Emulsion type acrylic acid retanning agent and preparation method thereof

Abstract

The invention discloses an emulsion type acrylic acid retanning agent and a preparation method thereof, and relates to the technical field of leather chemical production, and the preparation method of the emulsion type acrylic acid retanning agent comprises the following steps: reacting fatty alcohol (acid) polyoxyethylene ether (ester) with maleic anhydride to obtain an intermediate; and initiating copolymerization with a vinyl monomer in a reaction medium water by using persulfate to obtain an emulsion type product. Wherein the mass ratio of the intermediate to the ethylene monomer is 1.0: (1.2-3.6), the reaction temperature is 80-95 DEG C, the reaction time is 3-5 hours, the pH value is 3-4, the use amount of the initiator is 0.5-2.5% of the total mass of the intermediate and the monomer, the finished product is stable and not layered, the preparation is simple, the cost is lower, and the processed leather is full, soft and good in filling.

Description

Technical Field

[0001] The invention relates to the technical field of leather chemical production, in particular to an emulsion type acrylic acid retanning agent and a preparation method thereof. Background Art

[0002] Emulsion type acrylic retanning agent is a chemical widely used in leather processing, which can improve the quality and performance of leather. With the development of the leather industry, the requirements for leather retanning agents are getting higher and higher. Emulsion type acrylic retanning agent has gradually become one of the important varieties of leather retanning agents due to its good performance.

[0003] To manufacture this type of product, some use acrylic acid and natural oils, such as sulfated castor oil, to carry out emulsion grafting copolymerization in water; some use acrylic acid and fatty alcohol (meth) acrylate emulsion copolymerization in the presence of an emulsifier to obtain; and some use alkyl polyoxyethylene ether (meth) acrylate copolymerization with acrylic acid. Among them, the product prepared by copolymerization of alkyl polyoxyethylene ether (meth) acrylate and acrylic acid is plump and soft, has good filling properties, and its cost is relatively high. Currently, only imported products are widely used. However, the above products have the disadvantage of poor stability, which is specifically reflected in the inconvenience of use in winter, easy stratification, and some are soft and insufficiently filled. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] Therefore, the first object of the present invention is to provide a method for preparing an emulsion type acrylic retanning agent, wherein the finished product is stable and non-stratified, the preparation is simple, the cost is low, and the processed leather is plump, soft, and well filled.

[0006] To achieve the above object, the first aspect of the present invention provides a method for preparing an emulsion type acrylic acid retanning agent, comprising the following steps: S1, a nonionic surfactant and maleic anhydride react to obtain an intermediate; S2, the intermediate and the vinyl monomer undergo copolymerization reaction under the action of the reaction medium, the emulsifier and the initiator to obtain an emulsion type acrylic acid retanning agent.

[0007] Furthermore, the nonionic surfactant is selected from: one of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ether, fatty alcohol polyoxyethylene ester, and fatty acid polyoxyethylene ester.

[0008] Furthermore, the polymerization reaction temperature is 80-95° C., the reaction time is 3-5 hours, and the pH is controlled at 3-4.

[0009] Furthermore, the vinyl monomer is selected from one or more of acrylic acid, methacrylic acid, acrylamide and maleic acid; and the mass ratio of the intermediate to the vinyl monomer is 1.0:1.2-3.6.

[0010] Furthermore, the initiator is selected from one or a combination of ammonium persulfate, potassium persulfate and sodium persulfate, and the amount used is 0.5-2.5% of the total mass of the intermediate and the monomer; and the reaction medium is water.

[0011] Furthermore, in the nonionic surfactant, the alcohol or acid C number of the saturated / unsaturated fatty alcohol or unsaturated fatty acid is 10 to 22, and the number of polyoxyethylene chain segments is 3 to 10.

[0012] Furthermore, the molar ratio of the nonionic surfactant to maleic anhydride is 1:1.02-1.05.

[0013] Furthermore, the emulsifier is one or a mixture of dodecylbenzenesulfonic acid, dodecylsulfonic acid, sodium dodecyl sulfate, disodium alkyl succinate, and the amount used is 1 to 4.5% of the total mass of the intermediate and the monomer.

[0014] Furthermore, the intermediate reaction temperature is 90-115° C., and the reaction time is 2-3 hours.

[0015] Another object of the present invention is to provide an emulsion type acrylic acid retanning agent obtained by the above-mentioned preparation method.

[0016] Beneficial effects: The present invention obtains an intermediate containing unsaturated double bonds by reacting fatty alcohol (acid) polyoxyethylene ether (ester) with maleic anhydride, and then performs emulsion polymerization with ethylene monomers in water to obtain the product. The finished product is stable and does not delaminate, is simple to make, and has low cost. The processed leather is plump, soft, and well filled.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0018] Embodiments of the present invention are described in detail below, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The following examples are exemplary and are intended to be used to explain the present invention, but are not to be construed as limitations of the present invention. On the contrary, embodiments of the present invention include all changes, modifications and equivalents falling within the spirit and connotation of the appended claims.

[0019] The following describes the emulsion type acrylic retanning agent and the preparation method thereof according to the embodiment of the present invention.

[0020] The preparation method of the emulsion type acrylic acid retanning agent of the present invention is achieved by the following steps: Step 1: The molar ratio of nonionic surfactant to maleic anhydride is 1:1.05, the reaction temperature is 90-115° C., and the reaction time is 2-3 hours to obtain an intermediate.

[0021] The nonionic surfactant raw material is selected from one of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ether, fatty alcohol polyoxyethylene ester and fatty acid polyoxyethylene ester, wherein the C number of the alcohol or acid is 10 to 22 saturated / unsaturated fatty alcohol or unsaturated fatty acid, and the number of polyoxyethylene chain segments is 3 to 10. The intermediate is reacted with maleic anhydride to obtain an intermediate, which is used to replace the expensive commercial alkyl polyoxyethylene ether (meth) acrylate, with low cost and stable finished product without stratification.

[0022] Step 2: The intermediate and the vinyl monomer undergo copolymerization under the action of a reaction medium, an emulsifier, and an initiator to obtain an emulsion type acrylic acid retanning agent. The polymerization temperature is 80 to 95° C. and the reaction time is 3 to 5 hours.

[0023] The reaction medium is water, preferably deionized water. The emulsifier is a mixture of one or two of dodecylbenzene sulfonic acid, dodecyl sulfonic acid, sodium dodecyl sulfate, and disodium alkyl succinate. The dosage is 1 to 4.5% of the total mass of the intermediate and monomer. The initiator is selected from one or a combination of ammonium persulfate, sodium persulfate or potassium persulfate. The dosage is 0.5 to 2.5% of the total mass of the intermediate and monomer. The vinyl monomer is selected from one or more of acrylic acid, methacrylic acid, acrylamide and maleic acid. The mass ratio of the intermediate to the vinyl monomer is 1.0:1.2 to 3.6. If the vinyl monomer is one or more of acrylic acid, methacrylic acid and maleic acid, it needs to be moderately neutralized with a 30% NaOH solution, and the pH is controlled at 3 to 4.

[0024] In step 2, in the presence of an emulsifier, the intermediate is added once or in portions, the temperature is raised to 80-90° C., and ethylene monomer and initiator solution are continuously added dropwise. The addition time is 90-120 minutes and the reaction time is 3-5 hours.

[0025] Example 1 32.6 parts of AEO-5 fatty alcohol (acid) polyoxyethylene ether (ester) and 8 parts of maleic anhydride are added to the reactor, stirred and heated, kept at 100-110°C for 2.5 hours, and after the reaction is completed, 5 parts of sodium dodecylbenzene sulfonate and 290 parts of deionized water are added. 195 parts of acrylic acid are added to 129 parts of deionized water, and 37.4 parts of 30% NaOH solution are added under stirring for standby use. 31.5 parts of 4% ammonium persulfate solution and slightly neutralized acrylic acid solution are added dropwise at 80-90°C for 60 minutes. After adding the materials, keep warm for 2 hours, cool down and discharge the materials to obtain an emulsion type acrylic acid retanning agent with a solid content of about 33%. The finished product is stored for 12 months without stratification, and the leather obtained is plump, soft and well filled.

[0026] Example 2 33.8 parts of AEO-7 fatty alcohol (acid) polyoxyethylene ether (ester) and 6.9 parts of maleic anhydride are added to the reactor, stirred and heated, kept at 100-110°C for 2.5 hours, and after the reaction is completed, 5 parts of sodium dodecylbenzene sulfonate and 290 parts of deionized water are added. 195 parts of acrylic acid are added to 129 parts of deionized water, and 37.4 parts of 30% NaOH solution are added under stirring for standby use. 31.5 parts of 4% ammonium persulfate solution and slightly neutralized acrylic acid solution are added dropwise at 80-90°C for 60 minutes. After adding the materials, keep warm for 2 hours, cool down and discharge the materials to obtain an emulsion type acrylic acid retanning agent with a solid content of about 33%. The finished product is stored for 12 months without stratification, and the leather obtained is plump, soft and well filled.

[0027] Example 3 12.8 parts of AEO-3 fatty alcohol (acid) polyoxyethylene ether (ester), 28.4 parts of AEO-7 and 9.85 parts of maleic anhydride are added to the reactor, stirred and heated, kept at 100-110°C for 2.5 hours, and the reaction is completed. 5 parts of sodium dodecylbenzene sulfonate and 290 parts of deionized water are added. 195 parts of acrylic acid are added to 129 parts of deionized water, and 37.4 parts of 30% NaOH solution are added under stirring for standby use. 31.5 parts of 4% ammonium persulfate solution and slightly neutralized acrylic acid solution are added dropwise at 80-90°C for 60 minutes. After adding the materials, keep warm for 2 hours, cool down and discharge the materials to obtain an emulsion type acrylic acid retanning agent with a solid content of about 33%. The finished product is stored for 12 months without stratification, and the leather obtained is plump, soft and well filled.

[0028] Example 4 61 parts of polyethylene glycol, 400 parts of oleate and 9 parts of maleic anhydride are added to the reactor, stirred and heated, kept at 100-110°C for 2.5 hours, and after the reaction is completed, 5 parts of sodium dodecylbenzene sulfonate and 290 parts of deionized water are added. 150 parts of acrylic acid are added to 106 parts of deionized water, and 33 parts of 30% NaOH solution are added under stirring for neutralization. 24 parts of 14% ammonium persulfate solution and slightly neutralized acrylic acid solution are added dropwise at 80-90°C for 60 minutes. After adding the materials, keep warm for 2 hours, cool down and discharge the materials to obtain an emulsion type acrylic acid retanning agent with a solid content of about 33%. The finished product has not been stratified after being stored for 10 months, and the leather obtained is plump, soft and well filled.

[0029] In summary, the present invention obtains an intermediate containing an unsaturated double bond by reacting a fatty alcohol (acid) polyoxyethylene ether (ester) with maleic anhydride, and then performs emulsion polymerization with an ethylene monomer in water to obtain a product. Compared with the product obtained by emulsion copolymerization of acrylic acid and fatty alcohol (meth) acrylate in the presence of an emulsifier; or the product prepared by copolymerization of alkyl polyoxyethylene ether (meth) acrylate and acrylic acid, the cost is lower and the finished product has better stability, is not easy to delaminate, and the processed leather is plump, soft and well filled.

[0030] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and deform the above embodiments within the scope of the present invention.

Claims

1. A method for preparing an emulsion type acrylic acid retanning agent, characterized in that: The following steps are involved: S1, a nonionic surfactant and maleic anhydride react to obtain an intermediate; S2, the intermediate and the vinyl monomer undergo copolymerization reaction under the action of the reaction medium, the emulsifier and the initiator to obtain an emulsion type acrylic acid retanning agent.

2. The method for preparing an emulsion type acrylic acid retanning agent according to claim 1, characterized in that: The nonionic surfactant is selected from the group consisting of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ether, fatty alcohol polyoxyethylene ester, and fatty acid polyoxyethylene ester.

3. The method for preparing an emulsion type acrylic acid retanning agent according to claim 1, characterized in that: The polymerization reaction temperature is 80-95° C., the reaction time is 3-5 hours, and the pH is controlled at 3-4.

4. The method for preparing an emulsion type acrylic acid retanning agent according to claim 1, characterized in that: The vinyl monomer is selected from one or more of acrylic acid, methacrylic acid, acrylamide and maleic acid; the mass ratio of the intermediate to the vinyl monomer is 1.0:1.2-3.

6.

5. The method for preparing an emulsion type acrylic acid retanning agent according to claim 1, characterized in that: The initiator is selected from one or a combination of ammonium persulfate, potassium persulfate and sodium persulfate, and the amount used is 0.5-2.5% of the total mass of the intermediate and the monomer; the reaction medium is water.

6. The method for preparing an emulsion type acrylic acid retanning agent according to claim 2, characterized in that: In the nonionic surfactant, the alcohol or acid C number is 10 to 22, and the saturated / unsaturated fatty alcohol or unsaturated fatty acid has 3 to 10 polyoxyethylene chain segments.

7. The method for preparing an emulsion type acrylic acid retanning agent according to claim 2, characterized in that: The molar ratio of the nonionic surfactant to maleic anhydride is 1:1.02-1.

05.

8. The method for preparing an emulsion type acrylic acid retanning agent according to claim 1, characterized in that: The emulsifier is one or a mixture of dodecylbenzenesulfonic acid, dodecylsulfonic acid, sodium dodecyl sulfate, disodium alkyl succinate, and the amount used is 1-4.5% of the total weight of the intermediate and the monomer.

9. The method for preparing an emulsion type acrylic acid retanning agent according to claim 1, characterized in that: The intermediate reaction temperature is 90-115° C., and the reaction time is 2-3 hours.

10. An emulsion type acrylic retanning agent, characterized in that The emulsion type acrylic retanning agent is obtained by the preparation method of any one of claims 1 to 9.