JP4752187B2 - Ethylene resin composition - Google Patents

Description

  The present invention relates to an ethylene-based resin composition comprising an ethylene homopolymer having a specific molecular weight distribution pattern or a copolymer comprising ethylene and an α-olefin having 3 to 20 carbon atoms, and a high-pressure radical polymerization method low-density polyethylene. More specifically, an ethylene resin composition comprising an ethylene polymer having a broad molecular weight distribution on the high molecular weight side and a high-pressure radical polymerization method low-density polyethylene, excellent in moldability and mechanical properties. About.

  Ethylene polymers have excellent mechanical properties such as rigidity, impact resistance, ESCR, elongation characteristics, and durability, as well as excellent chemical resistance and electrical characteristics. It is used in various fields such as pipes and blow containers.

  The properties required for good processing of an ethylene polymer vary depending on the molding method and application.For example, when producing a film by the inflation molding method, in order to stably obtain a good film at high speed A relatively high melt tension is required so that there is no bubble shaking or breakage. Similar characteristics are also necessary to suppress neck-in during T-die molding or to suppress sagging of the parison during blow molding.

  In extrusion molding, it is also an important characteristic that the shear stress of the ethylene polymer under a high shear rate is small. By reducing the load during extrusion, it becomes possible to cope with high-speed molding, the rough surface of the extruded resin is suppressed, the quality of the molded product is improved, the power consumption during molding is reduced and the economy is improved, etc. There are benefits.

  However, in molecular design such as molecular structure, molecular weight and molecular weight distribution of ethylene polymer, mechanical properties and moldability are often contradictory. For example, ethylene copolymer obtained by metallocene catalyst has molecular weight distribution. In addition, the composition distribution is narrower than that obtained with a Ziegler catalyst, and the impact resistance and the tear strength of the film are improved, but the moldability is lowered.

  In general, an ethylene polymer having a wide molecular weight distribution is advantageous in improving molding processability. Further, an ethylene polymer having a wide molecular weight distribution can greatly improve molding processability by containing a higher molecular weight component (that is, having a higher Z average molecular weight) than an ethylene polymer having a narrow molecular weight distribution. Conventionally, in order to broaden the molecular weight distribution, an ethylene polymer has been produced by using a plurality of reactors or by polymerization using a Cr catalyst. However, when a plurality of reactors are used, polymer particles having substantially only high molecular weight components are by-produced, and when a Cr catalyst is used, it has a large amount of olefin ends and has a wide half-value width in GPC. Only a polymer having a wide molecular weight distribution could be obtained.

  Therefore, if an ethylene polymer having a molecular structure characteristic in which a high molecular weight component and a low molecular weight component are homogeneously mixed with each other having a substantially narrow molecular weight distribution by a metallocene catalyst and a high Z average molecular weight can be obtained. Material with a good balance between mechanical properties and moldability, and its industrial value is extremely high.

  As a method for producing a polyolefin by polymerization of olefin, it is already known to use a catalyst system comprising a combination of a transition metal compound and an organometallic compound. Kaminsky et al. Have reported that a catalyst using metallocene and methylaluminoxane exhibits high activity when producing an olefin polymer containing propylene (see, for example, Patent Document 1).

  However, although the catalyst system disclosed herein is excellent in polymerization activity, since the catalyst system is soluble in the reaction system, a solution polymerization system is often adopted, and not only the production process is limited, but also the industrial system. In order to produce a polymer exhibiting particularly useful physical properties, it is necessary to use a large amount of a relatively expensive methylaluminoxane. For this reason, when these catalyst systems are used, there are problems such as cost and a large amount of aluminum remaining in the polymer.

  On the other hand, as an example of a heterogeneous metallocene catalyst, a catalyst system using a clay compound ion-exchanged with an organic cation as a cocatalyst is disclosed, and high polymerization activity is realized (for example, Patent Documents 2 and 3). However, all have a narrow molecular weight distribution, and only a resin equivalent to a conventional metallocene catalyst resin could be obtained.

  In order to broaden the molecular weight distribution of a polymer in a metallocene catalyst, a method using a plurality of metallocene catalysts exhibiting different polymerization behaviors has been studied. For example, two types of metallocenes having different conformers are used and supported on an aluminoxane. In this method, the molecular weight distribution Mz / Mw on the high molecular weight side that exerts a remarkable effect on processability is smaller than Mw / Mn (for example, see Patent Document 5).

  On the other hand, a method of blending low-density polyethylene is known for the purpose of improving the processability of ethylene-based polymers produced using metallocene catalysts. Although stability is improved, the effect of lowering the shear stress applied to the resin at a high shear rate during extrusion cannot be said to be sufficient, and there was a problem that the skin of the molded body was liable to occur due to the occurrence of melt fracture ( For example, see Patent Document 6).

JP 58-19309 A

JP 7-224106 A Japanese Patent Laid-Open No. 10-324708 JP 11-335408 A JP-A-9-227613 JP-A-6-65443

  An object of this invention is to provide the ethylene-type resin composition which can manufacture the film excellent in the moldability, and also excellent in the mechanical characteristic.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors conducted polymerization under specific conditions using a specific catalyst for olefin polymerization, so that the molecular weight distribution is moderately wide and the high molecular weight The spread of molecular weight distribution on the side is particularly large, and an ethylene polymer with a unique molecular structure and composition in which polymers with different molecular weights are homogeneously mixed has high melt tension and low stress at high shear. I found it. As a result of further research, an ethylene resin composition obtained by blending the ethylene polymer with high-pressure radical polymerization low-density polyethylene has a film with extremely excellent moldability and excellent mechanical strength. As a result, the inventors have found that the above problems can be solved.

That is, the present invention is (A) an ethylene homopolymer or a copolymer composed of ethylene and an α-olefin having 3 to 20 carbon atoms,
(1) The density is 900 to 975 kg / m ³ ,
(2) The melt flow rate (MFR, load 2.16 kg, temperature 190 ° C. condition) is 0.01 to 100 g / 10 minutes,
(3) Mw / Mn determined by gel permeation chromatography (GPC) measurement is 3.0 or more,
(4) Satisfying the relationship of (Mz / Mw) − (Mw / Mn) ≧ 0.5 determined by gel permeation chromatography (GPC) measurement,
(5) From a molecular weight pattern obtained by gel permeation chromatography (GPC) measurement, a molecular weight component having a molecular weight of 1,000,000 g / mol or more is 0.1 to 5.0% by weight of the total weight of the polymer,
(6) 1 to 99% by weight of an ethylene polymer satisfying the relationship of half width (Log (MH / ML)) <1.1 from the molecular weight pattern obtained by gel permeation chromatography (GPC) measurement, and ( B) (1 ′) density obtained by the high-pressure radical polymerization method is 910 to 930 kg / m ³ ,
(2 ′) Low density polyethylene 99 to 1% by weight with a melt flow rate (MFR, load 2.16 kg, temperature 190 ° C.) of 0.01 to 100 g / 10 min.
It is related with the ethylene-type resin composition characterized by comprising.

  The present invention is described in detail below.

  The (A) ethylene polymer according to the present invention is an ethylene homopolymer or a copolymer obtained by polymerizing ethylene and an α-olefin having 3 to 20 carbon atoms.

  Examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, styrene, and ethylidene norbornene. Etc. can be illustrated. Further, two or more kinds of these α-olefins can be mixed and used.

The density of the (A) ethylene polymer according to the present invention is a value measured by a density gradient tube method according to JIS K6922-1 (1997), and is 900 to 975 kg / m ³ , more preferably 915. It is -975 kg / m < ³ >, More preferably, it is 925-970 kg / m < ³ >, Most preferably, it is 930-965 kg / m < ³ >. If the above range (900 to 975 kg / m ³ ) is exceeded, the film becomes too stiff, and if it is below the range, the film loses its elasticity.

  The melt flow rate (MFR, load 2.16 kg, temperature 190 ° C. condition) of the (A) ethylene polymer according to the present invention is a melt indexer (manufactured by Toyo Seiki Seisakusho Co., Ltd.) in accordance with JIS K6922-1 (1997). ), 0.01 to 100 g / 10 min, preferably 0.05 to 30 g / 10 min, more preferably 0.1 to 25 g / 10 min, particularly preferably 0.2 to 20 g / 10 min. When the MFR is larger than the above range (0.01 to 100 g / 10 min), the melt tension of the resin is insufficient, making it difficult to form a stable film, and smaller than the above range (0.01 to 100 g / 10 min). And the extrusion load at the time of a molding process becomes large, and neither is preferable.

  The weight average molecular weight (Mw), number average molecular weight (Mn), Z average molecular weight (Mz) of the ethylene-based polymer (A) according to the present invention, and the ratio thereof, Mw / Mn and Mz / Mw, are gel perm It was measured by an association chromatography (GPC). Tosoh Co., Ltd. HLC-8121GPC / HT is used as the GPC apparatus, Tosoh Co., Ltd. TSKgel GMHhr-H (20) HT is used as the column, the column temperature is set to 140 ° C., and 1 is used as the eluent. It was measured using 2,4-trichlorobenzene. A measurement sample was prepared at a concentration of 1.0 mg / ml, and 0.3 ml was injected and measured. The calibration curve of molecular weight used was calibrated by a universal calibration method using a polystyrene sample having a known molecular weight. Mw / Mn of the ethylene-based polymer of the present invention is 3.0 or more, more preferably 3.5 or more. If Mw / Mn is less than 3.0, the shear stress applied to the resin under a high shear rate at the time of molding increases, which causes problems in workability such as an increase in extrusion load, which is not preferable.

  The (A) ethylene polymer according to the present invention has a relationship of (Mz / Mw) − (Mw / Mn) ≧ 0.5, and the molecular weight distribution clearly spreads on the high molecular weight side in the GPC chart. Is a feature. This brings about a unique effect on the fluidity at the time of melting, and good moldability is obtained. In addition, by satisfying this relationship, when an ethylene polymer is formed into a molded product, elution or bleeding of the low molecular weight component is relatively small, and the high molecular weight component and the low molecular weight component are easily compatible. .

  The (A) ethylene polymer according to the present invention is characterized in that a molecular weight component having a molecular weight of 1,000,000 g / mol or more is 0.1 to 5.0% by weight of the total weight of the polymer from a molecular weight pattern obtained from GPC. To do. When the molecular weight component having a molecular weight of 1 million g / mol or more is less than 0.1% by weight of the total weight of the polymer, the effect of improving the workability is low. The problem of wax generation due to increasing low molecular weight components arises.

The (A) ethylene polymer according to the present invention satisfies the relationship of half width (Log (M _H / M _L )) <1.1 from the molecular weight pattern obtained by GPC measurement, more preferably half width (Log ( M _H / M _L )) <1.05 is satisfied. By satisfying this relationship, a substantially narrow molecular weight distribution is obtained, and a high mechanical strength equivalent to that of an ethylene polymer having a narrow molecular weight distribution polymerized by one type of metallocene catalyst is exhibited. In addition, it is possible to reduce the amount of elution that affects the quality of the product. Here, the half-value width of the molecular weight pattern indicates the spread of the spectrum (degree of molecular weight distribution) around the peak top (maximum frequency) of the maximum peak among the molecular weight distribution patterns in GPC. That is, the intensity of the spectrum is the half width of the width of the GPC spectral lines at the peak top where that is the half of the (maximum frequency) (M _H the high molecular weight side, _{respectively,} the low molecular weight side and M _L) . In addition, when a plurality of peaks are observed, calculation is performed from the maximum one of the peaks.

  In the GPC pattern of the (A) ethylene-based polymer according to the present invention, the number of maximum values of the molecular weight distribution is not particularly limited, but preferably has a single maximum value. Those having a plurality of maximum values may cause problems in stretchability when formed into a film or the like.

  The method for producing the (A) ethylene polymer according to the present invention is not particularly limited. For example, in the presence of a Ziegler catalyst, a Phillips catalyst or a metallocene catalyst, ethylene is polymerized alone or ethylene and an α-olefin having 3 to 20 carbon atoms are produced. The method of making it copolymerize is mentioned. Among them, for example, an ethylene heavy polymer obtained in the presence of a metallocene catalyst described in JP-A-7-224106, JP-A-9-59310, JP-A-10-223112, JP-A-10-231313, etc. The coalescence is preferable because the low molecular weight component contained in the polymer is small, and the stickiness of the surface of the molded product is reduced.

  The (A) ethylene polymer according to the present invention is produced by slurry polymerization or gas phase polymerization. The ethylene polymer is preferably obtained by polymerization in a single reactor. Particularly preferably, it is continuously produced in a single reactor, and further produced by a method of separating and purifying continuously produced ethylene polymer and unreacted monomers, polymerization aids and solvents. The The solvent for slurry polymerization may be any organic solvent that is generally used, and specific examples include benzene, toluene, xylene, propane, butane, pentane, hexane, heptane, cyclohexane, and methylene chloride. .

  There are no particular restrictions on the polymerization conditions such as polymerization temperature, polymerization time, polymerization pressure, and monomer concentration in producing the (A) ethylene polymer using the olefin polymerization catalyst shown in the present invention. In this case, the polymerization temperature is −100 to 100 ° C., preferably 0 to 100 ° C., the polymerization time is preferably 10 seconds to 20 hours, and the polymerization pressure is preferably in the range of normal pressure to 10 MPa. It is also possible to adjust the molecular weight using hydrogen during polymerization. In the case of gas phase polymerization, the polymerization temperature is preferably −100 to 120 ° C., preferably 0 to 110 ° C., the polymerization time is 10 seconds to 20 hours, and the polymerization pressure is preferably in the range of normal pressure to 10 MPa. It is also possible to adjust the molecular weight using hydrogen during polymerization. Among these, slurry polymerization is more preferable in view of the removal rate of wax components and the like.

  The (B) high-pressure radical polymerization method low-density polyethylene according to the present invention is a polyethylene produced by a high-pressure radical polymerization method, and is obtained by polymerizing ethylene by a known method.

Density of the present invention in accordance with (B) a high-pressure radical polymerization process low-density polyethylene is 910~930kg / ^{m 3,} preferably 915~928kg / ^{m 3} because the transparency of the molded film is improved, and even more preferably 917 to 925 kg / m ³ .

  The melt flow rate (MFR, load 2.16 kg, temperature 190 ° C. condition) of the (B) high-pressure radical polymerization method (B) according to the present invention is 0.01 to 100 g / 10 min, and the film has good workability. Therefore, 0.05 to 70 g / 10 min is preferable, and 0.1 to 50 g / 10 min is more preferable.

  In addition, (B) high-pressure radical polymerization method low-density polyethylene according to the present invention is not limited to the object of the present invention, and other α-olefin, vinyl acetate, acrylate ester and other polymerizable monomers can be used. The copolymer may be used.

  The ethylene-based resin composition of the present invention comprises (A) the ethylene-based polymer and (B) the high-pressure radical polymerization method low-density polyethylene. The mixing ratio is arbitrary, but since the mechanical strength becomes good, the weight ratio ((A) :( B)) of (A) ethylene polymer and (B) high-pressure radical polymerization method low density polyethylene is It is in the range of 99: 1 to 1:99, more preferably in the range of 99: 1 to 10:90, still more preferably in the range of 99: 1 to 30:70, particularly preferably 99: 1 to 1. The range is 40:60.

  The ethylene resin composition of the present invention includes an antioxidant, an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, a chlorine absorber, an antistatic agent, as long as the object of the present invention is not impaired. Additives such as antifogging agents, slip agents, lubricants, antiblocking agents, nucleating agents, pigments, dyes, plasticizers, flame retardants, inorganic fillers and organic fillers may be blended as necessary.

  The ethylene-based resin composition of the present invention can be produced using a known method. For example, a method of mixing and kneading each component using various kneaders such as a Banbury mixer, a roll mixer, a kneader, a high-speed rotary mixer, and an extruder, preferably a single screw or twin screw extruder can be used. Moreover, the pellets mixed by dry blending can be kneaded and used during film forming.

  The ethylene-based resin composition of the present invention can be processed into a film using a known method. For example, a film can be obtained by processing by air-cooled inflation molding, water-cooled inflation molding, T-die molding, or the like. The molding temperature is not particularly limited, but is preferably in the range of 140 to 240 ° C. because stable molding can be performed.

  The ethylene-based resin composition can be stably molded because (A) the ethylene-based polymer exhibits a high melt tension when it contains a large amount of high molecular weight components. Further, since the shear stress in the high shear rate region is low, the load during extrusion molding is small, high-speed molding is possible, power consumption can be reduced, and the resulting film is unlikely to cause rough skin. Moreover, since it has a substantially narrow molecular weight distribution, a film having excellent mechanical strength can be obtained.

  The film comprising the ethylene resin composition of the present invention may be a single layer film, but can also be used as a laminate having at least one layer of the film of the present invention. The film comprising the ethylene resin composition of the present invention is made of polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, polypropylene, propylene-α-olefin block copolymer, propylene-α-olefin random. Olefin polymers such as copolymers, vinyl alcohol polymers, ethylene-vinyl alcohol copolymers, polybutene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyethylene terephthalate, polybutylene terephthalate and other polyesters, nylon It can be used by laminating with polyamide, polycarbonate, (meth) acrylic resin, polyurethane, cellulosic resin and the like.

  The lamination method is preferably a co-extrusion method such as multilayer air-cooled inflation molding, multilayer water-cooled inflation molding, multilayer T-die molding, or dry lamination method.

  The thickness of the film comprising the ethylene polymer of the present invention and the laminate having the film as at least one layer is not particularly limited, but is preferably in the range of 30 to 200 μm from the viewpoints of economy and workability.

  A film comprising the ethylene-based resin composition of the present invention and a laminate having the film as at least one layer include a standard bag, a heavy bag, a rice bag, a wrap film, a masking film, a cleaning bag, a fiber packaging bag, a fashion bag, and a laminar. On the other hand, it can be used for sugar bags, oil packaging bags, water packaging bags, packaging films for food packaging, stretched tapes, infusion bags, agricultural materials, and the like.

  The ethylene-based resin composition of the present invention can also be used for bottles and infusion bags by blow molding, tubes and pipes by extrusion molding, daily miscellaneous goods by injection molding, foams and fibers by extrusion foaming, and the like.

  The ethylene-based resin composition of the present invention has a specific molecular weight distribution, particularly a molecular structure exhibiting a wide molecular weight distribution on the high molecular weight side, and a composition in which a high molecular weight component and a low molecular weight component are homogeneously mixed (A). Since it is a blend of an ethylene-based polymer and (B) high-pressure radical polymerization method low-density polyethylene, it has high melt tension and low work stress in a high shear rate region, so it has excellent workability. In addition, a film having characteristics excellent in strength balance, which is a characteristic of a metallocene-based ethylene polymer, can be produced.

  EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

  In the present invention, physical properties of (A) the ethylene polymer and the ethylene resin composition were evaluated as follows.

[Bubble stability]
The stability of bubbles at the time of forming an inflation film was visually evaluated.
○: Stable molding without bubble shaking △: Slight bubble shaking but little film wrinkle × Large bubble shaking and many wrinkles in the molded film [Film Skin]
The state of rough skin on the surface of the molded film was evaluated by visual and tactile sensations.
○: There is no rough skin, and the film surface is smooth. Δ: The skin surface is slightly rough, but the surface of the film is almost smooth by tactile sensation. Strain]
Based on JIS K6922-2 (1997), it measured with the tensile tester (model number DCS-100) by Shimadzu Corporation.

Production Example 1
Production of Ethylene Polymer (A-1) The polymerization operation, reaction and solvent purification were all performed under an inert gas atmosphere. Moreover, the solvent etc. which were used for the reaction were all purified, dried and deoxygenated by a known method in advance. Furthermore, the compound used for the reaction was synthesized and identified by a known method.

[Preparation of modified clay compound]
1000 g of synthetic hectorite (Laponite RD; manufactured by Laporte) was treated with 8 L of 60% ethanol aqueous solution of dimethylaniline hydrochloride (1 mol) and washed with water to obtain 1250 g of an organically modified clay compound.

[Preparation of solid catalyst]
To a 5 L flask, 450 g of an organically modified clay compound synthesized according to [Preparation of modified clay compound] and 1.4 kg of hexane were added, and then 1.78 kg (1.8 mol) of a 20 wt% solution of triisobutylaluminum in hexane, bis ( 7.32 g (18 mmol) of n-butyl-cyclopentadienyl) zirconium dichloride was added, heated to 60 ° C. and stirred for 1 hour. The reaction solution was cooled to 45 ° C., and the supernatant was removed by a gradient method. After diluting this with hexane to 4.5 L, 0.66 g (1.8 mmol) of diphenylmethylene (3-trimethylsilyl-cyclopentadienyl-9-fluorenyl) zirconium dichloride was added to obtain a solid catalyst.

[polymerization]
A polymerization vessel having an internal volume of 300 L was continuously supplied with 105 kg / hour of hexane, 30.0 kg / hour of ethylene, 1.0 kg / hour of 1-butene, 20 NL / hour of hydrogen and the obtained solid catalyst. Moreover, it superposed | polymerized at 85 degreeC of superposition | polymerization temperature, respectively supplying continuously so that the density | concentration of the triisobutyl aluminum in a liquid might be set to 0.93 mmol / kg hexane. The obtained polymer had an MFR of 3.7 g / 10 min and a density of 942 kg / m ³ . Table 1 shows the values measured for the physical properties of the obtained ethylene-based polymer.

[Granulation]
0.04 parts by weight of Irganox 1076 (manufactured by Ciba Specialty Chemicals) as an antioxidant and 100% by weight of GSY-P101 (API) with respect to 100 parts by weight of the obtained powder of ethylene polymer (A-1) Co., Ltd.) and 0.04 parts by weight of DHT-4A (Kyowa Chemical Industry Co., Ltd.) as a chlorine absorbent were blended, and a Henschel mixer (Model No. FM75C, Mitsui Miike Seisakusho Co., Ltd.) at 820 rpm for 1 minute. Mixed. Then, using a 50 mmφ single screw extruder (model number PDA-50 manufactured by Plako), the mixture was kneaded at a set temperature of 200 ° C. and a rotation speed of 100 rpm to form a pellet.

  The ethylene-based polymer (A-1) was used in Examples 1 to 3.

Production Example 2
Production of ethylene polymer (A-2) [Preparation of solid catalyst]
To a 5 L flask, 450 g of an organically modified clay compound synthesized according to [Preparation of modified clay compound] described in Production Example 1 and 1.4 kg of hexane were added, and then 1.78 kg (1.78 kg) of a 20 wt% solution of triisobutylaluminum in hexane. 8 mol), 7.32 g (18 mmol) of bis (n-butyl-cyclopentadienyl) zirconium dichloride was added, and the mixture was heated to 60 ° C. and stirred for 1 hour. Thus, a catalyst solution was obtained.

[polymerization]
Polymerization was carried out in the same manner as in Production Example 1 except that the solid catalyst obtained in Production Example 2 was used and 0.4 kg / hour of 1-butene and 15 NL / hour of hydrogen were used. The obtained polymer had an MFR of 3.7 g / 10 min and a density of 942 kg / m ³ . Table 1 shows the values measured for the physical properties of the obtained ethylene-based polymer.

[Granulation]
The obtained ethylene polymer (A-2) powder was pelletized by the same method as in Production Example 1.

  The ethylene-based polymer (A-2) was used in Comparative Examples 1 to 3.

Production Example 3
Production of ethylene polymer (A-3) Polymerization was carried out in the same manner as in Production Example 1 except that 1-butene was changed to 0.25 kg / hour and hydrogen was changed to 15 NL / hour. The obtained polymer had an MFR of 0.9 g / 10 min and a density of 954 kg / m ³ . Table 1 shows the values measured for the physical properties of the obtained ethylene-based polymer.

[Granulation]
The obtained ethylene polymer (A-3) powder was pelletized by the same method as in Production Example 1.

  The ethylene polymer (A-3) was used in Example 4.

Production Example 4
Production of ethylene polymer (A-4) [Preparation of solid catalyst]
To a 5 L flask, 450 g of an organically modified clay compound synthesized according to [Preparation of modified clay compound] described in Production Example 1 and 1.4 kg of hexane were added, and then 1.78 kg (1.78 kg) of a 20 wt% solution of triisobutylaluminum in hexane. 8 mol) and 7.06 g (18 mmol) of bis (indenyl) zirconium dichloride were added, heated to 60 ° C. and stirred for 1 hour, and then the supernatant was removed by a gradient method and diluted with hexane to obtain a catalyst solution.

[polymerization]
Polymerization was carried out in the same manner as in Production Example 1 except that 1-butene was not added and hydrogen was changed to 8 NL / hour using the solid catalyst obtained in Production Example 4. The obtained polymer had an MFR of 0.9 g / 10 min and a density of 954 kg / m ³ . Table 1 shows the values measured for the physical properties of the obtained ethylene-based polymer.

[Granulation]
The obtained ethylene polymer (A-4) powder was pelletized by the same method as in Production Example 1.

  The ethylene polymer (A-4) was used in Comparative Example 4.

Example 1
[Preparation of ethylene resin composition]
Ethylene polymer (A-1) obtained in Production Example 1 and (B) high-pressure radical polymerization method low-density polyethylene (“Petrocene 176” manufactured by Tosoh, density 924 kg / m ³ , MFR 1.0 g / 10 min, the following ( B-1) was dry blended at a weight ratio (A-1) :( B-1) = 85: 15. Thereafter, using a 50 mmφ single screw extruder (model number PDA-50) manufactured by Plako Co., Ltd., an ethylene-based resin composition was obtained by kneading at a set temperature of 200 ° C. and a rotation speed of 100 rpm.

[Film processing]
Using the above-mentioned ethylene-based resin composition, a set temperature of 190 ° C. by an air-cooled single layer inflation molding machine (model number LL50B, extruder screw diameter 50 mmφ, die diameter 75 mmφ, lip clearance 2 mm, dual slit type air ring) manufactured by Plako An inflation film having a thickness of 50 μm was molded under molding conditions of an extrusion rate of 18 kg / hour, a take-up speed of 14 m / min, and a blow ratio of 2.1. The outer surface of the film was subjected to corona discharge treatment so that the surface tension was 0.048 N / m. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. The moldability and mechanical properties of the film were good.

Example 2
Example 1 except that the weight ratio of the ethylene polymer (A-1) and the high pressure radical polymerization method low density polyethylene (B-1) was changed to (A-1) :( B-1) = 50: 50. An ethylene-based resin composition was prepared in the same manner, and an inflation film having a thickness of 50 μm was formed in the same manner as in Example 1. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. The moldability and mechanical properties of the film were good.

Example 3
Example 1 except that the weight ratio of the ethylene polymer (A-1) and the high-pressure radical polymerization method low-density polyethylene (B-1) was changed to (A-1) :( B-1) = 10: 90. An ethylene-based resin composition was prepared in the same manner, and an inflation film having a thickness of 50 μm was formed in the same manner as in Example 1. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. The moldability and mechanical properties of the film were good.

Comparative Example 1
[Preparation of ethylene resin composition]
Using the ethylene polymer (A-2) obtained in Production Example 2 and the high pressure radical polymerization method low density polyethylene (B-1), an ethylene resin composition was prepared in the same manner as in Example 1.

[Film processing]
A blown film having a thickness of 50 μm was formed in the same manner as in Example 1 using the above ethylene-based resin composition. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. Bubble stability was poor and stable molding was not possible. Moreover, compared with Example 1, the power consumption value and the resin pressure value at the time of extrusion were high.

Comparative Example 2
Comparative Example 1 except that the weight ratio of the ethylene polymer (A-2) and the high-pressure radical polymerization method low-density polyethylene (B-1) was changed to (A-2) :( B-1) = 50: 50. An ethylene-based resin composition was prepared in the same manner, and an inflation film having a thickness of 50 μm was formed in the same manner as in Example 1. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. Compared with Example 1, the power consumption value and the resin pressure value during extrusion were higher.

Comparative Example 3
Comparative Example 1 except that the weight ratio of the ethylene polymer (A-2) and the high-pressure radical polymerization method low-density polyethylene (B-1) was changed to (A-2) :( B-1) = 10: 90. An ethylene-based resin composition was prepared in the same manner, and an inflation film having a thickness of 50 μm was formed in the same manner as in Example 1. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. Compared with Example 1, the power consumption value and the resin pressure value during extrusion were higher.

Example 4
[Preparation of ethylene resin composition]
An ethylene resin composition was prepared in the same manner as in Example 1 except that the ethylene polymer (A-3) obtained in Production Example 3 was used instead of the ethylene polymer (A-1). did.

[Film processing]
A blown film having a thickness of 50 μm was formed in the same manner as in Example 1 using the above ethylene-based resin composition. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. The moldability and mechanical properties of the film were good.

Comparative Example 4
[Preparation of ethylene resin composition]
An ethylene resin composition was prepared in the same manner as in Example 1 except that the ethylene polymer (A-4) obtained in Production Example 4 was used instead of the ethylene polymer (A-1). .

[Film processing]
A blown film having a thickness of 50 μm was formed in the same manner as in Example 1 using the above ethylene-based resin composition. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. Melt fracture occurred and the skin of the formed film was poor. Moreover, compared with Example 3, the power consumption value and resin pressure value at the time of extrusion were high.

Comparative Example 5
[Preparation of ethylene resin composition]
Instead of the ethylene polymer (A-1), “Nipolon Hard 5110” manufactured by Tosoh Corporation (density 960 kg / m ³ , MFR 0.9 g / 10 min, hereinafter abbreviated as A-5. Values measured for physical properties are shown in Table 1. The ethylene-based resin composition was prepared in the same manner as in Example 1 except that the above was used.

[Film processing]
A blown film having a thickness of 50 μm was formed in the same manner as in Example 1 using the above ethylene-based resin composition. Table 2 shows the film physical properties, the power consumption value at the time of film forming, and the resin pressure value. The tensile fracture nominal strain in the TD direction of the film (the direction perpendicular to the flow direction during film formation) was 0, and the mechanical strength of the film was inferior.

Example 5
[Production of laminate]
The film formed in Example 1 was dry laminated with a 15 μm nylon film (Harden N1102 manufactured by Toyobo Co., Ltd.) using a dry laminator (model name: pilot coater) manufactured by Inoue Metal Co., Ltd. As the adhesive, a polyether-based polyurethane adhesive (the main agent, Seika Bond A-154-2, manufactured by Dainichi Seika Co., Ltd., a curing agent, Seika Bond C-88, manufactured by Dainichi Seika Co., Ltd.) is used, and the adhesive coating amount is 2.5 g / m ^2. Met. After lamination, an aging treatment was performed in an oven maintained at 40 ° C. for 40 hours to obtain an ethylene resin composition / nylon laminate.

  As is clear when Examples 1 to 3 and Comparative Examples 1 to 3 are compared, (A-1) and (A-2) are MFR ethylene-1-butene copolymers having almost the same density and the same. Although the same amount of high-pressure radical polymerization method low-density polyethylene was blended, Examples 1 to 3 had better bubble stability and lower power consumption and resin pressure, so the ethylene-based resin composition of the present invention Has good workability. Further, as apparent from the comparison between Example 4 and Comparative Example 4, the skin of the film of Comparative Example 4 was deteriorated, whereas the skin of the film of Example 4 was very good. The ethylene resin composition can produce a product having a good appearance. Moreover, in Comparative Example 5 using the ethylene-based polymer (A-5) produced using a Ziegler catalyst, the tensile fracture nominal strain in the TD direction (direction perpendicular to the flow direction during film forming) of the film was 0. On the other hand, since the film of Example 4 has good elongation in the TD direction, it is superior in mechanical strength to a film using an ethylene polymer based on a Ziegler catalyst.

Claims (3)

(A) an ethylene homopolymer or a copolymer comprising ethylene and an α-olefin having 3 to 20 carbon atoms,
(1) The density is 900 to 975 kg / m ³ ,
(2) The melt flow rate (MFR, load 2.16 kg, temperature 190 ° C. condition) is 0.01 to 100 g / 10 minutes,
(3) Mw / Mn determined by gel permeation chromatography (GPC) measurement is 3.0 or more,
(4) Satisfying the relationship of (Mz / Mw) − (Mw / Mn) ≧ 0.5 determined by gel permeation chromatography (GPC) measurement,
(5) From a molecular weight pattern obtained by gel permeation chromatography (GPC) measurement, a molecular weight component having a molecular weight of 1,000,000 g / mol or more is 0.1 to 5.0% by weight of the total weight of the polymer,
(6) From the molecular weight pattern obtained by gel permeation chromatography (GPC) measurement, the relationship of half width (Log (MH / ML)) <1.1 is satisfied.
(Here, the full width at half maximum of the molecular weight pattern indicates the spread of the spectrum (degree of molecular weight distribution) around the peak top (maximum frequency) of the GPC molecular weight distribution pattern, and the intensity in the spectrum is the peak top (maximum (The frequency of the GPC spectrum line at half the frequency) is MH and the low molecular weight side is ML, respectively.
1 to 99% by weight of an ethylene-based polymer, and (B) a density (1 ′) obtained by a high-pressure radical polymerization method is 910 to 930 kg / m ³ ,
(2 ′) Low density polyethylene 99 to 1% by weight with a melt flow rate (MFR, load 2.16 kg, temperature 190 ° C.) of 0.01 to 100 g / 10 min.
An ethylene-based resin composition comprising: A film comprising the ethylene-based resin composition according to claim 1. A laminate having at least one layer of the film according to claim 2 formed by a coextrusion molding method or a dry lamination method.