Leather Dyes: Key Insights Unveiled
The dye used for dyeing protein leather fibers is calledleather dye.leather dyeIt is easily soluble in water, and the process of absorption, fixation, and coloring of leather fibers in an acidic medium is called dyeing.leather dyeIt requires vivid colors and must have excellent "affinity" for leather fibers and various fastness functions, such as light fastness, wash fastness, dry and wet rubbing fastness, light resistance, sweat resistance, migration resistance, and other professional indicators for leather dyeing.
leather dyeThe classification mainly includes the following types:
1. Acid dyes are anionic dyes used for dyeing leather fibers in an acidic bath. According to dyeing characteristics and application methods, they can be divided into strong acid dyes and weak acid dyes. Strong acid dyes have a simple structure, small organic molecular structure, and a high proportion of sulfonic acid groups. In dyeing,leather dyethey basically exist in ionic form, and good coloring must be done in a strong acidic medium to be used for dyeing leather fibers.
2. Direct dyes are dyes that can dye cotton, linen, and viscose cellulose fibers directly without the help of mordants. Some varieties of direct dyes can be used directly for leather dyeing in acidic media. Direct dyes have a large molecular weight, slow penetration, and a more complex production process than monoazo acid dyes. The product price is low, but the indicators such as wet fastness, wash fastness, light fastness, and wet rubbing fastness are not suitable for leather fiber dyeing, making themleather dyeproducts that have been eliminated from the market.
3. Weak acid dyes and leather acid complex dyes have excellent indicators such as brightness, rapid penetration, light fastness, water resistance, and migration resistance. The products do not contain aromatic amines and heavy metals, making them green and environmentally friendly, and they are currently the main products in both domestic and foreignleather dyemarkets.
4. Leather acid complex dyes and neutral dyes are both ionic acid dyes. When dyeing leather fibers, it is suitable to dye leather in a strong acid bath. Like weak acid dyes, they have a strong affinity for leather fibers, but compared to weak acid dyes, the exposure is higher, and the chelation effect of metal ions greatly improves the washing fastness, with sunlight fastness generally at6-7levels.
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