JP2002273782A - Melt extrusion molding method for polyethylene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a melt extrusion molding method for a polyethylene resin composition which controls the generation of 'gum' on a die extrusion surface and can maintain various physical properties of an obtained molding, especially transparency, on a practical level. SOLUTION: In the method, the polyethylene resin composition comprising a specified ethylene-α-olefin copolymer whose melt flow rate is within a constant range, whose density is within a specified range, whose composition distribution variation coefficient is within a specified range, in which the weight ratio and density of its cold xylene soluble part are in a specified relationship, and whose weight ratio is within a constant range and a specified ethylene-α-olefin copolymer whose melt flow rate is within a constant range, whose density is within a specified range, whose composition distribution variation coefficient is within a specified range, and whose weight ratio is within a constant range is melt extrusion-molded with a shear rate in die outlet set in conditions within a specified range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melt-extrusion of a polyethylene resin composition. More specifically, a method for melt-extrusion of a polyethylene-based resin composition capable of suppressing the occurrence of “measles” on a die extrusion surface and maintaining various physical properties, particularly transparency, of the obtained molded product at a practical level. It is about.

[0002]

2. Description of the Related Art Polyethylene films have been used as packaging materials because they are easy to handle. Recently, ethylene / α-olefin copolymers obtained using metallocene catalysts having excellent film strength and anti-blocking properties have been used. Coalescence is used.

For example, JP-A-7-330977 discloses an ethylene-α-olefin copolymer having a density of 0.905 to 0.940 g / cm ³ , which can be obtained by using a homogeneous catalyst such as metallocene. 0.945 coalescence and density
g / cm ³ or more, a polyethylene-based resin composition in which transparency, stiffness and anti-blocking property are improved in a well-balanced manner, and a film obtained using the composition are described. .

JP-A-11-181173 discloses an ethylene / α-olefin copolymer having a density of 0.880 to 0.935 g / cm ³ which can be produced by a catalyst containing a metallocene compound. 0.91 density
An ethylene / α-olefin copolymer composition comprising a low-density polyethylene obtained by a high-pressure radical polymerization method of 0 to 0.935 g / cm ³ and having excellent transparency and moldability at a high level, and a composition thereof. The films obtained with the described are described.

In the production of a film obtained using the polyethylene resin composition described in JP-A-7-330977 and JP-A-11-181173,
As a method of improving the productivity, speeding up of film forming can be mentioned. However, when the extrusion amount at the time of molding is increased and the polyethylene resin composition is melt-extruded under high discharge conditions or high-speed conditions, some of the degraded products and additives of the polyethylene resin composition are formed on the surface of the extrusion surface of the die. Alternatively, so-called “meani” such as decomposed products may be generated, and the “meani” may adhere to the surface of the molded product extruded from the die, or generate streak-like irregularities on the surface of the molded product. Therefore, it was necessary to remove "Mani". As a method of removing the “meani” from the extrusion surface of the die, usually, a method of temporarily interrupting the forming process and cleaning the extrusion surface of the die has been used. Was.

[0006] As a method for preventing the occurrence of “measles”, for example, Japanese Patent Application Laid-Open No. 8-197602 discloses a method.
The polyolefin resin composition containing a carboxylic acid amide-based wax was subjected to a shearing rate of 3000 seconds at the die outlet.
^-1 Melt extrusion molding under the following conditions, a method for preventing the occurrence of `` Mani '' on the die extrusion surface, and a method for melt extrusion molding of a polyolefin resin which does not adversely affect various physical properties of the obtained molded product. When a wax having a low molecular weight such as a carboxylic acid amide-based wax is added, the transparency of a molded article may be remarkably reduced, and further improvement has been demanded.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to suppress the occurrence of "measuring" on the die extrusion surface and to maintain various physical properties, particularly transparency, of the obtained molded product at a practical level. It is an object of the present invention to provide a method for melt-extrusion of a polyethylene resin composition which can be obtained.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above situation, and as a result, have found that the melt flow rate is within a certain range, the density is within a specific range, and the composition distribution variation coefficient. Is a specific range, the weight ratio of the cold xylene-soluble portion and the density have a specific relationship, a specific ethylene α-olefin copolymer weight ratio is a certain range,
And a specific ethylene / α in which the melt flow rate is in a constant range, the density is in a specific range, the composition distribution variation coefficient is in a specific range, and the weight ratio is in a constant range.
-A polyethylene-based resin composition comprising an olefin copolymer, a melt extrusion molding method of a polyethylene-based resin composition for melt-extrusion molding with a shear rate at a die outlet in a specific range can solve the above problems, The present invention has been completed.

That is, according to the present invention, the melt flow rate (MFR) is 0.1 to 20 g / 10 min, the density (d) is 905 to 935 Kg / m ³ , and the following (formula 1) Cx = σ / SCBave. (Equation 1) (where, σ represents the standard deviation of the composition distribution, and SCBave. Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C)). The distribution variation coefficient (Cx) is 0.6 or less, and the weight ratio (a) and density (d) of the cold xylene-soluble portion are as follows (Equation 2): a <(4.8 × 10 ⁻⁵ ) × (950) −d) ³ + (10 ⁻⁶ ) × (950−d) ⁴ +1 (Formula 2) (where a is the weight ratio (wt%) of the cold xylene-soluble portion, and d is the density (Kg / m) ³⁾ represent.) resulting et al by copolymerizing ethylene and carbon atoms 3 to 12 amino α- olefins having a relationship That the ethylene · alpha-olefin copolymer (A) 80 to 97 wt%, and a melt flow rate (MFR) is 2 to 30 g / 10 min, density (d) is 860~900Kg / m ^3, The composition distribution variation coefficient (Cx) obtained from the above (Equation 1) is 0.5 or less;
Ethylene · alpha-olefin copolymer (B) a polyethylene resin composition comprising 20-3 wt%, 200sec ^-1 ~1000sec ^-1 shear rate of the die outlet (v)
The present invention relates to a method for melt-extrusion of a polyethylene-based resin composition, characterized in that melt-extrusion molding is performed under the following conditions. Hereinafter, the present invention will be described in detail.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Ethylene / α used in the present invention
The olefin copolymer (A) is a copolymer of ethylene and an α-olefin obtained by copolymerizing ethylene and one or more α-olefins having 3 to 12 carbon atoms.
Examples of the α-olefin having 3 to 12 carbon atoms include propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, dodecene-1, 4, and the like. -Methyl-pentene-1,4
-Methylhexene-1, vinylcyclohexane and the like. Preferably, they are butene-1, hexene-1, and octene-1. More preferably, they are hexene-1.

[0011] Ethylene / α-olefin copolymer (A)
Are, for example, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-hexene-1
Copolymers, ethylene-octene-1 copolymers and the like are mentioned, and ethylene-hexene-1 copolymer is preferable.

The ethylene / α-olefin copolymer (A) used in the present invention has a melt flow rate (MFR) of 0.1 to 20 g / 10 min, preferably 0.5 to 2 g / min.
0 g / 10 min, more preferably 0.5 to 10 g
/ 10 min, most preferably 2 to 5 g / 10 min. If the MFR is less than 0.1 g / 10 minutes, the extrusion load may be too high in forming the film,
If it exceeds 20 g / 10 minutes, the tear strength of the film may decrease.

The density (d) of the ethylene / α-olefin copolymer (A) used in the present invention is from 880 to 935K.
g / m ³ , preferably 890-930 Kg / m ³ , and more preferably 910-930 Kg / m ³ . When the density (d) is less than 880 kg / m ³ , the rigidity of the film becomes low, and it may not be suitable for use as a packaging film in terms of handleability, and 935
If it exceeds kg / m ^3, which may impact strength of the film is lowered.

The ethylene / α-olefin copolymer (A) used in the present invention has a composition distribution variation coefficient (Cx) obtained from the following (formula 1) of 0.6 or less, and preferably 0.2 to 0. .55. Cx = σ / SCBave. (Equation 1) (where, σ represents the standard deviation of the composition distribution, and SCBave. Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C).) The composition distribution variation coefficient (Cx) indicates a measure of the composition distribution, and a smaller value indicates a narrower composition distribution. If the composition distribution variation coefficient (Cx) exceeds 0.6, the tear strength and anti-blocking properties of the film may be poor.

The weight ratio (a) and the density (d) of the cold xylene-soluble portion of the ethylene / α-olefin copolymer (A) used in the present invention have the following relationship (formula 2). Preferably has the relationship of the following (formula 3), and more preferably has the relationship of the following (formula 4). a <(4.8 × 10 ⁻⁵ ) × (950-d) ³ + (10 ⁻⁶ ) × (950-d) ⁴ +1 (Formula 2) (where, a is the weight ratio of the cold xylene-soluble portion) (Weight%), and d represents the density (Kg / m ³ ). A <(4.8 × 10 ⁻⁵ ) × (950-d) ³ + (10 ⁻⁶ ) × (950-d) ⁴ (Equation 3) (where a is the weight ratio (wt%) of the cold xylene-soluble portion, and d represents the density (Kg / m ³ ).) A <(4.8 × 10 ⁻⁵ ) × (950-d) ³ (Equation 4) (where a is the weight ratio (% by weight) of the cold xylene-soluble portion, and d represents the density (Kg / m ³ ).) Cold xylene-soluble portion When the weight ratio (a) and the density (d) do not have the relationship of (Equation 2), the tear strength of the film may be reduced or the anti-blocking property may be deteriorated.

The ethylene / α-olefin used in the present invention
The method for producing the vinyl copolymer (A) is not particularly limited.
Not a known polymerization method using a known catalyst.
It is. As a known catalyst, for example, a transition metal compound
And the like, preferably a cyclopentadiene
Transition metal compound having a group having an anion skeleton,
This is a catalyst containing a so-called metallocene compound. More preferred
New metallocene compounds have the general formula ML_cX_nc(Where
M is the transition of group 4 or lanthanide series of the periodic table of elements
It is a transfer metal atom. L is a cyclopentadiene-type anion
A group having a skeleton or a group containing a hetero atom.
At least one has a cyclopentadiene-type anion skeleton.
It is a group to do. A plurality of Ls may be cross-linked to each other.
X is a halogen atom, hydrogen or a hydrocarbon having 1 to 20 carbon atoms
Group. n represents the valence of the transition metal atom, and c represents 0 <
It is an integer satisfying c ≦ n. ). Up
The transition metal compound described above may be used alone, or 2
More than one type may be used in combination. In addition, the above transition metal compounds
As a catalyst containing a substance, a transition metal compound, triethyl
Organic materials such as aluminum and triisobutylaluminum
Alumoxa such as luminium compounds and methylalumoxane
Compounds and / or trityltetrakispentafluor
Rophenylborate, N, N-dimethylanilinium
Ionic properties such as trakispentafluorophenylborate
The compounds are used in combination. Also, the above transition gold
Catalysts containing metal compounds include transition metal compounds and organic compounds.
A luminium compound, an alumoxane compound, and / or
An on-active compound or the like _Two, Al_TwoO_ThreeInorganic particulates such as
Carrier or particulate organic such as polyethylene and polystyrene
Used as a catalyst supported or impregnated on a polymer carrier
Is also good.

The polymerization method of the ethylene / α-olefin copolymer (A) used in the present invention includes, for example, a solution polymerization method, a slurry polymerization method, a high pressure ionic polymerization method, a gas phase polymerization method and the like. Preferably, a gas phase polymerization method and a high pressure ionic polymerization method are used.

In the present invention, ethylene / α-olefin copolymer (B) is defined as ethylene and at least one kind of carbon atom having 3 to 1 carbon atoms.
It is a copolymer of ethylene and an α-olefin obtained by copolymerizing two α-olefins. Examples of the α-olefin having 3 to 12 carbon atoms include the aforementioned ethylene
Carbon atom 3 used in α-olefin copolymer (A)
Examples of the ethylene / α-olefin copolymer (B) include, for example, ethylene / α-olefin used as the above-mentioned ethylene / α-olefin copolymer (A). And the same as the olefin copolymer.

The ethylene / α-olefin copolymer (B) used in the present invention has a melt flow rate (MFR) of 2 to 30 g / 30 minutes, preferably 2 to 25 g / 1.
0 minutes, more preferably 2 to 20 g / 10 minutes. When the MFR is less than 2 g / 10 minutes, a large amount of “measuring” may be generated on the die extrusion surface, and 30 g / 10 min.
If the amount exceeds minutes, the transparency and impact strength of the film may be reduced.

The density (d) of the ethylene / α-olefin copolymer (B) used in the present invention is from 860 to 900 kg.
/ M is ^3, preferably 870～895Kg / m ^3, more preferably from 880～895Kg / m ^3. When the density (d) is less than 860 Kg / m ³ , the rigidity of the film is low, and it may not be suitable for use as a packaging film in terms of handling properties, or the blocking may be deteriorated, and 900 kg / m ^3. If it exceeds m ³ , a large amount of “stickiness” may be generated on the die extrusion surface.

The ethylene / α-olefin copolymer (B) used in the present invention has a composition distribution variation coefficient (Cx) obtained from the following (formula 1) of 0.5 or less, preferably 0.2 to 0. .4. Cx = σ / SCBave. (Equation 1) (where, σ represents the standard deviation of the composition distribution, and SCBave. Represents the average value (1 / 1000C) of the number of short-chain branches per 1000 carbon atoms (1000C).) When the composition distribution variation coefficient (Cx) exceeds 0.5, the tear strength and the anti-blocking property of the molten film may be inferior, and a large amount of "stickiness" may be generated on the die extrusion surface.

The method for producing the ethylene / α-olefin copolymer (B) used in the present invention is not particularly limited, and includes a known polymerization method using a known catalyst. Known catalysts include, for example, the aforementioned ethylene
Examples include a catalyst containing the same transition metal compound as the catalyst used in the production of the α-olefin copolymer (A). Preferably, a transition metal compound having a group having a cyclopentadiene-type anion skeleton, a so-called metallocene-based A catalyst containing a compound. Further, as the catalyst containing the above transition metal compound, similar to the catalyst used for producing the above-mentioned ethylene / α-olefin copolymer (A), the transition metal compound may be an organoaluminum compound, an alumoxane compound,
And / or ionic compounds in combination.
Further, as the catalyst containing the above transition metal compound, similarly to the catalyst used for producing the above-mentioned ethylene / α-olefin copolymer (A), a transition metal compound, an organoaluminum compound, an alumoxane compound, and / or An ionic compound or the like may be used as a catalyst carried or impregnated on a particulate inorganic carrier or a particulate organic polymer carrier.

The polymerization method of the ethylene / α-olefin copolymer (B) used in the present invention is, for example, the same as the polymerization method used in the production of the ethylene / α-olefin copolymer (A) described above. A polymerization method is mentioned.

Ethylene / α-olefin copolymer (A) in the polyethylene resin composition used in the present invention
The weight ratio of the ethylene / α-olefin copolymer (B) is 8% for the ethylene / α-olefin copolymer (A).
0 to 97% by weight, and the ethylene / α-olefin copolymer (B) is 20 to 3% by weight. Preferably, the ethylene / α-olefin copolymer (A) is 85 to 97% by weight.
(That is, the ethylene / α-olefin copolymer (B) is 1
5 to 3 parts by weight). More preferably, the ethylene / α-olefin copolymer (A) is 90 to 97% by weight.
(That is, the ethylene / α-olefin copolymer (B) is 1
0 to 3% by weight).

Ethylene / α-olefin copolymer (A)
Is less than 80% by weight (that is, when the ethylene / α-olefin copolymer (B) exceeds 20% by weight), the rigidity of the film is low, and the film for packaging is difficult in terms of handling properties. When the weight ratio of the ethylene / α-olefin copolymer (A) exceeds 97% by weight (that is, ethylene / α
-When the olefin copolymer (B) is less than 3% by weight),
A large amount of “stain” may occur on the die extrusion surface.

The method for producing the polyethylene resin composition used in the present invention is not particularly limited, and may be a known blending method. As a known blending method, for example, an ethylene / α-olefin copolymer (A)
A dry blending method and a melt blending method of the component and the ethylene / α-olefin copolymer (B) component are exemplified. Various blenders such as a Henschel mixer and a tumbler mixer can be used for the dry blending method.
Various mixers such as a single screw extruder, a twin screw extruder, a Banbury mixer, and a hot roll can be used.

The shear rate of the die exit in the melt extrusion process of the polyethylene resin composition of the present invention (v) is 200sec ^-1 ~1000sec ^-1, preferably 300sec ^-1 ~800sec ^-1, more preferably is 500sec ^-1 ~700sec ^-1. When the shear rate (v) at the die exit exceeds 1000 sec ^-1 ,
Occurrence of "Mayani" may increase for 200 seconds.
If it is less than ^-1 , productivity may decrease.

The ethylene / α-olefin copolymer (A), the ethylene / α-olefin copolymer (B) and the polyethylene resin composition used in the present invention are in a range that does not impair the objects and effects of the present invention. In the above, if necessary, additives such as an antioxidant, a lubricant, an antistatic agent, a processability improver, and an anti-blocking agent can be added. As the antioxidant, for example, 2,6-di-t-butyl-
p-cresol (BHT), tetrakis [methylene-3
-(3,5-Di-t-butyl-4-hydroxyphenyl) propionate] methane (manufactured by Ciba Specialty Chemicals, trade name: IRGANOX 1010)
And n-octadecyl-3- (4′-hydroxy-3,
5'-di-t-butylphenyl) propionate (manufactured by Ciba Specialty Chemicals, trade name: IRGA)
Phenolic stabilizers such as NOX 1076), and phosphite-based stabilizers such as bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite and tris (2,4-di-t-butylphenyl) phosphite And the like.

As the lubricant, for example, erucamide,
Higher fatty acid amides, higher fatty acid esters and the like,
Examples of the antistatic agent include glycerin esters of fatty acids having 8 to 22 carbon atoms, sorbitanates, and polyethylene glycol esters. Examples of the processability improvers include fatty acid metal salts such as calcium stearate. Examples of the anti-blocking agent include silica, diatomaceous earth, calcium carbonate, and talc.

The above various additives are added to a polyethylene resin composition obtained by previously blending the ethylene / α-olefin copolymer (A) and the ethylene / α-olefin copolymer (B). Ethylene α-
It may be used by adding to each of the olefin copolymer (A) and the ethylene / α-olefin copolymer (B), or the additive may be used as the ethylene / α-olefin copolymer (A) or the ethylene / α-olefin. -It may be used as a master batch of the olefin copolymer (B).

The method for producing a polyethylene film using the method for melt-extrusion of the polyethylene resin composition of the present invention is not particularly limited, and a known film production method can be used. Known methods for producing a film include, for example, an inflation method and a T-die casting method, and preferably a T-die casting method. Examples of an apparatus used for producing a polyethylene film using the method for melt-extrusion of the polyethylene resin composition of the present invention include a known apparatus for producing an inflation film and a T-die cast film.
Preferably, it is a T-die cast film production apparatus.

The extrusion die used in the melt extrusion molding method of the polyethylene resin composition of the present invention includes:
There is no particular limitation, and various extrusion dies generally used in a melt extrusion molding method can be used. For example, a T die attached to a cast extruder used for forming a sheet or a film, a spiral die attached to an inflation extruder, a laminating die used for forming a laminated film or a laminated sheet, and the like. Can be

The polyethylene film obtained by the method of melt-extrusion of the polyethylene resin composition of the present invention is also used as a polyethylene multilayer film in which the polyethylene film is laminated on a substrate. Examples of the base material used for the polyethylene multilayer film include cellophane, paper, paperboard, woven fabric, aluminum foil, polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and stretched polypropylene. Can be

The method for laminating a polyethylene film obtained by the melt extrusion molding method of the polyethylene resin composition of the present invention to a substrate (lamination method) includes, for example, a dry lamination method, a wet lamination method, and a sand lamination method. And a hot melt lamination method.

[0035]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The methods for measuring physical properties described in Examples and Comparative Examples are shown below. (1) Density (d, unit: Kg / m ³ ) Measured according to the method specified in JIS K6760. (2) Melt flow rate (MFR, unit: g / 10 min) According to the method specified in JIS K6760, load 2.
The measurement was performed at 16 kg and a temperature of 190 ° C.

(3) Coefficient of variation in composition distribution (Cx) Measured using a multifunctional LC manufactured by Tosoh Corporation. The ethylene-α-olefin copolymer used in the present invention is dissolved (concentration: 0.2 g / 20 ml) in an ortho-dichlorobenzene (ODCB) solvent heated to 145 ° C., and placed in a column filled with sea sand in a column oven. Put the oven temperature at 40
The temperature was lowered to 125 ° C. at a rate of 60 ° C./60 minutes, and the temperature was lowered from 125 ° C. to −15 ° C. over 14 hours. Then, 10
Temperature at a rate of 60 ° C./60 minutes, and then to 125 ° C.
The relative concentration and the degree of branching of the copolymer flowing out during that time were measured by FT-IR connected to a column. Data was taken at 7 points at equal intervals between 10 ° C. The temperature was raised to the final temperature while obtaining the relative concentration of the copolymer flowing out at each set temperature and the degree of branching (SCB) per 1000 main chain carbons.
However, the relationship between each elution temperature and the degree of branching followed (Equation 5) regardless of the type of comonomer. At a temperature where SCB was negative, no elution was observed. SCB = −0.7322 × elution temperature (° C.) + 70.68 (Equation 5) A composition distribution curve is obtained from the obtained relative concentration and the degree of branching, and the average per 1000 carbons obtained from (Equation 6) from this curve. The degree of short chain branching (SCBave.) And the standard deviation (σ) of the composition distribution obtained from (Equation 7) were obtained, and the composition distribution variation coefficient Cx representing the width of the distribution was calculated from the following (Equation 2). Cx = σ / SCBave. (Equation 2) Average short-chain branching degree (SCBave.) = ΣN (i) · W (i) (Equation 6) N (i): Short-chain branching degree W of the i-th data sampling point W (i): Relative density of the i-th data sampling point, that is, ΣW (i) = 1, standard deviation of composition distribution (σ) = ｛Σ (N (i) −SCBave.) ² · W (i)｝ ^0.5 (Equation 7)

(4) Cold xylene soluble part (a, unit: wt%) US code of federal regulations, Food and Drugs
Measured according to the method specified in 175.1520 of Administration.

Ethylene / α used in Examples and Comparative Examples
Table 1 shows the physical properties of the olefin copolymer (A), and Table 2 shows the physical properties of the ethylene / α-olefin copolymer (B) component.

Example 1 or 2, Comparative Examples 1 to 4 Ethylene / α-olefin copolymer (A) component, Ethylene / α-olefin copolymer (B) component, crosslinked acrylic resin particles, diatomaceous earth and ethylenebis Oleic acid amide and erucic acid amide were mixed with a tumble mixer. Table 3 shows the compositions of the compositions of Example 1 or 2 and Comparative Examples 1 to 4 obtained by mixing. Next, the obtained composition was placed in a 40 mmφ extruder manufactured by Tanabe Plastics Machine Co., Ltd.
Attach T die with 7mmφ, lip opening 1.5mm, processing temperature 240 ° C, extrusion amount 7.5kg each
/ Hr, 11 kg / hr, 19 kg / hr, and the shear rate at the die exit are 200 sec ^-1 and 300 sec, respectively.
Under the conditions of ⁻¹ and 540 sec ⁻¹ , continuous melt extrusion was performed for 2 hours, and the occurrence state of “Mani” adhering to the die outlet was visually observed. The shear rate (v) at the die exit was calculated from the following (Equation 8). Table 4 shows the results of the occurrence status of “Mani”. Shear rate v = 6 × Q × V × (10 6/3600) / w × t 2 ( Equation 8) Q: throughput rate of the resin [kg / hr] w: Die width [mm] t: Lip opening [mm V: Specific volume of resin [cm ³ / g] Specific volume of resin V = 1.17 + 9.0 × 10 ⁻⁴ × (T-25) (Equation 9) (Guble equation; low-density polyethylene) T: Resin Temperature [° C]

[0040]

[Table 1] (Note 1) a '= (4.8 × 10 ⁻⁵ ) × (950−d) ³ + (10 ⁻⁶ ) × (950−d) ⁴ +1 (Formula 2 ′) A1: Ethylene / hexene-1 Polymer (manufactured by Nippon Evolu Co., Ltd., Sumitomo Chemical Co., Ltd.), Sumikasen EF
V405)

[0041]

[Table 2] B1: Ethylene hexene-1 copolymer (Mitsui Chemicals, Inc.)
B2: Ethylene butene-1 polymer (Exelen, NO377, manufactured by Sumitomo Chemical Co., Ltd.) B3: Ethylene butene-1 polymer (Exelen, NO392, manufactured by Sumitomo Chemical Co., Ltd.) B4: Ethylene hexene-1 copolymer (manufactured by Nippon Evolu Co., Ltd., sold by Sumitomo Chemical Co., Ltd., Sumikasen EF)
V401) B5: ethylene-butene-1 copolymer (Excellen VL, VL200 manufactured by Sumitomo Chemical Co., Ltd.)

[0042]

[Table 3] C1: Organic anti-blocking agent (manufactured by Nippon Shokubai Co., Ltd., crosslinked polymethyl methacrylate resin powder, MA1010, weight average particle size = 10 μm)

[0043]

[Table 4] ◎: "Mayani" hardly occurred. ：: The occurrence of “measles” was very small. ×: The occurrence of “meani” was large.

Example 1 or 2 that satisfies the requirements of the present invention
Indicates that the occurrence of “measles” is suppressed.
On the other hand, Comparative Example 1, which does not satisfy the MFR of the ethylene / α-olefin copolymer (B), which is a requirement of the present invention,
Comparative Example 2 not satisfying the density, Comparative Example 3 not satisfying the composition distribution variation coefficient, and Comparative Example not satisfying the weight ratio of the ethylene / α-olefin copolymer (A) and the ethylene / α-olefin copolymer (B) In the case of No. 4, it can be seen that the suppression of the occurrence of “measles” is insufficient.

[0045]

As described above in detail, the use of the method for melt-extrusion of the polyethylene-based resin composition of the present invention suppresses the occurrence of "stickiness" on the extrusion surface of the die. Physical properties, particularly transparency, can be maintained at a practical level.

Continued on the front page (72) Inventor Daigo Nakanishi 5-1, Anesaki Beach, Ichihara-shi, Chiba F-term (reference) in Sumitomo Chemical Co., Ltd. 4F207 AA04E AA12E AM32 AR17 AR18 KA01 KA17 KA19 KL84 KM15 4J002 BB051 BB052 BB151 BB152 BB181 BB182 FD020 FD070 FD100 FD170

Claims (1)

[Claims] 1. A melt flow rate (MFR) of 0.1 to 1.
20 g / 10 min, density (d) 905-935K
g / m ³ , and the following (Formula 1) Cx = σ / SCBave. (Formula 1) (In the formula, σ is the standard deviation of the composition distribution, and SCBave. is the number of short-chain branches per 1000 carbon atoms (1000 C). Of the composition distribution (Cx) is 0.6 or less, and the weight ratio (a) and density (d) of the cold xylene-soluble portion are as follows: 2) a <(4.8 × 10 ⁻⁵ ) × (950−d) ³ + (10 ⁻⁶ ) × (950−d) ⁴ +1 (Equation 2) (where a is the soluble xylene soluble part) Ethylene / α-olefin obtained by copolymerizing ethylene having a relation of density (Kg / m ³ ) with α-olefin having 3 to 12 carbon atoms. 80 to 97% by weight of the copolymer (A) and a melt flow rate (MFR) of 2 to 30 g / 10 min. , The density (d) is 860~900Kg / m ^3, the composition distribution variation coefficient obtained from (Equation 1) (Cx) is 0.5 or less,
Ethylene · alpha-olefin copolymer (B) a polyethylene resin composition comprising 20-3 wt%, 200sec ^-1 ~1000sec ^-1 shear rate of the die outlet (v)
Melt extrusion molding of a polyethylene-based resin composition, characterized in that melt extrusion molding is performed under the following conditions.