JP3551485B2 - Polyolefin composite film - Google Patents

Description

【００２５】
【比較例１】
実施例１において、乳化液から共重合体粒子を分離する際の水洗を１回のみとして得た水滴保持時間が２秒以内である架橋アクリル−スチレン系共重合体粒子（平均粒径、粒度分布、粒子形状、粒子組成は実施例１と同じ）を用いる以外は実施例１と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００２６】
【比較例２】を削除します。
【００２７】
【比較例３】
実施例１と同じ方法で水洗した水滴保持時間が１０分以上の平均粒径が８μｍのほぼ単分散の粒径分布を示す球状の架橋アクリル−スチレン系共重合体微粒子（組成は実施例１と同じ）を用いる以外は実施例１と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００２８】
【比較例４】を削除します。
【００２９】
【比較例５】を削除します。
【００３０】
【比較例６】
実施例１の方法において、基層用樹脂に対しても表面層用樹脂に配合したのと同じ架橋アクリル−スチレン系共重合体微粒子をポリプロピレン１００重量部に対して０．１５重量部を配合するよう変更する以外は、実施例１と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００３１】
【実施例２】
実施例１の方法において、架橋アクリル−スチレン系共重合体微粒子に替えて、水滴保持時間が８分の平均粒径が１．７μｍのほぼ単分散の粒度分布を示す球状の架橋アクリル系微粒子〔組成；メチルメタクリレ−ト／トリメチロ−ルプロパントリメタクリレ−ト＝９８／２（重量比）〕を用い、かつ、その添加量を０．１０重量部とする以外は、実施例１と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００３２】
【比較例７】
実施例２の方法において、水滴保持時間が２秒以内の架橋アクリル系粒子を用いる以外は、実施例２と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００３３】
【比較例８】
実施例２の方法において、基層用樹脂にも表面層用樹脂に配合したと同じ架橋アクリル系粒子をポリプロピレン１００重量部に対して０．１０重量部配合するよう変更する以外は、実施例１と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００３４】
【比較例９】
比較例７の方法において、基層用樹脂にも表面層用樹脂に配合したと同じ架橋アクリル系粒子をポリプロピレン１００重量部に対して０．１０重量部を配合するよう変更する以外は、比較例７と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００３５】
【実施例３】
実施例１の方法において、架橋アクリル−スチレン系共重合体粒子に替えて、ポリマ−型のシランカップリング剤で表面処理して得た水滴保持時間が１０分以上、平均粒径が１．３μｍのほぼ単分散の粒径分布を示す球状の架橋ポリスチレン系粒子〔懸濁重合で調製、組成；スチレン／ジビニルベンゼン＝９８／２（重量比）〕を用いる以外は、実施例１と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００３６】
【比較例１０】
実施例３の方法において、架橋ポリスチレン系粒子の表面処理を行わず、水滴保持時間が２秒以内の粒子を用いる以外は、実施例３と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００３７】
【比較例１１】
実施例３の方法において、基層用樹脂にも表面層用樹脂に配合したと同じ架橋スチレン系粒子をポリプロピレン１００重量部に対して０．１５重量部を配合するよう変更する以外は、実施例１と同じ方法でフイルムを得た。特性値を〔表１〕に示す。
【００３８】
【比較例１２】を削除します。
【００３９】
実施例１〜３で得られた本発明のフイルムは、何れも優れた透明性と、良好な滑り性及び耐ブロッキング性を示し、著しく高品質であった。一方、比較例１で得られたフイルムは、透明性及び耐ブロッキング性に劣り低品質であった。なお透明性の評価方法として一般に用いられている「曇価」では、比較例１のフイルムは実施例のものとあまり大きな差がないが、肉眼観察での透明性との相関性が高い狭角拡散透過値では著しく劣っていることがわかる。
【００４０】
比較例２で得られたフイルムは、透明性は良好であるが、耐ブロッキング性に劣り、比較例３，７，９，１０，及び１２で得られたフイルムは透明性及び耐ブロッキング性に劣り、比較例４で得られたフイルムは滑り性及び耐ブロッキング性に劣り、比較例５，６，８及び１１で得られたフイルムは透明性に劣っており、何れも低品質であった。
【００４１】
【発明の効果】
本発明のポリオレフィン系フイルムは、複層構成で、かつ水滴保持時間の長い特定の表面特性を有した有機ポリマ−微粒子を特定量配合した構成であるので、透明性と共に、滑り性及び耐ブロッキング性にも優れており、例えば各種の包装用材料として広く利用することができる。特に透明性に優れているが故に透明性が高度に要求される包装用分野に好適に使用することができる。[0001]
[Industrial applications]
The present invention relates to a polyolefin-based composite film which is excellent in transparency, slipperiness and blocking resistance and is suitably used in the field of packaging or other fields where transparency is highly required.
[0002]
[Prior art]
As a method of improving the slipperiness and blocking resistance of a conventional polyolefin film, for example, adding inorganic fine particles such as silica, calcium carbonate, clay, titanium white, and zeolite, and changing the surface properties of the film to prevent blocking. (JP-B-52-16134, JP-A-3-9938). However, the fine particles of the inorganic substance are easily aggregated, the transparency of the polyolefin composite film is impaired due to a large difference in the refractive index from the polyolefin resin, and the affinity between the polypropylene resin and the inorganic substance is low. Voids are generated around the substance and the transparency is reduced.
[0003]
Therefore, it is impossible to add a sufficient amount of the particulate inorganic substance to give satisfactory slipperiness and blocking resistance to a stretched film requiring transparency for the above-mentioned reason. In order to compensate for the drawbacks of the polyolefin film to which the inorganic substance of these fine particles is added, as a polypropylene composite film to which fine particles of an organic polymer are added, a cross-linked structure having a particle size of 3 to 40 μ with respect to the polypropylene resin and a melting point A polymer fine powder having no polymer is uniformly mixed in an amount of 0.02 to 0.8% by weight with respect to a polypropylene resin, melt-extruded, cooled, and then stretched at least uniaxially. No. 57-64522), and for a stretched polyolefin film, a condensed resin having a spherical triazine ring having an average particle diameter of 0.5 to 10 μm is used in an amount of 0.01 to 0.1 wt. % Of a stretched polyolefin film which is stretched at least 4 times or more in a uniaxial direction (Japanese Unexamined Patent Publication No. 62-39219).
[0004]
However, according to the study results of the present inventors, conventional polyolefin-based composite films using organic polymer fine particles are excellent in transparency and scratch resistance as compared with polyolefin-based composite films using inorganic fine particles, The balance between the transparency, the slipperiness and the blocking resistance is insufficient, and has not yet reached a level satisfying high market requirements.
[0005]
[Problems to be solved by the invention]
As described above, for the polyolefin-based composite film having excellent transparency, slipperiness and blocking resistance, not only the conventional method of adding inorganic fine particles, but also the conventional method of using organic polymer particles. As described above, there is a problem that the polyolefin composite film is insufficient, and the level of transparency, slipperiness and blocking resistance of the polyolefin composite film does not reach a level that satisfies a high market demand. That is, when the amount of fine particles to be added to the polyolefin-based composite film is reduced in order to achieve a high degree of transparency, slipperiness and blocking resistance are deteriorated, and workability in the film manufacturing process and processing process is problematic. In contrast, when the properties of the slipping property and the blocking resistance are satisfied, the transparency is reduced, so that the polyolefin composite film is excellent in both the transparency and the properties opposite to the slipping property and the blocking resistance. Has not yet been obtained.
In view of the above, an object of the present invention is to provide a polyolefin-based composite film having excellent transparency, slipperiness, and blocking resistance.
[0006]
[Means for Solving the Problems]
A first aspect of the present invention is an organic polymer fine particle having an average particle size of 0.4 to 7.0 μm and a water droplet holding time of 10 seconds or more on at least one surface of a base film of a composite film formed of a polyolefin-based polymer. A polyolefin-based composite comprising a multilayer and a film of a polyolefin-based polymer containing 0.01 to 2 parts by weight with respect to 100% by weight of the polyolefin-based polymer whose surface layer is a polyolefin-based composite. It is about film.
[0007]
Secondly, in the first aspect of the present invention, the organic polymer fine particles are a monomer containing an acrylic monomer or a methacrylic monomer (abbreviated as (meth) acrylic monomer) and / or a styrene monomer. A polyolefin-based composite film, which is a polymer comprising components.
[0008]
A third aspect of the present invention relates to the polyolefin composite film of the first and second aspects, wherein the thickness of the film of the surface layer is 0.03 to 4 μm.
Here, the water drop holding time is
The organic polymer fine particles were sandwiched between two biaxially stretched polypropylene films on a horizontal and smooth table, and the upper film was lightly pressed by hand to form a smooth organic polymer fine particle layer having a thickness of 2 mm. Then, gently remove the upper film. A drop of water having a diameter of 2 mm is dropped from a height of 1 cm onto the surface of the obtained organic polymer fine particle layer with a spoid, and the time until the water drop is absorbed by the organic polymer fine particle layer and disappears.
[0009]
Examples of the polyolefin constituting the polyolefin composite film of the present invention include a homopolymer such as propylene, ethylene, butene and 4-methylpentene-1 or a mixture of these copolymers for both the base layer and the surface layer. The types of the polyolefins constituting the base layer and the surface layer may be the same or different, and any type may be used.
[0010]
The organic polymer fine particles used in the present invention are not particularly limited as long as they are non-melting at the melt molding temperature of the polyolefin and have heat resistance to withstand the same temperature, and are obtained by an addition polymerization method. And those obtained by a polycondensation or polyaddition reaction method. The polymer constituting the organic polymer fine particles may be a non-crosslinked type or a crosslinked type, but the crosslinked type is more preferred from the viewpoint of heat resistance.
[0011]
The method of forming the polymer into fine particles is not limited, but a method of directly forming fine particles during polymerization using a method such as emulsion polymerization or suspension polymerization is preferred. When these polymerization methods are employed, a means for copolymerizing a small amount of a polar monomer having a special structure capable of imparting self-emulsification may be employed. The shape of the polymer fine particles is not particularly limited, but is preferably substantially spherical or rugby ball-shaped.
[0012]
As the organic polymer fine particles of the present invention, it is preferable to use polymer fine particles composed of a (meth) acrylic monomer and / or a styrene monomer. That is, a homopolymer of a (meth) acrylic monomer or a styrene monomer, a copolymer of a (meth) acrylic monomer (including a copolymer higher than a copolymer, the same applies hereinafter), and a copolymer of a styrene monomer. Or a copolymer of a (meth) acrylic monomer and a styrene monomer. Among them, preferred is a cross-linked (meth) acrylic-styrene-based copolymer, which is excellent in balance among transparency, slipperiness, heat resistance, water drop holding time and the like.
[0013]
Examples of the (meth) acrylic monomer component include acrylic acid such as acrylic acid, methyl acrylate, ethyl acrylate, and butyl acrylate, and ester derivatives thereof, and methacrylic acid, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. Methacrylic acid or its ester derivative is mentioned. These monomers may be used alone or in combination of two or more. If the amount is small, a metal salt of acrylic acid or methacrylic acid, an amide derivative, or an ester derivative having a special structure such as hydroxylethyl ester or dimethylaminoethyl ester may be used.
[0014]
Examples of the styrene monomer component include styrene such as styrene, methylstyrene, α-methylstyrene, and β-methylstyrene, and derivatives thereof. If the content is 20% by weight or less of the total monomer components, a polymerizable vinyl monomer such as vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile or the like may be copolymerized. Examples of the cross-linking method include a method of copolymerizing a polyfunctional monomer such as divinyl benzene or diglyceric acid ester of ethylene glycol or dimethacrylic acid ester at the time of forming the fine particle polymer, or a method of post-crosslinking after forming the polymer. Examples include, but are not limited to:
[0015]
The organic polymer fine particles in the present invention must have a water droplet retention time of at least 10 seconds as measured by the above method. It is preferably at least 1 minute, more preferably at least 5 minutes. The water droplet holding time defines the degree of hydrophobicity of the organic polymer fine particles. If the water droplet holding time is less than 10 seconds, a film that is highly transparent and has good slipperiness and blocking resistance can be obtained. I can't.
[0016]
Means for setting the water droplet holding time to 10 seconds or longer is not particularly limited, but the following method is recommended.
(1) Optimize the structure of the polymer constituting the fine particles.
{Circle around (2)} Optimizing the polymerization method and the method for preparing fine particles, and unevenly distributing the component having a hydrophobic group on the surface of the fine particles.
{Circle around (3)} When the emulsion is prepared by a method of directly forming fine particles by an emulsion polymerization method or a suspension polymerization method, a surfactant used at the time of polymerization and a monomer for imparting self-emulsifying properties are optimized.
(4) When preparing by a method of directly forming fine particles by an emulsion polymerization method or a suspension polymerization method, sufficiently wash the fine particles when separating them from a solvent such as water, and use a hydrophilic additive such as a surfactant. And residual monomers are removed.
(5) The surface of the fine particles is coated with a hydrophobic monomer or polymer.
{Circle around (6)} The surface is treated with a surface treating agent such as a silane coupling agent or a titanate coupling agent.
[0017]
The average particle size of the organic polymer fine particles in the present invention needs to be in the range of 0.4 to 7.0 μm. If the thickness is less than 0.4 μm, the effect of improving the slip property is undesirably reduced. On the other hand, if the thickness exceeds 7.0 μm, the effect of improving the slip property reaches saturation, but the transparency is unfavorably deteriorated. Further, the particle size distribution of the organic polymer fine particles is preferably a sharp in order to satisfy transparency, slipperiness and blocking resistance. The average particle size of the organic polymer fine particles was obtained by taking a photograph with a scanning electron microscope, measuring the Feret diameter in the horizontal direction using an image analyzer, and displaying the average value. .
[0018]
In the present invention, the mixing ratio of the organic polymer fine particles in the film to the surface layer is set to 0.01 to 2 parts by weight based on 100 parts by weight of the polyolefin. Preferably it is 0.02-0.5 weight part. If the amount of the organic polymer fine particles is less than 0.01 part by weight, it is impossible to impart slipperiness and blocking resistance to the film. Although the properties are sufficiently provided, the transparency of the film is significantly impaired, which is not preferable.
The optimum value of the average particle diameter and the blending ratio of the above-mentioned organic polymer-fine particles varies depending on the type of the polyolefin, the thickness and the structure of the film, the presence or absence of stretching, etc., so that it is within the range described above in accordance with the intended film characteristics. It is better to set it arbitrarily.
The necessity of blending the above organic polymer fine particles with the polyolefin constituting the base layer is not particularly limited, but if it is blended in the base layer, the transparency of the film is reduced. Therefore, it is used in a field where transparency is highly required. In the case of a film, the compounding of the organic polymer fine particles is preferably limited to only the surface layer.
[0019]
In the polyolefin-based composite film of the present invention, organic or inorganic fine particles other than the organic polymer fine particles may be used together, or higher fatty acid amides, higher fatty acid esters, waxes, metal stones may be used as long as the effects of the present invention are not impaired. It is possible to improve the slipperiness by using a lubricant such as Ken together. The use of a lubricant is rather preferred. In addition, there are no restrictions on the use of known stabilizers, antistatic agents, ultraviolet absorbers, processing aids, plasticizers, and the like, which are usually added to the polyolefin film.
The method for mixing the above-mentioned organic polymer fine particles and additives with the polyolefin is not particularly limited, but is uniformly mixed with a mixer such as a V-type blender, a screw-type blender, a drive render, a ribbon blender, and a Henschel mixer. Then, a method of kneading and pelletizing may be used.
[0020]
The method for laminating the polyolefin-based composite film of the present invention is not particularly limited, and may be carried out by any of a coextrusion method and a lamination method. However, from the viewpoint of economy, the coextrusion method is preferred. . In the present invention, the film thickness of the surface layer needs to be 0.03 to 4 μm. Further, the thickness is more preferably 0.05 to 3 μm. If it is less than 0.03 μm, the effect of improving the slipperiness and the blocking resistance is not sufficient, which is not preferable. Conversely, if it exceeds 4 μm, the effect of improving the slipperiness and the blocking resistance is saturated, and the transparency is undesirably reduced. The total film thickness in the present invention is determined according to the use, but is usually in the range of 6 to 100 μm, preferably 10 to 50 μm.
[0021]
The composite film of the present invention may be an unstretched casting film simply extruded, or a stretched film obtained by stretching the casting film in a uniaxial or biaxial direction. This is particularly preferred. Further, it is useful in application development to subject the film of the present invention to a surface treatment for improving adhesiveness, such as a corona discharge treatment, a plasma treatment, and an ultraviolet irradiation treatment.
[0022]
Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples, and all changes and implementations within the scope of the above or the following description are possible without departing from the scope of the present invention. Within the technical scope of The measuring method used in the examples is as follows.
(1) Haze value According to JIS-K6714, the haze value was measured with a haze tester J manufactured by Toyo Seiki.
(2) Narrow angle diffuse transmission value Measured using a visual transparency tester manufactured by Toyo Seiki Seisaku-sho, Ltd. The smaller the measured value, the higher the transparency.
(3) Coefficient of friction was measured at 20 ° C. × 65% RH according to ASTM-D1894.
(4) The anti-blocking film is cut into a piece of 80 mm × 120 mm with a cutter, and two pieces of the cut pieces are overlapped with each other by being shifted vertically by 20 mm in the longitudinal direction to form a sample. Five sets of this sample are alternately stacked with type paper, sandwiched between glass plates, and then subjected to a load of 2 kg and left at 50 ° C. for 48 hours. The sample was taken out, allowed to cool, recut in the longitudinal direction at a width of 20 mm to obtain a test piece, and the test piece was measured for shear stress at a tensile speed of 220 mm / min.
[0023]
Embodiment 1
As the resin for the base layer, a composition obtained by mixing 0.3 parts by weight of glycerin resin acid ester and 0.3 parts by weight of erucamide with 100 parts by weight of polypropylene having a melt index of 2.5 g / 10 minutes was used as the resin for the surface layer. Spherical crosslinked acryl-styrene system having a water droplet retention time of 10 minutes or more and an average particle size of 1.1 μm and a substantially monodisperse particle size distribution with respect to 100 parts by weight of polypropylene having a melt index of 2.5 g / 10 minutes. Copolymer particles [A monomer component composed of methyl methacrylate / n-butyl acrylate / styrene / divinylbenzene = 36/27/36/1 (weight ratio) is polymerized by an emulsion polymerization method, and is prepared from the emulsion. When separating the copolymer particles, washing with water is repeated 5 times to sufficiently remove the surfactant adhering to the surface of the fine particles. Using a composition obtained by mixing 0.15 parts by weight, 0.3 parts by weight of glycerin resin acid ester and 0.3 parts by weight of erucamide, the above resin for the base layer and the resin for the surface layer are separately extruded. It is melted, the melt is joined between dies, and a three-layer melt obtained by laminating a surface layer on both sides of a base layer is quenched by a cooling roll at 20 ° C., and is unstretched to a total thickness of 0.90 mm. A sheet was obtained. [Thickness ratio of (surface layer / base layer / surface layer) = 1/23/1]. This unstretched sheet is stretched 4.5 times in the machine direction at a stretching temperature of 40 ° C. by utilizing a difference in roll peripheral speed of a longitudinal stretching machine, and subsequently stretched at a stretching temperature of 155 ° C. by a tenter type stretching machine. The film was stretched 8 times in the transverse direction. Next, heat treatment was performed at 160 ° C. to form a biaxially stretched film having a thickness of about 25 μm, and then one surface was subjected to a corona discharge treatment. Table 1 shows the characteristic values of the obtained films.
[0024]
[Table 1]

[0025]
[Comparative Example 1]
In Example 1, crosslinked acrylic-styrene-based copolymer particles (average particle size, particle size distribution) obtained by performing water washing only once when separating the copolymer particles from the emulsion and having a water droplet holding time of 2 seconds or less , A particle shape and a particle composition were the same as in Example 1, except that a film was obtained in the same manner as in Example 1. The characteristic values are shown in [Table 1].
[0026]
[Comparative Example 2] is deleted.
[0027]
[Comparative Example 3]
Spherical crosslinked acryl-styrene copolymer fine particles exhibiting a substantially monodisperse particle size distribution having an average particle size of 8 μm and a water droplet retention time of 10 minutes or more washed with water in the same manner as in Example 1 (the composition is the same as that of Example 1). A film was obtained in the same manner as in Example 1 except that the same was used. The characteristic values are shown in [Table 1].
[0028]
[Comparative Example 4] is deleted.
[0029]
[Comparative Example 5] is deleted.
[0030]
[Comparative Example 6]
In the method of Example 1, 0.15 parts by weight of the same crosslinked acryl-styrene-based copolymer fine particles as the resin for the surface layer was added to the resin for the base layer, relative to 100 parts by weight of polypropylene. A film was obtained in the same manner as in Example 1, except for the change. The characteristic values are shown in [Table 1].
[0031]
Embodiment 2
In the method of Example 1, in place of the crosslinked acrylic-styrene-based copolymer fine particles, spherical crosslinked acrylic fine particles exhibiting a substantially monodispersed particle size distribution with an average particle size of 1.7 μm for a water droplet holding time of 8 minutes [ Composition: Methyl methacrylate / trimethylolpropane trimethacrylate = 98/2 (weight ratio)] and the amount added was 0.10 parts by weight, the same as Example 1. A film was obtained by the method. The characteristic values are shown in [Table 1].
[0032]
[Comparative Example 7]
A film was obtained in the same manner as in Example 2, except that the crosslinked acrylic particles having a water droplet holding time of 2 seconds or less were used. The characteristic values are shown in [Table 1].
[0033]
[Comparative Example 8]
The method of Example 2 was the same as that of Example 1, except that the same cross-linked acrylic particles as used in the resin for the base layer were also added to the resin for the surface layer in an amount of 0.10 parts by weight based on 100 parts by weight of polypropylene. A film was obtained in the same manner. The characteristic values are shown in [Table 1].
[0034]
[Comparative Example 9]
Comparative Example 7 was the same as Comparative Example 7 except that the same crosslinked acrylic particles as those used in the base layer resin were also added to the resin for the surface layer so that 0.10 parts by weight was added to 100 parts by weight of polypropylene. A film was obtained in the same manner as described above. The characteristic values are shown in [Table 1].
[0035]
Embodiment 3
In the method of Example 1, a water droplet holding time obtained by performing a surface treatment with a polymer-type silane coupling agent in place of the crosslinked acrylic-styrene copolymer particles is 10 minutes or more, and the average particle diameter is 1.3 μm. In the same manner as in Example 1 except that spherical cross-linked polystyrene-based particles (prepared by suspension polymerization, composition; styrene / divinylbenzene = 98/2 (weight ratio)) exhibiting a substantially monodisperse particle size distribution of I got a film. The characteristic values are shown in [Table 1].
[0036]
[Comparative Example 10]
A film was obtained in the same manner as in Example 3, except that the surface treatment of the crosslinked polystyrene-based particles was not performed and the particles having a water droplet holding time of 2 seconds or less were used. The characteristic values are shown in [Table 1].
[0037]
[Comparative Example 11]
Example 1 was repeated except that the same crosslinked styrene-based particles as used in the resin for the base layer and in the resin for the surface layer were added in an amount of 0.15 parts by weight with respect to 100 parts by weight of polypropylene in the method of Example 3. A film was obtained in the same manner as described above. The characteristic values are shown in [Table 1].
[0038]
[Comparative Example 12] is deleted.
[0039]
Each of the films of the present invention obtained in Examples 1 to 3 exhibited excellent transparency, good sliding properties and blocking resistance, and was extremely high in quality. On the other hand, the film obtained in Comparative Example 1 was inferior in transparency and blocking resistance and was of low quality. In the “haze value” which is generally used as a method of evaluating transparency, the film of Comparative Example 1 does not have much difference from that of the example, but has a high narrow-angle which has a high correlation with the transparency by visual observation. It can be seen that the diffuse transmission value is remarkably inferior.
[0040]
The film obtained in Comparative Example 2 has good transparency but is inferior in blocking resistance, and the films obtained in Comparative Examples 3, 7, 9, 10, and 12 are inferior in transparency and blocking resistance. The film obtained in Comparative Example 4 was inferior in slipperiness and blocking resistance, and the films obtained in Comparative Examples 5, 6, 8 and 11 were inferior in transparency, and all were of low quality.
[0041]
【The invention's effect】
The polyolefin film of the present invention has a multi-layer structure, and a structure in which a specific amount of organic polymer fine particles having a specific surface property having a long water droplet holding time is blended, so that, together with transparency, slipperiness and blocking resistance And can be widely used, for example, as various packaging materials. Particularly, since it is excellent in transparency, it can be suitably used in the field of packaging where transparency is highly required.

Claims (3)

A polyolefin-based composition in which organic polymer fine particles having an average particle size of 0.4 to 7.0 μm and a water droplet retention time of 10 seconds or more are blended on at least one surface of at least one surface of the base layer of the composite film formed from the polyolefin-based polymer. A polyolefin-based composite film comprising a polyolefin-based polymer film containing 0.01 to 2% by weight with respect to 100% by weight of a polymer, which is laminated and laminated. 2. The polyolefin composite film according to claim 1, wherein the organic polymer fine particles are a polymer comprising a monomer component containing a (meth) acrylic monomer and / or a styrene monomer.
Here, the (meth) acrylic monomer is an abbreviation for an acrylic monomer or a methacrylic monomer. 3. The polyolefin-based composite film according to claim 1, wherein the thickness of the film of the surface layer is 0.03 to 4.0 [mu] m.