Disulfonate-based polymer charge control agent and preparation method and application thereof

Abstract

The invention provides a bisulfonate-based polymer electronegative charge control agent as well as a preparation method and application thereof. The disulfonate-based polymer charge control agent has a structure as shown in a formula I, and the unique chemical structure endows the disulfonate-based polymer charge control agent with excellent charge control capability, so that the disulfonate-based polymer charge control agent has the advantages of high charge density, high stability, high dispersity, high compatibility with powdered ink resin and the like, and the performance of the disulfonate-based polymer charge control agent can be compared favorably with that of a conventional commercial tert-butyl salicylic acid metal complex; the performance requirements of high-speed printing ink powder are completely met. Formula I

Description

Technical Field

[0001] This invention belongs to the field of toner preparation technology, specifically relating to a charge regulator in the preparation of developer toner for laser printing and electrostatic copying, and more specifically to a disulfonate-based polymer charge regulator, its preparation method, and its application. Background Technology

[0002] In electrostatic copying and laser printing technologies, the charge properties of toner directly affect image quality and printing efficiency. The toner charge control agent (CCA) is a key component of toner formulation; its function is to regulate the surface charge of toner particles, ensuring uniformity and stability of charge, thereby reducing background gray, improving image resolution, and increasing transfer efficiency.

[0003] Currently, common charge control agents include metal salts, quaternary ammonium compounds, and resin-based agents. However, these materials all have certain limitations. Some metal-based agents (such as chromium-containing compounds) pose environmental and health risks, while some sodium sulfonate salt agents, although environmentally friendly, suffer from poor resin compatibility and uneven dispersion. Quaternary ammonium salt agents have poor thermal stability and are prone to decomposition during high-temperature fixing. Traditional resin-based agents, while relatively safe, have insufficient charge control efficiency, which may lead to uneven toner charging or reduced durability.

[0004] In recent years, polymeric charge control agents have attracted widespread attention due to their structural designability, environmental friendliness, and good compatibility with toner resins. Disulfonate-based polymeric charge control agents, on the other hand, are a class of polymers whose repeating molecular chain units simultaneously contain two sulfonic acid groups (—SO3). - These ionomers possess unique chemical structures that endow them with excellent charge control capabilities, allowing for further optimization of charge response speed and humidity stability. They are particularly suitable for applications in high-speed printing and complex climatic conditions. Furthermore, the performance of these polymers can be customized through monomer selection and degree of polymerization control, meeting the compatibility requirements of different resin systems (such as polyester and styrene-acrylic resins).

[0005] Therefore, developing toner charge regulators based on disulfonate polymers can not only solve the environmental and performance bottlenecks of traditional CCA, but also provide new ideas for the design of high-performance and environmentally friendly toners, and has significant industrial application value. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a disulfonate-based polymer, which, as a negative charge regulator, has advantages such as fast charging rate, high charge density, good charge retention, strong environmental adaptability, and good compatibility with common toner substrates such as polyester and styrene-acrylic resin.

[0007] To achieve the above objectives, the present invention provides a disulfonate-based polymer having a structure as shown in Formula I:

[0008] Formula I Where M is a divalent metal ion, such as Zn or Ca ions; X is S or -CH=CH-; m is 1 Integers of 4; n is 5 The number 50.

[0009] According to an embodiment of the invention, m is 1, 2, or 3, and / or n is 10. The number 40.

[0010] According to a preferred embodiment of the present invention, m is 3, and / or n is 20. The number 30.

[0011] According to an embodiment of the present invention, n is 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50.

[0012] According to an embodiment of the present invention, M is a Zn ion, and / or X is S.

[0013] According to an embodiment of the present invention, M is a Ca ion, and / or X is -CH=CH-.

[0014] In one embodiment, the disulfonate polymer (denoted as P(CPDTZn)) has a structure as shown in Formula IA, where n is a number from 20 to 30, for example, about 28:

[0015] Formula I-A.

[0016] In one embodiment, the disulfonate polymer (denoted as P(CPDBCa)) has a structure as shown in Formula IB, where n is a number from 20 to 30, for example, about 22:

[0017] Formula I-B.

[0018] The present invention also provides a method for preparing the above-mentioned disulfonate-based polymer, comprising the following steps:

[0019] Where M, X, m, and n are as defined above; S1. Compound I-1 and the inner sulfonate ester were reacted via a nucleophilic substitution reaction to give compound I-2; S2. Compound I-2 reacts with bromosuccinimide via bromination to give compound I-3; S3. Compound I-3 reacts with dipinazoboronic acid ester to give compound I-4; S4. Compound I-3 and Compound I-4 were polymerized by catalytic coupling polymerization to obtain Polymer I-5; S5. Polymer I-5 undergoes cation exchange with metal ion M to obtain the disulfonate-based polymer shown in Formula I.

[0020] According to an embodiment of the present invention, step S1 includes: dissolving compound I-1 (e.g., dithiophenecyclopentadiene, dibenzocyclopentadiene) and tert-butylammonium bromide in dimethyl sulfoxide, purging with an inert gas (argon) to remove oxygen, and then adding an alkaline aqueous solution (e.g., sodium hydroxide aqueous solution) and a sulfonate (e.g., 1,3-propanesulfonate lactone), stirring the reaction at room temperature to obtain compound I-2.

[0021] According to an embodiment of the present invention, step S2 includes: dissolving compound I-2 in a mixed solution of DMF and water, adding a DMF solution of bromosuccinimide under light-protected conditions, and stirring the reaction at room temperature to obtain compound I-3.

[0022] According to an embodiment of the present invention, step S3 includes: under an inert atmosphere, mixing compound I-3, bis-pinacol boronic acid ester, catalyst (e.g., dichloro[1,1'-bis(diphenylphosphine)ferrocene]palladium), potassium acetate, and DMSO, heating and refluxing (e.g., refluxing at 100~140°C for 16~30h), and cooling to room temperature to obtain compound I-4.

[0023] According to an embodiment of the present invention, the catalyst used for catalytic coupling polymerization in step S4 is tetrakis(triphenylphosphine)palladium.

[0024] According to an embodiment of the present invention, step S4 includes: dissolving compound I-3, compound I-4 and sodium carbonate in a mixed solvent of DMF and water under an inert atmosphere, then adding a catalyst, and heating and stirring the reaction (e.g., stirring at 80~100°C for 30~60h) to obtain polymer I-5.

[0025] According to an embodiment of the present invention, the metal ion M in step S5 is provided by a chloride of metal M, such as zinc chloride or calcium chloride.

[0026] According to an embodiment of the present invention, step S5 includes: dissolving polymer I-5 in a mixed solvent of methanol and water, then adding an aqueous chloride solution of metal M, heating the reaction and then cooling (for example, reacting at 70~90°C for 16~30h and then cooling to 30~40°C), filtering and washing, and vacuum drying to obtain the disulfonate-based polymer.

[0027] The present invention also provides the application of the disulfonate-based polymer as a negatively charged polymer charge regulator.

[0028] Specifically, the disulfonate polymer is used as a negatively charged polymer charge regulator in the preparation of developer toner for laser printing and electrostatic copying.

[0029] The present invention also provides a negatively charged polymeric charge regulator, which comprises or is the disulfonate-based polymer.

[0030] The present invention also provides a negatively charged toner comprising the above-mentioned disulfonate polymers, such as P(CPDTZn) and P(CPDBCa).

[0031] According to an embodiment of the present invention, the negatively charged toner further includes resin, pigment, wax and / or external additives to adjust flowability.

[0032] According to an embodiment of the present invention, the resin is selected from one or more of polyester, polycarbonate and styrene-acrylate copolymer.

[0033] According to an embodiment of the present invention, the pigment is a commonly used pigment in the art, such as carbon black or β-copper phthalocyanine.

[0034] According to an embodiment of the present invention, the wax is selected from one or more of synthetic waxes and natural waxes, such as polyethylene wax.

[0035] According to an embodiment of the present invention, the external additive for adjusting flowability is selected from one or both of titanium dioxide and silica powder.

[0036] According to an embodiment of the present invention, the mass ratio of the disulfonate polymer, pigment, wax, and resin is (1:1). 15): (5) 20): (5) 20): (60) 100), for example (5) 10): (5) 20): (10) 20): (80) 100).

[0037] According to an embodiment of the present invention, the D50 particle size of the negatively charged toner is 5~10µm.

[0038] The present invention also provides a method for preparing the negatively charged toner as described above, comprising the following steps: (1) The disulfonate polymer, resin, pigment and wax are melt-blended at high temperature; (2) Cool, press, and crush the compound obtained in step (1); (3) The pulverized material obtained in step (2) is finely pulverized and collected in grades to obtain, for example, a particle size of 3. 25µm raw starch; Alternatively, it may further include step (4) mixing the external additives that adjust the flowability with the raw powder obtained in step (3) to obtain the finished toner.

[0039] The beneficial effects of this invention are as follows: The disulfonate polymers of this invention are a class of molecular chain repeating units containing two sulfonic acid groups (-SO3). - The polymer is an ionic polymer. The relatively dense sulfonic acid groups of the polymer endow it with excellent charge control ability: (1) High charge density: The two sulfonic acid groups provide stronger anionic properties, making the toner more likely to be negatively charged, and the amount of charge can be precisely controlled by the polymer concentration to match the needs of different developing systems; (2) High stability: Not only can the rigid structure of the polymer skeleton suppress charge decay and ensure that the charge remains stable during long-term storage or high-temperature environment, but the dual ionic sites can work together to further optimize the charge response speed and humidity stability; (3) High dispersibility: The long-chain polymer can uniformly coat the surface of the toner particles, reducing image defects (such as background gray or scattering) caused by uneven charge distribution; (4) High compatibility: It has good compatibility with common toner substrates such as polyester and styrene-acrylic resin, and is not prone to agglomeration or clumping problems. Attached Figure Description

[0040] Figure 1 This describes the synthetic route for preparing the disulfonate-based polymer P(CPDTZn) in Example 1; Figure 2 This is the synthetic route for preparing the disulfonate-based polymer P (CPDBCa) in Example 2. Detailed Implementation

[0041] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0042] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0043] Example 1 The synthetic route of the disulfonate-based polymer P(CPDTZn) in this embodiment is as follows: Figure 1As shown, the main steps include: using dithiophenecyclopentadiene (compound I-1) and 1,3-propanesulfonyl lactone as starting materials, compound I-2 is obtained through nucleophilic substitution, compound I-3 is obtained through bromination, and compound I-4 is obtained through boron esterification. Compound I-3 and compound I-4 are then subjected to catalytic coupling polymerization to obtain polymer I-5, and finally, cation exchange with metal ions is performed to obtain the disulfonate polymer shown in formula I-A.

[0044] Synthesis of Compound I-2: Dithiophenecyclopentadiene (CPDT) (Compound I-1) (3.0 g, 16.86 mmol) and tert-butylammonium bromide (450 mg, 1.35 mmol) were sequentially dissolved in 30 mL of dimethyl sulfoxide (DMSO). After purging the resulting solution with argon for 15 minutes, a 40% aqueous solution of sodium hydroxide (11.2 g, 0.28 mol) was added, followed by 1,3-propanesulfonate lactone (8.55 g, 70 mmol). The reaction mixture was stirred at room temperature for 3 hours, then poured into 200 mL of acetone. The yellow precipitate was collected by vacuum filtration. The precipitate was washed several times with ethanol to remove residual sodium hydroxide, yielding a pale yellow solid, Compound I-2. The synthesis of Compound I-2... 1 H NMR (400 MHz, D2O) δ: 7.39 (d, 2H), 7.18 (d,2H), 2.67 (t, 4H), 2.13 (t, 4H), 1.34 (m, 4H). Synthesis of Compound I-3: Compound I-2 was dissolved in a mixed solution of DMF (150 mL) and water (40 mL). Then, under light-protected conditions, bromosuccinimide (NBS) dissolved in 150 mL of DMF (10.5 g, 59.0 mmol) was slowly added through a constant-pressure dropping funnel. The reaction mixture was stirred at room temperature for 1 hour, then poured into acetone. The precipitated pale yellow precipitate was collected and washed with acetone. The crude product was purified by reversed-phase silica gel C-18 column chromatography using a water / alcohol mixture as eluent, finally yielding compound I-3 (8.25 g, 50% yield). The synthesis of compound I-3... 1 H NMR (400 MHz, D2O) δ: 7.23 (s, 2H), 2.66 (t,4H), 2.09 (t, 4H), 1.29 (m, 4H). Synthesis of Compound I-4: Under an argon atmosphere, compound I-3 (3.12 g, 5 mmol), bis-pinacolborate (5.08 g, 20 mmol), catalyst dichloro[1,1'-bis(diphenylphosphine)ferrocene]palladium (Pd(dppf)Cl2) (183 mg, 0.25 mmol), and potassium acetate (1.96 g, 20 mmol) were added sequentially to a reaction flask, followed by the injection of 100 mL of toluene using a syringe. The mixture was heated at 120 °C. o After reflux for 24 hours and cooling to room temperature, the mixture was poured into acetone and filtered to obtain the crude product of compound I-4. The crude product was purified by reversed-phase silica gel column chromatography using a water / alcohol mixture as eluent, ultimately yielding compound I-4 (2.78 g, 78% yield). 1 H NMR (400 MHz, D2O) δ: 7.20 (s, 2H), 2.63 (t, 4H), 2.08 (t, 4H), 1.29 (m, 4H), 1.20 (s, 24H).

[0045] Synthesis of P(CPDTNa2): Under an argon atmosphere, compounds I-3 (0.90 g, 1.44 mmol), I-4 (1.04 g, 1.44 mmol), and sodium carbonate (0.76 g, 7.20 mmol) were dissolved in a mixed solvent of anhydrous DMF (18 mL) and deionized water (4.5 mL). After bubbling to remove oxygen for 5 minutes under argon protection, tetrakis(triphenylphosphine)palladium (36 mg, 31 μmol) was added. The reaction system was stirred at 90 °C for 48 hours, and then the reaction solution was poured into acetone to precipitate. After collecting the precipitate by filtration, the crude product was dissolved in methanol and precipitated again in deionized water. After filtration, it was washed several times with acetone to obtain polymer P(CPDTNa2) (0.92 g, yield 68.6%). The molecular weight of polymer P(CPDTNa2) is Mn: 11.6 kDa (n is approximately 25), PDI: 2.26; 1 H NMR (400 MHz, DMSO- d 6 ): δ 7.25 (s, 2H), 2.75 2.62 (m, 4H), 2.23 2.15 (t, 4H), 1.42 1.15 (m, 4H). Elemental analysis for C 15 H 14Na2O6S4: C: 38.79%; H: 3.04%. Found (%): C: 36.50; H: 2.76. Synthesis of P(CPDTZn): 464 mg of polymer P(CPDTNa2) was dissolved in a mixed solution of 20 mL methanol and 2 mL water. Then, a solution of zinc chloride (0.68 g, 5 mmol) dissolved in 5 mL water was added dropwise. The reaction mixture was heated to 80 °C and reacted for 24 hours, then cooled to 35 °C, filtered, washed four times with water, and dried under vacuum at 70 °C to obtain the target product P(CPDTZn) (381 mg, 79%). The target product P(CPDTZn) has the following Mn values: 13.52 kDa (n approximately 28), PDI: 2.14. 1 H NMR (400 MHz, DMSO- d 6 ): δ 7.27 (s, 2H), 2.78 2.65 (m, 4H), 2.26 2.20 (t, 4H), 1.50 1.23 (m, 4H). Elemental analysis for C 15 H 14 ZnO6S4: C: 37.23%; H: 2.92%. Found (%): C: 37.55; H: 3.34. Example 2 The synthetic route of the polymer charge control agent P(CPDTZn) involved in the disulfonate-based polymer invention of this embodiment is as follows: Figure 2 As shown.

[0046] Synthesis of Compound II-2: Dibenzocyclopentadiene (CPDB) (Compound II-1) (2.80 g, 16.86 mmol) and tert-butylammonium bromide (450 mg, 1.35 mmol) were dissolved sequentially in 30 mL of dimethyl sulfoxide (DMSO). After purging the solution with argon for 15 minutes, a 40% aqueous solution of sodium hydroxide (11.2 g, 0.28 mol) was added, followed by 1,3-propanesulfonate lactone (8.55 g, 70 mmol). The reaction mixture was stirred at room temperature for 3 hours, then poured into 200 mL of acetone. The yellow precipitate was collected by vacuum filtration. The precipitate was washed several times with ethanol to remove residual sodium hydroxide, yielding a pale yellow solid, Compound II-2. The synthesis of Compound II-2... 1H NMR (400 MHz, D2O) δ: 7.85 (d, 2H), 7.53 (d,2H), 7.35 (m, 2H), 7.24 (m, 2H), 2.63 (t, 4H), 2.10 (t, 4H), 1.32 (m, 4H). Synthesis of Compound II-3: Compound II-2 was dissolved in a mixed solution of DMF (150 mL) and water (40 mL). Then, under light-protected conditions, bromosuccinimide (NBS) dissolved in 150 mL DMF (10.5 g, 59.0 mmol) was slowly added through a constant-pressure dropping funnel. The reaction mixture was stirred at room temperature for 1 hour, then poured into acetone. The precipitated pale yellow precipitate was collected and washed with acetone. The crude product was purified by reversed-phase silica gel C-18 column chromatography using a water / alcohol mixture as eluent, finally yielding compound II-3 (8.25 g, 50% yield). Compound II-3... 1 H NMR (400 MHz, D2O) δ: 7.95 (s, 2H), 7.60 (d, 2H), 7.30 (d, 2H), 2.68 (t, 4H), 2.12 (t, 4H), 1.30 (m, 4H).

[0047] Synthesis of Compound ⅠI-4: Under an argon atmosphere, compound ⅠI-3 (3.06 g, 5 mmol), bis-pinacolborate (5.08 g, 20 mmol), catalyst dichloro[1,1'-bis(diphenylphosphine)ferrocene]palladium (Pd(dppf)Cl2) (183 mg, 0.25 mmol), and potassium acetate (1.96 g, 20 mmol) were added sequentially to a reaction flask, followed by the injection of 100 mL of toluene using a syringe. The mixture was heated to 120 °C. o After reflux for 24 hours and cooling to room temperature, the mixture was poured into acetone and filtered to obtain the crude product of compound II-4. The crude product was purified by reversed-phase silica gel column chromatography using a water / alcohol mixture as eluent, ultimately yielding compound II-4 (2.29 g, 65% yield). The crude product of compound II-4... 1 H NMR (400 MHz, D2O) δ: 7.70 (s, 2H), 7.33 (d, 2H), 7.15 (d, 2H), 2.68 (t, 4H), 2.12 (t, 4H), 1.30 (m, 4H), 1.20 (s, 24H).

[0048] Synthesis of P(CPDBNa2): Under an argon atmosphere, compounds II-3 (0.88 g, 1.44 mmol), II-4 (1.02 g, 1.44 mmol), and sodium carbonate (0.76 g, 7.20 mmol) were dissolved in a mixed solvent of anhydrous DMF (18 mL) and deionized water (4.5 mL). After bubbling to remove oxygen for 5 minutes under argon protection, tetrakis(triphenylphosphine)palladium (36 mg, 31 μmol) was added. The reaction system was stirred at 90 °C for 48 hours, and then the reaction solution was poured into acetone to precipitate. After collecting the precipitate by filtration, the crude product was dissolved in methanol and precipitated again in deionized water. After filtration, it was washed several times with acetone to obtain polymer P(CPDBNa2) (0.80 g, yield 61.6%). The molecular weight of polymer P(CPDBNa2) is Mn: 9.49 kDa (n is approximately 21), PDI: 2.05; 1 H NMR (400 MHz, DMSO- d 6 ): δ 7.84 (s, 2H), 7.50 (d, 2H), 7.31 (d,2H), 2.66 (t, 4H), 2.12 (t, 4H), 1.31 (m, 4H); Elemental analysis forC 19 H 18 Na2O6S2: C: 50.44%; H: 4.01%. Found (%): C: 50.78; H: 4.45%.

[0049] Synthesis of P(CPDBCa): 452 mg of polymer P(CPDBNa2) was dissolved in a mixed solution of 20 mL methanol and 2 mL water. Then, a solution of calcium chloride (0.68 g, 5 mmol) dissolved in 5 mL water was added dropwise. The reaction mixture was heated to 80 °C and reacted for 24 hours. The mixture was then cooled to 35 °C, filtered, washed four times with water, and dried under vacuum at 70 °C to obtain the target product P(CPDBCa) (303 mg, 68%). The target product P(CPDBCa) has the following Mn values: 8.96 kDa (n approximately 22), PDI: 2.01. 1 H NMR (400 MHz, DMSO- d 6 ): δ 7.83 (s, 2H), 7.52 (d, 2H), 7.33 (d, 2H), 2.76 2.60 (m, 4H), 2.22 2.18 (t, 4H), 1.52 1.20 (m, 4H); Elemental analysis for C 19 H 18 CaO6S2: C: 51.11%; H: 4.06%. Found (%): C: 51.54; H: 4.35.

[0050] Example 3 Ten parts by weight of P(CPDTZn) prepared in Example 1, used as a negatively charged polymeric charge regulator, were added to a high-speed mixer along with 90 parts by weight of phenyl-butyl acrylate copolymer resin, 10 parts by weight of β-copper phthalocyanine, and 15 parts by weight of polypropylene wax. The mixture was stirred until homogeneous at 130 °C. 160 o Melt-mix at the melting temperature of C 2 Extrusion for 5 hours (extrusion rate of 5) (8 kg / h), after cooling and tableting to form tablets, are then mechanically crushed to a particle size of 2. Coarse particles of 3 mm were then fed into an air jet mill at a speed of 0.6 mm. 1 MPa pressure and 20 The material is then further pulverized at a frequency of 40 Hz, and then transferred to an ultrafine pulverization and classification system at a frequency of 10000. 15000rpm and 60 100 m 3 The wind speed was classified according to / h, and D was collected. 50 In 5 Graded toner raw powder with a thickness of 10 µm. The electrical properties and environmental stability parameters of the toner raw powder samples are shown in Tables 1 and 2, respectively, and the printing uniformity test results are shown in Table 3.

[0051] Example 4 Except for replacing P(CPDTZn) with the charge control agent P(CPDBCa), all other steps were the same as in Example 3. The electrical properties and environmental stability parameters of the toner raw powder samples are shown in Tables 1 and 2, respectively.

[0052] Comparative Example 1 Except for replacing P(CPDTZn) with zinc 3,5-tert-butylsalicylate charge modifier, which is widely used in industry, the remaining steps are the same as in Example 3. The electrical properties and environmental stability parameters of the toner raw powder samples are shown in Tables 1 and 2, respectively, and the printing uniformity test is shown in Table 3.

[0053] Comparative Example 2 Except for replacing P(CPDTZn) with commercially available zinc p-polystyrene sulfonate charge modifier, the remaining steps were the same as in Example 3. The electrical properties and environmental stability parameters of the toner raw powder samples are shown in Tables 1 and 2, respectively, and the printing uniformity test is shown in Table 3.

[0054] Table 1 Example 3 4. Charge of toner at different charging times in Comparative Examples 1 and 2

[0055] Table 2 Example 3 4. The charge on Comparative Examples 1 and 2 under different environments and after 30 days of storage ( (µC / g) comparison

[0056] Table 3 Example 3 4. Comparison of the uniformity of toner printing effect between Comparative Examples 1 and 2

[0057] As can be seen from Tables 1 to 3, the disulfonate polymer charge control agent of the present invention not only has the characteristics of fast charging rate, high charge density and good charge retention (Table 1), but also exhibits good environmental adaptability and storage stability (Table 2), and excellent printing uniformity (Table 3). Its performance is even better than the 3,5-tert-butylsalicylic acid metal complex and similar charge control agents that are currently widely used in industry.

[0058] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A disulfonate-based polymer having a structure as shown in Formula I: Formula I in, M is a divalent metal ion, such as Zn or Ca ions; X is S or -CH=CH-; m is 1. Integers of 4; n is 5 The number 50.

2. The bissulfonate-based polymer according to claim 1, characterized in that, m is 1, 2, or 3, and / or n is 10. The number 40.

3. The disulfonate-based polymer according to claim 1, characterized in that, M represents Zn ions, and X represents S; Alternatively, M can be a Ca ion and X can be -CH=CH-.

4. According to claim 1, the disulfonate-based polymer has a structure as shown in Formula IA, wherein n is a number from 20 to 30: Formula I-A; Alternatively, the disulfonate polymer has a structure as shown in Formula IB, where n is a number from 20 to 30: Formula I-B.

5. A method for preparing the disulfonate-based polymer according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: S1. Compound I-1 and the inner sulfonate ester were reacted via a nucleophilic substitution reaction to give compound I-2; S2. Compound I-2 reacts with bromosuccinimide via bromination to give compound I-3; S3. Compound I-3 reacts with dipinazoboronic acid ester to give compound I-4; S4. Compound I-3 and Compound I-4 were polymerized by catalytic coupling polymerization to obtain Polymer I-5; S5. Polymer I-5 undergoes cation exchange with metal ion M to obtain the disulfonate-based polymer shown in Formula I.

6. The preparation method according to claim 5, characterized in that, Step S1 includes: dissolving compound I-1 (e.g., dithiophenecyclopentadiene, dibenzocyclopentadiene) and tert-butylammonium bromide in dimethyl sulfoxide, purging with an inert gas (argon) to remove oxygen, then adding an alkaline aqueous solution and a sulfonate (e.g., 1,3-propanesulfonate lactone), stirring at room temperature to react and obtain compound I-2; And / or, step S2 includes: dissolving compound I-2 in a mixed solution of DMF and water, adding a DMF solution of bromosuccinimide under light-protected conditions, and stirring the reaction at room temperature to obtain compound I-3; And / or, step S3 includes: under an inert atmosphere, mixing compound I-3, bis-pinacol boronic acid ester, catalyst, potassium acetate and DMSO, heating under reflux, and cooling to room temperature to obtain compound I-4; And / or, step S4 includes: under an inert atmosphere, dissolving compound I-3, compound I-4 and sodium carbonate in a mixed solvent of DMF and water, then adding a catalyst, heating and stirring the reaction to obtain polymer I-5; And / or, the metal ion M in step S5 is provided by the chloride of metal M; And / or, step S5 includes: dissolving polymer I-5 in a mixed solvent of methanol and water, then adding an aqueous chloride solution of metal M, heating the reaction and then cooling, filtering and washing, and vacuum drying to obtain the disulfonate-based polymer.

7. The use of the disulfonate polymer according to any one of claims 1-4 as a charge-regulating agent for negatively charged polymers; Preferably, the disulfonate polymer is used as a negatively charged polymer charge regulator in the preparation of developer toner for laser printing and electrostatic copying.

8. A negatively charged polymeric charge regulator comprising or comprising the disulfonate polymer as described in any one of claims 1 to 4.

9. A negatively charged toner comprising the disulfonate-based polymer according to any one of claims 1 to 4; Preferably, the negatively charged toner further includes resin, pigment, wax, and / or external additives to adjust flowability.

10. The method for preparing the negatively charged toner according to claim 9, comprising the following steps: (1) The disulfonate polymer, resin, pigment and wax are melt-blended at high temperature; (2) Cool, press, and crush the compound obtained in step (1); (3) The pulverized material obtained in step (2) is finely pulverized and collected in grades to obtain, for example, a particle size of 3. 25µm raw starch; Alternatively, it may further include step (4) mixing the external additives that adjust the flowability with the raw powder obtained in step (3) to obtain the finished toner.

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