JP5979985B2 - Olefin polymer composition and film comprising the composition - Google Patents

Description

  The present invention relates to an olefin polymer composition comprising a crosslinked ultrahigh molecular weight olefin polymer that has been crosslinked by irradiating radiation to the ultra high molecular weight olefin polymer. More specifically, the present invention relates to a blocking phenomenon during film formation. The present invention relates to an olefin polymer composition that can be reduced and a film comprising the composition.

  Films made of olefin polymers are widely used as various packaging materials because they are excellent in transparency and mechanical properties. However, when films made of an olefin polymer are stacked on each other (for example, a laminated shape, a roll shape, etc.), a so-called blocking phenomenon occurs in which the films are in close contact with each other. Therefore, conventionally, in order to improve the blocking resistance of the olefin polymer film, an antiblocking agent is added to improve the blocking resistance (for example, see Patent Document 1).

  As an anti-blocking agent for an olefin polymer film, it is known that an inorganic substance such as fine powdered silica, zeolite, talc, calcium carbonate, diatomaceous earth is used (for example, see Patent Document 2). However, since these inorganic substances have high hardness and are indefinite, there is a problem that the films are easily damaged when the films having the inorganic substance arranged on the surface are rubbed with each other.

  Moreover, the method of using an acrylic resin particle for an antiblocking agent is known (for example, refer patent document 3). However, since the acrylic resin particles have insufficient affinity with the olefin polymer, there is a problem that the antiblocking agent made of the acrylic resin particles drops off during film formation or secondary processing.

  In order to solve the above problem, a method of using olefin polymer particles having a good affinity for the olefin polymer as an antiblocking agent has also been proposed. Olefin polymer particles are more flexible than the above-mentioned inorganic substances and have a higher affinity with the base olefin polymer than other polymer particles, so that the scratch resistance of the film is improved and the film is resistant to damage. Blocking property can be improved. As such polymer particles, ultra-high molecular weight olefin polymer particles are known (see, for example, Patent Document 4).

JP-A-6-73202 JP-A-49-23245 International Publication No. 2009/044925 JP 2008-88248 A

  Based on the above-described background art, the present inventors have studied an anti-blocking agent composed of ultrahigh molecular weight olefin polymer particles with the aim of further improving the performance of a film composed of an olefin polymer. Specifically, an attempt was made to improve the blocking resistance by reducing the particle size and highly dispersing an antiblocking agent in the olefin polymer.

  As a result, it has been found that the ultra-high molecular weight olefin polymer particles have a property of being easily re-aggregated at the time of heat kneading with another olefin polymer as the particle diameter becomes smaller. Alternatively, the inventors have found that the particle shape is not maintained and becomes indefinite due to heat and stress during heat kneading.

  The agglomeration of these particles and the change of the particle shape cause a defective appearance of the product, particularly in the production of an olefin polymer film having a film thickness of 30 μm or less, and further the phenomenon that the effect of blocking resistance is weakened. Was found.

  As a result of the background art described above and the results of the above studies, the problem to be solved by the present invention is to improve the blocking resistance of the olefin polymer film and to give heat resistance by applying a specific treatment as an antiblocking agent. Another object of the present invention is to provide an olefin polymer composition containing the specified ultrahigh molecular weight olefin polymer and a film comprising the composition.

  The present inventors have intensively studied to solve the above problems. As a result, the inventors have found that the above problems can be solved by an olefin polymer composition having the following configuration, and have completed the present invention.

That is, the olefin polymer composition in the present invention is a crosslinked ultrahigh molecular weight obtained by irradiating an olefin polymer and an ultrahigh molecular weight olefin polymer satisfying the following requirements (i) to (iii) by irradiation. It contains an olefin polymer.
(I) Intrinsic viscosity [η] measured in a decalin solvent at 135 ° C. is 5 to 50 dl / g
(Ii) an average particle size _{d 50} is, 3 to 30 .mu.m
(Iii) At least 95% by weight or more passes through a sieve having a mesh size of 37 μm. In the present invention, the radiation dose is preferably 20 to 700 kGy.

  In the present invention, the content of the crosslinked ultrahigh molecular weight olefin polymer is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the olefin polymer.

  In the present invention, the ultra high molecular weight olefin polymer is preferably an ultra high molecular weight ethylene polymer.

  In the present invention, the olefin polymer is preferably an ethylene polymer, a propylene polymer or a 4-methyl-1-pentene polymer.

  Moreover, the film in this invention consists of the said olefin polymer composition, It is characterized by the above-mentioned.

  The olefin polymer composition of the present invention is excellent in blocking resistance when formed into a film. Moreover, since the aggregation of the added ultra high molecular weight olefin polymer particles does not occur, a film having a good appearance can be obtained.

It is the optical microscope photograph (200 times) which observed the dispersion state of the ethylene polymer particle in the pellet in Example 1 and the comparative example 1. FIG. It is the optical microscope photograph (200 times) which observed the dispersion state of the ethylene polymer particle in the pellet in Example 3 and Comparative Example 3. FIG.

  The olefin polymer composition of the present invention includes an olefin polymer and a crosslinked ultrahigh molecular weight olefin polymer obtained by irradiating and crosslinking an ultrahigh molecular weight olefin polymer satisfying the following requirements (i) to (iii): A polymer.

Hereinafter, after describing the crosslinked ultrahigh molecular weight olefin polymer, the olefin polymer composition of the present invention will be described.
(Crosslinked ultra-high molecular weight olefin polymer)
A cross-linked ultra-high molecular weight olefin polymer, which is one of the components of the resin composition according to the present invention, is obtained by irradiating and crosslinking an ultra-high molecular weight olefin polymer having specific physical properties. It is a thing.

  In the present invention, an olefin polymer having an intrinsic viscosity [η] of 5 dl / g or more measured in a 135 ° C. decalin solvent may be referred to as an ultrahigh molecular weight olefin polymer.

Hereinafter, a method for preparing the ultrahigh molecular weight olefin polymer and the crosslinked ultrahigh molecular weight olefin polymer will be described.
<Ultra high molecular weight olefin polymer>
The ultra high molecular weight olefin polymer used as a raw material for the crosslinked ultra high molecular weight olefin polymer satisfies the following requirements (i) to (iii).
(I) Intrinsic viscosity [η] measured in a decalin solvent at 135 ° C. is 5 to 50 dl / g
(Ii) an average particle size _{d 50} is, 3 to 30 .mu.m
(Iii) At least 95% by weight or more passes through a 37 μm mesh sieve. Requirements (i) to (iii) will be described below.
・ Requirement (i)
In the present invention, the intrinsic viscosity [η] of the ultrahigh molecular weight olefin polymer measured in a 135 ° C. decalin solvent is 5 to 50 dl / g, preferably 5 to 40 dl / g, more preferably 5 to 30 dl / g. is there.

It is preferable for the intrinsic viscosity to be in the above-mentioned range since it is excellent in wear resistance and self-lubricating properties.
・ Requirement (ii)
In the present invention, the average particle size d ₅₀ of the ultra-high molecular weight olefin polymer is a value at which the integrated value of the particle size distribution is 50% by measurement of the weight-based particle size distribution by the Coulter counter method, ₅₀ is in the range of 3 to 30 μm, preferably 3 to 25 μm, more preferably 3 to 20 μm, and still more preferably 3 to 15 μm.

When the average particle size is 30 μm or less, the impact strength of the molded article made of the olefin polymer composition obtained by blending with the olefin polymer is improved. Moreover, it is preferable at the point from which the external appearance of the molded object obtained becomes more favorable. On the other hand, when the average particle diameter is 3 μm or more, it is preferable because the handling of particles during molding is good.
・ Requirements (iii)
In the present invention, the ultra high molecular weight olefin polymer uses a vibrating sieve or an ultrasonic vibrating sieve and passes through a mesh sieve (Tyler # 400) having a mesh size of 37 μm, and more preferably 98% by weight. % Or more, more preferably 99.7% or more, and most preferably 100%.

  A passage amount greater than 95% by weight means that the abundance of coarse particles is small. When there are few coarse particles, the presence of a crosslinked ultra-high molecular weight olefin polymer produced from the ultra-high molecular weight olefin polymer in the olefin polymer composition allows the added substance (particles) to effectively block blocking. Therefore, it is considered preferable.

  In the present invention, the ultrahigh molecular weight olefin polymer is a homopolymer such as polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene and a small amount of other α-olefins, for example, , Propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene and the like, preferably ethylene-based polymers, particularly preferably ethylene homopolymers. is there.

In the present invention, the production method of the ultrahigh molecular weight olefin polymer is not particularly limited as long as it satisfies the above requirements (i) to (iii). For example, it is produced by the method disclosed in the following documents. Can do.
(1) International Publication No. 2006/054696 (2) International Publication No. 2008/013144 (3) International Publication No. 2009/011231 (4) International Publication No. 2010/074073 <Crosslinked Ultra High Molecular Weight Olefin Polymer Preparation>
In the present invention, the crosslinked ultrahigh molecular weight olefin polymer is obtained by irradiating the above-described ultrahigh molecular weight olefin polymer with radiation.

  By irradiating the ultrahigh molecular weight olefin-based polymer with radiation, the molecular chain is broken and crosslinked, and as a result, the molecular chains are combined at the crosslinking point. As a result, the molecular chain cannot flow freely even at the glass transition temperature or higher than the melting point, and the high temperature characteristics are improved. Furthermore, the shape can be maintained even under stress, and the mechanical properties can be maintained.

  As radiation, there are α rays, β rays, γ rays, electron rays, ions, etc., and any of them can be used, but electron rays or γ rays are suitable.

  Although the radiation dose varies depending on the monomer species constituting the ultrahigh molecular weight olefin polymer to be used, it is usually 20 to 700 kGy, preferably 100 to 500 kGy.

  When the irradiation dose is within the above range, the crosslinking reaction of the ultrahigh molecular weight olefin polymer proceeds efficiently, and the crosslinked ultrahigh molecular weight olefin polymer thus obtained is used in the olefin polymer composition. Then, reaggregation of particles can be suppressed.

On the other hand, when the irradiation dose is 700 kGy or more, the polymer is deteriorated severely, and when the irradiation dose is 20 kGy or less, the crosslinking of the polymer chain does not proceed or is not preferable.
[Olefin polymer composition]
The olefin polymer composition according to the present invention is obtained by using the above-mentioned crosslinked ultrahigh molecular weight olefin polymer as an antiblocking agent and further mixing with the olefin polymer.

  Examples of the olefin polymer that can be used in the present invention include those obtained by polymerizing one or more olefins selected from ethylene and linear or branched α-olefins having 3 to 20 carbon atoms. It is done.

  Specific examples of the linear or branched α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene and 4-methyl-1. -Pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene and the like. As these α-olefins, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene and 4-methyl-1-pentene are preferable.

  In addition, as a monomer component which comprises an olefin polymer in this invention, in addition to the alpha olefin mentioned above, in the range which does not impair the objective of this invention, a cyclic olefin, a functionalized vinyl compound, a polar group (for example, a carbonyl group, a hydroxyl group) , An ether bond group, etc.) and a monomer having a polymerizable carbon-carbon double bond in the molecule (hereinafter also referred to as a polar group-containing monomer), a conjugated diene, a non-conjugated polyene, and the like.

  Cyclic olefins include cyclic olefins having 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms, such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 2-methyl 1,4,5. , 8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene and the like.

  Examples of functionalized vinyl compounds include aromatic vinyl compounds and alicyclic vinyl compounds. Examples of the aromatic vinyl compound include mono- or poly-styrene such as styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, o, p-dimethyl styrene, o-ethyl styrene, m-ethyl styrene, p-ethyl styrene. Alkylstyrene; functional group-containing styrene derivatives such as methoxystyrene, ethoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzyl acetate, hydroxystyrene, o-chlorostyrene, p-chlorostyrene; and 3-phenylpropylene, 4 -Phenylpropylene, α-methylstyrene and the like are mentioned, and examples of the alicyclic vinyl compound include vinylcyclohexane and vinylcycloheptane.

  Of the olefin polymers described above, an ethylene polymer, a propylene polymer, or a 4-methyl-1-pentene polymer is preferably used.

  The ethylene polymer contains ethylene as a main constituent monomer component, and usually contains 50 mol% or more, preferably 80 mol% or more of ethylene. Specific examples of the ethylene polymer include high pressure method low density polyethylene (LDPE), linear short chain branched polyethylene (LLDPE), medium and low pressure method high density polyethylene (HDPE), and very low density polyethylene (VLDPE). It is done.

More specific ethylene-based polymer, density 940 kg / ^{m 3} or more 980 kg / ^{m 3} of less than high density polyethylene is in the range, low-density polyethylene in the range of density of 900 kg / ^{m 3} or more 940 than kg / ^{m 3,} Examples thereof include medium density polyethylene, linear low density polyethylene, ultra low density polyethylene, and blends thereof. Which of these is adopted is not particularly limited, but low density polyethylene and linear low density polyethylene are preferred from the viewpoint of excellent balance between transparency and processability. The density of the ethylene polymer is measured according to the density gradient tube method of JIS K7112.

  The melt index (MI) of the ethylene polymer is usually 0.01 to 100 g / 10 minutes, preferably 0.02 to 50 g / 10 minutes, more preferably 0.02 to 30 g / 10 minutes. MI is measured in accordance with JIS K7210 under conditions of 190 ° C. and a test load of 21.18N.

  The ethylene-based polymer refers to an ethylene homopolymer, a copolymer of ethylene and a small amount of α-olefin, or a blend thereof. The copolymer component of the copolymer is preferably 50 mol% or less, more preferably 20 mol% or less of all monomer units. As an example of the copolymer component of the copolymer, an olefin having 2 to 20 carbon atoms is preferable. Examples of the olefin having 2 to 20 carbon atoms include linear or branched α-olefins, cyclic olefins, and functional groups. Vinyl chloride compounds, polar group-containing monomers, conjugated dienes, non-conjugated polyenes, and the like.

  The propylene-based polymer contains propylene as a main constituent monomer, and usually contains propylene in an amount of 50 mol% or more, preferably 80 mol% or more. Specific examples of the propylene polymer include a propylene homopolymer, a block copolymer or a random copolymer of the above-described α-olefin other than propylene and propylene, or a blend thereof. Which of these is adopted is not particularly limited, but a homopolymer having a high melting point and rigidity is preferred from the viewpoint of suppressing the stickiness of the olefin-based resin composition.

The density of the propylene polymer is usually in the range of 895 to 930 kg / m ³ . The density of the polypropylene polymer is measured according to the density gradient tube method of JIS K7112.

  The melt index (MI) of the propylene-based polymer is usually in the range of 0.01 to 200 g / 10 minutes, preferably 1 to 100 g / 10 minutes, more preferably 1 to 50 g / 10 minutes. MI is measured according to JIS K7210 at 230 ° C. and a test load of 21.18 N.

  The 4-methyl-1-pentene polymer contains 4-methyl-1-pentene as a main constituent monomer, and usually contains 50 mol% or more, preferably 80 mol% or more of 4-methyl-1-pentene. . Specific examples of the 4-methyl-1-pentene polymer include 4-methyl-1-pentene homopolymer, 4-methyl-1-pentene, ethylene, and a linear or branched chain having 3 to 20 carbon atoms. Block copolymer or random copolymer with α-olefin (excluding 4-methyl-1-pentene), or a blend thereof.

The density of the 4-methyl-1-pentene polymer is usually in the range of 820 to 850 kg / m ³ . The density of the 4-methyl-1-pentene polymer is measured according to the density gradient tube method of JIS K7112.

  The melt index (MI) of the 4-methyl-1-pentene polymer is usually in the range of 0.01 to 200 g / 10 minutes, preferably 1 to 100 g / 10 minutes, more preferably 1 to 50 g / 10 minutes. is there. MI is measured in accordance with JIS K7210 under conditions of 260 ° C. and a test load of 49.03 N. When MI is in the above range, the 4-methyl-1-pentene polymer is excellent in moldability and mechanical strength characteristics.

  In the present invention, the blending ratio of the crosslinked ultrahigh molecular weight olefin polymer and the olefin polymer constituting the olefin polymer composition is 0 parts by weight of the crosslinked ultrahigh molecular weight olefin polymer with respect to 100 parts by weight of the olefin polymer. 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight.

When the blending ratio of the crosslinked ultrahigh molecular weight olefin polymer is less than 0.1 parts by weight, the effect of improving the blocking resistance may be diminished, and when it exceeds 20 parts by weight, the surface appearance of the molded product may be deteriorated. .
[Method for producing olefin polymer composition]
The manufacturing method of the olefin polymer composition of this invention is demonstrated.

  In the olefin polymer composition, the above-mentioned crosslinked ultrahigh molecular weight olefin polymer and olefin polymer components are blended in specific amounts, and, if necessary, additives described later are blended and mixed. Can be obtained.

About the mixing method of each component, various well-known methods, for example, a multistage polymerization method, a plastmill, a Henschel mixer, a V-blender, a ribbon blender, a tumbler, a blender, a kneader ruder or the like, or after mixing, a single screw extruder A method of granulating or pulverizing after melt-kneading with a twin screw extruder, kneader, Banbury mixer or the like can be employed. By this method, it is possible to obtain a high-quality olefin polymer composition in which each component and additive are uniformly dispersed and mixed.
〔Additive〕
In the olefin polymer composition of the present invention, a nucleating agent, a heat stabilizer, an antioxidant, a weathering stabilizer, an antistatic agent, a slip agent, as necessary, as long as the object of the present invention is not impaired. Antifogging agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, fillers, antiblocking agents other than crosslinked ultrahigh molecular weight olefin polymers, and the like can be blended.

  As the nucleating agent, dibenzylidene sorbitol nucleating agent, phosphate ester nucleating agent, rosin nucleating agent, benzoic acid metal salt nucleating agent, fluorinated polyethylene, 2,2-methylenebis (4,6-di-t -Butylphenyl) sodium phosphate, pimelic acid and salts thereof, 2,6-naphthalene dicarboxylic acid dicyclohexyl amide and the like can be used. Although there is no restriction | limiting in particular in a compounding quantity, It is preferable that there are about 0.1-1 weight part with respect to 100 weight part of olefin polymer compositions. There is no restriction | limiting in particular in a mixing | blending timing, It can add during superposition | polymerization, after superposition | polymerization, or a shaping | molding process.

  A known antioxidant can be used as the antioxidant. Specifically, a hindered phenol compound, a sulfur-based antioxidant, a lactone-based antioxidant, an organic phosphite compound, an organic phosphonite compound, or a combination of these can be used.

  Examples of the lubricant include sodium, calcium and magnesium salts of saturated or unsaturated fatty acids such as lauric acid, palmitic acid, oleic acid and stearic acid, and these may be used alone or in combination of two or more. it can. Further, the blending amount of such a lubricant is usually 0.1 to 3 parts by weight, preferably about 0.1 to 2 parts by weight with respect to 100 parts by weight of the olefin polymer composition.

As the slip agent, it is preferable to use amides of saturated or unsaturated fatty acids such as lauric acid, palmitic acid, oleic acid, stearic acid, erucic acid and hebenic acid, or bisamides of these saturated or unsaturated fatty acids. Of these, erucic acid amide and ethylene bisstearamide are particularly preferred. These fatty acid amides are preferably blended in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the olefin polymer composition.
[Film made of olefin polymer composition]
The film of the present invention can be obtained by melt-extruding the olefin polymer composition described above in the range of 160 to 320 ° C. The film of the present invention is preferably obtained by further uniaxially or biaxially stretching a molded product obtained by molding into a film or sheet by a T-die extrusion molding method or the like.

  In the present invention, “film” is a convenient name for indicating the external structure of an olefin polymer, and “film” is a general term for a molded product on a plane, and includes other films. , Sheet, membrane (membrane), and tape.

  Since the film of the present invention contains the above-mentioned crosslinked ultra-high molecular weight olefin polymer as an anti-blocking agent component, it can be expected to be excellent in blocking resistance. The reason for this is that the crosslinked ultra-high molecular weight olefin polymer is smaller in particle size than conventional olefin polymer particles, and its molecular weight is cross-linked by radiation to increase the molecular weight. It is considered that the particles are finely dispersed throughout the polymer composition without agglomeration during melt kneading. As a result, it is considered that the presence of a polymer aggregating component called “butsu” in the film can be reduced, and a film having an excellent surface appearance can be obtained. Furthermore, it is considered that the unevenness on the surface of the film becomes fine and uniform, and the blocking resistance and the scratch resistance of the film can be improved.

  Specific applications of such films include food packaging films (outer layers, inner layers, sealants, single layers), medical packaging films, pharmaceutical packaging films, industrial packaging films, stretch films, wrap films, stretched films, and breathability. Film, moisture-proof sheet, anti-slip sheet, light-shielding film, film for laminate substrate, foam film, building material skin material, release film such as release film for flexible printed circuit board, release film for rigid board, release for rigid flexible board Mold film, release film for advanced composite material, release film for curing carbon fiber composite material, release film for curing glass fiber composite material, release film for curing aramid fiber composite material, release film for curing nanocomposite material, Release film for filler filler curing, release film for semiconductor encapsulation, release Cushion film for film, release film for fuel cell, release film for various rubber sheets, release film for urethane curing, release film for epoxy curing, surface protective film such as protective film for resin plate, protective film for polarizing plate Protective films for LCD panels, protective films for optical components, protective films for lenses, protective films for electrical components and electrical appliances, protective films for mobile phones, protective films for PCs, protective films for mirror plates, protective films for sheets, office Goods, sanitary goods, garbage bags.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples at all unless the summary is exceeded.

In the following examples, the intrinsic viscosity [η], the average particle diameter d ₅₀ , and the proportion of particles that passed through a 37 μm mesh sieve were measured by the following method. Moreover, the measurement of the resin composition and the film was performed as follows.
(Intrinsic viscosity [η])
The intrinsic viscosity [η] was measured in decalin at a temperature of 135 ° C. by dissolving an ultrahigh molecular weight ethylene polymer in decalin.
(Average particle diameter d ₅₀ )
The average particle size d _50, using the Beckman Multisizer threes, was calculated from the weight-based particle size distribution by Coulter counter method.
(Percentage of particles passing through a 37 μm mesh sieve)
The ratio of particles that passed through a 37 μm mesh sieve was calculated as the ratio of the ultra high molecular weight ethylene polymer obtained using a sieve having an aperture of 37 μm to the mass of the particles on the sieve and the total mass of the particles. The
(Optical microscope)
The particle dispersion state in the resin composition pellets in the following examples and comparative examples was measured at a magnification of 200 times using a Nikon optical microscope (MICROPHOT-FXA).
(Number of films)
The resin compositions in the following Examples and Comparative Examples were melt film kneading temperatures in a twin-screw extruder with an inflation film molding machine (manufactured by Thermoplastic Co., Ltd., 20 mm Φ inflation film manufacturing apparatus) with a twin screw extruder, take-off speed 2 An inflation film having a thickness of 30 μm was obtained at a blow-up ratio of 2.0 to 2.5 m / min.

This film was cut into a 5.0 cm square, and the number of bumps (polymer aggregates having a particle size of 100 μm or more) present was counted visually.
[Production Example 1]
<Production of crosslinked ultrahigh molecular weight ethylene polymer>
(I) (A) Preparation of magnesium-containing carrier component Decane was added to 95.2 g (1.0 mol) of anhydrous magnesium chloride and 390.6 g (3.0 mol) of 2-ethylhexyl alcohol to make a total of 1000 mL. A time reaction was performed to obtain a homogeneous solution. Next, 100 mL of the homogeneous solution (100 mmol in terms of magnesium atom), 50 mL of purified decane and 560 mL of chlorobenzene were charged into a flask with an internal volume of 1000 mL sufficiently purged with nitrogen, and Clairemix CLM-0.8S manufactured by Organo Corporation was used. While stirring at a rotational speed of 15000 rpm, while maintaining the liquid temperature at 0 ° C., 110 mmol of triethylaluminum diluted with purified decane was added dropwise over 30 minutes. Thereafter, the liquid temperature was raised to 80 ° C. over 4 hours and reacted for 1 hour. Next, while maintaining the temperature at 80 ° C., 202 mmol of purified decane-diluted triethylaluminum was again added dropwise over 30 minutes, and then the reaction was further carried out for 1 hour. After completion of the reaction, the solid part was collected by filtration, thoroughly washed with toluene, and 100 mL of toluene was added to obtain a toluene slurry of a magnesium-containing carrier component.
(Ii) Preparation of (B) Solid Catalyst Component A flask with an internal volume of 1000 mL sufficiently purged with nitrogen was charged with 20 mmol of the component (A) obtained by adjusting the magnesium-containing support component and 600 mL of purified toluene in terms of magnesium atom. Then, 38.9 mL of the following transition metal compound (I) in toluene (0.0001 mmol / mL) was added dropwise over 20 minutes while maintaining the temperature at room temperature with stirring. After stirring for 1 hour, the solid part was collected by filtration, thoroughly washed with toluene, and purified decane was added to form a 200 mL decane slurry of the solid catalyst component (B).

(Iii) Preparation of ultra-high molecular weight ethylene polymer Charged 500 mL of purified heptane into a 1 L SUS autoclave sufficiently purged with nitrogen and allowed to flow 100 L / hr of ethylene at room temperature for 15 minutes. Saturated. Subsequently, after the temperature was raised to 65 ° C., 1.25 mL of triethylaluminum decane solution (1.0 mmol / mL in terms of Al atoms) was passed with ethylene flowing at 12 L / hr, and (B) the solid catalyst component was converted to Zr atoms. The mixture was stirred for 3 minutes while maintaining the temperature, and immediately after adding 40 mg of Emulgen E-108 (manufactured by Kao Corporation), pressure increase of ethylene pressure was started. The ethylene pressure was increased to 0.8 MPa · G over 10 minutes, and polymerization was carried out at 70 ° C. for 2 hours while supplying ethylene so as to maintain the pressure. Thereafter, the autoclave was cooled to depressurize ethylene. The obtained polymer slurry was filtered, washed with hexane, and dried under reduced pressure at 80 ° C. for 10 hours to obtain 40.9 g of an ultrahigh molecular weight ethylene polymer (1). When ultra high molecular weight ethylene polymer (1) was measured by a Coulter counter method, the average particle size d ₅₀ was 9.0 .mu.m. The ultra high molecular weight ethylene polymer particles produced had an intrinsic viscosity [η] of 23.0 dl / g in 135 ° C. decalin, and 99% by weight of the particles passed through a 37 μm mesh sieve.
(Iv) Preparation of Crosslinked Ultra High Molecular Weight Ethylene Polymer The ultra high molecular weight ethylene polymer (1) obtained in (iii) above is irradiated with an electron beam with an irradiation dose of 200 kGy, thereby producing crosslinked ultra high molecular weight ethylene. A polymer (1) was obtained.
[Example 1]
Linear short chain branched polyethylene (manufactured by Prime Polymer Co., Ltd., “Evolue (SP2040)”, density: 918 kg / m ³ , comonomer: 1-hexene, MI (230 ° C., 21.18 N load) 3.8 g / 10 Min) 10 parts by weight of the cross-linked ultra-high molecular weight ethylene polymer (1) obtained in Production Example 1 is added to 100 parts by weight, and 190 using a twin screw extruder (Technobel, KZW15-30MG). The resin composition (1) was obtained by melt-kneading at ° C.

  The pellet of the obtained resin composition (1) is cut out to about 1 mm square, arranged between two cover glasses, and resin composition on a microscope heating and cooling stage (LK-600) manufactured by Japan Hightech Co., Ltd. The resin was melted by heating to above the melting point. Appropriate pressure is applied from above the cover glass to form a thin film, cooled to room temperature at 100 ° C./min, and the particle dispersion state in the resin composition is changed to a Nikon optical microscope (MICROPHOT-FXA) (200 times). And observed. The observation results are shown in FIG. As apparent from the figure, it was confirmed that the particles were dispersed without agglomeration.

Using the resin composition (1) obtained as described above, an inflation film having a thickness of 30 μm was obtained by the method described above. This film was cut out in a 5.0 cm square, and the number of bumps present was counted visually. Table 1 shows the results of the number of protrusions.
[Example 2]
In Example 1, the linear short-chain branched polyethylene was changed to high-density polyethylene (manufactured by Prime Polymer Co., Ltd., “Hi-X (7000F)”, density 952 kg / m ³ , MI (230 ° C., 21.18 N load) 0.04 g. / 10 minutes), and a resin composition (2) was obtained in the same manner as in Example 1 except that the mixture was melt-kneaded at 250 ° C.

When the particle dispersion state in the obtained resin composition (2) was observed, it was confirmed that there was no aggregation of particles and the dispersion state was good. In addition, the number of irregularities in the 30 μm-thick inflation film obtained by the above-described method using the resin composition (2) was also measured in the same manner as in Example 1. The results are shown in Table 1.
[Example 3]
In Example 1, the linear short-chain branched polyethylene was converted to polypropylene (manufactured by Prime Polymer Co., Ltd., “Prime Polypro (F107)” density 910 kg / m ³ , MI (230 ° C., 21.18 N load) 6.0 g / 10 minutes), and a resin composition (3) was obtained in the same manner as in Example 1 except that the mixture was melt-kneaded at 200 ° C.

  The particle dispersion state in the obtained resin composition (3) was observed with an optical microscope. The observation results are shown in FIG. As apparent from the figure, it was confirmed that the particles were dispersed without agglomeration.

In addition, the number of irregularities in the 30 μm-thick inflation film obtained by the above-described method using the resin composition (3) was also measured in the same manner as in Example 1. The results are shown in Table 1.
[Example 4]
In Example 1, the linear short-chain branched polyethylene was converted into poly-4-methyl-1-pentene (manufactured by Mitsui Chemicals, “TPX (MX002)” density 833 kg / m ³ , MI (260 ° C., 49.03 N load). ) 21 g / 10 min), and a resin composition (4) was obtained in the same manner as in Example 1 except that the mixture was melt-kneaded at 270 ° C.

  When the particle dispersion state in the obtained resin composition (4) was observed, it was confirmed that there was no aggregation of particles and the dispersion state was good.

In addition, the number of irregularities in the 30 μm-thick inflation film obtained by the above-described method using the resin composition (4) was also measured in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 1]
A resin composition (5) was obtained in the same manner as in Example 1, except that the crosslinked ultrahigh molecular weight ethylene polymer (1) in Example 1 was changed to the ultrahigh molecular weight ethylene polymer particles obtained in Production Example 1. It was.

  The particle dispersion state in the obtained resin composition (5) was observed with an optical microscope. The observation results are shown in FIG. As is clear from the figure, it was confirmed that the particles were aggregated.

  In addition, the number of irregularities in the 30 μm-thick inflation film obtained by the above method using the resin composition (5) was also measured in the same manner as in Example 1. The results are shown in Table 1.

In Comparative Example 1, since the ultrahigh molecular weight ethylene polymer particles to be added are not subjected to the electron beam irradiation treatment, cross-linking between molecules does not occur. As a result, the heat resistance is poor, and the ethylene polymer particles are regenerated. Aggregated and the film appearance deteriorated.
[Comparative Example 2]
A resin composition (6) was obtained in the same manner as in Example 2, except that the crosslinked ultrahigh molecular weight ethylene polymer (1) in Example 2 was changed to the ultrahigh molecular weight ethylene polymer particles obtained in Production Example 1. It was.

  When the particle dispersion state in the obtained resin composition (6) was observed, it was confirmed that the particles were aggregated.

In addition, the number of irregularities in the 30 μm-thick inflation film obtained by the above-described method using the resin composition (6) was also measured in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 3]
A resin composition (7) was obtained in the same manner as in Example 3 except that the crosslinked ultrahigh molecular weight ethylene polymer (1) in Example 3 was changed to the ultrahigh molecular weight ethylene polymer particles obtained in Production Example 1. It was.

  The particle dispersion state in the obtained resin composition (7) was observed with an optical microscope. The observation results are shown in FIG. As is clear from the figure, it was confirmed that the particles were aggregated.

In addition, the number of irregularities in the 30 μm-thick inflation film obtained by the above-described method using the resin composition (7) was also measured in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 4]
A resin composition (8) was obtained in the same manner as in Example 4 except that the crosslinked ultrahigh molecular weight ethylene polymer (1) in Example 3 was changed to the ultrahigh molecular weight ethylene polymer particles obtained in Production Example 1. It was.

  When the particle dispersion state in the obtained resin composition (8) was observed, it was confirmed that the particles were aggregated.

  Further, the number of bumps of the 30 μm-thick inflation film obtained by the above-described method using the resin composition (8) was also measured in the same manner as in Example 1. The results are shown in Table 1.

  As is clear from the comparison of the above Examples and Comparative Examples, it contains a crosslinked ultrahigh molecular weight ethylene polymer that is crosslinked by irradiating a specific amount of radiation to the specific ultrahigh molecular weight ethylene polymer defined in the present invention. The olefin polymer composition has no aggregation between particles, and a film having a good appearance can be obtained when a film is formed using the composition.

  In particular, as is clear from the comparison between Example 1 and Comparative Example 1 in FIG. 1 and Example 3 and Comparative Example 3 in FIG. 2, the olefin polymer composition according to the present invention is composed of ethylene polymer particles. The surprising result was no reagglomeration and good dispersion.

From the above points, the olefin polymer composition according to the present invention has the advantage of not causing reaggregation of polymer particles, has excellent release properties, blocking resistance, and has a good appearance. This is particularly effective in the field of molded articles such as films.

Claims (9)

An olefin polymer;
And cross-linking ultrahigh molecular weight olefinic polymer,
Containing
The method for producing an olefin polymer composition, wherein the content of the crosslinked ultrahigh molecular weight olefin polymer is 0.1 to 20 parts by weight with respect to 100 parts by weight of the olefin polymer .
The crosslinked ultrahigh molecular weight olefin polymer is formed by irradiating the ultra high molecular weight olefin polymer satisfying the following requirements (i) to (iii) with radiation to be crosslinked,
A method for producing an olefin polymer composition .
(I) Intrinsic viscosity [η] measured in a decalin solvent at 135 ° C. is 5 to 50 dl / g
(Ii) The average particle diameter d ₅₀ is 3 to 25 μm.
(Iii) At least 95% by weight passes through a 37 μm mesh sieve The method for producing an olefin-based polymer composition according to claim 1, wherein an irradiation dose of the radiation is 20 to 700 kGy. 3. The olefin polymer composition according to claim 1 , wherein a content of the crosslinked ultrahigh molecular weight olefin polymer is 0.5 to 15 parts by weight with respect to 100 parts by weight of the olefin polymer. A process for producing an olefin polymer composition. The content of the crosslinked ultrahigh molecular weight olefin polymer in the olefin polymer composition is 1 to 10 parts by weight with respect to 100 parts by weight of the olefin polymer. The manufacturing method of the olefin polymer composition as described in claim | item. The method for producing an olefin polymer composition according to any one of claims 1 to 4 , wherein the ultrahigh molecular weight olefin polymer is an ultrahigh molecular weight ethylene polymer. The method for producing an olefin polymer composition according to any one of claims 1 to 5 , wherein the olefin polymer is an ethylene polymer, a propylene polymer, or a 4-methyl-1-pentene polymer. . Average particle diameter d of the ultra high molecular weight olefin polymer ₅₀ Is 3-20 micrometers, The manufacturing method of the olefin type polymer composition of any one of Claims 1-6. The method for producing an olefin polymer composition according to any one of claims 1 to 7, wherein the olefin polymer and the crosslinked ultrahigh molecular weight olefin polymer are melt-kneaded. To produce an olefin polymer composition by the method according to any one of claims 1-8, to produce a film from the composition, method of producing a film.