Labeled molded object
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2026-01-27
- Publication Date
- 2026-04-28
Smart Images
Figure 2025052688000001
Abstract
Description
Labeled molded product
[0001] The present invention relates to a labeled molded article.
[0002] Contactless IC tags such as RFID (Radio Frequency Identification) tags have been used in various fields, including transportation, distribution, sales management, factory process management, inventory management, product delivery, and package handling. For example, Patent Document 1 proposes a method of embedding an RFID tag in the side of a synthetic resin container. Patent Document 2 proposes a method of placing an RFID inlay with a thermoplastic adhesive in a molding die with the adhesive exposed, and then feeding a heated container material into the molding die. Patent Document 2 provides a method for manufacturing a container with an RFID inlay bonded to the outer surface of the container using this method.
[0003] Furthermore, Patent Document 3 proposes an in-mold label having an antenna and an IC chip in the inner layer, and a labeled thermoplastic resin container formed using the same. The in-mold label of Patent Document 3 protects the IC module during the manufacturing process by sealing and fixing the IC module between at least two thermoplastic resin films.
[0004] JP 2021-31104 A JP 2023-46872 A JP 2006-48016 A
[0005] Recently, in order to reduce the burden on the environment, there has been a demand to recycle resin containers used in various products as new resources after use. However, in the case of the containers described in Patent Documents 1 and 2, the RFID is embedded in the container itself or firmly attached to the container. Therefore, while they can be used for a variety of purposes, it is not easy to remove the RFID and recycle the container after use. Furthermore, the in-mold label described in Patent Document 3 requires an antenna and an IC chip to be sandwiched between two thermoplastic resin films, and therefore is expected to provide a simpler manufacturing process.
[0006] As a result of intensive research conducted by the inventors to solve the above problems, they discovered the present invention, which relates to a labeled molded article having an RFID inlay between the label and the molded article, and in which the adhesive strength between the molded article and the RFID inlay and the adhesive strength between the molded article and the label are not more than a predetermined level. According to the present invention, sufficient adhesive strength is maintained between the label and the molded article when the molded article is in use, and the RFID inlay can be easily removed from the molded article together with the label when recycling.
[0007] That is, the present invention is as follows.
[0008] [1] A molded body and a label disposed on the surface of the molded body, further comprising an RFID inlay disposed between the molded body and the label, wherein the molded body contains a thermoplastic resin at least in a surface layer, the label layer has a base layer containing a thermoplastic resin, and the adhesive strength (P 成形体－インレイ ) is 100 gf / 15 mm or less, and the adhesive strength (P インレイ－ラベル ) or less, and the adhesive strength between the molded body and the label (P 成形体－ラベル ) is 90 to 300 gf / 15 mm.
[0009] [2] The labeled molded article according to [1], wherein the label has a heat seal layer, and the label and the molded article are heat-sealed by the heat seal layer.
[0010] [3] The labeled molded article according to [1] or [2], wherein the label has a coating layer on the outermost surface of the molded article.
[0011] [4] The labeled molded article according to any one of [1] to [3], wherein the RFID inlay is adhered to the label directly or via another layer.
[0012] [5] Adhesion strength between the molded body and the RFID inlay (P 成形体－インレイ ) is the adhesive strength (P インレイ－ラベル ) The labeled molded article according to any one of [1] to [4].
[0013] [6] The adhesive strength between the RFID inlay and the molded body (P 成形体 - インレイ ), and the adhesive strength between the RFID inlay and the label (P インレイ - ラベル ) are all 50 gf / 15 mm or less.
[0014] [7] The labeled molded article according to any one of [2] to [6], wherein the heat seal layer is a porous layer.
[0015] [8] A label having the RFID inlay used to manufacture a labeled molded article according to any one of [1] to [7].
[0016] According to the present invention, it is possible to provide a labeled molded article that achieves high recyclability and does not require a complicated manufacturing process. The labeled molded article of the present invention has an RFID inlay disposed between the molded article and the label, and therefore can be used as a non-contact IC tag for product management, logistics management, etc.
[0017] Fig. 1 is a cross-sectional view showing an example of a labeled molded product in a first embodiment. Fig. 2 is a cross-sectional view showing an example of the label of Fig. 1 peeled from the molded product. Fig. 3 is a cross-sectional view showing an example of the labeled molded product in a second embodiment. Fig. 4 is a cross-sectional view showing an example of the label of Fig. 3 peeled from the molded product. Fig. 5 is a cross-sectional view showing an example of the labeled molded product in a third embodiment. Fig. 6 is a cross-sectional view showing an example of the label of Fig. 5 peeled from the molded product.
[0018] The labeled molded article of the present invention will be described below. The following description is one embodiment (typical example) of the present invention, and the present invention is not limited thereto.
[0019] In the following description, the term "(meth)acrylic" refers to both acrylic and methacrylic.
[0020] The labeled molded article of this embodiment includes a molded article and a label disposed on the surface of the molded article, and further includes an RFID inlay disposed between the molded article and the label, and the adhesive strength (P成形体 - インレイ ) is 100 gf / 15 mm or less, and the adhesive strength (P インレイ - ラベル ) or less, and the adhesive strength between the molded body and the label (P 成形体 - ラベル ) is 90 to 300 gf / 15 mm.
[0021] An example of a labeled molded product is a labeled molded product 1 in which a label 20 is disposed on the surface of a molded product 30, as shown in Figure 1. The labeled molded product 1 has an RFID inlay 10 between the molded product 30 and the label 20. There are no limitations on the size of the label 20 relative to the size of the RFID inlay 10. It is preferable that the entire surface of the RFID inlay 10 is covered with the label 20.
[0022] The labeled molded article of this embodiment has an adhesive strength (P 成形体 - インレイ By making the adhesive strength (P) between the molded body and the RFID inlay 100 gf / 15 mm or less, the RFID can be easily removed from the molded body in a recycling process after use of the molded body. 成形体 - インレイ Since a smaller adhesive strength is more suitable for recycling, it is preferably 90 gf / 15 mm or less, and particularly preferably 50 gf / 15 mm or less, i.e., the two are not substantially adhered to each other. Here, in this embodiment, "not substantially adhered" refers to a state in which the adhesive strength is 50 gf / 15 mm or less, and refers to a case in which the adhesive strength cannot be evaluated when the following evaluation test is performed.
[0023] The adhesive strength can be measured in accordance with JIS K6854-3:1999 by cutting the labeled portion of the molded article into a strip of 15 mm width and T-peeling it at a tensile strength of 300 mm / min using a tensile tester.
[0024] Adhesion strength between molded body and RFID inlay (P 成形体 - インレイ ) is the adhesive strength between the RFID inlay and the label (P インレイ - ラベル ) or less ((P成形体 - インレイ ) ≦ (P インレイ - ラベル )) However, the adhesive strength between the molded body and the RFID inlay (P 成形体 - インレイ ) and the adhesive strength between the RFID inlay and the label (P インレイ - ラベル ) is 50 gf / 15 mm or less, i.e., there is no substantial adhesion, (P 成形体 - インレイ ) = (P インレイ - ラベル ), that is, the adhesive strength is considered to be about the same. More specifically, the adhesive strength (P 成形体 - インレイ ) is 50 gf / 15 mm or less, that is, when the two are not substantially adhered to each other, the adhesive strength (P インレイ - ラベル ) is 50 gf / 15 mm or less, that is, the two are not substantially bonded together, or if they are bonded together, the bond strength is arbitrary. 成形体 - インレイ ) is greater than 50 gf / 15 mm, i.e., when both are adhered, the adhesive strength (P インレイ - ラベル ) is the adhesive strength between the molded body and the RFID inlay (P 成形体 - インレイ ) is greater than ((P インレイ - ラベル )>(P 成形体 - インレイ ) is preferable. When the adhesive strengths between the molded product and the RFID inlay, and between the RFID inlay and the label, respectively, are in such a relationship, when the label is peeled from the molded product in the recycling process, the RFID inlay is either removed together with the label while still adhering to it, or is peeled off from the label and removed separately. This makes it easy to separate the RFID inlay from the molded product or the label, facilitating the recovery of the molded product or the label in the recycling process.
[0025] From the above, the adhesive strength between the molded article and the RFID inlay, and between the RFID inlay and the label, is the adhesive strength between the RFID inlay and the label (P インレイ - ラベル ) is the adhesive strength between the molded body and the RFID inlay (P 成形体 - インレイ ) (i.e., the adhesive strength between the molded body and the RFID inlay is smaller than the adhesive strength between the label and the RFID inlay), or the inlay is not substantially adhered to either the molded body or the label (the adhesive strengths are both 50 gf / 15 mm or less). 成形体 - インレイ ) is the adhesive strength between the label and the RFID inlay (P インレイ - ラベル ) is smaller than ((P 成形体 - インレイ ) < (P インレイ - ラベル ) is more preferred.
[0026] Adhesion strength between molded body and label (P 成形体 - ラベル The adhesive strength between the molded body and the label (P 成形体 - ラベル When the adhesive strength is equal to or less than the upper limit, the label can be easily peeled from the molded product during the recycling process, and as a result, the RFID tag can be removed from the molded product. When the adhesive strength is equal to or greater than the lower limit, the label does not peel from the molded product during use, and the molded product can be used for various purposes without any problems.
[0027] Adhesion strength between molded body and label (P 成形体 - ラベル ) is preferably 270 gf / 15 mm or less, more preferably 200 gf / 15 mm or less, and is preferably 100 gf / 15 mm or more, more preferably 130 gf / 15 mm or more.
[0028] [RFID Inlay] The RFID inlay used in this embodiment may have a known configuration and is not particularly limited. Specifically, the RFID inlay may include an RFID antenna attached to a support and an IC chip connected to the RFID antenna. The RFID inlay reads information from / writes information to the IC chip through contactless communication with a reader / writer. When the RFID inlay is attached to a label, a thermoplastic resin adhesive layer may be directly provided on the antenna and IC chip mounting surface of the RFID inlay support, and the RFID inlay may be attached to the label via this adhesive layer. Furthermore, the RFID inlay used in this embodiment may have the surface having the RFID antenna and IC chip sealed with resin. When sealed, the RFID inlay may be directly attached to the label, i.e., via only the sealing resin, or may have an adhesive layer separate from the sealing resin and be attached to the label via this adhesive layer.
[0029] When the resin contained in the outermost layer of the molded article is a non-polar resin such as polypropylene or polyethylene, the support or sealing resin of the RFID inlay is preferably a polar resin such as polyethylene terephthalate, since the molded article has low adhesion to polar resins, which is preferable because it is easier to satisfy the adhesive strength relationship of the present invention described above.
[0030] [Substrate Layer] The substrate layer contains a thermoplastic resin. Examples of the thermoplastic resin contained in the substrate layer include an olefin-based resin, an ester-based resin, an amide-based resin, a polyvinyl chloride resin, a polystyrene resin, and a polycarbonate resin. From the viewpoint of mechanical strength, the substrate layer preferably contains an olefin-based resin or an ester-based resin as the thermoplastic resin, and more preferably contains an olefin-based resin. Two or more types of thermoplastic resins may be mixed together to be used for the substrate layer.
[0031] Examples of olefin-based resins include propylene-based resins and ethylene-based resins, etc. From the viewpoints of moldability and mechanical strength, propylene-based resins are preferred.
[0032] The propylene-based resin is not particularly limited as long as propylene is used as the main monomer. Examples include isotactic polymers and syndiotactic polymers obtained by homopolymerizing propylene. Furthermore, propylene-α-olefin copolymers, which are copolymers of propylene as the main component with α-olefins such as ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene, can also be used. Here, the term "main component" refers to a copolymer that accounts for 50% by mass or more of the monomers constituting the copolymer. The copolymer may be a binary or ternary or higher multi-component copolymer, and may be a random or block copolymer. Furthermore, a propylene homopolymer and a propylene copolymer may be used in combination. Among these, a propylene homopolymer is preferred as the main raw material for the base layer because it is easy to handle.
[0033] The ethylene-based resin may have a density of 0.940 to 0.965 g / cm ３ High density polyethylene, density 0.920 to 0.934 g / cm ３ Medium density polyethylene, density 0.900 to 0.920 g / cm ３ linear low-density polyethylene; copolymers mainly composed of ethylene or the like copolymerized with α-olefins such as propylene, butene, hexene, heptene, octene, and 4-methyl-1-pentene; ethylene-(meth)acrylic acid alkyl ester copolymers; ethylene-(meth)acrylic acid copolymers or metal salts thereof (metals include zinc, aluminum, lithium, sodium, potassium, and the like); and ethylene-cyclic olefin copolymers.
[0034] Examples of the ester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of the amide resin include nylon-6, nylon-6,6, nylon-6,10, and nylon-6,12.
[0035] The content of the thermoplastic resin in the base layer is preferably 50% by mass or more, more preferably 70% by mass or more. If the content is 50% by mass or more, the mechanical strength of the base layer is likely to be improved. On the other hand, there is no particular upper limit to the content of the thermoplastic resin, and it may be 100% by mass, or it may be less than 100% by mass by adding fillers and additives described below within a range that does not affect strength or moldability.
[0036] <Filler> The base layer may contain a filler. By containing a filler, voids are easily formed inside with the filler as a nucleus, and whiteness or opacity can be increased. Examples of fillers that can be used in the base layer include inorganic fillers and organic fillers. Various fillers may be used alone or in combination of two or more.
[0037] Examples of inorganic fillers include inorganic particles such as heavy calcium carbonate, light calcium carbonate, calcined clay, silica, diatomaceous earth, white clay, talc, titanium oxide such as rutile titanium dioxide, barium sulfate, aluminum sulfate, zinc oxide, magnesium oxide, mica, sericite, bentonite, sepiolite, vermiculite, dolomite, wollastonite, and glass fiber. Among these, heavy calcium carbonate, clay, and diatomaceous earth are preferred because they have good pore formability and are inexpensive. Note that the surface of the inorganic filler may be surface-treated with a surface treatment agent such as a fatty acid to improve dispersibility.
[0038] Examples of organic fillers include those made of resins that are incompatible with the thermoplastic resin contained in the base layer, and when the thermoplastic resin is an olefin-based resin, examples include organic particles that are incompatible with the thermoplastic resin, such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyamide, polycarbonate, polystyrene, cyclic olefin homopolymer, ethylene-cyclic olefin copolymer, polyethylene sulfide, polyimide, polymethacrylate, polyether ether ketone, polyphenylene sulfide, or melamine resin. One of the above inorganic fillers or organic fillers can be used alone, or two or more can be used in combination.
[0039] From the viewpoint of increasing the whiteness or opacity of the substrate layer, the content of the filler in the substrate layer is preferably 10% by mass or more, more preferably 15% by mass or more. Also, from the viewpoint of increasing the uniformity of the molding of the substrate layer, the content of the filler in the substrate layer is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less. On the other hand, from the viewpoint of increasing the transparency of the substrate layer, the content of the filler in the substrate layer may be less than 10% by mass or may even be 0% by mass.
[0040] From the viewpoint of ease of pore formation, the average particle size of the inorganic or organic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, and even more preferably 0.1 μm or more. From the viewpoint of imparting mechanical strength such as tear resistance, the average particle size of the inorganic or organic filler is preferably 15 μm or less, more preferably 5 μm or less, and even more preferably 2 μm or less.
[0041] The average particle diameter of the inorganic filler is the volume average particle diameter (cumulative 50% particle diameter) D corresponding to 50% of the cumulative volume measured by a particle measuring device, for example, a laser diffraction particle size distribution measuring device (Microtrac, manufactured by Nikkiso Co., Ltd.). ５０ The average particle size of the organic filler is the average dispersed particle size when dispersed in a thermoplastic resin by melt-kneading and dispersion. The average dispersed particle size can be determined by observing a cut surface of a thermoplastic resin film containing an organic filler with an electron microscope, measuring the maximum diameters of at least 10 particles, and calculating the average value. Note that the average particle size in this embodiment is the volume-average particle size.
[0042] <Porosity> When the substrate layer has pores inside, the porosity, which represents the proportion of pores in the layer, is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more, from the viewpoint of obtaining opacity. From the viewpoint of maintaining mechanical strength, the porosity is preferably 70% or less, more preferably 55% or less, and even more preferably 40% or less. On the other hand, from the viewpoint of increasing the transparency of the substrate layer, the porosity may be less than 10% or even 0%.
[0043] In addition, from the viewpoint of facilitating gravity separation from the molded article in the recycling process, it is preferable that the specific gravity of the label is low and the porosity of the base layer is high. The porosity can be determined from the ratio of the area occupied by pores to a certain region of the cross section of a sample observed with an electron microscope.
[0044] Generally, the higher the filler content, the higher the porosity, the higher the whiteness or opacity of the base layer, and the lower the specific gravity. The filler content or porosity can be selected depending on the transparency, whiteness, specific gravity, etc. required for the laminate.
[0045] <Other Additives> Depending on the required physical properties, the substrate layer may contain components such as sterically hindered phenol-based, phosphorus-based, amine-based, sulfur-based, and other antioxidants; sterically hindered amine-based, benzotriazole-based, benzophenone-based, and other light stabilizers; dispersants; or antistatic agents. When the substrate layer contains these components, the content of each component is preferably 0.001 to 1 mass % relative to the total mass of the components constituting the substrate layer.
[0046] From the viewpoint of layer strength, the thickness of the substrate layer is preferably 20 μm or more, more preferably 40 μm or more. From the viewpoint of reducing the weight of the label, the thickness of the substrate layer is preferably 200 μm or less, more preferably 150 μm or less. The substrate layer may have a single-layer structure or a multi-layer structure. The substrate layer is preferably in the form of a sheet, and may be unstretched or stretched.
[0047] [Label] The material and configuration of the label of this embodiment are not particularly limited as long as it has the above-described base layer and has the above-described adhesive strength with the molded article. Such a label exhibits good peelability during the recycling process. The label may have, for example, a heat seal layer on the surface of the base layer facing the molded article. Furthermore, the outermost layer of the label facing the molded article may have a coating layer that functions to adjust the adhesive strength of the label.
[0048] More specifically, for example, a first embodiment is a label 20 having a coating layer 22 on the surface of a base layer 21 facing the molded article 30, as shown in Fig. 1. A second embodiment is a label having a base layer 21 and a heat seal layer 23, and having a coating layer 22 on the surface of the heat seal layer 23 facing the molded article 30, as shown in Fig. 3. Both of these are embodiments in which the coating layer 22 is on the outermost layer (the outermost layer) of the label facing the molded article 30.
[0049] 5 , there is a label 20 having a base layer 21 and a brittle heat seal layer 23. In the second and third embodiments, the label 20 and the molded article 30 are thermally fused together by the heat seal layer 23.
[0050] In the first and second embodiments, the label 20 peels off at the interface with the molded article 30 (FIGS. 2 and 4), and in the third embodiment, the label 20 peels off due to cohesive failure of the brittle heat seal layer 23 (FIG. 6). Each of these embodiments will be described below in order.
[0051] <First Aspect: Label Having a Coating Layer on the Surface of the Base Layer> The first aspect is an example in which the label does not have a heat-sealing layer, as described below, and is an example in which the label is attached to a molded article by in-mold molding such as injection molding ( FIG. 1 ). For example, if the surface layer (outermost layer) of the molded article and the base layer of the label are both layers primarily composed of polyolefin, a label can be attached by in-mold molding without providing a heat-sealing layer to the label if a molding method such as injection molding is used, in which the molding temperature is relatively high and the resin pressure during molding is high. Here, the term "main component" refers to a resin that accounts for 50% or more by mass of the thermoplastic resin contained in the layer. It is preferable to provide a coating layer on the surface of the label facing the molded article in order to adjust the adhesive strength between the label and the molded article within the desired range.
[0052] As shown in FIG. 2, when the label 20 having the coating layer 22 is peeled off from the molded body 30, the label 20 peels off at the interface with the molded body 30.
[0053] The coating layer improves the adhesive strength (P 成形体－ラベル) to a desired value, and the material is not limited as long as it has such an effect. For example, when the outermost layer of the molded article is a layer mainly composed of polyolefin, which is a non-polar resin, the coating layer is preferably a layer containing a polar resin that does not have heat-sealing properties (hereinafter, may be simply referred to as "polar resin"). Here, "not having heat-sealing properties" refers to a resin that does not melt even when heat is applied, a resin with a glass transition temperature of 100°C or higher, or a resin that does not have a melting point. The polar resin contained in the coating layer suppresses heat fusion of the molded article to the base layer, and increases the adhesive strength (P 成形体 - ラベル When the outermost layer of the molded body and the outermost layer of the base layer on the molded body side are both made of non-polar resins, the adhesive strength (P 成形体 - ラベル ) is particularly notable.
[0054] Examples of polar resins that do not have heat-sealing properties include ethyleneimine resins and cationic polymer antistatic agents having an ammonium salt structure, a phosphonium salt structure, or the like. Examples of ethyleneimine resins include polyethyleneimine, poly(ethyleneimine-urea), ethyleneimine adducts of polyamine polyamides, alkyl-modified products thereof, cycloalkyl-modified products, aryl-modified products, allyl-modified products, aralkyl-modified products, benzyl-modified products, cyclopentyl-modified products, cyclic aliphatic hydrocarbon-modified products, glycidol-modified products, and hydroxides thereof. Among the cationic polymer antistatic agents, antistatic agents having an ammonium salt structure are more preferred, acrylic resins having a tertiary or quaternary ammonium salt structure are particularly preferred, and acrylic resins having a quaternary ammonium salt structure are most preferred.
[0055] The thickness of the coating layer containing a polar resin is preferably 0.01 μm or more, more preferably 0.02 μm or more, and even more preferably 0.03 μm or more, in order to appropriately reduce the adhesion between the outermost layer of the molded article and the substrate layer, and is preferably 1.5 μm or less, more preferably 1.0 μm or less, and even more preferably 0.5 μm or less.
[0056] The coating layer containing a polar resin can be formed, for example, by applying an aqueous solution or solution containing the polar resin to the surface of the substrate and drying it. The substrate surface on which the coating layer is to be formed is preferably activated by corona discharge treatment to improve the adhesion and wettability of the coating layer.
[0057] A release varnish layer can also be used as the coating layer. Examples of release varnishes include varnishes containing silicone resins and varnishes containing fluorine compounds. The release varnish layer is preferably provided at an area ratio of about 40 to 80% of the surface of the substrate layer. The area ratio of the coating layer may be selected from the above range depending on the degree of adhesive strength between the outermost layer of the molded body and the substrate layer, and masking may be performed as necessary during coating. The thickness of the release varnish layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, in order to appropriately reduce the adhesive strength between the outermost layer of the molded body and the substrate layer. It is also preferably 10 μm or less, more preferably 5 μm or less. The coating layer is used to reduce the adhesive strength (P 成形体－ラベル ) to a desired value, the thickness of the layer may vary, and the layer may be arranged in a non-uniform pattern such as a dot pattern.
[0058] <Second Aspect: Having a Base Material Layer and a Heat-Seal Layer, and Having a Coating Layer on the Surface of the Heat-Seal Layer Facing the Molded Product> In labeled molded products produced using a molding method such as blow molding, which does not require a high molding temperature and does not require a high resin pressure during molding, the label preferably has a heat-seal layer. Examples of heat-seal layers include known ones, and the layer preferably contains a thermoplastic resin having a low melting point of about 60 to 130°C.
[0059] The thermoplastic resin used in the heat seal layer has a density of, for example, 0.900 to 0.935 g / cm ３ Low or medium density polyethylene, with a density of 0.880 to 0.940 g / cm ３Preferred examples of such polyethylene resins include linear polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid alkyl ester copolymer, ethylene-methacrylic acid alkyl ester copolymer in which the alkyl group has 1 to 8 carbon atoms, and metal salts of ethylene-methacrylic acid copolymers such as Zn, Al, Li, K, and Na, each having a melting point of 60 to 130° C. Among these, low-density or medium-density polyethylene or linear polyethylene having a crystallinity of 10 to 60% as measured by X-ray method and a number-average molecular weight of 10,000 to 40,000 is preferred.
[0060] The heat seal layer may have a single layer structure or a multilayer structure. From the viewpoint of enhancing adhesiveness, the thickness of the heat seal layer (total thickness in the case of a multilayer structure) is preferably 0.5 μm or more, more preferably 0.7 μm or more, and even more preferably 1 μm or more. On the other hand, from the viewpoint of suppressing cohesive failure within the heat seal layer, the thickness is preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less. Therefore, the thickness of the heat seal layer is preferably 0.5 to 10 μm, more preferably 0.7 to 7 μm, and even more preferably 1 to 5 μm.
[0061] In order to adjust the adhesive strength between the heat seal layer and the molded article within a desired range, it is preferable to provide a coating layer on the surface of the heat seal layer facing the molded article. Examples of the coating layer include the same layers as those listed in the first aspect, and preferred examples are also the same.
[0062] <Third Aspect: Label Having a Base Layer and a Brittle Heat-Seal Layer> In this aspect, the label has a brittle, weak heat-seal layer. A labeled molded article having a label of this aspect can be peeled from the molded article by cohesive failure of the label itself. An example of a brittle heat-seal layer is a heat-seal layer that is a porous resin layer with an open surface. The molten thermoplastic resin composition, which is the material for the molded article, penetrates the openings in the heat-seal layer surface, providing an anchoring effect that firmly adheres the layer to the molded article surface. However, because the heat-seal layer itself is brittle and weak, it can be easily peeled from the molded article by cohesive failure of the layer. In this case, as shown in Figure 6, a portion 23a of the heat-seal layer peels off together with the label 20, while another portion 23b of the heat-seal layer remains on the molded article.
[0063] The heat seal layer, which is a porous resin layer with an open surface (hereinafter sometimes simply referred to as "porous heat seal layer"), is preferably produced by stretching a resin composition containing a thermoplastic resin and a filler. To facilitate cohesive failure, it is preferable to blend at least two mutually incompatible resins as the thermoplastic resin and stretch the resin in a phase-separated state. Peeling occurs not only at the interface between the resin and the filler but also at the interface between these resins, allowing the heat seal layer to be peeled off in a uniform plane.
[0064] Examples of thermoplastic resins include blends of crystalline polypropylene and thermoplastic resins incompatible with the crystalline polypropylene resin. The crystallinity of the crystalline polypropylene resin is typically 65% or higher, preferably 66% or higher, and particularly preferably 67 to 80%. If the crystallinity is 65% or higher, compatibility between the amorphous portion contained in the crystalline polypropylene resin and the incompatible thermoplastic resin is less likely to progress, making it easier to achieve the initial interfacial peeling effect and appropriately reducing the stress (adhesive strength) required for peeling. Furthermore, if the crystallinity is 80% or lower, the resin is easily commercially available. The crystallinity can be determined, for example, by the method described in International Publication No. 2012 / 002510.
[0065] Examples of thermoplastic resins incompatible with the crystalline polypropylene resin include polyethylene resins, styrene-based resins, cyclic polyolefin resins, ethylene-cyclic olefin copolymer resins, polyamide-based resins such as nylon-6, nylon-6,6, nylon-6,10, and nylon-6,12, thermoplastic polyester-based resins such as polyethylene terephthalate and its copolymers, polyethylene naphthalate, polybutylene terephthalate, polybutylene succinate, polylactic acid, and aliphatic polyesters, and polycarbonates. These may also be used in combination of two or more. Among these, polyethylene resins are preferred from the viewpoints of chemical resistance, production costs, and the like.
[0066] In the present invention, "incompatible" means that when a blend of a crystalline polypropylene resin and an incompatible thermoplastic resin is observed under an electron microscope, it has a morphology of a sea-island structure, and the dimensions of the structure are 0.3 to 10 μm.
[0067] In the blend, the content of the thermoplastic resin incompatible with the crystalline polypropylene resin relative to 100 parts by weight of the crystalline polypropylene resin is usually 105 to 300 parts by weight, preferably 120 to 280 parts by weight, and more preferably 140 to 270 parts by weight. When the content of the incompatible thermoplastic resin is within the above range, cohesive failure in the heat seal layer proceeds more smoothly.
[0068] The filler contained in the porous heat seal layer may be the same as those listed in the base layer section, but it is particularly preferable to include an inorganic filler whose surface has been hydrophobized. By using a hydrophobized inorganic filler, interfacial peeling between the filler and the crystalline polypropylene is more likely to occur, making it possible to provide a label that is more easily separated from the molded product.
[0069] Examples of surface treatment agents used in the hydrophobic treatment include paraffin, fatty acids having 12 to 22 carbon atoms, or salts thereof. The average particle size of the filler is preferably 0.1 μm or more, more preferably 0.2 μm or more, and preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 0.5 μm or less. A relatively small average particle size is preferred because this allows for the formation of fine, uniform pores in the porous heat seal layer, and it is preferable to use precipitated calcium carbonate with uniform particle size and shape.
[0070] The porous heat-seal layer typically contains 30 to 60% by mass, preferably 35 to 50% by mass, of a blend of a crystalline polypropylene resin and a thermoplastic resin incompatible with the crystalline polypropylene resin, and typically contains 40 to 70% by mass, preferably 50 to 65% by mass, of a filler. The heat-seal layer is preferably stretched at least uniaxially. By setting the filler content in the porous heat-seal layer to 40% by mass or more, sufficient peelability is easily achieved, while by setting the filler content to 70% by mass or less, molding stability of the layer is easily achieved.
[0071] By forming a layer using the above-mentioned composition and stretching it, the porous heat-sealable layer can be made to have a large number of interconnected pores inside. Therefore, when a label having such a layer is attached to a molded product, even if air remains between the heat-sealable layer and the molded product, it is pushed out into the resin through the interconnected pores and discharged to the outside, which is preferable because it is less likely to remain between the two and cause swelling of the label.
[0072] The surface opening rate of the porous heat seal layer is preferably 7 to 60%, more preferably 12 to 50%, and particularly preferably 15 to 40%. If the surface opening rate is 7% or more, sufficient adhesion is likely to be obtained. If the surface opening rate is 60% or less, the layer is less likely to break during stretch molding. Here, "surface opening rate" refers to the area ratio of pores to the observation area when the surface of the heat seal layer facing the molded product is observed with an electron microscope.
[0073] The porosity of the porous heat seal layer is preferably 20 to 65%, more preferably 30 to 55%, and particularly preferably 35 to 50%. A porosity of 20% or more tends to provide sufficient adhesiveness. A porosity of 60% or less makes the layer less likely to break during stretch molding. The surface opening rate and porosity can be determined by the method described in International Publication No. 2012 / 002510.
[0074] The porous heat-sealing layer may contain a dispersant for the filler or various known additives as needed, provided that the effects of the present invention are not impaired. The heat-sealing layer may have a single layer or a multi-layer structure.
[0075] [Optional Layer] In the label of this embodiment, each layer may be a single layer or a laminate consisting of multiple layers. A printing layer (print-receiving layer) may be provided on the surface of the substrate layer opposite the heat-sealing layer. The label may also have layers other than those described above, provided that the effects of the present invention are not impaired. Each layer may be unstretched or stretched. Layers with different stretching or different numbers of stretching axes may be combined, and it is preferred that one or more layers be stretched. Furthermore, the heat-sealing layer may have a variable thickness, and may have a specific shape embossed on the surface by embossing, as described below.
[0076] [Label Manufacturing Method] The label manufacturing method of the present embodiment is not particularly limited, and can be manufactured by, for example, forming and laminating a film of a base layer and any layer such as a heat seal layer, etc. Methods for forming the film of each layer include film molding methods such as extrusion molding (cast molding) using a T-die, inflation molding using a round die, and calender molding using a rolling roll.
[0077] Examples of lamination methods for each film include coextrusion, extrusion lamination, and coating, and these methods can be combined. As mentioned above, the coating layer is preferably formed by a coating method. The surface of the heat-sealing layer may be embossed. By forming irregularities on the surface of the heat-sealing layer by embossing, it is possible to suppress the occurrence of blisters when a label is attached to a molded product.
[0078] Each layer may be an unstretched film or a stretched film. Furthermore, each layer may be stretched individually before lamination, or may be stretched together after lamination. The unstretched layer and the stretched layer may be stretched again after lamination. The stretching method may be appropriately selected from known methods, such as a longitudinal stretching method utilizing the difference in peripheral speed between rolls, a transverse stretching method using a tenter oven, or a sequential biaxial stretching method combining these.
[0079] [Molded Article] The molded article of this embodiment is not particularly limited as long as it contains a thermoplastic resin at least in the surface layer. For manufacturing reasons, it is preferable that the entire molded article be made of a thermoplastic resin, not just the surface layer. Examples of thermoplastic resins for the molded article include high-density polyethylene, polypropylene, polyester, polystyrene, polyvinyl chloride, and polycarbonate. Among these, high-density polyethylene, polypropylene, polyester, and polystyrene are particularly suitable.
[0080] The labeled molded article of this embodiment can be obtained by, for example, direct blow molding, in which a molten resin parison is pressed against the inner wall of a mold using compressed air, stretch blow molding using a preform, or injection molding, in which a thermoplastic resin composition for manufacturing a molded article is injected into a mold using an injection device and then cooled and solidified. By placing a label and RFID inlay in the mold in advance, the RFID inlay and label can be attached simultaneously with molding.
[0081] Labeled molded articles can also be obtained by differential pressure molding. After placing a label and an RFID inlay on the inner surface of the lower female mold of a differential pressure molding die, the label can be fixed to the inner wall of the die by suction, and then the thermoplastic resin composition for producing the molded article can be introduced above the lower female mold, and the label can be fused integrally to the outer wall of the molded article by differential pressure. Differential pressure molding can be either vacuum molding or pressure molding, but generally, differential pressure molding that combines both and utilizes plug assist is preferred.
[0082] In either molding method, a label with an RFID inlay attached thereto may be prepared in advance, and the label may be placed in a mold so that the surface opposite the RFID inlay is in contact with the inner wall of the mold, followed by molding. Alternatively, the RFID inlay may be placed on the label in the mold, and then the thermoplastic resin composition may be introduced into the mold to form the label. The adhesive strength between the molded product and the RFID inlay depends on the compatibility between the thermoplastic resin contained in the outermost layer of the molded product and the thermoplastic resin contained in the surface of the RFID inlay that is in contact with the outermost layer of the molded product, such as the support layer or encapsulating resin of the RFID inlay. Therefore, the adhesive strength between the molded product and the RFID inlay can be kept low by using resins that have low compatibility with each other. If the label has a heat-seal layer, the RFID inlay may be attached or placed on the surface of the heat-seal layer before molding.
[0083] The shape of the molded article of this embodiment is not limited, and examples thereof include various molded articles obtained by the above-mentioned manufacturing method, such as bottles, cups, squeeze containers, container lids, and boxes. The labeled molded article of this embodiment can be easily separated into the molded article, label, and RFID inlay using a general recycling process. In a general recycling process, recovered used molded articles are crushed into flakes using a crusher, and then the molded article and label are separated using differences in specific gravity, etc. For the labeled molded article of this embodiment, the label is easily peeled off from the molded article during the crushing process. At this time, the IC chip and RFID antenna portion contained in the RFID inlay are also separated from the molded article and label flakes, which have different specific gravities. As a result, the molded article flakes and label flakes can be recovered with high purity, achieving high recyclability.
[0084] The present embodiment will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts," "%," and the like refer to mass ratios unless otherwise specified. The ratios of raw materials used in solutions or dispersions (units: "parts by mass," "% by mass") are all values calculated on a solids basis.
[0085] [Manufacturing of labeled molded articles with RFID inlays adhered or arranged] Labeled molded articles with RFID inlays adhered or arranged for Examples 1 to 9 and Comparative Example 1 were manufactured according to the following procedure. Details of the materials used in each Example and Comparative Example are summarized in Table 1. Table 2 also summarizes the types and blending ratios (mass%) of materials used in manufacturing the labels for each Example and Comparative Example, as well as the thicknesses of the heat seal layer and coat layer. The symbols in Table 2 correspond to the symbols in Table 1.
[0086]
[0087] [Example 1] As materials for forming the base layer, 70% by mass of PP-1, a polypropylene resin, and 30% by mass of CaCO3-1, an inorganic filler, were melt-kneaded in an extruder set at 250°C, extruded into a sheet through a die, and cooled to 70°C in a cooling device to obtain a single-layer unstretched film. This unstretched film was heated to 145°C and then stretched 5 times in the longitudinal direction using the difference in peripheral speed between multiple rolls to obtain a longitudinal uniaxially stretched film.
[0088] Separately, as a porous heat-sealing layer forming material, 19% by mass of PP-2, a crystalline polypropylene resin, 19% by mass of HDPE-1, a thermoplastic resin incompatible with crystalline polypropylene resin, 59.5% by mass of CaCO3-2, an inorganic filler, and 0.5% by mass of D-1 and 2% by mass of D-2, which are dispersants, were melt-kneaded in an extruder set at 250 ° C., extruded into a sheet through a die, and laminated on one side of the longitudinal uniaxially stretched film. #150 line gravure embossed metal cooling roll and matte rubber roll, the porous heat-sealing layer side was guided so that the metal cooling roll was in contact with the metal cooling roll, and the two were joined by narrow pressure to transfer the embossed pattern to the porous heat-sealing layer side, and cooled by a cooling roll to obtain a laminate having a two-layer structure.
[0089] The obtained laminate was heated to 153°C in an oven, then stretched 9 times in the transverse direction using a tenter stretching machine, and then heat-treated at 170°C to obtain a laminated resin film consisting of a base layer (biaxially stretched layer) / porous heat-seal layer (uniaxially stretched layer) (third embodiment: label having a base layer and a brittle heat-seal layer). The thickness of the obtained laminated resin film was 105 μm, of which the thickness of the porous heat-seal layer was 6 μm, and the porosity of the porous heat-seal layer was 60%.
[0090] Next, an RFID inlay (60 μm thick support, 20 μm thick antenna, 140 μm thick IC chip) mounted on a polyethylene terephthalate support was coated with adhesive G-1 on the antenna and IC chip surfaces using a bar coater. This coated surface was adhered to the surface of the porous heat seal layer of the laminated resin film, and the laminate was punched into a rectangle 70 mm wide and 90 mm long to obtain a label with an RFID inlay attached.
[0091] Next, using an injection molding machine (manufactured by Niigata Machine Techno Co., Ltd., machine name: MDV50ST-S7000) and a mold (size: 128 mm x 148 mm) capable of molding a plate-shaped molded body, the label was placed on one side of the mold so that the heat seal layer faced the cavity side (molded body resin side) and fixed on the mold by suction. Thereafter, the mold was clamped, and the molded body forming resin PP-3 listed in Table 1 was melted at 200 ° C. and injection molded into the mold at an injection pressure of 30 MPa, and then the mold was cooled for 8 seconds with cooling water at 20 ° C. Note that "INJ" in Table 2 represents injection molding. After cooling, the mold was opened to obtain a labeled molded body of the third embodiment.
[0092] [Example 2] Label production and molding were carried out in the same manner as in Example 1, except that HDPE-2 resin for forming a molded body shown in Table 1 was used instead of PP-3 resin for forming a molded body, to obtain a labeled molded body of the third embodiment.
[0093] [Example 3] A label with an RFID inlay attached was manufactured in the same manner as in Example 1, except that the label size was changed to a rectangle of 120 mm wide and 150 mm long, and a molded product was obtained by the following direct blow molding method instead of injection molding. Note that "Blow" in Table 2 represents direct blow molding.
[0094] A direct blow molding machine (manufactured by Tahara Corporation, machine name: TPF-706B-E1) and a mold capable of molding a 3 L container were used. The label was placed on one side of the mold with the porous heat seal layer facing the cavity (molded body resin side) and fixed onto the mold by suction. The molded body-forming resin EPCP was then melted at 200°C and extruded into a parison shape. After introducing the parison between the halves of the mold, the halves were clamped together. Compressed air at 0.5 MPa was then supplied into the parison, expanding the parison and adhering it to the mold to form a container shape and attaching the label. The halves were then cooled with 20°C cooling water for 20 seconds. After cooling, the molds were opened to obtain a labeled molded body of the third embodiment.
[0095] [Example 4] Label production and molding were carried out in the same manner as in Example 3, except that the resin for forming a molded body, HDPE-3, listed in Table 1, was used instead of the resin for forming a molded body, EPCP, to obtain a labeled molded body of the third embodiment.
[0096] Example 5 A label was produced and molded in the same manner as in Example 4, except that CaCO3-1 was used instead of CaCO3-2 used in the porous heat seal layer, to obtain a labeled molded article of the third embodiment.
[0097] Example 6 A label was produced and molded in the same manner as in Example 4, except that G-2 was used instead of G-1 as the adhesive for the RFID inlay, to obtain a labeled molded article of the third embodiment.
[0098] [Example 7] As materials for forming the base layer, 70% by mass of PP-1, a polypropylene resin, and 30% by mass of CaCO3-1, an inorganic filler, were melt-kneaded in an extruder set at 250°C, extruded into a sheet through a die, and cooled to 70°C in a cooling device to obtain a single-layer unstretched film. This unstretched film was heated to 145°C and then stretched 5 times in the longitudinal direction using the difference in peripheral speed between multiple rolls to obtain a longitudinal uniaxially stretched film.
[0099] The obtained longitudinally uniaxially stretched film was heated to 153°C in an oven, then stretched 9 times in the transverse direction using a tenter stretching machine, and then heat-treated at 170°C to obtain a substrate layer that was a biaxially stretched resin film. At this time, the thickness of the substrate layer was 95 µm.
[0100] One side of the obtained substrate layer was subjected to a corona discharge treatment using a corona discharge treatment device (manufactured by Kasuga Electric Co., Ltd., device name: HF400F). The corona discharge treatment was performed with a gap of 5 mm between a 0.8 m long aluminum discharge electrode and a treater roll, a line treatment speed of 15 m / min, and an applied energy density of 4200 J / m ２ Next, a coating layer material, PEI (30% by mass aqueous solution), was applied to the surface that had been subjected to the corona discharge treatment so that the solid content after drying was 0.2 g / m ２The coating was performed using a bar coater. After coating, the film was dried in an oven to obtain a laminated resin film (first embodiment: label layer having a coating layer on the surface of the base layer). The thickness of the coating layer at this time was 0.2 μm. Next, a label was produced using the same RFID inlay as in Example 1. The label was placed with the coating layer facing the cavity side (molded body resin side) and fixed on a mold by suction, and then injection molding was performed in the same manner as in Example 1 to obtain a labeled molded body of the first embodiment.
[0101] Example 8 The same procedure as in Example 7 was carried out except that the resin for forming a molded body, HDPE-2, shown in Table 1, was used instead of the resin for forming a molded body, PP-3, to obtain a labeled molded body of the first embodiment.
[0102] [Example 9] As materials for forming the base layer, 70% by mass of PP-1, a polypropylene resin, and 30% by mass of CaCO3-1, an inorganic filler, were melt-kneaded in an extruder set at 250°C, extruded into a sheet through a die, and cooled to 70°C in a cooling device to obtain a single-layer unstretched film. This unstretched film was heated to 145°C and then stretched 5 times in the longitudinal direction using the difference in peripheral speed between multiple rolls to obtain a longitudinal uniaxially stretched film.
[0103] Separately, as a material for forming a heat-seal layer, m-PE shown in Table 1 was melt-kneaded in an extruder set at 190°C, extruded through a die into a sheet, and laminated on one side of the above-mentioned longitudinally uniaxially stretched film. The sheet was introduced between a metal cooling roll with a #150 line gravure embossed pattern and a matte rubber roll so that the heat-seal layer side was in contact with the metal cooling roll, and the two were joined by nip pressure to transfer the embossed pattern to the heat-seal layer side. The sheet was then cooled by the cooling roll to obtain a laminate having a two-layer structure.
[0104] Next, the laminate was heated to 153°C in an oven, stretched 9 times in the transverse direction using a tenter stretching machine, and then heat-treated at 170°C to obtain a laminated resin film consisting of a base layer (biaxially stretched layer) / heat-seal layer (uniaxially stretched layer). The thickness of the obtained laminated resin film was 105 µm, of which the thickness of the heat-seal layer was 3 µm.
[0105] The surface of the heat seal layer of the obtained laminated resin film was subjected to a corona discharge treatment using a corona discharge treatment device (manufactured by Kasuga Electric Co., Ltd., device name: HF400F). The corona discharge treatment was performed with a gap of 5 mm between a 0.8 m long aluminum discharge electrode and a treater roll, a line treatment speed of 15 m / min, and an applied energy density of 4200 J / m. ２ Next, a coating layer material, PEI (30% by mass aqueous solution), was applied to the surface that had been subjected to the corona discharge treatment so that the solid content after drying was 0.2 g / m ２ The coating was performed using a bar coater. After coating, the film was dried in an oven to obtain a laminated resin film (second embodiment) having a substrate layer and a heat seal layer, and a coating layer on the molded body-side surface of the heat seal layer. The thickness of the heat seal layer was 3 μm, and the thickness of the coating layer was 0.2 μm.
[0106] Next, label production and molding were carried out in the same manner as in Example 1 to obtain a labeled molded article of the second embodiment.
[0107] Comparative Example 1 A label was produced and molded in the same manner as in Example 9, except that the surface of the heat seal layer of the laminated resin film was not subjected to corona treatment and no coating layer was formed.
[0108] [Evaluation Method] (Thickness of Label and RFID Inlay) The thickness of the label and RFID inlay was measured using a constant pressure thickness measuring instrument (manufactured by Teclock Corporation, "PG-01J") in accordance with JIS K7130:1999.
[0109] (Thickness of Heat Seal Layer and Coating Layer) The labels produced in each Example and Comparative Example were embedded in epoxy resin and solidified, and then a cut surface parallel to the thickness direction of the label (i.e., perpendicular to the surface direction) was prepared using a microtome. This cut surface was metallized by metal deposition, and then the cross-sectional thicknesses of the heat seal layer and coating layer were photographed at 3000 times magnification using a scanning electron microscope (manufactured by JEOL Ltd., instrument name: Neoscope JCM-6000) and the thicknesses were measured.
[0110] (Cross-sectional porosity of porous heat seal layer) The cross-sectional image obtained above was subjected to binarization and image processing using an image analyzer (manufactured by Nireco Corporation, device name: Luzex IID) to determine the porosity. The cross-sectional porosity was calculated by dividing the area of the void region partitioned by the thermoplastic resin composition by the area of the entire observation region. The inorganic filler in the voids observed in the cross-sectional image was treated as voids.
[0111] (Adhesion Strength Evaluation) After storing the labeled molded article for one week in an environment of 23°C and 50% relative humidity, the labeled portion of the molded article was cut into 15 mm wide strips in accordance with JIS K6854-3:1999, and the adhesive strength between the label and the molded article, and the adhesive strength between the label and the RFID inlay were determined by T-peel at a tensile strength of 300 mm / min using a tensile tester (manufactured by A&D Corporation, device name: Tensilon RTG-1225). Note that the adhesive strength between the RFID inlay and the molded article was very weak, making it impossible to evaluate the adhesive strength. When a 15 mm wide strip sample was cut from the portion where the molded article / RFID inlay / label were sequentially laminated, the RFID inlay peeled off from the molded article. This is thought to be because the support for the RFID inlay was a polyethylene terephthalate (polar resin) film, while the resin used to form the molded article was polyolefin (non-polar resin), and therefore there was almost (substantially) no adhesion between them.
[0112] (Evaluation of Crushing of Labeled Molded Articles) 1.5 kg of each labeled molded article obtained in each Example and Comparative Example was prepared and crushed using a crusher (Morita Seiki Co., Ltd., machine name: XL-15). After crushing, the crushed material was collected and the crushed state was visually confirmed. It was confirmed whether the RFID inlay and label were adhered to the molded article.
[0113] Label peelability: If it was A1 or A2, it was judged to be suitable for practical use. A1: The label peels off from the molded product, but a thin heat seal layer remains on the surface of the molded product. A2: The label peels off from the molded product, and the heat seal layer and the layer derived from the label do not remain on the surface of the molded product. C: The label does not peel off from the molded product.
[0114] RFID inlay peelability: A1, A2, or A3 was judged to be suitable for practical use. A1: The RFID inlay peeled from the molded product and adhered to the label. A2: The RFID inlay peeled from the molded product and partially peeled from the label. A3: The RFID inlay peeled from the molded product and also peeled from the label. C: The RFID inlay did not peel from the molded product.
[0115] [Evaluation] Table 2 shows the configuration of the labeled molded article and the evaluation results.
[0116] In Examples 1 to 6, the state of the labeled molded article after crushing was such that a thin layer of the porous heat seal layer, which had undergone cohesive failure, remained on the surface of the crushed molded article pieces, but the label's base layer and RFID inlay were not present. Furthermore, in Examples 1 to 5, the RFID inlay and label were adhered, so the RFID inlay was attached to the crushed label pieces. However, the brittle heat seal layer was destroyed by shear during the crushing test, and some of the RFID inlay pieces peeled off from the label pieces. Furthermore, in Example 6, by changing the adhesive for the RFID inlay to an easy-adhesion type, the label pieces and RFID inlay pieces were able to be completely separated after crushing.
[0117] On the other hand, in all cases of Examples 1 to 6, the RFID inlay was completely peeled off from the molded body in the crushing test. As mentioned above, the adhesive strength between the RFID inlay and the molded body was very weak, and when the measurement sample containing the RFID inlay was cut into a strip with a width of 15 mm, the RFID inlay peeled off from the molded body. Since the adhesive strength between the molded body and the RFID inlay could not be measured (it was thought to be 50 gf / 15 mm or less), it is thought that in Examples 1 to 6, the molded body and the RFID inlay were hardly (substantially) adhered to each other.
[0118] In the labeled molded articles of the first embodiment in Examples 7 and 8, and the labeled molded article of the second embodiment in Example 9, the labels were completely peeled off from the molded articles in the crushing test, and no heat seal layer or label-derived layer remained on the surface of the molded article pieces. This is thought to be because the polar resin contained in the coating layer does not exhibit adhesive properties to the polyolefin (non-polar resin) that is the main component of the molded article, and the coating layer reduced the adhesiveness between the label and the molded article, thereby adjusting the adhesive strength within the range specified in the present invention. The adhesive strength between the RFID inlay and the molded article in Examples 7 and 8 was similar to that of Examples 1 to 6, and the RFID inlay was completely peeled off from the molded article in the crushing test. Furthermore, because the adhesion between the RFID inlay and the label was strong, the RFID inlay adhered to the crushed label pieces.
[0119] The labeled molded product of Comparative Example 1 had a higher adhesive strength between the label and the molded product than those of Examples 1 to 9. This is thought to be because the heat seal layer was firmly attached to the molded product. Furthermore, the labeled molded product of Comparative Example 1 could not be separated from the label after the crushing test.
[0120] REFERENCE SIGNS LIST 1 labeled molded article 10 RFID inlay 20 label 21 substrate layer 22 coating layer 23, 23a, 23b heat seal layer 24 printing layer 30 molded article
Claims
1. Molded body and, The molded body comprises a label disposed on its surface, The molded body and the label further have an RFID inlay positioned between them. The molded article contains a thermoplastic resin in at least its surface layer, The label has a substrate layer containing a thermoplastic resin, The adhesive strength (P) between the molded body and the RFID inlay 成形体 - インレイ The adhesive strength (P) between the RFID inlay and the label is 100 gf / 15 mm or less, and the adhesive strength (P) between the RFID inlay and the label is 100 gf / 15 mm or less. インレイ - ラベル ) and below, Adhesion strength between the molded body and the label (P 成形体 - ラベル A labeled molded body with a pressure of 90-300 gf / 15 mm.
2. The labeled molded body according to claim 1, wherein the label has a heat seal layer, and the label and the molded body are heat-fused together by the heat seal layer.
3. The labeled molded body according to claim 1, wherein the label has a coating layer on the outermost surface of the molded body.
4. The labeled molded article according to claim 1, wherein the RFID inlay is adhered to the label directly or via another layer.
5. The adhesive strength (P 成形体 - インレイ ) between the molded body and the RFID inlay is smaller than the adhesive strength (P インレイ - ラベル ) between the RFID inlay and the label. The labeled molded body according to claim 4.
6. The adhesive strength (P) between the RFID inlay and the molded body 成形体 - インレイ ), and the adhesive strength between the RFID inlay and the label (P インレイ - ラベル The labeled molded article according to claim 1, wherein all of the gf / 15 mm or less are 50 gf / 15 mm or less.
7. The labeled molded article according to claim 2, wherein the heat-seal layer is a porous layer.
8. The labeled molded article according to claim 3, wherein the coating layer comprises a polar resin or release varnish that does not have heat-sealing properties.
9. The labeled molded article according to claim 8, wherein the polar resin that does not have heat sealability is a resin with a glass transition temperature of 100°C or higher or a resin that does not have a melting point.
10. The labeled molded article according to claim 8, wherein the polar resin that does not have heat sealability is an ethyleneimine resin, or a cationic polymer-type antistatic agent having an ammonium salt structure or a phosphonium salt structure.
11. The labeled molded article according to claim 7, wherein the porous layer is a stretched layer of a resin composition containing a thermoplastic resin and a filler.
12. A label having an RFID inlay used to manufacture a labeled molded article according to any one of claims 1 to 11.