JP2007191221A - Sheet for heat-sealing lid material, and lid material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for heat-sealing lid materials and lid materials, which have a strength high enough to protect contents, while saving resources, and which have easy-to-open properties to be easily opened by hand. <P>SOLUTION: The sheet 12 for heat-sealing lid materials is provided with a hot-melt adhesive printed into a predetermined shape where the adhesive is applied with a pattern template on one surface of a base material from which a plurality of lid materials heat-sealed to receptacles are punched out. The shapes are annular parts of the receptacles, corresponding to the flanges of the receptacles. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  [Technical Field] The present invention relates to a sheet for a heat sealing lid material that can be easily opened for use in plastic containers, paper containers, and composite containers for storing food, pharmaceuticals, electronic components, and other articles. And lid material.

  2. Description of the Related Art Conventionally, in containers that contain food or the like, the container opening is sealed with a lid material in order to protect the contents. And as for the lid | cover material used, thermal adhesives (heat sealing agent), such as a hot-melt-adhesive agent, are uniformly apply | coated by the same thickness to the whole surface (back surface in the state which sealed the container) of the base material. For this reason, when heat sealing is performed on the flange portion of the container, the entire surface of the flange portion is generally heat sealed with the same thickness, that is, the same strength.

  However, in such a case, the adhesive strength becomes strong, but there is a problem that a large force is required for opening at the time of opening, and the lid material is torn during the opening. As a means for improving the openability, as described in JP-A-11-292140, a protrusion is provided on the flange portion of the container, and heat sealing is performed at a portion where the inclination is provided on the protrusion. Although proposed, it is not sufficient in terms of stability of easy opening. In addition, in the case of a heat-sealing lid material using a hot melt adhesive, the heat adhesive is applied to the entire surface of the lid material, but only the portion corresponding to the flange portion of the container is actually heat-sealed. It is not preferable from the viewpoint of resource saving. Furthermore, in the case of a heat-sealing lid material using a hot-melt adhesive, the adhesive strength of the lid material is determined by the adhesive strength of the hot-melt adhesive itself. . However, when a hot-melt adhesive having a low adhesive strength is used, the sealing performance is deteriorated in a high-temperature environment exceeding 30 ° C., such as in summer when the internal pressure of the container increases. Particularly, yogurt foods and the like are stored in a room at around 45 ° C. after packaging and sealing because of fermentation of lactic acid bacteria, and therefore higher heat resistance is required without impairing easy-openability.

  The present invention is a heat-resistant heat-opening agent that uses a hot-melt adhesive that can save resources and can be easily opened with bare hands while having sufficient sealing strength to protect the contents. An object is to provide a sealing lid. Furthermore, this invention makes it a technical subject to provide the lid | cover material provided with both easy-opening property and heat resistance.

  In order to solve the above-mentioned problems, the sheet of the heat sealing lid material of the present invention is a hot melt bonding method using a plate having a predetermined shape on one side of a base material for punching a plurality of lid materials to be heat sealed to a container. The agent is printed in a shape in which a hot melt adhesive for the lid is provided (Claim 1).

  Since the hot melt adhesive layer is partially formed in this way, it has sufficient strength to protect the contents, and compared to the case where the adhesive is applied to the entire surface of the lid as in the prior art. Since the amount of adhesive applied is small, resource saving can be achieved.

  It is a sheet | seat of the lid | cover material for heat sealing of this invention, Comprising: The said shape substantially respond | corresponds to the shape of a lid | cover material, and leaves the substantially L-shaped range of the front-end | tip so that a width | variety may spread gradually from a front-end | tip in the opening direction. It is preferable that it is provided as described above (claim 2). Further, the shape may be an annular portion corresponding to the flange portion of the container (Claim 3), and is a ring-shaped one having a circular outer contour sharpened at the opening start portion and an inner contour. (Claim 4).

  A sheet of the above-described heat sealing lid material, which is wound into a roll, is preferred (Claim 5). A sheet wound in such a roll shape, in which a hot melt adhesive is printed in a predetermined shape so as to compensate for an uncoated portion of the adhesive in a portion not corresponding to the cover material of the base material (Claim 6). Furthermore, it is preferable that the predetermined shape is a curve having a predetermined width in which a linear line continuously extending in the longitudinal direction of the sheet, a row of rings, or a concentric circular arc concentric with the flange of the lid member is continuous (invention). Item 7).

  The second aspect of the sheet of the heat sealing lid material of the present invention is a base material comprising an outer layer film and an inner layer film, and a hot melt adhesive layer provided on the inner surface side of the inner layer film leaving a speckled range. The inner layer film has thermal adhesiveness with the flange portion of the container, and the thermal bonding temperature is equal to or higher than the melting temperature of the hot melt adhesive (Claim 8).

  A sheet of such a heat sealing lid material, in which the area ratio of the spotted range is 1/10 to 1/4 (claim 9), is preferred.

  In the heat sealing lid material of the present invention, the shape in which the hot melt adhesive is provided may be such that the peel width gradually increases along the opening direction from the opening start portion. In this case, the lid can be easily peeled off at the start of opening, is less likely to break along the way, and the container is surely sealed.

  Moreover, the hot melt adhesive may be applied so that the application area density of the adhesive increases from the outside toward the inside in the region corresponding to the flange portion of the container. In that case, it is easy to open and sealing is reliable.

  The lid material of the present invention is obtained by punching from the above-mentioned heat sealing lid material sheet.

  Since the lid material of the present invention is partially provided with the hot melt adhesive layer, it is easy to use because it is easy to open while maintaining the strength to protect the contents. Furthermore, heat resistance and sealing strength can be improved while maintaining easy-openability by a combination of a partial hot melt adhesive layer and a base material having thermal adhesiveness to the container.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a lid 1 according to this embodiment and a container 2 that is heat sealed with the lid. The container 2 is a container mainly made of plastic, paper or the like that contains food or the like, and has a flange portion 3 around the opening 4. The lid member 1 includes a base material 11 and a hot melt adhesive layer 5 formed on the surface of the back side of the base material 11. FIGS. 2 a to d show the configuration of the lid member 1, and FIG. 2 a shows the back surface of the lid member 1, and the hot melt adhesive layer 5 is formed on the annular surface corresponding to the flange portion 3 of the container 2. Is provided. That is, the hot melt adhesive layer is not formed in the circular region 1 a corresponding to the opening of the central container 2. In FIG. 2, reference numeral 6 denotes an opening tab. By pulling the tab 6, an opening start position (site closest to the tip of the tab 6 in the range of the hot melt adhesive layer 5) 7 from the opening end position ( Within the range of the hot melt adhesive layer 5, the lid 1 is peeled off to the rear portion 8 inside the annular region corresponding to the flange (see FIG. 2 d).

  As the material of the container 2, for example, various plastics such as polypropylene, polyethylene, polyethylene terephthalate, polystyrene, polycarbonate, etc., or a laminate of aluminum foil and paper can be used.

  As a material of the base material 11 of the lid 1, for example, an outer layer film such as polypropylene, polyethylene terephthalate or nylon is provided with a barrier layer such as an aluminum foil, an aluminum vapor deposition film, an alumina / silica vapor deposition film, if necessary. If necessary, polyethylene, ethylene-vinyl acetate copolymer (EVA) or the like may be laminated on the inner layer, and one or more overcoat layers, printing layers, coated papers, and the like may be further laminated. There is no particular limitation. 2b and 2c show the lid 1 having a base material 11 on which an outer layer film 9 and an inner layer film 10 are laminated, respectively. If the container 2 is not a synthetic resin such as paper, metal, or glass, the material of the base material is not so much affected. However, if the container 2 is made of a synthetic resin, the inner layer (inner layer) of the base material 11 depends on the type. A preferable material is selected for the film 10). That is, the material of the inner layer film 10 of the base material 11 is usually a material that does not have thermal adhesiveness with the material of the container 2. For example, when the container 2 is polyvinyl chloride (PVC), polyethylene or polypropylene is used as the inner layer film 10, or when the container 2 is polystyrene, polyethylene is used as the inner layer film 10. However, as will be described later, the inner layer film 10 may have a thermal adhesive property, for example, the same material or a compatible material.

  Examples of the hot-melt adhesive include, as a main component, commonly used ethylene-vinyl acetate copolymers, waxes, tackifiers, styrenic block copolymers, polyesters, polyamides, and the like. Various things, such as a composition, can be used.

  In the embodiment shown in FIG. 2a, the application shape of the hot melt adhesive layer 5 is such that the application area in the vicinity of the opening start part 7 to be opened by hand is small, and the application area increases toward the opening end part 8 along the opening direction. It has come to expand. That is, in the region corresponding to the tab, the hot melt adhesive layer 5 is not provided, but is an annular region corresponding to the flange portion 3 and the range excluding the left and right arcuate portions (portions surrounded by the arc and straight line) 7a. Is provided with a hot-melt adhesive layer 5. Therefore, the shape of the hot melt adhesive layer 5 is somewhat rounded and sharp on the opening start portion 7 side, and the width (peeling width) of the hot melt adhesive layer 5 increases almost proportionally in the opening direction. Go. Therefore, the peeling resistance at the initial stage of opening is small, and the peeling resistance gradually increases. Thereby, it can open easily by hand from the opening start part 7, and the cover material 1 is not torn during the opening. On the other hand, since the hot melt adhesive layer 5 is densely formed on the inner peripheral side, there is no problem in terms of content protection even if the coating area is small.

  The thickness of the hot melt adhesive layer 5 is uniform in the embodiment shown in FIG. 2b. This is easy to form the hot melt adhesive layer 5. On the other hand, in FIG. 2c, in the vicinity of the opening start position 7, the thickness gradually increases, for example, linearly in the opening direction. Therefore, it is easier to peel off at the start of opening. In the embodiment shown in FIG. 2d, the thickness gradually increases, for example, in an arc shape from the vicinity of the opening start position to the vicinity of the intermediate position. This is also easy to peel off at the beginning, and since the peeling resistance gradually increases with a loose change, it is more difficult to break along the way. In the embodiment of FIG. 2d, the substrate 11 is shown as a single layer, but it may be a laminated material of two layers or more as shown in FIGS.

  In the lid member 1 shown in FIGS. 3a and 3b, the thickness of the hot melt adhesive layer 5 is substantially uniform, and the planar range thereof is changed. That is, in the annular region corresponding to the flange portion of the container, the hot melt adhesive layer 5 is located in the outer region 7b of the arcuate contour that protrudes outward from the opening start position 7 side to the middle. Does not form. Therefore, the peeling resistance gradually increases in this case up to the vicinity of the opening end position 8. Therefore, the opening operation can be performed smoothly.

  In the embodiment shown in FIG. 4 a, the hot melt adhesive layer 5 is formed on almost the entire area other than the tab 6 in the ring-shaped range corresponding to the flange portion 3 of the container 2 when viewed in plan. However, as shown in FIG. 4b, the thickness of the ring-shaped hot melt adhesive layer 5 increases from the outside toward the inside, for example, linearly. This increases the adhesive strength on the inside, making the protection of the contents more reliable, and since the peel strength starting from the opening start position 7 becomes weak at the time of opening, it can be easily opened with bare hands, Peeling is easy even during opening, and the lid material 1 is prevented from being broken in the middle.

  Further, as shown in FIGS. 5a and 5b, the planar application shape of the hot melt adhesive layer 5 shown in FIG. 3a and the pattern of the thickness distribution of the hot melt adhesive layer 5 shown in FIG. 4b are combined. The hot melt adhesive layer 5 may be formed.

  FIG. 6 shows a balance between easy-openability and protection of contents by roughening the application area of the hot melt adhesive in the vicinity of the opening start portion 7 and making it dense in other areas. That is, in this embodiment, in the vicinity of the opening start portion 7, a small spot-like region 5c where a large number of adhesives are not provided is formed, and the amount of hot melt adhesive applied per unit area is substantially reduced. Yes. Therefore, in the vicinity of the opening start position 7, the lid 1 can be easily peeled off.

  The application shape and thickness distribution pattern of the hot-melt adhesive layer 5 are not particularly limited because they vary depending on the type of hot-melt adhesive, the size of the flange portion 3 of the container 2, the contents, and the like. . For example, in the above embodiment, the hot melt adhesive layer 5 is not provided in the circular region 1a corresponding to the opening of the container, but as shown in FIG. 7, the hot melt adhesive layer 5 is not formed in the region 1a corresponding to the opening. An adhesive layer 5 may be provided. This increases the amount of hot melt adhesive used compared to the previous embodiment, but the hot melt adhesive layer 5 acts as a cushion to protect solid contents such as tablets and electronic components. And is relatively tolerant of printing misalignment. Moreover, it is substantially the same as the previous embodiment in terms of ease of peeling.

  FIG. 8 shows a sheet 12 for punching the lid 1 shown in FIG. 2a. The sheet 12 is wound in a roll shape, and the hot melt adhesive layer 5 has a specific shape on one side of the sheet 12, that is, only the range corresponding to the flange portion except the range 1a corresponding to the opening of the container. In addition, it is applied in a ring-shaped application shape having a circular outer contour and an inner contour each sharpened at the opening start portion 7. Such a coated shape can be formed by a method similar to gravure printing using a plate having a predetermined shape. This can significantly reduce the amount of adhesive used compared to the case where a hot melt adhesive layer is provided on the entire surface of the sheet 12.

  FIG. 9 shows another application shape of the hot melt adhesive layer, except for the tab 12 on the sheet 12 and the L-shaped area 13 adjacent thereto, the hot melt adhesive layer substantially corresponding to the shape of the cover material. 5 is applied by using a plate having a predetermined shape. That is, this forms a substantially L-shaped contour 14 that gradually widens in the opening direction with the opening start portion 7 as a tip, and the hot melt adhesive layer 5 is formed in the outer L-shaped range 13 of the contour 14. Without being provided, a hot melt adhesive layer 5 is provided in the range 1a corresponding to the opening of the container. A line corresponding to the outline of the lid member 1 is indicated by a broken line 15. In some cases, a hot melt adhesive layer may be provided outside the broken line 15.

  FIG. 10 shows still another application shape of the hot-melt adhesive layer, and a slightly outer region 16 is excluded from the L-shaped contour 14 having the opening start portion 7 of each lid member 1 of the sheet 12 as the tip. A hot melt adhesive layer 5 is formed on almost the entire surface. In this case, the amount of adhesive applied is not much less than that of the conventional one, but the ease of peeling off the lid material at the time of opening is almost the same as that of the above-described embodiment. Furthermore, the hot-melt adhesive layer 5 at the portion covering the opening of the container has a cushioning action and protects the contents. Moreover, since this thing has apply | coated the adhesive agent to the substantially whole sheet | seat, there exists an advantage which is hard to produce an unevenness | corrugation when it winds on a roll, and is easy to wind.

  That is, in the sheet 12 of FIG. 8 and FIG. 9, since the hot melt adhesive layer 5 is provided at the center part in the form of dots, when wound on a roll, the center part swells and the peripheral part has wrinkles, etc. Need attention. However, when the hot melt adhesive layer 5 is provided on almost the entire surface as shown in FIG. 10, since the coated surface is flat, it is easy to wind the sheet as much as the conventional sheet coated with the adhesive. In addition, even when an adhesive is applied to the outside of the broken line 14 of the sheet 12 in FIG.

  FIG. 11 is the same as FIG. 8 in the shape of the hot melt adhesive layer 5 applied to the lid part, but the linear part 18 extending continuously in the longitudinal direction of the sheet 12 at the center part and both side parts, The same adhesive is applied with the same thickness. Therefore, when the sheet 12 is wound, it is possible to prevent the roll from rising only at the central portion and becoming unstable, and the amount of adhesive used can be greatly reduced.

  Note that the shape of the adhesive layer of the linear portion 18 is not limited to the linear shape as shown in FIG. 11, but various shapes that compensate for the uncoated portion of the adhesive, such as a ring row 18a as shown in FIG. Various shapes such as a curved line 18b having a predetermined width in which arcs concentric with the flange are continuous as shown in FIG. 13 can be formed, and the roll becomes stable when the roll is further wound.

  14 is the same as FIG. 9 in the application shape of the hot melt adhesive layer 5 to the lid 1 part, but as in FIG. 11, the same hot melt is applied to the central part and the linear part 18 on both sides. An adhesive layer is provided. In this case as well, the roll can be stabilized as in FIG. 11, and the amount of adhesive used can be greatly reduced.

  FIG. 15 shows a range 19 in which the hot melt adhesive layer 5 is not provided over the entire surface of one side of the sheet 12 from which the lid material 1 is punched. This product is easy to produce, and the lid material is easily peeled off to some extent and is not easily broken in the middle. In addition, the sealing performance of the container is sufficiently high. In this case as well, the roll when the sheet is wound is stabilized as in FIG.

  In addition, the range 19 where the hot melt adhesive layer 5 is not provided is not limited to a dot-like shape, but various pattern shapes are possible. However, the necessity of a continuous pattern of the adhesive layer 5 means a sealing property. Needless to say, it has inevitability. In addition, there are a method of changing the adhesive strength by changing the size of the spots in the range 19, and a method of changing the adhesive strength by partially changing the area density, and the area density of the non-coated portion. And the coating amount of the coating portion can be adjusted by a combination of both depending on the type of screen of the gravure plate, and the adhesive strength and the sealing performance suitable for the purpose can be obtained.

  Furthermore, new fields can be developed by utilizing this coating method. That is, as described above, a heat-bondable synthetic resin such as PE, EVA, PP, PS or the like is used for the inner layer of the base material currently used in the market (see reference numeral 10 in FIG. 2). Are coated on the surface of the base material having thermal adhesiveness, and the surface of the base material and the hot melt adhesive layer are bonded. Here, the hot melt adhesive layer is utilized to prevent the opening of the base material and the plastic container from being directly heat-bonded to make the opening difficult, and to facilitate the opening. That is, when the base material of the lid and the material of the container are the same or compatible, for example, in the case of FIG. 2, when the container 2 and the inner layer film 10 are both polyethylene, both are polypropylene, or both are ethylene-vinyl acetate. In the case of copolymers, when they are directly heat bonded, they are heat bonded to such an extent that they cannot be peeled off. Therefore, the adhesive strength is adjusted by interposing a hot melt adhesive layer between them.

  However, as described above, when the hot melt adhesive coating area ratio is appropriately selected, such as by applying the hot melt adhesive layer 5 in a pattern that leaves a relatively small area 19 in the form of dots, it is easy to open. Thus, it is possible to obtain further sealing strength within the range in which the above is maintained. That is, when a hot melt adhesive layer is applied in a graphic form as shown in FIG. 15 to a base material provided with an inner layer having thermal adhesiveness to the container, the main adhesive force is the hot melt adhesive. The thermal bonding between the uncoated areas 19 and the mating plastic container 10 provides complementary adhesion. As a result, it is possible to realize thermal bonding having adhesive properties different from thermal bonding using only a hot-melt adhesive, particularly heat resistance and cold resistance.

  If the base material of the lid and the container cannot be directly thermally bonded, a heat seal layer having thermal adhesiveness with the container can be formed on the surface of the base material in advance by coating such as printing. . Moreover, you may provide a heat seal layer in adhesive surfaces, such as a flange by the side of a container. The heat-seal layer by coating here is obtained by dissolving a thermoplastic resin material such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, etc. with a solvent, and applying it to the surface of the substrate by printing, etc. , Which is dried and solvent removed. In other words, “the surface of the base material has thermal adhesiveness to the container” in the claims means that, in addition to the case where a thermal adhesive film is laminated on the base material itself, such a thermoplastic material is used for heating. This includes cases where a sealing layer is formed. In addition, when forming a heat seal layer with a film, it is provided on the entire surface of the base material. However, when a heat seal layer is provided by coating such as printing, it is provided on the entire surface of the base material and hot-melt heat bonding. It can also be partially provided on the part where the agent is not provided, or, in some cases, can be partially applied on the hot melt thermal adhesive layer. When the heat seal layer is partially provided, it can be provided by the same method as when the hot melt adhesive layer is partially provided by various printing coating methods such as gravure printing.

  In the case of the combined use of heat bonding with a hot melt adhesive and heat bonding with a heat seal layer, various adhesive strengths and easy-opening properties are brought about depending on the temperature at the time of heat bonding. That is, since the hot melt adhesive is a material in which a material in a liquid state at a temperature equal to or higher than the melting temperature is applied to the base material, the bonding temperature is relatively low. On the other hand, heat seal layers formed by coating with heat seal films and solvents often have a relatively high melting temperature. Therefore, when the lid is heat bonded to the container at a low temperature, the heat seal layer is thermally bonded. On the other hand, the adhesive strength and heat resistance tend to be low, while the force is weak and thus easy-openability is improved. On the contrary, when heat-bonding at a high temperature, the adhesive strength by the heat seal layer is increased, and the heat resistance is improved, but the easy-openability is decreased.

  16a and 16b show a lid material obtained by cutting the sheet 12 of FIG. 15 in accordance with the contour of the flange of the container, and is substantially the same as that of FIG. 1 except for the pattern of the hot melt adhesive layer 5. . That is, the lid material 1 is provided with the hot melt adhesive layer 5 on the inner surface of the base material 11 composed of the outer layer film 9 and the inner layer film 10, leaving a spot-like area 19. The outer layer film 9 and the inner layer film 10 constituting the substrate 11 are the same as those in FIGS. The material of the hot melt adhesive layer 5 is also the same as that shown in FIGS.

  When the lid 1 is thermally bonded to the flange portion of the container having thermal adhesiveness with the inner layer film 10 at a predetermined temperature, the dot-like inner layer film 10 is strongly thermally bonded to the flange portion of the container, and the other part is hot. The melt adhesive layer 5 is thermally bonded with a lower strength. The overall adhesive strength and easy-openability depend on the area ratio of the spot-like area (blank part) 19 where the hot melt adhesive layer 5 is not provided and the thermal bonding temperature. For example, since the area ratio of the group-like area 19 is about 1/10 to 1/4, when peeling off from the tab 6, the lid 1 is peeled off easily and easily from the flange portion of the container. be able to. Furthermore, the portion where the inner layer 10 and the container are directly thermally bonded has high heat resistance, so that even if it is stored in a room at about 45 ° C. after packaging, such as yogurt food, it maintains a sufficiently high sealing performance. sell.

  Next, the arrangement state of the group-like areas 19 and the smoothness when the cover material is peeled off will be described. 17a and 17b show the application patterns of the hot melt adhesive 5 in which the blank portions 19 are arranged at equal intervals in the vertical and horizontal directions, respectively. In FIG. 17a, each blank portion 19 is circular, and in FIG. 17b, the blank portion 19 is square. In those lid materials, when the lid material 1 is peeled off along the arrangement direction (arrows A1, A2) (see imaginary line), an operation of peeling a portion (peeling line P1) where the blank portions 19 are arranged; The operation of peeling off the portion (peeling line P2) where the hot melt adhesive layer 5 is continuous occurs alternately. Therefore, if the blank portion 19 is strongly thermally bonded to the container and the peel strength is larger than the peel strength of the hot melt adhesive layer 5, the blank portion 19 is peeled off with a strong force in the area where the blank portion 19 is lined up. Peel off with a weak force. Therefore, a large level difference occurs in the peeling strength in each range, and the peeling operation is not smooth. In addition, even when the blank portion 19 is not thermally bonded to the container, it is the reverse of the above, but there is some difference in the peel strength.

  On the other hand, when peeling off in an oblique direction with respect to the arrangement direction of the blank portions 19 as indicated by arrows B1 and B2, the next blank portion 19 is passed before passing through the row of blank portions 19 where the peeling line P3 is present. It will come to the line. Therefore, the level difference of the peeling strength is much smaller, and the peeling can be performed smoothly. In addition, you may make it peel in the direction between arrow A1 and arrow B1 like arrow C1. From the above, when the lid member 1 is cut, it is preferable that the tab 6 for determining the peeling direction is directed obliquely with respect to the arrangement direction of the blank portions 19 as shown in FIG.

  FIG. 18 shows an application pattern of the hot-melt adhesive layer 5 in which large circular blank portions 19a are diagonally arranged and a smaller circular blank portion 19b is arranged between the large circular blank portions 19a. Yes. This can also provide a stable peeling operation.

  FIG. 19 shows a preferred embodiment of the lid 1 used for the paper container 2. In general, in a paper container, a body is made by rolling paper, and a joint at that time also appears in the flange portion 3. For this reason, in the case of a lid used for a conventional paper container, when the lid is heat sealed to the flange of the container, the hot melt adhesive can sufficiently enter the stepped portion. A thick hot melt adhesive layer is provided.

  In the lid 1 of FIG. 19, the thickness of the hot melt adhesive layer 5 is increased at the portion 21 corresponding to the step portion 20 of the flange portion 3 of the container 2 and is decreased at the other portions. Therefore, the amount of adhesive used can be reduced. The method of partially increasing the thickness of the hot-melt adhesive layer 5 is the same as in the above-described embodiment, and can be provided by a method similar to printing using a plate.

Hereinafter, the present invention will be described with reference to examples and comparative examples.
[Examples 1-4 and Comparative Examples 1-2]
A container 30 and a lid 31 shown in FIG. 20 were prepared. The lid is printed on the surface of a polyethylene terephthalate film 32 (thickness 12 μm, trade name “E5100” manufactured by Toyobo Co., Ltd.), and the back surface is aluminum foil 33 (thickness 20 μm, manufactured by Nippon Light Metal Co., Ltd.). AIN30H-O) and a hot melt adhesive layer 34 provided on the surface of the aluminum foil were used as a base material, and punched into a circle having a tab 35 and a diameter d of 82 mm as shown in FIG. .

  In Examples 1 to 4 and Comparative Examples 1 and 2, the hot-melt adhesive layer 34 includes a hot-melt adhesive mainly composed of an ethylene-vinyl acetate copolymer (EVA), a wax, and a tackifier. Leader product name “Hotmelt 60-3”) was used.

  The application shape and application thickness pattern of the hot melt adhesive to the lid material 31 of Examples 1 to 4 are the patterns shown in FIGS. 3 to 6, and Comparative Examples 1 and 2 were applied to the entire surface. Their application shape, application thickness, and heat sealing conditions are shown in Table 1. Moreover, the container 30 used the polystyrene. The container 30 was filled with 130 g of water, and the lid member 31 was heat sealed using a flat plate heat bonding plate.

The following tests were performed on the packages produced in each of the examples and comparative examples. The results are shown in Table 2.
(1) The tab 35 of the lid 31 of the openable package is sandwiched between the thumb and the index finger and pulled in a 45 ° direction (an elevation angle of 45 ° as viewed from the opening start direction, a direction indicated by an arrow in FIG. 22), and the following criteria The degree of opening was evaluated.
○: Can be opened smoothly. The water of the contents will not scatter and stick to the lid or spill.
X: Opening is not easy, and an impact is applied when opening. The water in the contents spills or splashes.
(2) Reverse the top of the protective packaging and use the vibration tester (Bio-Shaker BR-30 manufactured by Taitec Co., Ltd.) to leak the contents after 12 hours at a vibration speed of 100 times / minute. Checked and evaluated the degree of opening according to the following criteria.
○: No leakage of contents.
X: The content exudes and leaks.

As is clear from Table 2, in Comparative Example 1, the protective property is high, but the unsealing property is not preferable. In Comparative Example 2, opening is easy but protection is low. On the other hand, in an Example, there is no leakage of the content in a vibration model test, and the lid | cover material has smooth openability.
[Heat-resistant creep resistance test]
[Examples 5 to 7 and Comparative Example 3]
Inner layer side of a base material in which an inner layer of a low density polyethylene (LDPE) film having a thickness of 0.015 mm, an aluminum foil having a thickness of 0.020 mm, and an outer layer of a polyethylene terephthalate (PET) film having a thickness of 0.012 mm are laminated. In addition, a hot-melt adhesive (trade name AS100M-2) manufactured by Leader Co., Ltd. is applied at a thickness of 0.050 mm so that the white space 19 in the form of dots shown in FIG. Coating was performed so that the ratios were 70%, 60%, and 50%, and lid materials of Examples 5, 6 and 7 were obtained. Similarly, the entire surface was coated (coating area ratio 100%) to obtain a cover material of Comparative Example 3.

The lid materials of Examples 5 to 7 and Comparative Example 3 were applied to a paper having a basis weight of 100 g / m ² coated with a 0.020 mm-thick low density polyethylene (LDPE) film, and the hot melt adhesive layer was applied to the LDPE surface. The layers were stacked so as to be in contact with each other, and thermally bonded at two types of heat sealing temperatures of 140 ° C. × 1 second and 170 ° C. × 1 second. The obtained product was cut into a width of 15 mm to form a strip, and the environmental temperature at which a load of 100 g was suspended on the paper side and maintained for 5 minutes was measured to confirm the heat-resistant creep resistance. The results are shown in Table 3.

From Table 3, the cover material of Comparative Example 3 provided with a hot melt adhesive layer on the entire surface can only last for 5 minutes at an ambient temperature of 58 ° C., but the application area ratio is 70%, 60% and It can be seen that 50% of the lids of Examples 5, 6 and 7 can all withstand high temperatures.
[Sealing strength test]
[Comparative Example 4]
The base material used in Example 5 in which the hot melt adhesive layer was not provided (coating area ratio 0%) was used as the lid material of Comparative Example 4. In each of the lid materials of Examples 5 to 7 and Comparative Examples 3 and 4, a lid was applied to the opening of a paper cup (capacity 120 cc) made of 0.012 mm thick low density polyethylene (LDPE) coated on the inner surface. Then, heat sealing was performed at a heat sealing temperature of 140 ° C. and 160 ° C. Nothing was placed in the paper cup, and compressed air was introduced from the bottom with a needle to measure the pressure (unit: mmHg) when the lid was peeled off. The results are shown in Table 4.

  As can be seen from Table 4, the lid material of Comparative Example 3 having the hot melt adhesive layer coated on the entire surface has a low strength, but gradually increases as the coating area decreases. The higher the heat seal temperature, the stronger the strength, which indicates that the seal strength between the LDPEs appears in addition to the hot melt adhesive layer. In Comparative Example 4 where the coating area ratio was 0%, the sealing strength was too high, and the opening was difficult. It can be seen that the combination of the hot melt adhesive layer coated in a pattern and the primer base material is effective in making the heat resistant creep resistance and the heat sealing strength appropriate.

It is explanatory drawing which shows the cover material and container concerning one Embodiment of this invention. 2a is a rear view showing the shape of the hot melt adhesive layer applied to the lid, FIGS. 2b and 2c are cross-sectional views corresponding to line XX of FIG. 2a of the other lid, and FIG. 2d is the lid when opened. It is explanatory drawing of material. It is explanatory drawing which shows the shape of the hot-melt-adhesive agent layer in this invention. It is explanatory drawing which shows the other shape of the hot-melt-adhesive agent layer in this invention. It is explanatory drawing which shows the other shape of the hot-melt-adhesive agent layer in this invention. It is explanatory drawing which shows the other shape of the hot-melt-adhesive agent layer in this invention. It is explanatory drawing which shows the shape of the hot-melt-adhesive agent layer used by the comparative example. It is explanatory drawing which shows the sheet | seat for obtaining the cover material of this invention. It is explanatory drawing which shows the sheet | seat for obtaining the other cover material of this invention. It is explanatory drawing which shows the sheet | seat for obtaining the other cover material of this invention. It is explanatory drawing which shows the sheet | seat for obtaining the other cover material of this invention. It is explanatory drawing which shows the sheet | seat for obtaining the other cover material of this invention. It is explanatory drawing which shows the sheet | seat for obtaining the other cover material of this invention. It is explanatory drawing which shows the sheet | seat for obtaining the other cover material of this invention. It is explanatory drawing which shows the sheet | seat for obtaining the other cover material of this invention. 16a and 16b are a bottom view and a side view showing another embodiment of the lid member of the present invention. 17a and 17b are plan views showing other embodiments of the application pattern of the hot melt adhesive layer in the lid member of the present invention, respectively, and FIG. 17c is a bottom view showing still another embodiment of the lid member of the present invention. is there. It is a top view which shows other embodiment of the application pattern of the hot-melt-adhesive agent layer in the cover material of this invention. It is principal part sectional drawing which shows other embodiment of the cover material of this invention. It is explanatory drawing which shows the cover material and container which were used by the Example and the comparative example. It is a top view of the cover material used by the Example and the comparative example. It is explanatory drawing which shows the peeling test method used by the Example and the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cover material 2 Container 3 Flange part 4 Opening part 5 Hot-melt-adhesive agent layer 11 Base material 1a Area | region 6 Tab 7 Opening start position 8 Opening end position 9 Outer layer film 10 Interior film 7a Arcuate part 7b Outside range 12 Sheet 13 L-shape Shaped region 15 Lid contour 14 L-shaped contour 16 Outer region 18 Linear portion 18a Ring row 18b Curve 19 Range not provided with hot melt adhesive layer 20 Step portion 21 Region corresponding to step portion 30 Container 31 Lid material 32 Film 33 Aluminum foil 34 Hot melt adhesive layer 35 Tab

Claims (10)

A hot-melt adhesive printed on a surface of a base material for punching a plurality of lid materials to be heat-sealed with respect to a container, using a plate with a predetermined shape, in a shape in which the hot-melt adhesive of the lid material is provided. Sealing lid sheet. The heat sealing according to claim 1, wherein the shape substantially corresponds to the shape of the lid member, and is provided so as to leave a substantially L-shaped range of the tip so that the width gradually increases in the opening direction from the tip. Cover sheet. The sheet | seat of the lid | cover material for heat sealing of Claim 1 whose said shape is a cyclic | annular part corresponded to the flange part of a container. The sheet | seat of the lid | cover material for heat sealing of Claim 3 whose said shape is a ring-shaped thing which has the circular external outline sharpened in the opening start part, and an internal outline. The sheet | seat of the lid | cover material for heat sealing of Claim 1 wound by roll shape. The sheet | seat of the cover material for heat sealing of Claim 5 by which the hot-melt-adhesive was printed in the predetermined | prescribed shape so that the uncoated part of an adhesive agent might be supplemented in the site | part which does not respond | correspond to the cover material of the said base material. . The heat according to claim 6, wherein the predetermined shape is a curve having a predetermined width in which a linear line continuously extending in a longitudinal direction of the sheet, a row of rings, or a concentric circular arc concentric with a flange of the lid member. Sealing lid sheet. It consists of a base material composed of an outer layer film and an inner layer film, and a hot melt adhesive layer provided on the inner surface side of the inner layer film leaving a spot-like range,
The sheet | seat of the lid | cover material for heat sealing whose said inner layer film has a heat bonding property with the flange part of a container, and whose heat bonding temperature is more than the melting temperature of a hot melt adhesive. The sheet | seat of the lid | cover material for heat sealing of Claim 8 whose area ratio of the said spot-like range is 1/10-1/4. A heat sealing lid material obtained by punching from a sheet of the heat sealing lid material according to claim 1.

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