CA1124948A - Process for preparing a copolymer - Google Patents
Process for preparing a copolymerInfo
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- CA1124948A CA1124948A CA338,437A CA338437A CA1124948A CA 1124948 A CA1124948 A CA 1124948A CA 338437 A CA338437 A CA 338437A CA 1124948 A CA1124948 A CA 1124948A
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- magnesium
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- ethylene
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F210/16—Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
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- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process is provided herein for preparing an ethylene-?-olefin copolymer having a density of 0.850 to 0.945. In the process, ethylene and 1 to 40 mol% thereof of an ?-olefin having 5 to 18 carbon atoms are co-polymerized in a substantially solvent-free vapour phase condition and in the presence of a catalyst comprising a solid substance and an organo-aluminum compound, in which the solid substance contains magnesium and at least one of titanium and vanadium. The copolymer so produced is superior in transparency, appearance and gloss, and its flexibility and elasticity are excellent both at low temperatures and at room temperatures. Despite such an excellent flexibility, the resulting polymer exhibits equal or even superior strength to that of ordinary polyolefins. The copolymer is very superior in weathering- and chemicals-resistance, as well as having super-ior electrical characteristics, e g , dielectric loss, break-down voltage and resistivity. The copolymer exhibits very superior characteristics with respect to resistance to impact and to environmental stress cracking. The copolymer can be formed into films, sheets, hollow containers, electric wires and various other products by known forming methods, e.g., extrusion molding, blow molding, injection molding, press forming and vacuum forming.
Because of its excellent strength, elongation, transparency, anti-blocking property, heat-sealing property and flexibility, it provides good films.
Because of its low hexane extract, it can be safely used as a food packing film. Because of its transparency, stiffness and resistance to environ-mental stress cracking, it is also suited to blow molding. Because of its excellent electrical characteristics and easy application to extrusion molding, it can be used as an insulator for electric wires.
A process is provided herein for preparing an ethylene-?-olefin copolymer having a density of 0.850 to 0.945. In the process, ethylene and 1 to 40 mol% thereof of an ?-olefin having 5 to 18 carbon atoms are co-polymerized in a substantially solvent-free vapour phase condition and in the presence of a catalyst comprising a solid substance and an organo-aluminum compound, in which the solid substance contains magnesium and at least one of titanium and vanadium. The copolymer so produced is superior in transparency, appearance and gloss, and its flexibility and elasticity are excellent both at low temperatures and at room temperatures. Despite such an excellent flexibility, the resulting polymer exhibits equal or even superior strength to that of ordinary polyolefins. The copolymer is very superior in weathering- and chemicals-resistance, as well as having super-ior electrical characteristics, e g , dielectric loss, break-down voltage and resistivity. The copolymer exhibits very superior characteristics with respect to resistance to impact and to environmental stress cracking. The copolymer can be formed into films, sheets, hollow containers, electric wires and various other products by known forming methods, e.g., extrusion molding, blow molding, injection molding, press forming and vacuum forming.
Because of its excellent strength, elongation, transparency, anti-blocking property, heat-sealing property and flexibility, it provides good films.
Because of its low hexane extract, it can be safely used as a food packing film. Because of its transparency, stiffness and resistance to environ-mental stress cracking, it is also suited to blow molding. Because of its excellent electrical characteristics and easy application to extrusion molding, it can be used as an insulator for electric wires.
Description
112g9~8 This invention relates to a process for preparing a medium or low density ethylene copolymer according to the vapour phase polymeriza-tion procedure using a Ziegler-type catalyst of high activity.
Polyethylenes obtained by polymerization using a catalyst con-sisting of a transition metal compound and an organometallic compound are generally prepared according to the slurry polymerization process, and only those having a density not lower than 0.945 are produced, which value is considered to be the limit in order to prevent polymer deposition and fouling on the inner wall or stirrer in the reactor interior at the time of polymerization.
Medium or low density polyethylenes having a density below 0.945 g/cm are prepared mainly by the so-called high pressure process using a radical catalyst. Quite recently, high-temperature solution polymerizations using a Ziegler-type catalyst have also been tried. Copolymerizing ethylene and other -olefins using a catalyst containing a vanadium compound as one component has also been tried in order to prepare an elastomeric copolymer.
These polyolefin series plastics prepared according to the high pressure process or high-temperature solution polymerization using a Ziegler-type catalyst, and elastomers prepared using a vanadium compound-containing catalyst, exhibit superior performances and are used in variousapplications. For example, low density polyethylenes prepared according to the high pressure process are superior in transparency and flexibility, and so are used in the field of films. Elastomers resulting from the poly-merization of ethylene and propylene, or as the case may be, dienes, e.g., dicyclopentadiene and ethylidenenorbornene, using a vanadium-containin~
catalyst, namely EPM and EPDM, have no unsaturated bond in the main chain, for which reason they provide elastomers superior in heat- and weathering-resistance, and so are often used for tires and tubes.
However, polyethylenes prepared by the high pressure process are disadvantageous in that they have low melting point, and have low 11249~8 stiffness, that is, they are inferior in heat resistance, and also in strength. Medium density polyethylenes prepared according to the high-temperature solution polymerization process are inferior in transparency and give a sticky impression.
In order to provide an improvement in the resistance to environ-mental stress cracking, it is necessary to impart an elastomeric character to plastics. In order to take advantage of their thermoelasticity, it is necessary to impart strength based on crystallinity to elastomers. It is a well-known fact, however, that if both components are mixed together for such purpose, it will result in deterioration of some physical properties, e.g., tensile strength and rigidity.
However, if a soft or semi-hard resin is prepared, which resin itself is neither a crystalline plastic nor an elastomer, but has an intermediate structure and exhibits a high grade of elongation, then such resin itself will become suited for the above-mentioned purpose. It is also possible to blend it with other plastics, thereby imparting an elastomer character thereto and improving the properties of the plastics.
A production method has been reported for a resin which exhibits such an intermediate physical property. Many problems have to be solved before such production methods can be applied on an industrial scale.
For example, Japanese Patent Publication No. 11028/71 discloses a solution polymerization using an aromatic hydrocarbon solvent for the preparation of an ethylene-C~ -olefin copolymer. This method, however, suffers the disadvantage that the catalyst efficiency is poor and, because it is a solution polymerization, it is troublesome to separate and recover the solvent.
Japanese Patent Publication No.26185/72 proposes the copolymeriza-tion of ethylene and an ~ -olefin using an aliphatic hydrocarbon halide as a solvent. This method suffers the disadvantage that a large amount of a low molecular weight copolymer is produced, probably because the hydrocarbon llZ4948 halide solvent acts as a molecular weight adjuster, so that an article formed thereof is sticky on the surface. That patent publication also discloses the use of lower hydrocarbons of C3 to C5 as a solvent. In the polymerization using these solvents, however, it is necessary to raise the reaction pressure due to the vapour pressure from the solvents. In the solvent recovery step, moreover, it is necessary to compress and cool the solvent for its liquefaction.
Furthermore, in Japanese Patent Laying Open Print No. 41784/76, a slurry copolymerization of ethylene and butene-l is disclosed. In this case, there are found drawbacks exist, namely that the polymerization temperature and the composition of the starting materials must be specified very accurately and at values outside the specified range the slurry becomes milky or mushy, which makes reactor operation and slurry transport difficult.
The above-mentioned drawbacks are based on the low catalyst activity, the troublesomeness of solvent separation and recovery because of a solution polymerization, a large quantity production of a low mole-cular weight copolymer due to chain transfer with solvent, and the neces-sity of specifying the polymerization temperature and the composition of starting materials in slurry polymerization to maintain the slurried state of polymer. The need to provide an extremely large amount of comonomer is a further drawback encountered in the above-proposed methods.
Recently, it has been taught that a catalyst system prepared by first attaching a transition metal to a magnesium-containing solid carrier, e.g., MgO, Mg(OH)2, MgC12, MgCO3, or Mg(OH)Cl, and then combining it with an organometallic compound, can serve as a catalyst of a remarkably high activity in olefin polymerization. It is also known that the reaction product of an organomagnesium compound, e.g., RMgX, R2Mg or RMg(OR) and a transition metal compound can act as a high polymerization catalyst for olefins (see, for example, Japanese Patent Publication No. 12105/64, Belgian Patent No. 742,112, Japanese Patent Publications Nos. 13050/68 and 9548/70).
However, even if a slurry polymerization or solution polymeriza-tion is carried out using such a high activity catalyst with carrier with a view to attaining reduction in density of polymer, the foregoing drawbacks heretofore have not been completely solved.
By a broad aspect of this invention, a process is provided for preparing an ethylene-C~~olefin copolymer having a density of 0.850 to 0.945, which comprises copolymerizing ethylene and 1 to 40 mol% thereof of ~<-olefin having 5 to 18 carbon atoms in a substantially solvent-free vapour phase condition and in the presence of a catalyst comprising a solid sub-stance and an organoaluminum compound, the solid substance containing magnesium and at least one of titanium and vanadium.
By a variant thereof, the solid substance is obtained by attaching the at least one of a titanium compound ar.d a vanadium compound to the magnesium-containing inorganic solid carrier.
By another variant, the solid substance is a reaction product of the organoma~nesium compound and the at least one of a titanium compound and a vanadium compound.
By a variation thereof, the magnesium-containing inorganic solid carrier is selected from the group consisting of metallic magnesium, mag-nesium hydroxide, magnesium carbonate, magnesium oxide and magnesium chloride.
By a further variation, the magnesium-containing inorganic solid carrier is selected from the group consisting of a double salt, a double oxide, a carbonate, a chloride and a hydroxide containing magnesium atom and a metal selected from the group consisting of silicon, aluminum and calcium.
By still a further variation, the magnesium-containing inorganic solid carrier is further treated or reacted with a material selected from the group consisting of an oxygen-containing compound, a sulfur-containing 11249~8 compound, a hydrocarbon and a halogen-containing substance.
By yet another variation, the at least one of the titanium and the vanadium compound is a halide, alkoxyhalide, oxide or halogenated oxide of at least one of titanium and vanadium.
By a variation thereof, the organomagnesium compound is a compound represented by the general formula RMgX, R2Mg and RMg(OR), wherein R is an organic radical and X is halogen.
By another variation, the at least one of the titanium compound and the vanadium compound is used as the addition product with an organo-carboxylic acid ester in the preparation of the solid substance.
By yet another variation, the magnesium-containing inorganic solid carrier is contacted with an organocarboxylic acid ester before its use in the preparation of the solid substance.
By another variant, the organoaluminum compound is used as the addition product with an organocarboxylic acid ester.
By a further variant, the catalyst system is prèpared in the presence of an organocarboxylic acid ester.
By yet a further variant, the copolymerization is carried out at a temperature in the range of from 20 to 110C. and at a pressure in the range of from atmospheric to 70 kg/cm G.
By yet another variant, the copolymerization is carried out in the presence of hydrogen.
By a further variant, the catalyst system is contacted beforehand with an~C-olefin for 1 minute to 24 hours at a temperature in the range of from 0 to 200~C. and at a pressure in the range of from -1 to 100 kg/cm G, and thereafter the copolymerization is carried out.
By yet another variant, the CC-olefin to be copolymerized with ethylene is a member selected from the group consisting of pentene-l, hexene-l, 4-methylpentene-1, heptene-l, octene-l, nonene-l, decene-l, dodecene-l, tridecene-l, tetradecene-l, pentadecene-l, hexadecene-l, 1~24948 heptadecene-l, octadecene-l, and mixtures thereof.
Having made comprehensive studies about the foregoing technical problems, it has now been discoverecl that the various drawbacks associated with the solution or slurry polymerization, e.g., low polymerization activity, polymer adhesion, low bulk density and the production of coarse polymer particles, may be obviated by the process of aspects of this inven-tion. According to the process of an aspect of this invention, a vapour phase polymerization reaction can be conducted extremely stably, and be-sides, the catalyst removing step can be omitted. Accordingly, a vapour phase polymerization process is provided for the copolymerization of ethy-lene and an ~C-olefin having 5 to 18 carbon atoms which as a whole is very simple. Furthermore, the copolymer of ethylene and an ~ -olefin of C5 to C18 prepared according to the process of an aspect of this invention is very superior in strength, impact resistance, transparency and resistance to environmental stress cracking, though a detailed description on this respect will be given hereinafter.
In more particular terms, this invention thus provides a process for preparing an ethylene-~-olefin copolymer having a density of 0.850 to 0.945, wherein a mixture of ethylene and 1 to 40 mol% thereof of an ~-olefin having 5 to 18 carbon atoms is contacted in vapour phase condition with a catalyst comprising a solid substance and an organoaluminum compound, the solid substance containing magnesium and at least one of titanium and vanadium. It has been found that, according to the process of aspects of this invention, that is, i-f a vapour phase polymerization is carried out using ethylene and an ~-olefin of C5 to C18 in a quantitative ratio within the range specified herein and in the presence of a catalyst comprising a solid substance and an organoaluminum compound, the solid substance con-taining magnesium and at least one of titanium and vanadium, a vapour phase polymerization reaction is effected in extremely high activity and very stably. Despite the resulting polymer having stickiness, the process 11~49~8 provides a reduced production ratio of coarse or ultra-fine particles, improved particle properties, high bulk density and minimized adhesion to reactor and conglomeration of polymer particles. It is quite unexpected and surprising that, according to the process of aspects of this invention, not only can a vapour phase polymerization reaction be carried out extremely smoothly, but also medium and low density ethylene copolymers can be obtained easily.
In the process of aspects of this invention, moreover, the copolymerization reaction can be conducted even at a relatively low tem-perature easily to provide medium or low density ethylene polymers. Thisis very advantageous when viewed from the standpoint of adhesion to reactor and conglomeration of product. This point is also an advantage of the invention. Furthermore, the process of aspects of this invention easily provides medium or low density ethylene copolymers having a high melt index, and this point is another advantage of the invention. Because of these advantages, the copolymer can be obtained efficiently by vapour phase polymerization.
~ -olefins of C5 - C18 to be copolymerized with ethylene in the process of aspects of this invention function to adjust the density and molecular weight of copolymer, and the resulting copolymer is superior in transparency, appearance and gloss. Its flexibility and elasticity are excellent at low temperatures and at room temperatures. Despite such an excellent flexibility, the resulting polymer exhibits equal or even superior strength to that of ordinary polyolefins. The copolymer obtained according to the process of aspects of this invention contains few unsatu-rated bonds, residual catalyst or other impurities, and thus is very superior in weathering- and chemicals-resistance, as well as electrical characteristics, e.g., dielectric loss, break-down voltage and resistivity.
The copolymer exhibits very superior characteristics with respect to resis-tance to impact and to environmental stress cracking. Having these llZ4~48 characteristics, the copolymer prepared according to the process of aspectsof this invention can be formed into films, sheets, hollow containers, electric wires, and various other products by known forming procedures, e.g., extrusion moldingS blow molding, injection molding, press forming and vacuum forming. Films prepared from the copolymer have excellent strength, elongation, transparency, anti-blocking property, heat-sealing property and flexibility. What is worthy of special mention, however, is that according to the process of aspects of this invention, the hexane extract is very small in quantity and so a copolymer is provided which satisfies the "U.S. Food Medicines Adminstration Standard on Extracts to be Contacted with Food" (n-hexane extract at 50C. should be below 5.5% by weight), and the copolymer can be safely used as food packing film. Since the copolymer is superior in transparency, stiffness and resistance to environmental stress cracking, it is also suited to blow molding, Further-more, the copolymer is a very superior resin also for use as an electric wire because of excellent electrical characteristics and easy application to extrusion molding.
In addition, the copolymer prepared according to the process of aspects of this invention contains olefins as components, so is very similar in structure and composition to known polyolefin resins. It can be adjusted to be low in crystallinity, for which reason it is compatible with other polyolefin resins, and is specially compatible with high and low density polyethylene, polypropylene, and ethylene-vinyl acetate copolymers. By blending the copolymer with these resins, it is possible to improve resistance to impact, to cold and to environmental stress cracking.
The catalyst system used in the process of aspects of this inven-tion comprises the combination of a solid substance and an organoaluminum compound, the solid substance containing magnesium and at least one of titanium and vanadium. The solid substance is obtained by attaching at 11~4948 least one of a titanium compound and a vanadium compound, by a known pro-cedure, to an inorganic solid carrler typical of which are metallic magnesium, magnesium hydroxide,-magnesium carbonate, magnesium oxide and magnesium chloride; or double salts, double oxides, carbonates, chlorides, or hydroxides containing a metal selected from the group consisting of silicon, aluminum and calcium, and magnesium atoms; further, these inorganic solid carriers may be treated or reacted with an oxygen-containing compound, a sulfur-containing compound, a hydrocarbon or a halogen-containing sub~stance.
As the at least one of a titanium compound and a vanadium compound referred to herein,mention may be made of halides, alkoxyhalides, oxides and halogenated oxides of at least one of titanium and vanadium. Examples are tetravalent titanium compounds, e.g., titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, monoethoxytrichlorotitanium, diethoxy-dichlorotitanium, triethoxymonochlorotitanium, tetraethoxytitanium, mono-isopropoxytrichlorotitanium, diisopropoxydichlorotitanium and tetraiso-propoxytitanium; various titanium trihalides obtained by reducing titanium tetrahalides with hydrogen, aluminum, titanium or an organometallic com-pound; trivalent titanium compounds obtained by reducing various tetra-valent alkoxytitanium halides with an organometallic compound; tetravalent vanadium compounds, e.g., vanadium tetrachloride; pentavalent vanadium compounds, e.g., vanadium oxytrichloride and orthoalkylvanadate; and tri-valent vanadium compounds, e.g., vanadium trichloride and vanadium triethoxide.
Among these titanium compounds and vanadium compounds, tetravalent titanium compounds are especially preferred.
The catalyst which may be used in the process of aspects of this invention comprises the combination of a solid substance, which is obtained by attaching at least one of a titanium compound and a vanadium compound to the solid carrier exempllified previously, and an organoaluminum compound.
By way of illustrating preferred catalyst systems, mention may be made of the combination of an organoaluminum compound with the follow-ing solid substances (the R in the following formulae represents an organic radical and X represents halogen): MgO~RX-TiC14 system (see Japanese Patent Publication No. 3514/76), Mg-SiC14-ROH-TiC14 system (see Japanese Patent Publication No. 23864/75), MgC12-Al(OR)3-TiC14 system (see Japanese Patent Publications Nos. 152/76 and 15111/77), MgC12-SiC14-ROH-TiC14 system (see Japanese Patent Laying Open Print No.
196581/74), Mg(OOCR)2-Al(OR)3-TiC14 system (see Japanese Patent Publication No. 11710/77), Mg-POC13-TiC14 system (see Japanese Patent Publication No.
153/76), and MgC12-AlOCl-TiC14 system (see Japanese Patent ~aying Open Print No. 133386/76).
To illustrate another example of catalyst system which may be suitably used in the process of aspects of this invention, mention may be made of the combination of the reaction product of an organomagnesium com-pound, e.g, a Grignard compound and at least one of a titanium compound and a vanadium compound, and an organoaluminum compound. As the organo-magnesium compound there may be used those represented by the general formulae RMgX, R2Mg and RMg(OR) wherein R is an organic radical and X is halogen, and ether complexes thereof, or these organomagnesium compounds after modification with other organometallic compounds, e.g., organosodium, organolithium, organopotassium, organoboron, organocalcium and organozinc.
Such catalyst systems, for example, comprise the combination of the following solid substances and an organoaluminum compound;
RMgX-TiC14 system (see Japanese Patent Publication No. 39470/75), RMgX- Cl - ~ OH - TiC14 system (see Japanese Patent Laying Open Print No. 119977/74), RMgX- ~ OH - TiC14 system (see Japanese 11~4948 Patent Laying Open Print No. 119982/74).
In these catalyst systems, at least one of a titanium compound and a vanadium compound may be used as the addition product with an organo-carboxylic acid ester. Furthermore, the magnesium-containing solid carriers previously exemplified may be contacted, before use, with an organocar-boxylic acid ester. Also an organoaluminum compound may be used as the addition product with an organocarboxylic acid ester. Furthermore, in every case in the process of aspects of this invention, the catalyst systems used therein may be prepared in the presence of an organocarboxylic acid ester and this causes no troublè.
As the organocarboxylic acid ester referred to herein. there may be employed various aliphatic, alicyclic and aromatic carboxylic acid esters, preferably aromatic carboxylic acids of C7 to C12, e.g., alkyl-esters, e.g., methyl and ethyl of benzoic acid, anisic acid and toluic acid.
Examples of organoaluminum compounds which may be used in the process of aspects of this invention are those represented by the general formulae R3Al, R2AlX, RAlX2, R2AlOR, RAl(OR)X and R3A12X3 wherein R is Cl to C20 alkyl or aryl, X is halogen and R may be the same or different, e.g., triethylaluminum, triisobutylaluminum, trihexylaluminum, tricotylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, and mixtures thereof.
The amount of an organoaluminum compound to be used in the process of aspects of this invention is not specially limited, but usually it may range from 0.1 to 1000 mols per mol of a transition metal compound.
In the polymerization reaction, a mixture of ethylene and an -olefin of C5 to C18 is allowed to polymerize in the vapour phase using a known reactor, e.g., a fluidized bed or agitation vessel.
The polymerization conditions involve temperatures ranging usually from 20 to 110C., preferably from 50 to 100C., and pressures from atmospheric pressure to 70 kg/cm G, preferably from 2 to 60 kg/cm G.
11249~8 Adjustment of the molecular weight can be made by changing the polymeriza-tion temperature, the molar ratio of catalyst or the amount of comonomer, but the addition of hydrogen into the polymerization system is more effec-tive for this purpose. Of cource, the process of aspects of this invention can be applied, without any trouble, to two or more stage polymerization reactions involving different polymerization conditions, e.g., different hydrogen and comonomer concentrations and different polymerization tempera-tures.
In the process of aspects of this invention, moreover, the fore-going catalyst system may be contacted with an ~-olefin before its use in the vapour phase polymerization reaction whereby it is possible to improve the polymerization activity and to assure a more stable operation than in the untreated condition. Various <-olefins are employable in the above treatment, preferably those having 3 to 12 carbon atoms and more preferably those having 3 to 8 carbon atoms, typical of which are propylene, butene-l, pentene-l, 4-methylpentene-1, heptene-l, hexene-l, octene-l, and mixtures thereof. The temperature and time for such contact treatment for the cata-lyst used in the process of aspects of this invention with an ~-olefin can be selected in wide range, for example, 0 to 200C., preferably 0 to 110 110C., and 1 minute to 24 hours.
The amount of an ~ -olefin to be brought into contact with the catalyst can also be selected in wide range, but usually it ranges from 1 g to 50,000 g, preferably 5 g to-30,000 g, per gram of the solid substance and it is desired that 1 g to 500 g of the o~-olefin per gram of the solid substance be reacted. The pressure in such contact treatment can be optionally selected, but desirably it ranges from -1 to 100 kg/cm G.
In the above treatment of the catalyst with an ~-olefin, the total amount of an organoaluminum compound may be first combined with the solid substance and then contacted with the c~-olefin or alternatively part of the organoaluminum compound may be combined with the solid substance, l~Z49~
then contacted with the ~-olefin and the remaining portion of the organo-aluminum compound may be separately added in the vapour phase polymeriza-tion of ethylene. Furthermore, the catalyst may be contacted with an C-olefin in the presence of hydrogen gas, or other inert gas, e.g., nitrogen, argon or helium.
c~ -olefins to be copolymerized with ethylene in the process of aspects of this invention are those having 5 to 18 carbon atoms and they may be of a straight chain or branched. Examples are pentene-l, hexene-l, 4-methylpentene-1, heptene-l, octene-l, none-l, decene-l, undecene-l, dodecene-l, tridecene-l, tetradecene-l, pentadecene-l, hexadecene-l, hepta-decene-l, octadecene-l and mixtures thereof.
The amount of an ~ -olefin to be copolymerized with ethylene in the process of aspects of this invention should be in the range of from 1 to 40 mol% based on the amount of ethylene. Outside this range, it is impossible to obtain the product of aspects of this invention, namely an ethylene- ~-olefin copolymer having a density of 0.850 to 0.945. The amount of such ~<-olefin can be adjusted easily according to the composition ratio of the vapour phase in the polymerization vessel.
In the process of aspects of this invention, moreover, various dienes may be added as termonomers in the copolymerization reaction, e.g., butadiene, 1,4-hexadiene, 1,5-hexadiene, vinylnorbornene, ethylidenenorb-ornene and dicyclopentadiene.
Working examples of aspects of this invention are described below, but it is to be understood that these examples are for the purpose of illustrating the operation of the invention.
Example 1 1 kg of anhydrous magnesium chloride, 50 g of 1,2-dichloroethane and 170 g of titanium tetrachloride were subjected to ball milling for 16 hours at room temperature in a nitrogen atmosphere to allow the titanium compound to be attached to the carrier. The resulting solid substance 11;~4948 contained 35 mg of titanium per gram thereof.
A stainless steel autoclave was used as the apparatus for the vapour phase polymerization, and there were used a blower, a flow rate adjuster and a dry cyclone to form a loop, and the temperature of the autoclave was adjusted by passing warm water through the jacket.
To the autoclave adjusted to 85C. were fed the solid substance prepared above and triethylaluminum at the rates of 250 mg/hr and 50 mmol/hr, respectively, and also introduced were ethylene, 4-methylpentene-1 and hydrogen while making adjustment so that the 4-methylpentene-1/ethylene ratio (in molar ratio) in the vapour phase in the autoclave was 0.035 and the hydrogen gas pressure was 22% of the total pressure, and a polymeriza-tion was made while the gases in the system were circulated by the blower.
The resulting ethylene copolymer had a bulk density of 0.395, a melt index (MI) of 1.4 and a density of 0.930~ the greater part of which was composed of powders with particle sizes in the range of from 250 to 500~. The polymerization activity was high, 173,500 g copolymer/g Ti.
After continuous operation for 10 hours, the autoclave was opened and its interior was checked to find it was clean with no polymer adhesion to the inner wall and stirrer. That is, it is apparent that a very stable operation is assured according to the process of an aspect of this invention, though it was unattainable in the slurry polymeri~ation shown in Comparative Example 1 as will be referred to hereinafter.
The resulting copolymer was formed into a film 400 mm in fold diameter by 30~u thick through a 75 mm~ inflation film forming die in a 50 mm~ extruder, which film was superior in strength and in transparency.
The film was subjected to extraction with hexane at 50C. for 4 hours to give 2.10% extract.
Comparative Example 1 Using the same catalyst as that used in Example 1 and hexane as solvent, a continuous slurry polymerization was conducted at 85C.
11~4948 Hexane as polymerization solvent containing 5 mg/~ of the solid catalyst and 1 mmol/~ of triethylaluminum was fed at the rate of 40 ~/hr, and also fed were ethylene, 4-methylpentene-1 (20 mol% of ethylene) and hydrogen at the rates of 10 kg/hr, 6 kg/hr and 2Nm3/hr, respectively, and a continuous polymerization was made on condition that the residence time was 1 hour. The resulting copolymer was continuously withdrawn as slurry.
In 3 hours, the polymer slurry withdrawing pipe was obturated and the polymerization was compelled to be discontinued.
The interior of the reactor was checked to find that the hexane layer was emulsified and a large amount of a rubbery polymer adhered to the gas-liquid interface and also to the polymer withdrawing pipe.
The copolymer prepared above had a bulk density of 0.248, MI of 0.74 and a density of 0.932.
Example 2 Polymerization was carried out in the same manner as in Example 1 except that the 4-methylpentene-1/ethylene ratio was 0.14 and the hydrogen gas pressure was 15% of the total pressure.
The resulting ethylene copolymer had a MI of 2.3, a bulk density of 0.384 and a density of 0.896, and the polymerization activity was 147,000 g copolymer/g Ti.
After continuous operation for 10 hours, the interior of the reactor was checked to find no polymer adhesion to the inner wall and stirrer.
The copolymer after subjected to press forming was transparent, having a breaking point strength of 193 kg/cm2 and an elongation of 630%.
Example 3 Polymerization was carried out in the same manner as in Example 1 except that hexene-l was used in place of 4-methylpentene-1.
The resulting ethylene copolymer had a bulk density of 0.399, MI
of 1.3 and a density of 0.933, and the polymerization activity was 186,500 1124'9~8 g copolymer/g Ti.
After continuous operation for 10 hours, the polymerization was discontinued and the reactor inside was checked to find no polymer adhesion.
The resulting polymer was formed into an inflation film 30~u thick, which film was superior in strength and in transparency. The hexane extract of the film was 0.17%.
Example 4 830 g of anhydrous magnesium chloride, 50 g of aluminum oxychlor-ide and 170 g of titanium tetrachloride were subjected to ball milling for 16 hours at room temperature in a nitrogen atomsphere. The resulting solid substance contained 41 mg of titanium per gram thereof.
The solid substance prepared above and triethylaluminum were fed at the rates of 200 mg/hr and 50 mmol/hr, respectively, and a polymeriza-tion was made at 85C. in the same way as in Example 1, with the proviso that the comonomer to be copolymerized was hexene-l, the hexene-l/ethylene ratio in the vapour phase was 0.07 and the hydrogen gas pressure was 16%
of the total pressure.
After continuous operation for 10 hours, the interior of the autoclave was checked to find no polymer adhesion.
The resulting copolymer had a bulk density of 0.408, MI of 1.1 and a density of 0.915, and the polymerization activity was very high, 194,500 g ethylene-copolymer/g Ti.
The copolymer was fDrmed into a film 400 mm in fold diamter by 30J~ thick in the same manner as in Example 1, which film was superior in both strength and transparency. The hexane extract of the film was 0.36%.
Comparative Example 2 Using the same catalyst as that used in Example 2 and n-paraffin as solvent, a solution polymerization was carried out. That is, n-paraffin containing 25 mg/~ of the solid substance prepared in Example 2 and 5 mmol/~ of triethylaluminum was fed at the rate of 40Q /hr, and also ~lZ49~8 fed were ethylene, hexene-l and hydrogen at the rates of 10 kg/hr, 6 kg/hr and 550 N~ /hr, respectively and a continuous polymerization was made at 160C. on condition that the residence time was 1 hour. The resulting ethylene copolymer had a MI of 0.34 and a density of 0.947, and the poly-merization activity was 7,800 g copolymer/g Ti.
Thus in the case of a solution polymerization, despite a large amount of hexene-l used, the polymer density is not lowered so much and the polymerization activity is low, it being apparent that this is an example of inefficient polymerization.
Example 5 Copolymerization was carried out in the same manner as in Example 4 except that the hexene-l/ethylene ratio was 0.28 and the hydrogen gas pressure was 10% of the total pressure.
The resulting ethylene copolymer had a MI of 1.9, a bulk density of 0.379 and a density of 0.870, and the polymerization activity was 171,000 g copolymer/g Ti.
In 10 hours, the supply of the starting gases was stopped to terminate the polymerization reaction and the reactor inside was checked to find no polymer adhesion therein.
The resulting ethylene-hexene-l copolymer was subjected to press forming and the formed article was high in transparency, having a breaking point strength of 180 kg/cm and an elongation of 650%.
Example 6 A continuous polymerization was carried out in the same manner as in Example 4 except that an equimixture of hexene-l, octene-l and decene-l (trade name "DIALEN 610") was used as comonomer in place of hexene-l.
The resulting ethylene copolymer had a bulk density of 0.395, MI of 1.2 and a density of 0.918, and the polymerization activity was 190,300 g copolymer/g Ti.
1~24948 The copolymer was formed into an inflation film 30 ~ thick in the same way as in Example 1, which film was superior in both strength and stiffness and was high in transparency. The hexane extract of the film was 0.73%.
Example 7 830 g of anhydrous magnesium chloride, 120 g of anthracene and 170 g of titanium tetrachloride were subjected to ball milling in the same manner as in Example 1 to give a solid substance, which contained 40 mg of titanium per gram thereof.
Using the same apparatus as that used in Example 1, and at 80C.
there were fed the solid substance obtained above and triisobutylaluminum at the rates of 500 mg/hr and 150 mmol/hr, respectively, and also fed were DIALEN 610 (the trade name for an equimixture of hexene-l, octene-l and decene-l) as comonomer, ethylene and hydrogen while making adjustment so that the comonomer/ethylene ratio in the vapour phase was 0.14 and the hydrogen gas pressure was 15% of the total pressure.
The polymerization was continued stably for 10 hours, then the autoclave was opened and the reactor inside was checked to find no polymer adhesion therein.
The polymerization activty was 143,000 g copolymer/g Ti, and the resulting polymer had a bulk density of 0.394, MI of 2.6 and a density of 0.909.
The polymer was formed into an inflation film, which film was superior in both stiffness and transparency. The hexane extract of the film was 2.6%.
Example 8 Polymerization was carried out in the same manner as in Example 7 with the proviso that the polymerization temperature, the DIALEN 610/
ethylene ratio and the hydrogen gas pressure were adjusted to 85C., 0.07 and 30% of the total pressure, respectively.
llZ4~48 After continuous operation for 10 hours, the polymerization was discontinued and the interior of the autocalve was checked to find it was clean with no polymer adhesion therein.
The resulting copolymer had a bulk density of 0.395, MI of 6.4 and a density of 0.917, and the polymerization activity was 128,000 g copolymer/g Ti.
Example 9 Using the same catalyst as that used in Example 7, there was conducted polymerization in the same manner as in Example 7 with the pro-viso that dodecene was used in place of DIALEN 610 and the dodecene/ethy-lene ratio and the hydrogen gas pressure were adjusted to 0.25 and 10% of the total pressure, respectively.
The polymerization was continued for 10 hours without any trouble.
After termination of the reaction, the interior of the autoclave was checked to find no polymer adhesion therein.
The resulting copolymer had a bulk density of 0.389, MI of 1.9 and a density of 0.881, and the polymerization activity was 110,300 g copolymer/g Ti.
The copolymer after subjected to press forming was transparent and had a breaking point strength of 185 kg/cm2, an elongation of 700%.
Example 10 400 g of magnesium oxide and 1,300 g of anhydrous aluminum chloride were reacted together at 300C. for 4 hours, and 950 g of the reaction product and 170 g of titanium tetrachloride were treated in the same way as in Example 1 to give a solid substance, which contained 3 mg of titanium per gram thereof.
Using the same apparatus as that used in Example 1, there were fed as catalyst the solid substance prepared above and triisobutylaluminum at the rates of 500 mg/hr and 250 mmol/hr, respectively, and a polymeriza-tion was made at 85C. while there were circulated a mixed gas consisting llZ49~
of ethylene and 12% thereof in the vapour phase of 4-methylpentene-1 and hydrogen gas adjusted to 9% of the total pressure.
Af ter continuous operation for 18 hours, the reactor inside was checked to find no polymer adhesion therein.
The resulting copolymer had a bulk density of 0.443, MI of 0.68 and a density of 0.918, composed of oval particles of a narrow particle size distribution with an average particle diameter of 500JU. The poly-merization activity was 179,000 g copolymer/g Ti.
The copolymer, without pelletizing, was formed into a hollow 600 cc bottle by means of a high-speed blow molding machine, which bottle had a clean surface with no drawn-down observed.
Example ll Polymerization was carried out in the same manner as in Example 10 with the limitation that the proportion of 4-methylpentene-1 to ethylene was 5.5% and the hydrogen gas pressure was 30% of the total pressure.
In 10 hours, the polymerization was discontinued and the interior of the polymerization vessel was checked to find no polymer adhesion therein.
The resulting copolymer had a bulk density of 0.375, MI of 4.3 and a density of 0.930, and the polymerization activity was 181,000 g copolymer/g Ti.
Polyethylenes obtained by polymerization using a catalyst con-sisting of a transition metal compound and an organometallic compound are generally prepared according to the slurry polymerization process, and only those having a density not lower than 0.945 are produced, which value is considered to be the limit in order to prevent polymer deposition and fouling on the inner wall or stirrer in the reactor interior at the time of polymerization.
Medium or low density polyethylenes having a density below 0.945 g/cm are prepared mainly by the so-called high pressure process using a radical catalyst. Quite recently, high-temperature solution polymerizations using a Ziegler-type catalyst have also been tried. Copolymerizing ethylene and other -olefins using a catalyst containing a vanadium compound as one component has also been tried in order to prepare an elastomeric copolymer.
These polyolefin series plastics prepared according to the high pressure process or high-temperature solution polymerization using a Ziegler-type catalyst, and elastomers prepared using a vanadium compound-containing catalyst, exhibit superior performances and are used in variousapplications. For example, low density polyethylenes prepared according to the high pressure process are superior in transparency and flexibility, and so are used in the field of films. Elastomers resulting from the poly-merization of ethylene and propylene, or as the case may be, dienes, e.g., dicyclopentadiene and ethylidenenorbornene, using a vanadium-containin~
catalyst, namely EPM and EPDM, have no unsaturated bond in the main chain, for which reason they provide elastomers superior in heat- and weathering-resistance, and so are often used for tires and tubes.
However, polyethylenes prepared by the high pressure process are disadvantageous in that they have low melting point, and have low 11249~8 stiffness, that is, they are inferior in heat resistance, and also in strength. Medium density polyethylenes prepared according to the high-temperature solution polymerization process are inferior in transparency and give a sticky impression.
In order to provide an improvement in the resistance to environ-mental stress cracking, it is necessary to impart an elastomeric character to plastics. In order to take advantage of their thermoelasticity, it is necessary to impart strength based on crystallinity to elastomers. It is a well-known fact, however, that if both components are mixed together for such purpose, it will result in deterioration of some physical properties, e.g., tensile strength and rigidity.
However, if a soft or semi-hard resin is prepared, which resin itself is neither a crystalline plastic nor an elastomer, but has an intermediate structure and exhibits a high grade of elongation, then such resin itself will become suited for the above-mentioned purpose. It is also possible to blend it with other plastics, thereby imparting an elastomer character thereto and improving the properties of the plastics.
A production method has been reported for a resin which exhibits such an intermediate physical property. Many problems have to be solved before such production methods can be applied on an industrial scale.
For example, Japanese Patent Publication No. 11028/71 discloses a solution polymerization using an aromatic hydrocarbon solvent for the preparation of an ethylene-C~ -olefin copolymer. This method, however, suffers the disadvantage that the catalyst efficiency is poor and, because it is a solution polymerization, it is troublesome to separate and recover the solvent.
Japanese Patent Publication No.26185/72 proposes the copolymeriza-tion of ethylene and an ~ -olefin using an aliphatic hydrocarbon halide as a solvent. This method suffers the disadvantage that a large amount of a low molecular weight copolymer is produced, probably because the hydrocarbon llZ4948 halide solvent acts as a molecular weight adjuster, so that an article formed thereof is sticky on the surface. That patent publication also discloses the use of lower hydrocarbons of C3 to C5 as a solvent. In the polymerization using these solvents, however, it is necessary to raise the reaction pressure due to the vapour pressure from the solvents. In the solvent recovery step, moreover, it is necessary to compress and cool the solvent for its liquefaction.
Furthermore, in Japanese Patent Laying Open Print No. 41784/76, a slurry copolymerization of ethylene and butene-l is disclosed. In this case, there are found drawbacks exist, namely that the polymerization temperature and the composition of the starting materials must be specified very accurately and at values outside the specified range the slurry becomes milky or mushy, which makes reactor operation and slurry transport difficult.
The above-mentioned drawbacks are based on the low catalyst activity, the troublesomeness of solvent separation and recovery because of a solution polymerization, a large quantity production of a low mole-cular weight copolymer due to chain transfer with solvent, and the neces-sity of specifying the polymerization temperature and the composition of starting materials in slurry polymerization to maintain the slurried state of polymer. The need to provide an extremely large amount of comonomer is a further drawback encountered in the above-proposed methods.
Recently, it has been taught that a catalyst system prepared by first attaching a transition metal to a magnesium-containing solid carrier, e.g., MgO, Mg(OH)2, MgC12, MgCO3, or Mg(OH)Cl, and then combining it with an organometallic compound, can serve as a catalyst of a remarkably high activity in olefin polymerization. It is also known that the reaction product of an organomagnesium compound, e.g., RMgX, R2Mg or RMg(OR) and a transition metal compound can act as a high polymerization catalyst for olefins (see, for example, Japanese Patent Publication No. 12105/64, Belgian Patent No. 742,112, Japanese Patent Publications Nos. 13050/68 and 9548/70).
However, even if a slurry polymerization or solution polymeriza-tion is carried out using such a high activity catalyst with carrier with a view to attaining reduction in density of polymer, the foregoing drawbacks heretofore have not been completely solved.
By a broad aspect of this invention, a process is provided for preparing an ethylene-C~~olefin copolymer having a density of 0.850 to 0.945, which comprises copolymerizing ethylene and 1 to 40 mol% thereof of ~<-olefin having 5 to 18 carbon atoms in a substantially solvent-free vapour phase condition and in the presence of a catalyst comprising a solid sub-stance and an organoaluminum compound, the solid substance containing magnesium and at least one of titanium and vanadium.
By a variant thereof, the solid substance is obtained by attaching the at least one of a titanium compound ar.d a vanadium compound to the magnesium-containing inorganic solid carrier.
By another variant, the solid substance is a reaction product of the organoma~nesium compound and the at least one of a titanium compound and a vanadium compound.
By a variation thereof, the magnesium-containing inorganic solid carrier is selected from the group consisting of metallic magnesium, mag-nesium hydroxide, magnesium carbonate, magnesium oxide and magnesium chloride.
By a further variation, the magnesium-containing inorganic solid carrier is selected from the group consisting of a double salt, a double oxide, a carbonate, a chloride and a hydroxide containing magnesium atom and a metal selected from the group consisting of silicon, aluminum and calcium.
By still a further variation, the magnesium-containing inorganic solid carrier is further treated or reacted with a material selected from the group consisting of an oxygen-containing compound, a sulfur-containing 11249~8 compound, a hydrocarbon and a halogen-containing substance.
By yet another variation, the at least one of the titanium and the vanadium compound is a halide, alkoxyhalide, oxide or halogenated oxide of at least one of titanium and vanadium.
By a variation thereof, the organomagnesium compound is a compound represented by the general formula RMgX, R2Mg and RMg(OR), wherein R is an organic radical and X is halogen.
By another variation, the at least one of the titanium compound and the vanadium compound is used as the addition product with an organo-carboxylic acid ester in the preparation of the solid substance.
By yet another variation, the magnesium-containing inorganic solid carrier is contacted with an organocarboxylic acid ester before its use in the preparation of the solid substance.
By another variant, the organoaluminum compound is used as the addition product with an organocarboxylic acid ester.
By a further variant, the catalyst system is prèpared in the presence of an organocarboxylic acid ester.
By yet a further variant, the copolymerization is carried out at a temperature in the range of from 20 to 110C. and at a pressure in the range of from atmospheric to 70 kg/cm G.
By yet another variant, the copolymerization is carried out in the presence of hydrogen.
By a further variant, the catalyst system is contacted beforehand with an~C-olefin for 1 minute to 24 hours at a temperature in the range of from 0 to 200~C. and at a pressure in the range of from -1 to 100 kg/cm G, and thereafter the copolymerization is carried out.
By yet another variant, the CC-olefin to be copolymerized with ethylene is a member selected from the group consisting of pentene-l, hexene-l, 4-methylpentene-1, heptene-l, octene-l, nonene-l, decene-l, dodecene-l, tridecene-l, tetradecene-l, pentadecene-l, hexadecene-l, 1~24948 heptadecene-l, octadecene-l, and mixtures thereof.
Having made comprehensive studies about the foregoing technical problems, it has now been discoverecl that the various drawbacks associated with the solution or slurry polymerization, e.g., low polymerization activity, polymer adhesion, low bulk density and the production of coarse polymer particles, may be obviated by the process of aspects of this inven-tion. According to the process of an aspect of this invention, a vapour phase polymerization reaction can be conducted extremely stably, and be-sides, the catalyst removing step can be omitted. Accordingly, a vapour phase polymerization process is provided for the copolymerization of ethy-lene and an ~C-olefin having 5 to 18 carbon atoms which as a whole is very simple. Furthermore, the copolymer of ethylene and an ~ -olefin of C5 to C18 prepared according to the process of an aspect of this invention is very superior in strength, impact resistance, transparency and resistance to environmental stress cracking, though a detailed description on this respect will be given hereinafter.
In more particular terms, this invention thus provides a process for preparing an ethylene-~-olefin copolymer having a density of 0.850 to 0.945, wherein a mixture of ethylene and 1 to 40 mol% thereof of an ~-olefin having 5 to 18 carbon atoms is contacted in vapour phase condition with a catalyst comprising a solid substance and an organoaluminum compound, the solid substance containing magnesium and at least one of titanium and vanadium. It has been found that, according to the process of aspects of this invention, that is, i-f a vapour phase polymerization is carried out using ethylene and an ~-olefin of C5 to C18 in a quantitative ratio within the range specified herein and in the presence of a catalyst comprising a solid substance and an organoaluminum compound, the solid substance con-taining magnesium and at least one of titanium and vanadium, a vapour phase polymerization reaction is effected in extremely high activity and very stably. Despite the resulting polymer having stickiness, the process 11~49~8 provides a reduced production ratio of coarse or ultra-fine particles, improved particle properties, high bulk density and minimized adhesion to reactor and conglomeration of polymer particles. It is quite unexpected and surprising that, according to the process of aspects of this invention, not only can a vapour phase polymerization reaction be carried out extremely smoothly, but also medium and low density ethylene copolymers can be obtained easily.
In the process of aspects of this invention, moreover, the copolymerization reaction can be conducted even at a relatively low tem-perature easily to provide medium or low density ethylene polymers. Thisis very advantageous when viewed from the standpoint of adhesion to reactor and conglomeration of product. This point is also an advantage of the invention. Furthermore, the process of aspects of this invention easily provides medium or low density ethylene copolymers having a high melt index, and this point is another advantage of the invention. Because of these advantages, the copolymer can be obtained efficiently by vapour phase polymerization.
~ -olefins of C5 - C18 to be copolymerized with ethylene in the process of aspects of this invention function to adjust the density and molecular weight of copolymer, and the resulting copolymer is superior in transparency, appearance and gloss. Its flexibility and elasticity are excellent at low temperatures and at room temperatures. Despite such an excellent flexibility, the resulting polymer exhibits equal or even superior strength to that of ordinary polyolefins. The copolymer obtained according to the process of aspects of this invention contains few unsatu-rated bonds, residual catalyst or other impurities, and thus is very superior in weathering- and chemicals-resistance, as well as electrical characteristics, e.g., dielectric loss, break-down voltage and resistivity.
The copolymer exhibits very superior characteristics with respect to resis-tance to impact and to environmental stress cracking. Having these llZ4~48 characteristics, the copolymer prepared according to the process of aspectsof this invention can be formed into films, sheets, hollow containers, electric wires, and various other products by known forming procedures, e.g., extrusion moldingS blow molding, injection molding, press forming and vacuum forming. Films prepared from the copolymer have excellent strength, elongation, transparency, anti-blocking property, heat-sealing property and flexibility. What is worthy of special mention, however, is that according to the process of aspects of this invention, the hexane extract is very small in quantity and so a copolymer is provided which satisfies the "U.S. Food Medicines Adminstration Standard on Extracts to be Contacted with Food" (n-hexane extract at 50C. should be below 5.5% by weight), and the copolymer can be safely used as food packing film. Since the copolymer is superior in transparency, stiffness and resistance to environmental stress cracking, it is also suited to blow molding, Further-more, the copolymer is a very superior resin also for use as an electric wire because of excellent electrical characteristics and easy application to extrusion molding.
In addition, the copolymer prepared according to the process of aspects of this invention contains olefins as components, so is very similar in structure and composition to known polyolefin resins. It can be adjusted to be low in crystallinity, for which reason it is compatible with other polyolefin resins, and is specially compatible with high and low density polyethylene, polypropylene, and ethylene-vinyl acetate copolymers. By blending the copolymer with these resins, it is possible to improve resistance to impact, to cold and to environmental stress cracking.
The catalyst system used in the process of aspects of this inven-tion comprises the combination of a solid substance and an organoaluminum compound, the solid substance containing magnesium and at least one of titanium and vanadium. The solid substance is obtained by attaching at 11~4948 least one of a titanium compound and a vanadium compound, by a known pro-cedure, to an inorganic solid carrler typical of which are metallic magnesium, magnesium hydroxide,-magnesium carbonate, magnesium oxide and magnesium chloride; or double salts, double oxides, carbonates, chlorides, or hydroxides containing a metal selected from the group consisting of silicon, aluminum and calcium, and magnesium atoms; further, these inorganic solid carriers may be treated or reacted with an oxygen-containing compound, a sulfur-containing compound, a hydrocarbon or a halogen-containing sub~stance.
As the at least one of a titanium compound and a vanadium compound referred to herein,mention may be made of halides, alkoxyhalides, oxides and halogenated oxides of at least one of titanium and vanadium. Examples are tetravalent titanium compounds, e.g., titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, monoethoxytrichlorotitanium, diethoxy-dichlorotitanium, triethoxymonochlorotitanium, tetraethoxytitanium, mono-isopropoxytrichlorotitanium, diisopropoxydichlorotitanium and tetraiso-propoxytitanium; various titanium trihalides obtained by reducing titanium tetrahalides with hydrogen, aluminum, titanium or an organometallic com-pound; trivalent titanium compounds obtained by reducing various tetra-valent alkoxytitanium halides with an organometallic compound; tetravalent vanadium compounds, e.g., vanadium tetrachloride; pentavalent vanadium compounds, e.g., vanadium oxytrichloride and orthoalkylvanadate; and tri-valent vanadium compounds, e.g., vanadium trichloride and vanadium triethoxide.
Among these titanium compounds and vanadium compounds, tetravalent titanium compounds are especially preferred.
The catalyst which may be used in the process of aspects of this invention comprises the combination of a solid substance, which is obtained by attaching at least one of a titanium compound and a vanadium compound to the solid carrier exempllified previously, and an organoaluminum compound.
By way of illustrating preferred catalyst systems, mention may be made of the combination of an organoaluminum compound with the follow-ing solid substances (the R in the following formulae represents an organic radical and X represents halogen): MgO~RX-TiC14 system (see Japanese Patent Publication No. 3514/76), Mg-SiC14-ROH-TiC14 system (see Japanese Patent Publication No. 23864/75), MgC12-Al(OR)3-TiC14 system (see Japanese Patent Publications Nos. 152/76 and 15111/77), MgC12-SiC14-ROH-TiC14 system (see Japanese Patent Laying Open Print No.
196581/74), Mg(OOCR)2-Al(OR)3-TiC14 system (see Japanese Patent Publication No. 11710/77), Mg-POC13-TiC14 system (see Japanese Patent Publication No.
153/76), and MgC12-AlOCl-TiC14 system (see Japanese Patent ~aying Open Print No. 133386/76).
To illustrate another example of catalyst system which may be suitably used in the process of aspects of this invention, mention may be made of the combination of the reaction product of an organomagnesium com-pound, e.g, a Grignard compound and at least one of a titanium compound and a vanadium compound, and an organoaluminum compound. As the organo-magnesium compound there may be used those represented by the general formulae RMgX, R2Mg and RMg(OR) wherein R is an organic radical and X is halogen, and ether complexes thereof, or these organomagnesium compounds after modification with other organometallic compounds, e.g., organosodium, organolithium, organopotassium, organoboron, organocalcium and organozinc.
Such catalyst systems, for example, comprise the combination of the following solid substances and an organoaluminum compound;
RMgX-TiC14 system (see Japanese Patent Publication No. 39470/75), RMgX- Cl - ~ OH - TiC14 system (see Japanese Patent Laying Open Print No. 119977/74), RMgX- ~ OH - TiC14 system (see Japanese 11~4948 Patent Laying Open Print No. 119982/74).
In these catalyst systems, at least one of a titanium compound and a vanadium compound may be used as the addition product with an organo-carboxylic acid ester. Furthermore, the magnesium-containing solid carriers previously exemplified may be contacted, before use, with an organocar-boxylic acid ester. Also an organoaluminum compound may be used as the addition product with an organocarboxylic acid ester. Furthermore, in every case in the process of aspects of this invention, the catalyst systems used therein may be prepared in the presence of an organocarboxylic acid ester and this causes no troublè.
As the organocarboxylic acid ester referred to herein. there may be employed various aliphatic, alicyclic and aromatic carboxylic acid esters, preferably aromatic carboxylic acids of C7 to C12, e.g., alkyl-esters, e.g., methyl and ethyl of benzoic acid, anisic acid and toluic acid.
Examples of organoaluminum compounds which may be used in the process of aspects of this invention are those represented by the general formulae R3Al, R2AlX, RAlX2, R2AlOR, RAl(OR)X and R3A12X3 wherein R is Cl to C20 alkyl or aryl, X is halogen and R may be the same or different, e.g., triethylaluminum, triisobutylaluminum, trihexylaluminum, tricotylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, and mixtures thereof.
The amount of an organoaluminum compound to be used in the process of aspects of this invention is not specially limited, but usually it may range from 0.1 to 1000 mols per mol of a transition metal compound.
In the polymerization reaction, a mixture of ethylene and an -olefin of C5 to C18 is allowed to polymerize in the vapour phase using a known reactor, e.g., a fluidized bed or agitation vessel.
The polymerization conditions involve temperatures ranging usually from 20 to 110C., preferably from 50 to 100C., and pressures from atmospheric pressure to 70 kg/cm G, preferably from 2 to 60 kg/cm G.
11249~8 Adjustment of the molecular weight can be made by changing the polymeriza-tion temperature, the molar ratio of catalyst or the amount of comonomer, but the addition of hydrogen into the polymerization system is more effec-tive for this purpose. Of cource, the process of aspects of this invention can be applied, without any trouble, to two or more stage polymerization reactions involving different polymerization conditions, e.g., different hydrogen and comonomer concentrations and different polymerization tempera-tures.
In the process of aspects of this invention, moreover, the fore-going catalyst system may be contacted with an ~-olefin before its use in the vapour phase polymerization reaction whereby it is possible to improve the polymerization activity and to assure a more stable operation than in the untreated condition. Various <-olefins are employable in the above treatment, preferably those having 3 to 12 carbon atoms and more preferably those having 3 to 8 carbon atoms, typical of which are propylene, butene-l, pentene-l, 4-methylpentene-1, heptene-l, hexene-l, octene-l, and mixtures thereof. The temperature and time for such contact treatment for the cata-lyst used in the process of aspects of this invention with an ~-olefin can be selected in wide range, for example, 0 to 200C., preferably 0 to 110 110C., and 1 minute to 24 hours.
The amount of an ~ -olefin to be brought into contact with the catalyst can also be selected in wide range, but usually it ranges from 1 g to 50,000 g, preferably 5 g to-30,000 g, per gram of the solid substance and it is desired that 1 g to 500 g of the o~-olefin per gram of the solid substance be reacted. The pressure in such contact treatment can be optionally selected, but desirably it ranges from -1 to 100 kg/cm G.
In the above treatment of the catalyst with an ~-olefin, the total amount of an organoaluminum compound may be first combined with the solid substance and then contacted with the c~-olefin or alternatively part of the organoaluminum compound may be combined with the solid substance, l~Z49~
then contacted with the ~-olefin and the remaining portion of the organo-aluminum compound may be separately added in the vapour phase polymeriza-tion of ethylene. Furthermore, the catalyst may be contacted with an C-olefin in the presence of hydrogen gas, or other inert gas, e.g., nitrogen, argon or helium.
c~ -olefins to be copolymerized with ethylene in the process of aspects of this invention are those having 5 to 18 carbon atoms and they may be of a straight chain or branched. Examples are pentene-l, hexene-l, 4-methylpentene-1, heptene-l, octene-l, none-l, decene-l, undecene-l, dodecene-l, tridecene-l, tetradecene-l, pentadecene-l, hexadecene-l, hepta-decene-l, octadecene-l and mixtures thereof.
The amount of an ~ -olefin to be copolymerized with ethylene in the process of aspects of this invention should be in the range of from 1 to 40 mol% based on the amount of ethylene. Outside this range, it is impossible to obtain the product of aspects of this invention, namely an ethylene- ~-olefin copolymer having a density of 0.850 to 0.945. The amount of such ~<-olefin can be adjusted easily according to the composition ratio of the vapour phase in the polymerization vessel.
In the process of aspects of this invention, moreover, various dienes may be added as termonomers in the copolymerization reaction, e.g., butadiene, 1,4-hexadiene, 1,5-hexadiene, vinylnorbornene, ethylidenenorb-ornene and dicyclopentadiene.
Working examples of aspects of this invention are described below, but it is to be understood that these examples are for the purpose of illustrating the operation of the invention.
Example 1 1 kg of anhydrous magnesium chloride, 50 g of 1,2-dichloroethane and 170 g of titanium tetrachloride were subjected to ball milling for 16 hours at room temperature in a nitrogen atmosphere to allow the titanium compound to be attached to the carrier. The resulting solid substance 11;~4948 contained 35 mg of titanium per gram thereof.
A stainless steel autoclave was used as the apparatus for the vapour phase polymerization, and there were used a blower, a flow rate adjuster and a dry cyclone to form a loop, and the temperature of the autoclave was adjusted by passing warm water through the jacket.
To the autoclave adjusted to 85C. were fed the solid substance prepared above and triethylaluminum at the rates of 250 mg/hr and 50 mmol/hr, respectively, and also introduced were ethylene, 4-methylpentene-1 and hydrogen while making adjustment so that the 4-methylpentene-1/ethylene ratio (in molar ratio) in the vapour phase in the autoclave was 0.035 and the hydrogen gas pressure was 22% of the total pressure, and a polymeriza-tion was made while the gases in the system were circulated by the blower.
The resulting ethylene copolymer had a bulk density of 0.395, a melt index (MI) of 1.4 and a density of 0.930~ the greater part of which was composed of powders with particle sizes in the range of from 250 to 500~. The polymerization activity was high, 173,500 g copolymer/g Ti.
After continuous operation for 10 hours, the autoclave was opened and its interior was checked to find it was clean with no polymer adhesion to the inner wall and stirrer. That is, it is apparent that a very stable operation is assured according to the process of an aspect of this invention, though it was unattainable in the slurry polymeri~ation shown in Comparative Example 1 as will be referred to hereinafter.
The resulting copolymer was formed into a film 400 mm in fold diameter by 30~u thick through a 75 mm~ inflation film forming die in a 50 mm~ extruder, which film was superior in strength and in transparency.
The film was subjected to extraction with hexane at 50C. for 4 hours to give 2.10% extract.
Comparative Example 1 Using the same catalyst as that used in Example 1 and hexane as solvent, a continuous slurry polymerization was conducted at 85C.
11~4948 Hexane as polymerization solvent containing 5 mg/~ of the solid catalyst and 1 mmol/~ of triethylaluminum was fed at the rate of 40 ~/hr, and also fed were ethylene, 4-methylpentene-1 (20 mol% of ethylene) and hydrogen at the rates of 10 kg/hr, 6 kg/hr and 2Nm3/hr, respectively, and a continuous polymerization was made on condition that the residence time was 1 hour. The resulting copolymer was continuously withdrawn as slurry.
In 3 hours, the polymer slurry withdrawing pipe was obturated and the polymerization was compelled to be discontinued.
The interior of the reactor was checked to find that the hexane layer was emulsified and a large amount of a rubbery polymer adhered to the gas-liquid interface and also to the polymer withdrawing pipe.
The copolymer prepared above had a bulk density of 0.248, MI of 0.74 and a density of 0.932.
Example 2 Polymerization was carried out in the same manner as in Example 1 except that the 4-methylpentene-1/ethylene ratio was 0.14 and the hydrogen gas pressure was 15% of the total pressure.
The resulting ethylene copolymer had a MI of 2.3, a bulk density of 0.384 and a density of 0.896, and the polymerization activity was 147,000 g copolymer/g Ti.
After continuous operation for 10 hours, the interior of the reactor was checked to find no polymer adhesion to the inner wall and stirrer.
The copolymer after subjected to press forming was transparent, having a breaking point strength of 193 kg/cm2 and an elongation of 630%.
Example 3 Polymerization was carried out in the same manner as in Example 1 except that hexene-l was used in place of 4-methylpentene-1.
The resulting ethylene copolymer had a bulk density of 0.399, MI
of 1.3 and a density of 0.933, and the polymerization activity was 186,500 1124'9~8 g copolymer/g Ti.
After continuous operation for 10 hours, the polymerization was discontinued and the reactor inside was checked to find no polymer adhesion.
The resulting polymer was formed into an inflation film 30~u thick, which film was superior in strength and in transparency. The hexane extract of the film was 0.17%.
Example 4 830 g of anhydrous magnesium chloride, 50 g of aluminum oxychlor-ide and 170 g of titanium tetrachloride were subjected to ball milling for 16 hours at room temperature in a nitrogen atomsphere. The resulting solid substance contained 41 mg of titanium per gram thereof.
The solid substance prepared above and triethylaluminum were fed at the rates of 200 mg/hr and 50 mmol/hr, respectively, and a polymeriza-tion was made at 85C. in the same way as in Example 1, with the proviso that the comonomer to be copolymerized was hexene-l, the hexene-l/ethylene ratio in the vapour phase was 0.07 and the hydrogen gas pressure was 16%
of the total pressure.
After continuous operation for 10 hours, the interior of the autoclave was checked to find no polymer adhesion.
The resulting copolymer had a bulk density of 0.408, MI of 1.1 and a density of 0.915, and the polymerization activity was very high, 194,500 g ethylene-copolymer/g Ti.
The copolymer was fDrmed into a film 400 mm in fold diamter by 30J~ thick in the same manner as in Example 1, which film was superior in both strength and transparency. The hexane extract of the film was 0.36%.
Comparative Example 2 Using the same catalyst as that used in Example 2 and n-paraffin as solvent, a solution polymerization was carried out. That is, n-paraffin containing 25 mg/~ of the solid substance prepared in Example 2 and 5 mmol/~ of triethylaluminum was fed at the rate of 40Q /hr, and also ~lZ49~8 fed were ethylene, hexene-l and hydrogen at the rates of 10 kg/hr, 6 kg/hr and 550 N~ /hr, respectively and a continuous polymerization was made at 160C. on condition that the residence time was 1 hour. The resulting ethylene copolymer had a MI of 0.34 and a density of 0.947, and the poly-merization activity was 7,800 g copolymer/g Ti.
Thus in the case of a solution polymerization, despite a large amount of hexene-l used, the polymer density is not lowered so much and the polymerization activity is low, it being apparent that this is an example of inefficient polymerization.
Example 5 Copolymerization was carried out in the same manner as in Example 4 except that the hexene-l/ethylene ratio was 0.28 and the hydrogen gas pressure was 10% of the total pressure.
The resulting ethylene copolymer had a MI of 1.9, a bulk density of 0.379 and a density of 0.870, and the polymerization activity was 171,000 g copolymer/g Ti.
In 10 hours, the supply of the starting gases was stopped to terminate the polymerization reaction and the reactor inside was checked to find no polymer adhesion therein.
The resulting ethylene-hexene-l copolymer was subjected to press forming and the formed article was high in transparency, having a breaking point strength of 180 kg/cm and an elongation of 650%.
Example 6 A continuous polymerization was carried out in the same manner as in Example 4 except that an equimixture of hexene-l, octene-l and decene-l (trade name "DIALEN 610") was used as comonomer in place of hexene-l.
The resulting ethylene copolymer had a bulk density of 0.395, MI of 1.2 and a density of 0.918, and the polymerization activity was 190,300 g copolymer/g Ti.
1~24948 The copolymer was formed into an inflation film 30 ~ thick in the same way as in Example 1, which film was superior in both strength and stiffness and was high in transparency. The hexane extract of the film was 0.73%.
Example 7 830 g of anhydrous magnesium chloride, 120 g of anthracene and 170 g of titanium tetrachloride were subjected to ball milling in the same manner as in Example 1 to give a solid substance, which contained 40 mg of titanium per gram thereof.
Using the same apparatus as that used in Example 1, and at 80C.
there were fed the solid substance obtained above and triisobutylaluminum at the rates of 500 mg/hr and 150 mmol/hr, respectively, and also fed were DIALEN 610 (the trade name for an equimixture of hexene-l, octene-l and decene-l) as comonomer, ethylene and hydrogen while making adjustment so that the comonomer/ethylene ratio in the vapour phase was 0.14 and the hydrogen gas pressure was 15% of the total pressure.
The polymerization was continued stably for 10 hours, then the autoclave was opened and the reactor inside was checked to find no polymer adhesion therein.
The polymerization activty was 143,000 g copolymer/g Ti, and the resulting polymer had a bulk density of 0.394, MI of 2.6 and a density of 0.909.
The polymer was formed into an inflation film, which film was superior in both stiffness and transparency. The hexane extract of the film was 2.6%.
Example 8 Polymerization was carried out in the same manner as in Example 7 with the proviso that the polymerization temperature, the DIALEN 610/
ethylene ratio and the hydrogen gas pressure were adjusted to 85C., 0.07 and 30% of the total pressure, respectively.
llZ4~48 After continuous operation for 10 hours, the polymerization was discontinued and the interior of the autocalve was checked to find it was clean with no polymer adhesion therein.
The resulting copolymer had a bulk density of 0.395, MI of 6.4 and a density of 0.917, and the polymerization activity was 128,000 g copolymer/g Ti.
Example 9 Using the same catalyst as that used in Example 7, there was conducted polymerization in the same manner as in Example 7 with the pro-viso that dodecene was used in place of DIALEN 610 and the dodecene/ethy-lene ratio and the hydrogen gas pressure were adjusted to 0.25 and 10% of the total pressure, respectively.
The polymerization was continued for 10 hours without any trouble.
After termination of the reaction, the interior of the autoclave was checked to find no polymer adhesion therein.
The resulting copolymer had a bulk density of 0.389, MI of 1.9 and a density of 0.881, and the polymerization activity was 110,300 g copolymer/g Ti.
The copolymer after subjected to press forming was transparent and had a breaking point strength of 185 kg/cm2, an elongation of 700%.
Example 10 400 g of magnesium oxide and 1,300 g of anhydrous aluminum chloride were reacted together at 300C. for 4 hours, and 950 g of the reaction product and 170 g of titanium tetrachloride were treated in the same way as in Example 1 to give a solid substance, which contained 3 mg of titanium per gram thereof.
Using the same apparatus as that used in Example 1, there were fed as catalyst the solid substance prepared above and triisobutylaluminum at the rates of 500 mg/hr and 250 mmol/hr, respectively, and a polymeriza-tion was made at 85C. while there were circulated a mixed gas consisting llZ49~
of ethylene and 12% thereof in the vapour phase of 4-methylpentene-1 and hydrogen gas adjusted to 9% of the total pressure.
Af ter continuous operation for 18 hours, the reactor inside was checked to find no polymer adhesion therein.
The resulting copolymer had a bulk density of 0.443, MI of 0.68 and a density of 0.918, composed of oval particles of a narrow particle size distribution with an average particle diameter of 500JU. The poly-merization activity was 179,000 g copolymer/g Ti.
The copolymer, without pelletizing, was formed into a hollow 600 cc bottle by means of a high-speed blow molding machine, which bottle had a clean surface with no drawn-down observed.
Example ll Polymerization was carried out in the same manner as in Example 10 with the limitation that the proportion of 4-methylpentene-1 to ethylene was 5.5% and the hydrogen gas pressure was 30% of the total pressure.
In 10 hours, the polymerization was discontinued and the interior of the polymerization vessel was checked to find no polymer adhesion therein.
The resulting copolymer had a bulk density of 0.375, MI of 4.3 and a density of 0.930, and the polymerization activity was 181,000 g copolymer/g Ti.
Claims (16)
1. A process for preparing an ethylene-?-olefin copolymer having a density of 0.850 to 0.945, which comprises copolymerizing ethylene and 1 to 40 mol% thereof of ?-olefin having 5 to 18 carbon atoms in a substan-tially solvent-free vapour phase condition and in the presence of a cata-lyst comprising a solid substance and an organoaluminum compound, said solid substance containing magnesium and at least one of titanium and vanadium.
2. A process according to claim 1, in which said solid substance is obtained by attaching said at least one of a titanium compound and a vanadium compound to said magnesium-containing inorganic solid carrier.
3. A process according to claim 1, in which said solid substance is a reaction product of said organomagnesium compound and said at least one of a titanium compound and a vanadium compound.
4. A process according to claim 2, in which said magnesium-containing inorganic solid carrier is selected from the group consisting of metallic magnesium, magnesium hydroxide, magnesium carbonate, magnesium oxide and magnesium chloride.
5. A process according to claim 2, in which said magnesium-containing inorganic solid carrier is selected from the group consisting of a double salt, a double oxide, a carbonate, a chloride and a hydroxide containing magnesium atom and a metal selected from the group consisting of silicon, aluminum and calcium.
6. A process according to claim 2, in which said magnesium-containing inorganic solid carrier is further treated or reacted with a material selected from the group consisting of an oxygen-containing com-pound, a sulfur-containing compound, a hydrocarbon and a halogen-containing substance.
7. A process according to claims 2 or 3, in which said at least one of a titanium compound and a vanadium compound is a halide, alkoxy-halide, oxide or halogenated oxide of at least one of titanium and vanadium.
8. A process according to claim 3, in which said organomagnesium compound is a compound represented by the general formula RMgX, R2Mg and RMg(OR), wherein R is an organic radical and X is halogen.
9. A process according to claims 2 or 3, in which said at least one of a titanium compound and a vanadium compound is used as the addition product with an organocarboxylic acid ester in the preparation of said solid substance.
10. A process according to claim 2, in which said magnesium-containing inorganic solid carrier is contacted with an organocarboxylic acid ester before its use in the preparation of said solid substance.
11. A process according to claim 1, in which said organoaluminum compound is used as the addition product with an organocarboxylic acid ester.
12. A process according to claim 1, in which the catalyst system is prepared in the presence of an organocarboxylic acid ester.
13. A process according to claim 1, in which said copolymerization is carried out at a temperature in the range of from 20° to 110°C. and at a pressure in the range of from atmospheric to 70 kg/cm2?G.
14. A process acccording to claim 1, in which said copolymerization is carried out in the presence of hydrogen.
15. A process according to claim 1, in which said catalyst system is contacted beforehand with an ?-olefin for 1 minute to 24 hours at a temperature in the range of from 0° to 200°C. and at a pressure in the range of from -1 to 100 kg/cm2?G, and thereafter the copolymerization is carried out.
16. A process according to claim 1, in which said ?-olefin to be copolymerized with ethylene is a member selected from the group consis-ting of pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, nonene-l, decene-l, undecene-l, dodecene-l, tridecene-l, tetradecene-l, pentadecene-l, hexadecene-l, heptadecene-l, octadecene-l, and mixtures thereof.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13100778A JPS5558210A (en) | 1978-10-26 | 1978-10-26 | Production of copolymer |
| JP131007/1978 | 1978-10-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1124948A true CA1124948A (en) | 1982-06-01 |
Family
ID=15047775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA338,437A Expired CA1124948A (en) | 1978-10-26 | 1979-10-25 | Process for preparing a copolymer |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5558210A (en) |
| CA (1) | CA1124948A (en) |
| DE (1) | DE2943380A1 (en) |
| FR (1) | FR2439797A1 (en) |
| GB (1) | GB2034723B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7867588B2 (en) | 2001-12-17 | 2011-01-11 | Media Plus, Inc. | Polyethylene melt blends for high density polyethylene applications |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6042806B2 (en) * | 1979-12-26 | 1985-09-25 | 日石三菱株式会社 | Copolymer manufacturing method |
| JPS56155226A (en) * | 1980-05-02 | 1981-12-01 | Nippon Oil Co Ltd | Manufacture of radiation-bridged polyolefin |
| JPS5738837A (en) * | 1980-08-19 | 1982-03-03 | Mitsubishi Chem Ind Ltd | Production of polyolefin film |
| IT1210855B (en) * | 1982-02-12 | 1989-09-29 | Assoreni Ora Enichem Polimeri | LINEAR STRUCTURE ETHYLENE POLYMERS AND PROCESSES FOR THEIR PREPARATION. |
| JPS58157839A (en) * | 1982-03-16 | 1983-09-20 | Nippon Oil Co Ltd | Impact-resistant polyolefin resin composition |
| JPS5936110A (en) * | 1982-08-25 | 1984-02-28 | Asahi Chem Ind Co Ltd | Novel ethylene-alpha-olefin copolymer |
| FR2532649B1 (en) * | 1982-09-07 | 1986-08-29 | Bp Chimie Sa | COPOLYMERIZATION OF ETHYLENE AND HEXENE-1 IN A FLUIDIZED BED |
| JPS5975910A (en) * | 1982-10-25 | 1984-04-28 | Mitsui Petrochem Ind Ltd | Ethylene copolymer |
| JPS6072908A (en) * | 1983-09-30 | 1985-04-25 | Yotsukaichi Polymer:Kk | Production of ethylene copolymer |
| JPS6088016A (en) * | 1983-10-21 | 1985-05-17 | Mitsui Petrochem Ind Ltd | Ethylene copolymer |
| US5256351A (en) * | 1985-06-17 | 1993-10-26 | Viskase Corporation | Process for making biaxially stretched, heat shrinkable VLDPE films |
| US5059481A (en) * | 1985-06-17 | 1991-10-22 | Viskase Corporation | Biaxially stretched, heat shrinkable VLDPE film |
| CA1340037C (en) * | 1985-06-17 | 1998-09-08 | Stanley Lustig | Puncture resistant, heat-shrinkable films containing very low density polyethylene copolymer |
| US4976898A (en) * | 1985-06-17 | 1990-12-11 | Viskase Corporation | Process for making puncture resistant, heat-shrinkable films containing very low density polyethylene |
| DE3816397A1 (en) * | 1988-05-13 | 1989-11-23 | Basf Ag | ELECTRICAL CABLES CONTAINING INSULATIONS BASED ON EHTYLENE POLYMERISATES WITH HIGH RESISTANCE TO THE FORMATION OF WATER TREES |
| CA2003882C (en) | 1988-12-19 | 1997-01-07 | Edwin Rogers Smith | Heat shrinkable very low density polyethylene terpolymer film |
| NO903298L (en) * | 1989-07-26 | 1991-01-28 | Union Carbide Chem Plastic | PREPARATIONS RESISTANT TO TRIANGLE. |
| US6153551A (en) | 1997-07-14 | 2000-11-28 | Mobil Oil Corporation | Preparation of supported catalyst using trialkylaluminum-metallocene contact products |
| US6822051B2 (en) | 2002-03-29 | 2004-11-23 | Media Plus, Inc. | High density polyethylene melt blends for improved stress crack resistance in pipe |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL165180B (en) * | 1971-03-11 | 1980-10-15 | Stamicarbon | METHOD FOR POLYMERIZING ETHENE. |
| JPS4935345A (en) * | 1972-07-31 | 1974-04-01 | ||
| DE2331103C2 (en) * | 1973-06-19 | 1983-12-08 | Basf Ag, 6700 Ludwigshafen | Process for the production of small homo- or copolymers of ethylene |
| AR206852A1 (en) * | 1975-03-10 | 1976-08-23 | Union Carbide Corp | PROCEDURE FOR PREPARING LOW AND MEDIUM DENSITY ETHYLENE POLYMERS IN A FLUID BED REACTOR |
| IT1037112B (en) * | 1975-03-28 | 1979-11-10 | Montedison Spa | CATALYSTS FOR THE POLYMERIZATION OF OLFINES |
| JPS51133386A (en) * | 1975-05-15 | 1976-11-19 | Nippon Oil Co Ltd | A process for manufacturing a polyolefin |
| FR2312512A1 (en) * | 1975-05-27 | 1976-12-24 | Naphtachimie Sa | POLYMERIZATION OF OLEFINS IN A FLUIDIZED BED |
| US4120820A (en) * | 1976-12-01 | 1978-10-17 | The Dow Chemical Company | High efficiency catalyst for polymerizing olefins |
| JPS53104687A (en) * | 1977-02-25 | 1978-09-12 | Mitsui Petrochem Ind Ltd | Preparation of propylene-ethylene elastic copolymer |
| FR2405961A1 (en) * | 1977-10-12 | 1979-05-11 | Naphtachimie Sa | PROCESS FOR THE COPOLYMERIZATION OF OLEFINS IN A GAS PHASE IN THE PRESENCE OF A FLUIDIZED COPOLYMER BED AND A CATALYST CONTAINING TITANIUM AND MAGNESIUM |
| ZA791363B (en) * | 1978-03-31 | 1980-03-26 | Union Carbide Corp | Preparation of ethylene copolymers in fluid bed reactor |
| IT1110494B (en) * | 1978-08-02 | 1985-12-23 | Montedison Spa | ETHYLENE POLYMERS AND PROCEDURE FOR THEIR PREPARATION |
-
1978
- 1978-10-26 JP JP13100778A patent/JPS5558210A/en active Granted
-
1979
- 1979-10-24 GB GB7936884A patent/GB2034723B/en not_active Expired
- 1979-10-25 CA CA338,437A patent/CA1124948A/en not_active Expired
- 1979-10-26 DE DE19792943380 patent/DE2943380A1/en not_active Withdrawn
- 1979-10-26 FR FR7926694A patent/FR2439797A1/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7867588B2 (en) | 2001-12-17 | 2011-01-11 | Media Plus, Inc. | Polyethylene melt blends for high density polyethylene applications |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2439797A1 (en) | 1980-05-23 |
| DE2943380A1 (en) | 1980-05-08 |
| FR2439797B1 (en) | 1984-08-31 |
| JPS6320845B2 (en) | 1988-04-30 |
| JPS5558210A (en) | 1980-04-30 |
| GB2034723B (en) | 1983-04-13 |
| GB2034723A (en) | 1980-06-11 |
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