Butanox M-50 VR

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Organic peroxide

Organic peroxide

Butanox M-50 VR: medium-reactive, general purpose MEKP with low water content, including a vanishing red indicator system.

  • Product name

    Butanox M-50 VR
  • Chemical family

    Organic peroxide
  • CAS number

  • Physical form

  • Regional availability

    Africa, Asia Pacific, Europe, India, Latin America, Middle East, North America
  • Chemical name

    Methyl ethyl ketone peroxide
  • Applications

    Butanox M-50 VR is a general purpose methyl ethyl ketone peroxide (MEKP) for the curing of unsaturated polyester resins in the presence of a cobalt accelerator at room and elevated temperatures.Butanox M-50 VR offers all the advantages of a standard MEKP i.e. Butanox M-50. The Butanox M-50 VR includes a vanishing red indicator system that in most cases virtually disappears during cure. The red color is there when you need it i.e. during the mixing step, but will disappear during cure.The curing system Butanox M-50 VR/cobalt accelerator is particularly suitable for the curing of gelcoat resins, laminating resins, lacquers and castings; moreover the manufacture of light resistant parts may be possible contrary to the curing system benzoyl peroxide/amine accelerator. Practical experience throughout many years has proven that by the guaranteed low water content and the absence of polar compounds in Butanox M-50 VR, this peroxide is very suitable in GRP products for e.g. marine applications.

Market Segments

Thermoset composites

Detailed description

Butanox M-50 VR is the work horse in GRP curing systems, including a VR system. Medium-reactive, general purpose methyl ethyl ketone peroxide (MEKP) with guaranteed low water content, used for curing unsaturated polyester resins in the presence of a cobalt accelerator at room and elevated temperatures.


  • Curing agent


  • Engineered Stone,
  • Gelcoats,
  • Buttons,
  • Coatings,
  • Resin Transfer Molding,
  • Filament winding,
  • Hand lay up and spray up