BICYCLIC AMIDE ACETALS AS MOISTURE SCAVENGERS

Abstract: A process for removing water from its mixture with hydroxyl containing compounds by adding a bicyclic amide acetal to such mixture and allowing the water to react with the bicyclic amide acetal is disclosed.

Description: This invention relates to a method for removing trace amounts of water from mixtures of monohydroxyvinyl monomers with water by treatment of these mixtures with bicyclic amide acetals. Bicyclic amide acetals are relatively new materials. The preparation of some of the bicyclic amide acetals is more fully disclosed in US-A 4 683 077 and 4 605 746. Bicyclic amide acetals have been shown to undergo hydrolysis with excess of water to give the corresponding amide diol [Ann. Chem. 716, 135 (1968)] but no report or suggestion has been made that these materials might have unique water scavenging properties in the presence of monomers, polymers, and particularly materials which have reactive hydrogen functionality such as hydroxyl groups. The bicyclic amide acetals which are useful in this invention include those having the Formula I wherein R and R″ independendy represent hydrogen or an alkyl group having from 1 to 18 carbon atoms, and R″ also represents an alkyl ether, aryl or alkaryl ether group having from 1 to 18 carbon atoms, and R′ represents an alkyl group having from 1 to 18 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkaryl group having from 7 to 20 carbon atoms. Materials which can be conveniently dehydrated by bicyclic amide acetals include mono- -hydroxyvinyl monomers such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hyroxypropyl methacrylate, and the like. The process of this invention is carried out in the temperature range of from about room temperature up to about 200°C. The process of this invention is further illustrated in the following representative examples. EXAMPLE A sample of 101.4 g of hydroxy propyl methacrylate containing 0.446% by weight of water was treated with 3.84 g of bicyclic amide acetal of Formula I in which R′ represents methyl and R and R″ represent hydrogen. The mixture after standing at room temperature for 18 hours was found to contain 81 ppm of water.

Claims: A process for removing water from mixtures of monohydroxyvinyl monomers and water comprising adding to said mixtures a bicyclic amide acetal of the formula wherein R and R″ independently represent hydrogen or an alkyl group having from 1 to 18 carbon atoms, and R″ also represents an alkyl ether, aryl or alkaryl ether group having from 1 to 18 carbon atoms, and R′ represents an alkyl group having from 1 to 18 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkaryl group having from 7 to 20 carbon atoms and allowing the water to react with the bicyclic amide acetal at a temperature in the range of from about room temperature up to about 200°C. The process according to claim 1 wherein the bicyclic amide acetal is one in which R and R″ are hydrogen and R′ is methyl. The process according to claim 1 wherein the monohydroxyvinyl monomer is hydroxyethyl acrylate. The process according to claim 1 wherein the monohydroxyvinyl monomer is hydroxypropyl acrylate. The process according to claim 1 wherein the monohydroxyvinyl monomer is hydroxyethyl methacrylate. The process according to any one of claims 1 or 2 wherein the mono-hydroxyvinyl monomer is hydroxypropyl methacrylate.

Inventors: GOEL, ANIL B., RICHARDS, HARVEY J.
Applicants: ASHLAND OIL, INC.
Application year: 1986
Main classification: C07C29
IPC codes: C08G18