WO2019225282A1

WO2019225282A1 - Polypropylene-based composite film and packaging material using same

Info

Publication number: WO2019225282A1
Application number: PCT/JP2019/017550
Authority: WO
Inventors: 安岡涼; 村田太一; 松浦洋一; 土本達郎; 深貝佳孝
Original assignee: 東レフィルム加工株式会社
Priority date: 2018-05-21
Filing date: 2019-04-25
Publication date: 2019-11-28
Also published as: KR20210012996A; JPWO2019225282A1; TW202003245A; JP7237827B2; TWI797330B; CN111757809A

Abstract

Provided are: a polypropylene-based composite film which can exhibit a high heat sealing ability in a temperature range from a lower temperature to a higher temperature, has excellent low-temperature impact resistance and excellent resistance to whitening on bending, and makes it possible to keep the amount of a lubricant in the surface of the film at a value falling within a proper range to achieve a desired value for the static friction coefficient of the surface of the film even when the film is laminated and is then aged at 60°C; and a packaging material using the polypropylene-based composite film. A polypropylene-based composite film characterized by comprising at least two layers composed of a layer A and a layer B, wherein the main component of the layer A is a propylene-based random copolymer having a melt flow rate of 2 to 10 g/10 min. at 230°C and a melting point of 130 to 150°C, the main component of the layer B is a resin composition which contains 100 parts by weight of a propylene-ethylene block copolymer (a) having a ratio of a limiting viscosity [η] Cxs of a 20°C xylene soluble fraction to a limiting viscosity [η] Cxis of a 20°C xylene insoluble fraction (i.e., [η]Cxs/[η]Cxis) of 1.6 or more and 10 to 90 parts by weight of a low-density polyethylene-based polymer (b), the layer A contains a fatty acid amide-type lubricant in an amount of 200 to 2000 ppm, and the layer B contains a fatty acid amide-type lubricant in an amount of 500 to 5000 ppm.

Description

Polypropylene composite film and packaging material using the same

The present invention relates to a polypropylene-based composite film having high heat seal strength from a low temperature, easy slipping, low temperature impact resistance, and bending whitening resistance, and a packaging material using the same.

It is widely known that a polypropylene film is used as a packaging film. In addition, a polypropylene film and a polyethylene terephthalate (PET) film or a nylon (Ny) film, particularly a stretched PET film or a stretched nylon film (ONy), A packaging material in which aluminum foil is laminated is widely known.

In general, an organic lubricant is added to a polypropylene film used for a packaging film, and the lubricant oozes out to the surface of the film after film formation, thereby exhibiting good slipperiness. In a conventional polypropylene film, it sticks to a film such as a stretched PET film, ONy, or aluminum foil via an adhesive, and bleeds onto the film surface when aged at a certain temperature to cure the adhesive. Since the organic lubricant (particularly fatty acid amide-based lubricant) that came out re-transferred into the film, there was a tendency for slipping to become worse.

In retort applications, it is practiced to keep the slipperiness by laminating with a film such as stretched PET film or ONy, but if the amount of lubricant to be sprinkled becomes too much, Problems such as surface problems may occur.

In addition, it may not be satisfactorily used in battery packaging applications where slipperiness is required for draw molding, and other films are laminated on polypropylene film to form a laminate, which is aged at 40 ° C to less than 60 ° C. Even in such a case, it is desirable that the film surface has good slipperiness, particularly a static friction coefficient of a certain level or less, for example, a static friction coefficient of 0.3 or less.

With respect to such a request, Patent Document 1 discloses that an unsaturated fatty acid amide having a melting point of 70 to 90 ° C. is 0.02 to 0.2% by weight, and an unsaturated fatty acid bisamide having a melting point of 115 to 135 ° C. is 0.01 to 0.12% by weight. However, when ethylene / α-olefin is used, the heat resistance is inferior, and when this knowledge is applied to a polypropylene system, unsaturated fatty acid amide and unsaturated fatty acid bisamide are Although the amount needs to be increased and the coefficient of friction can be kept low, the amount of lubricant on the film surface becomes too large after the aging treatment, causing deposits on the rolls and the like, resulting in problems in the working environment.

In Patent Document 2, a lubricant having an optimum aging temperature of less than 40 ° C such as erucamide is added to both outer layers, and a lubricant having an optimum aging temperature of 40 ° C or more such as behenamide or ethylenebisamide is added to the intermediate layer. As described in the examples, a polypropylene multilayer film and a composite film having a three-layer structure using a propylene / ethylene random copolymer for an intermediate layer and a propylene / ethylene random copolymer for at least one outer layer are provided. It is disclosed. In each example of Patent Document 2, when a special lubricant is added to each layer, a case where a coefficient of static friction between the surfaces after aging of the laminated film of 0.3 or less is achieved can be seen, which will be described later. According to the knowledge of the present inventors, when both the intermediate layer and the surface layer are composed of a propylene / ethylene random copolymer, a high heat seal strength from low temperature to high temperature, low temperature impact resistance, slipperiness It was difficult to achieve both insulating properties. Moreover, although the film using the propylene-ethylene block copolymer of patent document 3 as a raw material is known, high heat seal strength from low temperature to high temperature, low temperature impact resistance, bending whitening resistance, slipperiness, It was difficult to achieve both insulation properties.

As described above, when used as a packaging film, the polypropylene film has excellent properties such as bending whitening resistance, low temperature impact resistance, and slipperiness in a well-balanced manner in addition to the heat sealability described above. However, conventional films have not always been able to satisfy high demands in recent years. Especially in recent years, with regard to low temperature impact resistance, bag breaking strength under severe conditions that can not be torn even when repeatedly dropped from a relatively high position in a bag containing contents may be required ( Especially in retort applications, there is a need for bag breaking strength under such severe conditions), but a polypropylene film designed for low temperature impact resistance based on the criteria for bag breaking strength under such severe conditions. Is not found.

JP-A-9-77881 Japanese Patent Laid-Open No. 11-334004 JP-A-10-87744

Therefore, the problem of the present invention is that the heat sealing force is high from low temperature to high temperature, excellent in low temperature impact resistance and bending whitening resistance, and even if the film is aged at 60 ° C., the amount of lubricant on the film surface is within an appropriate range. It is to provide a polypropylene-based composite film that can be maintained and achieve a desirable value as a coefficient of static friction on the film surface, and a packaging material using the same.

In order to solve the above problems, the polypropylene composite film of the present invention has the following configuration.

It consists of at least two layers of A layer / B layer. The A layer is mainly composed of a propylene random copolymer having a melt flow rate at 230 ° C. of 2 to 10 g / 10 minutes and a melting point of 130 to 150 ° C. The layer has a ratio ([η] Cxs / [η] Cxis) of the intrinsic viscosity [η] Cxs of the soluble part of 20 ° C. xylene to the intrinsic viscosity [η] Cxis of the insoluble part of 1.6 or more. The main component is a resin composition in which 10 to 90 parts by weight of a low density polyethylene polymer (b) is blended with 100 parts by weight of the ethylene block copolymer (a), and the A layer contains 200 to 200 fatty acid amide lubricants. The polypropylene layer is a polypropylene composite film containing 2000 ppm, and the B layer contains 500 to 5000 ppm of a fatty acid amide lubricant.

A laminate in which at least one selected from the group consisting of a biaxially stretched polyethylene terephthalate film, a biaxially stretched polypropylene film, a biaxially stretched nylon film, and an aluminum foil is laminated on the surface opposite to the A layer side of the polypropylene-based composite film described above. Is the body.

A battery packaging material using the laminate described above.

A retort packaging material using the laminate described above.

According to the present invention, the amount of lubricant on the film surface at normal temperature (23 ° C.) can be maintained within an appropriate range, and the amount of lubricant on the film surface can be maintained within an appropriate range even after aging at 60 ° C. The static friction coefficient of the surface can be suppressed to 0.3 or less, and a polypropylene composite film suitable for battery packaging materials requiring slipperiness and a packaging material including the same can be realized.

In particular, in view of the requirements for bag breaking strength under severe conditions of retort packaging materials, it is possible to satisfy the requirements, and also to satisfy heat balance and low-temperature impact resistance in a well-balanced manner. A polypropylene composite film suitable for a packaging material for packaging, and a packaging material including the same can be realized.

The polypropylene composite film of the present invention comprises at least two layers of A layer / B layer, and the A layer contains a propylene random copolymer as a main component. On one side of the A layer, a propylene / ethylene block copolymer (a) and a low density polyethylene resin (b), more preferably a block copolymer having a styrene block as the polymer (c), or crystalline A block copolymer having an olefin block, more preferably, a B layer containing a propylene random copolymer (d) is provided.

The layer A of the polypropylene composite film of the present invention is mainly composed of a propylene random copolymer having a melt flow rate at 230 ° C. (hereinafter abbreviated as MFR) of 2 to 10 g / 10 min and a melting point of 130 to 150 ° C. And In the present invention, the main component in the A layer means a component exceeding 50% by weight in the A layer. When the propylene random copolymer is 50% by weight or less, the heat seal strength at 130 ° C. and 160 ° C. decreases.

Further, when the MFR at 230 ° C. of the propylene random copolymer of the A layer is less than 2 g / 10 minutes, the uniform lamination property with the B layer may be deteriorated, and the low temperature heat seal strength at 130 ° C. may be deteriorated. If it exceeds 10 g / 10 minutes, the bleed-out property of the lubricant may deteriorate and the slip property may decrease.

The propylene random copolymer of layer A is a copolymer of propylene and at least one α-olefin, and examples of the α-olefin include ethylene, butene, and octene. From the viewpoint of heat sealability, a propylene / ethylene random copolymer of ethylene is preferable.

The layer A of the polypropylene composite film of the present invention preferably contains the propylene random copolymer as a main component and 200 to 2000 ppm of a fatty acid amide lubricant. If the content of the fatty acid amide-based lubricant is less than 200 ppm, the slipperiness may be deteriorated. If it exceeds 2000 ppm, heat scattering may increase during melt extrusion, and the film-forming property may deteriorate due to contamination of the process. The low-temperature heat seal strength may also be reduced.

Examples of the fatty acid amide-based lubricant include oleic acid amide, erucic acid amide, stearic acid amide, palmitic acid amide, behenic acid amide and the like, and particularly, resin composition in which erucic acid amide is used in the polypropylene-based composite film of the present invention. It is preferable from the viewpoint of dispersibility in water and expression of slipperiness.

In addition, when 300 to 5000 ppm of inorganic or organic particles are added to the layer A within a range that does not impair the heat sealability, the slipping property is improved even if the content of the fatty acid amide-based lubricant is reduced. When the polypropylene composite film is wound up in a long length, defects due to defects such as wrinkles and air loss are reduced. If the content is 300 ppm or less, the effect of imparting slipperiness is not observed, and if it exceeds 5000 ppm, the heat sealability may be lowered.

Preferred examples of the inorganic particles include silica, zeolite, and calcium carbonate, and preferred examples of the organic particles include crosslinked PS and crosslinked PMMA. Their average particle size is preferably in the range of 1 to 5 μm. If the average particle size is less than 1 μm, the effect of addition is not observed, and if it exceeds 5 μm, the heat sealing force may be reduced.

The B layer of the polypropylene composite film of the present invention is the ratio of the intrinsic viscosity [η] Cxs of the soluble part of xylene at 20 ° C. to the intrinsic viscosity [η] Cxis of the insoluble part ([η] Cxs / [η] Cxis). However, the main component is a resin composition comprising a propylene / ethylene block copolymer (a) having a molecular weight of 1.6 or more and a low density polyethylene polymer (b). In the present invention, the main component in the B layer means a component exceeding 50% by weight in the B layer.

The propylene / ethylene block copolymer (a) of the B layer of the polypropylene-based composite film of the present invention is a ratio of the intrinsic viscosity [η] Cxs of the soluble part of xylene and the intrinsic viscosity [η] Cxis of the insoluble part at 20 ° C. ([Η] Cxs / [η] Cxis) is 1.6 or more, preferably in the range of 1.6 to 2.0. If [η] Cxs / [η] Cxis is less than 1.6, the resin is reduced due to a decrease in heat seal strength due to film crushing when heat-sealed at 160 ° C. or higher, and pressure is applied during heat sealing or drawing. Overflow may occur and contamination of the packaging material manufacturing process may occur. Also, if [η] Cxs / [η] Cxis exceeds 2.0, a small gel-like defect is formed in the film, resulting in film protrusion, and air is taken into the interface when laminating with other base materials, resulting in laminate strength In addition, the heat seal strength may decrease and the content may leak.

Further, the propylene / ethylene block copolymer (a) of the B layer has a proportion of a polypropylene portion of 20 ° C. xylene insoluble part of 70 to 85% by weight, and the intrinsic viscosity [η] Cxis of the xylene insoluble part is 1.5 to 2.0 dl / g, and the intrinsic viscosity [η] Cxs of the 20 ° C. xylene-soluble part indicating the ratio of the ethylene / propylene copolymer rubber component is 2.4 to 4.0 dl / g. Preferably there is. If the intrinsic viscosity [η] Cxis of the xylene-insoluble part is less than 1.5, the film may be thinned due to crushing of the film during heat sealing or drawing, and if it exceeds 2.0 dl / g, the film becomes too hard. As a result, the drawability may deteriorate. In addition, when the intrinsic viscosity [η] Cxs of the xylene soluble part is less than 2.4 dl / g, the seal strength may be lowered. When the intrinsic viscosity exceeds 4.0 dl / g, the particle size of the rubber component is very large. Cracks may occur at the sea-island structure interface, resulting in low-temperature impact resistance and reduced heat sealability.

Here, the 20 ° C. xylene insoluble part and the soluble part are the above-mentioned propylene / ethylene block copolymer pellets completely dissolved in boiling xylene, then cooled to 20 ° C. and allowed to stand for 4 hours or more. When this was separated into a precipitate and a solution, the precipitate was called a 20 ° C. xylene insoluble part, and the part obtained by drying the solution part (filtrate) at 70 ° C. under reduced pressure was the xylene soluble part. Called.

The propylene / ethylene block copolymer has an intrinsic viscosity of xylene-insoluble and soluble components, and a method for adjusting the melt flow rate includes hydrogen gas in each step during the polymerization of the propylene / ethylene block copolymer. A method of adding a molecular weight adjusting agent such as a metal compound, a method of adding an additive when melt-kneading and pelletizing a polymer obtained in powder form, a melt-kneading of a polymer obtained in powder form, and pelletizing A method for adjusting the kneading conditions during the process can be mentioned.

In addition, as a manufacturing method of the propylene / ethylene block copolymer used in the present invention, a method of polymerizing propylene, ethylene or the like as a raw material using a catalyst can be mentioned. Here, a Ziegler-Natta type or metallocene catalyst can be used as the catalyst, and for example, those described in JP-A-07-216017 can be preferably used.

Specifically, (1) in the presence of an organosilicon compound having an Si—O bond and an ester compound, the general formula Ti (OR) _a X _4-a (wherein R is a hydrocarbon group having 1 to 20 carbon atoms) X is a halogen atom, a is 0 <a ≦ 4, preferably 2 ≦ a ≦ 4, particularly preferably a = 4). The resulting solid product is treated with an ester compound. Then, a trivalent titanium compound-containing solid catalyst obtained by treating with a mixture of an ether compound and titanium tetrachloride or a mixture of an ether compound, titanium tetrachloride and an ester compound, (2) an organoaluminum compound, (3 And a catalyst system comprising an electron donating compound (dialkyldimethoxysilane or the like is preferably used).

As a method for producing the copolymer (a), from the viewpoint of productivity and low temperature impact resistance, a polymer part mainly composed of propylene is polymerized in the first step substantially in the absence of an inert agent, It is preferable to use a method in which the ethylene / propylene copolymer portion is polymerized in the gas phase in the second step.

Here, the polymer part mainly composed of propylene is preferably a propylene homopolymer having a melting point of 160 ° C. or higher from the viewpoint of heat resistance, rigidity, etc. It may be a copolymer with a small amount of α-olefin such as ethylene and 1-butene.

In the B layer in the polypropylene composite film of the present invention, a low density polyethylene polymer (b) is blended with the propylene / ethylene block copolymer (a). According to the knowledge of the present inventors, when the polypropylene composite film of the present invention is cracked (whitened) at the interface of the sea-island structure of the film, for example, during deformation of drawing for battery exterior use, There is a concern that some electrolyte will leak. Therefore, it is necessary to design the dispersion of the rubber component at the island portion in the propylene / ethylene block copolymer to be extremely small, and the dispersion can be extremely small by containing the low density polyethylene polymer.

In addition, by blending the low density polyethylene polymer (b), the low temperature impact resistance and the bending whitening resistance are improved by increasing the glass transition point component lower than that of the propylene / ethylene block copolymer. In addition, by uniformly finely dispersing the rubber component in the B layer, when used for packaging materials for retort, the occurrence of unevenness (swelling skin) due to swelling of the film by the oily food of the contents is suppressed (anti-resistance) Yuzu skin properties can be improved). The low-density polyethylene resin (b) is preferably a low-density polyethylene, a linear low-density polyethylene, or the like, but the linear low-density polyethylene is a rubber component in the propylene / ethylene block copolymer. This is preferable because the dispersion effect is high, and the resistance to bending whitening and the skin resistance is improved.

The density of the linear low-density polyethylene is in the range of 0.900 to 0.935 g / cm ³ and the MFR is in the range of 0.5 to 20 g / 10 min. It is preferable because the dispersibility is good and the effect of dispersing the rubber component of the propylene / ethylene block copolymer is high.

The method for producing the linear low density polyethylene is not particularly limited, and those produced using a conventional Ziegler-Natta catalyst or a metallocene catalyst can be used.

Furthermore, the above propylene / ethylene block copolymer does not impair the required physical properties of high-performance ethylene-based or styrene-based elastomers that are produced by combining a catalyst technology that achieves a high rubber content and a polymerization process technology. To the extent, that is, 5 to 30% by weight can be contained. Thereby, the dispersion of the sea-island structure can be reduced as in the case of the low-density polyethylene-based polymer.

The layer B in the polypropylene composite film of the present invention is a resin composition in which 15 to 90 parts by weight of the low density polyethylene polymer (b) is blended with 100 parts by weight of the propylene / ethylene block copolymer (a). It has a main component.

When the low density polyethylene polymer (b) is less than 15 parts by weight with respect to 100 parts by weight of the propylene / ethylene block copolymer (a), whitening due to cracks at the time of drawing using, for example, a battery packaging material May occur, and there is a concern that the electrolyte as the content may leak. Moreover, when using it for the retort and the packaging material of an oil-based foodstuff, a yuzu skin may become large and an external appearance defect may arise.

If the low-density polyethylene polymer (b) exceeds 90 parts by weight with respect to 100 parts by weight of the propylene / ethylene block copolymer (a), the shift of the lubricant to the film surface layer is reduced and the slipperiness is poor. In addition, the low temperature impact resistance may be deteriorated. Further, the dispersibility may be deteriorated, and a streak-like defect may be generated at the time of melt extrusion to deteriorate the film forming property.

When the content of the fatty acid amide-based lubricant in the B layer is 500 to 5000 ppm, the polypropylene composite film of the present invention is aged at 60 ° C. or higher for curing the adhesive after lamination with other materials. In addition, the fatty acid amide-based lubricant in the B layer moves to the B layer surface side, and further from there to the A layer. As a result, when it is aged at 60 ° C. or higher, the lubricant contained in the A layer tends to be transferred in the A layer, whereas it is transferred from the B layer to the A layer. Fatty acid amide bleeds on the film surface after aging for 3 days at an optimum range of the amount of lubricant, for example, on the film surface that is properly balanced with the lubricant thus resulting in the problem of slipperiness after lamination. The range of the amount of lubricant can be maintained in the range of 3 to 20 mg / m ² , preferably 5 to 15 mg / m ² , and a static friction coefficient of 0.3 or less between the surfaces of the A layers is achieved.

B layer is a block copolymer having a styrene block with respect to 100 parts by weight of the propylene / ethylene block copolymer (a) and 10 to 90 parts by weight of the low density polyethylene polymer (b), or By adding a resin composition in which 5 to 20 parts by weight of the polymer (c), which is a block copolymer having a crystalline olefin block, is blended, the rubber component in the portion to be islands in the propylene / ethylene block copolymer is further dispersed. Can be small.

The block copolymer having a styrene block or the block copolymer having a crystalline olefin block as the polymer (c) has a block copolymer (c1) having a styrene block or a crystalline olefin block. It is a block copolymer (c2). Examples of the block copolymer (c1) having a styrene block used in the present invention include those provided in JP-A-3-128957. Specifically, the polymer block is composed of a styrene monomer (c3) and a conjugated diene monomer (c4). The styrene monomer (c3) is not particularly limited, and specific examples include styrene, α-methyl styrene, paramethyl styrene, etc. Among these, styrene and α-methyl styrene are preferable, and the polymerization point is high. In particular, styrene is preferable.

Examples of the conjugated diene monomer (c4) include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, Examples include 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene and the like. Among these, a polybutadiene block is preferable because it is excellent in rubber elasticity expressed by the polymer block and can impart excellent impact resistance to the finally obtained polypropylene-based composite film of the present invention.

A commercially available product that can be particularly preferably used as such a block copolymer (c1) having a styrene block includes a styrene / ethylene butylene / styrene triblock copolymer (hereinafter abbreviated as SEBS). . The ethylene butylene block portion is easily compatible with the polypropylene-based resin, and the effect of increasing the compatibility with the propylene / ethylene block copolymer (a) is high. The content of polystyrene block in SEBS is preferably 12 to 67% by weight. When the content of the polystyrene block is 12% by weight or more, the blocking resistance is good, and when it is 67% by weight or less, the low-temperature impact resistance is good. Further, an MFR at 230 ° C. of 0.5 to 10 g / 10 min is preferable. When the MFR is 0.5 g / 10 min or more, the dispersibility of the mixed resin is good, and when the MFR is 10 g / 10 min or less, the low temperature impact resistance is good.

The block copolymer (c2) having a crystalline olefin block used in the present invention is a copolymer having a block (c5) made of crystalline polyolefin and another block (c6) not having crystallinity, Preferably, the other block (c6) has a block made of a role diene polymer.

Examples of the block copolymer (c2) having such a crystalline olefin block include those provided in JP-A-3-128957. Specifically, a polybutadiene polymer block having a low 1,2-vinyl bond content (for example, 25% or less) and a polymer mainly composed of a conjugated diene compound, which contains 1,2- and 3,4-bonds. A copolymer composed of a polymer block having a high rate (for example, 50% or more) is synthesized, and the polybutadiene portion is made to have a structure similar to polyethylene by hydrogenating the copolymer to form a crystalline polymer block. And the like.

Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl. 1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene, and the like. From the viewpoint of industrial availability, 1,3-butadiene and isoprene are preferably used. As a commercially available product that can be particularly preferably used as such a block copolymer having a crystalline olefin block, a block copolymer having a configuration of polyethylene, ethylene butylene, and polyethylene (hereinafter abbreviated as CEBC) can be mentioned. Since the ethylene butylene block portion is easily compatible with the polypropylene resin and the polyethylene block portion is easily compatible with the polyethylene resin, the propylene / ethylene block copolymer (a) and the low density polyethylene polymer (b ) Is highly effective in increasing compatibility. The polyethylene block content in CEBC is preferably 15 to 40% by weight. When the content of the polyethylene block is 15% by weight or more, the blocking resistance is good, and when it is 40% by weight or less, the low-temperature impact resistance is good. Further, an MFR at 230 ° C. of 0.5 to 10 g / 10 min is preferable. When the MFR is 0.5 g / 10 min or more, the dispersibility of the mixed resin is good, and when the MFR is 10 g / 10 min or less, the low temperature impact resistance is good.

The B layer has a melt flow rate of 2 to 10 g at 230 ° C. with respect to 100 parts by weight of the propylene / ethylene block copolymer (a) and 10 to 90 parts by weight of the low density polyethylene polymer (b). / 10 minutes, by forming a resin composition containing 10 to 50 parts by weight of the propylene random copolymer (d) having a melting point of 130 to 150 ° C., the interfacial adhesive force with the A layer is increased. As a result, the heat seal strength is increased, which is preferable. When the addition amount of the propylene random copolymer (d) is less than 10 parts by weight, the effect of improving the heat seal strength is not observed, and when it exceeds 50 parts by weight, the low temperature impact resistance may be lowered.

The propylene random copolymer (d) is preferably a random copolymer with an α-olefin such as ethylene, butene, octene, etc., and a propylene / ethylene random copolymer of a copolymer with ethylene is a heat. This is preferable because the range in which both the sealing force and the sliding property can be compatible is wide.

If the melting point of the propylene random copolymer (d) is less than 130 ° C., the layer thickness may be reduced depending on the temperature and pressure at the time of heat sealing, and if the melting point exceeds 150 ° C., the low temperature impact resistance is lowered. Sometimes.

The polypropylene-based composite film of the present invention comprises at least a two-layer structure of A layer / B layer, but the MFR at 230 ° C. is 2 to 10 g / m on the other surface of the B layer in the present invention. A three-layer laminate of layer A / layer B / layer C comprising a main component of a propylene random copolymer having a melting point of 130 to 150 ° C. for 10 minutes and a layer C containing 200 to 2000 ppm of a fatty acid amide lubricant. This is preferable because the laminate strength with other base materials is increased. The reason for this is that when the film surface is subjected to corona discharge treatment to increase the wetting tension, and the adhesive is applied and laminated with another substrate, the surface of the C layer is smoother than the B layer and the bleed-out amount of the lubricant is increased. It is thought that it is low.

In the polypropylene based composite film of the present invention, the static friction coefficient after aging at 23 ° C. for 3 days between the A layer surfaces is preferably 0.3 or less, and more preferably in the range of 0.1 to 0.3. Further, in the polypropylene based composite film of the present invention, the coefficient of static friction after aging at 60 ° C. for 3 days between the A layer surfaces is preferably 0.3 or less, and more preferably in the range of 0.1 to 0.3. If the static friction coefficient between the A layer surfaces exceeds 0.3, battery packaging materials that require slipperiness by drawing, film breakage occurs during molding, resulting in poor product yield, and packaging materials for retort foods. When a bag is processed and used for a flat bag, a standing pouch, etc., the opening of the bag may be poor and the content filling property may be deteriorated. If the static friction coefficient between the A layer surfaces is less than 0.1, a shift may occur when stacking bag-fabricated products.

In addition, when the amount of the lubricant is in the optimum range, the static friction coefficient when the A layer surface and the B layer surface or the C layer surface are overlapped is 0.3 or less, so that the polypropylene composite film of the present invention is wound up in a long length. Occasionally, traps and air pockets are reduced and productivity is improved.

When the content of the fatty acid amide-based lubricant in the B layer is less than 500 ppm, the amount of the fatty acid amide-based lubricant on the surface of the A layer is small, the coefficient of static friction between the A layer surfaces exceeds 0.3, and slipperiness may be deteriorated. It may not be satisfactorily used in battery packaging applications where slipperiness is required by drawing. In addition, if it exceeds 5000 ppm, the friction coefficient can be kept low, but the amount of lubricant on the film surface becomes too large, and the lubricant may adhere to the roll or the like in the film forming or laminating process, which may cause problems in the working environment. . Moreover, when heat-sealing, a lubricant may accumulate at the film interface, and the heat-sealing strength may be reduced.

The thickness of the A layer or C layer of the polypropylene composite film of the present invention is preferably 1 μm or more, and the total thickness is preferably in the range of 20 to 200 μm.

When the thickness of the A layer or the C layer is less than 1 μm, sufficient heat seal strength at 130 ° C. and 160 ° C. may not be obtained, and the range of 2 to 30 μm is preferable. Further, if the total thickness is less than 20 μm, the low temperature impact resistance may not be sufficiently obtained, and there is a concern that the electrolyte solution of the battery, which is the contents, or the retort food may leak. On the other hand, when the total thickness exceeds 200 μm, the laminate processability is lowered and the production cost is increased, which is not preferable.

The volume resistivity of the polypropylene composite film of the present invention is preferably in the range of 1 × 10 ¹¹ to 1 × 10 ¹⁴ Ω · m. The battery packaging material required electrical insulation, the volume resistivity is less than 1 × 10 ¹¹ Ω · m poor insulating properties, there is the battery performance decreases, and when it exceeds 1 × 10 ¹⁴ Ω · m electrostatic May cause problems in laminating properties and battery performance.

In order to make the volume resistivity in the range of 1 × 10 ¹¹ to 1 × 10 ¹⁴ Ω · m, the A layer and the C layer contain 200 to 2000 ppm of fatty acid amide lubricant, and the B layer contains a fatty acid amide lubricant. This can be achieved by adding 500 to 5000 ppm.

The polypropylene composite film of the present invention has a heat seal strength at 130 ° C. of the A layer surfaces of 30 N / 15 mm or more, and a heat seal strength at 160 ° C. or more of 55 N / 15 mm or more. When used as a packaging material, it is preferable in protecting contents.

The packaging material for retort foods requires low-temperature sealing properties, and if the heat seal strength at 130 ° C. between the A layer surfaces is less than 30 N / 15 mm, the contents of the food may leak after retort processing. In addition, when the heat seal strength at 160 ° C. or higher is less than 55 N / 15 mm, when used as a battery packaging material, leakage of electrolyte due to an increase in internal pressure due to heat during charging and discharging, or when used as a retort food packaging material, Liquid leakage may occur from the heat seal part in the bag drop test.

The present invention also provides a battery outer packaging bag and a retort packaging bag made of the laminate as described above.

In the polypropylene composite film of the present invention, the laminate is formed by laminating at least one selected from a biaxially stretched polyethylene terephthalate film, a biaxially stretched polypropylene film, a biaxially stretched nylon film, and an aluminum foil on the opposite side of the A layer. We also provide packaging materials.

As a manufacturing method of the laminate, a normal dry laminating method in which an adhesive is attached to the constituent film of the laminate can be suitably employed. However, if necessary, the polypropylene composite film of the present invention and the base material layer can be attached. For the bonding, a method of extruding and laminating a directly-adhesive polyolefin resin can also be adopted.

The dry laminating adhesive is not particularly limited. For example, when laminating with a biaxially stretched polyethylene terephthalate film, a polyol selected from the group consisting of polyurethane polyols, polyester polyols and polyether polyols. And a two-component reactive adhesive composed of a first liquid composed of one or more of the above and a second liquid (curing agent) composed of isocyanate. When laminating with an aluminum foil, for example, an adhesive layer formed of a polyurethane adhesive, an acrylic adhesive, an epoxy adhesive, a polyolefin adhesive, an elastomer adhesive, a fluorine adhesive, etc. Can be mentioned. Among them, it is preferable to use an acrylic adhesive or a polyolefin-based adhesive, and when used as a battery packaging material, the electrolytic solution resistance and the water vapor barrier property can be improved.

These laminates are used after being processed into packaging materials such as molded sheets, flat bags, standing pouches, etc., using the polypropylene composite film of the present invention as a sealing layer. In addition, the laminated structure of these laminates is required for packaging materials, for example, sealing performance to satisfy the quality retention period of the food to be packaged, size that can handle the weight of the contents, low-temperature impact resistance, electrolyte resistance, etc. It is appropriately selected depending on.

Hereinafter, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto. Moreover, the measuring method of various physical-property values and the evaluation method are shown below.

(1) Content of 20 ° C. xylene insoluble part and soluble part After 5 g of polypropylene pellets are completely dissolved in 500 mL of boiling xylene (grade 1 manufactured by Kanto Chemical Co., Ltd.), the temperature is lowered to 20 ° C. and left for 4 hours or more. To do. Thereafter, this was filtered into a precipitate and a solution to separate into a soluble part and an insoluble part. For the soluble part, the filtrate was dried and dried at 70 ° C. under reduced pressure, and the weight was measured to determine the content (% by weight).

(2) Intrinsic viscosity of 20 ° C. xylene soluble part and insoluble part ([η] Cxs, [η] Cxis)
Using the sample separated into the soluble part and the insoluble part according to the above (1), measurement was performed in 135 ° C. tetralin using an Ubbelohde viscometer.

(3) Ethylene content of the copolymer The ethylene content was measured by infrared spectroscopy according to the method described in Polymer Analysis Handbook (1995, published by Kinokuniya).

(4) Melt flow rate (MFR)
In accordance with JIS K7210 (1999), the propylene random copolymer and the propylene / ethylene block copolymer were measured at a temperature of 230 ° C., and the low density polyethylene polymer was measured at a temperature of 190 ° C. under a load of 21.18 N, respectively.

(5) Melting point of resin Using a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation), the highest peak temperature of the melting peak when heated from 20 ° C. at a rate of 10 ° C./min and heated to 250 ° C. Was the melting point.

(6) Density of resin It measured by the measuring method by a density gradient tube based on JISK7112 (1999).

(7) Heat seal strength For battery packaging materials, a biaxially stretched PET film (PET-BO) with a thickness of 12 μm, a nylon 6 stretched film (ONy) with a thickness of 15 μm, and aluminum with a thickness of 40 μm formed on both sides. The foil and the B layer or C layer of the polypropylene composite film of the present invention are bonded together by an ordinary dry laminating method using a urethane adhesive, and aged at 60 ° C. for 3 days, and then PET-BO / adhesive / ONy. / Adhesive / Aluminum foil / Adhesive / A laminate (A) of the polypropylene composite film of the present invention (outermost layer A layer surface) was obtained.

In the retort packaging material, a stretched PET film having a thickness of 12 μm, an ONy film having a thickness of 15 μm, and the polypropylene composite film of the present invention are bonded together by a normal dry laminating method using a urethane-based adhesive, and 40 ° C. Was aged for 3 days to obtain a laminate (B) of PET-BO / adhesive / ONy / adhesive / polypropylene composite film of the present invention (outermost layer A layer surface).

For evaluation of the battery packaging material, using the laminate (A), a flat plate heat sealer was used, and the A layer surfaces were overlapped with each other under the conditions of a seal temperature of 160 ° C., a seal pressure of 0.2 MPa, and a soot seal time of 2 seconds. After heat sealing, it was cut into strips with a width of 15 mm, and the heat seal strength was measured by a T-type peeling method at a tensile speed of 300 mm / min using Tensilon manufactured by Orientec. When the heat seal strength was 55 N / 15 mm or more, (◯), and less than 55 N / 15 mm were (×).

Moreover, as evaluation for retort packaging materials, using the said laminated body (B), a flat plate heat sealer is used, A layer surface is piled up, seal temperature 130 degreeC and 160 degreeC, seal pressure 0.2 MPa, seal time After heat-sealing under conditions of 1 second, after cutting into a strip of 15 mm width and performing a retort treatment at 130 ° C. for 30 minutes, using a Tensilon manufactured by Orientec Corporation at a tensile speed of 300 mm / min, The heat seal strength was measured by a mold peeling method. If the heat seal strength at 130 ° C. was 30 N / 15 mm or more, it was rated as (◯), and less than 30 N / 15 mm was marked as (×). Further, the heat seal strength at 160 ° C. was evaluated as (◯) when the heat seal strength was 55 N / 15 mm or more, and (x) when less than 55 N / 15 mm.

(8) Low-temperature impact resistance Using the laminate (B) for retort packaging material prepared by the above heat seal strength measurement, two of the laminates are made of the polypropylene composite film (layer A surface) of the present invention on the inner surface of the bag. A standing pouch having a bag size of 150 mm × 285 mm was prepared using a CA-450-10 type heat sealer manufactured by Fuji Impulse Co., Ltd., with a heating time of 1.4 seconds and a cooling time of 3.0 seconds. This bag is filled with 1 L of 0.1% by weight saline and then retorted at 135 ° C. for 30 minutes. After the retort-treated bag is stored in a refrigerator at 0 ° C. for 24 hours, it is dropped from a height of 50 cm onto a flat floor (n number: 20), and the number of times until the bag is broken is recorded. In this evaluation method, the average number of n times of 20 times until the bag breaks is 30 times or more as good low temperature impact resistance (◯), and less than 30 times as low temperature impact resistance failure (×). evaluated.

(9) Scratch-skin resistance Using the laminate (B) for retort packaging material prepared by the above heat seal strength measurement, two laminates were used as the inner surface of the bag. Heat-sealed under the conditions of a seal temperature of 160 ° C., a seal pressure of 0.2 MPa, and a seal time of 2 seconds, and a three-sided bag (flat bag, seal width of 5 mm) of 160 mm × 210 mm (internal dimensions) )created. After this bag was filled with a commercially available retort curry (Retort Curry “Kukure Curry / Dry” manufactured by House Food Industry Co., Ltd.), the surface roughness of the laminate immediately after retorting at 130 ° C. for 30 minutes was visually determined. The rating was evaluated as Rank 1 for those that did not occur at all, Rank 2 for those that occurred slightly, Rank 3 for those that occurred slightly, Rank 4 for those that occurred clearly, and Rank 5 for those that occurred severely. In this evaluation method, Rank 1 was rated as excellent scratch skin resistance (◎), Rank 2 as excellent scratch skin resistance (耐), and Ranks 4 and 5 as poor scratch skin resistance (×).

(10) Folding whitening resistance After the above retort packaging material laminate (B) was retorted at 130 ° C. for 30 minutes, using a MIT bending tester manufactured by Toyo Seiki Seisakusho, the sample width was 10 mm and the bending angle was 135 degrees. (Left and right) After bending 100 times under the condition of a load of 5.04 N, the whitening state of the bent portion was visually determined (n number of 5). Rank 1 for non-whitening, rank 2 for slightly whitening, rank 3 for light whitening, rank 4 for whitening clearly, rank whitening and the bent portion is white and linear Rated as 5. In this evaluation method, ranks 1 and 2 were evaluated as good folding whitening resistance (◯), and ranks 4 and 5 were rated as poor bending whitening resistance (×).

(11) Film Thickness and Thickness Configuration The film thickness was measured at any 10 points on the film using a dial gauge according to JIS K7130 (1992) A-2 method. The average value was divided by 10 to obtain the film thickness.

The thickness of each layer in the case of a laminated film is determined by embedding the laminated film in an epoxy resin, cutting out the film cross section with a microtome, observing the cross section with a scanning electron microscope at a magnification of 3,000 times, The thickness was calculated.

(12) Coefficient of static friction Measurement was performed according to JIS K7125 (1999) using the A-layer surfaces of the polypropylene-based composite film of the present invention or by overlapping the A-layer surface and the B-layer or C-layer.

(13) Volume resistivity In accordance with JIS K6911 (1995), 500 V is applied between the electrodes between the circular electrodes by the double ring electrode method (measurement of resistivity of 10 ⁸ to 10 ¹⁶ Ω insulator). The resistance value after 1 minute was measured and determined.

(14) Process passability and drawability In the film-forming process of the polypropylene composite film of the present invention, laminating disorder and process roll contamination, and the laminate laminate process for preparing the heat seal strength measurement sample as described in (7) above. Then, the following evaluations were made in view of the occurrence of stains and wrinkles on the process roll and the protrusion of the resin during the drawing.
○: Roll stains and wrinkles were not generated in the film forming process and the laminating process, a product having a good appearance was obtained, and the drawability was also good.
X: Roll stains, wrinkles and the like were generated in the film forming process and the laminating process, and the resin protruded during drawing.

The following were prepared as resins and lubricants for the A layer, B layer, and C layer of Examples and Comparative Examples.
(1) Propylene random copolymer-1
Propylene / ethylene random copolymer (denoted as “EPC-1”) having an MFR of 3.3 g / 10 min and a melting point of 142 ° C.
(2) Propylene random copolymer-2
Propylene-ethylene random copolymer (denoted as “EPC-2”) having a melting point of 138 ° C. with an MFR of 6.0 g / 10 min.
(3) Propylene random copolymer-3
Propylene-ethylene random copolymer (denoted as “EPC-3”) having a melting point of 127 ° C. with an MFR of 12.0 g / 10 min.
(4) Propylene random copolymer-4
A propylene / ethylene random copolymer (denoted as “EPC-4”) having an MFR of 1.5 g / 10 min and a melting point of 132 ° C.
(5) Propylene random copolymer-5
Propylene / ethylene random copolymer having a melting point of 156 ° C. (denoted as “EPC-5”), MFR 5.0 g / 10 min.
(6) Propylene / ethylene block copolymer-1
20 ° C. xylene soluble part 10% by weight, intrinsic viscosity [η] Cxs 3.2 dl / g of the soluble part, 20 ° C. xylene insoluble part 90% by weight, intrinsic viscosity [η] Cxis 1.9 dl / g of the insoluble part, [Η] Cxs / [η] Cxis = 1.68 propylene / ethylene block copolymer (indicated as “BPP-1”).
(7) Propylene / ethylene block copolymer-2
20 ° C. xylene soluble part 10% by weight, intrinsic viscosity [η] Cxs 3.6 dl / g of the soluble part, 20 ° C. xylene insoluble part 90% by weight, intrinsic viscosity [η] Cxis 1.82 dl / g of the insoluble part, [Η] Cxs / [η] Cxis = 1.98 propylene / ethylene block copolymer (indicated as “BPP-2”).
(8) Propylene / ethylene block copolymer-3
20 ° C. xylene soluble part 20% by weight, intrinsic viscosity [η] Cxs 2.5 dl / g of the soluble part, 20 ° C. xylene insoluble part 80% by weight, intrinsic viscosity [η] Cxis 1.8 dl / g of the insoluble part, [Η] Cxs / [η] Cxis = 1.39 propylene / ethylene block copolymer (indicated as “BPP-3”).
(9) Propylene / ethylene block copolymer-4
20 ° C. xylene soluble part 20% by weight, soluble part intrinsic viscosity [η] Cxs 2.6 dl / g, 20 ° C. xylene insoluble part 80% by weight, insoluble part intrinsic viscosity [η] Cxis 1.71 dl / g, [Η] Cxs / [η] Cxis = 1.52 propylene / ethylene block copolymer (indicated as “BPP-4”).
(10) Low density polyethylene polymer-1
Linear low density polyethylene (designated “LLDPE”) with a density of 0.921 g / cm ³ and MFR of 2.2 g / 10 min.
(11) Fatty acid amide lubricant As the fatty acid amide lubricant, erucic acid amide was used.

In Examples 1 to 5 and Comparative Examples 1 to 3, as shown in Table 1, erucic acid amide was mixed with the propylene random copolymers EPC-1 to EPC-5 as the A layer composition. The composition of the B layer is a propylene / ethylene block copolymer (BPP-) having a ratio of xylene soluble part [η] Cxs and insoluble part [η] Cxis at 20 ° C. of [η] Cxs / [η] Cxis of 1.68. 1), linear low density polyethylene (LLDPE) as a low density polyethylene polymer, and erucic acid amide were mixed. Each of the A layer and the B layer was supplied to separate extruders to prepare a non-stretched polypropylene composite film composed of a two-layer coextrusion of A layer / B layer. The thickness of each layer was set to 40 μm in total of 5 μm / 35 μm.

In Examples 6 to 9 and Comparative Examples 4 to 10, as shown in Table 1, erucic acid amide was mixed with propylene random copolymer EPC-1 as the composition of layer A and layer C. As the B layer composition, erucic acid amide was mixed with a resin composition in which BPP-1 or BPP-2 of propylene / ethylene block copolymer, LLDPE, and EPC-1 of propylene random copolymer were mixed. Each of the A layer, the B layer, and the C layer was supplied to separate extruders to prepare a non-stretched polypropylene-based composite film composed of a three-layer coextrusion of A layer / B layer / C layer. The thickness of each layer was set to 40 μm in total of 5 μm / 30 μm / 5 μm.

In Example 10, A layer / B layer / C layer were made to have the same raw material composition as Example 6, and the thickness of each layer was 80 μm in total of 10 μm / 60 μm / 10 μm.

In Example 11, the same formulation as in Example 6 was used except that a propylene / ethylene block copolymer (BPP-2) having [η] Cxs / [η] Cxis of 1.98 was used as the B layer composition. An unstretched polypropylene-based composite film composed of three-layer coextrusion of layer / B layer / C layer was produced.

As shown in Table 1, Examples 1 to 5 are excellent in process passability, low-temperature impact resistance, resistance to bending whitening, and scratch resistance, and have sufficient seal strength at 130 ° C and 160 ° C. The static friction coefficient was 0.3 or less and good slipping property, and the volume resistivity was in the range of 1 × 10 ¹¹ to 1 × 10 ¹⁴ Ω · m.

In Examples 6 to 9, an unstretched polypropylene-based composite film composed of a three-layer coextrusion of A layer / B layer / C layer was used, but the process passability, drawability, low temperature impact resistance, and bending whitening resistance It has excellent scratch resistance, has sufficient seal strength at 130 ° C. and 160 ° C., has a static friction coefficient of 0.3 or less, has good slipperiness, and has a volume resistivity of 1 × 10 ¹¹ to 1 It was in the range of × 10 ¹⁴ Ω · m.

In Example 10, the total thickness was 80 μm, but it was excellent in process passability, drawability, low temperature impact resistance, bending whitening resistance, and scratch skin resistance, and seal strengths of 130 ° C. and 160 ° C. In addition, the coefficient of static friction was 0.3 or less and good slipping property, and the volume resistivity was 3.2 × 10 ¹² Ω · m.

In Example 11, a propylene / ethylene block copolymer (BPP-2) having [η] Cxs / [η] Cxis of 1.98 was used as the B layer composition. It has excellent low-temperature impact resistance, anti-bending whitening resistance, and scratch-proof skin resistance, sufficient seal strength at 130 ° C and 160 ° C, a static friction coefficient of 0.3 or less, and good slipperiness. The resistivity was 7.0 × 10 ¹² Ω · m.

In Comparative Example 1, since the MFR of layer A exceeds 10 g / 10 min and the melting point is less than 130 ° C, the heat seal strength at 160 ° C is low, the amount of lubricant bleed on the surface of layer A is small, The static friction coefficient was high, the slipperiness was poor, and the process passability was poor.

In Comparative Example 2, since the MFR of the A layer was as low as 1.5 g / 10 min, the uniform lamination with the B layer was poor, the film formation stability was poor, and the heat seal strength at 130 ° C. was also low. It was.

In Comparative Example 3, since the melting point of the A layer is as high as 156 ° C., the heat seal strength at 130 ° C. and 160 ° C. is low, the coefficient of static friction between the A layer surfaces is high, and the slipperiness is poor, and wrinkles enter during the lamination process. The process passability was inferior.

In Comparative Example 4, since the content of erucic acid amide in the A layer is as low as 150 ppm, the amount of lubricant bleed on the surface layer of the A layer is small and the slipperiness is inferior. Met.

In Comparative Example 5, since the content of erucic acid amide in the A layer was as high as 2500 ppm, the static friction coefficient was 0.3 or less, but the lubricant was adhered to the process roll, and the process passability was poor. It was. Further, since the amount of lubricant in the A layer was large, the heat seal strength at 130 ° C. was also low.

Comparative Example 6 was inferior in low-temperature impact resistance due to a large amount of LLDPE, inferior in slipperiness due to a small amount of lubricant bleed on the surface layer A, and inferior in process passability.

In Comparative Example 7, since the amount of LLDPE was small, it was inferior in bending whitening resistance and scratch skin resistance, and also had low heat seal strength.

In Comparative Example 8, since the amount of erucamide added to the B layer was as small as 300 ppm, the amount of lubricant bleed on the surface layer of the A layer was small and the slipperiness was poor. Moreover, since the volume resistivity was as high as 2.5 × 10 ¹⁵ Ω · m, static electricity was generated and the process passability was poor.

In Comparative Example 9, since the content of erucic amide in the B layer is as high as 6000 ppm, the amount of lubricant bleed on the surface layer of the A layer is excessive, and the lubricant adheres to the process roll, and the heat seal strength is low. Thus, the volume resistivity was as low as 3.5 × 10 ¹⁰ Ω · m, and the insulation was poor when used as a battery packaging material.

Comparative Example 10 was the same as Example 6 except that the propylene / ethylene block copolymer (BPP-3) having [η] Cxs / [η] Cxis of 1.39 was used as the main component for the B layer. Thus, an unstretched polypropylene-based composite film composed of three-layer coextrusion of A layer / B layer / C layer was produced. The thickness of each layer was set to 40 μm in total of 5 μm / 30 μm / 5 μm. Since [η] Cxs / [η] Cxis is less than 1.6, when heat-sealed, the film is crushed and thinned to reduce the heat-sealing force, and the resin is not protruded by pressurization during drawing. It was seen.

Comparative Example 11 was the same as Example 6 except that the propylene / ethylene block copolymer (BPP-4) having [η] Cxs / [η] Cxis of 1.52 was used as the main component for the B layer. Thus, an unstretched polypropylene-based composite film composed of three-layer coextrusion of A layer / B layer / C layer was produced. Although [η] Cxs / [η] Cxis was close to 1.6, the resin was protruded by pressurization during drawing, and the heat seal strength was low due to thinning during heat sealing.

In Examples 12 to 21 and Comparative Examples 12 to 15, as shown in Table 1, erucic acid amide was mixed with the propylene random copolymers EPC-1 to EPC-5 as the A layer composition. The composition of the B layer is a propylene / ethylene block copolymer (BPP-) having a ratio of xylene soluble part [η] Cxs and insoluble part [η] Cxis at 20 ° C. of [η] Cxs / [η] Cxis of 1.68. 1), linear low density polyethylene (LLDPE) as a low density polyethylene polymer, and styrene / ethylene butylene / styrene triblock copolymer (SEBS) or polyethylene / ethylene butylene / polyethylene triblock copolymer (SEBS) CEBC) and erucic amide were mixed. Each of the A layer and the B layer was supplied to separate extruders to prepare a non-stretched polypropylene composite film composed of a two-layer coextrusion of A layer / B layer. The thickness of each layer was set to 40 μm in total of 5 μm / 35 μm.

In Examples 22 to 29 and Comparative Examples 16 to 21, as shown in Table 1, erucic acid amide was mixed with propylene random copolymer EPC-1 as the composition of the A layer and the C layer. B layer composition is BPP-1 or BPP-2 of propylene / ethylene block copolymer and LLDPE and SEBS or CEBC, and EPC-1 of propylene random copolymer is mixed with erucic acid amide. Mixed. Each of the A layer, the B layer, and the C layer was supplied to separate extruders to prepare a non-stretched polypropylene-based composite film composed of a three-layer coextrusion of A layer / B layer / C layer. The thickness of each layer was set to 40 μm in total of 5 μm / 30 μm / 5 μm.

In Example 30, A layer / B layer / C layer were made to have the same raw material composition as Example 22, and the thickness of each layer was 80 μm in total of 10 μm / 60 μm / 10 μm.

As shown in Table 1, in Examples 12 to 21, the process passability, the low temperature impact resistance, the bending whitening resistance are further excellent, the seal strengths at 130 ° C. and 160 ° C. are sufficient, and the static friction coefficient is The slip resistance was 0.3 or less and the volume resistivity was in the range of 1 × 10 ¹¹ to 1 × 10 ¹⁴ Ω · m.

In Examples 22 to 29, a non-stretched polypropylene-based composite film composed of a three-layer coextrusion of A layer / B layer / C layer was used, but the process passability, drawability, low temperature impact resistance, and bending whitening resistance With excellent seal strength at 130 ° C and 160 ° C, a coefficient of static friction of 0.3 or less and good slipperiness, and a volume resistivity of 1 × 10 ¹¹ to 1 × 10 ¹⁴ Ω · m.

In Example 30, the total thickness was 80 μm, but it was excellent in process passability, drawability, low temperature impact resistance, and bending whitening resistance, and had sufficient seal strength at 130 ° C. and 160 ° C. Yes, the coefficient of static friction was 0.3 or less and good slipping property, and the volume resistivity was 3.2 × 10 ¹² Ω · m.

In Comparative Examples 12 and 13, since the MFR of the A layer exceeds 10 g / 10 min and the melting point is less than 130 ° C, the heat seal strength at 160 ° C is low, the amount of lubricant bleed on the surface of the A layer is small, and the surface of the A layer The coefficient of static friction between them was high, the slipperiness was poor, and the process passability was poor.

In Comparative Example 14, since the MFR of the A layer was as low as 1.5 g / 10 min, the uniform lamination with the B layer was poor, the film formation stability was poor, and the heat seal strength at 130 ° C. was also low. It was.

In Comparative Example 15, since the melting point of the A layer is as high as 156 ° C., the heat seal strength at 130 ° C. and 160 ° C. is low, the coefficient of static friction between the A layer surfaces is high and the slipperiness is poor, and wrinkles enter during the lamination process. The process passability was inferior.

In Comparative Example 16, since the content of erucic acid amide in the A layer is as low as 150 ppm, the amount of the lubricant bleed on the surface of the A layer is small and the slipperiness is inferior. Met.

In Comparative Example 17, since the content of erucic acid amide in the A layer was as high as 2500 ppm, although the static friction coefficient was 0.3 or less, there was adhesion of the lubricant to the process roll, and the process passability was poor. It was. Further, since the amount of lubricant in the A layer was large, the heat seal strength at 130 ° C. was also low.

Comparative Example 18 was inferior in low-temperature impact resistance due to the large amount of LDPE blended in layer B, inferior in slipperiness due to a small amount of lubricant bleed in the surface layer A and inferior in process passability.

In Comparative Example 19, since the amount of LLDPE in the B layer was small, the folding whitening resistance was inferior and the heat seal strength was low.

In Comparative Example 20, since the amount of erucic acid amide added to the B layer was as small as 300 ppm, the amount of lubricant bleed on the surface layer of the A layer was small, and the slipperiness was poor. Moreover, since the volume resistivity was as high as 2.5 × 10 ¹⁵ Ω · m, static electricity was generated and the process passability was poor.

In Comparative Example 21, since the content of erucamide in the B layer is as high as 6000 ppm, the amount of lubricant bleed on the surface layer of the A layer is excessive, and the lubricant adheres to the process roll, and the heat seal strength is low. Thus, the volume resistivity was as low as 3.5 × 10 ¹⁰ Ω · m, and the insulation was poor when used as a battery packaging material.

The polypropylene-based composite film of the present invention and a packaging material using the polypropylene-based composite film have high heat-sealing power, excellent slipperiness, and can be suitably used for battery exterior applications. The polypropylene composite film of the present invention and a packaging material using the same are packaging materials for retort foods that are excellent in slipperiness, low-temperature impact resistance, and skin-resistant properties, and that require heat seal strength at low temperatures. Can be suitably used.

Claims

It consists of at least two layers of A layer / B layer,
Layer A is composed mainly of a propylene random copolymer having a melt flow rate at 230 ° C. of 2 to 10 g / 10 min and a melting point of 130 to 150 ° C.
Layer B is propylene having a ratio ([η] Cxs / [η] Cxis) of the intrinsic viscosity [η] Cxs of the soluble part of 20 ° C. xylene to the intrinsic viscosity [η] Cxis of the insoluble part of 1.6 or more. The main component is a resin composition in which 10 to 90 parts by weight of the low density polyethylene polymer (b) is blended with 100 parts by weight of the ethylene block copolymer (a).
Layer A contains 200-2000 ppm of fatty acid amide lubricant,
Layer B contains a polypropylene based composite film containing 500 to 5000 ppm of fatty acid amide based lubricant.
The polymer (B) is a block copolymer having a styrene block or a block copolymer having a crystalline olefin block with respect to 100 parts by weight of the propylene / ethylene block copolymer (a). The polypropylene composite film according to claim 1, wherein 5) to 20 parts by weight of c) is blended.
The polypropylene-based composite film according to claim 1 or 2, wherein the polymer (c) of the B layer is a styrene / ethylene butylene / styrene triblock copolymer.
The polypropylene-based composite film according to claim 1 or 2, wherein the polymer (c) of the B layer is a polyethylene / ethylene butylene / polyethylene triblock copolymer.
Layer B is a propylene-based random copolymer having a melt flow rate of 2 to 10 g / 10 min at 230 ° C. and a melting point of 130 to 150 ° C. with respect to 100 parts by weight of the propylene / ethylene block copolymer (a). 5. The polypropylene based composite film according to claim 1, wherein 10 to 50 parts by weight of the polymer (d) is blended.
A layer in which a C layer containing a propylene random copolymer having a melt flow rate at 230 ° C. of 2 to 10 g / 10 min and a melting point of 130 to 150 ° C. as a main component and containing 200 to 2000 ppm of a fatty acid amide lubricant is laminated. The polypropylene composite film according to any one of claims 1 to 5, comprising a three-layer laminate of / B layer / C layer.
The polypropylene composite film according to claim 6, wherein the thickness of the C layer is 1 μm or more and the total thickness is in the range of 20 to 200 μm.
The polypropylene composite film according to any one of claims 1 to 7, wherein the layer A has a thickness of 1 µm or more and a total thickness in the range of 20 to 200 µm.
The polypropylene based composite film according to any one of claims 1 to 8, wherein the static friction coefficient between the A layer surfaces is 0.3 or less after aging at 23 ° C for 3 days.
The polypropylene composite film according to any one of claims 1 to 9, wherein the static friction coefficient between the A layer surfaces is 0.3 or less after aging at 60 ° C for 3 days.
11. The polypropylene based composite film according to claim 1, wherein the volume resistivity is in the range of 1 × 10 11 to 1 × 10 14 Ω · m.
The surface of the polypropylene-based composite film according to any one of claims 1 to 11 is selected from the group consisting of a biaxially stretched polyethylene terephthalate film, a biaxially stretched polypropylene film, a biaxially stretched nylon film, and an aluminum foil. A laminate in which at least one is laminated.
The heat seal strength at 130 ° C. between the A layer surfaces of the laminated polypropylene-based composite film is 30 N / 15 mm or more, and the heat seal strength at 160 ° C. or more is 55 N / 15 mm or more. The laminated body of description.
A battery packaging material using the laminate according to claim 12 or 13.
A packaging material for retort using the laminate according to claim 12 or 13.