JP2021191688A - Packaging material - Google Patents

Abstract

To provide a packaging material that is highly recyclable, has excellent heat resistance and strength, and can be heat-sealed.SOLUTION: The packaging material of the present invention includes a base material, a seal layer arranged on at least one side of the base material, and an adhesive layer arranged between the base material and the seal layer, in which the base material contains an ultra-high molecular weight polyethylene-based resin having a viscosity-average molecular weight of 300,000 or more, a content ratio of the ultra high molecular weight polyethylene-based resin is 40 pts.wt. or more, with respect to 100 pts.wt. of resins in the base material, a thickness of the base material is 5 μm to 80 μm, a melting point of the base material is higher than a melting point of the seal layer by 30°C or more, and the seal layer contains a low molecular weight polyethylene-based resin.SELECTED DRAWING: Figure 1

Description

The present invention relates to a packaging material.

Polyethylene film is used as a packaging material because it has appropriate flexibility, is excellent in transparency, moisture resistance, chemical resistance, etc., and is inexpensive. A polyethylene film having a melting point of 100 ° C. to 140 ° C. is also useful as a packaging material having heat-sealing properties.

However, the polyethylene film has low rigidity, impact resistance, heat resistance, etc., and from the viewpoint of durability, there are some applications in which it cannot be used by itself. In order to solve such a problem, a packaging material obtained by laminating a polyethylene film and another resin film (for example, a polyester film or a polyamide film) is often used.

On the other hand, in recent years, social problems such as waste plastics have been attracting attention, and along with the increasing demand for the construction of a sound material-cycle society, improvement of the recyclability of packaging materials is required. The packaging material in which different material films are combined as described above has a problem that it is difficult to recycle such as material recycling and chemical recycling. To solve such a problem, a packaging material made of a base material / polyethylene sealant film using a polyethielen film having a relatively high rigidity as a base material has been studied. However, it is difficult to secure the rigidity of the polyethylene film, and it is necessary to make the film thicker. A packaging material composed of a thick film has a problem of poor tearability. Further, when the polyethylene film is used as a base material, there is also a problem that the heating temperature region at the time of heat sealing becomes narrow because the heat resistance of the base material is low.

JP-A-2019-171860 Japanese Unexamined Patent Publication No. 2018-52120

The present invention has been made to solve the above problems, and an object of the present invention is to provide a packaging material having high recyclability, excellent heat resistance and strength, and heat-sealable. ..

The packaging material of the present invention comprises a base material, a seal layer arranged on at least one side of the base material, and an adhesive layer arranged between the base material and the seal layer, and the base material comprises. The ultra-high molecular weight polyethylene resin having a viscosity average molecular weight of 300,000 or more is contained, and the content ratio of the ultra high molecular weight polyethylene resin is 40 parts by weight or more with respect to 100 parts by weight of the resin in the base material. The thickness of the base material is 5 μm to 80 μm, the melting point of the base material is higher than the melting point of the sealing layer by 30 ° C. or more, and the sealing layer contains a low molecular weight polyethylene-based resin.
In one embodiment, the substrate is a stretched film.
In one embodiment, the substrate further comprises a thermoplastic resin (B).
In one embodiment, the substrate further comprises a condensed hydroxy fatty acid and / or an alcohol ester (C) thereof.
In one embodiment, the tensile elastic modulus of the packaging material at 23 ° C. is 800 MPa or more.

According to the present invention, it is possible to provide a packaging material which is highly recyclable, has excellent heat resistance and strength, and can be heat-sealed because it can be composed only of a polyethylene-based resin.

It is a schematic sectional drawing of the packaging material by one Embodiment of this invention.

A. Packaging Material FIG. 1 is a schematic cross-sectional view of a packaging material according to one embodiment of the present invention. The packaging material 100 includes a base material 10 and a sealing layer 20 arranged on at least one side of the base material 10. An adhesive layer 30 is arranged between the base material 10 and the seal layer 20. The base material 10 contains an ultra-high molecular weight polyethylene resin (A). The seal layer 20 contains a low molecular weight polyethylene-based resin. In one embodiment, the packaging material may include any suitable other layer. In one embodiment, when the packaging material includes a layer made of a material other than the polyethylene-based resin, the content ratio of the material other than the polyethylene-based resin in the packaging material is 10% by weight or less. Preferably, the packaging material comprises only a layer made of a polyethylene resin.

The packaging material has heat-sealing properties. In the present specification, the heat-sealing property means a property that the film contact surfaces are melted and bonded by laminating the packaging materials and heating the film. In one embodiment, the packaging material exhibits heat sealability at a temperature of 80 ° C. or higher (preferably 80 ° C. to 200 ° C., more preferably 100 ° C. to 170 ° C.). In the above-mentioned packaging material, heat-sealing properties can be exhibited by bringing the sealing layers into contact with each other. The packaging material of the present invention is also advantageous in that it can be used as a sheet at a high temperature, and can be heat-sealed even at a temperature of, for example, 160 ° C to 170 ° C. Excellent sealing strength can be obtained by sealing at a high temperature. The pressurizing conditions for heat sealing are, for example, a sealing pressure of 0.05 to 0.3 MPa and a sealing time of 0.3 to 3 seconds.

The sealing strength when the packaging material is sealed at 160 ° C. is preferably 25 N / 15 mm or more, and more preferably 35 N / mm or more. The upper limit of the seal strength is not particularly limited, but is usually equal to or less than the tensile breaking strength of the package. The method for measuring the seal strength will be described later.

The viscosity average molecular weight of the ultra-high molecular weight polyethylene resin is larger than 300,000. "Ultra high molecular weight polyethylene resin" and "low molecular weight polyethylene resin" are distinguished by the viscosity average molecular weight. That is, in the present specification, the "low molecular weight polyethylene resin" means a polyethylene resin having a smaller viscosity average molecular weight than the "ultra high molecular weight polyethylene resin", and in one embodiment, the viscosity average molecular weight is It means a polyethylene-based resin that is less than 300,000. In the present specification, the polyethylene-based resin (ultra-high molecular weight polyethylene-based resin, low-molecular-weight polyethylene-based resin, etc.) means a resin containing 50 mol% or more of ethylene-derived structural units.

The packaging material of the present invention is excellent in heel sheet property by providing a sealing layer containing a low molecular weight polyethylene resin. Further, since the base material exhibits excellent mechanical properties by containing an ultra-high molecular weight polyethylene-based resin, the packaging material of the present invention is excellent in physical properties such as rigidity, strength, and impact resistance. Further, since the packaging material can be composed of the same type of resin, it is excellent in recyclability.

The thickness of the packaging material is preferably 20 μm to 120 μm, more preferably 30 μm to 80 μm.

The tensile strength of the packaging material at 23 ° C. is preferably 50 MPa or more, more preferably 50 MPa to 700 MPa, and further preferably 70 MPa to 500 MPa. Within such a range, a base material having excellent mechanical strength can be obtained. Tensile strength can be measured according to JIS K 7161. The tensile strength of the packaging material is mainly dominated by the properties of the substrate. In one embodiment, the tensile strength means the tensile strength in the flow direction (MD) in the production of the base material (during the rolling and molding of the molten sheet).

The tensile elastic modulus of the packaging material at 23 ° C. is preferably 800 MPa or more, more preferably 800 MPa to 20000 MPa, and further preferably 1000 MPa to 15000 MPa. Within such a range, it is possible to obtain a packaging material in which shrinkage and curl in the width direction are suppressed. The tensile strength of the packaging material is mainly dominated by the properties of the substrate. The elastic modulus can be measured according to JIS K 7161. In the present specification, the "tensile elastic modulus of the packaging material at 23 ° C." means the tensile elastic modulus at 23 ° C. in the direction in which the measured value is the largest in the plane of the packaging material. In one embodiment, the tensile strength of the packaging material means the tensile strength in the flow direction (MD) in the production of the base material (during the rolling and molding of the molten sheet). In another embodiment, the tensile strength of the packaging material means the tensile strength in the direction perpendicular to the flow direction (MD) (during the rolling and molding of the molten sheet) when the base material is manufactured (TD).

The rigidity of the packaging material at 23 ° C. is preferably 5 kN to 1370 kN, and more preferably 7 kN to 1000 kN. Rigidity is determined by the product of the elastic modulus and the thickness.

In the present invention, the thickness of the packaging material can be reduced by providing a base material capable of exhibiting excellent mechanical properties. The packaging material of the present invention has high sealing strength even if it is thin. Further, the packaging material of the present invention has high linear tearability because the molecular chains are oriented in the flow direction (MD) and the orthogonal direction (TD) at the time of film production. Specifically, in the above-mentioned packaging material, when tearing and opening, the meandering of the tear line is prevented, and the tear line can be extended in a desired direction.

A-1. Base material As described above, the base material contains an ultra-high molecular weight polyethylene resin (A). The content ratio of the ultra-high molecular weight polyethylene resin (A) is 40 parts by weight or more with respect to 100 parts by weight of the resin in the base material. The thickness of the base material is 5 μm to 80 μm. Further, the melting point of the base material is higher than the melting point of the seal layer by 30 ° C. or more.

The thickness of the base material is 5 μm to 80 μm, more preferably 5 μm to 60 μm, and further preferably 10 μm to 50 μm as described above. Within such a range, a base material having preferable rigidity can be used.

The tensile strength of the base material at 23 ° C. is preferably 50 MPa or more, more preferably 50 MPa to 700 MPa, and further preferably 70 MPa to 500 MPa. Within such a range, a base material having excellent mechanical strength can be obtained. As mentioned above, the tensile strength can be measured according to JIS K 7161. In one embodiment, the tensile strength means the tensile strength in the flow direction (MD) in the production of the base material (during the rolling and molding of the molten sheet).

The tensile elastic modulus of the base material at 23 ° C. is preferably 800 MPa or more, more preferably 800 MPa to 20000 MPa, and further preferably 1000 MPa to 15000 MPa. Within such a range, it is possible to obtain a packaging material in which shrinkage and curl in the width direction are suppressed. As described above, the elastic modulus can be measured according to JIS K 7161. In the present specification, the "tensile elastic modulus of the base material at 23 ° C." means the tensile elastic modulus at 23 ° C. in the direction in which the measured value is the largest in the plane of the base material. In one embodiment, the tensile strength means the tensile strength in the flow direction (MD) in the production of the base material (during the rolling and molding of the molten sheet). In another embodiment, the tensile strength means the tensile strength in the direction (TD) orthogonal to the flow direction (MD) (during molten sheet rolling and molding) when the base material is manufactured.

The rigidity of the base material at 23 ° C. is preferably 5 kN to 1370 kN, more preferably 7 kN to 1000 kN. Rigidity is determined by the product of the elastic modulus and the thickness.

The 30 μm equivalent moisture permeability of the packaging material is preferably 15 g / m ² · d or less, and more preferably 10 g / m ² · d or less. Within such a range, when the packaging material is used as the packaging material, spoilage of the contents can be remarkably prevented. The lower the 30 μm equivalent moisture permeability of the packaging material, the more preferable, but the lower limit thereof is, for example, 1 g / m ² · d, more preferably 0.5 g / m ² · d. The moisture permeability is the amount of water vapor (g) that passes through a sample with a diameter of 80 mm in 24 hours under the conditions of a temperature of 40 ° C. and a humidity of 90% RH in accordance with the JIS K 7129 moisture permeability test (humidity sensitive sensor method). It is a value obtained by measurement. Further, the 30 μm equivalent moisture permeability is calculated by multiplying the moisture permeability obtained by the above measurement by (30 μm / thickness of the packaging material (μm)).

The base material has an endothermic peak L of less than 140 ° C. and an endothermic peak H of 140 ° C. or higher at the first temperature rise in the DSC measurement. The endothermic peak L is preferably at 110 ° C to 139 ° C, more preferably at 125 ° C to 139 ° C. The endothermic peak H is preferably at 142 ° C to 160 ° C, more preferably at 144 ° C to 158 ° C. The base material of the present invention has a plurality of endothermic peaks as described above, whereby a base material having excellent mechanical strength and heat resistance can be obtained. In one embodiment, the base material reduces or eliminates the endothermic peak H of 140 ° C. or higher at the second temperature rise in the DSC measurement. Having an endothermic peak H that disappears (or decreases) at the second temperature rise suggests that the substrate has a highly oriented molecular chain. For the endothermic peak, use DSC to raise the temperature from 30 ° C to 230 ° C at a start temperature of 10 ° C / min and a temperature decrease rate of 10 ° C / min, hold at 230 ° C for 3 minutes, lower the temperature to 30 ° C, and then further 230. It can be measured by raising the temperature to ° C.

The melting point of the base material is preferably 100 ° C. or higher, more preferably 100 ° C. to 200 ° C., and even more preferably 120 ° C. to 160 ° C. Within such a range, it is possible to form a base material that can withstand heat sealing at high temperatures (for example, does not melt). The melting point of the base material is the melting point (Tm) determined by differential scanning calorimetry (DSC) according to JIS K 7121, and is determined from the endothermic peak at the highest temperature among the endothermic peaks produced by DSC.

As described above, the melting point of the base material is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, and even more preferably 40 ° C. or higher than the melting point of the seal layer. Within such a range, a packaging material that can be heat-sealed at a high temperature can be obtained. The upper limit of the difference between the melting point of the base material and the melting point of the seal layer is, for example, 60 ° C. The melting point of the seal layer is the melting point (Tm) determined by differential scanning calorimetry (DSC) according to JIS K 7121, and is determined from the endothermic peak at the lowest temperature among the endothermic peaks produced by DSC.

In one embodiment, the base material can be obtained by molding a resin composition containing an ultra-high molecular weight polyethylene-based resin (A) by rolling and molding a melt sheet. In one embodiment, the substrate (ie, the resin composition) comprises a thermoplastic resin (B). Further, in one embodiment, the substrate (that is, the resin composition) contains a condensed hydroxy fatty acid and / or an alcohol ester (C) thereof (hereinafter, also simply referred to as compound (C)). By adding the thermoplastic resin (B) and / or the compound (C), a resin composition having excellent moldability by rolling and molding a molten sheet can be obtained. The molten sheet rolling molding refers to a molding method in which a resin composition is rolled between two or more rolls to form a film having a predetermined thickness (details will be described later).

(Ultra High Molecular Weight Polyethylene Resin (A))
The viscosity average molecular weight of the ultra-high molecular weight polyethylene resin (A) is 300,000 or more as described above. By using the ultra-high molecular weight polyethylene resin (A) having such a viscosity average molecular weight, it is possible to obtain a base material having excellent wear resistance, self-lubricating property, impact resistance, low temperature characteristics, chemical resistance and heat resistance. can. The viscosity average molecular weight of the ultra-high molecular weight polyethylene resin (A) is preferably 300,000 to 15 million, more preferably 500,000 to 8 million, and even more preferably 1 million to 6 million. Within such a range, a base material having excellent rigidity and strength can be obtained. The base material may contain two or more types of ultra-high molecular weight polyethylene resins (A) having different molecular weights. The viscosity average molecular weight (Mv) can be measured by the viscosity method specified in ASTMD4020. Specifically, the ultimate viscosity (η (dl / g)) can be measured based on the viscosity method of ASTMD4020, and the viscosity average molecular weight (Mv) can be obtained from the following equation (1).
Mv = 5.37 × 10 ⁴ η ^1.37 ... (1)
The ultimate viscosity of the ultra-high molecular weight polyethylene resin (A) is, for example, 3.5 dl / g or more. The upper limit of the ultimate viscosity of the ultra-high molecular weight polyethylene resin is, for example, 60 dl / g or less.

The ultra-high molecular weight polyethylene resin (A) may be a homopolymer of ethylene, or may be a copolymer of ethylene and another monomer copolymerizable with the ethylene. The content ratio of the ethylene-derived structural unit in the ultra-high molecular weight polyethylene resin (A) is preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more.

Examples of other monomers copolymerizable with ethylene include α-olefins having 3 or more carbon atoms (preferably 3 to 20 carbon atoms). Examples of the α-olefin having 3 or more carbon atoms include propylene, 1-butene, isobutene, 1-pentene, and 2-methyl-.
1-butene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1- Examples thereof include tetradecene, 1-hexadecene, 1-octadecene, 1-icocene and the like.

The ultra-high molecular weight polyethylene resin (A) can be produced by any suitable method. For example, the above-mentioned monomer can be obtained by polymerizing in the presence of any suitable catalyst by the method described in JP-A-58-83006.

The content ratio of the ultra-high molecular weight polyethylene resin (A) is preferably 40 parts by weight or more, more preferably 40 parts by weight to 90 parts by weight, and more preferably with respect to 100 parts by weight of the resin in the base material. Is 40 parts by weight to 80 parts by weight, and particularly preferably 40 parts by weight to 70 parts by weight.

(Thermoplastic resin (B))
The viscosity average molecular weight of the thermoplastic resin (B) is smaller than the viscosity average molecular weight of the ultra-high molecular weight polyethylene resin (A). The viscosity average molecular weight of the thermoplastic resin (B) is preferably less than 300,000. Within such a range, the fluidity of the resin composition can be enhanced by adding the thermoplastic resin (B) to the resin composition for forming the substrate. In one embodiment, the viscosity average molecular weight of the thermoplastic resin (B) is 200,000 or less. Within such a range, a resin composition having particularly excellent molding processability can be obtained.

The melt flow rate of the thermoplastic resin (B) at 190 ° C. and 2.16 kgf is preferably 0.01 g / 10 min to 150 g / 10 min, more preferably 0.1 g / 10 min to 100 g / 10 min, and even more preferably. Is 10 g / 10 min to 90 g / 10 min, and particularly preferably 20 g / 10 min to 80 g / 10 min. Within such a range, it is possible to obtain a base material which is particularly excellent in molding processability and which fully exhibits the characteristics derived from the ultra-high molecular weight polyethylene resin (A).

Examples of the thermoplastic resin (B) include olefin resins (for example, homopolymers of α-olefins, copolymers composed of two or more kinds of α-olefins, and the like).

As the α-olefin constituting the thermoplastic resin (B), an α-olefin having 2 to 10 carbon atoms is preferable, an α-olefin having 2 to 8 carbon atoms is more preferable, and ethylene, propylene or 1-butene is preferable. More preferred.

In one embodiment, a polyethylene-based resin other than the ultra-high molecular weight polyethylene-based resin (A) is used as the thermoplastic resin (B). The content of the ethylene-derived structural unit in the polyethylene resin is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 95 mol% or more. Examples of the structural unit other than the structural unit derived from ethylene include a structural unit derived from a monomer copolymerizable with ethylene, for example, propylene, 1-butene, isobutene, 1-pentene, 2-methyl-1-butene. , 3-Methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1 -Constituent units derived from hexadecene, 1-octadecene, 1-icocene and the like can be mentioned. In the present specification, the "polyethylene resin other than the ultra-high molecular weight polyethylene resin (A)" means a polyethylene resin having a viscosity average molecular weight of the thermoplastic resin (B) of less than 300,000.

The melt flow rate of the polyethylene resin at 190 ° C. and 2.16 kgf is preferably 0.01 g / 10 min to 150 g / 10 min, more preferably 0.1 g / 10 min to 100 g / 10 min, and further preferably 10 g. It is / 10min to 90g / 10min, and particularly preferably 20g / 10min to 80g / 10min. Within such a range, it is possible to obtain a base material which is particularly excellent in molding processability and which fully exhibits the characteristics derived from the ultra-high molecular weight polyethylene resin (A).

In another embodiment, a polypropylene-based resin is used as the thermoplastic resin (B). The polypropylene-based resin is advantageous in that it has excellent compatibility with the ultra-high molecular weight polyethylene-based resin (A). The polypropylene-based resin may be a homopolymer of propylene, or may be a copolymer of propylene and a monomer copolymerizable with propylene. Examples of the copolymer include random polypropylene composed of a propylene-derived constituent unit and an ethylene-derived constituent unit, block polypropylene composed of a propylene-derived constituent unit and an ethylene-derived constituent unit, and a propylene-derived constituent unit. Examples thereof include a polypropylene tarpolymer composed of a unit, a structural unit derived from ethylene, and a structural unit derived from 1-butene. Examples of the stereoregularity of these polypropylene-based resins include syndiotactic polypropylene and atactic polypropylene. Further, long-chain branched polypropylene having a branched structure and the like can also be mentioned. These resins may be used alone or in combination of two or more. The content ratio of the propylene-derived constituent unit in the polypropylene-based resin is preferably 50 mol% or more, more preferably 80 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more. That is all.

The melt flow rate of the propylene-based resin at 230 ° C. and 2.16 kgf is preferably 0.1 g / 10 min to 1000 g / 10 min, and more preferably 0.5 g / 10 min to 800 g / 10 min. More preferably, it is 1 g / 10 minutes to 500 g / 10 minutes. Within such a range, it is possible to obtain a base material which is particularly excellent in molding processability and which fully exhibits the characteristics derived from the ultra-high molecular weight polyethylene resin (A).

The content ratio of the thermoplastic resin (B) is preferably 20 parts by weight to 95 parts by weight, more preferably 30 parts by weight to 85 parts by weight, still more preferably, with respect to 100 parts by weight of the resin in the base material. Is 40 to 80 parts by weight. Within such a range, a resin composition having excellent moldability can be prepared, and a base material having sufficiently exhibited the characteristics derived from the ultra-high molecular weight polyethylene resin (A) can be obtained. ..

(Condensed hydroxy fatty acid and / or its alcohol ester (C))
By containing the condensed hydroxy fatty acid and / or its alcohol ester (C), the fluidity of the resin composition can be enhanced, and as a result, a substrate having excellent moldability can be obtained by rolling and molding a melt sheet. can.

The condensed hydroxy fatty acid can be obtained by dehydrating and condensing the hydroxy fatty acid. The condensed hydroxy fatty acid can be obtained by dehydration condensation by adding an alkaline catalyst such as caustic soda to the hydroxy fatty acid and removing the reaction water under heating.

The condensed hydroxy fatty acid is a condensed product of hydroxy fatty acid, and the degree of condensation thereof is preferably 2 or more, more preferably 4 or more. The upper limit of the degree of condensation of the condensed hydroxy fatty acid is, for example, 20. The degree of condensation can be calculated from the acid value of the raw material hydroxy fatty acid and the acid value after the condensation reaction.

The hydroxy fatty acid is a fatty acid having one or more hydroxyl groups in the molecule. Specific examples of hydroxy fatty acids include, for example, ricinolic acid, 12-hydroxystearic acid, sabinic acid, 2-hydroxytetradecanoic acid, iprolic acid, 2-hydroxyhexadecanoic acid, yarapinolic acid, uniperic acid, ambrettoric acid, allurit. Acids, 2-hydroxyoctadecanoic acid, 18-hydroxyoctadecanoic acid, 9,10-dihydroxyoctadecanoic acid, camlorene acid, ferronic acid, celebronic acid and the like can be mentioned. The hydroxy fatty acid may be used alone or in combination of two or more.

The alcohol ester of the condensed hydroxy fatty acid can be obtained by subjecting the condensed hydroxy fatty acid to an alcohol in an esterification reaction. The alcohol ester of the condensed hydroxy fatty acid is, for example, a mixture of the condensed hydroxy fatty acid and an alcohol, an alkaline catalyst such as caustic soda or an acid catalyst such as phosphoric acid is added to the obtained mixture, and the reaction water is removed under heating. Can be obtained. The progress of esterification during this reaction can be confirmed by measuring the acid value, saponification value, hydroxyl value and the like. As described above, the degree of condensation of the condensed hydroxy fatty acid used here is preferably 2 or more, and more preferably 4 or more.

Examples of the alcohol include monohydric alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; and dihydric alcohols such as ethylene glycol and propylene glycol. Moreover, you may use a polyhydric alcohol as the said alcohol. Examples of the polyhydric alcohol include alcan polyols such as pentaerythritol and glycerin; polyalcan polyols which are polymers of the alcan polyols; sugars such as sucrose; sugar derivatives typified by sugar alcohols such as sorbitol and mannitol. Can be mentioned. These alcohols may be used alone or in combination of two or more.

Specific examples of the condensed hydroxy fatty acid synthesized from the above compound as a raw material and / or its alcohol ester (C) include condensed ricinoleic acid obtained by dehydrating and condensing ricinoleic acid and condensed 12 hydroxysteary obtained by dehydrating and condensing 12 hydroxystearic acid. Acid, condensed lysinoreic acid and hexaglycerin ester of glycerin 6 polymer, condensed ricinoleic acid hexaglycerin ester, condensed ricinoleic acid and tetraglycerin ester of glycerin 4 polymer, condensed ricinoleic acid tetraglycerin ester, condensed 12 hydroxysteer Examples thereof include condensed 12 hydroxystearic acid propylene glycol ester which is an ester of acid and propylene glycol, condensed linoleic acid propylene glycol ester which is an ester of condensed lysinoreic acid and propylene glycol, and the like. These may be used alone or in combination of two or more.

The content ratio of the condensed hydroxy fatty acid and the alcohol ester (C) thereof is preferably 0.1 part by weight to 10 parts by weight, and more preferably 0.2 parts by weight to the part based on 100 parts by weight of the resin in the base material. It is 8 parts by weight, more preferably 0.3 parts by weight to 5 parts by weight, still more preferably 0.4 parts by weight to 5 parts by weight. Within such a range, a resin composition having excellent fluidity can be prepared, and a base material having sufficiently exhibited the characteristics derived from the ultra-high molecular weight polyethylene resin (A) can be obtained. .. The "content ratio of the condensed hydroxy fatty acid and its alcohol ester (C)" means the total content ratio of the condensed hydroxy fatty acid and the alcohol ester of the condensed hydroxy fatty acid. Therefore, when the base material contains only the condensed hydroxy fatty acid as the compound (C), the "content ratio of the condensed hydroxy fatty acid and its alcohol ester (C)" means the content ratio of the condensed hydroxy fatty acid. When the base material contains only the alcohol ester of the condensed hydroxy fatty acid as the compound (C), the "content ratio of the condensed hydroxy fatty acid and its alcohol ester (C)" means the content ratio of the alcohol ester of the condensed hydroxy fatty acid. means.

(Other ingredients)
The substrate may further contain any suitable additive, if desired. As additives, for example, as additives, for example, flow modifiers, antistatic agents, heat stabilizers, stabilizers such as weather resistant agents, colorants such as pigments and dyes, lubricants, cross-linking agents, and cross-linking aids. , Anti-blocking agent, antistatic agent, anti-fog agent, organic filler, inorganic filler and the like.

Examples of the flow modifier include various silicone oils such as polydimethylsiloxane, liquid lubricants, various aliphatic compounds or metal salts thereof, alicyclic compounds, various waxes, solid lubricants, and various surface lubricants. Examples thereof include a mixture thereof. In one embodiment, a fatty acid amide (preferably erucic acid amide) is used as the flow modifier. The content ratio of the fatty acid amide is, for example, 0.05 part by weight to 1 part by weight with respect to 100 parts by weight of the resin constituting the base material. By adding the fatty acid amide in this way, the thin film formability of the base material is improved.

Examples of the silicone oil include dimethylpolysiloxane type, methylhydrogenpolysiloxane type, both-terminal hydroxypolysiloxane type, methylphenylpolysiloxane type, alkyl-modified silicone type, amino-modified silicone type, carboxyl-modified silicone type, and higher fatty acids. Examples thereof include modified silicone type, epoxy-modified silicone type, vinyl group-containing silicone type, alcohol-modified silicone type, polyether-modified silicone type, alkyl / polyether-modified silicone type, and fluorxane-modified silicone type silicone oil.

Examples of the liquid lubricant include polyglycol oil, polyphenyl ether oil, ester oil, phosphate ester oil, polychlorotrifluoroethylene oil, fluoroester oil, chlorinated biphenyl oil, synthetic lubricating oil such as silicone oil, and ethylene. Examples thereof include −α—olefin copolymerized synthetic lubricating oil.

Examples of the aliphatic compound include fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and oleic acid; ethylene bis-stearic acid amide, stearic acid amide, oleic acid amide, erucic acid amide and ethylene bis. -Oleic acid amide, caprin amide, laurin amide, palmitin amide, stearyl amide, etc., behensan amide, hydroxystearic acid amide, N-oleyl partimate amide, N-stearyl stearyl amide, N-stearyl oleic acid amide, N- Oleyl stearate amide, N-stearyl erucate amide, methylol stealic acid amide, methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, hexamethylene Bistearic acid amide, hexamethylene bisbechenic acid amide, hexamethylene hydroxystearic acid amide, N, N'-dystearyl adipic acid amide, N, N'-dystearyl sebacic acid amide, ethylene biserucate amide, hexamethylene bis Fatty acid amides such as oleic acid amides, N, N'-diorail adipic acid amides, N, N'-diorail sevacinic acid amides; dioctyl ethers {(C ₈ H ₁₇ ) ₂ O}, didecyl ethers {(C _10). Ether compounds of fatty acids such as H ₂₅ ) ₂ O}, didodecyl ether {(C ₁₂ H ₂₅ ) ₂ O}, dioctadecyl ether {(C ₁₈ H ₃₇ ) _{2 O}; methyltetradecyl ketone {CH 3} CO ( CH ₂ ) ₁₃ CH ₃ }, n-propylhexisadecyl ketone {CH ₃ (CH ₂ ) ₂ CO (CH ₂ ) ₁₅ CH ₃ }, didotesil ketone {CH ₃ (CH ₂ ) ₁₁ CO (CH ₂ ) ₁₁ CH ₃ }, Dioctadecylketone {CH ₃ (CH ₂ ) ₁₇ CO (CH ₂ ) ₁₇ CH ₃ }, a ketone compound of fatty acids such as octyl laurate {CH ₃ (CH ₂ ) ₁₀ COO (CH ₂ ) ₇ CH ₃ }, Ethyl palmitate {CH ₃ (CH ₂ ) ₁₄ COOCH ₂ CH ₃ }, butyl stearate {CH ₃ (CH ₂ ) ₁₆ COO (CH ₂ ) ₃ CH ₃ }, octyl stearate {CH ₃ (C) H ₂ ) ₁₆ COO (CH ₂ ) ₇ CH ₃ } and other fatty acid ester compounds; laurin alcohol, myristyl alcohol, cetyl alcohol (CH ₃ (CH ₂ ) ₁₄ CH ₂ OH), heptadecyl alcohol (CH ₃ (CH ₂₎₎ ) ₁₅ CH ₂ OH), stearyl alcohol (CH ₃ (CH ₂ ) ₁₆ CH ₂ OH), ceryl alcohol (CH ₃ (CH ₂ ) ₂₄ CH ₂ OH), behenyl alcohol (CH ₃ (CH ₂ ) ₇ C (CH)) ₁₁ CHOH) and other fatty alcohols; and the like.

Examples of metal salts of fatty acids include calcium stearate, magnesium stearate, barium stearate, lithium stearate, sodium stearate, zinc stearate, dinclaulate, zinc behenate, calcium montanate, magnesium montanate, and barium montanate. , Lithium montanate, sodium montanate, zinc montanate, calcium behenate, magnesium behenate, barium behenate, lithium behenate sodium behenate, zinc behenate, calcium laurate, magnesium laurate, barium laurate, lithium laurate , Sodium laurate, zinc laurate, calcium 12-hydroxystearate, magnesium 12-hydroxystearate, barium 12-hydroxystearate, lithium 12-hydroxystearate, sodium 12-hydroxystearate and the like.

Examples of the alicyclic compound include esterified rosin, cyclic terpene resin, terpene resin derivative, polycyclopentadiene, hydrogenated polycyclopentadiene, and 1,3-pentadiene or conjugated diolefin containing dicyclopentadiene as a main component. Examples thereof include a polycyclopentadiene-based resin and a dicyclopentadiene-based petroleum resin which have been polymerized.

Examples of the waxes include n-alkanes having 22 or more carbon atoms such as n-nonane, n-decane, n-undecane, n-dodecane, n-tetradecane, n-octadecane, docosan, tricosan, tetracosan, and triacane. A mixture of low-grade n-alkanes containing these as the main components; medium- and low-grade polymers obtained by copolymerizing so-called paraffin wax, ethylene or ethylene separated and purified from petroleum with other α-olefins. Ester wax, high pressure method polyethylene wax, ethylene copolymer wax, medium / low pressure method polyethylene, high pressure method polyethylene and other polyethylene whose molecular weight has been reduced by heat reduction, etc., and oxides or maleic acid modification of those waxes, etc. Oxidation wax, maleic acid-modified wax, montanic acid ester-based wax, fatty acid derivative wax (eg, dicarboxylic acid ester, glycerin fatty acid ester, amido wax) and the like.

Examples of the solid lubricant include graphite, molybdenum disulfide, boron nitride, tungsten disulfide, lead oxide, glass powder, and metal soap.

Examples of the surfactant include glycerin monostearate, palm-hardened oil monoglyceride, oleic acid monoglyceride, rapeseed hardened oil fatty acid mono-diglyceride, self-emulsifying stearic acid mono-diglyceride, oleic acid mono-diglyceride, and capric acid monoglyceride lauric acid. Monoglycerol, capric acid monoglycerol, caprylic acid mono-diglycerol, caprylic acid diglycerol, mono-dioleate diglycerin, mono-dystearate diglycerin, monostearate diglycerin, pentaoleate decaglycerin, pentastearate decaglycerin, pentastearate Decaglycerin acid, decaglycerin decaoleine, decaglycerin decastearate, pentaglycerin trioleate, pentaglycerin hexastearate, decaglycerin monolaurate, decaglycerin monomyristine, decaglycerin monooleate, decaglycerin monostearate, Decaglycerin distearate, pentaglycerin monolaurate, pentaglycerin monomyristate, pentaglycerin monooleate, pentaglycerin monostearate, sorbitan monostearate, sorbitan monooleate, sorbitan triorate, propylene glycol monostearate, monoolein Examples thereof include propylene glycol acid and the like.

Examples of the anti-mayani agent include a fluorine-based elastomer, a 12-hydroxystearic acid metal salt, a basic 12-hydroxystearic acid metal salt, a carboxylic acid amide-based wax, and the like.

Examples of the antistatic agent include a low molecular weight surfactant type antistatic agent, a polymer type antistatic agent and the like. Examples of the low molecular weight surface active agent type antistatic agent include a cationic antistatic agent having a cationic group such as a quaternary ammonium salt, a pyridinium salt, and a tertiary amino group, a sulfonic acid base, and a sulfuric acid. Anionic antistatic agents having anionic groups such as ester bases, phosphate ester bases, and sulfonic acid bases, amino acid antistatic agents, amphoteric antistatic agents such as aminosulfate ester antistatic agents, amino alcohol antistatic agents, and glycerin antistatic agents. Examples thereof include nonionic antistatic agents such as antioxidants and polyethylene glycol antistatic agents. Examples of the polymer type antistatic agent include nonionic polymers such as polyethylene oxide, polypropylene oxide, polyethylene glycol, polyether ester amide, polyether ester, polyether polyolefin, and ethylene oxide / epichlorohydrin-based copolymer. Type antistatic agent, anionic polymer type antistatic agent such as polystyrene sulfonic acid, quaternary ammonium base-containing acrylate polymer, quaternary ammonium base-containing styrene polymer, quaternary ammonium base-containing polyethylene glycol methacrylate-based copolymer Examples thereof include cationic polymer-type antistatic agents such as.

Further, from the viewpoint of imparting an antistatic function, a conductive substance can be used. Examples of the conductive substance include metals, metal oxides, particles coated with metal or metal oxides, inorganic metal salt compounds, carbon-based materials, modified silicone materials, ionic organic compounds, nonionic organic compounds, and conductive substances. Examples thereof include sexual polymers and ionic liquids. Examples of the metal include gold, silver, platinum, copper, nickel, iron, palladium, aluminum, gallium, indium, tin and the like. Examples of the metal oxide include zinc oxide, antimony oxide, tin oxide, cerium oxide, indium oxide, indium tin oxide (ITO), metal-doped tin oxide, and metal-doped zinc oxide. Examples of the metal-doped tin oxide include antimony-doped tin oxide (ATO). Examples of the inorganic metal salt compound include metal silicate, metal titanate, alkali metal sulfate, alkali metal nitrate, alkali metal perchlorate, alkali metal sulfonate, alkali metal carboxylate, and tetrafluorohoe. Examples thereof include a metal complex of an acid and a metal complex of hexafluorophosphate. Examples of carbon-based materials include carbon black, graphite, carbon fiber, carbon nanotubes, fullerenes, graphene and the like. Examples of the conductive material include a conductive filler. Examples of the conductive filler include carbon-based, metal-based, metal oxide-based, and metal-coated conductive fillers. Examples of the carbon-based conductive filler include Ketjen black, acetylene black, oil furnace black and the like. Examples of the metal constituting the metallic conductive filler include Ag, Ni, Cu, Zn, Al, and stainless steel. Examples of the metal oxide constituting the metal oxide-based conductive filler include SnO2, In2O3, ZnO and the like. As the metal coating conductive filler, for example, Ni, Al or the like is used as the coating material, and mica, glass beads, glass fiber, carbon fiber, calcium carbonate, zinc oxide, titanium oxide or the like is used as the base filler. Filler is adopted.

In one embodiment, a carbon-based conductive filler (preferably Ketjen Black) is used. The content ratio of the carbon-based conductive filler is, for example, 2 parts by weight to 20 parts by weight with respect to 100 parts by weight of the resin in the resin composition. Thus the addition of carbon-based conductive filler, the surface resistivity ^{(e.g., 10 3 Ω / □ ~10 5} Ω / □) to obtain a resin may form a properly configured molded composition be able to.

Examples of the coloring material include perylene red (CI PigmentRed 178), quinacridon red (CI Pigment 122, 202), anthracinone yellow (CI Pigment Yellow 147), and benzimizazolone yellow (CI). Organic pigments such as PigmentYellow180, 181), Monoazolechiello (CI Pigment 183), Copper Phthalusin Blue (CI PigmentBlue15-1), Copper Phtalianin Green (CI PigmentGreen7); Titanium dioxide (C) I. PigmentWhite6), zinc sulfide (CIPigmentWhite22), carbon black (CIPigmentBlack7), fired black (CIPigmentBlack28), bismuth vanadate yellow (CIPigmentYellow184), nickel titanium. Yellow (CI PigmentYellow53), Chrome Titanium Yellow (CI PigmentBrown24), Valve Handle (CI PigmentRed101), Chromium Oxide (CI PigmentGreen17), Cobalt Green (CI PigmentGreen19), Examples thereof include inorganic pigments such as ultramarine (CI PigmentBlue 29), cobalt blue (CI Pigment Blue 28), ultramarine violet (CI Pigment Violet 15) and aluminum (CI Pigment matal 1).

(Manufacturing method of base material)
In one embodiment, the substrate is a stretched film. The stretched film means, for example, a film obtained through any one of stretching by rolling, stretching by a tenter (TD stretching), and stretching by a roll (MD stretching). The substrate can be produced by any suitable method, including, for example, stretching by rolling sheet rolling. Examples of the production method include a method of preparing the above resin composition containing an ultra-high molecular weight polyethylene-based resin (A) and rolling and molding the resin composition in a molten sheet. As described above, the resin composition may further comprise the thermoplastic resin (B), the condensed hydroxy fatty acid and / or its alcohol ester (C), and the additives added as needed.

In one embodiment, the resin composition comprises an ultra-high molecular weight polyethylene resin (A), a thermoplastic resin (B), a condensed hydroxy fatty acid and / or an alcohol ester (C) thereof, as required. It can be prepared by melt-kneading with the additive to be added. Examples of the melt-kneading method include a method using a single-screw extruder, a multi-screw extruder, a tandem extruder, a Banbury mixer and the like. If the above resin is melt-kneaded in the presence of condensed hydroxy fatty acid and / or its alcohol ester (C), the generation of lumps can be suppressed and a resin composition having a good resin dispersion can be obtained.

The processing temperature in the melt-kneading is preferably a temperature at which the resin contained in the resin composition can be melted. The temperature is preferably 120 ° C. to 350 ° C., more preferably 140 ° C. to 330 ° C., still more preferably 150 ° C. to 300 ° C., and particularly preferably 160 ° C. to 250 ° C.

The melt sheet rolling molding refers to a molding method in which a resin composition is rolled between two or more rolls to form a film having a predetermined thickness. Typically, the resin composition melt-kneaded and released from the T-die is subjected to the rolling. In the present invention, a base material having the above characteristics can be obtained by adopting the molten sheet rolling molding. As these molten sheet rolling moldings, the polishing roll method and calendar molding used in T-die extrusion molding are preferably used. Examples of the T-die extrusion molding include a horizontal arrangement roll method and a vertical arrangement method. The number of rolls is preferably 3 or more, and equipment having a mechanism capable of rolling between each roll can be used. Examples of the calendar molding apparatus include a two-series calendar, a three-series calendar, a four-series calendar, an S-type calendar, an inverted L-type calendar, a Z-type calendar, and an oblique Z-type calendar.

The lip clearance of the T-die is preferably 0.2 mm to 5 mm, more preferably 1 mm to 3 mm. The temperature at the outlet of the T die is preferably 150 ° C. to 300 ° C., more preferably 200 ° C. to 280 ° C. The temperature of the T-die can be adjusted according to the temperature of the desired resin composition.

The number of rolling times may be one or a plurality of times. By setting the number of rolling times to a plurality of times, high strength (increasing MD tensile strength, increasing MD elastic modulus) can be achieved, and a substrate having a large degree of crystal orientation can be obtained. The number of rolling times is preferably 2 to 6 times, and more preferably 2 to 4 times.

Preferably, the rolling roll is heated. The temperature of the rolling roll is preferably 90 ° C to 200 ° C, more preferably 100 ° C to 180 ° C, and even more preferably 120 ° C to 160 ° C. The temperatures of the plurality of rolling rolls may be the same or different.

The linear pressure applied to the rolling roll is preferably 15 kg / cm to 300 kg / cm, more preferably 30 kg / cm to 200 kg / cm, and even more preferably 50 kg / cm to 150 kg / cm.

The machining speed in calender molding can be set to any suitable speed.

The method for producing the base material may include a stretching step (for example, a roll stretching step, a tenter stretching step, etc.). The stretching step can be performed, for example, after the molten sheet rolling and molding process. As a stretching method, for example, MD stretching by a roll can be adopted. The MD stretch ratio is, for example, 1.1 to 5 times. By stretching at such a magnification, a packaging material having good moldability and excellent strength can be obtained. Further, the base material may be obtained not only by MD stretching but also by TD stretching such as tenter stretching. The TD stretch ratio is, for example, 1.1 to 8 times, preferably 3 to 7 times, and more preferably 4 to 6 times. When the TD stretch ratio is in this range, the homogeneity in the TD direction is improved. In the tenter stretching step, the temperature of the tenter oven is generally preferably 110 to 155 ° C. Below 100 ° C, there is a high possibility of fracture during stretching, and above 155 ° C, rigidity may decrease. In one embodiment, the draw ratio of MD / TD is adjusted to improve the tearability.

The base material may be subjected to any suitable surface treatment. For example, by applying a surface treatment, a packaging material having excellent adhesion between the base material and the adhesive layer can be obtained. Examples of the surface treatment include corona treatment, frame treatment, plasma treatment and the like. In addition to the surface treatment applied to the substrate, a metal layer such as an alumina layer, a silicon dioxide layer, and an aluminum layer and a metal oxide layer can be provided by a method such as thin film deposition, and various coating methods can be used. Therefore, oxygen barrier property, antistatic property, conductivity, antifogging property and the like can be imparted. In particular, as a method for imparting oxygen barrier properties, a method for forming a coating layer in which an inorganic layered compound is dispersed in a water-soluble resin such as a polyvinyl alcohol resin, and a method for forming a coating layer for a polyvinyl chloride resin or a polyvinylidene chloride resin are formed. Techniques to be used can be mentioned. This coating layer can be formed by a coating facility using a gravure roll or the like. By forming such a coating layer, an oxygen barrier property can be added to the effect of the present invention, and a water vapor barrier property can be added by selecting a coating layer and devising heat history conditions. Examples of such a coating agent include Exevia NOH1200, NOH2200, NOH3000 manufactured by Sumitomo Chemical Co., Ltd. and LG-OX barrier agent manufactured by Tokyo Ink Co., Ltd.

A-2. Seal layer The thickness of the seal layer is preferably 5 μm to 100 μm, more preferably 10 μm to 70 μm, and even more preferably 20 μm to 60 μm.

The melting point of the seal layer is preferably 80 ° C to 130 ° C, more preferably 90 ° C to 125 ° C. Within such a range, a packaging material having excellent heat-sealing properties can be obtained at a low heat-sealing temperature. When the seal layer has a multi-layer structure, the melting point of the outermost layer arranged on the side opposite to the base material is preferably in the above range.

The seal layer is composed of a film (polyethylene resin film) formed of any suitable low molecular weight polyethylene resin. The polyethylene-based resin constituting the polyethylene-based resin film may be a homopolymer of ethylene or a copolymer of a monomer copolymerizable with ethylene. Examples of the polyethylene-based resin include low-density polyethylene (LDPE), linear short-chain branched polyethylene (LLDPE), high-density polyethylene (HDPE), ethylene / vinyl acetate copolymer, and ethylene / unsaturated carboxylic acid copolymer. , Polyethylene / unsaturated carboxylic acid ester copolymer, polyethylene / carbon monoxide copolymer, polyethylene / styrene copolymer and the like. The polyethylene-based resin film constituting the seal layer can be produced by any suitable method such as (co) extrusion T die casting method and (co) extrusion inflation method.

As described above, the viscosity average molecular weight of the low molecular weight polyethylene resin constituting the polyethylene resin film is preferably less than 300,000. In one embodiment, the melt flow rate of the low molecular weight polyethylene resin having such a molecular weight at 190 ° C. and 2.16 kgf is preferably 0.5 g / 10 min or more, and more preferably 0.5 g / 10 min to. It is 20 g / 10 min, more preferably 1 g / 10 min to 15 g / 10 min. Within such a range, a polyethylene-based resin film having excellent production efficiency can be obtained, and a high-strength packaging material / packaging material can be provided. Further, when the polyethylene-based resin film is molded by the (co) extrusion T die casting method, the (co) extrusion inflation method, or the like, the melt flow rate is 1 g / 10 min to 8 g / 10 min from the viewpoint of moldability. Is particularly preferable.

Density of the low molecular weight polyethylene resin constituting the polyethylene resin film is not it may vary by factors such as the molecular structure ^is preferably ^{880kg / m 3 ~940kg / m 3} , 885kg / m 3 ~930kg / It ^{is more preferably m 3} or less, and particularly preferably ^{895 kg / m 3 to} 925 kg / m ^3. As the density decreases, the melting point decreases, so if a low-molecular-weight ethylene resin with a density in this range is used for the surface of the seal layer, the packaging material can be heat-sealed at a lower temperature, and the condition range for heat-sealing can be changed. It may be possible to make it wider.

The polyethylene-based resin film constituting the seal layer may contain any suitable additive. Examples of the additive include additives usually used for polyolefins such as tackifiers, antioxidants, lubricants, neutralizers, blocking inhibitors, surfactants and slip agents.

A-3. Adhesive Layer The adhesive layer contains any suitable adhesive. Examples of the adhesive include a solvent-based adhesive, a solvent-free adhesive, a hot melt-based adhesive, an emulsion-based adhesive, and the like. Examples of the solvent-based adhesive include aromatic polyester-based adhesives, aliphatic polyester-based adhesives, aromatic polyether-based adhesives, aliphatic polyether-based adhesives, urethane polyester-based adhesives, and the like. Be done. Of these, aromatic polyester-based adhesives and aliphatic polyester-based adhesives are preferable from the viewpoint of high heat resistance.

The thickness of the adhesive layer is preferably 1 μm to 5 μm, more preferably 1 μm to 3 μm.

B. Manufacturing method of packaging material The above packaging material can be manufactured by any suitable method. In one embodiment, the packaging material can be manufactured by the dry laminating method. For example, the packaging material is a polyethylene-based resin film in which an adhesive diluted with a solvent is applied (applied / dried) on a base material to form an adhesive layer, and a seal layer is formed on the adhesive layer. Can be obtained by laminating.

C. Composite In one embodiment, the packaging material can be used by laminating with another film, if necessary. Examples of other films include linear low-density polyethylene films, low-density polyethylene films, high-density polyethylene films, polyethylene-based resin films such as ethylene / vinyl acetate copolymer films, polypropylene films, polyethylene terephthalates, and polybutylene terephthalates. Such as polyester film, nylon 6, polyamide film such as nylon 66, ethylene-vinyl acetate copolymer saponified film, polyvinyl alcohol film, polyvinyl chloride film, polyvinylidene chloride film, polycarbonate film, cellulose-based film and the like. , Polyethylene resin film is suitable from the viewpoint of recycling. When laminating a film other than the polyethylene-based resin film, the thickness of the film other than the polyethylene-based resin film is preferably 10% or less, preferably 5% or less, based on the total thickness, from the viewpoint of recycling suitability. Is more preferable, and 3% or less is further preferable.

Further, the other film may be an aluminum vapor deposition, an alumina vapor deposition, a silicon dioxide vapor deposition, an acrylic treatment, or a film having a vapor deposition thin film made of a metal such as aluminum, alumina, silica, or a metal oxide.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, parts and% are based on the weight standard. The evaluation methods in the examples and comparative examples are as follows.
[Melting point]
The melting point (Tm1) of the seal layer was determined by differential scanning calorimetry (DSC) according to JIS K 7121. Heated in N ₂ gas from 23 ° C. while flowing at 30 ml / min up to 230 ° C. heating rate = 10 ° C. / min, to obtain a DSC curve of the IchiNoboru Nukutoki, measurement temperature 70 ° C. or higher 180 ° C. temperature below The melting point (Tm) was measured from the heat absorption peak due to the melting behavior of polyethylene in the range. The temperature at which the endothermic peak on the lowest temperature side was generated was read and defined as Tm1.
The melting point (Tm2) of the base material was also the same as above, and a DSC curve was obtained. From the DSC curve, the temperature at which the endothermic peak on the highest temperature side was generated was read as Tm2.
[Seal strength]
The packaging material was cut into a size of 400 mm in length and 300 mm in width to obtain sample A.
This sample was bent in half in the width direction with the seal layer inside, and the seal layers were joined to each other by a heat sealer. The sealing temperature was as shown in Table 1, the sealing time was 1 second, and the sealing pressure was 0.1 MPa.
Further, the sheeted portion was cut out to a length of 180 mm × 150 mm to obtain a sample B.
Using this sample B, the seal strength was measured with a tensile tester compliant with JIS Z 1711 under the conditions of a peeling speed of 300 m / min and a peeling angle of 180 degrees.
[Straight line tearability]
The packaging material was cut into a size of 200 mm (MD) × 100 mm (TD) in width to obtain a sample C. The length direction of this sample C was the extrusion direction and the rolling direction (MD) when molding the base material.
Two 100 mm cuts in the length direction (MD) were made in parallel on one side in the width direction (TD) at locations 15 mm apart from the center of the side in the width direction (cut spacing: 30 mm). Further, on an aluminum plate having a thickness of 0.1 mm and a thickness of 150 mm × 150 mm, the cut portion of the sample C is made to protrude from the aluminum plate (protruding length: 50 mm), and the sample C is fixed with a tape to obtain a sample D. rice field. At this time, the cut portion (length: 50 mm) on the aluminum plate and the end portion on the side opposite to the cut portion of the sample C were fixed with tape.
The sample D obtained as described above was fixed to the tensile tester, the notch portion at the end on the protruding side from the aluminum plate was chucked, and the sample D was torn at an angle of 180 ° (tear speed 1000 mm). / Min). The tear length was 70 mm.
After the above operation, the cut interval (T1) at the place where the tear length was 50 mm was measured.
The linear tearability was evaluated by the difference between the notch interval T0 (30 mm) made in the sample C and the above T1. The closer the value calculated by T0-T1 is to zero, the closer the tear line is to a straight line, that is, the better the straight line tearability. On the contrary, the farther the value calculated by T0-T1 is from zero, the worse the defect. In order to develop good linear tearability, | T0-T1 | is preferably 2 or less, and more preferably 1 or less.
[Elastic modulus, rigidity]
The tensile elastic modulus of the packaging material is in accordance with JIS K 7161, the thickness is measured with a thickness gauge, and then the tensile elastic modulus in the MD direction and TD direction of the packaging material is measured at a tensile speed of 1 mm / min. The measured value of was taken as the tensile elastic modulus. The product of this tensile modulus and the thickness was taken as the rigidity.

[Example 1]
60 parts by weight of an ultra-high molecular weight polyethylene resin (made by Asahi Kasei Co., Ltd., trade name "Sunfine UH850") with an average viscosity of 2 million, and a thermoplastic resin (polyethylene resin; manufactured by Asahi Kasei Co., Ltd., trade name "Suntech J300P", MFR ( 190 ° C / 2.16 kgf): 40 g / 10 min) 40 parts by weight and 2 parts by weight of the compound (condensed tetraglycerin lysinoleate; degree of condensation of hydroxy fatty acid 10) 2 parts by weight are mixed and the temperature of the polyethylene composition is 210 ° C. It was melt-kneaded with a controlled φ40 mm single-screw extruder and melt-extruded from a 450 mm wide T-die. Then, it was rolled and molded in a calendar facility equipped with 6 rolls to obtain a rolled film made of an ultra-high molecular weight polyethylene composition having a thickness of 50 μm. This rolled film was heated in an oven of a tenter transverse stretching machine whose temperature was controlled to 135 ° C. and stretched 5 times in the width direction to prepare a film (UPE-1) composed of a 10 μm ultrahigh molecular weight polyethylene composition. This film was used as a base material for packaging materials. This UPE-1 is unwound from a film feeder of a dry laminator, and an adhesive diluted with ethyl acetate using a gravure roll (manufactured by Mitsui Chemicals, Inc., trade name "Takelac A-310 / Takenate A-3", aromatic ester type). (Adhesive) was ^{applied under the condition of 4 g / m 2,} and after evaporating the diluting solvent in the oven controlled at 60 ° C., the LLDPE film (S-PE1) constituting the seal layer fed out from the other feeding machine. ) (Manufactured by Futamura Chemical Co., Ltd., trade name "LL-XUMN", thickness: 40 μm) was overlapped with a corona-treated surface, crimped with a rubber roll and a metal roll, and then wound up. After winding, it was aged for 48 hours in an oven adjusted to 40 ° C. to obtain a packaging material.
The obtained packaging material was subjected to the above evaluation. The results are shown in Table 1.

[Comparative Example 1]
Example 1 except that an LLDPE film (K-PE1) (manufactured by Toyobo Co., Ltd., trade name "LIX L6100", thickness: 70 μm) was used instead of the film (UPE-1) made of an ultra-high molecular weight polyethylene composition. The packaging material was prepared in the same manner as above.
The obtained packaging material was subjected to the above evaluation. The results are shown in Table 1.

As is clear from Table 1, the packaging material of the present invention provided with a base material containing an ultra-high molecular weight polyethylene-based resin has excellent sealing strength and can be sealed at a high temperature. In the packaging material of the comparative example, the base material was partially melted in the 140 ° C. seal and the 150 ° C. seal, and the base material component adhered to the seal bar of the heat sealer. Further, in the 160 ° C. seal and the 170 ° C. seal, the melting of the base material became remarkable.
Further, since the packaging material of the present invention includes a base material having a high elastic modulus and high rigidity, it is also advantageous in terms of strength.
Further, the packaging material of the present invention is also excellent in linear tearability.

The packaging material of the present invention is a material that has excellent adhesiveness in addition to rigidity, strength, and impact resistance and is easy to recycle. It can be used as a packaging material.

10 Base material 20 Seal layer 30 Adhesive layer 100 Packaging material

Claims (5)

With the base material
A sealing layer disposed on at least one side of the substrate, and
It comprises an adhesive layer disposed between the substrate and the seal layer.
The substrate contains an ultra-high molecular weight polyethylene-based resin having a viscosity average molecular weight of 300,000 or more.
The content ratio of the ultra-high molecular weight polyethylene resin is 40 parts by weight or more with respect to 100 parts by weight of the resin in the base material.
The thickness of the base material is 5 μm to 80 μm, and the thickness of the base material is 5 μm to 80 μm.
The melting point of the base material is higher than the melting point of the seal layer by 30 ° C. or more.
The seal layer contains a low molecular weight polyethylene resin.
Packaging material. The packaging material according to claim 1, wherein the base material is a stretched film. The packaging material according to claim 1 or 2, wherein the base material further contains a thermoplastic resin (B). The packaging material according to any one of claims 1 to 3, wherein the substrate further contains a condensed hydroxy fatty acid and / or an alcohol ester (C) thereof. The packaging material according to any one of claims 1 to 4, wherein the packaging material has a tensile elastic modulus of 800 MPa or more at 23 ° C.

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