Coating for inner wall of steel shell of alkaline zinc-manganese battery and preparation method of coating

Abstract

The invention discloses a coating for the inner wall of a steel shell of an alkaline zinc-manganese battery and a preparation method of the coating. The coating is prepared by mixing inorganic silicon modified polyurea resin, conductive powder, a conductive powder solvent, an adhesive and pigment, and the inorganic silicon modified polyurea resin is obtained by copolymerization modification of an inorganic material and polyurea resin, the coating is prepared from the following raw materials in percentage by weight: 15%-25% of inorganic silicon modified polyurea resin, 15%-25% of conductive powder, 30%-60% of a conductive powder solvent, 1%-5% of an adhesive and 1%-5% of pigment, the inorganic silicon modified polyurea resin and the conductive powder of a carbon material are adopted as main raw materials, and carboxyl contained in the inorganic silicon modified polyurea resin can be utilized, so that the inorganic silicon modified polyurea resin has good wettability and leveling property on a base material and the conductive powder, and a coating film is uniform and consistent, and therefore, a dispersing agent, a leveling agent, a wetting agent and the like do not need to be added during preparation of the coating, and the preparation process is simple. Therefore, the production cost of the coating is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of coating preparation, in particular to a coating for the inner wall of an alkaline zinc-manganese battery steel shell and a preparation method thereof. Background Art

[0002] Paint is a material applied to the surface of an object to be protected or decorated, and can form a continuous film that adheres firmly to the object. It is usually a viscous liquid made of resin, oil or emulsion, with or without pigments, fillers and corresponding additives, and prepared with organic solvents or water. In the current production process of alkaline zinc-manganese battery steel shells, in order to promote full contact between the steel shell and the positive electrode material, reduce the internal resistance of the battery, protect the steel shell, reduce the corrosion of the steel shell by corrosive substances, extend the storage period of the battery, and enhance the discharge effect of the battery, the inner wall of the alkaline zinc-manganese battery steel shell is usually sprayed; According to the authorization publication number CN110885597A for a water-based conductive graphite emulsion for alkaline zinc-manganese batteries and its preparation method, and the authorization publication number CN102306795B for a water-based conductive agent for alkaline manganese batteries and its production method, it can be seen that the above two patents are both known prior art and both have the advantages of good conductivity, water resistance, wear resistance and strong corrosion resistance. However, during the production process of the above two patents, both use water-based resin as the base material. Due to the poor adhesion of the resin material itself, this will cause the coating to easily fall off after spraying and film formation. In addition, the above two patents require the addition of additives such as dispersants, leveling agents and wetting agents during production, thereby increasing the production cost of the coating. Therefore, we have proposed a coating for the inner wall of the steel shell of an alkaline zinc-manganese battery and a preparation method thereof. Summary of the Invention

[0003] In view of the deficiencies raised in the above background technology, the present invention provides a coating for the inner wall of the steel shell of an alkaline zinc-manganese battery and a preparation method thereof, which solves the problems raised in the above background technology.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a coating for the inner wall of a steel shell of an alkaline zinc-manganese battery, the coating comprising the following components: an inorganic silicon-modified polyurea resin, a conductive powder, a conductive powder solvent, an adhesive, and a pigment are mixed to obtain the coating, and the inorganic silicon-modified polyurea resin is obtained by copolymerization and modification of an inorganic material and a polyurea resin; Among them, the proportions of the raw materials of the coating are, in terms of mass fraction, inorganic silicon modified polyurea resin (15%-25%), conductive powder (15%-25%), conductive powder solvent (30%-60%), adhesive (1%-5%) and pigment (1%-5%), and the total proportion of each component is 100%.

[0005] Preferably, the raw material components of the coating are proportioned as follows, in terms of mass fraction: 20% inorganic silicon modified polyurea resin, 20% conductive powder, 55% conductive powder solvent, 3% adhesive and 2% pigment, and the total proportion of each component is 100%.

[0006] Preferably, the conductive powder is carbon-based, specifically carbon powder, and the conductive powder is used to enhance the conductive properties of the coating, and the adhesive is propylene glycol methyl ether.

[0007] Preferably, the raw materials of the inorganic silicon modified polyurea resin include the following components: polyurea resin, inorganic silicon material, modifier and inorganic mineral material, wherein the mass fraction of each component is polyurea resin (75%-85%), inorganic silicon material (5%-15%), modifier (1%-10%) and inorganic mineral material (1%-10%), and the total proportion of each component is 100%.

[0008] Preferably, the raw material proportions of the inorganic silicon modified polyurea resin are as follows, in percentage by mass: polyurea resin 80%, inorganic silicon material 10%, modifier 5% and inorganic mineral material 5%, and the total proportion of each component is 100%.

[0009] Preferably, the method for obtaining the inorganic silicon-modified polyurea resin by copolymerization modification comprises the following specific operations: (1) Prepare the reactants: Use weighing tools to weigh the raw materials required for the reaction one by one, and place the weighed raw materials aside for later use; (2) Mixing and heating: gradually add the prepared polyurea resin and inorganic silicon material into the reactor in proportion, and gradually heat it to a predetermined temperature, so as to improve the reaction activity of the polyurea resin. Then, stir it with a stirring mechanism to ensure that the polyurea resin and the inorganic silicon material are fully mixed; (3) Adding modifier: When the mixture in step (2) reaches a certain temperature, slowly add the pre-weighed modifier three times, with one-third of the amount each time; (4) Reaction and copolymerization: After adding the modifier, it is allowed to react for a period of time within a specific temperature range to complete the copolymerization reaction; (5) Adding inorganic mineral materials: After the copolymerization reaction is completed, continue to add inorganic mineral materials to the reactor to enhance the performance of the resin; (6) Vacuum distillation and cooling: The reaction mixture in the reactor is subjected to vacuum distillation to separate small molecular substances in the system, that is, to separate free formaldehyde, water and methanol mixture, which is used to improve the quality and purity of the resin. The reaction mixture is then cooled to room temperature to obtain the desired inorganic silicon modified polyurea resin.

[0010] Preferably, in step (2), the predetermined temperature range of the reactor is 90°C-120°C, in step (3), the modifier is added when the temperature range of the mixture reaches about 140°C, in step (4), the temperature range of the copolymerization reaction is 130°C-150°C, and the copolymerization reaction time is 1h-3h, and in step (6), the reaction mixture is cooled by air cooling.

[0011] Preferably, the modifier is an organic silicon monomer, and the modifier is used to improve the film-forming property and hydrophobicity of the resin, and the inorganic mineral material is an inorganic mineral powder, and the inorganic mineral material is used to enhance the wear resistance and corrosion resistance of the resin.

[0012] A method for preparing the coating according to any one of claims 1 to 8, comprising the following steps: S1. First, add the inorganic silicon modified polyurea resin to a mixing kettle, heat and stir it, and then slowly add the pigment into the mixing kettle to uniformly mix the inorganic silicon modified polyurea resin and the pigment. The purpose of heating and stirring is to accelerate the diffusion rate of the pigment molecules so that the pigment molecules can quickly fuse with the inorganic silicon modified polyurea resin. S2. When the mixture in the mixing kettle in step S1 is naturally cooled to room temperature, conductive powder and conductive powder solvent are added into the mixing kettle and stirred to allow the conductive powder and conductive powder solvent to be fully mixed; S3. After the conductive powder and the conductive powder solvent are fused in step S2, the adhesive is continued to be added into the mixing kettle and stirred and mixed again until the adhesive is fully fused, thereby obtaining the desired coating.

[0013] Preferably, in step S1, the temperature range of the heating and stirring is 45° C.-80° C., and an electric stirring rod is used for stirring.

[0014] Compared with the prior art, the present invention provides a coating for the inner wall of the steel shell of an alkaline zinc-manganese battery and a preparation method thereof, which has the following beneficial effects: The coating for the inner wall of the steel shell of an alkaline zinc-manganese battery and the preparation method thereof use inorganic silicon-modified polyurea resin and conductive powder of a carbon-based material as main raw materials. The carboxyl groups contained in the inorganic silicon-modified polyurea resin can be utilized to make the coating have good wettability to the substrate and the conductive powder, good leveling properties, and a uniform coating film. In this way, there is no need to add dispersants, leveling agents, wetting agents, etc. during the preparation of the coating, thereby reducing the production cost of the coating. At the same time, the prepared coating is very suitable for airless spraying process in battery factories. After it is sprayed on the inner wall of the steel shell of the alkaline zinc-manganese battery, the coating layer has a short hardening time and good adhesion ability. The use of carbon as a conductive powder can reduce the internal resistance of the battery due to its conductivity, thereby improving the discharge effect of the battery.

[0015] The coating for the inner wall of the steel shell of an alkaline zinc-manganese battery and the preparation method thereof modify a polyurea resin by using an inorganic silicon material, so that the inorganic silicon-modified polyurea resin can have some characteristics of both polyurea resin and inorganic silicon material. Traditional polyurea resin has poor adhesion and a long curing time, while the polyurea resin modified with inorganic silicon has the advantages of strong adhesion and a short curing time, and further enhances the water resistance, wear resistance and corrosion resistance of the polyurea resin itself, thereby significantly improving the water resistance, wear resistance and corrosion resistance of the inner wall of the steel shell of the alkaline zinc-manganese battery after spraying. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] Example 1:

[0018] A coating for the inner wall of an alkaline zinc-manganese battery steel casing, wherein the raw materials of the coating include the following components: an inorganic silicon-modified polyurea resin, a conductive powder (carbon-based conductive powder), a conductive powder solvent, an adhesive, and a pigment. The proportions of the raw materials of the coating, calculated by mass percentage, are as follows: 15% inorganic silicon-modified polyurea resin, 25% conductive powder, 55% conductive powder solvent, 3% adhesive, and 2% pigment, with the total proportion of the components being 100%. The preparation method of the coating comprises the following steps: S1. First, add the inorganic silicon modified polyurea resin to a mixing kettle, and heat and stir it in a temperature range of 45° C. to 80° C. using an electric stirring rod. Then, slowly add the pigment into the mixing kettle to uniformly mix the inorganic silicon modified polyurea resin and the pigment. The purpose of heating and stirring is to accelerate the diffusion rate of the pigment molecules so that the pigment molecules can quickly fuse with the inorganic silicon modified polyurea resin. S2. When the mixture in the mixing kettle in step S1 is naturally cooled to room temperature, carbon powder and conductive powder solvent are added into the mixing kettle and stirred to allow the carbon powder and conductive powder solvent to be fully mixed; S3. After the carbon powder and conductive powder solvent in step S2 are fused, adhesive (propylene glycol methyl ether) is added to the mixing kettle and stirred again until the adhesive is fully fused, thereby obtaining the desired coating.

[0019] Example 2:

[0020] A coating for the inner wall of an alkaline zinc-manganese battery steel casing, wherein the raw materials of the coating include the following components: an inorganic silicon-modified polyurea resin, a conductive powder (carbon-based conductive powder), a conductive powder solvent, an adhesive, and a pigment. The proportions of the raw materials of the coating, calculated by mass percentage, are as follows: 20% inorganic silicon-modified polyurea resin, 20% conductive powder, 55% conductive powder solvent, 3% adhesive, and 2% pigment, with the total proportion of the components being 100%. The preparation method of the coating comprises the following steps: S1. First, add the inorganic silicon modified polyurea resin to a mixing kettle, and heat and stir it in a temperature range of 45° C. to 80° C. using an electric stirring rod. Then, slowly add the pigment into the mixing kettle to uniformly mix the inorganic silicon modified polyurea resin and the pigment. The purpose of heating and stirring is to accelerate the diffusion rate of the pigment molecules so that the pigment molecules can quickly fuse with the inorganic silicon modified polyurea resin. S2. When the mixture in the mixing kettle in step S1 is naturally cooled to room temperature, carbon powder and conductive powder solvent are added into the mixing kettle and stirred to allow the carbon powder and conductive powder solvent to be fully mixed; S3. After the carbon powder and conductive powder solvent in step S2 are fused, adhesive (propylene glycol methyl ether) is added to the mixing kettle and stirred again until the adhesive is fully fused, thereby obtaining the desired coating.

[0021] Example 3:

[0022] A coating for the inner wall of an alkaline zinc-manganese battery steel casing, wherein the raw materials of the coating include the following components: an inorganic silicon-modified polyurea resin, a conductive powder (carbon-based conductive powder), a conductive powder solvent, an adhesive, and a pigment. The proportions of the raw materials of the coating, calculated by mass percentage, are as follows: 25% inorganic silicon-modified polyurea resin, 15% conductive powder, 55% conductive powder solvent, 3% adhesive, and 2% pigment, with the total proportion of the components being 100%. The preparation method of the coating comprises the following steps: S1. First, add the inorganic silicon modified polyurea resin to a mixing kettle, and heat and stir it in a temperature range of 45° C. to 80° C. using an electric stirring rod. Then, slowly add the pigment into the mixing kettle to uniformly mix the inorganic silicon modified polyurea resin and the pigment. The purpose of heating and stirring is to accelerate the diffusion rate of the pigment molecules so that the pigment molecules can quickly fuse with the inorganic silicon modified polyurea resin. S2. When the mixture in the mixing kettle in step S1 is naturally cooled to room temperature, carbon powder and conductive powder solvent are added into the mixing kettle and stirred to allow the carbon powder and conductive powder solvent to be fully mixed; S3. After the carbon powder and conductive powder solvent in step S2 are fused, adhesive (propylene glycol methyl ether) is added to the mixing kettle and stirred again until the adhesive is fully fused, thereby obtaining the desired coating.

[0023] In the above technical solution, the coatings prepared by the methods of Example 1, Example 2 and Example 3 were applied to the inner wall of the steel shell of an alkaline zinc-manganese battery and the performance test was performed as follows: First, the prepared coating is evenly sprayed onto the inner wall of the alkaline zinc-manganese battery steel shell using a spraying device, and the inner wall of the alkaline zinc-manganese battery steel shell coated with the coating is heated using a heating device. At this time, the coating can harden due to heat absorption, so that the coating can adhere to the inner wall of the alkaline zinc-manganese battery steel shell; Next, during the heat-hardening process of the coating on the inner wall of the steel shell of the alkaline zinc-manganese battery, the hardening performance of the coating layer was tested and the hardening time of the coating was observed; Finally, 3M tape was used to conduct a pull-off test on the inner wall of the hardened alkaline zinc-manganese battery steel shell. Specifically, the 3M tape was attached to the inner wall of the alkaline zinc-manganese battery steel shell, and the tape was torn off. Then the peeling of the paint on the tape was observed. Generally, the qualification requirement of the battery factory is that the pull-off rate of the 3M tape is less than 5%.

[0024] The coating leveling performance test is based on the provisions of ASTM D4062-2024 "Test Method for Determination of Smoothness of Paint by Drawdown Method"; the higher the level on the leveling scale of 0 to 10, the better the leveling performance. The coating hardening performance test was conducted based on the provisions of GB / T 1728-1979 "Determination of Drying Time of Coatings and Putty Films"; for example, at 25° C., the hardening time of the coating in Example 1 was 90 seconds.

[0025] Based on the standard of "3M Tape Adhesion Test Method", the adhesion of the coating, that is, the pull-off rate, was tested. Under the same force, the pull-off rate of the coating in Example 1 was 0.5%.

[0026] Conductivity is assessed by measuring the surface or volume resistance of the coating based on GB / T 1410-2006 (Test method for volume resistivity and surface resistivity of solid electrical insulating materials). Coatings with good conductivity have a resistivity of 0.1-1 Ω·m. The lower the resistivity, the better the conductivity.

[0027] By applying the coatings prepared by the methods of Examples 1, 2, and 3 above to the inner wall of the steel case of an alkaline zinc-manganese battery for testing and comparison, it can be seen that the coating prepared by the method of Example 2, after being sprayed onto the inner wall of the steel case of the alkaline zinc-manganese battery, has the best adhesion (i.e., the 3M tape pull-off rate) and the shortest curing time. The comparative results of Examples 1, 2, and 3 are shown in the following table: Example 1 Example 2 Example 3 Leveling (grade) 7 8 8 Hardening time (S) 90 70 95 Pull-off rate (%) 0.5 0 0 Resistivity (Ω·m) 0.3 0.3 0.5 In the above scheme, it should be noted that: the proportions of the raw materials of the coating are as follows, calculated by mass percentage: 20% inorganic silicon-modified polyurea resin, 20% conductive powder, 55% conductive powder solvent, 3% adhesive, and 2% pigment, with the total proportion of the components being 100%. The prepared coating, after being sprayed onto the inner wall of the steel shell of an alkaline zinc-manganese battery, has a short curing time and the best adhesion (i.e., the coating layer does not fall off 100% when tested with a 3M tape). At the same time, the coating made of inorganic silicon modified polyurea resin and conductive powder solvent is very suitable for airless spraying process in battery factories. In addition, since the inorganic silicon modified polyurea resin contains carboxyl groups, it has good wettability to the substrate and conductive powder, good leveling, and uniform coating film. No dispersant and wetting agent are required. The coating has excellent adhesion and good protection for the inner wall of the steel shell of the alkaline zinc-manganese battery. In addition, the use of carbon as conductive powder can reduce the internal resistance of the battery due to its conductivity, thereby improving the discharge effect of the battery.

[0028] Example 4:

[0029] The difference between this embodiment and the second embodiment is that the raw materials of the inorganic silicon modified polyurea resin include the following components: polyurea resin, inorganic silicon material, modifier (organic silicon monomer) and inorganic mineral material (inorganic mineral powder). The proportions of the raw materials of the inorganic silicon modified polyurea resin are as follows, calculated by mass fraction: 75% polyurea resin, 15% inorganic silicon material, 5% modifier (organic silicon monomer) and 5% inorganic mineral material. The total proportion of the components is 100%. The preparation method of the inorganic silicon modified polyurea resin includes the following steps: (1) Prepare the reactants: Use weighing tools to weigh the raw materials required for the reaction one by one, and place the weighed raw materials aside for later use; (2) Mixing and heating: Add the prepared polyurea resin and inorganic silicon material gradually into the reactor in proportion, and gradually heat it to a predetermined temperature (temperature range is 90℃-120℃), and then stir it with a stirring mechanism to ensure that the polyurea resin and inorganic silicon material are fully mixed; (3) Adding modifier: When the temperature of the mixture in step (2) reaches 140°C, slowly add pre-weighed organosilicon monomer three times, each time with one-third of the amount, and the organosilicon monomer is used to improve the film-forming property and hydrophobicity of the resin; (4) Reaction and copolymerization: After adding the organosilicon monomer, react it at a temperature of 130℃-150℃ for 1h-3h to complete the copolymerization reaction; (5) Adding inorganic mineral materials: After the copolymerization reaction is completed, continue to add inorganic mineral powder to the reactor, which can enhance the wear resistance and corrosion resistance of the resin; (6) Vacuum distillation and cooling: The reaction mixture in the reactor is subjected to vacuum distillation to separate the small molecular substances in the system, that is, to separate the free formaldehyde, water and methanol mixture, which is used to improve the quality and purity of the resin. The reaction mixture is then cooled to room temperature by air cooling to obtain the desired inorganic silicon modified polyurea resin.

[0030] Embodiment 5:

[0031] The difference between this embodiment and the second embodiment is that the raw materials of the inorganic silicon modified polyurea resin include the following components: polyurea resin, inorganic silicon material, modifier (organic silicon monomer) and inorganic mineral material (inorganic mineral powder). The proportions of the raw materials of the inorganic silicon modified polyurea resin are as follows, calculated by mass fraction: 80% polyurea resin, 10% inorganic silicon material, 5% modifier (organic silicon monomer) and 5% inorganic mineral material. The total proportion of the components is 100%. The preparation method of the inorganic silicon modified polyurea resin includes the following steps: (1) Prepare the reactants: Use weighing tools to weigh the raw materials required for the reaction one by one, and place the weighed raw materials aside for later use; (2) Mixing and heating: Add the prepared polyurea resin and inorganic silicon material gradually into the reactor in proportion, and gradually heat it to a predetermined temperature (temperature range is 90℃-120℃), and then stir it with a stirring mechanism to ensure that the polyurea resin and inorganic silicon material are fully mixed; (3) Adding modifier: When the temperature of the mixture in step (2) reaches 140°C, slowly add pre-weighed organosilicon monomer three times, each time with one-third of the amount, and the organosilicon monomer is used to improve the film-forming property and hydrophobicity of the resin; (4) Reaction and copolymerization: After adding the organosilicon monomer, react it at a temperature of 130℃-150℃ for 1h-3h to complete the copolymerization reaction; (5) Adding inorganic mineral materials: After the copolymerization reaction is completed, continue to add inorganic mineral powder to the reactor, which can enhance the wear resistance and corrosion resistance of the resin; (6) Vacuum distillation and cooling: The reaction mixture in the reactor is subjected to vacuum distillation to separate the small molecular substances in the system, that is, to separate the free formaldehyde, water and methanol mixture, which is used to improve the quality and purity of the resin. The reaction mixture is then cooled to room temperature by air cooling to obtain the desired inorganic silicon modified polyurea resin.

[0032] Example 6:

[0033] The difference between this embodiment and the second embodiment is that the raw materials of the inorganic silicon modified polyurea resin include the following components: polyurea resin, inorganic silicon material, modifier (organic silicon monomer) and inorganic mineral material (inorganic mineral powder). The proportions of the raw materials of the inorganic silicon modified polyurea resin are as follows, calculated by mass fraction: 85% polyurea resin, 5% inorganic silicon material, 5% modifier (organic silicon monomer) and 5% inorganic mineral material. The total proportion of the components is 100%. The preparation method of the inorganic silicon modified polyurea resin includes the following steps: (1) Prepare the reactants: Use weighing tools to weigh the raw materials required for the reaction one by one, and place the weighed raw materials aside for later use; (2) Mixing and heating: Add the prepared polyurea resin and inorganic silicon material gradually into the reactor in proportion, and gradually heat it to a predetermined temperature (temperature range is 90℃-120℃), and then stir it with a stirring mechanism to ensure that the polyurea resin and inorganic silicon material are fully mixed; (3) Adding modifier: When the temperature of the mixture in step (2) reaches 140°C, slowly add pre-weighed organosilicon monomer three times, each time with one-third of the amount, and the organosilicon monomer is used to improve the film-forming property and hydrophobicity of the resin; (4) Reaction and copolymerization: After adding the organosilicon monomer, react it at a temperature of 130℃-150℃ for 1h-3h to complete the copolymerization reaction; (5) Adding inorganic mineral materials: After the copolymerization reaction is completed, continue to add inorganic mineral powder to the reactor, which can enhance the wear resistance and corrosion resistance of the resin; (6) Vacuum distillation and cooling: The reaction mixture in the reactor is subjected to vacuum distillation to separate the small molecular substances in the system, that is, to separate the free formaldehyde, water and methanol mixture, which is used to improve the quality and purity of the resin. The reaction mixture is then cooled to room temperature by air cooling to obtain the desired inorganic silicon modified polyurea resin.

[0034] The water resistance of coatings is tested based on the provisions of standard GB / T 1733-1993 "Water resistance test of paint films"; the higher the water resistance level among the 1 to 5 levels, the better the water resistance.

[0035] The abrasion resistance of coatings is tested based on the provisions of GB / T 1768-2006 "Determination of Scrub Resistance of Coating Films" and is tested under the conditions of 1000g / 1000 revolutions. For example, an abrasion resistance of 10mg means that the coating loses 10mg under the conditions of 1000g / 1000 revolutions. The higher the value, the worse the abrasion resistance.

[0036] Based on the provisions of GB / T 10125 "Test for Corrosion Resistance of Coatings", the coating is subjected to CASS test and rated by the percentage of corrosion area, which is divided into levels 1-5. Level 1 means no defects and level 5 means severe corrosion. The higher the level, the worse the corrosion resistance.

[0037] By applying the inorganic silicon-modified polyurea resin prepared by the methods of Examples 4, 5 and 6 above to the raw materials for preparing the coating, the prepared coatings were tested and compared. It can be seen that the inorganic silicon-modified polyurea resin prepared by the method of Example 5 is used as the raw material for the coating, and after the coating is sprayed on the inner wall of the alkaline zinc-manganese battery steel shell, the alkaline zinc-manganese battery steel shell has the best water resistance, wear resistance and corrosion resistance. The comparative results of Examples 4, 5 and 6 are shown in the following table: Example 4 Example 5 Example 6 Water resistance (grade) 4 5 5 Abrasion resistance (mg) 1 1 1.5 Corrosion resistance (grade) 1.5 1.5 1.8 In the above scheme, it should be noted that: the raw material ratios of the inorganic silicon-modified polyurea resin are as follows, calculated by mass percentage: 80% polyurea resin, 10% inorganic silicon material, 5% modifier (organic silicon monomer), and 5% inorganic mineral material, with the total ratio of each component being 100%. The prepared inorganic silicon-modified polyurea resin is applied to the raw materials of the coating. The produced coating is then sprayed on the inner wall of the steel shell of an alkaline zinc-manganese battery and tested. It is found that the inner wall of the steel shell of the alkaline zinc-manganese battery has the best water resistance, wear resistance, and corrosion resistance. At the same time, the polyurea resin is modified with inorganic silicon materials, so that the inorganic silicon-modified polyurea resin has some characteristics of both polyurea resin and inorganic silicon materials. For traditional polyurea resin, its adhesion ability is poor and the curing time is long, while the polyurea resin modified with inorganic silicon has the advantages of strong adhesion and short curing time, and further enhances the water resistance, wear resistance and corrosion resistance of the polyurea resin itself.

[0038] In summary, it can be seen that: in combination with Example 2 and Example 5 of the present application, the proportions of the raw materials of the coating are as follows, in terms of mass fraction percentage: inorganic silicon modified polyurea resin 20%, conductive powder 20%, conductive powder solvent 55%, adhesive 3% and pigment 2%, and the total proportion of each component is 100%. (Among them, the proportions of the raw materials of the inorganic silicon modified polyurea resin are as follows: polyurea resin 80%, inorganic silicon material 10%, modifier 5% and inorganic mineral material 5%, and the total proportion of each component is 100%). In the process of preparing the coating, Since the inorganic silicon modified polyurea resin contains carboxyl groups, it has good wettability to the substrate and conductive powder, good leveling properties, and a uniform coating film. There is no need to add dispersants, leveling agents, and wetting agents, thereby reducing the production cost of the coating. Moreover, after the prepared coating is sprayed onto the inner wall of the alkaline zinc-manganese battery steel shell, the coating layer has a short hardening time and the best adhesion (that is, when a pull-off test is performed using 3M tape, the coating layer does not fall off 100%). At the same time, the conductive properties, water resistance, wear resistance, and corrosion resistance of the inner wall of the alkaline zinc-manganese battery steel shell are also significantly enhanced.

[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and alterations may be made to these embodiments without departing from the principles of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coating for the inner wall of an alkaline zinc-manganese battery steel shell, characterized in that: The coating comprises the following components: inorganic silicon modified polyurea resin, conductive powder, conductive powder solvent, adhesive and pigment are mixed to obtain the coating, and inorganic material and polyurea resin are copolymerized and modified to obtain the inorganic silicon modified polyurea resin; Among them, the proportions of the raw materials of the coating are, in terms of mass fraction, inorganic silicon modified polyurea resin (15%-25%), conductive powder (15%-25%), conductive powder solvent (30%-60%), adhesive (1%-5%) and pigment (1%-5%), and the total proportion of each component is 100%.

2. The coating for the inner wall of the steel shell of the alkaline zinc-manganese battery according to claim 1, characterized in that: Calculated by mass percentage, the proportions of the raw materials of the coating are as follows: 20% inorganic silicon modified polyurea resin, 20% conductive powder, 55% conductive powder solvent, 3% adhesive and 2% pigment, and the total proportion of the components is 100%.

3. The coating for the inner wall of the steel shell of the alkaline zinc-manganese battery according to claim 1, characterized in that: The conductive powder is a carbon-based conductive powder, specifically carbon powder, and the carbon-based conductive powder is used to enhance the conductive performance of the coating. The adhesive is propylene glycol methyl ether.

4. The coating for the inner wall of the steel shell of the alkaline zinc-manganese battery according to claim 1, characterized in that: The raw materials of the inorganic silicon modified polyurea resin include the following components: polyurea resin, inorganic silicon material, modifier and inorganic mineral material, wherein the mass fractions of each component are polyurea resin (75%-85%), inorganic silicon material (5%-15%), modifier (1%-10%) and inorganic mineral material (1%-10%), and the total proportion of each component is 100%.

5. The coating for the inner wall of the steel shell of the alkaline zinc-manganese battery according to claim 4, characterized in that: Calculated by mass percentage, the raw material proportions of the inorganic silicon modified polyurea resin are as follows: polyurea resin 80%, inorganic silicon material 10%, modifier 5% and inorganic mineral material 5%, and the total proportion of each component is 100%.

6. The coating for the inner wall of the steel shell of the alkaline zinc-manganese battery according to claim 4, characterized in that: The method for obtaining the inorganic silicon-modified polyurea resin by copolymerization modification is specifically performed as follows: (1) Prepare the reactants: Use weighing tools to weigh the raw materials required for the reaction one by one, and place the weighed raw materials aside for later use; (2) Mixing and heating: gradually add the prepared polyurea resin and inorganic silicon material into the reactor in proportion, and gradually heat it to a predetermined temperature, so as to improve the reaction activity of the polyurea resin. Then, stir it with a stirring mechanism to ensure that the polyurea resin and the inorganic silicon material are fully mixed; (3) Adding modifier: When the mixture in step (2) reaches a certain temperature, slowly add the pre-weighed modifier three times, with one-third of the amount each time; (4) Reaction and copolymerization: After adding the modifier, it is allowed to react for a period of time within a specific temperature range to complete the copolymerization reaction; (5) Adding inorganic mineral materials: After the copolymerization reaction is completed, continue to add inorganic mineral materials to the reactor to enhance the performance of the resin; (6) Vacuum distillation and cooling: The reaction mixture in the reactor is subjected to vacuum distillation to separate small molecular substances in the system, that is, to separate free formaldehyde, water and methanol mixture, which is used to improve the quality and purity of the resin. The reaction mixture is then cooled to room temperature to obtain the desired inorganic silicon modified polyurea resin.

7. The coating for the inner wall of the steel shell of the alkaline zinc-manganese battery according to claim 6, characterized in that: In step (2), the predetermined temperature range of the reactor is 90°C-120°C. In step (3), the modifier is added when the temperature range of the mixture reaches about 140°C. In step (4), the temperature range of the copolymerization reaction is 130°C-150°C, and the copolymerization reaction time is 1h-3h. In step (6), the reaction mixture is cooled by air cooling.

8. The coating for the inner wall of the steel shell of the alkaline zinc-manganese battery according to claim 6, characterized in that: The modifier is an organic silicon monomer, and the modifier is used to improve the film-forming property and hydrophobicity of the resin. The inorganic mineral material is an inorganic mineral powder, and the inorganic mineral material is used to enhance the wear resistance and corrosion resistance of the resin.

9. A method for preparing a coating according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. First, add the inorganic silicon modified polyurea resin to a mixing kettle, heat and stir it, and then slowly add the pigment into the mixing kettle to uniformly mix the inorganic silicon modified polyurea resin and the pigment. The purpose of heating and stirring is to accelerate the diffusion rate of the pigment molecules so that the pigment molecules can quickly fuse with the inorganic silicon modified polyurea resin. S2. When the mixture in the mixing kettle in step S1 is naturally cooled to room temperature, conductive powder and conductive powder solvent are added into the mixing kettle and stirred to allow the conductive powder and conductive powder solvent to be fully mixed; S3. After the conductive powder and the conductive powder solvent are fused in step S2, the adhesive is continued to be added into the mixing kettle and stirred and mixed again until the adhesive is fully fused, thereby obtaining the desired coating.

10. The method for preparing the coating according to claim 9, characterized in that: In step S1, the temperature range of the heating and stirring is 45° C.-80° C., and an electric stirring rod is used for stirring.