NCJ Number
183891
Journal
Journal of Forensic Sciences Volume: 44 Issue: 6 Dated: November 1999 Pages: 1151-1175
Date Published
November 1999
Length
25 pages
Annotation
Previous papers in this series identified several organic pigments used in U.S. automobile original (OEM) paint topcoats (1974-1989); two yellow organic pigments were identified. The current paper describes the identification, analysis, and occurrence of three more yellow organic pigments that were used in the monocoats (single-layer finishes) analyzed in the previous studies.
Abstract
Two yellow organic pigments, Benzimidazolone Yellow 3G and Benzimidazolone Yellow 4G, were identified in previous work in this study. The current study identified and analyzed the following other yellow organic pigments used in these finishes: Isoindolinone Yellow 3R, Isoindoline Yellow, and Anthrapyrimidine Yellow. Based on a spectral survey of yellow, orange, brown, and green nonmetallic monocoats in the Reference Collection of Automotive Paints, absorptions of Isoindolinone Yellow 3R were observed in the spectra of approximately three dozen yellow monocoats and one dozen orange ones. Isoindoline Yellow was identified in a single orange nonmetallic enamel. This pigment is now more common, since it was one of several replacements for Chrome Yellow, a popular lead-containing pigment that is no longer used in U.S. automobile OEM finishes; it was identified in several recent yellow nonmetallic basecoat/clearcoat finishes. Weak absorptions of Anthrapyrimidine Yellow were identified in the spectrum of a single yellow nonmetallic enamel. Spectra of several other yellow organic automotive paint pigments are also presented and discussed. 13 figures, 2 tables, and 17 references