In the field of digital office and high-end printing, color toner has become the core consumables of laser printers and copiers, and its performance directly affects the output quality, equipment life and environmental protection indicators. From the traditional physical crushing method to the modern chemical polymerization method, from single blackness control to nano-level color management, the research and development of color toner is undergoing a leapfrog development from "functional realization" to "precise control". This article will deeply analyze the technological evolution and market value of color toner from four dimensions: technical principles, manufacturing processes, application scenarios and industry trends.
1. Technical principles: precise coordination of electrostatic imaging and color reproductionThe imaging process of laser printing and copying is essentially the development and fixing of electrostatic latent images. Take HP's reverse development technology as an example: the laser head forms an electrostatic latent image on the surface of the photosensitive drum (OPC) through a laser beam. After the negatively charged color toner is adsorbed by the magnetic roller, it is transferred to the latent image area through the principle of attraction of opposite charges, and finally heated and melted by the fixing unit to embed the toner into the paper fiber. In this process, color toner needs to meet three major technical requirements at the same time:Precise charge control: Color toner needs to achieve uniform charge through charge control particles to ensure stable voltage during the transfer process from magnetic roller to OPC to paper. For example, Canon color laser printers use nano-level charge regulators to control the fluctuation range of toner charge within ±5%, significantly reducing leakage and bottom ash.Particle size and morphology optimization: The particle size of color toner directly affects resolution and color performance. The particle size of toner produced by traditional pulverization is about 10 microns, while chemical polymerization methods (such as suspension polymerization and emulsion polymerization) can reduce the particle size to less than 5 microns and control the particle morphology to be nearly spherical, reduce light scattering, and improve color saturation. Fuji Xerox's toner prepared by "emulsion polymerization/co-flocculation method" has achieved color difference control of ΔE < 1.5 on the three primary colors of cyan, magenta, and yellow.Environmental adaptability: Color toner needs to be adapted to different fixing methods (hot pressing fixing, cold fixing, infrared radiation fixing) and media types (plain paper, coated paper, synthetic paper). For example, the Pantum "Kangda" series printers use ceramic sheet low-temperature heating technology to reduce the fixing temperature from 180°C to 160°C, which not only reduces energy consumption, but also avoids carbonization of toner caused by high temperature, ensuring color reproduction.2. Upgrade from physical crushing to chemical polymerizationThe manufacturing process of color toner directly affects its performance and cost. The current mainstream technologies include physical crushing and chemical polymerization:Physical crushing method:Toner is prepared through processes such as melt mixing, low-temperature mechanical crushing, and airflow classification. Its advantages are simple process and low cost, but there are problems such as wide particle size distribution and uneven dispersion of colorants, which lead to easy sticking of rollers, low resolution, and high waste powder rate (up to 30% or more) during printing. This method is mostly used in low-end black and white toner production.Chemical polymerization method:Suspension polymerization method: monomers (such as styrene, acrylate), colorants (organic pigments/inorganic pigments) and wax are used as raw materials, and polymerization is initiated by aqueous initiators to form core-shell structure toner. This method can accurately control the particle size (D50=5-9 microns) and shell thickness (accounting for 1-8% of the toner mass), significantly improving the charging performance and fluidity. For example, the color toner produced by Canon using suspension polymerization can still maintain a waste powder rate of <5% during high-speed printing (≥60 pages/minute).Emulsion polymerization method: Powders with a particle size of <5 microns are prepared by adjusting surfactants and shear rates. This method can achieve non-spherical particle design, improve toner recovery rate and cleaning efficiency. Konica Minolta's "co-flocculation technology" uses toner prepared by emulsion polymerization to achieve a transfer efficiency of 98% in color copiers.Innovative technology:The "Toner PRO+" technology released by Gezhige, through surface modification of nanoparticles (such as methacryloxypropyltrimethoxysilane modification), allows nano-silica additives to be chemically bonded to resins, solving the problem of additive shedding caused by traditional mechanical mixing. This technology improves the charging stability of toner by 40%, and can still maintain a color difference of ΔE < 2 after continuous printing of 100,000 pages.3. Coverage from office documents to high-end printingThe application of color toner has penetrated into many fields, and its performance requirements vary depending on the scenario:Office document printing:Toner is required to have high blackness (L* < 20), low waste powder rate (< 8%) and fast fixing (fixing time < 15 seconds). The Pantum "Kangda" series printers use multi-roller collaborative paper feeding technology and triple stable collaborative transmission technology to achieve a continuous printing jam rate of 400,000 pages of less than 0.02‰, while supporting functions such as mobile phone remote printing and one-key intelligent deviation correction to meet the 24-hour uninterrupted printing needs of government affairs, finance and other industries.Commercial printing:Color reproduction (color gamut coverage > 90% NTSC) and light resistance (≥ level 5) must be taken into account. Fuji Xerox's "emulsion polymerization toner" can achieve a resolution of 1200×1200dpi in advertising poster printing, and the color difference ΔE <3 after 6 months of outdoor exposure.Industrial label printing:Toner is required to have wear resistance (pencil hardness ≥ 3H) and chemical resistance (resistance to alcohol wiping ≥ 50 times). The "Blue Diamond Drum Core" technology launched by Nasda increases the toner transfer efficiency by 25% by depositing a diamond-like coating on the drum core surface, which is suitable for label printing in logistics, medical and other industries.
4. Industry trends: green, intelligent and customized
Green and environmental protection:
With the tightening of EU RoHS, REACH and other regulations, low VOC (volatile organic compounds) and degradable toner have become the focus of research and development. For example, Gezhige's "Large Capacity Easy Powder Addition 2.0" technology increases the single powder addition amount by 30% by optimizing the fluidity of toner, while reducing dust leakage and reducing the risk of user inhalation.
