Anti-aging agent as well as synthesis method and application thereof

Abstract

The invention belongs to the field of rubber additives, and particularly relates to an anti-aging agent as well as a synthesis method and application thereof. RT base and a phenol compound are used as raw materials for synthesis under the action of a catalyst; the phenol compound is a mixture of phenol and o-methylphenol. According to the invention, RT base (p-aminodiphenylamine) is used as a precursor and reacts with phenol or o-methylphenol in the presence of a catalyst to produce the anti-aging agent. Salt-containing waste water is not generated in the precursor production process, and compared with hydroquinone serving as a precursor, the precursor has the obvious cost advantage and the environment-friendly advantage.

Description

Technical Field

[0001] This invention belongs to the field of rubber additives, specifically relating to an antioxidant, its synthesis method, and its application. Background Technology

[0002] Antioxidant DTPD is suitable for synthetic rubbers such as natural rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, and chloroprene rubber. It is a typical post-oxidation rubber antioxidant. Due to its non-volatile, extraction-resistant, and continuous antioxidant effect, it is widely used in bias tires and radial tires at home and abroad. As a p-phenylenediamine antioxidant, it has the potential to replace 6PPD and has a very broad application prospect.

[0003] Traditional production processes use hydroquinone as a precursor, which reacts with aniline / o-methylaniline under catalytic conditions to produce the antioxidant DTPD. However, hydroquinone is a relatively expensive raw material, and the synthesis process generates saline wastewater, resulting in high water treatment costs. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for synthesizing an antioxidant.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for synthesizing an antioxidant, using the following formula (I):

[0007]

[0008] The synthesis is carried out using RT-based products and phenolic compounds as raw materials under the action of a catalyst; the phenolic compounds are a mixture of phenol and o-methylphenol.

[0009] The catalyst is an organic sulfonic acid; preferably p-aminobenzenesulfonic acid.

[0010] The amount of catalyst added is 0.1%-2% of RT-PS; preferably 0.5%.

[0011] The molar ratio of RT-pes to phenol or phenolic compounds is 1:(1-1.4); preferably 1:(1.2-1.4).

[0012] The phenolic compound is a mixture of phenol and o-methylphenol; the molar ratio of phenol to o-methylphenol is 1:(0.5-2); preferably 1:1.

[0013] The method for synthesizing the antioxidant specifically includes the following steps:

[0014] S1: Add RT-based compounds, phenolic compounds, and catalyst to the reaction vessel;

[0015] S2: The reaction temperature starts to carry water from 150±10 degrees and gradually increases to 210±10 degrees. The water-containing phenols carried out are returned to the reaction system after being dehydrated by distillation.

[0016] S3: Neutralize the reaction liquid with a saturated sodium carbonate solution at a temperature of 100±10 degrees Celsius. After neutralization, separate the aqueous phase.

[0017] S4: Distill the organic phase to 250±10 degrees Celsius and evaporate excess residual volatile organic phenols to obtain the final product.

[0018] The present invention also includes an antioxidant obtained by the synthesis method described above.

[0019] The antioxidants mentioned include N-(4-aminophenyl)-2-methylaniline and N-(4-aminophenyl)aniline.

[0020] The present invention also includes an application of the antioxidant as a rubber additive.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This invention uses RT-p-aminodiphenylamine as a precursor, which reacts with phenol or o-methylphenol under catalytic conditions to produce an antioxidant. This precursor production process does not generate saline wastewater, and compared to using hydroquinone as a precursor, it has significant cost and environmental advantages. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to embodiments.

[0024] Example 1

[0025] The following formula (I) is used for preparation, and the same applies below;

[0026]

[0027] Specifically, the following steps are included:

[0028] S1: RT peroxide, phenolic compounds and catalyst are added sequentially to the reactor; the molar ratio of the catalyst p-aminobenzenesulfonic acid, RT peroxide and phenol, o-methylphenol is controlled at 1:0.5:0.5, and the amount of catalyst is 0.5% of RT peroxide.

[0029] S2: The reaction temperature starts to carry water from 150 degrees and gradually increases to 210 degrees. The water-containing phenols carried out are returned to the reaction system after being dehydrated by distillation.

[0030] S3: Neutralize the reaction liquid with a saturated sodium carbonate solution at a temperature of 100 degrees Celsius. After neutralization, separate the aqueous phase.

[0031] S4: Distill the organic phase to 250 degrees Celsius and evaporate excess residual volatile organic phenols to obtain the final product.

[0032] Example 2

[0033] A method for synthesizing an antioxidant includes the following steps:

[0034] S1: RT peroxide, phenolic compounds and catalyst are added sequentially to the reactor; the molar ratio of the catalyst p-aminobenzenesulfonic acid, RT peroxide and phenol, o-methylphenol is controlled at 1:0.6:0.6, and the amount of catalyst is 0.5% of RT peroxide.

[0035] S2: The reaction temperature starts to carry water from 150 degrees and gradually increases to 210 degrees. The water-containing phenols carried out are returned to the reaction system after being dehydrated by distillation.

[0036] S3: Neutralize the reaction liquid with a saturated sodium carbonate solution at a temperature of 100 degrees Celsius. After neutralization, separate the aqueous phase.

[0037] S4: Distill the organic phase to 250 degrees Celsius and evaporate excess residual volatile organic phenols to obtain the final product.

[0038] Example 3

[0039] A method for synthesizing an antioxidant includes the following steps:

[0040] S1: RT peroxide, phenolic compounds and catalyst are added sequentially to the reactor; the molar ratio of the catalyst p-aminobenzenesulfonic acid, RT peroxide and phenol, o-methylphenol is controlled at 1:0.7:0.7, and the amount of catalyst is 0.5% of RT peroxide.

[0041] S2: The reaction temperature starts to carry water from 150 degrees and gradually increases to 210 degrees. The water-containing phenols carried out are returned to the reaction system after being dehydrated by distillation.

[0042] S3: Neutralize the reaction liquid with a saturated sodium carbonate solution at a temperature of 100 degrees Celsius. After neutralization, separate the aqueous phase.

[0043] S4: Distill the organic phase to 250 degrees Celsius and evaporate excess residual volatile organic phenols to obtain the final product.

[0044] Comparative Example 1

[0045] A method for synthesizing an antioxidant includes the following steps:

[0046] S1: RT peroxide, phenol and catalyst are added sequentially to the reactor. The molar ratio of the catalyst p-aminobenzenesulfonic acid, RT peroxide and phenol is controlled at 1:1.2, and the amount of catalyst is 0.5% of RT peroxide.

[0047] S2: The reaction temperature starts to carry water from 150 degrees and gradually increases to 210 degrees. The water-containing phenols carried out are returned to the reaction system after being dehydrated by distillation.

[0048] S3: Neutralize the reaction liquid with a saturated sodium carbonate solution at a temperature of 100 degrees Celsius. After neutralization, separate the aqueous phase.

[0049] S4: Distill the organic phase to 250 degrees Celsius and evaporate excess residual volatile organic phenols to obtain the final product.

[0050] Comparative Example 2

[0051] A method for synthesizing an antioxidant includes the following steps:

[0052] S1: RT peroxide, o-methylphenol and catalyst are added sequentially to the reactor. The molar ratio of the catalyst p-aminobenzenesulfonic acid, RT peroxide and o-methylphenol is controlled at 1:1.2, and the amount of catalyst is 0.5% of RT peroxide.

[0053] S2: The reaction temperature starts to carry water from 150 degrees and gradually increases to 210 degrees. The water-containing phenols carried out are returned to the reaction system after being dehydrated by distillation.

[0054] S3: Neutralize the reaction liquid with a saturated sodium carbonate solution at a temperature of 100 degrees Celsius. After neutralization, separate the aqueous phase.

[0055] S4: Distill the organic phase to 250 degrees Celsius and evaporate excess residual volatile organic phenols to obtain the final product.

[0056] The results of different embodiments and important reaction parameters are shown in Table 1, wherein the total effective amount is the sum of the products N-(4-aminophenyl)-2-methylaniline and N-(4-aminophenyl)aniline.

[0057] Table 1

[0058]

[0059] Results and Discussion

[0060] Comparing Examples 1, 2, and 3, the amount of phenol compound fed into Example 1 was insufficient, resulting in a lower total effective content. In Examples 2 and 3, the effective contents were very close. The increased feeding ratio of the mixed amine would increase the energy consumption of the remaining mixed amine in the recovery reaction. Therefore, Example 2 is preferred from the perspective of product energy consumption. Using o-methylphenol and phenol alone is also not ideal.

[0061] Product performance testing

[0062] Example 2 and the purchased Yangzhou Yechang antioxidant DTPD were used as Comparative Example 3 for product performance testing. The experimental formulas are shown in Table 1 below.

[0063] Table 1

[0064] Material Name Formula component content natural rubber 50 Butadiene rubber 50 stearic acid 2 Zinc oxide 3.5 N660 50 Aromatic oils 4 Accelerator TBBS 1.0 sulfur 1.5 Anti-aging agents 2 total 164

[0065] Test requirements:

[0066] 1. Vulcanization curve at 151℃, Mooney scorch at 127℃, Mooney viscosity;

[0067] 2. Tensile strength, elongation at break, stress at 100% and 300% of constant elongation, and hardness at 151℃ for 30 min;

[0068] 3. Tensile strength, elongation at break, 100% and 300% constant elongation stress, and hardness after aging at 151℃ for 30 min and 100℃ for 48 h.

[0069] 4. Test specimens at 151℃ for 30 minutes, ozone aging test, observe the surface cracking of the specimens at 2h, 4h, 8h, 24h, 48h, and 72h.

[0070] 5. Ozone test conditions

[0071] Ozone concentration, (50±5)×10⁻⁸; test temperature, (40±2)℃; elongation, static tensile test, 20%.

[0072] The sulfur transformation characteristics (151℃ sulfur transformation instrument) are shown in Table 2.

[0073] Table 2

[0074]

[0075]

[0076] The physical properties (vulcanization conditions: 151℃*30min) are shown in Table 3;

[0077] Table 3

[0078]

[0079]

[0080] Ozone aging performance (ozone concentration 50 pphm, temperature 40℃, 20% tensile) is shown in Table 4.

[0081] Table 4

[0082] time Example 2 Comparative Example 3 2h Grade 0, no cracks Grade 0, no cracks 4h Grade 0, no cracks Grade 0, no cracks 8h Surface cracks Surface cracks 24h 1b 1b 48h 2a 2a 72h 3c 3c

[0083] Conclusion: The antioxidant synthesized via this route achieves essentially the same anti-aging effect as commercially available DTPD.

[0084] In summary, this invention uses RT-p-aminodiphenylamine as a precursor, which reacts with phenol or o-methylphenol under catalytic conditions to produce an antioxidant. This precursor production process does not generate saline wastewater, and compared to using hydroquinone as a precursor, it has significant cost and environmental advantages.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for synthesizing an antioxidant, characterized in that, The preparation is carried out using the following formula (I):

2. The method for synthesizing the antioxidant according to claim 1, characterized in that, The synthesis is carried out using RT-based products and phenolic compounds as raw materials under the action of a catalyst; the phenolic compounds are a mixture of phenol and o-methylphenol.

3. The method for synthesizing the antioxidant according to claim 2, characterized in that, The catalyst is an organic sulfonic acid; preferably p-aminobenzenesulfonic acid.

4. The method for synthesizing the antioxidant according to claim 2, characterized in that, The amount of catalyst added is 0.1%-2% of RT-PS; preferably 0.5%.

5. The method for synthesizing the antioxidant according to claim 2, characterized in that, The molar ratio of RT-pes to phenol and phenolic compounds is 1:(1-1.4).

6. The method for synthesizing the antioxidant according to claim 2, characterized in that, The phenolic compound is a mixture of phenol and o-methylphenol; the molar ratio of phenol to o-methylphenol is 1:(0.5-2); preferably 1:

1.

7. The method for synthesizing the antioxidant according to claim 2, characterized in that, Specifically, the following steps are included: S1: Add RT-based compounds, phenolic compounds, and catalyst to the reaction vessel; S2: The reaction temperature starts to carry water from 150±10 degrees and gradually increases to 210±10 degrees. The water-containing phenols carried out are returned to the reaction system after being dehydrated by distillation. S3: Neutralize the reaction liquid with a saturated sodium carbonate solution at a temperature of 100±10 degrees Celsius. After neutralization, separate the aqueous phase. S4: Distill the organic phase to 250±10 degrees Celsius and evaporate excess residual volatile organic phenols to obtain the final product.

8. An antioxidant obtained by the synthesis method according to any one of claims 1-7.

9. The antioxidant according to claim 8, characterized in that, Including N-(4-aminophenyl)-2-methylaniline and N-(4-aminophenyl)aniline.

10. The application of the antioxidant according to claim 8 or 9, characterized in that, It is used as a rubber additive.

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