Vinylec K Polyvinyl Formal Resin 400g
Appearance: White to straw colored free flowing powder
Chemical Name: Polyvinyl formal
Odor: Slightly pungent
CAS#: 63450-15-7 (all four grades)
Specific Gravity: 1.23
Bottle, 400 g
At one time, Formvar® was the registered trade name of the polyvinyl formal resin produced by Monsanto Chemical Company in St. Louise, MO USA. In recent years, that business unit was sold, as part of a plan of divestiture of certain businesses, and is now manufactured under the name Vinylec®.
From all that we can determine, the properties and characteristics of the new Vinylec grades are indistinguishable from the earlier Formvar grades. We obviously can not guarantee that to be the case, so if you have in the past been using one or the other of the Formvar grades, you will have to be the one to do the testing to confirm that what you are purchasing now as Vinylec is indeed "plug in compatible" with the former Formvar grade designations. We do know that the Vinylec resin is made in an entirely different plant than where the Formvar resins were originally made.
We are often times asked questions about Formvar resins that involve applications outside of the electron microscope application. We therefore offer this overview on Formvar resin. However, we do not have molecular weight information for any of these Formvar resin materials.
Formvar is a registered trade name for polyvinyl formal, which is a family of polymers formed from polyvinyl alcohol and formaldehyde as copolymers with polyvinyl acetate; another description is "modified polyvinyl acetal resins". They have found diverse applications, including wire insulation, coatings for musical instruments, adhesives and support films for electron microscopy. The specific compositions used by various wire manufacturers are generally not disclosed, and the details of exactly what is in a particular formulation are closely guarded, so it is difficult to say whether the specific type that is used for electron microscopy support films is the same as a particular wire manufacturer uses to coat copper wire.
However, the polymer has been long used as a principle ingredient in enamels used to provide electrical insulation on magnetic wire. It is also being used for the coating of magnetic tape. The polymer has a high softening point, excellent electric insulation characteristics, flexibility and abrasion resistance.
And because it is completely halogen free, it offers some additional benefit from an environmental standpoint.
Four different grades of the resin are available. Originally called Formvar, it seems that there is a slow conversion to its new name, of Vinylec.