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
2000-08-18
2003-10-07
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S087000, C525S080000, C525S083000, C525S084000, C525S070000, C525S331900, C525S332600, C152S209100
Reexamination Certificate
active
06630535
ABSTRACT:
TECHNICAL FIELD
The present invention is directed toward rubber compositions and vulcanizates that exhibit damping over a wide temperature and frequency range. More particularly, these compositions and vulcanizates include a damping component, which includes a comb polymer. In a preferred embodiment the vulcanizates are tire components.
BACKGROUND OF THE INVENTION
Damping is the absorption of energy, such as vibrational or sound energy, by a material in contact with the source of that energy. Damping vibrational energy from a number of sources such as motors and engines can be desirable.
Viscoelastic materials are often employed for damping applications. Energy is absorbed by the viscoelastic material and converted into heat. Ideally, viscoelastic materials employed for damping are effective over a wide range of temperatures and frequencies.
The viscoelastic nature of materials can be mathematically represented by the formula G*=G′+iG″ where G* is the complex shear modulus, G′ is the elastic or storage modulus, G″ is the viscous or loss modulus, and i={square root over (−1)}. The damping effectiveness of viscoelastic materials can be quantified by measuring viscoelastic response to a periodic stress or strain. Results of dynamic mechanical tests are generally given in terms of G′ and G″, where G″ is directly related to the amount of mechanical energy converted to heat, i.e., damping.
The ratio of G″ to G′ is often referred to as tan &dgr;,
tan
δ
=
G
″
G
′
which quantifies a material's ability to dissipate mechanical energy versus the purely elastic storage of mechanical motion during one cycle of oscillatory movement. Tan &dgr; can be measured by a dynamic analyzer, which can sweep many frequencies at a fixed temperature, then repeat that sweep at several other temperatures, followed by the development of a master curve of tan &dgr; versus frequency by curve alignment. An alternate method measures tan &dgr; at constant frequency over a temperature range.
In common practice, the tan &dgr; of a material is usually broadened by taking advantage of the glass transition temperature of several materials within a temperature range. U.S. Pat. No. 5,494,981 teaches a composition that comprises resins that are cured in sequential fashion by using a single catalyst. The catalyst is a Bronsted acid that activates an epoxy resin component and then activates cyanate trimerization into polytriazines. The composition provides a glass transition damping peak around 100° C. and is understood to be heat stable over a temperature range of about 0° to at least 300° C.
Although numerous compositions are known for damping, there is a need for improved damping compositions that exhibit a high degree of damping over a wide range of temperatures and frequencies without involving glass transition peaks. Enhancing hysteresis (tan &dgr;) by using superposition of glass transition peaks is not desirable because the modulus of the material drops dramatically at or about the glass transition temperature.
REFERENCES:
patent: 5221716 (1993-06-01), Jalics et al.
patent: 5300569 (1994-04-01), Drake et al.
patent: 5342896 (1994-08-01), Jalics et al.
patent: 5494981 (1996-02-01), Gorodisher et al.
patent: 5506320 (1996-04-01), Yu
patent: 5733965 (1998-03-01), Scholl et al.
patent: 5756580 (1998-05-01), Natori et al.
patent: 5905116 (1999-05-01), Wang et al.
patent: 5994468 (1999-11-01), Wang et al.
patent: 6054532 (2000-04-01), Wang et al.
patent: 6107409 (2000-08-01), Hogan et al.
patent: 6133354 (2000-10-01), Wang et al.
patent: 6207763 (2001-03-01), Wang et al.
patent: 6248827 (2001-06-01), Wang et al.
patent: 6251994 (2001-06-01), Wang et al.
patent: 6268427 (2001-07-01), Wang et al.
patent: 6359064 (2002-03-01), Wang et al.
patent: 3526549 (1987-02-01), None
patent: 0 585 012 (1994-03-01), None
patent: 0 448 902 (1996-05-01), None
patent: 0 879 831 (1998-11-01), None
patent: 0 924 225 (1999-06-01), None
patent: 0 955 316 (1999-11-01), None
patent: 0 955 317 (1999-11-01), None
patent: 0 955 318 (1999-11-01), None
patent: 0 955 319 (1999-11-01), None
patent: 0 955 320 (1999-11-01), None
patent: 0 955 329 (1999-11-01), None
patent: 0 955 330 (1999-11-01), None
patent: 0 964 006 (1999-12-01), None
patent: WO 00/49085 (2000-08-01), None
“Size Distribution for Aggregates of Associating Polymers. II. Linear Packing” by Wang and Safran,J. Chem. Phys. 89(8), pp. 5323-5328, Oct. 1998.
“Surfactant-Induced Lyotropic Behavior of Flexible Polymer Solutions” by Fredrickson,Macromolecules26, pp. 2825-2831, 1993.
“Functionalized Polymers and Macromonomers” by Hsieh and Quirk,Anionic Polymerization: Principles and Practical Applications, pp. 291-306, 1996.
“From comb Polymers to Polysoaps: a Monte Carlo Attempt” by Rouault,Macromol. Theory Simul. 7, pp. 359-365, 1998.
“Regular Comb Polystyrenes and Graft Polyisoprene/Polystyrene Copolymers with Double Branches (“Centipedes”). Quality of (1,3-Phenylene)bis(3-methyl-1-phenylpentylidene) dilithium Initiator in the Presence of Polar Additives” by Iatrou et al.,Macromolecules31, pp. 6697-6701, 1998.
“Reactive Extrusion in the Preparation of Carboxyl-Containing Polymers and Their Utilization as Compatibilizing Agents” by Gaylord, Reactive Extrusion Principles and Practice, Hanser Publishing, pp. 55-65, 1992.
Hall James E.
Hergenrother William L.
Hogan Terrence E.
Krom James A.
Pakdel Peyman
Bridgestone Corporation
Lee Rip A
Palmer Meredith E.
Reginelli Arthur M.
Wu David W.
LandOfFree
Rubber compositions & vulcanizates including comb polymers does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rubber compositions & vulcanizates including comb polymers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rubber compositions & vulcanizates including comb polymers will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3174481