Polyethylene resin film

Abstract

To provide a polyethylene-based resin film which is excellent in heat sealability, non-blocking property and slipperiness, leaves little residue upon incineration, and also has excellent appearance and scratch resistance.SOLUTION: A polyethylene-based resin film has at least a layer A made of a polyethylene-based resin composition, a polyethylene-based resin composition constituting the layer A satisfies the following 1) to 3), and at least one surface of the layer A satisfies both of the followings 4) and 5). 1) To include polyethylene-based resin having a density of 900 kg / m3 or more 935 kg / m3 or less by 90 wt.% or more. 2) To include particles made of polyethylene-based resin having an average particle diameter of 5 to 20 μm. 3) To have a content of organic lubricant of 0.16 wt.% or more. 4) To have a three-dimensional surface roughness SRa of 0.05 to 0.2 μm. 5) To have a maximum projection height SRmax of 2 to 15 μm.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyethylene resin film, and a laminate and a package using the same. [Background technology]

[0002] In recent years, packaging or containers using films have been used in a wide range of fields due to their convenience, resource conservation, reduced environmental impact, etc. Compared to conventional molded containers and molded products, films have the advantages of being lightweight, easy to dispose of, and low cost.

[0003] Sealant films are generally used by laminating them with a base film such as a biaxially oriented nylon film, a biaxially oriented ester film, or a biaxially oriented polypropylene film, which has poorer low-temperature thermal adhesion than the sealant film. When the film is stored in a roll after being laminated with such a base film, blocking occurs between the sealant film and the base film, making it difficult to unwind the laminate film before bag-making, or blocking occurs between the sealant films that form the inner surface of the bag during bag-making, making it difficult to fill the food. Therefore, a known method is to sprinkle powder such as starch on the surface of the sealant film to avoid the above-mentioned blocking between the sealant film and the substrate, and between sealant films themselves. However, this method not only contaminates the area around the film processing equipment, but also significantly deteriorates the appearance of the packaged food, or powder adhering to the sealant film gets mixed directly into the package along with the food, or reduces the heat seal strength.

[0004] Therefore, polyethylene resin films using inorganic fine powder or inorganic fine particles such as silica in polyethylene resin have been reported.

[0005] However, this method has the problem that scratches are likely to occur when film surfaces containing inorganic fine powder or inorganic particles such as silica added to polyethylene resin films are rubbed against each other, and when the sealant fill or the laminate with the base film passes through a laminating machine or bag-making machine, the inorganic fine powder or inorganic particles are likely to fall off, causing scratches and foreign matter problems.

[0006] Furthermore, a polyethylene resin film using organic crosslinked particles made of a copolymer mainly composed of an acrylic monomer and a styrene monomer has been reported. However, this method is not as susceptible to damage as inorganic particles, but it is still not sufficient, and the problem of particles falling off still remains.

[0007] Furthermore, in order to improve the blocking resistance of polyethylene resin films, it has been reported that low-density polyethylene resin or high-density polyethylene resin is added to linear low-density polyethylene resin (see, for example, Patent Documents 1 and 2).

[0008] However, these methods have had problems such as deterioration in mechanical strength properties such as tensile strength and transparency, and also have poor blocking resistance. Furthermore, a polyethylene resin film has been reported in which particles made of a high-molecular-weight polyethylene resin are added to a high-density polyethylene resin. However, this method has the problem that it is inferior in mechanical strength properties such as tear strength, heat sealability at low temperatures, and transparency, and that the addition of particles made of polyethylene resin actually makes blocking resistance and slipperiness unstable. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 10-120849 [Patent Document 2] Japanese Patent Application Laid-Open No. 10-87909

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] An object of the present invention is to provide a polyethylene-based resin film that is excellent in appearance, heat sealability, stable blocking resistance, stable slipperiness, and also excellent in scratch resistance. Another object is to provide a laminate using this polyethylene-based resin film and further a package.

MEANS FOR SOLVING THE PROBLEMS

[0011] As a result of intensive studies, the present inventors have found that by controlling the protrusion height and the content of an organic lubricant on the surface of a layer composed of a polyethylene-based resin composition containing a polyethylene-based resin having a specific density range and particles made of a polyethylene-based resin, it has been found that the above problems can be solved, and the present invention has been completed.

[0012] That is, the present invention is a polyethylene-based resin film having at least one layer A composed of a polyethylene-based resin composition, wherein the polyethylene-based resin composition constituting the layer A satisfies the following 1) to 3), and at least one surface of the layer A satisfies both the following 4) and 5). 1) It contains a polyethylene-based resin having a density of 900 kg / m 3 or more and 935 kg / m 3 or less. 2) It contains particles made of a polyethylene-based resin. 3) The content of the organic lubricant is 0.16% by weight or more. 4) The three-dimensional surface roughness SRa is 0.05 to 0.2 μm. 5) The maximum peak height SRmax is 2 to 15 μm.

[0013] Another aspect is a polyethylene-based resin film having at least one A layer made of a polyethylene-based resin composition, wherein the polyethylene-based resin composition constituting the A layer satisfies the following 1) to 3), and at least one surface of the A layer satisfies both the following 4) and 5). 1) The density is 900 kg / m 3 or more and 935 kg / m 3 or less. 2) It contains particles made of a polyethylene-based resin. 3) The content of the organic lubricant is 0.16% by weight or more. 4) The three-dimensional surface roughness SRa is 0.05 to 0.2 μm. 5) The maximum peak height SRmax is 2 to 15 μm.

[0014] In this case, it is preferable that the resin hardness of the particles made of the polyethylene-based resin is D70 or less. The polyethylene-based resin multilayer film according to claim 1 or 2. Also, in this case, it is preferable that the viscosity-average molecular weight of the particles made of the polyethylene-based resin is 1.5 million or more and the melting peak temperature by DSC is 150°C or less.

[0015] Furthermore, in this case, it is preferable that the average particle diameter of the particles made of the polyethylene-based resin is 5 to 15 μm.

[0016] Furthermore, in this case, it is preferable that the content of the particles made of the polyethylene-based resin in the polyethylene-based resin composition constituting the A layer is 0.2 to 2.0% by weight.

[0017] Furthermore, in this case, it is preferable that the blocking value between the surfaces of the A layer is 200 mN / 70 mm or less.

[0018] Furthermore, in this case, it is preferable that the change amount of haze after 100 abrasions with a load of 200 g when the surfaces of the A layer are set in a Gakushin type abrasion tester manufactured by Yasuda Seiki Co., Ltd. is 5% or less.

[0019] Furthermore, in this case, a laminate including the base film composed of the polyethylene-based resin film and the composition described above is preferable.

[0020] Furthermore, in this case, a packaging bag including the laminate is preferable.

Advantages of the Invention

[0021] The present invention can provide a polyethylene-based resin film excellent in appearance, heat sealability, stable antiblocking property, and stable slipperiness, and particularly excellent in scratch resistance. Further, a laminate using this polyethylene-based resin film and a packaging body can be provided.

Embodiments for Carrying Out the Invention

[0022] (A layer made of a polyethylene-based resin composition) The A layer in the present invention is made of a polyethylene-based resin composition. The polyethylene-based resin composition mainly contains a polyethylene-based resin and also contains particles made of the polyethylene-based resin. The polyethylene-based resin composition preferably contains 50% by weight or more of the polyethylene-based resin, more preferably 70% by weight, and even more preferably 90% by weight or more. (Polyethylene-based resin) The polyethylene-based resin in the present invention is any one of a homopolymer of an ethylene monomer, a copolymer of an ethylene monomer and an α-olefin, and a mixture thereof. Examples of the α-olefin include propylene, butene-1, hexene-1, 4-methylpentene-1, octene-1, decene-1, and the like.

[0023] The density range of the polyethylene-based resin is 900 to 935 kg / m 3 is more preferable, 910 to 933 kg / m 3 is even more preferable, and 910 to 930 kg / m 3 is particularly preferable. When the density is 935 kg / m 3The following polyethylene resins have a low heat-sealing start temperature, are easy to process into bags, and have excellent transparency. More importantly, when the density is 935 kg / m 3 When the following polyethylene resins are used, it becomes easy for the three-dimensional surface roughness SRa of at least one surface of the A layer to be 0.05 μm or more and the maximum peak height SRmax to be 2 μm or more due to the particles made of the polyethylene resin. The polyethylene resin film easily obtains slipperiness, anti-blocking property, and scratch resistance. Therefore, the present inventors have found that wrinkles and bumps are less likely to occur in coating, printing, and bag-making processes, and transparency is also easily maintained. In particular, the anti-blocking property hardly varies with each measured value of the four measurements and becomes stable. Also, when a polyethylene resin with a density of 900 kg / m 3 When the above polyethylene resin is used, it is easy to control the three-dimensional surface roughness SRa of at least one surface of the A layer to 0.2 μm or less and the maximum peak height SRmax to 15 μm or less by the particles made of the polyethylene resin, and it is easy to improve transparency and firmness.

[0024] The anti-blocking property is measured by subjecting a sample with the A-layer surfaces of the film overlapped to a heat press (model: SA-303 manufactured by Tester Sangyo Co., Ltd.) to a pressure treatment with a size of 7 cm × 7 cm, a temperature of 50 °C, a pressure of 18 MPa, and a time of 15 minutes. The blocked sample and a bar (diameter: 6 mm, material: aluminum) are attached to an autograph (model: UA-3122 manufactured by Shimadzu Corporation) so that the bar and the peeling surface are horizontal, and the force when the bar peels the blocking part at a speed of 200 m / min is measured four times, and the average value is used as an index. When a polyethylene resin with a density of 935 kg / m3 or less is used, not only are the measured values of the four measurements less likely to vary, but also there is a tendency that the heat-sealing start temperature is less likely to increase. It is preferable that the variation in each measured value of the four measurements is at the same level as when inorganic particles are used. The reason why the measured values do not vary much for each measurement sample is thought to be that when particles made of polyethylene with a density of 935 kg / m3 or less and polyethylene-based resin are melt-mixed, changes in particle size due to factors such as a decrease in the viscosity average molecular weight of the particles made of polyethylene-based resin or entanglement of molecular chains with polyethylene-based resins other than the particles made of polyethylene-based resin do not occur easily, and as a result, the protrusions formed on the surface are uniform.

[0025] Scratch resistance was determined by placing the A-layer surfaces of polyethylene resin films together in a Yasuda Seiki Gakushin abrasion tester and rubbing them 100 times with a load of 200g, and measuring the change in haze afterwards. Haze was measured at the centre of the film (width x length = 50mm x 180mm) before it was placed on the abrasion table (points were placed at the edges, and points were placed on both ends of the surface opposite the abraded surface that did not affect the haze measurement), and then measuring the haze at the same position after abrasion to determine the difference.

[0026] From the viewpoint of film-forming properties, the polyethylene resin preferably has a melt flow rate (hereinafter sometimes referred to as MFR) of about 2.5 to 4.5 g / min. Here, MFR is measured in accordance with ASTM D1893-67. The polyethylene resin is synthesized by a method known per se.

[0027] When using a polyethylene resin with a low MFR of 2.5 g / 10 min or less, as explained in the density section, the particle size tends to change due to a decrease in the viscosity average molecular weight of the polyethylene resin particles and entanglement of molecular chains with polyethylene resins other than the particles, so care must be taken with the extrusion conditions. When producing films at high speed using a large film-making machine, an MFR of around 3 to 4 g / 10 min is particularly preferable for film-forming properties.

[0028] From the viewpoint of heat resistance and the like, the melting point of the polyethylene resin is preferably 85°C or higher, more preferably 100°C or higher, and particularly preferably 110°C or higher.

[0029] The polyethylene resin may be a single type, but it is also possible to blend two or more polyethylene resins with different densities within the above density range. When blending two or more polyethylene resins with different densities, the average density and blending ratio can be estimated by GPC measurement or density measurement.

[0030] As the polyethylene resin with a density of 900 - 935 kg / m 3 as described above, high-pressure low-density polyethylene (LDPE) which is transparent, rich in flexibility, and on average excellent in tear strength and tensile strength, linear low-density polyethylene (LLDPE) obtained by copolymerizing a small amount of butene-1, hexene-1, and octene-1 and having many short molecular chains in the molecular chain and excellent in sealing performance and physical strength, and metallocene-catalyzed linear low-density polyethylene (LLDPE) which exhibits a very sharp molecular weight distribution, has a uniform comonomer distribution, and is excellent in tear, tensile, puncture strength, and pinhole resistance can be selected according to its use. As the polyethylene resin used for the seal layer, it is also possible to use commercially available products. For example, Yumelite (registered trademark) 2040FC, 0540F, 3540FC manufactured by Ube Maruzen Polyethylene Co., Ltd., Sumika Sen (registered trademark) E FV402, E FV405 manufactured by Sumitomo Chemical Co., Ltd., etc. can be mentioned.

[0031] (Particles made of polyethylene resin) The particles made of polyethylene resin contained in the polyethylene resin composition constituting the A layer preferably have a viscosity-average molecular weight of 1.5 million or more, more preferably 1.6 million or more, and even more preferably 1.7 million or more. Also, 2.5 million or less is preferable, 2.4 million or less is more preferable, and 2.3 million or less is even more preferable. If the viscosity-average molecular weight of the particles made of polyethylene resin is within this range, it becomes possible to control the average particle diameter of the particles made of polyethylene resin, and by using it in combination with a polyethylene resin of a specific density, the three-dimensional surface roughness SRa of at least one surface of the A layer can be made 0.05 - 0.2 μm, and the maximum peak height SRmax can be made 2 - 15 μm. The reason is that the difference in molecular weight between the particles made of polyethylene resin and the polyethylene resin other than the particles made of polyethylene resin is very large, so the molecules do not mix well enough, and even in the film obtained by melt mixing and extrusion, it is easy for the particles made of polyethylene resin to maintain a shape close to spherical, and aggregation due to fusion or adhesion between particles is also unlikely to occur. Therefore, it is presumed that protrusions with controlled shapes can be formed on the film surface. When the viscosity average molecular weight of the particles made of polyethylene resin is 1.5 million or more, and the temperature during melt mixing with the polyethylene resin other than the particles made of polyethylene resin is higher than the melting point peak of the particles made of polyethylene resin, even under the conditions of shear by a large extruder or high draw ratio during film formation, decomposition due to heat or shear, or fusion and aggregation between the particles made of polyethylene resin, or changes in the particle size and shape of the particles made of polyethylene resin due to partial compatibility with the polyethylene resin other than the particles made of polyethylene resin are less likely to occur. Therefore, it becomes easier to form protrusions with controlled shapes such as inorganic particles or organic crosslinked resin particles, and not only is the function as an antiblocking agent sufficient, but it also hardly affects the appearance such as transparency, the mechanical strength of the film, or the heat sealability. Furthermore, and this is also surprising, although the particles made of polyethylene resin with a viscosity average molecular weight of 1.5 million or more have the property of being difficult to aggregate in the polyethylene resin, it has been found that they have a characteristic that inorganic particles and organic crosslinked resin particles do not have, that is, they are difficult to fall off from the polyethylene resin near the film surface. When the viscosity average molecular weight is 1.5 million to 2.5 million, it becomes easy to set the average particle size to 5 to 20 μm, and when melt mixing the seal layer raw material, extruding, and forming a film, there is a tendency to easily form suitable protrusions on the film surface. Also, when the viscosity average molecular weight of the particles made of polyethylene resin is 1.5 million or more, the particles themselves have lubricity, which contributes to improving antiblocking and slipperiness. Moreover, since the particles made of polyethylene resin are soft, it is considered that the scratch resistance is also improved.

[0032] The resin hardness of the particles made of a polyethylene-based resin is preferably D70 or less. When the hardness is 70 or less, it is less likely for defects to occur in the laminated layer of the film, such as the vapor deposition layer, and the barrier property is less likely to decrease. A hardness of D68 or less is more preferable. In addition, when the hardness of the particles made of a polyethylene-based resin is D60 or more, the slipperiness is also improved, and the slipperiness is less likely to deteriorate even when heated during film processing.

[0033] The particles made of a polyethylene-based resin are a homopolymer of an ethylene monomer, a copolymer of an ethylene monomer and an α-olefin, or a mixture thereof. Examples of the α-olefin include propylene, butene-1, hexene-1, 4-methylpentene-1, octene-1, decene-1, and the like.

[0034] The density range of the particles made of a polyethylene-based resin is preferably 930 to 950 kg / m 3 and more preferably 935 to 945 kg / m 3 and even more preferably 937 to 942 kg / m 3 Particles made of a polyethylene resin with a density less than 930 kg / m 3 are soft, and it is difficult to maintain the particle shape during melt extrusion, and the blocking resistance is likely to decrease. Also, particles made of a polyethylene resin with a density greater than 950 kg / m 3 are hard, the scratch resistance is likely to decrease, and the affinity with the base polyethylene resin decreases, so the adhesion resistance may decrease.

[0035] The average particle diameter of the particles made of a polyethylene-based resin contained in the polyethylene-based resin composition constituting the A layer is preferably 5 μm or more, more preferably 6 μm or more, and even more preferably 7 μm or more. Also, the average particle diameter is preferably 20 μm or less, more preferably 17 μm or less, and particularly preferably 15 μm or less. In addition, it is preferable that the particles do not contain particles having a particle size of 30 μm or more. Even if the average particle size is 20 μm or less, if the particles having a particle size of 30 μm or more are contained in a predetermined amount of 10% or more, the maximum peak height of the film surface is likely to exceed 15 μm. Then, when the film surface is visually observed, the unevenness described later occurs. In addition, particles of 30 μm or more are not preferable in that they have the same appearance as the gel-like defect and the quality deteriorates.

[0036] By setting the average particle size of the particles made of the polyethylene-based resin to 5 μm or more, the slipperiness and blocking resistance can be improved. In addition, when the average particle size is 20 μm or less, the three-dimensional surface roughness SRa and the maximum protrusion height SRmax of at least one surface of the A layer do not become too large, and when compared with the case where particles made of the same weight of the polyethylene-based resin are added, the number of protrusions increases. Therefore, it is easy to obtain sufficient slipperiness, blocking resistance, and scratch resistance for film processing.

[0037] Furthermore, the average particle size of the particles made of the polyethylene-based resin is less likely to change in particle size due to crushing or aggregation during kneading during extrusion than relatively soft inorganic particles such as talc and calcium carbonate, and it is easy to control the average particle size (before and after extrusion). By setting the average particle size of the particles made of the polyethylene-based resin in the range of 5 to 20 μm, protrusions due to coarse particles are almost eliminated, and since the hardness of the protrusions themselves is lower than that of inorganic particles, the adverse effects on the other surface of the A layer or the coat provided on a layer different from the A layer are suppressed.

[0038] As the content of the particles made of the polyethylene-based resin in the polyethylene-based resin composition constituting the A layer, it is preferably 0.2% by weight or more, more preferably 0.3% by weight or more, and even more preferably 0.4% by weight or more with respect to the polyethylene-based resin composition. Also, 2.0% by weight or less is preferable, 1.5% by weight or less is more preferable, and 1.0% by weight or less is even more preferable. When the addition amount of the particles made of the polyethylene-based resin is 0.2% by weight or more, the maximum peak height of at least one of the A layer surfaces is within a specified area (0.2 mm 2)It becomes easier to make it 2 μm or more on the side, and it becomes easier to obtain blocking resistance and slipperiness. Further, when the addition amount of the particles made of a polyethylene resin is 2.0% by weight or less, the protrusions on the surface of the A layer do not become too many, and transparency and low-temperature sealability are also likely to be improved.

[0039] The polyethylene resin composition constituting the A layer contains an organic lubricant. The slipperiness and blocking resistance effect of the film are improved, and the handleability of the film is improved. As the reason, it is considered that the organic lubricant bleeds out and exists on the film surface, thereby exhibiting a lubricant effect and a mold release effect. Further, it is preferable to add an organic lubricant having a melting point of room temperature or higher. Examples of the organic lubricant include fatty acid amides and fatty acid esters. Specifically, oleic acid amide, erucic acid amide, behenic acid amide, ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, ethylene bisstearic acid amide, etc. These may be used alone, but it is preferable to use two or more kinds in combination because the slipperiness and blocking prevention effect can be maintained even in a harsh environment.

[0040] The lower limit of the content of the organic lubricant in the polyethylene resin composition constituting the A layer is preferably 0.16% by weight or more, preferably 0.18% by weight, more preferably 0.19% by weight, and particularly preferably 0.21% by weight. When it is 0.16% by weight or more, the slipperiness is likely to be stable immediately after film formation. The upper limit is preferably 0.3% by weight, more preferably 0.25% by weight. When it is 0.3% by weight or less, it does not slip too much and is less likely to turn white over time.

[0041] When inorganic particles are contained in the A layer, it is preferable that the average particle size is sufficiently smaller than the average particle size of the particles made of a polyethylene resin. Preferably, the average particle size of the inorganic particles is 50% or less of the average particle size of the particles made of a polyethylene resin, and it is preferable not to contain coarse particles having an average particle size of 2 times or more. In the polyethylene-based resin composition constituting the A layer, the content of inorganic particles is preferably 0.20% by weight or less, more preferably 0.10% by weight or less, still more preferably 0.05% by weight or less, and most preferably 0% by weight. By setting the content of inorganic particles to 0.20% by weight or less, not only the residue at the time of incineration is reduced, but also an effect close to the case of adding only particles made of polyethylene resin such as scratch resistance and non-drop-off of particles is easily obtained.

[0042] Even when adding inorganic particles, if the above particle size is added and the residue at the time of film incineration is 500 ppm or less, the incineration residue can be made extremely small compared to a film containing conventional inorganic particles when the film is incinerated. The inorganic particles referred to here are inorganic substances generally used as anti-blocking agents such as silica, talc, calcium carbonate, diatomaceous earth, zeolite, etc.

[0043] When the A layer contains crosslinked organic particles, it is preferable that the average particle size is sufficiently smaller than the average particle size of particles made of the polyethylene-based resin. Preferably, the average particle size of the crosslinked organic particles is 50% or less of the average particle size of the particles made of the polyethylene-based resin and preferably contains almost no coarse particles that are 2 times or more the average particle size. Yes. In the polyethylene-based resin composition constituting the A layer, the content of the crosslinked organic particles is preferably equal to or less than the same amount as the particles made of the polyethylene-based resin from the viewpoint of suppressing die meandering and cost. In the polyethylene-based resin composition constituting the A layer, as in the case of inorganic particles, in order to obtain the effect of adding particles made of polyethylene resin such as scratch resistance and non-drop-off of particles most effectively, it is most preferable not to contain crosslinked organic particles either. The crosslinked organic particles referred to here are organic crosslinked particles typified by polymethyl acrylate resin and the like.

[0044] (Polyethylene-based resin composition) The density range of the polyethylene-based resin composition constituting the A layer is 900 - 935 kg / m3 is preferable, and 910~933 kg / m 3 is more preferable, and 910~930 kg / m 3 is even more preferable, and 915~928 kg / m 3 is particularly preferable, and 915~925 kg / m 3 is particularly preferable. When the density is less than 900 kg / m 3 for the polyethylene resin, blocking resistance tends to decrease. When the density is 935 kg / m 3 or less, the polyethylene resin composition has a low heat seal start temperature, is easy to bag-make, and has excellent transparency. More importantly, when using a polyethylene resin with a density of 940 kg / m 3 or less, the polyethylene resin multilayer film is likely to obtain stable blocking resistance or stable slipperiness. The inventors have found that due to the synergistic effect of the organic lubricant contained in the polyethylene resin composition constituting the A layer and the surface protrusions composed of polyethylene resin particles, it is extremely excellent in scratch resistance.

[0045] Regarding the polyethylene resin composition, from the viewpoint of film-forming properties and the like, the melt flow rate (hereinafter sometimes referred to as MFR) is preferably about 2.5~4.5 g / min. Here, MFR was measured in accordance with ASTM D1893-67.

[0046] (Multilayer structure) The polyethylene resin film of the present invention may have a multilayer structure. In the case of a multilayer, in addition to the A layer, one or two or more other layers can be provided. As a specific method of such multilayer formation, a general multilayer device (such as a multilayer feed block, a static mixer, a multilayer multi-manifold, etc.) can be used. For example, a method of laminating thermoplastic resins sent from different flow paths using two or more extruders into multiple layers using a field block, a static mixer, a multi-manifold die, etc. can be used. Also, it is possible to introduce the above-mentioned multilayer device into the melt line from the extruder to the T-die using only one extruder.

[0047] In the case of a three-layer structure, it is preferable that the other layers be an intermediate layer (layer B) and a laminate layer (layer C), respectively, and be included in this order. In this case, the outermost layers are layer A and layer C, respectively.

[0048] Examples of the polyethylene-based resin used for the intermediate layer (layer B) and the laminate layer (layer C) include those obtained by mixing one or more selected from ethylene-α-olefin copolymers and high-pressure polyethylene. The above ethylene-α-olefin copolymer is a copolymer of ethylene and an α-olefin having 4 to 18 carbon atoms, and examples of the α-olefin include butene-1, hexene-1, 4-methylpentene-1, octene-1, and decene-1. The films obtained from these polyethylene-based resins have excellent heat seal strength, hot tack property, sealability for contaminants, and impact resistance. The polyethylene-based resin may be mixed with other resins, such as ethylene-vinyl acetate copolymer and ethylene-acrylic acid ester copolymer, as long as these properties are not impaired.

[0049] At this time, the polyethylene-based resins used for the intermediate layer (layer B) and the laminate layer (layer C) may be the same or different. Also, particles made of a polyethylene-based resin may or may not be added. However, since laminate floating is likely to occur if there are large-diameter particles such as coarse particles in the laminate layer, it is preferable not to add them.

[0050] In this case, it is preferable that the average density of the polyethylene resin composition constituting each layer of the film is A layer ≤ intermediate layer (layer B) ≤ laminate layer (layer C). Since the organic lubricant incorporated is less likely to move to the layer with a higher density, it is effective for maintaining the slipperiness of layer A after lamination or for maintaining the lamination strength over time.

[0051] At this time, the lower limit of the density of the polyethylene resin composition constituting the intermediate layer (layer B) is preferably 900 kg / m 3 and more preferably 920 kg / m3 and more preferably 930 kg / m 3 If the thickness is less than the above, the material may be weak and difficult to process. The upper limit of the density of the intermediate layer (B layer) is preferably 960 kg / m 3 and more preferably 940 kg / m 3 and more preferably 935 kg / m 3 is.

[0052] The polyethylene resin composition constituting the intermediate layer (layer B) of the polyethylene resin film of the present invention may contain the organic organic lubricant, and the lower limit of the organic organic lubricant is preferably 100 ppm. If the amount is less than the above, the slipperiness may be deteriorated. The upper limit of the organic lubricant in the polyethylene resin composition constituting the intermediate layer is preferably 2000 ppm, more preferably 1500 ppm. If the upper limit is exceeded, the film may become too slippery, causing slippage during winding or whitening over time.

[0053] The recovered resin may be blended in the intermediate layer (layer B) of the film of the present invention to an extent that does not impair the quality of the recovered resin.

[0054] In the present invention, it is preferable to subject the laminate layer (layer C) surface of the polyethylene resin film described above to actinic ray treatment such as corona treatment, which improves the laminate strength.

[0055] When the polyethylene resin film of the present invention is two-layered, it is preferable that layer A is a sealing layer and the other layer is a laminating layer (layer C).

[0056] (Three-dimensional surface roughness SRa) The three-dimensional surface roughness SRa of the seal layer of the polyethylene-based resin multilayer film of the present invention is preferably 0.05 μm or more. When SRa is 0.05 μm or more, excellent slip properties and blocking resistance are achieved. SRa is more preferably 0.07 μm or more, and particularly preferably 0.1 μm or more. The three-dimensional surface roughness SRa of the seal layer of the polyethylene-based resin multilayer film of the present invention is preferably 0.2 μm or less. When SRa is 0.2 μm or less, the transparency is less likely to decrease. It is more preferable that SRa is 0.18 μm or less. It is preferable that the particle size is 0.16 μm or less, and particularly preferable that the particle size is 0.16 μm or less. The measurement is carried out by the method described in the "Implementation" section. (Maximum protrusion height SRmax) The maximum projection height on at least one surface of Layer A of the polyethylene resin film of the present invention must be 2 μm or more and 15 μm or less. If the maximum projection height SRmax exceeds 15 μm, it will cause poor appearance, which is not preferable. The measurement method is the method described in the examples.

[0057] (Heat seal starting temperature) The upper limit of the heat-seal initiation temperature of the polyethylene resin film in a laminate obtained by laminating a biaxially oriented nylon film (15 μm) and a polyethylene resin film is preferably 140° C., more preferably 130° C. If the temperature exceeds the above range, sealing may become difficult.

[0058] (achieved heat seal strength) The lower limit of the heat seal strength that can be achieved by the polyethylene resin film of a laminate obtained by laminating a biaxially oriented nylon film (15 μm) and a polyethylene resin film at 150° C. is preferably 30 N / 15 mm, more preferably 35 N / 15 mm. If it is less than this, the bag may be prone to tearing after bag formation. The upper limit of the heat seal strength at 150°C of the polyethylene resin film of a laminate obtained by laminating a biaxially oriented nylon film (15 μm) and a polyethylene resin film is preferably approximately the same as the breaking strength of the laminated nylon. When the breaking strength is equal to that of the nylon, it means that the lamination strength is sufficiently high and the peel strength of the seal interface is also sufficiently high. The measurement method is the method described in the Examples.

[0059] (Blocking strength) The blocking strength of the polyethylene resin film in a laminate obtained by laminating a biaxially oriented nylon film (15 μm) and a polyethylene resin film is preferably as low as possible, more preferably 200 mN / 70 mm or less, and even more preferably 150 mN / 70 mm. If it exceeds the above range, the powder-free properties and the ease of opening the bag will not be sufficient. The measurement method is as described in the Examples.

[0060] (coefficient of friction) The lower limit of the static friction coefficient of the polyethylene resin film in the laminate obtained by laminating a biaxially oriented nylon film (15 μm) and a polyethylene resin film is preferably 0.05, more preferably 0.08. If it is less than the above, the film may slip too much during winding, which may cause misalignment of the film. The upper limit of the static friction coefficient after lamination is preferably 0.70, more preferably 0.5. If it exceeds this limit, the opening properties of the bag after it is made and the filling properties of the contents may be poor, and loss during processing may increase. The measurement is carried out by the method described in the Examples.

[0061] (Hayes) The lower limit of the haze of the polyethylene resin film of the present invention is preferably 3%, more preferably 4%, and even more preferably 5%. If the haze is less than the above, the antiblocking agent may not be present on the surface sufficiently, which may cause blocking. The upper limit of haze is preferably 18%, more preferably 16%, and even more preferably 13%. If the haze exceeds the upper limit, it may become difficult to see the contents. The measurement method is the method described in the examples.

[0062] (Flickering) It is preferable that the polyethylene resin film of the present invention exhibits almost no flickering or exhibits fine flickering that is uniform and not particularly bothersome. The measurement method is the method described in the Examples. So-called non-powder types, which have blocking resistance without sprinkling powder such as starch on the film surface, have traditionally contained inorganic particles with an average particle size of about 10 μm, but these often contain coarse particles and are prone to flickering and poor transparency.

[0063] (scratch resistance) A laminate obtained by laminating a biaxially oriented nylon film (15 μm) and a polyethylene resin film has a haze change of preferably 3% or less, more preferably 2% or less, even more preferably 1% or less, and particularly preferably 0.5% or less, even after the polyethylene resin film surfaces are rubbed together. The measurement method is the same as that described in the examples. Conventional non-powder types have blocking resistance without sprinkling powder such as starch on the film surface, and some have added inorganic particles with an average particle size of about 10 μm. However, because inorganic particles are much harder than polyethylene resin, scratch resistance tends to be poor even when sufficient organic lubricant is present on the film surface.

[0064] (Young's modulus) The lower limit of the Young's modulus (MD) of the polyethylene resin film of the present invention is preferably 60 MPa, more preferably 70 MPa. If it is less than this, the film may be too weak and difficult to process. The upper limit of the Young's modulus (MD) is preferably 600 MPa, more preferably 500 MPa.

[0065] The lower limit of the Young's modulus (TD) of the polyethylene resin film of the present invention is preferably 60 MPa, more preferably 70 MPa. If it is less than this, the film may be too weak and difficult to process. The upper limit of the Young's modulus (TD) is preferably 600 MPa, more preferably 500 MPa.

[0066] (Laminate) The polyethylene-based resin multilayer film of the present invention can also be used as a packaging film or a packaging sheet in a laminate configuration in which at least one other substrate film is further laminated. The substrate film is not particularly limited, and examples thereof include polyolefin films such as polyethylene and polypropylene, styrene resin films, polyester films such as polyethylene terephthalate and polybutylene terephthalate, polyamide films such as nylon 6 and nylon 6,6, or stretched films thereof, laminated films of polyolefin films and gas-barrier resin films such as polyamide films or ethylene-vinyl alcohol copolymer films, and, if necessary, metal foils such as aluminum, or vapor-deposited films or paper on which aluminum, silica, etc. are vapor-deposited, and are appropriately selected and used depending on the intended use of the laminate. These substrate films can be used alone or in combination of two or more types.

[0067] In this case, it is preferable to have the substrate film adjacent to the laminate layer side of the polyethylene-based resin multilayer film.

[0068] A method for laminating the polyethylene-based resin multilayer film onto the above-mentioned substrate film can be adopted, which involves dry laminating the substrate film and the polyethylene-based resin multilayer film. In this case, the structure can be polyethylene-based resin multilayer film / adhesive layer / other substrate film. For the adhesive layer, an anchor coating agent such as a urethane-based or isocyanate-based adhesive can be used, or a modified polyolefin such as an unsaturated carboxylic acid-grafted polyolefin can be used as the adhesive resin, thereby enabling strong bonding of adjacent layers.

[0069] There are no particular restrictions on the thickness of the laminate, but when the laminate is used as a film for a lid or the like, it is preferably 10 to 200 μm, and when it is used as a sheet for cups or trays, it is preferably 200 to 1000 μm.

[0070] (packaging) The seal layer surfaces of the sealant film of the above-described laminate are faced to each other, or the seal layer surface of the sealant film layer of the laminate is faced to another base film, and then at least a part of the periphery thereof is heat-sealed from the laminate layer side so as to have a desired container shape, whereby a container can be manufactured. Further, by heat-sealing the entire periphery, a sealed bag-shaped container can be manufactured. When the forming process of this bag-shaped container is combined with the filling process of the content, that is, after heat-sealing the bottom and side portions of the bag-shaped container, the content is filled, and then the upper portion is heat-sealed, a package can be manufactured. Therefore, this laminate can be used for an automatic packaging apparatus for solid substances such as snack foods, powders, or liquid materials.

[0071] Further, a container obtained by filling a container formed into a cup shape by vacuum forming or pressure air forming, a container obtained by injection molding or blow molding, or a container formed from a paper base material with a content, and then covering the laminate of the present invention as a lid material and heat-sealing it also provides a container in which the content is packaged.

Example

[0072] Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not particularly limited by the following examples. The detailed description of the present invention and the measured values of each item in the examples were measured by the following methods.

[0073] Hereinafter, embodiments of the present invention will be described in detail. (1) Method for measuring particles made of a polyethylene-based resin For particles made of a polyethylene-based resin, each physical property of the raw material resin before processing was measured. Even after film formation, it is also possible to separate and measure particles made of a polyethylene-based resin by a method such as completely dissolving them in decane to the particles and then separating the high molecular weight portion by GPC or the like.

[0074] (2) The viscosity average molecular weight of the particles made of polyethylene resin was measured in accordance with ASTM-D4020.

[0075] (3) The average particle diameter of the particles made of polyethylene resin The average particle diameter of the particles made of polyethylene resin before use was measured as follows. The particles were dispersed in ion-exchanged water stirred at a predetermined rotational speed (about 5000 rpm) using a stirrer, and the dispersion was added to isotonic (physiological saline) and further dispersed with an ultrasonic disperser. Then, the particle size distribution was determined by the Coulter counter method and calculated as the average particle diameter.

[0076] (4) The particle size distribution of the particles made of polyethylene resin The ratio of particles with a particle diameter of 30 μm or more among the particles made of polyethylene resin before use was calculated from the particle size distribution determined by the Coulter counter method.

[0077] (5) The melting point of the particles made of polyethylene resin The melting point of the particles made of polyethylene resin before use was measured using a differential scanning calorimeter (DSC) manufactured by SII, with a sample amount of 10 mg and a heating rate of 10 °C / min. The melting endothermic peak temperature detected here was taken as the melting point.

[0078] (6) The density, MFR, and melting point of polyethylene resins other than the particles made of polyethylene resin The raw materials before film formation were measured by the following methods respectively. In addition, for the polyethylene resin forming the layer containing particles made of polyethylene resin, if it is a single layer, the entire layer; if it is a laminate, after confirming the layer structure with an electron microscope or the like, the surface was shaved off with a thickness less than that of the surface layer, and the solvent was removed from the filtered solution obtained in (1) above, and the measurement can be carried out in the same manner. When shaving from a laminate, it can be done by laminating on a PET film or the like and then shaving off the surface layer with a razor or the like.

[0079] (Density) It was measured by the density gradient tube method in accordance with JIS-K7112.

[0080] (Melt flow rate: MFR) (g / 10 min) Measurement was carried out at a temperature of 190°C in accordance with JIS-K7210.

[0081] (Melting Point) Measurement was performed using a differential scanning calorimeter (DSC) manufactured by SII, with a sample weight of 10 mg and a heating rate of 10° C. / min. The detected melting endothermic peak temperature was taken as the melting point.

[0082] (7) Content (wt%) of inorganic particles in the resin composition The content of inorganic particles in the resin composition was calculated from the amount added in the raw material resin composition before processing. Even after film formation, inorganic particles can be separated and measured by dissolving the film in decane as a solvent at a temperature at which the film completely dissolves, and then filtering the residue with a filter with a filtering accuracy of 1 to 2 μm.

[0083] (8) Amount of residue after incineration of film (ppm) Approximately 30 g of film was weighed to the first decimal place using a precision balance (rounded to the second decimal place). The crucible was pre-baked at 700°C for 1 hour, and after it had cooled to below 100°C, it was seasoned in a glass desiccator until it reached room temperature, and the weight of the crucible was then measured. The film was then placed in the crucible and incinerated in an electric furnace at 700°C for 2 hours. After turning off the heater, the temperature was allowed to cool to around 100°C, and the crucible was transferred to a glass desiccator and seasoned for 30 minutes until it reached room temperature. The difference in the crucible weight before and after incineration was then divided by the film weight to calculate the residue amount.

[0084] (9) Filter pressure increase (film forming processability) The resin composition used in the sealing layer of Comparative Example 1 was passed through a Naslon sintered filter with a filtration accuracy of 120 μm using a Troughton testing machine at a resin temperature of 230°C, and discharged at a rate of 1 kg / hour over a filtration area of 81π square millimeters for 5 hours. The amount of pressure rise (ΔMPa) was used as the standard (△), and the results were classified as ◎, ○, △, or × as follows. ⊚: The amount of pressure increase is 5% or less of the amount at the start of extrusion. ◯: The amount of pressure increase is 10% or less of that at the start of extrusion. △: The amount of pressure increase is 15% or less of that at the start of extrusion. ×: The amount of pressure increase is 20% or less of that at the start of extrusion.

[0085] (10) Lip staining (film forming processability) The resin composition used for the sealing layer was extruded at 230°C for 5 hours using an extruder with a strand die (2 holes, 5 mm diameter) at a discharge rate of 20 kg / hour. The lip staining was visually observed, and the results were classified as ◎, ○, △, or × using the criterion (△). ◎: Almost no lip stains can be seen. ○: Slight lip staining is observed. △: Lip stains are clearly visible. ×: Lip stains grew and streaky depressions appeared in the strands.

[0086] (11) Three-dimensional surface roughness SRa In accordance with JIS B0601-1994, a contact surface roughness tester (manufactured by Kosaka Laboratory, model ET4000A) was used to measure 100 randomly selected measurement areas of 1 mm x 0.2 mm from a 3 cm x 3 cm square film piece, with a low-frequency cutoff λs of 0.08 mm, a length of 1000 μm, and a pitch of 2 μm. From the obtained cross-sectional curve, the three-dimensional surface roughness SRa of the seal layer surface of the polyethylene resin multilayer film was calculated using the three-dimensional surface roughness analysis program TDA-22 in accordance with JIS B0601-1994. Measurements were carried out using the above method with n=3, and the average value of the three-dimensional surface roughness SRx was calculated.

[0087] (12) Maximum projection height SRmax In accordance with JIS B0601-1994, a contact surface roughness tester (manufactured by Kosaka Laboratory, model ET4000A) was used to measure 100 randomly selected measurement areas of 1 mm x 0.2 mm from a 3 cm x 3 cm square film piece, with a low-frequency cutoff λs of 0.08 mm, a length of 1000 μm, and a pitch of 2 μm. Using the three-dimensional surface roughness analysis program TDA-22 based on the obtained cross-sectional curve, in accordance with JIS B0601-1994, the maximum protrusion height SRmax was calculated. In the above method, the measurement was carried out with n = 3, and the average value of the maximum protrusion height SRmax was obtained.

[0088] (13) Heat seal start temperature (°C) An adhesive for dry lamination (TM569, CAT-10L) manufactured by Toyo Morton was applied to the corona surface of a nylon film (biaxially stretched nylon film manufactured by Toyobo: N1100, 15 μm) so that the solid content was 3 g / m2, and after removing the solvent by volatilization in an oven at 80 °C, the corona surface of the polyethylene resin film and the coated surface of the adhesive were nipped and laminated on a temperature-controlled roll at 60 °C. The laminated film after lamination was aged at 40 °C for 2 days. Heat sealing was performed on the prepared laminated sample at a seal pressure of 0.1 MPa, a seal time of 0.5 seconds, and a seal temperature of 90 to 160 °C at a 10 °C pitch and a width of 10 mm. The heat-sealed sample was cut into strips so that the heat-seal width became 15 mm, set on an autograph (model: UA-3122 manufactured by Shimadzu Corporation), and the maximum value of the strength of peeling the seal surface at a speed of 200 mm / min was measured with n = 3. The heat-seal strength and the heat-seal temperature at each temperature were plotted. The heat-seal temperature at which it became 4.9 N / 15 mm was read from the graph connecting the plots with a straight line and taken as the heat-seal start temperature.

[0089] (14) Reached heat-seal strength (N / 15 mm) An adhesive for dry lamination (TM569, CAT-10L) manufactured by Toyo Morton was applied to the corona surface of a nylon film (biaxially stretched nylon film manufactured by Toyobo: N1100, 15 μm) so that the solid content was 3 g / m 2It was applied so as to become, and after removing the solvent by volatilization in an oven at 80°C, the corona surface of the polyethylene resin film and the coated surface of the adhesive were nipped and laminated on a temperature-controlled roll at 60°C. The laminated film obtained by lamination was aged at 40°C for 2 days. A heat seal with a seal pressure of 0.1 MPa, a seal time of 0.5 seconds, and a seal temperature of 120 to 190°C at a 10°C pitch and a width of 10 mm was performed on the produced laminated sample. The heat-sealed sample was cut into strips so that the heat-seal width became 15 mm, set on an autograph (Model: UA-3122, manufactured by Shimadzu Corporation), and the maximum value of the strength at which the seal surface was peeled at a speed of 200 mm / min was measured with n = 3, and the heat-seal strength with the highest average value was taken as the achieved seal strength.

[0090] (15) Blocking strength (mN / 70 mm) A laminated film with a nylon film (biaxially oriented nylon film: N1100, 15 μm, manufactured by Toyobo Co., Ltd.) was produced as follows. On the corona surface of the nylon film, an adhesive for dry lamination (TM569, CAT-10L, manufactured by Toyo Morton) was applied so that the solid content was 3 g / m 2 It was applied so as to become, and after removing the solvent by volatilization in an oven at 80°C, the corona surface of the polyethylene resin film and the coated surface of the adhesive were nipped and laminated on a temperature-controlled roll at 60°C. The laminated film obtained by lamination was aged at 40°C for 2 days. A sample (10 cm × 15 cm) with the A-layer surfaces overlapped was placed on a heat press (manufactured by Tester Sangyo Co., Ltd., Model: SA-303) such that the edge of an aluminum plate (2 mm thick) with a size of 7 cm × 7 cm was placed at a position 1 cm inside in the longitudinal direction (15 cm) at the center of the sample width (10 cm). A pressure treatment was performed at a temperature of 50°C, a gauge pressure of 18 MPa, and a time of 15 minutes. The sample blocked by this pressure treatment and a bar (diameter 6 mm, material: aluminum) were attached to an autograph (Model: UA-3122, manufactured by Shimadzu Corporation), and the force when the bar peeled the blocking part at a speed (200 m / min) was measured. In this case, it is assumed that the bar and the peeling surface are horizontal. Four measurements were made for the same sample and the average value was shown.

[0091] (16) Coefficient of static friction A laminated film with a nylon film (biaxially stretched nylon film manufactured by Toyobo Co., Ltd.: N1100, 15 μm) was prepared as follows. An adhesive for dry lamination (TM569, CAT-10L) manufactured by Toyo Morton was applied to the corona-treated surface of the nylon film so that the solid content was 3 g / m 2 . After the solvent was volatilized and removed in an oven at 80°C, the corona-treated surface of the polyethylene resin film and the adhesive-coated surface were nipped and laminated on a temperature-controlled roll at 60°C. The laminated film was aged at 40°C for 2 days. The coefficient of static friction between the surfaces of the polyethylene resin films of the prepared laminated film was measured in an environment of 23°C and 65% RH in accordance with JIS-K-7125.

[0092] (17) Haze Only the polyethylene resin film was measured using a direct-reading haze meter manufactured by Toyo Seiki Seisaku-sho, Ltd. in accordance with JIS-K-7105. Haze (%) = [Td (diffuse transmittance %) / Tt (total light transmittance %)] x 100

[0093] (18) Feeling of unevenness Only the polyethylene resin film was visually observed, and the feeling of unevenness was classified into the following ◎, ○, △, ×. ◎: Almost no bright spots are felt. ○: There are fine bright spots but they are uniform and not particularly noticeable. △: There are bright spots partially and a feeling of foreign matter is felt. ×: There are bright spots all over the surface and the transparency is impaired.

[0094] (19) Scratch resistance (mechanical evaluation) The scratch resistance was determined by the amount of change in haze after 40 rubs with a load of 200 g, with the seal surfaces of the films set against each other on a Kagayama Seiki Co., Ltd. friction tester for academic research (Friction Tester II with a 20×20 mm flat friction element, a 100 mm sliding arc length on the test piece table). The haze measurement was taken at the center of the film (width × length = 30 mm × 180 mm, 50×50 mm for the flat friction element) on the friction table before being set on the friction table, and the haze at the same position before and after friction was measured and the difference was obtained. The haze measurement was taken at the center of the film (width × length = 30 mm × 180 mm, 50×50 mm for the flat friction element) on the friction table before being set on the friction table, and the haze at the same position before and after friction was measured and the difference was obtained.

[0095] (20) Scratch resistance (visual evaluation) A laminated film with a nylon film (biaxially stretched nylon film manufactured by Toyobo Co., Ltd.: N1100, 15 μm) was prepared as follows. An adhesive for dry lamination (TM569, CAT-10L) manufactured by Toyo Morton was applied to the corona-treated surface of the nylon film so that the solid content was 3 g / m 2 After applying and then removing the solvent by volatilization in an 80°C oven, the corona-treated surface of the polyethylene resin film and the adhesive-coated surface were nipped and laminated on a temperature-controlled roll at 60°C. The laminated film was aged at 40°C for 2 days. The polyethylene resin film surfaces of the prepared laminated film were pinched with fingers so that they overlapped and rubbed 10 times, and then visually observed, and the ease of scratching was classified with ◎, ○, △, × as follows. ◎: Almost no scratches. ○: Thin streak-like scratches appear but no whitening. △: Thin streak-like densification and partial whitening are observed. ×: The rubbed area almost whitens.

[0096] Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples. The following raw materials were used in the Examples and Comparative Examples. (Polyethylene resin) (1) Ube Mitsui Polyethylene Co., Ltd.'s Yumelite (registered trademark) 0540F (metallocene linear low-density polyethylene, density 904 kg / m 3, MFR 4.0g / 10min, melting point 111℃) (2) Sumikathene (registered trademark) E FV402 manufactured by Sumitomo Chemical Co., Ltd. (metallocene catalyst-based LLDPE, density: 913 kg / m 3 , MFR: 3.8g / 10min, Melting point: 115℃) (3) Sumikathene (registered trademark) E FV405 (metallocene catalyst-based LLDPE, density: 923 kg / m) manufactured by Sumitomo Chemical Co., Ltd. 3 , MFR: 3.8g / 10min, Melting point: 118℃) (4) Sumikathene (registered trademark) E FV407 (metallocene catalyst-based LLDPE, density: 930 kg / m) manufactured by Sumitomo Chemical Co., Ltd. 3 , MFR: 3.2g / 10min, Melting point: 124℃) (5) Ube Maruzen Polyethylene Co., Ltd. Umerit (registered trademark) 3540FC (metallocene catalyst-based LLDPE, density: 931 kg / m 3 , MFR: 3.6g / 10min, Melting point: 123℃) (6) Ube Maruzen Polyethylene Co., Ltd. Umerit (registered trademark) 4540F (metallocene catalyst-based LLDPE, density: 944 kg / m 3 , MFR: 4.0g / 10min, Melting point: 128℃)

[0097] (Particles made of polyethylene resin) (1) Mipelon PM200 (average particle size 10 μm, melting point 136°C, density 940 kg / m), manufactured by Mitsui Chemicals, Inc. 3 , viscosity average molecular weight 1.8 million, over 30 μm 0% of particles of this size, resin hardness D65, ultra-high molecular weight polyethylene particles) (2) Mipelon XM221U (average particle size 25 μm, melting point 136, density 940 kg / m), manufactured by Mitsui Chemicals, Inc. 3 , viscosity average molecular weight 2 million, percentage of particles with a diameter of more than 30 μm is 25%, resin hardness D65, ultra-high molecular weight polyethylene particles)

[0098] (Inorganic particles) (1) Grefco, Inc., Dicalite WF (diatomaceous earth, processed to an average particle size of 5 μm using a pin mill) (2) A masterbatch was prepared and used by mixing Sumitomo Chemical's FV402 with 15% MB based on spherical silica particles (KMP-130-10, average particle size 10 μm) manufactured by Shin-Etsu Silicone Co., Ltd.

[0099] (Masterbatch) (1) A masterbatch (1) containing 15 wt% of Mipelon PM200 was prepared by mixing Mipelon PM200 with Sumitomo Chemical's Sumikasen (registered trademark) E FV405. (2) A masterbatch (2) containing 15 wt% of Mipelon XM221U was prepared by mixing Mipelon XM221U with Sumitomo Chemical's Sumikasen (registered trademark) E FV405. (3) A masterbatch (3) containing 20 wt% of Dicellite WF manufactured by Grefco, Inc. was prepared by mixing Dicellite WF manufactured by Grefco, Inc. with Sumitomo Chemical's Sumikasen (registered trademark) E FV405. (4) A masterbatch (4) containing 15 wt% of KMP-130-10 manufactured by Shin-Etsu Silicone Co., Ltd. was prepared by mixing KMP-130-10 manufactured by Shin-Etsu Silicone Co., Ltd. with Sumitomo Chemical's Sumikasen (registered trademark) E FV405. (5) A masterbatch (5) containing 4 wt% of erucic acid amide was prepared by mixing erucic acid amide with Sumitomo Chemical's Sumikasen (registered trademark) E FV402. (6) A masterbatch (6) containing 2 wt% of ethylene bisoleic acid amide was prepared by mixing ethylene bisoleic acid amide with Sumitomo Chemical's Sumikasen (registered trademark) E FV402.

[0100] (Example 1) [Composition for seal layer] A composition for the seal layer was prepared using a composition obtained by mixing 86.25 wt% of Yumelite (registered trademark) 0540F manufactured by Ube Maruzen Polyethylene Co., Ltd., 4 wt% of masterbatch (1), 1.25 wt% of masterbatch (5), and 8.5 wt% of masterbatch (6). [Composition for laminate layer] A composition for the laminate layer was prepared using only Sumitomo Chemical's FV402. [Composition for intermediate layer] A composition for the intermediate layer was prepared using a composition obtained by mixing 99.4% by weight of FV402 manufactured by Sumitomo Chemical Co., Ltd., 0.5% by weight of masterbatch (5), and 0.1% by weight of masterbatch (6). The composition for the laminate layer, the composition for the intermediate layer, and the composition for the seal layer were melt-extruded at 240°C using an extruder equipped with a T-die in the order of the composition for the laminate layer, the composition for the intermediate layer, and the composition for the seal layer, and such that the thickness ratio of the laminate layer, the intermediate layer, and the seal layer was 8:34:8. Subsequently, a corona discharge treatment was performed on the surface of the laminate layer. Then, it was wound around a roll at a speed of 150 m / min to obtain a polyethylene-based resin multilayer film with a thickness of 50 μm and a wetting tension of the treated surface of 45 mN / m.

[0101] (Example 2) In the seal layer, 86% by weight of Sumicasen (registered trademark) E FV402 manufactured by Sumitomo Chemical Co., Ltd., 4% by weight of masterbatch (1), 1.50% by weight of masterbatch (5), and 8.5% by weight of masterbatch (6) were mixed. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1 except that only Sumicasen (registered trademark) E FV405 manufactured by Sumitomo Chemical Co., Ltd. was used instead.

[0102] (Example 3) In the seal layer, 87.75% by weight of Sumicasen (registered trademark) E FV405 manufactured by Sumitomo Chemical Co., Ltd., 4% by weight of masterbatch (1), 1.25% by weight of masterbatch (5), and 7% by weight of masterbatch (6) were mixed. In the intermediate layer, Sumicasen (registered trademark) E FV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Sumicasen (registered trademark) E FV405 manufactured by Sumitomo Chemical Co., Ltd. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1 except that only Sumicasen (registered trademark) E FV407 manufactured by Sumitomo Chemical Co., Ltd. was used instead.

[0103] (Example 4) In the seal layer, 84.75 wt% of Sumikaexcel (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd., 8 wt% of masterbatch (1), 1.25 wt% of masterbatch (5), and 6 wt% of masterbatch (6) were mixed. In the intermediate layer, Sumikaexcel (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Sumikaexcel (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1, except that only Sumikaexcel (registered trademark) EFV407 manufactured by Sumitomo Chemical Co., Ltd. was used.

[0104] (Example 5) In the seal layer, 86.75 wt% of Yumelite (registered trademark) 3540F manufactured by Ube Maruzen Polyethylene Co., Ltd., 4 wt% of masterbatch (1), 1.75 wt% of masterbatch (5), and 7.5 wt% of masterbatch (6) were mixed. In the intermediate layer, Sumikaexcel (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Yumelite (registered trademark) 3540F manufactured by Ube Maruzen Polyethylene Co., Ltd. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1, except that only Yumelite (registered trademark) 3540F manufactured by Ube Maruzen Polyethylene Co., Ltd. was used.

[0105] (Example 6) In the seal layer, 86.75 wt% of Sumikaexcel (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd., 4 wt% of masterbatch (1), 0.5 wt% of masterbatch (3), 1.25 wt% of masterbatch (5), and 7.5 wt% of masterbatch (6) were mixed. In the intermediate layer, Sumikaexcel (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Sumikaexcel (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1, except that only Sumikaexcel (registered trademark) EFV407 manufactured by Sumitomo Chemical Co., Ltd. was used.

[0106] (Example 7) In the seal layer, 87.25 wt% of Sumikaexcel (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd., 4 wt% of masterbatch (1), 1.25 wt% of masterbatch (5), and 7.5 wt% of masterbatch (6) were mixed. In the intermediate layer, Sumikaexcel (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Sumikaexcel (registered trademark) EFV405. In the laminate layer, a polyethylene resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1, except that only Sumikaexcel (registered trademark) EFV407 manufactured by Sumitomo Chemical Co., Ltd. was used.

[0107] The polyethylene resin films obtained in Examples 1 to 7 contained almost no inorganic particles larger than the particle size of the particles composed of the polyethylene resin, so they were excellent in scratch resistance, low-temperature heat sealability, antiblocking property, slipperiness, and appearance. Moreover, the residue at the time of film incineration was extremely small, and the film-forming processability was also excellent, such as almost no meandering or filter pressure increase.

[0108] (Comparative Example 1) In the seal layer, 82.25 wt% of Sumikaexcel (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd., 2.5 wt% of masterbatch (3), 8 wt% of masterbatch (4), 1.25 wt% of masterbatch (5), and 6 wt% of masterbatch (6) were mixed. In the intermediate layer, Sumikaexcel (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Sumikaexcel (registered trademark) EFV405. In the laminate layer, a polyethylene resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1, except that only Sumikaexcel (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd. was used. The film obtained in Comparative Example 1 was excellent in antiblocking property and slipperiness, had a slightly uneven feeling, had a large amount of inorganic residue after incineration, was particularly inferior in scratch resistance, and was also slightly inferior in film-forming processability.

[0109] (Comparative Example 2) In the seal layer, 90.25% by weight of Sumikasen (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd., 2.5% by weight of masterbatch (3), 1.25% by weight of masterbatch (5), and 6% by weight of masterbatch (6) were mixed. In the intermediate layer, Sumikasen (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Sumikasen (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1 except that only Sumikasen (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd. was used. The film obtained in Comparative Example 2 had relatively few residues and excellent non-uniformity, but was inferior in blocking resistance, scratch resistance, and slipperiness.

[0110] (Comparative Example 3) In the seal layer, 87.75% by weight of Sumikasen (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd., 1% by weight of masterbatch (1), 2.5% by weight of masterbatch (3), 1.25% by weight of masterbatch (5), and 7.5% by weight of masterbatch (6) were mixed. In the intermediate layer, Sumikasen (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Sumikasen (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1 except that only Sumikasen (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd. was used. The film obtained in Comparative Example 3 had relatively few residues and was slightly superior in scratch resistance, but had few protrusions and was inferior in blocking resistance.

[0111] (Comparative Example 4) In the seal layer, 87.25% by weight of Yumebutano Polyethylene Co., Ltd.'s Yumelite (registered trademark) 4540F, 4% by weight of masterbatch (1), 1.25% by weight of masterbatch (5), and 7.5% by weight of masterbatch (6) were mixed. In the intermediate layer, Sumika Sen (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Yumebutano Polyethylene Co., Ltd.'s Yumelite (registered trademark) 4540F. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1 except that only Yumebutano Polyethylene Co., Ltd.'s Yumelite (registered trademark) 4540F was used. The film obtained in Comparative Example 4 had relatively few residues and excellent scratch resistance. However, due to the high resin density, the surface protrusions caused by polyethylene-based particles were not stable, and the antiblocking property and slipperiness were not sufficient, and there was also a large variation.

[0112] (Comparative Example 5) In the seal layer, 87.25% by weight of Sumika Sen (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd., 4% by weight of masterbatch (2), 1.25% by weight of masterbatch (5), and 7.5% by weight of masterbatch (6) were mixed. In the intermediate layer, Sumika Sen (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd. was changed to Sumika Sen (registered trademark) EFV405 manufactured by Sumitomo Chemical Co., Ltd. In the laminate layer, a polyethylene-based resin multilayer film and a vapor-deposited film were obtained in the same manner as in Example 1 except that only Sumika Sen (registered trademark) EFV407 manufactured by Sumitomo Chemical Co., Ltd. was used. The film obtained in Comparative Example 5 had few residues and excellent scratch resistance. However, even though the addition amount was large, the particle size was large, so the protrusion density was low, and the antiblocking property and unevenness feeling were inferior.

[0113] (Comparative Example 6) In the seal layer, a composition was prepared by mixing 86.25% by weight of Yumelite (registered trademark) 0540F manufactured by Ube Maruzen Polyethylene Co., Ltd., 4% by weight of masterbatch (1), 1.25% by weight of masterbatch (5), and 5.0% by weight of masterbatch (6). A polyethylene resin multilayer film and a vapor deposition film were obtained in the same manner as in Example 1 except that the composition for the seal layer was used.

[0114] (Comparative Example 7) In the seal layer, a composition was prepared by mixing 95.90% by weight of Sumikasen (registered trademark) EFV402 manufactured by Sumitomo Chemical Co., Ltd., 4% by weight of masterbatch (1), 1.25% by weight of masterbatch (5), and 5.0% by weight of masterbatch (6). A polyethylene resin multilayer film and a vapor deposition film were obtained in the same manner as in Example 2 except that the composition for the seal layer was used.

[0115] The results are shown in Tables 1 and 2.

[0116]

Table 1

[0117]

Table 2

[0118] As described above, the polyethylene resin film of the present invention has been described based on a plurality of examples. However, the present invention is not limited to the configurations described in the above examples, and the configuration can be appropriately changed without departing from the gist thereof, such as appropriately combining the configurations described in each example.

Industrial Applicability

[0119] The polyethylene resin film described in the present invention has excellent properties and can be suitably used for films for a wide range of applications such as food packaging.

Claims

1. It has at least an A layer made of a polyethylene-based resin composition, and the polyethylene-based resin composition constituting the A layer satisfies the following 1) to 3): and a polyethylene-based resin film in which at least one surface of the A layer satisfies both the following 4) and 5). 1) It contains 90% by weight or more of a polyethylene-based resin having a density of 900 kg / m ３ or more and 935 kg / m ３ or less. 2) It contains particles made of a polyethylene-based resin having an average particle size of 5 to 20 μm. 3) The content of the organic lubricant is 0.16% by weight or more. 4) The three-dimensional surface roughness SRa is 0.05 to 0.2 μm. 5) The maximum peak height SRmax is 2 to 15 μm.

2. The polyethylene-based resin film according to Claim 1, wherein the resin hardness of the particles made of the polyethylene-based resin is D70 or less.

3. The polyethylene-based resin film according to Claim 1 or 2, wherein the viscosity-average molecular weight of the particles made of the polyethylene-based resin is 1.5 million or more.

4. The polyethylene-based resin film according to Claim 1 or 2, wherein the content of the particles of the polyethylene-based resin in the polyethylene-based resin composition constituting the A layer is 0.2 to 2.0% by mass.

5. The polyethylene-based resin film according to Claim 1 or 2, wherein the blocking value between the surfaces of the A layer is 200 mN / 70 mm or less.

6. The polyethylene-based resin film according to Claim 1 or 2, wherein the amount of change in haze after 100 abrasions with a load of 200 g when the surfaces of the A layer are set on a Gakushin type abrasion tester manufactured by Yasuda Seiki Co., Ltd. is 3% or less.

7. A laminate including the polyethylene-based resin film according to any one of Claims 1 to 6 and a base film made of a thermoplastic resin composition.

8. A packaging bag including the laminate according to Claim 7.

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