JPS649326B2 - - Google Patents

Description

[Detailed description of the invention]

[] BACKGROUND TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for producing an unsaturated copolymer by copolymerizing an α-olefin and a specific non-conjugated diene. More specifically, the present invention relates to a method for producing this particular unsaturated copolymer with high polymerization activity, ie, in high yield. Prior art As a technology for producing an unsaturated copolymer by copolymerizing α-olefin and polyene using a Ziegler-Natsuta catalyst, ethylene, propylene, propylene, The technique of producing so-called EPDM by terpolymerizing and non-conjugated diene is well known industrially. Various types of non-conjugated dienes are known for use in the production of EPDM, including dienes with a cyclic structure such as norbornadiene, dicyclopentadiene, propenylnorbornene, methylenenorbornene, and ethylidene norbornene, 1,4-hexadiene, Linear dienes such as 1,5-octadiene, 1,6-decadiene, and 1,9-octadecadiene are used. The Ziegler-Natsuta catalyst, whose transition metal component is a vanadium compound, is typical for the production of EPDM, but this catalyst has the following runner-up points. In other words, even if a small amount of vanadium remains in the resulting copolymer, the copolymer is easily colored, so a complicated process for sufficient decatalysis after polymerization is essential; copolymers cannot be obtained, and the polymerization activity decreases significantly over time. On the other hand, an attempt was made to copolymerize α-olefin and the above polyene using a Ziegler-Natsuta catalyst using a titanium compound as a transition metal component, which is typical for producing crystalline or resinous polyolefins and is also advantageous industrially. Then, instead of not having the above-mentioned drawbacks seen with vanadium-based catalysts, other problems are encountered. In other words, the effect of the coexisting polyene significantly inhibits molecular weight control by hydrogen, or conversely, even a slight change in the amount of hydrogen added causes a significant change in molecular weight, making it difficult to use on a practical scale. Either molecular weight control is markedly difficult, polymerization activity is markedly reduced, or the stereoregularity of the resulting copolymer is markedly reduced. For example, a solid catalyst component (a) derived from magnesium chloride, titanium tetrachloride, and ethyl benzoate as essential components;
When cis-1,4-hexadiene is copolymerized with propylene using a highly stereoregular catalyst consisting of triethylaluminum (b) and ethyl p-toluate (c), cis-1,4-hexadiene is copolymerized. Only 4% by volume of the feed concentration (content of cis-1,4-hexadiene units in the copolymer: 1.6 mol%)
In this case, the catalytic activity decreased to one-tenth of that in the case of propylene homopolymerization, and the resulting copolymer contained only a small amount of boiling n-heptane insoluble matter (abbreviated as II hereafter).
It becomes only 65% (see Comparative Example 1). Furthermore, when ethylidene norbornene is copolymerized with ethylene using a catalyst consisting of triethylaluminum and a solid catalyst component containing magnesium chloride and ethoxytitanium trichloride as essential components, the molecular weight cannot be controlled at all by hydrogen (comparison (See Example 2), the molding of the resulting copolymer is extremely difficult and cannot be put to practical use. It is well known that the presence of hydrogen in the polymerization system of α-olefin using a Ziegler-Natsuta catalyst lowers the molecular weight of the resulting polymer, and the behavior of hydrogen as a molecular weight control agent is important for the production of crystalline or resinous polyolefins. This seems to be particularly noticeable when Hydrogen, as long as it is used in an appropriate amount, changes only the molecular weight of the resulting polymer and changes other properties of the polymer, such as stereoregularity, copolymerizability between comonomers in the case of copolymers, and catalyst polymerization. It is said that it does not have much effect on activity. However, as mentioned above, in a copolymerization system in which a nonconjugated diene coexists on a catalyst whose transition metal component is a titanium compound, hydrogen exhibits disadvantageous behavior.
Furthermore, in this copolymerization system, titanium-based catalysts have extremely poor practical value. Known techniques for copolymerizing α-olefin and branched 1,4-hexadiene derivatives using a Ziegler-Natsuta catalyst in which the transition metal component is a titanium compound include British Patent No. 1268149 and U.S. Patent No. 3933769. There are techniques described in the specifications of No. 1 and No. 3991262. The invention described in British Patent No. 1268149 uses a special titanium trichloride composition that has been extremely finely divided into a colloidal state as a transition metal component, and the average particle size of the resulting copolymer is
It is characterized by being colloidal with a size of 0.02 to 0.5 microns. The inventions described in US Pat. Nos. 3,933,769 and 3,991,262 are characterized in that the resulting copolymer is a rubbery copolymer that is soluble in a hydrocarbon solvent at room temperature. However, in these three known inventions, the molecular weight is not controlled by hydrogen. [] Summary of the invention Purpose: Various shapes (liquids, wax-like materials, rubber-like materials, thermoplastic resin-like materials, thermoplastic elastomer-like materials) having a C=C bond in the side chain and having freely controlled molecular weight If α-olefin copolymers (such as ) can be produced as desired and efficiently, cross-linking and various tree groups can be easily introduced by addition reactions to C=C bonds or substitution reactions to allyl positions. Therefore, it is revolutionary in planning new developments in polyolefin materials, and the establishment of a method for producing such a copolymer has been eagerly awaited among those skilled in the art. The present invention aims to provide an answer to this point. Summary The method for producing an unsaturated copolymer according to the present invention comprises one or more α-olefins (A) selected from α-olefins having 2 to 12 carbon atoms and a non-conjugated diene.
The method for producing an unsaturated copolymer by copolymerization with (B) is characterized by the following requirements (1) to (3). (1) As a polymerization catalyst, a Ziegler-Natsuta catalyst, which is a combination of a halogen-containing titanium compound or its composition and an organoaluminum compound, is used; (2) the non-conjugated diene is a branched 1,4-diene represented by the formula (); to be, (Here, R ¹ represents an alkyl group having 8 or less carbon atoms, and R ² and R ³ each represent a hydrogen atom or an alkyl group having 8 or less carbon atoms. Therefore,
R ² and R ³ are both hydrogen atoms), and (3) copolymerization is carried out in the presence of hydrogen. Effects The present invention shows that if a limited diene, that is, a branched 1,4-diene of the formula () is copolymerized using an industrially advantageous titanium-based Ziegler-Natsuta catalyst, hydrogen will have the following effects. It is based on the discovery of the fact that Molecular weight can be freely controlled with practical ease using hydrogen. Activity is significantly improved by adding hydrogen during polymerization. Considering that molecular weight control is almost impossible when a cyclic diene such as ethylidene norbornene is used as a comonomer (see Comparative Example 2 below), this should be considered unexpected. There is little decrease in polymerization activity due to the addition of the branched 1,4-diene represented by formula (). Moreover, when this specific diene is used as a comonomer, the activity is improved compared to when no hydrogen is added.
In severe cases, it can even be improved several times. α-olefins are propylene, 3-methylbutene-1,3-methylpentene-1, and 4
-Methylpentene-1, when the stereoregular copolymerization is carried out, there is little decrease in so-called II, and therefore there is little increase in soluble copolymer, and slurry polymerization is carried out. In this case, the copolymerization can be carried out while maintaining a high slurry concentration with almost no decrease in bulk density, and therefore productivity is good and the resulting copolymer is easy to handle. Generally, alpha-olefins, such as propylene,
In stereoregular copolymerization in slurry form,
As the content of comonomers, such as ethylene, butene-1, hexene-1,4-methylpentene-1, etc., increases, the II of the copolymer decreases, increasing the solubility in solvents and decreasing the bulk density, resulting in a polymerization system. It was common knowledge that the viscosity of the liquid would increase, making it difficult to operate the plant, and that a decline in productivity could not be avoided. Therefore, when the branched 1,4-diene represented by the formula () of the present invention is used as a comonomer in stereoregular copolymerization, the increase in the amount of solvent-soluble polymer in slurry polymerization is significantly small; The fact that there is almost no decrease in bulk density is truly surprising and cannot be inferred from conventionally known facts. [] Detailed description of the invention 1 α-olefin (A) The α-olefin to be copolymerized with the branched 1,4-diene used in the present invention is selected from α-olefins having 2 to 12 carbon atoms. Specifically, for example, ethylene, propylene, butene-1,3-methylbutene-1, pentene-1,3-methylpentene-
These include 1,4-methylpentene-1, hexene-1, octene-1, decene-1, dodecene-1 and styrene. In this way, "α-olefin" as used in the present invention includes aryl ethylene (especially hydrocarbon compounds) such as styrene in addition to ethylene, ethylene homologs, and alkyl ethylene.
Alternatively, it also includes cycloalkylethylene. The α-olefin used in the present invention may be a mixture of two or more selected from these. In particular, α-olefins selected from ethylene, propylene, butene-1, hexene-1,4-methylpentene-1, octene-1, and decene-1 are copolymers with branched 1,4-dienes. It is a practically important and preferred α-olefin in the present invention. 2 Branched 1,4-diene Examples of the branched 1,4-diene represented by the formula (), which is one of the features of the present invention, include 4-methyl-1,4-hexadiene, 5-methyl-1,4 ―
Hexadiene, 4-ethyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene,
4-methyl-1,4-heptadiene, 4-ethyl-1,4-heptadiene, 5-methyl-1,4-
Heptadiene, 4-ethyl-1,4-octadiene, 5-methyl-1,4-octadiene, 4-n
-propyl-1,4-decadiene and the like. Among these, particularly preferred examples of branched 1,4-dienes are 4-methyl-1,4-hexadiene and 5-methyl-1,4-hexadiene. These branched dienes may be a mixture of two or more types, and a mixture of 4-methyl-1,4-hexadiene and 5-methyl-1,4-hexadiene is particularly suitable. 3 Polymerization Catalyst 1 Transition Metal Component The Ziegler-Natsuta catalyst to be used in the present invention is not particularly limited as long as the transition metal component is a halogen-containing titanium compound or a composition thereof, and any suitable conventionally known combination may be used. be able to. Examples of halogen-containing titanium compounds or compositions thereof include (a) halogenated titanium compounds such as titanium tetrachloride, titanium trichloride and compositions thereof (e.g. 3TiCl ₃ .AlCl ₃ ), titanium dichloride and compositions thereof; (b) Titanium halogen compounds such as titanium tetrachloride, ethoxytitanium trichloride, titanium trichloride, etc. are used as carriers (here, carrier is not only a compound that simply functions as a carrier, but also a titanium compound and additives as necessary). It also means a compound that forms a complex complex with other components in the compound and has subtle effects on polymerization activity, stereoregularity, molecular weight distribution, etc.For example, silica, alumina, silica, alumina, titania, Magnesia, magnesium chloride and compositions thereof (for example, compositions consisting of magnesium chloride and a Lewis acid, compositions consisting of magnesium chloride and a metal oxide, etc.) magnesium oxychloride, reaction products of magnesium oxychloride and alkyl aluminum dichloride etc.) may include so-called supported catalyst components, which are optionally supported together with electron-donating compounds such as organic acid esters, water, amines, amides, ethers, and alcohols. In the present invention, when referring to a halogen-containing titanium compound as a "composition," it mainly consists of a halogen-containing titanium compound, and usually contains up to 30% by weight of a Lewis acid (e.g., aluminum chloride, antimony trichloride, halogen In addition to the composition containing a phosphorus compound, etc.) and/or an electron donor (for example, ethers, organic acid esters, organic acid amides, phosphoric acid amides, amines, phosphines, etc.), the supported catalyst It also means ingredients. Suitable for use in the present invention are, for example:
Titanium tetrachloride, titanium trichloride or titanium trichloride composition (e.g. TiCl ₃ nAlCl ₃ ) obtained by reducing titanium tetrachloride with various reducing agents (e.g. hydrogen, aluminum, titanium, organic aluminum, etc.),
A titanium trichloride composition obtained by co-pulverizing this titanium trichloride (composition) with an electron donor such as an organic acid ester, ether, phosphoric acid amide, amine, etc., titanium tetrachloride reduced with organoaluminium. After that, a titanium trichloride composition obtained by ether treatment and Lewis acid treatment, a reaction product of magnesium oxychloride and alkyl aluminum dichloride (a compound obtained by further reacting this with a siloxane compound if desired), or magnesium chloride. as a carrier, an electron donor (selected from organic acid esters, alcohols, amines, organic acid amides, ethers, and water), and a halogen-containing titanium compound (e.g., titanium tetrachloride, titanium trichloride, alkoxy trichloride). This is a supported catalyst component in which titanium, etc.) is supported as an essential component. 2 Reducing Agent Component The organometallic compound component, which is the other component of the Ziegler-Natsuta catalyst to be combined with the halogen-containing titanium compound or its composition, is an organoaluminum compound. Examples of organoaluminum compounds that are usually preferably used include compounds represented by the following formula. R ⁴ _o AlX _3-o where R ⁴ is a hydrocarbon residue having about 1 to 10 carbon atoms,
X represents a hydrogen atom, a halogen atom, an alkoxy group having about 1 to 10 carbon atoms, an aryloxy group, or a siloxy group, and n is a number expressed as 0<n≦3. Examples of these organoaluminum compounds include (a) trialkyl aluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, triisoprenylaluminum, and tri-n-hexylaluminum; (b)
Dialkyl aluminum halides such as diethylaluminum chloride, di-n-propylaluminum chloride, and diisobutyl aluminum chloride; Alkylaluminum sesquihalides such as n-propylaluminum sesquichloride, (e) alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride, (f)
Dialkyl aluminum alkoxides or aryl oxides such as diethylaluminum ethoxide, diethylaluminium isopropoxide, di-n-propylaluminium-2,6-di-tert-butylphenoxide, (t)dimethylaluminum trimethylsiloxide, diethylaluminium dialkyl aluminum siloxides such as trimethyl siloxide, and the like. Alternatively, it may be a reaction product of these organoaluminum compounds and water or a secondary amine. These organoaluminum compounds may be used alone or in a mixture of two or more. 3 Optional Components In the copolymerization according to the present invention, in order to obtain a copolymer with particularly excellent stereoregularity, various compounds such as iodine or electron-donating substances (such as ethers, It may be convenient to use organic acid esters, amines, phosphoric acid amides, phosphines, etc.). 4. Composition Ratio There is no particular restriction on the composition ratio of the catalyst, and any suitable quantitative ratio may be used. Usually, about 0.1 to 2000 mol, preferably 0.5 to 1000 mol, and more preferably 1.0 to 500 mol of the organometallic compound is used per titanium atom. The amount of the electron donating compound used as the third component of the catalyst varies depending on the amount of the organometallic compound, but is usually about 0.01 to 1.0 mol per 1 mol of the organometallic compound. is normal. 4. Addition of hydrogen during polymerization The most distinctive feature of the present invention is that the copolymerization is carried out in the presence of hydrogen. As mentioned above, it is known that hydrogen is added during copolymerization of α-olefin and diene. In the present invention, the addition of hydrogen to the copolymerization system itself can be carried out in accordance with conventionally known methods or any other suitable method. Normally, the required amount of hydrogen will be added in its entirety at the start of polymerization or added in portions over time. On the other hand, the amount of hydrogen added varies greatly depending on the type of α-olefin and branched 1,4-diene, the type of polymerization catalyst, and polymerization conditions (temperature, pressure, catalyst amount ratio, etc.), and the resulting copolymer It is possible to set an appropriate hydrogen partial pressure according to the application. Specifically, for example, (a) the melt index is 1 to 5 g/
To obtain a stereoregular copolymer of propylene and 4-methyl-1,4-hexadiene in about 10 minutes,
When using a titanium trichloride composition and a diethylaluminium chloride catalyst, the hydrogen partial pressure is 0.1 to 1.0 at 60°C and a propylene partial pressure of 6 to 10 Kg/ ^cm2.
Kg/ ^cm2 , (b) Melt index 50-100
g/10 minutes to obtain a crystalline copolymer of ethylene and 4-methyl-1,4-hexadiene using a reaction product of magnesium oxychloride and an alkyl aluminum dichloride or a supported catalyst using magnesium chloride as a carrier. When using trialkyl aluminum catalyst, 85℃, ethylene partial pressure 4.5Kg/
cm ² condition, a hydrogen partial pressure of about 2 to 10 Kg/cm ² is appropriate. 5 Copolymerization Polymerization conditions using a Ziegler-Natsuta catalyst in which the transition metal component is a halogen-containing titanium compound or a composition thereof can generally be used. That is, the polymerization temperature is 0 to 250°C, preferably 20 to 250°C.
About 180°C, particularly preferably about 30 to 150°C, polymerization pressure from normal pressure to 150Kg/cm ² , preferably from normal pressure to 90°C
Kg/cm ² , particularly preferably normal pressure to 50 Kg/cm ² , is suitable. There are no particular restrictions on the polymerization mode, and (a) a slurry or solution method using an inert solvent, and (b) a polymerization method in which α-olefin and/or branched 1,4-diene are used as a solvent without substantially adding a solvent. Slurry or solution methods that serve the purpose, or (c) gas phase methods in which the copolymerization reaction is carried out without using a substantially liquid solvent and in which the monomer is kept in a substantially gaseous state, are all applicable to the present invention. Can be applied. The manner in which α-olefin and diene are supplied is also arbitrary. From the viewpoint of ease of operation, it may be convenient to mix both at a predetermined ratio, or one of them (especially α-olefin) can be added in portions, taking into account the copolymerization reaction ratio of both. 6 Produced Copolymer 1 Copolymer Composition In the method according to the present invention, in addition to binary copolymerization of one kind of α-olefin and one kind of branched 1,4-diene, multi-component copolymerization, for example, one kind of α- Ternary or quaternary copolymerization of olefin and two or more branched 1,4-dienes, or copolymerization of two or more α-olefins and two or more branched 1,4-dienes. Copolymerization of quaternary or quinary or more elements is possible. Branches 1 and 4 represented by formula () in the copolymer
- The content of diene units is usually 0.01 to 50 mol%, preferably 0.02 to 20 mol%, particularly preferably 0.1 to 10
mol%. This content can be controlled by changing the ratio of α-olefin and branched 1,4-diene in the copolymerization reaction system. 2 Shape and use of copolymer The present invention allows α-olefin and branched 1,4-
Unsaturated copolymers of various molecular weights and shapes can be produced efficiently depending on the combination of dienes, selection of catalyst system, amount of hydrogen added during copolymerization, etc., but this is especially true for the production of thermoplastic resins. suitable. Examples of copolymer shapes include wax-like products,
Examples include liquid rubber-like materials, solid rubber-like materials, thermoplastic elastomers, thermoplastic resins, and the like. The copolymer that can be produced by the method of the present invention is
to the side chain

[Formula] An α-olefin copolymer with freely controlled molecular weight.
Therefore, it is easy to crosslink, introduce various polar groups, and graft polymerize through addition reactions to C=C bonds, substitution reactions to allyl positions, etc., and as a base resin for paints, it has excellent paintability, adhesiveness, As a new polyolefin material such as modified polyolefin, which has significantly improved printability and gas barrier properties, its uses are countless. 7 Experimental Example 1 Preparation of Solid Catalyst Component The method for producing the halogen-containing titanium compound or its composition (hereinafter abbreviated as solid catalyst component) used in Examples and Comparative Examples is as follows. Solid catalyst component A 20 g of magnesium chloride and 3 g of trimethylsiloxyaluminum dichloride were placed in a vibrating mill pot (made of stainless steel, capacity 1.2 liters,
A stainless steel ball with a diameter of 12.7 mm is filled to an apparent volume of 1.1 liters.
Under the conditions of amplitude 3.5mm, frequency 24.2Hz, acceleration 8.3G
Co-milled for 12 hours. Next, 5.3ml of ethyl benzoate
After co-pulverizing for 2 hours, add ethyl benzoate.
5.3 ml was added and co-milled for 2 hours. Finally, 7.4 ml of titanium tetrachloride was added and co-pulverized for an additional 24 hours.
8 g of this final co-pulverized product was divided into three-necked flasks and made into a slurry of a mixed solvent consisting of 75 ml of 1,2-dichloroethane and 25 ml of hexane, 0.2 g of iodine trichloride was added, and the slurry was reacted at 75° C. for 2 hours.
The solid product was separated and washed 7 times with 50 ml of hexane to obtain solid catalyst component A. This solid catalyst component A
contained 1.94% titanium by weight. Solid catalyst component B: 0.6 liters of hexane and 0.15 liters of titanium tetrachloride
Add diethylaluminium chloride to a 2 liter flask with stirring (160 rpm).
A solution of 0.173 liters dissolved in 0.45 liters of hexane was added dropwise over 4 hours while keeping the temperature inside the flask at 1°C. After the dropwise addition was completed, the mixture was kept at 1° C. for 15 minutes with stirring, then the temperature was raised to 65° C. within 1 hour, and the mixture was stirred at this temperature for 1 hour. The resulting solid was separated from the liquid phase and washed five times with 0.5 liters of hexane. Next, this solid was suspended in 1.7 liters of hexane, 0.26 liters of di-isoamyl ether was added, and the mixture was stirred at 35° C. for 1 hour. The solid reactant was separated from the liquid phase and dissolved in 0.5 liters of hexane at 25°C.
Washed twice. This solid reactant was then suspended in 0.85 liters of a 40% by volume titanium tetrachloride solution in hexane and heated at 65°C.
The mixture was stirred for 2 hours. The solid product was separated from the liquid phase and washed five times with 0.5 liters of hexane to obtain solid catalyst component B. This solid catalyst component B is a composition consisting mostly of δ-type porous titanium trichloride. Solid Catalyst Component C 20 g of magnesium chloride and 14 g of ethoxytrichlorotitanium were charged into the vibratory mill used for producing solid catalyst component A and co-pulverized for 24 hours. 3 g of this co-pulverized product was made into a slurry in 70 ml of 1,2-dichloroethane, 0.1 g of iodine trichloride was added, and the mixture was stirred at 80° C. for 2 hours. The solid product was separated from the liquid phase and thoroughly washed with hexane to obtain solid catalyst component C. This solid catalyst component contained 9.1% by weight of titanium. 2 Copolymerization Example 1 An electric vapor induction stirred stainless steel autoclave with an internal capacity of 1 liter was thoroughly dried and then degassed with dry propylene. 0.4 liters of well-dried n-heptane and an 8:2 mixture of 4-methyl-1,4-hexadiene and 5-methyl-1,4-hexadiene (hereinafter referred to as methyl-1,
0.1 liter (abbreviated as 4-hexadiene) (20
% by volume) into this autoclave under a stream of propylene gas. Next, 300 mg of triethylaluminum (hereinafter abbreviated as TEA), ethyl p-toluate in an amount equivalent to 0.26 mol per 1 mol of TEA, and 72.2 mg of the solid catalyst component A were added in this order to the autoclave at room temperature, and hydrogen A predetermined amount of gas was added, and the total pressure was maintained at 7 kg/cm ² G by pressurizing with propylene gas, and copolymerization was carried out at 60° C. for 1.5 hours. After polymerization, residual gas was purged, the solid copolymer was separated by filtration, and after drying, II, bulk density (BD), melt index (MI) and melting point (Tm) were measured by conventional methods.
The content of methyl-1,4-hexadiene is
A 0.5 mm press sheet was molded and measured using infrared absorption spectroscopy. Meanwhile, the liquid was concentrated and the soluble copolymer dissolved in the liquid medium was recovered. These results are shown in Table 1. Reference Example 1 The entire procedure of Example 1 was followed except that 0.5 liters of n-heptane was used instead of methyl-1,4-hexadiene, 36.1 milligrams of solid catalyst component A, and 150 milligrams of TEA were used. The homopolymerization of was carried out in the presence of hydrogen.
The results are shown in Table 1. Comparative Example 1 Cis- instead of methyl-1,4-hexadiene
Propylene and cis-1,4-hexadiene were copolymerized in the same manner as in Example 1, except that 0.02 liters of 1,4-hexadiene and 0.48 liters of n-heptane as a solvent were used. The results are shown in Table 1.

【table】

[Table] When Example 1 is compared with Reference Example 1 and Comparative Example 1, the following will be easily understood. First of all, when the methyl-1,4-hexadiene of the present invention is used as a comonomer, it is easy to control the molecular weight (correlated with MI) with hydrogen, but the cis-
When 1,4-hexadiene is used as a comonomer, even a slight change in the amount of hydrogen causes a large change in MI, making it extremely difficult to control the molecular weight. Second, when the methyl-1,4-hexadiene of the present invention is used as a comonomer, the activity increases significantly as the amount of hydrogen increases. This phenomenon is a major feature not seen in propylene homopolymerization.
Third, even when the methyl-1,4-hexadiene of the present invention is copolymerized with propylene, II and BD hardly decrease, and in the case of cis-1,4-hexadiene, these decreases are significant. This is in good contrast to the . Fourth, the activity of copolymerization of propylene with methyl-1,4-hexadiene is significantly greater than the activity of copolymerization with cis-1,4-hexadiene in the presence of hydrogen. FIG. 1 illustrates the relationship between the amount of hydrogen added and specific activity for Example 1 and Reference Example 1 (details will be described later). Example 2 0.4 liters of n-heptane, methyl-1,4-
Copolymerization with propylene was carried out using 0.1 liter of hexadiene, 160 mg of the solid catalyst component B and 1600 mg of diethylaluminum chloride as catalysts, and 150 ml of hydrogen at a total pressure of 7.
The test was carried out under the conditions of Kg/cm ² G/60°C/2.5 hours. The results were as follows. Polymerization activity 1130 (g-polymer/g-solid catalyst) II 97.5 (%) BD 0.48 (g/ml) MI 1.1 (g/10 min) Tm 154 (°C) Comonomer content 1.8 (mol%) Example 3 With ethylene Copolymerization with methyl-1,4-hexadiene was carried out using the same equipment as in Example 1, using 0.4 liters of n-heptane and methyl-1,4-hexadiene as solvents.
- Using 0.1 liter of hexadiene, 10 milligrams of the solid catalyst component C and 200 milligrams of TEA as catalysts, the partial pressure of ethylene was 4.5 kg/
The reaction was carried out at 85° C. for 1.5 hours while maintaining the temperature at cm ² G and varying the hydrogen partial pressure. The results are shown in Table 2. Reference example 2 Without using methyl-1,4-hexadiene,
Ethylene homopolymerization was carried out at various hydrogen partial pressures in the same manner as in Example 3, except that 0.5 liters of n-heptane, 5.0 milligrams of solid catalyst component C, and 100 milligrams of TEA were used. The results are shown in Table 2.

[Table] FIG. 2 illustrates the relationship between hydrogen partial pressure and specific activity for Example 3 and Reference Example 2 (details will be described later). Comparative Example 2 Ethylene copolymerization was carried out in the same manner as in Example 3 except that 0.1 liter of methyl-1,4-hexadiene was replaced with 0.1 liter of ethylidene norbornel. The results are shown in Table 2. The activity was significantly lower than that of methyl-1,4-hexadiene, and even at a hydrogen partial pressure of 4.5 Kg/cm ² G, the molten copolymer had no fluidity and could not be measured for MI. It can be seen that molecular weight cannot be controlled by hydrogen. 3 Illustration of the influence of hydrogen Figure 1 shows that when the amount of hydrogen added during polymerization is zero and the polymerization activity is 1, propylene and methyl-1,
This figure shows changes in specific activity due to hydrogenation in copolymerization with 4-hexadiene (Example 1) and propylene homopolymerization (Reference Example 1). From this figure, the homopolymerization of propylene (curve 2)
In contrast, in the copolymerization of propylene and methyl-1,4-hexadiene (curve 1), the activity significantly improves as the hydrogen amount increases. I understand. Figure 2 shows that when the polymerization activity is 1 when the hydrogen partial pressure is zero during polymerization, ethylene and methyl-1,4
- This figure shows changes in specific activity depending on hydrogen partial pressure in copolymerization with hexadiene (Example 3) and homopolymerization of ethylene (Reference Example 2). This figure shows that in the homopolymerization of ethylene (curve 4), the polymerization activity decreases markedly as the hydrogen partial pressure increases, whereas ethylene and methyl-1,4
-It can be seen that in copolymerization with hexadiene (curve 3), on the contrary, the polymerization activity is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a graph showing the results of Example 1 and Reference Example 1. FIG. 2 is a graph showing the results of Example 3 and Reference Example 2. Curve Example 1 Example 1 2 Reference Example 1 3 Example 2 4 Reference Example 2 FIG. 3 is a flowchart to help understand the technical content of the present invention regarding Ziegler catalysts.

Claims (1)

[Scope of Claims] 1. An unsaturated copolymer is produced by copolymerizing one or more α-olefins (A) selected from α-olefins having 2 to 12 carbon atoms and a nonconjugated diene (B). A method for producing an unsaturated copolymer, which is characterized by the following requirements (1) to (3). (1) As a polymerization catalyst, a Ziegler-Natsuta catalyst, which is a combination of a halogen-containing titanium compound or its composition and an organoaluminum compound, is used; (2) the non-conjugated diene is a branched 1,4-diene represented by the formula (); to be, (Here, R ¹ represents an alkyl group having 8 or less carbon atoms, and R ² and R ³ each represent a hydrogen atom or an alkyl group having 8 or less carbon atoms. However,
R ² and R ³ are both hydrogen atoms), and (3) copolymerization is carried out in the presence of hydrogen.