John E Bond

US Patent:

61691437, Jan 2, 2001

Filed:

Jun 7, 1995

Appl. No.:

8/487326

Inventors:

Edward J. Dalgewicz - Millstone NJ
John Bond - Pittsburgh PA
Richard Freundlich - Plainsboro NJ

Assignee:

Lawson Mardon Thermaplate Corporation - Piscataway NJ

International Classification:

C08G 6348

US Classification:

525 64

Abstract:

Polyester composition with improved impact properties, improved oxygen permeability and improved dimensional shrinkage during heating. Impact modifiers are dissolved into a molten polyester to form a eutectic alloy. On slow cooling, the eutectic alloy of the invention freezes to form a mixture of particles of the impact modifier embedded in a matrix of the polyester. By controlling the solidification of the melt, the size and distribution of the precipitates from the melt can be controlled, which allows control of the mechanical properties. The precipitation can also be controlled either by homogenous nucleation or by heterogeneous nucleation through the addition of a nucleating agent or the introduction of a suitable surface for nucleation. The invention also provides a process of manufacturing the above polyester, an article comprising this polyester and a process for making this article. The crystalline polyester article is useful as a container for microwavable, ovenable and/or frozen foods, and has improved gas barrier properties, impact strength, and post-mold dimensional stability between -60. degree. C. and 200. degree. C.

US Patent:

60779047, Jun 20, 2000

Filed:

Jul 17, 1992

Appl. No.:

7/914388

Inventors:

Edward J. Dalgewicz - Millstone NJ
John Bond - Pittsburgh PA
Richard Freundlich - Plainsboro NJ

Assignee:

Lawson Mardon Thermaplate Corporation - Piscataway NJ

International Classification:

C08L 6702

US Classification:

525 64

Abstract:

Polyester composition with improved impact properties, improved oxygen permeability and improved dimensional shrinkage during heating. Impact modifiers are dissolved into a molten polyester to form a eutectic alloy. On slow cooling, the eutectic alloy of the invention freezes to form a mixture of particles of the impact modifier embedded in a matrix of the polyester. By controlling the solidification of the melt, the size and distribution of the precipitates from the melt can be controlled, which allows control of the mechanical properties. The precipitation can also be controlled either by homogenous nucleation or by heterogeneous nucleation through the addition of a nucleating agent or the introduction of a suitable surface for nucleation. The invention also provides a process of manufacturing the above polyester, an article comprising this polyester and a process for making this article. The crystalline polyester article is useful as a container for microwavable, ovenable and/or frozen foods, and has improved gas barrier properties, impact strength, and post-mold dimensional stability between -60. degree. C. and 200. degree. C.