Daniel J Dershowitz

US Patent:

8344172, Jan 1, 2013

Filed:

Mar 25, 2011

Appl. No.:

13/071952

Inventors:

Rick Tabor - Glenview IL, US
Brian K. Mirous - Evanston IL, US
Timothy L. Lambert - Lindenhurst IL, US
Michael E. O'Brien - Hainesville IL, US
Matthew I. Levinson - Skokie IL, US
Daniel J. Dershowitz - Columbus OH, US

Assignee:

Stepan Company - Northfield IL

International Classification:

C07C 69/76

US Classification:

560 8, 560 85, 560 54, 560217

Abstract:

A process for making bis(aryloxyalkyl)terephthalates useful as antiplasticizers for thermoplastic polyesters is disclosed. Dimethyl terephthalate is reacted with an excess of an aryloxyalkanol in the presence of a condensation catalyst to produce an intermediate mixture comprising a bis(aryloxyalkyl)terephthalate, a mono(aryloxyalkyl)terephthalate, and unreacted aryloxyalkanol. This mixture continues to react at reduced pressure while unreacted aryloxyalkanol is removed and the mono-ester content is reduced to less than 1 mole % based on the combined amounts of mono- and bis-esters. Both steps are performed substantially in the absence of oxygen. Additional unreacted aryloxyalkanol is then removed to provide a purified bis(aryloxyalkyl)terephthalate having an overall purity of at least 98 mole % and a yellowness index less than 10. Careful control over catalysis, exposure to air, and other process conditions enables the preparation of high yields of bis(aryloxyalkyl)terephthalates that have low color and other valuable attributes. A method of producing bis(aryloxyalkyl)terephthalate articles having improved compressive strength is also disclosed.

US Patent:

20020081259, Jun 27, 2002

Filed:

Dec 27, 2000

Appl. No.:

09/749201

Inventors:

Daniel Dershowitz - Columbus OH, US
Ryan Mears - Mesquite TX, US
Jay Schnaith - Powell OH, US
Curtis Dove - Colorado Springs CO, US
Sadhana Mahapatra - Bridgewater NJ, US
Kevin Wadsworth - Columbus OH, US

International Classification:

C01C001/00

US Classification:

423/352000

Abstract:

Commercial grade ammonia is purified for use in production of semiconductors by initially passing the liquid ammonia through a liquid phase oil separation system. This removes the vast majority of the impurities. The filtered liquid ammonia is then passed through a vaporizer which quiescently forms ammonia vapor and prevents entrainment of impurities within the ammonia vapor. The vapor passes through a vapor filtration system and subsequently to a bubble column. The bubble column is designed so that the bubbles are small enough and travel at a rate which ensures that any entrapped particle within the bubble will have time to migrate to the surface of the bubble and thereby pass through the liquid phase. The collected vapor is directed through subsequent vapor filters and is collected. If anhydrous ammonia is desired, the ammonia vapor is collected upstream of the bubble column.

US Patent:

20030108473, Jun 12, 2003

Filed:

Jan 22, 2003

Appl. No.:

10/349065

Inventors:

Daniel Dershowitz - Columbus OH, US
Ryan Mears - Mesquite TX, US
Jay Schnaith - Powell OH, US
Curtis Dove - Colorado Springs CO, US
Sadhana Mahapatra - Bridgewater NJ, US
Kevin Wadsworth - Columbus OH, US

Assignee:

Ashland Inc. - Covington KY

International Classification:

C01C001/02
F26B007/00

US Classification:

423/352000, 159/023000, 159/047100, 159/DIG004

Abstract:

Commercial grade ammonia is purified for use in production of semiconductors by initially passing the liquid ammonia through a liquid phase oil separation system. This removes the vast majority of the impurities. The filtered liquid ammonia is then passed through a vaporizer which quiescently forms ammonia vapor and prevents entrainment of impurities within the ammonia vapor. The vapor passes through a vapor filtration system and subsequently to a bubble column. The bubble column is designed so that the bubbles are small enough and travel at a rate which ensures that any entrapped particle within the bubble will have time to migrate to the surface of the bubble and thereby pass through the liquid phase. The collected vapor is directed through subsequent vapor filters and is collected. If anhydrous ammonia is desired, the ammonia vapor is collected upstream of the bubble column.

US Patent:

20130085216, Apr 4, 2013

Filed:

Nov 25, 2012

Appl. No.:

13/684541

Inventors:

Rick Tabor - Glenview IL, US
Brian K. Mirous - Evanston IL, US
Timothy L. Lambert - Lidenhurst IL, US
Michael E. O'Brien - Hianesville IL, US
Matthew I. Levinson - Skokie IL, US
Daniel J. Dershowitz - Columbus OH, US

International Classification:

C07C 67/29

US Classification:

524292, 560 73

Abstract:

A process for making bis(aryloxyalkyl)terephthalates useful as antiplasticizers for thermoplastic polyesters is disclosed. Dimethyl terephthalate is reacted with an excess of an aryloxyalkanol in the presence of a condensation catalyst to produce an intermediate mixture comprising a bis(aryloxyalkyl)terephthalate, a mono(aryloxyalkyl)terephthalate, and unreacted aryloxyalkanol. This mixture continues to react at reduced pressure while unreacted aryloxyalkanol is removed and the mono-ester content is reduced to less than 1 mole % based on the combined amounts of mono- and bis-esters. Both steps are performed substantially in the absence of oxygen. Additional unreacted aryloxyalkanol is then removed to provide a purified bis(aryloxyalkyl)terephthalate having an overall purity of at least 98 mole % and a yellowness index less than 10. Careful control over catalysis, exposure to air, and other process conditions enables the preparation of high yields of bis(aryloxyalkyl)terephthalates that have low color and other valuable attributes. A method of producing bis(aryloxyalkyl)terephthalate articles having improved compressive strength is also disclosed.

US Patent:

20140155531, Jun 5, 2014

Filed:

Feb 7, 2014

Appl. No.:

14/175911

Inventors:

Rick TABOR - Plymouth MI, US
Brian K. MIROUS - Evanston IL, US
Timothy L. Lambert - Lindenhurst IL, US
Michael E. O'BRIEN - Hainesville IL, US
Matthew I. LEVINSON - Skokie IL, US
Daniel J. DERSHOWITZ - Buffalo Grove IL, US

Assignee:

STEPAN - Chicago IL

International Classification:

C08K 5/134

US Classification:

524292

Abstract:

A process for making bis(aryloxyalkyl)terephthalates useful as antiplasticizers for thermoplastic polyesters is disclosed. Dimethyl terephthalate is reacted with an excess of an aryloxyalkanol in the presence of a condensation catalyst to produce an intermediate mixture comprising a bis(aryloxyalkyl)terephthalate, a mono(aryloxyalkyl)terephthalate, and unreacted aryloxyalkanol. This mixture continues to react at reduced pressure while unreacted aryloxyalkanol is removed and the mono-ester content is reduced to less than 1 mole % based on the combined amounts of mono- and bis-esters. Both steps are performed substantially in the absence of oxygen. Additional unreacted aryloxyalkanol is then removed to provide a purified bis(aryloxyalkyl)terephthalate having an overall purity of at least 98 mole % and a yellowness index less than 10. Careful control over catalysis, exposure to air, and other process conditions enables the preparation of high yields of bis(aryloxyalkyl)terephthalates that have low color and other valuable attributes. A method of producing bis(aryloxyalkyl)terephthalate articles having improved compressive strength is also disclosed.