Polyvinylbutyral , 15.0-18.0s, butyaldehyde 70-75% , 63148-65-2
CAS NO.：63148-65-2
Empirical Formula: C16H28O5
Molecular Weight:
MDL number: MFCD00084458
EINECS: 613-158-6
| Pack Size | Price | Stock | Quantity |
| 500g | RMB68.00 | In Stock |
|
| 1kg | RMB119.20 | In Stock |
|
| 2.5kg | RMB278.40 | In Stock |
|
| others | Enquire |
PRODUCT Properties
| Melting point: | 165-185°C |
| Density | 1.08 |
| refractive index | 1.485 |
| form | Free-Flowing Powder |
| color | White |
| Water Solubility | insoluble |
| Stability: | Stable. Combustible. Dust may form explosive mixture with air. Incompatible with strong oxidizing agents. |
Description and Uses
Polyvinyl butyral (PVB) is a synthetic resin obtained by the condensation reaction
of PVA and butyraldehyde in the presence of acid catalyst. Since the acetalization
reaction cannot be carried out completely, the molecular chain of PVB contains three
functional groups, butyral, alcohol hydroxyl and acetate, the latter two of which come
from PVA. The chemical structure is:
The proportion of these three groups can be controlled by changing the reaction conditions, but they are randomly distributed in the long molecular chain. The proportion and distribution of the three are different, and the properties of PVB are also
different.
The main application of poly(vinyl butyral) is as interlayers in safety glass
laminates. In this application, a pure (colourless, light-stable) product with
high hydroxyl content (for good adhesion) is required. Such material is
preferably prepared from poly(vinyl alcohol) rather than directly from
poly(vinyl acetate). In a typical process, completely hydrolysed poly(vinyl
alcohol) is suspended in ethanol and then butyraldehyde and a small quantity of sulphuric acid (catalyst) are added. The mixture is heated at 800℃ for 6
hours. Water is then added to the product with rapid agitation and the
poly(vinyl butyral) is precipitated as granules, which are washed with alkali
and dried.
Poly(vinyl butyral) is generally softer than
poly(vinyl formal) with lower softening point, hardness and tensile strength.
In commercial polymers the hydroxyl content exerts a major influence on the
solubility characteristics. Most grades are soluble in alcohols, glycol ethers
and dioxan and as the hydroxyl content decreases the polymers become more
soluble in ketones and esters.
Poly(vinyl butyral) used in safety glass generally has 78-80% butyral
content, 18-19% hydroxyl content and less than 2% acetate content. For this
application the polymer is plasticized with an ester such as dibutyl sebacate
to the extent of about 30 parts of plasticizer per 100 parts of polymer; the
compound is then sheeted by calendering. To produce safety glass, the sheet is
placed between two pieces of glass and the laminate is then bonded under
heat and pressure.
Safety
| Symbol(GHS) |  GHS07 |
| Signal word | Warning |
| Hazard statements | H315-H335-H319 |
| Precautionary statements | P264-P280-P302+P352-P321-P332+P313-P362-P264-P280-P305+P351+P338-P337+P313P |
| Hazard Codes | Xi |
| Risk Statements | 36/37/38 |
| Safety Statements | 26-36-24/25 |
| WGK Germany | 1 |
| RTECS | TR4955000 |
| HS Code | 39059990 |
