JPS62153307A - Ethlene copolymer - Google Patents

Abstract

PURPOSE:To obtain an ethylene/alpha-olefin random copolymer having a specified orientation coefficient, etc., and excellent transparency, impact strength, tear strength, etc., by copolymerizing ethylene with an alpha-olefin. CONSTITUTION:Ethylene is copolymerized with 1.0-30wt% 3-12C alpha-olefin at -80-100 deg.C and atmospheric pressure to an elevated pressure in the presence of a catalyst system comprising 1 mol of a V compound and 1-100 mol of an organoaluminum compound and a solvent by using, if necessary, a MW modifier such as H2. In this way, an ethylene/(3-12C) alpha-olefin random copoly mer which has a density of 0.890-0.940g/cm<3>, an intrisic viscosity of 1.0-3.5dl/g (as measured in tetrachlorobenzene at 135 deg.C and in which the orientation func tion of an amorphous chain, fam, upon cold drawing satisfies the relationship of formula I (wherein lambda is a draw ratio of sample), which, when analyzed by differential scanning calorimetry, shows a single sharp melting peak and satisfies the relationship of formula II (wherein Tm is the melting peak temperature and DELTAm is the melting enthalpy) and has an average spherulite radius <=4mm (as measured by laser beam small angle scattering method).

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to ethylene copolymers. More specifically, it relates to a random copolymer of ethylene and α-olefin.

<Prior art> In recent years, copolymers of ethylene and α-olefins have been produced using various polymerization methods, and linear low-density polyethylene (hereinafter referred to as
- Sometimes referred to as LLDPEJ. ), low-density polyethylene (hereinafter sometimes referred to as "LDPE"), widely used as a soft resin or elastomer7~)5
Of these, linear low-density polyethylene and soft resins are mainly produced using Ziegler catalysts by gas phase methods, slurry methods, solution methods, and high-pressure ionic polymerization methods. These compositional distributions are generally wide, and there are problems such as poor transparency due to the presence of highly crystalline components, and adhesion and stickiness of molded products due to low crystallinity or amorphous components. There is.

On the other hand, low-density polyethylene produced by high-pressure radical polymerization is generally a resin with excellent transparency, but it has poor mechanical properties such as tear strength, impact strength, and environmental stress cracking resistance (E8CR). Ethylene-α-olefin copolymers produced using type catalysts have problems such as poor transparency, even if they have a density comparable to or lower than that of low-density polyethylene produced by high-pressure radical polymerization. 0 <Problems to be solved by the invention> Under such current circumstances, the problems to be solved by the invention, that is, the purpose of the present invention, are to improve the ethylene-α- The purpose of the present invention is to provide olefin random copolymers. <Means for solving the problems> The present inventors have developed detailed structures of various ethylene-α-olefin copolymers obtained under various polymerization conditions. The analysis revealed that the optical properties and optical properties are greatly influenced by the uniformity of the higher-order structure (crystalline state) of the copolymer, and that the higher-order structure is based on the basic molecular structure and WS structure. The inventors have discovered that this directly corresponds to the uniformity between molecules, leading to the present invention.

That is, the present invention provides a kite with a density of 0.890 to 0.940 f and a kite with an intrinsic viscosity [y] (measured at 185° C. in tetrachlorobenzene) of 1.0 to 3.5 dll? , and ethylene and α having 1 to 20% by weight of carbon atoms of 8 to 12 whose orientation function fam of amorphous chains when cold-stretched satisfies the following relationship:
- Concerning fundum copolymers with olefins.

fam≧0.05λ+0.20 (λ≧2) However, here λ indicates the stretching ratio of the sample.0 The present invention is based on the following knowledge. It is mainly the composition distribution that determines the superiority or inferiority of mechanical properties.In other words, copolymers produced with titanium-based Tigue-Fu catalysts generally have a wide intermolecular composition distribution and are highly crystalline, containing only a small amount of one comonomer unit. The comonomer content contained in a single polymer is distributed over a wide range, from high-strength polymers to low-crystalline polymers containing a very large number of comonomer units. This creates a wide distribution of crystallinity, which causes the polymer to be unable to exhibit the mechanical strength that originally homogeneous polymers possess. It is said that the tie molecule that runs through the core has a major influence. In other words, the various chains that make up the amorphous part where stress is concentrated during polyethylene deformation,
Among the tie molecules, the loop molecules ()t-μ de molecules that leave the crystal and return to the same crystal, and the molecular ends, the tie molecules are the ones that are most oriented and bear the stress during deformation. Therefore, It is thought that the more tie molecules there are, and the more uniformly they are oriented during deformation, the stronger the mechanical strength will be.

Tie molecules do not have anisotropy, especially in unoriented samples, but when they are deformed, they become tense and take on a more stable trans-type conformational structure to support the stress, and also form amorphous chains in the stretching direction. 〇For this reason, it is thought that the orientation of the trans chains in the amorphous part directly provides information about the tie molecules. ◎The degree of orientation of the amorphous trans chains and its concentration according to the polarized infrared spectrum μ is greatly influenced by the crystallinity of the sample (S-
Homeda.

Makromol*kular* Chemfe, 18
L787 (1984)).

In other words, when the degree of crystallinity changes, the degree of orientation changes even with the same deformation rate.

Therefore, in a polyethylene sample with a wide distribution of crystallinity, when deformed, the tie molecules become non-uniformly oriented, stress is concentrated on some tie molecules, and high strength cannot be obtained. For example, in an ethylene copolymer with a narrow composition distribution and therefore a narrow distribution of crystallinity, the tension of the tie molecules is uniform, and the concentration of effective tie molecules that actually support stress is high, resulting in poor mechanical strength. As a result of intensive studies based on this idea, the present inventors found that an ethylene-α-olefin copolymer having a density within a certain range and a molecular weight above a certain level has a uniform crystal thickness. They discovered that amorphous trans chains with a certain degree of orientation have extremely high mechanical strength and excellent transparency compared to conventional commercially available polyethylene. The present invention will be explained in detail below. The copolymer of the present invention has similar density and intrinsic viscosity compared to ordinary copolymers, and the amorphous trans chains exhibit a large degree of orientation. This characteristic indicates that the copolymer of the present invention has a high concentration of effective tie molecules that support stress during deformation. The degree of orientation of crystalline trans chains can be determined as follows (S,
Dle Makroml@kulare Ch@m
1ee 185-787 (1984)).

Using 7 polarized infrared vectors, J35Q5cIn
-' internal reference band and 2Q15cm-' and 139
Absorption intensity A, respectively for the 4m-' trans-linked band. >s t At5sa and dichroism D2゜I
II'' D1114 is measured (here, D is the ratio of the absorption intensity of light polarized perpendicular to the stretching direction to that of light polarized parallel to it: A///A). Assuming additivity of the amorphous part, 0 f(tot)=μef"r)+(1-/jc) f""
) Coconi f(tot) ha whole, f(er) ha crystal part, f
(am) is the orientation function of the trans chain in the amorphous part, μ
C is the proportion of all transmethylene chains present in the crystal part expressed by the following formula.

μe-1/("k1185AtatsALF"Alm-
≦, %FW, anl) where k is the 7μ extinction coefficient of the subscript wavenumber band, and the value reported by Tein et al. can be used (B, E, Reed, R, S,
St@In, Macromolecule@s, 1゜1
16 (1968)) The sample was placed in an infrared beam bath, stretched at a constant speed, and kept in the stretched state.
Measure the infrared spectrum and find the orientation function. The copolymer of the present invention has a higher amorphous trans chain orientation function (fam) than conventional high-pressure LDPE or commercially available LLDPI, and when the stretching ratio is λ, fam and λ satisfy the following relationship: . A copolymer that satisfies the relationship fam≧0.05λ+0.20 (λ≧2) has much stronger tensile strength and impact strength than high-pressure LDPE or commercially available LLDPE. Those smaller than 0.05λ + 0.20 are equivalent to or lower than commercially available ILDPK, and no new characteristics can be found in the strength. It is characterized by a narrow thickness distribution, and as a result, this characteristic can also be seen in the relationship between melting peak temperature and endothermic amount in differential scanning calorimetry.

The copolymer of the present invention has a single sharp melting peak, and its peak temperature ('Trn: °C) and endotherm jl (
ΔHm:CaJt/f) is 0 that satisfies the following relationship.
ΔHm≦0.75Tm-56 (Tm≧80) Generally, commercially available LLDPI has multiple melting peaks, or even if there is only one apparent melting peak, it shows a broad melting curve with a long tail on the low temperature side. The apparent highest melting point is 1
Although the temperature is over 20°C, the overall heat absorption is not so high.

This suggests that the crystal thickness of commercially available LLDPH has a very wide distribution.Also, high-pressure LDPK generally has one sharp melting peak, but the melting peak towards the low temperature side Due to the skirting, the total endothermic amount is larger than that of the copolymer of the present invention, which does not satisfy the above formula.In other words, from a thermal analysis point of view, the copolymer of the present invention is more crystallized than the high-pressure LDPE. A copolymer that satisfies the above formula has a narrow crystal thickness distribution and therefore has excellent mechanical elasticity because the tie molecules are uniformly tensed during deformation according to the above-mentioned concept.

Other characteristics of the copolymer of the present invention include a slower crystallization rate and a smaller spherulite size than commercially available LLDPE. As mentioned above, commercially available LLDPE has a wide composition distribution and contains a highly crystalline component, so this component acts as a core during crystallization, promoting crystallization and increasing the spherulite size. Since it does not contain a highly crystalline component like LLDPE, the crystallization rate is slower than that of LLDPI even if the copolymer has the same density as LLDPI, and the spherulites do not grow as large. Although the crystallization rate and spherulite size generally vary depending on the crystallization conditions, the spherulite radius of the copolymer of the present invention is usually 4 μm or less, and the density of the copolymer of the present invention is 0.
890 to 0.940t7crA, preferably 0
．． In the range of 900 to Q, 985 f//ctA. If the density is less than 0.890 f/d, it is not preferred because of the stickiness of the molded product. If it exceeds 0.940 PA, the impact strength will decrease due to high crystallinity, and the high mechanical strength characteristic of the copolymer of the present invention cannot be fully exhibited, and the transparency of the molded product will also be poor, so it is not preferable. .

On the other hand, the intrinsic viscosity of the copolymer [value is 1.0 to 3.5 d]
It is desirable that it be in the range of i/f. If (3) is less than 1.0, even if the composition distribution is narrow due to the small molecular weight,
Those with a molecular weight exceeding @3.5, which do not have high mechanical strength, are not suitable for various processing as a single substance due to their high molecular weights.

The comonomer component for copolymerization has 8 to 12 carbon atoms.
of α-olefins can be used. Specifically, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 8-methyl-1-butene, 4-methy/L/-1-pentene, 5 −
Methyl-1-hexene, 5-methy/L/-1-heptene, 8-methy/L/-1-pentene, 8-methy/L/-
1-hexene, 4-methy/L'-1-hexene, 8-methy/l/-1-heptene, and mixtures thereof can also be used.

More preferably, 1-butene, l-hexe:/, 1-
octene, 3-methyl-1-pentene, 4-methy1v-
1-pentene is used. It is desirable that these components be contained in the copolymer in an amount of usually 1.0 to 80% by weight, preferably 3.0 to 20% by weight, in order to obtain a copolymer having the above density.

In the production of this copolymer, the catalyst and polymerization conditions must be selected appropriately.A catalyst system consisting of a vanadium compound and an organoaluminum compound is used as the catalyst.

Conventionally, so-called chib-two type catalysts have been particularly effective in producing ethylene copolymers, but among them, catalysts made from trivalent to delta-valent vanadium compounds (such as vanadium oxytrichloride) and organoaluminum compounds that are soluble in the polymerization solvent are used. It is well known that this catalyst has an extremely excellent effect on the copolymerization of ethylene and α-olefin. It is widely practiced industrially to produce F-7 tomer by co-merging ethylene with propylene or butene-1 using an O catalyst system (for example, Japanese Patent Publication No. 44-96 G8, (Japanese Patent Publication No. 46-11028, Japanese Patent Publication No. 47-26185) 0 However, this catalyst system is used when producing a copolymer with a high ethylene content (ethylene content of 70% by weight or more), or when the temperature is lower than 20°C. When polymerization is allowed to proceed at high temperatures, there are disadvantages in that the molecular weight distribution and composition distribution of the copolymer are wide and it is difficult to obtain a homogeneous copolymer.

For example, in the solution polymerization of FSTMER, high molecular weight components and highly crystalline components become insoluble in the polymerization solvent and precipitate during polymerization, resulting in operational problems such as blockage of polymer liquid extraction fins in industrial scale polymerization equipment. This can easily cause problems.

Therefore, as a catalyst for obtaining the copolymer of the present invention, a combination of a vanadium compound obtained by reacting vanadium trichloride with an alcohol and an organoaluminum compound is particularly effective.

This catalyst system has higher polymerizability than the above-mentioned soluble catalyst systems, and can also be used in polymerization at temperatures higher than 20°C, and the ethylene content in the copolymer exceeds 7 orm%. Even when producing an olefin copolymer, it has the characteristics of providing a homogeneous copolymer with narrow composition distribution and molecular weight distribution.

On the other hand, organoaluminum compounds have the general formula Y, -pAj
Xp (where Y is a hydrocarbon group, X is a halogen or alkoxy group, p is a expressed as 1 < p × 2), and it can be carried out with alkylaluminum sesquihalides, alkylaluminum cybarides, etc. Among them, aluminum sesquichloride is preferred.

When producing an ethylene copolymer using the vanadium compound and the organoaluminum compound, the molar ratio of the vanadium compound and the organoaluminum compound is usually 1:
It can be applied at a ratio of 1 to 1:100, preferably 1:2 to 1:30.

Polymerization can be carried out by the nullary polymerization method in the coexistence of a 11 catalyst and a 1 solvent.
Saturated hydrocarbons such as heptane and octane are preferred.

It is also possible to copolymerize ethylene in a liquid α-olefin using the catalyst system of the present invention in the absence of a hydrocarbon solvent ◇ The polymerization temperature can be varied within a wide range, but the total ~1
〇The polymerization is carried out at 00°C, and particularly preferably in the range of -80 to 80°C.〇The polymerization is carried out under atmospheric pressure or under pressure, and can be either batch polymerization or continuous polymerization.

In producing a copolymer by the method of the present invention, commonly used molecular weight regulators can be used in order to obtain a copolymer with an arbitrary molecular weight. In other words, diethylzinc, arylchloride, Phyto, pyridine-
N-oxide, hydrogen, etc. are often used, and hydrogen is particularly preferred◇ Next, methods for measuring various physical properties are shown. (1) Density: Determined according to JIB K6760-1981.

(Odor limiting viscosity f: Measured in trichlorobenzene at 185°C.

The stretching was carried out at room temperature and at a stretching speed of 24 mVmin.

(4) Comonomer-ra: Calculated from the infrared absorption spectrum of the copolymer.

(5) Melting temperature, endothermic amount: Birkin-Elmer Co. (Pe
Using a differential scanning calorimeter DSC2 model (manufactured by RKIN E1m@r), the sample was first held at 150°C for 5 minutes, then lowered at a rate of 5°C/min, and when it reached 30°C, the temperature was increased in 5°C steps. Then, the peak temperature of the melting power was read.

The amount of endotherm is calculated using the indium standard sample. The curve area was calculated using

(6) Molecular weight distribution: Measured at 140°C using orthodichlorobenzene as a solvent, and using Toyo Soda's Geyvermic Exchange Chromatography 811. (7) Spherulite size: Measured at 100 Kv' at 160°C. o
A quenched press sheet with a thickness of about 100 urns was prepared under the pressure of A, and it was determined by small-angle laser light scattering (5ALS). ◇That is, H-mass scattering obtained by passing the incident light through an analyzer with vertical polarization and the scattered light with horizontal polarization. R, S from the scattering angle θ that gives the maximum value of the image intensity distribution.

Using the formula St@in, the spherulite radius R is I asked for it.

θ=2sin-'(λ/*R) Here λ is the wavelength of the laser light (6328A).

(8) Tensile strength, elongation, etc.: JIS K-6760
〇(9) Tensile impact strength determined according to: A8TM D-1
0 obtained in accordance with 822 <Example> Next, the present invention will be specifically explained by examples, but the present invention is not limited to the examples as long as it does not depart from the gist.0 Example 1 ~4 Capacity Synthesis of Vanadium Compound 0.029 mol of vanadium trichloride and ethyl alcohol/'0.21 in an argon-substituted 109 mJ flask.
After adding 6 mo/I' and reacting at 50°C for 1 hour with stirring, 40 mj of n-hebutane was added and dried under reduced pressure at room temperature with stirring to obtain a pale green solid powder insoluble in n-hebutane. A vanadium compound was obtained.

When this vanadium compound was decomposed with pure water and its composition analyzed, 21% by weight of vanadium atoms, 48% by weight of chlorine atoms, and 40% by weight of C, H, OH were detected. decomposed with heavy water) and GC-M
When analyzed with S, C, H, and 00 were not detected.

Therefore, this vanadium compound is VCj, -2,IC,H
,OH (general formula V (OR)rnCJ,!n-nROH
It was a compound where Om and n are 0 and 2,1).

The X-ray powder spectrum of this vanadium compound is AST
M15-882 reports trichloride/< completely different from sodium), spectra specific to vanadium trichloride lv (
That is, d=5.75A, d-2,67A, d=
(Diffraction lines such as 1.74λ) were not observed 〇(B) Copolymerization of ethylene-butene-1 A 2J Sebafupur flask was equipped with a stirrer, a thermometer, a dropping funnel, and a reflux repulsion tube, and the pressure was reduced. After that, replace with nitrogen. Dry n-hexane lI was put into this flask and kept at a constant temperature of 80°C, and the vanadium compound (r) obtained in Example 1 was added.
It is abbreviated as A acid component. ) was added thereto for 10 minutes at a flow rate of 10 N115') to dissolve the mixed gas.

Next, a predetermined amount of ethylaluminum sesquichloride (abbreviated as rn component) (hereinafter, molecular formula (ClH8) 1.I
AI" was added (calculated as 7 for 10 m) to start copolymerization. The above mixed gas was flowed for 15 minutes while stirring, and polymerization was carried out at 80°C.

Under the present polymerization conditions, the polymer precipitated as the polymerization reaction progressed. On the other hand, even when a part of the n-hexane solvent was poured into a large amount of methanol, no polymer was precipitated at all, and all of the polymerized polymer was found to be insoluble in n-hexane. The precipitated polymer was mixed with methanol.
Table 1 shows the polymerization conditions and polymer yield, and Table 2 shows the physical properties of the obtained copolymer. Comparative Example 1 Used in Examples 1 to 4. Instead of the vanadium compound, 0.2 mmol of vanadium oxytrichloride (abbreviated as "A'component") which is soluble in the polymerization solvent and 2.0 mmol of ethylaluminum sesquichloride (abbreviated as rB acid component). Copolymerization was carried out in the same manner as in (B) of Examples 1 to 4, except that the mixed gas having the same composition as in Example 8 was dissolved at 80°C, and then the B component and the ^ component were added. The 0 results are shown in Tables 1 and 2 together with Examples 1 to 4.
In addition, the physical properties of commercially available polyethylene are also shown in Table 2 for comparison. Compared with Examples 1 to 4, the obtained copolymers were compositionally heterogeneous and had inferior mechanical strength. It was 〇5! Example 5 Synthesis of vanadium compound 0.068 mol of vanadium trichloride and 56 mJ of n-hebutane were added to argon-substituted 200 mJ fufusco, and the temperature was raised to 50°C, and 170.25 mol of methylalyl:I was added. In addition, the reaction was carried out for 1 hour at 50°C under stirring in an argon stream, and after the reaction, the supernatant liquid was extracted with a glass filter, washed 8 times with 50mj of n-hebutane, and dried under reduced pressure. - A dark green solid powdered vanadium compound insoluble in hebutane was obtained.0 The composition of this vanadium compound was analyzed in the same manner as in Examples 1 to 4: 21% by weight of vanadium atoms, 42% by weight of chlorine atoms, CHOH was 40% by weight, and CH and OD were not detected ◇ Therefore, this vanadium compound was VCIx-8,
OCR, 0H (general formula V (OR)-Cj s”m @
It was a compound in which m and n of nROH are O and 3.0). Further, in the X-ray powder spectrum of this compound, similar to the vanadium compounds obtained in Examples 1 to 4, no spectrum peculiar to vanadium dichloride was observed.

(B) Copolymer of ethylene-butene-1 After replacing with rugone, add 200 ml of dried n-hebutane and 0.150 mmol of the vanadium compound obtained in the above solution, and adjust the internal temperature of the flask with a thermometer and a stirrer. To 60℃! +It was warm.

A mixed gas containing 97 mol % of ethylene and 87 p% of butene-1 was flowed through this at a flow rate of 1 Nl for 15 minutes to dissolve the mixed gas.

Then ethylaluminum sesquichloride 2.90
mmol was added to start copolymerization.◎The above mixed gas was flowed for 80 minutes while stirring to perform polymerization at 80℃, and the polymer solution was poured into a large amount of methanol to recover the entire amount of copolymer.O Obtained The copolymer has a molecular weight of 3.70f, and the polymerization activity is determined by the polymerization amount (f) of the copolymer per 1 mmol of vanadium atoms (
Hereinafter, it will be abbreviated as rPolym@r/vI. ) is expressed as
Example 1 where P o 1 ym@r/V=58
As in ~4, the polymer was insoluble in total jin-hexane ◇ Table 8 shows the polymerization conditions and polymer yield, and Table 4 shows the physical properties of the obtained copolymer 〇 Comparative example 2 Example 50 Copolymerization was carried out in the same manner as in Example 5, except that 0.15 mmol of vanadium oxytrichloride and 1.65 mmol of ethylaluminum sesquichloride, which were soluble in the polymerization solvent, were used instead of the vanadium compound. , 5.92
A copolymer of o Polyrner/V x 89 was obtained.
Met. According to the differential scanning calorimetry analysis of the copolymer, the melting curve was broader overall than that of the copolymer obtained in Example 5, even though the melting peak temperature was about the same, and the composition distribution was different. It was spacious.

Table tfS8 and Table 4 show the polymerization conditions, results, etc. together with Example 5. 90 Examples 6 to 8 Example 5 Copolymerization of ethylene and hexene-1 was carried out using the same reactor as in (B).■ Hexene-1 was 0.88 tAj, and ethylene was 5Njt.
The above was simultaneously supplied to the reaction system at a constant rate for 15 minutes, and the hydrogen concentration was changed to obtain an ethylene-hexene-1 copolymer.
It was 148-77.

Table 5 shows polymerization conditions, polymer yield, etc., and Table 6 shows various physical properties of the obtained copolymer.

Comparative Example 8 Ethylene and hexene were prepared under the same conditions as in Example 6, except that as the vanadium compound, 0.20 mm7μ of vanadium oxytrichloride and 2.00 mm7μ of aluminum sesquichloride, which are soluble in the polymerization solvent, were used. Copolymerization with 1 and n-
A copolymer insoluble in hexane was obtained at 13.84 F (P
o 1) ryn@r/V-91).

According to differential scanning calorimetry, this material has a wide composition distribution;
As shown in Tables 5 and 6, despite having a high (5), the mechanical properties were inferior to that of the copolymer obtained in Example 6. For comparison, the physical properties of LLDPE are also shown in Table 6. Example 9 Synthesis of vanadium compound After replacing the 1j flask with a dropping funnel with argon,
= 0.852 mol of vanadium chloride and 500 mol of h-hegetane
mJ was added, the temperature was raised to 60°C, and 1.82 mol of ethyl alcohol was added dropwise from the dropping funnel over 10 minutes.Next, the oil path was heated to 120°C, and the temperature was raised to 60°C under stirring in an argon stream.
After the reaction for several hours, remove the supernatant using a force filter, and
It was washed 8 times with 50 mJ of n-hebutane and dried under reduced pressure to obtain a solid powdered vanadium compound insoluble in n-hebutane.

The composition of this vanadium compound was analyzed in the same manner as in Examples 1 to 4. Vanadium atoms were 19% by weight, chlorine atoms were 81% by weight, C, H, OH were 85% by weight, C, Hl
The OD was 8% by weight. Therefore, this vanadium compound is V(QC,H,). ,,C1□,,・2. OC,
It was a compound represented by H,OH. In addition, in the X-ray powder spectrum of this compound, similar to the vanadium compounds obtained in Examples 1 to 4 (5), no spectra specific to vanadium trichloride were observed.0 (B) Copolymerization of ethylene-decene-1 The procedure was repeated in the same manner as in Examples 6 to 8, except that 0, it t mmol of the vanadium compound obtained above and 2.28 mmol of ethamium sesquiculotide were used, and decene-1 was 0.
．． 8897 minutes, ethylene was supplied at a rate of 5 NJ/min for 4 minutes to perform copolymerization. During the polymerization, the polymer precipitated and no n-hexane soluble portion was present. Table 7 shows the polymerization conditions, polymer yield, etc., and Table 8 shows the physical properties of the obtained copolymer.

Comparative Example 4 Vanadium oxytrichloride was used as a vanadium compound at a concentration of 0.
Copolymerization of ethylene and decene-1 was carried out in the same manner as in Example 9 except that 200 mmol was used, and 13.08 f of a copolymer insoluble in n-hexane was obtained.
@r/Y = 90, which was the same as Example 9, but this copolymer had a wide composition distribution and had inferior mechanical properties to the copolymer of Example 9. Tables 7 and 8 The polymerization conditions, physical properties of the copolymer, etc. are shown in conjunction with Example 9. Effects of the Invention The present invention provides an ethylene-α-olefin random copolymer with excellent transparency, impact strength, tear strength, etc. Coalescing is provided.

Claims (1)

[Claims] (1) Density 0.890 to 0.940 g/cm^3,
Ethylene having an intrinsic viscosity [η] (measured at 135°C in tetrachlorobenzene) of 1.0 to 3.5 dl/g and an amorphous chain orientation function fam satisfying the following relationship when cold-stretched. α with 30% by weight of carbon atoms from 3 to 12
- Random copolymers with olefins. fam≧0.05λ+0.20 (λ≧2) where λ indicates the stretching ratio of the sample. (2) Claim 1, which has a single sharp melting peak in differential scanning calorimetry, and whose melting peak temperature (Tm) and heat of fusion (ΔHm) satisfy the following relationship: ethylene copolymer. ΔHm≦0.75Tm-56 (Tm≧80) (3) The average spherulite radius obtained by small-angle laser light scattering method is 4μ
The copolymer according to claim 1, which has a molecular weight of not more than m. (4) Density is 0.900 to 0.935g/cm^3
The copolymer according to claim 1, which is (5) The copolymer according to claim 1, wherein the α-olefin has 4 to 10 carbon atoms.