Ronald L Saxton

US Patent:

43384056, Jul 6, 1982

Filed:

Dec 12, 1980

Appl. No.:

6/215814

Inventors:

Ronald L. Saxton - West Grove PA

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08F 812

US Classification:

525 62

Abstract:

Improved process for the preparation of partially alcoholyzed polyvinyl acetate having good compositional uniformity comprises rapid premixing of the polyvinyl acetate polymer and base catalyst solutions in a static mixer and carrying out the alcoholysis reaction in an intermeshing, self-wiping, twin-rotor mixer or mixing extruder. The process yields polyvinyl alcohol product having a maximum hot water insoluble fraction of about 1. 1% by weight obtained by the proper adjustment of the feed temperature, the shear rate in the premixer and the catalyst concentration in the catalyst feed solution.

US Patent:

39636879, Jun 15, 1976

Filed:

Jan 2, 1975

Appl. No.:

5/538160

Inventors:

Ronald Luther Saxton - West Grove PA

Assignee:

E. I. Du Pont de Nemours and Company - Wilmington DE

International Classification:

C08F 216
C08F22044

US Classification:

526 66

Abstract:

A two-vessel continuous reactor system is used to make a uniform acrylonitrile copolymer containing 65 to 85% by weight acrylonitrile polymerized units and 35 to 15% by weight of styrene polymerized units. Into a first reactor are fed a free radical initiator together with an emulsified feed containing acrylonitrile, styrene and a chain transfer agent. Formation of polymer seed particles takes place in the first reactor and an outlet stream is continuously introduced into a second reactor together with added free radical initiator and a second aqueous emulsified feed containing acrylonitrile, styrene, and a chain transfer agent to continue growth of the seed particles. Conditions of particle initiation in the first reactor as opposed to particle growth in the second reactor are carefully separated to obtain noncyclical operation with low levels of coagulum formation in both reactors together with a final low emulsifier content in the polymer. The acrylonitrile copolymer is useful for articles where barrier properties are desirable to retard passage of oxygen, carbon dioxide and water vapor, e. g. , carbonated beverage bottles.

US Patent:

50326325, Jul 16, 1991

Filed:

May 15, 1990

Appl. No.:

7/523566

Inventors:

Ronald L. Saxton - West Grove PA

Assignee:

E. I. du Pont de Nemours and Company - Wilmington DE

International Classification:

C08K 55333
C08K 509

US Classification:

524139

Abstract:

A composition of a copolymer of ethylene and vinyl alcohol, 0. 01 to 0. 5 weight percent of a monovalent or divalent metal salt of an aliphatic carboxylic acid having 3 to 9 carbon atoms and 0. 05 to 0. 5 weight percent of a hindered phenolic antioxidant exhibits improved stability toward oxidative gel formation at elevated temperatures.