Starch-based water filtration reinforcing agent as well as raw material composition, preparation method and application of starch-based water filtration reinforcing agent

Abstract

The invention discloses a starch-based water filtration reinforcing agent, and a raw material composition, a preparation method and application thereof. The starch-based water filtration reinforcing agent comprises the following raw materials in parts by weight: 100 parts of starch, 0.05-0.30 part of an expansion inhibitor, 10-30 parts of liquid caustic soda, 10-30 parts of an etherifying agent, 1-10 parts of a cationic monomer, 1-10 parts of an anionic monomer, 1-20 parts of acrylamide and 0.05-5 parts of an initiator. The starch-based water filtration reinforcing agent is prepared by taking starch as a main raw material and performing etherification modification and graft copolymerization on monomers such as a cationic monomer, an anionic monomer and acrylamide. The product provided by the invention has retention and drainage aiding effects in a papermaking wet end process, and the chemical content in papermaking wastewater is effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of water filtration enhancers, and specifically relates to a starch-based water filtration enhancer, a raw material composition thereof, and a preparation method and application thereof. Background Art

[0002] With the development of paper machines towards high speed and large scale, and the large-scale use of secondary fibers such as waste paper and deinked pulp in recent years, papermaking has become more and more dependent on wet-end additives, which makes the retention and filtration technologies of the wet end of papermaking more and more important. Adding retention aids to the slurry can increase the retention rate of fine components in the slurry and save fiber raw materials; since the content of fine components in white water is reduced, the white water is easy to clarify, the drainage pollution is reduced, and the blanket can be kept clean for a long time, so the paper machine can operate better. Filter aids are used to increase the dehydration rate of wet paper webs from the papermaking mesh and improve their filterability. In terms of promoting the coagulation of fine components and fibers, the filtration effect and retention effect are interlinked, so filter aids are often also retention aids.

[0003] At present, the existing retention and drainage aid products include cationic starch, polyacrylamide, chitosan and emulsion polymers. These products have different limitations. Cationic starch has the disadvantages of large dosage and low enhancement efficiency; polyacrylamide products have high costs; chitosan products have limited raw material sources and high production costs; emulsion polymers have the problem of high impurity content. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a starch-based water drainage enhancer, a raw material composition thereof, and a preparation method and application thereof.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] In one aspect, the present invention provides a raw material composition of a starch-based water drainage enhancer, which comprises the following raw materials in parts by weight:

[0007] 100 parts of starch, 0.05-0.30 parts of swelling inhibitor, 10-30 parts of liquid alkali, 10-30 parts of etherifying agent, 1-10 parts of cationic monomer, 1-10 parts of anionic monomer, 1-20 parts of acrylamide, and 0.05-5 parts of initiator.

[0008] In some embodiments, the starch is selected from one of corn starch, tapioca starch, potato starch, and wheat starch;

[0009] In some embodiments, the swelling inhibitor is selected from at least one of sodium sulfate, sodium chloride, and sodium persulfate;

[0010] In some embodiments, the etherifying agent is 2,3-epoxypropyltrimethylammonium chloride or 3-chloro-2-hydroxypropyltrimethylammonium chloride;

[0011] In some embodiments, the cationic monomer is selected from at least one of methacryloyloxyethyl dimethylbenzyl ammonium chloride, methacryloyloxyethyl dimethylbutyl ammonium bromide, methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, and dimethyl diallyl ammonium chloride;

[0012] In some embodiments, the anionic monomer is selected from at least one of acrylic acid, methacrylic acid, and maleic acid;

[0013] In some embodiments, the initiator is ammonium persulfate or potassium persulfate;

[0014] In some embodiments, the weight percentage of the swelling inhibitor is 0.2 to 0.3 parts;

[0015] In some embodiments, the weight proportion of the liquid caustic soda is 15 to 25 parts;

[0016] In some embodiments, the weight percentage of the etherifying agent is 15 to 25 parts;

[0017] In some embodiments, the cationic monomer is present in an amount of 3 to 8 parts by weight;

[0018] In some embodiments, the weight percentage of the anionic monomer is 3 to 8 parts;

[0019] In some embodiments, the weight percentage of acrylamide is 5 to 15 parts;

[0020] In some embodiments, the weight percentage of the initiator is 0.1 to 2 parts;

[0021] In some embodiments, the raw material composition of the starch-based drainage enhancer further includes water; preferably, the weight percentage of the water is 300 to 500 parts.

[0022] In another aspect, the present invention provides a method for preparing a starch-based water-drainage enhancer, wherein the raw materials of the starch-based water-drainage enhancer include the raw material composition of the starch-based water-drainage enhancer, and the method specifically comprises the following steps:

[0023] (1) starch, water and swelling inhibitor are mixed, and liquid alkali and etherifying agent are added to react at 50-70° C. After the reaction is completed, the temperature is lowered and the pH is adjusted to 6-8 to obtain a starch solution;

[0024] (2) The starch solution is mixed with a cationic monomer, an anionic monomer and acrylamide, the temperature is raised to 50-80° C., an initiator is added and the temperature is kept constant to obtain the starch-based water-drainage enhancer.

[0025] In step (1) and step (2), the mixing can be conventional in the art, generally a stirring operation.

[0026] In step (1), the reaction time is 1 to 4 hours;

[0027] In step (1), the temperature is lowered to below 45°C;

[0028] In step (1), the pH is adjusted to 6-8 by using a pH adjusting agent, and the pH adjusting agent is selected from one of acetic acid, citric acid, sulfuric acid, hydrochloric acid, tartaric acid, carbonic acid, and oxalic acid.

[0029] In step (2), the insulation time is 1 to 4 hours.

[0030] The third aspect of the present invention provides a starch-based water drainage enhancing agent, which is prepared by the preparation method of the starch-based water drainage enhancing agent as described above.

[0031] The fourth aspect of the present invention provides the use of a starch-based drainage enhancer in papermaking.

[0032] The beneficial effects of the present invention are:

[0033] 1. The present invention uses starch as the main raw material, and obtains a starch-based water filtration enhancer by etherification modification, graft copolymerization of cationic monomers, anionic monomers, acrylamide and other monomers. The starch-based water filtration enhancer has a good molecular structure and a greatly increased molecular weight compared to the original starch. The flexible branched chains on the grafts interpenetrate with the rigid chains of the starch skeleton, and the countless amide groups on the grafted branched chains form hydrogen bonds with the hydroxyl groups of the cellulose or hemicellulose molecules of the pulp, which have a very strong adsorption effect and a good enhancement effect on paper. In addition, the cationic monomers and anionic monomers introduced on the side chains give the branched chains a certain charge distribution, which has a good coagulation and adsorption effect on the fine fibers and fillers in the pulp, can enhance the retention of fine fibers, and effectively reduce the chemical content in papermaking wastewater. The starch derivatives of the present application are more shear-resistant than etherified modified cationic starch, and have better application effects in the era of high-speed paper machines.

[0034] 2. The water filter enhancer of the present invention contains cationic groups and anionic groups, has a wide pH application range, and is not interfered by anionic garbage in the system.

[0035] 3. The present invention is a free radical polymerization mechanism, including three stages: chain initiation, chain growth and chain termination. In this process, free radicals or rays attack the macromolecules of starch, activating and dehydrogenating the -OH to generate starch free radicals, which then combine with acrylamide monomers to generate new free radicals, which continue to react with the monomers to achieve chain growth, thus avoiding the problem of high impurity content in the prior art.

[0036] 4. The present invention adopts the method of grafting starch with acrylamide to synthesize the water filtration enhancer, with starch as the main raw material, and is degradable. In addition, starch, as a natural macromolecular compound, has a wide range of sources, such as corn, potatoes, wheat, etc., which can be used as the raw material for extracting starch, so its cost is relatively low. Although the price of acrylamide itself may be high, in the graft copolymerization reaction, it is not used in large quantities in the form of a pure product, but through a chemical reaction with starch to form a new macromolecular compound, thereby reducing the direct use cost of acrylamide. DETAILED DESCRIPTION

[0037] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are selected according to conventional methods and conditions, or according to the product specifications. In addition, the reagents and raw materials used in the present invention are conventional commercial products unless otherwise specified.

[0038] Example 1

[0039] A starch-based water-drainage enhancer, the raw material composition of which is shown in Table 1;

[0040] Table 1

[0041]

[0042]

[0043] The preparation method comprises the following steps:

[0044] (1) Add 100 g corn starch and 300 g water to a four-necked flask equipped with a condenser reflux tube, a thermometer, and a stirrer, add 0.05 g sodium sulfate, add 10 g liquid alkali and 10 g etherifying agent 2,3-epoxypropyltrimethylammonium chloride at 50°C, react for 1 hour, cool the prepared starch solution to below 45°C, adjust the pH to 6-8, and set aside.

[0045] (2) The starch solution was mixed evenly with 1 g of methacryloyloxyethyl dimethylbenzyl ammonium chloride, 1 g of acrylic acid and 1 g of acrylamide, the temperature was raised to 50° C., 0.05 g of ammonium persulfate was added, and the mixture was kept warm for 4 h to obtain a starch-based water filter enhancer.

[0046] Example 2

[0047] A starch-based water-drainage enhancer, the raw material composition of which is shown in Table 2;

[0048] Table 2

[0049]

[0050]

[0051] The preparation method comprises the following steps:

[0052] (1) Add 100 g of cassava starch and 500 g of water into a four-necked flask equipped with a condenser reflux tube, a thermometer, and a stirrer, add 0.30 g of sodium persulfate, add 30 g of liquid caustic soda and 30 g of etherifying agent 3-chloro-2-hydroxypropyltrimethylammonium chloride at 60° C., react for 3 h, cool the prepared starch solution to below 45° C., adjust the pH to 6-8, and set aside;

[0053] (2) The starch solution was mixed evenly with 5 g of methacryloyloxyethyl dimethylbutyl ammonium bromide, 5 g of methacryloyloxyethyl trimethyl ammonium chloride, 10 g of acrylic acid and 20 g of acrylamide, the temperature was raised to 60° C., 5 g of ammonium persulfate was added, and the mixture was kept warm for 3 h to obtain a starch-based water filtration enhancer.

[0054] Example 3

[0055] A starch-based water-drainage enhancer, the raw material composition of which is shown in Table 3;

[0056] Table 3

[0057] Specific compounds Mass(g) Starch: wheat starch 100 water 400 Swelling inhibitor: Sodium chloride 0.15 Liquid caustic soda 15 Etherifying agent: 2,3-Epoxypropyltrimethylammonium chloride 15 Cationic monomer: Acryloyloxyethyl trimethyl ammonium chloride 3 Cationic monomer: Dimethyldiallylammonium chloride 3 Anionic monomer: Maleic acid 5 Acrylamide 10 Initiator: Potassium persulfate 2.5 pH adjuster: hydrochloric acid 5

[0058] The preparation method comprises the following steps:

[0059] (1) Add 100 g of wheat starch and 400 g of water to a four-necked flask equipped with a condenser reflux tube, a thermometer, and a stirrer, add 0.15 g of sodium chloride, add 15 g of liquid alkali and 15 g of etherifying agent 2,3-epoxypropyltrimethylammonium chloride at 50° C., react for 3 h, cool the prepared starch solution to below 45° C., adjust the pH to 6-8, and set aside;

[0060] (2) The starch solution was mixed evenly with 3 g of acryloyloxyethyl trimethyl ammonium chloride, 3 g of dimethyl diallyl ammonium chloride, 5 g of maleic acid and 10 g of acrylamide, the temperature was raised to 70° C., 2.5 g of potassium persulfate was added, and the mixture was kept warm for 4 h to obtain a starch-based water filter enhancer.

[0061] Example 4

[0062] A starch-based water-drainage enhancer, the raw material composition of which is shown in Table 4;

[0063] Table 4

[0064] Specific compounds Mass(g) Starch: corn starch 100 water 300 Swelling inhibitor: sodium sulfate 0.2 Liquid caustic soda 15 Etherifying agent: 2,3-Epoxypropyltrimethylammonium chloride 15 Cationic monomer: Methacryloyloxyethyl dimethylbenzyl ammonium chloride 3 Anionic monomer: acrylic acid 3 Acrylamide 5 Initiator: ammonium persulfate 0.1 pH adjuster: acetic acid 8

[0065] The preparation method comprises the following steps:

[0066] (1) Add 100 g corn starch and 300 g water to a four-necked flask equipped with a condenser reflux tube, a thermometer, and a stirrer, add 0.2 g sodium sulfate, add 15 g liquid alkali and 15 g etherifying agent 2,3-epoxypropyltrimethylammonium chloride at 50° C., react for 1 h, cool the prepared starch solution to below 45° C., adjust the pH to 6-8, and set aside.

[0067] (2) The starch solution was mixed evenly with 3 g of methacryloyloxyethyl dimethylbenzyl ammonium chloride, 3 g of acrylic acid and 5 g of acrylamide, the temperature was raised to 50° C., 0.1 g of ammonium persulfate was added, and the mixture was kept warm for 4 h to obtain a starch-based water filter enhancer.

[0068] Example 5

[0069] A starch-based water-drainage enhancer, the raw material composition of which is shown in Table 5;

[0070] Table 5

[0071] Specific compounds Mass(g) Starch: corn starch 100 water 300 Swelling inhibitor: sodium sulfate 0.25 Liquid caustic soda 20 Etherifying agent: 2,3-Epoxypropyltrimethylammonium chloride 20 Cationic monomer: Methacryloyloxyethyl dimethylbenzyl ammonium chloride 6 Anionic monomer: acrylic acid 6 Acrylamide 10 Initiator: ammonium persulfate 0.15 pH adjuster: acetic acid 8

[0072] The preparation method comprises the following steps:

[0073] (1) Add 100 g corn starch and 300 g water to a four-necked flask equipped with a condenser reflux tube, a thermometer, and a stirrer, add 0.25 g sodium sulfate, add 20 g liquid alkali and 20 g etherifying agent 2,3-epoxypropyltrimethylammonium chloride at 50°C, react for 1 hour, cool the prepared starch solution to below 45°C, adjust the pH to 6-8, and set aside.

[0074] (2) The starch solution was mixed evenly with 6 g of methacryloyloxyethyl dimethylbenzyl ammonium chloride, 6 g of acrylic acid and 10 g of acrylamide, the temperature was raised to 50° C., 0.15 g of ammonium persulfate was added, and the mixture was kept warm for 4 h to obtain a starch-based water filter enhancer.

[0075] Example 6

[0076] A starch-based water-drainage enhancer, the raw material composition of which is shown in Table 6;

[0077] Table 6

[0078] Specific compounds Mass(g) Starch: corn starch 100 water 300 Swelling inhibitor: sodium sulfate 0.3 Liquid caustic soda 25 Etherifying agent: 2,3-Epoxypropyltrimethylammonium chloride 25 Cationic monomer: Methacryloyloxyethyl dimethylbenzyl ammonium chloride 8 Anionic monomer: acrylic acid 8 Acrylamide 15 Initiator: ammonium persulfate 0.2 pH adjuster: acetic acid 8

[0079] The preparation method comprises the following steps:

[0080] (1) Add 100 g corn starch and 300 g water to a four-necked flask equipped with a condenser reflux tube, a thermometer, and a stirrer, add 0.3 g sodium sulfate, add 25 g liquid alkali and 25 g etherifying agent 2,3-epoxypropyltrimethylammonium chloride at 50°C, react for 1 hour, cool the prepared starch solution to below 45°C, adjust the pH to 6-8, and set aside.

[0081] (2) The starch solution was mixed evenly with 8 g of methacryloyloxyethyl dimethylbenzyl ammonium chloride, 8 g of acrylic acid and 15 g of acrylamide, the temperature was raised to 50° C., 0.2 g of ammonium persulfate was added, and the mixture was kept warm for 4 h to obtain a starch-based water filter enhancer.

[0082] Comparative Example 1

[0083] The technical solution of Example 1 is adopted, except that the addition of cationic monomer, anionic monomer and acrylamide is omitted in step (2).

[0084] Comparative Example 2

[0085] The technical solution of Example 1 is adopted, except that the methacryloyloxyethyl dimethylbenzyl ammonium chloride in step (2) is replaced by 1-allyl-3-methylimidazole chloride.

[0086] Comparative Example 3

[0087] The technical solution of Example 1 is adopted, except that the acrylic acid in step (2) is replaced by acetic acid.

[0088] Comparative Example 4

[0089] The technical solution of Example 1 is adopted, except that the acrylamide in step (2) is replaced by N-hydroxymethyl acrylamide.

[0090] Comparative Example 5

[0091] The technical solution of Example 1 is adopted, except that the 2,3-epoxypropyltrimethylammonium chloride in step (2) is replaced by ethylene oxide.

[0092] Comparative Example 6

[0093] Commercially available product, water filtration enhancer produced by Aosai New Materials Co., Ltd.

[0094] Effect Example

[0095] The products of Examples 1 to 6 and Comparative Examples 1 to 6 were used for papermaking, and the properties of the obtained papers were tested. The test standards or methods are as follows:

[0096] 1. Ring compression strength test: Test in accordance with GB / T 2679.8-2016.

[0097] 2. Internal bonding strength test: Test in accordance with GB / T 26203-2023.

[0098] 3. Tensile strength test: Tested in accordance with GB / T 12914-2018.

[0099] 4. Water filtration performance test: Test in accordance with GB / T 18402-2001.

[0100] Performance test comparison: The addition amount of the products of Examples 1 to 6 and Comparative Examples 1 to 6 is 10 kg / ton of paper. The performance test results are listed in Tables 7 and 8, where the blank sample is a sample without adding drainage enhancer during papermaking.

[0101] Table 7 Handwritten sheet index detection

[0102]

[0103] Table 8 Water filtration speed data

[0104]

[0105]

[0106] It can be seen from Tables 7 and 8 that the use of the water filterability enhancers in Examples 1 to 6 of the present invention can improve the uniformity of dispersion of the enhancer in the pulp while ensuring the enhancing performance of the enhancer, thereby improving the water filterability during papermaking, thereby making the product have good water filterability.

[0107] Finally, it should be noted that in the present invention, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0108] Although the present disclosure has been disclosed above through the description of the specific embodiments of the present disclosure, it should be understood that those skilled in the art can design various modifications, improvements or equivalents to the present disclosure within the spirit and scope of the attached scheme. These modifications, improvements or equivalents should also be considered to be included in the scope of protection claimed by the present disclosure.

Claims

1. A raw material composition of a starch-based water-drainage enhancer, characterized in that: It contains the following raw materials in parts by weight: 100 parts of starch, 0.05-0.30 parts of swelling inhibitor, 10-30 parts of liquid alkali, 10-30 parts of etherifying agent, 1-10 parts of cationic monomer, 1-10 parts of anionic monomer, 1-20 parts of acrylamide, and 0.05-5 parts of initiator.

2. The raw material composition of the starch-based water drainage enhancer according to claim 1, characterized in that: The starch is selected from one of corn starch, tapioca starch, potato starch and wheat starch; And / or, the expansion inhibitor is selected from at least one of sodium sulfate, sodium chloride and sodium persulfate; And / or, the etherifying agent is 2,3-epoxypropyltrimethylammonium chloride or 3-chloro-2-hydroxypropyltrimethylammonium chloride; and / or, the cationic monomer is at least one selected from methacryloyloxyethyl dimethylbenzyl ammonium chloride, methacryloyloxyethyl dimethylbutyl ammonium bromide, methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, and dimethyl diallyl ammonium chloride; And / or, the anionic monomer is selected from at least one of acrylic acid, methacrylic acid and maleic acid; And / or, the initiator is ammonium persulfate or potassium persulfate.

3. The raw material composition of the starch-based water drainage enhancer according to any one of claims 1, characterized in that: The weight portion of the expansion inhibitor is 0.2 to 0.3 parts; And / or, the weight proportion of the liquid caustic soda is 15 to 25 parts; And / or, the weight proportion of the etherifying agent is 15 to 25 parts; and / or, the weight proportion of the cationic monomer is 3 to 8 parts; And / or, the weight proportion of the anionic monomer is 3 to 8 parts; And / or, the weight proportion of the acrylamide is 5 to 15 parts; And / or, the weight portion of the initiator is 0.1 to 2 parts.

4. The raw material composition of the starch-based drainage enhancer according to any one of claims 1, characterized in that: The raw material composition of the starch-based water-drainage enhancer further includes water; preferably, the weight proportion of the water is 300 to 500 parts.

5. A method for preparing a starch-based water-drainage enhancer, characterized in that: The raw material of the starch-based water-drainage enhancer comprises the raw material composition of the starch-based water-drainage enhancer according to any one of claims 1 to 4, and specifically comprises the following steps: (1) starch, water and swelling inhibitor are mixed, and liquid alkali and etherifying agent are added to react at 50-70° C. After the reaction is completed, the temperature is lowered and the pH is adjusted to 6-8 to obtain a starch solution; (2) The starch solution is mixed with a cationic monomer, an anionic monomer and acrylamide, the temperature is raised to 50-80° C., an initiator is added and the temperature is kept constant to obtain the starch-based water-drainage enhancer.

6. The method for preparing the starch-based water drainage enhancer according to claim 5, characterized in that: The preparation method satisfies at least one of the following conditions: In step (1), the reaction time is 1 to 4 hours; In step (1), the temperature is lowered to below 45°C; In step (1), the pH is adjusted to 6-8 by using a pH adjusting agent.

7. The method for preparing the starch-based water drainage enhancer according to claim 6, characterized in that: The pH regulator is selected from one of acetic acid, citric acid, sulfuric acid, hydrochloric acid, tartaric acid, carbonic acid and oxalic acid.

8. The method for preparing the starch-based water drainage enhancer according to claim 5, characterized in that: In step (2), the insulation time is 1 to 4 hours.

9. A starch-based water drainage enhancer, characterized in that: The starch-based water-drainage enhancer is prepared by the preparation method of the starch-based water-drainage enhancer according to any one of claims 5 to 8.

10. Use of the starch-based drainage enhancer according to claim 9 in papermaking.

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