Polyvinyl butyral

Structural formula
	Structure section with 75% degree of acetalization ; (R = n -C 3 H 7 )
General
Surname	Polyvinyl butyral
CAS number	63148-65-2
Monomers / partial structures	polyvinyl alcohol acetalized with butanal
Type of polymer	Thermoplastic
properties
Physical state	firmly
Glass temperature	68 ° C
Water absorption	4-6 wt%
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Polyvinyl butyral (PVB) is a plastic from the group of polyvinyl acetals . PVB is mainly used as a hot melt adhesive in the form of intermediate foils for laminated safety glass.

Manufacturing

PVB is made of polyvinyl alcohol by acetalization with butanal produced in the polymer as shown below clipping with a degree of acetalization of 75%:

For statistical reasons, a maximum functionalization of around 80% can be achieved. Since polyvinyl alcohol is produced by hydrolysing polyvinyl acetate , technical PVB also contains acetyl groups (at least approx. 2%).

properties

Polyvinyl butyrals with a low degree of acetalization are water-soluble, highly acetalized resins dissolve in alcohols. PVB resins with a higher proportion of acetyl groups are also soluble in aromatics. When used as an intermediate layer between panes of glass, complete functionalization is not desired, since the free OH groups enable better bonding to the glass.

use

For example, PVB is used, among other things, as an intermediate layer between the glass panes of windshields , as it is characterized by a splinter-binding effect and high tear resistance.

Furthermore, PVB resins are used as binders , e.g. B. in printing inks , anti-corrosion primers, plastic and wood coatings, packaging coatings and pigment preparations. They are also used as temporary binders for ceramics , as they burn without leaving any residue at temperatures above 500 ° C.

Trade names

PVB: Butvar, Mowital, Pioloform
PVB films: BUTACITE, SAFLEX, S-Lec, TROSIFOL, EVERLAM

literature

Entry on polyvinyl butyrals. In: Römpp Online . Georg Thieme Verlag, accessed on October 1, 2014.

Individual evidence

↑ ^a ^b Manufacturer's data sheet : Polyvinyl butyral 30
↑ ^a ^b data sheet Butvar ^® B-98 from Sigma-Aldrich , accessed on May 25, 2017 ( PDF ).
↑ Sebastian Kotzenburg, Michael Maskus, Oskar Nuyken: Polymers: Synthesis, Properties and Applications . Springer Spectrum, Berlin 2014, ISBN 3-642-34772-X , p. 430-431 .

[kremer-1] Manufacturer's data sheet : Polyvinyl butyral 30

[Sigma-2] ta sheet Butvar ^® B-98 from Sigma-Aldrich , accessed on May 25, 2017 ( PDF ).

[Kotzenburg-3] Sebastian Kotzenburg, Michael Maskus, Oskar Nuyken: Polymers: Synthesis, Properties and Applications . Springer Spectrum, Berlin 2014, ISBN 3-642-34772-X , p. 430-431 .