Basics of organic pigments

Organic pigments areorganic pigments are colored organics, but not all colored substances can be used as organic pigments. For colored substances to become pigments, they must have the following properties:
bright colors that give colorants (or substrates) a firm color;
insoluble with water, organic solvents, or application media;
are easily dispersed evenly in the application medium and are not subject to the physical and chemical effects of the applied medium throughout the dispersion process, retaining their inherent crystalline construction
Organic pigments and dyes are similar organic pigments and dyes are colored organic compounds, from the chemical structure of organic pigments and dyes, the two are very similar, and even some organic compounds can be used as dyes and organic pigments, but organic pigments and dyes are indeed two different concepts, the difference between them is mainly different application performance
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. The traditional use of dyes is to dye textiles, while the traditional use of pigments is to color non-textiles (e.g. inks, paints, coatings, plastics, rubber, etc.). This is because dyes have affinity (or directness) to textiles, can be absorbed by fiber molecules, solidified, and pigments are affinity for all coloring objects, mainly by resin, adhesives and other film-forming substances and coloring objects combined. Dyes generally dissolve in the use of media in the process of use, even dispersing dyes or reducing dyes, in dyeing also underwent a process from the crystal state dissolved in water into a molecular state and then dyed to the fiber. Therefore, the color of the dye itself does not represent its color on the fabric. Pigments always exist in their original crystal state because they are insoluble in the medium used. Therefore, the color of the pigment itself represents its color in the substrate. Because of this, the crystal state of the pigment is very important to the pigment, and the crystal state of the dye is not so important, or the crystal state of the dye itself is not closely related to its dyeing behavior.
pigments and dyes are different concepts, they can be used in certain situations. For example, some tantalum reduction dyes, they are insoluble dyes, but after pigmentation can also be used as pigments. These dyes are called pigment-like dyes, or dye-type pigments.the similarity between organic pigments and inorganic pigmentsin recent years, organic pigments have developed very rapidly because they have many unique advantages over inorganic pigments. Organic pigments can be prepared in a wide variety by changing the molecular structure, and have brighter colors and brighter tones than inorganic pigments. Organic pigments also have a much higher coloring force than inorganic pigments, can be prepared high coloring force, high transparency varieties to meet the requirements of high-grade coatings and printing inks. Most organic pigment varieties are less toxic, while most inorganic pigments contain heavy metals, such as chromium yellow, red dan, zhu hong, etc. have a certain toxicity. Low-grade organic pigment varieties are inferior to inorganic pigments in terms of sun-resistant fastness, climate-resistant fastness, heat-resistant and solvent-resistant properties, but some high-grade organic pigment varieties (e.g., ketone pigments, tanning pigments, etc.) have excellent sun-resistant fastness. climate fastness, heat resistance and solvent resistance, and their acid/alkali resistance is also better than inormeric pigments, because some inormeric pigments have poor acid/alkali resistance, such as: chromium yellow hydrogen sulfide will turn black, alkali will turn red; Organic pigment varieties, types, yields and applications are growing and expanding, has become a class of important fine chemical products.history of the development of organic pigments a long history of human use of pigments. Archaeologists have found that humans have been using colored inorgetable objects since 30,000 years ago, such as herring, hemath iron ore, etc. as a "color material" used in painting and other purposes, which can be proved by ancient murals, rock paintings. This kind of herring and hetero-iron ore used as "color material" is actually the most primitive inorgeable pigment.
when the use of organic pigments began, it is difficult to determine its exact age, because ancient organic pigments are easy to fade, it is difficult to retain to this day. In ancient times, as a complement to inorgable colors, humans used plant-based colors (e.g., grass, weed) or animal-based colors (e.g. Ter purple, from a conch). Since colorants were extracted from plants and animals at the time, biologists called them Pigment, the word for today's pigments. The word Pigment comes from the Latin Pigmentum, a pigment extracted from the roots of a plant called Pingere. Modern scientific studies have shown that the colored components of the grass are mainly sisin (1,2-dihydroxyquine), and the colored components of the grass are mainly indigo. These two substances, or their derivatives, are still used as pigments today. Of course, from today's point of view, these organic colors are soluble and should be classified as dyes rather than organic pigments, but at least they are the origin of modern organic pigments.
the mid-19th century, synthetic dyes emerged on a large scale, which also laid the foundation for the synthetic industry of organic pigments. Organic pigments are gradually developed with the development of dye industry.
In 1856, the British chemist Perkin prepared the first synthetic dye, Mauveine, and in 1858, the German chemist Gryess discovered the heavy nitride reaction of aniline, and in 1861 Mene discovered the coupling of aniline heavy nitrogen salts with aromatics or aromatic phenols before it began to synthetic dyes and organic pigments.
So far, the development of organic pigments in accordance with the time process can be divided into the following three stages:
1) from nothing to have
at this stage synthesized from Lisor red pigments to palladig pigments, pigment chromatography is basically complete. Organic pigment varieties began to replace inorganic pigment varieties
2) the advent of high-performance organic pigments
With the rapid development of polymeric materials and people's demand for quality of life, the application of colorant performance also put forward higher requirements, thus driving the development and production of various types of new organic pigments. At this stage, a number of high-performance organic pigments (High Performance Pigment, or HPP) have emerged. These pigments are mainly yellow, orange, red and purple, their sun-resistant fastness, climate-resistant fastness, heat-resistant fastness and migration-resistant fastness are very good;
3) Improve the production process and apply diversification
Between 1980 and 1990, the development rate of organic pigments began to slow down, during which time the emergence of new pigments less, the real realization of industrial production of varieties only a large category, namely, hybrid ring structure of red pigments ---DPP pigments. Since 1995, the introduction of new structural organic pigments has been almost non-existent, as the European Union has a REACH regulation, the introduction of a very strict policy on the introduction of new chemicals, the need for a series of tests, the cost of more than 550,000 euros. This seriously hit the enterprise (especially fine chemical enterprises) research and development of new structural products enthusiasm, the industry's focus on technology development has shifted to the following aspects:
to seek a more reasonable synthetic route, change raw materials, reduce the production costs of existing varieties, to solve or reduce environmental pollution;
seeking applications in other fields, especially in high-tech fields, such as: indyl pigments for optical discs, dyes, arid pigments, indisin pigments for laser printing, electrostectrectrelectrelectration, -series pigments, -series pigments for solar heat storage, DPP pigments for color liquid crystal filters, etc.;
to develop new application dosage forms, such as inks for digital inkjet printing, pre-dispersed pigments for acrylic fiber pigment coloring, pigments for transsexual hair coloring hairspray, and so on.
application of organic pigments in the 30th greatly improves its added value, thus greatly promoting the pigment manufacturers to develop new uses of pigments and applications of dosage forms.
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