Colorant FOR PA

1) Inorganic pigments suitable for PA

Inorganic pigments are superior to organic pigments in light resistance, weather resistance, migration resistance, and chemical resistance. They are generally suitable for plastics. However, the color strength and brightness are much worse. When a good color is required, organic pigments are preferred. In addition, inorganic pigments have high reflective index. They are often used in opaque products.

The inorganic pigments that can be used for nylon are: C.I Pigment Yellow 184, Pigment Blue 29, Pigment Blue 28, Pigment Green 50, Titanium Dioxide, Carbon Black, etc.

2）Solvent dyes suitable for PA

3）Organic pigments suitable for PA

Generally speaking, organic pigments show higher color strength and vividness than inorganic pigments. PA has a higher processing temperature and higher requirements on the heat resistance stability of the pigments. At the same time, PA resins show extremely strong reducibility when they are melted, making many organic pigments for plastics unsuitable for use in nylon.

1. Azo pigments: As PA resins show extremely strong reducibility when melting, they are commonly used in polypropylene fibers with azo red and azo yellow pigments that have good heat resistance. They will fade and change during nylon melt processing. Dark, not suitable for coloring PA.

2 Perylene pigments: Perylene pigments are one of the ideal colorants for plastic coloring, due to their good heat resistance stability. Therefore, it can be used for coloring most plastics. However, they will undergo a reversible reduction reaction in the PA melt, so they are not suitable for the coloring of PA.

.Fused ring ketone (reduced) pigments: in plastics, fused ring ketones (reduced) organic pigments have excellent light fastness, good solvent resistance, migration resistance, heat stability, some of them Red and yellow pigments are suitable for PA coloring. Others include quinacridones.

4. Phthalocyanine pigments: due to the planarity and symmetry of the phthalocyanine molecular structure, it has good stability and excellent heat resistance, light, migration, acid and alkali properties. Although the structure of copper phthalocyanine is complex, the raw material cost is low, so it is a relatively economical pigment. Its blue and green pigment varieties are suitable for PA coloring.

5. New metal complex pigments: In recent years, nickel complex pigments containing benzimidazole groups or isoindoline groups have been developed. They also have excellent properties and are suitable for the coloring of almost all plastics such as PA and PESPC.

Less blue and green can be used for PA, mainly phthalocyanines, but they can basically meet the application requirements. The red and purple varieties to choose from are relatively abundant, while the yellow and orange varieties are relatively rare. It is worth noting that some of the light-colored varieties are also limited in their application in nylon due to their poor water resistance and alkali resistance. Among the light-colored organic pigment varieties suitable for nylon, there are three important varieties: CI Pigment Yellow 150, 192 and Pigment Orange 68. Their thermal stability, light fastness, solvent resistance and chemical stability are all very good. It can fully meet the requirements of nylon processing and is worthy of attention.

C.I. Pigment Yellow 192 is formed by the condensation of intermediate 5,6-diaminobenzimidazolone and 1,8-naphthalenedicarboxylic acid anhydride in an inert solvent. It was first proposed by Sandoz Company in Germany, and the newer yellow variety put on the market by Clariant has excellent heat and light fastness properties. It is mainly used for coloring of engineering plastics and polyamide syrup without color change in polyamide fiber.

C.I. Pigment Orange 68 is another important type of pigment suitable for nylon coloring. Its chemical structure contains a benzimidazolone structure to ensure intermolecular force; at the same time, it has a nickel complex structure to ensure intramolecular stability. Therefore, the pigment is similar to phthalocyanine pigments, with high thermal stability and light fastness; although its color is not very bright, it can be used as an opaque component, mixed with CI Pigment Yellow 150, 192, and can also be mixed with inorganic Pigment or solvent orange 60 solvent red 135 or solvent red 179 are mixed to obtain brilliant orange, brilliant red and purple sauce colors with excellent thermal and light stability in polyamide. C. I. Pigment Orange 68 is prepared by condensing 5,6-diaminobenzimidazolone and 2-hydroxy-1-naphthaldehyde in methoxymethanol, and then complexing with nickel。