KONICA MINOLTA

About Konica Minolta

Giving Shape to Ideas

High-Chroma toner

Background to development

Color reproduction difference between display and printing

Digital camera images and smartphone/PC displays etc. are commonly seen in our daily lives. The hues of these images and displays become somewhat “flat” on paper with Print on Demand.

This is because display images are reproduced with three primary colors of light (RGB: red, green, and blue), and printed images are reproduced with four primary colors used in the printing process (CMYK: cyan, magenta, yellow, and black). In other words, while display images consist of colors produced by light emission, printed images (which do not emit light) consist of reflected light. This means that there is a fundamental difference between display images and printed images.

All those engaged in Print on Demand aspired to overcome this fundamental difference and reproduce the vivid and clear hues of display images on paper.

Goal

  • To create vivid color toner that can reproduce colors close to those of display images in printing

Konica Minolta technology

Achieving high-chroma and high-brightness toner

Taking advantage of its proprietary design and production expertise, Konica Minolta developed new coloring agents (color pigments) for Simitri HD+ toner (polymerized toner for low-temperature fixing), and eventually developed High-Chroma toner that achieves color reproduction areas close to those of RGB with even higher chroma and brightness. The High-Chroma toner delivers vivid and clear hues as shown on displays that could not be reproduced in conventional printing.

The High-Chroma toner is also characterized by high weather resistance (against temperature, humidity, and light etc.) and fading resistance that is expected of printed matter. As this is a dry-type toner, it eliminates the need for drying after printing, and helps reduce the delivery period for printing.

*  At present, High-Chroma toner is used only in High-Chroma printing compatible products.

Success

  • 1.Achieving color reproduction areas close to those of RGB by expanding the color space of magenta, blue and green compared with general CMYK
  • 2.Increasing weather resistance (against temperature, humidity, light etc.) and fading resistance

Key technology

Color pigment design technology

Of the various materials that make up toner, pigments determine the colors. In High-Chroma toner, Konica Minolta succeeded in developing copper chelate-type magenta color pigment and phthalocyanine-type cyan color pigment through molecular design by applying the company’s proprietary color pigment technologies.

In the development process, molecular design was applied in producing color pigments while optimizing the necessary spectral absorption characteristics, in order to reproduce colors on displays. Color pigments characterized by excellent absorption spectra as well as optimal hue angle and chroma were developed by utilizing the synthetic technologies refined through many years of operations.

Notably, the magenta color pigment is highly unique in that it is derived from the molecular framework named pyrazolotriazole (which was used in Konica Minolta’s color photos) and pigment chelation technologies for dye-sublimation printers. This particular pigment achieves high color reproduction performance far surpassing that of conventional color pigments.

These color pigments are highly stable as compounds, and ensure high weather resistance against temperature, humidity, light etc. and fading resistance.

Toner production technology using chelate dyestuff

In the polymerization process in which Simitri Toner (polymerized toner) is manufactured, latex is combined with coloring agents (color pigments) through a chemical reaction in order to produce toner particles.

The key feature of High-Chroma toner is the color development of chelate dyestuff that was introduced as the new color pigments. The structure of chelate dyestuff is different from those of conventional color pigments. Thus, when chelate dyestuff manufactured in the conventional production process was used as toner, unique hues of chelate dyestuff could not be produced. For this reason, a new production process was introduced based on our expertise gained during the development of the dye-sublimation printer. Specifically, color is developed when latex is combined with chelate-type color pigments through a chemical reaction, thereby ensuring the development of vivid colors.

This new color pigment design technology and new toner production technology led to the development of the High-Chroma toner which is unmatched by our competitors.

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