JPH0580493B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a low-crystalline ethylene random copolymer. More specifically, the present invention relates to a low-crystalline ethylene-based random copolymer that has a narrow molecular weight distribution and composition distribution, and is excellent in transparency, surface non-adhesion, and mechanical properties. [Prior art] Conventionally, low-crystalline ethylene/α-olefin/non-conjugated polyene copolymers such as ethylene/propylene/non-conjugated diene copolymer rubber have been used for molding elastic polymers that require weather resistance and heat resistance. Demand is also increasing for applications such as modifiers for various resins. A known method for producing it is to copolymerize ethylene, α-olefin, and non-conjugated polyene in the presence of a titanium-based catalyst consisting of a titanium compound and an organoaluminum compound or a vanadium-based catalyst consisting of a vanadium compound and an organoaluminum compound. It is being Low-crystalline ethylene/α-olefin/nonconjugated polyene copolymers obtained with titanium-based catalysts generally have poor random copolymerizability, wide molecular weight distribution and composition distribution, and poor transparency, surface non-adhesion, and mechanical properties. It's on.
In addition, the low-crystalline ethylene/α-olefin/nonconjugated polyene copolymer obtained with a vanadium-based catalyst has improved random copolymerizability, narrower molecular weight distribution and compositional distribution, and narrower molecular weight and composition distributions than those obtained with a titanium-based catalyst. Although transparency, surface non-adhesiveness, and mechanical properties are considerably improved, these properties are still insufficient for applications where these properties are strictly required. - Non-conjugated polyene copolymers are required. On the other hand, a catalyst comprising a zirconium compound and an aluminoxane has been proposed as a new Ziegler type olefin polymerization catalyst in the following series of prior art documents. However, none of these prior art documents contain low-crystalline ethylene, α-olefin,
There is no description specifically suggesting a non-conjugated polyene copolymer. JP-A-58-19309 describes the following formula (cyclopentadienyl) ₂ MeRHal where R is cyclopentadienyl, C ₁ to C ₆
- alkyl, halogen, Me is a transition metal, Hal is a halogen, and a transition metal-containing compound represented by the following formula Al ₂ OR ₄ (Al(R)-O) _o , where R is methyl or ethyl and n is 4
consisting of a linear aluminoxane represented by the number ~20 or a cyclic aluminoxane represented by the following formula (Al(R)-O) _o+2 , where the definitions of R and n are the same as above. A method is described in which ethylene and one or more _C3 to _C12 α-olefins are polymerized at temperatures from -50°C to 200°C in the presence of a catalyst. In the same bulletin,
To adjust the density of the resulting polyethylene, 10
It is stated that the polymerization of ethylene should be carried out in the presence of small amounts of up to % by weight of somewhat long-chain alpha-olefins or mixtures. In Japanese Patent Application Laid-open No. 59-95292, the following formula is

[Formula] Here, n is 2 to 40, and R is C ₁ to C ₆ alkyl.

[Formula] Here, the definitions of n and R are the same as above, and an invention relating to a method for producing a cyclic aluminoxane represented by the following is described. The publication states that when olefin polymerization is performed by mixing, for example, methylaluminoxane produced by the same production method with a titanium or zirconium bis(cyclopentadienyl) compound, the amount of olefin produced per gram of transition metal and per hour is ,
It is stated that more than 25 million g of polyethylene can be obtained. In Japanese Patent Application Laid-open No. 60-35005, the following formula is

[Problem that the invention seeks to solve]

An object of the present invention is to provide a novel low-crystalline ethylene random copolymer. Another object of the present invention is to provide an ethylene-based random copolymer that has a narrow molecular weight distribution and composition distribution, is excellent in transparency, surface non-adhesion, and mechanical properties, and has low crystallinity. Still another object of the present invention is, for example, stress at break,
The object of the present invention is to provide a low-crystalline ethylene-based random copolymer that is excellent in mechanical properties such as elongation at break. Further objects and advantages of the present invention will become apparent from the description below. [Means and effects for solving the problems] The objects and advantages of the present invention are that ethylene,
A low-crystalline ethylene-based random copolymer from an α-olefin having 3 to 10 carbon atoms and a nonconjugated polyene having 5 to 20 carbon atoms, the content of which is (a) ethylene component 50 to 95 moles; %, and the content of α-olefin component is 5 to 50%.
(b) the intrinsic viscosity [η] measured in decalin at 135°C;
is in the range of 0.5 to 10 dl/g, (c) the molecular weight distribution (w/n) determined by gel permeation chromatography is 3 or less, and (d) the crystallization rate determined by X-ray diffraction method. (e) The following formula () B≡P _OE /2P _O・P _E ... () [In the formula, P _E is the ethylene component derived from the non-conjugated polyene component in the copolymer. represents the molar fraction of the ethylene component, P _O represents the molar fraction of the α-olefin component, and P _OE represents the molar fraction of the α-olefin/ethylene chain in all dyad chains. The value is in a range that satisfies the following formula () 1.00≦B≦2 ... (), and (f) ^{the 13} C-NMR spectrum shows that two adjacent tertiary groups in the copolymer main chain (g) A low-crystalline ethylene-based random copolymer characterized by having a boiling methyl acetate soluble portion of 2.0% by weight or less, in which αβ and βγ signals based on methylene chains between carbon atoms are not observed. achieved. The low-crystalline ethylene-based random copolymer of the present invention is produced by producing ethylene in the presence of a catalyst consisting of (A) a zirconium hydride compound having a group having conjugated π electrons as a ligand, and (B) aluminoxane. , α-olefins having 3 to 10 carbon atoms and 5 to 20 carbon atoms
It can be produced by a method of copolymerizing non-conjugated polyenes. The zirconium hydride compound (A) having the above-mentioned group having conjugated π electrons as a ligand can be prepared, for example, by the following formula () R ¹ R ² R ³ ZrH ... () where R ¹ represents a cycloalkadienyl group. ,
R ² and R ³ are a cycloalkadienyl group, an aryl group, an alkyl group, a halogen atom, or a hydrogen atom. The cycloalkadienyl group is, for example, a cyclopentadienyl group, a methylcyclopentadienyl group,
These include ethylcyclopentadienyl group, dimethylcyclopentadienyl group, indenyl group, and tetrahydroindenyl group. Examples of the alkyl group for R ² and R ³ include a methyl group, ethyl group, propyl group, isopropyl group, butyl group, and examples of the aryl group include a phenyl group, benzyl group, and neophyl group. For example, examples of the halogen atom include fluorine, chlorine, and bromine. Examples of the zirconium hydride compound include the following compounds. Bis (cyclopentadienyl) zirconium monochloride monohydride, bis (cyclopentadienyl) zirconium monobromide monohydride, bis (cyclopentadienyl) methyl zirconium hydride, bis (cyclopentadienyl) ethyl zirconium hydride, bis ( cyclopentadienyl)cyclohexylzirconium hydride, bis(cyclopentadienyl)phenylzirconium hydride, bis(cyclopentadienyl)benzylzirconium hydride, bis(cyclopentadienyl)neopentylzirconium hydride, bis(methylcyclopentadi) enyl)zirconium monochloride monohydride, bisindenylzirconium monochloride monohydride, The above zirconium hydride compounds can be used as is, but solvents such as toluene such as bis(cyclopentadienyl)zirconium monochloride monohydride may be used as is. It is preferable to use the compound that is poorly soluble in the organic aluminum compound after contacting it with the organoaluminum compound. By this operation, a zirconium hydride compound that is poorly soluble in a solvent can be made easily soluble in a solvent. Specifically, the organoaluminum compound to be brought into contact with the zirconium hydride compound is trimethylaluminum, triethylaluminum,
Trialkyl aluminum such as tributyl aluminum, trialkenyl aluminum such as triisoprenyl aluminum, dialkyl aluminum alkoxide such as dimethyl aluminum methoxide, diethyl aluminum ethoxide, dibutyl aluminum butoxide, methyl aluminum sesquimethoxide, ethyl aluminum sesquiethoxide, etc. In addition to alkyl aluminum sesquialkoxides, partially alkoxylated alkylaluminums with an average composition of R ¹ _2.5 Al(OR ² ) _0.5 , etc., dialkyls such as dimethylaluminum chloride, diethylaluminum chloride, dimethylaluminum bromide Examples include partially halogenated aluminum alkyls such as aluminum halide, alkyl aluminum sesquihalides such as methylaluminum sesquichloride and ethylaluminum sesquichloride, and alkyl aluminum dihalides such as methylaluminum dichloride and ethylaluminum dichloride. The reaction of both compounds is preferably carried out in a hydrocarbon medium while blocking light, and the mixing molar ratio of the organoaluminum compound and zirconium compound (Al/Zr)
is 0.5 to 30, preferably 1 to 20, and the concentration of zirconium is 0.001 to 1 per liquid phase.
It is sufficient to keep the amount in mole, preferably about 0.005 to 0.1 mole, and to bring the two into contact at a reaction temperature of about 0 to 120°C. The hydrocarbon medium can be selected from those exemplified as the polymerization solvent described later. Specifically, the aluminoxane (B) of the catalyst component used in the above method has the general formula () or the general formula ()

[ka]

[Sample preparation]

(a) Transfer the sample to an Erlenmeyer flask together with o-dichlorobenzene solvent to a concentration of 0.1 wt%. (b) Add 0.05 wt% of the anti-aging agent 2,6-di-tert-butyl-p-cresol to the polymer solution in the Erlenmeyer flask containing the sample. (c) Heat the Erlenmeyer flask to 140°C and stir for about 30 minutes to dissolve. (d) Apply the liquid to GPC. [GPC measurement conditions] It was carried out under the following conditions. (a) Equipment manufactured by Waters (150C-ALC/GPC) (b) Column manufactured by Toyo Soda (GMH type) (c) Sample amount 400μ (d) Temperature 140℃ (e) Flow rate 1ml/min The crystalline ethylene random copolymer has low crystallinity, and its crystallinity determined by X-ray diffraction is 30% or less, preferably 20% or less, and particularly preferably in the range of 0 to 15%. Furthermore, the low-crystalline ethylene random copolymer of the present invention has the following formula () B≡P _OE /2P _O・P _E ... () [In the formula, P _E is the non-conjugated polyene component in the copolymer. [ _PO] indicates the mole content of the ethylene component, including the ethylene component derived from The B value is within a range that satisfies the following formula () 1.00≦B≦2 (). The above B value is an index representing the distribution state of each monomer in the copolymer chain.
(Macromolecules, 15 , 353 (1982)), GJRay
(Macromolecules, 10 , 773 (1977)) et al., it is calculated by determining the above definitions P _E , P _O and P _OE . The larger the B value, the fewer block-like chains, the more uniform the distribution of ethylene and α-olefin, and the narrower the composition distribution of the copolymer. The low crystalline ethylene random copolymer of the present invention preferably has the following B value. 1.2−0.2×P _E ≦B≦1/P _E , more preferably the general formula 1.3−0.3×P _E ≦B≦1/P _E , particularly preferably the general formula 1.4−0.4×P _E ≦B≦1/P _E , The composition distribution B value is approximately in a 10mmφ sample tube.
The ^13C -NMR spectrum of a sample obtained by uniformly dissolving 200mg of copolymer in 1ml of hexachlorobutadiene is usually measured at a measurement temperature of 120℃ and a measurement frequency of 120℃.
25.05MHz, spectrum width 1500Hz, filter width
1500Hz, pulse repetition time 4.2sec, pulse width
Measurement was performed under measurement conditions of 7 μsec and 2000 to 5000 integration times, and calculations were made by determining P _E , P _O , and P _OE from this spectrum. Furthermore, in the 13C-NMR spectrum of the low-crystalline ethylene random copolymer of the present invention, there are αβ and βγ signals based on methylene chains between two adjacent tertiary carbon atoms in the copolymer main chain. is not observed. For example, in the copolymer chain part of ethylene and 1-butene, the following bonds:

[C] is the tertiary carbon on the left derived from 1-hexane, and the three methylene groups in the center are α, β,
On the other hand, when viewed from the tertiary carbon on the right side, the positions are α, β, and γ from the right. Therefore, in the above bonding unit, there are methylene groups that give αγ and ββ signals, but there are no methylene groups that give αβ and βγ signals. Similarly, a lower bond in which 1-butenes are bonded head-to-tail:

In the formula, there is only a methylene group that gives an αα signal, and there are no methylene groups that give αβ and βγ signals. On the other hand, the following combination

[ka] and

〔Example〕

Next, the present invention will be specifically explained using examples. Example 1 Preparation of zirconium catalyst 30 ml of toluene and bis(cyclopentadienyl) were placed in a 100 ml glass flask that was sufficiently purged with nitrogen.
2 mmol of zirconium monochloride monohydride was charged and made into a slurry. Trimethylaluminum diluted with toluene (1M solution)
20 mmol was added dropwise at room temperature. After the dropwise addition was completed, the temperature was raised to 60°C and the mixture was reacted for 1 hour.
Bis(cyclopentadienyl)zirconium monochloride monohydride was dissolved in toluene and the solution turned dark red. Incidentally, the above reaction was carried out in the absence of light. Preparation of methylaminoxane 13.9 g of magnesium chloride hexahydrate and 125 ml of toluene were placed in a 400 ml glass flask that had been sufficiently purged with argon, and after cooling to 0°C, toluene was added.
250 mmol of trimethylaluminum diluted in 125 ml was added dropwise. After the dropwise addition was completed, the temperature was raised to 70°C and the reaction was continued at that temperature for 96 hours. After the reaction, solid-liquid separation was performed by filtration, and toluene was removed from the separated liquid under reduced pressure to obtain 7.3 g of methylaminooxane as a white solid.
I got it. The molecular weight determined by freezing point depression in benzene was 1910, and the m value of the aluminoxane was 31. During the polymerization, the aluminoxane was redissolved in toluene. Polymerization Using the continuous polymerization reactor in step 2, purified toluene was added at 1/hr, methylaluminoxane was added at 5 mg atom/hr in terms of aluminum atoms, and the zirconium catalyst prepared above was added at 1×10 ^-2 in terms of zirconium atoms. Ethylene 360
/hr, 1-butene 240/hr, and dicyclopentadiene 3g/hr were continuously supplied at a rate of 25°C, normal pressure, residence time 1 hour, and polymer concentration 15g/hr. Ivy. The generated polymer solution is continuously extracted from the polymerization vessel,
Polymerization was stopped by adding a small amount of methanol, and the polymer solution was further transferred into a large amount of methanol, and the precipitated polymer was dried under reduced pressure at 80° C. for 12 hours. Ethylene content 89.4 mol%, 1-butene content 9.4 mol%, dicyclopentadiene content 1.2 mol%, [η] 1.41 dl/g, iodine value 9.5, w/
A rubbery polymer was obtained with n=2.13, crystallinity 6.1%, B value 1.09, boiling methyl acetate soluble portion 0.25% by weight, and density 0.888 g/cm ³ . JIS K of this polymer
- Stress at break, elongation at break, JIS A hardness measured according to JIS K-6301, and transparency (haze value) of a 1 mm thick sheet formed according to JIS K-6758.
were 110Kg/cm ² , 980%, 74, and 2.1%, respectively. In the ¹³ C-NMR spectrum of the obtained polymer, no αβ and βγ dicnals based on methylene chains between two adjacent tertiary carbon atoms were observed. Activity per unit zirconium is 1500g
-Polymer/milligram atom-Zr. Furthermore, 100 parts by weight of copolymer, 5 parts by weight of zinc white,
Stearic acid, 1.5 parts by weight, Carbon Black 55
Parts by weight, 10 parts by weight of naphthenic oil, 0.5 parts by weight of 2-mercaptobenzothiazole, 1.5 parts by weight of tetramethylthiuram monosulfide, 1.0 parts by weight of sulfur.
A blend was prepared by kneading parts by weight using an 8-inch oven roll at a roll temperature of 50°C for 30 minutes. This compound was press-vulcanized at 160° C. for 30 minutes, and the resulting vulcanizate was subjected to a tensile test according to JIS K-6301. Vulcanized physical properties are 300% modulus 180
Kg/cm ² , stress at break 350Kg/cm ² , elongation at break 440
%, JIS A hardness was 85. Examples 2 to 9, Comparative Example 1 Example 1 except that polymerization was performed under the conditions shown in Table 1.
I went exactly the same way. 13C− of the obtained polymer
In the NMR spectrum, dicnals at αβ and βγ positions based on methylene chains between two adjacent tertiary carbon atoms were not observed. The results are shown in Table 3. In addition, the compounding method during vulcanization in Examples 7 to 9 was changed as follows. In Example 7, 100 parts by weight of copolymer, 5 parts by weight of zinc white, 1 part by weight of stearic acid, 80 parts by weight of carbon black, 10 parts by weight of naphthenic oil, 1.0 parts by weight of sulfur, 2 parts by weight of naphthenic oil.
-0.5 parts by weight of methylcaptobenzothiazole, 1.0 parts by weight of tetramethylthiuram monosulfide In Examples 8 and 9, 100 parts by weight of copolymer, 5 parts by weight of zinc white, 1 part by weight of stearic acid, 40 parts by weight of carbon black. , 30 parts by weight of naphthenic oil, 1.5 parts by weight of sulfur, 2
- 1.5 parts by weight of methylcaptobenzothiazole, 0.5 parts by weight of tetramethylthiuram monosulfide Vulcanization time 20 minutes Comparative example 2 Using 15 continuous polymerization reactors, purified hexane was mixed at 5/hr, vanadyl trichloride and ethanol were mixed at 1/hr. A vanadium catalyst reacted at a molar ratio of 1:1 is 3.5 mg atom/hr in terms of vanadium atoms, and an organic aluminum prepared by mixing ethylaluminum sesquichloride and ethylaluminum dichloride in a molar ratio of 7/3 is 35 mg atom/hr in terms of aluminum atoms. Ethylene 380/hr and 1-butene were simultaneously supplied in the polymerization vessel at a rate of 380/hr.
270-hr, hydrogen 2/hr and dicyclopentadiene 30 g/hr were continuously supplied at the polymerization temperature.
Polymerization was carried out at 60° C., residence time: 1 hour, and polymer concentration: 70 g/min. At this time, the pressure inside the polymerization vessel was 7.2 Kg/cm ² (gauge). The subsequent operations were performed in the same manner as in Example 1. In the 13C-NMR spectrum of this polymer, signals at the αβ and βγ positions were observed due to methylene chains between two adjacent tertiary carbon atoms. The results are shown in Table 3. Comparative Examples 3 and 4 The same procedure as Comparative Example 2 was conducted except that polymerization was carried out under the conditions shown in Table 2. ^13C of the resulting polymer
-NMR spectra include αβ and βγ positions based on methylene chains between two adjacent tertiary carbon atoms.
A signal was observed. The results are shown in Table 3. Comparative Example 5 Preparation of titanium catalyst 800 with built-in 2.8Kg SUS ball (15mmφ)
2g of tetrabutoxytitanium in a ml SUS pot
and 20 g of anhydrous magnesium chloride were added thereto and pulverized for 8 hours under a nitrogen atmosphere (vibration mill). The co-ground product was transferred to 200 ml of ethylene dichloride and heated at 80°C for 2 hours. Thereafter, the co-pulverized product was separated and washed with n-decane until free titanium tetrachloride was no longer detected. In 1 g of the catalyst thus obtained,
21 mg of titanium atoms were supported. Polymerization Using the same polymerization apparatus as in Example 1, purified decane was added at 1/hr, ethylaluminum sesquichloride was added at 5 milligram atoms/hr in terms of aluminum atoms,
The titanium catalyst prepared above is calculated in terms of titanium atoms.
Continuously supplying ethylene at a rate of 0.25 milligram atoms/hr, 300/hr of ethylene simultaneously in the polymerization vessel,
1-butene 100/hr, and 5-ethylidene-
2-Norbornene was continuously supplied at a rate of 10 g/hr, the polymerization temperature was 110 DEG C. under normal pressure, the residence time was 1 hour, and the polymer concentration was 22 g/hr.
The subsequent operations were performed in the same manner as in Example 1. The activity per unit titanium was 90 g-polymer/milligram atom-Ti. ¹³ C− of the obtained polymer
In the NMR spectrum, no signals at the αβ and βγ positions based on the methylene chain between two adjacent tertiary carbon atoms were observed.

【table】

【table】

【table】

〔Effect of the invention〕

As described above, the low-crystalline ethylene random copolymer of the present invention has a narrow molecular weight distribution and a narrow composition distribution.
It has excellent transparency, non-stick surface and low crystallinity.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the process for producing the copolymer of the present invention.

Claims (1)

[Scope of Claims] 1. A low-crystalline ethylene-based random copolymer of ethylene, an α-olefin having 3 to 10 carbon atoms, and a nonconjugated polyene having 5 to 20 carbon atoms, comprising: (a) ethylene; The content of the components is in the range of 50 to 95 mol%, and the content of the α-olefin component is in the range of 5 to 50%.
(b) the intrinsic viscosity [η] measured in decalin at 135°C;
is in the range of 0.5 to 10 dl/g, (c) the molecular weight distribution (w/n) determined by gel permeation chromatography is 3 or less, and (d) the crystal size determined by X-ray diffraction (e) The following formula () B≡P _OE /2P _O・P _E () [In the formula, P _E represents the ethylene component derived from the non-conjugated polyene component in the copolymer. Indicates the molar fraction of the ethylene component not included, P _O indicates the molar fraction of the α-olefin component, and P _OE is the total
Indicates the mole fraction of α-olefin/ethylene chain in the dyad chain] The B ^value , expressed as (g) The boiling methyl acetate soluble fraction is 2% by weight or less. A low-crystalline ethylene-based random copolymer.