Stock material or miscellaneous articles – Hollow or container type article – Polymer or resin containing
Reexamination Certificate
1998-09-04
2002-06-25
Pyon, Harold (Department: 1772)
Stock material or miscellaneous articles
Hollow or container type article
Polymer or resin containing
C138S118000, C156S166000, C156S171000, C156S181000, C156S244210, C428S036920
Reexamination Certificate
active
06410110
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to thermosetting resin pipe and pipe fittings made of metathesis polymerized olefins, and methods for producing the same. More particularly, the invention relates to thermosetting resin pipe and pipe fittings made of polycycloolefins wherein the cycloolefins are polymerized through Ring Opening Metathesis Polymerization (ROMP) reactions.
BACKGROUND PRIOR ART
Many polymers of olefins produced through metathesis polymerization reactions, especially polymers of cycloolefins produced through ROMP reactions, are tough and rigid, and have good chemical resistance. It is desirable to produce pipe and pipe fittings out of such material for use in many applications.
Generally, one method of producing articles out of thermosetting resins is to create a reaction mixture by mixing a liquid monomer and a polymerization catalyst. The mixture is then processed or worked through an appropriate polymer processing technique to shape the desired article, and the polymerization reaction proceeds (the article “cures”) to form the desired polymer article. The time during which the liquid monomer/catalyst mixture can be worked or processed after the monomer and catalyst are mixed is called the “pot life” of the polymerization reaction.
Several significant problems have existed regarding the production of pipe out of metathesis polymerized olefins using such techniques. For the most part, these problems are due to the metathesis catalyst systems that are used.
The original catalyst systems used for metathesis reactions were of the Ziegler type. A variety of other systems have alpo been developed based on tungsten and molybdenum. All of these catalyst systems have significant drawbacks for use in making thermosetting resin pipe.
With these catalyst systems, the polymerization reaction has a very short pot life, and there are no good methods for controlling the rate of polymerization once the reaction mixture is formed. Due to the short pot life of these metathesis reactions, many traditional methods for making thermosetting resin pipe and pipe fittings are generally not feasible, because to successfully produce pipe, the reaction mixture must not gel before the pipe is completely formed. In many methods of production, the short pot life adds significant complexity to the methods and requires the use of special procedures to produce pipe or pipe fittings. For example, in rotational and centrifugal casting methods, pressure is typically required in the casting environment to ensure that gas bubbles that form using the old catalysts are removed from within the monomer prior to the gelling of the monomer due to the rapid polymerization. Additionally, the monomer must immediately be moved to the casting position within the casting mold such that the monomer is in the correct pipe casting position prior to the gelling of the monomer.
Furthermore, uncontrolled cross-linking takes place during these rapid metathesis polymerization reactions, therefor not allowing for maximum chain growth and molecular weight of the polymer. Therefore, polymers with less desirable properties are produced with these catalyst systems. This uncontrolled cross-linking also does not allow for the easy production of random and block copolymers or terpolymers having unique properties.
Additionally, these metathesis catalyst systems are all easily poisoned by impurities, air, moisture, and by many pigments, fillers, and additives. Therefore, the production of pipe and pipe fittings using these catalysts must occur under very controlled conditions and with exceptionally high purity grades of monomer. Methods such as filament winding, pultrusion, centrifugal casting and rotational molding are very difficult to perform in the inert environment needed for the traditional catalysts. This greatly increases the cost of producing reinforced and unreinforced thermosetting resin pipe and pipe fittings made of metathesis polymerized olefins.
Due to these drawbacks and difficulties, pipe made of metathesis polymerized olefins has been very difficult to produce. Even when it has been possible to produce such pipe, the production costs are quite expensive, and often economically unfeasible. As a result, such pipes and pipe fittings, which have excellent chemical resistance and improved physical properties, have not been widely available.
It is desirable to provide for reinforced and unreinforced thermosetting resin pipe made of metathesis polymerized olefins, especially a ROMP reaction polymerized cycloolefin polymer, and a method for producing the same, wherein these drawbacks and difficulties can be substantially avoided.
SUMMARY OF THE INVENTION
The present invention addresses these needs by providing for pipes and pipe fittings made of metathesis polymerized olefins, and a method for making the same, using a ruthenium or osmium carbene complex catalyst to polymerize the olefin. In the current invention, many of the drawbacks and difficulties discussed above are minimized or avoided.
The use of the ruthenium or osmium carbene complex catalyst allows the metathesis reaction to be slowed down and more easily controlled, thereby providing for longer pot lives as desired for pipe production. As a result, methods such as rotational molding and centrifugal casting can be used without the need to pressurize the casting tube, or perform other operations necessary to counteract the short pot life of the old catalysts.
The use of a ruthenium or osmium catalysts also provides for increased chain growth and molecular weight prior to cross-linking, thereby providing for polymers with better properties. Also, the use of these catalysts provides controlled cross-linking, and the easy production of random and block copolymers, and random and block terpolymers, thereby allowing for the production of pipes made of metathesis polymerized polyolefins having unique and better physical characteristics than previously produced. For example, pipe and pipe fittings with better ductility and impact resistance can be produced through these methods.
Additionally, the ruthenium and osmium catalysts are not easily poisoned by impurities, air, moisture, and by many pigments, fillers, and additives.
Therefore, the production of pipe and pipe fittings from metathesis polymerized polyolefins is simplified using this method.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description and claims.
Before embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of the composition and concentration of components set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION OF AN EMBODIMENT
The invention provides thermosetting resin pipe and pipe fittings made from metathesis polymerized olefins, and methods for producing the same. The olefin metathesis reactions are catalyzed by ruthenium or osmium carbene complex catalysts to produce polyolefin pipe and pipe fittings. The pot life of the olefin polymerization reaction can be extended using the ruthenium or osmium carbene metathesis catalysts and known methods for extending the pot lives of reactions using these catalysts. The extended pot life allows pipe and pipe fittings to be made through processes that were unavailable or difficult to use prior to the current invention. Additionally, the ruthenium or osmium carbene metathesis catalysts are more tolerant of impurities than traditional metathesis catalysts, and therefore the presence of additives, bonding agents, impurities, and some low grade monomers do not substantially adversely affect the catalysts.
In accordance with this invention, an olefin monomer is polymerized through metathesis catalysis with a rut
Cagle Larry L.
Drake Steven D.
Warner Mark W.
Woodson Charles S.
A.O. Smith Corp.
Nolan Sandra M.
Pyon Harold
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