Preparation method of acrylic resin, supergravity reaction device and application method

Abstract

The invention provides a preparation method of acrylic resin, a supergravity reaction device and an application method.The preparation method comprises the steps that S100, water and an initiator are placed in the supergravity reaction device, and a first mixed solution is obtained; s200, adding an acrylic monomer into the first mixed solution, and carrying out heat preservation to obtain a second mixed solution; s300, adjusting the pH value of the second mixed solution to be neutral to obtain acrylic resin; wherein the supergravity reaction device comprises a supergravity machine. According to the preparation method of the acrylic resin, the molecular weight and viscosity of the acrylic resin can be accurately controlled, the molecular weight distribution of a polymer is narrow, the filling performance on leather is good, the quality of a leather product is effectively improved, the requirement of the market for high-performance leather is met, and the preparation method has important significance for promoting progress and development of the whole industry.

Description

Technical Field

[0001] The invention relates to the technical field of leather auxiliaries, and in particular to a preparation method of acrylic resin, a supergravity reaction device and an application method. Background Art

[0002] Retanning agents are mainly used for filling and modification of leather. By retanning the leather in the leather making process, the quality of the tanned leather can be further improved, making the finished leather plump, soft, and having better flexibility and elasticity. In the traditional leather making industry, polymer resin retanning agents have been widely used due to their mature preparation and application processes, and their advantages such as many active groups and good structural adjustability. They are currently the most used retanning materials.

[0003] Acrylic polymers with a molecular weight of 10,000-20,000 are generally used as retanning agents, i.e., acrylic resin retanning agents. The molecular weight, molecular weight distribution, and solid content of acrylic resin retanning agents have a great influence on the filling effect of the leather blank and the appearance of the leather after tanning, so the quality of acrylic resin retanning agents largely determines the quality of the leather. However, acrylic acid polymerization reaction rate is fast and the product performance controllability is poor, which limits its development in the retanning agent industry. Therefore, it is urgent to develop a method for preparing acrylic resin, and the obtained acrylic resin product has stable and controllable performance to reduce its adverse effects on leather due to uncontrollable product performance. Summary of the invention

[0004] The problem solved by the present invention is to provide a method for preparing an acrylic resin, which can accurately control the molecular weight and viscosity of the acrylic resin, and the polymer molecular weight distribution is narrow, has good filling performance for leather, effectively improves the quality of leather products, meets the market demand for high-performance leather, and is of great significance for promoting the progress and development of the entire industry.

[0005] To this end, the first object of the present invention is to provide a method for preparing acrylic resin.

[0006] The second object of the present invention is to provide a supergravity reaction device.

[0007] The third object of the present invention is to provide an application method of acrylic resin.

[0008] To achieve the first objective of the present invention, the technical solution of the present invention provides a method for preparing an acrylic resin, comprising: S100, placing water and an initiator in a supergravity reaction device to obtain a first mixed liquid; S200, adding an acrylic monomer to the first mixed liquid, keeping it warm, to obtain a second mixed liquid; S300, adjusting the pH value of the second mixed liquid to neutral to obtain an acrylic resin; wherein the supergravity reaction device comprises a supergravity machine.

[0009] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the present invention first mixes water and initiator evenly to create good conditions for the subsequent polymerization reaction; then, the monomer and the initiator in the first mixed solution are quickly mixed in a very short time, on the one hand, providing a uniform concentration field, and on the other hand, the heat transfer is enhanced by the supergravity reaction device, the internal liquid temperature of the reaction device is effectively controlled, and the "gel effect" caused by local overheating is prevented; finally, by adjusting the pH value of the second mixed solution, the stability of the acrylic resin is regulated to ensure that the acrylic resin will not have acid-base imbalance during storage and use. The present invention combines supergravity technology with the mechanism of free radical polymerization to enhance molecular mixing, mass transfer and heat transfer, thereby effectively regulating the molecular weight, molecular weight distribution and solid content of the polymer.

[0010] In one technical solution of the present invention, in parts by mass, water:initiator:monomer=(80-120):(0.7-1.1):(45-60).

[0011] Compared with the prior art, the technical effect achieved by adopting the technical scheme is as follows: the preparation method of acrylic resin of the present invention can regulate the molecular weight, molecular weight distribution and solid content of the polymer to a certain extent by regulating the raw material feed ratio, thereby meeting the application scenario requirements of the retanning agent. Water is used as a reaction medium, and the amount of water will affect the concentration and reaction rate of the reactants. Properly increasing the amount of water can increase the solubility of the reactants and promote the polymerization reaction, but too much water may cause the viscosity of the polymer to decrease, affecting the quality of the product; the initiator can quickly generate free radicals to initiate the polymerization reaction. The amount of initiator needs to be precisely controlled, and too much or too little will affect the molecular weight and molecular weight distribution of the polymer; the purity and feed amount of the monomer directly affect the quality and performance of the polymer. The present invention strengthens the free radical polymerization reaction process and the heat transfer process through an ultra-gravity device, and regulates the molecular weight, molecular weight distribution and solid content of the acrylic resin; by adjusting the feed amount of the monomer, the molecular weight and solid content of the polymer are synergistically controlled, the performance of the product is further improved, and the controllability and safety of the production process are enhanced, which has guiding significance for industrial applications.

[0012] In a technical solution of the present invention, in S100, the rotation speed of the ultra-gravity machine reaction device is set to 300rpm-1500rpm; in S100, the temperature of the first mixed liquid is 75°C-100°C.

[0013] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: In step S100, water and initiator are placed in a supergravity reaction device, and the speed of the supergravity machine is set to 300rpm-1500rpm, in order to ensure that the initiator and water can be fully mixed to form a uniform first mixed liquid to regulate the molecular weight, molecular weight distribution and solid content of the polymer. At the same time, this speed range also helps to control the reaction temperature and pressure and prevent the occurrence of side reactions. In step S100, the temperature of the first mixed liquid is controlled between 75°C and 100°C. Within this temperature range, the initiator can fully play its role and promote the polymerization reaction of the monomer, while avoiding the occurrence of side reactions and the decline of product performance caused by excessively high temperatures.

[0014] In a technical solution of the present invention, the type of initiator includes at least one of ammonium persulfate, potassium persulfate, 2,2-azobisisobutyronitrile and dimethyl azobisisobutyrate.

[0015] Compared with the prior art, the technical effect achieved by adopting this technical solution is: when selecting an initiator, it is necessary to comprehensively consider factors such as its decomposition rate constant, active oxygen content, critical temperature and activation energy. These parameters directly affect the performance and applicable conditions of the initiator, thereby determining the rate of the polymerization reaction and the quality of the product. The present invention uses ultra-gravity technology to strengthen free radical polymerization to prepare a molecular weight controllable acrylic resin. Ammonium persulfate, potassium persulfate, 2,2-azobisisobutyronitrile and dimethyl azobisisobutyrate are used as initiators, which are soluble in the reaction system, have good stability and high reaction efficiency, and can effectively control the polymerization reaction of acrylic monomers.

[0016] In one technical solution of the present invention, in S200, the dripping speed of the acrylic monomer is 0.5 mL / min-2 mL / min; in S200, the heat preservation time is 30 min-90 min.

[0017] Compared with the existing technology, the technical effect achieved by adopting this technical solution is as follows: the dripping speed of acrylic monomer is controlled between 0.5mL / min and 2mL / min. This speed range ensures the smooth progress of the polymerization reaction and avoids the problem of excessive molecular weight caused by too fast dripping or gel effect caused by too slow dripping; the insulation time is set to 30 minutes to 90 minutes. This time period is crucial to ensure that the monomer fully reacts and forms a high molecular weight polymer, and it also helps to improve the uniformity and stability of the product.

[0018] In one technical solution of the present invention, the type of acrylic monomer includes at least one of acrylic acid, acrylonitrile, butyl acrylate and ethyl methacrylate.

[0019] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: different acrylic monomers can provide different functional groups during the polymerization process to obtain polymerization products with different properties. Among the acrylic monomers selected by the present invention, acrylic acid can improve the resin's finishing properties on pigments and fillers and its adhesion to substrates; acrylonitrile has good weather resistance, can improve the UV resistance of the retanning agent resin, so that it has a longer service life when used outdoors, and at the same time increases the diversity of materials; butyl acrylate has good water resistance and alcohol resistance, improves the flexibility of the retanning agent resin, and promotes film formation; methacrylate can provide functional groups for cross-linking, enhance the multifunctionality of the resin, and has a positive effect on improving the flexibility of the retanning agent resin and promoting film formation, and has good water resistance and alcohol resistance; those skilled in the art can make a selection based on the types of acrylic monomers disclosed in this application in combination with specific application requirements.

[0020] In a technical solution of the present invention, S300 specifically includes: S310, cooling the second mixed liquid to the first reaction temperature, adding alkaline solution for neutralization reaction, S320, controlling the temperature during the addition to be not higher than the second reaction temperature, and after the addition is completed, keeping the temperature for a period of time and cooling to room temperature to obtain acrylic resin.

[0021] Compared with the prior art, the technical effect achieved by adopting the technical scheme is as follows: when the second mixed solution is cooled to the first reaction temperature, the temperature change needs to be monitored to ensure that the temperature is stable within a preset range to avoid the influence of too high or too low temperature on the product performance. When the alkali solution is added dropwise, the temperature is controlled not to be higher than the second reaction temperature in order to prevent the reaction from being too violent, resulting in side reactions or a decrease in product quality. After the addition is completed, the mixture is continued to be stirred and cooled to room temperature. This step helps to ensure that the reaction is complete and the properties of the final product are stable. By controlling the temperature and the dripping speed, the monomer polymerization reaction can be effectively avoided to be too fast or to release more heat, ensuring the stability and uniformity of the product. Appropriate reaction temperature and neutralization conditions help to improve the performance of acrylic resin, including mechanical properties, wear resistance and water resistance. Temperature control and appropriate stirring can reduce safety risks during the reaction and prevent problems such as thermal runaway. Through these steps, high-performance acrylic resin can be effectively synthesized to meet the needs of industrial applications.

[0022] In one technical solution of the present invention, in S310, the first reaction temperature is 35°C-45°C; in S320, the second reaction temperature is 40°C; in S320, the dropping time is 10min-90min; in S320, the insulation time is 10min-30min.

[0023] Compared with the prior art, the technical effect achieved by adopting the technical scheme is as follows: the present invention ensures the controllability of the reaction during the synthesis of the acrylic resin and the quality of the final product, strengthens the mixing degree of the polymerization reaction monomer and the free radical and the strong exothermic process of the reaction, and improves the uniformity and stability of the product, thereby obtaining an acrylic resin with a narrow molecular weight distribution and good stability.

[0024] In a technical solution of the present invention, the type of alkali solution includes at least one of sodium hydroxide, potassium hydroxide, ammonia water, potassium carbonate and triethanolamine.

[0025] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: each alkali solution selected by the present invention has its specific advantages: sodium hydroxide, as a strong alkalinity, can effectively neutralize acidic substances, is relatively cheap and easy to obtain; potassium hydroxide is similar to sodium hydroxide, but has a higher alkalinity and can achieve better reaction rate control; ammonia water is relatively mild alkalinity, easy to volatilize, and helps to remove it after the reaction; potassium carbonate is soluble in water, easy to control the progress of the neutralization reaction, and more environmentally friendly; triethanolamine is an organic base with good solubility, which helps the water solubility and stability of the resin. Above, those skilled in the art can make a selection according to the types of alkali solutions disclosed in this application in combination with specific application requirements.

[0026] To achieve the second purpose of the present invention, the technical solution of the present invention provides a hypergravity reaction device, including: a hypergravity machine of any of the above technical solutions; and a reactor, wherein the reactor is connected to the hypergravity machine.

[0027] Furthermore, the reactor is connected to the supergravity machine via a pump.

[0028] Furthermore, the reactor is connected to the ultra-gravity machine via a peristaltic pump.

[0029] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the supergravity reaction device of the present invention, by setting up a supergravity machine and a reactor, allows the raw materials of acrylic resin to be circulated and premixed in the reaction device, effectively improving the dispersibility of the initiator during the reaction process and reducing the implosion phenomenon during the heat preservation polymerization in the flask. This is not only meaningful for the process research of producing high-quality polyacrylic acid resin series products, but also develops broad application prospects for supergravity machines.

[0030] To achieve the third purpose of the present invention, the technical solution of the present invention provides an application method of acrylic resin, and the acrylic resin obtained by the preparation method of acrylic resin in any of the above technical solutions or the supergravity reaction device is used as a retanning agent.

[0031] Compared with the prior art, the technical effects achieved by adopting the technical scheme are as follows: the acrylic resin prepared by the preparation method of the present invention or the ultra-gravity reaction device is used as a retanning agent, and the molecular weight can be precisely controlled, the permeability and binding ability can be adjusted, so that it can be better combined with leather fibers and the retanning effect can be improved; it has more uniform physical and chemical properties, can provide a more consistent retanning effect, and avoid performance fluctuations caused by molecular weight differences; it improves the softness, fullness and mechanical strength of the leather, while maintaining good air permeability and aging resistance; and significantly improves the quality and processing performance of the leather. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic structural diagram of a supergravity reaction device provided in an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 100-supergravity reaction device; 110-supergravity machine; 120-reactor; 130-pump. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0036] Refer to the following Figure 1 The technical solutions of some embodiments of the present invention are described.

[0037] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising: S100, placing water and an initiator in a supergravity reaction device, setting the speed of the supergravity machine to 300rpm-1500rpm, heating to a temperature of 75°C-100°C, and obtaining a first mixed solution; S200, dropping an acrylic monomer into the first mixed solution at a speed of 0.5mL / min-2mL / min, and keeping the temperature for 30min-90min to obtain a second mixed solution; S300, cooling the second mixed solution to 35°C-45°C, dropping an alkali solution to carry out a neutralization reaction until the pH value is neutral, and controlling the temperature during the dropping to be no higher than 40°C, the dropping time is 10min-90min, and after the dropping is completed, keeping the temperature for 10min-30min, and cooling to room temperature to obtain an acrylic resin; wherein the supergravity reaction device comprises a supergravity machine; in terms of mass parts, water:initiator:monomer=(80-120):(0.7-1.1):(45-60).

[0038] For example, the type of initiator includes at least one of ammonium persulfate, potassium persulfate, 2,2-azobisisobutyronitrile and dimethyl azobisisobutyrate;

[0039] For example, the type of acrylic monomer includes at least one of acrylic acid, acrylonitrile, butyl acrylate and ethyl methacrylate;

[0040] For example, the type of alkali solution includes at least one of sodium hydroxide, potassium hydroxide, ammonia water, potassium carbonate and triethanolamine.

[0041] The molecular weight of acrylic acid polymers determines the purpose of acrylic acid polymers. During production, the molecular weight can be controlled by changing the process according to the needs. Low molecular weight acrylic acid polymers and their salts with a molecular weight of 500-5000 are mainly used as dispersants, etc.; 4 -10 6 Medium molecular weight acrylic acid polymers and their salts are mainly used as thickeners, etc. 6 -10 7 High molecular weight acrylic polymers and their salts are mainly used as water absorbents, etc.; acrylic polymers with a molecular weight of 10,000-20,000 are generally used as retanning agents, namely acrylic resin retanning agents.

[0042] The polymerization reaction rate of acrylic acid is fast, and the product performance controllability is poor. However, the quality of the leather after tanning is highly dependent on the quality of the retanning agent. Based on this problem, the present invention develops a preparation method of acrylic resin, which combines ultra-gravity technology with a free radical polymerization mechanism, can accurately control the molecular weight and viscosity of the acrylic resin, and the polymer molecular weight distribution is narrow, which solves the problem that restricts the development of acrylic resin in the retanning agent industry and promotes the progress of the polymer resin retanning agent industry.

[0043] In some implementations of the embodiments of the present application, the embodiments of the present invention further provide a hypergravity reaction device 100 , comprising: the hypergravity machine 110 of any of the above embodiments; and a reactor 120 , wherein the reactor 120 is connected to the hypergravity machine 110 .

[0044] For example, the reactor 120 is connected to the ultra-gravity machine 110 via a pump 130 .

[0045] For example, the reactor 120 is connected to the ultra-gravity machine 110 via a peristaltic pump.

[0046] The microscopic process of free radical polymerization can be completed in only 0.1-1s. It is a fast reaction, and its characteristic rate is generally greater than or equal to the rate of microscopic mixing. For fast reactions, the degree of microscopic mixing can have a direct impact on the molecular weight and molecular weight distribution of the polymer product, and at the same time has an impact on whether the reaction points in the reaction equipment are generated, how many are generated, and the polymorphic phenomenon, and is closely related. The average residence time of the polymerization reaction in a conventional stirred tank reactor is long, and the use of the supergravity reaction device of the present invention can shorten the average residence time of the reaction, and the microscopic mixing capacity is greatly enhanced, thereby promoting the mass transfer and heat transfer rate of the reaction in the equipment.

[0047] [Example 1]

[0048] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0049] S100, placing water and ammonium persulfate in a supergravity reaction device, setting the speed of the supergravity machine to 900 rpm, heating to a temperature of 85° C., and obtaining a first mixed solution;

[0050] S200, adding acrylic acid dropwise to the first mixed solution at a rate of 1 mL / min, and keeping the mixture warm for 30 min to obtain a second mixed solution;

[0051] S300, cooling the second mixed solution to 40°C, adding sodium hydroxide solution dropwise to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the addition, the addition time is 30 minutes, and after the addition is completed, the temperature is kept for 10 minutes and cooled to room temperature to obtain acrylic resin 1#;

[0052] The supergravity reaction device includes a supergravity machine; in terms of mass, water: ammonium persulfate: acrylic acid = 90:1:50.

[0053] [Example 2]

[0054] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0055] S100, placing water and ammonium persulfate in a supergravity reaction device, setting the speed of the supergravity machine to 1500 rpm, heating to a temperature of 85° C., and obtaining a first mixed solution;

[0056] S200, adding butyl acrylate to the first mixed solution at a rate of 1 mL / min, and keeping the mixture warm for 90 min to obtain a second mixed solution;

[0057] S300, cooling the second mixed solution to 45°C, adding sodium hydroxide solution dropwise to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the addition, the addition time is 30 minutes, and after the addition is completed, the temperature is kept for 20 minutes and then cooled to room temperature to obtain acrylic resin 2#;

[0058] Among them, the supergravity reaction device includes a supergravity machine; in terms of mass, water: ammonium persulfate: butyl acrylate = 90:1:50.

[0059] [Example 3]

[0060] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0061] S100, placing water and potassium persulfate in a supergravity reaction device, setting the speed of the supergravity machine to 900 rpm, heating to a temperature of 100° C., and obtaining a first mixed solution;

[0062] S200, adding butyl acrylate to the first mixed solution at a rate of 1 mL / min, and keeping the mixture warm for 30 min to obtain a second mixed solution;

[0063] S300, cooling the second mixed solution to 40°C, adding potassium hydroxide solution dropwise to carry out neutralization reaction until the pH value is neutral, and controlling the temperature during the addition to be no higher than 35°C, the adding time is 30 minutes, and after the addition is completed, keeping the temperature for 20 minutes, and cooling to room temperature to obtain acrylic resin 3#;

[0064] Among them, the supergravity reaction device includes a supergravity machine; in terms of mass, water: potassium persulfate: butyl acrylate = 90:1:50.

[0065] [Example 4]

[0066] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0067] S100, placing water and dimethyl azobisisobutyrate in a supergravity reaction device, setting the speed of the supergravity machine to 300 rpm, heating to a temperature of 85° C., and obtaining a first mixed solution;

[0068] S200, adding butyl acrylate to the first mixed solution at a rate of 0.5 mL / min, and keeping the mixture warm for 60 min to obtain a second mixed solution;

[0069] S300, cooling the second mixed solution to 45°C, dropping triethanolamine solution to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the dropping, the dropping time is 30 minutes, and after the dropping is completed, keeping the temperature for 20 minutes, and cooling to room temperature to obtain acrylic resin 4#;

[0070] The supergravity reaction device includes a supergravity machine; in terms of mass, water: dimethyl azobisisobutyrate: butyl acrylate = 120:0.7:50.

[0071] [Example 5]

[0072] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0073] S100, placing water and dimethyl azobisisobutyrate in a supergravity reaction device, setting the speed of the supergravity machine to 1500 rpm, and heating to a temperature of 85° C. to obtain a first mixed solution;

[0074] S200, adding butyl acrylate to the first mixed solution at a rate of 1 mL / min, and keeping the mixture warm for 30 min to obtain a second mixed solution;

[0075] S300, cooling the second mixed solution to 40°C, dropping potassium carbonate solution to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the dropping, the dropping time is 30 minutes, and after the dropping is completed, keeping the temperature for 30 minutes, and cooling to room temperature to obtain acrylic resin 5#;

[0076] The supergravity reaction device includes a supergravity machine; in terms of mass, water: dimethyl azobisisobutyrate: butyl acrylate = 120:1.1:60.

[0077] [Example 6]

[0078] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0079] S100, placing water and dimethyl azobisisobutyrate in a supergravity reaction device, setting the speed of the supergravity machine to 600 rpm, heating to a temperature of 83° C., and obtaining a first mixed solution;

[0080] S200, adding ethyl methacrylate dropwise to the first mixed solution at a rate of 1.5 mL / min, and keeping the mixture warm for 45 min to obtain a second mixed solution;

[0081] S300, cooling the second mixed solution to 40°C, adding sodium hydroxide solution dropwise to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the addition, the addition time is 30 minutes, and after the addition is completed, the temperature is kept for 20 minutes and cooled to room temperature to obtain acrylic resin 6#;

[0082] Among them, the supergravity reaction device includes a supergravity machine; in terms of mass, water: dimethyl azobisisobutyrate: ethyl methacrylate = 100: 1.1: 55.

[0083] [Example 7]

[0084] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0085] S100, placing water and potassium persulfate in a supergravity reaction device, setting the speed of the supergravity machine to 900 rpm, heating to a temperature of 87° C., and obtaining a first mixed solution;

[0086] S200, adding acrylonitrile and acrylic acid mixed solution to the first mixed solution at a rate of 1 mL / min, and keeping the temperature for 50 min to obtain a second mixed solution;

[0087] S300, cooling the second mixed solution to 40°C, adding sodium hydroxide solution dropwise to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the addition, the addition time is 30 minutes, and after the addition is completed, the temperature is kept for 20 minutes and cooled to room temperature to obtain acrylic resin 7#;

[0088] The supergravity reaction device includes a supergravity machine; in terms of mass, water: potassium persulfate: acrylonitrile and acrylic acid mixed solution = 120:1.1:60.

[0089] [Example 8]

[0090] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0091] S100, placing water and dimethyl azobisisobutyrate in a supergravity reaction device, setting the speed of the supergravity machine to 900 rpm, heating to a temperature of 83° C., and obtaining a first mixed solution;

[0092] S200, adding butyl acrylate to the first mixed solution at a rate of 0.8 mL / min, and keeping the mixture warm for 60 min to obtain a second mixed solution;

[0093] S300, cooling the second mixed solution to 40°C, adding sodium hydroxide solution dropwise to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the addition, the addition time is 30 minutes, and after the addition is completed, the temperature is kept for 20 minutes and cooled to room temperature to obtain acrylic resin 8#;

[0094] Among them, the supergravity reaction device includes a supergravity machine; in terms of mass, water: dimethyl azobisisobutyrate: butyl acrylate = 100:1:50.

[0095] [Example 9]

[0096] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0097] S100, placing water and 2,2-azobisisobutyronitrile in a supergravity reaction device, setting the speed of the supergravity machine to 900 rpm, heating to a temperature of 85° C., and obtaining a first mixed solution;

[0098] S200, adding butyl acrylate to the first mixed solution at a rate of 0.8 mL / min, and keeping the mixture warm for 30 min to obtain a second mixed solution;

[0099] S300, cooling the second mixed solution to 40°C, adding sodium hydroxide solution dropwise to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the addition, the addition time is 30 minutes, and after the addition is completed, the temperature is kept for 20 minutes and cooled to room temperature to obtain acrylic resin 9#;

[0100] Among them, the supergravity reaction device includes a supergravity machine; in terms of mass, water: 2,2-azobisisobutyronitrile: butyl acrylate = 100:1:55.

[0101] [Comparative Example 1]

[0102] An embodiment of the present invention provides a method for preparing an acrylic resin, comprising:

[0103] S100, placing water and dimethyl azobisisobutyrate in a reaction device, heating to 83° C., and mixing evenly to obtain a first mixed solution;

[0104] S200, adding butyl acrylate to the first mixed solution at a rate of 1 mL / min, and keeping the mixture warm for 45 min to obtain a second mixed solution;

[0105] S300, cooling the second mixed solution to 40°C, adding sodium hydroxide solution dropwise to carry out neutralization reaction until the pH value is neutral, and controlling the temperature to be no higher than 40°C during the addition, the addition time is 30 minutes, and after the addition is completed, the temperature is kept for 20 minutes and cooled to room temperature to obtain acrylic resin 10#;

[0106] Among them, the supergravity reaction device includes a supergravity machine; in terms of mass, water: dimethyl azobisisobutyrate: butyl acrylate = 100:1:55.

[0107]

[0108]

[0109] It can be seen from the above table that Examples 1-9 adopt a method for preparing an acrylic resin of the present invention, and the molecular weight of the obtained acrylic resin is between 12000-18000, which meets the application requirements of the retanning agent; the molecular weight distribution is between 1.08-1.43, the molecular weight distribution is narrow, the polymer molecular weight distribution is uniform, the intermolecular force is small, the rheology is good, and the tanning and filling effect is good; the solid content is between 39-45, the viscosity is low, and it is easier to penetrate into the leather fiber, which helps to improve the uniform distribution of the retanning agent, and it is easier to achieve selective filling, reduce the difference between different parts of the leather, and improve the overall uniformity of the leather. Comparative Example 1 adopts a conventional method for polymerizing an acrylic resin, and the molecular weight is greater than 20000, which does not meet the application requirements of the retanning agent; and the molecular weight distribution is wide, the polymer molecular weight is uneven, and the filling performance is poor; the solid content is high, which is not conducive to the tanning operation. In summary, the performance of the acrylic resin product obtained by adopting the method for preparing an acrylic resin of the present invention is stable and controllable, and has good filling performance for leather.

[0110] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0111] In this specification, the writing method of "S100", "S200" and "S300" is to facilitate the description of the embodiments of the present invention. The present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the order of the specific embodiments of the above writing method.

[0112] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for preparing an acrylic resin, characterized in that: The preparation method comprises: S100, placing water and an initiator in a supergravity reaction device to obtain a first mixed solution; S200, adding acrylic monomer to the first mixed solution, keeping the temperature, to obtain a second mixed solution; S300, adjusting the pH value of the second mixed solution to neutral to obtain an acrylic resin; Wherein, the hypergravity reaction device includes a hypergravity machine.

2. The method for preparing an acrylic resin according to claim 1, wherein: In terms of parts by mass, the water:initiator:monomer=(80-120):(0.7-1.1):(45-60).

3. The method for preparing an acrylic resin according to claim 1, characterized in that: In the S100, the rotation speed of the ultra-gravity reaction device is set to 300 rpm-1500 rpm; In the S100, the temperature of the first mixed liquid is 75°C-100°C.

4. The method for preparing an acrylic resin according to claim 1, wherein: The type of the initiator includes at least one of ammonium persulfate, potassium persulfate, 2,2-azobisisobutyronitrile and dimethyl azobisisobutyrate.

5. The method for preparing acrylic resin according to claim 1, characterized in that: In the step S200, the dropping speed of the acrylic monomer is 0.5 mL / min-2 mL / min; In the S200, the insulation time is 30 min-90 min.

6. The method for preparing acrylic resin according to claim 1, characterized in that: The acrylic monomer includes at least one of acrylic acid, acrylonitrile, butyl acrylate and ethyl methacrylate.

7. The method for preparing an acrylic resin according to claim 1, characterized in that: The S300 specifically includes: S310, cooling the second mixed solution to the first reaction temperature, and adding alkali solution dropwise to carry out a neutralization reaction, S320, controlling the temperature during the dropwise addition to be not higher than the second reaction temperature, and after the dropwise addition is completed, maintaining the temperature for a period of time and cooling to room temperature to obtain the acrylic resin.

8. The method for preparing acrylic resin according to claim 7, characterized in that: In the S310, the first reaction temperature is 35°C-45°C; In the S310, the type of the alkali solution includes at least one of sodium hydroxide, potassium hydroxide, ammonia water, potassium carbonate and triethanolamine; In the S320, the second reaction temperature is 40°C; In the S320, the dropping time is 10 min-90 min; In the S320, the insulation time is 10 min-30 min.

9. A supergravity reaction device, characterized in that: The supergravity reaction device comprises: The hypergravity machine according to any one of claims 1 to 8; A reactor is connected to the supergravity machine.

10. An application method of acrylic resin, characterized in that: The acrylic resin obtained by the preparation method of the acrylic resin according to any one of claims 1 to 8 or the high gravity reaction device according to claim 9 is used as a retanning agent.

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