Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2001-04-17
2001-10-09
Pezzuto, Helen L. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S131000, C526S157000, C526S335000, C526S336000, C526S340300
Reexamination Certificate
active
06300448
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a polymeric resin which is the reaction product of the polymerization reaction between dicyclopentadiene and limonene. Use of the polymeric resins of the present invention in a rubber tire stock improves the traction and handling of the tire.
SUMMARY OF THE INVENTION
The present invention relates to a polymeric dicyclopentadiene/limonene resin. The polymeric resins of the present invention have softening points ranging from about 50° C. to about 220° C., and a molecular weight of from about 500 to about 42,000. The present invention also includes a blend of dicyclopentadiene/limonene resins and rubber stocks containing the dicyclopentadiene/limonene resin.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a polymeric resin consisting essentially of the reaction product of the polymerization reaction between dicyclopentadiene and limonene and having a softening point ranging from about 50° C. to about 220° C. and a molecular weight ranging from about 500 to about 42,000.
In addition, the present invention relates to a resin composition comprising a blend of two or more polymeric resins wherein each resin consists essentially of the reaction product of the polymerization reaction between dicyclopentadiene and limonene. Alternatively, the blend can be formed in-situ; that is, the reaction temperature may be raised during the polymerization to increase the molecular weight distribution and broaden the softening point.
In addition, there is disclosed a pneumatic tire having a tread comprised of a rubber stock comprising (1) a rubber selected from the group consisting of natural rubber, rubber derived from a diene monomer or mixtures thereof, and (2) a polymeric resin composition consisting essentially of the reaction product of the polymerization reaction between dicyclopentadiene and limonene; said resin having a softening point ranging from about 50 to about 220° C. and a molecular weight ranging from about 500 to about 42,000.
There is also disclosed a rubber stock comprising (1) a rubber selected from the group consisting of natural rubber, rubber derived from a diene monomer or mixtures thereof, and (2) a polymeric resin composition consisting essentially of the reaction product of the polymerization reaction between dicyclopentadiene and limonene; said resin having a softening point ranging from about 50 to about 220° C. and a molecular weight ranging from about 500 to about 42,000.
The terms “polymeric compound” and “polymer” when used to describe the resins of the present invention are intended to only include those molecules which contain a monomeric unit derived from dicyclopentadiene and limonene and where at least one of the monomeric units derived from the dicyclopentadiene or limonene is repeated. Therefore, the compounds formed by the reaction of a single dicyclopentadiene molecule and a single limonene are not polymeric as the term is used herein. The term monomeric unit means a structure that occurs in a polymeric compound and which differs from the structure of dicyclopentadiene or limonene due to changes resulting from molecular reorientation during the linking to the adjacent structure. These changes may include addition to a double bond or the addition or removal of a hydrogen atom from the dicyclopentadiene or limonene.
The molar ratio of the dicyclopentadiene to limonene in the polymerization reaction may vary, depending on the desired properties of the final polymeric product. For example, the molar ratio of the dicyclopentadiene to limonene as starting material may range from about 1:10 to about 10:1. The preferred molar ratio of dicyclopentadiene to limonene may range from about 5:1 to 1:5 as starting material. The most preferred ratio ranges from about 2:1 to 1:2. As to the final product, the molar ratio of polymeric units derived from the dicyclopentadiene to limonene may range from about 8:1 to 1:8. The preferred molar ratio of dicyclopentadiene to limonene in the final product ranges from about 1:3 to 3:1 with a range of from about 2.1:1 to 1:2.1, being particularly preferred.
The polymerization reaction between the dicyclopentadiene may be a thermal (no catalyst) polymerization, or catalyzed, i.e., conducted in the presence of an acid catalyst. Examples of acid catalysts that may be used include Bronsted acid and Lewis acid-type catalysts. Such known acid catalysts include H
2
SO
4
, HCl, H
3
PO
4
; metal halides such as BF
3
, BCl
3
, AlCl
3
, AlBr
3
, SnCl
4
, ZnCl
2
, SbCl
3
and their etherates. The choice of a particular catalyst is dependent upon factors including the melting or boiling points of the reactants, desired rate of reaction, solvent, and pressure and temperature limitation of the production equipment, etc. When higher yields are desired, the metal halides or their etherates may be utilized. The preferred acid catalysts are BF
3
and AlCl
3
. The most preferred catalyst is AlCl
3
.
In the catalyzed polymerization process, the amount of catalyst may range from about 0.1 to about 20 weight percent of catalyst based on the total weight of reactants to be polymerized. Preferably, a range of from about 3 to about 5 weight percent of catalyst is preferred. The optimum concentration of catalyst depends on the nature of the solvent, if any, which effects the solubility of the catalyst as well as on the stirring efficiency inside the polymerization reactor. High catalyst concentration reduces the resin molecular weight distribution and, therefore, limits the amount of feed additive required is for controlling the resin molecular weight.
The polymerization reaction may be carried out neat (without solvent) at or above the melting points of the reactants, or can be carried out in the presence of a solvent. The solvent may be an aliphatic C
6
-C
12
hydrocarbon, an aromatic or haloaromatic (C
6
-C
9
) hydrocarbon, or a C
6
-C
9
aliphatic halohydrocarbon. Examples of suitable solvents include hexane, heptane, cyclohexane, benzene, toluene, xylene, and chlorobenzene. The preferred solvents are hexane and cyclohexane.
The polymerization reaction may be conducted under a variety of operating conditions. The reaction pressure may vary and range from about one atmosphere to about 100 atmospheres with a pressure of from about two atmospheres to about ten atmospheres being preferred. The reaction temperature may range from about 0 to 100° C. with a preferred range being from about 30 to 50° C.
Depending on the reactivity of the reactants, amount of catalyst, reaction pressure and reaction temperature, the reaction time may vary. Generally speaking, the reaction time varies from about 1 to about 8 hours.
The molecular weight distribution of the polymeric resin of the present invention may range from about 500 to about 42,000. In a particularly preferred embodiment of the present invention, the resin composition comprises a blend of two or more individual polymeric resins each one of which is the reaction product of a polymerization reaction between dicyclopentadiene and limonene. Each individual polymeric resin preferably differs from the other by having a different molecular weight range. Generally speaking, all of the polymeric resins will exhibit some lower molecular weight values, however, not all of the individual resins may include the higher molecular values. In the alternative, all of the resins may have distributions that vary by their lower molecular values with the high molecular weight value relatively being the same. For example, when the resin blend comprises three individual polymeric resins, the first resin may have a molecular weight ranging from about 700 to about 24,000, the second resin may have a molecular weight ranging from about 700 to about 36,000, and the third resin may have a molecular weight ranging from about 700 to about 42,000.
In accordance to another embodiment of the present invention, the resin composition may comprise a blend of four individual resins. In accordance with this embodiment, the first resin may have a molecular weight ranging from
Keith Denise Jeannette
Segatta Thomas Joseph
Wideman Lawson Gibson
Hendricks Bruce J.
Pezzuto Helen L.
The Goodyear Tire & Rubber Company
LandOfFree
Polymeric dicyclopentadiene/limonene resin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polymeric dicyclopentadiene/limonene resin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polymeric dicyclopentadiene/limonene resin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2604556