Description
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Mowital® is Kuraray's trade name for a comprehensive program of different polyvinyl butyrals. As a base, polymer polyvinyl alcohol is acetalized using butyraldehyde in a special process. The program range of Mowital® contains polymers of different chain lengths/degrees of polymerization (expressed as specific viscosity in organic solvents), as well as degrees of acetalization. In our nomenclature the suffix' "T", "H" and "HH", respectively, indicate increasing degrees of acetalization.
Molecular structure
The molecular structure of Mowital can be described as a terpolymer consisting of (sequences) of polyvinyl alcohol, polyvinyl acetate and polyvinyl butyral. Varying the ratio of these sequences the properties of Mowital® can be fine-tuned: e.g. solubility in various solvents and their compatibility with other polymers. Chemical reactivity is also dependent on this ratio and again, can be fine-tuned.
Thus, like in polyvinyl alcohol, the residual OH-groups of the polyvinyl butyral polymer chain undergo cross-linking reactions with compatible (di-)isocyanates, epoxy-molecules, urea-, phenolic- or melamine-resins and such like.
Main applications
One of the most important applications is the production of Films for laminated safety glass (windscreen), as well as for architectural purposes. Polyvinyl butyral is, however, also suitable for keying and anti-corrosion primers protecting metals or heating pipes from rust and provides a suitable substrate for painted coatings. Another main field of applications is high-quality printing inks.
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