Articles formed from foamable polypropylene polymer

Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C525S191000, C525S240000, C521S134000, C521S142000

Reexamination Certificate

active

06306960

ABSTRACT:

FIELD OF THE INVENTION
This invention relates generally to polypropylene polymers, their uses, and to methods of their production.
BACKGROUND
Among the three most versatile commodity plastics, which are polyethylene (PE), polystyrene (PS) and polypropylene (PP), polypropylene is considered to possess the most favorable properties profile of the three for a variety of applications. These applications include, for example, oriented and non-oriented films, textile fibers, nonwovens and a variety of injection molded parts. Comparing the properties, it is well known that polypropylene has a higher modulus and heat deflection temperature (HDT) than polyethylene. The higher the modulus and HDT, the more suited the polymer is for durable applications in the appliance and automotive segments. Additionally, because polypropylene is nonpolar, it resists degradation by common solvents, such as acids and alkalis. Compared to polystyrene, polypropylene is preferred in applications requiring good organoleptic performance, high barrier properties and the living hinge property. Finally, polypropylene blends well with a variety of other polymers, and in impact-modified form occupies a dominant position in the automotive industry in the areas of bumpers, side panels, floor mats, dashboards and instrument panels.
However, there exist some polymer applications where polypropylene is not the preferred plastic of choice. Examples of such polymer application areas include thermoforming and foaming. Foamed polymers find usage in automotive, marine, appliance and packaging applications because of their good insulating and structural properties at low added weight. Thermoforming is a popular fabricating mode that competes favorably with injection molding in the making of thin-walled containers. Polypropylene's deficiencies in foaming and thermoforming are believed to be related to its generally poor melt strength and rapid melt viscosity drop, poor sheet sag and comparatively slow crystallization kinetics. For example, to successfully foam an article formed from a polyolefin, it is desirable that the polyolefin selected for foaming possess high melt strength. With high melt strength, the bubble growth rate within the polyolefin can be controlled without premature bursting. Controlling bubble growth rate is also important for ensuring a uniform distribution of cell sizes, which leads to greater product uniformity. Additionally, broader polymer processing temperature windows are desirable so that when the polymer is used in an article forming process, the temperature variances along the process line are less disruptive to the fabrication of a quality product.
So that manufactures of plastic articles and the consuming public may more fully benefit from the use of polypropylene in a broader array of applications, further development and investigation is needed in the area of polypropylene compositions and methods of manufacturing. This is particularly so, as described above, when the article manufacturing process requires that the polymer be foamed.


REFERENCES:
patent: 4530914 (1985-07-01), Ewen et al.
patent: 4542199 (1985-09-01), Kaminsky et al.
patent: 4665208 (1987-05-01), Welborn, Jr. et al.
patent: 4701432 (1987-10-01), Welborn, Jr.
patent: 4769910 (1988-09-01), Noon
patent: 4808561 (1989-02-01), Welborn, Jr.
patent: 4849487 (1989-07-01), Kaminsky et al.
patent: 4871705 (1989-10-01), Hoel
patent: 4874734 (1989-10-01), Kioka et al.
patent: 4908463 (1990-03-01), Bottelberghe
patent: 4921825 (1990-05-01), Kioka et al.
patent: 4923833 (1990-05-01), Kioka et al.
patent: 4924018 (1990-05-01), Bottleberghe
patent: 4933403 (1990-06-01), Kaminsky et al.
patent: 4937299 (1990-06-01), Ewen et al.
patent: 4952540 (1990-08-01), Kioka et al.
patent: 4968827 (1990-11-01), Davis
patent: 5017714 (1991-05-01), Welborn, Jr.
patent: 5026798 (1991-06-01), Canich
patent: 5057475 (1991-10-01), Canich et al.
patent: 5091352 (1992-02-01), Kioka et al.
patent: 5103031 (1992-04-01), Smith, Jr.
patent: 5120867 (1992-06-01), Welborn, Jr.
patent: 5145819 (1992-09-01), Winter et al.
patent: 5157137 (1992-10-01), Sangokoya
patent: 5198401 (1993-03-01), Turner et al.
patent: 5204419 (1993-04-01), Tsutsui et al.
patent: 5206199 (1993-04-01), Kioka et al.
patent: 5235081 (1993-08-01), Sangokoya
patent: 5239022 (1993-08-01), Winter et al.
patent: 5240894 (1993-08-01), Burkhardt et al.
patent: 5243001 (1993-09-01), Winter et al.
patent: 5248801 (1993-09-01), Sangokoya
patent: 5252389 (1993-10-01), Schmidt et al.
patent: 5276208 (1994-01-01), Winter et al.
patent: 5278119 (1994-01-01), Turner et al.
patent: 5280074 (1994-01-01), Schreck et al.
patent: 5296434 (1994-03-01), Karl et al.
patent: 5304614 (1994-04-01), Winter et al.
patent: 5308815 (1994-05-01), Sangokoya
patent: 5322902 (1994-06-01), Schreck et al.
patent: 5324800 (1994-06-01), Welborn, Jr. et al.
patent: 5329032 (1994-07-01), Tran et al.
patent: 5329033 (1994-07-01), Spaleck et al.
patent: 5346925 (1994-09-01), Sugano et al.
patent: 5350723 (1994-09-01), Neithamer et al.
patent: 5350817 (1994-09-01), Winter et al.
patent: 5374752 (1994-12-01), Winter et al.
patent: 5391790 (1995-02-01), Rohrmann et al.
patent: 5407884 (1995-04-01), Turner et al.
patent: 5468781 (1995-11-01), Sugano et al.
patent: 5483002 (1996-01-01), Seelert et al.
patent: 5483014 (1996-01-01), Turner et al.
patent: 5510502 (1996-04-01), Sugano et al.
patent: 5532325 (1996-07-01), Oka et al.
patent: 5605936 (1997-02-01), DeNicola, Jr. et al.
patent: 5643847 (1997-07-01), Walzer, Jr.
patent: 5672668 (1997-09-01), Winter et al.
patent: 5714427 (1998-02-01), Winter et al.
patent: 6174930 (2001-01-01), Agarwal et al.
patent: 2133181 (1995-03-01), None
patent: 0 279 586 B (1988-08-01), None
patent: 0 279 863 B (1988-08-01), None
patent: 0 277 004 (1988-08-01), None
patent: 0 354 893 B (1990-02-01), None
patent: 0 426 637 (1991-05-01), None
patent: 0 495 375 (1992-07-01), None
patent: 0 500 944 (1992-09-01), None
patent: 0 507 876 (1992-10-01), None
patent: 0 520 732 (1992-12-01), None
patent: 0 551 277B (1993-07-01), None
patent: 0 561 476 (1993-09-01), None
patent: 0 570 982 (1993-11-01), None
patent: 0 576 403 (1993-12-01), None
patent: 0 594 218 (1994-04-01), None
patent: 0 611 795 A1 (1994-08-01), None
patent: 0 662 979 B (1995-07-01), None
patent: 0 672 689 (1995-09-01), None
patent: 0 670 334 (1995-09-01), None
patent: 0 736 552 A2 (1996-10-01), None
patent: WO 94/03506 (1994-02-01), None
patent: WO 94/10180 (1994-05-01), None
patent: WO 94/28034 (1994-12-01), None
patent: WO 95/08285 (1995-03-01), None
patent: WO 96/00245 (1996-01-01), None
patent: WO 96/00243 (1996-01-01), None
patent: WO 98/10016 (1998-03-01), None
patent: WO 99/16797 (1999-04-01), None
Ferdinand R.W.P. Wild, et al., “ansa-Metallocene Derivatives—VII. Synthesis and Crystal Structure of a Chiral ansa-Zirconocene Derivative with Ethylene-Bridged Tetrahydroindenyl Ligands”—Journal of Organometallic Chemicstry, v.288, pp. 63-67, (1985).
Derwent Abstract for DE 196 22 083 A1, Dec. 4, 1997.
Derwent Abstract for EP 0 516 018 A2, Dec. 2, 1992.
Derwent Abstract for EP 0 702 030 A1, Mar. 20, 1996.
Derwent Abstract for EP 0 320 762 B1, Jun. 21, 1989.
Derwent Abstract of EP 0 549 900, Jul. 7, 1993.
Derwent Abstract of EP 0 576 970, Jan. 5, 1994.
“Termination of Polymer Chain Growth,” Zeigler-Natta Catalysts and Polymerizations, J. Boor, Jr., pp. 244-260 (Academic Press 1979).

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Articles formed from foamable polypropylene polymer does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Articles formed from foamable polypropylene polymer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Articles formed from foamable polypropylene polymer will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2609615

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.