JP2604945B2 - Inflation film of copolymer of ethylene and α-olefin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a copolymer of ethylene and α-olefin having excellent tensile properties, impact resistance and rigidity, excellent transparency, tear resistance and creep properties, and a good balance between heat resistance and low-temperature heat sealability. The present invention relates to a combined inflation film.

[0002] High-pressure low-density polyethylene (hereinafter HP-L)
DPE) is flexible and has relatively good transparency, so it is used in all fields such as films, hollow containers, injection molded products, pipes, steel pipe coating materials, electric wire coating materials, and foam molded products. ing. However, HP-LDPE, on the other hand, has impact resistance, tear resistance, environmental stress crack resistance (E
SCR) and its use is partially restricted.

On the other hand, low-density polyethylene (hereinafter sometimes referred to as L-LDPE) obtained by copolymerizing ethylene and α-olefin having 3 or more carbon atoms under a medium / low pressure using a transition metal catalyst, Compared to HP-LDPE, it is superior in mechanical strength and ESCR, and has good transparency. Therefore, it is expected to partially replace HP-LDPE.
However, in recent years, there has been a demand for a resin having higher strength corresponding to a higher speed of a packaging machine such as a bag making machine and a filling and packaging machine. Monofilament obtained from high-density polyethylene is high in strength but lacks flexibility, whereas monofilament obtained from HP-LDPE is flexible but inferior in tensile strength, and balances flexibility and tensile strength. There is also a demand for monofilament. From such a viewpoint, the present applicant has previously proposed a novel ethylene copolymer (Japanese Patent Application Laid-Open No. 53-92987), but the ethylene copolymer specifically disclosed herein has a somewhat broad composition distribution, It has been found that rigidity and tensile strength are insufficient due to the inclusion of low molecular weight and low crystallinity. Further, as an ethylene copolymer having a single melting point, for example, a method disclosed in JP-B-46-21212 or JP-A-57-105411 has been proposed. The ethylene copolymer has a disadvantage that heat resistance is inferior when heat sealability at low temperature is imparted, and heat sealability at low temperature is inferior when heat resistance is increased by increasing the melting point. Further, an ethylene / α-olefin copolymer having a specific long-chain branching index and a specific short-chain branch distribution (Japanese Patent Laid-Open No.
No. 126809) has been proposed, but those specifically disclosed therein have a wide composition distribution and are inferior in transparency and impact resistance.

Accordingly, the present inventors have proposed a copolymer which is excellent in rigidity, tensile strength and impact resistance, has good transparency, tear resistance and creep resistance, and has good heat resistance and low temperature heat sealability. As a result of studying the development of the present invention, it was found that the above object can be achieved by setting the composition distribution and the molecular weight distribution to specific ranges, and the present invention has been achieved.

That is, the present invention relates to: (A) a melt flow rate measured at 190 ° C. under a load of 2.16 kg of 0.01 to 200 g / 10 mi;
n, (B) a density of 0.900 to 0.945 g / c
m ³ , (C) a composition distribution parameter (U) represented by the following formula (1) is 100 or less;

[0006]

U = 100 × (Cw / Cn−1) (1) where Cw represents the weight average branching degree and Cn represents the number average branching degree.

(D) The weight average molecular weight Mwh of the high ethylene content component and the weight average molecular weight Mw of the low ethylene content component
l is Mwh / Mwl of 1.05 or more, and the ratio (Mw) between the molecular weight distribution of the high ethylene content component (Mwh / Mnh) and the molecular weight distribution of the low ethylene content component (Mwl / Mnl)
h / Mnh) / (Mwl / Mnl) is 1 or less. (E) There are a plurality of melting points measured by a differential scanning calorimeter (DSC), and the highest melting point (T
₁ ) is equal to or higher than the temperature represented by the following formula (5) and 130
℃ or less,

[0008]

T ₁ ≧ 175d−43 (5) where d is a numerical value represented by the density of the copolymer (g / cm ³ ).

[0009] (F) a differential scanning calorimeter (DSC) highest melting point of the crystalline heat of fusion as determined by: _{H 1} and all crystal fusion heat: the ratio _H 1 / _{H T} and _{H T} is 0.6 or less, and ( G)
Α-olefin copolymerized with ethylene has 4 carbon atoms
Ethylene and α
-To provide an inflation film of a copolymer with olefin.

The copolymer of the present invention comprises the following (A) to (G)
Defined by

(A) The melt flow rate (hereinafter abbreviated as MFR) measured at 190 ° C. under a load of 2.16 kg is 0.01 to 200 g / 10 min, and preferably 0.1 to 200 g / 10 min.
The range is from 05 to 150 g / 10 min. MFR
Is more than 200 g / 10 min, it is not preferable because moldability and mechanical strength are inferior.
Those with less than n have high melt viscosity and poor moldability. The MFR in the present invention is a value measured by ASTM D1238E.

(B) a density of 0.900 to 0.94
5 g / cm ³ , preferably 0.910 to 0.940
g / cm ³ . The density is 0.900 g / cm ³
If it is less than 0.945 g / cm ³ , transparency, tear resistance, impact resistance and low-temperature heat sealability are inferior. The density in the present invention is a value measured by ASTM D1505.

(C) The composition distribution is 100 or less, preferably 90 or less as a composition distribution parameter (U) represented by the following formula (1).

[0014]

U = 100 × (Cw / Cn−1)
(1) where Cw represents the weight average branching degree and Cn represents the number average branching degree.

When U exceeds 100, the composition distribution is wide and the transparency, tear resistance, impact resistance and low-temperature heat sealability are poor. Cw and Cn in the present invention are values measured by the following method. That is, in order to separate the composition of the copolymer, the copolymer is dissolved in a mixed solvent of p-xylene and butyl cellosolve (volume ratio: 80/20), and then diatomaceous earth (trade name: Celite # 560 Dijon Manville) (Made in the U.S.A.) and packed in a cylindrical column, and while the solvent having the same composition as the mixed solvent is transferred and discharged into the column, the temperature in the column is lowered from 30 ° C. to 5 ° C.
The temperature was raised stepwise to 120 ° C. in increments of ° C., and the coated copolymer was separated and then reprecipitated in methanol, followed by filtration and drying to obtain a separated product. Next, the number of branches C per 1000 carbon atoms of each fraction was determined by the same ¹³ C-NMR method as in the following item (D), and the number of branches C and the cumulative weight fraction I of each fractionation section were determined.
Cw and Cn were determined by the least squares method, assuming that (w) followed the following lognormal distribution (Equation (2)).

[0016]

(Equation 6)

Where β ² is represented by β ² = 2In (Cw / Cn) (3), and Co ² is represented by Co ² = Cw · Cn (4).

The number of branches C by ¹³ C-NMR method is
G. FIG. J. Ray, P.M. E. FIG. Johnson and J.S.
R. Knox) Macromolecules, 10 ,
773 (1977), ¹³ C-
Using the signal of methylene carbon observed in the NMR spectrum, it was determined from the area intensity.

(D) Weight average molecular weight of high ethylene content component: Mwh and weight average molecular weight of low ethylene content component:
The ratio Mwh / Mwl to Mwl is 1.05 or more, preferably in the range of 1.05 to 10, and the molecular weight distribution of the high ethylene content component (Mwh / Mnh) and the molecular weight distribution of the low ethylene content component (Mwl / Mnl) ) And the ratio (Mwh
/ Mnh) / (Mwl / Mnl) is 1 or less, preferably in the range of 0.1 to 1.0. The weight average molecular weight Mwh of the high ethylene content component and the weight average molecular weight Mwl of the low ethylene content component are low with respect to the average degree of branching of the unfractionated ethylene / α-olefin copolymer obtained from each fraction obtained by the composition fractionation method. When the two branches are divided into the branch side and the high branch side (if none of the branching degrees of each fraction match the average branching degree, the fraction closest to the average branching degree is divided into two equal parts, and (Added to the high branch side)
Is the weight average molecular weight Mwh of the component with a high ethylene content on the low branch side, and the weight average molecular weight Mwl of the component with a low ethylene content on the high branch side. or,
The weight-average molecular weight Mw of each fraction obtained by the composition fractionation and the unfractionated copolymer was measured by gel permeation chromatography (GPC), and the GPC curves of the high ethylene content component and the low ethylene content component were determined by gel permeation chromatography (GPC). ,
It was determined by multiplying the GPC curve of each fraction by its weight fraction and synthesizing. Mwh / Mwl is 1.05 or more, and (Mwh / Mnh) / (Mwl / Mnl) is 1
The following is characterized by including a high ethylene content high molecular weight component, a low ethylene content low molecular weight component and a low ethylene content high molecular weight component, and not including a high ethylene content low molecular weight component. By including the components, tensile strength, rigidity and impact resistance are particularly improved.
Still further, the ethylene / α-olefin copolymer of the present invention is obtained by measuring Mw of each fraction having a narrow composition distribution obtained by the above-mentioned composition fractionation by GPC, thereby obtaining Mw.
When defined as follows on a molecular weight-composition distribution diagram represented by w and the degree of branching (ethylene content), the tensile strength, rigidity, and impact resistance are further improved without lowering other physical properties such as transparency. It is preferable because it becomes a copolymer having good fluidity and extrudability.

That is, taking the composition (degree of branching) on the X-axis, the molecular weight (M) on the Y-axis, and the weight fraction on the Z-axis, in the three-dimensional composition-molecular weight distribution diagram, the degree of branching and the undivided ethylene The molecular weight at 1/10 and 2/10 of the maximum value of the weight fraction (Z-axis) corresponding to the degree of branching corresponding to the value shown in Table 1 with the ratio of the α-olefin copolymer to the average degree of branching The ratio M / Mwa of (M) to the weight-average molecular weight (Mwa) of the unfractionated ethylene / α-olefin copolymer is expressed by a common logarithm log ₁₀ (M / Mwa), where the values are on the low molecular weight side and the high molecular weight, respectively. Side is in the range of Table 1.

[0021]

[Table 1]

The measurement of M, Mw and Mn by GPC was performed under the following conditions.

Apparatus: 150C type manufactured by Waters Co., Ltd. Column: TSK GMH-6 (6 mmφ × 600 mm) manufactured by Toyo Soda Kogyo Co., Ltd. Solvent: o-dichlorobenzene (ODCB) Temperature: 135 ° C. Flow rate: 1.0 ml / min Injection Concentration: 30 mg / 20 ml ODCB (injection volume: 400 μl) The column elution volume was calibrated by a universal method using standard polystyrene manufactured by Toyo Soda Kogyo Co., Ltd. and Prescia Chemical Co., Ltd.

(E) The copolymer of the present invention has a plurality of melting points measured by DSC, and among the plurality of melting points, the highest melting point (T ₁ ) is equal to or higher than the temperature represented by the following formula (5). , Preferably not less than the temperature represented by the formula (6) and not more than 130 ° C, preferably not more than 125 ° C. T ₁ is one less than the temperature of the formula (5) is inferior in heat resistance, which T ₁ is exceeding 130 ° C. is inferior in transparency.

T ₁ ≧ 175d−43 (5) T ₁ ≧ 175d-42.5 (6) where d is a numerical value represented by the density (g / cm ³ ) of the copolymer. It is.

In the present invention, the melting point and the heat of crystal fusion in the item (F) were measured by the following methods. That is, using a differential scanning calorimeter, a sample (about 3 mg)
After melting at 5 ° C for 5 minutes, the temperature was lowered to 20 ° C at 10 ° C / min.
After holding at the same temperature for 10 minutes, the temperature was raised to 150 ° C. at a rate of 10 ° C./min to measure an endothermic curve. Then connect the points between 60 ° C. and 130 ° C. in an endothermic curve as shown in FIGS. 1 and 2, a straight line (base line) and the partial total crystal fusion heat surrounded by the endothermic curve (H _T), The temperatures corresponding to the peaks or shoulders appearing on the endothermic curve were defined as T ₁ , T ₂ ,. The heat of crystal fusion H ₁ of T ₁ is a perpendicular line is dropped to a temperature axis from immediately cold side minimum point of T ₁ as of FIG. 1 if T ₁ is appears as a peak, surrounded by said vertical line and the base line and the endothermic curve It is the part on the high temperature side (hatched part), and when it appears as a shoulder, as shown in FIG.
A tangent is drawn in the immediate inflection point of the low-temperature side and the high-temperature side of the change curve and T ₂ of the Shiyoruda, a perpendicular line is drawn from two of the tangent of the intersection,
This is a high temperature side portion (hatched portion) surrounded by the perpendicular line, the baseline, and the endothermic curve.

(F) H ₁ measured by the DSC
And the ratio of H _T (H ₁ / H _T ) is 0.6 or less, preferably 0.01 to 0.55. That H ₁ / _{H T} exceeds 0.6, the low-temperature heat sealability, poor transparency.

(G) The α-olefin copolymerized with ethylene has 4 to 20 carbon atoms, preferably 6 to 18 carbon atoms.
Range. Α-Olefin having 4 to 20 carbon atoms specifically includes, for example, 1-butene, 1-hexene, 4-
Methyl-1-pentene, 1-heptene, 1-octene,
1-decene, 1-tetradecene, 1-octadecene and mixtures thereof. When propylene is used as α-olefin, tear resistance, impact resistance and environmental stress crack resistance are poor.

As a method for producing the copolymer of the present invention, both the composition distribution and the molecular weight distribution are narrow.
A method in which two components, high ethylene / high molecular weight component, low ethylene / low molecular weight component, and low ethylene / high molecular weight component are separately polymerized beforehand and then mechanically mixed, and each component is polymerized in one polymerization reaction system. After or during the mixing, a method of mixing uniformly and uniformly, or a method of combining these methods can be exemplified.

In order to mechanically mix the components to obtain the copolymer of the present invention, it is necessary to pay careful attention so that the components do not cause poor dispersion. Examples of the melt kneader used for mixing include a Banbury mixer, a kneader, a twin-screw extruder, and a single-screw extruder. The order in which the mechanical mixing is performed is not particularly limited.

To polymerize in one polymerization reaction system means to produce a polymer mixture by sequentially or simultaneously producing each component in one or more reactors, and in a plurality of reactors. When simultaneously polymerizing the components, it is preferable to mix these components up to the inlet of the extruder. In the case of sequential polymerization, the components may be generated in any order. In particular, low molecular weight components are produced first in terms of molecular weight, and high density components (high ethylene content components) are produced first in terms of density. It is preferable from the viewpoint of the polymerization operation and suitable for industrial production.

The components to be formed are not limited to the above-mentioned three components. For example, a low ethylene component having a narrow composition distribution and a wide molecular weight distribution and a low ethylene component having a narrow composition distribution and a high molecular weight distribution with a high molecular weight distribution and a high ethylene content are preferable. In addition, two components such as a high molecular weight component having a narrow molecular weight distribution and a low molecular weight component having a narrow composition distribution and a low molecular weight distribution and a low molecular weight distribution may be used. In short, the obtained copolymer satisfies the above items (A) to (G). The composition and molecular weight of each component to be polymerized in advance are not particularly limited as long as it is known, but a production method using the above three components is preferable to sufficiently control the composition and molecular weight of the obtained copolymer.

The component having a narrow composition distribution and a narrow molecular weight distribution can be produced, for example, by the following method. For example, a titanium catalyst component (A) obtained by treating a highly active solid component (a) containing titanium, magnesium and halogen as essential components and having a specific surface area of 50 m ² / g or more with an alcohol (b), an organoaluminum Ethylene and α-olefin are copolymerized to a predetermined density using a catalyst formed from the compound catalyst component (B) and the halogen compound catalyst component (C). At this time, when part or all of the organoaluminum compound catalyst component (B) is a halogen compound, the use of the halogen compound catalyst component (C) can be omitted.

The highly active solid component (a) itself can be a highly active titanium catalyst component, and is already widely known. Basically, a magnesium compound and a titanium compound are reacted so as to obtain a solid component having a large specific surface area, with or without the use of an auxiliary reaction reagent.
The solid component (a) has a specific surface area of preferably about 50 to about 1000 m ² / g, more preferably about 80 to about 900 m ² / g, and its composition generally has a titanium content of about 0.2 to about 900 m ² / g. 18% by weight, preferably about 0.3
To about 15% by weight, halogen / titanium (atomic ratio) of about 4 to about 300, preferably about 5 to about 200, and magnesium / titanium (atomic ratio) of about 1.8 to about 20.
0, preferably about 2 to about 120. In addition to these components, other elements, metals, functional groups, electron donors and the like may be optionally contained. For example, aluminum or silicon may be contained as another element or metal, and an alkoxy group or an aryloxy group may be contained as a functional group. An example of a preferred method for producing the solid component is a method in which a complex of a magnesium halide and an alcohol is treated with an organometallic compound, and the treated product is reacted with a titanium compound. Details of this method are described in, for example, Japanese Patent Publication No. 50-322.
No. 70 is described.

Examples of the alcohol used for treating the highly active solid component (a) include aliphatic, alicyclic and aromatic alcohols, which have a substituent such as an alkoxy group. You may. More specifically, methanol, ethanol, n-propanol,
iso-propanol, tert-butanol, n-hexanol, n-octanol, 2-ethylhexanol, n-decanol, oleyl alcohol, cyclopentanol, cyclohexanol, benzyl alcohol,
Isopropylbenzyl alcohol, cumyl alcohol,
Methoxyethanol and the like can be exemplified. Among them, it is particularly preferable to use an aliphatic alcohol having 1 to 18 carbon atoms.

The alcohol treatment is preferably carried out in an inert hydrocarbon such as hexane or heptane. Usually, the solid component (a) is added in an amount of 0.005 to 0.2 mol / l, preferably 0.01 to 0.1 mol / l. Mol / l,
It is preferred that the alcohol is contacted with the titanium in the solid component (a) at a rate of 1 to 80 mol, particularly 2 to 50 mol per atom of titanium. Although the reaction conditions vary depending on the type of alcohol, the reaction is usually carried out at a temperature of -20 to + 150 ° C, preferably -10 ° C to + 100 ° C, for several minutes to 10 hours, preferably for about 10 minutes to 5 hours. Good to do. By the alcohol treatment, the alcohol is incorporated into the solid component in the form of an alcohol and / or an alkoxy group. The treatment is carried out so that the amount becomes 3 to 100 mol, particularly 5 to 80 mol, per atom of titanium. It is preferred to do so. Due to this reaction, a part of titanium may be desorbed from the solid component. When such a solvent-soluble component is present, after the reaction is completed, the obtained titanium catalyst component is thoroughly washed with an inert solvent, and It is good to be subjected to polymerization.

The organoaluminum compound catalyst component (B) used together with the titanium catalyst component (A) thus obtained.
Is a compound represented by the general formula R _n AlX _3-n (R is a hydrocarbon group, X is a halogen, 0 <n ≦ 3), and specifically, triethylaluminum, triisobutylaluminum Such as trialkylaluminum, diethylaluminum chloride, dialkylaluminum halide such as diisobutylaluminum chloride, ethylaluminum sesquichloride, alkylaluminum sesquihalide such as ethylaluminum sesquibromide, alkylaluminum dichloride such as ethylaluminum dichloride, or these. Mixtures and the like can be exemplified. When the later-described halogen compound catalyst component (C) is not used, the above-mentioned general formula (1.5) is such that the average composition is 1.5 ≦ n ≦ 2.0, preferably 1.5 ≦ n ≦ 1.8. It is preferable to use the component (B).

The halogen compound catalyst component (C) is a halogenated hydrocarbon such as ethyl chloride or isopropyl chloride, or a compound capable of acting as a halogenating agent for the component (B) such as silicon tetrachloride. When a halogenated hydrocarbon is used, it can be used in an amount of about 2 to 5 mol per 1 mol of the component (B). When a halogenating agent such as silicon tetrachloride is used, the total of the halogens of the components (B) and (C) is 0.5 to 2 atoms, preferably 1 to 1 atom of aluminum in the component (B).
It is preferable to use them at a ratio of from 1.5 to 1.5 atoms.

The copolymerization of ethylene can be carried out in the presence or absence of an inert diluent, for example at a temperature of from 0 to about 300 ° C., in the liquid phase or in the gas phase. Particularly, in the presence of an inert hydrocarbon, under conditions where the ethylene copolymer dissolves, the temperature is about 120 to 300 ° C., preferably about 13 ° C.
When the copolymerization is carried out at a temperature of about 0 to 250 ° C., a desired ethylene copolymer can be easily obtained. The amount of the titanium catalyst component (A) used is about 0.5 in terms of titanium atoms.
0005 to about 1 mmol / l, preferably about 0.001
To about 0.1 mol / l, and the organoaluminum compound catalyst component (B) is an amount that maintains the polymerization activity.
/ Ti (atomic ratio) is about 1 to about 2000, preferably about 10 to about 500.
The polymerization pressure is generally from atmospheric pressure to about 100 kg / cm ² , preferably from about 2 to about 50 kg / cm ² .

The copolymer of the present invention is excellent not only in HP-LDPE but also in tensile properties, impact resistance and rigidity, and excellent in transparency, tear resistance and creep properties, compared to conventional L-LDPE. In particular, it is suitable for filaments, tapes and films for packaging, because it is in harmony with heat resistance and low-temperature heat sealability.
It can be processed into various molded products such as films, sheets, tapes, monofilaments, containers, daily necessities, pipes and tubes by inflation / film molding, hollow molding, injection molding, extrusion molding, powder molding and the like. .
Also, various films can be formed by extrusion coating or co-extrusion molding on other films, and they are also used for applications such as steel tube covering materials, electric wire covering materials, and foam molded products.

[0041] The copolymer of the present invention may contain other thermoplastic resins,
For example, HP-LDPE, medium density polyethylene, high density polyethylene, polypropylene, poly 1-butene, poly 4
-Methyl-1-pentene, a copolymer of ethylene and propylene or 1-butene with low crystalline or amorphous,
It can also be used by blending with a polyolefin such as a propylene-1-butene copolymer. Or petroleum resin, wax, heat stabilizer, weather stabilizer, antistatic agent,
An anti-blocking agent, a lubricant, a nucleating agent, a pigment, a dye, an inorganic or organic filler, a synthetic rubber, a natural rubber, or the like can be blended and used.

Now, the present invention will be described in further detail with reference to Examples. However, the present invention is by no means restricted to these Examples unless it exceeds the gist thereof.

[0043]

Example 1 <Catalyst preparation> Under a nitrogen atmosphere, 1 mol of commercially available anhydrous magnesium chloride was suspended in dehydrated and purified hexane 21, and 6 mol of ethanol was added dropwise with stirring over 1 hour. Reacted for 1 hour. 2.6 mol of diethylaluminum chloride was added dropwise thereto at room temperature, and stirring was continued for 2 hours. Next, after adding 6 mol of titanium tetrachloride, the system was heated to 80 ° C.
The reaction was carried out with stirring for hours. The solid part after the reaction was separated and washed repeatedly with purified hexane. The composition of the solid (A-1) was as follows.

[0044]

Then, 500 mmol of ethanol was added at room temperature with respect to 50 mmol of Ti in A-1 suspended in purified hexane, and the mixture was heated to 50 ° C. and reacted for 1.5 hours. After the reaction, the solid portion was washed repeatedly with purified hexane. The composition of the catalyst (B-1) thus obtained was as follows.

[0046]

<Polymerization> Using three continuous polymerization reactors having an internal volume of 2001, hexane dehydrated and purified as a solvent, and (B-1) an organic Al compound component obtained above as a Ti catalyst component,
Using a 1: 3 mixture of diethylaluminum monochloride and ethylaluminum sesquichloride, a polymerization temperature of 165 ° C., a total pressure of 30 kg / cm ² , an average residence time of 1 hour, and a concentration of the produced polymer with respect to the solvent hexane of 130 g /
Continuous copolymerization of ethylene and 4-methyl-1-pentene (4MP-1) was carried out under the common condition of 1. The feed rates of the Ti catalyst component, the organic Al compound component, ethylene, 4-methyl-1-pentene, and hydrogen in each polymerization reactor were changed as shown in Table 2.
After the produced copolymer is discharged from each reactor,
The mixture was introduced into a mixing tank and mixed at 160 ° C. for an average residence time of 15 minutes. At this time, the mixing ratio becomes 1: 1: 1. 135 ° C in a decalin solvent of a copolymer polymerized in each reactor
In Table 3, the intrinsic viscosity [η] (dl / g), MFR, i-Bu branching degree, and density (D) are shown in Table 3, the basic physical properties of the copolymer after mixing are shown in Table 4, and the branching degree and Table 5 shows the relationship with the molecular weight.

Next, the copolymer was made into a film having a width of 350 mm and a thickness of 30 μm using a commercially available tumbler film molding machine for high-pressure polyethylene (manufactured by Modern Machinery). Molding conditions are: resin temperature 180 ° C, screw rotation speed 100r
pm, die diameter 100mmφ, die slit width 0.7mm
It is. Next, the film was evaluated by the following method. Haze (%): ASTM D1003 Impact strength (kg · cm / cm): Performed using a film impact tester manufactured by Toyo Seiki. The impact head sphere is 1 "φ
And

Elmendorf Tear Strength (kg / cm): JIS Z 1702 Heat Sealing Initiation Temperature (° C.): Using a heat sealer manufactured by Toyo Tester, heat sealing was performed at a specified temperature under a pressure of 2 kg / cm ^{2 for} a sealing time of 1 second. The test piece width was 15 mm, and the peel test speed was 300 mm / min. The heat-sealing start temperature was a temperature at which the test piece began to break in the peeling test, not according to the peeling of the sealing surface but to the breaking of the raw material portion.

The copolymer is press-molded to obtain
A 200 mm × 200 mm × 2 mm test piece was prepared, and the following physical properties were measured.

Vicat softening point (° C.): ASTM D 1525 Stress at yield (kg / cm ² ): ASTM D 638 Tensile strength at break (kg / cm ² ): ASTM D 638 Elongation at break (%): ASTM D 638 Results Are shown in Table 6.

Example 2 The procedure of Example 1 was repeated, except that the supply rates of the respective catalyst components, 4-methyl-1-pentene and hydrogen were changed as shown in Table 2. Polymerization and mixing operations were performed. Table 3 shows the results of the copolymer obtained in each reactor, and Tables 4 to 6 show the results of the copolymer after mixing.

Example 3 The same polymerization reactor as in Example 1 was used, and the reactor R-1 was used.
, Continuous polymerization was carried out at a polymer concentration of 65 g / l using the same catalyst components as in the polymerization in each reactor of Example 1. In reactor R-2, a Ti catalyst component was used in Example 1. The obtained (A-1), diethyl aluminum monochloride was used as the organic Al compound component, the polymer concentration was set to 130 g / l as in Example 1, and continuous polymerization was performed at a supply rate of each component shown in Table 2. Was done. As in Example 1, the mixing operation was performed in the mixing tank. At this time, the respective mixing ratios are 1: 2. The results are shown in Tables 3 to 6.

Examples 4 to 6 In the same manner as in Example 1, except that the supply rates of each catalyst component, 4-methyl-1-pentene and hydrogen were changed as shown in Table 2, Continuous copolymerization and mixing operations were performed. Table 3 shows the results of the copolymer obtained in each reactor, and Tables 4 to 6 show the results of the copolymer after mixing.

Comparative Example 1 Only one polymerization reactor was used, (A-1) obtained in Example 1 as a Ti catalyst component, triethylaluminum was used as an organic Al compound component under continuous conditions shown in Table 2. Polymerization was performed. The results are shown in Tables 3 to 6.

The polymer obtained here has a considerably wide composition distribution and contains many highly crystalline and low crystalline materials.
Transparency and low temperature heat sealability were poor.

Comparative Example 2 In Example 3, the catalyst component R
As in Example 3, except that the feed rates of 4-methyl-1-pentene and hydrogen in R-1, R-2 were changed as shown in Table 2, and the polymer concentration in the reactor R-1 was changed to 130 g / l. Polymerization and mixing were performed. At this time, the mixing ratio of the produced copolymer is 1: 1. The results are shown in Tables 3 to 6.

Since the polymer obtained here had a high ethylene content and a small amount of high molecular weight components, it was inferior in yield point stress and breaking point tensile strength.

Comparative Example 3 Two polymerization reactors similar to those in Example 1 were used,
(A-1) as a catalyst component, triethylaluminum as an organic Al compound component, and a polymer concentration of 130 g
/ L, continuous polymerization and mixing were performed under the conditions shown in Table 2. At this time, the mixing ratio of the produced copolymer is 1: 1. The results are shown in Tables 3 to 6.

The polymer obtained here has a considerably wide composition distribution, and includes high-crystalline and low-crystalline ones, so that its transparency, blocking resistance, and low-temperature heat sealability are not yet sufficient. Furthermore, since the content of the high molecular weight component was low with a high ethylene content, the yield point stress and the tensile strength at break were inferior.

[0061]

[Table 2]

[0062]

[Table 3]

[0063]

[Table 4]

[0064]

[Table 5]

[0065]

[Table 6]

[0066]

[Table 7]

[0067]

[Table 8]

[0068]

[Table 9]

[0069]

[Table 10]

[0070]

[Table 11]

[0071]

[Table 12]

[0072]

[Table 13]

[Brief description of the drawings]

FIG. 1 shows an endothermic curve of an ethylene copolymer by DSC.

FIG. 2 shows an endothermic curve of the ethylene copolymer by DSC.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 23:04

Claims (1)

(57) [Claims] (A) The melt flow rate measured at 190 ° C. under a load of 2.16 kg is 0.01 to 200.
g / 10 min, (B) Density 0.900 to 0.945 g / c
m ³ , (C) The composition distribution parameter (U) represented by the following equation (1) is 100 or less : U = 100 × (Cw / Cn−1) (1) where Cw Represents the weight average branching degree and Cn represents the number average branching degree. (D) The ratio Mwh of the weight average molecular weight Mwh of the high ethylene content component to the weight average molecular weight Mwl of the low ethylene content component
/ Mwl is 1.05 or more, and the ratio (Mwh / Mnh) between the molecular weight distribution (Mwh / Mnh) of the high ethylene content component and the molecular weight distribution (Mwl / Mnl) of the low ethylene content component
/ (Mwl / Mnl) is 1 or less, (E) There are a plurality of melting points measured by a differential scanning calorimeter (DSC), and the highest melting point (T
₁ ) is equal to or higher than the temperature represented by the following formula (5) and 130
T ₁ ≧ 175d-43 (5) where d is a numerical value represented by the density of the copolymer (g / cm ³ ). (F) Differential scanning calorie total (DSC) highest melting point of the crystalline heat of fusion as determined by: _{H 1} and all crystal fusion heat ratio of the _{H T H} 1 / _H
T is 0.6 or less, and (G) copolymerized with ethylene are α- olefin is inflation Chillon Huy of a copolymer of ethylene and α- olefin, which is a range of 20 C 4 -C
Lum .