Preparation method of organic cobalt salt for improving strength and elongation product of rubber

Abstract

The invention discloses a preparation method of an organic cobalt salt for improving the product strength and elongation of rubber, and belongs to the technical field of organic cobalt salt preparation, the preparation method comprises the following steps: S1, raw material preparation: 38-42 parts of cobalt hydroxide, 42-46 parts of neodecanoic acid, 42-46 parts of pivalic acid, 12-14 parts of propionic acid, 40-50 parts of n-butyl propionate and 18-22 parts of zinc oxide; s2, raw material pretreatment: cobalt hydroxide: performing recrystallization purification operation on cobalt hydroxide; the purity of neodecanoic acid, pivaloic acid and propionic acid is further improved by adopting a rectification method; n-butyl propionate; on the basis of a conventional cobalt neodecanoate formula, the optimal proportion of various organic acids is adjusted to meet the optimal strength and elongation product effect of the rubber, and meanwhile, by adjusting the optimal proportion of various organic acids and adding an optimal functional aid, the optimal strength and elongation product effect of the rubber is met.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of organic cobalt salts of rubber, and in particular relates to a method for preparing an organic cobalt salt for improving the strength-elongation product of rubber. Background Art

[0002] Traditional cobalt salts, with their excellent adhesion-promoting properties, are irreplaceable in rubbers formulated with metal backbones. However, cobalt ions also significantly affect the tensile properties of rubber after vulcanization. This complicates the formulation of rubbers that require both a metal backbone and certain tensile properties. To address this, we propose a method for preparing organic cobalt salts for improving the strength-elongation product of rubber. Summary of the Invention

[0003] The present invention provides a method for preparing an organic cobalt salt for improving the strength-elongation product of rubber, so as to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for preparing an organic cobalt salt for improving the strength and elongation product of rubber, comprising the following steps:

[0005] S1. Raw materials preparation: cobalt hydroxide: 38-42 parts, neodecanoic acid: 42-46 parts, pivalic acid: 42-46 parts, propionic acid: 12-14 parts, n-butyl propionate: 40-50 parts, and zinc oxide: 18-22 parts;

[0006] S2. Raw material pretreatment:

[0007] Cobalt hydroxide: Recrystallize and purify cobalt hydroxide;

[0008] Neodecanoic acid, pivalic acid and propionic acid: use distillation to further improve their purity;

[0009] Butyl propionate: The pore size of the molecular sieve is Molecular sieve drying treatment;

[0010] The drying time is 24h to 48h, ensuring that the moisture content is less than 0.05%;

[0011] Zinc oxide: Dry at 100℃~120℃ for 2h~3h to remove adsorbed moisture;

[0012] S3. Add n-butyl propionate as a solvent to the reactor. n-butyl propionate is added dropwise at a rate of 5 mL / min to 10 mL / min while slowly stirring at a rate of 50 rpm to 100 rpm.

[0013] S4, adding cobalt hydroxide, adding in batches, stirring to form a pink suspension;

[0014] S5. Raise the temperature to 90°C to 100°C and start the reflux device;

[0015] S6. Add neodecanoic acid, pivalic acid, and propionic acid dropwise in sequence, controlling the addition rate to avoid local overheating;

[0016] S7. Reflux for 2 hours to ensure sufficient salt formation. During the reflux reaction, a double-layer stirring blade is used, with the upper blade being a pusher blade and the lower blade being a turbine blade. The speed of the pusher blade is 200 rpm to 300 rpm, and the speed of the turbine blade is 300 rpm to 400 rpm.

[0017] S8. Raise the temperature to 175°C to 185°C and distill at a negative pressure of ≤-0.085 MPa for 1.5 hours to remove wastewater and residual solvent;

[0018] S9. When adding zinc oxide, pre-disperse the zinc oxide in the solvent in the reactor, add the zinc oxide and stir in the reactor for 1 hour at a stirring speed of 200 rpm to 300 rpm to obtain a blue-purple granular product.

[0019] Furthermore, in step S2, neodecanoic acid, pivalic acid, and propionic acid are distilled through a distillation tower, and the operating conditions of the distillation tower are: 30 to 50 plates, 3 to 5 reflux ratio, and 190° C. to 200° C.

[0020] Furthermore, before the step S3, the reaction container is cleaned by soaking it in a 2% sodium hydroxide solution for 2 to 3 hours, and then rinsing it with clean water until it becomes neutral;

[0021] The reaction vessel is passivated by soaking it in a 10% nitric acid solution for 1 to 2 hours and then rinsing it with clean water.

[0022] Furthermore, in step S4, an equal amount of cobalt hydroxide is added to the reaction vessel in 3 to 5 batches, and during the stirring process to form a pink suspension, the mixture is first stirred at a low speed of 100 rpm to 150 rpm for 5 to 10 minutes to initially disperse the cobalt hydroxide, and then the stirring speed is gradually increased to 300 to 400 rpm and stirred for 20 to 30 minutes until a uniform suspension is formed.

[0023] Furthermore, in step S4, during the stirring process of the cobalt hydroxide, ultrasonic treatment is performed using an ultrasonic auxiliary device with an ultrasonic power of 200W to 300W, and the ultrasonic treatment is performed for 1 to 2 minutes every 5 minutes of stirring.

[0024] Furthermore, in step S5, the temperature is first raised to 80°C at a rate of 1°C / min to 2°C / min, kept constant for 10min to 15min, and then raised to 90°C / min to 100°C at a rate of 2°C / min to 3°C / min. After the reflux device is turned on, ensure that the reflux ratio is 2 to 3.

[0025] Furthermore, in step S6, the dropping speed of neodecanoic acid is controlled at 2 mL / min to 3 mL / min, the dropping speed of pivalic acid is controlled at 3 mL / min to 4 mL / min, and the dropping speed of propionic acid is controlled at 1 mL / min to 2 mL / min;

[0026] During the process of adding the acid dropwise, nitrogen gas was introduced into the reactor at a flow rate of 5 mL / min to 10 mL / min.

[0027] Furthermore, in step S8, during the distillation process, fractions at different stages are collected for analysis, the distillation process is divided into three stages: initial distillation, middle distillation, and final distillation, and the fractions at each stage are subjected to component analysis;

[0028] The primary distillation stage is mainly for the distillation of low-boiling point impurities and part of the solvent;

[0029] The middle distillation stage is where the main wastewater and residual solvents are distilled off;

[0030] The final distillation stage is the distillation of high boiling point impurities.

[0031] Furthermore, in step S9, a high-speed disperser is used to pre-disperse the zinc oxide in the solvent in the reaction kettle at a rotation speed of 1000 rpm to 1500 rpm for 5 minutes to 10 minutes.

[0032] The beneficial effects of the present invention are:

[0033] 1. The organic cobalt salt for rubber strength and elongation prepared by the present invention is prepared by adjusting the optimal ratio of various organic acids on the basis of the conventional cobalt neodecanoate formula to achieve the effect of optimal rubber strength and elongation.

[0034] 2. The organic cobalt salt for rubber strength and elongation prepared by the present invention is formulated by adjusting the optimal ratio of various organic acids and adding optimal functional additives to achieve the effect of optimal rubber strength and elongation.

[0035] 3. The organic cobalt salt with high strength and elongation of rubber prepared by the present invention can ensure that the product quality meets the requirements under the conditions of solvent, reaction temperature and reaction time, and also meets the needs of energy conservation and emission reduction. DETAILED DESCRIPTION

[0036] In order to further understand the content, features and effects of the present invention, the following examples are given to illustrate in detail.

[0037] Example 1:

[0038] A method for preparing an organic cobalt salt for improving the strength and elongation of rubber comprises the following steps:

[0039] S1. Raw materials preparation: 40 parts of cobalt hydroxide, 44 parts of neodecanoic acid, 44 parts of pivalic acid, 13 parts of propionic acid, 40 parts of n-butyl propionate, and 20 parts of zinc oxide;

[0040] S2. Raw material pretreatment:

[0041] Cobalt hydroxide: Recrystallize and purify cobalt hydroxide;

[0042] Neodecanoic acid, pivalic acid, and propionic acid: Use distillation to further improve their purity. Distillation is carried out in a distillation tower. The operating conditions of the distillation tower are: 30-50 plates, 3-5 reflux ratio, and 190-200°C top temperature.

[0043] Butyl propionate: The pore size of the molecular sieve is Molecular sieve drying treatment, drying time is

[0044] 24h~48h, ensure its water content is less than 0.05%;

[0045] Zinc oxide: Dry at 100℃~120℃ for 2h~3h to remove adsorbed moisture;

[0046] S3. Before step S3, the reaction vessel is cleaned by soaking it in a 2% sodium hydroxide solution for 2 to 3 hours, and then rinsing it with clean water until it becomes neutral;

[0047] Perform passivation treatment on the reaction vessel by soaking it in a 10% nitric acid solution for 1 to 2 hours and then rinsing it with clean water;

[0048] After rinsing, use clean compressed air to blow dry to ensure that there is no nitric acid residue in the container;

[0049] n-Butyl propionate was added as a solvent to the reactor by dropwise addition at a rate of 5 mL / min to 10 mL / min while slowly stirring at a rate of 50 rpm to 100 rpm.

[0050] S4, adding cobalt hydroxide, when adding cobalt hydroxide, adding in batches, adding equal amounts of cobalt hydroxide to the reaction vessel in 3 to 5 batches, stirring to form a pink suspension, stirring to form a pink suspension, first stirring at a low speed of 100 rpm to 150 rpm for 5 min to 10 min to preliminarily disperse the cobalt hydroxide, then gradually increasing the stirring speed to 300 min to 400 rpm, stirring for 20 min to 30 min, until a uniform suspension is formed;

[0051] During the stirring process of the cobalt hydroxide, an ultrasonic auxiliary device with an ultrasonic power of 200W to 300W is used for ultrasonic treatment, and the ultrasonic treatment is performed for 1min to 2min every 5min of stirring;

[0052] S5. Raise the temperature to 90°C to 100°C, turn on the reflux device, first raise the temperature to 80°C at a rate of 1°C / min to 2°C / min, keep the temperature constant for 10min to 15min, then raise the temperature to 90°C / min to 100°C at a rate of 2°C / min to 3°C / min. After turning on the reflux device, ensure that the reflux ratio is 2 to 3;

[0053] S6. Add neodecanoic acid, pivalic acid, and propionic acid dropwise in sequence, controlling the addition rate to avoid local overheating. The addition rate of neodecanoic acid is controlled at 2 mL / min to 3 mL / min, the addition rate of pivalic acid is controlled at 3 mL / min to 4 mL / min, and the addition rate of propionic acid is controlled at 1 mL / min to 2 mL / min.

[0054] During the addition of acid, nitrogen was introduced into the reactor at a flow rate of 5 mL / min to 10 mL / min.

[0055] S7. Reflux for 2 hours to ensure sufficient salt formation. During the reflux reaction, a double-layer stirring blade is used, with the upper blade being a pusher blade and the lower blade being a turbine blade. The speed of the pusher blade is 200 rpm to 300 rpm, and the speed of the turbine blade is 300 rpm to 400 rpm.

[0056] S8. Raise the temperature to 175°C to 185°C and distill at a negative pressure of ≤-0.085 MPa for 1.5 hours to remove wastewater and residual solvent;

[0057] During the distillation process, fractions from different stages are collected for analysis. The distillation process is divided into three stages: initial distillation, middle distillation, and final distillation. The components of the fractions from each stage are analyzed.

[0058] The primary distillation stage is mainly for the distillation of low-boiling point impurities and part of the solvent;

[0059] The middle distillation stage is where the main wastewater and residual solvents are distilled off;

[0060] The final distillation stage is the distillation of high-boiling-point impurities;

[0061] S9. When adding zinc oxide, pre-disperse the zinc oxide in the solvent in the reactor first, use a high-speed disperser to pre-disperse the zinc oxide in the solvent in the reactor, pre-disperse it at a speed of 1000rpm to 1500rpm for 5min to 10min, add zinc oxide and stir it in the reactor for 1h at a stirring speed of 200rpm to 300rpm, and obtain a blue-purple granular product.

[0062] Example 2:

[0063] S1. Raw materials preparation: 38 parts of cobalt hydroxide, 42 parts of neodecanoic acid, 42 parts of pivalic acid, 12 parts of propionic acid, 45 parts of n-butyl propionate, and 18 parts of zinc oxide;

[0064] S2. Raw material pretreatment:

[0065] Cobalt hydroxide: Recrystallize and purify cobalt hydroxide;

[0066] Neodecanoic acid, pivalic acid, and propionic acid: Use distillation to further improve their purity. Distillation is carried out in a distillation tower. The operating conditions of the distillation tower are: 30-50 plates, 3-5 reflux ratio, and 190-200°C top temperature.

[0067] Butyl propionate: The pore size of the molecular sieve is Molecular sieve drying treatment, drying time is

[0068] 24h~48h, ensure its water content is less than 0.05%;

[0069] Zinc oxide: Dry at 100℃~120℃ for 2h~3h to remove adsorbed moisture;

[0070] S3. Before step S3, the reaction vessel is cleaned by soaking it in a 2% sodium hydroxide solution for 2 to 3 hours, and then rinsing it with clean water until it becomes neutral;

[0071] Perform passivation treatment on the reaction vessel by soaking it in a 10% nitric acid solution for 1 to 2 hours and then rinsing it with clean water;

[0072] n-Butyl propionate was added as a solvent to the reactor by dropwise addition at a rate of 5 mL / min to 10 mL / min while slowly stirring at a rate of 50 rpm to 100 rpm.

[0073] S4, adding cobalt hydroxide, when adding cobalt hydroxide, adding in batches, adding equal amounts of cobalt hydroxide to the reaction vessel in 3 to 5 batches, stirring to form a pink suspension, stirring to form a pink suspension, first stirring at a low speed of 100 rpm to 150 rpm for 5 min to 10 min to preliminarily disperse the cobalt hydroxide, then gradually increasing the stirring speed to 300 min to 400 rpm, stirring for 20 min to 30 min, until a uniform suspension is formed;

[0074] During the stirring process of the cobalt hydroxide, an ultrasonic auxiliary device with an ultrasonic power of 200W to 300W is used for ultrasonic treatment, and the ultrasonic treatment is performed for 1min to 2min every 5min of stirring;

[0075] S5. Raise the temperature to 90°C to 100°C, turn on the reflux device, first raise the temperature to 80°C at a rate of 1°C / min to 2°C / min, keep the temperature constant for 10min to 15min, then raise the temperature to 90°C / min to 100°C at a rate of 2°C / min to 3°C / min. After turning on the reflux device, ensure that the reflux ratio is 2 to 3;

[0076] S6. Add neodecanoic acid, pivalic acid, and propionic acid dropwise in sequence, controlling the addition rate to avoid local overheating. The addition rate of neodecanoic acid is controlled at 2 mL / min to 3 mL / min, the addition rate of pivalic acid is controlled at 3 mL / min to 4 mL / min, and the addition rate of propionic acid is controlled at 1 mL / min to 2 mL / min.

[0077] During the addition of acid, nitrogen was introduced into the reactor at a flow rate of 5 mL / min to 10 mL / min.

[0078] S7. Reflux for 2 hours to ensure sufficient salt formation. During the reflux reaction, a double-layer stirring blade is used, with the upper blade being a pusher blade and the lower blade being a turbine blade. The speed of the pusher blade is 200 rpm to 300 rpm, and the speed of the turbine blade is 300 rpm to 400 rpm.

[0079] S8. Raise the temperature to 175°C to 185°C and distill at a negative pressure of ≤-0.085 MPa for 1.5 hours to remove wastewater and residual solvent;

[0080] During the distillation process, fractions from different stages are collected for analysis. The distillation process is divided into three stages: initial distillation, middle distillation, and final distillation. The components of the fractions from each stage are analyzed.

[0081] The primary distillation stage is mainly for the distillation of low-boiling point impurities and part of the solvent;

[0082] The middle distillation stage is where the main wastewater and residual solvents are distilled off;

[0083] The final distillation stage is the distillation of high-boiling-point impurities;

[0084] S9. When adding zinc oxide, pre-disperse the zinc oxide in the solvent in the reactor first, use a high-speed disperser to pre-disperse the zinc oxide in the solvent in the reactor, pre-disperse it at a speed of 1000rpm to 1500rpm for 5min to 10min, add zinc oxide and stir it in the reactor for 1h at a stirring speed of 200rpm to 300rpm, and obtain a blue-purple granular product.

[0085] Example 3:

[0086] S1. Raw materials preparation: 42 parts of cobalt hydroxide, 46 parts of neodecanoic acid, 46 parts of pivalic acid, 14 parts of propionic acid, 50 parts of n-butyl propionate, and 22 parts of zinc oxide;

[0087] S2. Raw material pretreatment:

[0088] Cobalt hydroxide: Recrystallize and purify cobalt hydroxide;

[0089] Neodecanoic acid, pivalic acid, and propionic acid: Use distillation to further improve their purity. Distillation is carried out in a distillation tower. The operating conditions of the distillation tower are: 30-50 plates, 3-5 reflux ratio, and 190-200°C top temperature.

[0090] Butyl propionate: The pore size of the molecular sieve is Molecular sieve drying treatment, drying time is

[0091] 24h~48h, ensure its water content is less than 0.05%;

[0092] Zinc oxide: Dry at 100℃~120℃ for 2h~3h to remove adsorbed moisture;

[0093] S3. Before step S3, the reaction vessel is cleaned by soaking it in a 2% sodium hydroxide solution for 2 to 3 hours, and then rinsing it with clean water until it becomes neutral;

[0094] Perform passivation treatment on the reaction vessel by soaking it in a 10% nitric acid solution for 1 to 2 hours and then rinsing it with clean water;

[0095] n-Butyl propionate was added as a solvent to the reactor by dropwise addition at a rate of 5 mL / min to 10 mL / min while slowly stirring at a rate of 50 rpm to 100 rpm.

[0096] S4, adding cobalt hydroxide, when adding cobalt hydroxide, adding in batches, adding equal amounts of cobalt hydroxide to the reaction vessel in 3 to 5 batches, stirring to form a pink suspension, stirring to form a pink suspension, first stirring at a low speed of 100 rpm to 150 rpm for 5 min to 10 min to preliminarily disperse the cobalt hydroxide, then gradually increasing the stirring speed to 300 min to 400 rpm, stirring for 20 min to 30 min, until a uniform suspension is formed;

[0097] During the stirring process of the cobalt hydroxide, an ultrasonic auxiliary device with an ultrasonic power of 200W to 300W is used for ultrasonic treatment, and the ultrasonic treatment is performed for 1min to 2min every 5min of stirring;

[0098] S5. Raise the temperature to 90°C to 100°C, turn on the reflux device, first raise the temperature to 80°C at a rate of 1°C / min to 2°C / min, keep the temperature constant for 10min to 15min, then raise the temperature to 90°C / min to 100°C at a rate of 2°C / min to 3°C / min. After turning on the reflux device, ensure that the reflux ratio is 2 to 3;

[0099] S6. Add neodecanoic acid, pivalic acid, and propionic acid dropwise in sequence, controlling the addition rate to avoid local overheating. The addition rate of neodecanoic acid is controlled at 2 mL / min to 3 mL / min, the addition rate of pivalic acid is controlled at 3 mL / min to 4 mL / min, and the addition rate of propionic acid is controlled at 1 mL / min to 2 mL / min.

[0100] During the addition of acid, nitrogen was introduced into the reactor at a flow rate of 5 mL / min to 10 mL / min.

[0101] S7. Reflux for 2 hours to ensure sufficient salt formation. During the reflux reaction, a double-layer stirring blade is used, with the upper blade being a pusher blade and the lower blade being a turbine blade. The speed of the pusher blade is 200 rpm to 300 rpm, and the speed of the turbine blade is 300 rpm to 400 rpm.

[0102] S8. Raise the temperature to 175°C to 185°C and distill at a negative pressure of ≤-0.085 MPa for 1.5 hours to remove wastewater and residual solvent;

[0103] During the distillation process, fractions from different stages are collected for analysis. The distillation process is divided into three stages: initial distillation, middle distillation, and final distillation. The components of the fractions from each stage are analyzed.

[0104] The primary distillation stage is mainly for the distillation of low-boiling point impurities and part of the solvent;

[0105] The middle distillation stage is where the main wastewater and residual solvents are distilled off;

[0106] The final distillation stage is the distillation of high-boiling-point impurities;

[0107] S9. When adding zinc oxide, pre-disperse the zinc oxide in the solvent in the reactor first, use a high-speed disperser to pre-disperse the zinc oxide in the solvent in the reactor, pre-disperse it at a speed of 1000rpm to 1500rpm for 5min to 10min, add zinc oxide and stir it in the reactor for 1h at a stirring speed of 200rpm to 300rpm, and obtain a blue-purple granular product.

[0108] Table 1 Test data of organic cobalt salts of Examples 1 to 3:

[0109]

[0110] Table 2 Test data of organic cobalt salts of Examples 1 to 3:

[0111]

[0112] From the above examples, it can be seen that, under the same conditions, the organic cobalt salt of the present invention adjusts the optimal ratio of various organic acids compared with cobalt salts on the conventional market to achieve the effect of optimal strength and elongation of rubber, and the specific gravity and special requirements can be adjusted according to the actual rubber formula.

[0113] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an organic cobalt salt for increasing the strength and elongation of rubber, characterized in that: The following steps are involved: S1. Raw materials preparation: cobalt hydroxide: 38-42 parts, neodecanoic acid: 42-46 parts, pivalic acid: 42-46 parts, propionic acid: 12-14 parts, n-butyl propionate: 40-50 parts, and zinc oxide: 18-22 parts; S2. Raw material pretreatment: Cobalt hydroxide: Recrystallize and purify cobalt hydroxide; Neodecanoic acid, pivalic acid and propionic acid: use distillation to further improve their purity; Butyl propionate: The pore size of the molecular sieve is Molecular sieve drying treatment, the drying time is 24h ~ 48h, to ensure that the water content is less than 0.05%; Zinc oxide: Dry at 100℃~120℃ for 2h~3h to remove adsorbed moisture; S3. Add n-butyl propionate as a solvent to the reactor. n-butyl propionate is added dropwise at a rate of 5 mL / min to 10 mL / min while slowly stirring at a rate of 50 rpm to 100 rpm. S4, adding cobalt hydroxide, adding in batches, with the interval between each addition being 5min to 10min, and stirring to form a pink suspension; S5. Raise the temperature to 90℃~100℃ and start the reflux device. During the reflux reaction, check the condensation effect of the reflux device regularly. If condensation is found on the surface of the condenser tube, adjust the temperature or flow rate of the condensed water to ensure the reflux ratio is 2~3. S6. Add neodecanoic acid, pivalic acid, and propionic acid dropwise in sequence. After adding each acid, wait 5 to 10 minutes before adding the next acid. Control the addition speed to avoid local overheating. S7, reflux reaction for 2 hours to ensure sufficient salt formation, during the reflux reaction, a double-layer stirring blade is used, the upper blade is a propeller blade, and the lower blade is a turbine blade. The speed of the propeller blade is 200 rpm to 300 rpm, and the speed of the turbine blade is 300 rpm to 400 rpm; S8. Raise the temperature to 175°C to 185°C and distill at a negative pressure of ≤-0.085 MPa for 1.5 hours to remove wastewater and residual solvent; S9. When adding zinc oxide, pre-disperse the zinc oxide in the solvent in the reactor, add the zinc oxide and stir in the reactor for 1 hour at a stirring speed of 200 rpm to 300 rpm to obtain a blue-purple granular product.

2. The method for preparing an organic cobalt salt for improving the strength-elongation product of rubber according to claim 1, wherein: In step S2, neodecanoic acid, pivalic acid, and propionic acid are distilled through a distillation tower. The operating conditions of the distillation tower are: 30 to 50 plates, 3 to 5 reflux ratio, and 190 to 200° C.

3. The method for preparing an organic cobalt salt for improving the strength-elongation product of rubber according to claim 1, wherein: Before the step S3, the reaction container is cleaned by soaking it in a 2% sodium hydroxide solution for 2 to 3 hours, and then rinsing it with clean water until it is neutral; Perform passivation treatment on the reaction vessel by soaking it in a 10% nitric acid solution for 1 to 2 hours and then rinsing it with clean water; Use clean compressed air to blow dry and ensure that there is no nitric acid residue in the container.

4. The method for preparing an organic cobalt salt for improving the strength-elongation product of rubber according to claim 1, wherein: In step S4, an equal amount of cobalt hydroxide is added to the reaction container in 3 to 5 batches, and during the stirring process to form a pink suspension, the mixture is first stirred at a low speed of 100 rpm to 150 rpm for 5 to 10 minutes to initially disperse the cobalt hydroxide, and then the stirring speed is gradually increased to 300 to 400 rpm and stirred for 20 to 30 minutes until a uniform suspension is formed.

5. The method for preparing an organic cobalt salt for improving the strength-elongation product of rubber according to claim 4, characterized in that: In step S4, while stirring the cobalt hydroxide, an ultrasonic auxiliary device with an ultrasonic power of 200W to 300W is used for ultrasonic treatment, and the ultrasonic treatment is performed for 1 to 2 minutes every 5 minutes of stirring; The ultrasonic probe should be placed in the center of the bottom of the reaction vessel.

6. The method for preparing an organic cobalt salt for improving the strength-elongation product of rubber according to claim 1, characterized in that: In step S5, the temperature is first raised to 80°C at a rate of 1°C / min to 2°C / min, the stirring speed is 100 rpm to 150 rpm, and the temperature is kept constant for 10 min to 15 min. During the 10 min to 15 min period, the stirring speed is 150 rpm to 200 rpm. Then, the temperature is raised to 90°C / min-100°C at a rate of 2°C / min-3°C / min. During the temperature increase to 90°C / min-100°C, the stirring speed is 200rpm-250rpm. After the reflux device is turned on, the reflux ratio is ensured to be 2-3.

7. The method for preparing an organic cobalt salt for improving the strength-elongation product of rubber according to claim 1, characterized in that: In step S6, the dropping speed of neodecanoic acid is controlled at 2 mL / min to 3 mL / min, the dropping speed of pivalic acid is controlled at 3 mL / min to 4 mL / min, and the dropping speed of propionic acid is controlled at 1 mL / min to 2 mL / min; After each drop of acid is added, observe the changes in the temperature, color, and stirring state of the reaction system; During the process of adding the acid dropwise, nitrogen gas was introduced into the reactor at a flow rate of 5 mL / min to 10 mL / min.

8. The method for preparing an organic cobalt salt for improving the strength-elongation product of rubber according to claim 1, wherein: In step S8, during the distillation process, fractions at different stages are collected for analysis. The distillation process is divided into three stages: initial distillation, middle distillation, and final distillation. The fractions at each stage are analyzed for composition. The primary distillation stage is mainly for the distillation of low-boiling point impurities and part of the solvent; The middle distillation stage is where the main wastewater and residual solvents are distilled off; The final distillation stage is the distillation of high boiling point impurities.

9. The method for preparing an organic cobalt salt for improving the strength-elongation product of rubber according to claim 1, characterized in that: In step S9, a high-speed disperser is used to pre-disperse the zinc oxide in the solvent in the reaction kettle at a speed of 1000 rpm to 1500 rpm for 5 to 10 minutes; During the reaction, samples were taken every 15 to 20 minutes, and the contents of cobalt and zinc in the reaction system were analyzed by inductively coupled plasma emission spectrometry.

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