Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Cellular products or processes of preparing a cellular...
Reexamination Certificate
2001-11-14
2003-06-24
Cooney, Jr., John M. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Cellular products or processes of preparing a cellular...
C521S170000, C521S174000
Reexamination Certificate
active
06583194
ABSTRACT:
TECHNICAL FIELD
This invention relates in general to foam compositions, and more specifically to foams that are elastic above the glass transition temperature (T
g
) and rigid at room temperature, and that possess hibernated elastic memory in the rigid state.
BACKGROUND ART
U.S. Pat. No. 4,725,627 to Arnason et al. discloses a squeezable toy which is said to possess dimensional memory. The toy is made from an elastic material that will change dimension under force, and when the force is removed it will return to its original shape. There is no suggestion of a foam that is elastic above the T
g
and rigid at room temperature, and that possesses hibernated elastic memory in the rigid state.
U.S. Pat. No. 5,032,622 to Herrington et al. discloses a densifiable and re-expandable polyurethane foam. The T
g
of the foam is very broad, starting at a temperature well below room temperature. As a result, the foam retains some elastomeric character at room temperature—it is not rigid at room temperature. The foam can be flexed and compressed at room temperature. As an illustration, the patent describes crushing the foam at room temperature to mechanically open the cells of the foam. If the foam was rigid at room temperature, the crushing would break and destroy the foam.
U.S. Pat. No. 5,418,261 to Helsemans et al. discloses polyurethane foams having shape memory. The foams are prepared with polyoxyalkylene polyols containing oxyethylene residues. The polyols have an average oxyethylene content of at least 86% by weight. Foams prepared with oxyethylene based polyols have various disadvantages, such as hydrophilicity and other shortcomings, that limit the applications of the foams.
“Cold hibernated elastic memory (CHEM) self-deployable structures”, Sokolowski et al., SPIE '99 International Symposium on Smart Structures and Materials, Mar. 1-5, 1999, describes shape memory polymeric foams and structures made with the foams. There is no disclosure of the chemical structure of the foams.
SUMMARY OF THE INVENTION
The invention relates to a polymeric foam, preferably a polyurethane foam, having a glass transition temperature, T
g
, which is at or above room temperature (21° C.). The foam is rigid at room temperature and elastic above the T
g
. The foam has shape memory such that when it is deformed at a temperature above the T
g
and the temperature is then lowered to room temperature or below, the foam retains its deformed shape, and when the temperature is then raised above the T
g
the foam returns substantially to its original shape. In other words, the foam possesses hibernated elastic memory in the rigid state. The foam is also hydrophobic, which allows it to be used in many applications where hydrophilic foams are unsuitable.
REFERENCES:
patent: 4725627 (1988-02-01), Arnason et al.
patent: 5032622 (1991-07-01), Herrington et al.
patent: 5049591 (1991-09-01), Hayashi et al.
patent: 5066091 (1991-11-01), Stoy et al.
patent: 5093384 (1992-03-01), Hayashi et al.
patent: 5098776 (1992-03-01), Kobayashi et al.
patent: 5145935 (1992-09-01), Hayashi
patent: 5155199 (1992-10-01), Hayashi
patent: 5192301 (1993-03-01), Kamiya et al.
patent: 5418261 (1995-05-01), Helsemans et al.
patent: 5441489 (1995-08-01), Utsumi et al.
patent: 5445140 (1995-08-01), Tovey
patent: 5478619 (1995-12-01), Fujikura et al.
patent: 5506300 (1996-04-01), Ward et al.
patent: 5634913 (1997-06-01), Stinger
patent: 5665822 (1997-09-01), Bitler et al.
patent: 5902518 (1999-05-01), Khazai et al.
patent: 5908447 (1999-06-01), Schroeppel et al.
patent: 6024764 (2000-02-01), Schroeppel
patent: 6069319 (2000-05-01), Davis, Jr. et al.
patent: 6083442 (2000-07-01), Gabilly
patent: 6090479 (2000-07-01), Shirato et al.
patent: 6099948 (2000-08-01), Paver, Jr.
patent: 6156842 (2000-12-01), Hoenig et al.
patent: 6160084 (2000-12-01), Langer et al.
patent: 2001/0018120 (2001-08-01), Murakami et al.
patent: 2002/0043736 (2002-04-01), Murakami et al.
patent: 361418 (1990-04-01), None
patent: 365954 (1990-05-01), None
patent: 608626 (1994-08-01), None
patent: 06298988 (1994-10-01), None
patent: 09059418 (1997-03-01), None
patent: 09085840 (1997-03-01), None
patent: 10095058 (1998-04-01), None
patent: 2000248101 (2000-09-01), None
Tey, et al., “Influence of long-term storage in cold hibernation on strain recovery and recovery stress of polyurethane shape memory polymer foam,” Smart Mater. Struc. 10 (2001) 321-325.
Tobushi et al., “Thermomechanical properties of polyurethane-shape memory polymer foam,” J. Advanced Sci., 12 (2000) 281-286.
Tobushi et al., “Strain fixity and recovery of polyurethane-shape memory polymer foam,” Trans. Mater. Res. Soc. Jpn. (2001), 26(1) (Abstract).
Lee, Bo Sun; “Structure and Thermomechanical Properties of Polyurethane Block Copolymers with Shape Memory Effect,” Macromolecules 2001, 34, 6431-6437.
Hayashi, “Properties and Applications of Polyurethane-Series Shape Memory Polymer,” International Progress in Urethanes, 6 (1993) 90-115.
Cadogan, “Rigidization mechanisms and materials,” Progress in Astronautics and Aeronautics (2001) (Gossamer Spacecraft: Membrane and Inflatable Structures Technology for Space Applications), Chapter 7, pp. 257-279.
Gordon, R.F., Applcations of Shape Memory Polyurethanes,: Proceedings of the First International Conference on Shape Memory and Supereastic technologies, Pacific Grove, California, USA, 1994, pp. 115-120.
Li, F., et al., “Studies on Thermally Stimulated Shape Memry Effect of Segmented Polyurethanes,” J. Appl. Polym. Sci., 1997, 64, 1511-1516.
Takahashi, T., “ Structure and Properties of Shape-Memory Polyurethane Block Copolymers,”; J. Appl. Polym. Sci., 1996, 60, 1061-1069.
Kim, B.K., et. al., “Polyurethane ionomers having shape memory effects,” Polymer, 1998, 39 (13), 2803-2808.
Tobushi, H. et al., “Thermomechanical properties in a thin film of shape memory polymer of polyurethane series,” Smart Mater.Struct., 1996, 5, 483-491.
Kim, B.K. et al., “Shape memory behavior of amorphous polyurethanes,” J. Macrmol. Sci., —Physics, 2001, B40(6), 1179-1191.
Kim, B.K. and Lee, S.Y., Polyurethanes having shape memory effects,: Polymer, 1996, 39 (26), 5781-5793.
Li, F., et al., “Polyurethane/Conducting Carbon Black Composites: Structure, Electric Conductivity, Strain Recovery Behavior, and Their Relationships,” J. Appl. Polym. Sci., 2000, 75, 68-77.
“Cold Hibernated Elastic Memory (CHEM) Self-Deployable Structures”, SPIE '99 International Symposium on Smart Structures and Materials, Mar. 1999.
Hanschke, E., et al, Clear Nonionic Polyurethane hydrogels For Biomedical Applications, New Orleans, Proceedings of the SPI 34thAnnual Technical/Marketing Conference, p. 94, (1992).
Harrington, R., et al, “Chapter 9: Slabstock Foam” in: Flexible Polyurethane Foams (United States, The Dow Chemical Company; (1997) p. 9.30.
Frisch, K.C., “Chapter 31: High-Performance Polyurethanes” in: Hatada, K., et al., Macromolecular Design of Polymeric Materials (New York, Marcel Dekker;(1997), p. 529.
Saunders, J.H. and Frisch, K.C., “Chapter VII: Flexible Foams” in: Polyurethanes, Chemistry and Technology (New York, John Wiley & Sons,(1964), p. 173.
Brooks & Kushman P.C.
Cooney Jr. John M.
LandOfFree
Foams having shape memory does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Foams having shape memory, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Foams having shape memory will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3124534