Plastic colorants are chemical compounds used to color plastic. Those compounds come in a form of dyes and pigments. The type of a colorant is chosen based on the type of a polymeric resin, that needs to be colored. [citation needed] Dyes are usually used with polycarbonates, polystyrene and acrylic polymers. Pigments are better suited for use with polyolefins.[1] [2]

The colorant must satisfy various constraints, for example, the compound must be[3] chemically compatible with the base resin, be a suitable match with a color standard (see e.g. International Color Consortium), be chemically stable, which in this case means being able to survive the stresses and processing temperature (heat stability) in the fabrication process and be durable enough to match the life duration of the product.

The parameters of the compound vary with a desired effect, which may include the final product being pearlescent, metallic, fluorescent, phosphorescent, thermochromic or photochromic.[4]

The exact chemical formula will furthermore depend on the type of application: general purpose, food contact item, toy, package subject to CONEG,[5] etc.[4]

Different methods for delivering colorants in molding plastics include masterbatches (concentrates), a method which involves a concentrate being separated into resin, cube blends ("salt & pepper mixes" - dry blending) which are natural polymers, already sprayed into natural polymers, surface coating, and precolored resins, which involve using precolored materials to make manufacturing cheaper.[6][7]

Examples

Colorant Chemical class Type
Diarylide pigment azo dye pigment
Sudan stain azo dye dye
Oil Blue A anthraquinone dye
Disperse Red 11 anthraquinone dye

See also

References

  1. ^ Nishikants (2013-06-28). "Plastic colorant and its role in plastic industry". Share and Discover Knowledge on LinkedIn SlideShare. Retrieved 2017-07-18.
  2. ^ "Plastic Colorants Guide for Injection Molded Parts". RevPart. 2016-01-26. Retrieved 2017-07-18.
  3. ^ Sepe M (2012-01-28). "Working with Color Concentrates". Plastics Technology. Retrieved 2017-07-18.
  4. ^ a b "Colorants for Plastic Industry,Dyes for Plastics Industry,Pigments for Plastics Industry". Dyes and Pigments, Dyes Manufacturers, Dyes Intermediates, Pigments Suppliers, Wholesale Dyes Intermediates. Archived from the original on 2019-03-04. Retrieved 2017-07-18.
  5. ^ "Toxics in Packaging Clearinghouse". Collation of Northeastern Governors (CONEG).
  6. ^ "Methods of Coloring Plastics". RTP Company. October 2013. Retrieved 2017-07-18.
  7. ^ "Effect of coloring methods on properties of plastics". Polyplastics.com. Retrieved 2017-07-18.


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