JP2019206616A - Olefin-based polymer composition and film - Google Patents

Abstract

To provide an olefin-based polymer composition that is excellent in anti-blocking properties and falling-off resistance of an antiblocking agent when formed into a film.SOLUTION: The olefin-based polymer composition contains (A) an olefin-based polymer and (B) a resin fine particle satisfying requirements (I) and (II) as given below in which the resin fine particle (B) is a radiation-crosslinked product of an ultra-high molecular weight olefin-based polymer. Requirement (I): the average particle size d50 of the resin fine particle is in the range of 1.0 to 35.0 μm; and requirement (II): the particle size d90 of the resin fine particle whose cumulative weight fraction attains 90% is in the range of 5.0 to 40.0 μm.SELECTED DRAWING: None

Description

  The present invention relates to an olefin polymer composition and a film.

  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. Blocking property can be improved. As such polymer particles, ultra-high molecular weight olefin polymer particles are known (see, for example, Patent Document 4). Moreover, the technique which prevents aggregation of particle | grains is known by using the bridge | crosslinking ultra high molecular weight olefin polymer which bridge | crosslinked the ultra high molecular weight olefin polymer particle | grains by radiation irradiation (for example, refer patent document 5).

JP-A-6-073202 JP 49-023245 International Publication No. 2009/044925 JP 2008-088248 A JP 2013-245345 A

  Dropping off of the anti-blocking agent may cause problems such as contamination of the molding machine, peripheral contamination when used as a film, for example, contamination of the contents when used as a packaging material. The inventors of the present invention aimed to realize further excellent blocking resistance and drop-off resistance in an olefin polymer film. That is, the subject of this invention is providing the olefin polymer composition which is excellent in blocking resistance when it is set as a film, and the anti-blocking property of an antiblocking agent.

  The present inventors have intensively studied to solve the above problems. As a result, it has been found that the above-mentioned problems can be solved by an olefin polymer composition having the following constitution, and the present invention has been solved.

That is, the present invention relates to the following [1] to [5].
[1] An olefin polymer (A) and resin fine particles (B) satisfying the following requirements (I) and (II), wherein the resin fine particles (B) are radiation of an ultrahigh molecular weight olefin polymer. An olefin polymer composition which is a crosslinked product.
(I) The average particle diameter d50 is in the range of 1.0 to 35.0 μm.
(II) The particle diameter d90 at which the cumulative weight fraction is 90% is in the range of 5.0 to 40.0 μm.

  [2] In the requirement (I), d50 is in the range of 1.0 to 3.0 μm, and in the requirement (II), d90 is in the range of 5.0 to 8.0 μm. ] The olefin polymer composition of description.

  [3] The content of the resin fine particles (B) is in the range of 0.1 to 20 parts by mass with respect to a total of 100 parts by mass of the olefin polymer (A) and the resin fine particles (B). The olefin polymer composition according to [1] or [2].

  [4] The above [1] to [3], wherein the olefin polymer (A) is at least one selected from an ethylene polymer, a propylene polymer, and a 4-methyl-1-pentene polymer. The olefin polymer composition according to any one of the above.

  [5] A film formed from the olefin polymer composition according to any one of [1] to [4].

  ADVANTAGE OF THE INVENTION According to this invention, the film which is excellent in blocking resistance and the anti-drop-off property of an antiblocking agent, and the olefin polymer composition which can provide it can be provided.

2 is a scanning electron microscope (SEM) image in Example 1. FIG. 6 is a scanning electron microscope (SEM) image in Comparative Example 2. 10 is a scanning electron microscope (SEM) image in Comparative Example 4.

Hereinafter, the olefin polymer composition according to the present invention and the film formed therefrom will be specifically described.
[Olefin polymer composition]
The olefin polymer composition of the present invention contains an olefin polymer (A) and resin fine particles (B). The content of the resin fine particles (B) is usually 0.1 to 20 parts by mass, preferably 0.1 to 10 parts per 100 parts by mass in total of the olefin polymer (A) and the resin fine particles (B). It is in the range of 0.3 to 5.0 parts by mass, more preferably 0.3 to 5.0 parts by mass. Being equal to or higher than the lower limit is preferable in blocking resistance of the obtained film, and being not higher than the upper limit is preferable in terms of mechanical properties of the obtained film and drop-off resistance of the antiblocking agent.

<Resin fine particles (B)>
The resin fine particle (B) is a radiation cross-linked product of an ultrahigh molecular weight olefin polymer and satisfies the requirements (I) and (II).
Requirement (I) The average particle diameter d50 is in the range of 1.0 to 35.0 μm. In the present invention, the average particle size d50 is a value at which the integrated value of the particle shape distribution becomes 50% by weight by measurement of the weight-based particle size distribution by the Coulter counter method. Preferably, d50 is in the range of 1.0 to 3.0 μm. It exists in the said range in the blocking resistance. Moreover, it can adjust to the said range by adjusting a catalyst seed | species in the manufacturing method mentioned later.

  Requirement (II) The particle diameter d90 at which the cumulative weight fraction is 90% is in the range of 5.0 to 40.0 μm. Preferably, d90 is in the range of 5.0 to 8.0 μm. d90 in the above range indicates that the particle size distribution is relatively narrow, and is preferable in terms of blocking resistance and dropout resistance. d90 can be adjusted within the above range by adjusting the catalyst species in the production method described later.

<Method for producing resin fine particles (B)>
The resin fine particles (B) are a radiation cross-linked product of an ultrahigh molecular weight olefin polymer. Hereinafter, the radiation cross-linked product of the ultra high molecular weight olefin polymer is also referred to as a crosslinked ultra high molecular weight olefin polymer.
The production method for the case where the resin fine particles (B) are crosslinked ultrahigh molecular weight olefin-based polymers will be described below.
The ultra high molecular weight olefin polymer used as a raw material for the crosslinked ultra high molecular weight olefin polymer preferably satisfies the requirements (I) and (II) in the same manner as the resin fine particles (B). ) Is preferably satisfied.

  Requirement (i) The intrinsic viscosity [η] measured in a decalin solvent at 135 ° C. is in the range of 5 to 50 dl / g, preferably 5 to 40 dl / g, more preferably 5 to 30 dl / g. When the intrinsic viscosity is within the above range, it is preferable in terms of wear resistance of the olefin polymer composition containing the resin fine particles (B) to be obtained.

  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, etc., preferably ethylene-based polymers, particularly preferably ethylene homopolymers. is there.

In the present invention, the ultra high molecular weight olefin polymer can be produced, for example, by the method disclosed in the following literature.
(1) International Publication No. 2006/054696 (2) International Publication No. 2008/013144 (3) International Publication No. 2009/011231 (4) International Publication No. 2010/074073

<Preparation of cross-linked ultra high molecular weight olefin polymer>
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 polymer with radiation, the molecular chain is broken and cross-linked, and as a result, the molecular chain is combined at the cross-linking 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.

Examples of radiation include α rays, β rays, γ rays, electron beams, ions, and the like. 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 exceeds 700 kGy, deterioration of the polymer may be severe, and when the irradiation dose is less than 20 kGy, the crosslinking of the polymer chain may not proceed or be delayed.

<Olefin polymer (A)>
Examples of the olefin polymer that can be used as the olefin polymer (A) in the present invention include one or more olefins selected from ethylene and linear or branched α-olefins having 3 to 20 carbon atoms. The thing obtained by superposition | polymerization is mentioned.

  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 the range which does not impair the objective of this invention other than the alpha olefin mentioned above, 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. Alkyl styrene; methoxy styrene, ethoxy styrene, vinyl benzoic acid, methyl vinyl benzoate, vinyl benzyl acetate, hydroxy styrene, o-chlorostyrene, p-chlorostyrene and other functional group-containing styrene derivatives; and 3-phenylpropylene, 4- Examples include phenylpropylene and α-methylstyrene, 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 low density polyethylene (LLDPE), medium and low pressure method high density polyethylene (HDPE), and very low density polyethylene (VLDPE). .

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 is in a range of less than the density 900 kg / m ³ or more 940 kg / m ^3, middle Examples thereof include 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 flow rate (MFR) of the ethylene-based polymer is usually in the range of 0.01 to 100 g / 10 minutes, preferably 0.02 to 50 g / 10 minutes, more preferably 0.02 to 30 g / 10 minutes. The MFR is measured under the conditions of 190 ° C. and a test load of 2.16 kg according to JIS K7210.

  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 3 to 20 carbon atoms is preferable, and the olefin having 3 to 20 carbon atoms includes a linear or branched α-olefin, a cyclic olefin, and a functional group. 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 preferable from the viewpoint of suppressing the stickiness of the olefin polymer composition.

The density of the propylene-based 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 flow rate (MFR) of the propylene 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. MFR is measured in accordance with JIS K7210 under conditions of 230 ° C. and a test load of 2.16 kg.

  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. A block copolymer or a random copolymer with at least one selected from α-olefins (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 flow rate (MFR) 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. MFR is measured under the conditions of 260 ° C. and test load of 5.0 kg in accordance with JIS K7210. When the MFR is within the above range, the 4-methyl-1-pentene polymer is excellent in moldability and mechanical strength characteristics.

<Method for producing olefin polymer composition>
In the olefin polymer composition, the above-mentioned resin fine particles (B) and olefin polymer (A) 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.

<Additives>
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 its salt, 2,6-naphthalene dicarboxylic acid dicyclohexyl amide and the like can be used. Although the compounding quantity of a nucleating agent does not have a restriction | limiting in particular, It is preferable that there are about 0.1-1 mass part with respect to 100 mass parts 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 admixture of two or more. it can. Moreover, the compounding quantity of this lubricant is 0.1-3 mass parts normally with respect to 100 mass parts of olefin polymer compositions, Preferably it is desirable that it is about 0.1-2 mass parts.

  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 mass with respect to 100 parts by mass of the olefin polymer composition.

[Film formed from olefin polymer composition]
The film of the present invention can be obtained, for example, by melt-extruding the above-described olefin polymer composition usually 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 excellent in 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, the Example shown below does not intend limiting this invention to this.
[Olefin polymer (A)]
In Examples and Comparative Examples, as an olefin polymer (A), Prime Polymer Co., Ltd. LLDPE Evolue (trademark) SP2040 (density 918 kg / m ³ , MFR (190 ° C., 2.16 kg load) 3.8 g / 10 min) )It was used.

[Production Example 1] Production of resin fine particles (B-1)
[Preparation of solid component (Y-1)]
In a 2 L glass vessel equipped with a stirrer sufficiently purged with nitrogen, anhydrous magnesium chloride 95.2 g (1.0 mol), dehydrated decane 442 mL, 2-ethylhexyl alcohol 260.4 g (2.0 mol), and 2-octyldodecyl alcohol 298. 5 g (1.0 mol) was charged and reacted at 155 ° C. for 4 hours to obtain a uniform transparent solution. Next, in another 1 L glass vessel equipped with a stirrer that was sufficiently purged with nitrogen, the homogeneous transparent solution was charged with 610 mL of dehydrated decane corresponding to 100 mmol in terms of Mg atoms, and homogenizer (CLEAMIX CLM-1.5S manufactured by M Technique Co., Ltd.). While maintaining the liquid temperature at 0 ° C. under strong stirring at a rotational speed of 15000 rpm, 109 mmol of triethylaluminum was slowly added dropwise. Thereafter, the liquid temperature was raised to 80 ° C. over 4 hours, and 188 mmol of triethylaluminum was slowly added again while maintaining the temperature at 80 ° C., and the reaction was continued for another hour. After completion of the reaction, the solid part was collected by filtration, thoroughly washed with dehydrated toluene, and 200 mL of dehydrated toluene was added to obtain a toluene slurry of the solid component (Y-1). A part of this toluene slurry was collected, and the particle size of the solid component (Y-1) was measured by a dynamic light scattering method.

[Preparation of solid catalyst component (Z-1)]
100 mL of dehydrated toluene was charged into a 300 mL glass vessel equipped with a stirrer sufficiently purged with nitrogen, and 5.0 mmol of the toluene slurry of the solid component (Y-1) prepared above was charged in terms of Mg atoms. Next, 16.7 mL of a toluene solution of a transition metal compound represented by the following formula [1] (0.001 mmol / mL in terms of Zr atom) was charged dropwise and reacted at room temperature for 1 hour. Thereafter, the supernatant was removed by decantation, and washed with dehydrated toluene three times and with dehydrated decane twice to prepare a decane slurry of the solid catalyst component (Z-1). When a portion of the resulting decane slurry of the solid catalyst component (Z-1) was collected and examined for concentration, the Zr concentration was 0.000578 mmol / mL.

Ph represents a phenyl group.

[Ethylene polymerization]
In a 1 L autoclave equipped with a stirrer sufficiently purged with nitrogen, 500 mL of dehydrated heptane was charged, and 100 L / hr of ethylene was allowed to flow at room temperature for 15 minutes to saturate the liquid phase and gas phase with ethylene. Subsequently, after the temperature was raised to 70 ° C., 1.00 mmol of triisobutylaluminum in terms of Al atom and 0.0037 mmol of solid catalyst component (Z-1) in terms of Zr atom were charged while ethylene was allowed to flow at 12 L / hr. The mixture was stirred for 3 minutes while maintaining the temperature, and immediately after adding 60 mg of Emulgen E-108 (manufactured by Kao Corporation), pressure increase of ethylene pressure was started. After the total pressure reached 0.3 MPa · G, 3.5 mL of hydrogen was inserted, and polymerization was performed at 70 ° C. for 2 hours while supplying ethylene so as to maintain the pressure. After completion of the polymerization, the obtained polymer was washed with hexane, preliminarily dried under reduced pressure at 80 ° C. for 1 hour, and further dried under reduced pressure at 110 ° C. for 10 hours. The obtained polyethylene was 37.0 g, the catalytic activity was 50.0 kg / mmol-Zr · h, and the intrinsic viscosity [η] measured in decalin at 135 ° C. was 13.0 dl / g (ultra high molecular weight ethylene polymer). Met.
The ultrahigh molecular weight ethylene polymer obtained above was irradiated with an electron beam with an irradiation dose of 200 kGy to obtain a crosslinked ultra high molecular weight ethylene polymer.

[Production Example 2] Production of resin fine particles (B-2)
[Preparation of solid component (Y-2)]
A 2 L glass container equipped with a stirrer sufficiently purged with nitrogen was charged with 95.2 g (1.0 mol) of anhydrous magnesium chloride, 442 mL of dehydrated decane, and 390.6 g (3.0 mol) of 2-ethylhexyl alcohol. A time reaction was performed to obtain a uniform transparent solution. Next, in another 1 L glass vessel equipped with a stirrer which was sufficiently purged with nitrogen, the homogeneous transparent solution was charged with 100 mmol in terms of Mg atoms, 458 mL of dehydrated decane and 152 mL of chlorobenzene, and homogenizer (CLEAMIX CLM- manufactured by M Technique Co., Ltd.). Under strong stirring at 1.5 S and 15,000 rpm, 109 mmol of triethylaluminum was slowly added dropwise while maintaining the liquid temperature at 0 ° C. Thereafter, the liquid temperature was raised to 80 ° C. over 4 hours, and 188 mmol of triethylaluminum was slowly added again while maintaining the temperature at 80 ° C., and the reaction was continued for another hour. After completion of the reaction, the solid part was collected by filtration, thoroughly washed with dehydrated toluene, and 200 mL of dehydrated toluene was added to obtain a toluene slurry of the solid component (Y-2). A part of this toluene slurry was sampled and the particle size of the solid component (Y-2) was measured by a dynamic light scattering method.

[Preparation of solid catalyst component (Z-2)]
100 mL of dehydrated toluene was charged into a 300 mL glass container equipped with a stirrer sufficiently purged with nitrogen, and 5.0 mmol of the toluene slurry of the solid component (Y-2) prepared above was charged in terms of Mg atoms. Next, 8.35 mL of a toluene solution of the transition metal compound represented by the formula [1] (0.001 mmol / mL in terms of Zr atom) was charged dropwise and reacted at room temperature for 1 hour. Thereafter, the supernatant was removed by decantation, and washed with dehydrated toluene three times and with dehydrated decane twice to prepare a decane slurry of the solid catalyst component (Z-2). A portion of the resulting decane slurry of the solid catalyst component (Z-2) was sampled to examine the concentration. As a result, the Zr concentration was 0.000312 mmol / mL.

[Ethylene polymerization]
In a 1 L autoclave equipped with a stirrer sufficiently purged with nitrogen, 500 mL of dehydrated heptane was charged, and 100 L / hr of ethylene was allowed to flow at room temperature for 15 minutes to saturate the liquid phase and gas phase with ethylene. Subsequently, after the temperature was raised to 60 ° C., 0.50 mmol of triethylaluminum in terms of Al atom and 0.00025 mmol in terms of Zr atom were charged with triethylaluminum while circulating ethylene at 12 L / hr. The mixture was stirred for 3 minutes while maintaining the temperature, and immediately after adding 10 mg of Emulgen E-108 (manufactured by Kao Corporation), pressure increase of ethylene pressure was started. After the total pressure reached 0.8 MPa · G, 3.5 mL of hydrogen was inserted, and polymerization was performed at 60 ° C. for 2.5 hours while supplying ethylene so as to maintain the pressure. After completion of the polymerization, the obtained polymer was washed with hexane, preliminarily dried under reduced pressure at 80 ° C. for 1 hour, and further dried under reduced pressure at 110 ° C. for 10 hours. The obtained polyethylene was 108.0 g, the catalytic activity was 144.0 kg / mmol-Zr · h, and the intrinsic viscosity [η] measured in decalin at 135 ° C. was 23.2 dl / g (ultra high molecular weight ethylene polymer). Met.
The ultrahigh molecular weight ethylene polymer obtained above was irradiated with an electron beam with an irradiation dose of 200 kGy to obtain a crosslinked ultra high molecular weight ethylene polymer.

[Production Example 3] Production of resin fine particles (B-3)
[Preparation of solid component (Y-3)]
In a 2 L glass container equipped with a stirrer sufficiently purged with nitrogen, anhydrous magnesium chloride 95.2 g (1.0 mol), dehydrated decane 442 mL, 2-ethylhexyl alcohol 325.5 g (2.5 mol), and 2-octyldodecyl alcohol 149. 25 g (0.5 mol) was charged and reacted at 155 ° C. for 4 hours to obtain a uniform transparent solution. Next, in another 1 L glass vessel equipped with a stirrer which was sufficiently purged with nitrogen, the homogeneous transparent solution was charged with 100 mmol in terms of Mg atoms, 458 mL of dehydrated decane and 152 mL of chlorobenzene, and homogenizer (CLEAMIX CLM- manufactured by M Technique Co., Ltd.). Under strong stirring at 1.5 S and 15,000 rpm, 109 mmol of triethylaluminum was slowly added dropwise while maintaining the liquid temperature at 0 ° C. Thereafter, the liquid temperature was raised to 80 ° C. over 4 hours, and 188 mmol of triethylaluminum was slowly added again while maintaining the temperature at 80 ° C., and the reaction was continued for another hour. After completion of the reaction, the solid part was collected by filtration, thoroughly washed with dehydrated toluene, and 200 mL of dehydrated toluene was added to obtain a toluene slurry of the solid component (Y-3). A part of this toluene slurry was sampled and the particle size of the solid component (Y-3) was measured by a dynamic light scattering method.

[Preparation of solid catalyst component (Z-3)]
100 mL of dehydrated toluene was charged into a 300 mL glass vessel equipped with a stirrer sufficiently purged with nitrogen, and 5.0 mmol of the toluene slurry of the solid component (Y-3) prepared above was charged in terms of Mg atoms. Subsequently, 2.5 mL of a toluene solution of the transition metal compound represented by the formula [1] (0.001 mmol / mL in terms of Zr atom) was charged dropwise and reacted at room temperature for 1 hour. Thereafter, the supernatant liquid was removed by decantation, and washed with dehydrated toluene three times and with dehydrated decane twice to prepare a decane slurry of the solid catalyst component (Z-3). When a part of the resulting decane slurry of the solid catalyst component (Z-3) was sampled to examine the concentration, the Zr concentration was 0.0000876 mmol / mL.

[Ethylene polymerization]
In a 1 L autoclave equipped with a stirrer sufficiently purged with nitrogen, 500 mL of dehydrated heptane was charged, and 100 L / hr of ethylene was allowed to flow at room temperature for 15 minutes to saturate the liquid phase and gas phase with ethylene. Subsequently, after the temperature was raised to 70 ° C., 1.25 mmol of triethylaluminum in terms of Al atom and 0.00025 mmol of Zr atom in terms of solid catalyst component (Z-3) were charged while ethylene was allowed to flow at 12 L / hr. The mixture was stirred for 3 minutes while maintaining the temperature, and immediately after 40 mg of Emulgen E-108 (manufactured by Kao Corporation) was added, pressure increase of ethylene pressure was started. After the total pressure reached 0.3 MPa · G, 3.5 mL of hydrogen was inserted, and polymerization was performed at 70 ° C. for 1 hour while supplying ethylene so as to maintain the pressure. After completion of the polymerization, the obtained polymer was washed with hexane, preliminarily dried under reduced pressure at 80 ° C. for 1 hour, and further dried under reduced pressure at 110 ° C. for 10 hours. The obtained polyethylene was 31.0 g, the catalytic activity was 124.0 kg / mmol-Zr · h, and the intrinsic viscosity [η] measured in decalin at 135 ° C. was 12.7 dl / g (ultra high molecular weight ethylene polymer). Met.
The ultrahigh molecular weight ethylene polymer obtained above was irradiated with an electron beam with an irradiation dose of 200 kGy to obtain a crosslinked ultra high molecular weight ethylene polymer.

[Other fine particles]
The following were used as fine particles not corresponding to the resin fine particles (B).
Silica (Fuji Silysia Co., Ltd., Silo Hovic 4004 P-90114)
Modified silica (Fuji Silysia Co., Ltd., Silicia 780 QK-1081)
PMMA (manufactured by Nippon Shokubai Co., Ltd., MA1010 d50: 10.3 μm)

[Evaluation of resin fine particles]
The resin fine particles were evaluated by the following method. The evaluation results are shown in Table 1.

<Average particle diameter d50, particle diameter d90 at which cumulative weight fraction is 90%>
The average particle size d50 and the particle size d90 with a cumulative weight fraction of 90% were calculated from the weight-based particle size distribution by the Coulter Counter method using a Beckman Multisizer Three.

[Example 1]
To 209.0 parts by mass of SP2040, 1.0 part by mass of the resin fine particles (B-1) obtained in Production Example 1 were added, and at 190 ° C. using a twin-screw extruder (manufactured by Technobell, KZW15-30MG). The polymer composition was obtained by melt-kneading.

[Examples 2 to 4, Comparative Examples 1 to 4]
A polymer composition was obtained in the same manner as in Example 1 except that the resin fine particles were changed to the types and blending ratios shown in Table 2. For Comparative Example 1, SP2040 was used as it was.

[Production of film]
The polymer compositions obtained in the Examples and Comparative Examples were set to 190 ° C. for the cylinder and the die temperature in an inflation film molding machine (manufactured by Thermoplastic Co., Ltd., 20 mmφ inflation film production apparatus), and the take-up speed was 2.5 m / min. An inflation film having a blow-up ratio of 2.0 to 2.5 and a thickness of 60 μm was obtained.

[Evaluation of film]
The film formed from the obtained polymer composition was evaluated by the following method. The evaluation results are shown in Table 2.

<Static friction coefficient, Dynamic friction coefficient>
In accordance with JIS K7218 “Plastic sliding wear test A method”, measurement was performed using a Matsubara type frictional wear tester. The test conditions were: partner material: S45C, speed: 50 cm / sec, distance: 3 km, load: 15 kg, measurement environment temperature: 23 ° C.

<Tensile test>
Based on ASTM D638, the test piece shape was ASTM No. 4, the tensile speed was 50 mm / min, and the tensile strength (TS: MPa) and the elongation at break (EL:%) were determined. Each of the TD direction and MD direction of the film was evaluated.

<Bending test>
In accordance with ASTM D790, the test piece shape is 12.7 mm (width) x 3.2 mm (thickness) x 127 mm (length), the bending span is 48.0 mm, the test speed is 5.0 mm / min, and bending is performed. The elastic modulus (FM: MPa) was determined. Each of the TD direction and MD direction of the film was evaluated.

<Falling resistance>
For Example 1 and Comparative Examples 2 and 4, the drop resistance of the fine particles was evaluated. The sample after measurement of the static friction coefficient and the dynamic friction coefficient was observed with a scanning microscope (SEM). Using JSM-6510 (manufactured by JEOL Ltd.) as a scanning microscope, measurement was carried out in an acceleration voltage: 5 kV, high vacuum mode. Shown in FIGS.

[Contrast between Example and Comparative Example]
Compared to Comparative Example 1 in which the resin fine particles (B) are not added, Examples 1 to 4 have small static friction coefficient and dynamic friction coefficient, and are excellent in blocking resistance. Moreover, since the Example uses the olefin resin fine particle compared with the comparative example 2 using the silica fine particle and the comparative example 4 using the acrylic fine particles, it can be seen that the resin fine particles have excellent drop-out resistance.

Claims (5)

An olefin polymer (A) and resin fine particles (B) satisfying the following requirements (I) and (II) are contained, and the resin fine particles (B) are a radiation cross-linked product of an ultrahigh molecular weight olefin polymer. An olefin polymer composition.
(I) The average particle diameter d50 is in the range of 1.0 to 35.0 μm.
(II) The particle diameter d90 at which the cumulative weight fraction is 90% is in the range of 5.0 to 40.0 μm.   The d50 is in the range of 1.0 to 3.0 μm in the requirement (I), and the d90 is in the range of 5.0 to 8.0 μm in the requirement (II). Olefin polymer composition.   Content of the said resin fine particle (B) exists in the range of 0.1-20 mass parts with respect to a total of 100 mass parts of the said olefin polymer (A) and the said resin fine particle (B). 3. The olefin polymer composition according to 1 or 2.   The olefin polymer (A) is at least one selected from an ethylene polymer, a propylene polymer, and a 4-methyl-1-pentene polymer, according to any one of claims 1 to 3. The olefin polymer composition described.   The film formed from the olefin polymer composition as described in any one of Claims 1-4.