A high-bio-based-content, air-tightness-excellent tire air-tight layer rubber composite material and a preparation method thereof

Abstract

The application provides a rubber composite material, which comprises, in parts by weight: 100 parts of raw rubber, 40-100 parts of reinforcing filler, 2-10 parts of activator, 4-10 parts of plasticizer, 2-15 parts of homogenizing agent, 2-15 parts of tackifying resin, 0.05-0.5 parts of magnesium oxide, 1.0-6.0 parts of accelerator and 0.5-3 parts of vulcanizing agent; the raw rubber comprises itaconate rubber and halogenated butyl rubber. The air-tight layer rubber provided by the application contains environment-friendly bio-based itaconate rubber, which is beneficial to energy saving and carbon reduction, and the itaconate rubber has certain side groups and is arranged closely, so that the itaconate rubber has certain gas barrier property; the itaconate rubber and butyl rubber are combined, so that the air-tight layer rubber has more excellent air-tightness and aging resistance than natural rubber.

Description

Technical Field

[0001] This invention belongs to the technical field of tire airtight layer rubber composite materials, and relates to a rubber composite material, its preparation method and application, especially a tire airtight layer rubber composite material with high bio-based content and excellent airtightness, its preparation method and application. Background Technology

[0002] With the increasing popularity of new energy vehicles, higher demands are placed on tire load-bearing capacity and instantaneous torque, which in turn places higher demands on tire air tightness. Insufficient tire inflation can lead to problems such as increased rolling resistance, sluggish handling response, longer braking distance, uneven tire wear, and increased stress on internal tire components, potentially resulting in tire blowouts.

[0003] The airtightness of a tire is mainly determined by its innermost rubber layer, also known as the airtight layer. High airtightness composite materials offer solutions for new energy vehicles by reducing the thickness of the airtight layer and lowering tire rolling resistance. In addition, bio-based composite materials also align with national environmental protection principles.

[0004] In the existing technology, the base rubber of the tire airtight layer is mostly a combination of natural rubber and halogenated butyl rubber. The main problem with this combination is that as the amount of natural rubber increases, the air permeability coefficient of the airtight layer increases, thereby reducing the tire's air retention performance, affecting the tire's service life and driving handling.

[0005] On the other hand, the main raw materials for butyl rubber used in the tire industry, such as isobutylene and isoprene, are derived from non-renewable petrochemical resources. As a major consumer of petrochemical resources, the rubber industry generates a large amount of wastewater and waste gas. Meanwhile, the development of biomass energy and bio-based chemicals is gaining increasing attention worldwide, as these resources are abundant and carbon-neutral. Developing bio-based synthetic elastomer composites based on bio-based chemicals is of great significance for sustainable development. Under the influence of relevant policies, the full utilization of low-carbon, renewable resources has received attention from countries around the world. In tire production, most raw materials heavily rely on rubber materials synthesized from fossil resources, resulting in high carbon emissions, which is highly detrimental to the sustainable development of the tire industry. Although bio-based materials have advantages over traditional petroleum-based materials, such as abundant reserves, carbon neutrality, and reduced raw material costs, and current research is gradually exploring the use of bio-based materials in various aspects, the product performance remains unsatisfactory. With the accelerated implementation of green transformation and upgrading in the rubber additives industry and the increasing pressure on environmental protection, various environmentally friendly additives have been successively applied to various rubber products. Replacing traditional additives with new environmentally friendly, non-toxic natural materials and green additives is of great significance to the sustainable development of the transmission belt industry and is also the main direction of technological development.

[0006] Therefore, how to obtain a suitable production process and rubber composite material, solve the above-mentioned problems of existing processes and rubber products, especially tire airtight layer rubber materials, and further improve the green and environmental protection level has become an important issue that many front-line production and R&D personnel and manufacturers in the industry urgently need to solve. Summary of the Invention

[0007] In view of this, the technical problem to be solved by the present invention is to provide a rubber composite material, its preparation method, and its application, particularly a tire airtight layer rubber composite material with high bio-based content and excellent airtightness. The airtight layer rubber provided by the present invention contains environmentally friendly bio-based itaconic acid ester rubber, which is beneficial for energy conservation and carbon reduction. At the same time, because itaconic acid ester rubber has certain side groups and a relatively dense arrangement, it has a certain gas barrier property; its composite with butyl rubber exhibits superior airtightness and aging resistance compared to natural rubber. Furthermore, the processing technology of the described airtight layer rubber is simple, requires low equipment standards, and has excellent processing performance, making it suitable for widespread use.

[0008] This invention provides a rubber composite material, comprising, by mass parts of raw materials:

[0009] 100 parts by weight of raw rubber;

[0010] The raw rubber includes itaconic acid ester rubber and halogenated butyl rubber;

[0011]

[0012] Preferably, in the raw rubber, the mass ratio of halogenated butyl rubber to itaconic acid ester rubber is (1-9):1;

[0013] The itaconic acid ester rubber is a binary, ternary, or quaternary copolymer containing itaconic acid ester and bio-based diene or petroleum-based conjugated diene.

[0014] The itaconic acid ester rubber is specifically a copolymer obtained by low-temperature emulsion polymerization of raw materials including dibutyl itaconic acid units and butadiene units;

[0015] The polymerization temperature of the low-temperature emulsion polymerization is 1–20°C.

[0016] Preferably, the itaconic acid ester is selected from one or more of dimethyl itaconic acid, diethyl itaconic acid, dipropyl itaconic acid, dibutyl itaconic acid, diisopropyl itaconic acid, diisobutyl itaconic acid, dipentyl itaconic acid, and diisopentyl itaconic acid.

[0017] The bio-based diene is a diene produced through microbial fermentation or a terpene derived from plants;

[0018] The petroleum-based conjugated diene is isoprene and / or butadiene;

[0019] The rubber composite material is a rubber composite material used for the airtight layer of a tire.

[0020] Preferably, the itaconic acid ester rubber further comprises a third component and / or a fourth component;

[0021] The third and fourth components are each independently selected from one or more of glycidyl methacrylate, styrene, vinyl chloride acetate, acrylamide, cyclopentadiene, ethylenediene norbornene, methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hydroxyethyl methacrylate, and 2-hydroxyethyl acrylate.

[0022] The reinforcing filler is one or more of the following: carbon black, pyrolysis carbon black, calcium carbonate, calcium sulfate, dolomite powder, clay, montmorillonite, clay, barium montmorillonite sulfate, talc, magnesium carbonate, magnesium silicate, graphene, and cellulose bio-based filler.

[0023] The vulcanizing agent is sulfur.

[0024] Preferably, the activator is one or more selected from zinc oxide, stearic acid, and magnesium oxide;

[0025] The plasticizer is one or more of naphthenic oil, aromatic oil, petroleum resin, epoxidized soybean oil, and palm oil;

[0026] The homogenizer is an aromatic hydrocarbon resin mixture;

[0027] The tackifying resin is phenolic resin and / or petroleum resin;

[0028] The accelerator is one or more of the following: thiazole accelerators, thiuram accelerators, dithiocarbamate accelerators, xanthate accelerators, guanidine accelerators, aldehyde amine accelerators, sulfenamide accelerators, and thiourea accelerators.

[0029] This invention provides a method for preparing a rubber composite material as described in any one of the above technical solutions, comprising the following steps:

[0030] 1) After raw rubber is masticated in an internal mixer, masticated rubber is obtained;

[0031] 2) Add reinforcing filler, plasticizer, magnesium oxide, homogenizer and tackifying resin to the plasticized rubber obtained in the above steps, mix and then discharge the rubber to obtain a first-stage masterbatch.

[0032] 3) After cooling the first stage of masterbatch obtained in the above steps, continue to internally mix the first stage of masterbatch, vulcanizing agent, activator and accelerator, and discharge the rubber to obtain the second stage of final rubber.

[0033] 4) After the two-stage final compound obtained in the above steps is thinly passed on a two-roll mill, a compound is obtained. After vulcanization, a rubber composite material is obtained.

[0034] Preferably, the plasticizing time is 0.5 to 1.5 minutes;

[0035] The plasticizing temperature is 40–80°C;

[0036] The speed of the internal mixer during plasticizing is 40-80 rpm;

[0037] The mixing temperature is 110–150°C;

[0038] The mixing time is 4 to 8 minutes.

[0039] Preferably, the temperature after cooling is less than or equal to 80°C;

[0040] The temperature for continued intensive mixing is 90–130°C;

[0041] The continued intensive refining time is 1 to 3 minutes;

[0042] The number of thin-pass tests is 3 to 12;

[0043] The roller gap of the thin tube is 0.5 to 4.0 mm.

[0044] Preferably, the thin-walled section further includes a parking step;

[0045] The parking time is 18–24 hours;

[0046] The vulcanization temperature is 130–180°C;

[0047] The vulcanization time is 5 to 60 minutes;

[0048] The vulcanization pressure is 20 to 40 tons.

[0049] This invention provides the application of the rubber composite material described in any one of the above technical solutions or the rubber composite material prepared by the preparation method described in any one of the above technical solutions in tires.

[0050] This invention provides a rubber composite material, comprising, by weight parts of raw materials: 100 parts by weight of raw rubber, 40-100 parts by weight of reinforcing filler, 2-10 parts by weight of activator, 4-10 parts by weight of plasticizer, 2-15 parts by weight of homogenizer, 2-15 parts by weight of tackifying resin, 0.05-0.5 parts by weight of magnesium oxide, 1.0-6.0 parts by weight of accelerator, and 0.5-3 parts by weight of vulcanizing agent; wherein the raw rubber includes itaconic acid ester rubber and halogenated butyl rubber. Compared with the prior art, this invention specifically uses itaconic acid ester bio-based rubber as the matrix material and designs the vulcanization system, auxiliary agent system, and processing technology, etc., to design a tire airtight layer rubber composite material with high bio-based content and excellent airtightness. The airtight layer rubber provided by this invention contains environmentally friendly bio-based itaconic acid ester rubber, which is beneficial for energy conservation and carbon reduction. At the same time, because itaconic acid ester rubber has certain side groups and is arranged more closely, it has a certain gas barrier property. When combined with butyl rubber, it has better airtightness and aging resistance than natural rubber.

[0051] This invention replaces natural rubber or halogenated butyl rubber in traditional airtight layer formulations with bio-based itaconic acid ester rubber prepared from biomass resources in an equal amount, reducing dependence on petrochemical raw materials. Simultaneously, the resulting high-bio-based airtight layer composite material exhibits superior low permeability, aging resistance, and fatigue resistance compared to the same proportion of natural rubber, while also meeting other basic mechanical property requirements, significantly improving tire lifespan and complying with relevant policies.

[0052] In addition, the present invention also provides a corresponding preparation method, which has a simple processing technology, low equipment requirements, and excellent processing performance, making it more suitable for promotion and application in large-scale industrial production. Detailed Implementation

[0053] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims.

[0054] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0055] This invention provides a rubber composite material, comprising, by mass parts of raw materials:

[0056] 100 parts by weight of raw rubber;

[0057] The raw rubber includes itaconic acid ester rubber and halogenated butyl rubber;

[0058] 40-100 parts by weight of reinforcing filler;

[0059] Activator 2-10 parts by weight;

[0060] Plasticizer 4-10 parts by weight;

[0061] 2-15 parts by weight of homogenizer;

[0062] 2-15 parts by weight of tackifying resin;

[0063] Magnesium oxide 0.05–0.5 parts by weight;

[0064] Accelerator 1.0 to 6.0 parts by weight;

[0065] Vulcanizing agent: 0.5 to 3 parts by weight.

[0066] In this invention, the content of the reinforcing filler is 40-100 parts by weight, or 50-90 parts by weight, or 60-80 parts by weight.

[0067] In this invention, the content of the activator is 2 to 10 parts by weight, or 3 to 9 parts by weight, or 4 to 8 parts by weight, or 5 to 7 parts by weight.

[0068] In this invention, the content of the plasticizer is 4 to 10 parts by weight, or 5 to 9 parts by weight, or 6 to 8 parts by weight.

[0069] In this invention, the content of the homogenizer is 2 to 15 parts by weight, or 5 to 12 parts by weight, or 8 to 9 parts by weight.

[0070] In this invention, the content of the tackifying resin is 2 to 15 parts by weight, or 5 to 12 parts by weight, or 8 to 9 parts by weight.

[0071] In this invention, the content of magnesium oxide is 0.05 to 0.5 parts by weight, or 0.1 to 0.4 parts by weight, or 0.2 to 0.3 parts by weight.

[0072] In this invention, the content of the accelerator is 1.0 to 6.0 parts by weight, or 2.0 to 5.0 parts by weight, or 3.0 to 4.0 parts by weight.

[0073] In this invention, the content of the vulcanizing agent is 0.5 to 3 parts by weight, or 1.0 to 2.5 parts by weight, or 1.5 to 2.0 parts by weight.

[0074] In this invention, the mass ratio of halogenated butyl rubber to itaconic acid ester rubber in the raw rubber is preferably (1-9):1, more preferably (2-8):1, more preferably (3-7):1, and even more preferably (4-6):1.

[0075] In this invention, the itaconic acid ester rubber is preferably a binary, ternary, or quaternary copolymer containing itaconic acid ester and bio-based diene or petroleum-based conjugated diene.

[0076] In this invention, the itaconic acid ester rubber is preferably a copolymer obtained by low-temperature emulsion polymerization of raw materials including dibutyl itaconic acid units and butadiene units. Specifically, the itaconic acid ester rubber can be one or more of ItBR6600, ItBR6610, ItBR4710, and ItBR7410, and more preferably ItBR6600.

[0077] In this invention, the itaconic acid ester rubber is preferably a copolymer obtained by low-temperature emulsion polymerization of raw materials comprising dibutyl itaconic acid units and butadiene units. For example, itaconic acid ester rubber with the brand name ItBR6600. Specifically, see the method for preparing an itaconic acid ester / butadiene copolymer bioengineering rubber disclosed in Chinese Patent Application Publication No. CN104945817A, which specifically describes the prepared bio-based itaconic acid ester rubber.

[0078] In this invention, the polymerization temperature of the low-temperature emulsion polymerization is preferably 1 to 20°C, more preferably 5 to 16°C, and even more preferably 9 to 12°C.

[0079] In this invention, the itaconic acid ester is preferably selected from one or more of dimethyl itaconic acid, diethyl itaconic acid, dipropyl itaconic acid, dibutyl itaconic acid, diisopropyl itaconic acid, diisobutyl itaconic acid, dipentyl itaconic acid, and diisopentyl itaconic acid, and more preferably dimethyl itaconic acid, diethyl itaconic acid, dipropyl itaconic acid, dibutyl itaconic acid, diisopropyl itaconic acid, diisobutyl itaconic acid, dipentyl itaconic acid, or diisopentyl itaconic acid.

[0080] In this invention, the bio-based diene is preferably a diene produced by microbial fermentation or a terpene derived from plants.

[0081] In this invention, the petroleum-based conjugated diene is preferably isoprene and / or butadiene, more preferably isoprene or butadiene.

[0082] In this invention, the rubber composite material is preferably a rubber composite material used for the tire airtight layer.

[0083] In this invention, the itaconic acid ester rubber preferably includes a third component and / or a fourth component, more preferably a third component or a fourth component.

[0084] In this invention, the third and fourth components are each preferably selected independently from one or more of glycidyl methacrylate, styrene, vinyl chloride acetate, acrylamide, cyclopentadiene, ethylene-ide norbornene, methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hydroxyethyl methacrylate, and 2-hydroxyethyl acrylate, more preferably from glycidyl methacrylate, styrene, vinyl chloride acetate, acrylamide, cyclopentadiene, ethylene-ide norbornene, methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hydroxyethyl methacrylate, or 2-hydroxyethyl acrylate.

[0085] In this invention, the reinforcing filler is preferably one or more of carbon black, pyrolysis carbon black, calcium carbonate, calcium sulfate, dolomite powder, clay, montmorillonite, clay, barium montmorillonite sulfate, talc, magnesium carbonate, magnesium silicate, graphene, and cellulose bio-based filler, more preferably carbon black, pyrolysis carbon black, calcium carbonate, calcium sulfate, dolomite powder, clay, clay, montmorillonite, clay, barium montmorillonite sulfate, talc, magnesium carbonate, magnesium silicate, graphene, or cellulose bio-based filler.

[0086] In this invention, the vulcanizing agent is preferably sulfur;

[0087] In this invention, the bio-based raw material content (bio-based content, mass fraction) of the rubber composite material is preferably 45-60%, more preferably 48-57%, and even more preferably 51-54%. Compared to existing airtight layer rubber composite materials, this invention exhibits superior airtightness with the same amount of natural rubber.

[0088] In this invention, the activator is preferably one or more of zinc oxide, stearic acid and magnesium oxide, more preferably zinc oxide, stearic acid or magnesium oxide.

[0089] In this invention, the plasticizer is preferably one or more of naphthenic oil, aromatic oil, petroleum resin, epoxidized soybean oil and palm oil, more preferably naphthenic oil, aromatic oil, petroleum resin, epoxidized soybean oil or palm oil.

[0090] In this invention, the homogenizer is preferably an aromatic hydrocarbon resin mixture, specifically, the homogenizer can be 40MSF.

[0091] In this invention, the tackifying resin is preferably phenolic resin and / or petroleum resin, more preferably phenolic resin or petroleum resin. Specifically, the petroleum resin can be C5 petroleum resin and / or C9 petroleum resin.

[0092] In this invention, the accelerator is preferably one or more of thiazole accelerators, thiuram accelerators, dithiocarbamate accelerators, xanthate accelerators, guanidine accelerators, aldehyde amine accelerators, sulfenamide accelerators, and thiourea accelerators, more preferably thiazole accelerators, thiuram accelerators, dithiocarbamate accelerators, xanthate accelerators, guanidine accelerators, aldehyde amine accelerators, sulfenamide accelerators, or thiourea accelerators.

[0093] This invention provides a method for preparing a rubber composite material as described in any one of the above technical solutions, comprising the following steps:

[0094] 1) After raw rubber is masticated in an internal mixer, masticated rubber is obtained;

[0095] 2) Add reinforcing filler, plasticizer, magnesium oxide, homogenizer and tackifying resin to the plasticized rubber obtained in the above steps, mix and then discharge the rubber to obtain a first-stage masterbatch.

[0096] 3) After cooling the first stage of masterbatch obtained in the above steps, continue to internally mix the first stage of masterbatch, vulcanizing agent, activator and accelerator, and discharge the rubber to obtain the second stage of final rubber.

[0097] 4) After the two-stage final compound obtained in the above steps is thinly passed on a two-roll mill, a compound is obtained. After vulcanization, a rubber composite material is obtained.

[0098] The present invention first plasticizes raw rubber in an internal mixer to obtain plasticized rubber.

[0099] In this invention, the plasticizing time is preferably 0.5 to 1.5 min, more preferably 0.7 to 1.3 min, and even more preferably 0.9 to 1.1 min.

[0100] In this invention, the plasticizing temperature is preferably 40-80°C, more preferably 48-72°C, and even more preferably 56-64°C.

[0101] In this invention, the rotational speed of the internal mixer during plasticizing is preferably 40-80 rpm, more preferably 48-72 rpm, and even more preferably 56-64 rpm.

[0102] The present invention further adds reinforcing filler, plasticizer, magnesium oxide, homogenizer and tackifying resin to the plasticized rubber obtained in the above steps, and then mixes them to obtain a masterbatch.

[0103] In this invention, the mixing temperature is preferably 110-150°C, more preferably 115-145°C, even more preferably 120-140°C, and even more preferably 125-135°C.

[0104] In this invention, the mixing time is preferably 4 to 8 minutes, more preferably 4.5 to 7.5 minutes, more preferably 5 to 7 minutes, and even more preferably 5.5 to 6.5 minutes.

[0105] The present invention then cools the first stage of masterbatch obtained in the above steps, and then continues to mix the first stage of masterbatch, vulcanizing agent, activator and accelerator in an intensive manner, and discharges the rubber to obtain the second stage of final compound.

[0106] In this invention, the temperature after cooling is preferably less than or equal to 80°C.

[0107] In this invention, the temperature for continued kneading is preferably 90-130°C, more preferably 95-125°C, more preferably 100-120°C, and even more preferably 105-115°C.

[0108] In this invention, the duration of continued kneading is preferably 1 to 3 minutes, more preferably 1.4 to 2.6 minutes, and even more preferably 1.8 to 2.2 minutes.

[0109] Finally, the two-stage final compound obtained in the above steps is passed through a two-roll mill to obtain a mixed compound, which is then vulcanized to obtain a rubber composite material.

[0110] In this invention, the number of times the thin tube is passed through is preferably 3 to 12 times, more preferably 5 to 10 times, more preferably 7 to 9 times, and specifically 6 times.

[0111] In this invention, the roller gap of the thin tube is preferably 0.5 to 4.0 mm, more preferably 1.0 to 3.5 mm, even more preferably 1.5 to 3.0 mm, and even more preferably 2.0 to 2.5 mm.

[0112] In this invention, the thin-walled section preferably also includes a parking step.

[0113] In this invention, the parking time is preferably 18 to 24 hours, more preferably 19 to 23 hours, and even more preferably 20 to 22 hours.

[0114] In this invention, the vulcanization temperature is preferably 130-180°C, more preferably 140-170°C, and even more preferably 150-160°C.

[0115] In this invention, the vulcanization time is preferably 5 to 60 minutes, more preferably 15 to 50 minutes, and even more preferably 25 to 40 minutes.

[0116] In this invention, the vulcanization pressure is preferably 20 to 40 tons, more preferably 24 to 36 tons, and even more preferably 28 to 32 tons (t).

[0117] This invention provides the application of the rubber composite material described in any one of the above technical solutions or the rubber composite material prepared by the preparation method described in any one of the above technical solutions in tires.

[0118] This invention aims to complete and refine the overall technical solution, better ensure the composition and proportion of rubber composite materials, and further improve the comprehensive performance of rubber composite materials. The aforementioned high-bio-based, high-airtightness tire airtight layer rubber composite material, its preparation method, and specific applications may include the following:

[0119] A highly airtight, highly bio-based itaconic acid ester elastomer airtight layer adhesive and its preparation method are disclosed, comprising raw materials including the following components:

[0120] 100 parts raw rubber;

[0121] 40-100 parts of reinforcing filler;

[0122] Activator 2-10 parts;

[0123] Plasticizer 4-20 parts;

[0124] 2-15 parts homogenizer;

[0125] 2-15 parts of tackifying resin;

[0126] Magnesium oxide 0.05–0.5 parts;

[0127] Accelerator 1.0–6.0 parts;

[0128] Vulcanizing agent 0.5-3 parts;

[0129] The raw rubber is composed of halogenated butyl rubber and itaconic acid ester rubber in a mass ratio of 9:1 to 1:1.

[0130] The itaconic acid ester rubber is a binary, ternary, or quaternary copolymer containing itaconic acid ester and bio-based diene or petroleum-based conjugated diene. The itaconic acid ester can be selected from one or two of dimethyl itaconic acid, diethyl itaconic acid, di-n-propyl itaconic acid, di-n-butyl itaconic acid, diisopropyl itaconic acid, diisobutyl itaconic acid, di-n-pentyl itaconic acid, and diisopentyl itaconic acid. The bio-based diene refers to one or more terpenes produced through microbial fermentation or derived from plants, such as isoprene, butadiene, myrcene, limonene, etc. The petroleum-based conjugated diene is either isoprene or butadiene. It may also contain other third or fourth components, including glycidyl methacrylate, styrene, vinyl chloride acetate, acrylamide, cyclopentadiene, ethylene-imide norbornene, methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hydroxyethyl methacrylate, and 2-hydroxyethyl acrylate, one or two of these components.

[0131] The reinforcing filler may be one or more of the following: carbon black or pyrolysis carbon black, calcium carbonate, calcium sulfate, dolomite powder, clay, montmorillonite, montmorillonite barium sulfate, talc, magnesium carbonate, magnesium silicate, graphene, and cellulose bio-based filler.

[0132] The activator is composed of one or more of zinc oxide, stearic acid, and magnesium oxide, wherein zinc oxide is 1.5 to 5 parts, stearic acid is 1 to 3 parts, and magnesium oxide is 0 to 2.0 parts.

[0133] The plasticizer may be one or two of naphthenic oil, aromatic oil, and petroleum resin. Preferably, naphthenic oil can be used in an amount of 5-8 parts, or bio-based plasticizers such as epoxidized soybean oil and palm oil can be selected to increase the bio-based content in the formulation.

[0134] The accelerator is selected from one or more of thiazole accelerators, thiuram accelerators, dithiocarbamate accelerators, xanthate accelerators, guanidine accelerators, aldehyde amine accelerators, sulfenamide accelerators, and thiourea accelerators. Preferably, 1-3 parts of a thiazole accelerator are selected.

[0135] The vulcanizing agent may be sulfur.

[0136] The homogenizer is a mixture of aromatic hydrocarbon resins.

[0137] The tackifying resin is one or more of phenolic resin and petroleum resin.

[0138] This invention also proposes a method for preparing the high bio-based tire airtight layer rubber composite material, which includes the following steps:

[0139] (1) Plasticize raw rubber in an internal mixer according to a certain mass ratio;

[0140] (2) Add the expected mass proportions of reinforcing filler, homogenizer, stearic acid, magnesium oxide, tackifier and plasticizer to the plasticized rubber and mix them.

[0141] (3) When the temperature in the internal mixer reaches 110-150℃, the rubber is discharged to obtain a first-stage masterbatch;

[0142] (4) After the first stage of masterbatch in step (3) has cooled, put the masterbatch, sulfur, accelerator and activator into the internal mixer and continue to mix. When the temperature in the internal mixer reaches 90-130℃, discharge the rubber to obtain the second stage final rubber.

[0143] (5) Pass the two-stage final compound through a two-roll mill 6 times, with a 2mm roller gap, and then let it stand to obtain an airtight compound.

[0144] (6) The vulcanization characteristics of the compound obtained in step (5) are tested using a rotorless vulcanizer, and vulcanized rubber samples are obtained using a flat vulcanizer.

[0145] The mixing time of the masterbatch in the above steps is 4 min to 8 min; the cooling temperature is less than 80℃.

[0146] The final mixing time is 1 min to 3 min. The resting temperature is 20 to 30℃, and the time is 18 to 24 h.

[0147] The vulcanization temperature is 130℃~180℃, the pressure is 20 tons~40 tons, and the time is 5 min~60 min.

[0148] This invention provides a tire airtight layer rubber composite material with high bio-based content and excellent airtightness, as well as its preparation method and applications. Specifically, this invention uses itaconic acid ester bio-based rubber as the matrix material and designs the vulcanization system, additive system, and processing technology to create a tire airtight layer rubber composite material with high bio-based content and excellent airtightness. The airtight layer rubber provided by this invention contains environmentally friendly bio-based itaconic acid ester rubber, which is beneficial for energy conservation and carbon reduction. Furthermore, because itaconic acid ester rubber has certain side groups and a relatively dense arrangement, it possesses a certain degree of gas barrier properties. Its composite with butyl rubber exhibits superior airtightness and aging resistance compared to natural rubber.

[0149] This invention replaces natural rubber or halogenated butyl rubber in traditional airtight layer formulations with bio-based itaconic acid ester rubber prepared from biomass resources in an equal amount, reducing dependence on petrochemical raw materials. Simultaneously, the resulting high-bio-based airtight layer composite material exhibits superior low permeability, aging resistance, and fatigue resistance compared to the same proportion of natural rubber, while also meeting other basic mechanical property requirements, significantly improving tire lifespan and complying with relevant policies.

[0150] In addition, the present invention also provides a corresponding preparation method, which has a simple processing technology, low equipment requirements, and excellent processing performance, making it more suitable for promotion and application in large-scale industrial production.

[0151] To further illustrate the present invention, the following detailed description of a rubber composite material, its preparation method, and its application, in conjunction with embodiments, is provided. However, it should be understood that these embodiments are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are given only to further illustrate the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention. The scope of protection of the present invention is not limited to the following embodiments.

[0152] In the following examples, itaconic acid ester rubber: Shandong Jingbo Zhongju New Material Co., Ltd., commercially available grade ItBR6610, with a number average molecular weight of 220,000 to 320,000 and a weight average molecular weight of 650,000 to 900,000; natural rubber: commercially available, grade CV60, with a weight average molecular weight of 400,000 to 600,000; halogenated rubber: BIIR / CIIR, with a weight average molecular weight of 270,000 to 850,000; other raw and auxiliary materials are all commercially available products.

[0153] Example 1

[0154] A high-airtightness, high-bio-based itaconic acid ester elastomer airtight layer adhesive contains the following components by weight: 80 parts brominated butyl rubber, 20 parts itaconic acid ester rubber, 60 parts carbon black N660, 3 parts zinc oxide, 1 part stearic acid, 7 parts homogenizer 40MSF, 4 parts tackifying resin SP1068, 8 parts aromatic oil, 1.2 parts sulfur, 0.8 parts accelerator DM, 1.0 part accelerator CBS, and 0.15 parts magnesium oxide.

[0155] The steps of a method for preparing a high-airtightness, high-bio-based itaconic acid ester elastomer airtight layer adhesive are as follows:

[0156] (1) Plasticize itaconic acid ester rubber and brominated butyl rubber in a mixer for 1.5 min at a speed of 70 rpm;

[0157] (2) Add carbon black N660, homogenizer, stearic acid, magnesium oxide, tackifier and plasticizer in sequence and mix them. When the temperature in the internal mixer reaches 130℃, discharge the rubber to obtain a first-stage masterbatch.

[0158] (3) After the first stage of masterbatch from step (2) has cooled and been left to stand for more than 2 hours, put the masterbatch, sulfur, accelerator and zinc oxide into the internal mixer and continue to mix. When the temperature in the internal mixer reaches 110°C, discharge the rubber to obtain the second stage final rubber.

[0159] (4) Pass it through a two-roll mill 6 times, roll it out with a 2mm gap, and let it stand for 18 hours at a temperature of 20-30℃ to obtain tire airtight layer rubber compound.

[0160] (5) The vulcanization characteristics of the compound obtained in step (4) are tested using a rotorless vulcanizer, and vulcanized rubber samples are obtained using a flat vulcanizer.

[0161] The vulcanization temperature in step (5) is 150–180°C.

[0162] Example 2

[0163] A high-airtightness, high-bio-based itaconic acid ester elastomer airtight layer adhesive contains the following components by weight: 60 parts brominated butyl rubber, 40 parts itaconic acid ester rubber, 60 parts carbon black N660, 3 parts zinc oxide, 1 part stearic acid, 7 parts homogenizer 40MSF, 4 parts tackifying resin SP1068, 8 parts aromatic oil, 1.2 parts sulfur, 0.8 parts accelerator DM, 1.0 part accelerator CBS, and 0.15 parts magnesium oxide.

[0164] The airtight laminate composite material was prepared using the same preparation method as in Example 1.

[0165] Example 3

[0166] A high-airtightness, high-bio-based itaconic acid ester elastomer airtight layer adhesive contains the following components by weight: 50 parts brominated butyl rubber, 50 parts itaconic acid ester rubber, 60 parts carbon black N660, 3 parts zinc oxide, 1 part stearic acid, 7 parts homogenizer 40MSF, 4 parts tackifying resin SP1068, 8 parts aromatic oil, 1.2 parts sulfur, 0.8 parts accelerator DM, 1.0 part accelerator CBS, and 0.15 parts magnesium oxide.

[0167] The airtight laminate composite material was prepared using the same preparation method as in Example 1.

[0168] Comparative Example 1

[0169] A high-airtightness, high-bio-based itaconic acid ester elastomer airtight layer adhesive contains the following components by weight: 80 parts brominated butyl rubber, 20 parts natural rubber, 60 parts carbon black N660, 3 parts zinc oxide, 1 part stearic acid, 7 parts homogenizer 40MSF, 4 parts tackifying resin SP1068, 8 parts aromatic oil, 1.2 parts sulfur, 0.8 parts accelerator DM, and 1.0 part accelerator CBS.

[0170] The airtight laminate composite material was prepared using the same preparation method as in Example 1.

[0171] Comparative Example 2

[0172] A high-airtightness, high-bio-based itaconic acid ester elastomer airtight layer adhesive contains the following components by weight: 60 parts brominated butyl rubber, 40 parts natural rubber, 60 parts carbon black N660, 3 parts zinc oxide, 1 part stearic acid, 7 parts homogenizer 40MSF, 4 parts tackifying resin SP1068, 8 parts aromatic oil, 1.2 parts sulfur, 0.8 parts accelerator DM, and 1.0 part accelerator CBS.

[0173] The airtight laminated composite material was prepared using the same preparation method as in Example 1. The performance comparison of the airtight laminated composite materials prepared in the embodiments of the present invention is as follows (see Table 1). Table 1 shows the test results of the physical and mechanical properties of the airtight laminated composite materials prepared in the examples and comparative examples of the present invention.

[0174] Table 1

[0175]

[0176] As can be seen from Examples 1-3 and Comparative Examples 1-2, the airtight layer composite material prepared in the embodiments of the present invention exhibits a decreased permeability coefficient and excellent overall performance. Furthermore, the performance using 50 parts of bio-based itaconic acid ester rubber is still superior to that using 40 parts of natural rubber, indicating that increasing the bio-based content of tires through bio-based itaconic acid ester rubber is feasible. Simultaneously, the airtight layer composite material prepared using bio-based itaconic acid ester rubber shows improved aging performance and enhanced fatigue performance, contributing to extended tire lifespan and thus extending the material's service life, achieving the goal of reducing carbon emissions. The present invention uses bio-based itaconic acid ester rubber prepared from renewable biomass resources to partially replace natural rubber or halogenated butyl rubber in traditional formulations, meeting the requirements of green and low-carbon development and representing the current trend of sustainable green development.

[0177] The foregoing has provided a detailed description of a high-bio-based, high-airtightness tire airtight layer rubber composite material, its preparation method, and its applications. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the invention, including the best mode, and to enable any person skilled in the art to practice the invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A rubber composite material, characterized in that, Based on the mass fractions of raw materials, including: 100 parts by weight of raw rubber; The raw rubber includes itaconic acid ester rubber and halogenated butyl rubber; 40-100 parts by weight of reinforcing filler; Activator 2-10 parts by weight; Plasticizer 4-10 parts by weight; 2-15 parts by weight of homogenizer; 2-15 parts by weight of tackifying resin; Magnesium oxide 0.05~0.5 parts by weight; Accelerator 1.0~6.0 parts by weight; Vulcanizing agent: 0.5-3 parts by weight; In the raw rubber, the mass ratio of halogenated butyl rubber to itaconic acid ester rubber is (1~9):1; The itaconic acid ester rubber is a binary, ternary, or quaternary copolymer containing itaconic acid ester and bio-based diene or petroleum-based conjugated diene. The itaconic acid ester rubber is specifically a copolymer obtained by low-temperature emulsion polymerization of raw materials including dibutyl itaconic acid units and butadiene units; The polymerization temperature of the low-temperature emulsion polymerization is 1~20℃.

2. The rubber composite material according to claim 1, characterized in that, The itaconic acid ester is selected from one or more of dimethyl itaconic acid, diethyl itaconic acid, dipropyl itaconic acid, dibutyl itaconic acid, diisopropyl itaconic acid, diisobutyl itaconic acid, dipentyl itaconic acid, and diisopentyl itaconic acid. The bio-based diene is a diene produced through microbial fermentation or a terpene derived from plants.

3. The rubber composite material according to claim 1, characterized in that, The petroleum-based conjugated diene is isoprene and / or butadiene; The rubber composite material is a rubber composite material used for the airtight layer of a tire.

4. The rubber composite material according to claim 1, characterized in that, The itaconic acid ester rubber further includes a third component and / or a fourth component; The third and fourth components are each independently selected from one or more of glycidyl methacrylate, styrene, vinyl chloride acetate, acrylamide, cyclopentadiene, ethylenediene norbornene, methyl acrylate, ethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hydroxyethyl methacrylate, and 2-hydroxyethyl acrylate. The reinforcing filler is one or more of the following: carbon black, calcium carbonate, calcium sulfate, dolomite powder, kaolin, clay, montmorillonite, barium sulfate, talc, magnesium carbonate, magnesium silicate, graphene, and cellulose bio-based filler. The vulcanizing agent is sulfur.

5. The rubber composite material according to claim 1, characterized in that, The activator is one or more of zinc oxide, stearic acid, and magnesium oxide; The plasticizer is one or more of naphthenic oil, aromatic oil, petroleum resin, epoxidized soybean oil, and palm oil; The homogenizer is an aromatic hydrocarbon resin mixture; The tackifying resin is phenolic resin and / or petroleum resin; The accelerator is one or more of the following: thiazole accelerators, thiuram accelerators, dithiocarbamate accelerators, xanthate accelerators, guanidine accelerators, aldehyde amine accelerators, sulfenamide accelerators, and thiourea accelerators.

6. A method for preparing a rubber composite material as described in any one of claims 1 to 5, characterized in that, Includes the following steps: 1) Raw rubber is masticated in an internal mixer to obtain masticated rubber; 2) Add reinforcing filler, plasticizer, magnesium oxide, homogenizer and tackifying resin to the plasticized rubber obtained in the above steps, mix and then discharge the rubber to obtain a first-stage masterbatch. 3) After cooling the first stage of masterbatch obtained in the above steps, continue to internally mix the first stage of masterbatch, vulcanizing agent, activator and accelerator, and discharge the rubber to obtain the second stage of final rubber. 4) After the two-stage final compound obtained in the above steps is thinly passed on a two-roll mill, a compound is obtained. After vulcanization, a rubber composite material is obtained.

7. The preparation method according to claim 6, characterized in that, The plasticizing time is 0.5~1.5 min; The temperature of the plasticizing process is 40~80℃; The speed of the internal mixer during plasticizing is 40~80 rpm; The mixing temperature is 110~150℃; The mixing time is 4-8 minutes.

8. The preparation method according to claim 6, characterized in that, The temperature after cooling is less than or equal to 80°C; The temperature for continued intensive mixing is 90~130℃; The continued intensive refining time is 1-3 minutes; The number of thin-pass tests is 3 to 12; The roller gap of the thin tube is 0.5~4.0mm.

9. The preparation method according to claim 6, characterized in that, The thin-walled section also includes a parking step; The parking time is 18-24 hours; The vulcanization temperature is 130~180℃; The vulcanization time is 5-60 minutes; The vulcanization pressure is 20 to 40 tons.

10. The application of the rubber composite material according to any one of claims 1 to 5 or the rubber composite material prepared by the preparation method according to any one of claims 6 to 9 in tires.

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