Low-temperature fixing color environmentally friendly toner and preparation method thereof

Abstract

The present invention discloses a low-temperature fixing color environmentally friendly toner and a preparation method thereof, comprising: (1) uniformly mixing a polymerization monomer, an emulsifier, and water to obtain a mixed solution, wherein the polymerization monomer consists of styrene, butyl acrylate, and hydroxyethyl methacrylate; (2) mixing the mixed solution with a modified silica-coated pigment dispersion and a maleic anhydride-styrene grafted polyethylene wax emulsion, uniformly dispersing the mixture by ultrasonication, then adding an initiator and a chain transfer agent, adjusting the pH to a certain value, and heating and stirring the reaction to obtain the product. The low-temperature fixing color environmentally friendly toner of the present invention has a simple preparation process and low cost, is not easy to stick to the roller during printing, has high printing efficiency, and has high print pattern clarity. It has good print quality and can meet the use requirements of low-temperature fixing.

Description

Technical Field

[0001] The present invention relates to the technical field of printing materials, and in particular to low-temperature fixing color environmentally friendly toner and a preparation method thereof. Background Art

[0002] Laser printers are common office equipment. Their primary consumable is toner, which consists of resin, pigment, and additives. The core process of laser printer operation is the transfer and fixing of toner. During this process, toner particles adsorbed to paper are pressurized and heated, melting the resin in the toner and allowing it to penetrate the paper along with the pigment, thus forming a fixed image. During this process, if the required heating temperature is too high, harmful substances such as polycyclic aromatic hydrocarbons and dimethylnitramine in the toner can be volatilized, thus impacting the environment. Therefore, for environmental and health reasons, toners with lower heating temperatures and low-temperature fixing capabilities have broader application prospects.

[0003] Currently, toner production methods are primarily categorized into physical pulverization and chemical polymerization. The physical pulverization method involves mixing raw materials such as resin and pigment, followed by pulverization, grinding, grading, screening, and surface modification. This method produces toner with large particle size and uneven dispersion, resulting in unclear printed images. The chemical polymerization method involves uniformly mixing polymer monomers, pigments, wax, and other additives, followed by polymerization. This method successfully produces toner with smaller and more uniform particle size, making it the primary method for producing high-quality printing toner.

[0004] Because low-temperature fixing toners often require low-molecular-weight resins and waxes, they are prone to roller sticking during the printing process, impacting printing efficiency and quality. Furthermore, the low compatibility of the pigments used in color toners with the resins also reduces print quality. Therefore, developing color toners suitable for low-temperature fixing, without roller sticking, and with high-definition image clarity has become a key area of ​​research. Summary of the Invention

[0005] The purpose of the present invention is to remedy the defects of the prior art and provide a low-temperature fixing color environmentally friendly toner and a preparation method thereof.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for preparing low-temperature fixing color environmentally friendly toner comprises the following steps:

[0008] (1) uniformly mixing a polymerization monomer, an emulsifier, and water to obtain a mixed solution, wherein the polymerization monomer comprises styrene, butyl acrylate, and hydroxyethyl methacrylate in a mass ratio of 1:(0.1-0.2):(0.03-0.05);

[0009] (2) The mixed solution is mixed with a modified silica-coated pigment dispersion and a maleic anhydride-styrene grafted polyethylene wax emulsion, and then ultrasonically dispersed uniformly. Then, an initiator and a chain transfer agent are added, and the pH is adjusted to a certain value. The mixture is heated and stirred at 80-85° C. for 3-4 hours to obtain the product.

[0010] Preferably, the preparation method of the modified silica-coated pigment dispersion is: mixing anhydrous ethanol, ammonia water and water to obtain a mixed solvent; adding pigment, ethyl orthosilicate and γ-aminopropyltriethoxysilane to the mixed solvent, stirring and reacting at 40-60°C for 4-6 hours, and then filtering, washing and drying the obtained solid matter, and then adding it to water for ultrasonic dispersion to obtain the product.

[0011] Preferably, the concentration of the ammonia water is 25-28%.

[0012] Preferably, the volume ratio of anhydrous ethanol, ammonia water and water is 1:(0.1-0.2):(0.1-0.2), and the mass ratio of the pigment, tetraethyl orthosilicate and γ-aminopropyltriethoxysilane is 10:(0.5-2):(0.5-2).

[0013] Preferably, the preparation method of the maleic anhydride-styrene grafted polyethylene wax emulsion is as follows: low molecular weight polyethylene wax, styrene and maleic anhydride are added to toluene in a mass ratio of 100: (0.2-0.3): (3-5), heated and mixed at 90-95°C, then dicumyl peroxide is added, stirred and reacted at 120-130°C for 2-3 hours, and cooled to obtain maleic anhydride-styrene grafted polyethylene wax; the maleic anhydride-styrene grafted polyethylene wax and Tween-80 are added to water in a mass ratio of 1: (0.3-0.5), and then stirred in an autoclave at high temperature and high pressure at 110-120°C for 1-2 hours to obtain the product.

[0014] Preferably, the molecular weight of the low molecular weight polyethylene wax is 1500-2500 and the melting point is 100-105° C.; the amount of the dicumyl peroxide is 0.5-1% of the sum of the mass of styrene and maleic anhydride.

[0015] Preferably, in step (1), the mass ratio of the polymerization monomer, the emulsifier and water is (25-30): (3-5): (65-75); in step (2), the mass ratio of the mixed solution to the modified silica-coated pigment dispersion and the maleic anhydride-styrene grafted polyethylene wax emulsion is 100: (1-4): (8-10); in step (2), the amount of the initiator used is 0.1-0.3% of the mass of the polymerization monomer, and the amount of the chain transfer agent used is 0.5-1% of the mass of the polymerization monomer.

[0016] Preferably, the solid content of the modified silica-coated pigment dispersion is 20-30%, and the solid content of the maleic anhydride-styrene grafted polyethylene wax emulsion is 3-5%.

[0017] Preferably, in step (1), the emulsifier is sodium dodecyl sulfate, sodium dodecylbenzenesulfonate or Tween-80; in step (2), the initiator is ammonium persulfate, benzoyl peroxide or azobisisobutyronitrile, and the chain transfer agent is dodecanethiol.

[0018] Preferably, in step (2), the pH is adjusted to 8-9.

[0019] A low-temperature fixing color environmentally friendly carbon powder is prepared by the preparation method.

[0020] The advantages of the present invention are:

[0021] The invention adopts styrene, butyl acrylate and hydroxyethyl methacrylate as comonomers, so that the resin of the carbon powder has a low softening point and contains a certain hydroxyl group. The invention adopts amino-containing silane coupling agent KH-550 and tetraethyl orthosilicate to carry out in-situ coating modification on the pigment, so that the surface of the pigment has a silicon dioxide coating layer containing amino active groups. Maleic anhydride and styrene are adopted as composite monomers to carry out graft modification on low-molecular-weight polyethylene wax, so that the obtained wax emulsion contains maleic anhydride and styrene chain segments, which can interact with the resin and the pigment. Under the premise of increasing the amount of the wax emulsion and avoiding roller sticking, a highly compatible and relatively uniform system can still be formed. Combined with the optimization of process conditions, the carbon powder finally prepared can not only meet the needs of low-temperature development, but also has a high wax component content and is not prone to roller sticking during the printing process. At the same time, due to the appropriate particle size and uniform system, the carbon powder also has the advantages of good printing firmness, high printing quality and clear pattern. The preparation process is simple and the cost is low, and the carbon powder has good application prospects. DETAILED DESCRIPTION

[0022] Example 1

[0023] A method for preparing low-temperature fixing color environmentally friendly toner comprises the following steps:

[0024] (1) uniformly mixing a polymerization monomer, sodium lauryl sulfate, and water to obtain a mixed solution, wherein the polymerization monomer comprises styrene, butyl acrylate, and hydroxyethyl methacrylate in a mass ratio of 1:0.1:0.03, and the mass ratio of the polymerization monomer, sodium lauryl sulfate, and water is 25:3:65;

[0025] (2) The mixed solution is mixed with a modified silica-coated pigment dispersion having a solid content of 20% and a maleic anhydride-styrene grafted polyethylene wax emulsion having a solid content of 3% in a mass ratio of 100:4:10, and then ultrasonically dispersed evenly. Then, 0.1% of ammonium persulfate equivalent to the mass of the polymerized monomer and 0.5% of dodecyl mercaptan equivalent to the mass of the polymerized monomer are added, the pH is adjusted to 8, and the mixture is heated and stirred at 80°C for 4 hours to obtain the modified silica-coated pigment dispersion. The preparation method of the modified silica-coated pigment dispersion is as follows: anhydrous ethanol, 25% ammonia water and water are mixed evenly in a volume ratio of 1:0.1:0.1 to obtain a mixed solvent; pigment cobalt blue, ethyl orthosilicate and γ-aminopropyltriethoxysilane are added to the mixed solvent in a mass ratio of 10:0.5:0.5, and the mixture is stirred at 80°C for 4 hours. The mixture was stirred and reacted at 40°C for 6 hours, then filtered, and the obtained solid matter was washed and dried, and then added to water for ultrasonic dispersion to obtain the product; the preparation method of maleic anhydride-styrene grafted polyethylene wax emulsion was as follows: low molecular weight polyethylene wax with a molecular weight of 2500 and a melting point of 100°C, styrene and maleic anhydride were added to toluene in a mass ratio of 100:0.2:3, heated and mixed at 90°C, and then 0.5% diisopropylbenzene peroxide equivalent to the sum of the mass of styrene and maleic anhydride was added, stirred and reacted at 120°C for 3 hours, and cooled to obtain maleic anhydride-styrene grafted polyethylene wax, maleic anhydride-styrene grafted polyethylene wax and Tween-80 were added to water in a mass ratio of 1:0.3, and then stirred in an autoclave at high temperature and high pressure at 110°C for 2 hours to obtain the product.

[0026] Example 2

[0027] A method for preparing low-temperature fixing color environmentally friendly toner comprises the following steps:

[0028] (1) uniformly mixing a polymerization monomer, sodium lauryl sulfate, and water to obtain a mixed solution, wherein the polymerization monomer comprises styrene, butyl acrylate, and hydroxyethyl methacrylate in a mass ratio of 1:0.2:0.05, and the mass ratio of the polymerization monomer, sodium lauryl sulfate, and water is 30:5:75;

[0029] (2) The mixed solution is mixed with a modified silica-coated pigment dispersion having a solid content of 30% and a maleic anhydride-styrene grafted polyethylene wax emulsion having a solid content of 5% in a mass ratio of 100:1:8, and then ultrasonically dispersed evenly. Then, 0.3% of ammonium persulfate equivalent to the mass of the polymerized monomer and 1% of dodecanethiol equivalent to the mass of the polymerized monomer are added, the pH is adjusted to 9, and the mixture is heated and stirred at 85°C for 3 hours to obtain the modified silica-coated pigment dispersion. The preparation method of the modified silica-coated pigment dispersion is as follows: anhydrous ethanol, 25% ammonia water and water are mixed evenly in a volume ratio of 1:0.2:0.2 to obtain a mixed solvent; pigment cobalt blue, ethyl orthosilicate and γ-aminopropyltriethoxysilane are added to the mixed solvent in a mass ratio of 10:2:2, and the mixture is heated at 60°C for 3 hours. The mixture was stirred and reacted for 4 hours at room temperature, and then filtered. The obtained solid matter was washed and dried, and then added to water and ultrasonically dispersed evenly to obtain the product. The preparation method of maleic anhydride-styrene grafted polyethylene wax emulsion is as follows: low molecular weight polyethylene wax with a molecular weight of 2500 and a melting point of 100°C, styrene and maleic anhydride were added to toluene in a mass ratio of 100:0.3:5, heated and mixed evenly at 95°C, and then 1% diisopropylbenzene peroxide equivalent to the sum of the mass of styrene and maleic anhydride was added, stirred and reacted at 130°C for 2 hours, and cooled to obtain maleic anhydride-styrene grafted polyethylene wax, maleic anhydride-styrene grafted polyethylene wax and Tween-80 were added to water in a mass ratio of 1:0.5, and then stirred at high temperature and high pressure in an autoclave at 120°C for 1 hour to obtain the product.

[0030] Example 3

[0031] A method for preparing low-temperature fixing color environmentally friendly toner comprises the following steps:

[0032] (1) uniformly mixing a polymerization monomer, sodium lauryl sulfate, and water to obtain a mixed solution, wherein the polymerization monomer comprises styrene, butyl acrylate, and hydroxyethyl methacrylate in a mass ratio of 1:0.15:0.045, and the mass ratio of the polymerization monomer, sodium lauryl sulfate, and water is 28:4:68;

[0033] (2) The mixed solution is mixed with a modified silica-coated pigment dispersion having a solid content of 25% and a maleic anhydride-styrene grafted polyethylene wax emulsion having a solid content of 3-5% in a mass ratio of 100:3:9, and then ultrasonically dispersed evenly. Then, 0.2% of ammonium persulfate equivalent to the mass of the polymerized monomer and 0.8% of dodecyl mercaptan equivalent to the mass of the polymerized monomer are added, the pH is adjusted to 8.5, and the mixture is heated and stirred at 82°C for 3.5 hours to obtain the modified silica-coated pigment dispersion. The preparation method of the modified silica-coated pigment dispersion is as follows: anhydrous ethanol, 25% ammonia water and water are mixed evenly in a volume ratio of 1:0.15:0.15 to obtain a mixed solvent; pigment cobalt blue, ethyl orthosilicate and γ-aminopropyltriethoxysilane are added to the mixed solvent in a mass ratio of 10:1:1, and the mixture is stirred at 5°C for 1 hour. The mixture was stirred and reacted at 0°C for 5 hours, then filtered, the obtained solid matter was washed and dried, and then added to water and ultrasonically dispersed evenly to obtain the product; the preparation method of maleic anhydride-styrene grafted polyethylene wax emulsion was as follows: low molecular weight polyethylene wax with a molecular weight of 2500 and a melting point of 100°C, styrene and maleic anhydride were added to toluene in a mass ratio of 100:0.25:4, heated and mixed evenly at 92°C, and then 0.7% diisopropylbenzene peroxide equivalent to the sum of the mass of styrene and maleic anhydride was added, stirred and reacted at 125°C for 2.5 hours, and cooled to obtain maleic anhydride-styrene grafted polyethylene wax, maleic anhydride-styrene grafted polyethylene wax and Tween-80 were added to water in a mass ratio of 1:0.4, and then stirred in an autoclave at high temperature and high pressure at 115°C for 1.5 hours to obtain the product.

[0034] Comparative Example 1

[0035] The only difference between Comparative Example 1 and Example 1 is that in step (1), the polymerization monomers are composed of styrene and butyl acrylate in a mass ratio of 1:0.13.

[0036] Comparative Example 2

[0037] The only difference between Comparative Example 2 and Example 1 is that polyethylene wax emulsion is used instead of maleic anhydride-styrene grafted polyethylene wax emulsion, specifically as follows:

[0038] A method for preparing low-temperature fixing color environmentally friendly toner comprises the following steps:

[0039] (1) uniformly mixing a polymerization monomer, sodium lauryl sulfate, and water to obtain a mixed solution, wherein the polymerization monomer comprises styrene, butyl acrylate, and hydroxyethyl methacrylate in a mass ratio of 1:0.1:0.03, and the mass ratio of the polymerization monomer, sodium lauryl sulfate, and water is 25:3:65;

[0040] (2) The mixed solution is mixed with a modified silica-coated pigment dispersion having a solid content of 20% and a polyethylene wax emulsion having a solid content of 3% in a mass ratio of 100:4:10, and then ultrasonically dispersed to obtain a uniform mixture. Then, 0.1% of ammonium persulfate equivalent to the mass of the polymerized monomer and 0.5% of dodecanethiol equivalent to the mass of the polymerized monomer are added, the pH is adjusted to 8, and the mixture is heated and stirred at 80° C. for 4 h to obtain the modified silica-coated pigment dispersion. The preparation method of the modified silica-coated pigment dispersion is as follows: anhydrous ethanol, 25% ammonia water and water are mixed in a volume ratio of 1:0.1:0 .1 mix evenly to obtain a mixed solvent; add pigment cobalt blue, ethyl orthosilicate and γ-aminopropyltriethoxysilane to the mixed solvent in a mass ratio of 10:0.5:0.5, stir and react at 40°C for 6 hours, then filter, wash and dry the obtained solid matter, and then add it to water for ultrasonic dispersion to obtain the product; the preparation method of polyethylene wax emulsion is as follows: add low molecular weight polyethylene wax with a molecular weight of 2500 and a melting point of 100°C and Tween-80 in a mass ratio of 1:0.3 to water, and then stir at high temperature and high pressure at 110°C in a pressure autoclave for 2 hours to obtain the product.

[0041] Comparative Example 3

[0042] The only difference between Comparative Example 3 and Example 1 is that the modified silica-coated pigment dispersion is replaced by a silica-coated pigment dispersion, as follows:

[0043] A method for preparing low-temperature fixing color environmentally friendly toner comprises the following steps:

[0044] (1) uniformly mixing a polymerization monomer, sodium lauryl sulfate, and water to obtain a mixed solution, wherein the polymerization monomer comprises styrene, butyl acrylate, and hydroxyethyl methacrylate in a mass ratio of 1:0.1:0.03, and the mass ratio of the polymerization monomer, sodium lauryl sulfate, and water is 25:3:65;

[0045] (2) The mixed solution is mixed with a silica-coated pigment dispersion having a solid content of 20% and a maleic anhydride-styrene grafted polyethylene wax emulsion having a solid content of 3% in a mass ratio of 100:4:10, and then ultrasonically dispersed to obtain a uniform mixture. Then, 0.1% of ammonium persulfate equivalent to the mass of the polymerized monomer and 0.5% of dodecanethiol equivalent to the mass of the polymerized monomer are added, the pH is adjusted to 8, and the mixture is heated and stirred at 80°C for 4 hours to obtain the silica-coated pigment dispersion. The preparation method of the silica-coated pigment dispersion is as follows: anhydrous ethanol, 25% ammonia water and water are mixed to obtain a mixed solvent in a volume ratio of 1:0.1:0.1; pigment cobalt blue and ethyl orthosilicate are added to the mixed solvent in a mass ratio of 10:0.5, and the mixture is stirred and reacted at 40°C for 6 hours. , and then filter, wash and dry the obtained solid matter, and then add it to water for ultrasonic dispersion to obtain; the preparation method of maleic anhydride-styrene grafted polyethylene wax emulsion is as follows: low molecular weight polyethylene wax with a molecular weight of 2500 and a melting point of 100°C, styrene and maleic anhydride are added to toluene in a mass ratio of 100:0.2:3, heated and mixed at 90°C, and then 0.5% diisopropylbenzene peroxide equivalent to the sum of the mass of styrene and maleic anhydride is added, stirred and reacted at 120°C for 3h, and cooled to obtain maleic anhydride-styrene grafted polyethylene wax, maleic anhydride-styrene grafted polyethylene wax and Tween-80 are added to water in a mass ratio of 1:0.3, and then stirred in an autoclave at high temperature and high pressure at 110°C for 2h to obtain.

[0046] Test example

[0047] The toners produced in Example 1 and Comparative Examples 1-3 were subjected to performance testing. Particle size was measured using a laser particle size analyzer, and printing performance was tested using a low-temperature fusing laser printer. Roller sticking was tested by continuously printing 1,000 images with the toner, then resting overnight. The next day, the toner was observed to see if it ejected the toner during printing. If no toner ejected, it was considered non-sticky. The test results are shown in Table 1.

[0048] Table 1

[0049]

[0050] As can be seen from Table 1, the toner of the present invention is suitable for low-temperature fixing, has an appropriate particle size, is non-sticky, and exhibits high print fastness and good print quality. Comparative Examples 1 and 2, while having high wax content, suffer from poor compatibility between the components, which severely impacts system uniformity and results in unsatisfactory fixing fastness and anti-sticking properties. Comparative Example 3 exhibits good anti-sticking properties, but poor pigment compatibility results in low print quality.

Claims

1. A method for preparing low-temperature fixing color environmentally friendly toner, characterized in that: The steps include: (1) uniformly mixing a polymerization monomer, an emulsifier and water to obtain a mixed solution, wherein the polymerization monomer is composed of styrene, butyl acrylate and hydroxyethyl methacrylate in a mass ratio of 1: (0.1-0.2): (0.03-0.05); (2) The mixed solution is mixed with a modified silica-coated pigment dispersion and a maleic anhydride-styrene grafted polyethylene wax emulsion, and then ultrasonically dispersed uniformly. Then, an initiator and a chain transfer agent are added, and the pH is adjusted to a certain value. The mixture is heated and stirred at 80-85° C. for 3-4 hours to obtain the product; The preparation method of the maleic anhydride-styrene grafted polyethylene wax emulsion comprises the following steps: adding low molecular weight polyethylene wax, styrene and maleic anhydride in a mass ratio of 100:(0.2-0.3):(3-5) to toluene, heating and mixing at 90-95°C to uniformly mix, then adding dicumyl peroxide, stirring and reacting at 120-130°C for 2-3 hours, and cooling to obtain the maleic anhydride-styrene grafted polyethylene wax; and adding the maleic anhydride-styrene grafted polyethylene wax and Tween-80 in a mass ratio of 1:(0.3-0.5) to water, and then stirring in an autoclave at high temperature and high pressure at 110-120°C for 1-2 hours to obtain the emulsion.

2. The method for preparing a low-temperature fixing color environmentally friendly toner according to claim 1, characterized in that: The preparation method of the modified silica-coated pigment dispersion comprises the following steps: uniformly mixing anhydrous ethanol, ammonia water and water to obtain a mixed solvent; adding pigment, ethyl orthosilicate and γ-aminopropyltriethoxysilane to the mixed solvent, stirring and reacting at 40-60° C. for 4-6 hours, and then filtering; washing and drying the obtained solid matter, and then adding the solid matter to water for uniform ultrasonic dispersion to obtain the modified silica-coated pigment dispersion.

3. The method for preparing a low-temperature fixing color environmentally friendly toner according to claim 2, characterized in that: The volume ratio of the anhydrous ethanol, ammonia water and water is 1: (0.1-0.2): (0.1-0.2), and the mass ratio of the pigment, ethyl orthosilicate and γ-aminopropyltriethoxysilane is 10: (0.5-2): (0.5-2).

4. The method for preparing a low-temperature fixing color environmentally friendly toner according to claim 1, characterized in that: The molecular weight of the low molecular weight polyethylene wax is 1500-2500 and the melting point is 100-105° C. The amount of dicumyl peroxide used is 0.5-1% of the sum of the mass of styrene and maleic anhydride.

5. The method for preparing low-temperature fixing color environmentally friendly toner according to claim 1, characterized in that: In step (1), the mass ratio of the polymerization monomer, the emulsifier and water is (25-30): (3-5): (65-75); in step (2), the mass ratio of the mixed solution to the modified silica-coated pigment dispersion and the maleic anhydride-styrene grafted polyethylene wax emulsion is 100: (1-4): (8-10); in step (2), the amount of the initiator used is 0.1-0.3% of the mass of the polymerization monomer, and the amount of the chain transfer agent used is 0.5-1% of the mass of the polymerization monomer.

6. The method for preparing low-temperature fixing color environmentally friendly toner according to claim 1, characterized in that: The solid content of the modified silica-coated pigment dispersion is 20-30%, and the solid content of the maleic anhydride-styrene grafted polyethylene wax emulsion is 3-5%.

7. The method for preparing low-temperature fixing color environmentally friendly toner according to claim 1, characterized in that: In step (1), the emulsifier is sodium dodecyl sulfate, sodium dodecylbenzenesulfonate or Tween-80; in step (2), the initiator is ammonium persulfate, benzoyl peroxide or azobisisobutyronitrile, and the chain transfer agent is dodecanethiol.

8. The method for preparing low-temperature fixing color environmentally friendly toner according to claim 1, characterized in that: In step (2), the pH is adjusted to 8-9.

9. A low-temperature fixing color environmentally friendly toner, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.

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