg of 0.2 mol / L sodium hydroxide solution and heated in a constant temperature water bath at 80 °C for 6 h. Then, it was washed with deionized water and centrifuged at 1500 r / min for 20 min to obtain a precipitate. Finally, the precipitate was vacuum dried at 55 °C for 6 h and crushed to obtain pretreated lignin.

[0067] The pretreated lignin and 6 kg of titanate coupling agent NDZ-201 were dispersed in 200 kg of ethyl acetate solvent and heated in a constant temperature water bath at 70 °C for 6 h. Then, the mixture was washed with deionized water and centrifuged at 2000 r / min for 20 min to obtain a mixture. Finally, the mixture was vacuum dried at 50 °C for 6 h to obtain modified lignin.

[0068] Preparation Example 7

[0069] The preparation method of modified lignin is as follows:

[0070] First, 15 kg of lignin was dispersed in 135 kg of 0.19 mol / L sodium hydroxide solution and heated in a constant temperature water bath at 75 °C for 5 h. Then, it was washed with deionized water and centrifuged at 1250 r / min for 15 min to obtain a precipitate. Finally, the precipitate was vacuum dried at 45 °C for 5.5 h and crushed to obtain pretreated lignin.

[0071] The pretreated lignin and 5 kg of titanate coupling agent NDZ-201 were dispersed in 175 kg of ethyl acetate solvent and heated in a constant temperature water bath at 65 °C for 5 h. Then, the mixture was washed with deionized water and centrifuged at 1750 r / min for 15 min to obtain a mixture. Finally, the mixture was vacuum dried at a constant temperature of 45 °C for 5 h to obtain modified lignin.

[0072] Example 1

[0073] The rubber material used for the soles of paratrooper boots includes the following raw materials by weight:

[0074] 70 kg of thermoplastic polyurethane rubber;

[0075] 10 kg of functionalized modified carbon black / fumed silica interleaved particles were prepared in Preparation Example 2;

[0076] 3 kg of stearic acid;

[0077] 1.5 kg of zinc oxide;

[0078] Anti-aging agent 0410 3Kg;

[0079] Accelerator TMTD 1Kg;

[0080] 2 kg of sulfur.

[0081] A method for preparing a rubber material for the sole of paratrooper boots includes the following steps:

[0082] S1 Open Mixing: Plasticize the thermoplastic polyurethane rubber according to the required weight of the formula. The plasticizing temperature is 60℃ and the plasticizing time is 10min. Pass through the tube once to obtain the preformed rubber.

[0083] S2 Intensive Mixing: According to the required weight of the formula, zinc oxide, stearic acid, antioxidant 0410, accelerator TMTD, and functionalized modified carbon black / silica interleaved particles prepared in Example 2 were added sequentially to the preformed rubber of S1 open mixing and intensive mixing. The intensive mixing temperature was 100℃, the intensive mixing time was 15min, and the mixture was allowed to stand and cool for 20h to obtain the compound.

[0084] S3 vulcanization: Add sulfur to the mixed rubber obtained by S2 internal mixing according to the required weight of the formula, mix evenly and then vulcanize. The vulcanization temperature is 160℃ and the vulcanization time is 12min to obtain the rubber material for the sole of paratrooper boots.

[0085] Example 2

[0086] The rubber material used for the soles of paratrooper boots includes the following raw materials by weight:

[0087] 160 kg of thermoplastic polyurethane rubber;

[0088] 18 kg of functionalized modified carbon black / fumed silica interleaved particles were prepared in Preparation Example 2;

[0089] 5 kg of stearic acid;

[0090] 4 kg of zinc oxide;

[0091] Anti-aging agent 0410 5Kg;

[0092] Accelerator TETD 3Kg;

[0093] 3 kg of sulfur.

[0094] A method for preparing a rubber material for the sole of paratrooper boots includes the following steps:

[0095] S1 Open Mixing: Plasticize the thermoplastic polyurethane rubber according to the required weight of the formula. The plasticizing temperature is 70℃ and the plasticizing time is 20min. Pass through the plasticizer 3 times to obtain the preformed rubber.

[0096] S2 Intensive Mixing: According to the required weight of the formula, zinc oxide, stearic acid, antioxidant 0410, accelerator TETD, and functionalized modified carbon black / silica interleaved particles prepared in Example 2 were added sequentially to the preformed rubber of S1 open mixing and intensive mixing. The intensive mixing temperature was 120℃, the intensive mixing time was 25min, and the mixture was allowed to stand and cool for 26h to obtain the compounded rubber.

[0097] S3 vulcanization: Add sulfur to the mixed rubber obtained by S2 internal mixing according to the required weight of the formula, mix evenly and then vulcanize. The vulcanization temperature is 170℃ and the vulcanization time is 16min to obtain the rubber material for paratrooper boot soles.

[0098] Example 3

[0099] The rubber material used for the soles of paratrooper boots includes the following raw materials by weight:

[0100] 115 kg of thermoplastic polyurethane rubber;

[0101] 14 kg of functionalized modified carbon black / fumed silica interleaved particles were prepared in Preparation Example 2;

[0102] 4 kg of stearic acid;

[0103] 2.75 kg of zinc oxide;

[0104] Anti-aging agent 0410 4Kg;

[0105] Accelerator TBTD 2Kg;

[0106] 2.5 kg of sulfur.

[0107] A method for preparing a rubber material for the sole of paratrooper boots includes the following steps:

[0108] S1 Open Mixing: Plasticize the thermoplastic polyurethane rubber according to the required weight of the formula. The plasticizing temperature is 65℃ and the plasticizing time is 15min. Pass through the plasticizer twice to obtain the preformed rubber.

[0109] S2 Intensive Mixing: According to the required weight of the formula, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, and functionalized modified carbon black / silica interleaved particles prepared in Example 2 were added sequentially to the preformed rubber prepared by S1 open mixing and intensive mixing. The intensive mixing temperature was 110℃, the intensive mixing time was 20min, and the mixture was allowed to stand and cool for 23h to obtain the compounded rubber.

[0110] S3 vulcanization: Add sulfur to the mixed rubber obtained by S2 internal mixing according to the required weight of the formula, mix evenly and then vulcanize. The vulcanization temperature is 165℃ and the vulcanization time is 14min to obtain the rubber material for the sole of paratrooper boots.

[0111] Example 4

[0112] The difference from Example 3 is that the functionalized modified carbon black / silica interleaved particles prepared in Preparation Example 2 are replaced by the functionalized modified carbon black / silica interleaved particles prepared in Preparation Example 3 by the same mass.

[0113] Example 5

[0114] The difference from Example 3 is that the functionalized modified carbon black / silica interleaved particles prepared in Preparation Example 2 were replaced by functionalized modified carbon black / silica interleaved particles prepared in Preparation Example 4.

[0115] Example 6

[0116] The difference from Example 5 is that, during S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Example 4, and 2 kg of lignin were added sequentially to the preformed rubber from S1 open mixing for internal mixing.

[0117] Example 7

[0118] The difference from Example 5 is that, during S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Example 4, and 4 kg of lignin were added sequentially to the preformed rubber from S1 open mixing for internal mixing.

[0119] Example 8

[0120] The difference from Example 5 is that, during S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Example 4, and 3 kg of lignin were added sequentially to the preformed rubber from S1 open mixing for internal mixing.

[0121] Example 9

[0122] The difference from Example 8 is that the lignin was replaced by the modified lignin prepared in Preparation Example 5.

[0123] Example 10

[0124] The difference from Example 8 is that the lignin was replaced by the modified lignin prepared in Preparation Example 6.

[0125] Example 11

[0126] The difference from Example 8 is that the lignin was replaced by the modified lignin prepared in Preparation Example 7.

[0127] Example 12

[0128] The difference from Example 11 is that, during S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Preparation Example 4, 3 kg of modified lignin prepared in Preparation Example 7, and 1 kg of graphene oxide were added sequentially to the preformed rubber prepared in S1 open mixing for internal mixing.

[0129] Example 13

[0130] The difference from Example 11 is that, during S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Preparation Example 4, 3 kg of modified lignin prepared in Preparation Example 7, and 2 kg of graphene oxide were added sequentially to the preformed rubber prepared in S1 open mixing for internal mixing.

[0131] Example 14

[0132] The difference from Example 11 is that, during S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Preparation Example 4, 3 kg of modified lignin prepared in Preparation Example 7, and 1.5 kg of graphene oxide were added sequentially to the preformed rubber prepared in S1 open mixing for internal mixing.

[0133] Example 15

[0134] The difference from Example 14 is that, during S3 vulcanization, sulfur and 2 kg of methacrylic acid were added to the compound obtained from S2 internal mixing.

[0135] Example 16

[0136] The difference from Example 14 is that, during S3 vulcanization, sulfur and 3 kg of methacrylic acid were added to the compound obtained from S2 internal mixing.

[0137] Example 17

[0138] The difference from Example 14 is that, during S3 vulcanization, sulfur and 2.5 kg of methacrylic acid were added to the compound obtained from S2 internal mixing.

[0139] Example 18

[0140] The difference from Example 17 is that, during the S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Preparation Example 4, 3 kg of modified lignin prepared in Preparation Example 7, 1.5 kg of graphene oxide, and 1 kg of Scutellaria baicalensis root extract were added sequentially to the preformed rubber prepared in the S1 open mixing process.

[0141] Example 19

[0142] The difference from Example 17 is that, during the S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Preparation Example 4, 3 kg of modified lignin prepared in Preparation Example 7, 1.5 kg of graphene oxide, and 2 kg of Scutellaria baicalensis root extract were added sequentially to the preformed rubber from the S1 open mixing process.

[0143] Example 20

[0144] The difference from Example 17 is that, during the S2 internal mixing, zinc oxide, stearic acid, antioxidant 0410, accelerator TBTD, functionalized modified carbon black / white carbon black interlaced particles prepared in Preparation Example 4, 3 kg of modified lignin prepared in Preparation Example 7, 1.5 kg of graphene oxide, and 1.5 kg of Scutellaria baicalensis root extract were added sequentially to the preformed rubber prepared in the S1 open mixing process.

[0145] Comparative Example 1

[0146] The difference from Example 3 is that the functionalized modified carbon black / silica interleaved particles prepared in Preparation Example 2 were replaced with carbon black by an equal mass.

[0147] Comparative Example 2

[0148] The difference from Example 3 is that the functionalized modified carbon black / silica interleaved particles prepared in Preparation Example 2 were replaced with silica by an equal mass.

[0149] Comparative Example 3

[0150] The difference from Example 3 is that the accelerator TBTD is replaced with the accelerator DETU.

[0151] Performance testing:

[0152] The tensile strength of the rubber materials used for the soles of paratrooper boots in Examples 1-20 and Comparative Examples 1-3 was tested according to the method described in GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber". The test pieces were dumbbell-shaped with a minimum thickness of ≥2 mm. The results are shown in Table 1.

[0153] The right-angle tear strength of the rubber materials used for the soles of paratrooper boots in Examples 1-20 and Comparative Examples 1-3 was tested according to the method described in GB / T 529-2008 "Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser-shaped, right-angle and crescent-shaped specimens)". The materials were not cut, and the calendering direction of the materials was tested. The results are shown in Table 1.

[0154] The hardness of the rubber materials used for the soles of paratrooper boots in Examples 1-20 and Comparative Examples 1-3 was tested according to the method described in GB / T 3903.4-2017 "Test Methods for Hardness of Whole Footwear". The results are shown in Table 1.

[0155] The abrasion resistance of the rubber materials used for the soles of paratrooper boots in Examples 1-20 and Comparative Examples 1-3 was tested according to the method described in GB / T 3903.2-2017 "Test Methods for Abrasion Resistance of Whole Footwear". The results are shown in Table 1.

[0156] Table 1. Test Results Record of Rubber Material for Paratrooper Boot Soles

[0157]

[0158]

[0159] As can be seen from Table 1:

[0160] 1. A comparison of the test results of Examples 1-3 and Comparative Example 1 shows that functionalized modified carbon black / silica interleaved particles can improve the dispersion of polyurethane rubber, reduce the rolling resistance of the composite material, and improve the hardness and tensile strength of polyurethane rubber compared to carbon black.

[0161] 2. A comparison of the test results of Examples 1-3 and Comparative Example 2 shows that the functionalized modified carbon black / silica interwoven particles can improve the cross-linking of reinforcing fillers with polyurethane rubber compared to silica, thereby improving the hardness, abrasion resistance and tear strength of the rubber material used for paratrooper boot soles.

[0162] 3. A comparison of the test results of Examples 1-3 and Comparative Example 3 shows that the accelerator TBTD can increase the crosslinking density, which helps to improve the wear resistance and tensile strength of polyurethane rubber.

[0163] 4. A comparison of the test results of Examples 6-8 and Example 5 shows that lignin can introduce rigid benzene rings into polyurethane rubber, which helps to improve the hardness and wear resistance of polyurethane rubber.

[0164] 5. A comparison of the test results of Examples 9-11 and Example 8 shows that modified lignin helps to improve crosslinking density and hardness, thereby improving the tear resistance of polyurethane rubber.

[0165] 6. A comparison of the test results of Examples 12-14 and Example 11 shows that graphene oxide can not only improve the mechanical properties of polyurethane rubber, but also, when used in combination with modified lignin, can improve the dispersibility and compatibility of graphene oxide in polyurethane rubber, which helps to improve the hardness of polyurethane rubber.

[0166] 7. A comparison of the test results of Examples 15-17 and Example 12 shows that unsaturated carboxylates can not only increase the crosslinking density and tear strength of polyurethane rubber after vulcanization, but also form a crosslinking network structure with functionalized modified carbon black / fumed silica particles during vulcanization, which increases the crosslinking density and maintains a stable crosslinking density, thus helping to improve the wear resistance of polyurethane rubber.

[0167] 8. A comparison of the test results of Examples 18-20 and Example 17 shows that the root extract of Scutellaria baicalensis can not only improve the hardness and wear resistance of polyurethane rubber, but also the covalent cross-linking of the molecular chains of polyurethane rubber with the root extract of Scutellaria baicalensis helps to improve the mechanical properties, tear strength and tensile strength of polyurethane rubber.

[0168] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A rubber material for the sole of paratrooper boots, characterized in that: It includes the following raw materials in parts by weight: 70-160 parts of polyurethane rubber; 10-18 parts of functionalized modified carbon black / silica interleaved particles; 3-5 parts stearic acid; Zinc oxide 1.5-4 parts; Anti-aging agent 3-5 parts; Accelerator 1-3 parts; 2-3 parts of vulcanizing agent; The accelerator is any one of accelerator TMTD, accelerator TETD, and accelerator TBTD; The preparation process of the functionalized modified carbon black / silica interleaved particles is as follows: By weight, 30-50 parts of silica gel are added to 180-200 parts of a 0.14-0.16 mol / L sodium silicate solution adjusted to pH 7-8 with hydrochloric acid. After stirring and reacting at 60-70℃ for 10-16 min, a first mixture is obtained. The pH of the first mixture is then adjusted to 7-8, and 5-6 parts of a cationic surfactant are added to the first mixture to obtain a second mixture. The mixture is prepared by adding 3-5 parts of silica and 15-25 parts of carbon black to the second mixture and stirring at 70-90℃ for 20-24 min to obtain a suspension. The prepared suspension is centrifuged at 1500-2000 r / min for 10-20 min and washed with deionized water to obtain a precipitate. Finally, the precipitate is vacuum dried at a constant temperature of 40-50℃ to obtain functionalized modified carbon black / silica interphase particles.

2. The rubber material for paratrooper boot soles according to claim 1, characterized in that: It also includes lignin in parts by weight of 2-4 parts.

3. The rubber material for paratrooper boot soles according to claim 2, characterized in that: The lignin is modified, and the modification process is as follows: By weight, 10-20 parts of lignin are first dispersed in 120-150 parts of 0.18-0.2 mol / L sodium hydroxide solution and heated in a constant temperature water bath at 70-80℃ for 4-6 hours. Then, the mixture is washed with deionized water and centrifuged at 1000-1500 r / min for 10-20 minutes to obtain a precipitate. Finally, the precipitate is vacuum dried at a constant temperature of 35-55℃ for 5-6 hours and then crushed to obtain pretreated lignin. The pretreated lignin and 4-6 parts of titanate coupling agent are dispersed in 150-200 parts of ethyl acetate solvent and heated in a constant temperature water bath at 60-70℃ for 4-6 hours. Then, the mixture is washed with deionized water and centrifuged at 1500-2000 r / min for 10-20 minutes to obtain a mixture. Finally, the mixture is vacuum dried at a constant temperature of 40-50℃ for 4-6 hours to obtain modified lignin.

4. The rubber material for paratrooper boot soles according to claim 3, characterized in that: It also includes 1-2 parts by weight of graphene oxide.

5. The rubber material for paratrooper boot soles according to claim 4, characterized in that: It also includes 2-3 parts by weight of methacrylic acid.

6. The rubber material for paratrooper boot soles according to claim 1, characterized in that: It also includes 1-2 parts by weight of Scutellaria baicalensis root extract. The preparation process of the Scutellaria baicalensis root extract is as follows: First, wash the fresh and clean Scutellaria baicalensis root and cut it into shreds. Then, dry the Scutellaria baicalensis root shreds at 60°C for 4 hours, then pulverize them and filter them through a 60-mesh sieve to obtain dried Scutellaria baicalensis root shred powder. Then, reflux the Scutellaria baicalensis root shred powder with 80% ethanol at a ratio of 1:20 g / mL three times. The extraction temperature is 75°C and the extraction time is 3 hours. During the extraction process, the raw material is stirred once every 20 minutes for 3 minutes each time. The filtrate of the extraction is collected to obtain the extract. The extract is vacuum rotary evaporated at 40°C and then freeze-dried to obtain the Scutellaria baicalensis root extract.

7. A method for preparing a rubber material for the sole of paratrooper boots according to any one of claims 1-6, characterized in that, Includes the following steps: S1 Open Mixing: According to the weight parts specified in the formula, the polyurethane rubber is plasticized at a temperature of 60-70℃ for 10-20 minutes, and passed through a thin tube 1-3 times to obtain the preformed rubber. S2 Intensive Mixing: According to the required weight parts of the formula, zinc oxide, stearic acid, antioxidant, accelerator, and functionalized modified carbon black / fumed silica interlaced particles are added sequentially to the preformed rubber of S1 open mixing and intensive mixing. The intensive mixing temperature is 100-120℃, the intensive mixing time is 15-25min, and it is allowed to stand and cool for 20-26h to obtain the compounded rubber. S3 vulcanization: Add vulcanizing agent to the compound obtained by S2 internal mixing according to the required weight parts of the formula, mix evenly and then vulcanize. The vulcanization temperature is 160-170℃ and the vulcanization time is 12-16min to obtain the rubber material for paratrooper boot soles.

8. The method for preparing the rubber material for paratrooper boot soles according to claim 7, characterized in that: In S2 above, zinc oxide, stearic acid, antioxidant, accelerator, functionalized modified carbon black / white carbon black cross-linked particles, modified lignin, graphene oxide, and Scutellaria baicalensis root extract are added sequentially to the pre-mixed rubber in S1 according to the required weight parts of the formula. The mixture is then thoroughly mixed and kneaded at a temperature of 100-120℃ for 15-25 minutes, and allowed to stand and cool for 20-26 hours to obtain the compound rubber. In S3 above, according to the required weight parts of the formula, vulcanizing agent and methacrylic acid are added to the compound obtained by S2 internal mixing, and after being mixed evenly, vulcanization is carried out. The vulcanization temperature is 160-170℃ and the vulcanization time is 12-16min to obtain the rubber material for paratrooper boot soles.

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