Preparation method of a grinding aid activator for mineral powder and product thereof

Abstract

The application discloses a preparation method and product of a mineral powder grinding aid activator, relates to the technical field of mineral powder grinding aids, and comprises the following steps: modified alcohol amine preparation: adding trimellitic anhydride and triethanolamine into a first container; slowly adding a catalyst, after the dropping is completed, slowly dropping a mixed solution of triethanolamine and gamma-mercapto propyl trimethoxysilane into a reaction system, after the dropping is completed, adding deionized water, then slowly adding a neutralizing agent, neutralizing the reaction system to be neutral, and obtaining modified alcohol amine; graft polymerization: adding isoamyl alcohol polyoxyethylene ether, an initiator and deionized water into a second container, introducing high-purity nitrogen to remove oxygen, respectively dropping aqueous acrylic acid solution and aqueous reducing agent solution, slowly dropping the modified alcohol amine into the reaction system in the second container, after the dropping of the modified alcohol amine is completed, carrying out heat preservation reaction, completing covalent bond grafting, and obtaining the mineral powder grinding aid activator after neutralization. The application can form a novel grinding aid with the triple functions of grinding, dispersion and activation.

Description

Technical Field

[0001] This invention relates to the field of mineral powder grinding aid activators, and in particular to a method for preparing a mineral powder grinding aid activator and a product thereof. Background Technology

[0002] Mineral powder grinding aids are mainly used in the mineral powder grinding process to improve material dispersibility and reduce grinding resistance through physicochemical action, while also stimulating the gelling activity of mineral powder. Currently, mainstream mineral powder grinding aids on the market generally suffer from problems such as difficulty in synergistically achieving both grinding aid and activity stimulating functions, poor compatibility, and insufficient performance stability.

[0003] Traditional grinding aids such as triethanolamine have limited functions, focusing only on aiding grinding and reducing drag, and cannot efficiently activate the potential activity of mineral powders. They also have low product universality, making it difficult to adapt to different qualities of slag. At the same time, they can easily cause prolonged setting time and slow early strength development in mineral powder composite cementitious systems, and are greatly affected by fluctuations in dosage, raw materials and processes, which can easily lead to a decline in strength in the later stages. Some grinding aids contain chloride salts, which pose risks such as corrosion of steel bars and reduced durability, making it difficult to meet the needs of large-scale production of high-performance mineral powders and applications in green building materials.

[0004] Therefore, there is an urgent need to develop a mineral powder grinding aid that can simultaneously achieve efficient grinding assistance, activity activation, strong adaptability, stable performance, and safety and environmental protection. Summary of the Invention

[0005] This invention proposes a method and product for preparing a mineral powder grinding aid activator to solve the problems of existing mineral powder grinding aids, such as difficulty in achieving both grinding and activation effects, poor slag compatibility, imbalance in early and late strength development, insufficient performance stability, and safety hazards from chloride corrosion.

[0006] The present invention achieves the above objectives through the following technical solutions: This invention provides a method for preparing a mineral powder grinding aid activator, comprising: (1) Preparation of modified alkanolamine: Triphenyltricarboxylic anhydride and triethanolamine were added to the first container, the reaction system was stirred, and the temperature was slowly raised to 65-85℃. The anhydride opened the ring to form monoester / dieser, and the reaction system became clear or slightly turbid. Then the reaction system was cooled to 50-60℃, and the catalyst was slowly added dropwise. After the addition was completed, the mixture of triethanolamine and γ-mercaptopropyltrimethoxysilane was slowly added dropwise to the reaction system. After the addition was completed, the reaction was kept at 60-65℃. The reaction system was cooled to below 40℃, deionized water was added, and then a neutralizing agent was slowly added dropwise to neutralize the reaction system to neutrality, thus obtaining the modified alkanolamine. (2) Graft polymerization: Add isopentenyl alcohol polyoxyethylene ether, initiator and deionized water to the second container, stir, introduce high-purity nitrogen to remove oxygen, and then heat to 55-60℃ and keep constant temperature; add acrylic acid aqueous solution and reducing agent aqueous solution dropwise respectively. Before the acrylic acid aqueous solution and reducing agent aqueous solution are completely added, slowly add modified alkanolamine dropwise into the reaction system of the second container. After the modified alkanolamine is completely added, continue to keep the reaction at 60℃ to complete the covalent grafting; after the reaction is completed, cool the system naturally to below 40℃, and then add neutralizing agent to neutralize the system to neutrality to obtain mineral powder grinding aid activator.

[0007] Furthermore, in the raw materials for the preparation of modified alkanolamine, the molar ratio of the core components is trimellitic anhydride:triethanolamine:γ-mercaptopropyltrimethoxysilane = 1:(1.5-2.2):(1.0-1.2).

[0008] Furthermore, the triethanolamine added for the first time in the modified amine preparation step is 30%-50% of the total mass of triethanolamine.

[0009] Furthermore, in the modified alkanolamine preparation step, the amount of catalyst added is 1.0%-2.0% of the total mass of the corresponding modified alkanolamine preparation reaction system, and the amount of deionized water added is 10%-20% of the total mass of the corresponding modified alkanolamine preparation reaction system.

[0010] Furthermore, in the graft polymerization step, the mass ratio of isopentenyl alcohol polyoxyethylene ether to acrylic acid is 4:1-5:1.

[0011] Furthermore, in the graft polymerization step, the total amount of initiator is 0.5%-2.0% of the mass of isopentenyl alcohol polyoxyethylene ether, the reducing agent is 20%-30% of the total mass of initiator, and the amount of deionized water added is 40%-50% of the total mass of the system.

[0012] Furthermore, in the graft polymerization step, the amount of modified alkanolamine added is 20%-30% of the mass of isopentenyl alcohol polyoxyethylene ether.

[0013] Furthermore, in the graft polymerization step, the modified alkanolamine is slowly added dropwise into the reaction system when the acrylic acid aqueous solution and the reducing agent aqueous solution are added dropwise to 90%-95% or 10-15 minutes before the addition is completed.

[0014] Furthermore, the catalyst is concentrated sulfuric acid, the neutralizing agent is sodium hydroxide solution, the initiator is ammonium persulfate and hydrogen peroxide, and the reducing agent is vitamin C.

[0015] This invention discloses a mineral powder grinding aid activator, which is prepared by the aforementioned method for preparing a mineral powder grinding aid activator.

[0016] The present invention also provides a mineral powder grinding aid activator, which is prepared by the aforementioned method for preparing a mineral powder grinding aid activator.

[0017] The beneficial effects of this invention are as follows: This invention proposes a method and product for preparing a mineral powder grinding aid activator. By custom-synthesizing a thiol-functionalized modified alkanolamine intermediate, and utilizing the high chain transfer characteristics of thiol groups in free radical polymerization, the modified alkanolamine is precisely grafted onto the end of a polycarboxylate superplasticizer macromolecular chain with active growth free radicals via CS covalent bonds, forming a novel grinding aid with a single molecule that has the triple functions of grinding aid, dispersion, and activation. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] The specific embodiments of the present invention will be described in detail below.

[0021] Example 1 A method for preparing a mineral powder grinding aid activator, wherein the molar ratio of the core components in the raw materials is: trimellitic anhydride: triethanolamine: γ-mercaptopropyltrimethoxysilane = 1:1.7:1.1, and the amount of modified alkanolamine is 20% of the mass of isopentenyl alcohol polyoxyethylene ether. The specific preparation steps are as follows: 1.1 Preparation of modified alcoholamines.

[0022] Prepare raw materials: by weight, trimellitic anhydride: 192 parts, triethanolamine: 255 parts, γ-mercaptopropyltrimethoxysilane: 242 parts, 98% concentrated sulfuric acid: 15 parts, deionized water: 150 parts, 30% sodium hydroxide solution: 5 parts.

[0023] In a reactor (i.e., the first container) equipped with a stirrer, thermometer, and constant-pressure dropping funnel, 192 parts of trimellitic anhydride and 40% of the total mass of triethanolamine were added. The stirrer was started at 400 r / min, and the temperature was raised to 75°C and maintained for 1.0 h. The temperature was then lowered to 60°C, and concentrated sulfuric acid catalyst was slowly added dropwise at a rate of 2 drops / second to prevent local overheating and carbonization. After the addition was complete, the remaining mixture of triethanolamine and γ-mercaptopropyltrimethoxysilane was slowly added dropwise to the reaction system over 2.0 h through the constant-pressure dropping funnel. After the addition was complete, the reaction was maintained at 62°C for 4.0 h. The temperature was then cooled to below 40°C, and the pH of the system was adjusted to 7.0 to obtain a modified amine with a solid content of 65%.

[0024] 1.2 Grafting polymerization.

[0025] 1.21. Preliminary preparation: In a three-necked flask equipped with a stirrer, thermometer, constant pressure dropping funnel and nitrogen inlet tube, add 320 parts of isopentenyl alcohol polyoxyethylene ether (number average molecular weight Mn=2400), 3.2 parts of 30% hydrogen peroxide, 3.2 parts of ammonium persulfate and 300 parts of deionized water. Start stirring at 500 r / min. Purge with high-purity nitrogen at a flow rate of 0.8 L / min for 30 min to remove oxygen. Then raise the temperature to 58℃ and maintain a constant temperature.

[0026] 1.22. Two-liquid co-dropping: Two constant-pressure dropping funnels were opened simultaneously, and 86.4 parts of solution A (in which the mass ratio of acrylic acid to water in solution A is 1:1) and 38.4 parts of solution B (solution B is obtained by diluting vitamin C with water 20 times) were added dropwise. The addition of solutions A and B was completed in 2.5 hours, and the system temperature was maintained at 58°C and nitrogen protection was maintained throughout the process.

[0027] 1.23. Grafting reaction: When the total amount is added to 90%, 64 parts of modified alkanolamine are slowly added dropwise to the reaction system over a period of 20 minutes. After the addition is complete, the reaction is continued at 60°C for 2.0 hours. After the reaction is completed, the system is naturally cooled to 40°C and neutralized to pH 6.8 with 3.5 parts of 30% sodium hydroxide solution to obtain a grafted highly dispersed mineral powder grinding aid with a solid content of 52%.

[0028] Example 2 The difference between Example 2 and Example 1 is that in Example 2, the molar ratio of the core components of the raw materials in the modified alkanolamine preparation step is trimellitic anhydride:triethanolamine:γ-mercaptopropyltrimethoxysilane = 1:1.7:1.1, the amount of modified alkanolamine used in the graft polymerization step is 25% of the mass of isopentenyl alcohol polyoxyethylene ether, and the solid content of the final product is 55%.

[0029] Example 3 The difference between Example 3 and Example 1 is that in Example 3, the molar ratio of the core components of the raw materials in the modified alkanolamine preparation step is trimellitic anhydride:triethanolamine:γ-mercaptopropyltrimethoxysilane = 1:1.7:1.1, the amount of modified alkanolamine used in the graft polymerization step is 30% of the mass of isopentenyl alcohol polyoxyethylene ether, and the solid content of the final product is 58%.

[0030] Example 4 The difference between Example 4 and Example 1 is as follows: In Example 4, the molar ratio of the core components in the raw materials in the modified alkanolamine preparation step was trimellitic anhydride: triethanolamine: γ-mercaptopropyltrimethoxysilane = 1:1.9:1.1, and the amount of modified alkanolamine used in the graft polymerization step was 20% of the mass of isopentenyl alcohol polyoxyethylene ether.

[0031] In the preparation steps of the modified alkanolamine in Example 4, the following components were used by weight: 192 parts trimellitic anhydride, 285 parts triethanolamine, 242 parts γ-mercaptopropyltrimethoxysilane, 15 parts concentrated sulfuric acid (98% by mass), 150 parts deionized water, and 5 parts sodium hydroxide solution (30% by mass). The preparation process was the same as in Example 1, yielding a modified alkanolamine with a solid content of 65%.

[0032] In Example 4, the amount of modified alkanolamine used in the graft polymerization step was 20% of the mass of isopentenyl alcohol polyoxyethylene ether, and the rest of the process was the same as in Example 1. The final product had a solid content of 52%.

[0033] Example 5 The difference between Example 5 and Example 1 is: In Example 5, the molar ratio of the core components in the raw materials in the modified alkanolamine preparation step was trimellitic anhydride: triethanolamine: γ-mercaptopropyltrimethoxysilane = 1:1.9:1.1, and the amount of modified alkanolamine used in the graft polymerization step was 25% of the mass of isopentenyl alcohol polyoxyethylene ether.

[0034] In the preparation steps of the modified alkanolamine in Example 5, the following components were used by weight: trimellitic anhydride: 192 parts, triethanolamine: 285 parts, γ-mercaptopropyltrimethoxysilane: 242 parts, 98% concentrated sulfuric acid: 15 parts, deionized water: 150 parts, and 30% sodium hydroxide solution: 5 parts. The preparation process was the same as in Example 1, yielding a modified alkanolamine with a solid content of 65%.

[0035] In the graft polymerization step of Example 5, the amount of modified alkanolamine used was 20% of the mass of isopentenyl alcohol polyoxyethylene ether, and the rest of the process was the same as in Example 1. The final product had a solid content of 55%.

[0036] Example 6 The difference between Example 6 and Example 1 is: In Example 6, the molar ratio of the core components of the raw materials in the preparation step of the modified alkanolamine was trimellitic anhydride:triethanolamine:γ-mercaptopropyltrimethoxysilane = 1:1.9:1.1. The amount of modified alkanolamine used in the graft polymerization step was 30% of the mass of isopentenyl alcohol polyoxyethylene ether, and the solid content of the final product was 58%.

[0037] Example 7 The difference between Example 7 and Example 1 is as follows: In Example 7, the molar ratio of the core raw material components in the modified alkanolamine preparation step was trimellitic anhydride: triethanolamine: γ-mercaptopropyltrimethoxysilane = 1:2.1:1.1, and the amount of modified alkanolamine used in the graft polymerization step was 20% of the mass of isopentenyl alcohol polyoxyethylene ether.

[0038] In the preparation steps of the modified alkanolamine in Example 7, by weight, the following components were used: trimellitic anhydride: 192 parts, triethanolamine: 315 parts, γ-mercaptopropyltrimethoxysilane: 242 parts, 98% concentrated sulfuric acid: 15 parts, deionized water: 150 parts, and 30% sodium hydroxide solution: 5 parts. The preparation process was the same as in Example 1, yielding a modified alkanolamine with a solid content of 65%.

[0039] In the graft polymerization step of Example 7, the amount of modified alkanolamine used was 20% of the mass of isopentenyl alcohol polyoxyethylene ether, and the rest of the process was the same as in Example 1. The final product had a solid content of 52%.

[0040] Example 8 The difference between Example 8 and Example 1 is: In Example 8, the molar ratio of the core components of the raw materials in the preparation step of the modified alkanolamine was trimellitic anhydride: triethanolamine: γ-mercaptopropyltrimethoxysilane = 1:2.1:1.1. The amount of modified alkanolamine used in the graft polymerization step was 20% of the mass of isopentenyl alcohol polyoxyethylene ether, and the solid content of the final product was 55%.

[0041] Example 9 The difference between Example 9 and Example 1 is as follows: In Example 9, the molar ratio of the core raw material components in the modified alkanolamine preparation step was trimellitic anhydride:triethanolamine:γ-mercaptopropyltrimethoxysilane = 1:2.1:1.1. In the graft polymerization step, the amount of modified alkanolamine used was 30% of the mass of isopentenyl alcohol polyoxyethylene ether, and the final product had a solid content of 58%.

[0042] Comparative Example 1 is basically the same as Example 5, except that: no graft polymerization step was performed, and only ordinary alcohol amine and polycarboxylate superplasticizer were physically mixed.

[0043] All cases used the same dosage: 0.06%.

[0044] In all cases, the dosage of the mineral powder grinding aid activator and the comparative grinding aid was 0.06% of the mineral powder mass; the following specific surface area and activity index improvement values ​​were compared with conventional commercially available grinding aids as the benchmark. The test results are shown in Table 1 below.

[0045] Table 1

[0046] Under the same dosage of 0.06%, compared with conventional grinding aids, the present invention can significantly increase the specific surface area of ​​mineral powder, and effectively improve the early activity index of mineral powder at 7 days and the late activity index at 28 days, resulting in better grinding effect and more excellent mineral powder strength enhancement effect.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a mineral powder grinding aid activator, characterized in that, include: (1) Preparation of modified alkanolamine: Triphenyltricarboxylic anhydride and triethanolamine were added to the first container, the reaction system was stirred, and the temperature was slowly raised to 65-85℃. The anhydride opened the ring to form monoester / dieser, and the reaction system became clear or slightly turbid. Then the reaction system was cooled to 50-60℃, and the catalyst was slowly added dropwise. After the addition was completed, the mixture of triethanolamine and γ-mercaptopropyltrimethoxysilane was slowly added dropwise to the reaction system. After the addition was completed, the reaction was kept at 60-65℃. The reaction system was cooled to below 40℃, deionized water was added, and then a neutralizing agent was slowly added dropwise to neutralize the reaction system to neutrality, thus obtaining the modified alkanolamine. (2) Graft polymerization: Add isopentenyl alcohol polyoxyethylene ether, initiator and deionized water to the second container, stir, introduce high-purity nitrogen to remove oxygen, and then heat to 55-60℃ and keep constant temperature; add acrylic acid aqueous solution and reducing agent aqueous solution dropwise respectively. Before the acrylic acid aqueous solution and reducing agent aqueous solution are completely added, slowly add modified alkanolamine dropwise into the reaction system of the second container. After the modified alkanolamine is completely added, continue to keep the reaction at 60℃ to complete the covalent grafting; after the reaction is completed, cool the system naturally to below 40℃, and then add neutralizing agent to neutralize the system to neutrality to obtain mineral powder grinding aid activator.

2. The method for preparing a mineral powder grinding aid activator according to claim 1, characterized in that, In the preparation step of modified alkanolamine, the molar ratio of the core components in the raw materials is trimellitic anhydride:triethanolamine:γ-mercaptopropyltrimethoxysilane = 1:(1.5-2.2):(1.0-1.2).

3. The method for preparing a mineral powder grinding aid activator according to claim 1, characterized in that, In the preparation step of modified alkanolamine, the triethanolamine added for the first time is 30%-50% of the total mass of triethanolamine.

4. The method for preparing a mineral powder grinding aid activator according to claim 1, characterized in that, In the modified alkanolamine preparation step, the amount of catalyst added is 1.0%-2.0% of the total mass of the corresponding modified alkanolamine preparation reaction system, and the amount of deionized water added is 10%-20% of the total mass of the modified alkanolamine preparation reaction system.

5. The method for preparing a mineral powder grinding aid activator according to claim 1, characterized in that, In the graft polymerization step, the mass ratio of isopentenyl alcohol polyoxyethylene ether to acrylic acid is 4:1-5:

1.

6. The method for preparing a mineral powder grinding aid activator according to claim 1, characterized in that, In the graft polymerization step, the total amount of initiator is 0.5%-2.0% of the mass of isopentenyl alcohol polyoxyethylene ether, the reducing agent is 20%-30% of the total mass of initiator, and the amount of deionized water added is 40%-50% of the total mass of the system.

7. The method for preparing a mineral powder grinding aid activator according to claim 1, characterized in that, In the graft polymerization step, the amount of modified alkanolamine added is 20%-30% of the mass of isopentenyl alcohol polyoxyethylene ether.

8. The method for preparing a mineral powder grinding aid activator according to claim 1, characterized in that, In the graft polymerization step, the modified alkanolamine is slowly added dropwise into the reaction system when the acrylic acid aqueous solution and the reducing agent aqueous solution are added dropwise to 90%-95% or 10-15 minutes before the addition is completed.

9. The method for preparing a mineral powder grinding aid activator according to claim 1, characterized in that, The catalyst is concentrated sulfuric acid, the neutralizing agent is sodium hydroxide solution, the initiator is ammonium persulfate and hydrogen peroxide, and the reducing agent is vitamin C.

10. A mineral powder grinding aid activator, characterized in that, The mineral powder grinding aid activator is prepared by any one of the preparation methods of mineral powder grinding aid activator according to claims 1-9.

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