JPS5975909A - Ethylene/alpha-olefin copolymer resin - Google Patents

Abstract

PURPOSE:The titled resin excellent in rigidity, environmental stress cracking resistance, tear resistance, impact resistance, and transparency, and good in balance between heat resistance and low-temperature heat sealability, prepared by specifying composition and molecular weight distributions. CONSTITUTION:An ethylene/4-20Calpha-olefin copolymer resin having the following properties: MFR of 0.01-200g/10min; density of 0.900-0.945g/cm<3>; composition distribution parameter (U) defined by formula I (wherein Cw is a weight-average degree of branching, and Cn is a number-average degree of branching) of below 100; weight-average MW of high-ethylene content component Mwh/weight- average MW of low-ethylene content component Mwh ratio of below 1; MW distribution of high-ethylene content component (Mwh/Mnh)/MW distribution of low-ethylene content component (Mwl/Mnl) ratio of below 1; a plurality of melting points observed when measured with a differential scanning colorimeter (DSC); the maximum m.p. (T1) is higher than the temperature of the right hand side of formula II (wherein d is the density of the copolymer) and lower than 130 deg.C; and crystal melting heat quantity (H1)/total crystal melting heat quantity (Ht), of below 0.6.

Description

Detailed Description of the Invention The present invention provides an ethylene/α-olefin that has excellent environmental stress cracking resistance, rigidity, transparency, tear resistance, and impact resistance, and has a good balance of heat resistance and low-temperature heat sealability. Related to copolymer resin.

High-pressure low-density polyethylene (hereinafter sometimes referred to as HP-LIDPE) is flexible and has relatively good transparency, so it can be used in films, hollow containers, injection molded products, pipes, steel pipe coatings, electric wire coatings, foaming, etc. It is used in all fields such as molded products. However, HP-LDPR, on the other hand, has excellent impact resistance, tear resistance, and environmental stress cracking resistance (E'S C
R) etc., and its use is restricted in some areas.

On the other hand, low-density polyethylene (hereinafter sometimes referred to as LL-LDPE) obtained by copolymerizing ethylene and α-olefin having 3 or more carbon atoms under medium and low pressure using a transition metal catalyst is HP-' LI) Mechanical strength, ES compared to PE
Because it has excellent CR and good transparency, some use HP-L.
It is expected to replace DPE. However, in recent years, there has been a demand for resins with even higher strength and rigidity to meet the increasing speeds of packaging machines such as bag making machines and filling and packaging machines. From this point of view, the present applicant has previously developed a new ethylene copolymer (Japanese Patent Application Laid-Open No.
3-92887), but it was found that the ethylene copolymer specifically disclosed therein has a somewhat wide compositional distribution and includes low crystallinity, so it is somewhat lacking in rigidity. In addition, as an ethylene copolymer having a single melting point, for example, the method shown in Japanese Patent Publication No. 46-21212 or Japanese Patent Application Laid-open No. 57-105411 has been proposed. The first ethylene copolymer has the disadvantage that when it is imparted with low-temperature heat-sealability, its heat resistance is poor, and when its melting point is raised to impart heat resistance, its heat-sealability at low temperatures is poor. Furthermore, ethylene/α-olefin copolymers having a predetermined long chain branching index and a specific short chain branching distribution (Japanese Unexamined Patent Publication No. 57-1
No. 26809) has been proposed, but those specifically disclosed therein have a wide composition distribution and are poor in transparency and impact resistance.

Therefore, the present inventors have achieved excellent rigidity and ESCH, transparency, and
After studying the development of a copolymer that has tear resistance, impact resistance, and a good balance of heat resistance and low-temperature heat-sealability, we achieved the above objectives by adjusting the composition distribution and molecular weight distribution to a specific range. We found that it is possible and arrived at the present invention.

That is, in the present invention, (A) the melt 70-rate is 0.01 to 200 g/
10m1n.

(B) Density is 0.900 to 0.945 glon
.

(C) Composition distribution parameter (
U) is 100 or less, U=100X(0w7cm-1)"" (1) However, in the formula, Cw represents the weight average degree of branching and Cn represents the number average degree of branching.

(D) Ratio 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 ywh/
uwl is less than 1 and the ratio (Mwh/Mnh)/(
MWI/Mn1) is 1 or less, (E) differential scanning calorimeter (
There are multiple melting points measured by DSC), and among the multiple melting points, the highest melting point (T1) is equal to or higher than the temperature expressed by the following formula (5) and equal to or lower than 130°C, T1≧175 (1-43... -(5) However, in the formula, d is a value expressed by the density (g/z) of the copolymer.

(F) The ratio H1/HT of the heat of fusion of the crystal at the highest melting point: Hl measured by a differential scanning calorimeter (DSC) to the total heat of fusion of the crystal: HT is 0.6 or less, and (G) copolymerized with ethylene. An ethylene/α-olefin copolymer resin (hereinafter sometimes referred to as an ethylene copolymer) characterized in that the α-olefin used is in the range of 4 to 20 carbon atoms.
It provides:

The ethylene copolymer of the present invention is defined by the following (5) to (G).

(A) Melt flow rate (hereinafter abbreviated as VFR) is 0.
01 to 200g/10mln, preferably 0.05
to 150 g/10 m1n. MFR is 2
If it exceeds 0.00 g/10 m1n, it is not preferable because the moldability and mechanical strength are poor. Oi g/10 m
If it is less than in, the melt viscosity is high and the moldability is poor.

The MFR in the present invention is a value measured according to ASTM D 1238E.

(B) Density is 0.900 to 0.945 g/an
3, preferably in the range of 0.910 to 0.94 Cg/cm. If the density is less than 0.900 g/an, the blocking resistance will be poor, so it is not preferable.
Items over 67cm are transparent, tear resistant, impact resistant,
Low humidity heat sealability is poor. The density in the present invention is AS
This is a value measured using TMD 1505.

(C) The composition distribution parameter (ul) expressed by the following formula (1) is 1oo or less, preferably 9o or less.

U=100X(Cw/Cn-1) (1) where Cw represents the weight average degree of branching and Cn represents the number average degree of branching.

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. Specifically, in order to perform compositional fractionation of the ethylene copolymer, one polymer was dissolved in a mixed solvent of p-xylene and butyl cellosolve (volume ratio: 80/20), and diatomaceous earth (trade name: Celite etc. company (
A cylindrical column was filled with a cylindrical column, and a solvent with the same composition as the mixed solvent was transferred into the column.
While draining, reduce the internal temperature from 30°C to 5°C.
The coated ethylene copolymer was heated stepwise to 120° C. after being fractionated, reprecipitated in methanol, and dried separately to obtain a fractionated product. Next, the carbon number of each fraction is 100.
The number of branches C per 0 is the same as the following (1)) 13C-N
CW and Cn were determined by the least squares method, assuming that the number of branches C and the cumulative weight fraction I (wl) of each fractionation category followed the following log-normal distribution (Equation (2)).

However, in the formula, β2 is expressed as β2=21r+ (Cw/Cn) (3), and Co is expressed as C02=(:w-Cn +++ (4)).

In addition, the number of branches C determined by the 13C-NMR method is G and J.

Ray, P. E., Jo) 1nson and J.
R, Knox.

Macromolecules, l Cj, 775
(1'977), 150
It was determined from the area intensity using the methylene carbon signal observed in the NMR spectrum.

(D) Ratio y of the weight average molecular weight of the high ethylene content component: Mwh and the weight average molecular weight of the low ethylene content component: Mwl
wh/uw1 is less than 1, preferably 0.1 to 0.9
9, and the molecular weight distribution of the high ethylene content component (uw
b/nh) and the ratio of the molecular weight distribution of the low ethylene content component (u
wh /unh )/(ywl/yn1) is less than 1,
Preferably it is in the range of 0.1 to 1.0.

The weight average molecular weight wh of the high ethylene content component and the weight average molecular weight 14w1 of the low ethylene content component are determined based on the average branching degree of the unfractionated ethylene copolymer between each fraction obtained by the composition fractionation method. When divided into two on the branching side (if there is no branching degree that matches the average branching degree among the branching degrees of each fraction, divide the fraction closest to the average number of branches into two, and divide them into low-branching side and high-branching side, respectively) -9---
99=weight average molecular weight wh of the component with a high ethylene content, that is, the weight average molecular weight wh of the component with a high ethylene content, and weight average molecular weight Mwl of the component with a low branching side, that is, a component with a low ethylene content, respectively. In addition, the weight average molecular weight + of each fraction obtained by composition fractionation and the unfractionated ethylene/α-olefin copolymer was measured by 4W Hagel permeation chromatography (GPC), and the high ethylene, The content component GP (Jllfjl was determined by multiplying the ()PCII of each fraction by its weight fraction. wl/Mwh is less than 1, and ")
(Mwl/Mnl)/(MWh,/Mnb) is 1
The following means that it is characterized by containing a low molecular weight component with a high ethylene content, and by including this component, stiffness, E
The SCR is particularly improved. Furthermore, the ethylene/α-olefin copolymer of the present invention can be obtained by measuring the Mw of each fraction having a narrow composition distribution obtained by the above composition fractionation by GPC.
By measuring Mw and degree of branching (ethylene content)
When defined as follows on the molecular weight-composition distribution diagram expressed by This is preferable because it results in a copolymer with a high degree of stability.

That is, in a composition-molecular weight distribution diagram expressed six-dimensionally, with composition (branching degree) on the X axis, molecular weight (goods) on the Y axis, and weight fraction on the two axes, the degree of branching and unfractionated ethylene
The weight fraction corresponding to the degree of branching whose ratio to the average degree of branching of the α-olefin copolymer corresponds to the values shown in Table 1 (biaxial)
Molecular weight (goods) at 1/10 and 2/10 of the maximum value of
The ratio M/vya of the weight average molecular weight (ywa) of the unfractionated ethylene/α-olefin copolymer is expressed as the common logarithm log
The numerical values expressed in 1 g (M/uwa) must be within the ranges shown in Table 1 on the low molecular weight side and high molecular weight side, respectively.

Apparatus: 150C type column manufactured by Waters Co., Ltd. TSK OM H-6 (6) manufactured by Toyo Soda Kogyo Co., Ltd.
mmφX600mm) Solvent: 0-dichlorobenzene (ODC+-1) Temperature: 135°C Flow rate: 1. OJ/mj, n Injection concentration: 50mg/20m10DCB (injection ii”
↓400 tt (Rimata column elution volume was calibrated by the universal method using standard polystyrene manufactured by Toyo Soda Kogyo Co., Ltd. and Pressure Chemical Company.

(E) The ethylene/α-olefin copolymer of the present invention is D
There are multiple melting points measured by SC, and among the multiple melting points, the highest melting point (T1) is equal to or higher than the temperature expressed by the following formula (5), preferably equal to or higher than the temperature expressed by the formula (6). 130°C or less, preferably 125°C
It is as follows. Those whose T1 is less than the temperature expressed by formula (5) have poor heat resistance, and those whose T1 exceeds 130°C have poor transparency.

T1≧175d-43...(5) T1≧175c
l-42,5...(6) However, in the formula, d is a value expressed by the density (glon) of the copolymer.

The melting point and the heat of crystal fusion in term (F) in the present invention were measured by the following method. That is, using a differential scanning calorimeter, a sample (approximately 3 mg) was melted at 200'C for 5 minutes, then lowered to 20°C at a rate of 10°C/min, held at the same temperature for 1 minute, and then heated at 10°C/min. , n to 150'C, and an endothermic curve was measured. Next, as shown in Figures 1 and 2, connect the points of 60°C and 130°C on the endothermic curve, and define the part surrounded by the straight line (baseline) and the endothermic curve as the total heat of fusion of the crystal (HT). The temperatures corresponding to the portions appearing as peaks or shoulders on the endothermic curve were respectively designated as TT...T, n 2 from the high temperature side, and were defined as the melting point. In addition, when T1 appears as a peak, the heat of crystal fusion H1 of T1 is as shown in Fig. 1. A perpendicular line is drawn from the minimum point immediately on the low temperature side of T1 to the temperature coordinate axis, and the perpendicular line is surrounded by the baseline and the endothermic curve. The high temperature side part (
If it appears as a shoulder, draw a tangent at the inflection point immediately on the low temperature side of the shoulder and the inflection point on the high temperature side of T2, and draw a perpendicular line from the intersection of the two tangents, as shown in Figure 2. This is the high temperature side portion (shaded portion) surrounded by the perpendicular line, the baseline, and the endothermic curve.

(F) The ratio of TT1 to IT (H1/HT) measured by the DSC is 0.6 or less, preferably 0.01 to 0.55. If H1/'HT exceeds 0.6, the low-temperature heat sealability and transparency will be poor.

(C)) The σ-olefin copolymerized with ethylene has 4 to 20 carbon atoms. Preferably it is in the range of 6 to 1B. Specifically, the α-olefin having 4 to 20 carbon atoms includes, for example, 1-butene, 1-hexene, 4-methyl-1-
Pentene, 1-heptene, 1-octene, 1-decene,
When propylene is used as the Oα-olefin, which is 1-tetradecene, 1-octadecene, or a mixture thereof, the tear resistance, impact resistance, and environmental stress cracking resistance are poor.

The method for producing the ethylene copolymer of the present invention requires three components having narrow composition distributions and molecular weight distributions, namely, a low ethylene-low molecular weight component and a high ethylene-low molecular weight component.
A method in which a low molecular weight component and a low ethylene-high molecular weight component are prepolymerized separately and then mechanically mixed; or a method in which each component is polymerized in one polymerization reaction system, or uniformly polymerized while polymerizing the components;
A method of uniformly mixing or a method of combining these methods can be exemplified.

In order to obtain the ethylene copolymer of the present invention by mechanically mixing each component, it is necessary to pay sufficient attention to avoid poor dispersion of each component. Examples of the melt kneader used for mixing include a Banbury mixer, a kneader 1 twin screw extruder,
- A screw extruder etc. can be mentioned. Further, the order in which mechanical mixing is performed is not particularly limited.

Polymerization in one polymerization reaction system means producing a polymer mixture by producing each component sequentially or simultaneously in one or more reactors, and producing each component simultaneously in a number of reactors. When polymerizing the components, it is preferable to mix these components up to the inlet of the extruder. In addition, in the case of sequential polymerization, each component can be produced in any order, but in particular, in terms of molecular weight, the low molecular weight component is produced first, and in terms of density, the high density component (high ethylene content component) is produced first. It is preferable for polymerization operation to
Suitable for industrial production.

The components to be generated are not limited to the above three components, but include, for example, a low ethylene component with a narrow composition distribution and a wide molecular weight distribution, a low molecular weight component with a narrow composition distribution and high ethylene, or a low molecular weight component with a narrow composition distribution and a high molecular weight distribution. It may be two components, such as a low molecular weight component with a narrow composition distribution and a high molecular weight component with a narrow molecular weight distribution and low ethylene. As long as the ethylene copolymer satisfies the above (, A) to (G) terms, the composition and molecular weight of each component to be polymerized in advance are not particularly limited, but the composition and molecular weight of the obtained ethylene copolymer may be sufficiently controlled. For control, a manufacturing method using the three components described above is preferable.

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 obtained by treating a highly active solid component (a) with a specific surface area of 50 m/g or more containing titanium, magnesium and halogen as essential components with alfur (b), an organoaluminum compound catalyst component ( B)
Using a catalyst formed from the halogen compound catalyst component (Q), ethylene and α-olefin are copolymerized to a predetermined density.

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 (Q) can be omitted.

The highly active solid component (a) can itself be a highly active titanium catalyst component and is already widely known. Basically, a magnesium compound and a titanium compound are reacted with or without an auxiliary reaction agent so as to obtain a solid component with a large specific surface area. The solid component (a
) preferably has a specific surface area of about 50 to about 1000 m
/g% more preferably from about 80 to about 900 m/g; the composition generally includes a titanium content of from about 0.2 to about 18% by weight, preferably from about 0.3 to about 15% by weight; Halogen/titanium (atomic ratio) is about 4 to about 300, preferably about 5 to about 2oo, magnesium/titanium (atomic ratio) is about 1.
8 to about 200, preferably about 2 to about 120. In addition to these components, other elements, metals, functional groups, electron donors, etc. may be optionally included. For example, other elements or metals such as aluminum or silicon, and functional groups such as alkoxy groups or aryloxy groups may be included. One preferred method for producing the solid component is a method in which a complex of magnesium halide and 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. 50-32270.

The alcohols used in the treatment of the highly active solid component (a) include aliphatic, alicyclic or aromatic alcohols, and these include those having substituents such as alkoxy-18- groups. It's okay.

More specifically, methanol, ethanol, n-propanol, 180-propanol, tert-butanol, n-hexanol, n-octatool, 2-ethylhexanol, n-decanol, oleyl alcohol, cyclopentanol, cyclo Examples include hexanol, benzyl alcohol, isopropylbenzyl alcohol, cumyl alcohol, and methoxyethanol. Among these, it is particularly preferable to use aliphatic alcohols having 1 to 18 carbon atoms.

The alcohol treatment is preferably carried out in an inert hydrocarbon such as hexane or heptane, and usually the solid component (a) is mixed with 0.005 to 0.2 mofiv/l, particularly 0.01 mofiv/l.
1 to 0.1 mol/l of alcohol per 1 atom of titanium in solid component (a).
It is preferable to contact them in a molar ratio, particularly 2 to 50 molar. The reaction conditions vary depending on the type of alcohol, but are usually -20 to +150°C, preferably -10°C to +100°C, for several minutes to 10 minutes.
The reaction time is preferably about 10 minutes to 5 hours. By alcohol treatment, alcohol is incorporated into the solid component in the form of alcohol and/or alkoxy groups, with a concentration of 5 to 1 per titanium atom.
It is preferable to carry out the treatment so that the amount is 00 mol, particularly 5 to 80 mol. Part of the titanium may be detached from the solid component due to this reaction, and if such solvent-soluble components are present, after the reaction is complete, wash the obtained titanium catalyst component thoroughly with an inert solvent. It is better to subject it to polymerization.

The organoaluminum compound catalyst component (B) used together with the titanium catalyst component (A) thus obtained is typically represented by the general formula RnAlX3-9 (R is a hydrocarbon group, X is a halogen, 0<n≦3). Specifically, trialgylaluminum such as triethylaluminum and triisobutylaluminum, dialkylaluminum halides such as diethylaluminum chloride and diisobutylaluminum chloride, ethylaluminum heptasquichloride, and ethylaluminum sesquipromide. Examples include alkyl aluminum heptaskihalides, alkyl aluminum dichlorides such as ethyl aluminum dichloride, and mixtures thereof. When the halogen compound catalyst component (c) described later is not used, the average composition in the above general formula is 1.5≦n≦2.0, preferably 1.5≦n
It is preferable to use 1 ilE of the above (B) so that ≦1.8.

The halogen compound catalyst component (C) is a halogenated hydrocarbon such as ethyl chloride or isopropyl chloride, or one that can act as a halogenating agent for component (B) such as silicon tetrachloride. When a halogenated hydrocarbon is used, it can be used in a proportion of about 2 to 5 moles per mole of component (B).

In addition, when using a halogenating agent such as silicon tetrachloride, the total amount of halogen in component (B) and component (C) is 0.5 to 2 atoms per 1 atom of aluminum in component (B),
In particular, it is preferable to use them in a ratio of 1 to 1.5 atoms.

The copolymerization of ethylene can be carried out in the liquid phase or in the gas phase, for example at temperatures from 0 to about 600° C., in the presence or absence of an inert diluent. Particularly in the coexistence of an inert hydrocarbon, under conditions where the ethylene copolymer dissolves 120
to about 500℃, preferably 130 to 250℃
The desired ethylene copolymer can be easily obtained when copolymerization is carried out at a temperature of approximately
The amount of AJ used is about 0.0005 to about 1 mmol/(1°, preferably about 0.001 to about 0.1
mol/l, and organoaluminum compound catalyst component (
B) is an amount that maintains polymerization activity, and has an Al/Ti (atomic ratio) of about 1 to about 2,000. Preferably, the number is about 10 to about 500. The polymerization pressure is generally atmospheric pressure to about 1ookq/Cm, particularly about 2 to about 5
It is preferable to set it as θkg/1yn2.

The ethylene copolymer of the present invention has excellent ES CR% stiffness, good transparency, tear resistance, impact resistance, and heat resistance and low humidity heat resistance compared to HP LDPE as well as conventional L-LDPE. Due to its well-balanced sealing properties,
It is particularly suitable for packaging films, injection molded products, etc.
In addition to this application, it can be processed into various molded products such as films, sheets, monofilaments, tapes, containers, daily necessities, pipes, tubes, etc. by T-Guy molding, blown film molding, blow molding, injection molding, extrusion molding, powder molding, etc. can do. It can also be made into various composite films by extrusion or coextrusion molding with other films, and can also be used for applications such as steel W coating materials, electric wire sheathing materials, and foam molded products.

The ethylene copolymer of the present invention can be used with other thermoplastic resins such as HP-LDPE, medium density polyethylene, high density polyethylene, polypropylene 3, poly 1-butene, poly 4-
It can also be used in blends with polyolefins such as methyl-1-pentene, low-crystalline or non-crystalline copolymers of ethylene and propylene or 1-butene, and propylene-1-butene copolymers. Or petroleum resin,
Wax, heat-resistant stabilizers, weather-resistant stabilizers, antistatic agents, anti-blocking agents, lubricants, nucleating agents, pigments, dyes, inorganic or organic fillers, synthetic rubber, natural rubber, and the like can also be used in combination.

Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these embodiments in any way as long as it does not go beyond the gist of the invention.

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

1c1g'-' Mg A/. gt*) (w
t%) 3.7 67.0 20.0 0.4 4,8
Next, 500 mmol of ethanol was added at room temperature to 50 mmol of T1 of A-i suspended in purified hexane, the temperature was raised to 50''C, and the mixture was 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.

1.2 53.0 16.0 0. i22.6*)
The produced solid was decomposed and extracted with H2O-acetone, and then quantified as ethanol using gas chromatography.

<Polymerization> Three continuous polymerization reactors with an internal volume of 200 mm were used, each using dehydrated and purified hexane as a solvent, and diethylaluminum (B-1) and organic A (J as a compound component) obtained above as a T1 catalyst component. Using a 1:B mixture of monochloride and ethylaluminum sesquichloride, polymerization temperature: 165°C, total pressure: 30 & 9/α2, average residence time: 1
time, the concentration of the produced polymer relative to the solvent hexane was 130 g.
Continuous copolymerization of ethylene and 4-methyl-1-pentene (4MP-1) was carried out under the common conditions of /#. The feeding rates of the T1 catalyst component, 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 is 1:1:1. 135 of the copolymer polymerized in each reactor in decalin solvent.
Intrinsic viscosity [η) (d#/g) at °C, MFR (g/l
Table 3 shows the basic physical properties of the copolymer after mixing, and Table 5 shows the relationship between its composition and molecular weight.

Next, the copolymer was molded into a 20mmφmm-Blur film molding machine (manufactured by Brabender Co., Ltd.) to a width of 60mm and a thickness of 30μ.
It was made into a film. The molding conditions were a resin temperature of 180° C., a screw rotation speed of 40 rpm, a die diameter of 2/) mmφ, and a guide slit width Q of 5 mm.

Next, the film was evaluated by the following method.

Haze (%): ASTM D 1003 Impact Strength (
kg-cm/art): Tested using a Toyo Seiki film impact tester.

The impact head sphere was 1〃φ.

Elmendorf tear strength (/C7cm): JIS
Z 1702 Heat sealing start temperature ('C): Using a heat sealer manufactured by Toyo Tester, heat sealing was performed at the specified temperature at a pressure of 2 kg/an2 and a sealing time of 1 second. The test piece width was 15 mm, and the peel test speed was 300 mm/m1n. The heat sealing start temperature was set as the temperature at which the test piece began to break not due to peeling of the sealing surface but to the original fabric portion during the peel test.

Further, a test piece of 200 mm x 200 mm x 2 mm was prepared from the copolymer by press molding, and the following physical properties were measured.

ESCR (hours): ASTM D 1693 Biforce Softening Point ('C): ASTM D 1525 Yield Point Stress (kq/Cm): ASTM D 61 Results 6th
Shown in the table.

29- The ratio will be 2:1. The results are shown in Tables 3 to 6. Example 2 The same procedure as in Example 1 was carried out 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 carried out in the same manner as in Example 1. The results of the copolymers obtained in each reactor and the copolymers after mixing are shown in Tables 6 to 6.

Example 6 Two polymerization reactors similar to those in Example 1 were used, and in reactor R-1, the Ti catalyst component (AI obtained in Example 1) was used as the Ti catalyst component.
), diethylaluminum monochloride was used as the organic All compound component, the polymer concentration was set to 130 g/6 as in Example 1, and in reactor R-1, Example 1
Continuous polymerization was carried out using the same catalyst components as in the polymerization in each reactor, at a polymer concentration of 65 g/A', and at the feed rate of each component shown in Table 2. Mixing operation was performed in the same mixing tank as in Example 1. At this time, the rigidity was poor because the amount of each mixed 30-molecular weight component was small.

Comparative Example 1 Only one polymerization reactor was used, and (A-1) obtained in Example 1 was used as a Ti catalyst component, with 4*AI! Continuous polymerization and mixing were carried out under the conditions shown in Table 2 using triethylaluminum as the f-compound component. The results are shown in Tables 5 to 6.

The polymer obtained here had a wide compositional distribution and contained many highly crystalline and low crystalline substances, so it was inferior in transparency and low-temperature heat sealability.

Comparative Example 2 In Example 5, the catalyst component in reactor R-1, R
-2, and the supply rate of 4-methyl-1-pentene and hydrogen in n-1 and R-2.
Polymerization and mixing were carried out in the same manner as in Example 5 except for the changes shown in the table. The results are shown in Tables 5 and 6.

The polymer obtained here was prepared using two polymerization reactors similar to those in Example 1, each with a high ethylene content and a low In content.
Using (AI) as the catalyst component and triethylaluminum as the organic Ad compound component, the polymer concentration was 130 g.
/(J), continuous polymerization and mixing were carried out under the conditions shown in Table 2. At this time, the mixing ratio of the produced copolymers was 1:1.

The polymer obtained here has a wide composition distribution and includes high crystallinity and low crystallinity, so transparency and low-temperature heat sealability are still insufficient.

[Brief explanation of drawings]

FIGS. 1 and 2 show endothermic curves of ethylene copolymers determined by DSC. Go to application Mitsui Petrochemical Industries Co., Ltd. Agent Kazu Yamaguchi 41- Figure 1 2 Figure 2 2 130°C6o''C

Claims (1)

[Claims] (1) (A) Melt flow rate is 0.01 to 20
0g/10m1n. (B) Density is 0.900 to 0.945 g/G+. (C) The composition distribution parameter expressed by the following formula (1) is 100 or less, U=100X(Cw/Cn-1)...'(1) However,
In the formula, Cw represents the weight average degree of branching and Cn represents the number average degree of branching. (D) The ratio of the weight average molecular weight Mwh of the high ethylene content component to the weight average molecular weight wl of the low ethylene content component ywh/stone w1 is less than 1, and the molecular weight distribution (+awh/mnh) of the high ethylene content component and low ethylene tableware The ratio (ywh/unh)/(MWI/Mnl) to the molecular weight distribution (Mwl/Mnl) of the component is 1 or less, (E) There are multiple melting points measured by differential scanning calorimeter (DSC), and there are multiple melting points. The highest melting point (T
1) is at a temperature equal to or higher than the temperature expressed by the following formula (5), and 130
``C or less, T1≧175c1.-43...(5) However, in the formula, d is a value expressed by the density (gAm) of the copolymer. (F) Measured by differential scanning calorimeter (DSC) The ratio H1/HT of the highest melting point of the crystal heat of fusion i: H4 and the total crystal heat of fusion: HT is 0.6 or less, and (()) the α-olefin copolymerized with ethylene has a carbon number of 4 to 20. An ethylene/α-olefin copolymer resin characterized by the following.