JPWO2018003978A1 - Packaging sheet and package - Google Patents

Abstract

The present invention provides a packaging sheet that is excellent in heat sealability and is less likely to adhere to contents. A packaging sheet comprising a material film and a heat seal layer formed adjacent to at least one surface of the base film, wherein (1) the heat seal layer comprises a heat seal agent and a polyolefin-based film And the surface roughness Ra on the surface opposite to the base film is 1.00 to 7.00 μm. (2) The polyolefin particles have an average particle diameter D50 of 10 to 50 μm. The present invention relates to a packaging sheet having a melting point of 100 to 180 ° C. [Selection] Figure 1

Description

  The present invention relates to a novel packaging sheet and package. In particular, the present invention relates to a package sheet for use in a package for packaging a food that is easy to adhere to a surface and that is soft, peelable, and fragile, and a package using the same.

  In general, water-rich foods such as souffles, castellas and cakes have the property that the surface easily adheres to the material used to package them. When the food surface adheres to the packaging sheet, it becomes difficult to take out the food from the packaging, and there is also a problem that a part of the food adheres to the packaging sheet to cause peeling, damage and the like. For this reason, when packaging such a food, the non-adhesiveness with respect to the content especially is calculated | required by the packaging sheet.

  For example, Patent Document 1 discloses a product containing a food in a state containing air, and using an embossed film inside the package. The uneven shape of the surface of the embossed film reduces the contact area with the contents and reduces the adhesion of the contents to the inner surface of the package.

Unexamined-Japanese-Patent No. 2007-308191

  However, in the package as in Patent Document 1, as the content is softer, the surface of the content is deformed along the uneven shape of the surface of the embossed film, and the surface of the content adheres to the portion in contact with the surface of the embossed film. Resulting in. That is, in the package as described above, adhesion of the surface of the contents to the inner surface of the package can not be sufficiently prevented.

  In the case of heat-sealing the heat seal layers (hereinafter also referred to as "face-to-face heat seal") in the embossed film, there is a possibility that sufficient heat seal strength can not be obtained due to the uneven shape.

  Therefore, the main object of the present invention is to provide a packaging sheet which is excellent in surface heat sealability and less likely to adhere to the surface of the contents.

  As a result of intensive researches in view of the problems of the prior art, the inventor has found that the above object can be achieved by adopting a heat seal layer having a specific structure and physical properties for a packaging sheet and a package. We came to complete the invention.

That is, the present invention relates to a packaging sheet and a package.
1. What is claimed is: 1. A packaging sheet comprising a base film and a heat seal layer laminated on at least one surface of the base film,
(1) The heat seal layer contains a heat seal agent and polyolefin particles, and the surface roughness Ra on the surface opposite to the base film is 1.00 to 7.00 μm,
(2) The polyolefin-based particles have an average particle diameter D50 of 10 to 50 μm and a melting point of 100 to 180 ° C.
Packaging sheet characterized by.
2. The packaging sheet according to Item 1, wherein the specific gravity of the polyolefin-based particles is 0.93 to 1.06.
3. The packaging sheet according to Item 1, wherein the polyolefin-based particles are at least one of polyethylene-based particles and polypropylene-based particles.
4. 2. The packaging sheet according to item 1, wherein the base film is one or more of a polypropylene film, a polyethylene film and a polyester film.
5. The packaging sheet according to Item 1, wherein the amount of the heat seal layer formed is 0.5 to 10.0 g / m ² .
6. The packaging sheet according to item 1, wherein the heat sealing agent contains a polyolefin resin.
7. The packaging sheet according to the above item 1, further comprising an anti-adhesion layer comprising particles having water repellency and / or oil repellency on the surface of the heat seal layer.
8. It is a package body shape | molded by the packaging sheet in any one of said claim | item 1-7, Comprising:
(1) The packaging sheet is disposed such that the heat seal layer is on the inside of the package,
(2) The heat seal layers are joined at least in part,
A package characterized by
9. 9. A product, wherein the contents are contained in the inside of the package according to item 8, and at least a part of the heat seal layers are joined so that the contents are sealed in the package.

  According to the present invention, it is possible to provide a packaging sheet which is excellent in surface heat sealability and to which the contents are less likely to adhere. In particular, since the packaging sheet of the present invention is provided with a heat seal layer having a predetermined structure and physical properties on one side, even if the contents come in contact with the package molded with the heat seal layer disposed inside Even if it does not adhere easily. In particular, even if the food is soft and easily adheres to a packaging bag etc. because of the high water content, the heat seal layer of the present invention effectively exhibits the property of being hard to adhere due to the material and characteristics of the heat seal layer. be able to.

  On the other hand, the heat seal layer in the packaging sheet of the present invention is excellent in heat sealability even though it has high non-adhesion to food as described above, so the contents are more reliably sealed. Can. In particular, in the present invention, since particles made of a specific resin component such as polyolefin-based particles are dispersed in the heat seal layer, good heat sealability can be realized.

  In addition, when the packaging sheet of the present invention is formed with the surface on which the heat seal layer is formed inside, the inside of the package has a specific uneven shape, while the outside of the package can maintain a smooth surface, for example Raw materials of objects, barcodes, product names, expiration dates, etc. can be printed and displayed smoothly. In this respect, when using a conventional embossed film, it is difficult to print on the embossed film, so it is necessary to prepare a packaging sheet separately from the embossed film. When molding, it is not necessary to prepare and use such another packaging sheet.

  Such a packaging sheet or package can be suitably used for packaging various products such as medicines, cosmetics, etc. including food. In particular, for packaging foods that are easy to adhere to the packaging sheet due to the high water content and that are soft and easy to peel and damage (eg, western sweets, semi-sweet western sweets, Japanese sweets, sweet semi-sweets etc) It can be effectively used as a packaging sheet or a packaging body for containing the food.

It is a figure which shows the layer structure of the packaging sheet of this invention. It is a figure which shows an example of the package which used the packaging sheet of this invention.

1. Packaging sheet The packaging sheet of the present invention is a packaging sheet including a base film and a heat seal layer laminated on at least one surface of the base film,
(1) The heat seal layer contains a heat seal agent and polyolefin particles, and the surface roughness Ra on the surface opposite to the base film is 1.00 to 7.00 μm,
(2) The polyolefin-based particles have an average particle diameter D50 of 10 to 50 μm and a melting point of 100 to 180 ° C.
It is characterized by

  An example of the layer structure of the packaging sheet of this invention is shown in FIG. As shown in FIG. 1, in the packaging sheet 10 of the present invention, the heat seal layer 12 is laminated on one surface of the base film 11. In the heat seal layer 12, polyolefin-based particles 14 (in particular, a powder containing polyethylene-based particles and / or polypropylene-based particles) are dispersed in the heat sealing agent 13. Then, in the heat seal layer 14, predetermined irregularities are formed on the surface opposite to the base film 11 by the inclusion of polyolefin particles and the like. The heat seal layer 12 may be laminated directly adjacent to the base film 11 as shown in FIG. 1 or may be laminated via another layer (for example, a primer layer or the like).

  In the packaging sheet which has such a structure, the material of a heat seal layer and the said uneven | corrugated shape can exhibit predetermined | prescribed non-adhesiveness in combination. That is, even if the contents are in contact with the heat seal layer (or the adhesion preventing layer formed on the surface), the heat seal layer and the contents do not adhere to each other, and a good non-adhesion state can be maintained. it can. In particular, in the case of a food which has a relatively large amount of water, such as fresh confectionery or semi-preserved confectionery, and the surface is soft and easy to adhere, the surface of the food easily adheres to the general packaging sheet according to the prior art Although the properties are enhanced, the packaging sheet of the present invention can effectively suppress or prevent the adhesion of such fresh or semi-baked confectionery.

  In addition, since the melting point of the polyolefin-based particles contained in the heat seal layer is controlled to 100 to 180 ° C. (particularly 110 to 180 ° C.), high heat sealability can also be exhibited. In particular, excellent performance can be exhibited also in the heat sealability (hereinafter also referred to as "surface heat sealability") in the heat seal layers of the packaging sheet of the present invention. In particular, when the heat seal agent contains polypropylene as a resin component, higher heat sealability can be obtained.

  Below, the material which comprises the packaging sheet of this invention, a manufacturing method, a usage method, etc. are each demonstrated.

(1) Configuration of Packaging Sheet (1-1) Substrate Film In the present invention, a resin film known as a substrate film can be used. The material of the resinous film is not particularly limited, but one or two or more selected from among polypropylene resins, polyethylene resins and polyester resins can be appropriately used. Therefore, in the present invention, for example, at least one of a polypropylene film, a polyethylene film and a polyester film can be suitably used as a base film.

  The polypropylene-based film may be any film in which the content of polypropylene is 50% by weight or more, preferably 80% by weight or more, and more preferably 90% by weight or more. Therefore, as polypropylene, it may be, for example, any homopolymer or copolymer having propylene as a monomer. In addition, a mixed resin, a polymer alloy, or the like in which other resin components are mixed within the range that does not impair the effects of the present invention may be used. In the present invention, for example, biaxially oriented polypropylene having a high polypropylene purity (for example, a homopolymer of propylene etc.) can be suitably used. In the present invention, “main component” means that the content is 50% by weight or more (the same applies hereinafter). Therefore, it may be, for example, 80% by weight or more. Further, it may be, for example, 90% by weight or more.

  The polyethylene-based film may be any film having polyethylene as a main component. Polyethylene is a polymer film having a structure in which ethylene is polymerized. For example, high density polyethylene having a density of 0.92 to 0.96, low density polyethylene having a density of 0.91 to 0.92, a density Various polyethylenes, such as linear low density polyethylene of 0.94 or less can be used.

  The polyester film may be a film having polyester as a main component. As polyester, a polycondensate of polyvalent carboxylic acid and polyalcohol etc. can be used suitably. Therefore, as the polyester film, for example, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate and the like can be used.

  The base film may be either a stretched film or an unstretched film. Furthermore, as a stretched film, either a uniaxially stretched film or a biaxially stretched film can be used. Therefore, in the present invention, for example, a biaxially stretched polypropylene-based film (OPP) can be suitably used as a base film. As a result, excellent performance in tensile strength, transparency, moisture resistance, heat resistance, tearability and the like can be obtained, and it is also advantageous in that cost reduction can be achieved. In addition, as the biaxially oriented polypropylene-based film, various types of films subjected to surface treatment such as corona treatment can also be used as a substrate film.

  Furthermore, the substrate film may be either a single layer type or a multilayer type. As a multilayer resin film, for example, a heat seal type resin base film in which a heat seal layer is laminated on at least one surface of a film (particularly, a polyolefin film) can also be used. Thereby, higher sealability can be obtained. As such a heat seal type substrate film, known or commercially available one can be used.

  As such a heat seal type substrate film, for example, a biaxially oriented polypropylene-based film (OPP) (laminated film) of a double-sided or single-sided heat seal type can also be suitably used as the substrate film. That is, a laminated film in which a heat seal layer is laminated on at least one surface of a biaxially oriented polypropylene-based film can be suitably used as a base film. As the heat seal layer, for example, a polyethylene heat seal layer, a polypropylene heat seal layer or the like can be adopted.

  The thickness of the substrate film is not particularly limited, but is preferably 20 to 80 μm, and more preferably 25 to 50 μm. If the thickness of the base film is less than 20 μm, the heat of drying of the packaging sheet may be greatly expanded or contracted in the width direction or the flow direction, which may affect the processability. When the thickness of the substrate film exceeds 80 μm, the tearability and the like may be reduced.

  In the base film, for example, a printing layer, an overcoat layer, various films, etc. are provided on the side opposite to the side in contact with the contents, that is, the side exposed to the outside when formed as a package. You may provide suitably.

(1-2) Heat Sealing Layer The heat sealing layer contains a heat sealing agent and polyolefin particles, and has a feature that the surface roughness Ra on the surface is 1.00 to 7.00 μm. The heat seal layer is laminated on the base film, and is preferably disposed directly adjacent to the base film surface.

  In the packaging sheet of the present invention, the heat seal layer is disposed as the outermost layer (uppermost surface) or the lower layer of the antiadhesive layer. For example, as shown in FIG. 1, a layer configuration in which the heat seal layer 10 is disposed so as to be the outermost layer can be suitably adopted. That is, a layer configuration not having an adhesion preventing layer can also be suitably employed. Moreover, when a heat seal layer is arrange | positioned as a lower layer of an adhesion prevention layer, it is preferable to be arrange | positioned as a lower layer in the state adjacent to an adhesion prevention layer. Thereby, high heat sealability can be ensured more reliably.

  The surface roughness Ra of the heat seal layer is usually from 1.00 to 7.00 μm, preferably from 1.50 to 3.50 μm. If the surface roughness Ra is less than 1.00 μm, the desired adhesion preventing effect can not be obtained. On the other hand, if the surface roughness Ra exceeds 7.00 μm, the desired heat sealability can not be obtained. The surface roughness as described above can be suitably adjusted by, in particular, dispersing polyolefin-based particles in the heat seal layer.

Formation of the heat seal layer is not particularly limited, particularly preferably to 0.5~10.0g / ^{m 2,} more and more preferably set to 1.0~4.0g / ^{m 2.} If the formation amount is less than 0.5 g / m ² , the sealability is reduced, and the sealability as a package can not be ensured. For example, the content is oxidized, the content is leaked, and the content is reduced in shape retention There is a risk of causing Moreover, when the formation amount exceeds 10.0 g / m ² , the effect of the unevenness is reduced, and the contents may adhere to the inner surface of the package. Note that the amount of heat seal layer formed is not the total amount of heat seal material made of heat seal agent, polyethylene-based particles, etc., but the weight of the base film from the weight of the packaging sheet after drying after coating operation. Weight (weight per unit area).

  The thickness of the heat seal layer is not particularly limited as long as it falls within the range of the above-mentioned formation amount. For example, in the range of about 0.1-100 micrometers, according to the use etc. of a packaging sheet, it can set suitably.

Heat Sealing Agent As the heat sealing agent, an adhesive containing a known heat sealing component can be used. For example, in addition to the components of known sealant films, components used for adhesives such as a lacquer type adhesive, an easy peel adhesive, and a hot melt adhesive can be adopted. Moreover, as a heat sealing agent, the liquid-type commercial item etc. can also be used.

  The main component (resin component) constituting the heat seal layer is not limited and, for example, low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene, polyester, polystyrene, Epoxy resin, nitrocellulose resin, urethane resin, melamine resin, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, acrylic-vinyl chloride-vinyl acetate copolymer Polymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, polyethylene or polypropylene Activate polyolefin resin Acid-modified polyolefin resins modified with unsaturated carboxylic acids such as hydrofluoric acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid and itaconic acid, polyvinyl acetate resins, poly (meth) acrylic resins, polyacrylonitrile In addition to resins, polyvinyl chloride resins, and other heat-adhesive resins, blends of these resins, copolymers containing combinations of monomers constituting these, modified resins, and the like can be used. Therefore, for example, a mixture of an acrylic resin and a vinyl chloride-vinyl acetate copolymer can be suitably used as the resin component.

  The polyolefin-based particles are mainly composed of a polyolefin which is a polymer of monomers (olefins) such as ethylene and propylene as a raw material, and in particular, a homopolymer or copolymer having ethylene and / or propylene as a monomer is preferable. It can be adopted. As polyethylene, various polyethylenes such as low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene can be used.

  These polyolefin particles can be appropriately selected according to the base film to be used, the filling machine and the like. For example, when low-temperature sealability at about 80 ° C. to 120 ° C. is required, polyolefin-based particles containing polyethylene as a main component are preferable. For example, when heat resistance at 140 ° C. to 180 ° C. is required practically, polyolefin-based particles containing polypropylene as a main component are preferable.

  The polyolefin particles preferably have an average particle diameter D50 of 10 to 50 μm, and more preferably 15 to 30 μm. When the average particle diameter D50 of the polyolefin-based particles is less than 10 μm, the adhesion preventing effect due to the uneven shape on the surface of the heat seal layer is reduced. In addition, when the average particle diameter D50 of the polyolefin-based particles exceeds 50 μm, the heat sealability is reduced, and the sealability as a package can not be secured. For example, oxidation of contents, leakage of contents, retention of contents It may cause a decrease in sexuality. Further, even from the viewpoint of processing, for example, coating unevenness is likely to occur, which may affect the appearance or performance.

  The melting point of the polyolefin-based particles is usually 100 to 180 ° C., preferably 110 to 160 ° C., and more preferably 130 to 140 ° C. If the melting point of the polyolefin-based particles is less than 100 ° C., it will be melted by the drying heat at the time of processing, and the desired effect due to the desired uneven shape can not be obtained. Further, when the melting point exceeds 180 ° C., predetermined heat sealability can not be obtained.

  Further, the specific gravity of the polyolefin-based particles is not particularly limited, but generally, it is preferably 0.93 to 1.06. If the specific gravity is less than 0.93, it is likely to be difficult to maintain its shape because it becomes brittle. When the specific gravity exceeds 1.06, it tends to settle in the heat seal layer, which may affect the processability.

  The content (dispersion amount) of the polyolefin-based particles in the heat seal layer may be such an amount that the surface roughness Ra becomes 1.00 to 7.00 μm. For example, in the range of about 1 to 90% by weight in the heat seal layer, it can be appropriately adjusted according to the particle size, specific gravity and the like of the polyolefin particles to be used. Therefore, the content can be, for example, 10 to 60% by weight, and can be 15 to 50% by weight. Furthermore, it can also be set to, for example, 20 to 40% by weight.

(1-3) Anti-Adhesion Layer The packaging sheet of the present invention exhibits sufficient non-adhesion even with a heat seal layer alone, and further, if necessary, adhesion prevention including particles having water repellency and / or oil repellency. The layer may be formed on part or all of the heat seal layer. Thereby, even if the content is high in water content, it is possible to more effectively suppress or prevent sticking of the content to the packaging sheet and the like.

  Known or commercially available particles can be used as the particles. For example, inorganic oxide particles or metal oxide particles can be used. Among these oxide particles, at least one of particles (powder) of silicon oxide, titanium oxide, aluminum oxide, zinc oxide and the like can be suitably used. In particular, in the present invention, it is more preferable to use silicon oxide particles.

  These particles are preferably fine particles, in particular, the average primary particle diameter is more preferably 5 to 50 nm, and particularly preferably 7 to 30 nm.

  In the present invention, the measurement of the average primary particle size and the like can also be carried out using a transmission electron microscope or a scanning electron microscope. More specifically, it can be determined by photographing particles with a transmission electron microscope or scanning electron microscope, measuring the diameters of 200 or more particles on the photograph, and calculating the arithmetic mean value.

Such nano level particles can also be used known or commercially available. For example, as silica, product names "AEROSIL R972", "AEROSIL R972V", "AEROSIL R972CF", "AEROSIL R974", "AEROSIL RX200", "AEROSIL RY50", "AEROSIL NY50", "AEROSIL RY200S", AEROSIL RY300 "AEROSIL RY200" (above, made by Nippon Aerosil Co., Ltd.), "AEROSIL R202", "AEROSIL R805", "AEROSIL R711", "AEROSIL R7200", "AEROSIL R812", "AEROSIL R812S" (above, Evonik Degussa Company), “Silo Hobik 100”, “Silo Hobik 200”, “Silo Hobic 603” (above, Fuji Siri A Chemical Co., Ltd.) and the like. As the titania, product name "AEROXIDE TiO ₂ T805" (manufactured by Evonik Degussa Co., Ltd.) can be exemplified. Examples of the alumina include fine particles in which the particle surface is made hydrophobic by treating a product name "AEROXIDE Alu C" (manufactured by Evonik Degussa Co., Ltd.) with a silane coupling agent.

  Among these, hydrophobic silica fine particles can be suitably used. In particular, hydrophobic silica fine particles having a trimethylsilyl group on the surface are preferred in that superior non-stickiness can be obtained. As a commercial item corresponding to this, the above-mentioned "AEROSIL R812", "AEROSIL R812S" (all are products made by Evonik Degussa) etc. are mentioned, for example.

The adhesion amount (weight after drying) of the hydrophobic particles to be attached onto the heat seal layer is not particularly limited, but usually 0.01 to 10 g / m ² is preferable, 0.2 to 1.5 g / m ² It is more preferable to set it as 0.2 to 1 g / m ² .

  For example, metal oxide composite particles having oil repellency can also be used. By having a coating film containing such metal oxide composite particles, adhesion can be suitably reduced even in the case of contents having a high fat content. As a particle size of the metal oxide composite particles having oil repellency, those having a range equivalent to the above-described metal oxide composite particles having water repellency can be suitably used.

As particles used as metal oxide composite particles having oil repellency, for example, particles in which a coating layer such as polyfluoroalkyl methacrylate resin is formed on the surface of oxide fine particles to be a core can be used. As such oxide fine particles to be the core, for example, as silicon oxide, for example, product name "AEROSIL 200"("AEROSIL" is a registered trademark, hereinafter the same), "AEROSIL 130", "AEROSIL 300", "AEROSIL 50" And “AEROSIL 200 FAD” and “AEROSIL 380” (all manufactured by Nippon Aerosil Co., Ltd.). As a titanium oxide, a product name "AEROXIDE TiO ₂ T805" (manufactured by Evonik Degussa Co., Ltd.) and the like can be mentioned. Examples of the aluminum oxide include a product name “AEROXIDE Alu C 805” (manufactured by Evonik Degussa Co., Ltd.) and the like. By using the particles having such a covering layer, a strong covering layer having a relatively high adhesion because of its excellent affinity to metal oxide particles can be formed on the surface of the particles, and the content for the contents is high. Non-adhesiveness can be expressed.

  The content of the water-repellent and / or oil-repellent particles in the anti-adhesion layer is preferably, but not limited to, 10 to 100% by weight. As the content of the particles approaches 100% by weight, it is possible to obtain higher water repellency and / or oil repellency.

(2) Method of Producing Packaging Sheet The method of producing the packaging sheet of the present invention is not limited, and includes, for example, 1) applying a liquid composition containing a heat sealing agent and polyolefin particles to the surface of a substrate film. A manufacturing method, 2) a manufacturing method including a step of laminating a sheet containing a heat seal agent and polyolefin particles on the surface of a base film can be employed.

  In the method 1), a liquid composition containing a heat seal agent and polyolefin particles is used. As the liquid composition, for example, a dispersion obtained by dispersing polyethylene-based particles in a liquid heat sealing agent can also be suitably used.

  Moreover, in the said liquid composition, in order to disperse | distribute polyolefin type particle | grains especially and to apply | coat to the base film surface uniformly, it can also be used. The solvent is not particularly limited as long as the polyolefin particles used do not dissolve. For example, at least one of water, alcohol type (ethanol, isopropyl alcohol), toluene, xylene, ethyl acetate, butyl acetate, methylcyclohexane (MCH), ketone type (methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), etc.) It can be used as appropriate. These solvents can be removed by drying after applying a liquid composition to the substrate film surface. In particular, at least one of MCH, MEK and the like is preferable from the viewpoint that the environmental load can be reduced.

  In the liquid composition, polyethylene-based particles can be blended, for example, about 1 to 150 parts by weight with respect to 100 parts by weight of the heat sealing agent, but it is not particularly limited to this range. It can be set appropriately according to the working conditions and the like. Further, the solid content of the liquid composition can also be appropriately set according to the coating conditions and the like, for example, in the range of about 5 to 80% by weight, but is not limited thereto.

  The method for applying the above liquid composition to the surface of the base film is not particularly limited, and known methods such as roll coating, various gravure coating (for example, microgravure etc.), bar coating, doctor blade coating, brush coating etc. Can be adopted as appropriate.

  After applying the liquid composition, drying can be carried out as required. Drying may be either natural drying or heat drying. In the case of heat drying, for example, it may be in the range of 120 ° C. or less, and in particular, it may be set to about 60 to 100 ° C.

  The heat sealing agent of the above 2) and the method of laminating a sheet containing polyolefin type particles on the surface of a substrate film are not particularly limited, but, for example, dry lamination method, nonsolvent lamination method, extrusion lamination method, wet lamination method, heat lamination Well-known methods, such as a method, are suitably employable.

  In the case of forming the antiadhesive layer, the method of forming the same is not particularly limited. For example, a method including the step of applying a dispersion obtained by dispersing particles having water repellency and / or oil repellency in a solvent on a heat seal layer and then drying it can be suitably employed.

  The type of solvent used in the above-mentioned dispersion is not particularly limited, and other than water, for example, alcohol (such as ethanol), cyclohexane, toluene, acetone, isopropyl alcohol, propylene glycol, hexylene glycol, butyl diglycol, pentamethylene Organic solvents such as glycol, normal pentane, normal hexane and hexyl alcohol can be appropriately selected. Under the present circumstances, a trace amount dispersing agent, a coloring agent, an anti-settling agent, a viscosity modifier etc. can also be used together within the range which does not prevent the effect of this invention. The dispersion amount of the water-repellent and / or oil-repellent particles in the dispersion is not limited, and may be about 10 to 100 g / L.

  The method of applying the dispersion is not particularly limited. For example, known methods such as roll coating, gravure coating, bar coating, doctor blade coating, brushing and the like can be employed.

  Drying after application may be either natural drying or forced drying (heat drying), but from the industrial viewpoint, forced drying is preferred. The drying temperature is not limited as long as it does not affect the heat adhesive layer, but may usually be in the range of 150 ° C. or less, and can be, for example, about 70 to 120 ° C.

(3) Method of Use The packaging sheet of the present invention can be suitably used particularly as a constituent material of a package. In particular, it can be suitably used for a package formed by heat sealing on the surface. About composition of a package, etc., it mentions later 2. I will explain concretely in.

2. The present invention is a package formed by the package sheet of the present invention, wherein (1) the package sheet is disposed such that the heat seal layer is on the inside of the package, (2) the heat It includes a package characterized in that the seal layers are joined at least in part.

  Furthermore, the present invention also includes a product in which the contents are contained inside the package, and at least a part of the heat seal layers are joined so that the contents are sealed in the package. Do.

  FIG. 2 shows an outline (cross-sectional view) of a product whose contents are sealed in the package of the present invention. In addition, illustration of polyolefin type particle | grains is abbreviate | omitted in FIG. In the product 20 according to the present invention, the contents 21 are sealed in the package 15 of the present invention. The packaging body 15 prepares two packaging sheets 10 of this invention, arrange | positions so that the heat-seal layers 12 may mutually be opposite, and surface heat sealing is given by edge A and A '. In another embodiment, one packaging sheet 11 of the present invention is prepared, this is folded so that the heat seal layer is on the inner surface, and the edges are joined by surface heat sealing to construct a package. It is good.

  In FIG. 2, the package 15 is a package in a state of being sealed by heat sealing after containing the contents, but the present invention also covers the package before containing the contents. Therefore, a package (semi-finished product) which is heat-sealed at the other part except for the opening for containing the contents is also included in the present invention. For example, in FIG. 2, edge A is pre-heat-sealed and edge A 'is not heat-sealed, so that the contents can be accommodated from the opening at edge A'. A package is also included as a package of the present invention. In this case, after putting the contents into the package pair, the edge A 'can be sealed by heat sealing.

  In the present invention, “sealed” means a state in which the inside and the outside of the package are substantially shut off. Therefore, for example, as long as the contents do not go out, the ingress and egress of a trace amount of gas or the like is permitted.

  The shape of the package is not particularly limited, and can be suitably applied to, for example, a molded package, a belt-like side cover, a wrapping paper, a tray, a tube, and various bags. The form of the bag is not particularly limited. For example, the bag can be suitably used in any type such as a bottom seal bag, a side seal bag, a pillow bag, a gusset bag, and a pouch (standing pouch).

  Examples and comparative examples are shown below, and the features of the present invention are more specifically described. However, the scope of the present invention is not limited to the examples.

Example 1
Coating having a heat-sealable base film having a thickness of 40 μm, commercially available polyethylene-based particles having an average particle diameter D50 of 12 μm, a melting point of 136 ° C. and a specific gravity of 0.94, and a commercially available polyolefin-based resin An agent (heat seal coating agent, solid content 20% by weight) was prepared.
In the laminated film in which a polypropylene resin-containing layer for imparting heat sealability to one side of a biaxially oriented polypropylene film (OPP) was formed as the substrate film, the surface of the polypropylene resin-containing layer was further corona-treated A thing (it describes with "HS-OPP" hereafter) was used.
Heat-seal by mixing and dispersing 10 parts by weight of polyethylene-based particles in 90 parts by weight of the coating agent, coating this on the surface of a polypropylene resin-containing layer of a base film by a bar coater, and drying under conditions of 80 ° C. × 10 seconds A layer was formed. The target coating amount after drying at this time was 3.0 g / m ² . The laminate thus obtained was used as a packaging film.

Example 2
A packaging sheet was obtained in the same manner as in Example 1 except that commercially available polyethylene-based particles having an average particle diameter D50 of 30 μm, a melting point of 136 ° C., and a specific gravity of 0.94 were used instead of the polyethylene-based particles.

Example 3
A packaging sheet was obtained in the same manner as in Example 1 except that commercially available polypropylene particles having an average particle diameter D50 of 20 μm, a melting point of 155 ° C. and a specific gravity of 0.94 were used instead of the polyethylene particles.

Example 4
The same procedure as in Example 1 is repeated, except that a commercially available resin coating agent (a coating agent containing a mixture of a copolymer of an acrylic resin and a vinyl chloride / vinyl acetate copolymer as a resin component) is used instead of the coating agent. The packaging sheet was obtained.

Example 5
A laminate was produced in the same manner as in Example 1, and a coating film containing fine silica particles was formed on the surface of the heat seal layer of the laminate to obtain a packaging sheet having an antiadhesive layer. In order to form the coating film, a dispersion obtained by dispersing 1 part by weight of silica particles (AEROSIL "R812S" manufactured by Nippon Aerosil Co., Ltd.) with 100 parts by weight of ethanol was used. The obtained dispersion was coated on the surface of the heat seal layer of the laminate by a bar coater, and then dried under the conditions of 80 ° C. for 10 seconds. The above dispersion was applied such that the coating amount after drying was about 0.3 g / m ² .

Example 6
A commercially available polyethylene-based particle having an average particle diameter D50 of 30 μm, a melting point of 136 ° C., and a specific gravity of 0.94 is used instead of the above-mentioned polyethylene-based particle, and it has a commercially available heat sealability of 30 μm thickness as a base film. A packaging sheet was obtained in the same manner as Example 1, except that a polyethylene terephthalate film (a film in which a polyester resin layer was laminated by coextrusion on one side of a PET film) was used.

Example 7
A commercially available polyethylene-based particle having an average particle diameter D50 of 30 μm, a melting point of 136 ° C., and a specific gravity of 0.94 is used instead of the polyethylene-based particle and a commercially available biaxially stretched polyethylene terephthalate having a thickness of 12 μm as a substrate film. A laminated body (12 PET / D / 30 LDPE) prepared by dry laminating a film and a commercially available polyethylene film (low density polyethylene) having a thickness of 30 μm is prepared, and coated on the polyethylene film side as in Example 1. I got a packaging sheet.

Example 8
A commercially available polyethylene-based particle having an average particle diameter D50 of 30 μm, a melting point of 136 ° C., and a specific gravity of 0.94 is used instead of the polyethylene-based particle and a commercially available biaxially stretched polyethylene terephthalate having a thickness of 12 μm as a substrate film. A laminate (12 PET / D / 30 CPP) obtained by dry laminating a film and a commercially available non-oriented polypropylene film (CPP film) having a thickness of 30 μm is prepared, and coated on the polypropylene film side. The packaging sheet was obtained similarly.

Example 9
Instead of using a commercially available heat sealable base film having a thickness of 40 μm, it is possible to use a commercially available biaxially oriented polypropylene film (OPP) having a thickness of 40 μm that does not have heat sealability by itself as in Example 1 The packaging sheet was obtained similarly.

Comparative Example 1
The base film used alone in Example 1 was prepared and used as a packaging sheet.

Comparative example 2
A commercially available embossed biaxially oriented polypropylene-based film (PP / PP film laminated by coextrusion of a polypropylene resin as a heat seal layer on one side of the film) alone was used as a packaging sheet.

Comparative example 3
A packaging sheet was obtained in the same manner as in Example 1 except that commercially available polyethylene-based particles having an average particle diameter D50 of 9 μm, a melting point of 105 ° C., and a specific gravity of 0.92 were used instead of the polyethylene-based particles. .

Comparative example 4
A packaging sheet was obtained in the same manner as in Example 1 except that commercially available polyethylene-based particles having an average particle diameter D50 of 60 μm, a melting point of 136 ° C., and a specific gravity of 0.94 were used instead of the polyethylene-based particles.

Comparative example 5
Packaged in the same manner as in Example 1 except that commercially available crosslinked polymethyl methacrylate particles having an average particle diameter D50 of 20 μm, a melting point of 250 to 270 ° C. and a specific gravity of 1.2 were used instead of the polyethylene particles. I got a sheet.

Comparative example 6
Packaged in the same manner as in Example 1 except that commercially available crosslinked poly (methyl methacrylate) particles having an average particle diameter D50 of 50 μm, a melting point of 250 to 270 ° C. and a specific gravity of 1.2 were used instead of the polyethylene particles. I got a sheet.

Comparative example 7
Packaged in the same manner as in Example 1 except that commercially available crosslinked polyacrylate particles having an average particle diameter D50 of 30 μm, a melting point of 230 to 250 ° C. and a specific gravity of 1.1 were used instead of the polyethylene particles. I got a sheet.

Comparative Example 8
A packaging sheet is obtained in the same manner as in Example 1 except that commercially available crosslinked polystyrene particles having an average particle diameter D50 of 12 μm, a melting point of 250 to 270 ° C. and a specific gravity of 1.06 are used instead of the polyethylene particles. The

Comparative Example 9
A packaging sheet was obtained in the same manner as in Example 1 except that commercially available crosslinked acrylic polymer particles having an average particle diameter D50 of 20 μm, a melting point of 340 ° C., and a specific gravity of 1.2 were used instead of the polyethylene particles. .

Comparative example 10
A packaging sheet was obtained in the same manner as in Example 1, except that commercially available silica particles having an average particle diameter D50 of 30 μm, a melting point of 1650 ° C., and a specific gravity of 2.0 were used instead of the polyethylene particles.

Comparative example 11
A packaging sheet is obtained in the same manner as in Example 1 except that commercially available polyetheretherketone particles having an average particle diameter D50 of 20 μm, a melting point of 340 ° C. and a specific gravity of 1.32 are used instead of the polyethylene particles. The

Test Example 1
About the packaging sheet obtained by each Example and the comparative example, surface-to-surface heat-sealing property, non-adhesiveness, etc. were evaluated as shown below, respectively.

(1) Evaluation of surface heat sealability After heat-sealing the coated surfaces of the heat sealing agent of each sample using a 20 mm × 60 mm heat plate under the conditions of 150 ° C. × 3 kg / cm ² × 1 second, sealing It slitted in strip shape so that width | variety might be set to 15 mm, and produced three points of test pieces. The surface heat seal strength of the test pieces was measured with an autograph tester (EZ-LX manufactured by Shimadzu Corporation). More specifically, the seal strength (N) was a T peel test at a speed of 100 mm / min, three points were measured for each sample, and the average overweight strength (N) was determined. Taking into consideration the heat seal strength of the packaging sheet in practical use, the seal strength is 4N / 15mm or more "○", 2N / 15mm or more and 4N / 15mm or less "Δ", sample less than 2N / 15mm "X" And The results are shown in Tables 1-2.

(2) Evaluation of adhesion prevention performance As evaluation of adhesion prevention property, commercially available western fresh confectionery ("Fuwafuwa souffle whipped custard" by Yamazaki Seipan Co., Ltd.) (hereinafter referred to as "suffle") is prepared, and each package is prepared. The sheet was placed on a sheet, and the sample was left separately for 24 hours, 2 days and 4 days at room temperature 20 ° C. and humidity 25%. After that, the souffle was removed, and those with no sore deposits on the packaging sheet visually confirmed on the fourth day by "o", and no sore deposits on the second day, but the fourth day In this case, the sample in which the deposit was confirmed was regarded as “Δ”, and the sample with the slight swelling at 24 hours was regarded as “x”. The results are shown in Tables 1-2.

(3) Surface roughness (arithmetic mean roughness Ra)
Each sample was sampled to a size of 150 mm × 150 mm, and the arithmetic mean roughness Ra (μm) was measured according to the standard of JIS 2001 using a surface roughness meter (Surftest SV9634 · 3D, manufactured by Mitutoyo Co., Ltd.). Specifically, as measurement conditions, measurement length was measured as 17.5 mm, evaluation length: 12.5 mm, speed: 0.2 mm / s, number of measurement points: 17500, reference length: 2.5 mm. The results are shown in Tables 1-2.

  As is clear also from the results of Tables 1 to 2, heat seal containing polyolefin particles having an average particle diameter D50 of 10 μm to 50 μm and a melting point of 100 ° C. to 180 ° C. on at least one surface of a substrate film It is understood that the packaging sheet of the embodiment in which the layers are laminated has good heat sealability on both sides as compared with the comparative example, and that even the soft content can be effectively prevented from adhering to the packaging sheet.

Claims (9)

What is claimed is: 1. A packaging sheet comprising a base film and a heat seal layer laminated on at least one surface of the base film,
(1) The heat seal layer contains a heat seal agent and polyolefin particles, and the surface roughness Ra on the surface opposite to the base film is 1.00 to 7.00 μm,
(2) The polyolefin-based particles have an average particle diameter D50 of 10 to 50 μm and a melting point of 100 to 180 ° C.
Packaging sheet characterized by. The packaging sheet according to claim 1, wherein the specific gravity of the polyolefin-based particles is 0.93 to 1.06. The packaging sheet according to claim 1, wherein the polyolefin-based particles contain at least one of a polyethylene-based resin and a polypropylene-based resin. The packaging sheet according to claim 1, wherein the base film is one or more of a polypropylene film, a polyethylene film and a polyester film. The packaging sheet of Claim 1 whose formation amount of the said heat seal layer is 0.5-10.0 g / m < ² >. The packaging sheet according to claim 1, wherein the heat sealing agent comprises a polyolefin resin. The packaging sheet according to claim 1, further comprising an anti-adhesion layer comprising water-repellent and / or oil-repellent particles on the surface of the heat seal layer. It is a package body shape | molded by the packaging sheet in any one of Claims 1-7, Comprising:
(1) The packaging sheet is disposed such that the heat seal layer is on the inside of the package,
(2) The heat seal layers are joined at least in part,
A package characterized by A product in which contents are contained inside the package according to claim 8, and at least a part of the heat seal layers are joined so that the contents are sealed in the package.