Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Cellular products or processes of preparing a cellular...
Patent
1999-06-30
2000-10-24
Foelak, Morton
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Cellular products or processes of preparing a cellular...
521 63, 521153, 521154, C08J 928
Patent
active
061368741
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This application relates to microporous, open-celled polymeric foams made using monomers based on silicon or germanium.
BACKGROUND OF THE INVENTION
The development of microporous foams has been the subject of substantial commercial interest. Such foams have found utility in various applications, such as thermal, acoustic, electrical, and mechanical (e.g., for cushioning) insulators, absorbent materials, filters, membranes, carriers for inks, dyes, lubricants, and lotions, making items buoyant, and the like. References describing such uses and properties of foams include Oertel, G. "Polyurethane Handbook" Hanser Publishers, Munich, 1985, and Gibson, L. J.; Ashby, M. F. "Cellular Solids Structure and Properties" Pergamon Press, Oxford, 1988. The term "insulator" refers to any material which reduces the transfer of energy from one location to another. The term "absorbent" refers to materials which imbide and hold or distribute fluids, usually liquids, an example being a sponge. The term "filter" refers to materials which pass a fluid, either gas or liquid, while retaining impurities within the material by size exclusion. Other uses for foams are generally obvious to one skilled in the art.
For many uses, composite and generally conflicting requirements are placed on the foam itself. These may include (1) low density, (2) flexibility, (3) strength (compressive and tensile), (4) openness, and (5) control of morphology. Low density foams are more efficient since most uses require a certain volume and a low density foam will impose less mass to meet this objective. Flexible foams are typically generated by maintaining a relatively low glass transition temperature ("Tg") of the foam. Strength is a parameter which is inevitably sacrificed to achieve either lower Tg or lower density. Strength can be generated effectively by including crosslinking agents which link the polymeric chains of the foam together in a fashion which confers a degree of resistance to deformation and the ability to recover from deformation, e.g., elasticity. Openness and morphology are controlled principally by the method of foam formation and curing.
Accordingly, it would be desirable to be able to make an open-celled, high surface area polymeric foam material that: (1) has the lowest density consistent with the other requirements imposed on the foam; (2) is flexible; (3) is strong; (4) has a generally open-celled structure; and (5) can be manufactured so as to control the size of cells produced within the foam.
SUMMARY OF THE INVENTION
The present invention relates to polymeric foams comprising comonomers based on silicon and/or germanium. The term "comonomer" is used herein to denote that these required comonomers are generally to be used with other comonomers which may or may not contain silicon and/or germanium. These polymeric foams are preferably prepared by polymerization of certain water-in-oil emulsions having a relatively high ratio of water phase to oil phase, commonly known in the art as high internal phase emulsions, or "HIPEs". As used herein, polymeric foam materials which result from the polymerization of such emulsions are referred to hereafter as "HIPE foams." The HIPE foam materials of the present invention comprise a generally flexible, semi-flexible, or rigid nonionic polymeric foam structure of interconnected open-cells. Comonomers used to form HIPEs generally must be relatively insoluble in the aqueous phase of the emulsion.
The polymeric foam structures that are derived from HIPEs comprise at least about 5%, based on the weight of the foam, of one or more comonomer(s) selected from the group consisting of silicon-containing comonomers, germanium-containing comonomers, and mixtures thereof.
Preferably, the foams of the present invention will have: 90.degree. C.; and
The present invention relates to foams prepared via polymerization of a HIPE comprising a discontinuous water phase and a continuous oil phase wherein the ratio of water to oil is at least about 10:1. The water phase generally c
REFERENCES:
patent: 5306733 (1994-04-01), Adamski et al.
patent: 5340842 (1994-08-01), Adamski et al.
Dyer John Collins
Retzsch Herbert Louis
Foelak Morton
Hentz Mary Catherine
Milbrada Edward J.
Roof Carl J.
The Procter & Gamble & Company
LandOfFree
Microporous polymeric foams made with silicon or germanium based does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Microporous polymeric foams made with silicon or germanium based, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microporous polymeric foams made with silicon or germanium based will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1964744