Characteristics of polyvinyl butyrals
The different grades of Mowital® are thermoplastic polyvinyl butyral resins supplied as fine-grained, free-flowing powders. The degrees of acetalisation and polymerisation largely determine important properties of these grades, such as their solubility, film properties and ability to combine and react with other binders. Mowital® produces lightfast, tough-elastic films with a high inner strength.
The water resistance of the films rises as the number of butyral groups in the Mowital® molecule increases. Accordingly, coatings based on the highly butyralised Mowital® grades B 30 HH and B 60 HH display the greatest water resistance. Because the polarity of the molecule decreases as the degree of acetalisation rises, the HH grades (which have the lowest polarity) display the best solubility in non-polar solvents.
The glass transition temperature (Tg) of the Mowital® grades declines as the number of butyral groups increases and the degree of polymerisation decreases. Values between 60 and 85°C have been measured for the individual grades. (DSC; heating rate of 10 K/min).
Individualist with universal characteristics
Enormous number of applications
Essential component of prepregs and composite materials
Improved flexibility and good adhesion to various substrates
Prevents steel from rusting as a component of corrosion-protection primers
Excellent surface adhesion
Superior flow and pigment wetting properties
Special buid-up of retroreflective coatings in road traffic signs and markings