Low-temperature vulcanization process rubber outsole and preparation method thereof

Abstract

The present invention provides a low-temperature vulcanization process rubber outsole and its preparation method. The raw materials for the preparation include, by weight, 100 parts rubber, 30-50 parts filler, 2-10 parts active agent, 1-5 parts modified epoxidized soybean oil, 0.4-8 parts accelerator, and 1-5 parts coated sulfur. While meeting the basic physical property requirements of the current footwear industry for rubber outsoles and without requiring significant modifications or replacements to existing production processes or equipment, the vulcanization temperature can be lowered to 130°C, significantly reducing production energy consumption and carbon emissions. Furthermore, the selected raw materials are environmentally friendly and universal across different rubber types, resulting in the produced rubber outsole product exhibiting excellent yellowing resistance.

Description

Technical Field

[0001] The present invention relates to the field of C08L9 / 02, and in particular to a low-temperature vulcanization process rubber outsole and a preparation method thereof. Background Art

[0002] Due to the excellent wear resistance and anti-slip properties of rubber, rubber outsoles have always been an important component of shoe materials, especially in some special occasions, where rubber outsoles play an indispensable role.

[0003] In the production process of traditional rubber outsoles, the molding temperature is generally 150-160°C, so vulcanization is also the process with the highest energy consumption in the entire rubber outsole processing technology. For economic and environmental considerations, the footwear industry has always hoped to lower the vulcanization temperature in order to save energy, reduce carbon emissions, and reduce environmental pollution. CN102115553B discloses a room temperature / low temperature vulcanized chloroprene rubber compound, the raw materials of which include: chloroprene rubber, natural rubber, double-coated sulfur, sulfur S, T-ZnO whiskers, magnesium oxide, accelerator TM808, accelerator TMTD, etc. It can be vulcanized at room temperature / low temperature conditions, has good scorch resistance, and has good aging resistance and physical and mechanical properties as well as ozone resistance, oxidation resistance, and flame retardancy. However, lowering the vulcanization temperature will lead to prolonged vulcanization time and reduced production efficiency. In addition, low temperature will inevitably affect the bridging degree, thereby having an uncontrollable negative impact on product performance.

[0004] In recent years, there have been many research topics related to low-temperature vulcanization of rubber. CN111205532B provides a low-temperature vulcanized self-absorbed water vapor rubber compound at normal pressure. The raw materials include: base rubber, coated sulfur, vulcanization accelerator, zinc oxide, stearic acid, plasticizer, etc. The preparation method includes weighing and mixing, plasticating, one-stage mixing, cooling, two-stage mixing, rapid cooling, re-mixing and extrusion, and rubber vulcanization. Vulcanization can be carried out at normal pressure using hot air or hot water as the heating medium. It has good applicability, economy and operability. However, as described in the patent, the existing solutions mainly focus on the rubber extrusion process, while shoe materials mostly use the traditional molding process. Compared with the extrusion vulcanization process, shoe material rubber has more requirements on the scorch stability of the rubber during normal storage and the adjustable range of the rubber operation time during the production process. So far, the application solutions and related reports of low-temperature vulcanization in shoe materials are relatively few. Summary of the Invention

[0005] In response to the above problems, the present invention discloses a low-temperature vulcanization process rubber outsole. The raw materials for preparation include, by mass, 100 parts of rubber, 30-50 parts of filler, 3-10 parts of active agent, 1-5 parts of modified epoxidized soybean oil, 0.4-8 parts of accelerator, and 1-5 parts of coated sulfur.

[0006] In one embodiment, the rubber is selected from one or more of natural rubber and synthetic rubber.

[0007] Preferably, the rubber is a synthetic rubber, including but not limited to butadiene rubber, nitrile rubber, styrene-butadiene rubber, EPDM rubber, and isoprene rubber.

[0008] More preferably, the rubber is a combination of butadiene rubber, isoprene rubber and nitrile rubber, with a mass ratio of (40-80): (10-30): (10-30).

[0009] In one embodiment, the filler is selected from any one of light calcium carbonate, clay, wollastonite, and white carbon black.

[0010] Preferably, the filler is white carbon black.

[0011] More preferably, the silica is precipitated silica.

[0012] In one embodiment, the active agent is selected from one or more of alcohols, amines, metal oxides, and fatty acids.

[0013] Preferably, the active agent is a combination of alcohols, amines, metal oxides, and fatty acids, with a mass ratio of (1-5): (1-5): (3-8): (1-5).

[0014] More preferably, the alcohol active agent includes but is not limited to diethylene glycol, glycerol, polyethylene glycol, etc., and polyethylene glycol is more preferred.

[0015] More preferably, the average molecular weight of the polyethylene glycol is in the range of 4000-20000; more preferably, the average molecular weight of the polyethylene glycol is 4000.

[0016] More preferably, the amine active agent includes but is not limited to monoethanolamine, diethanolamine, triethanolamine, butanediamine, and hexamethylenetetramine, and more preferably triethanolamine.

[0017] More preferably, the metal oxide includes but is not limited to zinc oxide, magnesium oxide, and zinc peroxide, more preferably zinc peroxide.

[0018] Further preferably, the fatty acid includes but is not limited to stearic acid, lauric acid, myristic acid, palmitic acid, behenic acid, oleic acid, linoleic acid and erucic acid, more preferably stearic acid.

[0019] In one embodiment, the accelerator is selected from one or more of alkyl xanthate accelerators, alkyl phosphate accelerators, thiuram accelerators, alkyl dithiocarbamate accelerators, and sulfenamide accelerators.

[0020] Preferably, the accelerator is selected from a combination of alkyl xanthate accelerators, alkyl phosphate accelerators, and thiuram accelerators, with a mass ratio of (0.1-3): (0.1-3): (0.1-3).

[0021] More preferably, the alkyl xanthate accelerator includes one or a combination of diisopropyl xanthate, diisobutyl xanthate, diisoamyl xanthate, etc.

[0022] More preferably, the alkyl phosphate accelerator includes one or a combination of two of zinc dialkyl dithiophosphate and sodium dialkyl dithiophosphate.

[0023] Further preferably, the thiuram accelerator includes one or a combination of tetramethylthiuram disulfide, tetramethylthiuram monosulfide, tetrabenzylthiuram disulfide, and diisobutylthiuram disulfide.

[0024] In one embodiment, the raw materials for preparing the coated sulfur include: sulfur and a coating agent, and the mass ratio of the sulfur and the coating agent is (60-80): (20-40).

[0025] Preferably, the coating agent is selected from one or more of polyolefin resins, acrylic resins and other long-chain polymers, and other crystalline polymers, including but not limited to polyethylene, polypropylene, polymethyl methacrylate, polystyrene, polyurea-formaldehyde resin, and 2,2'-methylenebis(6-tert-butyl-4-methylphenol).

[0026] The present invention does not limit the preparation method of the coated sulfur, and it is sufficient to ensure that the outer layer of sulfur is coated with the above-mentioned materials. In addition, the coating includes single-layer coating and multi-layer coating, and those skilled in the art can choose according to actual conditions.

[0027] The present invention uses a combination of different types of active agents, including polyethylene glycol, triethanolamine, zinc peroxide and stearic acid, etc., and uses a sulfur microcapsule coated with a special material as the coated sulfur. At the same time, the accelerator system includes alkyl xanthate, alkyl phosphate and thiuram, etc., which are used in a certain proportion to reduce the vulcanization temperature of the rubber to 130°C. At the same time, it can effectively reduce the risk of scorch during the normal storage period of the rubber, so that it can better meet the current shoe material production process requirements. The applicant believes that the possible reason is that the coated sulfur is an external The sulfur is coated with a special material. This coating material has good compatibility with rubber, ensuring its dispersion in the rubber. Its softening point is higher than the rubber temperature during the second mixing (80-90°C), but lower than the set vulcanization temperature (130°C). Therefore, compared with ordinary sulfur, the coated sulfur can reduce the pre-crosslinking reaction of the rubber to a certain extent during the mixing process, thereby improving the scorch stability of the rubber during normal storage. At the set vulcanization temperature (130°C), the coating softens and breaks down, releasing the sulfur to participate normally in the vulcanization and crosslinking reaction of the rubber. Furthermore, the applicant uses a combination of four different accelerators, under the action of polyethylene glycol, triethanolamine, zinc peroxide, and stearic acid, combined with a preferred accelerator combination, to lower the vulcanization temperature and accelerate the vulcanization rate during rubber vulcanization, ensuring the normal and sufficient crosslinking reaction between rubber macromolecules at 130°C and further improving the physical and mechanical properties of the rubber.

[0028] In one embodiment, the raw materials for preparing the rubber outsole include, by mass: 1-5 parts of protective wax, 1-5 parts of antioxidant, and 6-10 parts of color glue.

[0029] In one embodiment, the protective wax is selected from one or more of paraffin wax, mixed crystal wax, and polyethylene wax.

[0030] In one embodiment, the antioxidant includes but is not limited to one or more of antioxidant RD, antioxidant AW, antioxidant CPL, antioxidant DNP, antioxidant BHT, antioxidant 405, antioxidant 264, antioxidant 1010, antioxidant 2246, antioxidant 1076, and antioxidant 1096.

[0031] The present invention does not limit the color glue, and those skilled in the art can choose according to actual needs.

[0032] Another aspect of the present invention discloses a method for preparing the rubber outsole, comprising the following steps: all raw materials except the coated sulfur and the accelerator are mixed in a banbury mixer to obtain a basic masterbatch, which is then properly stored after being produced; the stored basic masterbatch is mixed with the accelerator and the coated sulfur in an open mixer to obtain a final masterbatch; and finally, the final masterbatch is compression-vulcanized in a mold to obtain a shoe outsole product.

[0033] In one embodiment, raw materials, namely rubber, filler, modified epoxidized soybean oil, activator, protective wax and antioxidant are sequentially added into the internal mixer for internal mixing to obtain a basic masterbatch.

[0034] Preferably, cis-butadiene rubber, nitrile rubber, and isoprene rubber are added and hammered for 1-3 minutes, then zinc peroxide, stearic acid, and part of the precipitated silica are added and hammered for 2-4 minutes; finally, modified epoxy soybean oil, polyethylene glycol, triethanolamine, protective wax, BHT antioxidant, and the remaining precipitated silica are added and hammered for 2-5 minutes.

[0035] Further preferably, during the mixing process, the feed is preheated to 70-80°C and the discharge temperature is 120-125°C.

[0036] In one embodiment, the basic masterbatch obtained by the internal mixer is poured into a two-roll open mill for the first open milling. Cooling water is passed through the open mill. The open milling operation time is 5-8 minutes. The material temperature is controlled not to exceed 90°C during feeding. After mixing is completed, the roller spacing is set to 3-5mm to produce sheets. The sheets are passed through cooling water to further cool them down, and after the surface is dried, they are stacked and stored in the warehouse.

[0037] In one embodiment, the basic mixture obtained from the first mixing is mixed with a sulfur-promoting system through a two-roll mill, wherein the sulfur-promoting system includes coated sulfur and an accelerator. The temperature of the mixture is controlled at 70-85°C during the entire mixing period. After the mixing operation for 5-10 minutes, the final masterbatch is produced by sheeting with a thickness of 1-20 mm. The sheet is cooled by water to ensure that the temperature of the sheet is quickly reduced to below 50°C, and is placed aside for use after the surface moisture is air-dried.

[0038] Preferably, the final masterbatch flakes need to be sampled and tested for sulfur degradation properties to assess whether the rubber meets the set requirements.

[0039] In one embodiment, the compression vulcanization temperature is 130°C and the pressure is 150-200 kgf / cm 2 The molding time is 3-6 minutes. The mold is opened and the sole is taken out to obtain the shoe outsole product.

[0040] Beneficial effects

[0041] 1. Compared with the traditional shoe molding process, without significantly changing the existing production process and equipment, it can effectively reduce the vulcanization temperature by about 20-30℃, save energy and reduce carbon emissions, and significantly reduce product production costs. In addition, the raw materials selected are environmentally friendly and versatile, and the rubber outsole products produced have excellent yellowing resistance.

[0042] 2. This invention utilizes a combination of different active agents, specifically polyethylene glycol, triethanolamine, zinc peroxide, and stearic acid. A sulfur microcapsule coated with a special material is used as the coated sulfur. Furthermore, the accelerator system includes alkyl xanthates, alkyl phosphates, and thiuram, all combined in a specific proportion. This reduces the vulcanization temperature of the rubber compound to 130°C and effectively minimizes the risk of scorching during storage, enabling it to better meet current shoe production process requirements. DETAILED DESCRIPTION

[0043] The cis-butadiene rubber was purchased from Sinopec with the brand name BR9000.

[0044] The nitrile rubber was purchased from Lanxess Chemical with the brand name NBR-3965F.

[0045] The isoprene rubber was purchased from Ruiong Company with the brand name IR2200.

[0046] The precipitated silica was purchased from Intron Degussa with the brand name VN-3GR.

[0047] The modified epoxidized soybean oil has a CAS number of 8013-07-8 and was purchased from Shandong Shengxu Energy Co., Ltd.

[0048] The polyethylene glycol was purchased from Lotte Chemical Co., Ltd. of South Korea with the brand name PEG4000.

[0049] The triethanolamine accelerator was purchased from Jiangsu Ruiba New Material Technology Co., Ltd. with the brand name LS450.

[0050] The protective wax was purchased from Jiangsu Ruiba New Material Technology Co., Ltd. with the brand name RW159.

[0051] The BHT antioxidant was purchased from Lanxess Chemicals and its brand is Vulkanox BHT.

[0052] The diisopropyl xanthate was purchased from Jiangsu Ruiba New Material Technology Co., Ltd. with the brand name LSB-50.

[0053] The tetrabenzylthiuram disulfide was purchased from Jiangsu Ruiba New Material Technology Co., Ltd. with the brand name TBzTD-80.

[0054] The dialkyl dithiophosphate was purchased from Jiangsu Ruiba New Material Technology Co., Ltd. with the brand name LSC-50.

[0055] The ordinary sulfur pre-dispersion was purchased from Jiangsu Ruiba New Material Technology Co., Ltd., with the brand name S-80.

[0056] The black colored glue was purchased from Dongguan Guangfengxing Plastic Co., Ltd., model number R802.

[0057] Example 1

[0058] This embodiment 1 discloses a low-temperature vulcanization process rubber outsole. The raw materials, in parts by mass, are: 80 parts of cis-butadiene rubber, 10 parts of nitrile rubber, 10 parts of isoprene rubber, 5 parts of zinc peroxide, 1 part of stearic acid, 50 parts of precipitated silica, 3 parts of modified epoxidized soybean oil, 0.5 parts of polyethylene glycol, 3.5 parts of triethanolamine, 0.5 parts of protective wax, 1 part of BHT antioxidant, 2.2 parts of coated sulfur, 1.2 parts of diisopropyl xanthate, 0.8 parts of tetrabenzylthiuram disulfide, 2.0 parts of sodium dialkyl dithiophosphate, and 8 parts of black color glue.

[0059] The coating capsule material for coating the sulfur is polystyrene, and the mass ratio of the polystyrene to the sulfur is 25:75.

[0060] On the other hand, this embodiment 1 discloses a method for preparing the rubber outsole, which comprises the following steps:

[0061] (1) Preheat the internal mixer to 80℃, add cis-butadiene rubber, nitrile rubber, and isoprene rubber, and drop hammer to mix for 1 minute. Then add zinc peroxide, stearic acid, and 25 parts of precipitated silica to mix for 3 minutes. Finally, add modified epoxy soybean oil, polyethylene glycol, triethanolamine, protective wax, BHT antioxidant, and 25 parts of precipitated silica to mix for 3 minutes. The discharge temperature is 120℃, and then the material is discharged to a two-roll open mill.

[0062] (2) The two-roller mill is cooled by cooling water, and the roller temperature before mixing is controlled to be no higher than 40℃. The roller distance is set to 5-8mm. A turning machine is used to assist in the milling operation for 4 minutes, and the sheet is discharged after the sheet is discharged. The sheet is cooled in a supercooling water tank for 20 seconds and then taken out. After there is no obvious water droplets on the surface of the film, it is stacked and stored in the warehouse.

[0063] (3) The mixed rubber sheet of the first refining was put into a two-roller refining mill with cooling water, and after being thinned twice, it was rolled. Then polystyrene-coated sulfur, diisopropyl xanthate, tetrabenzylthiuram disulfide, sodium dialkyl dithiophosphate, and black color glue were put into the refining mill. After the masterbatch was fed through methods including rolling and triangle packing, a turning machine was used to assist in dispersion. The whole operation process took a total of 6 minutes. During this period, the temperature of the masterbatch did not exceed 90°C. Then, the roller spacing was set to 2mm to discharge the sheet. The sheet passed through a cooling water tank to ensure that the temperature of the sheet quickly dropped to below 50°C. Then, it was placed on a hanging rack to air-dry the moisture on the surface and stacked for use. During this period, samples were taken to detect sulfur changes to evaluate whether the rubber material met the set requirements. The sulfur rate results are shown in the table.

[0064] (4) The film obtained in step 3 is cut according to the required weight, and the mold temperature is set to 130°C and the molding pressure is 180kgf / cm 2 The hot pressing time after mold closing is 240 seconds. After the hot pressing is completed, the mold is opened to take out the vulcanized sample, and the physical properties are tested according to the process. The physical property results are shown in the table.

[0065] Example 2

[0066] This embodiment 2 discloses a low-temperature vulcanization process rubber outsole. The raw materials, in parts by mass, are: 80 parts of cis-butadiene rubber, 10 parts of nitrile rubber, 10 parts of isoprene rubber, 5 parts of zinc peroxide, 1 part of stearic acid, 50 parts of precipitated silica, 3 parts of modified epoxidized soybean oil, 0.5 parts of polyethylene glycol, 3.5 parts of triethanolamine, 0.5 parts of protective wax, 1 part of BHT antioxidant, 2.2 parts of polystyrene-coated sulfur, 1.2 parts of diisopropyl xanthate, 0.8 parts of tetrabenzylthiuram disulfide, 0.5 parts of sodium dialkyl dithiophosphate, and 8 parts of black color glue.

[0067] The coating agent for coating the sulfur is polystyrene, and the mass ratio of the polystyrene to the sulfur is 25:75.

[0068] On the other hand, this embodiment 2 discloses a method for preparing the rubber outsole, and the steps are as follows:

[0069] (1) Preheat the internal mixer to 80℃, add cis-butadiene rubber, nitrile rubber, and isoprene rubber, and drop hammer to mix for 1 minute. Then add zinc peroxide, stearic acid, and 25 parts of precipitated silica to mix for 3 minutes. Finally, add modified epoxy soybean oil, polyethylene glycol, triethanolamine, protective wax, BHT antioxidant, and 25 parts of precipitated silica to mix for 3 minutes. The discharge temperature is 120℃, and then the material is discharged to a two-roll open mill.

[0070] (2) The two-roller mill is cooled by cooling water, and the roller temperature is controlled not to be higher than 40℃. The roller distance is set to 5-8mm. The sheet is discharged after 4 minutes of operation with the help of a turning machine. The sheet is cooled in a supercooling water tank for 20 seconds and then taken out. When there is no obvious water droplets on the surface of the film, it is stacked and stored in the warehouse.

[0071] (3) The mixed rubber sheet of the first refining was put into a two-roller refining mill with cooling water, and after being thinned twice, it was rolled. Then polystyrene-coated sulfur, diisopropyl xanthate, tetrabenzylthiuram disulfide, sodium dialkyl dithiophosphate, and black color glue were put into the refining mill. After the masterbatch was fed through methods including rolling and triangle packing, a turning machine was used to assist in dispersion. The whole operation process took a total of 6 minutes. During this period, the temperature of the masterbatch did not exceed 90°C. Then, the roller spacing was set to 2mm to discharge the sheet. The sheet passed through a cooling water tank to ensure that the temperature of the sheet quickly dropped to below 50°C. Then, it was placed on a hanging rack to air-dry the moisture on the surface and stacked for use. During this period, samples were taken to detect sulfur changes to evaluate whether the rubber material met the set requirements. The sulfur rate results are shown in the table.

[0072] (4) The film obtained in step 3 is cut according to the required weight, and the mold temperature is set to 130°C and the molding pressure is 180kgf / cm 2 The hot pressing time after mold closing is 300 seconds. After the hot pressing is completed, the mold is opened to take out the vulcanized sample, and the physical properties are tested according to the process. The physical property results are shown in the table.

[0073] Example 3

[0074] This embodiment 3 discloses a low-temperature vulcanization process rubber outsole. The raw materials, in parts by mass, are: 50 parts of cis-butadiene rubber, 20 parts of styrene-butadiene rubber, 30 parts of isoprene rubber, 5 parts of zinc peroxide, 1 part of stearic acid, 35 parts of precipitated silica, 1 part of modified epoxidized soybean oil, 0.2 parts of polyethylene glycol, 2.7 parts of triethanolamine, 0.5 parts of protective wax, 1 part of BHT antioxidant, 2.2 parts of polystyrene-coated sulfur, 1.2 parts of diisopropyl xanthate, 0.7 parts of tetrabenzylthiuram disulfide, 1.8 parts of sodium dialkyl dithiophosphate, and 8 parts of black color glue.

[0075] The coating agent for coating the sulfur is polystyrene, and the mass ratio of the polystyrene to the sulfur is 25:75.

[0076] On the other hand, this embodiment 3 discloses a method for preparing the rubber outsole, which comprises the following steps:

[0077] (1) Preheat the internal mixer to 80℃, add cis-butadiene rubber, styrene-butadiene rubber, and isoprene rubber and drop hammer to mix for 1 minute, then add zinc peroxide, stearic acid, and 15 parts of precipitated silica and drop hammer to mix for 3 minutes; finally, add modified epoxy soybean oil, polyethylene glycol, triethanolamine, protective wax, BHT antioxidant, and 20 parts of precipitated silica and drop hammer to mix for 3 minutes. The discharge temperature is 120℃, and then the material is discharged to a two-roll open mill.

[0078] (2) The two-roller mill is cooled by cooling water, and the roller temperature is controlled not to be higher than 40℃. The roller distance is set to 5-8mm. The sheet is discharged after 4 minutes of operation with the help of a turning machine. The sheet is cooled in a supercooling water tank for 20 seconds and then taken out. When there is no obvious water droplets on the surface of the film, it is stacked and stored in the warehouse.

[0079] (3) The mixed rubber sheet of the first refining was put into a two-roller mill with cooling water, and after being thinned twice, it was rolled. Then polystyrene-coated sulfur, diisopropyl xanthate, tetrabenzylthiuram disulfide, zinc dibutyl dithiocarbamate, zinc dialkyl dithiophosphate, and black color glue were put into the mill. After the masterbatch was fed through methods including rolling and triangle wrapping, a turning machine was used to assist in dispersion. The whole operation process took a total of 6 minutes. During this period, the temperature of the masterbatch did not exceed 90°C. Then, the roller spacing was set to 2mm to discharge the sheet. The sheet passed through a cooling water tank to ensure that the temperature of the sheet quickly dropped to below 50°C. Then, it was placed on a hanging rack to air-dry the moisture on the surface and stacked for use. During this period, samples were taken to detect sulfur changes to evaluate whether the rubber material met the set requirements. The sulfur rate results are shown in the table.

[0080] (4) The film obtained in step 3 is cut according to the required weight, and the mold temperature is set to 130°C and the molding pressure is 180kgf / cm 2 The hot pressing time after mold closing is 240 seconds. After the hot pressing is completed, the mold is opened to take out the vulcanized sample, and the physical properties are tested according to the process. The physical property results are shown in the table.

[0081] Example 4

[0082] This embodiment 4 discloses a low-temperature vulcanization process rubber outsole. The raw materials, in parts by mass, are: 70 parts of cis-butadiene rubber, 15 parts of nitrile rubber, 15 parts of isoprene rubber, 5 parts of zinc peroxide, 1 part of stearic acid, 50 parts of precipitated silica, 3 parts of modified epoxidized soybean oil, 0.5 parts of polyethylene glycol, 3.5 parts of triethanolamine, 0.5 parts of protective wax, 1 part of BHT antioxidant, 2.2 parts of ordinary pre-dispersed sulfur, 1.2 parts of diisopropyl xanthate, 0.8 parts of tetrabenzylthiuram disulfide, 2.0 parts of sodium dialkyl dithiophosphate, and 8 parts of black color glue.

[0083] On the other hand, this embodiment 4 discloses a method for preparing the rubber outsole, and the steps are as follows:

[0084] (1) Preheat the internal mixer to 80℃, add cis-butadiene rubber, nitrile rubber, and isoprene rubber, and drop hammer to mix for 1 minute. Then add zinc peroxide, stearic acid, and 25 parts of precipitated silica to mix for 3 minutes. Finally, add modified epoxy soybean oil, polyethylene glycol, protective wax, BHT antioxidant, and 25 parts of precipitated silica to mix for 3 minutes. The discharge temperature is 120℃, and then the material is discharged to a two-roll open mill.

[0085] (2) The two-roller mill is cooled by cooling water, and the roller temperature before mixing is controlled to be no higher than 40℃. The roller distance is set to 5-8mm. A turning machine is used to assist in the milling operation for 4 minutes, and the sheet is discharged after the sheet is discharged. The sheet is cooled in a supercooling water tank for 20 seconds and then taken out. After there is no obvious water droplets on the surface of the film, it is stacked and stored in the warehouse.

[0086] (3) The first batch of mixed rubber was put into a two-roller mill with cooling water, and after being thinned twice, it was rolled. Then ordinary pre-dispersed sulfur, diisopropyl xanthate, tetrabenzylthiuram disulfide, sodium dialkyl dithiophosphate, and black color glue were put into the mill. After the masterbatch was fed through methods including rolling and triangle wrapping, a turning machine was used to assist in dispersion. The whole operation process took a total of 6 minutes. During this period, the temperature of the masterbatch did not exceed 90°C. Then, the roller spacing was set to 2mm to discharge the sheet. The sheet passed through a cooling water tank to ensure that the temperature of the sheet quickly dropped to below 50°C. Then, it was placed on a hanging rack to air-dry the moisture on the surface and stacked for use. During this period, samples were taken to detect sulfur changes to evaluate whether the rubber met the set requirements. The sulfur rate results are shown in the table.

[0087] (4) The film obtained in step 3 is cut according to the required weight, and the mold temperature is set to 130°C and the molding pressure is 180kgf / cm 2 The hot pressing time after mold closing is 240 seconds. After the hot pressing is completed, the mold is opened to take out the vulcanized sample, and the physical properties are tested according to the process. The physical property results are shown in the table.

[0088] Example 5

[0089] Example 5 discloses a low-temperature vulcanization process rubber outsole. The raw materials, in parts by mass, are: 70 parts of cis-butadiene rubber, 15 parts of nitrile rubber, 15 parts of isoprene rubber, 5 parts of zinc peroxide, 1 part of stearic acid, 50 parts of precipitated silica, 3 parts of modified epoxidized soybean oil, 4.0 parts of polyethylene glycol, 0.5 part of protective wax, 1 part of BHT antioxidant, 2.2 parts of polystyrene-coated sulfur, 1.2 parts of diisopropyl xanthate, 0.7 parts of tetrabenzylthiuram disulfide, 1.8 parts of sodium dialkyl dithiophosphate, and 8 parts of black colorant.

[0090] On the other hand, this embodiment 5 discloses a method for preparing the rubber outsole, and the steps are as follows:

[0091] (1) Preheat the internal mixer to 80℃, add cis-butadiene rubber, nitrile rubber, and isoprene rubber, and drop hammer to mix for 1 minute. Then add zinc peroxide, stearic acid, and 25 parts of precipitated silica to mix for 3 minutes. Finally, add modified epoxy soybean oil, polyethylene glycol, protective wax, BHT antioxidant, and 25 parts of precipitated silica to mix for 3 minutes. The discharge temperature is 120℃, and then the material is discharged to a two-roll open mill.

[0092] (2) The two-roller mill is cooled by cooling water, and the roller temperature before mixing is controlled to be no higher than 40℃. The roller distance is set to 5-8mm. A turning machine is used to assist in the milling operation for 4 minutes, and the sheet is discharged after the sheet is discharged. The sheet is cooled in a supercooling water tank for 20 seconds and then taken out. After there is no obvious water droplets on the surface of the film, it is stacked and stored in the warehouse.

[0093] (3) The mixed rubber sheet of the first refining was put into a two-roll open mill with cooling water, and after being thinned twice, it was rolled. Then polystyrene-coated sulfur, diisopropyl xanthate, tetrabenzylthiuram disulfide, sodium dialkyl dithiophosphate, and black color glue were put into the mill. After the masterbatch was fed through methods including rolling and triangle wrapping, a turning machine was used to assist in dispersion. The whole operation process took a total of 6 minutes. During this period, the temperature of the masterbatch did not exceed 90°C. Then, the roller spacing was set to 2mm to discharge the sheet. The sheet passed through a cooling water tank to ensure that the film temperature quickly dropped to below 50°C. Then, it was placed on a hanging rack to air-dry the moisture on the surface and stacked for use. During this period, samples were taken to detect sulfur changes to evaluate whether the rubber material met the set requirements. The sulfur rate results are shown in Tables 1 and 2.

[0094] (4) The film obtained in step 3 is cut according to the required weight, and the mold temperature is set to 130°C and the molding pressure is 180kgf / cm 2 The hot pressing time after mold closing is 240 seconds. After the hot pressing is completed, the mold is opened to take out the vulcanized sample, and the physical properties are tested according to the process. The physical property results are shown in the table.

[0095] Example 6

[0096] This embodiment 6 discloses a low-temperature vulcanization process rubber outsole, which includes the following raw materials, in parts by mass: 70 parts of cis-butadiene rubber, 15 parts of nitrile rubber, 15 parts of isoprene rubber, 5 parts of zinc oxide, 1 part of stearic acid, 50 parts of precipitated silica, 3 parts of modified epoxidized soybean oil, 0.5 parts of polyethylene glycol, 3.5 parts of triethanolamine, 0.5 parts of protective wax, 1 part of BHT antioxidant, 2.2 parts of polystyrene-coated sulfur, 3.5 parts of diisopropyl xanthate, 0.8 parts of tetrabenzylthiuram disulfide, 3.5 parts of sodium dialkyl dithiophosphate, and 8 parts of black color glue.

[0097] On the other hand, this embodiment 5 discloses a method for preparing the rubber outsole, and the steps are as follows:

[0098] (1) Preheat the internal mixer to 80℃, add cis-butadiene rubber, nitrile rubber, and isoprene rubber, and drop hammer to mix for 1 minute. Then add zinc oxide, stearic acid, and 25 parts of precipitated silica to mix for 3 minutes. Finally, add modified epoxy soybean oil, polyethylene glycol, protective wax, BHT antioxidant, and 25 parts of precipitated silica to mix for 3 minutes. The discharge temperature is 120℃, and then the material is discharged to a two-roll open mill.

[0099] (2) The two-roller mill is cooled by cooling water, and the roller temperature before mixing is controlled to be no higher than 40℃. The roller distance is set to 5-8mm. A turning machine is used to assist in the milling operation for 4 minutes, and the sheet is discharged after the sheet is discharged. The sheet is cooled in a supercooling water tank for 20 seconds and then taken out. After there is no obvious water droplets on the surface of the film, it is stacked and stored in the warehouse.

[0100] (3) The mixed rubber sheet of the first refining was put into a two-roll open mill with cooling water, and after being thinned twice, it was rolled. Then polystyrene-coated sulfur, diisopropyl xanthate, tetrabenzylthiuram disulfide, sodium dialkyl dithiophosphate, and black color glue were put into the mill. After the masterbatch was fed through methods including rolling and triangle wrapping, a turning machine was used to assist in dispersion. The whole operation process took a total of 6 minutes. During this period, the temperature of the masterbatch did not exceed 90°C. Then, the roller spacing was set to 2mm to discharge the sheet. The sheet passed through a cooling water tank to ensure that the film temperature quickly dropped to below 50°C. Then, it was placed on a hanging rack to air-dry the moisture on the surface and stacked for use. During this period, samples were taken to detect sulfur changes to evaluate whether the rubber material met the set requirements. The sulfur rate results are shown in Tables 1 and 2.

[0101] (4) The film obtained in step 3 is cut according to the required weight, and the mold temperature is set to 130°C and the molding pressure is 180kgf / cm 2 The hot pressing time after mold closing is 240 seconds. After the hot pressing is completed, the mold is opened to take out the vulcanized sample, and the physical properties are tested according to the process. The physical property results are shown in the table.

[0102] Table 1 First day sample sulfur rate test results

[0103]

[0104]

[0105] Table 2 Sulfur rate test results of samples after storage at room temperature for four days

[0106]

[0107] Remark:

[0108] 1. In the second operation of the sulfur-addition system in the refining process, the process 4 showed early scorching, which made it unsuitable for product production and test evaluation.

[0109] 2. Implementation 5 showed early scorching after being stored at room temperature for two days, making it unsuitable for product production and other test evaluations.

[0110] 3. The initial vulcanization rate in Implementation 6 was too fast to meet the requirements of the outsole vulcanization process. In addition, early scorching occurred after three days of storage at room temperature, making it unsuitable for product production and other test evaluations.

[0111] Performance Testing

[0112] 1. Hardness: Based on GB / T531 vulcanized rubber or thermoplastic rubber indentation hardness test method, the test temperature is room temperature, see Table 3 below.

[0113] 2. Mechanical properties: Based on GB / T528-2009, Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber. The test temperature is room temperature. See Table 3 below.

[0114] 3. Tear strength: According to GB / T529-2008, Determination of tear strength of vulcanized rubber or thermoplastic rubber, the test temperature is room temperature, see Table 3 below.

[0115] 4. DIN wear resistance test: Use KD-319DIN and conduct the test according to GB / T9867-2008 standard. The test temperature is room temperature. See Table 3 below.

[0116] Table 3 Sample physical property test results

[0117]

Claims

1. A vulcanized rubber outsole, characterized in that: The raw materials for preparation include, by weight: 100 parts of rubber, 30-50 parts of filler, 2-10 parts of active agent, 1-5 parts of modified epoxy soybean oil, 0.4-8 parts of accelerator, and 1-5 parts of coated sulfur; The active agent is a combination of polyethylene glycol, triethanolamine, zinc peroxide and stearic acid in a mass ratio of (1-5): (1-5): (3-8): (1-5); The accelerator is selected from a combination of alkyl xanthate accelerators, alkyl phosphate accelerators, and thiuram accelerators, with a mass ratio of (0.1-3): (0.1-3): (0.1-3); The raw materials for preparing the coated sulfur include: sulfur and a coating agent, and the mass ratio of the sulfur and the coating agent is (60-80): (20-40); the coating agent is polystyrene.

2. The rubber outsole according to claim 1, characterized in that: The rubber is selected from one or more of natural rubber and synthetic rubber.

3. The rubber outsole according to claim 1, characterized in that: The filler is selected from any one of light calcium carbonate, clay, wollastonite and white carbon black.

4. The rubber outsole according to claim 3, characterized in that: The filler is white carbon black; the white carbon black is precipitated white carbon black.

5. A method for preparing a rubber outsole according to any one of claims 1 to 4, characterized in that: The method for preparing a rubber outsole comprises the following steps: all raw materials except the coated sulfur and the accelerator are mixed in a banbury mixer to obtain a basic masterbatch, which is then properly stored after being produced; the stored basic masterbatch is mixed with the accelerator and the coated sulfur in an open mixer to obtain a final masterbatch; and finally, the final masterbatch is compression-vulcanized in a mold to obtain a shoe outsole product.

6. The method for preparing a rubber outsole according to claim 5, characterized in that: During the mixing process, the feed material needs to be preheated to 70-80°C before mixing, and the discharge temperature after mixing is 120-125°C.

Images