Preparation method of fast-wetting salt-tolerant polyacrylic resin

Abstract

The application discloses a preparation method of a fast-wetting salt-resistant polyacrylic acid resin, which comprises the following steps: (1) preparing an initiator solution: dissolving an initiator in a solvent to obtain a solution system A, wherein the initiator is selected from azobisisobutyronitrile or azobisisoheptyl nitrile; (2) preparing a monomer system: mixing monomer acrylic acid, allyl triethoxysilane, maleic anhydride and a crosslinking agent pentaerythritol triallyl ether to obtain a monomer system B; and (3) obtaining the fast-wetting salt-resistant polyacrylic acid resin through reaction: under the atmosphere of an inert gas and at a heating temperature, the solution system A and the monomer system B are simultaneously added into an emulsifier solution drop by drop, and then the reaction is carried out under heat preservation. The method is simple in process, and the obtained polyacrylic acid resin has the advantages of fast wetting, good salt resistance, excellent light transmittance and viscosity in a salt environment and the like.

Description

Technical Field

[0001] This invention relates to resin materials, and more specifically to a method for preparing a fast-wetting, salt-resistant polyacrylic acid resin. Background Technology

[0002] Polyacrylic acid resin is a polymer obtained by crosslinking monomers such as acrylic acid or methacrylic acid. Due to its good thickening properties, ability to improve the thixotropic properties of gel systems, and good stability, it is widely used in cosmetics, chemical and pharmaceutical fields.

[0003] CN102675558A discloses a method for preparing a salt-resistant thickener, which uses a polyoxyethylene ether-type nonionic hydrophilic monomer containing allyl and long-chain fatty alcohol segments to improve the salt resistance of the polymer, but the acrylic polymer gel prepared by it has poor light transmittance.

[0004] CN102964504A discloses a method for preparing a salt-resistant thickener. By introducing a small amount of octadecyl hydrophobic long chains onto the main chain of ammonium polyacrylate, a polyacrylic acid thickener with improved temperature and salt resistance can be obtained. The challenge of this process lies in improving salt resistance while preventing a decrease in light transmittance. It is difficult to reconcile the salt resistance and light transmittance of the resulting polyacrylic acid thickener.

[0005] CN104861104A discloses a method for preparing a fast-wetting carboxylic acid copolymer thickener. This process is complex, has low process stability, and the resulting polyacrylic acid thickener has poor salt resistance. Summary of the Invention

[0006] To overcome the above problems, the inventors discovered that by selecting monomers and configuring all monomers in a solution system, and then adding them dropwise to an initiator solution system, a fast-wetting, salt-resistant polyacrylic acid resin can be obtained. The process is simple, and the resulting polyacrylic acid resin has advantages such as rapid wetting, good salt resistance, and maintaining excellent light transmittance and viscosity in a salt environment, thus completing the present invention.

[0007] The purpose of this invention is to provide the following aspects:

[0008] 1. A method for preparing a fast-wetting, salt-resistant polyacrylic acid resin, the method comprising:

[0009] (1) Preparation of initiator solution: Dissolve the initiator in a solvent to obtain solution system A, wherein the initiator is selected from azobisisobutyronitrile or azobisisoheptanenitrile;

[0010] (2) Preparation of monomer system: Mix the monomers acrylic acid, allyltriethoxysilane, maleic anhydride and crosslinking agent pentaerythritol trially propyl ether to obtain monomer system B;

[0011] (3) The reaction yields fast-wetting, salt-resistant polyacrylic acid resin: In an inert gas atmosphere and at a heating temperature, solution system A and monomer system B are simultaneously added dropwise to the emulsifier solution, and the reaction is maintained at the temperature.

[0012] 2. The method for preparing the fast-wetting, salt-resistant polyacrylic acid resin as described in 1 above, wherein the solvent is a mixed solvent of cyclohexane and ethyl acetate, and the weight of ethyl acetate accounts for 1-50% of the total weight of the mixed solvent.

[0013] 3. The preparation method of the fast-wetting salt-resistant polyacrylic acid resin as described in 2 above, wherein the weight of ethyl acetate accounts for 15-20% of the total weight of the mixed solvent.

[0014] 4. The method for preparing the fast-wetting, salt-resistant polyacrylic acid resin as described in 2 above, wherein the weight of ethyl acetate accounts for 16.7% of the total weight of the mixed solvent.

[0015] 5. The preparation method of the fast-wetting, salt-resistant polyacrylic acid resin as described in 1 above, wherein the proportions of acrylic acid, allyltriethoxysilane, maleic anhydride, and the crosslinking agent pentaerythritol triallyl ether are as follows:

[0016]

[0017]

[0018] 6. The preparation method of the fast-wetting, salt-resistant polyacrylic acid resin as described in 5 above, wherein the proportions of acrylic acid, allyltriethoxysilane, maleic anhydride, and the crosslinking agent pentaerythritol triallyl ether are as follows:

[0019]

[0020] 7. The preparation method of the fast-wetting, salt-resistant polyacrylic acid resin as described in 5 above, wherein the proportions of acrylic acid, allyltriethoxysilane, maleic anhydride, and the crosslinking agent pentaerythritol triallyl ether are as follows:

[0021]

[0022] 8. The method for preparing the fast-wetting, salt-resistant polyacrylic acid resin as described in 1 above, wherein the weight of the initiator used is 0.01-2% of the weight of the acrylic acid.

[0023] 9. The method for preparing the fast-wetting, salt-resistant polyacrylic acid resin as described in 1 above, wherein the emulsifier is selected from glyceryl stearate, Span 60 or Span 80, and the amount of emulsifier used is 0.01-2% of the weight of acrylic acid.

[0024] 10. In the preparation method of the fast-wetting salt-resistant polyacrylic acid resin as described in 1 above, the heating temperature in step (3) is 40-80℃;

[0025] The dripping time is 0.5-2 hours;

[0026] The heat preservation reaction time is 1-5 hours.

[0027] The beneficial effects of this invention include:

[0028] (1) The method of the present invention is simple in process, easy to operate and easy to control;

[0029] (2) Select a specific combination of monomers, and combine them with a specific crosslinking agent and initiator to obtain high-performance polyacrylic resin through a simple process;

[0030] (3) The acrylic resin obtained by the method of the present invention has good rapid wetting and salt resistance, and can maintain excellent light transmittance and viscosity in a salt environment. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more apparent.

[0032] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0033] In this invention, the solvent system used is a mixture of cyclohexane and ethyl acetate. This solvent system not only effectively dissolves the initiator but also provides a stable solvent environment for the entire reaction, ensuring the performance of the resulting acrylic resin product.

[0034] In a preferred embodiment, the weight of ethyl acetate accounts for 1-50% of the total weight of the mixed solvent, more preferably 15-20%, and most preferably 16.7%.

[0035] In this invention, acrylic acid is selected as the base monomer, and allyltriethoxysilane and maleic anhydride are selected as modifying monomers. When these three monomers are combined in specific amounts, a high-performance acrylic resin can be obtained. In particular, the effect is further enhanced by adding a specific amount of pentaerythritol triallyl ether as a crosslinking agent.

[0036] In a preferred embodiment, the proportions of acrylic acid, allyltriethoxysilane, maleic anhydride, and the crosslinking agent pentaerythritol triallyl ether are as follows:

[0037]

[0038] More preferably, the ratio of acrylic acid, allyltriethoxysilane, maleic anhydride, and the crosslinking agent pentaerythritol triallyl ether is as follows:

[0039]

[0040] Most preferably, the ratio of acrylic acid, allyltriethoxysilane, maleic anhydride, and the crosslinking agent pentaerythritol triallyl ether is as follows:

[0041]

[0042] In the method of the present invention, azobisisobutyronitrile or azobisisoheptanenitrile is selected as the initiator, with azobisisobutyronitrile being more preferred. The inventors have found that its solution has a good initiation effect with the above monomer system, and the resulting acrylic resin has good performance.

[0043] In a preferred embodiment, the amount of initiator is 0.01-2% of the weight of acrylic acid, preferably 1%.

[0044] In the method of the present invention, an emulsifier selected from glyceryl stearate, Span 60 or Span 80 is used as an emulsifier, which can better promote the performance of the obtained acrylic resin.

[0045] In a preferred embodiment, the amount of emulsifier used is 0.01-2% of the weight of acrylic acid, preferably 0.2-0.6%, and most preferably 0.5%.

[0046] In this invention, the reaction is carried out under an inert atmosphere to ensure a reliable and stable degree of reaction. There are no particular limitations on the inert atmosphere, but a nitrogen atmosphere is preferred.

[0047] In a preferred embodiment, the reaction is carried out at a heating temperature, for example, a heating temperature of 40-80°C, preferably 50-55°C, and more preferably 50°C;

[0048] In a preferred embodiment, the initiator solution system A and monomer system B are added dropwise over a period of 0.5-2 hours, preferably 1 hour, followed by a reaction at a constant temperature for 1-5 hours, preferably 3 hours.

[0049] After the heat treatment reaction, granular acrylic resin can be obtained through conventional post-processing, such as cooling, filtration, washing, drying, and pulverization, for subsequent use.

[0050] Example

[0051] The present invention is further described below through specific examples; however, these examples are merely exemplary and do not constitute any limitation on the scope of protection of the present invention.

[0052] Example 1

[0053] (1) Preparation of initiator solution: Mix and dissolve 1.0 g azobisisobutyronitrile, 16.7 g ethyl acetate and 83.3 g cyclohexane to obtain solution system A;

[0054] (2) Preparation of monomer system: Mix 100g acrylic acid, 2.5g allyltriethoxysilane, 0.5g maleic anhydride and 0.5g pentaerythritol triallyl ether to obtain monomer system B;

[0055] (3) Reaction: Add 60g ethyl acetate and 300g cyclohexane to a 1000mL four-necked flask, mix well, add 0.5g glyceryl stearate, purge with nitrogen for protection, stir and heat to 50℃, and simultaneously add solution A and solution B dropwise for 1h. After the addition is completed, keep warm for 3h, and then cool, filter, wash, dry and pulverize to obtain fast-wetting salt-resistant polyacrylic acid resin 1.

[0056] Example 2

[0057] (1) Preparation of initiator solution: Mix and dissolve 1.0 g azobisisobutyronitrile, 20 g ethyl acetate and 80 g cyclohexane to obtain solution system A;

[0058] (2) Preparation of monomer system: Mix 100g acrylic acid, 2.5g allyltriethoxysilane, 0.5g maleic anhydride and 0.5g pentaerythritol triallyl ether to obtain monomer system B;

[0059] (3) Reaction: Add 75g ethyl acetate and 300g cyclohexane to a 1000mL four-necked flask, mix well, add 0.6g Span80, purge with nitrogen for protection, stir and heat to 55℃, and simultaneously add solution A and solution B dropwise for 1h. After the addition is completed, keep warm for 3h, and then cool, filter, wash, dry and pulverize to obtain fast-wetting salt-resistant polyacrylic acid resin 2.

[0060] Example 3

[0061] (1) Preparation of initiator solution: Mix and dissolve 1.0 g azobisisobutyronitrile, 15 g ethyl acetate and 85 g cyclohexane to obtain solution system A;

[0062] (2) Preparation of monomer system: Mix 100g acrylic acid, 2.5g allyltriethoxysilane, 0.5g maleic anhydride and 0.5g pentaerythritol triallyl ether to obtain monomer system B;

[0063] (3) Reaction: Add 60g of ethyl acetate and 340g of cyclohexane to a 1000mL four-necked flask, mix well, add 0.5g of Span60, purge with nitrogen for protection, stir and heat to 50℃, and simultaneously add solution A and solution B dropwise for 1h. After the addition is completed, keep warm for 3h, and then cool, filter, wash, dry and pulverize to obtain fast-wetting salt-resistant polyacrylic acid resin 3.

[0064] Comparative Example 1

[0065] (1) Preparation of initiator solution: Mix and dissolve 1.0 g of initiator acetylcyclohexyl sulfonyl peroxide, 16.7 g of ethyl acetate and 83.3 g of cyclohexane to obtain solution system A;

[0066] (2) Preparation of monomer system: Mix 100g acrylic acid, 2.5g lauryl methacrylate, 0.5g maleic anhydride and 0.5g pentaerythritol triallyl ether to obtain monomer system B;

[0067] (3) Reaction: Add 60g ethyl acetate and 300g cyclohexane to a 1000mL four-necked flask, mix well, add 0.5g glyceryl stearate, purge with nitrogen for protection, stir and heat to 50℃, and simultaneously add solution A and solution B dropwise for 1h. After the addition is completed, keep warm for 3h, then cool, filter, wash, dry and pulverize to obtain polyacrylic acid resin@11.

[0068] Comparative Example 2

[0069] (1) Preparation of initiator solution: Mix and dissolve 1.0g of initiator benzoyl peroxide, 16.7g of ethyl acetate and 83.3g of cyclohexane to obtain solution system A;

[0070] (2) Preparation of monomer system: Mix 100g acrylic acid, 2.5g lauryl methacrylate, 0.5g methacrylic acid and 0.5g trimethylolpropane diallyl ether to obtain monomer system B;

[0071] (3) Reaction: Add 60g of ethyl acetate and 300g of cyclohexane to a 1000mL four-necked flask, mix well, add 0.5g of sodium fatty alcohol polyoxyethylene ether sulfate, purge with nitrogen for protection, stir and heat to 60℃, and simultaneously add solution A and solution B dropwise for 2h. After the addition is completed, keep warm for 6h, then cool, filter, wash, dry and pulverize to obtain polyacrylic acid resin@12.

[0072] Comparative Example 3

[0073] (1) Preparation of initiator solution: Mix and dissolve 1.0g of initiator ammonium persulfate, 16.7g of ethyl acetate and 83.3g of cyclohexane to obtain solution system A;

[0074] (2) Preparation of monomer system: Mix 100g acrylic acid, 2.5g lauryl methacrylate, 0.5g maleic anhydride and 0.5g pentaerythritol triallyl ether to obtain monomer system B;

[0075] (3) Reaction: Add 60g ethyl acetate and 300g cyclohexane to a 1000mL four-necked flask, mix well, add 0.5g sodium dodecyl sulfate, purge with nitrogen for protection, stir and heat to 50℃, and simultaneously add solution A and solution B dropwise for 1h. After the addition is completed, keep warm for 3h, then cool, filter, wash, dry and pulverize to obtain polyacrylic acid resin@13.

[0076] Test case

[0077] The properties of the acrylic resin obtained above were tested, and the results are as follows:

[0078]

[0079] The polyacrylic resins of Examples 1-3, compared to the polyacrylic resins of Comparative Examples 1-3, have better wettability, salt resistance, light transmittance, and viscosity. When applied in formulations, they can effectively prevent the polyacrylic resin from combining with water to form a film, slow down further wetting of the interior by water, thus preventing agglomeration, and also cause viscosity loss (decrease). The resulting gel surface is smoother and can operate stably in high salinity environments, maintaining good chemical properties.

[0080] The present invention has been described in detail above with reference to preferred embodiments and exemplary examples. However, it should be noted that these specific embodiments are merely illustrative explanations of the invention and do not constitute any limitation on the scope of protection of the invention. Various improvements, equivalent substitutions, or modifications can be made to the technical content and embodiments of the present invention without departing from the spirit and scope of protection of the invention, and all such modifications fall within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for preparing a fast-wetting salt-tolerant polyacrylic acid resin, comprising: (1) preparing an initiator solution: dissolving an initiator in a solvent to obtain a solution system A, wherein the initiator is selected from azobisisobutyronitrile or azobisisoheptyl nitrile; (2) preparing a monomer system: mixing monomers of acrylic acid, allyl triethoxysilane, maleic anhydride and a crosslinking agent pentaerythritol triallyl ether to obtain a monomer system B; (3) obtaining the fast-wetting salt-tolerant polyacrylic acid resin by reaction: under an inert gas atmosphere and at a heating temperature, simultaneously adding the solution system A and the monomer system B into an emulsifier solution, and then incubating for reaction; The amount of acrylic acid, allyl triethoxysilane, maleic anhydride and pentaerythritol triallyl ether is as follows: acrylic acid 100 parts by weight allyl triethoxysilane 0.1-6 parts by weight maleic anhydride 0.1-2 parts by weight pentaerythritol triallyl ether 0.2-2 parts by weight.

2. The method of making a fast-wetting, salt-tolerant polyacrylic acid resin according to claim 1, wherein The solvent is a mixed solvent of cyclohexane and ethyl acetate, and the weight of ethyl acetate accounts for 1-50% of the total weight of the mixed solvent.

3. The preparation method of the fast-wetting, salt-resistant polyacrylic acid resin as described in claim 2, characterized in that, The weight of ethyl acetate accounts for 15-20% of the total weight of the mixed solvent.

4. The preparation method of the fast-wetting, salt-resistant polyacrylic acid resin as described in claim 2, characterized in that, The weight of ethyl acetate accounts for 16.7% of the total weight of the mixed solvent.

5. The method of making a fast-wetting, salt-tolerant polyacrylic acid resin according to claim 1, wherein The amount of acrylic acid, allyl triethoxysilane, maleic anhydride and pentaerythritol triallyl ether is as follows: acrylic acid 100 parts by weight allyl triethoxysilane 2-3 parts by weight maleic anhydride 0.4-0.8 parts by weight pentaerythritol triallyl ether 0.4-0.6 parts by weight.

6. The method of making a fast-wetting, salt-tolerant polyacrylic acid resin according to claim 1, wherein, The amount of acrylic acid, allyl triethoxysilane, maleic anhydride and pentaerythritol triallyl ether is as follows:

7. The method of making a fast-wetting, salt-tolerant polyacrylic acid resin according to claim 1, wherein The weight of the initiator used is 0.01-2% of the weight of the acrylic acid.

8. The method of making a fast-wetting, salt-tolerant polyacrylic acid resin according to claim 1, wherein, The emulsifier is selected from glyceryl stearate, Span 60 or Span 80, and the amount of the emulsifier is 0.01-2% of the weight of the acrylic acid.

9. The method of making a fast-wetting, salt-tolerant polyacrylic acid resin of claim 1, wherein, In step (3), The heating temperature is 40-80℃; The dropping time is 0.5-2h; The incubation time for reaction is 1-5h.

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