On Quantum Deformations of D=4 Conformal Algebra
  Three classes of classical r-matrices for sl(4,C) algebra are constructed in quasi-Frobenius algebra approach. They satisfy CYBE and are spanned respectively on 8,10,12 generators. The o(4,2) reality condition can be imposed only on the eight dimensional r matrices with dimension-full deformation parameters. Contrary to the Poincare algebra case, it appears that all deformations with a mass-like deformation parameter (kappa- deformations) are described by classical r-matrices satisfying CYBE. 
A. Frydryszak, J. Lukierski, P. Minnaert, M. Mozrzymas