JPS5922946A - Ethylene-alpha-olefin copolymer type resin composition of high quality for casting film and preparation thereof - Google Patents

Abstract

PURPOSE:A composition, prepared by incorporating two specific ethylene-alpha-olefin copolymers having different molecular weights in a specific proportion, and capable of giving films having improved transparency, impact strength, tear strength, heat-sealing properties and hot tack even by the ultrahigh-speed molding. CONSTITUTION:A composition obtained by incorporating (A) 60-70wt% ethylene-3-18C alpha-olefin copolymer having 0.895-0.935g/cm<3> density, 1.5-2.0dl/g intrinsic viscosity and 7-40 short side chains based on 1,000 carbon atoms with (B) 30-40wt% ethylene-3-18C alpha-olefin copolymer having 0.910-0.955g/cm<3> density, 0.6-1.5dl/g intrinsic viscosity and 5-35 short side chains based on 1,000 carbon atoms at 0.6-1.7 ratio (A/B) between the numbers of the short side chains in the copolymers (A) and (B). The resultant compositions has 0.910- 0.940g/cm<3>, preferably 0.910-0.929g/cm<3> density, 0.2-5g/10min, preferably 0.3- 4g/10min, melt index (MI) and 35-55 melt flow rate (MFR).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ethylene-α olefin copolymer resin composition for film forming and a method for producing the same. More specifically, a specific relatively high molecular weight ethylene-α olefin copolymer (copolymer-A) and a specific relatively low molecular weight ethylene-α olefin copolymer (copolymer-B)
) is mixed in a specific ratio to form an ethylene-α olefin copolymer system for film molding that has excellent processability and excellent transparency, impact strength, tear strength, heat sealability, and hot tack properties even in ultra-high-speed molded products. This invention relates to a resin composition and its production method using a multistage polymerization method.

Conventionally, low-density polyethylene (hereinafter referred to as
High-pressure polyethylene (high-pressure polyethylene) is known as a resin with relatively good transparency, and has been used for applications such as films and sheets. High-pressure polyethylene has excellent rheological properties in the melt, good productivity during extrusion processing, relatively low power consumption, and good nodal stability for blown film processing. In the case of film processing and extrusion lamination processing, there is little neck-in and overall processability is excellent, but on the other hand, the strength of the molded product is relatively weak.For example, in the case of blown film, tensile strength, tear strength, impact strength, etc. Even if it is small, it cannot be used because it has a thin wall, and since the price of petrochemical raw materials has skyrocketed, the fields in which it can be used have been restricted. Furthermore, with the advancement of automatic packaging systems in recent years, in addition to the requirement for low-temperature heat-sealing properties, since the contents are filled at the same time as heat-sealing, the sheet strength ( This property is called "contaminant sealability"), and in the packaging of oils, seal strength is required even when oil is attached to the seal part (this property is called "contaminant sealability"). However, high-pressure polyethylene still lacks such hot tack properties and impurity sealing properties.

On the other hand, a resin with a density similar to that of high-pressure polyethylene obtained by copolymerizing ethylene and α-olefin under medium-low pressure using a transition metal catalyst (hereinafter referred to as ethyl/α-olefin copolymer) is a molecular Although it has excellent mechanical strength because of its narrow 1-wage distribution, it has the problem of poor workability.

The inventors of the present invention conducted intensive studies to solve the problems of such ethylene-α-olefin coelectric resins, and as a result, we first determined the density, intrinsic viscosity, short chain branching degree, type of α-olefin, and even (weight). The relatively high molecular weight ethylene-α-olefin copolymer whose average molecular weight )/(number average molecular weight) of relatively low molecular weight ethylene-α
The ratio of the short chain branching degree of the ethylene-α olefin copolymer, which has a relatively high molecular weight, to the short chain branching degree of the ethylene-α olefin copolymer, which has a relatively low molecular weight, is specified for the olefin copolymer. By mixing the materials in such a way that they are within the above range, it is possible to obtain an ethylene-α olefin copolymer resin composition that has extremely superior processability, transparency, impact strength, tear strength, and heat-sealing properties compared to conventional techniques. I discovered that.

(Japanese Patent Application No. 56-14041) However, when the composition of the earlier invention is formed into a film, it can be processed at the same molding speed as high-pressure polyethylene (for example, 20 to 80 m/min). Although the film exhibits excellent physical properties, it was discovered that attempts to make the film thinner in order to achieve the excellent mechanical properties of the ethylene-α-olefin copolymer resulted in a film with inferior properties. child.

As a result of intensive studies in view of the above situation, the inventors of the present invention have determined that the intrinsic viscosity of copolymer-8 and copolymer-B has been further specified in the composition of the prior invention. By further specifying the mixing ratio of Polymer-8 and Copolymer-B, it has good processability even when film-formed at extremely high speeds, and has excellent transparency, impact strength, and MD tear strength. The present invention was completed by discovering that an ethylene-α-olefin copolymer resin composition can be obtained.

That is, the density is 0. '895 Q /cr1 or more, 0.9
135Q/cd or less, and the intrinsic viscosity is 1.5 dl/
9 or more, 2, Odl / f or less, carbon number 1000
Copolymer of ethylene with short chain branching number (degree of short chain branching) of 7 or more and 40 or less and alpha olefin having carbon numbers of 8 or more and 18 or less -A 60% by weight, 70% by weight and 96% or less, and density 0.910 f 1cr1 or more, 0.9551/di
The intrinsic viscosity is 0.6 ttt / 9 or more, 1.
5 dl/P or less, copolymer of ethylene with short chain branching number of 5 or more and 85 or less per 1000 carbon atoms and α-olefin having 8 or more and 18 or less carbon atoms -B 40% by weight or less, 8
0% by weight or more, at that time (copolymer-A
degree of short chain branching)/(degree of short chain branching of copolymer-B) is 0,
Density adjusted to be 6 or more and 1.7 or less is 0
．． 910 f/i or more, 0.940 f/cl or less, melt index 0.21/10 minutes or more, 5 f
/10 minutes or less, a melt flow ratio of 85 or more and 55 or less, excellent transparency and strength, suitable for film forming, and a multistage polymerization method for the composition. be.

The first feature of the present invention is that the processability is comparable to that of high-pressure polyethylene, and the transparency is almost the same, but it has excellent tensile strength, tear strength, and impact strength [1], and also has excellent hot tack. The object of the present invention is to provide an ethylene-1-year-old reflexine copolymer-based resin composition that has excellent heat-sealing properties, especially heat-sealing properties and impurity sealing properties.

The second feature of the present invention is that even if the film is molded at a much higher molding speed (50 to 60 m/min) than the usual molding speed of high-pressure polyethylene (20 to 80 m/min), it maintains transparency and impact strength. Because of the excellent tear strength of polyethylene and MD, when making the film 20 to 50% thinner than the film thickness of high-pressure polyethylene, there is no need to reduce the resin production and the benefits of thinning can be maximized.

The third feature of the present invention is that the extrusion processability is better than that of the conventional low-density ethylene-α-olefin copolymer with a narrow molecular weight distribution, so the high-pressure polyethylene extruder used in the conventional technique can be replaced with a The advantage is that it can be used without modification.

The fourth feature of the present invention is that even though the copolymer has a lower melt index than the conventional low density ethylene-α olefin copolymer with a narrow molecular weight distribution, the fluidity during actual processing is actually good. The stability of the bubble φ pull is excellent, and the mechanical strength can be easily balanced in the MD direction, so that a homogeneous film can be obtained.

The fifth feature of the present invention is that compared to conventional low-density ethylene-α-olefin copolymers, a lower density field can be obtained in a non-sticky state, so transparency, flexibility, and impact properties are particularly required. It is also suitable for various purposes.

The present invention will be explained in more detail below.

The relatively high molecular weight ethylene-alpha olefin copolymer (hereinafter copolymer) used as a component of the blend in the present invention.
A) and a relatively low molecular weight ethylene-α olefin copolymer (hereinafter abbreviated as copolymer-B) are:
It is a copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms. (representing an alkyl group), specific examples of which include propylene, butene-1,
Pentene-1, hexene-1, heptene-1, octene-1, nonene-1, dece-1,4-methylpentene-1
, 4-methylhexeno-1,4,4-dimethylpentene-1, and the like. Among these α-olefins, propylene has relatively little effect on improving wood invention, and α-olefins having 4 or more carbon atoms are preferred, particularly buteno-1, pentene-11, hexene-1, octene-1,4-methylpentene-1 etc. are preferable in terms of monomer manpower, copolymerizability, and quality of the obtained copolymer. Note that these α-olefins are 2
It is also possible to use two types in combination.

The density of copolymer-A depends on the content of α-olefin, which is a copolymerization component, and the intrinsic viscosity of the copolymer, but for the purpose of the wood invention, the density should be 0.895 f/cd or more, 0.895 f/cd or more.
The density is preferably 9851/crl or less, more preferably 0.895 f/lri or more, 0.9809/crl or less.
CD or less. If the density is less than 0.895 f/CI, the copolymer may adhere to walls during production, making production difficult, and in order to carry out the present invention using the copolymer with such a density, it may be difficult to produce the copolymer. Therefore, it is necessary to increase the density of the low molecular weight component, and the resulting resin composition has poor transparency and can only provide a film, which is undesirable.
At 98.5 f/crI or higher, the α-olefin content of the copolymer becomes extremely small, and when the present invention is carried out using the copolymer with such a density, mechanical strength and its MI) This is not preferable because it becomes difficult to balance the direction and TD force direction, and the heat sealing properties deteriorate.

Furthermore, the number of short chain branches per 1000 carbon atoms of the copolymer (abbreviated as short chain branching degree). In this case, if k is a straight chain alkyl group, the number of methyl groups at the branch end -CL (8/100 O
When C represents the short chain branching degree, and λ is a branched alkyl group, it becomes, for example, α branching, and half of the number of methyl groups at the branch end is taken as the short chain branching degree. ) is preferably 7 or more and 40 or less, more preferably 10 or more and 40 or less. The short chain branching in the ethylene-α-olefin copolymer is generated by the α-olefin and mainly plays the role of inhibiting crystallization of the ethylene chain and lowering the density, but the effect differs depending on the type of α-olefin. In addition to simply inhibiting crystallization, it is thought to have some kind of contribution to the generation of interlamellar molecules, which ultimately affects mechanical strength and thermal properties.

Therefore, if the degree of short chain branching is 7 or less, it is not preferable to carry out the present invention because it becomes difficult to maintain the mechanical strength and its balance in the MD force direction and TD direction, and the heat sealing properties deteriorate. If it is 40 or more, it is not preferable because it causes problems in manufacturing the copolymer and deteriorates the transparency of the resin composition obtained by mixing.

The molecular weight of the ethylene-α olefin combination is 1°5 in intrinsic viscosity (in 185p tetralin).
dl/1 or more and 2.0 dl/f or less are preferable.

If the intrinsic viscosity is less than 1.5 dl/f, the mechanical strength of the resin composition obtained by carrying out the present invention will be low, which is not preferable. 2. If it exceeds Odl / (!, it is not preferable because the transparency, impact strength, and MD tear strength will deteriorate when film is formed at high speed.
When forming a film at high speed, polymer products with an intrinsic viscosity exceeding 2.0 dl/f will undergo oriented crystallization because the process from melt bubble to solidified film is significantly affected by oriented crystallization. It is inferred that the orientation in the direction of hardness<MD occurs significantly, resulting in deterioration of transparency, impact strength, and MD tear strength.

Nao, the value of (weight average molecular weight)/(number average molecular weight), which is a measure of molecular weight distribution obtained by gel permeation chromatography (abbreviated as GPC) measurement of the copolymer, is preferably 2 or more and 10 or less, and more preferably Preferably 8 or more 8
It is as follows. If (weight average molecular weight)/(number average molecular weight) is 2 or less, it is difficult to produce such a copolymer, so it is not preferable, and if it is 10 or more, the mechanical strength of the resin composition obtained by implementing the present invention is However, this is not preferable because it causes blocking when it is made into a low drying film.

Next, the density of co-■1 coalescence-Is is 0.910 f/m or more,
0.9551/tl! The following is preferable, more preferably 0.915 f /c11 or more, 0.958 f
/ca or less. If the density is less than 0.910 f / cd, the mechanical strength of the resin composition obtained by implementing the present invention may decrease or blocking may occur due to bleeding of low-density, low-molecular-weight components to the film surface. If the density is undesirably 0.955f/α1 or more, the transparency of the resin composition obtained by carrying out the present invention will deteriorate, which is undesirable.

Further, the degree of short chain branching of the copolymer is preferably 5 or more and 35 or less, more preferably 7 or more and 80 or less. If the degree of short chain branching is 5 or less, the crystallization rate is high because the relatively low molecular weight component is present, and the transparency of the resin composition obtained by carrying out the present invention is deteriorated, so it is not preferable. This is undesirable because it causes a decrease in target strength and blocking.

In addition, the molecular weight of the copolymer is 0.6 dt79 in terms of intrinsic viscosity.
As mentioned above, it is preferable that the intrinsic viscosity is less than 0.6 dl/f.If the intrinsic viscosity is less than 0.6 dl/f, the transparency, impact strength, and MD tear strength will deteriorate when the film is formed at high speed, so it is not preferable. This is because low-molecular products with an intrinsic viscosity number of less than 0.6 tend to undergo oriented crystallization in cooperation with ultra-high-molecular products, and during high-speed film forming, orientation in the MD occurs significantly, resulting in poor transparency, impact strength, etc. It is presumed that the MD tear strength deteriorates. Moreover, if it is 165 dε/V or more, the fluidity of the resin composition obtained by carrying out the present invention becomes poor, which is not preferable.

In addition, the weight average molecular weight is determined by gel permeation chromatography (C, PC) of the copolymer.
The value of /(number average molecular weight) is preferably 2 or more and 10 or less,
More preferably, it is 8 or more and 8 or less. If the value of (weight average molecular weight)/(number average molecular weight) is 2 or less, it is difficult to produce such a □ copolymer, so it is not preferable, and if it is 10 or more, the resin composition obtained by carrying out the present invention This is not preferable because it tends to reduce mechanical strength and cause the film to become sticky.

Such an ethylene-α-olefin copolymer is obtained by copolymerizing f-tyrene and α-olefin having 3 or more and 18 or less carbon atoms under medium-low pressure using a transition metal catalyst. It can also be obtained by copolymerization using a transition metal catalyst under the same high pressure and high temperature conditions as those used to obtain high-pressure polyethylene.

There are no particular restrictions on catalysts or polymerization methods as long as they do not detract from the gist of the present invention. Examples of catalysts include so-called Ziegler-type catalysts and Phillips-type catalysts, and examples of polymerization methods include so-called slurry polymerization and gas phase polymerization. and solution polymerization. Among these, phase-supported Ziegler catalysts are advantageous for the present invention in terms of catalytic activity and copolymerizability. To give a specific example, inorganic compounds such as metal and silicon oxides, hydroxides, chlorides, carbonates, and mixtures and double salts of metals and silicon are effective as supports for carrier-supported Ziegler catalysts. Magnesium, titanium oxide, silica, alumina, magnesium carbonate, divalent metal hydroxychloride, magnesium hydroxide, magnesium chloride, magnesium alkoxide, magnesium haloalkoxide, magnesium door JL/JNium double oxide, magnesium and calcium double oxide Examples include things. Among these, magnesium compounds are particularly preferred.

In particular, when the following carriers are used, the relatively low density ethylene-α olefin copolymer resin composition of the present invention is free from stickiness, has good slurry properties, and has very little polymer adhesion to the polymerization tank. (see Japanese Patent Publication No. 55-28561). That is, the general formula ILnAffiX, an (here, the number of carbon atoms is 1)
~20 alkyl groups, aryl groups, alkenyl groups,
represents a halogen atom, and n represents a number of 0≦n≦8. ) and or a general formula IL'mS iX4-m (where IL' is an -r alkyl group having 1 to 20 carbon atoms, an aryl group, an alkenyl group, or a halogen atom, and m is 0≦ (Indicates the number n≦4.)
It is expressed as Silicon halide compound and general formula 1M
gX and or R12Mg (where R# is a carbon number of 1 to
20 alkyl, aryl, and alkenyl groups, and x represents a halogen atom. 1. React with an organomagnesium compound represented by ) in a solvent. The solid product obtained is an isolated phase.

On the other hand, examples of the transition metal compound C supported by the phase include titanium compounds, vanadium compounds, and hizirconium compounds. Specifically, titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, Titanium chloride, general formula T
An alkoxyhalogenated titanium compound or an aryloxyhalogenated titanium compound represented by 1(OR')4-P , vanadium tetrachloride, paodium oxytrichloride, zirconium tetrachloride, general formula Zr(OR)4-qXq (in the formula, l (represents a hydrocarbon group, X represents a halogen, q represents a number of 0<q<4) Examples include alkoxy zirconium halides and aryloxy zirconium halides.Among them, titanium compounds and/or vanadium compounds are used because they are non-sticky and have good slurry properties, and there is very little polymer adhesion to the polymerization tank. More preferred in the ethylene-alpha olefin co-If composite resin composition of the invention (Japanese Patent Publication No. 55-28561)
(see publication). Among them, titanium compounds are weather resistant,
Most preferred in terms of heat resistance.

Further, the carrier-supported Ziegler catalyst in the present invention is represented by the general formula Ti(OR)4-rXr (in the formula, R8 is a hydrocarbon group, X is a halogen, and r represents a number of 0≦r≦4). Also included are reaction products of a transition metal compound such as a titanium halide, an alkoxytitanium compound, an aryloxytitanium compound, an alkoxyhalogenated metal titanide, or an aryloxyhalogenated titanium compound and an organomagnesium compound.

On the other hand, in the polymerization reaction, the organometallic compound components that form a catalyst system together with the carrier-supported Ziegler catalyst include triethylaluminum, tri-n-propylaluminum, tri-butylal5nium, to-1-n-butylaluminum, trialkylaluminum such as tri-n-hexylaluminum, diethylaluminium monochloride, di-n-propylaluminum monochloride, di-butylaluminum monochloride, di-n-
Butylaluminum monochloride, dialkylaluminum monohalides such as di-n-hexylaluminum monochloride, ethylaluminum dichloride, n-propylaluminum dichloride, i-butylaluminum citalolide, n-butylaluminum dichloride, n-
Alkylaluminum cibarides such as hexylaluminum dichloride, organoaluminum compounds such as ethylaluminum sesquichloride, n-propylaluminum sesquichloride, i-butylaluminum sesquichloride, n-butylaluminum sesquichloride, n-hexylaluminum sesquichloride, etc. Other examples include organometallic compounds such as zinc. These organometallic compounds may be used alone or in combination.

A relatively high molecular weight ethylene-α olefin copolymer A and a relatively low molecular weight ethylene-α olefin copolymer B obtained by a normal medium-low pressure polymerization method using such a catalyst.
When mixing to obtain the composition of the present invention, (1) (degree of short chain branching of copolymer-A)/(degree of short chain branching of copolymer B) is 0.6 or more and 1.7 or less, More preferably 0.7 or more and 1.5 or less, most preferably ll! , a copolymer A having a short chain branching degree of 8 or more and 1.8 or less
, B is important. If the ratio (degree of short chain branching of copolymer-A)/(degree of short chain branching of copolymer-B) is 0.6 or less, the mechanical strength of the resulting composition will deteriorate. It is undesirable because it becomes difficult to maintain the balance in the vertical and horizontal directions of i, the heat sealing properties deteriorate, and the film becomes sticky. So I don't like it.

(2) The density of the resulting composition is 0.910f
/ cJ or more and preferably 0.94 Of / cl or less 0.91 Of / cr / 1 or more and 0
．． 985 f/cJ (the following are more preferable, 0.
Most preferably, it is 910 g/i or more and 0.929 f/cJ or less.

When the density is less than the lower limit, the mechanical strength of the composition decreases and the film becomes sticky, which is undesirable. When the density exceeds the upper limit, transparency deteriorates, which is undesirable.

(8) Furthermore, the melt index of the resulting composition is preferably 0.2 y/10 minutes or more and 5 F/10 or less, more preferably 0.8 g/10 minutes or more and 4 g/10 minutes or less. .

Furthermore, it is desirable that the melt flow ratio is 35 or more and 55 or less.

When the melt flow ratio is less than 85, the processability improvement effect of the composition of the present invention decreases, which is not preferable. Also, if the melt flow ratio exceeds 55, when forming a film at high speed,
This is not preferable because transparency, impact strength, and MD tear strength deteriorate.

The melt index and melt flow ratio of such compositions are appropriately set based on the end-use requirements of the composition, but their adjustment depends on the relative high temperature used to obtain the composition. Intrinsic viscosity of molecular weight meethylene-α-olefin copolymer-A and relatively low molecular weight ethylene-α-olefin copolymer-11, values of (superimposed average molecular weight)/(number average molecular weight) and eutectic polymer- This is done by adjusting the mixing ratio of human and copolymer-B. The intrinsic viscosity numbers of copolymer-8 and copolymer-B are [η]A (ell
/f), [η]B(dt/f), mixing ratio (weight fraction)
WA, WB (WA + WB = l')
Then, the intrinsic viscosity of the composition obtained by mixing [η]
′I゛(d7!/f) is approximately [η]A in [η]T
It is determined by WA + [η]n, and the melt index is almost uniquely determined by this [η]T. On the other hand, the melt flow ratio is [η
:]A/[:The larger the value of ηln, the larger it is in general, but since it also depends on WA and WB, it is difficult to express it unambiguously.Based on preliminary experiments, we have determined that the melt flow ratio has the desired melt flow ratio. η]A, [Fl]B, WA,
Determine WIS.

(4) In order to obtain a composition that satisfies the above (1), (2), and (3), the mixing ratio of copolymer-A and copolymer-B should be 60% by weight or higher than t96 for copolymer-A. And 70 heavy ff
1% or less, copolymer-B 40% by weight or less, 80 weight 96
The above is preferable. Copolymer-A.

It must be selected appropriately depending on the short chain branching degree, density, intrinsic viscosity number, molecular weight distribution of B and the density, melt index, and melt flow ratio of the desired composition, but the proportion to the copolymer When the proportion of copolymer-B is below the lower limit and above the upper limit, (intrinsic viscosity number of copolymer-A)/(
When the intrinsic viscosity of copolymer-B is set to 1.5 or more,
When forming a film at high speed, the orientation in the MD becomes significant, resulting in poor transparency, impact strength, and MD tear strength.
This is not preferable because the molecular weight distribution cannot be fully expanded.

The proportion of copolymer-A exceeds the upper limit, and the proportion of copolymer-B
If the ratio is below the lower limit, the processability of the resulting composition will deteriorate, which is not preferable.

In the composition of the present invention (copolymerization, intrinsic viscosity of body)
The reason why the film exhibits excellent physical properties even when /(intrinsic viscosity number of copolymer-B) is 1.5 or more is because the mixing ratio of low molecular weight components (of copolymer-B) is small. This is presumed to be because even though the intrinsic viscosity of B is somewhat small, its influence is small.

In addition, as long as it does not depart from the gist of the present invention, ethylene-α olefin copolymer-A having a relatively high molecular weight and ethylene-α olefin copolymer-1 having a relatively low molecular weight
There is no reason why 1 should be limited to mixing only one type of ethylene-alpha olefin copolymer-A, and for example, two or more ethylene- The α-olefin copolymer may also be used as an ethylene-α-olefin copolymer-B having a relatively low molecular weight in two layers of the same type. .

In the present invention, there is no particular restriction on the mixing method for producing the ethylene-α olefin copolymer resin composition, and any known method can be used. For example, after producing copolymer-8 and copolymer-B separately, two rolls, bread,
Batch-type melting cross-wire method by Barry Michiely, CI
A continuous melt mixing method using a twin-screw kneader or a single-screw extruder such as M (Japan Steel Works NM) or F CM (Kobe Steel New Co., Ltd.), or copolymer-A and co-m polymer-B. A common solution mixing method is to obtain a mixture by dissolving each component separately or together in a solvent and then removing the solvent after mixing. In particular, when copolymers-A and B are obtained by high-temperature solution polymerization, it is advantageous in terms of process to mix copolymers-A and B in a high-temperature solution state and then remove the solvent to obtain a composition.

It is also possible to mix by a method called two-stage polymerization or multi-stage polymerization. In this method, for example, after polymerizing for a certain period of time under polymerization conditions that yield copolymer-8, only the polymerization conditions are changed to obtain the desired copolymer-B while using the same catalyst. This is a method of mixing by polymerizing until the mixing ratio is reached. In this case, copolymer-8 and B may be polymerized in any order.

When using such a two-stage or multi-stage polymerization method,
This is an ideal mixing method since Copolymer-8 and Copolymer-B are easily molecularly dispersed. In any case, various mixing methods that provide a uniform composition can be employed depending on the purpose.

When the polyethylene resin composition of the present invention thus obtained is subjected to extrusion molding, it is a low-density ethylene-α-olefin copolymer (usually linear low-density polyethylene-■,!) obtained by the existing medium-low pressure method. It has much better processability than polyethylene (also known as DPE), is comparable to high-pressure polyethylene, and has good mechanical strength such as tensile strength, impact strength, and tear strength, so it is easy to mold. It is possible to reduce the wall thickness of the product, and furthermore, it has good transparency and heat sealing properties, so it can be used as a high-quality film for a wide range of applications such as high-speed bag making.

The composition of the invention may contain oxidation stabilizers, lubricants, antistatic agents, light stabilizers, anti-blotting agents, coloring pigments, etc., as necessary.
Various additives commonly used in the industry can be added, and other polymeric compounds can also be added in small amounts without departing from the gist of the present invention.

Next, definitions of physical property values used in the present invention (1)
Intrinsic viscosity number [η] of tetralin at 185°C.

[η] = 1 1.6 5X logarithm? Table=
t/l.

t: Concentration 0.2 d7! /Falling seconds at f 10: Falling seconds of only tetralin (2) According to the method specified in Density JiS-6760. (Measurement temperature: 20°C) However, if the degree of short chain branching of copolymer B (low molecular weight component) is high, it will be treated as a low-density dust field, and according to the regulations, it will be 100°C,
Although it may be necessary to perform annealing for 1 hour, copolymer B is uniformly compliant with the regulations regarding high-density dust fields (100
C., 1 hour annealing is not performed. ) according to
.

(3) FT-I using a C-labeled product described in the literature with a short chain branching degree of
It was determined by the RO difference spectrum method.

"Characterization and I-Sensitivity of Polymers" Published by Kagaku Doujin (Kagaku Special Issue 4B) Edited by Mitsuru Nagasawa et al. Published July 10, 1971, p. 181-1), 146 Quantitative formulas for each branch species are shown.

In addition, K7.25μ (extinction coefficient) is determined by the difference spectrum method using an ethylene homopolymer having almost the same molecular weight distribution as the test sample and the same [η] as a reference. The influence of methyl groups was excluded.

α-olefin R-CH== If K in CH2 is a straight-chain alkyl group, the number of methyl groups at the branch end -CH3/100 Q
When C represents the degree of short chain branching and k is a branched alkyl group,
For example, if the α-olefin is 4-methylpentene-1, the branch will be an i-butyl branch, and the degree of short chain branching will be half the number of methyl groups at the branch end. (4) Melt index (Ml) ASTM-D
According to the method specified in I288 Condition E.

(5) Melt flow ratio (MER) First, under ASTM-01288 condition F, MI21.8 (load 21.6 Kf; expressed as f number per 10 minutes at 190° C.) is determined.

Melt-low ratio = M I 21.6 / M 1 (MFR
) (6) Molecular weight distribution ("w/"N) GPC method (gel, vermeation, chromatography) Toyo Soda HLC-811 Column: TSK-GEL (GMSP+G7000H4
+GMH x 2 bottles) Solution 1: t, 2.4-trichlorobenzene (TCB) Temperature: 145°C Detector: Differential refractometer flow 11
: 1 ml/min concentration: 15~/10
OCTCII The measurement data for one standard polystyrene sample is shown below.

Next, the present invention will be explained in detail by way of examples.
The description is not limited to the examples unless it goes beyond the gist thereof.

Example 1 (1) Synthesis of organomagnesium compound In a 500 ml four-loaf flask equipped with a stirrer, a reflux condenser, and a dropping funnel, 16.5 g of ground magnesium for Grignard was placed. Air and moisture were removed by replacing the inside of the system with nitrogen. A dropping funnel was charged with 68 ml (0.65 mol) of n-dipyl chloride and 800 ml of n-butyl ether, and about somt m was added to the magnesium in the flask to start the reaction.

After the reaction started, the dropwise addition was continued at 50°C over 4 hours, and after the dropwise addition was completed, the reaction was continued at 60°C for an additional 1.5 hours. Thereafter, the reaction solution was cooled to room temperature, and unreacted magnesium was filtered off using a glass filter.

n-Butylmagnesium tallolide in this n-butyl ether was □hydrolyzed with 1N sulfuric acid, and the concentration was determined by back titration with □Normal sodium hydroxide (using phenolphthalein as an indicator). , 1, 96
mgl/l"'Q Ara?, :.

(2) Synthesis of solid catalyst component (500 ml equipped with W stirrer, dropping funnel, and thermometer)
The four-hole flask was thoroughly purged with nitrogen to remove air and moisture. 180 ml of n-butyl ether solution of n-butylmagnesium chloride synthesized in (1) (0.26
80rn of silicon tetrachloride in mol)! (0.2 mol)
was added dropwise from a dropping funnel at 50°C over 2 hours, and 60°C
The reaction was continued for an additional 1 hour at ℃.

After separating the produced white solid, it was washed with n-hebutane and dried under reduced pressure to obtain white solid 81.51. This white solid 1
0F was placed in a 100 mt four-loaf flask, immersed in 50 ml of titanium tetrachloride, and reacted at 100° C. for 1 hour with stirring.

After the reaction was completed, the product was washed with n-heptane, and the washing was repeated until no titanium tetrachloride was introduced into the washing solution, followed by drying under reduced pressure to obtain 7.91 solid catalyst components. This solid catalyst component 1
14 μ of titanium atoms were supported on each.

Example-2 Ethylene-α-olefin copolymer-A obtained by slurry polymerization method and ethylene-α-olefin copolymer-
Bj Tips 1: 1: Using the catalyst produced in Example 1, triethylaluminum as a cocatalyst, and n-butane as a solvent, polymerization was carried out at a temperature of 50°C, and the results are shown in Table 1. Butene-1 to have spec.
The concentration can be obtained by appropriately adjusting the hydrogen partial pressure and ethylene partial pressure.

In addition, for ethylene-α-olefin copolymer-A and ethylene-α-olefin copolymer-B obtained by solution polymerization, the catalyst produced in Example-1 and diethylaluminium monochloride as a cocatalyst were used. In addition, polymerization is carried out at a temperature of 140°C using n-hebutane as a solvent, and the α-olefin concentration, hydrogen partial pressure, and ethylene partial pressure are appropriately adjusted to meet the specifications shown in Table 1. It was obtained by

In the following examples, relatively high molecular weight ethylene-
A method of mixing α-olefin copolymer-A and relatively low molecular weight ethylene-α-olefin co-W polymer-11 using a Banbury kneader is shown below.

Copolymer-8 and copolymer-B are mixed at a predetermined weight ratio to give a total amount of 5.0re.

This is mixed in a Banbury kneader with a rotor speed of 150 to 2.
Knead for 5 minutes at 8 Orpm. The resin temperature should not exceed 250°C by thoroughly purging with nitrogen.

Examples-3, 4, 5, 6 Various ethylene-α-olefin copolymers-A and ethylene-α-olefin copolymers-B obtained in Example-2 were mixed as shown in Table 1. The composition was adjusted by the Banbury crosstalk method, and the density and M were as shown in Table 1.
A composition having an MFR of I.

Example-7 Using the catalyst obtained in Example-1 and triethylaluminum as a co-catalyst, the contents [s5z autoclave, 7.2 h of n-butane, 1.8 h of butene-1]
rr Maintain the preparation temperature at 6°C. Then add 1 b of hydrogen
/ ad pressurize and ma■? ,: When x--J-L/n was pressurized at 4.5 Kf/m, the total pressure was 18 h/c! It was l. Meanwhile, ethylene was fed so as to keep the ethylene/butene-1/hydrogen molar ratio of the liquid phase constant. In addition, when a portion of the produced polymer was extracted just before the end of the first stage polymerization and analyzed, it was found to have an intrinsic viscosity of 1.8 dl/f.

Short chain branching degree 29, density 0.908 f/di%Mw
/ ratio was adjusted to [) Kf/cd, common ratio was adjusted to 20 Kt/min, and the subsequent polymerization was carried out. The final density of the hole poly was 0.917 flea,
Meru index 0.8f/10min, melt flow ratio 42, intrinsic viscosity number 1.55dt/Lj, short chain branching degree 2
It was 9. When the amount of polymerization in the first and second stages was determined from the amount of ethylene feed, it was found that the polymer residue was 65, and the weight was 96, and the low molecular weight was 85, and the weight was 96. Based on the above data and the assumption of additivity between the intrinsic viscosity number and the short chain branching degree, the specifications of the low molecular weight one-manufacturer polymer obtained in the latter stage are calculated to have an intrinsic viscosity number of 1.
The short chain branching degree was 0 dl/77 and 29.

Example-8 The compositions prepared in Examples-8, 4, 5, 6, and 7, the compositions prepared in Comparative Examples-1, 2, and 8, and the compositions used in Comparative Example-4. A film was formed using a conventional low-density etylethy a olefin copolymer with a narrow molecular weight distribution under the following conditions.

Inflation processing conditions Extruder: Sedan 50■ Extruder screw; Full flight L/D == g, 6, C, R・22・8 da
A: Diameter 75nm Grip width: 1.2■ Setting temperature conditions: CI C2C8H・D1701901
90190190 (°C) Screw rotation speed H24rp
m Extrusion rate: 11.2 b/hr Blow-up ratio: 2.0 Frost line height: 400-500 m Take-up speed: 50 m/min Film thickness: 1.0 μ In addition, commercially available high-pressure polyethylene used in Comparative Example-5 A film was formed under the following conditions.

Setting temperature condition; Ct C2C8HD140 170
170 170 170 (°C) Frost line height: 800 Hot take-off speed: 2.5 m/min Film thickness: 20 μ These four conditions are the same as the inflation processing conditions mentioned above except that they are different.

As a result, the intrinsic viscosity of copolymer-A was 2.0 dl/
Comparative Example-1, which is a composition larger than f, and Comparative Example-
Regarding the low-density ethylene-α-olefin copolymer lζ with a narrow molecular weight distribution used in the prior art used in 8, the motor load was too high, and shark skin formed on the film surface, making it impossible to obtain a good film. Ta.

In Examples 8, 4, 5, 6, and 7 and Comparative Example 2°4.5, films with good appearance were obtained. The physical properties of the obtained film are shown in Table 2.

The composition films prepared in Examples 3, 4, 5, 6, and 7 had half the thickness of the high-pressure polyethylene film, and the absolute value of the dart impact strength (calculated in terms of thickness) The absolute value of Elmendol p tear strength of MD (value not converted into thickness) must be equivalent to or higher than that of
It can be seen that the film has a value comparable to the Elmendorf tear strength of the TD of high-pressure polyethylene film, and is very superior.

Furthermore, the transparency is found to be good, although it is slightly inferior to that of high-pressure polyethylene film, while the intrinsic viscosity of copolymer-B, which is a relatively low-molecular product, is lower than 0.6 dl/I. Regarding the small Comparative Example-2, the absolute value of the Elmendorf tear strength in the MD was extremely small, and the orientation in the MD was remarkable;
It can be seen that the dart impact strength is extremely low and the transparency is also very poor.

In addition, a low-density ethylene-α olein copolymer with a narrow molecular weight distribution of the prior art has a large melt index and exhibits almost the same motor load as the compositions of Examples 8, 4, 5, 6, and 7. Regarding Comparative Example 4, which is a composite, the transparency is as good as in the examples, and the absolute value of the MD Elmendorf tear strength is relatively good, but the dart impact strength is very poor.

The methods for measuring the various physical properties shown in Table 2 are shown below.

(+) Dirt impact strength Compliant with ASTM D1709A method.

It is shown as the absolute value of load (f') without converting into thickness.

(2) Elmendorf tear strength Compliant with JIS Z1702 law.

It is shown as the absolute value of intensity (fl') without converting into thickness.

(3) Hayes, ASTM DIQQ3 method compliant.

Comparative Examples-1, 2 Various ethylene-α 1st/fin copolymers-8 and ethylene-α 1st Nophino copolymers obtained in Example-2
A composition was prepared using the mixing ratio of B and B as shown in Table 1 and the Banbury kneading method, and r'F! Density, Ml, as shown in Table 1.

A composition having Mt.+(.2) was obtained.

Comparative Examples 3 and 4 Using the catalyst produced in Example 1, triethylaluminum as a cocatalyst, and n-butane as a solvent, polymerization was carried out at a temperature of 50°C, and the specifications shown in Table 1 were obtained. It is obtained by appropriately adjusting the butene concentration, hydrogen partial pressure, and ethylene partial pressure.
This is a low-density ethylene-α-olefin co-W composite with a narrow molecular weight distribution of the prior art.

Comparative Example-5 Commercially available high pressure polyethylene Sumikasen 0F208-1
(manufactured by Sumitomo Chemical Industries, Ltd.).

The specifications and physical properties of the film are shown in Tables 1 and 2.

Procedural amendment rl↑ (six times) ヰ、r Director-General of the License Agency Kazumi Wakasugi Relationship with the case Patent issuer A1 Address 5-15 Kitahama, Higashi-ku, Osaka Name (
209) Sumitomo Chemical Co., Ltd. Representative Sat
Takeshi 4, Agent

Claims (1)

[Claims] (1) Density is 0.895 f /c4 or more, 0.985
flct & below, the intrinsic viscosity is 1.5 dl/
11 or more, 2.0 dl / or less, carbon number 1000
A copolymer of ethylene having a short chain branching number (short chain branching degree) of 7 or more and 40 or less and an α-olefin having 3 or more carbon atoms and 18 or less carbon atoms -A 60% by weight or more and 70% by weight or less and 96% by weight,
Density is 0.9101/ca or more, 0.955 Da/cJ
Below, the intrinsic viscosity is 0.6 di/f or more, 1.5 d
7! Copolymer of ethylene with 5 or more and 85 or less short chain branches per 1000 carbon atoms and α-olefin with 8 or more and 18 or less carbon atoms - B40 weight 96 or less, 8
In this case, (degree of short chain branching of copolymer-A)/(degree of short chain branching of copolymer-B) is 0.6 or more, 1.7 or more. Adjust so that the density is 0.91 Of, /cd or more, 0.940f/
cJ or less, a melt index of 0.1 M/10 minutes or more and 5 y/10 minutes or less, and a melt flow ratio of 85 or more and 65 or less, excellent transparency and strength, and suitable for film forming. Polymer-based resin composition. (2) Copolymer-B and Copolymer-B are suitable for film forming according to claim 1, wherein (weight average molecular weight)/(number average molecular gk) is 2 or more and 10 or less. Ethylene-α olefin copolymer resin composition. (8) Copolymer-A and/or copolymer-B are ethylene-butene-1 copolymers, which are suitable for film forming according to claim 1 or 2. α-olefin copolymer-based resin composition. (4) Copolymer-B and/or Copolymer-B is an ethylene-hexene-1 copolymer (Claim No. 1)
Ethylene-α olefin copolymer based resin composition (5) suitable for film forming as described in item 1 or item 2), wherein copolymer-A and copolymer-B are ethylene-4-methylpentene-1 copolymer. 11. An ethylene-α olefin copolymer resin combination acid suitable for film forming according to claim 1 or 2, which is a composite. (6) Claim No. (1) in which copolymer-A and/or copolymer-B are ethylene-octene-1 or higher polymers.
Using the ethylene-α olefin co-t & system resin composition suitable for film forming described in item 1 or item 2), (A)] 2: Density is 0.8951/tJ or more, Q, 985y/- Below, polar: limiting viscosity is 1.5tt
l/I or more, 2. □ dt / 9 or less, carbon number 1
A process of forming a copolymer (copolymer-human) of ethylene having a short chain branching number (short chain branching degree) of 7 or more and 40 or less per 1,000 pieces and an α-olefin having 8 or more and 18 or less carbon atoms. and (c) process: density is 0.910P/- or more, 0, 9
559/cd or less, and the intrinsic viscosity is 0.6 dl
/ 1 or more and 1.5 dl/f or less, forming a coelectrolyte (copolymer-B) of ethylene with a short chain branching degree of 5 or more and 85 or less and an α-olefin having 8 or more carbon atoms and 18 or less As for the relationship between the step (c) and the Φ) step, the polymerization order of the step (f) and step (I3) may be either first, and after either step is completed, the polymerization may be continued in the presence of the copolymer. Then, (copolymer-
Adjusted so that the short chain branching degree of human)/' (short chain branching degree of copolymer-B) was 0.6 or more and 1.7 or less, and
60% by weight or more and 70% by weight or less as copolymer-A,
The copolymer-n has a density of 0.910g, with a density of 0.910g, with the amount of polymerization adjusted so that n is 40% or less and IO% or more.
/cJ or more, 0.940f/! An ethylene-alpha olefin copolymer based resin composition suitable for film forming having a melt index of 0.2 g/10 min or more and 5F/10 min or less and a melt flow ratio of 35 or more and 55 or less. Manufacturing method. (8) (Weight average molecule u) A of copolymer-human and copolymer-B in (A) step and (1'%) step
(Number average molecular Ima) is 2 or more and 10 or less, which is suitable for film forming according to claim (7).
A method for producing an α-olefin copolymer-based resin composition.