Copolymers of Ethylene and 1,3-Butadiene

Copolymers of Ethylene and 1,3-Butadiene

Europaisches Patentamt European Patent Office © Publication number: 0 526 955 A1 Office europeen des brevets EUROPEAN PATENT APPLICATION © Application number: 92203227.1 © Int. CI.5: B01D 9/00, C08F 210/00 @ Date of filing: 18.12.87 This application was filed on 21 - 10 - 1992 as a © Applicant: EXXON CHEMICAL PATENTS INC. divisional application to the application 1900 East Linden Avenue mentioned under INID code 60. Linden New Jersey 07036(US) ® Priority: 19.12.86 US 944385 @ Inventor: Stehling, Ferdinand Christian 214 Post Oak @ Date of publication of application: Baytown, Texas 77520(US) 10.02.93 Bulletin 93/06 © Publication number of the earlier application in © Representative: Veldhuizen, Albert Dirk accordance with Art.76 EPC: 0 275 676 Willem et al Exxon Chemical Limited Exxon Chemical © Designated Contracting States: Technology Centre PO Box 1 BE DE ES FR GB NL Abingdon Oxfordshire OX13 6BB(GB) © Copolymers of ethylene and 1,3-butadiene. © Ethylene copolymers having in their structure cyclopentane rings connected in the 1 and 2 positions. The ethylene copolymers of the invention may be formed from polymerization of ethylene and butadiene and preferably have a predominance of the copolymer units formed as 1 ,2-cyclopentane units, preferably trans 1 ,2- cyclopentane. Other butadiene units incorporate 1 ,2 and cis and trans 1 ,4 noncyclic. m Oi CO CM m Rank Xerox (UK) Business Services EP 0 526 955 A1 This invention relates to a new, improved catalyst useful for the polymerization and copolymerization of olefins and particularly useful for the polymerization of ethylene and copolymerization of ethylene with 1- olefins having 3 or more carbon atoms such as, for example, propylene, i-butene, 1-butene, 1-pentene, 1- hexene, and 1-octene; dienes such is butadiene, 1 ,7-octadiene, and 1 ,4-hexadiene or cyclic olefins such as 5 norbornene. The invention particularly relates to a new and improved heterogeneous transition metal containing supported catalyst which can be employed without the use of an organometallic cocatalyst in the polymerization of olefins. The invention further generally relates to a process for polymerization of ethylene alone or with other 1 -olefins or diolefins in the presence of the new supported transition metal containing catalyst comprising the reaction product of a metallocene and an alumoxane in the presence of an support io material such as silica. Traditionally, ethylene and 1 -olefins have been polymerized or copolymerized in the presence of hydrocarbon insoluble catalyst systems comprising a transition metal compound and an aluminum alkyl. More recently, active homogeneous catalyst systems comprising a bis(cyclopentadienyl)titanium dialkyl or a bis(cyclopentadienyl)-zirconium dialkyl, an aluminum trialkyl and water have been found to be useful for the 75 polymerization of ethylene. Such catalyst systems are generally referred to as "Ziegler-type catalysts". German Patent Application 2,608,863 discloses the use of a catalyst system for the polymerization of ethylene consisting of bis (cyclopentadienyl) titanium dialkyl, aluminum trialkyl and water. German Patent Application 2,608,933 discloses an ethylene polymerization catalyst system consisting of zirconium metallocenes of the general formula (cyclopentadienyl)nZrY4.n, wherein n stands for a number 20 in the range of 1 to 4, Y for R, CH2AIR2,CH2CH2AIR2 and CH2(H(AIR2)2, wherein R stands for alkyl or metallo alkyl, and an aluminum trialkyl cocatalyst and water. European Patent Application No. 0035242 discloses a process for preparing ethylene and atactic propylene polymers in the presence of a halogen-free Ziegler catalyst system of (1) cyclopentadienyl compound of the formula (cyclopentadienyl)nMeY4.n in which n is an integer from 1 to 4, Me is a transition 25 metal, especially zirconium, and Y is either hydrogen, a C1-C5 alkyl or metallo alkyl group or a radical having the following general formula CH2AIR2, CH2CH2AIR2 and CH2CH(AIR2)2 in which R represents a C1- C5 alkyl or metallo alkyl group, and (2) an alumoxane. Additional teachings of homogeneous catalyst systems comprising a metallocene and alumoxane are European Patent Application 0069951 of Kaminsky et al, U.S. 4,404,344 issued September 13, 1983 of Sinn 30 et al., and U.S. Applications 697,308 filed February 1, 1985, 501,588 filed May 27, 1983, 728,111 filed April 29, 1985 and 501,740 filed June 6, 1983, each commonly assigned to Exxon Research and Engineering Company. An advantage of the metallocene alumoxane homogeneous catalyst system is the very high activity obtained for ethylene polymerization. Another significant advantage is, unlike olefin polymers produced in 35 the presence of conventional heterogeneous Ziegler catalysts, terminal unsaturation is present in polymers produced in the presence of these homogeneous catalysts. Nevertheless, the catalysts suffer from a disadvantage, that is, the ratio of alumoxane to metallocene is high, for example in the order of 1,000 to 1 or greater. Such voluminous amounts of alumoxane would require extensive treatment of polymer product obtained in order to remove the undesirable aluminum. A second disadvantage, of the homogeneous 40 catalyst system which is also associated with traditional heterogeneous Ziegler catalysts, is the multiple of delivery systems required for introducing the individual catalyst components into the polymerization reactor. It would be highly desirable to provide a metallocene based catalyst which is commercially useful for the polymerization of olefins wherein the aluminum to transition metal ratio is within respectable ranges and further to provide a polymerization catalyst which does not require the presence of a cocatalyst thereby 45 reducing the number of delivery systems for introducing catalyst into polymerization reactor. There exists a need for new ethylene polymer structures from various comonomers wherein new/improved properties are obtained. Prior art polymers have suffered from one or more difficulties affecting their physical properties. The difficulties include broadened molecular weight distributions, broadened composition distribution of 50 comonomer, and inefficient distribution or dispersion of the comonomer along the polyethylene chain of the copolymer. Broadened molecular weight distribution of a polymer strongly influences its melt flow properties and such polymers tend to have a high concentration of high molecular weight molecules making them subject to orientation. As a result, such resins produced strongly anisotropic physical properties in the machine 55 versus transverse direction of a fabrication process and such properties are detrimental to a number of end use applications. Broad molecular weight distribution resins also frequently contain a significant portion of quite low molecular weight material. These molecules almost invariably contain high concentrations of comonomer 2 EP 0 526 955 A1 and therefore tend to be amorphous or of a low degree of crystallinity. Consequently, these materials exude to the surface of fabricated parts causing tackiness where not desired and/or interfere with other additives in the polymer designed according to the particular application. An example of this is the surface active property associated with slip agents in blown or cast film. 5 Most prior art copolymers tend to have a very broad composition distribution of comonomer, i.e., the distribution of comonomer among the polymer molecules being nonuniform, some molecules having a relatively high concentration of comonomer while others have a relatively low concentration of comonomer. This structural property of the prior art polymers allows that portion with low comonomer content to have a high melting point and vice versa leading to a broad melting range for the entire polymer composition. Of io course the presence of a high melting component is disadvantageous for many applications where softness is desired and may lead to undesired stiffness. On the other hand, the presence of high comonomer content materials of low melting point frequently results in a high quantity of extractables. Prior art materials are generally characterized by relatively inefficient use of comonomer moieties along the polyethylene chains. The distribution of the comonomer along the chain is very important in determining is the efficiency of use of the comonomer and the resulting properties of the polymer, especially with respect to crystallizability of the polymer. Such prior art polymers tend to have a high degree of clustering of the comonomer moieties along the polyethylene chain. That is, the comonomer units are adjacent or non- isolated along the chain resulting in inefficient use of the comonomer since only a single polyethylene chain interruption results when several comonomer units are contiguous. This has extremely important implica- 20 tions in the total amount of comonomer required to achieve the desired crystallinity. Also, it is often disadvantageous to include unneeded portions of comonomer, especially when dealing with less available and more expensive diene comonomers. Frequently, the requirement to use a higher portion of comonomer also tends to force the comonomer into low molecular weight, high comonomer content ends of the molecular weight distribution. Accordingly, improved ethylene copolymers, terpolymers, and interpolymers 25 in the entire range of amorphous to highly crystalline polymers is needed. Even though recognized as desirable to incorporate a significant percentage of diene into an ethylene

View Full Text

Details

  • File Type
    pdf
  • Upload Time
    -
  • Content Languages
    English
  • Upload User
    Anonymous/Not logged-in
  • File Pages
    29 Page
  • File Size
    -

Download

Channel Download Status
Express Download Enable

Copyright

We respect the copyrights and intellectual property rights of all users. All uploaded documents are either original works of the uploader or authorized works of the rightful owners.

  • Not to be reproduced or distributed without explicit permission.
  • Not used for commercial purposes outside of approved use cases.
  • Not used to infringe on the rights of the original creators.
  • If you believe any content infringes your copyright, please contact us immediately.

Support

For help with questions, suggestions, or problems, please contact us