High-whiteness natural rubber material and preparation method thereof

Abstract

The invention discloses a high-whiteness natural rubber material and a preparation method thereof, and relates to the technical field of rubber production. The invention discloses a rubber material which is characterized by comprising the following components in percentage by weight: 55%-60% of isoprene rubber, 20%-25% of silicon dioxide, 2%-5% of naphthenic oil, 2%-3% of zinc oxide, 0.3%-0.8% of octadecanoic acid, 0.8%-1% of polyethylene glycol, 0.3%-0.8% of microcrystalline wax, 0.8%-1% of 2-mercapto benzimidazole, 0.8%-1% of 935P, 0.8%-1% of vinyl tri (b-methoxyethoxy) silane, 5%-8% of titanium dioxide and 0.5%-0.8% of 2, 5-dimethyl-2, 5-bis (tert-butyl peroxide) hexane. According to the high-whiteness natural rubber material and the preparation method thereof, the isoprene rubber is adopted to replace natural rubber, and is combined with a peroxide vulcanization system rare in the natural rubber for matching, so that the high-whiteness natural rubber material not only can present high whiteness in vulcanized rubber, but also has excellent physical and mechanical properties of the material, and also has good processability and environmental protection sustainability; and a new way is opened up for research, development and application of rubber materials.

Description

Technical Field

[0001] The invention relates to the technical field of rubber production, in particular to a natural rubber material with high whiteness and a preparation method thereof. Background Art

[0002] With the development of society and the continuous improvement of people's living standards, the application scope of white rubber products is constantly expanding. When rubber is compounded, it is generally necessary to add a matrix rubber system, a reinforcement filling system, an activation system, an anti-aging system, a vulcanization system, etc. These system components will affect the whiteness of the vulcanized rubber and its products to a certain extent. Natural rubber is the earliest industrialized rubber and the rubber with the largest output and material consumption. However, natural rubber itself has a darker color, coupled with the conventional vulcanization combination (high sulfur and low promoter), resulting in very serious yellowing of vulcanized rubber and its related products, which cannot meet the demand for high whiteness. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present invention provides a natural rubber material with high whiteness and a preparation method thereof, which solves the problems raised in the above-mentioned background technology.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0005] In a first aspect, the present invention provides a natural rubber material with high whiteness, comprising the following components by weight:

[0006] Isoprene rubber 55%-60%, silicon dioxide 20%-25%, cyclohexane oil 2%-5%, zinc oxide 2%-3%, octadecanoic acid 0.3%-0.8%, polyethylene glycol 0.8%-1%, microcrystalline wax 0.3%-0.8%, 2-mercaptobenzimidazole 0.8%-1%, 935P 0.8%-1%, vinyl tris(b-methoxyethoxy) silane 0.8%-1%, titanium dioxide 5%-8%, 2,5-dimethyl-2,5-bis(tert-butyl peroxide) hexane 0.5%-0.8%.

[0007] Furthermore, the high whiteness natural rubber material contains the following components by weight:

[0008] Isoprene rubber 59%, silica 23%, cyclohexane oil 4%, zinc oxide 2.3%, octadecanoic acid 0.4%, polyethylene glycol 0.8%, microcrystalline wax 0.4%, 2-mercaptobenzimidazole 0.8%, 935P 0.9%, vinyl tri(b-methoxyethoxy) silane 0.8%, titanium dioxide 7%, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane 0.6.

[0009] Furthermore, the high whiteness natural rubber material contains the following components by weight:

[0010] Isoprene rubber 55%, silica 25%, cyclohexane oil 5%, zinc oxide 3%, octadecanoic acid 0.6%, polyethylene glycol 1%, microcrystalline wax 0.8%, 2-mercaptobenzimidazole 1%, 935P 1%, vinyl tri(b-methoxyethoxy) silane 1%, titanium dioxide 6%, 2,5-dimethyl-2,5-bis(tert-butyl peroxide) hexane 0.6.

[0011] Furthermore, the high whiteness natural rubber material contains the following components by weight:

[0012] Isoprene rubber 60%, silica 20%, naphthenic oil 2.6%, zinc oxide 3%, octadecanoic acid 0.8%, polyethylene glycol 1%, microcrystalline wax 0.8%, 2-mercaptobenzimidazole 1%, 935P 1%, vinyl tri(b-methoxyethoxy) silane 1%, titanium dioxide 8%, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane 0.8.

[0013] In a second aspect, the present invention further provides a method for preparing a natural rubber material with high whiteness, comprising the following steps:

[0014] S1. Weigh the materials according to the weight ratio;

[0015] S2. Put the isoprene rubber into the internal mixer, mix for 1 minute, and then lift the top bolt of the internal mixer;

[0016] S3, add silicon dioxide, cyclohexane oil, zinc oxide, octadecanoic acid, polyethylene glycol, microcrystalline wax, 2-mercaptobenzimidazole, 935P, vinyl tri(b-methoxyethoxy)silane, and titanium dioxide into an internal mixer, mix to 95° C., and lift the top bolt of the internal mixer again;

[0017] S4, adding 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane into an internal mixer, mixing to 105°C, and then draining the mixture;

[0018] S5. Put the discharged rubber into the open mill, pass the open mill 2mm thin 4-6 times, make 2 triangle packs, adjust the roller distance 6-8mm, cool the sheet, take samples for inspection, test hardness, strength, elongation, T10, T90 for inspection;

[0019] S6, the rubber that has passed the test is subjected to an open mixing mill for refining and molding, and then the molded rubber is placed in a mold in a vulcanization device for molding;

[0020] S7. Trim the vulcanized product and inspect its size and appearance to obtain qualified finished products.

[0021] Furthermore, in S2, when the isoprene rubber is fed into the internal mixer, the feeding temperature is not higher than 65°C.

[0022] Furthermore, in S6, the temperature of the mixing mill is 55-65°C.

[0023] Furthermore, in S6, the rubber is vulcanized under the conditions of a mold pressure of the vulcanization equipment of 180 to 200 Kgf / cm2 and a temperature of 155 to 165°C, and the vulcanization time is 280 to 320 seconds.

[0024] The present invention provides a natural rubber material with high whiteness and a preparation method thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. High whiteness characteristics: Isoprene rubber has a molecular structure that is highly similar to that of natural rubber, but is of higher purity and contains fewer impurities, so it can present a higher whiteness value during the vulcanization process. Combined with a specific peroxide vulcanization system, the vulcanization reaction process is further optimized, and the generation of vulcanization by-products is reduced, thereby significantly improving the whiteness of the product while ensuring the physical and mechanical properties of the rubber material, meeting the market demand for high-whiteness rubber products.

[0026] 2. Excellent physical and mechanical properties: The rubber material prepared by isoprene rubber and peroxide vulcanization system has excellent performance in key physical and mechanical performance indicators such as tensile strength and elongation at break. This is due to the excellent mechanical properties of isoprene rubber itself and the precise control of the cross-linking structure by the peroxide vulcanization system, which enables the rubber material to maintain high strength and toughness when subjected to external forces, thus extending the service life of the product.

[0027] 3. Good processing performance: The peroxide vulcanization system has the advantages of fast vulcanization speed and controllable vulcanization degree, which enables the rubber material to quickly reach the ideal vulcanization state during the processing and improves production efficiency. At the same time, the vulcanization system has little effect on the fluidity of the rubber material, which is conducive to the molding and subsequent processing of rubber products, reducing production difficulty and cost.

[0028] 4. Environmental protection and sustainability: As a synthetic natural rubber, isoprene rubber has a relatively abundant source of raw materials and a highly controllable production process, which helps reduce dependence on natural rubber resources. In addition, the peroxide vulcanization system produces fewer by-products during the vulcanization process, which has less pollution to the environment, and is in line with the current concept of green manufacturing and sustainable development.

[0029] 5. Broad application prospects: Since the rubber material prepared by this technical solution has excellent performance in whiteness, physical and mechanical properties and processing performance, it has broad application prospects. Especially in the fields with high requirements for material performance, such as high-end tires, rubber seals, rubber tubes, etc., this technical solution can provide a more high-quality and reliable rubber material solution. DETAILED DESCRIPTION

[0030] The technical solutions of the present invention are described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustration only and are not to be construed as limiting the scope of the present invention.

[0031] Example 1

[0032] A high whiteness natural rubber material containing the following components by weight:

[0033] Isoprene rubber 59%, silica 23%, cyclohexane oil 4%, zinc oxide 2.3%, octadecanoic acid 0.4%, polyethylene glycol 0.8%, microcrystalline wax 0.4%, 2-mercaptobenzimidazole 0.8%, 935P 0.9%, vinyl tri(b-methoxyethoxy) silane 0.8%, titanium dioxide 7%, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane 0.6.

[0034] The preparation method of the above-mentioned high-whiteness natural rubber material comprises the following steps:

[0035] S1. Weigh the materials according to the weight ratio;

[0036] S2. Put the isoprene rubber into an internal mixer (the feeding temperature is not higher than 65°C), mix for 1 minute, and then lift the top bolt of the internal mixer;

[0037] S3, add silicon dioxide, cyclohexane oil, zinc oxide, octadecanoic acid, polyethylene glycol, microcrystalline wax, 2-mercaptobenzimidazole, 935P, vinyl tri(b-methoxyethoxy)silane, and titanium dioxide into an internal mixer, mix to 95° C., and lift the top bolt of the internal mixer again;

[0038] S4, adding 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane into an internal mixer, mixing to 105°C, and then draining the mixture;

[0039] S5. Put the discharged rubber into the open mill, pass the open mill 2mm thin 4-6 times, make 2 triangle packs, adjust the roller distance 6-8mm, cool the sheet, take samples for inspection, test hardness, strength, elongation, T10, T90 for inspection;

[0040] S6, the qualified rubber is molded by an open mill (the temperature of the open mill is 55°C), and then the molded rubber is placed in a mold in a vulcanization equipment for molding (the pressure of the vulcanization equipment mold is 180Kgf / cm2, the temperature is 155°C, and the rubber is vulcanized for 280 seconds);

[0041] S7. Trim the vulcanized product and inspect its size and appearance to obtain qualified finished products.

[0042] Example 2

[0043] A high whiteness natural rubber material containing the following components by weight:

[0044] Isoprene rubber 55%, silica 25%, cyclohexane oil 5%, zinc oxide 3%, octadecanoic acid 0.6%, polyethylene glycol 1%, microcrystalline wax 0.8%, 2-mercaptobenzimidazole 1%, 935P 1%, vinyl tri(b-methoxyethoxy) silane 1%, titanium dioxide 6%, 2,5-dimethyl-2,5-bis(tert-butyl peroxide) hexane 0.6.

[0045] The preparation method of the above-mentioned high-whiteness natural rubber material comprises the following steps:

[0046] S1. Weigh the materials according to the weight ratio;

[0047] S2. Put the isoprene rubber into an internal mixer (the feeding temperature is not higher than 65°C), mix for 1 minute, and then lift the top bolt of the internal mixer;

[0048] S3, add silicon dioxide, cyclohexane oil, zinc oxide, octadecanoic acid, polyethylene glycol, microcrystalline wax, 2-mercaptobenzimidazole, 935P, vinyl tri(b-methoxyethoxy)silane, and titanium dioxide into an internal mixer, mix to 95° C., and lift the top bolt of the internal mixer again;

[0049] S4, adding 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane into an internal mixer, mixing to 105°C, and then draining the mixture;

[0050] S5. Put the discharged rubber into the open mill, pass the open mill 2mm thin 4-6 times, make 2 triangle packs, adjust the roller distance 6-8mm, cool the sheet, take samples for inspection, test hardness, strength, elongation, T10, T90 for inspection;

[0051] S6, the qualified rubber is molded by an open mill (the temperature of the open mill is 60°C), and then the molded rubber is placed in a mold in a vulcanization equipment for molding (the pressure of the vulcanization equipment mold is 190Kgf / cm2, the temperature is 160°C, and the rubber is vulcanized for 300 seconds);

[0052] S7. Trim the vulcanized product and inspect its size and appearance to obtain qualified finished products.

[0053] Example 3

[0054] A high whiteness natural rubber material containing the following components by weight:

[0055] Isoprene rubber 60%, silica 20%, naphthenic oil 2.6%, zinc oxide 3%, octadecanoic acid 0.8%, polyethylene glycol 1%, microcrystalline wax 0.8%, 2-mercaptobenzimidazole 1%, 935P 1%, vinyl tri(b-methoxyethoxy) silane 1%, titanium dioxide 8%, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane 0.8.

[0056] The preparation method of the above-mentioned high-whiteness natural rubber material comprises the following steps:

[0057] S1. Weigh the materials according to the weight ratio;

[0058] S2. Put the isoprene rubber into an internal mixer (the feeding temperature is not higher than 65°C), mix for 1 minute, and then lift the top bolt of the internal mixer;

[0059] S3, add silicon dioxide, cyclohexane oil, zinc oxide, octadecanoic acid, polyethylene glycol, microcrystalline wax, 2-mercaptobenzimidazole, 935P, vinyl tri(b-methoxyethoxy)silane, and titanium dioxide into an internal mixer, mix to 95° C., and lift the top bolt of the internal mixer again;

[0060] S4, adding 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane into an internal mixer, mixing to 105°C, and then draining the mixture;

[0061] S5. Put the discharged rubber into the open mill, pass the open mill 2mm thin 4-6 times, make 2 triangle packs, adjust the roller distance 6-8mm, cool the sheet, take samples for inspection, test hardness, strength, elongation, T10, T90 for inspection;

[0062] S6, the qualified rubber is molded by an open mill (the temperature of the open mill is 65°C), and then the molded rubber is placed in a mold in a vulcanization equipment for molding (the pressure of the vulcanization equipment mold is 200Kgf / cm2, the temperature is 165°C, and the rubber is vulcanized for 320 seconds);

[0063] S7. Trim the vulcanized product and inspect its size and appearance to obtain qualified finished products.

[0064] In the above three embodiments, isoprene rubber (artificial natural rubber) is used to replace traditional natural rubber, which greatly reduces the adverse effect of the dark color of traditional natural rubber on high whiteness, ensuring that the vulcanized rubber will not turn yellow due to the matrix rubber. In addition, in the above three embodiments, 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane is used to replace traditional sulfur vulcanization, which completely avoids the yellowing effect caused by the sulfur vulcanization process while ensuring certain mechanical and physical properties, thereby affecting whiteness, and also greatly improves the heat resistance of the material.

[0065] Experimental Section

[0066] In order to verify the effect of using isoprene rubber (synthetic natural rubber) and a specific peroxide vulcanization system on the whiteness and physical and mechanical properties of rubber materials, and compare them with traditional natural rubber formulas, the details are as follows:

[0067] Main raw materials: isoprene rubber (different proportions, adjusted according to Examples 1, 2, and 3), silicon dioxide, cyclohexane oil, zinc oxide, octadecanoic acid, polyethylene glycol, microcrystalline wax, 2-mercaptobenzimidazole, 935P, vinyl tris(β-methoxyethoxy)silane, titanium dioxide, 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane;

[0068] Equipment: internal mixer, open mixer, vulcanizing equipment, molds, hardness tester, tensile testing machine, whiteness tester, vulcanizer, etc.

[0069] Experimental groups: Three examples (Example 1, Example 2, Example 3) and a control group (traditional natural rubber formula) were set up;

[0070] Formula ratio: Accurately weigh each component material according to the specific requirements of each embodiment;

[0071] The experimental data are shown in the following table:

[0072] project Example 1 Example 2 Example 3 Control group Isoprene rubber content (%) 59 55 60 Traditional natural rubber Whiteness value 90.0 89.5 91.0 85.0 Hardness (Shore A) 60 62 61 58 Tensile strength(MPa) 25.0 26.5 27.0 24.0 Elongation at break (%) 450 470 460 420 T10(min) 2.5 2.4 2.3 3.0 T90(min) 10.0 9.8 9.5 12.0

[0073] Explanation:

[0074] Whiteness value: measured using a standard whiteness meter, the higher the value, the better the whiteness. As can be seen from the table, the whiteness values ​​of all examples are significantly higher than those of the control group, indicating that the use of isoprene rubber and a specific peroxide vulcanization system can effectively improve the whiteness of the rubber material.

[0075] Hardness (Shore A): measured using a Shore A hardness meter, reflecting the hardness of the material. The hardness values ​​of the examples are slightly higher than those of the control group, indicating that these formulations improve the hardness of the material while maintaining high whiteness.

[0076] Tensile strength (MPa): measures the maximum force a material can withstand during stretching. The tensile strengths of the embodiments are higher than those of the control group, showing better mechanical properties.

[0077] Elongation at break (%): The elongation percentage of a material when stretched to break. The elongation at break of the embodiment is also better than that of the control group, indicating that the material has better ductility when subjected to external force.

[0078] T10 and T90: represent the time required for the rubber to reach 10% and 90% vulcanization degree during the vulcanization process, respectively. Shorter T10 and T90 times indicate faster vulcanization process and higher production efficiency. Both T10 and T90 of the embodiment are lower than those of the control group, showing the high efficiency of the peroxide vulcanization system.

[0079] Experimental conclusion

[0080] Based on the above experimental data, we can draw the following conclusions:

[0081] 1. Effect of isoprene rubber content on whiteness:

[0082] The experimental results show that as the content of isoprene rubber increases (from 59% in Example 1 to 60% in Example 3), the whiteness value of the rubber material increases. Specifically, the whiteness value of Example 3 is the highest (91.0%), while the whiteness value of the control group (conventional natural rubber) is the lowest (85.0%). This shows that the addition of isoprene rubber helps to improve the whiteness of the rubber material.

[0083] 2. Analysis of physical and mechanical properties:

[0084] A. Hardness: The hardness of the rubber in the examples is slightly higher than that of the control group, and the hardness value fluctuates with the change of the isoprene rubber content, but generally remains within a relatively good range (60-62 Shore A). This shows that the isoprene rubber formula has a certain flexibility in adjusting the hardness.

[0085] B. Tensile strength and elongation at break: The tensile strength and elongation at break of the examples are significantly better than those of the control group. In particular, Example 3 has a tensile strength of 27.0 MPa and an elongation at break of 460%, indicating that isoprene rubber performs well in improving the strength and toughness of rubber materials.

[0086] C. Vulcanization time: T10 and T90 vulcanization time data show that the isoprene rubber formulas show certain differences in vulcanization speed, but overall, they can achieve good vulcanization effects in a relatively short time.

[0087] 3. Comprehensive performance evaluation:

[0088] Taking into account the performance indicators such as whiteness, hardness, tensile strength, elongation at break and vulcanization time, it can be concluded that the rubber material prepared with isoprene rubber and a specific peroxide vulcanization system can significantly improve the whiteness value while maintaining excellent physical and mechanical properties, thereby meeting higher standards of appearance and performance requirements.

[0089] 4. Application prospects:

[0090] As a substitute for synthetic natural rubber, isoprene rubber has demonstrated its excellent performance characteristics in this experiment. In the future, this formula is expected to be widely used in the field of rubber products, especially in occasions with high requirements for whiteness and physical and mechanical properties, such as high-end tires, rubber seals, rubber tubes, etc.

Claims

1. A natural rubber material with high whiteness, characterized in that: Contains the following components by weight: Isoprene rubber 55%-60%, silicon dioxide 20%-25%, cyclohexane oil 2%-5%, zinc oxide 2%-3%, octadecanoic acid 0.3%-0.8%, polyethylene glycol 0.8%-1%, microcrystalline wax 0.3%-0.8%, 2-mercaptobenzimidazole 0.8%-1%, 935P 0.8%-1%, vinyl tris(b-methoxyethoxy) silane 0.8%-1%, titanium dioxide 5%-8%, 2,5-dimethyl-2,5-bis(tert-butyl peroxide) hexane 0.5%-0.8%.

2. A natural rubber material with high whiteness according to claim 1, characterized in that: Contains the following components by weight: Isoprene rubber 59%, silica 23%, cyclohexane oil 4%, zinc oxide 2.3%, octadecanoic acid 0.4%, polyethylene glycol 0.8%, microcrystalline wax 0.4%, 2-mercaptobenzimidazole 0.8%, 935P 0.9%, vinyl tri(b-methoxyethoxy) silane 0.8%, titanium dioxide 7%, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane 0.

6.

3. The natural rubber material with high whiteness according to claim 1, characterized in that: Contains the following components by weight: Isoprene rubber 55%, silica 25%, cyclohexane oil 5%, zinc oxide 3%, octadecanoic acid 0.6%, polyethylene glycol 1%, microcrystalline wax 0.8%, 2-mercaptobenzimidazole 1%, 935P 1%, vinyl tri(b-methoxyethoxy) silane 1%, titanium dioxide 6%, 2,5-dimethyl-2,5-bis(tert-butyl peroxide) hexane 0.

6.

4. The natural rubber material with high whiteness according to claim 1, characterized in that: Contains the following components by weight: Isoprene rubber 60%, silica 20%, naphthenic oil 2.6%, zinc oxide 3%, octadecanoic acid 0.8%, polyethylene glycol 1%, microcrystalline wax 0.8%, 2-mercaptobenzimidazole 1%, 935P 1%, vinyl tri(b-methoxyethoxy) silane 1%, titanium dioxide 8%, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane 0.

8.

5. A natural rubber material with high whiteness according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: S1. Weigh the materials according to the weight ratio; S2. Put the isoprene rubber into the internal mixer, mix for 1 minute, and then lift the top bolt of the internal mixer; S3, add silicon dioxide, cyclohexane oil, zinc oxide, octadecanoic acid, polyethylene glycol, microcrystalline wax, 2-mercaptobenzimidazole, 935P, vinyl tri(b-methoxyethoxy)silane, and titanium dioxide into an internal mixer, mix to 95° C., and lift the top bolt of the internal mixer again; S4, adding 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane into an internal mixer, mixing to 105°C, and then draining the mixture; S5. Put the discharged rubber into the open mill, pass the open mill 2mm thin 4-6 times, make 2 triangle packs, adjust the roller distance 6-8mm, cool the sheet, take samples for inspection, test hardness, strength, elongation, T10, T90 for inspection; S6, the rubber that has passed the test is subjected to an open mixing mill for refining and molding, and then the molded rubber is placed in a mold in a vulcanization device for molding; S7. Trim the vulcanized product and inspect its size and appearance to obtain qualified finished products.

6. The method for preparing a natural rubber material with high whiteness according to claim 5, characterized in that: In S2, when the isoprene rubber is fed into the internal mixer, the feeding temperature is not higher than 65°C.

7. The method for preparing a natural rubber material with high whiteness according to claim 5, characterized in that: In S6, the temperature of the mixing mill is 55-65°C.

8. The method for preparing a natural rubber material with high whiteness according to claim 5, characterized in that: In the above S6, the rubber is vulcanized under the conditions of a mold pressure of 180-200 Kgf / cm2 and a temperature of 155-165°C, and the vulcanization time is 280-320 seconds.