Owing to their excellent adhesion properties, chlorinated polyolefins (CPOs) have long been successfully used for coating polyolefinic plastics such as polypropylene. In many sectors, coating systems must fulfil increasingly demanding requirements. Although good adhesion to the plastic substrate is essential, the coating often also has to be resistant to mechanical and chemical effects (e.g. fuel, steam jet). Many CPOs used for coating plastics have a MW in the range of 40,000 to 70,000. CPOs with higher molecular weights tend to have better resistance to chemicals. Thus the standard product TRAPYLEN® 145 S (MW approx. 110,000, chlorine content approx. 15 percent) has been used very successfully in primer applications. However, owing to its maximum solubility of around five percent in xylene, the incorporation of TRAPYLEN® 145 S in coating systems or the formulation of pigmented primers is rather challenging.
The new TRAPYLEN® masters this challenge: Solutions in xylene with a solids content of up to 20 percent can be achieved and thus provide a wider flexibility for formulating.