Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Plural component system comprising a - group i to iv metal...
Reexamination Certificate
1999-12-21
2001-02-06
Wood, Elizabeth D. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Plural component system comprising a - group i to iv metal...
C502S150000, C502S152000, C502S154000, C502S155000, C502S157000, C502S168000
Reexamination Certificate
active
06184168
ABSTRACT:
FIELD OF THE INVENTION
The instant invention broadly relates to catalysts used in the promotion of organic chemical reactions with a catalyst. More specifically, the invention relates to the use of a catalyst composition comprising a metallo-organic salt of a lanthanide element for promoting a polymerization synthesis which produces synthetic polymers from conjugated diene monomers. Still more specifically, the invention relates to the addition of a catalytically effective combination of two components: (1) an organic acid salt of a lanthanum series compound, and (2) an organolithium compound, for promoting the chemical synthesis of 1,4-trans-polybutadiene, while having further utility in the synthesis of diblock polymers.
BACKGROUND OF THE INVENTION
This invention relates to the polymerization of conjugated diene monomers using a catalyst system containing a compound of a rare earth element, i.e. an element having an atomic number of 57 to 71 inclusive.
Use of lanthanide series catalysts in the synthesis of 1,4-trans-polybutadiene is known in the prior art. For instance U.S. Pat. No. 4,619,982 to Jenkins, discloses the use of various catalyst systems containing rare earth compounds for the polymerization of conjugated diene monomers, in recent years. Examples of such disclosures are (1) Mazzei A., Makromol. Chem. Suppl. 4 61 (1981); (2) Witte J., Angew. Makromol. Chem. 94 119 (1981); (3) Shen Tse-Chuan et al, J. Pol. Sci. Polym. Chem. Ed. 18 3345 (1980); (4) Marwede G. and Sylvester G., Trans. 22nd Annual Proceedings of the International Institute of Synthetic Rubber Producers, Madrid Paper III-3 (1981). Such catalyst systems have two or three components, for example a lanthanoid alkyl, alkoxide or salt (e.g. neodymium tricarboxylate) with an organoaluminium compound and optionally a Lewis Acid. When a -allyl complex of a rare earth such as Ln(allyl) dioxane, where Ln also a lanthanide element, is used which gives a polymer of predominantly trans 1,4 content, and which needs no cocatalyst. Such -allyl catalysts are described in the paper by Mazzei referred to above and appear to proceed by an ionic mechanism.
One embodiment of the Jenkins invention discloses a two component catalyst for the homo polymerization of a conjugated diene or the copolymerization of a conjugated diene with one or more other conjugated dienes comprising (a) a salt of a rare earth element or a complex of a rare earth element and (b) an organo magnesium compound. The Jenkins invention also includes the use of a catalyst, as just defined, in the homo polymerization of a conjugated diene. Surprisingly, Jenkins found that the product of such a polymerization employing an organo magnesium compound as cocatalyst is a conjugated diene polymer having a very high content of trans isomer. The rare earth element in component (a) of the catalyst of are those having an atomic number of 57 (lanthanum) to 71 (lutetium). However, the polymerization activity of certain of these elements, e.g. samarium or europium, is known to be low. Thus, a compound of cerium, praseodymium, neodymium, gadolinium, terbium or dysprosium is preferred by Jenkins. A compound of two or more rare earth elements may be used. A compound of neodymium or “didymium” (which is a mixture of rare earth elements containing approximately 72% neodymium, 20% lanthanum and 8% praseodymium) is preferred. Preferably component (a) is soluble in hydrocarbon polymerization medium, examples being the carboxylates, alkoxides and diketones. Examples of compounds for use as component (a) are “didymium” versatate (derived from versatic acid, a synthetic acid composed of a mixture of highly branched isomers of C
10
monocarboxylic acids, sold by Shell Chemicals), praseodymium (2,2,6,6-tetramethyl-3,5-heptane dione). “Didymium” and especially neodymium “versatate” are preferred on the grounds of ready solubility, ease of preparation and stability. Component (b) of the catalyst is an organo magnesium compound. Dihydrocarbyl magnesium compounds of formula R
2
Mg where each R, which may be the same or different, is for example, an alkyl (including cycloalkyl), aryl, aralkyl, allyl or cyclodiene group. Dialkyl magnesium compounds, where each alkyl group has from 1 to 10 carbon atoms, are preferred. Magnesium dibutyl was particularly preferred by Jenkins on the grounds of ease of availability. The organo magnesium compound may also be a hydrocarbon soluble Grignard reagent of formula RMgX where R is a hydro-carbyl group such as exemplified above and X is chlorine, bromine or iodine. The molar ratio of component (a) to component (b) was preferably 0.01:1 to 0.5:1 more preferably 0.06:1 to 0.3:1. Absolute concentration of component (b) may be for example, 1 to 5 millimoles per hundred grams of polymerisable monomer. Similarly in the publication
Polymer,
1985, 26, p147, D. K. Jenkins disclosed experiments wherein high trans polybutadiene was obtained by using a catalyst system comprising a rare earth compound plus a magnesium dialkyl. The polymer appeared to contain some “live” chain ends.
In another U.S. Pat. No. 4,931,376, to Ikematsu et al, another process for the homopolymerization of a high-trans polybutadiene is described. Ikematsu provides a process for producing crystalline trans-butadiene polymers. The process comprises: using a complexed catalyst comprising (a) an organic acid salt of lanthanum or cerium and (b) an organic magnesium compound as the essential components. Lanthanum and cerium which are the main components in the complexed catalyst of the Ikematsu invention are metals occurring abundantly among lanthanide transition metals (rare earth metals) and commercially readily available at relatively low cost. Ikematsu unexpectedly found that a conjugated diene can be polymerized by using the complexed catalyst of the present invention to provide a conjugated diene polymer having high trans content at a very high activity, and yet the polymer obtained has a high molecular weight and a narrow molecular weight distribution, containing substantially no gel, the polymer thus obtained exhibiting excellent workability and physical properties. The organic acid salt of lanthanum or cerium which is the component (a) in the complexed catalyst of the present invention can readily be obtained by, for example, making an alkali metal salt of an organic acid as shown below to react with a chloride of lanthanum or cerium in water or an organic solvent such as alcohols, ketones, etc. The organic acid salt of lanthanum or cerium may contain inorganic salts of lanthanum or cerium or organic acids as the impurities in small amounts.
Various lanthanide series catalysts are known by the prior art. For instance, see: J. Am. Chem. Soc., vol. 104, pp. 6571-6473 (1982), Patricia L. Watson and D. Christopher Roe, “Beta-Alkyl Transfer in a Lanthanide Model for Chain Termination;” J. Am. Chem. Soc., vol. 107, pp. 8091-8103 (1985), Gerald Jeske, Harald Lauke, Heiko Mauermann, Paul N. Swepston, Herbert Schumann and Tobin J. Marks, “Highly Reactive Organolanthanides. Systematic Routes to and Olefin Chemistry of Early and Late Bis(pentamethylcyclopentadienyl) 4f Hydrocarbyl and Hydride Complexes.” Also exemplary in displaying the utility of lanthanide series compounds in catalyst systems for the production synthetic rubbers is U.S. Pat. No. 4,152,295 teaching the reaction of a conjugated diolefin with at least one compound selected from the group consisting of a carboxylic acid and a carboxylic acid anhydride in the presence of oxygen and a catalyst comprising a rare earth metal compound, an alkali metal compound and a halide compound.
U.S. Pat. No. 4,461,883 teaches a process for producing a conjugated diene polymer, characterized by polymerizing at least one conjugated diene with a catalyst consisting of: (A) a reaction product of a Lewis base and a carboxylate of a rare earth element of the lanthanum series represented by Ln(R
1
CO
2
)
3
wherein Ln is a rare earth element of the lanthanum series having an atomic number of 57 to 71 and R1 is a hydrocarbon substituent having 1 to 20 car
Bridgestone Corporation
Burleson David G.
Reginelli Arthur M.
Wood Elizabeth D.
LandOfFree
Synthesis of 1,4-trans-polybutadiene using a lanthanide... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Synthesis of 1,4-trans-polybutadiene using a lanthanide..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Synthesis of 1,4-trans-polybutadiene using a lanthanide... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2602190