Preparation method of electronic-grade water-soluble polycarboxylic acid

Abstract

The invention discloses a preparation method of electronic-grade water-soluble polycarboxylic acid, and belongs to the technical field of polycarboxylic acid purification. The method comprises the following steps: preparing a water-soluble polycarboxylic acid aqueous solution, enabling the water-soluble polycarboxylic acid aqueous solution to sequentially pass through an anion exchange column filled with anion exchange resin and a cation exchange column filled with cation exchange resin, and collecting the electronic-grade water-soluble polycarboxylic acid aqueous solution before the cation exchange column reaches a critical point for adsorbing qualified products; transferring the water-soluble polycarboxylic acid aqueous solution continuously treated by the cation exchange column into a container containing cation exchange resin, stirring and adsorbing for 1-2 hours, and performing suction filtration to obtain an electronic-grade water-soluble polycarboxylic acid aqueous solution; and after the anion exchange column and the cation exchange column treat a certain amount of water-soluble polycarboxylic acid aqueous solution, the water-soluble polycarboxylic acid aqueous solution is replaced. According to the purification method of the electronic-grade water-soluble polycarboxylic acid provided by the invention, through combination of dynamic adsorption and static adsorption, the use amount of resin is reduced without increasing working hours, the production cost is effectively reduced, and industrial popularization is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of polycarboxylic acid purification, and particularly relates to a method for preparing electronic-grade water-soluble polycarboxylic acid. Background Art

[0002] Water-soluble polycarboxylic acid is an excellent scale inhibitor and dispersant. It does not contain phosphorus and sulfur, is biodegradable, and is easily soluble in water. Its aqueous solution is weakly acidic and can improve the decontamination ability of anionic detergents. In addition, water-soluble polycarboxylic acid also has the properties of thickening, dispersing, flocculating, and film-forming. It is widely used in traditional industries such as coatings, mining, medical treatment, food, cosmetics, and water treatment agents. With the advancement of science and technology and social development, the use of electronic products has become more and more popular, and it is an important cornerstone in the fields of information communication, military industry, etc. Semiconductors, integrated circuits, display panels and other devices in electronic products are delicate operations in the preparation and cleaning process, and the purity of the raw materials and cleaning agents is very high. The concept of electronic-grade raw materials was proposed, and many electronic-grade raw materials were manufactured and used in the electronics industry.

[0003] Among them, electronic-grade water-soluble polycarboxylic acid is an aqueous dispersant made by homopolymerization of acrylic acid as a monomer. It has strong anti-redeposition ability in grinding, polishing, cleaning, etc. It can not only be used as an auxiliary agent in the production of electronic products, but also can be made into a cleaning agent for cleaning fine accessories of electronic products.

[0004] The preparation of electronic-grade water-soluble polycarboxylic acid is generally to remove various metal ion impurities by adsorption purification of industrial-grade water-soluble polycarboxylic acid using cation exchange resin. There are two types of resin adsorption, namely dynamic adsorption and static adsorption. In practical applications, dynamic adsorption takes less time, but the resin utilization rate is low; static adsorption has a high relative utilization rate of the resin, but the adsorption time is long. In view of the above problems, the present invention provides a method for purifying electronic-grade water-soluble polycarboxylic acid. Summary of the invention

[0005] In view of the problems that in the prior art, when purifying water-soluble polycarboxylic acid, dynamic adsorption consumes less time but has low resin utilization rate, while static adsorption has high resin relative utilization rate but long adsorption time, the present invention provides a method for preparing electronic-grade water-soluble polycarboxylic acid, which is purified by a combination of dynamic and static adsorption, effectively improving the resin utilization rate, saving the unit product resin dosage, and effectively controlling the purification time to obtain water-soluble polycarboxylic acid with electronic-grade purity.

[0006] The present invention is achieved through the following technical solutions: A method for preparing an electronic grade water-soluble polycarboxylic acid comprises the following steps: (1) preparing a water-soluble polycarboxylic acid aqueous solution, passing it through an anion exchange column filled with an anion exchange resin and a cation exchange column filled with a cation exchange resin in sequence, and collecting the electronic grade water-soluble polycarboxylic acid aqueous solution before the cation exchange column reaches the critical point of adsorbing qualified products; (2) transferring the water-soluble polycarboxylic acid aqueous solution after further treatment on the cation exchange column in step (1) to a container containing a cation exchange resin, stirring and adsorbing for 1 to 2 hours, and filtering to obtain an electronic grade water-soluble polycarboxylic acid aqueous solution; (3) After the anion exchange column and the cation exchange column have treated a certain amount of water-soluble polycarboxylic acid aqueous solution, they are replaced and steps (1) and (2) are repeated.

[0007] Furthermore, the anion exchange resin in step (1) is a strong base anion exchange resin, and the cation exchange resin is a hydrogen cation exchange resin.

[0008] Furthermore, a plurality of anion exchange columns and cation exchange columns in step (1) are connected in parallel.

[0009] Furthermore, the critical point of the adsorption of qualified products by the cation exchange column in step (1) is the adsorption of 0.15 to 0.2 times the mass of the cation resin in the exchange column.

[0010] Furthermore, in step (2), the mass ratio of the amount of the cation exchange resin to the water-soluble polycarboxylic acid aqueous solution in the container is 1-1.5:100.

[0011] Furthermore, multiple containers in step (2) can be connected in parallel.

[0012] Furthermore, the conditions for replacement in step (3) are: replacement is performed when the anion exchange column adsorbs 1 to 2 times the mass of the anion resin in the exchange column, and replacement is performed when the cation exchange column adsorbs 0.4 to 0.5 times the mass of the cation resin in the exchange column, and replacement is performed.

[0013] The applicant of the present invention has found through research that the anions in the water-soluble polycarboxylic acid aqueous solution are mainly sulfate, and the cations include various metal ions such as lithium, sodium, magnesium, sodium, calcium, arsenic, iron, manganese, nickel, etc. In the purification process, the column efficiency of the anion resin is much higher than that of the cationic resin. When treating a fixed mass of the water-soluble polycarboxylic acid aqueous solution, the amount of the anion resin used is much lower than the amount of the cationic resin used. Therefore, the reduction in the amount of resin used is concentrated on the reduction in the amount of the cationic resin used. Beneficial Effects

[0014] The method for purifying electronic-grade water-soluble polycarboxylic acid provided by the present invention reduces the amount of resin without increasing the working hours through the combination of dynamic adsorption and static adsorption, thereby effectively reducing the production cost and facilitating industrial promotion. DETAILED DESCRIPTION

[0015] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0016] In the embodiments and comparative examples of the present invention, the anion and cation exchange columns are cylinders with a length of 100 cm and a cross-sectional diameter of 5 cm; the anion resin uses an OH-type anion exchange resin; the cation resin uses an H-type cation exchange resin, the water-soluble polycarboxylic acid is produced by the company, and the mass percentage concentration of the water-soluble polycarboxylic acid aqueous solution is 20%.

[0017] In the present invention, 400g of OH type anion exchange resin is filled into an anion exchange column and then sealed, and 900g of H type cation exchange resin is filled into a cation exchange column and then sealed, and a plurality of anion and cation exchange columns are filled and set aside. Example 1

[0018] (1) passing a water-soluble polyacrylic acid aqueous solution through an anion exchange column and a cation exchange column in sequence, controlling a valve to collect the water-soluble polycarboxylic acid aqueous solution flowing out of the cation exchange column, and after collecting 855 g of the polyacrylic acid aqueous solution (denoted as A1), the polyacrylic acid aqueous solution that continues to flow out is transferred into a stirring tank ① through valve control, and after the stirring tank is enriched with 500.2 g of the polyacrylic acid aqueous solution (denoted as C1), the polyacrylic acid aqueous solution that continues to flow out is transferred into a parallel stirring tank ②; (2) Add 5 g of H-type cation exchange resin to stirring tank ①, start stirring, stir at room temperature for 1 hour and then filter with suction. The filtrate is 499.5 g of electronic grade polyacrylic acid aqueous solution product (denoted as A2). The same operation is performed on stirring tank ②; (3) After the anion exchange column has treated 3800 g of the polyacrylic acid aqueous solution, it is replaced with a parallel anion exchange column. After the cation exchange column has treated 1800 g of the polyacrylic acid aqueous solution, it is replaced with a parallel cation exchange column. The resin in the replaced ion exchange column is regenerated and reused.

[0019] ICP-MS-MS test: The values ​​of metal ion contents in A1, A2 and C1 are shown in Table 1. Example 2

[0020] (1) passing a water-soluble polyacrylic acid aqueous solution through an anion exchange column and a cation exchange column in sequence, controlling a valve to collect the polyacrylic acid aqueous solution flowing out of the cation exchange column, and after collecting 899.6 g of the polyacrylic acid aqueous solution (denoted as A3), the polyacrylic acid aqueous solution that continues to flow out is transferred into a stirring tank ① through valve control, and after the stirring tank is enriched with 500.1 g of the polyacrylic acid aqueous solution, the polyacrylic acid aqueous solution that continues to flow out is transferred into a parallel stirring tank ②; (2) Add 7.5 g of H-type cation exchange resin to stirring tank ①, start stirring, stir at room temperature for 2 h and then filter. The filtrate is 499.2 g of electronic grade polyacrylic acid aqueous solution (denoted as A4). The parallel stirring tanks are operated in the same manner. (3) After the anion exchange column has treated 4000 g of polyacrylic acid aqueous solution, it is replaced with a parallel anion exchange column. After the cation exchange column has treated 2250 g of polyacrylic acid aqueous solution, it is replaced with a parallel cation exchange column. The resin in the replaced ion exchange column is regenerated and reused.

[0021] ICP-MS-MS detection: The values ​​of the metal ion contents in A3 and A4 are shown in Table 1.

[0022] Comparative Example 1 (1) After treating 2250 g of the water-soluble polyacrylic acid aqueous solution with a cation exchange column, the cation exchange column was not replaced and the water-soluble polyacrylic acid aqueous solution was continued to be treated. After collecting 500.3 g of the polyacrylic acid aqueous solution with a stirred kettle ①, 500.2 g of the polyacrylic acid aqueous solution was continued to be collected with a stirred kettle ②;

[0023] (2) Add 7.5 g of H-type cation exchange resin to the stirred tank ①, start stirring, stir at room temperature for 2 h, and then filter to obtain 499.2 g of filtrate, which is recorded as B1;

[0024] (3) Add 25 g of H-type cation exchange resin to stirring tank ②, start stirring, stir at room temperature for 2 h, then take a sample, which is recorded as B2. Continue stirring at room temperature for 8 h, then filter and obtain 495.1 g of filtrate, which is recorded as B3.

[0025] ICP-MS-MS detection: The metal ion content values ​​of B1 and B2 are shown in Table 1.

[0026] Table 1 Metal ion content of each sample detected by ICP-MS-MS

[0027] From the results of samples A1, A3 and C1 in Table 1, it can be seen that the effective polyacrylic acid adsorption amount of the cationic resin is 0.2 times the mass of the cationic resin for dynamic cationic adsorption, that is, 100 parts of cationic resin can purify 20 parts of electronic grade water-soluble polycarboxylic acid; From the results of samples A2 and A4, it can be seen that after using the resin after the critical point for dynamic adsorption, static adsorption can also obtain qualified electronic-grade polyacrylic acid products. At this time, adding (1-1.5) parts of cationic resin can purify 20 parts of electronic-grade polyacrylic acid again, which greatly improves the adsorption capacity of the cationic resin. From the results of B1 and B2, it can be seen that when the cationic resin for dynamic adsorption treats a certain amount of polyacrylic acid, the adsorption amount of metal ions is significantly reduced. At this time, the mass of cationic resin for static adsorption needs to be increased. After increasing by 5 times, qualified electronic grade polyacrylic acid cannot be processed. The static adsorption time needs to be greatly extended to obtain qualified products. Therefore, from a comprehensive comparison of usage and reaction time, the adsorption amount when replacing the ion exchange column defined in the present invention is more reasonable, which can effectively reduce the usage of cationic resin, effectively control production time, and reduce production costs.

[0028] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing an electronic grade water-soluble polycarboxylic acid, characterized in that: The following steps are involved: (1) preparing a water-soluble polycarboxylic acid aqueous solution, passing it through an anion exchange column filled with an anion exchange resin and a cation exchange column filled with a cation exchange resin in sequence, and collecting the electronic grade water-soluble polycarboxylic acid aqueous solution before the cation exchange column reaches the critical point of adsorbing qualified products; (2) transferring the water-soluble polycarboxylic acid aqueous solution after further treatment on the cation exchange column in step (1) to a container containing a cation exchange resin, stirring and adsorbing for 1 to 2 hours, and filtering to obtain an electronic grade water-soluble polycarboxylic acid aqueous solution; (3) After the anion exchange column and the cation exchange column have treated a certain amount of water-soluble polycarboxylic acid aqueous solution, they are replaced and steps (1) and (2) are repeated.

2. The method for preparing electronic grade water-soluble polycarboxylic acid according to claim 1, characterized in that: The anion exchange resin described in step (1) is a strong base anion exchange resin, and the cation exchange resin is a hydrogen type cation exchange resin.

3. The method for preparing electronic grade water-soluble polycarboxylic acid according to claim 1, characterized in that: In step (1), a plurality of anion exchange columns and cation exchange columns are connected in parallel.

4. The method for preparing electronic grade water-soluble polycarboxylic acid according to claim 1, characterized in that: The critical point of the adsorption of qualified products by the cation exchange column in step (1) is the adsorption of 0.15 to 0.2 times the mass of the cation resin in the exchange column.

5. The method for preparing electronic grade water-soluble polycarboxylic acid according to claim 1, characterized in that: The mass ratio of the amount of the cation exchange resin to the water-soluble polycarboxylic acid aqueous solution in the container of step (2) is 1-1.5:

100.

6. The method for preparing electronic grade water-soluble polycarboxylic acid according to claim 1, characterized in that: Multiple containers in step (2) can be connected in parallel.

7. The method for preparing electronic grade water-soluble polycarboxylic acid according to claim 1, characterized in that: The conditions for replacement in step (3) are: replacement is performed when the anion exchange column adsorbs 1 to 2 times the mass of the anion resin in the exchange column; replacement is performed when the cation exchange column adsorbs 0.4 to 0.5 times the mass of the cation resin in the exchange column.

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