Carbomer, process for its preparation and use thereof

Abstract

The application provides a carbomer and a preparation method and application thereof. The preparation method comprises the following steps: adding a first solvent and a dispersing agent into a reaction container to obtain a first mixed solution; separately preparing an unsaturated carboxylic acid monomer solution, a crosslinking monomer solution, a hydrophobic monomer solution and a second mixed solution; adding the unsaturated carboxylic acid monomer solution, the crosslinking monomer solution, the hydrophobic monomer solution and the second mixed solution into the first mixed solution at 50-70 DEG C within x hours to obtain a third mixed solution, and keeping the third mixed solution for 2-3 hours after the addition is completed; wherein 3<=x<=6, the percentage content of the crosslinking monomer solution added every x / 4 hours decreases with time, and the percentage content of the hydrophobic monomer solution added every x / 4 hours increases with time; and adding an initiator into the third mixed solution again after the keeping is completed, and separating to obtain the carbomer. The prepared carbomer has good thickening performance and salt resistance.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of organic polymer material preparation, and particularly relates to a carbomer, a preparation method and application thereof. BACKGROUND

[0002] Household cleaning system formula takes high-efficiency stain removal, sterilization and disinfection as core targets, and contains a large amount of anionic surfactants, which are the main force of formula efficient cleaning. At present, the mainstream thickening in the household cleaning field depends on the addition of inorganic salts, which realizes system thickening by compressing the double electric layer of anionic surfactant micelles. However, some low-cost formulas using salt thickening are prone to stratification, turbidity and caking, which seriously affects the shelf life of products and consumer experience.

[0003] In comparison, as a classic high-molecular polymer thickening agent, carbomer has an indispensable position in the personal care field due to its good thickening efficiency, transparency and skin feel. However, due to the certain difference between household cleaning products and personal care products in formula system, if the traditional carbomer is directly applied to the household cleaning system, some problems will be faced: firstly, in order to consider the cost, a large amount of anionic surfactants are used in the formula, if the content of amphoteric surfactants or nonionic surfactants compounded with the anionic surfactants is very low, the whole formula system will be very thin; on the other hand, the introduction of high-concentration anionic surfactants and inorganic salts will seriously inhibit the stretching and hydration of the molecular chain of carbomer; the pH value of the household cleaning formula system is often high, which conflicts with the ideal use environment of the traditional carbomer. The above problems mean that the carbomer used in the household cleaning field not only requires excellent thickening performance, but also needs to provide thickening capacity in the alkaline environment, and also needs to have good electrolyte resistance. Based on this, it is necessary to develop a carbomer thickening agent which can overcome high ion concentration and is compatible with the household cleaning formula system. SUMMARY

[0004] The application aims to provide a carbomer, a preparation method and application thereof, so as to improve the thickening performance and salt resistance of the carbomer. The specific technical scheme is as follows:

[0005] The first aspect of the application provides a preparation method of a carbomer, comprising the following steps:

[0006] (1) The organic solvent is divided into five parts according to the mass ratio (45%~65%):(10%~15%):(10%~15%):(10%~15%):(5%~10%), which are first solvent, second solvent, third solvent, fourth solvent and fifth solvent respectively;

[0007] (2) The first solvent and a dispersing agent are added into a reaction container, and the temperature is raised to 50℃ to 70℃ to obtain a first mixed solution;

[0008] (3) dissolving the unsaturated carboxylic acid monomer in a second solvent to obtain an unsaturated carboxylic acid monomer solution, dissolving the crosslinking monomer in a third solvent to obtain a crosslinking monomer solution, dissolving the hydrophobic monomer in a fourth solvent to obtain a hydrophobic monomer solution, and dissolving the initiator in a fifth solvent to obtain a second mixed solution;

[0009] (4) at 50-70°C, the unsaturated carboxylic acid monomer solution, the crosslinking monomer solution, the hydrophobic monomer solution, and the second mixed solution are independently added dropwise into the first mixed solution within x hours to obtain a third mixed solution, and after the dropwise addition is completed, the third mixed solution is kept at the temperature for 2-3 hours; wherein 3≤x≤6, the percentage content of the crosslinking monomer solution added every x / 4 hours decreases over time based on the mass of the crosslinking monomer solution, and the percentage content of the hydrophobic monomer solution added every x / 4 hours increases over time based on the mass of the hydrophobic monomer solution;

[0010] (5) after the keeping at temperature is completed, the initiator is added again into the third mixed solution, and the third mixed solution is kept at 60-80°C for 1-2 hours, and then a carbomer is separated;

[0011] In the present application, the unsaturated carboxylic acid monomer, the crosslinking monomer, and the hydrophobic monomer are reaction monomers, the percentage content of the organic solvent is 78-89.8% based on the sum of the masses of the organic solvent, the reaction monomers, the initiator, and the dispersant, the percentage content of the reaction monomers is 10-20%, the percentage content of the initiator is 0.1-1%, and the percentage content of the dispersant is 0.1-1%.

[0012] In some embodiments of the present application, the crosslinking monomer solution is added in four stages, and the percentage content of each stage is 38-44% relative to the sum of the total amount, wherein the percentage content of the first stage is 38-44%, the percentage content of the second stage is 28-34%, the percentage content of the third stage is 18-24%, and the percentage content of the fourth stage is 8-14% based on the mass of the crosslinking monomer solution.

[0013] In some embodiments of the present application, the hydrophobic monomer solution is added in four stages, and the percentage content of each stage is 8-14% relative to the sum of the total amount, wherein the percentage content of the first stage is 8-14%, the percentage content of the second stage is 18-24%, the percentage content of the third stage is 28-34%, and the percentage content of the fourth stage is 38-44% based on the mass of the hydrophobic monomer solution.

[0014] In some embodiments of the present application, the mass percentage of the unsaturated carboxylic acid monomer solution added per unit time is equal based on the mass of the unsaturated carboxylic acid monomer solution; and the mass percentage of the second mixed solution added per unit time is equal based on the mass of the second mixed solution.

[0015] In some embodiments of the present application, the mass percentage of the unsaturated carboxylic acid monomer is 87% to 96%, the mass percentage of the crosslinking monomer is 1% to 3%, and the mass percentage of the hydrophobic monomer is 3% to 10% based on the mass of the reaction monomer.

[0016] In some embodiments of the present application, the initiator is added twice, and the ratio of the mass percentage of the initiator added in step (3) to the mass percentage of the initiator added in step (4) is (75%~85%):(15%~25%) based on the mass of the initiator.

[0017] In some embodiments of the present application, the unsaturated carboxylic acid monomer comprises at least one of acrylic acid, methacrylic acid, maleic acid, or itaconic acid.

[0018] In some embodiments of the present application, the crosslinking monomer comprises at least one of pentaerythritol diallyl ether, pentaerythritol triallyl ether, trimethylolpropane diallyl ether, or trimethylolpropane triallyl ether.

[0019] In some embodiments of the present application, the hydrophobic monomer comprises at least one of hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, docosyl acrylate, or docosyl methacrylate.

[0020] In some embodiments of the present application, at least one of the following characteristics is satisfied:

[0021] (1) the organic solvent comprises at least one of dichloromethane, n-hexane, cyclohexane, benzene, or ethyl acetate;

[0022] (2) the initiator comprises at least one of benzoyl peroxide, acetyl cyclohexyl sulfonyl peroxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, or di(3-methoxybutyl) peroxydicarbonate;

[0023] (3) the dispersant comprises at least one of polyoxyethylene dipolyhydroxy stearate, sorbitan fatty acid ester, polyoxyethylene fatty acid ester, or polyoxyethylene alkyl ether sulfonate.

[0024] The second aspect of the present application provides a carbomer prepared by the preparation method in any of the above embodiments.

[0025] The third aspect of the present application provides a use of the carbomer in any of the embodiments of the first and second aspects of the present application as a thickening agent for a household cleaning system.

[0026] The beneficial effects of the present application are:

[0027] The present application provides a carbomer, a preparation method and an application thereof. By using the preparation method of the present application, a relatively uniform and stable monomer distribution copolymer can be formed through the construction of a gradient network structure, and the synergistic improvement of thickening performance and salt resistance is realized. The internal dense crosslinking network ensures good neutralization swelling speed and thickening efficiency, and the external dense hydrophobic association point is conducive to resisting high content of electrolytes in the formula system. Therefore, the carbomer prepared by the present application has strong thickening capacity, good gel stability, and can overcome high ion concentration, and is compatible with household cleaning formula systems.

[0028] Of course, implementing any product or method of the present application does not necessarily require achieving all the advantages described above at the same time. DETAILED DESCRIPTION

[0029] The technical solutions in the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. All other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0030] The first aspect of the present application provides a preparation method of a carbomer, comprising the following steps:

[0031] (1) The organic solvent is divided into five parts according to the mass ratio (45%~65%):(10%~15%):(10%~15%):(10%~15%):(5%~10%), which are the first solvent, the second solvent, the third solvent, the fourth solvent and the fifth solvent, respectively. For example, based on the mass of the organic solvent, the mass percentage content W 11 may be 45%, 50%, 55%, 60%, 65% or a range composed of any two of them, the mass percentage content W 12 may be 10%, 11%, 12%, 13%, 14%, 15% or a range composed of any two of them, the mass percentage content W 13 may be 10%, 11%, 12%, 13%, 14%, 15% or a range composed of any two of them, the mass percentage content W 14 may be 10%, 11%, 12%, 13%, 14%, 15% or a range composed of any two of them, the mass percentage content W 155%, 6%, 7%, 8%, 9%, 10%, or a range defined by any two of them.

[0032] (2) adding the first solvent and the dispersant into the reaction container, and heating to 50-70°C to obtain a first mixture; for example, heating to T1 °C, and T1 can be 50°C, 55°C, 60°C, 65°C, 70°C, or a range defined by any two of them.

[0033] (3) dissolving the unsaturated carboxylic acid monomer in a second solvent to obtain an unsaturated carboxylic acid monomer solution, dissolving the crosslinking monomer in a third solvent to obtain a crosslinking monomer solution, dissolving the hydrophobic monomer in a fourth solvent to obtain a hydrophobic monomer solution, and dissolving the initiator in a fifth solvent to obtain a second mixture.

[0034] (4) at 50-70°C, adding the unsaturated carboxylic acid monomer solution, the crosslinking monomer solution, the hydrophobic monomer solution, and the second mixture into the first mixture separately within x hours to obtain a third mixture, and after the addition is completed, incubating for 2-3 hours; wherein 3≤x≤6, the percentage content of the crosslinking monomer solution added every x / 4 hours decreases over time based on the mass of the crosslinking monomer solution, and the percentage content of the hydrophobic monomer solution added every x / 4 hours increases over time based on the mass of the hydrophobic monomer solution. For example, the temperature of the solution being added is T2 °C, and T2 can be 50°C, 55°C, 60°C, 65°C, 70°C, or a range defined by any two of them; x can be 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, or a range defined by any two of them; and the incubation time after the addition is completed is t1 h, and t1 can be 2h, 2.2h, 2.4h, 2.5h, 2.8h, 3h, or a range defined by any two of them.

[0035] (5) after the incubation is completed, adding the initiator again into the third mixture, and continuing to incubate at 60-80°C for 1-2 hours, and then separating to obtain the carbomer. For example, the temperature during the continued incubation is T3 °C, and T3 can be 60°C, 65°C, 70°C, 75°C, 80°C, or a range defined by any two of them; and the continued incubation time is t2 h, and t2 can be 1h, 1.2h, 1.4h, 1.5h, 1.8h, 2h, or a range defined by any two of them.

[0036] The unsaturated carboxylic acid monomer, the crosslinking monomer and the hydrophobic monomer are reaction monomers, and the mass percentage content of the organic solvent is 78% to 89.8%, the mass percentage content of the reaction monomers is 10% to 20%, the mass percentage content of the initiator is 0.1% to 1%, and the mass percentage content of the dispersant is 0.1% to 1%, based on the sum of the mass of the organic solvent, the reaction monomers, the initiator and the dispersant. For example, the mass percentage content W1 of the organic solvent can be 78%, 80%, 82%, 84%, 85%, 88%, 89%, 89.8%, or a range formed by any two of them, the mass percentage content W2 of the reaction monomers can be 10%, 12%, 15%, 18%, 20%, or a range formed by any two of them, the mass percentage content W3 of the initiator can be 0.1%, 0.3%, 0.5%, 0.8%, 1%, or a range formed by any two of them, and the mass percentage content W4 of the dispersant can be 0.1%, 0.3%, 0.5%, 0.8%, 1%, or a range formed by any two of them, based on the sum of the mass of the organic solvent, the dispersant, the initiator and the reaction monomers.

[0037] Carbomer is generally a crosslinked network of acrylic acid, and thickening mainly depends on the ionization of carboxyl groups on the main chain after neutralization by alkali, the mutual repulsion of negative charges between carboxylate ions, the stretching of molecular chains to form a highly expanded network structure, thereby improving the viscosity of the system. However, household cleaning formula systems contain a large amount of ionic surfactants and inorganic electrolytes, and a large amount of counterions will have electrostatic interaction with the negative charges on the molecular chain of carbomer, shielding the electrostatic repulsion between charges, causing the molecular chain to curl again, and the viscosity of the system decreases. Then, it is found that the introduction of a hydrophobic monomer on the main chain can resist the destruction of electrolytes to the stretched state of the molecular chain to a certain extent.

[0038] The preparation process of the existing carbomer is mostly one-time feeding method, that is, all the reaction monomers are mixed uniformly and then directly reacted, which can cause the difference in reactivity of the monomers to be enlarged, and the distribution of the monomers to be uneven and uncontrollable. Therefore, the inventors design a gradient copolymer network structure, which is realized by controlling the dropwise process. Since all the monomers are slowly and continuously added to the system, by controlling the dropwise rate of each monomer, a relatively uniform and stable monomer distribution copolymer is realized. At the same time, the different solutions are independently added, and the crosslinking monomer solution and the hydrophobic monomer solution are added at variable rates. Specifically, the dropwise rate of the crosslinking monomer solution is added from slow to fast into the system, and the dropwise rate of the hydrophobic monomer solution is added from slow to fast into the system. In this way, since the crosslinking monomer solution added in the early stage is more, the crosslinking network in the chain segment grown in the early stage is more, and the internal crosslinking degree is the highest. The hydrophobic monomer solution added in the later stage is more, so that the hydrophobic unit in the chain segment grown in the later stage is more, and the hydrophobic monomer outside is relatively less, thereby forming a relatively smooth gradient network structure. When the carbomer is neutralized by alkali in the system, the internal hydrophilicity of the particle is stronger than the outside to form osmotic pressure, which is beneficial to the internal rapid swelling, and the internal crosslinking network skeleton further improves the thickening viscosity; on the other hand, the more hydrophobic side chain outside can better form an associated point to provide salt tolerance, which is beneficial to resisting high content of electrolyte in the formula system, and improves the salt tolerance of the product carbomer. Compared with the ordinary random copolymer carbomer, by using the method of the present application to prepare the carbomer, the "amphiphilic gradient" network structure of the carbomer is designed, which can bring more excellent thickening and salt tolerance performance, and is particularly suitable for household cleaning system.

[0039] In the polymerization process of the present application, one of the key steps is to add different functional reaction monomers to the reaction system in a controllable manner, so that they participate in the reaction according to the intended distribution. Theoretically, the most ideal dropwise addition mode is programmed variable speed dropwise addition, that is, the dropwise addition speed of the monomer presents a smooth and continuous change with time. However, this kind of dropwise addition scheme has higher requirements for equipment in laboratory and industrial production, which will lead to low cost-effectiveness. In order to significantly improve the operation convenience and repeatability of the process under the premise of ensuring the performance of the product, the present application proposes a simplified scheme of segmented uniform speed dropwise addition, that is, the dropwise addition time is divided into four stages, and the mass of the crosslinking monomer solution added in each stage is designed to be a decreasing gradient, and the mass of the hydrophobic monomer solution is designed to be an increasing gradient, and the sum of the four-stage dropwise addition percentage of each reaction monomer solution is 100%. To ensure that the entire reaction process is close to the ideal kinetic curve. If the number of segments is too small, the actual reaction process deviates too much from the ideal design, and it cannot effectively simulate the smooth transition of the monomer distribution, and if the number of segments is too large, it will lead to a complex operation procedure, which goes against the original intention of the simplified scheme. Experimental results show that the carbomer polymers prepared by the four-stage dropwise addition program have high batch performance stability, high repeatability, and the key performance can achieve the ideal effect. Among them, the reactivity ratio is a parameter for measuring the relative reactivity of different monomers in the copolymerization reaction. If the reactivity ratio difference is large, the monomers with high activity will preferentially polymerize in the early stage of the reaction, and the monomers with low activity will participate in the reaction in the later stage, thereby forming a non-uniform random copolymer structure.

[0040] In the present application, the control dropwise addition time x is within 3h~6h, giving the monomer concentration in the reaction system a dynamic change with time, thereby facilitating the control of the growth and distribution of the polymerization chain.

[0041] In the present application, the control of the temperature T1 at which the temperature is raised and the temperature T2 of the dropwise addition solution is 50℃ to 70℃, which is related to the reaction temperature, reaction time and half-life of the initiator, and the initiator is added throughout the process, keeping the initiation efficiency of the initiator consistent, so that the polymerization reaction is relatively stable and controllable, and the product carbomer has uniform quality.

[0042] In the present application, the temperature T3 during the continued holding is controlled to be 60℃ to 80℃, which is beneficial to the reaction of the residual unreacted monomers in the solution to be more complete, so that the product carbomer has high purity and yield.

[0043] The present application does not particularly limit the initial temperature of adding the first solvent and the dispersing agent in the reaction container, for example, the initial temperature of adding the first solvent and the dispersing agent can be room temperature 20℃~30℃. The present application does not particularly limit the reaction container, which can be a reaction kettle, for example. The separation step is not particularly limited, for example, the organic solvent in the reaction container can be removed by reducing pressure, and then vacuum drying and sieving to obtain the carbomer.

[0044] In some embodiments of the present application, after the first solvent and the dispersant are added into the reaction vessel, nitrogen is introduced to remove oxygen for ≥60 min before the temperature is raised. By the above arrangement, the oxygen concentration in the system is reduced, ensuring the smooth and controllable progress of the subsequent polymerization reaction, providing a guarantee for the formation of the preset gradient network structure, reducing the risk of the generation of oxidation by-products, and thus improving the purity of the final product carbomer.

[0045] In some embodiments of the present application, the crosslinking monomer solution maintains a constant dropping rate in each x / 4 h time period. The above arrangement is advantageous for simplifying the operation process and improving the repeatability of the production process and the consistency between product batches.

[0046] In some embodiments of the present application, the hydrophobic monomer solution maintains a constant dropping rate in each x / 4 h time period. The above arrangement is advantageous for simplifying the operation process and improving the repeatability of the production process and the consistency between product batches.

[0047] In some embodiments of the present application, based on the mass of the crosslinking monomer solution, the crosslinking monomer solution is added in four stages, and the total amount of each stage is 100%. The percentage of the first stage (0 h-x / 4 h) is 38-44%, the percentage of the second stage (x / 4 h-x / 2 h) is 28-34%, the percentage of the third stage (x / 2 h-3x / 4 h) is 18-24%, and the percentage of the fourth stage (3x / 4 h-x h) is 8-14%. By the above arrangement, more crosslinking monomer solution is added in the early stage, so that there are more crosslinking networks in the growing chain segments in the early stage of the reaction, which is advantageous for forming a high crosslinking density internal network core in the early stage of the polymerization reaction, and after neutralization, a solid three-dimensional skeleton can be constructed, thereby improving the thickening viscosity of the product. At the same time, the crosslinking monomer solution added in the later stage is low, which can provide more space for the polymer external hydrophobic association. Therefore, the prepared carbomer has good thickening performance and salt resistance.

[0048] In some embodiments of the present application, the hydrophobic monomer solution is added in four stages, and the total amount of each stage is 100% of the total amount, wherein: the percentage of the first stage is 8% to 14%, the percentage of the second stage is 18% to 24%, the percentage of the third stage is 28% to 34%, and the percentage of the fourth stage is 38% to 44%. Through the above setting, more hydrophobic monomer solution is added in the later stage, so that there are more hydrophobic units in the later growing chain segment, and more hydrophobic side chains on the outside of the polymer can better form association points to provide ion resistance, which is conducive to resisting high electrolyte content in the formula system, thereby improving the salt resistance of the prepared carbomer. At the same time, less hydrophobic monomer solution is added in the early stage, which reduces the risk of premature embedding of hydrophobic units in the interior to inhibit swelling, thereby helping to ensure the thickening ability of the hydrophilic network inside the polymer. Therefore, the prepared carbomer has good thickening performance and salt resistance.

[0049] In some embodiments of the present application, the mass percentage of the unsaturated carboxylic acid monomer solution added per unit time is equal based on the mass of the unsaturated carboxylic acid monomer solution, and the mass percentage of the second mixed solution added per unit time is equal based on the mass of the second mixed solution. Through the above setting, the uniform growth of the polymer main chain can be realized, which is conducive to the synchronous improvement of the overall osmotic pressure of the polymer, and the uniform addition of the initiator can make the gradient structure of decreasing cross-linking and increasing hydrophobicity complete and continuous, thereby providing a solid foundation for the "amphiphilic gradient" network structure of the carbomer. Therefore, the prepared carbomer has good thickening performance and salt resistance.

[0050] In the present application, the unit time can be per minute or per hour.

[0051] In some embodiments of the present application, the unsaturated carboxylic acid monomer solution maintains a constant addition rate during the addition process. The above setting is conducive to simplifying the operation process and improving the repeatability of the production process and the consistency between product batches.

[0052] In some embodiments of the present application, the second mixed solution maintains a constant addition rate during the addition process. The above setting is conducive to maintaining consistent initiation efficiency of the initiator, thereby making the polymerization reaction more stable and controllable.

[0053] In some embodiments of the present application, the mass percentage of the unsaturated carboxylic acid monomer is 87% to 96% based on the mass of the reaction monomer, the mass percentage of the cross-linking monomer is 1% to 3%, and the mass percentage of the hydrophobic monomer is 3% to 10%. For example, the mass percentage of the unsaturated carboxylic acid monomer W 21The mass percentage content W of the crosslinking monomer can be 87%, 88%, 90%, 92%, 95%, 96%, or a range formed by any two of the above values. 22 The mass percentage content W of the hydrophobic monomer can be 1%, 1.5%, 2%, 2.5%, 3%, or a range formed by any two of the above values. 23 The mass percentage content W of the hydrophobic monomer can be 1%, 1.5%, 2%, 2.5%, 3%, or a range formed by any two of the above values. Through the above setting, a high proportion of unsaturated carboxylic acid monomers enables the polymer to have sufficient hydration swelling capacity, providing a basis for thickening performance; an appropriate amount of crosslinking monomers builds a stable three-dimensional network skeleton, ensuring gel strength; and the proportion of the hydrophobic monomer is regulated to provide effective hydrophobic association while taking into account water, and thus the prepared carbomer has good thickening performance and salt resistance.

[0054] In some embodiments of the present application, the initiator is added in two steps, and the ratio of the mass percentage content of the initiator added in step (3) to the mass percentage content of the initiator added in step (4) is (75%-85%):(15%-25%) based on the mass of the initiator. For example, the mass percentage content W of the initiator added in step (3) is 75%-85% based on the mass of the initiator. 31 The mass percentage content W of the initiator added in step (4) can be 75%, 78%, 80%, 82%, 85%, or a range formed by any two of the above values. 32 The mass percentage content W of the initiator added in step (4) can be 75%, 78%, 80%, 82%, 85%, or a range formed by any two of the above values. Through the above setting, the first addition is conducive to building a gradient network structure, and the second supplemental addition can effectively initiate the residual monomers to continue to react, while making the three-dimensional structure more perfect, thereby improving the purity and gel strength of the product carbomer.

[0055] In some embodiments of the present application, the unsaturated carboxylic acid monomer includes at least one of acrylic acid, methacrylic acid, maleic acid, or itaconic acid. By selecting the above unsaturated carboxylic acid monomers, the polymer has sufficient hydration swelling capacity, providing a basis for thickening performance.

[0056] In some embodiments of the present application, the crosslinking monomer includes at least one of pentaerythritol diallyl ether, pentaerythritol triallyl ether, trimethylolpropane diallyl ether, or trimethylolpropane triallyl ether. By selecting the above crosslinking monomers, it is conducive to building a stable three-dimensional network skeleton, ensuring gel strength.

[0057] In some embodiments of the present application, the hydrophobic monomer comprises at least one of hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, docosyl acrylate or docosyl methacrylate. By selecting the above hydrophobic monomer, effective hydrophobic association can be provided, thereby improving the salt tolerance of the product carbomer.

[0058] In some embodiments of the present application, at least one of the following characteristics is satisfied:

[0059] (1) the organic solvent comprises at least one of dichloromethane, n-hexane, cyclohexane, benzene or ethyl acetate;

[0060] (2) the initiator comprises at least one of benzoyl peroxide, acetyl cyclohexyl sulfonyl peroxide, diisopropyl peroxide dicarbonate, di-n-propyl peroxide dicarbonate or di(3-methoxybutyl) peroxide dicarbonate;

[0061] (3) the dispersant comprises at least one of polyoxyethylene dipolyhydroxystearate, sorbitan fatty acid ester, polyoxyethylene fatty acid ester or polyoxyethylene alkyl ether sulfonate.

[0062] By selecting the above specific types, the organic solvent is conducive to good solubility of the monomer and controllable reaction; the initiator is conducive to smooth and sufficient reaction of the polymerization process; and the dispersant is conducive to reducing the risk of particle adhesion, so that the product carbomer has a relatively uniform particle size and good dispersibility. Therefore, the prepared carbomer has good thickening performance, salt tolerance and batch consistency.

[0063] The second aspect of the present application provides a carbomer prepared by the preparation method in any of the above embodiments.

[0064] The carbomer prepared by the method of the present application realizes the synergistic improvement of thickening performance and salt tolerance by constructing a gradient network structure; the internal dense crosslinking network ensures good neutral swelling speed and thickening efficiency, and the external dense hydrophobic association point is conducive to resisting high content of electrolyte in the formula system. Therefore, the carbomer prepared by the present application has strong thickening ability, good gel stability and can overcome high ion concentration, and is compatible with household cleaning formula systems.

[0065] The third aspect of the present application provides the use of the carbomer in any of the embodiments of the first aspect and the second aspect of the present application as a thickening agent for household cleaning systems.

[0066] Examples:

[0067] The following, examples and comparative examples are presented to more specifically explain the embodiments of the present application. Various tests and evaluations were performed according to the following methods. In addition, unless otherwise specified, "parts" and "%" are on a mass basis.

[0068] Test methods and apparatus:

[0069] 1% Hydrogel viscosity test:

[0070] Take 2 g Carbomer powder and evenly spread in 198 g deionized water, and let it stand until the powder is completely wet. Stir mechanically at a rate of 900 rpm for 10 min to evenly disperse the Carbomer. Then adjust the stirring speed to 300 rpm, and add 18% NaOH solution to the system to swell the Carbomer to a pH of 7-8. Continue stirring for 10 min to make the system uniform, and then centrifuge to remove bubbles after discharging. Let it stand at a constant temperature of 25°C for 2 h. Use a Brookfield RVT rotary viscometer to test the viscosity of the 1% hydrogel at 20 rpm, and record the viscosity data η after the instrument reading is stable for 1 min. 水 .

[0071] 1% Hydrogel viscosity test with 1% NaCl addition:

[0072] Take 2 g Carbomer powder and evenly spread in 198 g deionized water, and let it stand until the powder is completely wet. Stir mechanically at a rate of 900 rpm for 10 min to evenly disperse the Carbomer. Then adjust the stirring speed to 300 rpm, and add 18% NaOH solution to the system to swell the Carbomer to a pH of 7-8. Continue stirring for 10 min to make the system uniform, and then centrifuge to remove bubbles after discharging. Let it stand at a constant temperature of 25°C for 2 h. Use a Brookfield RVT rotary viscometer to test the viscosity of the 1% hydrogel at 20 rpm, and record the viscosity data η after the instrument reading is stable for 1 min. 盐 .

[0073] Viscosity retention rate calculation:

[0074] η 盐 / η 水 ) x 100%, and the larger the value, the higher the salt resistance of the Carbomer.

[0075] Formulation viscosity test:

[0076] The test formula is as follows: based on the total mass of the formula, the mass percentage of carbomer is 0.2%; the mass percentage of sodium fatty alcohol polyoxyethylene ether sulfate (AES) is 15%; the mass percentage of fatty alcohol polyoxyethylene ether-9 (AEO-9) is 2%; the mass percentage of sodium dodecyl sulfate (K12) is 3%; the mass percentage of 18% NaOH solution is 0.2%; the mass percentage of NaCl is 0.5%; and the mass percentage of water is 100% of the total formula.

[0077] Carbomer powder accounting for 0.2% of the total mass of the formula is uniformly spread in the formula amount of deionized water, and is allowed to stand until the powder is completely wet. The carbomer powder is uniformly dispersed by mechanical stirring at a speed of 900 rpm for 10 min. Then the stirring speed is adjusted to 300 rpm, and each surfactant in the formula table is added in turn and stirred uniformly. The formula amount of 18% NaOH solution is added under stirring to adjust the pH of the system to 7-8 to swell the carbomer, and finally the formula amount of NaCl is added. Stir for 10 min to make the system uniform, centrifuge and defoam after discharging, and stand at 25°C for 2 h. The formula viscosity is tested using a Brookfield RVT rotary viscometer at 20 rpm, and the viscosity data is recorded after the instrument reading is stable for 1 min.

[0078] Example 1-1:

[0079] (1) 480 g of organic solvent (mixed with cyclohexane and ethyl acetate in a mass ratio of 1:1) is divided into five parts according to a mass ratio of 62.5%:12.5%:8.33%:8.33%:8.33%, which are 300 g of the first solvent, 60 g of the second solvent, 40 g of the third solvent, 40 g of the fourth solvent, and 40 g of the fifth solvent;

[0080] (2) The first solvent, 2.0 g of dispersant sorbitan fatty acid ester, is added to the reaction kettle, stirred uniformly, and then heated to T1 55°C under nitrogen protection to obtain a first mixed solution;

[0081] (3) 90 g of unsaturated carboxylic acid monomer acrylic acid is dissolved in the second solvent to obtain an unsaturated carboxylic acid monomer solution, 1 g of crosslinking monomer pentaerythritol diallyl ether is dissolved in the third solvent to obtain a crosslinking monomer solution, 6 g of hydrophobic monomer stearyl acrylate is dissolved in the fourth solvent to obtain a hydrophobic monomer solution, and 0.5 g of initiator diisopropyl peroxydicarbonate is dissolved in the fifth solvent to obtain a second mixed solution;

[0082] (4) The above solutions are independently started to be added dropwise, the dropwise time x is 4 h, and the temperature is kept at T2 55°C during the period. Among them, the unsaturated carboxylic acid monomer solution and the second mixed solution are added into the system at a constant speed; based on the mass of the crosslinking monomer solution, the mass percentage content of the dropwise addition is 40% from 0 h to 1 h, 30% from 1 h to 2 h, 20% from 2 h to 3 h, and 10% from 3 h to 4 h; based on the mass of the hydrophobic monomer solution, the mass percentage content of the dropwise addition is 10% from 0 h to 1 h, 20% from 1 h to 2 h, 30% from 2 h to 3 h, and 40% from 3 h to 4 h. After the dropwise addition is completed, the temperature is kept at T2 55°C for 2 h;

[0083] (5) After the heat preservation is completed, the temperature is increased to T3 70°C, 0.1 g of initiator diisopropyl peroxydicarbonate is added into the system, and the heat preservation is continued for 2 h; after the reaction is completed, the solvent is removed through rotary evaporation and vacuum drying, and a white powdery carbomer is obtained after sieving.

[0084] Among them, based on the mass of the reaction monomers, the mass percentage content W 21 of the unsaturated carboxylic acid monomer is 92.78%, the mass percentage content W 22 of the crosslinking monomer is 1.03%, and the mass percentage content W 23 of the hydrophobic monomer is 6.19%.

[0085] Examples 1-2 to 1-14:

[0086] Except that the related preparation parameters are adjusted according to Table 1, the rest is the same as Example 1-1.

[0087] Examples 2-1 to 2-5:

[0088] Except that the related preparation parameters are adjusted according to Table 2, the rest is the same as Example 1-1. Among them, when the values of W 21 , W 22 , and W 23 change, the total mass of the added reaction monomers remains unchanged, and the mass of the unsaturated carboxylic acid monomer, the mass of the crosslinking monomer, and the mass of the hydrophobic monomer change accordingly.

[0089] Examples 3-1 to 3-2:

[0090] The rest is the same as Example 1-1 except that the mass percentage of the relevant components is adjusted according to Table 3. Among them, when the mass percentage of the organic solvent, the mass percentage of the reaction monomer, the mass percentage of the initiator, and the mass percentage of the dispersant change, the sum of the mass of the added organic solvent, the reaction monomer, the initiator, and the dispersant remains unchanged, the mass percentage of the unsaturated carboxylic acid monomer, the crosslinking monomer, and the hydrophobic monomer in the reaction monomer remains unchanged, and the mass of the added organic solvent, the mass of the reaction monomer, the mass of the initiator, and the mass of the dispersant change accordingly.

[0091] Comparative Example 1:

[0092] (1) 440 g of organic solvent (mixed with cyclohexane and ethyl acetate at a mass ratio of 1:1), 2.0 g of dispersant sorbitan fatty acid ester, 90 g of unsaturated carboxylic acid monomer acrylic acid, 1 g of crosslinking monomer pentaerythritol diallyl ether, and 6 g of hydrophobic monomer stearyl acrylate were added to a reaction kettle, stirred and dissolved uniformly, and then heated to 55°C under nitrogen protection;

[0093] (2) 0.5 g of initiator diisopropyl peroxydicarbonate was dissolved in 40 g of mixed organic solvent and stirred uniformly for use;

[0094] (3) The initiator solution was started to be added to the reaction system at a constant speed, and the dropping time was 3 h, during which the system temperature was maintained at 55°C. After the addition was completed, the temperature was maintained at 55°C for 2 h;

[0095] (4) After the incubation was completed, the temperature was raised to 70°C, 0.1 g of initiator diisopropyl peroxydicarbonate was added to the system, and the incubation was continued for 2 h; after the reaction was completed, the solvent was removed by rotary evaporation and vacuum drying, and a white powdery carbomer was obtained after sieving.

[0096] Comparative Example 2:

[0097] (1) 480 g of organic solvent (mixed with cyclohexane and ethyl acetate at a mass ratio of 1:1) was divided into five parts according to the mass ratio of 62.5%:12.5%:8.33%:8.33%:8.33%, which were 300 g of the first solvent, 60 g of the second solvent, 40 g of the third solvent, 40 g of the fourth solvent, and 40 g of the fifth solvent;

[0098] (2) The first solvent and 2.0 g of dispersant sorbitan fatty acid ester were added to the reaction kettle, stirred uniformly, and then heated to T1 55°C under nitrogen protection to obtain a first mixed solution;

[0099] (3) Dissolve 90g of unsaturated carboxylic acid monomer acrylic acid in a second solvent to obtain an unsaturated carboxylic acid monomer solution, dissolve 1g of crosslinking monomer pentaerythritol diallyl ether in a third solvent to obtain a crosslinking monomer solution, dissolve 6g of hydrophobic monomer octadecyl acrylate in a fourth solvent to obtain a hydrophobic monomer solution, and dissolve 0.5g of initiator diisopropyl peroxide dicarbonate in a fifth solvent to obtain a second mixture.

[0100] (4) The above solutions were added dropwise independently, with a dropping time of x of 4 hours, during which the temperature was maintained at T2 55℃. The unsaturated carboxylic acid monomer solution, cross-linking monomer solution, hydrophobic monomer solution, and the second mixture were added dropwise to the system simultaneously and at a uniform rate. After the dropping was completed, the system was kept at T2 55℃ for 2 hours.

[0101] (5) After the heat preservation is completed, the temperature is raised to T3 70℃, and 0.1g of initiator diisopropyl peroxide is added to the system and the heat preservation is continued for 2h. After the reaction is completed, the solvent is removed by rotary evaporation and vacuum drying, and the white powder carbomer is obtained after sieving.

[0102] Among them, the mass percentage W of unsaturated carboxylic acid monomers is based on the mass of the reacting monomers. 21 The content of crosslinking monomers was 92.78%, and the mass percentage W was... 22 The percentage of hydrophobic monomers (W) is 1.03%. 23 It is 6.19%.

[0103] Comparative Example 3:

[0104] (1) 480g of organic solvent (cyclohexane and ethyl acetate mixed in a mass ratio of 1:1) was divided into five parts in a mass ratio of 62.5%:12.5%:8.33%:8.33%:8.33%, namely 300g of the first solvent, 60g of the second solvent, 40g of the third solvent, 40g of the fourth solvent and 40g of the fifth solvent;

[0105] (2) Add the first solvent and 2.0g of dispersant sorbitol fatty acid ester to the reaction vessel, stir evenly, and then heat to T1 55℃ under nitrogen protection to obtain the first mixture;

[0106] (3) Dissolve 90g of unsaturated carboxylic acid monomer acrylic acid in a second solvent to obtain an unsaturated carboxylic acid monomer solution, dissolve 1g of crosslinking monomer pentaerythritol diallyl ether in a third solvent to obtain a crosslinking monomer solution, dissolve 6g of hydrophobic monomer octadecyl acrylate in a fourth solvent to obtain a hydrophobic monomer solution, and dissolve 0.5g of initiator diisopropyl peroxide dicarbonate in a fifth solvent to obtain a second mixture.

[0107] (4) The above solutions are independently started to be added dropwise, the dropwise time x is 4 h, and the temperature is kept at T2 55 ℃ during the period. Among them, the unsaturated carboxylic acid monomer solution and the second mixed solution are added into the system at a constant speed; based on the mass of the crosslinking monomer solution, the mass percentage content of the dropwise addition is 10% from 0 h to 1 h, 20% from 1 h to 2 h, 30% from 2 h to 3 h, and 40% from 3 h to 4 h; based on the mass of the hydrophobic monomer solution, the mass percentage content of the dropwise addition is 40% from 0 h to 1 h, 30% from 1 h to 2 h, 20% from 2 h to 3 h, and 10% from 3 h to 4 h. After the dropwise addition is completed, the temperature is kept at T2 55 ℃ for 2 h;

[0108] (5) After the heat preservation is completed, the temperature is increased to T3 70 ℃, 0.1 g of initiator diisopropyl peroxydicarbonate is added into the system, and the heat preservation is continued for 2 h; after the reaction is completed, the solvent is removed through rotary evaporation and vacuum drying, and a white powdery carbomer is obtained after sieving.

[0109] Among them, based on the mass of the reaction monomers, the mass percentage content W 21 of the unsaturated carboxylic acid monomer is 92.78%, the mass percentage content W 22 of the crosslinking monomer is 1.03%, and the mass percentage content W 23 of the hydrophobic monomer is 6.19%.

[0110] The preparation parameters and performance parameters of each example and comparative example are shown in Tables 1 to 3.

[0111] Table 1

[0112]

[0113] Note: “ / ” in Table 1 indicates no relevant preparation parameters.

[0114] Table 2

[0115]

[0116] Note: “ / ” in Table 2 indicates no relevant preparation parameters.

[0117] Table 3

[0118]

[0119] As can be seen from Examples 1-1 to 1-14 in Table 1, Examples 2-1 to 2-5 in Table 2, and Examples 3-1 to 3-2 in Table 3, using the preparation method within the scope of the present application, the crosslinking monomer solution and the hydrophobic monomer solution are added at a variable dropping rate, the carbomer obtained has a "amphiphilic gradient" network structure, can be applied to high surface activity and high salt household cleaning formula systems, and has relatively high viscosity. In Example 1-9, the decreasing gradient of the crosslinking monomer solution is relatively low, at this time the network strength of the carbomer itself is relatively insufficient, and the thickening capacity is relatively reduced; in Example 1-10, the decreasing gradient of the crosslinking monomer solution is relatively high, the local crosslinking concentration of the carbomer is relatively high, and the salt resistance is relatively reduced; in Example 1-11, the increasing gradient of the hydrophobic monomer solution is relatively low, the contribution of the hydrophobic monomer to the salt resistance of the system is reduced, and the salt resistance is relatively reduced; in Example 1-12, the dropping gradient of the hydrophobic monomer solution is relatively high, the local hydrophobic concentration is relatively high, which causes the carbomer to be too hydrophobic locally, affects the swelling performance of the carbomer, and the thickening capacity is relatively reduced.

[0120] In Comparative Example 1, all the reaction monomers are mixed and added, the reactivity of the crosslinking monomer is relatively large, and the crosslinking monomer participates in the reaction more in the early stage, at this time the difference in reactivity between the monomers is amplified, the distribution of the monomers is uneven and uncontrollable, and therefore the thickening performance and salt resistance of the obtained product carbomer are both poor, and the stability between product batches is also poor. In Comparative Example 2, all the monomer solutions are added at a uniform speed, at this time the crosslinking monomer is relatively uniformly distributed, and lacks local high crosslinking to provide thickening, therefore the thickening performance of the obtained carbomer is low, the utilization rate of the hydrophobic monomer is low, and therefore the salt resistance of the obtained carbomer is also poor. In Comparative Example 3, the crosslinking monomer solution is added from slow to fast, and the hydrophobic monomer solution is added from fast to slow, at this time the external crosslinking of the carbomer powder is too high, which causes the internal part of the powder to be difficult to swell, the thickening efficiency is poor, and the hydrophobic monomer is mostly embedded in the internal part of the carbomer, and the salt resistance efficiency is low.

[0121] In summary, using the preparation method of the present application, a relatively uniform and stable monomer distribution copolymer can be formed by constructing a gradient network structure, and the thickening performance and salt resistance are synergistically improved; the internal dense crosslinking network ensures good neutral swelling speed and thickening efficiency, and the external dense hydrophobic association point is beneficial to resisting high content electrolyte in the formula system. Therefore, the carbomer prepared by the present application has strong thickening capacity, good gel stability, and can overcome high ion concentration, and is compatible with household cleaning formula systems.

[0122] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for preparing carbomer, characterized in that, Includes the following steps: (1) The organic solvent is divided into five parts according to the mass ratio (45%~65%):(10%~15%):(10%~15%):(10%~15%):(5%~10%), namely the first solvent, the second solvent, the third solvent, the fourth solvent and the fifth solvent; (2) Add the first solvent and dispersant to the reaction vessel, and heat to 50°C to 70°C to obtain the first mixture; (3) Dissolve the unsaturated carboxylic acid monomer in the second solvent to obtain an unsaturated carboxylic acid monomer solution, dissolve the crosslinking monomer in the third solvent to obtain a crosslinking monomer solution, dissolve the hydrophobic monomer in the fourth solvent to obtain a hydrophobic monomer solution, and dissolve the initiator in the fifth solvent to obtain a second mixture; (4) At 50°C to 70°C, the unsaturated carboxylic acid monomer solution, the crosslinking monomer solution, the hydrophobic monomer solution, and the second mixture are independently added dropwise to the first mixture over x hours to obtain a third mixture. After the addition is completed, the mixture is kept warm for 2 to 3 hours. Wherein, 3 ≤ x ≤ 6. Based on the mass of the crosslinking monomer solution, the percentage of the crosslinking monomer solution added per x / 4 hours decreases over time, and based on the mass of the hydrophobic monomer solution, the percentage of the hydrophobic monomer solution added per x / 4 hours increases over time. (5) After the heat preservation is completed, the initiator is added to the third mixture again, and the mixture is kept at 60°C to 80°C for 1 to 2 hours. Then, carbomer is separated. Wherein, the unsaturated carboxylic acid monomer, the crosslinking monomer, and the hydrophobic monomer are reactive monomers. Based on the sum of the masses of the organic solvent, the reactive monomer, the initiator, and the dispersant, the mass percentage of the organic solvent is 78% to 89.8%, the mass percentage of the reactive monomer is 10% to 20%, the mass percentage of the initiator is 0.1% to 1%, and the mass percentage of the dispersant is 0.1% to 1%.

2. The preparation method according to claim 1, characterized in that, Based on the mass of the crosslinking monomer solution, the crosslinking monomer solution is added dropwise in four stages, with the sum of the dropwise amounts in each stage relative to the total amount being 100%. Specifically: the dropwise percentage from 0 h to x / 4 h is 38% to 44%, the dropwise percentage from x / 4 h to x / 2 h is 28% to 34%, the dropwise percentage from x / 2 h to 3x / 4 h is 18% to 24%, and the dropwise percentage from 3x / 4 h to x h is 8% to 14%.

3. The preparation method according to claim 1, characterized in that, Based on the mass of the hydrophobic monomer solution, the hydrophobic monomer solution is added dropwise in four stages, with the sum of the dropwise amounts in each stage relative to the total amount used being 100%. Specifically: the dropwise percentage from 0 h to x / 4 h is 8% to 14%, the dropwise percentage from x / 4 h to x / 2 h is 18% to 24%, the dropwise percentage from x / 2 h to 3x / 4 h is 28% to 34%, and the dropwise percentage from 3x / 4 h to x h is 38% to 44%.

4. The preparation method according to claim 1, characterized in that, Based on the mass of the unsaturated carboxylic acid monomer solution, the mass percentage of the unsaturated carboxylic acid monomer solution added per unit time is equal; based on the mass of the second mixture, the mass percentage of the second mixture added per unit time is equal.

5. The preparation method according to claim 1, characterized in that, Based on the mass of the reacting monomers, the unsaturated carboxylic acid monomer has a mass percentage content of 87% to 96%, the crosslinking monomer has a mass percentage content of 1% to 3%, and the hydrophobic monomer has a mass percentage content of 3% to 10%.

6. The preparation method according to claim 1, characterized in that, The initiator is added in two steps. Based on the mass of the initiator, the mass percentage of the initiator added in step (3) is (75%~85%):(15%~25%).

7. The preparation method according to any one of claims 1 to 6, characterized in that, The unsaturated carboxylic acid monomer includes at least one of acrylic acid, methacrylic acid, maleic acid, or itaconic acid.

8. The preparation method according to any one of claims 1 to 6, characterized in that, The crosslinking monomer includes at least one of pentaerythritol diallyl ether, pentaerythritol triallyl ether, trimethylolpropane diallyl ether, or trimethylolpropane triallyl ether.

9. The preparation method according to any one of claims 1 to 6, characterized in that, The hydrophobic monomer includes at least one of hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, docosahexadecyl acrylate, or docosahexadecyl methacrylate.

10. The preparation method according to any one of claims 1 to 3, characterized in that, It meets at least one of the following characteristics: (1) The organic solvent includes at least one of dichloromethane, n-hexane, cyclohexane, benzene or ethyl acetate; (2) The initiator includes at least one of benzoyl peroxide, acetylcyclohexyl peroxide sulfonyl peroxide, diisopropyl peroxide, di-n-propyl peroxide, or di(3-methoxybutyl peroxide); (3) The dispersant includes at least one of polyoxyethylene dihydroxy stearate, sorbitol fatty acid ester, polyoxyethylene fatty acid ester or polyoxyethylene alkyl ether sulfonate.

11. A carbomer, characterized in that, It is prepared by any one of claims 1 to 10.

12. Use of carbomer as a thickener in a household cleaning system according to claim 11.

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