Diphenylamine propyl triethoxy silane as well as preparation method and application thereof

Abstract

The invention discloses diphenylamine propyl triethoxy silane as well as a preparation method and application thereof, diphenylamine and chloropropyl triethoxy silane are taken as raw materials, and the diphenylamine propyl triethoxy silane is prepared through nucleophilic substitution reaction in the presence of an acid-binding agent. The product is colorless to faint yellow transparent liquid in appearance, the yield is 95% or above, the purity is 98% or above, and the use requirements are met. When the product is applied to green tires, not only can the dispersibility of the white carbon black be improved, but also the diphenylamine generated in the action process can play a role in delaying rubber aging and improving the processing performance of rubber materials, so that the product has industrial application value.

Description

Technical Field

[0001] The present invention relates to a multifunctional silane coupling agent for green tires, in particular to a multifunctional and environmentally friendly diphenylaminopropyltriethoxysilane and a preparation method and application thereof, belonging to the technical field of rubber additive synthesis. Background Art

[0002] Rubber is currently widely used in our daily life, medical industry, rail transportation industry and other industries, and plays an irreplaceable role in people's lives. Natural rubber and synthetic rubber are widely used in today's society and life, and with the continuous development of the economy, the demand for rubber in various industries is also growing. Silane coupling agents, as molecular bridges connecting inorganic materials and organic materials, are widely used in the fields of automobiles, aviation, medical care, construction, electronics, etc. For example, in the field of automobile tires, rubber has the problems of low strength and easy aging. Silica can be used as a reinforcing agent and filler for rubber to improve these problems of rubber. However, due to the large difference in the physical and chemical properties of the two, silica has poor dispersion in rubber. The introduction of silane coupling agents has effectively solved the problem of poor dispersion and significantly improved the processing and performance of tires.

[0003] Currently, the mainstream silane coupling agents are Si-69 and Si-75, which perform poorly in improving the aging of natural rubber systems. Therefore, in order to significantly improve the performance of natural rubber tires, it is necessary to develop new silane coupling agent molecules tailored to the molecular structure of natural rubber. Summary of the Invention

[0004] The present invention aims to provide a diphenylaminopropyltriethoxysilane. The silane contains a silylethoxy group and can react with the polar hydroxyl groups on the surface of silica during processing to reduce the surface polarity of silica and promote its dispersion in the rubber compound. In addition, the silane contains a diphenylamine group, which can delay the aging of the rubber compound during its application and extend the service life of tires or other rubber products. The silane is a multifunctional silane coupling agent.

[0005] The diphenylaminopropyltriethoxysilane provided by the present invention has the structural formula shown below:

[0006]

[0007] The present invention also provides a preparation method of diphenylaminopropyltriethoxysilane. The method uses diphenylamine and chloropropyltriethoxysilane as raw materials, and performs a nucleophilic substitution reaction under the action of an acid binding agent to obtain diphenylaminopropyltriethoxysilane.

[0008] Furthermore, the acid binding agent is at least one of triethylamine, pyridine, and tri-n-butylamine, preferably triethylamine.

[0009] Taking triethylamine as an acid binding agent as an example, the reaction formula is as follows:

[0010]

[0011] Furthermore, in the above method, the molar ratio of diphenylamine to the acid binding agent is 1.05-1.1:1, for example, 1.05:1, 1.06:1, 1.07:1, 1.08:1, 1.09:1, 1.1:1, preferably 1.05:1.

[0012] Furthermore, in the above method, the molar ratio of diphenylamine to chloropropyltriethoxysilane is 1.05-1.1:1, for example, 1.05:1, 1.06:1, 1.07:1, 1.08:1, 1.09:1, 1.1:1, preferably 1.05:1.

[0013] Furthermore, in the above method, the reaction temperature is 50-90°C, such as 50°C, 60°C, 70°C, 80°C, 90°C, preferably 70-80°C.

[0014] Furthermore, the above method specifically includes the following steps: mixing diphenylamine and an acid binding agent, then slowly adding chloropropyltriethoxysilane dropwise under controlled temperature, continuing to keep warm after the addition is complete to react, to obtain a reaction solution containing diphenylaminopropyltriethoxysilane, filtering the reaction solution to remove salt, and then distilling to obtain the target product diphenylaminopropyltriethoxysilane.

[0015] Furthermore, the dropping temperature of chloropropyltriethoxysilane is 50-90°C, preferably 70-80°C.

[0016] Furthermore, the dropwise addition time of chloropropyltriethoxysilane is 0.5-1 h, and after the dropwise addition is completed, the reaction is continued by heat preservation for 2-4 h, for example, 2 h, 3 h, or 4 h.

[0017] The diphenylaminopropyltriethoxysilane of the present invention is a multifunctional silane coupling agent that can effectively promote the dispersion of white carbon black in organic materials such as rubber and retard the aging of rubber products, thereby being used as a rubber additive. The rubber products are products containing natural rubber or synthetic rubber, such as tires or raw rubber compounds.

[0018] The present invention also provides a rubber product, which comprises diphenylaminopropyltriethoxysilane.

[0019] The present invention has the following advantages:

[0020] 1. The diphenylaminepropyltriethoxysilane of the present invention is applied to a green tire system containing silica, which not only modifies the surface of silica and promotes its dispersion; in addition, the diphenylamine produced during the reaction process can also delay rubber aging and improve the processing performance of the rubber compound, thereby extending the service life of the tire and effectively improving the aging phenomenon of the green tire during the application process. It has application advantages, high added value, and industrial value.

[0021] 2. The process of the present invention is convenient, the post-processing process is simple and easy to implement, the appearance of the obtained product is a light yellow to colorless transparent liquid, the yield is above 95%, and the product purity is above 98%, which meets the use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the H NMR spectrum of diphenylaminopropyltriethoxysilane obtained in Example 1. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the following examples, but the following examples are merely illustrative and do not limit the contents thereof.

[0024] In the following examples, the yield is calculated as follows: mass of the obtained product / theoretical mass of the product.

[0025] Example 1

[0026] In a 1L reactor, 240.5g of diphenylamine and 144g of triethylamine were added in sequence. The temperature was controlled at 70°C, stirring was started, and 326.5g of chloropropyltriethoxysilane was slowly added dropwise to the system. After about 1 hour, the addition of chloropropyltriethoxysilane was completed. The temperature was maintained and stirring was continued for about 2 hours. After the reaction was completed, the triethylamine salt was filtered to remove the triethylamine salt. Then, low-boiling impurities were removed by reduced pressure distillation at a pressure of -0.09 MPa and a temperature of 55°C to obtain 495.7g of the target product, which appeared as a light yellow to colorless transparent liquid. The yield was 97.9% based on chloropropyltriethoxysilane, and the product purity (HPLC) was 99.2%.

[0027] The H NMR spectrum of the obtained product is as follows Figure 1 shown.

[0028] Example 2

[0029] In a 1L reactor, 240.5g of diphenylamine and 144g of triethylamine were added in sequence. The temperature was controlled at 60°C, stirring was started, and 326.5g of chloropropyltriethoxysilane was slowly added dropwise to the system. After about 1 hour, the addition of chloropropyltriethoxysilane was completed. The temperature was maintained and stirring was continued for about 2 hours. After the reaction was completed, filtration was carried out and reduced pressure distillation was performed at a pressure of -0.09MPa and a temperature of 55°C to obtain 489.2g of the target product, which had an appearance of light yellow to colorless transparent liquid. The yield was 96.6% based on chloropropyltriethoxysilane, and the product purity (HPLC) was 98.7%.

[0030] Example 3

[0031] In a 1L reactor, 240.5g of diphenylamine and 144g of triethylamine were added in sequence. The temperature was controlled at 90°C, stirring was started, and 326.5g of chloropropyltriethoxysilane was slowly added dropwise to the system. After about 1 hour, the addition of chloropropyltriethoxysilane was completed. The temperature was maintained and stirring was continued for about 2 hours. After the reaction was completed, filtration was performed and reduced pressure distillation was performed at a pressure of -0.09MPa and a temperature of 55°C to obtain 484.5g of the target product, which was a light yellow to colorless transparent liquid. The yield was 95.7% based on chloropropyltriethoxysilane, and the product purity (HPLC) was 98.4%.

[0032] Example 4

[0033] In a 1L reactor, 240.5g of diphenylamine and 144g of triethylamine were added in sequence. The temperature was controlled at 70°C, stirring was started, and 326.5g of chloropropyltriethoxysilane was slowly added dropwise to the system. After about 1 hour, the addition of chloropropyltriethoxysilane was completed. The temperature was maintained and stirring was continued for about 3 hours. After the reaction was completed, filtration was carried out and reduced pressure distillation was performed at a pressure of -0.09 MPa and a temperature of 55°C to obtain 495.8g of the target product, which had an appearance of light yellow to colorless transparent liquid. The yield was 97.9% based on chloropropyltriethoxysilane, and the product purity (HPLC) was 98.2%.

[0034] Example 5

[0035] 240.5 g of diphenylamine and 112.6 g of pyridine were added sequentially to a 1 L reactor, the temperature was controlled at 70° C., stirring was started, and 326.5 g of chloropropyltriethoxysilane was slowly added dropwise to the system. After about 1 hour, the addition of chloropropyltriethoxysilane was completed, and stirring was continued at the temperature for about 2 hours. After the reaction was completed, filtration was performed and vacuum distillation was performed at a pressure of -0.09 MPa and a temperature of 55° C. to obtain 493.91 g of the target product, which was a light yellow to colorless transparent liquid in appearance. The yield was 97.5% based on chloropropyltriethoxysilane, and the product purity (HPLC) was 98.2%.

[0036] Comparative Example 1

[0037] Diphenylaminopropyltriethoxysilane was synthesized according to the method of Example 1, except that the reaction temperature was controlled at 100° C. during the addition of chloropropyltriethoxysilane and the reaction. The product yield, calculated as chloropropyltriethoxysilane, was 87.36%. The product was a yellow-brown liquid, and its purity was 89.54% as measured by high performance liquid chromatography.

[0038] Comparative Example 2

[0039] Diphenylaminopropyltriethoxysilane was synthesized according to the method of Example 1, except that the reaction temperature was controlled at 40° C. during the addition of chloropropyltriethoxysilane and the reaction. The product yield, calculated as chloropropyltriethoxysilane, was 82.35%. The product was a light yellow liquid, and its purity was 92.43% as measured by high performance liquid chromatography.

[0040] Comparative Example 3

[0041] Diphenylaminopropyltriethoxysilane was synthesized according to the method of Example 1, except that the addition of chloropropyltriethoxysilane was completed, and the temperature was maintained and stirring was continued for about 1 hour. The product yield was 78.82% based on chloropropyltriethoxysilane, and the appearance was a light yellow liquid. The purity was measured by high performance liquid chromatography and was 83.55%.

[0042] Performance Testing

[0043] 1. Rubber compound preparation

[0044] The rubber compound was prepared according to the rubber compound formula in Table 1 below. In Table 1, diphenylaminopropyltriethoxysilane, Si69, and a 1:1 mixture of Si69 and diphenylamine were used as silane coupling agents.

[0045] Table 1

[0046] parts by weight Recipe 1 Recipe 2 Recipe 3 Oil-filled SSBR 96.3 96.3 96.3 Butadiene rubber CB24 30 30 30 Silica 60 60 60 Carbon black N330 10 10 10 Diphenylaminopropyltriethoxysilane 5 - - Si69 - 5 - Si69+diphenylamine (mass ratio 1:1) - - 5 Accelerator DPG-80 2.5 2.5 2.5 ZnO-80 3.75 3.75 3.75 S-80 1.88 1.88 1.88 Accelerator CBS-80 1.88 1.88 1.88

[0047] 2. Preparation of rubber

[0048] 2.1, Stage 1 (in internal mixer)

[0049] Initial temperature 70-80℃, speed 72r / min; add oil-filled SSBR and butadiene rubber CB24, and press for 60s; lift the roller and add small materials (1 / 2 white carbon black, carbon black, silane coupling agent, ZnO-80) for 10s; mix for 60s; lift the roller for 10s and add the remaining 1 / 2 white carbon black; mix for 60s; lift the roller and clean for 10s; mix for 50s; lift the roller for 10s; press and mix for 50s; lift the roller empty for 10s; keep the roller at 145-155℃ for 180s; remove the glue.

[0050] 2.2, Second stage (in the mixing mill)

[0051] Add S-80 and accelerator, front roller 50℃, rear roller 60℃.

[0052] 3. Test methods

[0053] The scorch Mooney properties, vulcanization properties, mechanical properties and Payne effect of the rubber compound were tested. The Mooney scorch properties were measured according to GB / T1233-1992, the vulcanization properties were measured according to GB / T 9869-2014, the tensile mechanical properties were measured according to GB / T 528-2009, and the Payne effect properties were measured using a German Montek 3000 rubber rotorless vulcanization analyzer.

[0054] 4. Experimental results

[0055] The test results of each rubber compound are shown in Table 2.

[0056] Table 2

[0057]

[0058]

[0059] The performance test results in the table above show that:

[0060] 1) The scorch and Mooney data of diphenylaminepropyltriethoxysilane, silane coupling agent Si-69, and a mixture of Si-69 and diphenylamine show that the processing properties of the three silane coupling agents are comparable.

[0061] 2) From the initial physical properties and the physical properties after thermal oxidative aging data, it can be seen that the anti-aging performance of diphenylaminopropyltriethoxysilane is significantly improved compared with the silane coupling agent Si-69 and the mixture of Si-69 and diphenylamine.

[0062] From the corresponding data of Payne, it can be seen that the silica dispersibility of diphenylaminopropyltriethoxysilane, silane coupling agent Si-69, and the mixture of Si-69 and diphenylamine is comparable; the silica dispersibility of diphenylaminopropyltriethoxysilane is better than the other two.

Claims

1. A diphenylaminopropyltriethoxysilane, characterized in that It has the following structural formula:

2. A method for preparing diphenylaminopropyltriethoxysilane according to claim 1, characterized in that: The diphenylaminopropyltriethoxysilane is obtained by a substitution reaction between diphenylamine and chloropropyltriethoxysilane under the action of an acid binding agent.

3. The preparation method according to claim 2, wherein: The acid binding agent is at least one of triethylamine, pyridine and tri-n-butylamine, preferably triethylamine.

4. The preparation method according to claim 2 or 3, characterized in that: The molar ratio of diphenylamine, acid binding agent and chloropropyltriethoxysilane is 1.05-1.1:1.05-1.1:

1.

5. The preparation method according to claim 4, wherein: The molar ratio of diphenylamine, acid binding agent and chloropropyltriethoxysilane is 1.05:1.05:

1.

6. The preparation method according to claim 2, wherein: The reaction temperature is 50-90°C.

7. The preparation method according to claim 2 or 6, characterized in that: Chloropropyltriethoxysilane is added dropwise to the mixture of diphenylamine and the acid-binding agent over a period of 0.5-1 h. The reaction is continued for 2-4 h after the addition is complete.

8. Use of the diphenylaminopropyltriethoxysilane according to claim 1 in promoting the dispersion of silica in organic matter and / or delaying the aging of rubber products.

9. Use of the diphenylaminopropyltriethoxysilane according to claim 1 in a rubber product, preferably, the rubber product is a tire.

10. A rubber product, characterized by: Including the diphenylaminopropyltriethoxysilane according to claim 1.

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