Flame-retardant benzidine yellow pigment for ink and preparation method thereof

Abstract

The application discloses a kind of flame-retardant type benzidine yellow pigments for ink and a preparation method thereof, and belongs to the technical field of pigment preparation, by weight parts, including 1 portion of hyperbranched flame-retardant polymer and 50~100 portions of benzidine yellow;The hyperbranched flame-retardant polymer is a kind of hyperbranched structure macromolecule with fluorine-containing long-chain unit as skeleton, which is gradually grafted to construct, the flame-retardant type benzidine yellow pigment for ink prepared by the application has higher tinting strength, light resistance, flame retardancy and dispersibility, and can effectively inhibit the oxidation of pigment during use Fading, prolong the service life of pigment, and increase its stability.

Description

Technical Field

[0001] This invention belongs to the field of pigment preparation technology, specifically a benzidine yellow pigment for flame-retardant inks and its preparation method. Background Technology

[0002] With the continuous upgrading of material safety and fire resistance requirements in fields such as electronics, aerospace, transportation, and building decoration, flame-retardant inks have become key materials for ensuring product safety. However, existing flame-retardant ink systems generally suffer from problems such as poor compatibility between pigments and resin substrates, uneven dispersion of flame-retardant components, and unstable flame-retardant efficiency after film formation. This results in coatings that are easily combustible at high temperatures and release toxic fumes, making it difficult to meet the stringent safety standards of high-end applications.

[0003] Benzidine yellow pigment belongs to the diazo pigment family. Its molecular structure contains two benzene rings, and its skeletal structure is prone to thermal oxidative degradation at high temperatures, thus participating in the combustion process. Furthermore, the azo bonds are easily broken at high temperatures, releasing nitrogen-containing fragments that participate in the combustion chain reaction. In addition, benzidine yellow molecules do not contain halogens, phosphorus, nitrogen, or other flame-retardant elements, and lack self-extinguishing properties. Therefore, it is flammable when exposed to open flames or high heat, releasing toxic fumes during combustion. Currently, flame-retardant properties are generally achieved by adding large amounts of external flame retardants, but this reduces the color strength and film-forming properties of the ink. Therefore, developing a flame-retardant benzidine yellow pigment while maintaining the original pigment's excellent properties is of great significance. Summary of the Invention

[0004] To address the above problems, the present invention aims to provide a benzidine yellow pigment for flame-retardant inks and a method for preparing the same.

[0005] To achieve the above objectives, the present invention employs the following technical solution: A benzidine yellow pigment for flame-retardant inks, comprising, by weight, 1 part hyperbranched flame-retardant polymer and 50-100 parts benzidine yellow; The hyperbranched flame-retardant polymer is a hyperbranched flame-retardant polymer with fluorine-containing long-chain units as its backbone, constructed by multi-step branching from dimethyl hexadecanoate, triethylene glycol mono-p-toluenesulfonate, 1,2-ethylenediamine and N-tert-butoxycarbonyl-1,2-ethylenediamine as raw materials.

[0006] The hyperbranched flame-retardant polymer was prepared according to the following method: 1) Add dimethyl hexafluorodecanedioate to methanol, stir to dissolve, then add sodium hydroxide, and react at 25~30℃ for 10~15h. After the reaction is complete, add water, then add dichloromethane for extraction, and evaporate the organic solvent in the organic phase to obtain methyl hexafluorodecanedioate with one side deesterification. 2) Triethylene glycol mono-p-toluenesulfonate and the unilaterally deesterified hexafluorosepiacetic methyl ester prepared in step 1) were added to tetrahydrofuran and stirred until homogeneous. Then, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 4-dimethylaminopyridine were added and reacted at 25~40℃ for 12~24h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filtrate was washed with acetonitrile and dried to obtain a hexafluoro derivative with p-toluenesulfonate group at the end. 3) The hexadecyl fluoro derivative with p-toluenesulfonate group prepared in step 2) and 1,2-ethylenediamine were added to tetrahydrofuran and stirred until homogeneous. Then, base 1 was added and the mixture was reacted at 40-50℃ for 6-12 h. After the reaction was completed, the mixture was filtered. The solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 3-5 times and dried. The dried compound was added to an alcohol solvent and base 2 was added. The mixture was reacted at 25-40℃ for 5-10 h. After the reaction was completed, the mixture was filtered. The solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain the hexadecyl fluoro derivative with carboxyl group. 4) Add the terminal carboxyl hexadecyl fluoro derivative prepared in step 3) and N-tert-butoxycarbonyl-1,2-ethylenediamine to tetrahydrofuran, then add diethyl azodicarbonate and 1-hydroxybenzotriazole, and react at 25~40℃ for 5~10h. Then add 3mol / L hydrochloric acid and continue the reaction for 3~6h. After the reaction is completed, remove the solvent by vacuum distillation. Wash the residue with water 2~3 times and dry to obtain the terminal amino hexadecyl fluoro derivative. 5) The hexadecyl fluoro derivative with p-toluenesulfonate ester group prepared in step 2) and the hexadecyl fluoro derivative with terminal amino group prepared in step 4) are added to tetrahydrofuran, and then base 1 is added. The reaction is carried out at 40~50℃ for 6~12h. After the reaction is completed, the mixture is filtered, and the solvent is removed by vacuum distillation of the filtrate. The residue is washed with water 3~5 times and dried. The dried compound is added to an alcohol solvent, and then base 2 is added. The reaction is carried out at 25~40℃ for 5~10h. After the reaction is completed, the mixture is filtered, and the solvent is removed by vacuum distillation of the filtrate. The filter cake is washed with water and dried to obtain the further branched terminal carboxyl hexadecyl fluoro derivative. 6) The further branched terminal carboxyl hexafluoro derivative prepared in step 5) and N-tert-butoxycarbonyl-1,2-ethylenediamine were added to tetrahydrofuran, followed by diethyl azodicarbonate and 1-hydroxybenzotriazole. The reaction was carried out at 25-40℃ for 5-10 h, and then 3 mol / L hydrochloric acid was added to continue the reaction for 3-6 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed with water 2-3 times and dried to obtain the further branched terminal amino hexafluoro derivative. 7) The hexadecyl fluoro derivative with p-toluenesulfonate ester group prepared in step 2) and the further branched terminal amino hexadecyl fluoro derivative prepared in step 6) are added to tetrahydrofuran, and then base 1 is added. The reaction is carried out at 40~50℃ for 6~12h. After the reaction is completed, the mixture is filtered, and the solvent is removed by vacuum distillation of the filtrate. The residue is washed with water 3~5 times and dried. The dried compound is added to an alcohol solvent, and then base 2 is added. The reaction is carried out at 25~40℃ for 5~10h. After the reaction is completed, the mixture is filtered, and the solvent is removed by vacuum distillation of the filtrate. The filter cake is washed with water and dried to obtain a hyperbranched flame-retardant polymer.

[0007] The mass ratio of hexadecanoic acid dimethyl ester, methanol, sodium hydroxide, water and dichloromethane in step 1) is 1:5~10:0.08~0.09:5~10:5~10.

[0008] In step 2), the mass ratio of triethylene glycol mono-p-toluenesulfonate, unilaterally deesterified hexafluorodecanedioate methyl ester, tetrahydrofuran, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 4-dimethylaminopyridine is 1:1.65~2:10~15:0.55~0.75:0.1~0.4.

[0009] In step 3), the mass ratio of the hexadecyl fluoro derivative with a p-toluenesulfonate ester group, 1,2-ethylenediamine, tetrahydrofuran, base 1, alcohol solvent, and base 2 is 5.6~8:0.1:10~20:1~1.5:10~20:0.9~1.5.

[0010] In step 3), base 1 and base 2 are independently selected from potassium carbonate or sodium carbonate.

[0011] The alcohol solvent mentioned in step 3) is methanol or ethanol.

[0012] In step 4), the mass ratio of the terminal carboxyl group hexadecyl fluoro derivative, N-tert-butoxycarbonyl-1,2-ethylenediamine, tetrahydrofuran, diethyl azodicarbonate, 1-hydroxybenzotriazole, and hydrochloric acid is 1:0.15~0.2:10~15:0.26~0.38:0.2~0.3:0.5~0.8.

[0013] In step 5), the mass ratio of the hexadecyl derivative with a p-toluenesulfonate ester group, the terminal amino hexadecyl derivative, tetrahydrofuran, base 1, alcohol solvent and base 2 is 2.5~4:1:10~20:0.4~0.8:10~20:0.4~0.8.

[0014] In step 6), the mass ratio of the further branched terminal carboxyl hexadecyl derivative, N-tert-butoxycarbonyl-1,2-ethylenediamine, tetrahydrofuran, diethyl azodicarbonate, 1-hydroxybenzotriazole, and hydrochloric acid is 1:0.09~0.12:10~15:0.16~0.25:0.12~0.18:0.3~0.5.

[0015] In step 7), the mass ratio of the terminal group of the hexadecyl fluoro derivative with a p-toluenesulfonate group, the further branched terminal amino hexadecyl fluoro derivative, tetrahydrofuran, base 1, alcohol solvent and base 2 is 1.33~2:1:10~20:0.25~0.45:10~20:0.22~0.45.

[0016] The preparation method of the flame-retardant benzidine yellow pigment includes the following steps: By weight, 1 part of hyperbranched flame-retardant polymer is added to 150-200 parts of organic solvent, stirred and mixed evenly, then 50-100 parts of benzidine yellow are added, ultrasonically dispersed for 0.5-1 h, then 200-300 parts of unsuitable solvent are added, filtered, the resulting filter cake is washed and dried to obtain benzidine yellow pigment for flame-retardant ink.

[0017] The organic solvent is chloroform, acetone, acetonitrile, or tetrahydrofuran.

[0018] The unsuitable solvent is petroleum ether, n-hexane, or cyclohexane.

[0019] The present invention has the following advantages over the prior art: The benzidine yellow pigment for flame-retardant inks of this invention is composed of a hyperbranched flame-retardant polymer and benzidine yellow pigment. The hyperbranched flame-retardant polymer is a hyperbranched molecule with a three-dimensional topological structure, possessing a large specific surface area. Its exterior contains fluorinated segments and active carboxyl groups, while its interior has abundant cavities that can adsorb and encapsulate pigment molecules. This breaks away from the traditional physical blending mode of flame-retardant components and pigments, achieving uniform composite of flame-retardant components and pigments at the nanoscale. Furthermore, the benzidine yellow pigment is coated with hyperbranched flame-retardant polymer segments containing fluorinated segments. On one hand, these fluorinated segments migrate to the material surface at high temperatures to form a dense protective layer, isolating oxygen and heat. On the other hand, due to the hyperbranched coating, heat and mass transfer can be hindered at high temperatures, significantly improving the flame-retardant properties of the pigment. It also effectively inhibits oxidative fading of the pigment during use, extending its service life and increasing its stability.

[0020] The benzidine yellow pigment for flame-retardant inks of the present invention has a hyperbranched flame-retardant polymer that does not contain conjugated segments, thus the material as a whole exhibits transparent properties and does not cover the original color of the benzidine yellow pigment, maintaining the pigment's high tinting strength. Secondly, the hyperbranched flame-retardant polymer is a molecular form between small molecules and polymers, and the overall molecular shape is spherical, thus having extremely high dispersibility. It can be uniformly coated on the surface of the benzidine yellow pigment, reducing the aggregation between pigment particles and significantly improving the pigment's dispersibility and compatibility in the substrate. Detailed Implementation

[0021] To better understand the technical solution of the present invention, the following detailed embodiments further illustrate the above-mentioned content of the present invention. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following examples. All technologies implemented based on the above-mentioned content of the present invention fall within the scope of the present invention.

[0022] Example 1: Preparation of hyperbranched flame-retardant polymers: 1) Add 0.1 kg of dimethyl hexadecanoate to 0.5 kg of methanol, stir to dissolve, then add 0.008 kg of sodium hydroxide, react at 25 °C for 10 h, after the reaction is complete, add 0.5 kg of water, then add 0.5 kg of dichloromethane for extraction, and evaporate the organic solvent in the organic phase to obtain methyl hexadecanoate with one-sided deesterification. 1 H NMR (300 MHz, DMSO-) d 6 , 298 K) δ 12.25 (s, 1H), 3.63 (s, 3H).

[0023] 2) 0.1 kg of triethylene glycol mono-p-toluenesulfonate and 0.165 kg of deesterified hexafluoroselenoester methyl ester were added to 1 kg of tetrahydrofuran. After stirring and mixing evenly, 0.055 kg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.01 kg of 4-dimethylaminopyridine were added. The mixture was reacted at 25 °C for 12 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filtrate was washed with acetonitrile and dried to obtain a hexafluoro derivative with a p-toluenesulfonate group at the end. 1 H NMR (300MHz, DMSO-) d 6 , 298 K) δ 7.73 (d, 2H), 7.40 (d, 2H), 2.21 (t, 2H), 3.45-3.70 (m,17H), 2.41 (s, 3H).

[0024] 3) 0.56 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.01 kg of 1,2-ethylenediamine were added to 1 kg of tetrahydrofuran. After stirring and mixing evenly, 0.1 kg of potassium carbonate was added, and the mixture was reacted at 40 °C for 6 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water three times and dried. The dried compound was added to 1 kg of methanol, and then 0.09 kg of potassium carbonate was added. The mixture was reacted at 25 °C for 5 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain the hexadecyl fluoro derivative with a carboxyl end group. 4) 0.1 kg of terminal carboxyl hexadecyl fluoro derivative and 0.015 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1 kg of tetrahydrofuran, followed by 0.026 kg of diethyl azodicarbonate and 0.02 kg of 1-hydroxybenzotriazole. The mixture was reacted at 25 °C for 5 h, and then 0.05 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 3 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed twice with water and dried to obtain the terminal amino hexadecyl fluoro derivative. 5) 0.25 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a hexadecyl fluoro derivative with an amino end group were added to 1 kg of tetrahydrofuran, followed by 0.04 kg of potassium carbonate. The reaction was carried out at 40 °C for 6 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water three times and dried. The dried compound was added to 1 kg of methanol, followed by 0.04 kg of potassium carbonate. The reaction was carried out at 25 °C for 5 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a further branched hexadecyl fluoro derivative with a carboxyl end group. 6) 0.1 kg of further branched terminal carboxyl hexadecyl fluoro derivative and 0.009 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1 kg of tetrahydrofuran, followed by 0.016 kg of diethyl azodicarbonate and 0.012 kg of 1-hydroxybenzotriazole. The mixture was reacted at 25 °C for 5 h, and then 0.03 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 3 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed twice with water and dried to obtain the further branched terminal amino hexadecyl fluoro derivative. 7) 0.133 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a further branched terminal amino hexadecyl fluoro derivative were added to 1 kg of tetrahydrofuran, followed by 0.025 kg of potassium carbonate. The reaction was carried out at 40 °C for 6 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed three times with water and dried. The dried compound was added to 1 kg of methanol, followed by 0.022 kg of sodium carbonate. The reaction was carried out at 25 °C for 5 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a hyperbranched flame-retardant polymer. The number-average molecular weight (Mn) of the hyperbranched flame-retardant polymer was determined by GPC to be 1.6 × 10⁻⁶. 4 g / mol, PDI (Mw / Mn) is 1.81.

[0025] Preparation of benzidine yellow pigment for flame-retardant inks: 0.1 kg of hyperbranched flame-retardant polymer was added to 15 kg of chloroform and stirred until homogeneous. Then, 5 kg of benzidine yellow was added and ultrasonically dispersed for 0.5 h. 20 kg of petroleum ether was then added and filtered. The resulting filter cake was washed and dried to obtain benzidine yellow pigment for flame-retardant inks.

[0026] Example 2: Preparation of hyperbranched flame-retardant polymers: 1) Add 0.1 kg of dimethyl hexadecanoate to 0.6 kg of methanol, stir to dissolve, then add 0.0082 kg of sodium hydroxide, react at 26 °C for 11 h, after the reaction is complete, add 0.6 kg of water, then add 0.6 kg of dichloromethane for extraction, and evaporate the organic solvent in the organic phase to obtain methyl hexadecanoate with one side deesterification. 2) 0.1 kg of triethylene glycol mono-p-toluenesulfonate and 0.17 kg of methyl hexafluorosepiacetate with one side deesterified were added to 1.1 kg of tetrahydrofuran. After stirring and mixing evenly, 0.058 kg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.015 kg of 4-dimethylaminopyridine were added. The mixture was reacted at 30 °C for 15 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filtrate was washed with acetonitrile and dried to obtain a hexafluoro derivative with a p-toluenesulfonate group at the end. 3) 0.6 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.01 kg of 1,2-ethylenediamine were added to 1.2 kg of tetrahydrofuran. After stirring and mixing evenly, 0.11 kg of sodium carbonate was added, and the mixture was reacted at 43 °C for 7 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water four times and dried. The dried compound was added to 1.2 kg of ethanol, and then 0.1 kg of potassium carbonate was added. The mixture was reacted at 30 °C for 6 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain the hexadecyl fluoro derivative with a carboxyl end group. 4) 0.1 kg of terminal carboxyl hexadecyl fluoro derivative and 0.016 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.1 kg of tetrahydrofuran, followed by 0.028 kg of diethyl azodicarbonate and 0.022 kg of 1-hydroxybenzotriazole. The mixture was reacted at 30 °C for 6 h, and then 0.055 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 4 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the terminal amino hexadecyl fluoro derivative. 5) 0.27 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester group and 0.1 kg of a hexadecyl fluoro derivative with a terminal amino group were added to 1.2 kg of tetrahydrofuran, followed by 0.045 kg of sodium carbonate. The reaction was carried out at 42 °C for 8 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water four times and dried. The dried compound was added to 1.2 kg of ethanol, followed by 0.045 kg of sodium carbonate. The reaction was carried out at 30 °C for 6 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a further branched terminal carboxyl hexadecyl fluoro derivative. 6) 0.1 kg of further branched terminal carboxyl hexadecyl fluoro derivative and 0.01 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.1 kg of tetrahydrofuran, followed by 0.018 kg of diethyl azodicarbonate and 0.013 kg of 1-hydroxybenzotriazole. The mixture was reacted at 30 °C for 6 h, and then 0.035 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 4 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the further branched terminal amino hexadecyl fluoro derivative. 7) 0.14 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a further branched terminal amino hexadecyl fluoro derivative were added to 1.2 kg of tetrahydrofuran, followed by 0.03 kg of sodium carbonate. The mixture was reacted at 42 °C for 8 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water four times and dried. The dried compound was added to 1.2 kg of ethanol, followed by 0.025 kg of sodium carbonate. The mixture was reacted at 30 °C for 6 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a hyperbranched flame-retardant polymer.

[0027] Preparation of benzidine yellow pigment for flame-retardant inks: 0.1 kg of hyperbranched flame-retardant polymer was added to 16 kg of acetone and stirred until homogeneous. Then, 6 kg of benzidine yellow was added and ultrasonically dispersed for 0.6 h. 22 kg of n-hexane was then added and filtered. The resulting filter cake was washed and dried to obtain benzidine yellow pigment for flame-retardant inks.

[0028] Example 3: Preparation of hyperbranched flame-retardant polymers: 1) Add 0.1 kg of dimethyl hexadecanoate to 0.7 kg of methanol, stir to dissolve, then add 0.0085 kg of sodium hydroxide, react at 27 °C for 12 h, after the reaction is complete, add 0.7 kg of water, then add 0.7 kg of dichloromethane for extraction, and evaporate the organic solvent in the organic phase to obtain methyl hexadecanoate with one-sided deesterification. 2) 0.1 kg of triethylene glycol mono-p-toluenesulfonate and 0.175 kg of deesterified hexafluoroselenoester methyl ester were added to 1.2 kg of tetrahydrofuran. After stirring and mixing evenly, 0.063 kg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.02 kg of 4-dimethylaminopyridine were added. The mixture was reacted at 35 °C for 18 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filtrate was washed with acetonitrile and dried to obtain a hexafluoro derivative with a p-toluenesulfonate group at the end. 3) 0.65 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.01 kg of 1,2-ethylenediamine were added to 1.5 kg of tetrahydrofuran. After stirring and mixing evenly, 0.12 kg of potassium carbonate was added, and the mixture was reacted at 45 °C for 8 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 5 times and dried. The dried compound was added to 1.5 kg of methanol, and then 0.11 kg of sodium carbonate was added. The mixture was reacted at 35 °C for 7 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain the hexadecyl fluoro derivative with a carboxyl end group. 4) 0.1 kg of terminal carboxyl hexadecyl fluoro derivative and 0.017 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.2 kg of tetrahydrofuran, followed by 0.03 kg of diethyl azodicarbonate and 0.025 kg of 1-hydroxybenzotriazole. The mixture was reacted at 35 °C for 8 h, and then 0.06 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 5 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the terminal amino hexadecyl fluoro derivative. 5) 0.3 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a hexadecyl fluoro derivative with a terminal amino group were added to 1.5 kg of tetrahydrofuran, followed by 0.05 kg of potassium carbonate. The mixture was reacted at 45 °C for 10 h. After the reaction was completed, the mixture was filtered. The solvent in the filtrate was removed by vacuum distillation. The residue was washed with water five times and dried. The dried compound was added to 1.5 kg of ethanol, followed by 0.05 kg of sodium carbonate. The mixture was reacted at 35 °C for 7 h. After the reaction was completed, the mixture was filtered. The solvent in the filtrate was removed by vacuum distillation. The filter cake was washed with water and dried to obtain a further branched terminal carboxyl hexadecyl fluoro derivative. 6) 0.1 kg of further branched terminal carboxyl hexadecyl fluoro derivative and 0.011 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.2 kg of tetrahydrofuran, followed by 0.02 kg of diethyl azodicarbonate and 0.014 kg of 1-hydroxybenzotriazole. The mixture was reacted at 35 °C for 8 h, and then 0.04 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 4.5 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the further branched terminal amino hexadecyl fluoro derivative. 7) 0.15 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a further branched terminal amino hexadecyl fluoro derivative were added to 1.4 kg of tetrahydrofuran, followed by 0.035 kg of potassium carbonate. The mixture was reacted at 45 °C for 9 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 5 times and dried. The dried compound was added to 1.4 kg of methanol, followed by 0.03 kg of sodium carbonate. The mixture was reacted at 35 °C for 7 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a hyperbranched flame-retardant polymer.

[0029] Preparation of benzidine yellow pigment for flame-retardant inks: 0.1 kg of hyperbranched flame-retardant polymer was added to 17 kg of acetonitrile and stirred until homogeneous. Then, 7 kg of benzidine yellow was added and ultrasonically dispersed for 0.7 h. 24 kg of cyclohexane was then added and filtered. The resulting filter cake was washed and dried to obtain benzidine yellow pigment for flame-retardant inks.

[0030] Example 4: Preparation of hyperbranched flame-retardant polymers: 1) Add 0.1 kg of dimethyl hexadecanoate to 0.8 kg of methanol, stir to dissolve, then add 0.0088 kg of sodium hydroxide, react at 28 °C for 13 h, after the reaction is complete, add 0.8 kg of water, then add 0.8 kg of dichloromethane for extraction, and evaporate the organic solvent in the organic phase to obtain methyl hexadecanoate with one-sided deesterification. 2) 0.1 kg of triethylene glycol mono-p-toluenesulfonate and 0.18 kg of methyl hexafluorosepiacetate with one side deesterified were added to 1.3 kg of tetrahydrofuran. After stirring and mixing evenly, 0.068 kg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.025 kg of 4-dimethylaminopyridine were added. The mixture was reacted at 36 °C for 20 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filtrate was washed with acetonitrile and dried to obtain a hexafluoro derivative with a p-toluenesulfonate group at the end. 3) 0.7 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.01 kg of 1,2-ethylenediamine were added to 1.6 kg of tetrahydrofuran. After stirring and mixing evenly, 0.13 kg of sodium carbonate was added, and the mixture was reacted at 47 °C for 10 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 5 times and dried. The dried compound was added to 1.6 kg of methanol, and then 0.12 kg of sodium carbonate was added. The mixture was reacted at 36 °C for 8 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain the hexadecyl fluoro derivative with a carboxyl end group. 4) 0.1 kg of terminal carboxyl hexadecyl fluoro derivative and 0.018 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.3 kg of tetrahydrofuran, followed by 0.032 kg of diethyl azodicarbonate and 0.026 kg of 1-hydroxybenzotriazole. The mixture was reacted at 36 °C for 8 h, and then 0.07 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 5.5 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the terminal amino hexadecyl fluoro derivative. 5) 0.33 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester group and 0.1 kg of a hexadecyl fluoro derivative with a terminal amino group were added to 1.6 kg of tetrahydrofuran, followed by 0.06 kg of sodium carbonate. The reaction was carried out at 46 °C for 11 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 5 times and dried. The dried compound was added to 1.7 kg of methanol, followed by 0.06 kg of sodium carbonate. The reaction was carried out at 37 °C for 8 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a further branched terminal carboxyl hexadecyl fluoro derivative. 6) 0.1 kg of further branched terminal carboxyl hexadecyl fluoro derivative and 0.011 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.3 kg of tetrahydrofuran, followed by 0.021 kg of diethyl azodicarbonate and 0.015 kg of 1-hydroxybenzotriazole. The mixture was reacted at 36 °C for 8 h, and then 0.045 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 5 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the further branched terminal amino hexadecyl fluoro derivative. 7) 0.16 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a further branched terminal amino hexadecyl fluoro derivative were added to 1.6 kg of tetrahydrofuran, followed by 0.04 kg of potassium carbonate. The mixture was reacted at 46 °C for 10 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water five times and dried. The dried compound was added to 1.6 kg of methanol, followed by 0.035 kg of potassium carbonate. The mixture was reacted at 36 °C for 8 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a hyperbranched flame-retardant polymer.

[0031] Preparation of benzidine yellow pigment for flame-retardant inks: 0.1 kg of hyperbranched flame-retardant polymer was added to 18 kg of tetrahydrofuran and stirred until homogeneous. Then, 8 kg of benzidine yellow was added and ultrasonically dispersed for 0.8 h. 26 kg of n-hexane was then added and filtered. The resulting filter cake was washed and dried to obtain benzidine yellow pigment for flame-retardant inks.

[0032] Example 5: Preparation of hyperbranched flame-retardant polymers: 1) Add 0.1 kg of dimethyl hexadecanoate to 0.9 kg of methanol, stir to dissolve, then add 0.0089 kg of sodium hydroxide, react at 29 °C for 14 h, after the reaction is complete, add 0.9 kg of water, then add 0.9 kg of dichloromethane for extraction, and evaporate the organic solvent in the organic phase to obtain methyl hexadecanoate with one side deesterification. 2) 0.1 kg of triethylene glycol mono-p-toluenesulfonate and 0.19 kg of deesterified hexafluoroselenoester methyl ester were added to 1.4 kg of tetrahydrofuran. After stirring and mixing evenly, 0.071 kg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.03 kg of 4-dimethylaminopyridine were added. The mixture was reacted at 38 °C for 22 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filtrate was washed with acetonitrile and dried to obtain a hexafluoro derivative with a p-toluenesulfonate end group. 3) 0.75 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.01 kg of 1,2-ethylenediamine were added to 1.8 kg of tetrahydrofuran. After stirring and mixing evenly, 0.14 kg of sodium carbonate was added, and the mixture was reacted at 48 °C for 11 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 5 times and dried. The dried compound was added to 1.8 kg of ethanol, and then 0.13 kg of sodium carbonate was added. The mixture was reacted at 38 °C for 9 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain the hexadecyl fluoro derivative with a carboxyl end group. 4) 0.1 kg of terminal carboxyl hexadecyl fluoro derivative and 0.019 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.4 kg of tetrahydrofuran, followed by 0.035 kg of diethyl azodicarbonate and 0.028 kg of 1-hydroxybenzotriazole. The mixture was reacted at 38 °C for 9 h, and then 0.075 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 5.8 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the terminal amino hexadecyl fluoro derivative. 5) 0.36 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a hexadecyl fluoro derivative with a terminal amino group were added to 1.8 kg of tetrahydrofuran, followed by 0.07 kg of potassium carbonate. The mixture was reacted at 48 °C for 11 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water five times and dried. The dried compound was added to 1.8 kg of methanol, followed by 0.07 kg of sodium carbonate. The mixture was reacted at 39 °C for 9 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a further branched terminal carboxyl hexadecyl fluoro derivative. 6) 0.1 kg of further branched terminal carboxyl hexadecyl fluoro derivative and 0.011 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.4 kg of tetrahydrofuran, followed by 0.023 kg of diethyl azodicarbonate and 0.016 kg of 1-hydroxybenzotriazole. The mixture was reacted at 38 °C for 9 h, and then 0.048 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 5.5 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the further branched terminal amino hexadecyl fluoro derivative. 7) 0.18 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a further branched terminal amino hexadecyl fluoro derivative were added to 1.8 kg of tetrahydrofuran, followed by 0.043 kg of sodium carbonate. The reaction was carried out at 48 °C for 11 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water five times and dried. The dried compound was added to 1.8 kg of ethanol, followed by 0.04 kg of potassium carbonate. The reaction was carried out at 38 °C for 9 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a hyperbranched flame-retardant polymer.

[0033] Preparation of benzidine yellow pigment for flame-retardant inks: 0.1 kg of hyperbranched flame-retardant polymer was added to 19 kg of acetone and stirred until homogeneous. Then, 9 kg of benzidine yellow was added and ultrasonically dispersed for 0.9 h. 28 kg of cyclohexane was then added and filtered. The resulting filter cake was washed and dried to obtain benzidine yellow pigment for flame-retardant inks.

[0034] Example 6: Preparation of hyperbranched flame-retardant polymers: 1) Add 0.1 kg of dimethyl hexadecanoate to 1 kg of methanol, stir to dissolve, then add 0.009 kg of sodium hydroxide, react at 30 °C for 15 h, after the reaction is complete, add 1 kg of water, then add 1 kg of dichloromethane for extraction, and evaporate the organic solvent in the organic phase to obtain methyl hexadecanoate with one-sided deesterification. 2) Add 0.1 kg of triethylene glycol mono-p-toluenesulfonate and 0.2 kg of deesterified hexafluoroselenoester methyl ester to 1.5 kg of tetrahydrofuran. After stirring and mixing evenly, add 0.075 kg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 0.04 kg of 4-dimethylaminopyridine. React at 40 °C for 24 h. After the reaction is completed, filter, remove the solvent by vacuum distillation of the filtrate, wash with acetonitrile, and dry to obtain a hexafluoro derivative with p-toluenesulfonate group at the end. 3) 0.8 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.01 kg of 1,2-ethylenediamine were added to 2 kg of tetrahydrofuran. After stirring and mixing evenly, 0.15 kg of potassium carbonate was added, and the mixture was reacted at 50 °C for 12 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 5 times and dried. The dried compound was added to 2 kg of ethanol, and then 0.15 kg of potassium carbonate was added. The mixture was reacted at 40 °C for 10 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain the hexadecyl fluoro derivative with a carboxyl end group. 4) 0.1 kg of terminal carboxyl hexadecyl fluoro derivative and 0.02 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.5 kg of tetrahydrofuran, followed by 0.038 kg of diethyl azodicarbonate and 0.03 kg of 1-hydroxybenzotriazole. The mixture was reacted at 40 °C for 10 h, and then 0.08 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 6 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the terminal amino hexadecyl fluoro derivative. 5) 0.4 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester group and 0.1 kg of a hexadecyl fluoro derivative with a terminal amino group were added to 2 kg of tetrahydrofuran, followed by 0.08 kg of potassium carbonate. The mixture was reacted at 50 °C for 12 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 5 times and dried. The dried compound was added to 2 kg of ethanol, followed by 0.08 kg of sodium carbonate. The mixture was reacted at 40 °C for 10 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a further branched terminal carboxyl hexadecyl fluoro derivative. 6) 0.1 kg of further branched terminal carboxyl hexadecyl fluoro derivative and 0.012 kg of N-tert-butoxycarbonyl-1,2-ethylenediamine were added to 1.5 kg of tetrahydrofuran, followed by 0.025 kg of diethyl azodicarbonate and 0.018 kg of 1-hydroxybenzotriazole. The mixture was reacted at 40 °C for 10 h, and then 0.05 kg of 3 mol / L hydrochloric acid was added to continue the reaction for 6 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed three times with water and dried to obtain the further branched terminal amino hexadecyl fluoro derivative. 7) 0.2 kg of a hexadecyl fluoro derivative with a p-toluenesulfonate ester end group and 0.1 kg of a further branched terminal amino hexadecyl fluoro derivative were added to 2 kg of tetrahydrofuran, followed by 0.045 kg of sodium carbonate. The mixture was reacted at 50 °C for 12 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 5 times and dried. The dried compound was added to 2 kg of ethanol, followed by 0.045 kg of sodium carbonate. The mixture was reacted at 40 °C for 10 h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain a hyperbranched flame-retardant polymer.

[0035] Preparation of benzidine yellow pigment for flame-retardant inks: 0.1 kg of hyperbranched flame-retardant polymer was added to 20 kg of acetone and stirred until homogeneous. Then, 10 kg of benzidine yellow was added and ultrasonically dispersed for 1 hour. Then, 30 kg of cyclohexane was added and filtered. The resulting filter cake was washed and dried to obtain benzidine yellow pigment for flame-retardant inks.

[0036] Experimental Example Ten parts of the benzidine yellow pigment for flame-retardant ink prepared in Example 3 and 100 parts of acrylic latex coating were added to a high-speed disperser and stirred and ground at 2500 r / min. The ground slurry was transferred to filter paper, dried into a film, and then rinsed with a small amount of ethanol. The color uniformity of the residue on the filter paper and the color of the rinsing solution were observed. A comparative example was prepared using the company's own product, benzidine yellow GA (PY12) for ink. The experiment showed that the film made from the pigment prepared in Example 3, after ethanol rinsing, produced a basically colorless rinsing solution and a uniform color of the residue on the filter paper. The film prepared in the comparative example, after ethanol rinsing, produced a distinctly yellow rinsing solution and showed uneven color of the residue on the filter paper. This indicates that the benzidine yellow pigment for flame-retardant ink prepared in this invention did not damage its coating layer after grinding, and the hyperbranched flame-retardant polymer remained attached to the pigment surface, meeting the stability requirements during ink preparation and application.

[0037] The performance of the benzidine yellow pigments for flame-retardant inks prepared in Examples 1-6 was tested. Tinting strength was tested according to the method in GB1708-79; lightfastness was tested according to the method in standard GB1710-79; water resistance, acid resistance, and alkali resistance were tested according to the method in GB 5211.5-2008-T; and oil absorption was tested according to the method in GB / T 5211.15-2014. The comparative example was our own product, benzidine yellow GA (PY12) for inks. As shown in Table 1, the benzidine yellow pigment for flame-retardant inks prepared by this invention has strong tinting strength, as well as strong lightfastness and acid / alkali resistance, low oil absorption, and good dispersibility.

[0038] Table 1 Performance test results of pigments prepared in Examples 1-6

[0039] The benzidine yellow pigments for flame-retardant inks prepared in Examples 1-6 and the pigments of the comparative examples were uniformly coated onto a substrate with a coating thickness of 0.3 mm. After drying into a film, the coatings were cut into standard strips and subjected to combustion performance tests according to the method in GB / T 2406.2-2009. The test results are shown in Table 2. As can be seen from the results in Table 2, the pigments prepared in each example of the present invention can achieve the UL-94 V-0 flame retardant rating, with an oxygen index between 29.3% and 30.5%, which is significantly better than that of the comparative example. This indicates that the benzidine yellow pigments for flame-retardant inks prepared in the present invention have a stable and reliable flame-retardant effect.

[0040] Table 2. Test results of the combustion performance of the pigments in Examples 1-6 and the comparative examples.

[0041] While the specific embodiments of the present invention have been described above, they are not intended to limit the scope of protection of the present invention. Based on the technical solutions of the present invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the present invention.

Claims

1. A benzidine yellow pigment for flame-retardant inks, characterized in that: By weight, it comprises 1 part hyperbranched flame-retardant polymer and 50-100 parts benzidine yellow; The hyperbranched flame-retardant polymer is a hyperbranched flame-retardant polymer with fluorine-containing long-chain units as its backbone, constructed by multi-step branching from dimethyl hexadecanoate, triethylene glycol mono-p-toluenesulfonate, 1,2-ethylenediamine and N-tert-butoxycarbonyl-1,2-ethylenediamine as raw materials.

2. The benzidine yellow pigment for flame-retardant inks as described in claim 1, characterized in that: The hyperbranched flame-retardant polymer was prepared according to the following method: 1) Add dimethyl hexafluorodecanedioate to methanol, stir to dissolve, then add sodium hydroxide, and react at 25~30℃ for 10~15h. After the reaction is complete, add water, then add dichloromethane for extraction, and evaporate the organic solvent in the organic phase to obtain methyl hexafluorodecanedioate with one side deesterification. 2) Triethylene glycol mono-p-toluenesulfonate and the unilaterally deesterified hexafluorosepiacetic methyl ester prepared in step 1) were added to tetrahydrofuran and stirred until homogeneous. Then, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 4-dimethylaminopyridine were added and reacted at 25~40℃ for 12~24h. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation of the filtrate. The filtrate was washed with acetonitrile and dried to obtain a hexafluoro derivative with p-toluenesulfonate group at the end. 3) The hexadecyl fluoro derivative with p-toluenesulfonate group prepared in step 2) and 1,2-ethylenediamine were added to tetrahydrofuran and stirred until homogeneous. Then, base 1 was added and the mixture was reacted at 40-50℃ for 6-12 h. After the reaction was completed, the mixture was filtered. The solvent was removed by vacuum distillation of the filtrate. The residue was washed with water 3-5 times and dried. The dried compound was added to an alcohol solvent and base 2 was added. The mixture was reacted at 25-40℃ for 5-10 h. After the reaction was completed, the mixture was filtered. The solvent was removed by vacuum distillation of the filtrate. The filter cake was washed with water and dried to obtain the hexadecyl fluoro derivative with carboxyl group. 4) Add the terminal carboxyl hexadecyl fluoro derivative prepared in step 3) and N-tert-butoxycarbonyl-1,2-ethylenediamine to tetrahydrofuran, then add diethyl azodicarbonate and 1-hydroxybenzotriazole, and react at 25~40℃ for 5~10h. Then add 3mol / L hydrochloric acid and continue the reaction for 3~6h. After the reaction is completed, remove the solvent by vacuum distillation. Wash the residue with water 2~3 times and dry to obtain the terminal amino hexadecyl fluoro derivative. 5) The hexadecyl fluoro derivative with p-toluenesulfonate ester group prepared in step 2) and the hexadecyl fluoro derivative with terminal amino group prepared in step 4) are added to tetrahydrofuran, and then base 1 is added. The reaction is carried out at 40~50℃ for 6~12h. After the reaction is completed, the mixture is filtered, and the solvent is removed by vacuum distillation of the filtrate. The residue is washed with water 3~5 times and dried. The dried compound is added to an alcohol solvent, and then base 2 is added. The reaction is carried out at 25~40℃ for 5~10h. After the reaction is completed, the mixture is filtered, and the solvent is removed by vacuum distillation of the filtrate. The filter cake is washed with water and dried to obtain the further branched terminal carboxyl hexadecyl fluoro derivative. 6) The further branched terminal carboxyl hexafluoro derivative prepared in step 5) and N-tert-butoxycarbonyl-1,2-ethylenediamine were added to tetrahydrofuran, followed by diethyl azodicarbonate and 1-hydroxybenzotriazole. The reaction was carried out at 25-40℃ for 5-10 h, and then 3 mol / L hydrochloric acid was added to continue the reaction for 3-6 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was washed with water 2-3 times and dried to obtain the further branched terminal amino hexafluoro derivative. 7) The hexadecyl fluoro derivative with p-toluenesulfonate ester group prepared in step 2) and the further branched terminal amino hexadecyl fluoro derivative prepared in step 6) are added to tetrahydrofuran, and then base 1 is added. The reaction is carried out at 40~50℃ for 6~12h. After the reaction is completed, the mixture is filtered, and the solvent is removed by vacuum distillation of the filtrate. The residue is washed with water 3~5 times and dried. The dried compound is added to an alcohol solvent, and then base 2 is added. The reaction is carried out at 25~40℃ for 5~10h. After the reaction is completed, the mixture is filtered, and the solvent is removed by vacuum distillation of the filtrate. The filter cake is washed with water and dried to obtain a hyperbranched flame-retardant polymer.

3. The benzidine yellow pigment for flame-retardant inks as described in claim 2, characterized in that: The mass ratio of hexadecanoic acid dimethyl ester, methanol, sodium hydroxide, water and dichloromethane in step 1) is 1:5~10:0.08~0.09:5~10:5~10.

4. The benzidine yellow pigment for flame-retardant inks as described in claim 2, characterized in that: In step 2), the mass ratio of triethylene glycol mono-p-toluenesulfonate, unilaterally deesterified hexafluorodecanedioate methyl ester, tetrahydrofuran, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 4-dimethylaminopyridine is 1:1.65~2:10~15:0.55~0.75:0.1~0.

4.

5. The benzidine yellow pigment for flame-retardant inks as described in claim 2, characterized in that: In step 3), the mass ratio of the hexadecyl fluoro derivative with a p-toluenesulfonate ester group, 1,2-ethylenediamine, tetrahydrofuran, base 1, alcohol solvent, and base 2 is 5.6~8:0.1:10~20:1~1.5:10~20:0.9~1.5; in step 3), base 1 and base 2 are independently selected from potassium carbonate or sodium carbonate; in step 3), the alcohol solvent is methanol or ethanol.

6. The benzidine yellow pigment for flame-retardant inks as described in claim 2, characterized in that: In step 4), the mass ratio of the terminal carboxyl group hexadecyl fluoro derivative, N-tert-butoxycarbonyl-1,2-ethylenediamine, tetrahydrofuran, diethyl azodicarbonate, 1-hydroxybenzotriazole, and hydrochloric acid is 1:0.15~0.2:10~15:0.26~0.38:0.2~0.3:0.5~0.

8.

7. The benzidine yellow pigment for flame-retardant inks as described in claim 2, characterized in that: In step 5), the mass ratio of the hexadecyl derivative with a p-toluenesulfonate ester group, the terminal amino hexadecyl derivative, tetrahydrofuran, base 1, alcohol solvent and base 2 is 2.5~4:1:10~20:0.4~0.8:10~20:0.4~0.

8.

8. The benzidine yellow pigment for flame-retardant inks as described in claim 2, characterized in that: In step 6), the mass ratio of the further branched terminal carboxyl hexafluoro derivative, N-tert-butoxycarbonyl-1,2-ethylenediamine, tetrahydrofuran, diethyl azodicarbonate, 1-hydroxybenzotriazole, and hydrochloric acid is 1:0.09~0.12:10~15:0.16~0.25:0.12~0.18:0.3~0.5; in step 7), the mass ratio of the hexafluoro derivative with a p-toluenesulfonate ester end group, the further branched terminal amino hexafluoro derivative, tetrahydrofuran, base 1, alcohol solvent, and base 2 is 1.33~2:1:10~20:0.25~0.45:10~20:0.22~0.

45.

9. The method for preparing the benzidine yellow pigment for flame-retardant inks according to claim 1, characterized in that: Includes the following steps: By weight, 1 part of hyperbranched flame-retardant polymer is added to 150-200 parts of organic solvent, stirred and mixed evenly, then 50-100 parts of benzidine yellow are added, ultrasonically dispersed for 0.5-1 h, then 200-300 parts of unsuitable solvent are added, filtered, the resulting filter cake is washed and dried to obtain benzidine yellow pigment for flame-retardant ink.

10. The method for preparing benzidine yellow pigment for flame-retardant inks as described in claim 9, characterized in that: The organic solvent is chloroform, acetone, acetonitrile, or tetrahydrofuran; the undesirable solvent is petroleum ether, n-hexane, or cyclohexane.

Images