Azo silane coupling agent as well as synthesis method and application thereof

Abstract

The invention discloses an azo silane coupling agent as well as a synthesis method and application thereof, the azo silane coupling agent is obtained by carrying out substitution reaction on chloropropyltriethoxysilane and azodicarbonamide, and the azo silane coupling agent can improve the dispersity of white carbon black in natural rubber, so that the mechanical property and the processing stability of a rubber material are improved. Compared with a common silane coupling agent Si75 [bis-(triethoxysilylpropyl) disulfide], the product provided by the invention has a better dispersion effect on white carbon black in a rubber sizing material, the wear resistance of the sizing material can be improved, and the rolling resistance of the sizing material can be reduced.

Description

Technical Field

[0001] The invention relates to an azo silane coupling agent, and also to a synthesis method and application of the azo silane coupling agent, belonging to the technical field of chemical synthesis. Background Art

[0002] Azo silane coupling agent is a new type of rubber silane used in the tire industry. It is used as a coupling agent for silica-reinforced rubber compounds, especially fuel-efficient tires. Due to the low sulfur content in the molecular structure, it is not easy to burn and is safe to process. Studies have found that compared with silica rubber modified with coupling agent Si75 [bis-(triethoxysilylpropyl) disulfide], silica rubber modified with azo silane coupling agent has better wear resistance and lower rolling resistance.

[0003] At present, there are few reports on the synthesis and application of azo silane coupling agents. Summary of the invention

[0004] The object of the present invention is to provide an azo silane coupling agent, which is obtained by reacting an azo compound and a silane coupling agent. The azo silane coupling agent has a better effect of improving the dispersibility of white carbon black in a rubber compound than a silane coupling agent, and the rubber compound has better wear resistance and lower rolling resistance.

[0005] The azo silane coupling agent of the present invention has the following structural formula: The azo silane coupling agent is obtained by substitution reaction of chloropropyltriethoxysilane and azodicarbonamide. The synthesis method specifically comprises the following steps: Using chloropropyltriethoxysilane and azodicarbonamide as raw materials, triethylamine as solvent and acid binding agent, an azo silane coupling agent is obtained through substitution reaction. The reaction formula is as follows: Furthermore, the molecular formula of the azodicarbonamide is C2H4N4O2, and the molar ratio of chloropropyltriethoxysilane to azodicarbonamide is 1:0.5-1, for example, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, preferably 1:0.7-1.

[0006] Furthermore, the molar ratio of chloropropyltriethoxysilane to triethylamine is 1:1-1.3, for example, 1:1, 1:1.1, 1:1.2, 1:1.3.

[0007] Furthermore, chloropropyltriethoxysilane, azodicarbonamide and triethylamine are mixed and then heated to react. There is no special requirement for the mixing order of the three.

[0008] Furthermore, the present invention adopts a two-stage heating method to carry out the reaction, wherein the mixture of chloropropyltriethoxysilane, azodicarbonamide and triethylamine is first heated to 90-95°C for reflux reaction for 2-3 hours, and then heated to 120-125°C for reaction for 4-5 hours.

[0009] Furthermore, after the reaction is completed, the reaction liquid is post-treated to obtain an azo silane coupling agent product. The post-treatment process includes: cooling the reaction liquid to room temperature, filtering to remove the formed triethylamine hydrochloride and unreacted azodicarbonamide, and then distilling or vacuum distilling the filtrate to remove triethylamine, and the remainder is the final product.

[0010] The present invention also provides application of the azo silane coupling agent as a white carbon black dispersant.

[0011] The present invention has the following beneficial effects: 1. The present invention uses chloropropyltriethoxysilane and azodicarbonamide as raw materials, and obtains an azo silane coupling agent product through a substitution reaction. The product can improve the dispersibility of white carbon black in natural rubber, thereby improving the mechanical properties and processing stability of the rubber. Compared with the commonly used silane coupling agent Si75 [bis-(triethoxysilylpropyl) disulfide], the product of the present invention has a better dispersing effect on white carbon black in rubber rubber, can improve the wear resistance of the rubber, and reduce the rolling resistance of the rubber.

[0012] 2. The synthesis method of the present invention is simple and easy to operate, and triethylamine is used as both a solvent and an acid-binding agent, thereby improving the efficiency and yield of the reaction. The reaction adopts a two-stage temperature increase operation, thereby improving the reaction efficiency, and improving the yield and purity of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The HPLC chromatogram of the product obtained in Example 4 of the present invention is shown in FIG.

[0014] Figure 2 This is the H NMR spectrum of the product obtained in Example 4 of the present invention. DETAILED DESCRIPTION

[0015] The following is a description of exemplary embodiments of the present invention, including various details of the embodiments of the present invention to aid understanding, which should be considered as merely exemplary. Therefore, it should be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Likewise, for clarity and simplicity, descriptions of well-known functions, operations, and structures are omitted in the following description.

[0016] In the following examples and comparative examples, the calculation formula for the yield is: yield = mass of the obtained product / (0.5×molar amount of triethoxy chloropropylsilane×molecular weight of the azo silane coupling agent)×100%.

[0017] Example 1 238.4g (1mol) chloropropyltriethoxysilane, 101.19g triethylamine (1mol), 58.04g azodicarbonamide (0.5mol) were added to a three-necked flask, and the temperature was raised to 90-95°C to start reflux reaction. After 2h, the temperature was raised to 120-125°C, and the temperature was kept for 4h and then cooled to room temperature. The triethylamine hydrochloride and the unreacted azodicarbonamide were filtered, and the filtrate was taken for negative pressure distillation at a pressure of -0.08-0.09MPa and a temperature of 110°C. The distillation was considered to be complete when no fraction appeared on the condenser tube, and 6.8g of fraction was obtained, which was 98.7% of triethylamine by gas chromatography. The residue was the azo silane coupling agent product, a total of 152.04g, and the yield was 68.0% based on chloropropyltriethoxysilane. The product had a red oily liquid appearance and a purity of 84.68% by liquid chromatography.

[0018] Example 2 Add 238.4g (1mol) of chloropropyltriethoxysilane, 111.31g of triethylamine (1.1mol), and 58.04g of azodicarbonamide (0.5mol) into a three-necked flask, raise the temperature to 90-95℃ to start reflux reaction, raise the temperature to 120-125℃ after 2h, keep it warm for 4h and then cool it to room temperature, filter the triethylamine hydrochloride and unreacted azodicarbonamide, take the filtrate for negative pressure distillation, the pressure is -0.08-0.09MPa, the temperature is 110℃, and the distillation is considered to be complete when no fraction appears on the condenser, and 14.3g of fraction is obtained; 157.27g of azo silane coupling agent product, the yield is 70.4% based on chloropropyltriethoxysilane; the product is a red oily liquid, and the purity is 84.42% as determined by liquid chromatography.

[0019] Example 3 238.4g (1mol) of chloropropyltriethoxysilane, 111.31g of triethylamine (1.1mol) and 69.65g of azodicarbonamide (0.6mol) were added to a three-necked flask, and the temperature was raised to 90-95°C to start reflux reaction. After 2h, the temperature was raised to 120-125°C, and the temperature was kept for 4h and then cooled to room temperature. The triethylamine hydrochloride and unreacted azodicarbonamide were filtered, and the filtrate was taken for negative pressure distillation at a pressure of -0.08-0.09MPa and a temperature of 110°C. The distillation was considered to be complete when no fraction appeared on the condenser tube, and 166.54g of azo silane coupling agent product was obtained, and the yield was 74.5% based on chloropropyltriethoxysilane; the product was tested by liquid chromatography, and the purity was 85.33%.

[0020] Example 4 238.4g (1mol) of chloropropyltriethoxysilane, 111.31g of triethylamine (1.1mol) and 87.06g of azodicarbonamide (0.75mol) were added to a three-necked flask, and the temperature was raised to 90-95°C to start reflux reaction. After 2h, the temperature was raised to 120-125°C, kept warm for 4h and then cooled to room temperature. The triethylamine hydrochloride and unreacted azodicarbonamide were filtered, and the filtrate was subjected to negative pressure distillation at a pressure of -0.08-0.09MPa and a temperature of 110°C. The distillation was considered to be complete when no fraction appeared on the condenser tube, and 190.13g of azo silane coupling agent product was obtained, and the yield was 85.1% based on chloropropyltriethoxysilane. The product was tested by liquid chromatography, and the purity was 85.79%. Figure 1 HPLC chart of the obtained product. Figure 2 The NMR spectrum of the obtained product.

[0021] Example 5 Add 238.4g (1mol) of chloropropyltriethoxysilane, 111.31g of triethylamine (1.1mol), and 116.08g of azodicarbonamide (1mol) into a three-necked flask, raise the temperature to 90-95°C to start reflux reaction, raise the temperature to 120-125°C after 2h, keep warm for 4h and then cool to room temperature, filter triethylamine hydrochloride and unreacted azodicarbonamide, take the filtrate for negative pressure distillation, pressure -0.08-0.09MPa, temperature 110°C, no fraction appears on the condenser, it is considered that the distillation is complete, and 188.02g of azo silane coupling agent product is obtained, and the yield is 84.1% based on chloropropyltriethoxysilane; the product is tested by liquid chromatography, and the purity is 85.06%.

[0022] Example 6 Add 238.4g (1mol) of chloropropyltriethoxysilane, 122.44g of triethylamine (1.21mol), and 116.08g of azodicarbonamide (1mol) into a three-necked flask, raise the temperature to 90-95°C to start reflux reaction, raise the temperature to 120-125°C after 2h, keep warm for 4h and then cool to room temperature, filter triethylamine hydrochloride and unreacted azodicarbonamide, take the filtrate for negative pressure distillation, pressure -0.08~-0.09MPa, temperature 110°C, no fraction appears on the condenser, it is considered that the distillation is complete, and 184.27g of azo silane coupling agent product is obtained, and the yield is 82.4% based on chloropropyltriethoxysilane; the product is tested by liquid chromatography, and the purity is 85.50%.

[0023] Comparative Example 1 Add 238.4g (1mol) of chloropropyltriethoxysilane, 111.31g of triethylamine (1.1mol), and 116.08g of azodicarbonamide (1mol) into a three-necked flask, raise the temperature to 90-95°C to start reflux reaction, keep the temperature for 6h and then cool to room temperature, filter triethylamine hydrochloride and unreacted azodicarbonamide, take the filtrate for negative pressure distillation, the pressure is -0.08-0.09MPa, the temperature is 110°C, and the distillation is considered to be complete when no fraction appears on the condenser, and 170.97g of azo silane coupling agent product is obtained, and the yield is 76.5% based on chloropropyltriethoxysilane; the product is tested by liquid chromatography, and the purity is 83.51%.

[0024] Comparative Example 2 238.4g (1mol) of chloropropyltriethoxysilane, 111.31g of triethylamine (1.1mol) and 116.08g of azodicarbonamide (1mol) were added to a three-necked flask, and the temperature was raised to 50°C to start the reaction. After keeping the temperature for 8 hours, the temperature was lowered to room temperature, and triethylamine hydrochloride and unreacted azodicarbonamide were filtered out. The filtrate was taken for negative pressure distillation at a pressure of -0.08~-0.09MPa and a temperature of 110°C. The distillation was considered to be complete when no fraction appeared on the condenser tube, and 207.49g of azo silane coupling agent product was obtained, and the yield was 92.8% based on chloropropyltriethoxysilane. The product was tested by liquid chromatography, and the purity was 3.24%.

Claims

1. An azo silane coupling agent, characterized in that: It has the structural formula shown below: 。 2. A method for synthesizing the azo silane coupling agent according to claim 1, characterized in that: It is prepared by substitution reaction of chloropropyltriethoxysilane and azodicarbonamide.

3. The synthesis method according to claim 2, characterized in that: The azo silane coupling agent is obtained by using chloropropyltriethoxysilane and azodicarbonamide as raw materials, triethylamine as solvent and acid binding agent through substitution reaction.

4. The synthesis method according to claim 2 or 3, characterized in that: The molar ratio of chloropropyltriethoxysilane to azodicarbonamide is 1:0.5-1.

5. The synthesis method according to claim 3, characterized in that: The molar ratio of chloropropyltriethoxysilane to triethylamine is 1:1-1.

3.

6. The synthesis method according to any one of claims 2 to 5, characterized in that: The reactants were first heated to 90-95°C for reflux reaction for 2-3 hours, and then heated to 120-125°C for reaction for 4-5 hours.

7. Use of the azo silane coupling agent according to claim 1 as a dispersant for white carbon black.

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