JP2020019564A - Packaging sheet and package using the same - Google Patents

Abstract

To provide a packaging sheet whose adhesion preventing effect is difficult to be reduced by pressure, friction or the like.SOLUTION: Provided is a packaging sheet comprising a substrate film and sealant layers laminated on at least one surface of the substrate film, the packaging sheet being characterized in that (1) at least one layer among the sealant layers includes an exposed adhesion preventing surface and the surface has a surface roughness Ra of 2 to 12 μm, (2) the sealant layer including the adhesion preventing surface is constituted from a stretched film including a thermoplastic resin and particles for forming convexoconcave, and (3) the sealant layer has 10 to 55 g/mof an amount of adding the thermoplastic resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a novel packaging sheet and a package using the same. In particular, the present invention relates to a packaging sheet that is also excellent in anti-adhesion performance to a fluid content (packaged object).

  For example, in products such as cosmetics and pharmaceuticals, fluid contents (for example, lotion, gel, shampoo, rinse, etc.) have fluidity but high viscosity, so it is difficult to take them out of the package and it is difficult to take them all out. It takes a long time, or there is a problem that it is not possible to take out everything and a loss occurs.

  In addition, in the food products, foods having a soft surface, such as Western confectionery such as castella, sponge cake, and pancake, and Japanese confectionery such as dumplings and buns, are packaged when they come into contact with the package (inner surface). It has the property that food can easily adhere to the body surface. If a part of the contents adheres to the package, the appearance of the contents may be deteriorated, and there may be a problem that the workability at the time of opening the package, at the time of discarding, etc. is deteriorated.

  From the above viewpoints, in particular, in a product in which the content having adhesiveness is loaded into the package, the non-adhesion performance of the packaging material itself to the content is required.

  In order to reduce the contact area with the contents in order to improve the performance of preventing the adhesion of the package or the packaging material, embossing is applied to the surface of the packaging material that comes into contact with the contents to make the surface rough. . For example, an embossed film having an embossed surface at least on the side of an object to be packaged, and a packaged object selected from a food that easily loses its shape, a food that has surface tackiness and is easily detached from the surface, and a food that easily adheres to the surface. However, a food package characterized by being packaged in an aerated state is known (Patent Document 1).

Further, for example, a co-extruded multilayer film including two or more layers provided with a gas barrier layer and a heat seal layer, wherein the heat seal layer is formed of a polyolefin resin or a resin composition containing a polyolefin resin as a main component. When a three-dimensional surface roughness Ra per 6700 μm ^{2 of the} surface of the heat seal layer is 300 nm or more and 1000 nm or less and the package for filling the content using the film is produced, the heat seal is performed. A co-extruded multilayer film has been proposed in which the layers are arranged on the content side (Patent Document 2).

  In addition, there is a method in which the adhesion preventing performance of contents is enhanced by an adhesion preventing layer formed by specific fine particles. For example, a cover material including a base material, a sealant layer, fine particles having an average particle diameter of 5 to 1000 nanometers, and an adhesion preventing layer containing a binder for fixing the fine particles to the sealant layer is known. (Patent Document 3).

JP 2007-308191 A JP 2017-13479 International Publication W02014 / 038701

  However, these conventional packages have room for improvement, especially in terms of durability of anti-adhesion performance.

  In other words, in the case of a package in which the anti-adhesion performance is exhibited by the formation of unevenness by embossing, the content is loaded into the package to produce a product, and then the weight of the content is reduced within a certain period such as during transportation or storage of the product. Alternatively, there is a problem that unevenness gradually disappears due to strong contact, and the adhesion preventing effect is accordingly reduced.

  Further, even in a package using particles having an anti-adhesion effect, the particles may fall off due to pressure, friction, and the like received during a certain period such as during transportation or storage of the product, and the anti-adhesion effect may be reduced. .

  Therefore, a main object of the present invention is to provide a packaging sheet in which the effect of preventing adhesion is unlikely to be reduced even by pressure, friction, and the like.

  The present inventor has conducted intensive studies in view of the problems of the prior art, and as a result, has found that the above object can be achieved by employing a material having a specific structure and physical properties as a packaging sheet. Reached.

That is, the present invention relates to the following packaging sheet and a package using the same.
1. A packaging sheet including a base film and a sealant layer laminated on at least one surface of the base film,
(1) at least one of the sealant layers has an exposed anti-adhesion surface, and the surface has a surface roughness Ra of 2 to 12 μm;
(2) The sealant layer having the adhesion preventing surface is composed of a stretched film containing a thermoplastic resin and particles for forming unevenness,
(3) In the sealant layer, the applied amount of the thermoplastic resin per unit area of the packaging sheet is 10 to 55 g / m ² .
A packaging sheet characterized by the above.
2. Item 2. The packaging sheet according to Item 1, wherein the particles for forming unevenness have an average particle size D50 of 8 to 100 µm.
3. Item 3. The packaging sheet according to item 1 or 2, wherein the sealant layer having the adhesion preventing surface contains 3 to 50% by weight of the particles for forming unevenness in the sealant layer.
4. Item 4. The packaging sheet according to any one of Items 1 to 3, wherein the thermoplastic resin is a polyolefin resin.
5. Item 4. The packaging sheet according to any one of Items 1 to 3, wherein the thickness of the sealant layer having an adhesion preventing surface is 10 to 100 µm.
6. A package formed by the packaging sheet according to any one of the above items 1 to 5,
(1) It is arranged so that the adhesion preventing surface of the packaging sheet is in contact with the article to be packaged,
(2) A package characterized in that the sealant layers of the packaging sheet are joined at least partially.
7. An article to be packaged is accommodated inside the package according to the above item 6, and the article to be packaged is hermetically sealed in the package by joining at least a part of the sealant layers of the packaging sheet. Packaging products characterized by the fact that:

  ADVANTAGE OF THE INVENTION According to this invention, the packaging sheet which the adhesion prevention effect does not fall easily by pressure, friction, etc. can be provided. That is, it is possible to provide a packaging sheet that can more reliably maintain the effect of preventing adhesion to a packaged object (contents in a package). More specifically, it is possible to provide a packaging sheet that has a high resistance to friction, pressure, and the like, and can maintain a high adhesion prevention effect on an article to be packaged.

  In particular, in the packaging sheet of the present invention, at least one of the sealant layers is formed of a stretched film, and the surface of the stretched film has a specific surface roughness by being firmly fixed with the particles for forming unevenness. As such, the anti-adhesion surface has a high resistance to friction, pressure, etc. As a result, it is possible to provide a package that can maintain the anti-adhesion effect for a longer time than the conventional technology.

  Further, since the sealant layer of the sheet of the present invention has a structure having both an adhesion preventing surface and heat sealing properties, the shapes of the packaging sheet and the package are not restricted. Therefore, for example, in addition to the bag, a package of a three-dimensional molded product (for example, a tray, a bottle, a tube, or the like) can be formed.

  At the same time, since it has both an anti-adhesion surface and heat sealability, it is particularly excellent in heat sealability (the ability to join surfaces having a fixed area by heat sealing). In general, when heat-sealing surfaces having a certain area, the pressure applied per unit area is small, so that the heat-sealing property (bonding force) tends to be low. Since the prevention surface itself has heat sealing properties, high surface-to-surface heat sealing properties can be obtained. As a result, in a packaged product in which the packaged object is hermetically sealed in the package, high hermeticity can be obtained.

  The packaging sheet and package of the present invention having such features can be widely used for packaging various products such as foods, pharmaceuticals, cosmetics, and the like. In particular, since the packaging sheet and the package of the present invention can exhibit a high adhesion-preventing effect even on liquids or materials containing liquids, they can be suitably used for packaging liquids or materials containing liquids.

It is a figure which shows an example of the layer structure of the packaging sheet of this invention. It is a figure which shows an example of the layer structure of the packaging sheet of this invention. It is a figure which shows the state which carries out heat sealing using the packaging sheet of this invention. FIG. 3A shows a state in which the adhesion preventing surfaces of the packaging sheet are opposed to each other before heat sealing. FIG. 3B shows a state in which the adhesion preventing surfaces are heat-sealed (heat-bonded) at the heat-sealing portion H. It is a figure showing an embodiment of a package (bag) of the present invention. 4A is a plan view, and FIG. 4B is a view of FIG. 4A as viewed from the direction of the arrow.

1. Packaging sheet The packaging sheet of the present invention (the present invention sheet) is a packaging sheet including a base film and a sealant layer laminated on at least one surface of the base film,
(1) at least one of the sealant layers has an exposed anti-adhesion surface, and the surface has a surface roughness Ra of 2 to 12 μm;
(2) The sealant layer having the adhesion preventing surface is composed of a stretched film containing a thermoplastic resin and particles for forming unevenness,
(3) In the sealant layer, the applied amount of the thermoplastic resin per unit area of the packaging sheet is 10 to 55 g / m ² .
It is characterized by the following.

  FIG. 1 shows an example (cross-sectional configuration) of an embodiment of the sheet of the present invention. In the sheet 10 of the present invention, the sealant layer 12 is laminated on one surface of the base film 11. As shown in FIG. 1, the sealant layer 12 may be laminated so as to be in direct contact with the base film 11, or may be laminated on the base film 11 via another sealant layer (not shown). May be. The sealant layer 12 has a structure in which a plurality of irregularities forming particles 15 are dispersed in a matrix 14 containing a thermoplastic resin. As a result, an adhesion preventing surface having a predetermined surface roughness Ra is formed on the surface of the sealant layer 12. As described above, since the sheet of the present invention forms the surface where the anti-adhesion surface is exposed, a high anti-adhesion effect can be obtained.

FIG. 2 shows an example (cross-sectional configuration) of another embodiment of the sheet of the present invention. The sheet 10 of FIG. 2 differs from that of FIG. 1 in that the sealant layer 12 is composed of multiple layers (two multilayer sealant layers). In FIG. 2, the sealant layer 12 is formed of two sealant layers 12a and 12b, of which the sealant layer 12a has an uneven surface (adhesion prevention surface) where the sealant layer 12a is exposed, and the surface roughness Ra of the surface is 2. １２12 μm. That is, the sealant layer 12a is composed of a stretched film containing a thermoplastic resin and particles for forming unevenness. The lower sealant layer 12b is a layer that does not contain the particles for forming unevenness, and functions as a heat seal layer. In the embodiment of FIG. 2, the applied amount of the thermoplastic resin per unit area of the packaging sheet of the sealant layers 12 a and 12 b (total of both layers) is controlled to 10 to 55 g / m ² . The sheet of the present invention includes not only a case where the sealant layer has a two-layer structure as shown in FIG. 2 but also a case where the sealant layer has a structure of three or more layers. Since the sealant layer has a multilayer structure of two or more layers, the bonding portion between the surface of the base film and the surface of the sealant layer in contact with the surface of the sealant layer can be made a higher smooth surface, so that the bondability of both layers can be further improved. Can be enhanced. Further, when the sheetant layer has a multilayer structure (multilayer sealant layer), for example, if the material (especially thermoplastic resin) constituting each layer is the same, the boundary between the layers becomes unclear or the layers are integrated. However, both cases are included in the present invention. When a multilayer sealant layer is used, all of the sealant layers do not necessarily have to be stretched film layers, but it is preferable that all of the sealant layers be stretched film layers in terms of durability of the adhesion preventing effect. .

  Hereinafter, each layer and the like constituting the packaging sheet in the present invention will be described more specifically.

The base film The base film is not particularly limited. For example, synthetic resins (polyester, polyethylene, polypropylene, etc.), fibrous materials (paper, synthetic paper, nonwoven fabric, woven fabric, wood, etc.), metals (aluminum, aluminum) System alloys), glass, and the like, and composite materials thereof. Further, a laminate formed by laminating a plurality of these films, foils and the like can be used as the base film. In particular, 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 the base film.

  The base film may be a stretched film or an unstretched film. Further, as the stretched film, either a uniaxially stretched film or a biaxially stretched film can be used. In the present invention, for example, a stretched film can be suitably used as the base film. Therefore, for example, an inflation stretched film can also be suitably used. Thus, for example, a base film can be formed simultaneously with the formation of the sealant layer, and a laminate in which both layers are integrally laminated can be obtained. In addition, a biaxially stretched polypropylene film (OPP) can be used as the stretched film. Further, as the biaxially stretched polypropylene-based film, various types of films that have been subjected to a surface treatment such as a corona treatment can be used as the base film. By using a stretched film, excellent durability and the like can be obtained more reliably.

  Although the thickness of the base film is not limited, it can be appropriately set according to the use of the packaging sheet, the type of the article to be packaged, and the like. Generally, it can be set appropriately within a range of about 20 to 80 μm. When the thickness of the base film is less than 20 μm, the drying heat of the packaging sheet causes a large expansion and contraction in the width direction or the flow direction, which may affect the processability. When the thickness of the base film exceeds 80 μm, the tearability and the like may be reduced.

At least one of the sealant layers (for example, the sealant layer 12a in FIG. 2) has an exposed anti-adhesion surface, and the surface has a surface roughness Ra of 2 to 12 μm. The sealant layer having the adhesion preventing surface (also referred to as a “surface sealant layer” unless otherwise specified) is composed of a stretched film containing a thermoplastic resin and particles for forming unevenness. In the sheet of the present invention, the surface sealant layer functions not only as an adhesion preventing layer but also as a heat seal layer.

  As a basic configuration of the surface sealant layer, it is desirable to have a structure in which particles (powder) for forming unevenness are dispersed in a matrix containing a thermoplastic resin. Thereby, in the surface sealant layer, the anti-adhesion property and the heat sealing property can be effectively functioned simultaneously. When the sealant layer is a multilayer sealant layer composed of two or more layers, the sealant layer (also referred to as the “base sealant layer”) below the surface sealant layer does not contain a) particles for forming unevenness, and A layer containing a thermoplastic resin, and b) a layer containing no thermoplastic resin and containing a thermoplastic resin. For example, the sealant layer 12b shown in FIG. 2 corresponds to the underlying sealant layer, and has a configuration of the type a). The base sealant layer may be one layer or two or more layers, but usually may be about 1 to 3 layers.

  The thickness of the sealant layer is not particularly limited, but is usually about 10 to 100 μm, and particularly preferably 20 to 80 μm. Thereby, high heat sealing properties can be obtained while maintaining the adhesion preventing effect. Therefore, the thickness of the single layer of the surface sealant layer can be, for example, about 10 to 60 μm. The thickness of the sealant layer was calculated as an average thickness in one visual field by observing a cross section using an optical microscope. In addition, the said thickness is made into the total thickness when it is a multilayer sealant layer. When the sealant layers are formed on both sides of the base film, the total thickness of the sealant layers formed on one side is used.

1) Stretched film The stretched film constituting the sealant layer is not particularly limited, and examples include a flat method stretched film (uniaxially stretched film and biaxially stretched film), an inflation method stretched film, and the like. By using the stretched film as the sealant layer, it is possible to effectively form a predetermined anti-adhesion surface using the particles for forming unevenness, and to obtain excellent durability.

2) Anti-adhesion surface As described with reference to FIG. 1 or FIG. 2, the sealant layer is formed on both surfaces or one surface of the base film, and at least one layer (surface sealant layer) has an exposed adhesion prevention surface. And the surface roughness Ra of the surface is 2 to 12 μm (preferably 3 to 7 μm). By setting the surface roughness to such a value, it is possible to secure the thermal adhesion (particularly, heat sealing property) between the adhesion preventing surfaces and obtain an excellent adhesion preventing effect. If the surface roughness Ra is less than 2 μm, the desired adhesion preventing effect cannot be obtained. On the other hand, if the surface roughness Ra exceeds 12 μm, desired heat sealing properties cannot be obtained. The surface roughness as described above can be appropriately adjusted by dispersing the particles for forming unevenness particularly in a matrix containing a thermoplastic resin.

3) Components Constituting Sealant Layer A thermoplastic resin is included as a component composing the sealant layer. Thereby, heat sealability can be provided to the sealant layer. The surface sealant layer contains particles for forming irregularities in addition to the thermoplastic resin. In this case, the surface sealant layer preferably has a structure in which particles (powder) for forming unevenness are dispersed in a matrix containing a thermoplastic resin.

Thermoplastic resin As the thermoplastic resin, a resin having heat sealing properties can be suitably used. For example, low density polyethylene (including linear (linear) low density polyethylene, branched low density polyethylene, etc.), medium density polyethylene, high density polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate , Nylon-6, nylon-12, nylon-66, polyvinylidene chloride, polyvinyl chloride, polycarbonate and the like, and blended resins thereof. Among them, it is preferable to use at least one kind of low-density polyethylene (particularly, linear (linear) low-density polyethylene) in order to sufficiently obtain heat sealing strength. When the sealant layer is a multilayer sealant layer, the thermoplastic resins contained in each sealant layer may be the same or different. Therefore, as in the examples described later, any of the thermoplastic resins contained in each sealant layer may be polyethylene.

  The ratio of the thermoplastic resin in the sealant layer is not particularly limited, and can be appropriately set according to the desired heat sealability and the like. In particular, in the case of a surface sealant layer, the content is generally about 45 to 97% by weight, and particularly preferably 70 to 90% by weight. In the case of other sealant layers, it can usually be 45 to 100% by weight.

The amount of the thermoplastic resin applied to the sealant layer per unit area of the packaging sheet is usually about 10 to 55 g / m ² , and particularly preferably 15 to 25 g / m ² . Thereby, more excellent heat sealability, durability and the like can be obtained. In the case of a multi-layer sealant layer, the above-mentioned amount is the total amount of each sealant layer. When the sealant layers are formed on both sides of the base film, the total thickness of the sealant layers formed on one side is used.

Particles for forming unevenness The particles for forming unevenness are used for the purpose of imparting predetermined unevenness particularly to the exposed surface (surface) of the surface sealant layer. The material of the particles for forming concavo-convex is not limited as long as the particles include at least one of an organic component and an inorganic component. In addition, as long as the effect of the present invention is not impaired, the underlying sealant layer may contain particles for forming unevenness, or may not include particles for forming unevenness.

  As the inorganic component, for example, metals such as aluminum, copper, iron, titanium, silver, calcium or alloys or metal compounds containing these, aluminum oxide, silicon oxide, zinc oxide, oxides such as titanium oxide, glass, aluminum nitride, Ceramics such as silicon nitride can be suitably used.

  As the organic component, for example, acrylic resin, urethane resin, melamine resin, amino resin, epoxy resin, polyethylene resin, polystyrene resin, polypropylene resin, polyester resin, cellulose resin, vinyl chloride resin, polyvinyl Organic polymer components (or resin components) such as alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, polyacrylonitrile, and polyamide can be suitably used.

  Among the organic polymer components, those having a higher heat resistance than the thermoplastic resin used as the matrix of the sealant layer can be suitably used. For example, when a polyolefin-based resin is used as the thermoplastic resin, usually, particles for forming unevenness composed of an organic polymer component (or a resin component) having a heat resistance temperature of 230 ° C. or higher (for example, 230 to 300 ° C.) are preferably used. Can be.

  Among these irregularities forming particles, the irregularities imparting particles can withstand the temperature at which the thermoplastic resin, which is the main component of the matrix of the sealant layer, is melted during film formation, as well as miscibility with the thermoplastic resin and uniformity of the particles. In view of this, it is more preferable to use acrylic resin particles.

  The average particle diameter D50 of the particles for forming unevenness can be appropriately set according to the desired degree of surface roughness and the like, but is usually preferably 8 to 60 μm, and more preferably 20 to 50 μm. When the average particle diameter D50 is less than 8 μm, unevenness is not formed, and the adhesion preventing effect is reduced. Further, when the average particle diameter D50 is 60 μm or more, the irregularity-imparting particles may hinder heat sealing, and the heat sealing strength may be reduced. Also, when a film is formed by adding particles for forming irregularities to a thermoplastic resin, the particles may be clogged in a die of a resin extrusion port.

  The shape of the particles for forming irregularities is not limited, and may be, for example, any of a true spherical shape, a spherical shape, a hollow shape, and an irregular shape.

  The content of the particles for forming unevenness in the sealant layer (particularly, the surface sealant layer) is not limited, and is usually about 3 to 50% by weight, particularly preferably 10 to 30% by weight. Thereby, the predetermined surface roughness can be obtained more reliably. Therefore, for example, it can be 12 to 20% by weight. The content in the base sealant layer is usually about 0 to 50% by weight, particularly preferably 0 to 30% by weight. Therefore, the content of the concavo-convex forming particles in the base sealant layer can be set to about 0 to 3% by weight, or about 0 to 1% by weight.

Other Components The sealant layer of the present invention may appropriately contain other components (colorants and the like) as long as the effects of the present invention are not impaired.

Other Layers In the sheet of the present invention, other layers may be laminated as necessary. For example, each layer employed in a known or commercially available packaging sheet such as a printing layer (character / pattern layer), a protective layer, a primer layer and the like can be mentioned. However, in the present invention, it is particularly preferable that no other layer is laminated on the adhesion preventing surface of the surface sealant layer.

2. Method for Producing Packaging Sheet The method for producing the packaging sheet of the present invention is not particularly limited, but in particular, a step of forming a film for a sealant layer by stretching a starting material containing a thermoplastic resin and particles for forming unevenness ( (A sealant layer forming step) can be suitably adopted.

  As the thermoplastic resin and the particles for forming unevenness, those described in the above “1. Packaging sheet” can be employed. As for other components, conditions, and the like, those similar to those described in the above “1.

  The starting material containing these components is stretched. Thereby, a film for a sealant layer for forming a sealant layer (particularly, a surface sealant layer) can be obtained. The starting material may be in any form, for example, a melt-kneaded product, an unstretched molded product (unstretched laminate), or the like. The stretching method is not particularly limited, and as described above, for example, a flat method stretching (uniaxial stretching, biaxial stretching), an inflation method (tubular method) stretching, and the like. In particular, in the present invention, it is preferable to use an inflation stretching method in that a desired anti-adhesion surface can be effectively formed. These stretching processes themselves can be performed using a known or commercially available stretching apparatus.

  The stretching temperature can be appropriately changed according to the composition of the starting material to be used and the like, but is usually about 150 to 250 ° C, and particularly preferably 160 to 230 ° C. In the above temperature range, the film can be effectively stretched by an inflation method or the like.

  In addition, the stretching ratio may be generally such that the thickness of the obtained film for the sealant layer is in the range of about 10 to 100 μm (particularly, 20 to 80 μm), but is not limited thereto. In addition, the said thickness is made into the total thickness when it is a multilayer sealant layer. Therefore, the thickness of the single layer of the surface sealant layer can be, for example, about 10 to 60 μm.

  The film for a sealant layer obtained by the sealant layer forming step can be laminated on one or both sides of the base film, particularly as a film for forming a surface sealant layer. The laminating method is not particularly limited, and can be performed according to, for example, lamination using an adhesive. As the adhesive, a known or commercially available adhesive such as a dry laminate adhesive may be used.

  When laminating a film for a sealant layer for forming a surface sealant layer on a substrate film, the film may be laminated so as to be in direct contact with the substrate film, or between the film and the substrate film. Lamination may be performed with a base sealant layer (preferably, a sealant layer not containing particles for forming irregularities and containing a thermoplastic resin) interposed therebetween. By interposing such a base sealant layer, the base sealant layer can absorb irregularities on the surface of the surface sealant layer. As a result, a laminated film of a base film / base sealant layer / surface sealant layer which is strongly bonded to each other is provided. Can be obtained.

  In this case, when the base sealant layer is laminated, the base sealant layer may be composed of one layer or two or more layers. This makes it possible to further enhance the bonding property, sealing property, and the like when a package or a packaged product is manufactured using the sheet of the present invention. From this point of view, when a multilayer sealant layer is employed, it is desirable that each sealant layer be laminated in direct contact.

  In the case where the sealant layer is formed by inflation stretching, in the sealant layer forming step, for example, a) a film for forming a multilayer sealant layer (particularly a layer composed of a surface sealant layer and a base sealant layer), b) a sealant A laminated film including a layer and a base film, c) a laminated film including a surface sealant layer, a base sealant layer, and a base film in this order can also be obtained. These can also be performed using, for example, a known or commercially available multilayer inflation molding machine or the like. Thus, the manufacturing process can be simplified as compared with the case where the layers are stacked one by one. In addition, each layer can be stretched simultaneously. Thereby, both a base film and a sealant layer can be made into a stretched film layer. Also, when forming a multilayer sealant layer, both the surface sealant layer and the underlying sealant layer can be stretched.

3. Package and Packaged Product The sheet of the present invention can be used for various types of packages and packaged products as a packaging material. In particular, the package may be one in which the sealant layers of the packaging sheet are joined, or one in which the sealant layers of the packaging sheet are not joined (for example, a tray container). In the present invention, in particular, a package formed by the packaging sheet of the present invention, wherein (1) the adhesion preventing surface of the packaging sheet is arranged to be in contact with the article to be packaged; A package characterized in that the sealant layers are joined at least partially is preferable.

  Further, in the present invention, an object to be packaged is housed inside the package of the present invention, and the sealant layer of the packaging sheet is joined at least in part to allow the object to be packaged in the package. And packaging products characterized by being hermetically sealed.

  FIG. 3 shows a state in which the sheets of the present invention are joined by heat-sealing all over in manufacturing the package (bag) of the present invention. As shown in FIG. 3A, the adhesion preventing surfaces of the sealant layers 12 of the packaging sheets 10, 10 are opposed to each other. Next, as shown in FIG. 3B, heat sealing is performed in a state where the adhesion preventing surfaces are brought into contact with each other at a preset heat sealing portion H. Thereby, the ends of the packaging sheets are joined. By bonding the other heat-sealed portions in the same manner, a predetermined package body arranged so that the adhesion preventing surface of the packaging sheet is in contact with the article to be packaged can be produced.

  The package of the present invention is manufactured by, for example, a) preparing two sheets of the package of the present invention, arranging them so that the anti-adhesion surfaces face each other, and heat-sealing the entire surface with a predetermined heat seal portion. B) prepare one packaging sheet of the present invention, form it into a cylindrical shape so that the adhesion preventing surface is in contact with the object to be packaged (to be on the inner surface), Any method of manufacturing a package by heat sealing is also included.

  The package of the present invention may be a package in a state of being sealed by heat sealing after accommodating an article to be packaged, but a package before accommodating contents is also included in the present invention. Therefore, for example, a package (semi-finished product) in which an opening for accommodating an article to be packaged is left and the other part is heat-sealed is also included in the present invention. As an example, a bag having an opening also corresponds to the package of the present invention.

  In the packaged product of the present invention, an object to be packaged is accommodated inside the package of the present invention, and the object to be packaged in the package is formed by joining at least a part of the sealant layers of the packaging sheet. Sealed.

  In the present invention, “sealing” refers to a state where the inside and outside of the package are substantially shut off. Therefore, for example, as long as the contents do not go outside, entry and exit of a small amount of gas and the like are allowed.

  The article to be packaged is not particularly limited, and can be suitably used for packaging various products such as food, medicine, cosmetics, and the like. In particular, for packaging foods that tend to adhere to the packaging sheet because of their high water content and that are soft and easily peeled or damaged (eg, western confectionery, western confectionery, Japanese confectionery, Japanese confectionery, etc.). It can be effectively used as a packaging sheet or a package for containing the food. In particular, in the case of a food that has a relatively large amount of water, such as a raw confectionery or a semi-fresh confectionery, and has a soft and easily adhered surface, the surface of the food is easily adhered and adhered to a general packaging sheet according to the related art. Although the properties are enhanced, since the inner surface of the packaging sheet of the present invention is formed by the adhesion preventing surface, even such raw confectionery or semi-fresh confectionery can effectively suppress or prevent the adhesion.

  The shape of the package is not particularly limited, and can be suitably applied to, for example, a molded package, a band-shaped side cover, a wrapper, a tray, a tube, and various bags. The form of the bag is not particularly limited, and it can be suitably used for any type such as a bottom seal bag, a side seal bag, a pillow bag (gassho bag), a gusset bag, and a pouch (standing pouch). .

  The above-mentioned package or packaged product can be obtained by heat-sealing a predetermined portion of the sheet of the present invention so as to have a predetermined packaging form. For example, as shown in FIG. 4, when the pillow bag 20 is manufactured using the sheet of the present invention, the substantially rectangular sheet 10 of the present invention is formed into a cylindrical body, and the sheet of the present invention in the longitudinal direction of the cylindrical body is formed. Heat sealing is performed at a portion where the adhesion preventing surfaces of the edge portions are overlapped with each other as a heat sealing portion H2. With respect to either one of the upper bottom end and the lower bottom end of the tubular body, heat sealing is performed using a portion where the anti-adhesion surfaces of the sheet of the present invention are overlapped as a heat sealing portion H1. After the package (not shown) is loaded from the heat-sealed portion H1 'which has not yet been heat-sealed, the package is sealed by heat-sealing the heat-sealed portion H1'. You. These procedures and the like can be appropriately set according to the form and the like of the package to be produced. Thus, the packaged product of the present invention can be obtained.

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

Example 1
Commercially available low-density polyethylene (MFR: 2 g / 10 min, density: 924 kg / m ³ , softening temperature: 112 ° C.) (LDPE) as a thermoplastic resin for the matrix of the sealant layer, and commercially available fine particles for imparting irregularities Crosslinked polymethyl methacrylate fine particles (PMMA particles) (average particle diameter D50: 30 µm, softening point (heat-resistant temperature): 255 ° C, specific gravity: 1.2) were prepared.
100 parts by weight of low-density polyethylene were dry-blended with 20 parts by weight of crosslinked polymethyl methacrylate fine particles, and a compound resin was prepared using a twin-screw extruder. The resin melting temperature at the time of extrusion was 180 to 200 ° C. This compound resin was formed into a film having an uneven surface by using an inflation film forming machine. The temperature at the time of film formation was 180 to 220 ° C. The thickness of the formed film was 50 μm. Thus, a film for a sealant layer having an uneven surface (adhesion preventing surface) was produced.
Laminating one surface of the film for a sealant layer and a biaxially stretched polyester resin (film pressure: 25 μm) as a base material layer using a polyurethane-based dry laminate adhesive (dry weight: 3.5 g / m ² ) To obtain a packaging sheet. A package (pillow bag) was prepared in which the obtained packaging sheet was attached to the back and sealed on three sides. The inner surface of the obtained package had an uneven surface.

Example 2
A packaging sheet was prepared in the same manner as in Example 1 except that the amount of PMMA particles added was changed to 10 parts by weight, and this was back-sealed and sealed on three sides to prepare a package (pillow bag).

Example 3
A packaging sheet was produced in the same manner as in Example 1 except that the amount of PMMA particles added was changed to 30 parts by weight, and this was back-adhered and three-sided sealed to produce a package (pillow bag).

Example 4
A packaging sheet was prepared in the same manner as in Example 1 except that PMMA particles having an average particle diameter D50 of 50 μm were used, and this was back-sealed three-sided to prepare a package (pillow bag).

Example 5
A packaging sheet was prepared in the same manner as in Example 1 except that the PMMA particles were replaced with calcium carbonate particles (average particle size D50: 11 μm, shape: amorphous, specific gravity: 2.94), and this was attached to the backside three-side seal. Then, a package (pillow bag) was prepared.

Example 6
A packaging sheet was prepared in the same manner as in Example 5 except that calcium carbonate particles having an average particle size D50 of 27 μm were used, and this was back-adhered and three-side sealed to prepare a package (pillow bag).

Example 7
A packaging sheet was prepared in the same manner as in Example 1 except that the PMMA particles having an average particle diameter D50 of 80 μm were used, and this was back-sealed three-sided to prepare a package (pillow bag).

Example 8
First layer: LDPE of 20 μm, Second layer: LDPE of 20 μm, Third layer: 100 parts by weight of LDPE of 20 μm, commercially available fine particles of crosslinked poly (methyl methacrylate) (average particle diameter D50: 30 μm, softening point: 255 ° C., specific gravity: Using a mixture obtained by adding 20 parts by weight of 1.2) as a raw material, a film for a sealant layer composed of three layers was produced by a multilayer inflation molding machine.
The first layer of the film for a sealant layer and a biaxially stretched polyester resin (film pressure: 25 μm) as a substrate layer are bonded together using a polyurethane-based dry laminate adhesive (weight after drying: 3.5 g / m ² ). In this manner, a packaging sheet (a laminate composed of a base film / base sealant layer (first layer) / base sealant layer (second layer) / surface sealant layer (third layer)) was obtained. A package (pillow bag) was prepared in which the obtained packaging sheet was attached to the back and sealed on three sides. The inner surface of the obtained package had an uneven surface.

Example 9
First layer: LDPE of 20 μm, Second layer: LDPE of 20 μm, Third layer: 100 parts by weight of LDPE of 20 μm, and commercially available fine particles of crosslinked polymethyl methacrylate (average particle diameter D50: 50 μm, softening point: 255 ° C., specific gravity: Using a mixture obtained by adding 20 parts by weight of 1.2) as a raw material, a film for a sealant layer composed of three layers was produced by a multilayer inflation molding machine.
The first layer of the film for a sealant layer and a biaxially stretched polyester resin (film pressure: 25 μm) as a substrate layer are bonded together using a polyurethane-based dry laminate adhesive (weight after drying: 3.5 g / m ² ). In this manner, a packaging sheet (a laminate composed of a base film / base sealant layer (first layer) / base sealant layer (second layer) / surface sealant layer (third layer)) was obtained. A package (pillow bag) was prepared in which the obtained packaging sheet was attached to the back and sealed on three sides. The inner surface of the obtained package had an uneven surface.

Example 10
The sealant layer used in Example 1 and the biaxially stretched polyester resin (film pressure: 150 μm) are bonded together using a polyurethane-based dry laminating adhesive (dry weight: 3.5 g / m ² ) to produce a packaging sheet. did. Thereafter, a tray having a bottom area of 10 cm × 15 cm = 150 cm ² , a height of 3 cm, and a taper angle of 5 ° was produced using a pressure forming method (molding temperature: 150 ° C.). The inner surface of the obtained tray was an uneven surface.

Comparative Example 1
A packaging sheet was prepared in the same manner as in Example 1 except that particles having an average particle diameter D50 of 5 μm were used as PMMA particles, and this was back-adhered and three-side sealed to prepare a package (pillow bag).

Comparative Example 2
A sealant film formed to a thickness of 60 μm using low-density polyethylene (LDPE) is bonded to a commercially available biaxially stretched polyester film (16 μm in thickness), and the sealant film surface is embossed at 60 ° C. under a pressure of 100 kgf / cm. ^The embossed pattern was transferred under the condition of No. ^{2 to} give irregularities. For the embossed pattern, 40 mesh silk was used. The film obtained in this manner was back-adhered and sealed on three sides to prepare a package (pillow bag). The inner surface of the obtained package had an uneven surface.

Comparative Example 3
A packaging sheet was produced in the same manner as in Comparative Example 2 except that the embossed pattern used was 175 mesh silk, and this was attached to the back and sealed on three sides to produce a package (pillow bag).

Comparative Example 4
A packaging sheet was prepared in the same manner as in Comparative Example 3 except that a blasted embossed pattern was used, and this was back-sealed and sealed on three sides to prepare a package (pillow bag).

Comparative Example 5
A packaging sheet was produced in the same manner as in Comparative Example 3 except that the embossed handle used was a 151-mesh tortoise shell, and this was back-sealed and sealed on three sides to produce a package (pillow bag).

Comparative Example 6
The embossed film used in Comparative Example 4 and the biaxially stretched polyester resin (film pressure: 150 μm) were bonded together using a polyurethane-based dry laminating adhesive (dry weight: 3.5 g / m ² ) to produce a packaging sheet. . Thereafter, a tray having a bottom area of 10 cm × 15 cm = 150 cm ² , a height of 3 cm, and a taper angle of 5 ° was produced using a pressure forming method (molding temperature: 150 ° C.). The inner surface of the obtained tray was an uneven surface.

Comparative Example 7
A sealant film formed to a thickness of 60 μm using low-density polyethylene (LDPE) is bonded to a commercially available biaxially stretched polyester film (thickness 16 μm) to form a packaging sheet, which is then pasted and three-sided sealed for packaging. A body (pillow bag) was prepared. The inner surface of the obtained package had an uneven surface.

Comparative Example 8
A commercially available polyethylene-based particle having an average particle diameter D50 of 30 μm and a commercially available coating agent mainly composed of a polyolefin-based resin (heat seal coating agent, solid content: 20%) were prepared. 90 parts by weight of this coating agent was mixed and dispersed with 10 parts by weight of commercially available polyethylene particles, and this was coated on a commercially available biaxially stretched polyester film (16 μm in thickness) by a bar coater, and dried at 80 ° C. × 10 seconds. Thus, a heat seal layer was formed. The resin amount of the heat seal coat agent after drying at this time was 3.0 g / m ² . As a result, a packaging sheet was obtained. Next, the obtained packaging sheet was three-side-backed and sealed to produce a package (pillow bag). The inner surface of the obtained package had an uneven surface.

Comparative Example 9
90 parts by weight of a commercially available polyolefin resin-based coating agent (heat seal coating agent, solid content: 20%) was mixed and dispersed with 10 parts by weight of commercially available polyethylene particles, and the resin amount of the heat sealant after drying Was changed to 10.0 g / m ² , a packaging sheet was produced in the same manner as in Comparative Example 8, and the packaging sheet was back-backed and sealed on three sides to produce a package (pillow bag).

Comparative Example 10
A packaging sheet was prepared in the same manner as in Example 8, except that the thickness of the first layer of the sealant layer was changed to 10 μm, and this was back-sealed three-sided to prepare a package (pillow bag).

Test Example 1 (Adhesion test 1)
A commercially available confectionery (castella) was prepared, the castella serving as the content was placed on a package, sealed, and allowed to stand at room temperature of 20 ° C. and 25% of humidity for 4 days. After 4 days, the castella was peeled off from the package, and the amount (area ratio with respect to the contact surface) adhering to the film was visually confirmed and evaluated. When the amount of adhesion was less than 10%, it was indicated by “〇”, when it was 10% or more and less than 30%, it was indicated by “△”, and when it was 30% or more, it was indicated by “×”. Table 1 shows the results.

Test example 2 (adhesion test 2)
Glycerin was prepared for a slip test of cosmetics, the package was placed on a slope having a slope of 20 degrees, 1 ml of glycerin was dropped, and the time required to slide down a distance of 150 mm was measured. When the time required to slide down a 150 mm was less than 1 minute, it was marked with "〇". When it was more than 1 minute, it was marked with "△". When 50% or more of glycerin remained on the package, it was marked with "x". . Table 1 shows the results.

Test Example 3 (Surface roughness Ra evaluation)
Each sample was cut into a size of 150 mm × 150 mm, and the uneven surface thereof was measured with a surface roughness meter (Surtest SV 9634 / 3D manufactured by Mitutoyo Corporation) to determine the arithmetic average roughness Ra (μm) in accordance with the standard of JIS B0601 (2001). It was measured. Specifically, the measurement was performed under the following conditions: measurement length: 17.5 mm, evaluation length: 12.5 mm, speed: 0.2 mm / s, number of measurement points: 17,500, and reference length: 2.5 mm. Table 1 shows the results.

Test Example 4 (Heat seal strength on all sides)
The adhesion preventing surfaces are heat-sealed using a hot plate of 20 mm × 60 mm at 160 ° C. × 3 kg / cm ² × 1 second, and then slit into strips so that the seal width becomes 15 mm. Were prepared at three points. The heat seal strength of these test pieces was measured with an autograph tester (EZ-LX manufactured by Shimadzu Corporation). Specifically, the seal strength (N) was determined as a T-peel test at a speed of 100 mm / min, and three points were measured for each sample as described above, and the average excess strength (N) was obtained. In consideration of the heat sealing strength of practical packaging materials, 3N / 15 mm or more was evaluated as “〇”, 1N / 15 mm or more and less than 3 N / 15 mm was evaluated as “サ ン プ ル”, and samples less than 1 N / 15 mm were evaluated as “x”. Table 1 shows the results of the heat sealing strength.

Test Example 5 (Durability)
For the durability evaluation, a Gakushin type dyeing friction fastness tester (Yasuda Seiki Seisakusho Co., Ltd.) was used. Each sample was cut into a size of 15 mm × 150 mm, urethane rubber was brought into contact with the sample, and a durability test was performed under the conditions of a load: 4.9 N, a friction distance: 100 mm, and a speed: 30 reciprocations / min. "〇" when the value of the surface roughness Ra 'after 30 round trips is 70% or more compared to the Ra before evaluation, "△" when the value is 50% or more and less than 70%, and "△" when the value is less than 50%. × ”. Table 1 shows the durability results.

  As is evident from the results in Table 1, it is found that none of Comparative Examples 1 to 5 and Comparative Examples 7 to 11 provide satisfactory performance in durability. In addition, in Comparative Example 6, although the desired durability was obtained, the anti-adhesion performance was not obtained.

  On the other hand, in the packaging sheets of Examples 1 to 10, the sealant layer having the adhesion preventing surface provided with the predetermined surface roughness is formed by stretching the compound of the irregularity forming particles and the thermoplastic resin. Therefore, it can be seen that excellent performance is exhibited in each of the tests. In particular, even in the durability test, since the initial anti-adhesion surface is effectively maintained, it can be seen that excellent anti-adhesion performance can be maintained.

Claims (7)

A packaging sheet including a base film and a sealant layer laminated on at least one surface of the base film,
(1) at least one of the sealant layers has an exposed anti-adhesion surface, and the surface has a surface roughness Ra of 2 to 12 μm;
(2) The sealant layer having the adhesion preventing surface is composed of a stretched film containing a thermoplastic resin and particles for forming unevenness,
(3) In the sealant layer, the applied amount of the thermoplastic resin per unit area of the packaging sheet is 10 to 55 g / m ² .
A packaging sheet characterized by the above. The packaging sheet according to claim 1, wherein the average particle diameter D50 of the particles for forming unevenness is 8 to 100 μm. 3. The packaging sheet according to claim 1, wherein the sealant layer having the adhesion preventing surface contains 3 to 50% by weight of the particles for forming unevenness in the sealant layer. 4. The packaging sheet according to any one of claims 1 to 3, wherein the thermoplastic resin is a polyolefin-based resin. The packaging sheet according to any one of claims 1 to 3, wherein the thickness of the sealant layer having an adhesion preventing surface is 10 to 100 m. A package formed by the packaging sheet according to any one of claims 1 to 5,
(1) It is arranged so that the adhesion preventing surface of the packaging sheet is in contact with the article to be packaged,
(2) A package characterized in that the sealant layers of the packaging sheet are joined at least partially. An object to be packaged is contained inside the package according to claim 6, and the object to be packaged is hermetically sealed in the package by bonding at least a part of the sealant layers of the packaging sheet. Packaging products characterized by the fact that: