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
- Liquid color
- Vinyl dye
- Fuel dyes
References
- ^ Nishikants (2013-06-28). "Plastic colorant and its role in plastic industry". Share and Discover Knowledge on LinkedIn SlideShare. Retrieved 2017-07-18.
- ^ "Plastic Colorants Guide for Injection Molded Parts". RevPart. 2016-01-26. Retrieved 2017-07-18.
- ^ Sepe M (2012-01-28). "Working with Color Concentrates". Plastics Technology. Retrieved 2017-07-18.
- ^ 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.
- ^ "Toxics in Packaging Clearinghouse". Collation of Northeastern Governors (CONEG).
- ^ "Methods of Coloring Plastics". RTP Company. October 2013. Retrieved 2017-07-18.
- ^ "Effect of coloring methods on properties of plastics". Polyplastics.com. Retrieved 2017-07-18.
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