TW202146225A - Composite film, and layered film and layered body using same - Google Patents

Abstract

Provided are: a composite film having at least two layers, which are a base layer (A) and a heat seal layer (B), wherein the base layer (A) comprises a resin composition yielded by mixing 1 to 10 parts by weight of a polyethylene-based polymer (a2) with 100 parts by weight of a propylene random copolymer (a1) having a fusing point of 140 DEG C or higher, and the heat seal layer (B) comprises a resin composition yielded by mixing 5 to 50 parts by weight of an ethylene-[alpha]-olefin copolymer (b2) having a fusing point of 130 DEG C or lower with 100 parts by weight of a propylene random copolymer (b1) having a fusing point of 145 DEG C or lower; and a layered film and a layered body using the composite film. The invention can provide: a composite film demonstrating excellent low-temperature heat-sealability and blocking resistance, suitable air-tightness even when prior art bag production methods and fast filling speed are used, and excellent processability when layering a layer for imparting functionality on the surface of the film; and a layered film and a layered body using the composite film.

Description

Composite film and laminate film and laminate using the same

The present invention relates to a composite film and a laminate film and laminate using the same. More specifically, it relates to a composite film having excellent low-temperature heat-sealability and anti-blocking properties, and a laminate film in which a function-imparting layer is laminated on the composite film, and the composite film or a laminate of the laminate films is used.

As a laminate for food packaging, there are widely known substrate films used for polyethylene terephthalate (PET) films or nylon (Ny) films, especially stretched PET films or stretched nylon films (ONy). , a laminate in which a polypropylene-based film is laminated as a sealing film.

In particular, the non-stretch polypropylene-based film can be heat-sealed at low temperature and has excellent heat resistance and workability, so it is an excellent food packaging material. Here, the non-stretch polypropylene-based film imparts decoration such as metal evaporation, printing, and light blocking. It can be used in a wide range mainly for packaging applications.

Recently, under the background of the global increase in marine plastic waste, it is required to promote the recycling process of plastic packaging materials after use. As a laminate of biaxially stretched polypropylene/non-stretched polypropylene sealing film.

However, the laminated system of biaxially stretched polypropylene/non-stretched polypropylene sealing film has poor heat resistance, and the above-mentioned laminated body melts at the temperature of high-speed filling after conventional bag making, so it is necessary to reduce the bag making temperature and the filling speed. . Therefore, it becomes a big obstacle to application expansion.

Therefore, in order to solve the above-mentioned problems, for the purpose of improving low-temperature sealing properties during bag making and high-speed filling, a single-layer film composed of a propylene-α-olefin copolymer is known (refer to Patent Document 1), or a base film is known. The layer (A) and the sealing layer (B) are composed of two layers, and the melting point of the sealing layer is lowered (Patent Document 2) and the like.

However, in the films of Patent Document 1 and Patent Document 2, when a packaging bag is produced by heat-sealing with a hot plate, or when heat sealing is performed to seal food or the like in a bag-made product (the end of the hot plate), Due to insufficient melting of the sealing resin and insufficient bonding strength at the composite interface, that is, insufficient low-temperature heat sealability and deterioration of the sealability, the problem of obtaining productivity under the conventional bag making and high filling speed has not been solved. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 6-68050 [Patent Document 2] Japanese Patent Laid-Open No. 9-85912

(The problem that the invention intends to solve)

The object of the present invention is to provide a composite film having excellent low-temperature heat sealability and anti-blocking properties, good sealing properties under conventional bag-making and high-speed filling speeds, and excellent processability when the surface layer is functionally imparted to the film surface layer. and laminated films and laminates using the same. (Technical means to solve problems)

In order to solve the above-mentioned problems, the present invention adopts the following configuration. (1) A composite film having at least two layers of a base layer (A) and a heat seal layer (B), wherein the base layer (A) contains: a propylene-random copolymer having a melting point of 140° C. or higher A resin composition in which 1 to 10 parts by weight of polyethylene-based polymer (a2) is mixed into 100 parts by weight of compound (a1); the above-mentioned heat sealing layer (B) contains: propylene with a melting point of 145°C or less and random copolymerization A resin composition containing 5 to 50 parts by weight of the ethylene·α-olefin copolymer (b2) having a melting point of 130° C. or less is mixed with 100 parts by weight of the composite (b1). (2) The composite film according to (1), wherein the base layer (A) contains 30% by weight or less of the constituent components of the heat seal layer (B) as a self-recovery component of the composite film. (3) The composite film according to (1), wherein the propylene-random copolymer (a1) of the base layer (A) contains ethylene-propylene random copolymer and ethylene-propylene-1-butene 3-membered copolymer combination or a mixture of these. (4) The composite film according to (1), wherein the propylene/random copolymer (a1) of the base layer (A) has a melting point in the range of 140 to 155°C. (5) The composite film according to (1), wherein the polyethylene-based polymer (a2) of the base layer (A) contains high-density polyethylene. (6) The composite film according to (1), wherein the propylene/random copolymer (b1) of the heat sealing layer (B) contains an ethylene/propylene random copolymer and a propylene/1-butene random copolymer , ethylene·propylene·1-butene 3-membered copolymer or a mixture of these. (7) The composite film according to (1), wherein the α-olefin of the ethylene·α-olefin copolymer (b2) of the heat sealing layer (B) contains butene, hexene, octene, or the like. mixture. (8) The composite film according to (1), wherein the heat-sealing layer (B) contains 5 to 30 parts by weight of a thermoplastic elastomer. (9) The composite film according to any one of (1) to (8), wherein in the composite film according to any one of (1) to (8), an adhesive with a thickness of 20 μm is used by dry lamination. The heat-sealing strength of the biaxially stretched polypropylene film is 3N/15mm or more when the heat-sealing layers (B) sides of the composite film are overlapped and heat-sealed at 120°C (one-side heating). (10) A laminated film, which is attached to the surface of the base layer (A) of the composite film of (1), and is provided with a function-imparting layer for imparting a specific function. (11) The laminate film according to (10), wherein the specific function is at least one function selected from the group consisting of gas barrier properties, light shielding properties, gloss properties, wettability, easy adhesion to other substrates, and easy printability . (12) The laminated film according to (10) or (11), the oxygen transmission rate of which is 50 cc/m ² ·day or less at 23° C. and 0% humidity. (13) A laminate in which the composite film of (1) is laminated on another base material layer so that the base layer (A) thereof is on the side of the other base material layer. (14) A layered product in which the layered film of (10) is layered on another substrate layer such that the function-imparting layer is on the side of the other substrate layer. (15) The laminate according to (13) or (14), wherein the other base material layer is a biaxially stretched polypropylene film using a polypropylene resin having a stereoregularity of 90 to 98%. (Compared to the efficacy of the prior art)

By setting the composition of the composite film of the present invention, the low temperature heat sealability and anti-blocking property are excellent, the sealability is good under the conventional bag making and high-speed filling speed, and the surface area layer of the film is functionally imparted to the layer. The processability is excellent. Moreover, by the surface layer function imparting layer of the base layer (A), and other substrates are laminated thereon to form a laminated film or a laminated body for packaging, it can have a high degree of high-speed filling suitability, and can be filled in packaging. , to achieve superior productivity without failure.

Hereinafter, the present invention will be described in further detail along with preferred embodiments. The propylene/random copolymer (a1) used in the base layer (A) in the present invention may be ethylene/propylene random copolymer, ethylene/propylene block copolymer, ethylene/propylene/1-butene 3-membered copolymer The copolymer or a mixture of these is preferably an ethylene·propylene·butene random copolymer in terms of the adhesion between the layers and the secondary processability provided by the function.

When the melting point of the above-mentioned propylene-random copolymer (a1) is 140°C or higher, preferably in the range of 140-155°C, the high-speed filling property during bag making is excellent, and the lamination function provides the layer with processability and tightness. good, so better.

Moreover, the melt flow rate (hereinafter abbreviated as MFR) of the propylene/random copolymer (a1) may be in the range of 2 to 20 g/10 minutes, preferably 5 to 15 g/10 minutes. When the MFR is less than 2 g/10 minutes, the polymer fluidity during extrusion is insufficient; when the MFR exceeds 20 g/10 minutes, there may be problems with the film-forming stability during film-forming casting.

In the base layer (A), the rigidity of the film is increased by mixing 1 to 10 parts by weight of the polyethylene-based polymer (a2) with respect to 100 parts by weight of the above-mentioned propylene/random copolymer (a1). When it is less than 1 part by weight, the effect of imparting rigidity is not found, and when it is more than 10 parts by weight, the effect of imparting rigidity does not change even if it is mixed.

The above-mentioned polyethylene-based polymer (a2) is preferably high-density polyethylene. When the density of high-density polyethylene is in ^{the range of 0.935~0.965g/cm 3} , it is better in terms of the film's anti-blocking and sliding properties. When the density is less than 0.935 g/cm ³ , the effect of addition is not found; when the density exceeds 0.965 g/cm ³ , the surface of the film is too rough, and the density of the layer when the layer is provided with a lamination function may deteriorate.

The MFR of the polyethylene-based polymer (a2) may be in the range of 2 to 20 g/10 minutes, particularly preferably 5 to 15 g/10 minutes. When the MFR is less than 2g/10min, the dispersibility of the propylene/random copolymer (a1) deteriorates and the polymer fluidity during extrusion deteriorates; when it exceeds 20g/10min, melt fracture occurs and the A case of reduced membrane stability.

The base layer (A) in the present invention as described above may also contain 30% by weight or less of the constituent components of the heat seal layer (B) as follows, as a self-recovery component of the composite film of the present invention (that is, as a composite film) shavings or recovered edge components). Since the self-recycling component of the composite film can be recycled without greatly changing the composition or ratio of the main component of the base layer (A), the target performance of the composite film of the present invention can be ensured and the composite film of the present invention can be maintained. High production yield of thin films.

The propylene·random copolymer (b1) used in the heat sealing layer (B) in the present invention is preferably an ethylene·propylene random copolymer, a propylene·1-butene random copolymer, an ethylene·propylene·1 -Butene 3-membered copolymers or mixtures thereof, especially ethylene-propylene random copolymers, and mixtures of propylene-1-butene random copolymers can take both anti-blocking and low-temperature heat sealing properties into account, so better.

The melting point of the above-mentioned propylene/random copolymer (b1) is 145°C or lower. When the melting point exceeds 145° C., the low-temperature heat sealability may be deteriorated. The lower limit of the melting point is not limited, but is about 115°C. If it is less than this, the slipperiness of the film deteriorates, the coefficient of friction increases, and wrinkles are likely to occur during the film forming step or the vapor deposition step, and the film sticks when filling the contents of the bag-making product, resulting in poor opening. situation.

Moreover, the MFR of the said propylene/random copolymer (b1) becomes like this. Preferably it is the range of 3-20 g/10min, especially 5-15 g/10min. When the MFR is less than 3g/10min, the melt viscosity is too high, and it is difficult to stably extrude from the die during film formation; if it exceeds 20g/10min, there will be a problem of melt cracking, which will cause problems in film formation stability.

The mixing amount of the ethylene·α-olefin copolymer (b2) in the heat sealing layer (B) in the present invention must be mixed with 100 weight parts of the above-mentioned propylene·random copolymer (b1), 5~50 weight parts, more It is preferably 11 to 50 parts by weight. When the blending amount of the ethylene-α-olefin copolymer (b2) is less than 5 parts by weight, the low-temperature heat-sealability is lowered. When the composite film is laminated with other substrates and heat-sealed by a hot plate to produce a package , or when the sealing resin is insufficiently melted and filled when filling food, etc. in the bag-making product, poor sealing performance occurs. On the other hand, when the compounding amount exceeds 50 parts by weight, uneven flow occurs at the interface with the base layer (A), film-forming stability is deteriorated, the slack of the film is increased, and secondary workability is deteriorated.

The melting point of the ethylene·α-olefin copolymer (b2) is 130°C or lower. When the melting point exceeds 130° C., the curl of the film becomes large, and there are cases in which failure occurs during the secondary processing such as bag making or provision of a function-imparting layer. In addition, when the composite film and other base materials are laminated and heat-sealed with a hot plate to produce a package, or when the sealing resin is insufficiently melted and filled with food, etc. in a bag-made product, poor sealing properties may occur. . The lower limit of the melting point is not limited, but is about 100°C. If it is less than this, the slipperiness of the film is deteriorated, blocking is likely to occur, and when the bag product is filled with the contents, the unsealing property of the bag is lowered, and a failure may occur.

The α-olefin of the ethylene·α-olefin copolymer (b2) of the heat sealing layer (B) in the present invention comprises butene, hexene, octene or a mixture thereof, and the ethylene·α-olefin copolymer (b2) Preferred is linear low density polyethylene. Moreover, it is preferable to use the said linear low-density polyethylene from a viewpoint of sealing strength using what was produced by the metallocene type catalyst.

The above-mentioned linear low density polyethylene of a density of preferably 0.900 ~ 0.935g / cm ³ were, more preferably in a range of 0.915 ~ 0.930g / cm ³ of. When the density of linear low-density polyethylene is less than 0.900 g/cm ³ , the anti-blocking property decreases; when ^{the density exceeds 0.935 g/cm 3} , the dispersibility may decrease.

When the heat-sealing layer (B) in the present invention contains 5 to 30 parts by weight of the thermoplastic elastomer, it is preferable because the productivity and the sealing initiation temperature are lower.

The above thermoplastic elastic system refers to having rubber elasticity at 25°C by having a hard segment phase and a soft segment phase; on the other hand, by having a temperature ranging from 100°C to 300°C, which belongs to the forming temperature range of general thermoplastics A high-molecular-weight body that exhibits fluidity in the hard segment phase in the region and can be molded in the same way as general thermoplastic resins. As the thermoplastic elastomer used for the sealing layer, for example, polyester-based elastomers, polyolefin-based elastomers, polyamide-based elastomers, polyurethane-based elastomers, styrene-based elastomers, and Polyacrylic elastomers and the like are used alone or in combination. Among them, it is preferable to use a polyolefin-based elastomer and a hydrogenated styrene-based elastomer from the viewpoint of the low-temperature sealing properties of the obtained film.

As the polyolefin-based elastomer, a propylene-based elastomer and an ethylene-based elastomer are preferred.

The propylene-based elastomer is an elastomer containing a structural unit derived from propylene, and in one embodiment, is a copolymer containing a structural unit derived from propylene. In the above-mentioned propylene-based elastomer, the content of the constituent units derived from propylene is preferably 30 to 90% by weight, more preferably 50 to 90% by weight. Within such a range, an adhesive sheet excellent in stretchability can be obtained.

Examples of other copolymerization components constituting the above-mentioned propylene-based elastomer include ethylene, 1-butene, 2-methylpropene, 1-pentene, 3-methyl-1-butene, 1-hexene, Constituent units of monomers such as 4-methyl-1-pentene and 1-octene. Among them, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, etc. are preferred, and ethylene and 1-butene are particularly preferred. These can be used alone or in combination of two or more. In one Embodiment, the said propylene-type elastic system contains the structural unit derived from ethylene. In the above-mentioned propylene-based elastomer, the content ratio of the constituent unit derived from ethylene is preferably 5% by weight to 20% by weight, more preferably 8% by weight to 15% by weight.

The ethylene-based elastomer is preferably a low-crystalline random copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms, more preferably a low-crystalline random copolymer of ethylene and an α-olefin having 3 to 4 carbon atoms. The low-crystalline random copolymer of ethylene and α-olefin having 3 to 8 carbon atoms is preferably an ethylene-butene random copolymer having excellent low temperature sealing properties, more preferably an ethylene-1-butene random copolymer combined. When the content of the α-olefin having 3 to 8 carbon atoms is in the range of 5 to 25 wt %, preferably 10 to 20 wt %, it is preferable because both anti-blocking properties and low temperature sealing properties can be achieved.

The density of the ethylene-based elastomer is 0.865-0.890 g/cm ³ , and the endothermic heat of fusion during the heating process according to the differential scanning calorimeter (DSC) of JIS K7122 is preferably in the range of 5-30 J/g. When the density is less than 0.865 g/cm ³ , the blocking resistance is deteriorated, and when the density exceeds 0.890 g/cm ³ , the impact resistance may be deteriorated.

A hydrogenated styrene-based elastomer is a polymer comprising: a polymer block A mainly composed of at least one vinyl aromatic compound, and a polymer mainly composed of at least one hydrogenated conjugated diene compound Block B; The structure constituted includes, for example, a hydrogenated block copolymer containing ABA, BABA, BABAB, a mixture thereof, and the like. The hydrogenated block copolymer preferably contains 10 to 40% by weight of the vinyl aromatic compound.

Examples of the vinyl aromatic compound constituting the polymer block A include styrene and α-methylstyrene, and styrene is particularly preferred. In addition, examples of the conjugated diene compound before hydrogenation of the hydrogenated conjugated diene compound constituting the polymer block B include butadiene, isoprene, and 1,3-pentadiene, and particularly preferred are Butadiene, isoprene. In the vinyl aromatic compound-conjugated diene compound block copolymer, preferably 80%, preferably 90% or more of the aliphatic double bonds of the conjugated diene compound are hydrogenated and polymerized as an olefin-based compound Body block B.

As a representative hydrogenated styrene-based elastomer, in order to improve the weather resistance and heat resistance of the styrene-butadiene-styrene block copolymer, for example, styrene-butadiene-styrene, which is a hydrogenated product of hydrogenation of double bonds, is mentioned. The ethylene-butylene-styrene block copolymer (hereinafter abbreviated as SEBS), the hydrogenated product of the styrene-isoprene-styrene block copolymer (hereinafter abbreviated as SIS), etc., are particularly preferably SEBS. Among SEBS, those with low styrene content and high ethylene and butene content are superior in compatibility with the sea component composed of ethylene-propylene copolymer in the sealing layer. Specifically, "DYNARON" manufactured by JSR Corporation can be appropriately used. For "8601P", "TUFTEC" H1062 manufactured by Asahi Kasei Co., Ltd., or G1660 manufactured by KRATON POLYMER JAPAN Co., Ltd., the total weight of ethylene and butene relative to styrene is preferably in the range of 12/88 to 67/33.

In addition, the above-mentioned base layer (A) and heat-sealing layer (B) may contain antioxidants, heat-stabilizing agents, neutralizing agents, and antistatic agents within the range that does not impair the heat-sealability or the lamination properties of the function-imparting layers. , Hydrochloric acid absorbent, anti-blocking agent, slip agent, etc. These additives may be used alone or in combination of two or more.

As the anti-blocking agent, adding 300 to 5000 ppm of inorganic particles or organic particles is preferable because when the composite film of the present invention is wound into an elongated shape, wrinkles and defects due to poor ventilation are reduced. When the content of inorganic particles or organic particles is less than 300 ppm, the effect of imparting anti-blocking properties may not be found, and if it exceeds 5,000 ppm, the heat-sealing force may decrease.

Preferable examples of the inorganic particles include silica, zeolite, calcium carbonate, and the like, and examples of the organic particles include cross-linked polystyrene particles, cross-linked polymethyl methacrylate particles, and the like. These average particle diameters are preferably in the range of 1 to 5 μm. When the average particle diameter is less than 1 μm, the effect of the addition may not be found, and when it exceeds 5 μm, the heat sealing force may decrease.

磷雜環庚烷(「Sumilizer」GP)、及丙烯酸2[1-2-羥基-3,5-二第三戊基苯基]乙基]-4,6-二第三戊基苯基(「Sumilizer」GS)，尤其是此兩者併用時，於薄膜製膜時有效發揮氧化劣化抑制，有助於兼顧抗黏連性或低溫熱密封性，故較佳。又，作為抗氧化劑之添加量，係視所使用之抗氧化劑之種類而異，可於100~10000ppm之範圍內適當設定。Moreover, as specific examples of antioxidants, 2,6-di-tert-butylphenol (BHT), n-octadecyl-3-(3',5'-di-tert-butyl- 4'-Hydroxyphenyl)propionate ("Irganox" 1076, "Sumilizer" BP-76), tetra[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propane Acetate] methane ("Irganox" 1010, "Sumilizer" BP-101), ginseng (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanate ("Irganox" 3114, Mark AO-20) Wait. In addition, as phosphite-based (phosphorus-based) antioxidants, for example, ginseng (2,4-di-tert-butylphenyl) phosphite ("Irgafos" 168, Mark 2112), bismuth (2,4- Di-tert-butylphenyl)-4-4'-biphenyl-diphosphite ("Sandstab" P-EPQ), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite ("Ultranox" 626, Mark PEP-24G), distearyl pentaerythritol diphosphite (Mark PEP-8), etc. Among them, 6-[3-(3-tert-butyl-4-hydroxy-5-methyl)propoxy]-2 having both the functions of these hindered phenolic and phosphite esters is preferred ,4,8,10-Tetratert-butyldibenzo[d,f][1,3,2]-di

Phosphatane ("Sumilizer" GP), and 2[1-2-hydroxy-3,5-di-tert-pentylphenyl]ethyl]-4,6-di-tert-pentylphenyl acrylate ( "Sumilizer" GS), especially when the two are used together, is preferable because it effectively suppresses oxidative deterioration during film formation, and contributes to both blocking resistance and low-temperature heat sealability. In addition, the amount of the antioxidant to be added varies depending on the type of the antioxidant to be used, and can be appropriately set within the range of 100 to 10,000 ppm.

The composite film of the present invention may be constituted by a two-layer lamination of the base layer (A) and the heat-sealing layer (B) as described above, or may be constituted by three or more laminations in which other intermediate layers are interposed between the two layers. As the intermediate layer, the same propylene-based polymer as the base layer (A), or homopolypropylene or the like can be used to improve the strength or rigidity of the film laminate, or in terms of quality stabilization and cost reduction, the Fragments or regenerated particles obtained by pulverizing the thin film in the process of thickness adjustment or the slit debris generated in the process of producing the composite film of the present invention, or regenerated particles are mixed.

The lamination method of the composite film having the base layer (A), the heat sealing layer (B) and the intermediate layer in the present invention is not particularly limited, and generally it is melt extrusion, sleeve and sleeve using separate extruders. A method of lamination by a method such as a pinole or a feed block method, such as tubular compounding, and a method such as a co-extrusion multi-layer die method.

The thickness of the composite film in the present invention is not particularly limited, but is usually about 15 μm to 80 μm, and from the viewpoint of workability, it is particularly preferably 20 μm to 40 μm; the thickness ratio of the heat seal layer (B) is preferably the overall thickness 10~50%, more preferably 15~40%. When the thickness ratio of the heat-sealing layer (B) is less than 10%, the heat-sealing force may decrease and the sealing performance may be deteriorated. Moreover, when it exceeds 50 %, heat resistance may fall, high-speed filling property, and the secondary workability at the time of lamination|stacking of a function-imparting layer, or lamination|stacking with another base material may also worsen.

The composite film of the present invention can be used as a laminated film in which a function-imparting layer for imparting a specific function is provided on the surface of the base layer (A).

The function-imparting layer in the present invention refers to a layer that imparts a specific function to the above-mentioned composite film. The so-called specific function is at least one function selected from the group consisting of gas barrier properties, light shielding properties, gloss properties, easy adhesion with other substrates, and easy printability. A specific function may be only one function or several functions.

The gas-barrier property in the present invention refers to the gas-barrier property against oxygen, water vapor, nitrogen, and carbon dioxide gas, preferably, the gas-barrier property for oxygen and water vapor. The oxygen barrier property can be measured according to the method described in the Japan Industrial Association Standard (JIS K-7126). The oxygen barrier property in the present invention refers to the oxygen transmission rate at a temperature of 23°C and a relative humidity of 0%.

In addition, the water vapor barrier property can be measured according to the method described in the Japan Industrial Association (JIS K-7129B), and refers to the water vapor transmission rate at a temperature of 40°C and a relative humidity of 90%.

The oxygen permeability is preferably 50 cc/m ² ‧day‧atm or less, more preferably 30 cc/m ² ‧day‧atm or less.

The light-shielding property in the present invention refers to a function of total light transmittance of 5% or less measured by the method described in Japanese Industrial Standards (JIS K-7361). More preferably, the total light transmittance is less than 3%.

The glossiness in the present invention means the glossiness measured at 60° for both incident light and reflected light according to the method described in Japanese Industrial Standards (JIS Z-8741). The gloss after aluminum vapor deposition is preferably 300% or more, more preferably 400% or more.

In the present invention, the so-called easy adhesion with other substrates refers to the ease of adhesion with other substrates described later. The so-called ease of bonding refers to the ease of bonding to the base layer (A) of the composite film of the present invention. The ease of adhesion is not particularly limited, for example, the ease of adhesion of the adhesive used when laminating with other substrates to the base layer (A) of the composite film of the present invention; The ease of adhesion of the extruded resin to the base layer (A) of the composite film of the present invention; the ease of adhesion of the extruded resin to the base layer (A) of the composite film of the present invention during extrusion coating; The ease of adhesion of the sputtering and vapor deposition components to the base layer (A) of the composite film of the present invention during vacuum evaporation; or the adhesion of the resin applied during coating processing to the base layer (A) of the composite film of the present invention viscosity, etc.

Although it does not specifically limit as a method of providing easy-bonding adhesiveness, For example, the method of processing the surface of the base layer (A) of a composite film is mentioned. As a method of treating the surface, for example, corona treatment, flame treatment, plasma treatment, ozone treatment, ion treatment, sputtering treatment, sandblasting treatment, anchor coating and other surface modification treatment by resin, etc. are mentioned. For example, a method of chemically forming reactive functional groups on the surface of the base layer (A), etc.; adding particulate matter to resins such as anchor coating, and sputtering, sandblasting, etc. The method of roughening the surface to physically form the surface unevenness having an anchoring effect on the surface of the base layer (A) may be carried out by any method or a combination of any method. The method of treating the surface of the base layer (A) can be carried out in-line when the composite film of the present invention is formed, or can be carried out outside the line after the composite film is formed. In addition, only the surface treatment may be performed, or when the function-imparting layer is formed, the function-imparting layer may be continuously formed after the surface treatment of the base layer (A). The surface treatment may be performed after the function-imparting layer is formed.

The printability in the present invention refers to the ease of printing on the base layer (A) of the composite film of the present invention. Printing is performed in order to represent the text information, patterns, etc. necessary for the packaging bag or the like as a packaging body. The components of printing are made by adding various pigments, extenders, plasticizers, desiccants, etc. to conventional ink binder resins such as urethane, acrylic, nitrocellulose, and rubber. Consisting of inks made of additives such as stabilizers, the so-called ease of printing refers to easy adhesion of printing components during printing, and less drop-off such as dot-like drop-off of the ink.

It does not specifically limit as a method of providing easy printability, For example, the method of processing the surface of the base layer (A) of a composite film is mentioned. As a method of surface treatment, surface modification treatment by resin, such as corona treatment, flame treatment, plasma treatment, ozone treatment, ion treatment, anchor coating, etc. are mentioned, for example. For example, the method of forming a functional group with high reactivity to the printed ink on the surface of the base layer (A), etc.; the method of using an anchor coating resin to which the printed ink is easy to adhere; the wettability for improving the wettability A method of adding a modifier and the like to the anchor coating resin, and the like. The method of treating the surface of the base layer (A) can be carried out before printing, in-line when the composite film of the present invention is formed, or out-of-line after the composite film is formed. Also, only the surface treatment may be performed. Moreover, after winding up the composite film of this invention, the surface treatment of a base layer (A) may be performed, and printing may be performed continuously.

If the functions of gas barrier properties, light shielding properties, gloss properties, easy adhesion with other substrates, and easy printing properties in the present invention can be imparted, the function imparting layer can be an inorganic layer, an organic layer, or an inorganic-organic mixture. any of the layers. In addition, these may be a single layer, or may be a layer laminated by a plurality of layers. In the case of a plurality of laminations, the order of lamination is not particularly limited as long as the intended function is satisfied. As an inorganic substance layer, a metal layer, an inorganic oxide layer, etc. are mentioned, for example. Although it does not specifically limit as a metal layer, From a viewpoint of gas-barrier property, light-shielding property, glossiness, and cost, aluminum is preferable. Moreover, in the case where the content can be recognized and gas barrier properties are imparted, an inorganic oxide layer is preferable.

The thickness of the metal layer is preferably 20 nm or more and less than 100 nm, more preferably 22 nm or more and less than 80 nm. The optical density is practically 1.5 or more, and the metallic luster is practically 600% or more. When the thickness of the metal aluminum layer is 20 nm or less, the optical density becomes 1.5 or less, and the glossiness becomes 600% or less, the light-shielding property and metallic luster are lost, and the appearance is not practical. When the thickness of the metal aluminum layer is 100 nm or more, there is no problem in light-shielding property and metallic luster, but since the metal aluminum layer becomes thick, heat loss is easy to be lost in the vapor deposition layer, and the gas barrier performance and lamination strength are lowered.

Moreover, in the case where the content can be recognized and gas barrier properties are imparted, an inorganic oxide layer is preferable. The inorganic oxide is not particularly limited, and examples thereof include aluminum oxide, silicon oxide, magnesium oxide, zinc oxide, zinc oxide or zinc sulfide containing silicon oxide and aluminum oxide, and a mixture of zinc oxide-silicon dioxide-alumina. A layer consisting of a coexisting phase, a layer consisting of a coexisting phase of zinc sulfide and silicon dioxide, zinc sulfide and silicon dioxide, diamond-like carbon or a mixture thereof, etc., are preferably oxidized from the viewpoint of cost. Aluminum, silicon oxide, magnesium oxide, more preferably aluminum oxide, silicon oxide.

The method of forming these metal layers and inorganic oxide layers is not particularly limited, and a method of directly heating and evaporating the metal to form a metal layer on the surface of the base layer (A) of the composite film of the present invention can be used; Reactive evaporation method in which the evaporated metal reacts with oxygen to form an inorganic oxide layer; ion plating method in an oxygen atmosphere; sputtering method using the intended material as a plating target; sputtering during sputtering Reactive sputtering method in which particles react with oxygen gas; chemical vapor deposition method and other known methods.

Furthermore, before the formation of the metal layer and the inorganic oxide layer, a function-imparting layer may be present on the surface of the base layer (A) of the composite film of the present invention, and a function-imparting treatment may be performed. The thickness of the inorganic oxide layer is preferably 10 nm or more and less than 30 nm. When the film thickness is less than 10 nm, the lamination strength that cannot achieve the objective or the gas barrier performance may be insufficient. When the film thickness is 30 nm or more, the heat of reaction during the oxidation reaction of aluminum also increases, so that the base film may be deformed by the heat of reaction, and the appearance may not be practical. The thickness of the aluminum oxide layer and the metal aluminum layer can be calculated from the composition distribution (so-called depth profile) in the sputtering depth of aluminum and oxygen obtained by X-ray photoelectron spectroscopy or Ojie electron spectroscopy.

Examples of the organic layer include organic resin layers such as vinylidene chloride resins, polyvinyl alcohol-based resins, polyurethane resins, polyepoxy resins, polyester resins, polyacrylic resins, and ethylene vinyl alcohol copolymers. Combination etc.

As an inorganic-organic mixture layer, the thing which mixed an inorganic substance with the said organic resin, or what combined an organic resin and an inorganic component, etc. are mentioned, for example. As the inorganic substance to be mixed, either a flat inorganic substance or a particulate inorganic substance may be used. In the case of imparting light-shielding properties, titanium oxide or the like is preferable as the particulate inorganic material for the purpose of blocking light reflection.

The film thickness of the inorganic-organic mixture layer is preferably 0.5 to 1000 μm, more preferably 1 to 500 μm, still more preferably 1 to 100 μm, and particularly preferably 1 to 50 μm.

As the inorganic-organic mixed layer, a polyvinyl alcohol-based resin mixed with a metal alkoxide; an ethylene vinyl alcohol copolymer mixed with a metal alkoxide, etc. are mentioned. In addition, these organic substances and inorganic-organic mixtures may contain materials such as oxygen absorbers.

There is no particular limitation on the method for forming the organic material layer and the inorganic-organic mixture layer, and it can be formed on the base layer (A) of the composite film of the present invention, the function-imparting layer on the base layer (A), and the base layer (A) The above is processed by the function. For example, a roll coating method, a dip coating method, a bar coating method, a die coating method, a knife edge coating method, a gravure printing method, a contact coating method, a spin coating method, a spray coating method, etc., or a combination thereof can be used.

Next, on the base layer (A) of the composite film of the present invention, or the base layer (A) on which the above-mentioned function-imparting layer is laminated, another base layer can be laminated to further improve the function. The laminate structure of these laminates is adapted to the required characteristics of the packaging bag (for example, to satisfy the gas barrier properties during the quality preservation period of the packaged food, the size corresponding to the weight of the contents, the impact resistance, the visibility of the contents, etc.) Choose appropriately.

The above-mentioned other base material layer is not particularly limited as long as the properties such as mechanical strength, heat resistance, and light resistance are considered depending on the application, and typical examples include polyethylene terephthalate, polyethylene terephthalate, Polyester such as polyethylene naphthalate, polybutylene terephthalate, polybutylene 2,6-naphthalate; polyvinyl alcohol, ethylene-vinyl acetate copolymer saponification, polystyrene, Polyolefins such as polycarbonate, polyethylene and polypropylene; polyamides such as 6 nylon and 12 nylon; films and sheets of homopolymers or copolymers such as aromatic polyamides and polyimides. From the viewpoints of maintaining the strength of the contents, puncture resistance, etc., for example, a plastic film such as a polyamide film, a paper substrate, or a film layer obtained by laminating these plastic films with an adhesive or the like can be mentioned. A composite, a paper laminate obtained by laminating a polymer film and a paper substrate with an adhesive or the like. Among them, especially in the context of the increase of global marine plastic waste, the demand for the recycling of used plastic packaging materials has increased. A single material (single material) is constituted, and by making a laminate of biaxially stretched polypropylene and the composite film of the present invention, the same material can be recovered, which is preferable from the viewpoint of reducing environmental load.

The biaxially stretched polypropylene is preferably composed of a polypropylene resin in which the stereoregularity of propylene representing the ratio of methyl groups regularly arranged in a single direction is in the range of 90 to 98%. When the three-dimensional regularity is less than 90%, the rigidity of the film is reduced, the film stretches due to tension when the laminate with the above-mentioned composite film is made, and wrinkles are easily generated, the high-speed filling time of bag products, or the performance of the function-imparting layer. reduced situation. When the stereoregularity exceeds 98%, the crystallinity increases, the surface roughness of the film increases, and the viscosity of the function-imparting layer may decrease.

The method of laminating the above-mentioned other base material layer and the composite film of the present invention includes, for example, a dry lamination method, a wet lamination method, a There are known methods such as a solvent-free lamination method using a solvent and an extrusion sandwich lamination method by extruding a resin.

The laminate obtained by laminating the above-mentioned other base material layers, the composite film of the present invention, and the laminate film using the same can be suitably used as packaging bags and packaging containers. Examples of packaging bags and packaging containers include gusset bags, stand-up pouches, brick-type, flat-type, and the like. Those who fill and pack various items such as pharmaceuticals and other miscellaneous goods.

An example of the manufacturing method of the composite film of this invention is demonstrated below. Two extruders were used, and 100 parts by weight of the propylene-random copolymer (a1) of MFR3~12g/10min was mixed with 100 parts by weight of the base layer (A) resin for polyethylene polymerization Body (a2) 1 to 10 parts by weight of the resin composition is melted at a temperature of 220 to 270°C. Another extruder was used to copolymerize 100 parts by weight of the propylene-random copolymer (b1) with a melting point of 145°C or lower as the heat-sealing layer (B) mixed with ethylene and α-olefin with a melting point of 130°C or lower. Combined (b2) 5 to 50 parts by weight of the resin composition is melted at a temperature of 220 to 270°C. Laminate the base layer (A) and the heat-sealing layer (B) through a tubular compounding or co-extrusion multi-layer die, extrude it into a film shape through the die nozzle, and cast, cool and solidify with a cooling roller at 30~80°C to make a compound. film. At this time, the thickness ratio of the gap between the die lips and the cooled and solidified composite film (lip gap/film thickness=stretch ratio) is set to 20-50. By setting this stretching ratio, it is melted and oriented in the longitudinal direction, and then the cast film is subjected to heat treatment at 40 to 80° C. for 0.01 to 1 second by a heated mirror roll, whereby the Young's degree of the film can be increased. rate (rigidity). Next, the surface of the base layer (A) of the composite film, as an example of the function-imparting layer, is subjected to a mixed gas of nitrogen and carbon dioxide gas (volume ratio of carbon dioxide gas: 0.5 to 50%) for 20 to 60 W·min/minute. Corona discharge treatment of m ² and coiling can obtain the composite film of the present invention.

Next, as an example of the function-imparting layer in the above-mentioned composite film, it was installed in a vacuum evaporation apparatus, and aluminum was applied to the surface of the base layer (A) of the above-mentioned film with a film thickness of 30 nm according to a vacuum degree of ^{1.3×10 -2 Pa or more.} Metal vapor deposition can obtain metal vapor deposition laminated films. [Example]

The present invention will be described more specifically using Examples and Comparative Examples. [Examples 1 to 16, Comparative Examples 1 to 10] In Examples 1 to 16 and Comparative Examples 1 to 10 of the composite film, the laminated film, and the laminated body of the present invention, the following polyolefin-based resins were used. (1) Homopolypropylene: melting point of 162° C., MFR of 7.0 g/10 minutes (this is abbreviated as h-PP). (2) Ethylene·propylene random copolymer: melting point of 141° C., MFR of 7.0 g/10 minutes, and ethylene content of 4 mol % (referred to as r-EPC for short). (3) Ethylene·propylene·butene random copolymer: the melting point is 145°C, the ethylene content is 2 mol %, and the butene content is 5 mol % (referred to as r-EPBC① for short). (4) Ethylene·propylene·butene random copolymer: melting point 127°C, MFR 7.0g/10min, ethylene content 4 mol%, butene content 8 mol% (referred to as r-EPBC②). (5) Propylene·1-butene random copolymer: melting point of 125° C., MFR of 9.0 g/10 minutes, butene content of 19 mol % (referred to as r-PBC for short). (6) Ethylene·α-olefin: linear low-density polyethylene, melting point 124° C., MFR 5.0 g/10 minutes (α-olefin: butene, abbreviated as L-LDPE①). (7) Ethylene·α-olefin: linear low-density polyethylene, melting point 113° C., MFR 2.0 g/10 minutes (α-olefin: hexene, abbreviated as L-LDPE ②). (8) Polyethylene-based polymer: high-density polyethylene, melting point 134° C., MFR 1.5 g/10 minutes (this is abbreviated as HDPE). (9) Thermoplastic elastomer: propylene·α-olefin elastomer, melting point 110° C., MFR 3.0 g/10 minutes (α-olefin: 1-butene, this is abbreviated as elastomer).

The measurement values of each evaluation item in the detailed description of the present invention and the examples were measured according to the following methods. The characteristics of each sample in each Example and Comparative Example are shown in Tables 1 to 3.

(1) Melt Flow Rate (MFR) According to JIS K-7210-1999, the temperature of propylene-random copolymer and homopolypropylene system is 230℃, and the temperature of polyethylene-based polymer and polyethylene-α-olefin copolymer system is 190℃, respectively according to the load of 21.18 N is measured.

(2) Density According to JIS K-7112-1999, the measurement was carried out according to the measurement method of density gradient tube.

(3) Melting point (Tm) Using a differential scanning calorimeter DSC (DSC-60A) manufactured by Shimadzu Corporation, 5 mg of the sample was heated to 250°C at a rate of 10°C/min in nitrogen When the cooling rate was cooled to 10°C, and the temperature was raised again at a rate of 10°C/min, the melting point (Tm) was defined as the peak temperature of the endothermic peak accompanying the melting of the resin during the reheating.

(4) Film forming stability In the film-forming step of the composite film of the present invention, the following evaluations were performed by observing the adhesion of the film to the processing roll, the appearance of wrinkles, and the like of the film. ○: There is no sticking to the processing roller in the film forming step, the film forming property is good, and there is no wrinkle or contamination in the film, and the curl is small and the appearance is good. ╳: There is adhesion to the processing roller in the film-making step, the film-making stability is poor, and the film has wrinkles or pollution caused by the adhesion of the processing roller, and the curl is also large and the appearance is deteriorated.

(5) Measurement of relaxation (curling) After winding the composite film into a roll shape, it was cut to a predetermined width to prepare a product, and the film was pulled out from the product by 2m and stretched to a finger tension (3 to 4kg according to a spring balance) for confirmation. When slack is confirmed, the width is measured with a measuring device. If the slack width is less than 100mm, it is considered as qualified.

(6) Film thickness Using a dial gauge thickness gauge (JIS B-7509: 1974, the gauge head is 5 mmϕ flat), 10 points are measured at 10 cm intervals in the length and width directions of the film, and the average value is set.

(7) Thickness of each layer The film section was cut out with a microtome, and the section was observed at a magnification of 1000 times using a digital microscope VHX-100 (manufactured by KEYENCE Co., Ltd.), and the distance in the thickness direction of each layer was measured using the photographed section. The thickness of each layer is obtained by inverse calculation of the magnification. In addition, when the thickness of each layer was calculated|required, 5 cross-sectional photographs of a total of 5 places arbitrarily selected from mutually different measurement fields were used, and the average value of these was calculated.

(8) Low temperature heat sealability Weigh 30 parts by weight of Mitsui Chemicals Co., Ltd. polyether urethane-based dry lamination adhesive "TAKELAC" (registered trademark) A969V type, Mitsui Chemicals Co., Ltd. dry lamination hardener "TAKELAC" (registered Trademark) 10 parts by weight of A10 type and 100 parts by weight of ethyl acetate, and stirred for 30 minutes to prepare an adhesive solution for dry lamination with a solid concentration of 19% by weight. Next, the above-mentioned adhesive solution was applied on the surface of the base layer (A) by a bar coating method, and dried at 80° C. for 45 seconds to form an adhesive layer with a thickness of 2 μm. Next, on the adhesive layer, a 20 μm biaxially stretched polypropylene film (U-0, manufactured by Mitsui Chemicals Co., Ltd.) as another base material was superimposed so that the corona-treated surface and the adhesive layer faced each other, using "LAMIPACKER" (registered trademark) LPA330 manufactured by Fujitec Co., Ltd. was heated to 40° C. with a heating roller and bonded. This laminated film was kept in a furnace heated to 40° C. for 2 days to obtain a laminated body.

Next, the heat-sealing layers (B) of the laminated body film were overlapped with each other, and heat-sealed using a flat plate heating sealer under the conditions of a sealing temperature of 120° C., single-sided heating, a sealing pressure of 0.1 MPa, and a sealing time of 1 second, the resulting The heat-sealing strength of the sample was measured at a tensile speed of 300 mm/min using "TENSILON" manufactured by ORIENTEC Corporation. The low-temperature heat-sealing property was considered to be good when the heat-sealing strength at this time was 3 N/15 mm or more.

(9) Anti-blocking properties Prepare a film sample with a width of 30mm and a length of 100mm, make the base layer (A), the heat seal layer (B), and the heat seal layer (B) overlap each other in the range of 30mm×40mm, and apply 500g/12cm ^{The load of 2} , after heat treatment in a furnace of 40°C for 24 hours, and then placed in an environment of 23°C and a humidity of 65%RH for more than 30 minutes, use ORIENTEC's "TENSILON" to measure the shearing speed at a tensile speed of 300mm/min. Cut peel force. According to this measurement method, when the shear peeling force was 10 N/12 cm ² or less, the blocking resistance was regarded as "○", and 12 N/12 cm ² or more was regarded as "╳".

(10) Gas-barrier performance (oxygen penetration rate) The gas-barrier performance of a film in which metal vapor deposition, metal oxide vapor deposition, and an organic layer as a function-imparting layer are laminated on the base layer (A) of the composite film, is Under the conditions of temperature 23°C and humidity 0%RH, the oxygen permeability was measured according to the B method (isobaric method) described in JIS K7126 (2000 edition) using the oxygen permeability measuring device (OXTRAN 2/20) manufactured by MOCON, USA. transmittance. The samples were taken from the two ends and the central part of the film in the width direction, and the average value of the three measured values was taken as the oxygen permeability value in each example and comparative example, and the oxygen permeability value was 50cc. /m ² ‧24hr‧atm or less is regarded as good gas barrier performance.

(11) Shading (light transmittance) The total light transmittance was measured using a haze meter (NDH7000 manufactured by Nippon Denshoku Kogyo Co., Ltd.). A total light transmittance of 5% or less was considered to be good in light-shielding properties.

The gloss is measured using a variable-angle gloss meter from SUGA Testing Machine Co., Ltd.: UGV-5D, in accordance with JIS Z8741 (1983), for the vapor-deposited surface in the longitudinal direction (MD direction) of the film according to the incident angle of 60°/reflection angle of 60° ° was measured, and the measured value was an average value of three points in the width direction of the film. 600% or more is considered qualified.

(12) Evaluation of Easy-to-Join Adhesion Weigh 30 parts by weight of Mitsui Chemicals Co., Ltd. polyether urethane-based dry lamination adhesive "TAKELAC" (registered trademark) A969V type, Mitsui Chemicals Co., Ltd. dry lamination hardener "TAKELAC" (registered Trademark) 10 parts by weight of A10 type and 100 parts by weight of ethyl acetate, and stirred for 30 minutes to prepare an adhesive solution for dry lamination with a solid concentration of 19% by weight.

Next, the above-mentioned adhesive solution was coated on the function-imparting layer of the laminated film by bar coating, and dried at 80° C. for 45 seconds to form an adhesive layer with a thickness of 2 μm.

Next, on the adhesive layer, a 25 μm biaxially stretched polypropylene film (“TORAYFAN” (registered trademark) YT42, manufactured by Toray Film Co., Ltd.) as another base material was treated with a corona-treated surface and an adhesive. The layers were stacked so as to face each other, and "LAMIPACKER" (registered trademark) LPA330 manufactured by Fujitec Co., Ltd. was used, and the heating roller was heated to 40° C. and bonded together. This laminated film was kept in a furnace heated to 40° C. for 2 days to obtain a laminated body. Next, the laminated film was cut into pieces with a width of 15 mm and a length of 150 mm to prepare cut samples, and a tensile tester (RTG-1210 type) made by A&D (Strand) was used to make the interface between the composite film and the biaxially stretched polypropylene film. The strength was measured by peeling off at a tensile speed of 300 mm/min by the T-peel method. The obtained value was set as the dense tack strength (N/15mm). It was considered that the dense adhesive strength was 1 N/15 mm or more as good.

(13) Ease of printing In the function-imparting layer, the ink (LAMIC SR SC R white (M), manufactured by Dainisei Chemical Industry Co., Ltd.) and its dilution solvent (LAMIC SR hardener, manufactured by Dainisei Chemical Industry Co., Ltd.) are mixed in a ratio of 1:1. The obtained ink was applied to a thickness of about 1.0 μm, and dried in a hot-air oven at 100° C. for 30 seconds. After that, a transparent tape (Cellotape (registered trademark) No. 405 manufactured by NICHIBAN Co., Ltd., width 15 mm) was attached to the printing surface with a rubber roller, and then peeled off to observe the peeling state of the ink, and the adhesiveness of the ink was as follows. Ease of printing was evaluated in 5 stages. 5-stage evaluation: Ease of printing (lower side): 1st grade: more than 90% ink peeling, 2nd grade: 50~90% ink peeling, 3rd grade: 10~50% ink peeling, 4th grade: 1~10% ink peeling, 5th grade : No ink peeling: Easy printability (good side).

(14) Film thickness of the function-imparting layer In the observation method by transmission electron microscope, the thin film to be observed is sampled by the microsampling method, and then thinned using a focused ion beam processing apparatus (manufactured by Hitachi, Ltd., FB-2000). Then, for protection, carbon and tungsten protective films are formed. This sample was observed with a field emission type transmission electron microscope (HF-2200, manufactured by Hitachi, Ltd., hereinafter referred to as TEM).

[Example 1] As the base layer (A) of the composite film, 5 parts by weight of high-density polyethylene (HDPE), antioxidant ( The resin composition containing 0.125 parts by weight of "Irganox" (1010) manufactured by Ciba-Geigy Co., Ltd. and 0.3 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent was supplied to one extruder heated at 240° C. melted; as the heat-sealing layer (B), 80 parts by weight of the above-mentioned ethylene-propylene-butene random copolymer (r-EPBC②), 20 parts by weight of linear low-density polyethylene (L-LDPE①), Antioxidant ("Irganox" 1010 manufactured by Ciba-Geigy Co., Ltd.) 0.125 parts by weight, and 0.2 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent were supplied to another unit heated at 240°C. The extruder is melted; laminated extrusion is carried out in a multi-manifold die for 2-layer lamination heated at 240°C, and cast, cooled and solidified by a cooling roll at 50°C according to the draw ratio of 25. Then, heat treatment was performed for 0.05 seconds with a metal mirror roller heated at 47°C, and the surface of layer (A) ^{was subjected to corona discharge treatment at 26 W·min/m 2} and coiled to obtain a base layer (A) with a thickness of 20 μm, heat-sealed Layer (B) is a co-extruded 2-layer composite film with a thickness of 5 μm and a total thickness of 25 μm. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 2] In addition to being the base layer (A) of the composite film, 5 parts by weight of high-density polyethylene (HDPE), antioxidant (Ciba-Geigy The same procedure as in Example 1 was carried out, except that 0.125 parts by weight of "Irganox" (1010) manufactured by the company and 0.3 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent were used to obtain two coextruded layers. composite film. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 3] In addition to being the base layer (A) of the composite film, 91 parts by weight of ethylene-propylene-butene random copolymer (r-EPBC①), 9 parts by weight of high-density polyethylene (HDPE), antioxidant (Ciba- Co-extrusion 2 was obtained in the same manner as in Example 1, except that 0.125 parts by weight of "Irganox" (1010) manufactured by Geigy Co., Ltd. and 0.3 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent layered composite film. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 4] Except that as the base layer (A) of the composite film, 98 parts by weight of ethylene-propylene-butene random copolymer (r-EPBC①) and 2 parts by weight of high-density polyethylene (HDPE) are used, the rest are the same as those in Example 1. In the same way, a coextruded two-layer composite film was obtained. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 5] In addition to being the base layer (A) of the composite film, the linear low-density polyethylene ( 5 parts by weight of L-LDPE①), 0.125 parts by weight of antioxidant (“Irganox” 1010 manufactured by Ciba-Geigy Corporation), and 0.3 part by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent, the rest In the same manner as in Example 1, a coextruded two-layer composite film was obtained. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 6] In Example 2, except that the heat-sealing layer (B) was mixed with 95 parts by weight of ethylene-propylene-butene random copolymer (r-EPBC①), linear low-density polyethylene (L-LDPE①) 5 Parts by weight, 0.125 parts by weight of an antioxidant (“Irganox” 1010 manufactured by Ciba-Geigy Corporation), and 0.2 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent were used in the same manner as in Example 1. to obtain a co-extruded 2-layer composite film. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 7] In Example 2, except that the heat-sealing layer (B) was mixed with 50 parts by weight of ethylene-propylene-butene random copolymer (r-EPBC②) and 50 parts by weight of linear low-density polyethylene (L-LDPE①) Parts by weight, 0.125 parts by weight of an antioxidant (“Irganox” 1010 manufactured by Ciba-Geigy Corporation), and 0.2 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent were used in the same manner as in Example 1. to obtain a co-extruded 2-layer composite film. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 8] In Example 2, except that the heat-sealing layer (B) was a linear low-density polyethylene ( 20 parts by weight of L-LDPE ②), 0.125 parts by weight of antioxidant (“Irganox” 1010 manufactured by Ciba-Geigy Corporation), and 0.2 part by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent, the rest In the same manner as in Example 1, a coextruded two-layer composite film was obtained. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 9] In Example 2, except that the heat-sealing layer (B) was a linear low-density polyethylene (L- LDPE ②) 20 parts by weight, antioxidant (“Irganox” 1010 manufactured by Ciba-Geigy Corporation) 0.125 parts by weight, and 0.2 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent Example 1 was carried out in the same manner to obtain a co-extruded two-layer composite film. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 10] In Example 2, except that the heat-sealing layer (B) was a linear low-density polyethylene ( 20 parts by weight of L-LDPE ②), 0.125 parts by weight of antioxidant (“Irganox” 1010 manufactured by Ciba-Geigy Corporation), and 0.2 part by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent, the rest In the same manner as in Example 1, a coextruded two-layer composite film was obtained. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 11] In Example 2, except that the heat sealing layer (B) was mixed with 30 parts by weight of propylene-butene random copolymer (r-EPC) and propylene-1-butene random copolymer (r-PBC) 50 parts by weight, 20 parts by weight of linear low-density polyethylene (L-LDPE ②) with a melting point of 113°C, 0.125 parts by weight of antioxidant (“Irganox” 1010 manufactured by Ciba-Geigy Corporation), the average particle size of the anti-blocking agent Except for the resin composition containing 0.2 parts by weight of silica fine particles of 3 μm in diameter, the same procedure as in Example 1 was carried out to obtain a co-extruded two-layer composite film. The obtained composite film has good film-forming property, no film slack, excellent anti-blocking property and low-temperature heat-sealing property.

[Example 12] In Example 2, except that the heat sealing layer (B) was mixed with 20 parts by weight of propylene-butene random copolymer (r-EPC) and propylene-1-butene random copolymer (r-PBC) 50 parts by weight, 20 parts by weight of linear low-density polyethylene (L-LDPE ②) with a melting point of 113°C, a thermoplastic elastomer with a melting point of 110°C, MFR 3.0 g/10 minutes, and α-olefin is 1-butene Resin containing 10 parts by weight of propylene and 1-butene elastomer, 0.125 parts by weight of antioxidant ("Irganox" 1010 manufactured by Ciba-Geigy Corporation), and 0.2 parts by weight of silica fine particles with an average particle size of 3 μm as an anti-blocking agent Except for the composition, the same procedure as in Example 1 was carried out to obtain a co-extruded two-layer composite film. The obtained composite film has good film-forming properties, no slack in the film, and especially excellent low-temperature heat-sealing properties.

[Comparative Example 1] In addition to being the base layer (A) of the composite film, 5 parts by weight of high-density polyethylene (HDPE) and an antioxidant ("H-PP" manufactured by Ciba-Geigy Corporation) were mixed with homopolypropylene (h-PP) having a melting point of 162°C. Irganox" 1010) 0.125 parts by weight and 0.3 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent were carried out in the same manner as in Example 1 to obtain a co-extruded two-layer composite film. Since the main raw material of the base layer (A) is homopolypropylene (h-PP) with a melting point of 162°C, the lamination interface between the obtained composite film and the heat seal layer (B) is disturbed and the film-forming stability is deteriorated.

[Comparative Example 2] In addition to being the base layer (A) of the composite film, 5 parts by weight of high-density polyethylene (HDPE) was mixed with 95 parts by weight of ethylene-propylene-butene random copolymer (r-EPBC②) having a melting point of 127°C , 0.125 parts by weight of antioxidant ("Irganox" 1010 manufactured by Ciba-Geigy Co., Ltd.), and 0.3 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent, the rest was carried out in the same manner as in Example 1. A co-extruded 2-layer composite film was obtained. Since the obtained composite film has a low melting point of r-EPBC of the base layer (A), the blocking resistance is deteriorated.

[Comparative Example 3] In addition to being the base layer (A) of the composite film, 12 parts by weight of high-density polyethylene (HDPE), antioxidant ( Co-extrusion was obtained in the same manner as in Example 1, except that the resin composition contained 0.125 parts by weight of "Irganox" (1010) manufactured by Ciba-Geigy Co., Ltd. and 0.3 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent. 2 layers of composite film. Since the obtained composite film contains a large amount of high-density polyethylene (HDPE) in the base layer (A), the lamination interface disturbance occurs between the base layer (A) and the heat-sealing layer (B), and the film-forming stability is deteriorated.

[Comparative Example 4] In addition to being the base layer (A) of the composite film, an antioxidant ("Irganox" 1010 manufactured by Ciba-Geigy Co., Ltd.) was mixed with 100 parts by weight of an ethylene-propylene-butene random copolymer (r-EPBC①) 0.125 A co-extruded two-layer composite film was obtained in the same manner as in Example 1 except for the resin composition in parts by weight and 0.3 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent. Since the obtained composite film was not mixed with high-density polyethylene (HDPE) to the base layer (A), the blocking resistance was deteriorated.

[Comparative Example 5] In Example 2, an antioxidant ("Irganox" 1010 manufactured by Ciba-Geigy Corporation) was mixed with 100 parts by weight of the ethylene-propylene-butene random copolymer (r-EPBC②) except that the heat-sealing layer (B) was mixed. ) 0.125 parts by weight and 0.2 parts by weight of silica fine particles with an average particle size of 3 μm as an anti-blocking agent, the same procedure as in Example 1 was carried out to obtain a co-extruded two-layer composite film. The resulting composite film had low low-temperature heat-sealing strength and deteriorated low-temperature heat-sealing properties.

[Comparative Example 6] In Example 2, except that the heat-sealing layer (B) was mixed with 45 parts by weight of ethylene-propylene-butene random copolymer (r-EPBC②) and 55 parts by weight of linear low-density polyethylene (L-LDPE①) Parts by weight, 0.125 parts by weight of an antioxidant (“Irganox” 1010 manufactured by Ciba-Geigy Corporation), and 0.2 parts by weight of silica fine particles with an average particle diameter of 3 μm as an anti-blocking agent were used in the same manner as in Example 1. to obtain a co-extruded 2-layer composite film. In this composite film, the compatibility of r-EPBC② and L-LDPE① was deteriorated, uneven flow occurred at the interface with the base layer (A), the film forming stability was deteriorated, and the relaxation of the film was also large.

^{[Example 13] Using the composite film described in Example 11, aluminum was evaporated at a vacuum of 1.3 × 10 -2} Pa by a conventional roll-to-roll type vapor deposition machine, on the base layer (A) of the composite film. An aluminum layer of 40 nm was formed on the surface to obtain a laminated film. At 23°C and 0% humidity, the oxygen transmittance of this laminated film is ^{15cc/m 2} ‧day‧atm, the total light transmittance is 1.3%, the gloss is 600%, and the gas barrier properties, light shielding properties, and gloss properties are good.

[Comparative Example 7] Using the composite film described in Comparative Example 2, ^{aluminum was evaporated at a vacuum of 1.3×10 -2} Pa by a conventional roll-to-roll type vapor deposition machine, and the base layer (A) of the composite film was deposited on the base layer (A) of the composite film. An aluminum layer of 40 nm was formed on the surface to obtain a laminated film. The oxygen transmission rate of this laminated film was measured. At 23°C and 0% humidity, the oxygen transmission rate was 60cc/m ² ‧day‧atm, the total light transmission rate was 10%, and the gloss was 450%. Since the base layer (A) of the laminated film has a low melting point, heat loss during aluminum vapor deposition occurs, and gas barrier properties, light shielding properties, and gloss properties are deteriorated.

[Example 14] The composite film described in Example 2 was used ^{, and aluminum was evaporated at a vacuum of 1.3 × 10 -2} Pa by a conventional roll-to-roll type vapor deposition machine, and oxygen was introduced into the composite film. An alumina vapor deposition layer of 10 nm was formed on the surface of the base layer (A) to obtain a laminated thin film. The oxygen transmission rate of the above-mentioned laminated film was measured, and the oxygen transmission rate was 48cc/m ² ‧day‧atm at 23°C and 0% humidity, and the gas barrier property was good. Furthermore, a laminate was produced on the produced alumina according to the method described in the evaluation of the easy-bonding adhesion, and the close-adhesive strength was measured. The dense adhesive strength is 2.1N/15mm, and the easy-to-connect adhesiveness is good.

[Comparative Example 8] The composite film described in Comparative Example 3 was used ^{, and aluminum was evaporated at a vacuum degree of 1.3×10 -2} Pa by a normal roll-to-roll type vapor deposition machine, and oxygen was introduced into the above-mentioned composite film while introducing oxygen. An alumina vapor deposition layer of 10 nm was formed on the surface of the base layer (A) to obtain a laminated thin film. The oxygen permeability of the laminated film at 23°C and humidity of 0% was 55cc/m ² ‧day‧atm, and the density was 0.7N/15mm. In this laminated film, since the laminated interface between the base layer (A) and the heat seal layer (B) is disordered and the surface of the base layer (A) is rough, the laminated film of the aluminum vapor-deposited film is uneven, gas barrier properties and adhesive strength deterioration.

[Example 15] As the laminate of the organic layer on the base layer (A) of the composite film of Example 2, the ethylene content of 27 mol%, the degree of saponification of 99.8%, and the MFR of 4.0 g/10 minutes (under a load of 2160 g) , 210℃) ethylene vinyl alcohol (hereinafter referred to as EVOH) ("EVAL" L171B manufactured by KURARAY Co., Ltd.) and interfacial adhesive resin (hereinafter referred to as AD) (Admer QF500, manufactured by Mitsui Chemicals Co., Ltd.) in individual Melt kneading was carried out in the extruder respectively, and a 4-layer co-extruder was used to obtain four kinds of 4-layer multilayer films of EVOH/AD/base layer (A)/heat sealing layer (B) according to the extrusion temperature of 220°C. The thicknesses of these were 10 μm/5 μm/20 μm/5 μm, respectively. The oxygen transmission rate of the above-mentioned laminated film was measured, and the oxygen transmission rate was 5cc/m ² ‧day‧atm at 23°C and 0% humidity, and the gas barrier property was good. In addition, a laminate was produced on the produced EVOH according to the method described in the evaluation of the easy-bonding adhesion, and the close-adhesive strength was measured. The dense adhesive strength is 2.5N/15mm, and the easy-to-connect adhesiveness is good.

[Comparative Example 9] As the lamination of the organic material layer on the base layer (A) of the composite film described in Comparative Example 3, it was carried out in the same manner as in the above-mentioned Example 14, and the EVOH layer/AD layer was laminated. The oxygen transmission rate of the above laminated film was measured, and the oxygen transmission rate was 5cc/m ² ‧day‧atm at 23°C and 0% humidity, and the gas barrier property was good. The lamination interface between the layers (B) is disordered and the surface of the base layer (A) is rough, and the dense adhesive strength is as low as 0.7N/15mm.

[Example 16] To impart easy printability on the base layer (A) of the composite film of Example 2, an organic-inorganic mixture was prepared according to the following method, and a laminated film was obtained.

＜Organic ingredient solution＞ As the vinyl alcohol-based resin, modified polyvinyl alcohol containing a γ-butyrolactone structure having a carbonyl group in its cyclic structure (hereinafter, may be simply referred to as modified PVA. The degree of polymerization is 1,700, and the degree of saponification is 93.0%) is put into In a solvent with a weight ratio of water/isopropanol=97/3, the solution was heated and stirred at 90° C. to obtain an organic component solution with a solid content of 10% by weight.

<Inorganic component solution> In a solution that mixed 11.2 g of ethyl silicate 40 made by COLCOAT Co., Ltd. as a linear polysiloxane (ethyl silicate oligomer with an average of 5 polymers) and 16.9 g of methanol, drop 0.06N 7.0 g of an aqueous hydrochloric acid solution was used to obtain a 5-mer ethyl silicate hydrolyzate.

<Organic-inorganic mixture> Mix the modified PVA solution, the modified PVA solution, and the modified PVA solution _{according to the weight ratio of SiO 2} converted solid content (modified PVA solid content weight/SiO _{2 converted solid content weight) to be 85/15.} The solution was stirred with the inorganic component solution and diluted with water to obtain a coating liquid with a solid content of 12% by weight. This coating solution was applied on the base layer (A) of the composite film described in Example 2, dried to form an organic-inorganic substance with a thickness of 0.4 μm, and a laminated film was prepared. The 5-stage evaluation of the printability of this laminated film was rated as good as 5 grades.

[Comparative Example 10] The provision of easy printability on the base layer (A) of the composite film described in Comparative Example 3 was carried out in the same manner as in Example 16 to form an organic-inorganic mixture and prepare a laminated film. Since the surface of the base layer (A) was rough in this laminated film, the evaluation of printability was grade 3, and the printability was poor.

[Table 1] melting point density MFR unit Example °C g/cm ³ g/min 1 2 3 4 5 6 7 8 9 10 11 12 Functionality imparting layer none none none none none none none none none none none none Base layer (A) h-PP 162 0.900 7 parts by weight — — — — — — — — — — — — r-EPC① 141 0.900 7 parts by weight 95 — — — — — — — — — — — r-EPBC① 145 0.900 7 parts by weight — 95 91 98 95 95 95 95 95 95 95 95 r-EPBC② 127 0.900 7 parts by weight — — — — — — — — — — — — L-LDPE① 124 0.935 5 parts by weight — — — — 5 — — — — — — — L-LDPE② 113 0.913 2 parts by weight — — — — — — — — — — — — HDPE 134 0.952 1.5 parts by weight 5 5 9 2 — 5 5 5 5 5 5 5 Heat seal layer (B) r-EPC 141 0.900 7 parts by weight — — — — — — — — 80 — 30 20 r-PBC 125 0.900 9 parts by weight — — — — — — — — — 80 50 50 r-EPBC② 127 0.900 7 parts by weight 80 80 80 80 80 95 50 80 — — — — L-LDPE① 124 0.935 5 parts by weight 20 20 20 20 20 5 50 — — — — — L-LDPE② 113 0.913 5 parts by weight — — — — — — — 20 20 20 20 20 Elastomer 110 — 3 parts by weight — — — — — — — — — — — 10 Film Stability ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ anti-adhesion ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ Heat sealing strength [N/15mm] 120℃ 4 6 5 5 4 3 10 6 3 8 6 12 Relaxation evaluation ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ h-PP: homopolypropylene (melting point 162℃) r-EPC: ethylene-propylene random copolymer (melting point 141℃, ethylene content 4 mol%) r-EPBC①: ethylene-propylene-butene random copolymer ( Melting point 145℃, ethylene content 2 mol%, butene content 5 mol%) r-EPBC②: ethylene·propylene·butene random copolymer (melting point 127℃, ethylene content 4 mol%, butene content 8mol%) ear%) r-PBC: Propylene·1-butene random copolymer (melting point 125℃, butene content 19 mol%) L-LDPE①: Linear low density polyethylene (melting point 124℃, α-olefin= Butene) L-LDPE②: Low melting point linear low density polyethylene (melting point 113°C, α-olefin=hexene) Elastomer: Propylene·α-olefin elastomer (melting point 110°C, α-olefin=1-butene) ene) HDPE: high density polyethylene (melting point 128°C, density 0.955g/cm ³ )

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抗黏連性 ○

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○ ○ 熱密封強度[N/15mm] 120℃ 3 4 4 3 1 10 鬆弛評價 ○ ○ ○ ○ ○

均聚丙烯：熔點162℃ (將此簡稱為h-PP) 乙烯‧丙烯無規共聚合體：熔點141℃、乙烯含量4莫耳%(將此簡稱為r-EPC) 乙烯‧丙烯‧丁烯無規共聚合體：熔點145℃、乙烯含量2莫耳%、丁烯含量5莫耳%(將此簡稱為r-EPBC①) 乙烯‧丙烯‧丁烯無規共聚合體：熔點127℃、乙烯含量4莫耳%、丁烯含量8莫耳%(將此簡稱為r-EPBC②) 丙烯‧1-丁烯無規共聚合體：熔點125℃、丁烯含量19莫耳%(將此簡稱為r-PBC) 直鏈狀低密度聚乙烯：熔點124℃ (α-烯烴：丁烯，將此簡稱為L-LDPE①) 直鏈狀低密度聚乙烯：熔點113℃ (α-烯烴：己烯，將此簡稱為L-LDPE②) HDPE：高密度聚乙烯(熔點128℃、密度0.955g/cm³ )[Table 2] melting point density MFR unit Comparative example °C g/cm ³ g/min 1 2 3 4 5 6 Functionality imparting layer none none none none none none Base layer (A) h-PP 162 0.900 2 parts by weight 95 — — — — — r-EPC① 141 0.900 7 parts by weight — — — — — — r-EPBC① 145 0.900 7 parts by weight — — 88 100 95 95 r-EPBC② 127 0.900 7 parts by weight — 95 — — — — L-LDPE① 124 0.935 5 parts by weight — — — — — — L-LDPE② 113 0.913 2 parts by weight — — — — — — HDPE 134 0.952 1.5 parts by weight 5 5 12 0 5 5 Heat seal layer (B) r-EPC 141 0.900 7 parts by weight — — — — — — r-PBC 125 0.900 9 parts by weight — — — — — — r-EPBC② 127 0.900 7 parts by weight 80 80 80 80 100 45 L-LDPE① 124 0.935 5 parts by weight 20 20 20 20 — 55 L-LDPE② 113 0.913 2 parts by weight — — — — — — Film Stability

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anti-adhesion ○

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○ ○ Heat sealing strength [N/15mm] 120℃ 3 4 4 3 1 10 Relaxation evaluation ○ ○ ○ ○ ○

Homopolypropylene: melting point 162°C (referred to as h-PP) Ethylene·propylene random copolymer: melting point of 141°C, ethylene content of 4 mol% (referred to as r-EPC) ethylene·propylene·butene none Regular copolymer: melting point 145℃, ethylene content 2 mol%, butene content 5 mol% (referred to as r-EPBC①) Ethylene·propylene·butene random copolymer: melting point 127℃, ethylene content 4 mol% Ear%, butene content 8 mol% (referred to as r-EPBC②) Propylene·1-butene random copolymer: melting point 125°C, butene content 19 mol% (referred to as r-PBC) Linear low density polyethylene: melting point 124°C (α-olefin: butene, abbreviated as L-LDPE①) Linear low density polyethylene: melting point of 113°C (α-olefin: hexene, abbreviated as L-LDPE①) L-LDPE②) HDPE: high density polyethylene (melting point 128°C, density 0.955g/cm ³ )

[table 3] Melting point °C Density g/cm ³ MFR g/min unit Example 13 Comparative Example 7 Example 14 Comparative Example 8 Example 15 Comparative Example 9 Example 16 Comparative Example 10 Functionality imparting layer functional layer — — — — inorganic layer organic layer organic inorganic layer type Aluminum Evaporation Alumina evaporation EVOH/AD Modified PVA + Silane Lamination thickness μm 0.04 0.01 10/5 2 Base layer (A) h-PP 162 0.900 7 parts by weight — — — — — — — — r-EPC① 141 0.900 7 parts by weight — — — — — — — — r-EPBC① 145 0.900 7 parts by weight 95 — 95 88 95 88 95 88 r-EPBC② 127 0.900 7 parts by weight — 95 — — — — — — L-LDPE① 124 0.935 5 parts by weight — — — — — — — — L-LDPE② 113 0.913 2 parts by weight — — — — — — — — HDPE 128 0.955 1.5 parts by weight 5 5 5 12 5 12 5 12 Heat seal layer (B) r-EPC 141 0.900 7 parts by weight 30 — — — 30 — 30 — r-PBC 125 0.900 9 parts by weight 50 — — — 50 — 50 — r-EPBC② 127 0.900 7 parts by weight — 80 80 80 — 80 — 80 L-LDPE① 124 0.935 5 parts by weight — 20 20 20 — 20 — 20 L-LDPE② 113 0.913 2 parts by weight 20 — — — 20 — 20 — Oxygen transmission rate (23℃, 0%RH) cc/m ² ‧day 15 70 48 55 5 5 — — Total light transmittance (shading) % 1.3 10 — — — — — — Surface gloss (evaporated surface) % 600 350 — — — — — — Tight Adhesion Strength (Easy Bonding Adhesion) N/15mm 1 1 2.1 0.7 2.5 0.7 — — Ease of printing — — — — — — 5 3 h-PP: homopolypropylene (melting point 162℃) r-EPC: ethylene-propylene random copolymer (melting point 141℃, ethylene content 4 mol%) r-EPBC①: ethylene-propylene-butene random copolymer ( Melting point 145℃, ethylene content 2 mol%, butene content 5 mol%) r-EPBC②: ethylene·propylene·butene random copolymer (melting point 127℃, ethylene content 4 mol%, butene content 8mol%) ear%) r-PBC: Propylene·1-butene random copolymer (melting point 125℃, butene content 19 mol%) L-LDPE①: Linear low density polyethylene (melting point 124℃, α-olefin= Butene) L-LDPE②: Low melting point linear low density polyethylene (melting point 113°C, α-olefin=hexene) HDPE: High density polyethylene (melting point 128°C, density 0.955g/cm ³ ) EVOH: Ethylene content 27 mol%, degree of saponification 99.8%, MFR4.0g/10min (under 2160g load, 210℃) ethylene vinyl alcohol AD: interfacial adhesive resin (maleic anhydride modified polypropylene "Admer" QF500) (Industrial Availability)

By being used as the composite film of the present invention, the low-temperature heat sealability and anti-blocking properties are excellent, and the processability is excellent when the surface layer of the film is functionally imparted. Layer, and then other substrates are laminated on it to form a laminated body for packaging, which can have a high degree of high-speed filling suitability, and achieve excellent productivity without failure during packaging and filling.

Claims (15)

A composite film having at least two layers of a base layer (A) and a heat-sealing layer (B), wherein the base layer (A) contains: a propylene-random copolymer (a1) having a melting point of 140°C or higher ) 100 parts by weight of a resin composition in which 1 to 10 parts by weight of polyethylene-based polymer (a2) is mixed; the above-mentioned heat-sealing layer (B) contains: a propylene-random copolymer (b1) whose melting point is below 145°C ) A resin composition containing 5 to 50 parts by weight of an ethylene·α-olefin copolymer (b2) having a melting point of 130° C. or lower in 100 parts by weight. The composite film of claim 1, wherein the base layer (A) contains 30% by weight or less of the constituent components of the heat seal layer (B) as a self-recovery component of the composite film. The composite film according to claim 1, wherein the propylene/random copolymer (a1) of the base layer (A) contains an ethylene/propylene random copolymer, an ethylene/propylene/1-butene 3-membered copolymer, or the etc. mixture. The composite film according to claim 1, wherein the propylene/random copolymer (a1) of the base layer (A) has a melting point in the range of 140 to 155°C. The composite film according to claim 1, wherein the polyethylene-based polymer (a2) of the base layer (A) contains high-density polyethylene. The composite film according to claim 1, wherein the propylene-random copolymer (b1) of the heat-sealing layer (B) contains ethylene-propylene random copolymer, propylene-1-butene random copolymer, ethylene- Propylene·1-butene 3-membered copolymer or a mixture of these. The composite film of claim 1, wherein the α-olefin of the ethylene·α-olefin copolymer (b2) of the heat-sealing layer (B) contains butene, hexene, octene, or a mixture thereof. The composite film according to claim 1, wherein the heat-sealing layer (B) contains 5 to 30 parts by weight of a thermoplastic elastomer. The composite film according to any one of claims 1 to 8, wherein, in the composite film according to any one of claims 1 to 8, a biaxially stretched polypropylene film with a thickness of 20 μm is laminated by dry lamination using an adhesive, The heat-sealing strength when the heat-sealing layers (B) surfaces of the composite film are overlapped and heat-sealed at 120° C. (single-side heating) is 3 N/15 mm or more. A laminated film provided on the surface of the base layer (A) of the composite film of claim 1, and provided with a function-imparting layer for imparting a specific function. The laminated film according to claim 10, wherein the specific function is at least one function selected from the group consisting of gas barrier properties, light shielding properties, gloss properties, wettability, easy adhesion to other substrates, and easy printability. For the laminated film of claim 10 or 11, the oxygen transmission rate at 23°C and humidity of 0% is ^{less than 50cc/m 2} ·day. A laminate in which the composite film of claim 1 is laminated on another base material layer so that the base layer (A) thereof is on the side of the other base material layer. A layered product in which the layered film of claim 10 is layered on another substrate layer such that the function-imparting layer is on the side of the other substrate layer. The laminate according to claim 13 or 14, wherein the other base material layer is a biaxially stretched polypropylene film using a polypropylene resin with a stereoregularity of 90 to 98%.