KR20080022133A - Polyethylene resin laminate film - Google Patents

Abstract

[PROBLEMS] To provide a polyethylene resin laminate film, more specifically a polyethylene resin film having a good balance of heat-sealing property and stiffness of the film, having less fish-eyes, having little fisheyes and also having less unevenness in thickness. [MEANS FOR SOLVING PROBLEMS] A polyethylene resin laminate film having at least a laminate layer (A) and a seal layer (B), the laminate layer (A) comprising at least two polyethylene resins each having a density of 900 to 970 kg/m^3 and a molecular weight distribution (Mw/Mn) of 2. 0 to 3.5, the densities of the at least two polyethylene resins being different from each other, the average density of the laminate layer being 920 to 945 kg/m^3, the seal layer (B) comprising a polyethylene resin having a density of 900 to 930 kg/m^3, and the average density of the laminate layer (A) being larger than that of the seal layer (B). ® KIPO & WIPO 2008

Description

Polyethylene-based resin laminated film {POLYETHYLENE RESIN LAMINATE FILM}

The present invention relates to a polyethylene-based resin laminated film. More specifically, the present invention relates to a polyethylene-based resin laminated film which can not only balance heat sealability, blocking resistance and film stiffness, but also has fewer fish eyes and less thickness unevenness of the film.

Moreover, this invention relates to the polyethylene-type resin laminated film for freestanding containers. More specifically, the present invention relates to a polyethylene-based resin laminated film for a self-supporting container which can not only balance heat sealability, blocking resistance and film rigidity, but also has fewer fish eyes and less thickness unevenness of the film.

Since a polyethylene resin film is excellent in heat sealing property and impact resistance, it is used widely for packaging and containers, such as foodstuffs and daily necessities.

Recently, packaging or containers using films have been used in a wide range of fields due to convenience, resource saving, and environmental load reduction. Compared with conventional molding containers such as blow molding bottles, there is an advantage that the weight is light, the waste disposal is easy, and the distribution cost is low.

In a heat-sealing polyethylene resin film, a laminated polyethylene non-oriented film in which heat sealing and blocking resistance are balanced is disclosed (for example, see Patent Document 1 below).

Patent Document 1: Japanese Patent No. 3291969

In recent years, while the consumer's safety orientation has been strengthened, the market demand for foreign matters contained in the film has also been strict in the heat-sealing polyethylene resin film.

For example, even if it is not noticeable in a normal state such as when used as an inner layer material of a carton, the pack is ruptured at the time of collection so that it is noticeable to the consumer, causing anxiety about safety. This is happening. Moreover, when used as a transparent packaging bag, the fish eye which is a lump, such as a small spherical shape which arises in the product of a film, may stand out as a foreign material according to the color and shape of a content. These market demands require strict management. Particularly, since the fish eye is mainly composed of polymer insoluble matter or gelled material, in the method of filtration using a filter in a film forming process effective as a measure for reducing foreign matter content, the component forming the fish eye is filtered. May be deformed to pass through the filter, and may not be an effective means.

In addition, the stringency of the market demand for the thickness nonuniformity of the film is increasing also about the heat-sealing film in recent years. If the thickness nonuniformity of a film becomes large, the thickness nonuniformity of a film will generate | occur | produce a problem, such as a looseness of a film by the winding phenomenon which arises when the film is preserve | saved in roll shape. Therefore, in the case of a film having a large thickness nonuniformity, for example, when used as a laminate material, the processing operability is lowered due to the generation of wrinkles or the carry-in of air due to deformation such as loosening at the time of laminating processing, and wrinkles of the obtained product. It may lead to appearance defects such as transparency unevenness, variation in laminate strength, and the like.

Although the laminated polyethylene type unstretched film disclosed by the said patent document 1 can respond to a high market demand in the balance of heat sealing property and blocking resistance, regarding the fish eye and thickness nonuniformity mentioned above, it has met the recent high market demand. Since the market demand may not be sufficiently satisfied, the improvement is strongly desired.

Moreover, as one of the uses of a heat-sealing polyethylene resin film, there exists development as a raw material for freestanding containers. The market demand for the above self-supporting container is also strong. In particular, in recent years, the development of not only the cosmetic field but also the beverage and food fields has increased, and thus the higher demand for the above-mentioned quality has become stronger.

The heat-sealing polyethylene resin film used for freestanding containers requires not only properties such as heat sealability and blocking resistance, but also properties required for freestanding containers such as stiffness and impact resistance. The technique is disclosed (see, for example, Patent Documents 2 and 3 below).

Patent Document 2: Japanese Patent Application Laid-Open No. 9-235425

Patent Document 3: Japanese Patent Laid-Open No. 2000-238212

However, the polyethylene-based resin film disclosed in these patent documents is manufactured by the inflation film forming method, and was not sufficiently satisfactory in terms of thickness nonuniformity of the film. In addition, there was no sufficient response to the reduction of the fish eye.

In addition, since the polyethylene resin film for freestanding containers is used in combination with other materials, such as a polyester film, the handleability of a film in the processing process, such as lamination processing, for example in the said compounding, and productivity of processing The demand for is also heightened.

The present invention has been made in the background of the prior art, and relates to a polyethylene-based resin laminated film. More specifically, it is not only possible to balance heat sealing property, blocking resistance and rigidity of a film, but also to provide a polyethylene-based resin film with less fish eye and less thickness unevenness.

In addition, the present invention can provide a balance between heat sealability, blocking resistance and rigidity of a film, as well as providing a polyethylene-based resin film for an independent container with little fish eye and less thickness unevenness.

MEANS TO SOLVE THE PROBLEM The present inventors came to complete this invention as a result of earnestly researching in order to solve the said subject. That is, in this invention, the polyethylene-type resin laminated film which consists of at least a laminate layer (A) and a sealing layer (B) WHEREIN: A laminate layer (A) has a density of 900-970 kg / m <3>, and molecular weight distribution (Mw / Mn) is Two or more kinds of polyethylene resins having different densities of 2.0 to 3.5 are blended, and the average density thereof is 920 to 945 kg / m 3, and the sealing layer (B) is made of polyethylene resin having a density of 900 to 930 kg / m 3. A polyethylene-based resin laminated film is provided, characterized by simultaneously satisfying that the average density of the laminate layer (A) is greater than the average density of the sealing layer (B).

In this case, it is preferable that the fisheye whose maximum diameter of the said film is 0.2 mm or more is 5 pieces / 1000 cm <2> or less.

Moreover, in this case, it is preferable that the thickness nonuniformity of the width direction of the said film is within 7%.

In this case, it is preferable to provide an intermediate layer (C) made of polyethylene resin having an average density of 900 to 935 kg / m 3 between the laminate layer (A) and the sealing layer (B) of the film.

In addition, in this case, it is preferable that the average density of the polyethylene resin of each layer of the said film is laminate layer (A)> intermediate layer (C) ≥sealing layer (B).

Moreover, in this case, it is preferable to mix | blend 10-30 mass% of collection | recovery resin to the intermediate | middle layer (C) of the said film.

In this case, 0.5 to 1.5 mass% of spherical inorganic particles having an average particle diameter of 5 to 13 μm and 0.1 to 1.0 mass% of non-spherical inorganic particles having an average particle diameter of 1 to 6 μm are blended into at least the sealing layer (B) of the film. It is preferable.

In this case, the total thickness of the film provides a polyethylene-based resin laminated film for a self-supporting container, characterized in that 90 to 150 ㎛.

Effect of the Invention

The polyethylene resin laminated film of the present invention can not only balance the heat sealability and the rigidity of the film, but also has little fish eye and little thickness unevenness, and therefore is preferably used for packaging applications such as foods and daily necessities. Can be used.

In addition, the polyethylene-based resin laminated film for the self-supporting container of the present invention can not only balance the heat sealability and the rigidity of the film, but also has fewer fish eyes and less thickness nonuniformity. It can be used preferably for freestanding container use.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in detail.

MEANS TO SOLVE THE PROBLEM In the laminated polyethylene type unstretched film disclosed by the said patent document 1, the present inventors maintain the balance of the heat sealing property, blocking resistance, and the rigidity of a film which the said method has, and the method of solving the said subject. After earnestly examining, the present invention has been completed. That is, according to the present invention, the high molecular weight in the polyethylene resin as a raw material contributes greatly to the production of the fish eye, and by using the polyethylene resin having a narrow molecular weight distribution, it is possible to effectively suppress the production of the fish eye, By using a polyethylene resin with a narrow distribution, it is possible to improve deterioration such as film thickness unevenness due to a decrease in melt flowability of the resin, and to improve fish eye by blending two or more kinds of polyethylene resins having different densities. It discovered and completed the method of not only maintaining a conventionally well-known characteristic but also obtaining polyethylene-type laminated | multilayer film with few fisheye and little thickness nonuniformity.

In the polyethylene resin laminated film of the present invention, in the polyethylene resin laminated film comprising at least the laminate layer (A) and the sealing layer (B), the laminate layer (A) has a density of 900 to 965 kg / m 3 and a molecular weight distribution ( A polyethylene resin having Mw / Mn) of 2.0 to 3.5 in combination of two or more thereof, the average density of which is 920 to 945 kg / m 3, and the sealing layer (B) having a density of 900 to 930 kg / m 3. It is important to satisfy simultaneously that the average density of the laminate layer (A) is greater than the average density of the sealing layer (B).

The laminate of the laminate layer (A) and the sealing layer (B) affects the blocking resistance, stiffness, and rupture resistance of the film, which are properties important for low temperature heat sealability, film handleability, and the like, which are required as heat sealable films. The state can take balance such as elongation.

In the present invention, the laminate layer (A) is formed by blending two or more kinds of polyethylene resins having different densities having a density of 900 to 970 kg / m 3 and a molecular weight distribution (Mw / Mn) of 2.0 to 3.5, and the average density of 920 to It is preferable that it is 945 kg / m <3>. By the above correspondence, it is possible to impart properties such as elongation which affects the stiffness, rupture resistance, etc. of the film, which are important for the handleability of the film, and the like, and the suppression of the production of the fish eye and the reduction in thickness nonuniformity are possible.

Polyethylene resins having a density of less than 900 kg / m 3 are unsuitable because their handleability deteriorates. In addition, polyethylene resin having a density of more than 970 kg / m 3 is difficult to obtain because of difficulty in polymerization, and is not suitable. As for the density range of the raw material polyethylene resin used for mix | blending, 905-965 kg / m <3> is more preferable, and 910-960 kg / m <3> is more preferable.

As for the polyethylene resin used for the said mixing | blending, the molecular weight distribution (Mw / Mn) 2.0-3.5 are preferable. 2.2 to 3.3 are more preferable, and 2.4 to 3.1 are still more preferable. When a polyethylene-based resin having a molecular weight distribution (Mw / Mn) of less than 2.0 is used, it is difficult to stably produce in film production due to the occurrence of neck in, etc. due to the flow characteristics of the resin when molten, resulting in uneven thickness of the film. Leads to deterioration of the back. In addition, use of a polyethylene resin having a molecular weight distribution of greater than 3.5 is unsuitable because the production of fish eye caused by high molecular weight is increased.

In this invention, it is preferable to mix | blend 2 or more types of polyethylene resin from which the density of the said density range differs. By this correspondence, the fish eye generated by the high molecular weight component of the polyethylene resin can be reduced as described above. The reason is that in the case of polyethylene resins having the same density, the higher the density of the resin, the higher the molecular weight tends to increase. Therefore, the fish eye tends to increase as the resin density increases. Therefore, a mixture of two or more kinds of polyethylene resin having a low density and low fish eye and a polyethylene resin having a high density and fish eye has less fish eye when compared to a single polyethylene resin having the same density as the mixture. I guess. Although sufficient effect is expressed by 2 types of the said combinations, you may mix | blend 3 or more types as needed. Although the density difference of resin in the said mixture is not limited, It is preferable to generate the difference of 0.015 or more. It is more preferable to generate a difference of 0.020 or more. Since the fish eye of the mixed resin blended according to the said correspondence becomes small, the effect of this invention is expressed.

Moreover, by said correspondence, deterioration, such as the thickness nonuniformity of the film by the fall of the melt fluidity | liquidity of the said resin which is a subject produced by using polyethylene resin with said narrow molecular weight distribution, can be suppressed. The reason is not clear, but it is presumed to be due to the effect that the melt flow characteristics such as the dynamic viscosity of the melt are improved by the density difference of the resin.

In this invention, it is preferable to set it as said compounding so that average density may be 920-945 kg / m <3>. 925-940 kg / m <3> is more preferable, and 930-935 kg / m <3> is more preferable. If the average density is less than 920 kg / m 3, the rigidity of the laminated film is lowered and the handleability is lowered, which is not preferable. On the contrary, when it exceeds 945 kg / m <3>, since fish eye increases, it is unpreferable.

On the contrary, when it exceeds 945 kg / m 3, the rigidity of the film is improved and the self-supporting property is improved. However, the rupture resistance of the film is deteriorated, which is not preferable.

Although the compounding ratio of the polyethylene resin in the said mixing | blending is not limited, since the high density polyethylene resin shows the tendency for deterioration with respect to the production of fish-eye compared with the low density polyethylene resin, it reduces the compounding quantity of a high density polyethylene resin It is preferable. In order to make the compounding quantity of a high density polyethylene resin as small as possible, it is preferable to use resin as high as possible. For example, a polyethylene resin having a high density of 955 to 970 kg / m 3 and a polyethylene resin having a density of 900 to 935 kg / m 3 are blended at a ratio (mass ratio) of 5 to 15:95 to 85, respectively, and the average density is It is the most preferable embodiment to set it as 930-935 kg / m <3>. By the said combination, the effect of this invention can be expressed effectively.

In the present invention, the sealing layer (B), which is another constituent layer, is made of a polyethylene resin having a density of 900 to 930 kg / m 3, and the average density of the laminate layer (A) is larger than the average density of the sealing layer (B). desirable. By the said correspondence, the low temperature sealing of laminated | multilayer film and the rigidity of a film can be balanced. As for the density of the polyethylene resin which comprises the said sealing layer (B), it is more preferable that it is 910-925 kg / m <3>. If the density is less than 900 kg / m 3, blocking properties deteriorate. Conversely, if it exceeds 930 kg / m 3, the low temperature heat sealability deteriorates. The polyethylene resin which comprises the said sealing layer (B) may be single type, and may be 2 or more types of compounding system similarly to a laminate layer (A). In the case of the polyethylene resin which comprises the said sealing layer (B), since density is low, the influence of molecular weight distribution with respect to a fish eye becomes small compared with the above-mentioned laminate layer.

In the present invention, the total thickness is preferably 90 to 150 mu m. In the film used for the inner layer of a freestanding container, when thickness is thinner than 90 micrometers, there exists a problem that self-supporting property and burst resistance run short. In addition, if the thickness is larger than 150 µm, the self-supporting properties and the rupture resistance are improved, but since the flexibility is insufficient, there is a problem in that it is difficult to handle as a freestanding container.

With the above configuration, it is possible to impart properties such as elongation which affects the rigidity and rupture resistance of the film, which are important characteristics of the handleability of the self-supporting container film and the like, and the formation of the fish eye and the reduction in thickness nonuniformity are possible.

It is preferable to simultaneously satisfy the above-described configuration requirements. According to the said response, the effect of this invention can be expressed more effectively.

In this invention, you may provide an intermediate | middle layer (C) between the above laminated layers (A) and sealing layer (B). Since it becomes easy to balance the various characteristics of laminated | multilayer film by the said correspondence, it is preferable.

The polyethylene resin which comprises the said intermediate | middle layer (C) is 900-935 kg / m <3> in average density, and the average density of the polyethylene resin of each said layer is laminate layer (A)> intermediate layer (C) ≥sealing layer (B). It is preferable. As for the said density, it is more preferable that it is 910-925 kg / m <3>. The polyethylene resin which comprises the said intermediate | middle layer (C) may be single type, and may be 2 or more types of compounding system similarly to a laminate layer (A). In the case of the polyethylene resin which comprises the said intermediate | middle layer (C), since density is low, the influence of molecular weight distribution with respect to a fish eye becomes small compared with the above-mentioned laminate layer.

The polyethylene resin which comprises the said intermediate | middle layer (C) may be single type, and may be 2 or more types of compounding system similarly to a laminate layer (A). Intermediate layer (C) is 900-970 kg / m <3>, and is mix | blended 2 or more types of polyethylene from which the density differs in molecular weight distribution (Mw / Mn) 2.0-3.5, and the density is 920-945 kg / m <3>. desirable.

Polyethylene resins having a density of less than 900 kg / m 3 are not suitable because they are not rigid in themselves. As for the density range of the raw material polyethylene resin used for mix | blending, 905-965 kg / m <3> is more preferable, and 910-960 kg / m <3> is more preferable.

It is preferable that the polyethylene resin used for the said mixture is 2.0-3.5 in molecular weight distribution (Mw / Mn). 2.2 to 3.3 are more preferable, and 2.4 to 3.1 are still more preferable.

In this invention, it is preferable to mix | blend the collection | recovery resin which arises at the manufacturing process of the polyethylene type laminated | multilayer film of this invention in the said intermediate | middle layer (C), and to use. By this correspondence, the manufacturing cost of a laminated film can be reduced. Moreover, the quality fluctuation of the laminated | multilayer film by the fluctuation | variation of the use ratio of the said collection resin can be suppressed. In the case of carrying out the above-described method, management of the recovered resin is also an important factor of fish eye suppression. In most cases, products, incision fragments, etc. are reused and mixed with raw materials. The method of melt | dissolving these products, cut | disconnected debris, etc. into resin pellets, the method of making these products, cut | disconnected debris, etc. into pellet form, plate shape by pressure, and the method of making into pellet form in the semi-melt state are known. Since the method of melting and pelletizing melts with heat to form pellets, a crosslinking reaction occurs inside the resin, resulting in the occurrence of fish eyes. The method of pelletizing by pressure is not suitable for a soft film, the force to return to the original film form is strong even if it is a pellet, and since the shape may change with time, management is difficult. The method of pelletizing in a semi-molten state is preferable because it is uniform without being changed over time, and the fish eye is hardly generated.

It is also important to manage the products to be recovered, the dust accompanying the incision debris, foreign matters, and fine dust. If these materials are used as recovered materials in a state where dirt, foreign matter, fine dust, etc. are attached to them, they become the center and fish eyes are generated. It is important not only to control the air control in the recovery chamber, but also to ensure that dust, foreign matter and fine dust adheres to the recovery line. As the method, a recovery operation in a clean room is preferable. In addition, it is preferable to attach the static electricity removing device to the recovery device inlet in order to remove dust, foreign matter and fine dust adhering to the film.

As for the polyethylene resin used for this invention, linear low density polyethylene is preferable. It is preferable that linear low density polyethylene contains the copolymer of ethylene and the C3-C12 alpha olefin, and carbon number is chosen in the range of 4-8. Specific examples of these copolymerization components include propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, dodecene-1, 4-methyl-pentene-1, 4-methyl-hexene-1, etc. are mentioned.

The method for producing the above-mentioned linear low density polyethylene is not particularly limited, and a solution polymerization method using a complex catalyst such as a metallocene catalyst such as a Ziegler-Natta catalyst or a cyclopentadienyl metal compound or a nonmetallocene complex, What was manufactured by methods, such as a slurry polymerization method, a block polymerization method, and a solution polymerization method, can be used. The control method of the molecular weight distribution of the polyethylene resin which comprises a laminate layer (A) is not limited. For example, a polyethylene resin having a controlled molecular weight distribution produced using a complex catalyst such as a metallocene catalyst or a nonmetallocene complex may be used, or a general purpose polyethylene resin may be eluted.

Moreover, it is preferable to mix | blend antioxidant with polyethylene-type resin, The thing which has a phenol type and a phosphite system frame | skeleton in combination of phenol type, a phosphite type, or one molecule can also be used independently.

In this invention, it is preferable to mix | blend 0.5-1.5 mass% of spherical inorganic particles with an average particle diameter of 5-13 micrometers, and 0.1-1.0 mass% of non-spherical inorganic particles with an average particle diameter of 1-6 micrometers at least in a sealing layer (B). By this correspondence, low temperature sealing property can be maintained and a high blocking prevention effect can be provided.

As a reason, since a processus | protrusion is formed in the film surface by mix | blending an inorganic particle, it is guessed that the contact area of a film reduces and a blocking prevention effect is obtained as a result. Moreover, since complex protrusions are formed also in the recessed part of a film surface which mix | blended the inorganic particle which differs in a particle size and a shape, a more high blocking prevention effect can be acquired. In addition, said inorganic particle can also be mix | blended with a laminated layer (A) and an intermediate | middle layer (C) as needed.

By mix | blending the spherical inorganic particle of average particle diameter 5-10 micrometers, a high protrusion is formed in a film surface, and low protrusion can be formed in a film surface by mix | blending non-spherical inorganic particle of average particle diameter 1-6 micrometers. Films having protrusions of different height on the film surface are superior in blocking resistance than films having protrusions of the same height on the film surface.

As for the compounding quantity of the spherical inorganic particle of average particle diameter 5-10 micrometers, 0.5-1.5 mass% is preferable. If the amount is less than 0.5% by mass, blocking resistance is insufficient. Moreover, when the compounding quantity is more than 1.5 mass%, transparency of a film will deteriorate. As for the compounding quantity of the non-spherical inorganic particle of average particle diameter 1-6 weight%, 0.1-1.0 mass% is preferable. If the compounding quantity is less than 0.1 mass%, blocking resistance is insufficient. Moreover, when a compounding quantity is larger than 1.0 mass%, transparency of a film will deteriorate.

Although the composition of 5-13 micrometers spherical inorganic particle is not limited, Silica, a zeolite, etc. are preferable. It is also preferable that the surface is non-porous and the particle size distribution is narrow. The reason is that when the surface is porous, the film may foam due to the influence of moisture adsorbed on the inorganic particles, and the appearance may deteriorate. Moreover, when particle size distribution is wide, inorganic particle may accumulate in the lip part of T die in manufacture of a film, and may inhibit productivity. Although the composition of the said non-spherical inorganic particle is not limited, diatomaceous earth, talc, etc. are preferable. Since they have a smaller average particle diameter and a smaller amount of compound than spherical inorganic particles, they may be porous and have a wide particle size distribution.

In this invention, it is preferable to mix | blend 0.1-0.8 mass% of spherical inorganic particles with an average particle diameter of 5-13 micrometers in a laminate layer (A). As for an average particle diameter, 7-11 micrometers is more preferable. Moreover, as for compounding quantity, 0.2-0.7 mass% is preferable. The low-temperature-sealing polyethylene-based resin laminated film of the present invention is soft, and winding wrinkles are likely to occur in the step of winding the film in a roll shape. That is, it has the subject that the winding property of a film falls and it is important to satisfy said layer structure, but the winding property of a film can be improved further by the said correspondence. By satisfying the said range, both transparency of a film and winding property of a film are attained. For example, when the average particle diameter or compounding quantity exceeds the upper limit, since transparency of a film deteriorates, it is unpreferable. On the contrary, when it is less than a lower limit, since the effect of improving the windability of a film is lacking, it is not preferable.

The average particle diameter of the inorganic particles was measured based on the laser diffraction particle size distribution measuring method described in JIS K1150. Leeds & Northrup Co., Ltd. model: It measured using the Microtrac HRA model 9320-X100.

In order to obtain transparency, the T die method is preferable for the production method.

The transparency of polyethylene is affected by its crystal structure. Specifically, by making spherical crystals, transparency becomes good, and in order to obtain spherical crystals, it is necessary to increase the cooling rate of the film. In the inflation method, the cooling medium is air, whereas in the T-die method, a cooling roll is used, which is an advantageous manufacturing method for increasing the cooling rate.

As a structure of a polyethylene-type resin laminated | multilayer film, 5 to 40% of the layer ratio of a laminate layer is preferable. 10-30% is preferable and 15-25% is more preferable. When the layer ratio of the laminate layer is less than 5%, the elasticity of the film is insufficient, so that the weight quality such as the self-supporting property is impaired depending on the use. When the layer ratio exceeds 40%, the film strength is lowered, leading to rupture of the final product. By setting the layer ratio of the laminate layer to 5 to 40%, it becomes possible to balance the elasticity of the film and the film strength.

As for the total thickness of the polyethylene type laminated | multilayer film of this invention, 30-150 micrometers is preferable. If the thickness is less than 30 µm, the final packaged product tends to rupture, while if it is thicker than 150 µm, the final packaged product becomes difficult to handle and the convenience deteriorates. For example, in food packaging, since the content is light, 30 to 80 mu m is generally used. Moreover, in daily goods, such as a stand pouch for refilling of detergent, since the content is comparatively heavy and the product itself needs to be self-supporting, 90-150 micrometers in thickness is used.

In this invention, it is preferable to mix | blend an organic lubricant 100-100500 ppm at least in a heat sealing layer (B). 200-1400 ppm is more preferable, and 300-1300 ppm is still more preferable. By the said correspondence, the lubricity and the blocking prevention effect of a laminated | multilayer film improve, and the handleability of a film becomes excellent. As a reason, it is thought that a lubricant effect and a mold release effect were expressed because an organic lubricant bleeded out and exists in the film surface. Moreover, it is preferable to add an organic lubricant which has melting | fusing point above normal temperature. Organic lubricants include fatty acid amides and fatty acid esters. Specifically, oleic acid amide, erucic acid amide, behenic acid amide, ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, ethylene bis oleic acid amide and the like. Although these may be used independently, they are preferable because they can maintain a lubricity and a blocking prevention effect also in severe environment by using 2 or more types together. For example, if the erucic acid amide is less than 100 ppm, the lubricity is insufficient, and if it exceeds 1500 ppm, the lubricity may be satisfied, but the blocking prevention effect at high temperature cannot be satisfied. In this case, by using ethylenebisoleic acid amide having a relatively high melting point in combination, the blocking prevention effect at high temperature can be improved, and the lubricity and the blocking prevention effect can be compatible.

In this invention, it is preferable to mix | blend 2 or more types of organic lubricant from which melting | fusing point differs at least in a heat sealing layer (B). Lubricity and blocking resistance can be imparted by blending at least one organic lubricant having a melting point of less than 115 ° C with 100 to 500 ppm, and blending another 500 to 1500 ppm with an organic lubricant having a melting point of at least 115 ° C. have.

Organic lubricants having a melting point of less than 115 ° C. are effective for lubricity of the film, and organic lubricants having a melting point of 115 ° C. or higher are effective for blocking resistance of the film. Therefore, what mix | blended 2 or more types of organic lubricants can be made excellent in both lubricity and blocking resistance than the film which mix | blended any 1 type of organic lubricants.

Examples of the organic lubricant having a melting point of less than 115 ° C include oleic acid amide, erucic acid amide, paltimic acid amide, stearic acid amide, behenic acid amide and the like. Since these migrate relatively quickly to the film surface and contribute to the lubricity in a small amount, the blending amount is preferably 100 to 500 ppm. If it is less than 100 ppm, the lubricity is insufficient, and if it is more than 500 ppm, precipitation may occur on the surface of the film, and whitening may be a problem.

Examples of the organic lubricant having a melting point of 115 ° C. or higher include ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, ethylene bisrucic acid amide, ethylene bisbeheninic acid amide and ethylene bis stearic acid amide. They are relatively slow to transfer to the film surface and do not contribute to blocking resistance unless the blending amount is increased. As for compounding quantity, 500-1500 ppm is preferable. If it is less than 500 ppm, the blocking resistance is insufficient, and if it is more than 1500 ppm, precipitation may occur on the film surface, and whitening may be a problem.

In the self-supporting container, in the process of filling the contents, the folded bottom portion is smoothly enlarged and the contents need to be injected into the container. Moreover, in the process of manufacturing a freestanding container, it is necessary to move a member smoothly. Therefore, it is necessary to set it as the polyethylene-type resin laminated film excellent in lubricity and blocking resistance compared with a general packaging material use. These solutions can be solved by the above-mentioned solution.

In the present invention, the blocking resistance is preferably 150 mN / mm or less, more preferably 120 mN / mm.

Blocking resistance can be evaluated as follows.

The sample superimposed on the measurement surfaces is subjected to a pressurization treatment of a size of 7 cm × 7 cm, a temperature of 50 ° C., a pressure of 1400 Pa, and a time of 15 minutes in a thermal pressurizer (Tester Sangyo Co., Ltd. Model SA-303). A sample and a bar (6 mm in diameter, material: aluminum) blocked in this pressurization process were mounted on an autograph (SHIMAZU Corporation, UA-3122), and the bar was peeled off at a speed (200 m / min). The force at the time was measured. In this case, it is assumed that the bar and the peeling surface are horizontal. Four measurements were taken with respect to the same sample and displayed as average values.

It is preferable that the polyethylene-based laminated | multilayer film of this invention has 5/1000 cm <2> or less fisheye whose maximum diameter is 0.2 mm or more. It is more preferable that it is 4 pieces / 1000 cm <2> or less, and it is more preferable that it is 3 pieces / 1000 cm <2> or less. When the fish eye exceeds 5/1000 cm 2, for example, the fish eye is visually observed when the film is packaged with the film, and thus it is not preferable because it lowers the product image of the package.

Although reduction of the said fish eye can be achieved by satisfying the structure of this invention mentioned above, it is preferable to perform the following correspondence further. For example, the filter used for filtration of molten resin is important. It is a preferred embodiment to filter the molten resin in a melt extrusion process with a filter having a filtration accuracy of 100 µm or less. Here, filtration precision is the performance evaluated according to the method defined in JIS B8356: 1976. As for filtration precision, 80 micrometers is more preferable, and 60 micrometers is still more preferable. If the filtration accuracy exceeds 100 µm, it is not preferable because the removal and micronization of the gel foreign matter forming the fish eye deteriorates. The smaller the lower limit of the filtration accuracy is, the smaller the smaller it is in terms of elimination and micronization of the gel foreign matter, but the filtration area needs to be enlarged because the filtration pressure loss increases in proportion to the smaller. Therefore, the lower limit is preferably 30 µm. A large number of wire mesh filters are generally used, and the filtration capacity and the micronization efficiency change depending on the change in the shape of the tissue such as plain weave, twill weave, flat weave and twill weave, and the thickness and lamination structure of the lines used therein. Apart from these wire mesh filters, there are two types of metal sintered filters, powder sintered and solidified without squeezing a metal such as a nonwoven fabric. In particular, non-woven fabrics that are hardened without squeezing metal are uniformly laminated and sintered stainless steel fibers of micrometer order, and numerous contacts between the fibers are integrally bonded to each other, and are less classified into sieves and have high filtration accuracy. In addition, since the porosity is larger than that of other metal filter media, the pressure loss is small, and since the foreign material holding ability is higher than that of the wire mesh and the metal powder sintering filter, it has been particularly used in recent years. The wire mesh filter also does not exclude when the structure and lamination method are improved. Important matters in the selection, in particular, the olefin has a high melt viscosity, so it is preferable to select one having a low pressure loss and a high filtration capacity. The use of the above measures can express not only fish eye reduction but also an inhibitory effect of thickness nonuniformity reduction described later. Thickness nonuniformity is easy to produce when a pressure loss is large. Since this cuts off the pressure of the molten resin extruded by the filter, the pressure in the T die may become insufficient, resulting in unstable flow of the molten resin in the T die, resulting in thickness irregularities. As described above, it is possible to suppress this by using a filter having a low pressure loss.

The above-mentioned filtration is an embodiment more preferable to carry out by the multistage filtration method which provided two or more filters. By the said multistage filtration method, filtration and micronization efficiency improve and the problem of the said pressure loss also improves. In the said multistage filtration method, although the filter of the same filtration precision can be used, it is a more preferable embodiment to lower the value of filtration precision according to the flow direction of molten resin.

In addition, it is preferable that the polyethylene resin to be used performs inert gas substitution at the time of drying, and uses a dry thing. Deoxygenation by inert gas substitution inhibits oxidative decomposition at the time of injecting into the extruder and melting, leading to reduction of fish eyes. Moreover, it is also a preferred embodiment to substitute the inert gas so that oxygen is not injected into the hopper of the extruder for film forming or the silo in which the raw material is put, so that the raw material is not oxidized. The method also has the effect that the mixing of oxygen into the extruder together with the raw material resin is suppressed, leading to suppression of gel formation. The use of the above measures can express not only the gel production inhibition but also the inhibitory effect of the decomposition products affecting the odor or taste. As an inert gas to be used, there are rare gas-like elements, and for example, helium, neon, argon, krypton, xenon, and radon are six elements, but they are not practical because they are expensive. Inexpensive and readily available nitrogen gas is preferred.

It is preferable that the polyethylene-type laminated | multilayer film of this invention makes thickness nonuniformity of the width direction of a film into 7% within 1000 mm in width. Within 6% is more preferable, and within 5% is still more preferable. Moreover, it is preferable that the said thickness nonuniformity in this invention is satisfied by the roll of film width 400mm or more and film length 1000m or more. By the said correspondence, the winding phenomenon which arises when the film is preserve | saved in roll shape produces the problem of thickness nonuniformity of a film loosening of a film. Therefore, in the case of a film having a large thickness nonuniformity, for example, when used as a laminate material, deformation due to loosening at the time of laminating processing, the processing workability is lowered due to the occurrence of wrinkles or air inflow, Occurrence of appearance defects, such as a wrinkle and transparency nonuniformity, and fluctuation of laminate strength, can be suppressed.

Although suppression of the said thickness nonuniformity can be achieved by satisfying the structure of this invention mentioned above, it is preferable to perform the following correspondence.

For example, it is a preferred embodiment to optimize because the direction of flow of air around the die affects the thickness nonuniformity of the film. It is important to eliminate wind, which is a flow of air perpendicular to the molten resin sheet extruded from the die. This is because when the vertical wind hits the molten state, the molten resin sheet is shaken, and the thickness variation and partial cooling unevenness of the shaken portion occur, leading to thickness unevenness. One of the above measures is to make a fence around a die with a sheet, a plate, or the like, and to prevent the above-mentioned undesirable wind from reaching the die outlet surrounded by the fence. In addition, it is also a preferred embodiment to form a flow of wind in which the flow of the molten resin sheet at the die exit is not disturbed.

In addition, since the temperature unevenness around the die also affects the thickness unevenness, it is also important to make the temperature unevenness as small as possible. For example, placing a fence around the die also leads to improvement of the phenomenon, and is therefore recommended as a preferred embodiment. Moreover, heating in the state which raised humidity is a preferable embodiment because temperature nonuniformity becomes small.

In addition, improvement of the adhesion method of the molten resin sheet extruded from the die to the cooling roll is also an important factor in improving the film thickness precision. For example, the air nozzle method, the air chamber method, or the air knife method and the vacuum chamber method are widely used as a method of closely contacting the cooling rolls with air, but it is a preferred embodiment to operate the above three methods simultaneously. That is, at the time of close contact with the cooling roll of the molten resin sheet, both ends are fixed by an air nozzle method, pressurized to the cooling roll of the full width of the molten resin sheet by an air chamber method or an air knife method, and at the same time By acting to prevent the introduction of air between the molten resin sheet and the cooling roll, thickness unevenness is reduced. In the above method, the air structure of the air knife or the air chamber is not uniformly generated with respect to the molten resin sheet, and the suction structure of the vacuum chamber is uniform in the width and flow direction. It is also important to optimize the air volume and direction of the air in the air chamber, the suction degree and the suction direction of the vacuum chamber, and the like. Thereby, since the vibration of a molten resin sheet can be made small and thickness improvement is improved, it is recommended as one of effective means.

The selection of the air chamber method and the air knife method in the close contact method can be appropriately selected in relation to the space volume of the place where the device is installed and the performance of the vacuum chamber.

Hereinafter, although an Example demonstrates this invention in detail, it is not limited to this. In addition, the characteristic obtained by each Example was measured and evaluated by the following method.

(1) resin density

Density was evaluated according to JIS K7112: 1999.

(2) the average particle diameter of the inorganic particles

It measured based on the laser diffraction particle size distribution measuring method of JISK1150. Leeds & Northrup Co., Ltd. model: It measured using the Microtrac HRA model 9320-X100.

(3) fish eye

In the film of area 1000cm <2>, the gel-like thing of 0.2 mm (phi) or more was visually counted. In addition, the gel-like thing of polyethylene was judged to be a gel-like thing except the thing which can be judged clearly as a foreign material (fibrous form, carbide) by the magnified observation of a microscope.

(4) molecular weight distribution

Using gel permeation chromatography (GPC), the molecular weight distribution (Mw / Mn) was measured by the following measuring method. The measuring method is as follows.

Measuring Device: Waters 150CV

Columns: 2 AT-806MS

Adjustment of sample: The sample was dissolved in a solvent (0.3% injection of o-dichlorobenzene BHT) at 145 ° C to prepare a concentration of 1 mg / ml.

Measurement conditions: 0.4 ml of solution was introduced into the column at a flow rate of solvent (o-dichlorobenzene), temperature 145 ° C., 1.0 ml / min, and the sample concentration in the solution separated from the column was measured with a differential refractometer. The molecular weight prepared the universal calibration curve as a polystyrene standard sample, and obtained molecular weight distribution (Mw / Mn) of polystyrene conversion using the values of K = 0.7 and (alpha) = 4.2E-4.

(5) thickness non-uniformity

It evaluates according to JISK7130. Portions where some methods differ are described in detail below. The environment to be measured is performed at 23 ° C. × 50% RH indoors. The measurement cut | disconnects the both ends of a film by 5 cm, the sample cut | disconnected by the said both ends is divided into 40 equal parts in the width direction, and it displays in a measurement position. The dial gauge is used for the place except the portion indicated at the display position. The measurement is 15 cm in the film roll MD direction, 3 samples each in two places of the part which peeled twice from the part without wrinkles in the full width and surface layer part in the TD direction, and the part which peeled the part without wrinkles twice from the core part, respectively. Take the average of these 6 samples. The measuring instrument used has a minimum reading value of 0.001 mm. The precision is assumed to be equal to or higher than the dial gauge specified in JIS B7503: 1997. Thickness nonuniformity is calculated | required by following formula (1).

Thickness nonuniformity (%) = (maximum thickness-minimum thickness) / 6 mean value of sample * 100

(6) lubricity

The weight (1 kg) and the inclined surface are set so that the film surface measured by the friction angle tester (the Toyo Seiki Co., Ltd. model number: A-211402803) containing an inclined surface and a weight contacts. Slowly raise the angle of the slope (speed 2.7 ° / sec) and measure the angle at which the additional slope begins to slide. Tan (theta) of the angle (theta) was made into lubricity. Three measurements were taken on the same sample and displayed as average values.

(7) Blocking resistance

The sample superimposed on the measurement surfaces is subjected to a pressurization treatment of a size of 7 cm × 7 cm, a temperature of 50 ° C., a pressure of 1400 Pa, and a time of 15 minutes in a thermal pressurizer (Tester Sangyo Co., Ltd. Model SA-303). A sample and a bar (6 mm in diameter, material: aluminum) blocked in this pressurization process were mounted on an autograph (SHIMAZU Corporation, UA-3122), and the bar was peeled off at a speed (200 m / min). The force at the time was measured. In this case, the bar and the peeling surface are assumed to be horizontal. Four measurements were taken with respect to the same sample and displayed as average values.

(8) winding wrinkle

After leaving the film roll wound up 2000 m in thickness of 1000 mm with a thickness of 40 micrometers for 40 degreeC * 1 week, it is judged whether a wrinkle can be visually recognized by a roll surface layer.

(9) Pinhole resistance

The film was cut to 300 mm in length × 200 mm in width and twisted 3000 times at 5 ° C. in accordance with ASTM F329 using a Gelbo Flexometer (Tester Sangyo Co., Ltd. Model: Gelbo Flexure Tester with Thermostat) (Twisting speed: 40 rpm, twist angle of 400 °), the number of pinholes generated was measured three times for the same sample and expressed as an average value.

(Example 1)

Polyethylene-based composition of the laminate layer (A)

Polyethylene resin (Sumitomo Chemical Co., Ltd., FV407) 90% of resin density 930 kg / m <3>, molecular weight distribution 2.8 The composition which mixed%.

Polyethylene-based composition of the intermediate layer (C)

Polyethylene resin (Sumitomo Chemical Co., Ltd., FV405) 100% composition of resin density 925 kg / m <3>, molecular weight distribution 2.8.

Polyethylene-based composition of heat seal layer (B)

10 micrometers of spherical inorganic particles (Shin-Etsu Chemical Co., Ltd .: KMP120-10) 12000 with respect to 100% of resin density 925 kg / m <3> and polyethylene resin (Sumitomo Chemical Co., Ltd., FV405) of molecular weight distribution 2.8. 5000 ppm and non-spherical inorganic particles (White Filler, Mitsui Kosan Co., Ltd.) at 5000 ppm and an organic lubricant of less than 115 ° C (Nippon Kasei Co., Ltd .: Diamide L-200) 200 ppm and a melting point of 115 ° C or higher The composition which mixed 1000 ppm of organic lubricants (Nippon Kasei Co., Ltd .: Srifax O).

Using a three-stage single screw extruder with a screw diameter of 200 mm and a three-stage single screw extruder with a screw diameter of 200 mm, and a two-stage single screw extruder with a screw diameter of 100 mm, respectively, using the polyethylene resin composition for layer B, at a width of 3000 mm. A-layer, C-layer, and B-layer on a three-layered T-slot type die designed to have a free land in two stages, and the stepped portion has a curved shape to make the flow of molten resin uniform. Was introduced in order, and the outlet temperature of the die was extruded at 220 ° C. The lip spacing was 1.6 mm. The filter was supplied to the die by the two-stage filtration method which connected the filter of 100 micrometers of filtration precision and 50 micrometers in series. The filter was installed in every line of layers A to C. The molten resin sheet extruded from the dice | dies was cooled with the 30 degreeC cooling roll, and the polyethylene-type laminated | multilayer film which consists of 12/36/12 (micrometer) layer thickness was obtained by the structure of A layer / C layer / B layer. In addition, the silo and the hopper for supply to the extruder were also subjected to nitrogen gas replacement. At the time of cooling on a cooling roll, an air nozzle fixes both ends of the film on the cooling roll, presses the entire width of the molten resin sheet with a cooling roll with an air knife, and simultaneously operates a vacuum chamber between the molten resin sheet and the cooling roll. Of air was prevented. Both air nozzles were installed in series in the film advancing direction. In addition, the wind direction of the air knife was 45 degree | times with respect to the advancing direction of the extruded sheet | seat. Moreover, the direction of the suction port of the vacuum chamber was matched with the advancing direction of the extruded sheet. In addition, the circumference | surroundings of the dice | dies were surrounded by the sheet | seat, and wind was not made to contact a molten resin sheet. A film forming speed was performed at 100 m / min. The results obtained are shown in Table 1 below.

(Example 2)

Except having used 20 weight% of collection resin for C layer, it carried out similarly to Example 1, and obtained the film. The obtained results are shown in Table 1.

(Comparative Example 1)

Except having made the molecular weight distribution of A-C layer into 3.8, it carried out similarly to Example 1, and obtained the film. The obtained results are shown in Table 1. The fish eye of the film obtained by this comparative example fell.

(Comparative Example 2)

A film was obtained in the same manner as in Example 1 except that the layer A had a density of 933 kg / m 3 and a molecular weight distribution of 2.8. The obtained results are shown in Table 1. The film precision in this comparative example fell in thickness precision.

(Comparative Example 3)

A film was obtained in the same manner as in Example 1 except that the molecular weight distribution of the A to C layers was set to 3.8 and the A layer was set to a density of 933 kg / m 3. The obtained results are shown in Table 1. The fish eye of the film obtained by this comparative example fell.

(Example 3)

The polyethylene resin of the following compositions was used.

(1) Polyethylene Composition of Laminate Layer (A)

Polyethylene resin (Sumitomo Chemical Co., Ltd., FV407) 90% of resin density 930 kg / m <3>, molecular weight distribution 2.8 The composition which mixed%.

(2) Polyethylene-based composition of the intermediate layer (C)

Polyethylene resin (Sumitomo Chemical Co., Ltd., FV405) 100% of resin density 925 kg / m <3>, molecular weight distribution 2.8.

(3) Polyethylene Composition of Heat Seal Layer (B)

12000 ppm of 10 micrometers spherical inorganic particle (spherical silica KMP120-10) and 5 micrometers non-spherical inorganic particle with respect to 100% of polyethylene resins (Sumitomo Chemical Co., Ltd., FV405) of resin density 925 kg / m <3> and molecular weight distribution 2.8. 5000 ppm of particles (diatomaceous earth: White Filler) and 200 ppm of organic lubricant (erucamide: diamide L-200) with melting point below 115 ° C. and 1000 ppm of organic lubricant (ethylenebisoleic acid amide: Srifax O) with melting point above 115 ° C The composition mixed.

The polyethylene-based resin composition for the intermediate layer (C) was a three-stage single screw extruder having a screw diameter of 200 mm, and the polyethylene-based resin composition for the laminate layer (A) and the heat sealing layer (B), respectively, having two screw diameters of 100 mm. Using a three-stage single screw extruder, the three-layer type is designed to make the flow in the die uniform by making the free land in two stages at a width of 3000 mm and making the flow of the molten resin uniform. It introduced into die in the order of A layer / C layer / B layer, and the exit temperature of the die was extruded at 240 degreeC. The lip spacing was 1.6 mm. The filter was supplied to the die by the two-stage filtration method which connected the filter of 85 micrometers of filtration precision and 40 micrometers in series. The filter was installed in every line of layers A to C. The molten resin sheet extruded from the dice | dies was cooled with the 30 degreeC cooling roll, and the polyethylene type laminated | multilayer film which consists of 24/72/24 (micrometer) layer thickness was obtained by the structure of A layer / C layer / B layer. In addition, the silo and the hopper for supply to the extruder were also subjected to nitrogen gas replacement. At the time of cooling on a cooling roll, an air nozzle fixes both ends of the film on the cooling roll, presses the entire width of the molten resin sheet with a cooling roll with an air knife, and simultaneously operates a vacuum chamber between the molten resin sheet and the cooling roll. Of air was prevented. Both air nozzles were installed in series in the film advancing direction. In addition, the wind direction of the air knife was 45 degree | times with respect to the advancing direction of the extruded sheet | seat. Moreover, the direction of the suction port of the vacuum chamber was matched with the advancing direction of the extruded sheet. In addition, the circumference | surroundings of the dice | dies were surrounded by the sheet | seat, and wind was not made to contact a molten resin sheet. A film forming speed was performed at 50 m / min. The results obtained are shown in Table 2 below.

(Example 4)

In Example 3, the film was obtained like Example 3 except having used 20 weight% of collection resin for the polyethylene resin used for C layer. The results obtained are shown in Table 2 below.

(Comparative Example 4)

In Example 3, the film was obtained like Example 3 except having made the polyethylene resin used for A-layer the density 930 kg / m <3>, and molecular weight distribution 3.8. The obtained results are shown in Table 2. In the polyethylene resin film for self-supporting containers obtained in this comparative example, the fish eye was lowered.

(Comparative Example 5)

In Example 3, a film was obtained in the same manner as in Example 3 except that the polyethylene resin used for the A layer was used alone in a polyethylene resin having a density of 933 kg / m 3 and a molecular weight distribution of 2.8. The obtained results are shown in Table 2. The thickness nonuniformity of the polyethylene resin film for freestanding containers obtained by this comparative example fell.

(Comparative Example 6)

In Comparative Example 5, the film was obtained in the same manner as in Comparative Example 5 except that the addition of 10 µm spherical inorganic particles was stopped as inorganic particles used for the B layer and only 17000 ppm of 5 µm non-spherical inorganic particles were added. The obtained results are shown in Table 2. The polyethylene resin film for freestanding containers obtained by this comparative example had not only the subject but also the blocking resistance of the polyethylene resin film for freestanding containers obtained by the comparative example 5.

(Comparative Example 7)

In Comparative Example 5, as the organic lubricant used for the layer B, the addition of the organic lubricant having a melting point of less than 115 ° C was stopped, and only the organic lubricant having a melting point of 115 ° C or more was changed to be added at 1200 ppm, Comparative Example 5 The film was obtained in the same manner as. The obtained results are shown in Table 2. The polyethylene resin film for freestanding containers obtained by this comparative example had not only the subject matter but also lubricity of the polyethylene resin film for freestanding containers obtained by the comparative example 5.

The polyethylene resin laminated film of the present invention can not only balance heat sealability, blocking resistance and rigidity of the film, but also has little fish eye and little thickness nonuniformity. It can be used preferably. Therefore, the contribution to the industry is great.

Claims (9)

Polyethylene-based resin laminated film comprising at least a laminate layer (A) and a sealing layer (B), wherein the laminate layer (A) has a density of 900 to 970 kg / m 3 and a molecular weight distribution (Mw / Mn) of 2.0 to 3.5 Is made by blending two or more kinds of different polyethylene resins, the average density is 920 to 945 kg / m 3, and the sealing layer (B) is made of polyethylene resin having a density of 900 to 930 kg / m 3, and a laminate layer ( A polyethylene-based resin laminated film characterized by simultaneously satisfying that the average density of A) is larger than the average density of the sealing layer (B). The polyethylene-based resin laminated film according to claim 1, wherein the maximum fish diameter is 0.2 mm or more and five fish eyes / 1000 cm 2 or less. The thickness nonuniformity of the width direction of the said film is less than 7%, The polyethylene-type resin laminated film of Claim 1 characterized by the above-mentioned. The polyethylene system according to claim 1, wherein an intermediate layer (C) made of a polyethylene resin having an average density of 900 to 935 kg / m 3 is provided between the laminate layer (A) and the sealing layer (B) of the film. Resin laminated film. The polyethylene-based resin laminated film according to claim 1, wherein the average density of the polyethylene resin of each layer of the film is a laminate layer (A)> intermediate layer (C) ≥sealing layer (B). The polyethylene-based resin film of Claim 1 which mix | blends 10-30 mass% of collection | recovery resin to the intermediate | middle layer (C) of the said film. A 0.1-1.0 mass% blend of 0.5 to 1.5 mass% of spherical inorganic particles having an average particle diameter of 5 to 13 μm and non-spherical inorganic particles having an average particle diameter of 1 to 6 μm in at least the sealing layer (B) of the film. Polyethylene-based resin laminated film, characterized in that. A total of 500 to 1500 ppm of an organic lubricant having a melting point of less than 115 ° C and an organic lubricant having a melting point of at least 115 ° C are blended in at least the sealing layer (B) of the film. Polyethylene-based resin laminated film made. The polyethylene-based resin laminated film for freestanding containers according to claim 1, wherein the total thickness of the film is 90 to 150 µm.