Laminated material for lid, lid, and packaging body

Abstract

The invention relates to a laminated material for a cover, a cover, and a packaging body. Provided is a laminated material for lids, which is suitable for high-frequency induction heating sealing and has a barrier layer formed from a metal foil in the middle of the thickness thereof, said laminated material having properties such as no generation of fine cracks or cracks in the metal foil even when subjected to cyclic deformation fatigue. A material in which a heat-sealing layer is formed from a heat-fusible resin film and an embossed pattern formed from a plurality of independent protrusions is formed on the entire innermost surface of the heat-sealing layer is used as the laminated material (A) for the lid.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 202110803104.6, with the application date of July 15, 2021 and the invention name of "Laminated material for lid, lid and packaging body". Technical Field

[0002] The present invention relates to a laminated material for a lid. The laminated material for a lid is used to make a lid for heat-sealing a container filled with contents. Examples of the contents include products to be taken orally, such as liquid or solid foods or medicines (hereinafter, the term "contents" has the same meaning).

[0003] The present invention also relates to a lid formed of the above-mentioned laminated material for a lid, and a package body obtained by heat-sealing the above-mentioned container filled with a content with the lid.

[0004] In this specification, "aluminum" means "pure aluminum" or "aluminum alloy".

[0005] In this specification, the term "outside" refers to the direction of the upper surface side of the laminated material for a cover of the present invention and the cover formed by the laminated material for a cover, and this direction is equivalent to Figure 7 The so-called "inner side" refers to the lower surface side of the cover laminate and the cover, and also the side facing the opening peripheral edge of the container, which is equivalent to Figure 7 The down arrow in the direction of D2. Background Art

[0006] Conventionally, as a means of filling a container with contents and heat-sealing it with a cover formed of a gas-barrier cover laminate, a resistance heating type thermal head is used. In addition, when the cover laminate is, for example, a composite substrate having a metal foil (aluminum foil, etc.) as a barrier layer sandwiched in the middle of the thickness and a heat-sealing layer formed of a thermoplastic film disposed on the innermost surface, heat sealing can be performed using a high-frequency induction heating sealing device capable of high-speed and high-temperature heating (see Patent Document 1).

[0007] After the gas barrier cover is placed on the peripheral edge of the opening of the container filled with the contents, a high-frequency magnetic flux is generated under alternating current in a high-frequency induction heating sealing device, thereby performing sealing using high-frequency induction heating. At this time, the magnetic flux that passes through the metal foil forming the barrier layer of the cover generates Joule heat on the surface of the metal foil, and the heat-sealing layer on the inner side of the metal foil is melted by the heat, so that the peripheral edge of the opening of the container and the cover are thermally welded. As a result, a package with the contents sealed is obtained.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 9-77006 Summary of the invention

[0011] Problems to be solved by the invention

[0012] However, for the packaging body obtained by high-frequency induction heating sealing, when it is transported over long distances in a packaged state, it is possible that fine cracks, ruptures, etc. will occur on the metal foil forming the barrier layer of the lid. The applicant speculates that the reason is as follows. That is, the packaging body in the above-mentioned packaging state is subjected to long-term vibration during transportation, especially when it is shaken left and right, and the packaging bodies collide or press against each other. At this time, the internal pressure of each packaging body increases and decreases, and the lid repeatedly expands and contracts. In addition, it is believed that such repeated stress is continuously applied to the lid, and as periodic deformation fatigue accumulates on the metal foil forming the barrier layer, the metal foil forming the barrier layer of the lid undergoes cyclic fatigue, resulting in fine cracks, ruptures, etc. on the metal foil.

[0013] In view of the above problems, the main subject of the present invention is to provide a laminated material for lids, which is suitable for high-frequency induction heating sealing and has a barrier layer formed of a metal foil in the middle of the thickness, and the laminated material for lids has a performance that does not generate fine cracks, ruptures, etc. on the metal foil even after experiencing the above-mentioned cyclic fatigue (hereinafter sometimes referred to as internal pressure cracking resistance). In addition, another subject of the present invention is to provide a lid formed of the laminated material for lids and a packaging body having the lid as an element.

[0014] Means for solving problems

[0015] In order to solve the above-mentioned problems, the inventors of the present application have found that, as a cover laminate material for heat-sealing the container filled with the above-mentioned content, a heat-sealing layer formed of a heat-fusible resin film with an embossed pattern on the innermost surface has excellent resistance to internal pressure cracking. That is, the present invention relates to the following cover laminate material, a cover formed of the cover laminate material, and a packaging body having the cover as an element.

[0016] 1) A laminated material for a cover, which is a laminated material for a cover that is heat-fused to the peripheral edge of the opening of a container filled with contents in a manner that covers the opening of the container, and is characterized in that the laminated material for the cover comprises, from the outside, a protective resin layer, a barrier layer formed of a metal foil, an anchor coating, an adhesive layer and a heat-sealing layer, the heat-sealing layer is formed of a heat-fusible resin film, and an embossed pattern formed of a plurality of independent convex portions is formed over the entire range of the innermost surface of the heat-sealing layer.

[0017] 2) In the laminate material for a cover described in 1), the top of the convex portion is flat.

[0018] 3) In the laminated material for lid described in 1), the height of the convex portion is larger than the thickness of the heat seal layer before embossing and smaller than the total thickness of the adhesive layer and the heat seal layer before embossing.

[0019] 4) In the laminate material for cover described in 1), a printed ink layer and / or an anchor coating layer is interposed between the protective resin layer and the barrier layer.

[0020] 5) In the laminated material for lid according to 1), the metal foil forming the barrier layer has a tensile strength of 20 to 200 MPa when broken and a total elongation of 5 to 50% when broken.

[0021] 6) In the cover laminate material described in 1), it is characterized in that the heat sealing layer is composed of a heat-sealing layer and a base material layer, the heat-sealing layer is formed of a heat-sealing resin film, and the base material layer is arranged on the upper surface of the heat-sealing layer and is formed of a synthetic resin.

[0022] 7) In the laminated material for lids described in 1), the melt flow rate of the heat-fusible resin film forming the heat-seal layer is 2 to 15 g / 10 minutes.

[0023] 8) In the laminated material for lid described in 1), it is characterized in that the tensile strength at break in the machine direction (MD) and the tensile strength at break in the transverse direction (TD) of the heat-fusible resin film forming the heat-seal layer are both 40 to 100 MPa.

[0024] 9) In the cover laminate material described in 1), it is characterized in that the heat sealing layer is heat-fused to a sheet with a thickness of 0.3 mm formed by the same heat-fusible resin film as the heat-fusible resin film forming the heat sealing layer under the conditions of 160°C, 0.2 MPa and 1 second, and then, in a T-peel test according to JIS K6854-3, the cover laminate material and the sheet have a strength of 5 to 15 N / 15 mm when they are peeled off from each other at a tensile speed of 300 mm / min.

[0025] 10) In the laminated material for lid described in 1), a lubricant is attached to the outermost surface of the protective resin layer, and the protective resin layer and the heat-sealing layer do not contain a lubricant.

[0026] 11) In the laminated material for a cover described in 1), the protective resin layer contains a lubricant having a property of seeping out on the outermost surface of the protective resin layer to form a precipitated phase, and the heat seal layer does not contain a lubricant.

[0027] 12) In the cover laminate material described in 1), it is characterized in that the protective resin layer contains a lubricant having the property of seeping out on the outermost surface of the protective resin layer to form a precipitated phase, and the heat sealing layer contains a lubricant having the property of seeping out on the innermost surface of the heat sealing layer to form a precipitated phase.

[0028] 13) In the laminated material for a cover described in 1), the protective resin layer contains no lubricant, and the heat seal layer contains a lubricant having a property of seeping out on the innermost surface of the heat seal layer to form a precipitated phase.

[0029] 14) A cover, characterized in that it is formed of the laminated material for a cover according to any one of 1) to 13).

[0030] 15) A packaging body, characterized in that the lid described in 14) is placed on the peripheral edge of the opening of the container in a manner covering the opening of the container filled with contents, and is thermally welded by high-frequency induction heating to obtain the packaging body.

[0031] 16) A packaging body as described in 15), characterized in that, according to the T-peel test method specified in JIS K6854-3, the strength of the lid of the packaging body when peeled off from the opening edge of the container of the packaging body at a tensile speed of 300 mm / min is 5 to 15 N / 15 mm.

[0032] Effects of the Invention

[0033] The laminated material for lids described in 1) is characterized in that the heat seal layer forming the innermost surface is composed of a heat-fusible resin film. Therefore, the laminated material for lids and the lid formed therefrom have good resistance to internal pressure cracking. Specifically, for a package formed by heat-sealing a container filled with contents by means of a lid formed of the laminated material for lids described in 1) by high-frequency induction heating, even if the lid is repeatedly deformed in plane due to the increase or decrease of the internal pressure of the storage space during long-distance transportation in a packaged state, fine cracks, ruptures, etc. due to deformation fatigue will not occur on the metal foil forming the barrier layer of the lid.

[0034] In addition, for a cover formed of the cover laminate material of 1), even if it is subjected to the above-mentioned repeated planar deformation in a state of being heat-fused to the opening peripheral portion of the container, it will not peel off from the opening peripheral portion or produce seal retreat (hereinafter, such a property is sometimes referred to as internal pressure resistance sealing).

[0035] In addition, the cover laminate material described in 1) is also characterized in that an embossed pattern formed by a plurality of independent convex portions is formed over the entire range of the innermost surface of the heat-sealing layer. Moreover, according to this feature, the cover laminate material and the cover formed therefrom also have good resistance to internal pressure cracking and internal pressure sealing. The following is considered as the reason for this. That is, when the cover formed by the cover laminate material of 1) is heat-fused to the opening peripheral portion of the container, the gas in the container can be discharged to the outside of the container through the gap formed by the interval of the embossed pattern, thereby preventing the expansion of the cover during heat sealing in advance. In other words, since such so-called degassing can be performed, the cover can be kept flat for the packaging body. Therefore, for the packaging body, the appearance of the cover will not be damaged, and when the content is a fermented food such as a lactic acid bacteria beverage, the cover rupture caused by the increase in internal pressure can be prevented, and the so-called seal retreat can also be prevented.

[0036] 2) The laminated material for lids is characterized in that: 1) in the laminated material for lids, the top of the convex portion constituting the embossed pattern is flat, so that when the lid formed of the laminated material for lids is heat-fused to the peripheral edge of the opening of the container, the sealing accuracy and sealing strength become good.

[0037] 3) The laminated material for lids is characterized in that: 1) in the laminated material for lids, the height of the convex portion constituting the embossed pattern is limited to a predetermined range. Therefore, if a lid formed of the laminated material for lids is used, the exhaust inside the container during heat sealing can be more reliably performed.

[0038] 4) The laminated material for the cover is characterized in that: 1) In the laminated material for the cover, a printed ink layer and / or an anchor coating is sandwiched between the protective resin layer and the barrier layer, for example, by sandwiching the printed layer, 4) the laminated material for the cover and the cover formed thereby display the information and appearance design of the contents. In addition, if an anchor coating is provided on the inner side of the printed layer in order to improve the closeness between the printed layer and the barrier layer, the printed layer can be prevented from falling off, falling off, and shifting. On the other hand, it is also possible to provide only an anchor coating instead of a printed layer. In this case, since the closeness between the protective resin layer and the barrier layer can be improved, even if an object contacts the outermost surface of the protective resin layer and applies external force, the protective resin layer can be prevented from peeling off and falling off, and delamination between the two layers can be prevented.

[0039] 5) The laminated material for lids is characterized in that: 1) in the laminated material for lids, the tensile strength and the total elongation at break of the metal foil forming the barrier layer are respectively limited to a specified range. Therefore, it is more flexible to external stress and can prevent rupture.

[0040] 6) The laminated material for lids described in claim 1) is characterized in that: in the laminated material for lids described in claim 2), a heat-sealing layer is formed from the outside by a base material layer formed of a synthetic resin and a heat-sealing layer formed of a heat-fusible resin film. Therefore, for example, the sealing strength between the lid formed by the laminated material for lids described in claim 6) and the container can be improved, or the strength and cushioning of the lid itself can be improved. In addition, the laminated material for lids described in claim 6) and the lid formed therefrom also have good internal pressure sealing resistance and internal pressure cracking resistance.

[0041] 7) The laminated material for lids described in claim 1) is characterized in that: 1) in the laminated material for lids, the melt flow rate of the heat-fusible resin film forming the heat-sealing layer is limited to a specified range. Therefore, if a lid formed from the laminated material for lids is used, a container filled with contents can be heat-sealed more reliably in a short time during high-frequency induction heating sealing. In addition, since the laminated material for lids described in claim 7) and the lids formed therefrom have better resistance to internal pressure sealing and internal pressure cracking, there is no possibility of seal retreat, peeling of the heat-fused portion, cracking and rupture of the metal foil, etc.

[0042] 8) The characteristics of the laminated material for lids are as follows: 1) In the laminated material for lids, the tensile strength of the heat seal layer in the longitudinal direction (MD: Machine Direction) and the tensile strength in the transverse direction (TD: Transverse Direction) are both limited to a certain range. Therefore, the overall strength of the laminated material for lids is improved. In addition, the laminated material for lids has better resistance to internal pressure sealing and internal pressure cracking, and will not produce seal retreat, peeling of heat-welded parts, cracking and rupture of metal foil, etc. In addition, the laminated material for lids described in 8) and the lid formed thereby have sufficient tear strength and good resistance to straw puncture. If the resistance to straw puncture is good, for example, the resistance when a straw pierces the laminated material for lids and the lid formed thereby becomes smaller, and the straw will not bend or break.

[0043] 9) The laminated material for lids described in 1) is characterized in that, after being heat-fused to a specified sheet (adherent) under specified conditions, the strength when peeled off under specified conditions is limited to a specified range. Therefore, the package formed by heat-sealing the lid formed by the laminated material for lids will not be accidentally opened, the lid will not peel off, the seal will not retreat, etc. during transportation. In addition, the lid can be easily peeled off when it is opened.

[0044] 11) The laminated material for lids is characterized in that: 1) a lubricant is attached to the outermost surface of the protective resin layer of the laminated material for lids, and the lubricant reduces the coefficient of dynamic friction of the outermost surface, thereby achieving good external lubricity.

[0045] 12) The laminated material for a cover is characterized in that: 1) the protective resin layer of the laminated material for a cover contains a lubricant. The lubricant seeps out on the outermost surface of the protective resin layer to form a precipitated phase. Moreover, the precipitated phase reduces the dynamic friction coefficient of the outermost surface, thereby exerting good external lubricity.

[0046] 13) The cover laminate material is characterized in that: 1) both the protective resin layer and the heat seal layer of the cover laminate material contain lubricants, and the lubricant contained in the protective resin layer seeps out on the outermost surface of the protective resin layer to form a precipitated phase. On the other hand, when the cover laminate material described in 13) is wound to form a coil, the lubricant contained in the heat seal layer seeps out on the innermost surface of the heat seal layer to form a precipitated phase. Moreover, a part of the precipitated phase is transferred to the outermost surface of the protective resin layer that is closely attached to the inner side of the heat seal layer. Therefore, the cover laminate material described in 13) has lubricants from the protective resin layer and lubricants from the heat seal layer coexisting on its outermost surface. Moreover, through these lubricants, the dynamic friction coefficient of the outermost surface is reduced, and good external lubricity is exerted.

[0047] 14) The cover laminate material is characterized in that: 1) The heat seal layer of the cover laminate material contains a lubricant. When the cover laminate material described in 14) is wound to form a coil, the lubricant seeps out on the innermost surface of the heat seal layer to form a precipitated phase. Moreover, a part of the precipitated phase is transferred to the outermost surface of the protective resin layer that is closely attached to the inner side of the heat seal layer. Therefore, the cover laminate material of 14) has a lubricant from the heat seal layer on its outermost surface. Moreover, the lubricant reduces the dynamic friction coefficient of the outermost surface and exerts good external lubricity.

[0048] As described above, for a cover formed of the cover laminate material described in any one of 11) to 14), even if some external force is applied to the outermost surface of the cover, such as impact or strong friction due to contact with other objects, these forces are released in the horizontal direction. Therefore, the protective resin layer can be prevented from falling off or peeling off. In addition, when a printed layer is arranged on the inner side of the protective resin layer, the printed layer of the protective resin layer can be prevented from falling off, rubbing, peeling off, or falling off.

[0049] The package body described in 15) is an article obtained by heat-sealing a container filled with contents with the cover described in 14) by high-frequency induction heating. For this package body, the innermost heat-sealing layer of the cover forming the package body is composed of a heat-fusible resin film, and a prescribed embossing pattern is formed on the innermost surface of the heat-fusible resin film, so the resistance to internal pressure cracking and the resistance to internal pressure sealing are good. Therefore, even if external stress is periodically applied to the cover of the package body and the cover is repeatedly deformed, the seal of the heat-fused portion will not retreat or peel off. In addition, as the internal pressure of the package body increases or decreases, even if the cover is repeatedly deformed, no cracks or ruptures will occur on the metal foil forming the cover.

[0050] Regarding the package described in 16), in the package described in 15), the strength of the cover laminate when peeled off from the peripheral edge of the opening of the container under specified conditions is limited to a specified range, so that accidental opening will not occur during transportation. In addition, the cover can be easily peeled off when opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a vertical cross-sectional view of the laminated material for a lid of the present invention.

[0052] Figure 2 It is a vertical cross-sectional view of the laminated material for a lid of the present invention.

[0053] Figure 3 This is a perspective view of the embossed pattern of the laminate material for a lid of the present invention.

[0054] Figure 4 It is a top view of the embossed pattern of the laminate material for lids of the present invention.

[0055] Figure 5 It is a perspective view of the cover of the present invention.

[0056] Figure 6 It is a cross-sectional view of the packaging body of the present invention.

[0057] Figure 7 Schematic diagram showing an evaluation device for the internal pressure cracking resistance of a packaging body according to the present invention.

[0058] Description of Reference Numerals

[0059] 1 Cover laminate material

[0060] 11 Protective resin layer

[0061] 12 Printing ink layer

[0062] 13 Anchor coating

[0063] 14 Barrier layer

[0064] 15 Anchor coating

[0065] 16 Adhesive layer

[0066] 17 Heat seal layer

[0067] 17a Base material layer

[0068] 17b Heat seal layer

[0069] 18 Embossed pattern

[0070] 18a convex part

[0071] 18b Interval

[0072] 18c bottom

[0073] 2 Cover

[0074] 2a Main body

[0075] 2b Skirt

[0076] 3 Container

[0077] 31 Opening periphery

[0078] C Contents

[0079] 4 Packaging

[0080] 5 Internal pressure cracking resistance evaluation device

[0081] 51 Containment Department

[0082] 52 side wall

[0083] 53 Abutment member

[0084] D1 The direction in which cover 2 deforms outward

[0085] D2 The direction in which the cover 2 deforms inward DETAILED DESCRIPTION

[0086] Below, through Figures 1 to 7 The laminated material for a lid, the lid, and the package of the present invention will be described in detail. However, the scope of protection of the present invention is not limited to these drawings.

[0087] Figure 1 (a), (b), and (c) are schematic diagrams showing vertical cross sections of the laminated material 1 for a lid of the present invention.

[0088] Figure 1The cover laminate material 1 of (a) is a composite material in which a protective resin layer 11, a printed ink layer 12, an anchor coating layer 13, a barrier layer 14, an anchor coating layer 15, an adhesive layer 16, and a heat seal layer 17 are laminated in order from the outside. It should be noted that either or both of the printed ink layer 12 and the anchor coating layer 13 may be omitted.

[0089] Figure 1 The cover laminate material 1 of (b) is a composite material in which a protective resin layer 11, a barrier layer 14, an anchor coating layer 15, an adhesive layer 16, and a heat seal layer 17 are laminated in order from the outside, and both the printed ink layer 12 and the anchor coating layer 13 can be omitted.

[0090] Figure 1 The cover laminate material 1 of (c) is Figure 1 Similarly to the laminated material 1 for lid described in (b), a composite material is formed by laminating a protective resin layer 11, a barrier layer 14, an anchor coating layer 15, an adhesive layer 16, and a heat seal layer 17 in order from the outside. The heat seal layer 17 is formed by two independent layers, the outer layer constitutes a base material layer 17a, and a heat seal layer 17b is laminated on the lower surface of the base material layer.

[0091] Figure 1 In each of the cover laminate materials 1 of (a), (b) and (c), an embossed pattern 18 is formed on the innermost surface of the heat seal layer 17 .

[0092] The embossed pattern 18 is composed of a plurality of independent convex portions 18a, intervals 18b between the convex portions 18a, and a bottom surface 18c. The convex portions 18a exist in an island shape on the continuous phase formed by the bottom surface 18c.

[0093] Figure 2 The cover laminated material 1 of (a), (b), and (c) is for Figure 1 (b) The laminated material 1 for lid of the example in which the embossed pattern 18 is deformed. The details will be described later.

[0094] Figure 3 for Figure 2 (c) is a perspective view of the laminated material 1 for lids. The embossed pattern 18 is formed by regularly arranging a plurality of cylindrical protrusions 18a at equal intervals 18b on a flat bottom surface 18c.

[0095] Figure 4 This is an example of the pattern of the embossed pattern 18. The details will be described later.

[0096] Figure 5 2 is a perspective view of a cap 2 of the present invention. The cap 2 is in the shape of a cap and is composed of a substantially horizontal circular main body 2a and a skirt 2b extending downward from the periphery of the main body 2a.

[0097] Figure 6 (a) and (b) are cross-sectional views of a package body 4 of the present invention. The package body 4 is an article in which a container 3 filled with a content C is heat-sealed with a lid 2 by high-frequency induction heating sealing means.

[0098] Figure 6 The cover 2 of the package body 4 of (a) is Figure 5 In the cap-shaped form shown, the opening peripheral edge portion 21 of the container 3 constitutes a substantially upright rim.

[0099] Figure 6 The lid 2 of the package 4 of (b) is in a flat single-piece form, and the opening peripheral edge 31 of the container 3 filled with the content C is substantially horizontal and forms a flange with a certain width.

[0100] Figure 7 It is a schematic diagram of the evaluation device of the internal pressure cracking resistance of the package body 4. The details will be described later.

[0101] <Laminate material 1 for cover>

[0102] The protective resin layer 11 constitutes the outermost surface of the cover laminate 1 and improves its strength, durability, weather resistance, chemical resistance, etc., and can be composed of various known overcoats and / or synthetic resin films.

[0103] As the outer coating agent, there can be mentioned a composition obtained by dissolving various known binder resins that can be used as the outer coating agent in a solvent, and a curing agent can also be contained. As the binder resin, for example, nitrocellulose, shellac resin, epoxy resin, polyurethane resin, chlorinated polyolefin resin, acrylic resin and vinyl chloride-vinyl acetate copolymer can be mentioned. As the solvent, there can be mentioned various known organic solvents, and toluene, xylene, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, methanol, ethanol and isopropanol can be used as examples. As the curing agent, melamine curing agent, epoxy curing agent and epoxy melamine curing agent can be mentioned.

[0104] As synthetic resins for forming synthetic resin films, for example, polyesters such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate, polyamides, and polyolefins such as stretched polypropylene can be cited, and two or more films of the same or different types can be combined. As film-forming means of synthetic resins, for example, (co) extrusion molding (blow molding, T-die, etc.), stretching methods, lamination methods, etc. can be cited.

[0105] The overcoat agent and the synthetic resin film may also be combined. In this case, it is preferred that the overcoat agent is applied to the outside of the synthetic resin film so that the outermost surface of the protective resin layer 11 is formed by the overcoat layer.

[0106] The total thickness of the protective resin layer 11 is not particularly limited, but is generally 1 to 25 μm in consideration of the balance between the strength and weather resistance of the cover laminate 1 and the cover 2 and the accuracy of high-frequency induction heating sealing.

[0107] The printed ink layer 12 is an arbitrary layer sandwiched between the protective resin layer 11 and the anchor coating layer 13 or barrier layer 14 described later, forming text, graphics, and symbols to give information and appearance design of the contents C of the packaging body 4 to the cover laminate material 1 and the cover 2 formed therefrom.

[0108] The printing ink layer 12 is composed of various known printing inks.

[0109] As the printing ink, a composition obtained by dispersing a coloring material in various known vehicles composed of a binder resin and a solvent by various known means can be used, and a curing agent may be used in combination.

[0110] As the binder resin, for example, there can be mentioned nitrocellulose (nitrocellulose), shellac resin, epoxy resin, polyurethane resin, chlorinated polyolefin resin, polyamide resin, acrylic resin and vinyl chloride-vinyl acetate copolymer, which are not cured by active energy rays. In addition, as the binder resin of active energy ray curing type, various known di(meth)acrylates, tri(meth)acrylates and tetra(meth)acrylates, and poly(meth)acrylates such as (meth)acrylates having 5 to 6 (meth)acryloyl groups in the molecule can be used. Among the poly(meth)acrylates, various known modified poly(meth)acrylates such as urethane (meth)acrylates, epoxy (meth)acrylates and polyester (meth)acrylates are included. In the active energy ray curing type binder resin, as a photopolymerization initiator, a benzophenone-based initiator, an acetophenone-based initiator, a benzoin-based initiator, etc. can be combined. As a solvent, for example, organic solvents such as toluene, xylene, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, methanol, ethanol and isopropanol can be used. The curing agent may include, for example, polyfunctional isocyanates, polyfunctional epoxy compounds, polyfunctional oxazoline compounds, ketimine compounds, melamine compounds, etc. When the binder resin is an active energy ray-curable resin, various known (meth)acrylates may be used as reactive diluents.

[0111] As coloring materials, pigments and / or dyes can be cited. As pigments, examples include organic or inorganic pigments such as titanium dioxide, zinc white, glossy white, pearlite, barium carbonate, calcium carbonate, precipitated silica, aluminum oxide, talc, alumina white, mica, synthetic calcium silicate, magnesium carbonate, barium carbonate, carbon black, magnetite and iron red. As dyes, examples include anthraquinone dyes, azo dyes and quinoline dyes. The content of the coloring material in the printing ink is not particularly limited, usually 0.5 to 40% by weight, but from the perspective of ensuring the strength of the printing ink layer 12, suppressing its internal shedding and internal peeling, it is preferably 2 to 15% by weight. The size of the coloring material is not particularly limited. In the case of a pigment, the average primary particle size is usually 0.1 to 5 μm, preferably 0.5 to 3 μm.

[0112] The printing ink may contain appropriate amounts of various known silane coupling agents, curing agents, antistatic agents, and the like as other additives.

[0113] The printing ink layer 12 may also be Figure 1 Although the continuous layer such as the full coating shown in (a) is omitted in the figure, it can also be a discontinuous layer such as a dot or mesh. As the printing means, a known method such as gravure printing, offset printing, flexographic printing, etc. can be adopted.

[0114] The printing ink layer 12 can be a single color printing or a multi-color printing. In addition, it can be a single layer printing or a multi-layer printing of more than two layers.

[0115] The thickness of the entire printing ink layer 12 is not particularly limited, but is usually 0.5 to 2 μm per layer.

[0116] The anchor coating layer 13 is an optional layer formed as needed on the outer surface of the barrier layer 14. By interposing this layer between the protective resin layer 11 and / or the printed ink layer 12 and the barrier layer 14, interlayer adhesion can be improved to prevent delamination.

[0117] The anchor coating 13 is formed with various known anchoring agents. As the main agent of the anchoring agent, for example, nitrocellulose, shellac resin, epoxy resin, chlorinated polyolefin resin, polyamide resin, acrylic resin, vinyl chloride-vinyl acetate copolymer, polyurea-urethane resin, polyester resin, urea-formaldehyde resin, elastomeric resin, and polyurethane resin, etc. can be cited, and the above-mentioned organic solvents and curing agents can be used in combination. As an anchoring agent based on polyurethane resin, a two-component curing type polyether-polyurethane resin adhesive and / or a two-component curing type polyester-polyurethane resin adhesive is preferred. As a curing agent for the anchoring agent, for example, polyfunctional isocyanates, polyfunctional epoxy compounds, polyfunctional oxazoline compounds, ketimine compounds, etc. can be cited.

[0118] If a substance formed by the same or the same type of resin as the resin forming the protective resin layer 11 and / or the binder resin forming the above-mentioned printing ink is selected as the anchoring agent, the adhesion with the anchoring coating 13, the protective resin layer 11 and / or the printing ink layer 12 becomes better, and delamination between these layers, falling off, shedding and scratching of the printing ink layer 12 can be prevented.

[0119] The thickness of the anchor coating layer 13 is not particularly limited, but is usually 0.5 to 5 μm.

[0120] The barrier layer 14 is a heat generating portion for heat-melting the lid 2 to the opening peripheral portion 31 of the container 3 filled with the content C, and the barrier layer 14 is composed of a metal foil. When the lid 2 is placed on the opening peripheral portion 31 and subjected to high-frequency induction heating under pressure, the metal foil generates heat. Moreover, the Joule heat is conducted from the lower surface of the barrier layer 14 to the heat-sealing layer 17, and the heat-melting resin film forming the heat-sealing layer 17 melts, so that the lower surface of the lid 2 and the upper surface of the opening 31 are heat-melted. The heat-sealed lid 2 protects the content C filled in the package body 4 from gas, water vapor, light, etc.

[0121] As metal foil, for example, aluminum foil, iron foil, stainless steel foil, copper foil and nickel foil can be cited. Among them, if barrier function, formability and cost are taken into consideration, aluminum foil is suitable. As aluminum foil, pure aluminum foil or aluminum alloy foil can be cited. If the heating efficiency during high-frequency induction heating sealing is considered, pure aluminum foil or aluminum alloy foil containing 0.5 to 2% by mass of iron is preferred. As the pure aluminum foil, pure aluminum foil with a purity of 99.0% or more by mass is particularly preferred. In addition, as the aluminum alloy foil, Al-Fe aluminum alloy foil is preferred. In particular, for a material containing 0.7 to 1.3% by mass of Fe and 0.05 to 0.3% by mass of Si and the remainder being Al and inevitable impurities, a material containing 1.2 to 1.7% by mass of Fe and less than 0.15% by mass of Si and the remainder being Al and inevitable impurities, it is more preferred from the viewpoint of the formability of the cover 2. In addition, the aluminum foil can be any one of a soft material (O material) and a hard material (H18 material). Among them, from the viewpoint of formability, preferred are 1000 series aluminum foil O material and 8000 series aluminum foil O material specified in JIS H4160. Specifically, A1N30H-O, A8021H-O, and A8079H-O are suitable.

[0122] The physical properties of the metal foil are not particularly limited, but for example, when the tensile strength at break is 20 to 200 MPa and the total elongation at break is 5 to 50%, the cover laminate 1 and the cover 2 are difficult to break, and the metal foil forming the barrier layer 14 is not broken. The tensile strength and the total elongation are both measured values ​​based on the metal material tensile test method specified in JIS Z2241.

[0123] When the volume resistivity of the metal foil at 25° C. and at 100° C. is both 1 to 5 μΩ·cm, the heat generation during high-frequency induction heating sealing becomes good, and the sealing accuracy of the package body 4 is improved.

[0124] The metal foil can be formed with an easy-adhesive layer on either or both sides thereof using various known chemical conversion treatment solutions. Examples of the chemical conversion treatment solution include water-alcohol solutions containing phosphoric acid, chromium compounds, fluorine compounds and / or binder resins. Examples include: chromic acid and / or chromium (III) salts as chromium compounds, metal salts of fluorides and / or non-metallic salts of fluorides as fluorine compounds, and at least one selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins as binder resins. The amount of chemical conversion treatment solution applied is generally 0.1 to 50 mg / m2 so that the amount of chromium attached to each side of the metal foil is 1 to 50 mg / m2. 2 The range of .

[0125] The thickness of the barrier layer 14 is not particularly limited, but is preferably 5 to 80 μm in consideration of the strength, weather resistance, and heat transfer to the heat seal layer 17 of the cover laminate 1 and the cover 2 .

[0126] The anchor coating layer 15 is a layer provided for the purpose of making the barrier layer 14 and the adhesive layer 16 adhere closely to each other and preventing delamination between the two layers. The anchor coating layer 15 is composed of an anchor agent.

[0127] As the anchoring agent, the same material as that constituting the anchor coating layer 13 can be used. In particular, a two-component curable polyether-urethane resin adhesive and / or a two-component curable polyester-urethane resin adhesive is preferred, and the curing agent can also be the above-mentioned material.

[0128] The thickness of the anchor coating layer 15 is not particularly limited, but is usually 1 to 5 μm.

[0129] The adhesive layer 16 is a layer for joining the barrier layer 14 to the heat seal layer 17 in cooperation with the anchor coating layer 15. In addition, by providing the adhesive layer 16, the tear strength of the cover laminate 1 and the cover 2 is improved, thereby ensuring, for example, resistance to straw penetration.

[0130] The adhesive layer 16 is preferably composed of various known polyolefin resins. Examples of the polyolefin resin include polypropylene such as homopolypropylene, stretched polypropylene, unstretched polypropylene, and acid-modified polypropylene, polyethylene such as low-density polyethylene and linear low-density polyethylene, and ethylene-propylene random copolymers and ethylene-propylene block copolymers.

[0131] Among polyolefin resins, polyethylene has the following advantages. First, the pressure dispersion during high-frequency induction heating sealing is good. Second, the external stress applied to the lid 2 for a long time and repeatedly during transportation of the package 4 can be further alleviated. Third, the stress applied to the barrier layer 14 when the package 4 is opened is also well alleviated. As described above, when polyethylene is used as the polyolefin resin, the internal pressure sealing resistance and internal pressure cracking resistance of the lid laminate 1 and the lid 2 become good, and cracks and ruptures of the metal foil forming the barrier layer 14 are reduced.

[0132] The thickness of the adhesive layer 16 is not particularly limited, but is preferably 10 to 50 μm. By setting the thickness to be 10 μm or more, during high-frequency induction heating and sealing, the so-called resin escape will not occur at the opening peripheral portion 31 of the container 3 as the heat-welding portion, and it becomes easy to ensure the thickness of the heat-welding portion in the height direction. As a result, when the lid 2 is peeled off from the opening peripheral portion 31 when the package body 4 is unsealed, no glue residue or film residue will be generated. On the other hand, by setting the thickness to be 50 μm or less, during high-frequency induction heating and sealing, the Joule heat generated on the metal foil forming the barrier layer 14 is efficiently conducted to the heat-sealing layer 17, so that the sealing strength and sealing accuracy become good.

[0133] The heat seal layer 17 is a layer for thermally fusing the lid 2 to the opening peripheral edge portion 31 of the container 3 .

[0134] The heat seal layer 17 is formed of various known heat-sealable heat-fusible resin films. The heat-sealable resin films are melted by the Joule heat generated by the metal foil forming the barrier layer 14 during high-frequency induction heating and sealing, thereby bonding the lower surface of the lid 2 and the upper surface of the opening peripheral portion 31 of the container 3.

[0135] Examples of the heat-fusible resin include polyolefins, polyesters, and polyethylenes. Examples of polypropylene include homopolypropylene, stretched polypropylene, unstretched polypropylene, ethylene-propylene random copolymers, ethylene-propylene block copolymers, and acid-modified polypropylenes. Examples of polyethylene include low-density polyethylene and linear low-density polyethylenes. Examples of polyester include polyethylene terephthalate and polybutylene terephthalate. Examples of polyethylene include polystyrene.

[0136] The heat-fusible resin film can be regarded as a single film as a whole, regardless of the number of layers and the type of layers. For example, it can be used as a multi-layer laminated material formed of a single heat-fusible resin. In addition, it can also be used as a multi-layer laminated material formed of two or more heat-fusible resins. The number of layers is not limited, and can be about 1 to 5.

[0137] The heat-adhesive resin film can be formed by various known methods, for example, an extrusion method, a T-die method, etc. are mentioned.

[0138] The heat seal layer 17 can be formed in the following two ways.

[0139] Method 1: Refer to Figure 1 The heat seal layer 17 is formed only by the above-mentioned heat-fusible resin film.

[0140] Method 2: Refer to Figure 1 The heat seal layer 17 is composed of a base material layer 17a formed of a synthetic resin and a heat seal layer 17b formed of a heat-fusible resin film.

[0141] Hereinafter, when simply referred to as the heat seal layer 17 , this refers to both the heat seal layer 17 of the first embodiment and the heat seal layer 17 of the second embodiment unless otherwise specified.

[0142] The thickness of the heat seal layer 17 of the first embodiment is not particularly limited. If it is 5 to 40 μm, the thermal fusion bonding between the heat seal layer 17 and the opening peripheral edge portion 31 of the container 3 becomes good, and since the so-called resin escape during heat sealing does not occur, no glue residue or film residue is generated on the opening peripheral edge portion 31 when the packaging body 4 is opened.

[0143] The base material layer 17 a of the second embodiment is a layer arbitrarily interposed between the adhesive layer 16 and the heat seal layer 17 b in order to assist the thermal fusion property between the lid 2 and the opening peripheral edge portion 31 of the container 3 .

[0144] The substrate layer 17a is made of various known synthetic resins. Examples of the synthetic resin include polyolefins and polyesters. Examples of polypropylene include homopolypropylene, stretched polypropylene, unstretched polypropylene, poly(ethylene-propylene) random copolymers, polyethylene-polypropylene block copolymers, acid-modified polypropylene, low-density polyethylene, and linear low-density polyethylene. Examples of polyester include polyethylene terephthalate and polybutylene terephthalate. Among them, polyolefins are suitable from the viewpoint of the adhesion of the substrate layer 17a and the heat-sealing layer 17b.

[0145] The base material layer 17a can be formed of a film formed of a synthetic resin and / or an extruded layer formed of a synthetic resin, and the extruded layer is suitable.

[0146] If the base material layer 17a and the adhesive layer 16 are made of the same or the same type of synthetic resin (preferably polyolefin), the two layers will be well bonded during high-frequency induction heating sealing, so that, for example, when the lid 2 is peeled off from the opening edge 31 of the container 3, no rupture will occur.

[0147] When the heat seal layer 17 is formed by the base material layer 17a and the heat seal layer 17b, it is preferable that the synthetic resin forming the base material layer 17a and the heat-fusible resin forming the heat seal layer 17b are formed by extrusion layers. As the extrusion means, various known co-extrusion devices can be used.

[0148] Preferably, the heat seal layer 17 of the first embodiment and the heat seal layer 17b of the second embodiment are both composed of the same or the same type of heat-fusible resin to form the heat-fusible resin film and the resin forming the opening peripheral portion 31 of the container 3, so that the accuracy and strength of the high-frequency induction heating seal can be improved. Therefore, for example, even if inclusions such as dust and dirt are attached to the upper surface of the opening peripheral portion 31 as the sealing surface, the heat-fusible property between the cover laminate 1 or the cover 2 and the opening peripheral portion 31 is still very good. As a specific combination, a combination of selecting a polystyrene film as such a heat-fusible resin film and selecting polystyrene as the resin forming the opening peripheral portion 31 can be cited.

[0149] The thickness of the heat seal layer 17 is not particularly limited. For example, if the accuracy and strength of high-frequency induction heating sealing, the strength of the cover laminate 1 and the cover 2 are taken into consideration, the thickness T of the base layer 17a is generally 5 to 100 μm in both the first embodiment and the second embodiment. 17a The thickness T of the heat seal layer 17b is 17b The ratio T 17a / T 17b There are no particular limitations, but it is usually about 1 / 3 to 3 / 1.

[0150] The overall physical properties of the heat seal layer 17 are not particularly limited, and examples thereof include melt flow rate (JIS K7210), tensile strength at break (JIS K7127), and tensile elongation (JIS K7127).

[0151] The melt flow rate is a major factor related to the sealing accuracy and even the sealing strength of the lid 2, or the appearance of the lid 2 when the package 4 is opened. Specifically, for example, when the melt flow rate of the heat-fusible resin film constituting the heat-sealing layer 17 is 2 to 15 g / 10 minutes, the heat-fusible property between the heat-sealing layer 17 and the peripheral edge of the opening 31 becomes good, and the so-called resin escape does not occur, so that no film residue is generated when the package 4 is opened. It should be noted that, in the case of the second embodiment, the melt flow rate of the base layer 17a only needs to be lower than the melt flow rate of the heat-sealing layer 17b.

[0152] Regarding the tensile strength, if the tensile strength in the longitudinal direction MD and the tensile strength in the transverse direction TD of the heat-sealing layer 17 as a whole are both 40 to 100 MPa, even if the cover 2 is subjected to a long-term and long-period external stress cycle, no cracks will occur on the metal foil forming the barrier layer 14 during long-distance transportation of the packaging body 4, for example, in a state of multiple packages.

[0153] Regarding the tensile elongation, if the tensile elongation in the longitudinal direction MD and the tensile elongation in the transverse direction TD of the heat seal layer 17 are both 100-200%, the strength of the cover laminate 1 and the cover 2 is improved, so-called toughness becomes stronger. Therefore, for example, when the package body 4 is opened, the cover 2 will not be cracked.

[0154] It should be noted that the tensile strength at break and the tensile elongation are physical properties before the embossed pattern 18 is formed on the innermost surface of the heat seal layer 17 .

[0155] On the innermost surface of the heat seal layer 17, as Figures 1 to 4 As shown, the entire area is formed with an embossed pattern 18.

[0156] like Figure 1 As shown in FIG. 1 , the embossed pattern 18 is formed by a plurality of independent convex portions 18a. The convex portions 18a are scattered on the bottom surface 18c as a continuous surface at predetermined intervals 18b (refer to FIG. 1 ). Figure 3 and Figure 4 ).

[0157] If the embossed pattern 18 is formed on the innermost surface of the heat seal layer 17, when the lid 2 is heat-fused to the opening peripheral edge 31 of the container 3, the gas in the container 3 can be discharged to the outside of the container 3 through the gaps 18b in the embossed pattern 18, thereby improving the internal pressure cracking resistance and internal pressure sealing resistance. In addition, the expansion of the lid 2 during heat sealing can be prevented in advance, and the lid 2 can be kept flat in the package body 4.

[0158] The shape of the protrusion 18a is not particularly limited as long as it is an independent unit protrusion, and may be cylindrical, elliptical, or prism-shaped (see Figure 4 (a)), conical, trapezoidal, staggered, dotted (refer to Figure 4 (b)), annular, dome-shaped, etc. In addition, a plurality of convex portions 18a of different shapes may be assembled to form a specific pattern (see Figure 4 (c)).

[0159] Figure 1 The cross section of the convex portion 18a in (a), (b), and (c) is rectangular, the top is flat, and the bottom surface 18c is also flat.

[0160] Figure 2The top of the convex portion 18a of (a) is formed into a curved surface, and the bottom surface 18c is also formed into a concave curved surface.

[0161] Figure 2 The top of the convex portion 18a of (b) is formed into a curved surface, and the bottom surface 18c is formed into a flat shape.

[0162] Figure 2 The top of the convex portion 18a of (c) is formed in a flat shape, and the bottom surface 18c is also formed in a flat shape.

[0163] Figure 1 and Figure 2 The above methods are suitable for deflation, but especially in Figure 1 way, Figure 2 In the case of the embodiment (c), the top of the convex portion 18a is formed flat, so the efficiency of the above-mentioned degassing is very high, and it is easy to maintain the flatness of the cover 2 in the package body 4. In addition, in the case of these embodiments, when the cover 2 is heat-fused to the opening peripheral portion 31 of the container 3, the sealing accuracy and sealing strength are improved, so the resistance to internal pressure cracking and the resistance to internal pressure sealing become good.

[0164] Figure 3 The embossed pattern 18 with Figure 2 Corresponding to the embossing pattern of (c), convex portions 18a having a substantially cylindrical shape and a flat top are regularly and periodically arranged at a certain interval 18b on a flat bottom surface 18c.

[0165] Figure 4 1 is a top view of the embossed pattern 18.

[0166] Figure 4 The convex part 18a of the embossed pattern 18 of (a) is a rhombus shape. In addition, the bottom surface 18c is groove-shaped, and constitutes a linear passage.

[0167] Figure 4 The convex parts 18a of the embossed pattern 18 of (b) are circular (dot-shaped) and the bottom surface 18c is flat.

[0168] Figure 4 The embossed pattern 18 of (c) is composed of four elongated convex portions 18a constituting one grid, and circular convex portions 18a are arranged inside a predetermined grid. In addition, the bottom surface 18c is flat.

[0169] However, the above is an example, and the shape of the embossed pattern 18 is not limited.

[0170] The regularity of the protrusions 18a is not limited and may be Figure 4 That is periodic, and although not shown in the figure, it may be irregular.

[0171] The size of the protrusion 18a is also not limited. Figure 3 In the case of a substantially cylindrical shape as shown, the diameter of one unit can be, for example, approximately 100 μm to 1000 μm.

[0172] The density of the protrusions 18a is not particularly limited, and may be, for example, 1 to 127 protrusions / cm 2 about.

[0173] The height H of the protrusion 18 is not particularly limited, as long as it is greater than the thickness T of the heat seal layer 17. 17 and is greater than the combined thickness T of the adhesive layer 16 and the heat seal layer 17. 17 +T 16 It is sufficient to make the heat sealing process more reliable. 16 and T 17 All thicknesses are before embossing.

[0174] The size of the interval 18b is not particularly limited. Figure 3 In the case of the substantially cylindrical shape shown, the diameter may be 90 μm to 900 μm.

[0175] From the viewpoint of sealing accuracy and sealing strength, it is preferred that the bottom surface 18 c be flat and have an area larger than the total area of ​​the convex portions 18 a .

[0176] As a method for forming the embossed pattern 18 on the innermost surface of the heat seal layer 17, various known means can be used. Specifically, by pressing a pressure roller formed with a prescribed embossed pattern on the surface of the heat-fusible resin film constituting the heat seal layer 17, the embossed pattern 18 can be formed on the innermost surface of the heat seal layer 17. The pressure roller can be used in a cooled state or under heating. The cooling roller used when the heat-fusible resin film constituting the heat seal layer 17 is made by a co-extrusion method can also be used instead of the pressure roller. In this case, a prescribed embossed pattern is formed on the surface of the cooling roller. When a cooling roller is used, it is advantageous because the embossing process can be performed on a production line.

[0177] <How to use lubricant S>

[0178] However, when the package 4 is conveyed, transported, displayed, etc., external forces may be applied to the outermost surface of the cover 2 due to impact with other objects or strong friction. In addition, when the package 4 itself falls or the packages 4 collide with each other, such external forces may be applied to the outermost surface of the cover 2. At this time, the protective resin layer 11 may peel off or fall off, and further, cracks or fissures may occur in the metal foil forming the barrier layer 14 on the inner side of the protective resin layer 11.

[0179] In addition, when the cover packaging material 1 includes the printed ink layer 12, if such an external force is applied to the outermost surface of the protective resin layer 11, the printed ink layer 12 may be rubbed, shifted, or seeped out. In particular, when the protective resin layer 11 is formed of an overprint coating agent, the protective resin layer 11 may fall off together with the printed ink layer 12 due to such an external force.

[0180] Especially when the cover 2 is Figure 5 In the case of the cap-shaped cover shown, the above-mentioned technical problem caused by the external force applied to the outermost surface of the protective resin layer 11 is likely to occur at the periphery of the main body 2a, the edge of the skirt 2b, and the like.

[0181] The present invention proposes a solution to such a problem. Specifically, by making the lubricant S present on the outermost surface of the cover laminate material 1 in various ways, the outermost surface is given external lubricity and its dynamic friction coefficient is reduced. In addition, the external force applied to the outermost surface can be released in the horizontal direction. As a result, the peeling and falling off of the protective resin layer 11, the rubbing, peeling, falling off and falling off of the printed layer 12, and the cracking of the metal foil forming the barrier layer 14 can be prevented.

[0182] As the lubricant S, various known waxes and / or surfactants can be used without particular limitation.

[0183] Examples of the wax include natural wax and / or synthetic wax. Examples of the natural wax include animal and plant waxes such as candelilla wax, carnauba wax, rice wax, wood wax, beeswax, spermaceti wax, shellac wax, and lanolin wax, and examples of mineral waxes such as montan wax, ozokerite, and ceresin, and examples of petroleum waxes such as paraffin wax, microcrystalline wax, and petrolatum. On the other hand, as synthetic wax, hydrocarbon synthetic wax, for example, polyethylene wax, polypropylene wax and Fischer-Tropsch wax, hydrogenated wax, for example, hydrogenated castor oil and hydrogenated castor oil derivatives, etc., and modified wax, for example, wax obtained by grafting styrene on polyethylene-polypropylene copolymer, silicone wax (silicone wax), fluorine wax and amide wax (oleic acid amide, ricinoleic acid amide, erucic acid amide, N,N'-methylenebisstearic acid amide, N,N'-ethylenebisoleic acid amide, stearic acid monomethylamide, ricinoleic acid amide wax and stearate wax, etc.), and their complexes, etc. Among these waxes, hydrocarbon synthetic wax and modified wax (especially silicone wax and amide wax) are not only stable as materials, but also preferred in that the external lubricity of the outermost surface of the protective resin layer 11 becomes better. The shape of the wax is not particularly limited, and it can be a paste, a flake or a particle.

[0184] As surfactants, for example, at least one selected from the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants can be cited. As anionic surfactants, for example, sodium ricinoleate sulfate, sodium ricinoleate sulfate, sulfated amides, olefin sulfates, aliphatic alcohol sulfates, alkyl sulfonates, alkyl naphthalene sulfonates, alkyl benzene sulfonates, succinate sulfonates, etc. can be cited. As cationic surfactants, for example, primary amine salts, tertiary amine salts, quaternary ammonium compounds, pyridine derivatives, etc. can be cited. As amphoteric surfactants, for example, carboxylic acid derivatives, imidazoline derivatives, etc. can be cited. As nonionic surfactants, for example, partial fatty acid esters of polyols, ethylene oxide adducts of fatty alcohols, ethylene oxide adducts of fatty acids, ethylene oxide adducts of aliphatic amino or aliphatic amides, ethylene oxide adducts of alkylphenols, ethylene oxide adducts of partial fatty acid esters of polyols, etc. can be cited.

[0185] The wax and the surfactant may be used alone or in combination of two or more. In addition, the wax and the surfactant may be used in combination.

[0186] The lubricant S can be classified into lubricant S1, lubricant S2, and lubricant S3 according to its existence form or utilization form.

[0187] Lubricant S1: a lubricant that physically adheres to the outermost surface of the protective resin layer 11 from the outside.

[0188] Lubricant S2: This is a lubricant previously contained in the protective resin layer 11. It has the property of seeping out on the outermost surface of the layer 11 to form a precipitated phase.

[0189] Lubricant S3: is a lubricant previously contained in the heat seal layer 17. It has the property of seeping out on the innermost surface of the layer 17 to form a precipitated phase.

[0190] It should be noted that, in the present specification, when referred to simply as lubricant S, it refers to at least one lubricant selected from the group consisting of lubricant S1, lubricant S2, and lubricant S3.

[0191] The following is an example of how the lubricant S is used.

[0192] First lubricant method: The lubricant S1 is attached to the outermost surface of the protective resin layer 11 , the protective resin layer 11 does not contain the lubricant S2 , and the heat seal layer 17 does not contain the lubricant S3 .

[0193] Second lubricant mode: The protective resin layer 11 contains the lubricant S2, and the heat seal layer does not contain the lubricant S3.

[0194] · Third lubricant mode: The protective resin layer 11 contains the lubricant S2, and the heat seal layer 17 contains the lubricant S3.

[0195] Fourth lubricant embodiment: The protective resin layer 11 does not contain the lubricant S1, and the heat seal layer 17 contains the lubricant S3.

[0196] The first lubricant method can be achieved by applying lubricant S1 on the outermost surface of the protective resin layer 11 or by evaporating the lubricant. In the case of coating, for example, a composition in which lubricant S1 is dissolved or dispersed in a suitable organic solvent is applied on the outermost surface of the protective resin layer 11 by various known means, and the organic solvent is volatilized. As the coating means, for example, a sprayer, a gravure roller, a reverse roller, etc. can be cited. The content of lubricant S1 in such a composition is not particularly limited, and is usually 500ppm to 10000ppm based on weight. In the case of evaporation, for example, the lubricant S1 is heated in a vacuum chamber to vaporize it, and then evaporated on the outermost surface of the protective resin layer 11.

[0197] The second lubricant method is to include lubricant S2 in the protective resin layer 11 in advance, so that it seeps out to the outermost surface of the protective resin layer 11 over time to form a precipitated phase, and utilize the external lubricity exerted by the precipitated phase. There is no limitation on the means for including lubricant S2 in the outer coating agent or synthetic resin film constituting the protective resin layer 11, and various known methods can be used. The aging conditions for achieving the seepage are also not particularly limited, and the temperature is usually about room temperature to about 70°C, and the period is about 1 to 15 days.

[0198] When the protective resin layer 11 is formed of the above-mentioned overprint coating agent, it is preferable to select nitrocellulose as the binder resin and fatty acid amide wax as the lubricant S2 because it is easy to prevent the printed ink layer 12 from falling off, shifting, etc.

[0199] When the protective resin layer 11 is formed of the synthetic resin film, it is preferable to select polyolefin as the synthetic resin film and fatty acid amide wax and / or polyolefin as the lubricant S2 because it is easy to prevent the printed ink layer 12 from falling off or shifting.

[0200] The content of the lubricant S2 contained in the protective resin layer 11 is not particularly limited. For example, the amount of the lubricant S2 is preferably 40 to 2000 ppm based on the weight of the synthetic resin constituting the protective resin layer 11 containing the lubricant S2.

[0201] Similar to the second lubricant method, the third lubricant method is a method in which a lubricant S2 is pre-included in the protective resin layer 11, and is made to ooze out to the outermost surface of the protective resin layer 11 over time to form a precipitated phase, and the external lubricity exerted by the precipitated phase is utilized. At the same time, in this method, a lubricant S3 is also pre-included in the heat seal layer 17. The lubricant S3 oozes out to the innermost surface of the heat seal layer 17 to form a precipitated phase, and a part of the precipitated phase is attached to the outermost surface of the protective resin layer 11 through the transfer process described below.

[0202] The transfer process is carried out as follows, for example. Specifically, the cover laminate material 11 of this mode is wound into a roll to form a coil. Then, the coil is placed at a specified temperature for a specified time and ripened. In the coil, the radial stress generated by winding is gradually applied to a plurality of cover laminate materials 11 stacked on each other. Moreover, the stress becomes an internal pressure, so that the heat seal layer 17 of a cover laminate material 11 is firmly fitted with the protective resin layer 11 of another cover laminate material 11 adjacent to the lower surface side of the heat seal layer 17. Therefore, the lubricant S3 oozes out over time on the innermost surface of a certain heat seal layer 17 to form a precipitated phase, and under the above-mentioned internal pressure, the precipitated phase is transferred to the outermost surface of the protective resin layer 11 that is closely fitted with the heat seal layer 17.

[0203] There is no particular limitation on the method of making the heat-fusible resin film constituting the heat seal layer 17 contain the lubricant S3, and various known methods can be used. The aging conditions for achieving the seepage of the lubricant S3 are also not particularly limited, and generally the temperature is about room temperature to about 70°C, and the period is about 1 to 15 days.

[0204] The content of the lubricant S2 contained in the protective resin layer 11 is not particularly limited, but may be generally 40 ppm to 2000 ppm.

[0205] The content of the lubricant S3 contained in the heat seal layer 17 is not particularly limited, and may be generally 100 ppm to 8000 ppm.

[0206] The fourth lubricant mode is a mode in which the protective resin layer 11 does not contain the lubricant S1, and the heat seal layer 17 contains the lubricant S3. The lubricant S3 seeps out over time on the innermost surface of the layer 17 to form a precipitate phase, and a part of the precipitate phase adheres to the outermost surface of the protective resin layer 11 through the above-mentioned transfer process. Moreover, the outermost surface exerts external lubricity through the lubricant S3. The content of the lubricant S3 contained in the heat seal layer 17 is also not particularly limited, and is generally 100ppm to 8000ppm.

[0207] It should be noted that as a fifth lubricant method, there can be cited a method of attaching a lubricant S1 to the outermost surface of each protective resin layer 11 of the second lubricant method, the third lubricant method and the fourth lubricant method by using the above-mentioned coating method or vapor deposition method, which is also within the scope of the present invention.

[0208] In addition, in the third and fourth embodiments, when the heat seal layer 17 contains lubricant S3, the melt flow rate of the entire layer 17 is not particularly limited, and is generally 2 to 15 g / 10 minutes. In addition, for the tensile strength at break of the entire layer 17, the tensile strength at break in the longitudinal direction MD and the tensile strength at break in the transverse direction TD are generally 40 to 100 MPa. In addition, for the tensile elongation of the entire layer 17, the tensile strength at break in the longitudinal direction MD and the tensile elongation at break in the transverse direction TD are generally 100 to 200%. It should be noted that the tensile strength at break and the tensile elongation are physical properties before the embossed pattern is formed on the innermost surface of the heat seal layer 17 containing lubricant S3.

[0209] In each embodiment, the amount of the lubricant S present on the outermost surface of the protective resin layer 11 is not particularly limited, but is generally 0.05 to 1.0 μg / cm 2 The measuring method is not particularly limited, and for example, gas chromatography can be used.

[0210] In the case where the lubricant S is present on the outermost surface of the protective resin layer 11, the degree of external lubricity of the outermost surface can be evaluated by the dynamic friction coefficient (JIS K7125). This value is not particularly limited, but if it is greater than 0.05 and less than 0.3, the printed layer can be properly prevented from falling off, falling off, etc. In addition, when the package body 4 is unsealed, the unsealing operation becomes easier because the fingers grasping the cover 2 do not slip. From this point of view, the dynamic friction coefficient is preferably about 0.03 to 0.25. On the other hand, in the case where the lubricant S is not present on the outermost surface of the protective resin layer 11, the dynamic friction coefficient (JIS K7125) of the outermost surface is generally greater than 0.3 and less than 0.5.

[0211] <Manufacturing Method and Physical Properties of Laminated Material 1 for Lid>

[0212] The cover laminate material 1 can be produced by various known methods such as dry lamination, melt extrusion lamination, and heat lamination, and these methods may be combined.

[0213] The physical properties of the cover laminate 1 are not particularly limited. For example, when the tear strength measured by the Elmendorf method specified in JIS K7128-2 is 200 to 1200 mmN, the cover 2 is less likely to break when the package 3 is opened, and the cover 2 has good resistance to straw puncture.

[0214] <Cover 2>

[0215] The cover 2 is formed by processing the cover laminate 1 into a predetermined shape. The shape is not particularly limited and can be appropriately determined according to the shape of the container 3 and the way the package 4 is opened.

[0216] Figure 5 This is a perspective view of a cap-shaped cover 2. The cover 2 is composed of a substantially horizontal main body 2a and a skirt 2b extending downward from the peripheral edge of the main body 2a.

[0217] Figure 6 is a cross-sectional view of the packaging body 3. For example, Figure 6 As shown in (a), when the container 3 is bottle-shaped and the opening peripheral edge 31 is rim-shaped, the cover 2 may be cap-shaped. It should be noted that, although the illustration is omitted, it is self-evident that even if the container 3 is bottle-shaped, the opening peripheral edge 31 may be formed into a flange shape. In addition, for example, Figure 6 As shown in (b), when the container 3 is cup-shaped and the opening peripheral edge 31 is a substantially horizontal flange, the lid 2 may be a single piece and may be provided with a pull tab, a notch, or the like for opening the lid as required.

[0218] The sealing properties of the cover 2 are also not particularly limited.

[0219] For example:

[0220] (i) The heat seal layer 17 of the cover laminate 1 is heat-fused to a sheet having a thickness of 0.3 mm formed of the same heat-fusible resin film as that forming the heat seal layer 17 under the conditions of 160° C., 0.2 MPa and 1 second, and then,

[0221] (ii) when the strength when the cover laminate 1 is peeled from the sheet at a tensile speed of 300 mm / min in a T-peel test according to JIS K6854-3 is 5 to 15 N / 15 mm,

[0222] (iii) The seal retreat and peeling of the seal portion due to the increase in internal pressure during transportation of the package body 4 described above do not occur, leakage of the content C can be reliably prevented, and easy opening of the package body 4 can be ensured.

[0223] <Container 3>

[0224] The raw material of the container 3 is not limited, and is selected according to the heat-fusible property of the opening peripheral portion 31 and the lid 2, and the properties of the content C. As raw materials, for example, in addition to the thermoplastic synthetic resins such as the above-mentioned polyolefin, polyester and polyethylene resin, glass, iron, copper, aluminum, etc. can be cited. If the opening peripheral portion 31 of the container 3 is made of the same or the same type of heat-fusible resin film as the bottom heat-fusible resin film forming the heat-sealing layer 17, since the sealing accuracy and strength of the package 4 become good, it becomes easy to prevent the aforementioned seal from retreating, the peeling of the sealing portion, and the leakage of the content. As a specific combination, a combination of selecting polystyrene as the resin forming the opening peripheral portion 31 and selecting a polystyrene film as the heat-fusible resin film forming the heat-sealing layer 17 can be cited.

[0225] The shape of the container 3 is not particularly limited, and a cup shape, a bottle shape, a cylindrical shape, etc. can be cited. In addition, when the container 3 is a bottle shape, as Figure 6 As shown in (a), if the neck portion is formed into a tapered shape, a stable seal can be achieved. The method for manufacturing the container 3 is not particularly limited, and examples thereof include drawing, blow molding, vacuum molding, and compressed air molding.

[0226] <Content C>

[0227] Examples of the content C include products to be orally ingested, such as dairy products, milk drinks, lactic acid bacteria drinks, soft drinks, solid or liquid foods such as ham, cheese, curry, and sauce, and liquid or solid medicines.

[0228] <Packaging 4>

[0229] The package 4 is a package body in which the lid 2 is covered from the heat seal layer 17 side on the opening peripheral portion 31 of the container 3 filled with the content C, and is sealed by heat-fusion using a high-frequency induction heating sealing device. The sealing conditions are not particularly limited and are appropriately determined according to the types of materials of the lid 2 and the container 3, the specifications of the sealing device, etc.

[0230] The unsealing strength of the package 4 is not particularly limited, but in consideration of the balance between sealing and easy unsealing, the strength of the cover 2 heat-sealed to the opening peripheral portion 31 is preferably 5 to 15 N / 15 mm when peeled from the opening peripheral portion 31 of the container 3 at a tensile speed of 300 mm / min in a T-peel test according to JIS K6854-3. In this case, it is less likely to cause seal retreat and peeling of the seal portion due to the increase in internal pressure during transportation of the package 4, and leakage of the content C can be reliably prevented, while ensuring easy unsealing of the package 4. It should be noted that the unsealing strength is based on the premise that the raw materials of the heat-sealing layer 17 of the cover 2 and the opening peripheral portion 31 of the container 3 are the same or the same type of synthetic resin.

[0231] Figure 7 The schematic diagram of the evaluation device 5 for the resistance of the packaging body 4 to internal pressure cracking is shown. The device 5 comprises a receiving portion 51 with a concave cross-section for placing the packaging body 4, a side wall portion 52 which rises from the peripheral edge of the lower wall of the receiving portion 51, and a pair of abutment members 53 which are arranged at the middle of the height of the left and right side wall portions 52. In addition, the receiving portion 51 of the device 5 is connected to a driving motor not shown in the figure. When the motor is started, the receiving portion 51 vibrates a predetermined number of times (for example, 120 times / minute) within one minute and little by little in the left and right directions shown in the figure, and in conjunction with this, the packaging body 4 also oscillates left and right. Moreover, during each oscillation, the pair of abutment members 53 continuously collide with the main body of the packaging body 4, and the side wall portions of the packaging body 4 are alternately pressed in, thereby the internal pressure of the packaging body 4 repeatedly increases and decreases. Moreover, each time the internal pressure increases or decreases, the cover 2 moves outward, that is, toward the opening while being heat-fused to the peripheral edge portion 31 of the opening. Figure 7 The deformation is restored in the direction of the upward arrow D1, or inward, that is, toward Figure 7 The cover 2 is deformed in the direction of the downward arrow D2 and then restored. If such expansion and restoration are repeated, cycle fatigue will continue to accumulate on the metal foil forming the barrier layer 14 of the cover 2. When the metal foil cannot withstand the cycle fatigue, cracks will occur in the metal foil, which may cause leakage of the content C. However, the package body 4 of the present invention, as described above, has the heat-sealing layer 17 of the cover 2 formed of a heat-fusible resin film, and a predetermined embossed pattern is formed on the innermost surface of the heat-sealing layer 17, so that cracks in the metal foil caused by such cycle fatigue will not occur.

[0232] [Example]

[0233] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the technical scope of the present invention is not limited to these specific examples.

[0234] 1. Production of laminated materials for lids

[0235] <How to use without lubricant>

[0236] Example 1

[0237] An ethyl acetate solution of nitrocellulose (10 wt% nonvolatile matter, no lubricant) was applied to one surface of a 25 μm thick aluminum foil as A8079-O material specified in JIS H4160 and dried to form a protective resin layer of about 3 μm thickness, thereby producing an intermediate member A1.

[0238] Next, a commercially available two-component curable polyester-polyurethane adhesive was applied to the other surface of the aluminum foil forming the intermediate member A1 and cured under heating to form an anchor coating layer having a thickness of about 1 μm.

[0239] On the other hand, a composite film A1 for heat seal layer was prepared by coextrusion method. The composite film A1 was composed of a substrate layer with a thickness of 7 μm formed of low-density polyethylene resin (LDPE, without lubricant) and a heat seal layer with a thickness of 30 μm formed of polystyrene resin (without lubricant).

[0240] The physical properties of the composite film A1 are shown below.

[0241] Tensile strength at break: 85MPa in MD direction, 75MPa in TD direction

[0242] Tensile elongation: 115% in MD direction, 120% in TD direction

[0243] Melt flow rate of polystyrene resin forming heat seal layer: 8g / 10min

[0244] Next, a cooling roll having a dot-shaped embossed pattern was pressed against the innermost surface of the polystyrene resin layer forming the heat seal layer of the composite film A1, thereby forming a Figure 4 The dot-shaped embossed pattern shown in (b) of FIG. The convex portion of the embossed pattern has a diameter of 750 μm, a height of 50 μm, and a density of 2.2 pcs / cm 2 , the interval is 500μm, and the bottom surface is flat.

[0245] Finally, the anchor coating layer side surface of the intermediate member A1 and the substrate layer side surface of the composite film A1 were bonded together via an extrusion adhesive layer (30 μm thick) made of molten low-density polyethylene (LDPE) to prepare a cover laminate A1.

[0246] Embodiments 2 to 6

[0247] Except having used the materials shown in Table 1, it carried out similarly to Example 1, and produced the laminated materials A2 to A6 for lids.

[0248] <How to use lubricant>

[0249] (First lubricant method)

[0250] Example 7

[0251] A commercially available vinyl chloride-vinyl acetate copolymer anchoring agent (containing no pigment) was applied to one side of an aluminum foil having a thickness of 25 μm as an A8079-O material specified in JIS H4160, and cured under heating to form an anchor coating layer having a thickness of about 2 μm. Next, a white ink prepared by dispersing 10 wt% of titanium dioxide in the same anchoring agent was applied to the surface of the anchor coating layer using a bar coater to a thickness of about 1.5 μm to form a printed layer.

[0252] Next, an ethyl acetate solution of nitrocellulose (non-volatile content: 10% by weight, no lubricant) was applied to the surface of the printed layer and dried to form a protective resin layer with a thickness of 3 μm, thereby producing an intermediate member A7.

[0253] Next, a commercially available two-component curable polyester-polyurethane adhesive was applied to the other surface of the aluminum foil forming the intermediate member A7 and cured under heating to form an anchor coating layer having a thickness of 2 μm.

[0254] On the other hand, composite film A1 prepared in Example 1 was prepared as composite film A7 for heat seal layer. The same dot embossing pattern as in Example 1 was formed on the innermost surface of the polystyrene resin layer forming the heat seal layer of composite film A7.

[0255] Next, the anchor coating layer side surface of the intermediate member A7 and the substrate layer side surface of the composite film A7 were bonded together via an extrusion adhesive layer (30 μm thick) formed of molten low-density polyethylene (LDPE), thereby producing a cover laminate A7.

[0256] Next, a methyl ethyl ketone solution containing 1000 ppm by weight of polyethylene wax as a lubricant was sprayed on the outermost surface of the protective resin layer of the cover laminate material A7, and then gently wiped with a felt cloth. The lubricant was adhered to the outermost surface of the protective resin layer by drying at 120°C for 1 minute.

[0257] (Second lubricant method)

[0258] Example 8

[0259] A commercially available vinyl chloride-vinyl acetate copolymer-based anchoring agent (containing no pigment) was applied to one side of an aluminum foil having a thickness of 25 μm as an A8079-O material specified in JIS H4160, and cured under heating to form an anchor coating layer having a thickness of about 2 μm. Next, a printing ink prepared by dispersing 10 wt % of titanium dioxide in the same anchoring agent was applied to the surface of the anchor coating layer using a bar coater to a thickness of about 1.5 μm, thereby forming a printed layer.

[0260] Next, an overprint coating agent composed of an ethyl acetate solution of nitrocellulose (10% by weight of nonvolatile components) and a solution containing 1000 ppm of erucamide as a lubricant was applied to the surface of the printed layer, cured under heating, and then aged at 40° C. for 10 days to form a protective resin layer with a thickness of 3 μm, thereby producing an intermediate member A8. On the outermost surface of the protective resin layer, erucamide as a lubricant seeped out through the above-mentioned aging to form a precipitated phase.

[0261] Next, a commercially available two-component curable polyester-polyurethane adhesive was applied to the other surface of the aluminum foil forming the intermediate member A8 and cured under heating to form an anchor coating layer having a thickness of 2 μm.

[0262] On the other hand, the composite film A1 prepared in Example 1 was prepared as a composite film A8 for use in a heat seal layer. The same dot-shaped embossed pattern as in Example 1 was formed on the innermost surface of the heat seal layer of the composite film A8.

[0263] Finally, the anchor coating side surface of the intermediate member A8 and the substrate layer side surface of the composite film A8 were bonded together via an extrusion bonding layer (30 μm thick) formed of molten low-density polyethylene (LDPE), thereby producing a cover laminate A8.

[0264] (Third lubricant method)

[0265] Example 9

[0266] A commercially available vinyl chloride-vinyl acetate copolymer anchoring agent (containing no pigment) was applied to one side of an aluminum foil having a thickness of 25 μm as an A8079-O material specified in JIS H4160, and cured under heating to form an anchor coating layer having a thickness of about 2 μm. Next, a printing ink prepared by dispersing 10 wt% of titanium dioxide in the same anchoring agent was applied to the surface of the anchor coating layer using a bar coater to a thickness of about 1.5 μm, thereby forming a printed layer.

[0267] Next, an overprint coating agent composed of an ethyl acetate solution of nitrocellulose (10% by weight of nonvolatile components) and a solution containing 1000 ppm of erucamide as a lubricant was applied to the surface of the printed layer, cured under heating, and then aged at 40° C. for 10 days to form a protective resin layer with a thickness of 3 μm, thereby producing an intermediate member A9. On the outermost surface of the protective resin layer, erucamide as a lubricant seeped out through the above-mentioned aging to form a precipitated phase.

[0268] Next, a commercially available two-component curable polyester-polyurethane adhesive was applied to the other surface of the aluminum foil forming the intermediate member A9 and cured under heating to form an anchor coating layer having a thickness of 2 μm.

[0269] On the other hand, a composite film A9 for a heat-sealing layer is produced by a co-extrusion method. The film is composed of two layers: a substrate layer with a thickness of 7 μm formed by a molten low-density polyethylene resin (LDPE, without a lubricant) and a heat-sealing layer with a thickness of 30 μm formed by a molten polystyrene resin (containing 1500 ppm erucamide as a lubricant).

[0270] The physical properties of the composite film A9 are shown below.

[0271] Tensile strength at break: 90MPa in MD direction, 70MPa in TD direction

[0272] Tensile elongation: 130% in MD direction, 150% in TD direction

[0273] Melt flow rate of polystyrene resin forming heat seal layer: 6g / 10min

[0274] Next, the same dot-shaped embossing pattern as in Example 1 was formed on the innermost surface of the heat seal layer of the composite film A9.

[0275] Next, the anchor coating layer side surface of the intermediate member A9 and the substrate layer side surface of the composite film A9 were bonded together via an extrusion adhesive layer (30 μm thick) formed of molten low-density polyethylene (LDPE), thereby producing a cover laminate material 9.

[0276] Finally, the cover laminate A9 was wound with the heat seal layer on the inside to prepare a coil, and the coil was aged at 40°C for 10 days, thereby allowing erucic acid amide as a lubricant to seep out to the innermost surface of the heat seal layer and simultaneously be transferred to the outermost surface of the protective resin layer.

[0277] (4th lubricant method)

[0278] Example 10

[0279] A commercially available vinyl chloride-vinyl acetate copolymer anchor agent (containing no pigment) was applied to one surface of a 25 μm thick aluminum foil as an A8079-O material specified in JIS H4160 and cured under heating to form an anchor coating layer having a thickness of about 2 μm.

[0280] Next, a printing ink prepared by dispersing 10 wt % of titanium dioxide in the same anchor agent was applied to the surface of the anchor coating layer using a bar coater to a thickness of about 1.5 μm, thereby forming a printed layer.

[0281] Next, an ethyl acetate solution of nitrocellulose (10% by weight of nonvolatile matter, no lubricant) was applied to the surface of the printed layer and dried to form a protective resin layer with a thickness of 3 μm, thereby producing an intermediate member A10.

[0282] Next, a commercially available two-component curable polyester-polyurethane adhesive was applied to the other surface of the aluminum foil forming the intermediate member A10 and cured under heating to form an anchor coating layer having a thickness of 2 μm.

[0283] On the other hand, composite film A9 prepared in Example 9 was prepared as composite film A10 for use in the heat seal layer. The same dot-shaped embossed pattern as in Example 1 was formed on the innermost surface of the heat seal layer of composite film A10.

[0284] Next, the surface of the intermediate member A10 on the side of the anchoring coating and the surface of the composite film A10 on the side of the base material layer are bonded together by means of an extrusion adhesive layer (with a thickness of 30 μm) formed of molten low-density polyethylene (LDPE), thereby producing the laminate material A10 for the lid.

[0285] Finally, the laminate material A10 for the lid is wound in such a way that the heat-sealing layer becomes the inner side to produce a roll, and the roll is cured at 40 °C for 10 days, whereby erucamide as a lubricant oozes out to the innermost surface of the heat-sealing layer and, at the same time, is transferred to the outermost surface of the protective resin layer.

[0286] <Coefficient of kinetic friction of the outermost surface of the protective resin layer>

[0287] The coefficient of kinetic friction of the outermost surface of the protective resin layer forming the laminate material A1 for the lid was measured in accordance with JIS K7125 (the same applies hereinafter), and the result was 0.31. In the same manner, the coefficients of kinetic friction of the outermost surfaces of the protective resin layers of the laminate materials A2 to A10 for the lid were also measured. The results are shown in Tables 1 and 2.

[0288] <T-peel strength>

[0289] A short test piece with a length of 10 cm and a width of 15 mm was cut from the laminate material A1 for the lid, and this test piece was attached to a polystyrene resin test piece (15 mm × 10 cm) with a thickness of 0.3 mm from the side of its polystyrene resin layer (heat-sealing layer). A sealing machine heated to 160 °C was pressed against the upper surface of the nitrocellulose layer (protective resin layer) of the laminate at a pressure of 0.2 MPa for 1 second. Next, a T-peel strength test (JIS K6854-3) for peeling the two test pieces was carried out under the condition that the tensile speed was 300 mm / minute, and the peel strength was 11 N / 15 mm. In the same manner, the T-peel strengths of the laminate materials A2 to A10 for the lid were also measured. The results are shown in Tables 1 and 2.

[0290] <Tear strength>

[0291] The tear strength of the laminate material A1 for the lid was evaluated based on the Elmendorf method specified in JIS K7128-2, and the result was 500 mmN. In the same manner, the tear strengths of the laminate materials A2 to A10 for the lid were also measured. The results are shown in Tables 1 and 2. In addition, if it is 200 mmN or more and 1000 mmN or less, it is regarded as qualified.

[0292] <Sealing strength>

[0293] A short test piece of 10 cm in length was cut from the cover laminate material A1 with a width of 15 mm, and the test piece was attached to a polystyrene resin test piece (15 mm × 10 cm) with a thickness of 0.3 mm from one side of the polystyrene resin layer (thermal fusion layer). The sealer heated to 160°C was pressed from the upper surface of the nitrocellulose layer (protective resin layer) of the laminate at a pressure of 0.2 MPa for 1 second. Then, a T-peel strength test (JIS K6854-3) was performed to peel the two test pieces at a tensile speed of 300 mm / min. The peel strength was 11 N / 15 mm. The tear strength was also measured for the cover laminate materials A2 to A10 using the same method.

[0294] [Table 1]

[0295]

[0296] [Table 2]

[0297]

[0298] 2. Making the cover

[0299] A 50 mm square piece was cut from the cover laminate material A1 and drawn to produce a cap-shaped cover A1 (main body diameter 40 mm) with a circular main body (40 mm diameter) and a skirt. Covers A2 to A10 of the same size were produced in the same manner for the cover laminate materials A2 to A10.

[0300] 3. Packaging production and bursting strength test

[0301] The cap A1 was covered on the opening periphery (width 2 mm) of a cylindrical polystyrene container (opening outer diameter 40 mm, opening inner diameter 36 mm, height 80 mm) having an opening, and high-frequency sealing was performed under specified sealing conditions (output power 850, pressure 0.05 MPa, 1.4 seconds) using a commercially available high-frequency induction heating sealing device (model BMD-1S, manufactured by BME Co., Ltd.), thereby producing a package A1 without content. Packages A2 to A10 without content were produced in the same manner for caps A2 to A10.

[0302] Next, the bursting strength of the package A1 was measured according to the description of clause 8. of JIS Z2038:1998. Specifically, SEAL TESTER FKT-100 manufactured by Sun Scientific Co., Ltd. was used to insert an air needle near the center of the main body of the cover A1 forming the package A1, and the insertion port was sealed with a rubber sheet. On this basis, air flowed in from the compressor at a pressure increase rate of 13.3 kPa / 10 seconds to increase the internal pressure. Since it did not break even when the internal pressure was above 20 kPa, it was evaluated as ○. The bursting strength was also evaluated for the packages A2 to A10. The results are shown in Table 3. It should be noted that the values ​​in Table 3 are actual bursting strengths (kPa).

[0303] 4. Packaging production and internal pressure cracking resistance test

[0304] 60cc of water was added to the same cylindrical container as used in the above test 3., and the lid A1 was placed on the peripheral edge of the opening. Then, the above sealing device was used to perform high-frequency sealing under the prescribed sealing conditions (output power of 850, pressure of 0.2MPa, 1.0 second), thereby producing a package A1 containing the contents. Similarly, the lids A2 to A10 were used to produce packages A2 to A10 containing the contents.

[0305] Next, the package A1 is placed in Figure 7 In the internal pressure cracking resistance evaluation device shown in FIG. 1 , the container was vibrated 120 times per minute, and the container repeatedly collided with the abutment member provided on the inner surface of the side wall of the container. As a result, even if the package A1 was vibrated 10,000 times, no cracks were generated on the aluminum foil of the cover A1. The internal pressure resistance evaluation was also performed on the packages A2 to A10 containing the contents. The results are shown in Table 3.

[0306] [Table 3]

[0307]

[0308] Industrial Applicability

[0309] The cover laminate of the present invention is useful as a cover for sealing a container filled with, for example, liquid or solid food or a product to be orally ingested, such as a medicine, by high-frequency induction heating. In particular, it is useful as a cover for heat-sealing a container filled with a fermented beverage such as a lactic acid bacteria beverage.

Claims

1. A laminated material for a lid, which is a laminated material for a lid that is thermally fused to the peripheral edge of the opening of a container filled with a content so as to cover the opening of the container, characterized in that: The cover laminate material has, in order from the outside: Protective resin layer, Printing layer, A barrier layer formed of a metal foil, and The heat seal layer is formed of a thermoplastic resin. and, A lubricant is present on the outermost surface of the protective resin layer.

2. The laminate material for a cover according to claim 1, wherein: A lubricant is attached to the outermost surface of the protective resin layer. Furthermore, the protective resin layer and the heat-sealing layer do not contain a lubricant.

3. The laminate material for a cover according to claim 1, wherein: The protective resin layer contains a lubricant having a property of seeping out on the outermost surface of the protective resin layer to form a precipitated phase, Furthermore, the heat sealing layer does not contain a lubricant.

4. The laminate material for a cover according to claim 3, wherein: The amount of the lubricant contained in the protective resin layer is 40 ppm to 2000 ppm.

5. The laminate material for a cover according to claim 1, wherein: The protective resin layer contains a lubricant having a property of seeping out on the outermost surface of the protective resin layer to form a precipitated phase, Furthermore, the heat seal layer contains a lubricant having a property of seeping out on the innermost surface of the heat seal layer to form a precipitated phase.

6. The laminate material for a cover according to claim 5, wherein: The amount of the lubricant contained in the protective resin layer is 40 ppm to 2000 ppm.

7. The laminate material for a cover according to claim 5, wherein: The amount of the lubricant contained in the heat seal layer is 100 ppm to 8000 ppm.

8. The laminate material for a cover according to claim 1, wherein: The protective resin layer does not contain lubricant. Furthermore, the heat seal layer contains a lubricant having a property of seeping out on the innermost surface of the heat seal layer to form a precipitated phase.

9. The laminate material for a cover according to claim 8, wherein: The amount of the lubricant contained in the heat seal layer is 100 ppm to 8000 ppm.

10. The laminated material for a cover according to claim 1, wherein: The coefficient of dynamic friction of the outermost surface of the protective resin layer where the lubricant is present is 0.05 or more and less than 0.

3.

11. The laminate material for a cover according to claim 1, wherein: The amount of lubricant present on the outermost surface of the protective resin layer is 0.05 μg / cm 2 ~1.0 μg / cm 2 .

12. The laminated material for a cover according to claim 1, wherein: The heat seal layer is formed by a heat-fusible resin film and, An embossed pattern consisting of a plurality of independent convex portions is formed over the entire innermost surface of the heat seal layer.

13. The laminate material for a cover according to claim 12, wherein: The height of the protrusion is larger than the thickness of the heat seal layer and smaller than the total thickness of the adhesive layer and the heat seal layer.

14. A cover, characterized in that The cover is formed of the laminated material for a cover according to any one of claims 1 to 13.

15. A packaging body, characterized in that The lid of claim 14 is placed on the peripheral edge of the opening of a container filled with content so as to cover the opening of the container, and is heat-sealed by high-frequency induction heating.

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