CR Rubber (chloroprenic)

General characteristics

Articles produced with chloroprene rubber are generally highly inflammable, have a good resistance to ozone, weather, chemical agents and aging, medium resistance to oils, good mechanical characteristics and a good elasticity, even at very low temperatures.

  • Impact resistance: from 20 to 50%;
  • Elongation to breakage: from 100 to 800% and beyond;
  • Resistance to heat: up to 100°C and for a brief time up to 120°C. Hardness increases notably upon prolonged exposure to heat in the presence of oxygen;
  • Resistance to low temperatures: down to -40°C;
  • Electrical characteristics: CR, like NBR, is a semiconductor, for which the vulcanizates of this rubber are not suitable for electrical insulation;
  • Gas permeability: notably inferior to those of NR, IR, BR, SBR, EPM and EPDM and on the order of magnitude of NBR vulcanizates;
  • Resistance to ozone, aging and weather: CR vulcanizates, when formulated correctly, offer better resistance to ozone, aging and weather with respect to other unsaturated rubbers such as NBR and SBR.

Chemical resistance

Good resistance to:

  • Paraffinic mineral oils;
  • Silicone oils and greases;
  • Water and aqueous solutions (in the composition of special compounds);
  • Refrigerants, such as ammonia, carbon dioxide and Freon.

Medium resistance to:

  • Naphthenic mineral oils;
  • Low molecular weight aliphatic hydrocarbons (propane, butane, benzene).

Not resistant to:

  • Aromatic hydrocarbons (benzene);
  • Polar solvents such as ketones, esters and ethers;
  • Flame resistant liquids of the HFD group;

CR vulcanizates with the conventional composition have a fairly high water absorbance and are inferior to NBR and SBR in this respect.

Fields of application

CR is used in those rubber articles for which high flame retardancy and good resistance to weather, aging and chemical agents are necessary. Items belonging to this group include conveyor belts, gaskets, tubes, cylinder coatings, coatings in general, coverings for cables, and rubber textiles.