Master batch type vulcanizing aid and preparation method thereof, rubber composition, rubber product and tire

Abstract

The invention provides a masterbatch type vulcanizing aid and a preparation method thereof, a rubber composition, a rubber product and a tire. The preparation method comprises the following steps: S1, carrying out pre-reaction on stearic acid, an anti-aging agent and a vulcanization system to obtain a pre-reaction mixture; and S2, mixing the pre-reaction mixture with rubber to obtain the rubber master batch type vulcanizing aid. Under the catalytic action of stearic acid, an anti-aging agent reacts with a reagent in a vulcanization system to generate an active intermediate, the active intermediate has the effect of promoting vulcanization and has the effect of activating an accelerant in advance, so that the active intermediate can replace zinc oxide, and a product obtained after the reaction is mixed with rubber, so that the rubber is obtained. The formed masterbatch can be used for preparing rubber products such as tires which are completely free of zinc elements, zinc-free emission can be realized, and the masterbatch is environment-friendly.

Description

[0001] This invention is a divisional application of the invention patent application filed on May 30, 2024, with application number 2024106924399 and invention title "Masterbatch-type vulcanization aids and their preparation methods, rubber compositions, rubber articles and tires". Technical Field

[0002] This invention relates to the field of tire tread rubber preparation technology, and more specifically, to a masterbatch-type vulcanization aid and its preparation method, rubber compositions, rubber products, and tires. Background Technology

[0003] Zinc in tire treads can pollute the environment. The European Commission Directive 2400 / 73 / EC and the California SB1260 bill proposed in 2016 both recommend restricting the use of zinc or zinc oxide in tires.

[0004] However, zinc oxide or zinc-based additives act as vulcanizing activators during vulcanization, increasing crosslinking density, thereby improving rubber compound hardness and ensuring compound performance. Tires manufactured using this method maintain good rolling resistance and grip. Removing zinc from commonly used formulations, under current production processes, often results in reduced crosslinking, leading to decreased mechanical properties, lower hardness, increased hysteresis, higher rolling resistance, and reduced grip. Typically, diene rubber compositions require at least 2 phr of zinc oxide. Existing rubber compositions without zinc, using conventional tire rubber manufacturing processes, exhibit low mechanical properties, low hardness, and significantly reduced grip and abrasion resistance.

[0005] Researchers both domestically and internationally have begun investigating the environmental issues associated with zinc in tire tread rubber. Patent application CN115678038B discloses a method using lignin-zinc salt complexes to replace zinc oxide. Leveraging the good dispersion of this complex, the amount of zinc oxide used is reduced. When applied to tire tread rubber, it can ensure tire wear resistance, reduce rolling resistance, and extend tire lifespan. While this patent reduces zinc usage by improving zinc dispersion, it cannot completely eliminate the environmental hazards of zinc. Patent CN102300917B discloses a rubber composition containing no zinc or less than 0.5 phr of zinc for tire manufacturing. It improves the processability of the zinc-free composition (i.e., reduces viscosity and extends scorch time) through the application of end-capped mercaptosilanes. Although this patent can reduce zinc usage or even eliminate zinc altogether, it requires the use of specific end-capped mercaptosilanes, which may further react during high-temperature mixing to generate mercapto groups, resulting in a certain degree of irritation and odor, posing safety concerns.

[0006] Improving the performance of tire tread rubber without using zinc is of significant social and economic value. Summary of the Invention

[0007] The main objective of this invention is to provide a masterbatch-type vulcanization aid and its preparation method, rubber composition, rubber products and tires, in order to solve the problem of environmental pollution caused by zinc in the tread rubber of the prior art.

[0008] To achieve the above objectives, according to one aspect of the present invention, a method for preparing a masterbatch-type vulcanization aid is provided, the method comprising: step S1, pre-reacting stearic acid, an antioxidant and a vulcanization system to obtain a pre-reaction mixture; and step S2, mixing the pre-reaction mixture with rubber to obtain the masterbatch-type vulcanization aid.

[0009] Furthermore, the pre-reaction temperature is 100-190 °C, and the reaction time is 1 min-120 min;

[0010] Preferably, the pre-reaction temperature is 110-170 °C and the reaction time is 5 min-50 min.

[0011] Furthermore, the pre-reaction is carried out in a solvent, preferably one or more of butanol, octanol, N-methylpyrrolidone, octane, nonane, decane, toluene, and xylene.

[0012] Preferably, step S2 includes removing the solvent from the pre-reaction mixture and then mixing it with rubber to obtain a masterbatch-type vulcanization aid; or,

[0013] Step S2 includes mixing the pre-reaction mixture containing solvent with rubber, then removing the solvent to obtain a masterbatch-type vulcanization aid.

[0014] Furthermore, the antioxidant is a phenylenediamine-based antioxidant; preferably, the antioxidant has the structure shown in Formula I:

[0015] Formula I

[0016] In formula I, R 1 Selected from C1-C 18 chain hydrocarbon group, C3-C 18 alicyclic hydrocarbon group or C6-C 18 aromatic group, R 2 R 3 R 4 R 5 Each independently selected from C1-C 18 The chain hydrocarbon group, R 2 With R 3 Or R 4 With R 5 They can also form adipose rings individually or simultaneously, R 6 Selected from, R6 Selected from H, C1-C 18 chain hydrocarbon group, C3-C 18 alicyclic hydrocarbon group or C6-C 18 The aromatic group; x=0 or 1, y=0 or 1, z=0 or 1, w=0 or 1, and at least one of x and w is 1, and at least one of y and z is 1.

[0017] Furthermore, the vulcanization system includes any one or more of vulcanizing agents and accelerators. The vulcanizing agents include any one or more of sulfur-based and sulfur carrier-based agents, and the accelerators include any one or more of sulfenamide-based and thiazole-based accelerators. Preferably, the accelerators include any one or more of CZ, DCBS, MBTS, MBT, and TBBS.

[0018] The rubber is any one or more of natural rubber, styrene-butadiene rubber, isoprene rubber, natural eucommia gum, polyisoprene rubber, butadiene rubber, halogenated butyl rubber, and ethylene propylene diene monomer (EPDM) rubber; preferably, the rubber is a rubber containing formula II.

[0019] Formula II

[0020] Among them, a, b, c, d, e, and f are each independent integers greater than or equal to 0, and a, b, c, d, e, and f are not all 0 at the same time.

[0021] Furthermore, the weight ratio of stearic acid to antioxidant is 1:1 to 1:1.25; the weight ratio of vulcanization system to antioxidant is 0.8:1 to 1.15:1.

[0022] To achieve the above objectives, according to one aspect of the present invention, a masterbatch-type vulcanization aid is provided, which is prepared by any of the above preparation methods.

[0023] According to another aspect of this application, a rubber composition is provided, characterized in that, by weight, it comprises 0 to 130 parts of elastomer, 25 to 35 parts of masterbatch-type vulcanizing aid, 20 to 170 parts of filler and 1 to 5 parts of other additives, wherein the masterbatch-type vulcanizing aid is the aforementioned masterbatch-type vulcanizing aid.

[0024] Furthermore, the filler includes any one or more of carbon-based fillers, silicon-based fillers, carbon-silicon dual-phase fillers, and clay; preferably, the specific surface area of ​​the filler is 10~500 m². 2 / g, further preferably 30~300 m 2 / g, more preferably 50~300 m 2 / g;

[0025] Other additives include any one or more of resins, processing oils, vulcanizing agents, and silane coupling agents;

[0026] Preferably, by weight, it comprises 30-100 parts elastomer, 26-31 parts masterbatch-type vulcanizing aid, 50-130 parts filler, and 1.4-4.5 parts other additives.

[0027] According to an advantageous aspect of this application, a rubber article is provided, which is prepared from any of the rubber compositions described above.

[0028] According to another aspect of this application, a tire is provided that contains the aforementioned rubber article.

[0029] By applying the technical solution of this invention, under the catalysis of stearic acid, the antioxidant and reagents in the vulcanization system react to generate an active intermediate. This active intermediate promotes vulcanization and acts as an early activation accelerator, allowing it to replace the role of zinc oxide. The reaction product is mixed with rubber to form a masterbatch that can be used to prepare rubber products such as tires that are completely free of zinc, achieving zero zinc emissions and being environmentally friendly. At the same time, the masterbatch-type vulcanization aid prepared by the above method enables rubber compositions containing it to achieve crosslinking density, hardness, tensile stress, and hysteresis properties close to those of zinc-containing rubber compositions, even without zinc. Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0031] As analyzed in the background section of this application, the existing technology has the problem of environmental pollution caused by zinc in tire tread rubber. The existing methods can only reduce the zinc content in the rubber, but cannot completely avoid the environmental impact caused by zinc. On the other hand, it is difficult to meet the usage requirements of tire tread rubber without zinc. In order to solve this problem, this application provides a masterbatch-type vulcanization aid and its preparation method, a rubber composition, a rubber product and a tire.

[0032] According to a typical embodiment of this application, a method for preparing a masterbatch-type vulcanization aid is provided. The preparation method includes: step S1, pre-reacting stearic acid, antioxidant and vulcanization system to obtain a pre-reaction mixture; step S2, mixing the pre-reaction mixture with rubber to obtain a masterbatch-type vulcanization aid.

[0033] In the above preparation method, under the catalysis of stearic acid, the antioxidant and the reagents in the vulcanization system react to generate an active intermediate. This active intermediate promotes vulcanization and acts as an early activation accelerator, allowing it to replace the role of zinc oxide. The reaction product is mixed with rubber to form a masterbatch that can be used to prepare tires and other rubber products that are completely free of zinc, achieving zero zinc emissions and being environmentally friendly. At the same time, the masterbatch-type vulcanization aid prepared by the above method enables rubber compositions containing it to achieve crosslinking density, hardness, tensile stress, and hysteresis properties close to those of zinc-containing rubber compositions, even without zinc.

[0034] Taking phenylenediamine antioxidants and 2-thiobenzothiazole sulfurization system pharmaceuticals as an example, the reaction that occurs in the pre-reaction is shown in the following reaction equation, and the product has the effect of promoting the sulfurization reaction.

[0035]

[0036] In some embodiments of this application, in order to promote the efficient conduct of the pre-reaction, the reaction temperature of the pre-reaction is 100-190 °C and the reaction time is 1 min-120 min; in order to further improve the activity of the intermediate, preferably, the reaction temperature of the pre-reaction is 110-170 °C and the reaction time is 5 min-50 min.

[0037] In some typical embodiments of this application, in order to uniformly disperse the components participating in the pre-reaction and improve the reaction rate and conversion rate, the pre-reaction is carried out in a solvent. Preferably, the solvent is any one or more of butanol, octanol, N-methylpyrrolidone, octane, nonane, decane, toluene, and xylene, which not only has good solubility for the various components participating in the reaction, but also promotes the pre-reaction.

[0038] In some embodiments of this application, the pre-reaction mixture containing solvent is first desolventized before being mixed with rubber. That is, step S2 includes: removing the solvent from the pre-reaction mixture and then mixing it with rubber to obtain a masterbatch-type vulcanization aid.

[0039] In some embodiments of this application, the solvent-containing pre-reaction mixture is mixed with rubber, and then the solvent is removed. That is, step S2 includes mixing the solvent-containing pre-reaction mixture with rubber, removing the solvent, and obtaining a masterbatch-type vulcanization aid.

[0040] The method for removing the solvent added during the pre-reaction process can be selected from the existing technology, and this application is not limited to it. For example, the solvent removed by distillation can be recovered and reused.

[0041] The antioxidants mentioned above can be selected from existing technologies. Preferably, the antioxidants are phenylenediamine antioxidants. More preferably, the antioxidants have the structure shown in Formula I. Antioxidants with this structure not only have high activity in the active intermediate formed after the pre-reaction with the vulcanization system, but also have low toxicity and are more environmentally friendly.

[0042] Formula I

[0043] In formula I, R 1 Selected from C1-C 18 chain hydrocarbon group, C3-C 18 alicyclic hydrocarbon group or C6-C 18 aromatic group, R 2 R 3 R 4 R 5 Each independently selected from C1-C 18 The chain hydrocarbon group, R 2 With R 3 Or R 4 With R 5 They can also form adipose rings individually or simultaneously, R 6 Selected from, R 6 Selected from H, C1-C 18 chain hydrocarbon group, C3-C 18 alicyclic hydrocarbon group or C6-C 18 The aromatic group; x=0 or 1, y=0 or 1, z=0 or 1, w=0 or 1, and at least one of x and w has a value of 1, and at least one of y and z has a value of 1. Further, the above-mentioned vulcanization system includes any one or more of vulcanizing agents and accelerators. The vulcanizing agent includes any one or more of sulfur-based and sulfur-carrier-based agents, and the accelerator includes any one or more of sulfenamide-based and thiazole-based accelerators. Preferably, the accelerator includes any one or more of CZ, DCBS, MBTS, MBT, and TBBS.

[0044] The aforementioned rubbers can be selected from existing technologies, such as using natural polymers or synthetic polymers. For example, the natural rubbers include, but are not limited to, natural rubber, eucommia gum, and chrysanthemum gum. The synthetic polymers include, but are not limited to, monomers polymerized in solution (i.e., solution-polymerized rubber), monomers polymerized in emulsion (i.e., emulsion-polymerized rubber), and monomers polymerized in bulk. The solution-polymerized rubber is a homopolymer or copolymer of ethylene, propylene, butene, pentene, hexene, hepten, dienes with 4-7 carbon atoms or trienes with 6-7 carbon atoms, or olefin monomers containing other atoms or functional groups. These other atoms or functional groups include silicon atoms, fluorine atoms, chlorine atoms, nitrogen atoms, oxygen atoms, sulfur atoms, ester groups, amino ester groups, and cyano groups. It also includes homopolymers and copolymers containing the aforementioned monomers, including, but not limited to, polybutadiene, polyisoprene, styrene-butadiene rubber, ethylene-propylene rubber, butyl rubber, nitrile rubber, chloroprene rubber, silicone rubber, fluororubber, polyurethane rubber, chlorosulfonated polyethylene rubber, and acrylate rubber.

[0045] In some embodiments of this application, the rubber is any one or more of natural rubber, styrene-butadiene rubber, isoprene rubber, natural eucommia rubber, polyisoprene rubber, butadiene rubber, halogenated butyl rubber, and EPDM rubber, and has better overall performance.

[0046] In some preferred embodiments of this application, the rubber is a rubber containing Formula II, which can better synergize with the pre-reaction mixture and significantly improve the overall effect of the masterbatch-type vulcanizing aid. Preferably, the rubber containing Formula II accounts for more than 35 wt% of the total rubber in the masterbatch-type vulcanizing aid, and more preferably 60 wt% to 100 wt%.

[0047] Formula II

[0048] In Equation II, a, b, c, d, e, and f are each independent integers greater than or equal to 0, and a, b, c, d, e, and f are not all 0 at the same time.

[0049] Preferably, at least two of a, b, c, d, e, and f are not zero. The repeating units are randomly distributed.

[0050] In some preferred embodiments of this application, the rubber having the chemical formula II structure has a higher crosslinking density, where a, b, and c are 0 and d, e, and f are not 0; or a, b, and c are not 0 and d, e, and f are 0; or a, b, c, and d are 0 and e and f are not 0.

[0051] Furthermore, the sum of the number of alkenyl double bonds and aromatic groups on the side groups and branches of the rubber shown in Formula II accounts for more than 15% of the total number of alkenyl double bonds and aromatic groups in the rubber, for example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 90%, or any range between the two. Those skilled in the art will understand that the structure of Formula II may contain only side groups or branches, and the side groups or branches may contain only alkenyl double bonds or aromatic groups, wherein the number of alkenyl double bonds or aromatic groups on the side groups or branches accounts for more than 15% of the total number of all alkenyl double bonds and aromatic groups in the rubber molecule.

[0052] To further improve the performance of masterbatch-type vulcanization aids, the molecular weight of the rubber is preferably 10 million to 40 million, more preferably 50 million to 30 million, and even more preferably 10 million to 4 million.

[0053] In some typical embodiments of this application, to better utilize the catalytic effect of stearic acid, the weight ratio of stearic acid to antioxidant is 1:1 to 1:1.25; preferably, the weight ratio of vulcanization system to antioxidant is 0.8:1 to 1.15:1, resulting in a product with higher activity. There are no particular requirements for the proportion of rubber in the masterbatch-type vulcanization aid. In some embodiments of this application, for ease of subsequent use, the rubber content in the masterbatch-type vulcanization aid is 50 to 95 wt%.

[0054] The stearic acid used in step S1 can be selected from existing technologies. This application does not have any special requirements, and will not be elaborated here.

[0055] According to another typical embodiment of this application, a masterbatch-type vulcanization aid is provided, which is prepared by any of the above-described preparation methods.

[0056] In the masterbatch-type vulcanizing aid prepared by the above method, the antioxidant reacts with the reagents in the vulcanization system under the catalysis of stearic acid to generate an active intermediate. This active intermediate promotes vulcanization and acts as an early activation accelerator, allowing it to replace the role of zinc oxide. The reaction product is mixed with rubber to form a masterbatch that can be used to prepare tires and other rubber products that are completely free of zinc, achieving zero zinc emissions and being environmentally friendly. At the same time, this masterbatch-type vulcanizing aid enables rubber compositions containing it to achieve crosslinking density, hardness, tensile stress, and hysteresis properties close to those of zinc-containing rubber compositions, even without zinc.

[0057] According to another typical embodiment of this application, a rubber composition is provided, which, by weight, comprises 0 to 100 parts of elastomer, 25 to 35 parts of masterbatch-type vulcanizing aid, 20 to 170 parts of filler and 1 to 5 parts of other additives, wherein the masterbatch-type vulcanizing aid is the aforementioned masterbatch-type vulcanizing aid.

[0058] The rubber composition of this application, through the use of the aforementioned masterbatch-type vulcanizing aid, can be used to prepare rubber products such as tires that are completely free of zinc, achieving zero zinc emissions and being environmentally friendly. At the same time, the masterbatch-type vulcanizing aid enables the rubber composition containing it to obtain crosslinking density, hardness, tensile stress, and hysteresis properties close to those of zinc-containing rubber compositions, even without zinc.

[0059] The elastomers mentioned above can be selected from existing technologies, or selected in the same way as the rubbers in masterbatch-type vulcanizing auxiliaries, and can be the same as or different from the rubbers in masterbatch-type vulcanizing auxiliaries.

[0060] The rubber composition of this application exhibits good adaptability to fillers, which can be selected from existing fillers. For example, the fillers include any one or more of carbon-based fillers, silicon-based fillers, carbon-silicon dual-phase fillers, and clay. Preferably, the specific surface area of ​​the filler is 10~500 m². 2 / g, further preferably 30~300 m 2 / g, more preferably 50~300m 2 / g.

[0061] Those skilled in the art can select other additives with suitable functions according to the specific application environment and requirements of the rubber. For example, other additives include any one or more of resins, processing oils, vulcanizing agents, and silane coupling agents. The types of these additives can be selected from the prior art, and this application does not have any special requirements, so they will not be described in detail here.

[0062] In some embodiments of this application, in order to better leverage the synergistic effect of each component, the rubber composition comprises, by weight, 30-100 parts elastomer, 26-31 parts masterbatch-type vulcanizing aid, 50-130 parts filler, and 1.4-4.5 parts other additives.

[0063] According to another typical embodiment of this application, a rubber article is provided, which is prepared from any of the above-described rubber compositions. By using the aforementioned masterbatch-type vulcanizing aid, the rubber article achieves zinc-free emissions, making it environmentally friendly; simultaneously, the rubber article, without zinc, obtains crosslinking density, and rubber compound properties such as hardness, tensile stress, and hysteresis close to those of zinc-containing rubber articles.

[0064] The method for preparing rubber using the above rubber composition can be selected from the prior art, and this application does not limit it. As an example, rubber products can be prepared using the above rubber composition as raw material by the following method: (a) The elastomer, filler, zinc-free masterbatch type vulcanizing agent, and other functional additives are mixed in one or more batches by kneading, and the mixing temperature reaches 125 °C~200 °C to discharge the rubber as a first-stage masterbatch; (b) The first-stage masterbatch is subjected to one or more thermomechanical kneadings, and the rubber is discharged at a kneading temperature of 125 °C~180 °C for 0~1200 s to obtain a second-stage masterbatch; if there are any remaining processing aids, fillers, and antioxidants, they are all added at once or in batches at this stage; (3) The second-stage masterbatch is mixed with the vulcanization system in an internal mixer at a mixing temperature ≤120 °C, and the rubber is discharged to obtain the final compound; (4) The final compound is vulcanized on a flat vulcanizing machine to obtain a vulcanized rubber.

[0065] According to a fifth typical embodiment of this application, a tire is provided that contains the aforementioned rubber product. Through the use of the masterbatch-type vulcanizing agent, the tire achieves zinc-free emissions, making it environmentally friendly; simultaneously, it exhibits excellent overall performance without the need for zinc.

[0066] The beneficial effects that this application can achieve will be further illustrated below with reference to embodiments and comparative examples.

[0067] Example 1

[0068] 10 phr stearic acid, 10 phr antioxidant 4020, and 10 phr vulcanization accelerator TBBS were mixed in decane and pre-reacted at 160°C for 30 min. After the solvent was removed from the reaction system, it was mixed with 96.3 phr SSBR and 30 phr BR to obtain a zinc-free masterbatch type vulcanization aid.

[0069] Add SSBR and BR to the internal mixer and knead. Then add carbon black N234 and the above-mentioned zinc-free masterbatch type vulcanizing aid, and continue kneading until the mixture is uniform. During kneading, the temperature is controlled at 150-160 °C.

[0070] Add sulfur and knead, keeping the temperature below 110 °C during kneading.

[0071] The obtained rubber composition was vulcanized to obtain vulcanized rubber, and the physical properties of the rubber compound were tested.

[0072] Comparative Example 1

[0073] Add SSBR and BR to the internal mixer, knead for a period of time, then add carbon black N234, stearic acid, zinc oxide, antioxidant 4020, and accelerator TBBS and continue kneading until the mixture is uniform. During kneading, the temperature is controlled at 150-160 °C.

[0074] Add sulfur and knead, keeping the temperature below 110 °C during kneading.

[0075] The obtained rubber composition was vulcanized to obtain vulcanized rubber, and the physical properties of the rubber compound were tested.

[0076] Example 2

[0077] 10 phr stearic acid, 12.5 phr antioxidant A, and 11.5 phr vulcanization accelerator CZ were mixed in xylene and pre-reacted at 130 °C for 40 min. After the solvent was removed from the reaction system, it was mixed with 100 phr IR to obtain a zinc-free masterbatch type vulcanization aid.

[0078] Add IR to the internal mixer and knead, then add silica, Si69, and the above-mentioned zinc-free masterbatch type vulcanizing aid, and continue kneading until the mixture is uniform. During kneading, the temperature is controlled at 150-160 °C.

[0079] Add sulfur and DPG, knead, and keep the temperature below 120 °C during kneading;

[0080] The obtained rubber composition was vulcanized to obtain vulcanized rubber, and the physical properties of the rubber compound were tested.

[0081] Comparative Example 2

[0082] Add IR to the internal mixer and knead. Then add silica, Si69, stearic acid, zinc oxide, antioxidant A, and accelerator CZ. Continue kneading until the mixture is uniform. During kneading, the temperature is controlled at 150-160 °C.

[0083] Add sulfur and DPG, knead, and keep the temperature below 120 °C during kneading;

[0084] The obtained rubber composition was vulcanized to obtain vulcanized rubber, and the physical properties of the rubber compound were tested.

[0085] The above rubber compound formulations are summarized in Table 1 below.

[0086] Table 1

[0087]

[0088] The sources and parameters of the various raw materials used in each embodiment and comparative example are as follows:

[0089] IR, Qingdao Ecos New Materials Co., Ltd.;

[0090] Silica, NEWSIL 1165-MP, Wuxi Quecheng Silicon Industry Co., Ltd., with a specific surface area of ​​165 m². 2 / g;

[0091] Carbon black, N234, Shandong Zhongxiang Polymer Materials Co., Ltd., with a specific surface area of ​​119 m². 2 / g;

[0092] Si69, a silane coupling agent, is produced by Nanjing Shuguang Chemical Group Co., Ltd.

[0093] SSBR, Dushanzi Petrochemical (25% styrene, 64% vinyl);

[0094] SBR, Qilu Petrochemical ESBR1502 (styrene content 23.5%).

[0095] BR, Qilu Petrochemical BR9000 (nickel-based high cis-butadiene, cis content 97%).

[0096] NR, Xishuangbanna Sinochem Rubber Co., Ltd. SCR5;

[0097] Stearic acid, PF1808, Licheng Sdn Bhd, Malaysia;

[0098] Zinc oxide, Dalian Zinc Oxide Plant;

[0099] Antioxidant 4020, Jiangsu Sheng'ao Chemical Co., Ltd.;

[0100] Antioxidant 4010NA, Shandong Shangshun Chemical Co., Ltd.;

[0101] Antioxidant 7PPD, Jiangsu Shengao Chemical Co., Ltd.;

[0102] Anti-aging agent A, synthesized in-house.

[0103]

[0104] Anti-aging agent B, synthesized in-house.

[0105]

[0106] Anti-aging agent C, synthesized in-house.

[0107]

[0108] Anti-aging agent D, synthesized in-house.

[0109]

[0110] Anti-aging agent E, synthesized in-house.

[0111]

[0112] Anti-aging agent F, synthesized in-house.

[0113]

[0114] Accelerator CZ, Shandong Shangshun Chemical Co., Ltd.;

[0115] Accelerator TBBS, Shandong Shangshun Chemical Co., Ltd.;

[0116] Accelerator MBTS, Chaoyang Tianming Industry & Trade Co., Ltd.;

[0117] Accelerator DPG, Shandong Shanxian Chemical Co., Ltd.;

[0118] Sulfur, Wudi Jinsheng Chemical Co., Ltd.

[0119] The vulcanization characteristics of the rubber compounds prepared in the above examples and comparative examples were determined according to GB / T16584-1996 "Determination of vulcanization characteristics of rubber using a rotorless vulcanizing apparatus". The test results are shown in Table 2.

[0120] The physical properties (tensile strength, elongation at break, stress at 100% elongation, and stress at 300% elongation) of the rubber compounds prepared in the above examples and comparative examples were determined in accordance with GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber". The results are shown in Table 2.

[0121] The hardness of the rubber compounds prepared in the above examples and comparative examples was determined according to GB / T 531.1-2008 Test method for indentation hardness of vulcanized rubber or thermoplastic rubber - Part 1: Shore hardness tester method (Shore hardness) and the test results are shown in Table 2.

[0122] The elastic modulus of the rubber compound at 20°C was determined according to GB / T9870.1-2006 Determination of dynamic properties of vulcanized rubber or thermoplastic rubber - Part 1: General rules. The tanδmax of the rubber compounds prepared in the above examples and comparative examples was determined using a rotational rheometer. The test results are shown in Table 2.

[0123] In Table 2 and the subsequent tables of physical property test results, for ease of comparison, the test data of each embodiment are based on the corresponding comparative examples with the same composition except for zinc oxide, and the resulting index values ​​are obtained. For example, in Table 1, the MH value of Example 1 is the ratio of its measured value to the number of measured MH values ​​of Comparative Example 1 × 100; the larger the value, the higher the index.

[0124] Table 2

[0125]

[0126] As can be seen from the results in Table 2, the rubber compounds prepared by the rubber composition of the present invention (Examples 1 and 2) are similar to conventional zinc-containing rubber compounds (corresponding to Examples 1 and 2 respectively) in terms of crosslinking density, modulus, stress, hardness, mechanical properties and hysteresis properties, and can be used in rubber products and tires.

[0127] The preparation process of zinc-free masterbatch type vulcanizing aids 3-9 is the same as that of zinc-free masterbatch type vulcanizing aids in Example 1. The difference lies in the amount of specific components involved in the preparation process and the process parameters of the pre-reaction. The amount of specific components involved in zinc-free masterbatch type vulcanizing aids 3-9 is shown in Table 3 below, and the process parameters are shown in Table 4 below.

[0128] Table 3

[0129]

[0130] Table 4

[0131]

[0132] Zinc-free masterbatch type vulcanizing aids 10-14 were prepared. Their formulation and preparation process were the same as those of zinc-free masterbatch type vulcanizing aid 6. The only difference was the pre-reaction parameters listed in Table 5.

[0133] Table 5

[0134]

[0135] Examples 3-9 were prepared using the same method as Example 1, and Comparative Examples 3-9 were prepared using the same method as Comparative Example 1. Their formulations are shown in Tables 6 and 7 below. Furthermore, the rubber compound formulations and preparation processes for Examples 10-14 were the same as those for Example 6, except that the zinc-free masterbatch vulcanizing aids in Examples 10-14 were zinc-free masterbatch vulcanizing aids 10-14, which are not listed.

[0136] Table 6

[0137]

[0138] Table 7

[0139]

[0140] Examples 3-9 and Comparative Examples 3-9 were tested using the same test method as Example 1, and the results are shown in Tables 8 and 9.

[0141] Table 8

[0142]

[0143] Table 9

[0144]

[0145] As can be seen from Tables 8 and 9, the rubber compounds containing zinc-free masterbatch type vulcanizing auxiliaries prepared by the method of the present invention (Examples 3-9) and conventional zinc-containing rubber compounds (corresponding to Examples 3-9 respectively) meet the requirements in terms of performance parameters after vulcanization testing, and can be applied to the production and manufacturing of rubber products and tires.

[0146] In addition, after aging, the vulcanized rubber compounds of Examples 2, 3, 5, 7-9 were extracted and analyzed by liquid chromatography-tandem high-resolution mass spectrometry (UPLC-HRMS / MS). No quinone compounds were detected, indicating that the environmentally friendly p-aniline antioxidant AF used in this application does not produce highly toxic quinone conversion products in the rubber residues, and is relatively environmentally friendly.

[0147] Table 10

[0148]

[0149] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: Using this preparation method, under the catalysis of stearic acid, the antioxidant and the reagents in the vulcanization system react to generate an active intermediate. This active intermediate has the effect of promoting vulcanization and plays the role of activating the accelerator in advance, so that the active intermediate can replace the role of zinc oxide. The reaction product is mixed with rubber, and the resulting masterbatch can be used to prepare rubber products such as tires that are completely free of zinc, which can achieve zero zinc emissions and is environmentally friendly. At the same time, the masterbatch-type vulcanization aid prepared by the above preparation method can enable rubber compositions containing it to obtain crosslinking density, hardness, tensile stress, and hysteresis properties close to those of zinc-containing rubber compositions without zinc.

[0150] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a masterbatch-type vulcanizing aid, characterized in that, include: Step S1: Stearic acid, antioxidant, and vulcanization system are pre-reacted to obtain a pre-reaction mixture; Step S2: Mix the pre-reaction mixture with rubber to obtain the masterbatch-type vulcanization aid; The antioxidant is a phenylenediamine antioxidant, and the vulcanization system includes an accelerator, which includes any one or more of sulfenamide accelerators and thiazole accelerators.

2. The preparation method according to claim 1, characterized in that, The pre-reaction temperature is 100-190 °C, and the reaction time is 1 min-120 min. Preferably, the pre-reaction temperature is 110-170 °C and the reaction time is 5 min-50 min.

3. The preparation method according to claim 1, characterized in that, The pre-reaction is carried out in a solvent, preferably one or more of butanol, octanol, N-methylpyrrolidone, octane, nonane, decane, toluene, and xylene. Preferably, step S2 includes removing the solvent from the pre-reaction mixture and then mixing it with the rubber to obtain a masterbatch-type vulcanization aid; or, Step S2 includes mixing the pre-reaction mixture containing solvent with the rubber, then removing the solvent to obtain the masterbatch-type vulcanization aid.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The antioxidant has the structure shown in Formula I: Formula I In formula I, R 1 Selected from C1-C 18 chain hydrocarbon group, C3-C 18 alicyclic hydrocarbon group or C6-C 18 aromatic group, R 2 R 3 R 4 R 5 Each independently selected from C1-C 18 The chain hydrocarbon group, R 2 With R 3 Or R 4 With R 5 They can also form adipose rings individually or simultaneously, R 6 Selected from, R 6 Selected from H, C1-C 18 chain hydrocarbon group, C3-C 18 alicyclic hydrocarbon group or C6-C 18 The aromatic group; x=0 or 1, y=0 or 1, z=0 or 1, w=0 or 1, and at least one of x and w is 1, and at least one of y and z is 1.

5. The preparation method according to any one of claims 1 to 3, characterized in that, The accelerator includes any one or more of CZ, DCBS, MBTS, MBT and TBBS; And / or, the rubber is any one or more of natural rubber, styrene-butadiene rubber, isoprene rubber, natural eucommia rubber, polyisoprene rubber, butadiene rubber, halogenated butyl rubber and ethylene propylene diene monomer (EPDM) rubber; Preferably, the rubber is a rubber containing formula II: Formula II Among them, a, b, c, d, e, and f are each independent integers greater than or equal to 0, and a, b, c, d, e, and f are not all 0 at the same time.

6. The preparation method according to any one of claims 1 to 3, characterized in that, The weight ratio of stearic acid to antioxidant is 1:1 to 1:1.25; the weight ratio of vulcanization system to antioxidant is 0.8:1 to 1.15:

1.

7. A masterbatch-type vulcanization aid, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 6.

8. A rubber composition, characterized in that, The product comprises, by weight, 0-130 parts elastomer, 25-35 parts masterbatch-type vulcanizing aid, 20-170 parts filler and 1-5 parts other aids, wherein the masterbatch-type vulcanizing aid is the masterbatch-type vulcanizing aid as described in claim 7.

9. The rubber composition according to claim 8, characterized in that, The filler includes any one or more of carbon-based fillers, silicon-based fillers, carbon-silicon dual-phase fillers, and clay; preferably, the specific surface area of ​​the filler is 10~500 m². 2 / g, further preferably 30~300 m 2 / g, more preferably 50~300 m 2 / g; The other additives include any one or more of resins, processing oils, vulcanizing agents, and silane coupling agents; Preferably, by weight, it comprises 30-100 parts elastomer, 26-31 parts masterbatch-type vulcanizing aid, 50-130 parts filler, and 1.4-4.5 parts other additives.

10. A rubber product, characterized in that, It is prepared from the rubber composition according to claim 8 or claim 9.

11. A tire, characterized in that, The rubber article comprising the description of claim 10.

Images