Saint-gobain Vitrage

E.i. Dupont De Nemours and Company

Robert Degeilh

Daniel Dages

A process for the preparation of a polyvinyl butyral having improved properties comprises subjecting a polyvinyl alcohol in an aqueous medium in the presence of butyraldehyde and an acid catalyst and ethoxylated alkylphenol sulfate having the formula

Process for the production of polyvinyl butyral having improved

Process for the production of a plasticized polyvinyl butyral particularly used for gluing a base onto glazings. The polyvinyl butyral is obtained by the reaction of a butyric aldehyde with a polyvinyl alcohol, demonstrating a level of hydrolysis greater than 95%, and a viscosity greater than 50 cP, in the presence of an acid catalyst and an emulsifier, the quantity of butyric aldehyde being such that the level of hydroxylation of the polyvinyl butyral obtained is between 22 and 26%.

Process for the production of a plasticized polyvinyl butyral for gluing

A process for the preparation of a polyvinyl butyral having improved properties comprises subjecting a polyvinyl alcohol in an aqueous medium in the presence of butyraldehyde and an acid catalyst and sodium dioctyl sulfosuccinate (DOS), effective as an emulsifier, neutralizing the reaction mixture to a pH of 5, and thereafter recovering the polyvinyl butyral by separating it from the reaction liquors and thoroughly washing it with water.

Process for the preparation of polyvinyl butyral having improved

The invention relates to a process for preparing polyvinyl butyral comprising simultaneously introducing into a reaction medium containing a mixture of water and a portion of reactive polyvinyl alcohol, maintained initially at a temperature below about 20.degree. C., a stream of an aqueous solution of polyvinyl alcohol corresponding to the complement of the reactive polyvinyl alcohol and a stream of butyraldehyde and cooling the reaction mixture during the introduction of the polyvinyl alcohol and butyraldehyde. The reaction is also carried out in the presence of an acid catalyst and an emulsifying agent. The polyvinyl butyral obtained is used, after plasticizing, as an interlayer in laminated glass.

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Le Port Marly, France

Robert Degeilh