Efficient thickening polyacrylate as well as preparation method and application thereof

Abstract

The invention provides efficient thickening polyacrylate as well as a preparation method and application thereof. The preparation method of the polyacrylate comprises the following steps: mixing acrylic acid with a hydrophobic monomer, adding a zwitterionic functional monomer, adding a cross-linking agent, an initiator and an emulsifier, and mixing to obtain a monomer mixed solution; performing step-by-step polymerization on the functional monomers, firstly adding part of the monomer mixed solution to perform core layer polymerization, raising the temperature after a core layer is formed, adding amino modified siloxane into the residual monomer mixed solution, and adding the mixture into a system to perform shell layer polymerization to form a core-shell structure and the like. According to the polyacrylate, core-shell structure powder polyacrylate with hydrophobic-hydrophilic and ion-hydrogen bond interaction is constructed through a step-by-step polymerization process. The salt resistance of the polyacrylate is obviously improved, good transparency and stable thickening effect are kept in a formula system with high ionic strength or functional protein, and the polyacrylate can be widely applied to various personal care formulas.

Description

Technical Field

[0001] This invention relates to the field of thickener technology, specifically to a high-efficiency thickening polyacrylate, its preparation method, and its application. Background Technology

[0002] As consumers increasingly demand higher quality personal care products such as shampoos, shower gels, conditioners, lotions, and serums, formulators are paying more attention to user experience and stability. In these products, thickeners play a crucial role in imparting viscosity, improving feel and flowability, and stabilizing emulsion systems. While traditional water-soluble polymers (such as carboxymethyl cellulose and xanthan gum) possess certain thickening properties, they often fail to simultaneously meet the demands of high-end formulations in terms of salt resistance, transparency, and texture.

[0003] In existing technologies, acrylic acid and its esters (collectively known as polyacrylates) thickeners are widely used in the personal care and cosmetics fields due to their excellent thickening efficiency, transparency, thixotropy, and good compatibility. For example, carbomer series thickeners are typically obtained by polymerizing acrylic acid and a small amount of long-chain alkyl acrylates and crosslinking agents in an aqueous or solvent phase. Neutralization and pH adjustment are usually required to activate the thickening effect during use. Compared with traditional polysaccharide thickeners, polyacrylate materials have stronger suspending power, better refreshing feel, and better transparency, and are therefore widely used in modern formulations.

[0004] Despite the excellent performance of polyacrylate thickeners, their salt resistance remains a challenge in practical applications. In high-salinity or high-ionic-strength environments, the traditional polyacrylate network structure is easily disrupted, leading to a significant decrease in viscosity. Consequently, when multiple ions or functional proteins are present in the formulation, problems such as turbidity and precipitation can easily occur. Summary of the Invention

[0005] To address the shortcomings of the existing technology, one objective of this invention is to provide a method for preparing a highly efficient thickening polyacrylate. This method utilizes a stepwise polymerization process to construct a core-shell structured powder polyacrylate with hydrophobic-hydrophilic and ionic-hydrogen bonding interactions. This polyacrylate exhibits significantly improved salt resistance and maintains good transparency and stable thickening effects in formulations with high ionic strength or the presence of functional proteins, making it widely applicable in various personal care formulations.

[0006] The inventors proposed the following inventive ideas regarding monomer system and polymer structure control: introducing functional monomers containing sulfonic acid functional groups and amino-modified siloxanes into the polymerization system, and using a stepwise polymerization process to precisely position them in the polymer shell, constructing a dynamic and stable sulfonic acid-amino hydrogen bond network, which enables the prepared polyacrylate to have stronger controllability and maintain high viscosity in a high ionic environment, effectively solving the problems of large viscosity decrease and turbid precipitation of traditional polyacrylate thickeners in various ionic or functional protein environments.

[0007] To solve the above-mentioned technical problems, the present invention provides the following specific technical solutions:

[0008] A method for preparing a highly efficient thickening polyacrylate, the method comprising the following steps;

[0009] S1: N,N-dimethylethylenediamine undergoes a first-step amidation reaction with methacryloyl chloride, followed by the addition of 1,3-propanesulfonic acid lactone for a second-step quaternization / ring-opening reaction, and post-treatment to obtain a zwitterionic functional monomer of sulfobetaine type.

[0010] S2: Acrylic acid is mixed with hydrophobic monomers, zwitterionic functional monomers are added, and crosslinking agents, initiators and emulsifiers are added and mixed to obtain a monomer mixed solution;

[0011] S3: Functional monomers are polymerized stepwise. First, a portion of the monomer mixture solution is added for core-layer polymerization. After the core layer is formed, the temperature is raised, and amino-modified siloxane is added to the remaining monomer mixture solution and then added to the system for shell-layer polymerization to form a core-shell structure.

[0012] S4: Filter and wash to remove unreacted monomers and oligomers, dry, and pulverize to obtain polyacrylate powder.

[0013] For example, the synthesis reaction of sulfobetaine-type zwitterionic functional monomers is shown below:

[0014]

[0015] For example, the synthesis reaction of the amide intermediate is shown below:

[0016]

[0017] In one embodiment of the present invention, the molar ratio of N,N-dimethylethylenediamine to methacryloyl chloride in S1 is 1:1.05-1.10.

[0018] In one embodiment of the present invention, the first amidation reaction in S1 takes 3-5 hours.

[0019] In one embodiment of the present invention, the molar ratio of N,N-dimethylethylenediamine to 1,3-propanesulfonic acid lactone in S1 is 1:1.0-1.05.

[0020] In one embodiment of the present invention, the second step of quaternization / ring-opening reaction in S1 takes 7-9 hours.

[0021] In one embodiment of the present invention, S2 contains acrylic acid accounting for 85-97 wt% of the total amount of acrylic acid, hydrophobic monomers and zwitterionic monomers.

[0022] In one embodiment of the present invention, the hydrophobic monomer in S2 is a C10-C30 alkyl acrylate; preferably, the hydrophobic monomer accounts for 2 to 10 wt% of the total amount of acrylic acid, hydrophobic monomer and zwitterionic monomer.

[0023] In one embodiment of the present invention, the zwitterionic functional monomer in S2 accounts for 1 to 5 wt% of the total amount of acrylic acid, hydrophobic monomer and zwitterionic monomer.

[0024] In one embodiment of the present invention, the crosslinking agent in S2 is an allyl ether crosslinking agent, preferably one or more of pentaerythritol triallyl ether, trimethylolpropane triallyl ether, trimethylolpropane diallyl ether, and ethylene glycol diallyl ether; preferably, the total amount of crosslinking agent accounts for 0.2 to 1% of the total amount of monomer.

[0025] In one embodiment of the present invention, the initiator in S2 is a peroxide initiator, preferably one or more of diisopropyl peroxide dicarbonate, dicyclohexyl peroxide dicarbonate, di(hexadecyl) peroxide dicarbonate, dodecyl peroxide, and benzoyl peroxide; preferably, the total amount of initiator accounts for 0.2% to 1% of the total amount of monomer.

[0026] In one embodiment of the present invention, the emulsifier in S2 is polyoxyethylene dehydrated sorbitan fatty acid ester, preferably one or more of Tween 20, Tween 40, Tween 60, and Tween 80; preferably, the amount of emulsifier accounts for 0.2 to 1 wt% of the total monomer.

[0027] In one embodiment of the present invention, the solvent in S3 is a weakly polar and / or non-polar solvent, preferably one or more of cyclohexane, ethyl acetate and benzene, more preferably cyclohexane and / or ethyl acetate; preferably, the solvent has a mass fraction of 80-90% in the reaction system.

[0028] In one embodiment of the present invention, 30-50% of the total mass of the monomer mixture solution is added to the core-layer polymerization in S3; preferably, the temperature of the core-layer polymerization is 40-60°C and the reaction time is 3-5 hours.

[0029] In one embodiment of the present invention, the amino-modified siloxane in S3 is one or more of aminopropyltriethoxysilane, aminopropyltrimethoxysilane, and aminoethylaminopropylmethyldimethoxysilane; preferably, the amount of amino-modified siloxane is 0.1 to 2 wt% of the total amount of the monomer; preferably, the shell polymerization temperature is 60 to 80°C, and the remaining monomer is kept at this temperature for 3 to 5 hours after addition.

[0030] In one embodiment of the invention, the drying in S4 uses fluidized bed drying or spray drying.

[0031] Another object of the present invention is to provide a highly efficient thickening polyacrylate.

[0032] A highly efficient thickening polyacrylate, wherein the polyacrylate is prepared by the above-described preparation method, and the polyacrylate is a powdered thickener with an average particle size of 1-20 micrometers, preferably 1-3 micrometers.

[0033] In one embodiment of the present invention, the polyacrylate has a viscosity greater than 10000 mPa·s at 25°C.

[0034] In one embodiment of the present invention, the polyacrylate does not flocculate or precipitate when combined with functional proteins and / or nutritional factors.

[0035] Another object of the present invention is to provide an application of a highly efficient thickening polyacrylate.

[0036] An application of a highly efficient thickening polyacrylate, wherein the polyacrylate is prepared by the above-described preparation method or is the polyacrylate described above, wherein the polyacrylate is used as a thickener, preferably in personal care products, and more preferably in shampoos, shower gels, conditioners, lotions, serums, and face masks.

[0037] Another object of the present invention is to provide a method for using highly efficient thickened polyacrylate.

[0038] A method for using a highly efficient thickening polyacrylate, wherein the polyacrylate is prepared by the above-described preparation method, or is the polyacrylate described above, or is applied to the above-described applications, wherein the polyacrylate is pre-dispersed with water at a mass ratio of ≤1:100 and swells under conditions of pH 5.0 to 8.0 to form a high-viscosity transparent colloid.

[0039] Compared with the prior art, the high-efficiency thickening polyacrylate of the present invention has the following beneficial effects;

[0040] This invention significantly improves the salt resistance of products by introducing functional monomers containing sulfonic acid functional groups and amino-modified siloxanes to construct a dynamic and stable sulfonic acid-amino hydrogen bond network and a three-dimensional cross-linked structure. The resulting product maintains high viscosity even in environments with high concentrations of ions, effectively solving the problems of significant viscosity decrease and turbidity precipitation in traditional polyacrylate thickeners under various ionic or functional protein environments. Attached Figure Description

[0041] Figure 1 Infrared spectrum of zwitterionic functional monomer of sulfobetaine type prepared in Example 1. Detailed Implementation

[0042] This invention addresses the common problems in personal care product formulations, such as viscosity decay of thickeners and poor compatibility with active ingredients due to high-salt environments. It provides a method for preparing powdered polyacrylates that combines high salt tolerance with good compatibility. This method utilizes the regulatory effect of a dynamic hydrogen bond network between sulfonic acid groups and amino groups, enabling the resulting powdered thickener to possess high salt tolerance and maintain high viscosity and stability in formulations containing surfactants and electrolytes, such as shampoos, shower gels, conditioners, lotions, and serums.

[0043] In this embodiment, the various reaction conditions, process flows and formulations are for illustrative purposes only. Any equivalent substitutions or modifications made within the spirit and scope of the claims of this invention shall be deemed to fall within the scope of protection of this invention.

[0044] Main Raw Material Information Table

[0045]

[0046]

[0047] Preparation Example 1

[0048] Preparation of sulfobetaine-type zwitterionic functional monomer: Under inert gas protection, 1 mol of N,N-dimethylethylenediamine and 1.1 mol of methacryloyl chloride were reacted in acetonitrile solvent at 0℃ for 5 h to synthesize an amide intermediate. After the reaction was completed, 1.05 mol of 1,3-propanesulfonic acid lactone was added, and the temperature was raised to 60℃ for 9 h. After the reaction was completed, the monomer was obtained by filtration, distillation, and recrystallization with acetone.

[0049] The FT-IR spectra of the target monomer were determined using the potassium bromide pellet method. Instrument manufacturer: Thermo Fisher Scientific, Model: Nicoleti S50.

[0050] The characteristic absorption peak in the FT-IR spectrum of Preparation Example 1 is at 3430 cm⁻¹. -1 (characteristic absorption peak of quaternary ammonium salt), 3350 cm⁻¹ -1 (NH stretching vibration, amide bond), 3040cm -1 (Wide ammonium absorption band), 1720cm -1 (C=C stretching vibration, carbon-carbon double bond), 1640cm -1 (C=O stretching vibration, amide bond), 1470cm -1 (CN stretching vibration, quaternary ammonium group), 1200cm -1 (S=O stretching vibration, sulfonic acid group), the above characteristic absorption peaks confirm that the functional group composition of the target monomer is consistent with the designed structure, and it is confirmed to be a zwitterionic functional monomer of sulfobetaine type.

[0051] Preparation Example 2

[0052] Preparation of sulfobetaine-type zwitterionic functional monomer: Under inert gas protection, 1 mol of N,N-dimethylethylenediamine and 1.0 mol of methacryloyl chloride were reacted in acetonitrile solvent at 5 °C for 3 h to synthesize an amide intermediate. After the reaction was completed, 1.0 mol of 1,3-propanesulfonic acid lactone was added, and the temperature was raised to 60 °C for 7 h. After the reaction was completed, the monomer was obtained by filtration, distillation, and recrystallization with acetone.

[0053] Example 1

[0054] The raw materials for Example 1 are as follows:

[0055] raw material mass / g Remark acrylic acid 1092 Main monomer Octadecyl methacrylate 72 hydrophobic monomers sulfobetaine zwitterion monomer 36 Functional unit aminopropyltrimethoxysilane 36 Paired Modifying Agents Pentaerythritol Triallyl Ether 7.2 Crosslinking agent diisopropyl peroxide 7.2 Initiator Twain 20 7.2 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0056] 1. Preparation of monomer mixed solution: Prepare acrylic acid and octadecyl methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate in a mass ratio of 1:1. While stirring continuously, add sulfobetaine zwitterionic functional monomer, pentaerythritol triallyl ether, diisopropyl peroxide dicarbonate and Tween 20 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0057] 2. Stepwise polymerization of functional monomers: 40% of the above monomer mixture solution was added to a 1:1 mixture of cyclohexane and ethyl acetate, and the mixture was heated to 50°C and held for 4 hours for core-layer polymerization. After the core layer was formed, the formulated amount of aminopropyltrimethoxysilane was added to the remaining monomer mixture solution, and the mixture was heated to 70°C. The remaining monomers were then added dropwise to the reaction system over 2 hours for shell-layer polymerization. The mixture was held for 4 hours to form a core-shell structure of a sulfonic acid-amino dynamic hydrogen bond network.

[0058] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0059] Example 2

[0060] The raw materials for Example 2 are as follows:

[0061] raw material mass / g Remark acrylic acid 1164 Main monomer Dodecyl methacrylate 24 hydrophobic monomers sulfobetaine zwitterion monomer 12 Functional unit aminopropyltrimethoxysilane 24 Paired Modifying Agents Pentaerythritol Triallyl Ether 7.2 Crosslinking agent diisopropyl peroxide 7.2 Initiator Twain 20 7.2 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0062] 1. Preparation of monomer mixed solution: Prepare acrylic acid and dodecyl methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate in a mass ratio of 1:1. While stirring continuously, add sulfobetaine zwitterionic functional monomer, pentaerythritol triallyl ether, diisopropyl peroxide dicarbonate and Tween 20 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0063] 2. Stepwise polymerization of functional monomers: 40% of the above monomer mixture solution was added to a 1:1 mixture of cyclohexane and ethyl acetate, and the mixture was heated to 50°C and held for 4 hours for core-layer polymerization. After the core layer was formed, the formulated amount of aminopropyltrimethoxysilane was added to the remaining monomer mixture solution, and the mixture was heated to 70°C. The remaining monomers were then added dropwise to the reaction system over 2 hours for shell-layer polymerization. The mixture was held for 4 hours to form a core-shell structure of a sulfonic acid-amino dynamic hydrogen bond network.

[0064] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0065] Example 3

[0066] The raw materials for Example 3 are as follows:

[0067] raw material mass / g Remark acrylic acid 1020 Main monomer 2,2-methacrylate 120 hydrophobic monomers sulfobetaine zwitterion monomer 60 Functional unit aminopropyltrimethoxysilane 30 Paired Modifying Agents Trimethylolpropane-tracepropyl ether 7.2 Crosslinking agent Benzoyl peroxide 7.2 Initiator Twain 20 7.2 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0068] 1. Preparation of monomer mixed solution: Prepare acrylic acid and methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate in a mass ratio of 1:1. While stirring continuously, add sulfobetaine zwitterionic functional monomer, trimethylolpropane triallyl ether, benzoyl peroxide and Tween 20 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0069] 2. Stepwise polymerization of functional monomers: 40% of the above monomer mixture solution was added to a 1:1 mixture of cyclohexane and ethyl acetate, and the mixture was heated to 50°C and held for 4 hours for core-layer polymerization. After the core layer was formed, the formulated amount of aminopropyltrimethoxysilane was added to the remaining monomer mixture solution, and the mixture was heated to 70°C. The remaining monomers were then added dropwise to the reaction system over 2 hours for shell-layer polymerization. The mixture was held for 4 hours to form a core-shell structure of a sulfonic acid-amino dynamic hydrogen bond network.

[0070] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0071] Example 4

[0072] The raw materials for Example 4 are as follows:

[0073] raw material mass / g Remark acrylic acid 1092 Main monomer Octadecyl methacrylate 72 hydrophobic monomers sulfobetaine zwitterion monomer 36 Functional unit aminopropyltriethoxysilane 36 Paired Modifying Agents Pentaerythritol Triallyl Ether 2.4 Crosslinking agent diisopropyl peroxide 2.4 Initiator Twain 80 7.2 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0074] 1. Preparation of monomer mixed solution: Prepare acrylic acid and octadecyl methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate in a mass ratio of 1:1. While stirring continuously, add sulfobetaine zwitterionic functional monomer, pentaerythritol triallyl ether, diisopropyl peroxide dicarbonate and Tween 80 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0075] 2. Stepwise polymerization of functional monomers: 50% of the above monomer mixture solution was added to a mixed solvent of 6 kg of cyclohexane and ethyl acetate in a 1:1 mass ratio, and then the temperature was raised to 40°C and held for 5 h for core-layer polymerization. After the core layer was formed, the prescribed amount of aminopropyltriethoxysilane was added to the remaining monomer mixture solution, and then the temperature was raised to 60°C. The remaining monomers were added dropwise to the reaction system over 1 h to carry out shell-layer polymerization. The reaction was held for 5 h to form a core-shell structure of a sulfonic acid-amino dynamic hydrogen bond network.

[0076] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0077] Example 5

[0078] The raw materials for Example 5 are as follows:

[0079] raw material mass / g Remark acrylic acid 1092 Main monomer Octadecyl methacrylate 72 hydrophobic monomers sulfobetaine zwitterion monomer 36 Functional unit aminoethylaminopropylmethyldimethoxysilane 36 Paired Modifying Agents Pentaerythritol Triallyl Ether 12 Crosslinking agent diisopropyl peroxide 12 Initiator Twain 20 7.2 emulsifier benzene 7000 solvent

[0080] 1. Preparation of monomer mixed solution: Prepare acrylic acid and octadecyl methacrylate according to the proportions in the table, then add 1 kg of benzene solvent, and add sulfobetaine zwitterionic functional monomer, pentaerythritol triallyl ether, diisopropyl peroxide and Tween 20 in sequence according to the mass in the table above while stirring continuously. Mix evenly to obtain monomer mixed solution.

[0081] 2. Stepwise polymerization of functional monomers: 30% of the above monomer mixture solution was added to 6 kg of benzene solvent, and then the temperature was raised to 60°C and held for 3 h for core-layer polymerization. After the core layer was formed, the prescribed amount of aminoethylaminopropylmethyldimethoxysilane was added to the remaining monomer mixture solution, and then the temperature was raised to 60°C. The remaining monomers were then added dropwise to the reaction system over 2 h for shell-layer polymerization. The mixture was held for 5 h to form a core-shell structure of a sulfonic acid-amino dynamic hydrogen bond network.

[0082] 3. The obtained reaction slurry was filtered and washed with benzene solvent to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0083] Example 6

[0084] The raw materials for Example 6 are as follows:

[0085] raw material mass / g Remark acrylic acid 1092 Main monomer Octadecyl methacrylate 72 hydrophobic monomers sulfobetaine zwitterion monomer 36 Functional unit aminopropyltrimethoxysilane 36 Paired Modifying Agents Ethylene glycol diallyl ether 7.2 Crosslinking agent Peroxydodecyl 7.2 Initiator Twain 20 12 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0086] 1. Preparation of monomer mixed solution: Prepare acrylic acid and octadecyl methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate in a mass ratio of 1:1. While stirring continuously, add sulfobetaine zwitterionic functional monomer, ethylene glycol diallyl ether, dodecyl peroxide and Tween 20 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0087] 2. Stepwise polymerization of functional monomers: 40% of the above monomer mixture solution was added to a mixed solvent of 6 kg cyclohexane and ethyl acetate in a 1:1 mass ratio, and then the temperature was raised to 60°C and held for 4 h for core-layer polymerization. After the core layer was formed, the prescribed amount of aminopropyltrimethoxysilane was added to the remaining monomer mixture solution, and then the temperature was raised to 80°C. The remaining monomers were then added dropwise to the reaction system over 3 h for shell-layer polymerization. The mixture was held for 3 h to form a core-shell structure of a sulfonic acid-amino dynamic hydrogen bond network.

[0088] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0089] Example 7

[0090] The raw materials for Example 7 are as follows:

[0091] raw material mass / g Remark acrylic acid 1092 Main monomer Octadecyl methacrylate 72 hydrophobic monomers sulfobetaine zwitterion monomer 36 Functional unit aminoethylaminopropylmethyldimethoxysilane 60 Paired Modifying Agents Pentaerythritol Triallyl Ether 7.2 Crosslinking agent diisopropyl peroxide 7.2 Initiator Twain 60 2.4 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0092] 1. Preparation of monomer mixed solution: Prepare acrylic acid and octadecyl methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate in a mass ratio of 1:1. While stirring continuously, add sulfobetaine zwitterionic functional monomer, pentaerythritol triallyl ether, diisopropyl peroxide dicarbonate and Tween 60 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0093] 2. Stepwise polymerization of functional monomers: 40% of the above monomer mixture solution was added to a mixed solvent of 6 kg cyclohexane and ethyl acetate in a 1:1 mass ratio, and then the temperature was raised to 40°C and held for 5 h for core-layer polymerization. After the core layer was formed, the prescribed amount of aminoethylaminopropylmethyldimethoxysilane was added to the remaining monomer mixture solution, and then the temperature was raised to 80°C. The remaining monomers were then added dropwise to the reaction system over 3 h for shell-layer polymerization. The mixture was held for 3 h to form a core-shell structure of a sulfonic acid-amino dynamic hydrogen bond network.

[0094] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0095] Comparative Example 1

[0096] The raw materials for Comparative Example 1 are as follows:

[0097] raw material mass / g Remark acrylic acid 1128 Main monomer Octadecyl methacrylate 72 hydrophobic monomers sulfobetaine zwitterion monomer 0 Functional unit aminopropyltrimethoxysilane 36 Paired Modifying Agents Pentaerythritol Triallyl Ether 7.2 Crosslinking agent diisopropyl peroxide 7.2 Initiator Twain 20 7.2 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0098] 1. Preparation of monomer mixed solution: Prepare acrylic acid and octadecyl methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate mixed solvent in a mass ratio of 1:1. While stirring continuously, add pentaerythritol triallyl ether, diisopropyl peroxide and Tween 20 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0099] 2. Stepwise polymerization of functional monomers: 40% of the above monomer mixture solution was added to a mixed solvent of 6 kg of cyclohexane and ethyl acetate in a 1:1 mass ratio. The mixture was then heated to 50°C and held for 4 hours for core-layer polymerization. After the core layer was formed, the formulated amount of aminopropyltrimethoxysilane was added to the remaining monomer mixture solution. The mixture was then heated to 70°C, and the remaining monomers were added dropwise to the reaction system over 2 hours for shell-layer polymerization. The mixture was held at this temperature for 4 hours to form a core-shell structure.

[0100] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0101] Comparative Example 2

[0102] The raw materials for Comparative Example 2 are as follows:

[0103] raw material mass / g Remark acrylic acid 1092 Main monomer Octadecyl methacrylate 72 hydrophobic monomers sulfobetaine zwitterion monomer 36 Functional unit aminopropyltrimethoxysilane 0 Paired Modifying Agents Pentaerythritol Triallyl Ether 7.2 Crosslinking agent diisopropyl peroxide 7.2 Initiator Twain 20 7.2 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0104] 1. Preparation of monomer mixed solution: Prepare acrylic acid and octadecyl methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate in a mass ratio of 1:1. While stirring continuously, add sulfobetaine zwitterionic functional monomer, pentaerythritol triallyl ether, diisopropyl peroxide dicarbonate and Tween 20 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0105] 2. Stepwise polymerization of functional monomers: 40% of the above monomer mixture solution was added to a 1:1 mixture of cyclohexane and ethyl acetate in 6 kg of solvent. The mixture was then heated to 50°C and held at that temperature for 4 h to carry out core-layer polymerization. After the core layer was formed, the temperature was raised to 70°C and the remaining monomers were added dropwise to the reaction system over 2 h to carry out shell-layer polymerization. The mixture was held at that temperature for 4 h to form a core-shell structure.

[0106] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0107] Comparative Example 3

[0108] The raw materials for Comparative Example 3 are as follows:

[0109] raw material mass / g Remark acrylic acid 1092 Main monomer Octadecyl methacrylate 72 hydrophobic monomers sulfobetaine zwitterion monomer 0 Functional unit aminopropyltrimethoxysilane 0 Paired Modifying Agents Pentaerythritol Triallyl Ether 7.2 Crosslinking agent diisopropyl peroxide 7.2 Initiator Twain 20 7.2 emulsifier Cyclohexane 3500 solvent Ethyl acetate 3500 solvent

[0110] 1. Preparation of monomer mixed solution: Prepare acrylic acid and octadecyl methacrylate according to the proportion in the table, then add 1 kg of cyclohexane and ethyl acetate mixed solvent in a mass ratio of 1:1. While stirring continuously, add pentaerythritol triallyl ether, diisopropyl peroxide and Tween 20 in sequence according to the mass in the table above, and mix evenly to obtain monomer mixed solution.

[0111] 2. Stepwise polymerization of functional monomers: 40% of the above monomer mixture solution was added to a 1:1 mixture of cyclohexane and ethyl acetate in 6 kg of solvent. The mixture was then heated to 50°C and held at that temperature for 4 h to carry out core-layer polymerization. After the core layer was formed, the temperature was raised to 70°C and the remaining monomers were added dropwise to the reaction system over 2 h to carry out shell-layer polymerization. The mixture was held at that temperature for 4 h to form a core-shell structure.

[0112] 3. The obtained reaction slurry was filtered and washed with a mixed solvent of cyclohexane and ethyl acetate in a mass ratio of 1:1 to remove unreacted monomers and oligomers. Then it was fed into a fluidized bed to dry at 80°C and pulverized and sieved to obtain polyacrylate powder with an average particle size of 2 micrometers.

[0113] Main Equipment Information Table:

[0114] Equipment Name model factory mixer RW20 IKA Viscometer DVRV Bo Lifei Spectrophotometer Type 7200 Unico centrifuge H17.5 Lu Xiangyi, Shanghai

[0115] Test method:

[0116] 1. Viscosity and transmittance of the aqueous phase of 1% gel:

[0117] Weigh 198g of deionized water into a 300ml wide-mouth plastic bottle and add 2g of polyacrylate powder. After the powder surface is moistened, place the plastic bottle under an electric mixer and stir at 800rpm for 30min. Then reduce the speed to 300rpm and neutralize with 18wt% sodium hydroxide aqueous solution while stirring until the pH reaches 7.0. Continue stirring for 30min, centrifuge to remove foam, and test the viscosity. Then, take a portion of the hydrogel and place it in a 1ml cuvette, and use a spectrophotometer to test its transmittance at 420nm.

[0118] 2. Viscosity and transmittance of the aqueous phase of 1% gel + 1% NaCl:

[0119] Weigh 198g of deionized water into a 300ml wide-mouth plastic bottle and add 2g of polyacrylate powder. After the powder surface is moistened, place the plastic bottle under an electric mixer and stir at 800rpm for 30min. Then reduce the speed to 300rpm and neutralize with 18wt% sodium hydroxide aqueous solution while stirring until the pH reaches 7.5. Add 2g of NaCl and continue stirring for 30min. Centrifuge to remove bubbles and test the viscosity. Then, take a portion of the hydrogel and place it in a 1ml cuvette, and use a spectrophotometer to test its transmittance at 420nm.

[0120] 3. Formulation viscosity and light transmittance:

[0121]

[0122] The formulation containing salt, functional proteins, and multiple active ingredients is shown in the table above. Weigh an appropriate amount of powder into a wide-mouth plastic bottle. After the powder surface is moistened with water, place the bottle under an electric mixer and stir at 800 rpm for 30 minutes. Then reduce the speed to 300 rpm and add the remaining functional substances while stirring. Finally, add sodium chloride and fragrance, and continue stirring for 30 minutes. Centrifuge to remove foam and test the viscosity. Then, take a portion of the hydrogel and place it in a 1 ml cuvette. Use a spectrophotometer to test its transmittance at 420 nm.

[0123] Aqueous gel and formulation properties of products from different embodiments:

[0124]

[0125]

[0126] Compared with Example 1, Comparative Example 1 differs in that only pairing modification auxiliaries were added to the reaction formulation, without the addition of zwitterionic functional monomers. As a result, hydrogen bonds with dynamic regulation effects could not be formed in the shell, leading to poor salt resistance and formulation performance.

[0127] Compared with Example 1, Comparative Example 2 differs in that only zwitterionic functional monomers were added to the reaction formulation, without the addition of pairing modification auxiliaries. Similarly, it is unable to form hydrogen bonds with dynamic regulation in the shell layer, resulting in poor salt resistance and formulation performance.

[0128] Compared with Example 1, Comparative Example 3 differs in that no zwitterionic functional monomers and pairing modification agents were added to the reaction formulation, the shell layer lacked substances with regulatory functions, and the salt resistance and formulation performance were very poor.

[0129] The overall evaluation of the implementation effects of this invention is as follows;

[0130] In the examples, the addition of functional monomers containing sulfonic acid groups and amino-modified siloxanes significantly improved the resistance of polyacrylates to electrolyte interference. Test data confirmed that, in solutions containing salt ions, the ionic viscosity was generally higher than that of traditional thickeners.

[0131] Because it possesses both hydrophobic-hydrophilic and ionic-hydrogen bonding interactions, the thickener of this invention maintains good appearance and viscosity in cationic, anionic, and nonionic surfactants, as well as various active protein systems, without producing undesirable precipitation or stratification. The powder obtained by this invention can be used in various personal care products such as shampoos, conditioners, lotions, serums, and facial masks, and exhibits excellent transparency, flowability, and controllability.

[0132] The advantages of the preparation and application of this invention are explained below;

[0133] 1. A core-shell structured powdered polyacrylate with hydrophobic-hydrophilic and ionic-hydrogen bonding interactions was constructed through a stepwise polymerization process. A dynamic hydrogen bond network structure of sulfonic acid groups and amino groups was introduced into the shell layer. This structure maintains network stability, high viscosity, and transparency in formulations with high ionic strength, significantly improving salt resistance and compatibility. The product can be used in personal care products such as shampoos, shower gels, conditioners, lotions, serums, and facial masks. It exhibits good compatibility with various anionic and cationic surfactants and active ingredients, and is not prone to turbidity, flocculation, or precipitation, meeting the thickening and stabilization requirements of different formulation systems.

[0134] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A process for the preparation of a high efficiency thickening polyacrylate, characterized in that, The preparation method comprises the following steps: S1: N,N-dimethylethylene diamine and methacryloyl chloride are subjected to a first step amidation reaction, 1,3-propanesultone is added to perform a second step quaternary ammonium / ring-opening reaction, and post-treatment is performed to obtain a sulfobetaine type zwitterionic functional monomer; S2: acrylic acid is mixed with a hydrophobic monomer, the zwitterionic functional monomer is added, a crosslinking agent, an initiator and an emulsifier are mixed to obtain a monomer mixed solution; S3: The functional monomer is stepwise polymerized, part of the monomer mixed solution is first added to perform core layer polymerization, after the core layer is formed, the temperature is increased, and amino-modified siloxane is added to the remaining monomer mixed solution to perform shell layer polymerization, thereby forming a core-shell structure; S4: Filtration, washing, removal of unreacted monomers and oligomers, drying, crushing and obtaining a polyacrylate powder.

2. The production method according to claim 1, characterized by, In S1, the molar ratio of N,N-dimethylethylene diamine to methacryloyl chloride is 1:1.05-1.10; And / or, the first step amidation reaction time in S1 is 3-5 hours; And / or, the molar ratio of N,N-dimethylethylene diamine to 1,3-propanesultone in S1 is 1:1.0-1.05; And / or, the second step quaternary ammonium / ring-opening reaction time in S1 is 7-9 hours.

3. The production method according to claim 1, characterized by, In S2, the amount of acrylic acid accounts for 85-97wt% of the total amount of acrylic acid, hydrophobic monomer and zwitterionic monomer; And / or, the hydrophobic monomer in S2 is C10-C30 alkyl acrylate; Preferably, the amount of hydrophobic monomer accounts for 2-10wt% of the total amount of acrylic acid, hydrophobic monomer and zwitterionic monomer; And / or, the amount of zwitterionic functional monomer in S2 accounts for 1-5wt% of the total amount of acrylic acid, hydrophobic monomer and zwitterionic monomer; And / or, the crosslinking agent in S2 is one or more of allyl ether crosslinking agents, preferably pentaerythritol triallyl ether, trimethylolpropane triallyl ether, trimethylolpropane diallyl ether and ethylene glycol diallyl ether; Preferably, the total amount of crosslinking agent accounts for 0.2-1% of the total amount of monomer; And / or, the initiator in S2 is one or more of peroxide initiators, preferably diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, di(hexadecyl) peroxydicarbonate, diperazelaoyl, benzoyl peroxide; Preferably, the total amount of initiator accounts for 0.2-1% of the total amount of monomer; And / or, the emulsifier in S2 is one or more of polyoxyethylene sorbitan fatty acid esters, preferably Tween 20, Tween 40, Tween 60 and Tween 80; Preferably, the amount of emulsifier accounts for 0.2-1wt% of the total amount of monomer.

4. The preparation method according to claim 1, characterized in that, In S3, the solvent is a weak polar and / or non-polar solvent, preferably one or more of cyclohexane, ethyl acetate and benzene, more preferably cyclohexane and / or ethyl acetate; Preferably, the mass fraction of the solvent in the reaction system is 80-90%; And / or, the amount of monomer mixed solution added in the core layer polymerization in S3 accounts for 30-50% of the total mass of the monomer mixed solution; Preferably, the temperature of the core layer polymerization is 40-60℃, and the reaction time is 3-5 hours; And / or, the amino-modified siloxane in S3 is one or more of aminopropyl triethoxysilane, aminopropyl trimethoxysilane and aminoethyl aminopropyl methyl dimethoxysilane. Preferably, the amino-modified siloxane is used in an amount of 0.1-2 wt% of the total monomers; Preferably, the temperature of the shell polymerization is 60-80℃, and the remaining monomers are added and kept for 3-5 hours after the addition is completed.

5. The preparation method according to claim 1, characterized in that, In S4, fluidized bed drying or spray drying is used for drying.

6. A highly efficient thickening polyacrylate, which is produced by the production method according to any one of claims 1 to 5, characterized in that The polyacrylate is a powder thickening agent with an average particle size of 1-20 microns, preferably 1-3 microns; And / or, the viscosity of the polyacrylate is greater than 10000 mPa·s at 25℃; And / or, the polyacrylate does not flocculate and precipitate when combined with functional proteins and / or nutritional factors.

7. Use of the high-efficiency thickening polyacrylate prepared by the method of any one of claims 1-5, or the polyacrylate of claim 6, as a thickening agent, preferably in personal care products, more preferably in shampoo, body wash, hair conditioner, emulsion, serum, and mask.

8. A method for using the high-efficiency thickening polyacrylate prepared by the method of any one of claims 1-5, or the polyacrylate of claim 6, or in the use of claim 7, wherein the polyacrylate is pre-dispersed with water in a mass ratio of ≤1:100, and swells to form a high-viscosity transparent colloid under the condition of pH 5.0-8.0.

Images