JP3391531B2 - Polyethylene resin composition and film comprising the composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyethylene resin composition having excellent anti-blocking properties and slipperiness and improved scratch resistance between films, and a film comprising the composition.

[0002]

BACKGROUND OF THE INVENTION Polyethylene-based films are widely used as packaging materials for various articles such as food packaging. When the films are stacked, the films adhere to each other, so-called It has a drawback that it causes blocking, remarkably lowers workability of packaging and the like, and cannot be used when opening property is bad.

Conventionally, a method of mixing fine particles of an inorganic substance such as silica or talc with polyethylene is generally practiced as a means for preventing the blocking of the polyethylene film. However, when imparting anti-blocking properties to the polyethylene-based film using the above inorganic material,
There are drawbacks such that the transparency is remarkably lowered, or the surface is scratched when the films are rubbed with each other to deteriorate the transparency.

[0004]

In view of such circumstances, the inventors of the present invention have earnestly studied to solve the conventional problems, and as a result, found that a resin composition containing a crosslinked resin powder with respect to a polyethylene resin Finds that it has a good balance of anti-blocking property and transparency, and has little scratches,
The present invention has been completed.

That is, the present invention relates to a resin powder having an average particle diameter of 2 to 15 μm with respect to 100 parts by weight of a polyethylene resin.
The present invention provides a polyethylene-based resin composition characterized by containing 0.05 to 2 parts by weight of crosslinked polymethylmethacrylate powder, and a film comprising the composition.

The present invention will be described in detail below. Examples of the polyethylene-based resin of the present invention include ethylene-α-olefin copolymer, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid. Examples thereof include ester copolymers, ethylene-methacrylic acid copolymers, ethylene-methacrylic acid ester copolymers and the like, and mixtures thereof.

The polyethylene resin used in the present invention can be produced by a radical polymerization method or an ionic polymerization method. The polyethylene resin obtained by the radical polymerization method is obtained by copolymerizing ethylene alone or ethylene and a monomer capable of radical polymerization with a free radical generator such as organic peroxide or oxygen. Examples of the radically polymerizable monomer include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, their esterified products, acid anhydrides, and vinyl esters such as vinyl acetate. Examples of the esterified product of unsaturated carboxylic acid include ethyl acrylate, methyl methacrylate, glycidyl methacrylate and the like. These monomers may be used alone or in combination of two or more. The polymerization reaction is usually carried out at a polymerization temperature of 130 to 300 ° C.
It is carried out under a polymerization pressure of 500 to 3000 kg / cm ² . The polyethylene-based resin obtained by the ionic polymerization method is obtained by polymerizing ethylene alone or ethylene and an α-olefin having 3 to 18 carbon atoms using a transition metal solid catalyst or a metallocene-based homogeneous catalyst, and the polymerization reaction is usually Polymerization temperature of 30 ° C to 300 ° C, atmospheric pressure to 30 ° C
It is carried out under a polymerization pressure of 00 kg / cm ² , in the presence or absence of a solvent, in a gas-solid, liquid-solid or homogeneous liquid layer. Examples of the α-olefin include propylene, butene-1, 4-methylpentene-1, hexene-
1, octene-1, decene-1, octadecene-1 and the like are used, but α-olefins having 4 to 10 carbon atoms are preferable. These α-olefins may be used alone or in combination of two or more.

The density of the polyethylene resin used in the present invention is usually 0.940 g / cm ³ or less, preferably 0.9.
It is 900 to 0.935 g / cm ³ . Density is 0.9
When it is higher than 40 g / cm ³ , the heat-sealing property at low temperature or high speed is poor when used as a packaging material with nylon or the like as a composite film.

The MFR of the polyethylene resin used in the present invention is usually in the range of 0.1 to 50 g / 10 minutes, preferably 0.8 to 30 g / 10 minutes.

The crosslinked poly (methyl methacrylate) powder used in the present invention has an average particle size of 2 which does not melt at a film forming temperature of a polyethylene resin, for example, about 130 to 350 ° C.
It is a crosslinked resin powder having a particle size of 15 μm . The method for crosslinking polymethyl methacrylate is not particularly limited,
A method using a conventionally known crosslinking agent may be used.

The blending amount of the above resin powder is 0.05 to 2 parts by weight based on 100 parts by weight of the polyethylene resin.
If the amount of the resin powder is less than 0.05 parts by weight, the anti-blocking property is poor, and if it exceeds 2 parts by weight, the transparency is poor.

The method for producing the polyethylene resin composition of the present invention is not particularly limited, and may be, for example, a method of uniformly mixing the components used in the present invention. As a mixing method, each component is a known method in the above range, for example, using a Banbury mixer, a kneader, a twin-screw kneader or the like, a method of melt-kneading and granulating, or a high-concentration master of each component with a Banbury mixer or the like. A method of preparing a batch and dry blending using a mixer such as a tumbler blender, a tumble mixer, and a Henschel mixer, a method of performing melt-kneading granulation with a single-screw extruder, a twin-screw extruder, etc. after mixing Can be adopted.

Next, the resin composition of the present invention may use an organic fatty acid amide as a lubricant, and an antioxidant,
Various kinds of compounding agents which are usually added to polyolefins such as antistatic agents, anti-drip agents and weather-resistant agents may be used within a range that does not impair the object of the present invention.

Examples of the organic fatty acid amides include saturated fatty acid amides, unsaturated fatty acid amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, etc. These can be used not only in one kind but also in two or more kinds. Examples of the saturated fatty acid amide include stearic acid amide and behenic acid amide, and examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Examples of the saturated fatty acid bisamide include ethylene bisstearic acid amide, and examples of the unsaturated fatty acid bisamide include ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, and N, N ′ dioleyl sebacic acid amide. Among these, stearic acid amide, behenic acid amide, oleic acid amide, erucic acid amide and ethylenebisoleic acid amide are preferable. The amount of organic fatty acid amide compounded is
Usually 0.01 per 100 parts by weight of polyethylene resin
~ 0.5 parts by weight.

The film of the present invention can be produced by using the resin composition of the present invention as a raw material resin by a known technique such as an inflation method or a T-die method at a temperature at which the raw material resin melts or higher. The thickness of the film can be adjusted by selecting the extrusion rate of the resin and the pulling rate of the film. The resin temperature during processing is usually selected within the range from the complete melting temperature to 350 ° C.

In the case of a single layer in the film of the present invention, the thickness of the film is 5 to 500 μm, particularly 10 to 200 μm.
It is desirable that it is m. If the thickness is less than this range,
In addition to being difficult to process, it is not easy to handle when laminating, and if it is thick, processing becomes difficult. Further, the film of the present invention is not limited to a monolayer film, and can be made into a two-layer or two-layer or more coextrusion film by combining polyethylene resins with each other or with another thermoplastic resin.

[0017]

As described above in detail, according to the present invention, the transparency is maintained while the anti-blocking property and the slip property are excellent.
It is possible to provide a polyethylene resin composition having improved scratch resistance between films and a film made of the composition. Further, the film of the present invention has the above-mentioned properties and is useful as a packaging film.

[0018]

EXAMPLES Next, the present invention will be explained based on examples.
The present invention is not limited to these. The methods for measuring physical property values in Examples and Comparative Examples will be described below. (1) Density According to the method specified in JIS K6760. (2) Melt flow rate (MFR) According to the method specified in JIS K6760. (3) Average particle size Coulter counter
R) method. (4) Based on Haze ASTM D1003. (5) Sliding property, manufactured by Toyo Seiki Co., Ltd., size 10 using a friction angle measuring machine
Using a load of 0 (longitudinal) × 63 (horizontal) × 19 (high) mm and a weight of 1 kg, the sliding angle θ between the films was measured at a tilt rising speed of 2.7 ° / sec and displayed as tan θ. The smaller this value is, the better the slipperiness is. (6) The blocking film was accelerated at a temperature of 40 ° C. under a load of 30 g / cm ² for 18 hours to promote film adhesion, and then a test piece cut into a size of 22 cm × 10 cm was fixed on a jig so that an adhesive surface was 10 cm × 10 cm. When the peeling moving load speed is 20 g / min, the load required for peeling the entire film (g /
It is represented by 100 cm ² ). (7) Scratchability A stainless steel pipe having an outer diameter of 10 mm is passed between the folded films, and is brought into contact with the film surface fixed without sagging and the jig film surface fixed on the shaker. While reciprocating 40 mm at a speed of 60 times / minute, 1
Rub the films together for a minute. Measure Haze,
The difference in haze before and after scratching (ΔHaze). The smaller the number, the less likely it is to scratch.

Next, the polyethylene resins used in Examples and Comparative Examples will be described. LL-1: ethylene-hexene-1 copolymer MFR =
2.0 g / 10 minutes, density = 0.912 g / cm ³ LL-2: ethylene-butene-1 copolymer MFR =
2.0 g / 10 minutes, density = 0.905 g / cm ³ LL-3: ethylene-butene-1 copolymer MFR =
2.0 g / 10 min, density = 0.930 g / cm ³ LL-4: ethylene-hexene-1 copolymer MFR =
20 g / 10 min, density = 0.920 g / cm ³ LL-5: ethylene-butene-1 copolymer MFR =
0.8 g / 10 min, density = 0.919 g / cm ³ LL-6: ethylene-butene-1 copolymer MFR =
0.8 g / 10 min, density = 0.925 g / cm ³ LD: ethylene polymer MFR = 2.0 g / 10
Min, density = 0.923 g / cm ³ EVA: ethylene-vinyl acetate copolymer MFR =
2.0g / 10min, vinyl acetate content = 5wt%

Example 1 100 parts by weight of polyethylene resin LL-1 and 100 parts by weight of crosslinked polymethylmethacrylate having an average particle size of 3.0 μm (Matsumoto Microsphere M-201 manufactured by Matsumoto Yushi Co., Ltd.)
The resin composition in which 0.5 parts by weight and 0.06 parts by weight of erucic acid amide were respectively mixed was placed in a 50 mmφ extruder (manufactured by Tanabe Plastics Co., Ltd., screw L / D = 32), a die width of 400 mm and a die lip of 0. .7 mm, straight manifold hold type T-die attached, die set temperature 240
A film having a thickness of 50 μm was obtained by cooling with a 600 mm semi-matt roll controlled at 75 ° C. under the conditions of 0 ° C. and an extrusion rate of 10 kg / hr, and winding the film on a paper tube. The evaluation results are shown in Table 1.

Example 2 0.5 parts by weight of the crosslinked polymethylmethacrylate used in Example 1 was added to the crosslinked polymethylmethacrylate having an average particle size of 5.3 μm (Jurimer MB-SX manufactured by Nippon Pure Chemical Industries, Ltd.). A film was processed in the same manner as in Example 1 except that the above was performed. The evaluation results are shown in Table 1.

Example 3 0.5 part by weight of crosslinked polymethylmethacrylate (Eposta MA1006 manufactured by Nippon Shokubai Co., Ltd.) having an average particle size of 6.5 μm and 100 parts by weight of erucamide were added to 100 parts by weight of polyethylene resin LL-2. A film was processed in the same manner as in Example 1 except that 0.06 part by weight was blended. The evaluation results are shown in Table 1.

Comparative Example 1 A film was processed in the same manner as in Example 1 except that 0.5 part by weight of silica having an average particle size of 5.5 μm was used in place of the crosslinked polymethylmethacrylate used in Example 1. . The evaluation results are shown in Table 1.

Comparative Example 2 A film was processed in the same manner as in Example 1 except that 0.5 part by weight of an aluminosilicate having an average particle size of 5.1 μm was used in place of the crosslinked polymethyl methacrylate used in Example 1. did. The evaluation results are shown in Table 1.

Comparative Example 5 In place of the crosslinked polymethylmethacrylate used in Example 1, 0.5 part by weight of a crosslinked silicone resin having an average particle size of 4.5 μm (TOSPEARL 145 manufactured by Toshiba Silycorn Co., Ltd.) was used. Was processed into a film in the same manner as in Example 1. The evaluation results are shown in Table 1.

Example 5 0.2 parts by weight of crosslinked polymethylmethacrylate (MR-2G manufactured by Soken Chemical Co., Ltd.) having an average particle diameter of 2.5 μm and erucic acid amide per 100 parts by weight of polyethylene resin LL-3. A film was processed in the same manner as in Example 1 except that 0.05 part by weight was compounded and the semi-matte roll temperature was set to 50 ° C. The evaluation results are shown in Table 1.

Comparative Example 3 Example 1 was repeated except that 0.2 part by weight of silica having an average particle size of 3.1 μm was used instead of the crosslinked polymethylmethacrylate used in Example 5 and the semi-mat roll temperature was 50 ° C. The film was processed in the same manner as in. The evaluation results are shown in Table 1.

Example 6 0.5 part by weight of crosslinked polymethylmethacrylate (Eposta MA1013 manufactured by Nippon Shokubai Co., Ltd.) having an average particle size of 13 μm was added to 100 parts by weight of polyethylene resin LL-4, and a die set temperature was set. Was processed in the same manner as in Example 1 except that the temperature was set to 210 ° C. The evaluation results are shown in Table 1.

Example 7 Polyethylene resin LL-5 80% by weight and 20 LD
To 100 parts by weight of the resin mixture obtained by adding the mixture by weight of 100% by weight, crosslinked polymethylmethacrylate having an average particle diameter of 3.0 μm (Matsumoto Microsphere M20 manufactured by Matsumoto Yushi Co., Ltd.)
1) A resin composition containing 0.4 parts by weight, 0.15 parts by weight of erucic acid amide and 0.04 parts by weight of stearic acid amide, respectively, was put into a spiral die having a die diameter of 125 mmφ, a die lip of 2.0 mm and an air ring with an iris. Inflation molding machine equipped (made by Placo, screw 50 mmφ, L
/ D = 28) and extruded under conditions of a die set temperature of 200 ° C. and an extrusion rate of 25 kg / hr, and a blow-up ratio of 1.
In 8, a film having a thickness of 30 μm was obtained. The evaluation results are shown in Table 1.

Comparative Example 4 A film was processed in the same manner as in Example 7 except that 0.4 part by weight of an aluminosilicate having an average particle size of 3.0 μm was used in place of the crosslinked polymethylmethacrylate used in Example 7. did. The evaluation results are shown in Table 1.

Example 8 Polyethylene resin LL-6 80% by weight and LD 20
Average particle size of 3.0 μm with respect to 100 parts by weight in total
A film was processed in the same manner as in Example 7 except that 0.3 part by weight of cross-linked polymethyl methacrylate (Matsumoto Yushi Co., Ltd. Matsumoto Microspheres M201) and 0.12 part by weight of erucamide were blended. . The evaluation results are shown in Table 1.

Example 9 Crosslinked polymethylmethacrylate (Matsumoto Microsphere M201 manufactured by Matsumoto Yushi Co., Ltd.) having an average particle size of 3.0 μm was added to 100 parts by weight of LD of polyethylene resin.
A resin composition containing 8 parts by weight and 0.08 parts by weight of oleic acid amide was used, and a die diameter of 100 mmφ and a die lip of 0.8
Inflation molding machine equipped with spiral die and air ring of mm (made by Tommy, screw 50mmφ, L / D = 2
Using 8), die set temperature 150 ° C, extrusion rate 20 kg
The film having a blow-up ratio of 1.8 and a thickness of 30 μm was obtained by extrusion under the condition of / hr. The evaluation results are shown in Table 1.

Example 10 In place of the LD used in Example 9, EVA was used, and Example 9 was used.
A film was processed in the same manner as in Example 9 except that 0.08 parts by weight of oleic acid amide and 0.04 part by weight of stearic acid amide were used in place of the oleic acid amide used in Step 1. The evaluation results are shown in Table 1.

[0034]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-50-51142 (JP, A) JP-A-57-131254 (JP, A) JP-A-62-215646 (JP, A) JP-A-4- 189837 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 23/00-23/36 C08K 3/00-13/08 C08J 5/18

Claims (3)

(57) [Claims] 1. To 100 parts by weight of polyethylene resin,
A polyethylene resin composition comprising 0.05 to 2 parts by weight of crosslinked polymethylmethacrylate powder, which is a resin powder having an average particle size of 2 to 15 μm . 2. A film comprising the polyethylene resin composition according to claim 1 . 3. The film is, claim a packaging film
The film according to 2 .