Pigment Yellow 191

Product NamePIGMENT YELLOW 191
SynonymsC.I.Pigment Yellow 191; C.I.PY191; PY191; P.Y.191
CAS NO.129423-54-7
Molecular Weight486.91
Molecular FormulaC17H13ClN4O7S2
ColorYellow powder

Molecular structure formula:  

Fastness Properties of Pigment Yellow 191:

Light Fastness7
Heat Resistance(℃)300
Water Resistance5
Oil Resistance5
Acid Resistance5
Alkali Resistance5
Alcohol Resistance4

Main application: Plastic

We have various pigment grades and properties to meet different customers’ needs, please specify your application and requirements so that we can recommend accordingly.  E-mail: sy@sypigment.com

Product Description of Pigment Yellow 191:

The shade of Pigment Yellow 191 is similar to CI Pigment Yellow 83, with low color power, but excellent heat resistance. In high-density polyethylene (HDPE, 1/3 standard depth), it has a heat resistance of 300°C, no dimensional deformation, and has good heat resistance. Light fastness (level 7-8); excellent migration resistance in plastic PVC; temperature resistance up to 330°C in polycarbonate, and resistance to organic solvents. It is mainly used for coloring traffic paint in the United States.

Pigment Yellow 191 is an economical red-shade yellow pigment with excellent heat stability and resistance properties. It is an ideal replacement for diarylide and lead chromate pigments.

TDS (Pigment Yellow 191) MSDS (Pigment Yellow 191)


  • Pigment Yellow 191
  • 129423-54-7
  • C.I. Pigment Yellow 191
  • C.I. Pigment 191
  • Benzenesulfonic acid, 4-chloro-2-(2-(4,5-dihydro-3-methyl-5-oxo-1-(3-sulfophenyl)-1H-pyrazol-4-yl)diazenyl)-5-methyl-, calcium salt (1:1)
  • Benzenesulfonic acid, 4-chloro-2-[2-[4,5-dihydro-3-methyl-5-oxo-1-(3-sulfophenyl)-1H-pyrazol-4-yl]diazenyl]-5-methyl-, calcium salt (1:1)
  • DTXSID4051293
  • P.Y.191

IUPAC Name:  calcium;4-chloro-5-methyl-2-[[3-methyl-5-oxo-1-(3-sulfonatophenyl)-4H-pyrazol-4-yl]diazenyl]benzenesulfonate

InChI: InChI=1S/C17H15ClN4O7S2.Ca/c1-9-6-15(31(27,28)29)14(8-13(9)18)19-20-16-10(2)21-22(17(16)23)11-4-3-5-12(7-11)30(24,25)26;/h3-8,16H,1-2H3,(H,24,25,26)(H,27,28,29);/q;+2/p-2


Canonical SMILES: CC1=CC(=C(C=C1Cl)N=NC2C(=NN(C2=O)C3=CC(=CC=C3)S(=O)(=O)[O-])C)S(=O)(=O)[O-].[Ca+2]

Property NameProperty Value
Molecular Weight525
Hydrogen Bond Donor Count0
Hydrogen Bond Acceptor Count10
Rotatable Bond Count3
Exact Mass523.9540097
Monoisotopic Mass523.9540097
Topological Polar Surface Area189 Ų
Heavy Atom Count32
Formal Charge0
Isotope Atom Count0
Defined Atom Stereocenter Count0
Undefined Atom Stereocenter Count1
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
Covalently-Bonded Unit Count2
Compound Is CanonicalizedYes