Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F3/00—Labels, tag tickets, or similar identification or indication means; Seals; Postage or like stamps
  • G09F3/04—Labels, tag tickets, or similar identification or indication means; Seals; Postage or like stamps to be fastened or secured by the material of the label itself, e.g. by thermo-adhesion
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D25/00—Details of other kinds or types of rigid or semi-rigid containers
  • B65D25/20—External fittings
• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
  • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
  • G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
  • G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
  • G06K19/077—Constructional details, e.g. mounting of circuits in the carrier
  • G06K19/07749—Constructional details, e.g. mounting of circuits in the carrier the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
  • G06K19/07758—Constructional details, e.g. mounting of circuits in the carrier the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag
  • G06K19/0776—Constructional details, e.g. mounting of circuits in the carrier the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag the adhering arrangement being a layer of adhesive, so that the record carrier can function as a sticker
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F3/00—Labels, tag tickets, or similar identification or indication means; Seals; Postage or like stamps
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
  • G09F3/00—Labels, tag tickets, or similar identification or indication means; Seals; Postage or like stamps
  • G09F3/02—Forms or constructions
  • G09F2003/0257—Multilayer

Definitions

• the present invention relates to a molded body with a label.
• 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 mold with the adhesive exposed, and then supplying a heated container material into the mold. With this method, Patent Document 2 provides a method of manufacturing a container with an RFID inlay bonded to the outer surface of the container.
• 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 this.
• the in-mold label of Patent Document 3 seals and fixes the IC module between at least two thermoplastic resin films, thereby protecting the IC module during the manufacturing process, etc.
• the present invention which relates to a labeled molded body having an RFID inlay between the label and the molded body, and in which the adhesive strength between the molded body and the RFID inlay and the adhesive strength between the molded body and the label are below a predetermined level. According to the present invention, there is sufficient adhesive strength between the label and the molded body when the molded body is in use, and the RFID inlay can be easily removed from the molded body together with the label when recycling.
• the present invention is as follows.
• the molded body contains a thermoplastic resin at least in a surface layer,
• the label layer has a base layer containing a thermoplastic resin, the adhesive strength between the molded article and the RFID inlay (P molded article-inlay ) is 100 gf/15 mm or less, and the adhesive strength between the RFID inlay and the label (P inlay-label ) is 100 gf/15 mm or less,
• the labeled molded article has an adhesive strength between the molded article and the label (P molded article-label ) of 90 to 300 gf/15 mm.
• [6] A labeled molded product described in any of [1] to [5], wherein the adhesive strength between the RFID inlay and the molded product (P molded product - inlay ) and the adhesive strength between the RFID inlay and the label (P inlay - label ) are both 50 gf/15 mm or less.
• the present invention provides a labeled molded product that is highly recyclable and does not require a complicated manufacturing process.
• the labeled molded product of the present invention has an RFID inlay disposed between the molded product and the label, and can therefore be used as a non-contact IC tag for product management, logistics management, etc.
• FIG. 2 is a cross-sectional view showing an example of a labeled molded article in the first embodiment.
• FIG. 2 is a cross-sectional view showing an example of the label of FIG. 1 peeled off from the molded article.
• FIG. 4 is a cross-sectional view showing an example of a labeled molded article in a second embodiment.
• FIG. 4 is a cross-sectional view showing an example of the label of FIG. 3 peeled off from the molded product.
• FIG. 11 is a cross-sectional view showing an example of a labeled molded article according to a third embodiment.
• FIG. 6 is a cross-sectional view showing an example of the label of FIG. 5 peeled off from the molded product.
• (meth)acrylic refers to both acrylic and methacrylic.
• 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.
• the labeled molded body has an adhesive strength between the molded body and the RFID inlay (P molded body - inlay ) of 100 gf/15 mm or less, and an adhesive strength between the RFID inlay and the label (P inlay -label ) of 90 to 300 gf/15 mm.
• An example of a labeled molded body is a labeled molded body 1 in which a label 20 is disposed on the surface of a molded body 30, as shown in FIG. 1.
• the labeled molded body 1 has an RFID inlay 10 between the molded body 30 and the label 20.
• the adhesive strength between the molded article and the RFID inlay (P molded article - inlay ) is 100 gf/15 mm or less, so that the RFID can be easily removed from the molded article in the recycling process after the molded article is used. Since the smaller the adhesive strength between the molded article and the RFID inlay (P molded article - inlay ) is, the more suitable it is for recycling, it is preferably 90 gf/15 mm or less, and it is particularly preferable that it is 50 gf/15 mm or less, that is, the two are not substantially adhered to each other.
• substantially not 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.
• the adhesive strength can be measured according to JIS K6854-3:1999 by cutting the part of the molded article to which the label is attached into a strip 15 mm wide, and using a tensile tester to perform a T-peel at a tensile strength of 300 mm/min.
• the adhesive strength between the molded article and the RFID inlay is equal to or less than the adhesive strength between the RFID inlay and the label (P inlay - label ) ((P molded article - inlay ) ⁇ (P inlay - label )).
• the adhesive strength between the molded article and the RFID inlay is 50 gf/15 mm or less, i.e., they are not substantially adhered to each other
• the adhesive strength between the RFID inlay and the label is 50 gf/15 mm or less, i.e., they are not substantially adhered to each other, or if they are adhered to each other, the adhesive strength is arbitrary.
• the adhesive strength between the molded product and the RFID inlay is greater than 50 gf/15 mm, i.e., when the two are adhered to each other, it is preferable that the adhesive strength between the RFID inlay and the label (P inlay - label ) is greater than the adhesive strength between the molded product and the RFID inlay (P molded product - inlay ) ((P inlay -label)>(P molded product - inlay )).
• 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 adhered to it, or is peeled off from the label and separated and removed separately. This makes it easy to separate the RFID inlay from the molded product or the label, and allows the molded product or the label to be easily recovered in the recycling process.
• the adhesive strength between the molded article and the RFID inlay, and between the RFID inlay and the label is such that the adhesive strength between the RFID inlay and the label (P inlay - label ) is greater than the adhesive strength between the molded article and the RFID inlay (P molded article - inlay ) (i.e., the adhesive strength between the molded article and the RFID inlay is less than the adhesive strength between the label and the RFID inlay), or that the inlay is not substantially adhered to either the molded article or the label (adhesive strengths are both 50 gf/15 mm or less).
• the adhesive strength between the molded article and the RFID inlay is less than the adhesive strength between the label and the RFID inlay (P inlay - label ) ((P molded article - inlay ) ⁇ (P inlay - label )).
• the adhesive strength between the molded product and the label (P molded product - label ) is 90 to 300 gf/15 mm.
• the adhesive strength between the molded product and the label (P molded product - label ) is equal to or less than the upper limit, the label is easily peeled off from the molded product in the recycling process, and as a result, the RFID is removed from the molded product.
• the adhesive strength is equal to or more than the lower limit, the label does not peel off from the molded product when the molded product is used, and the molded product can be used for various purposes without problems.
• the adhesive strength between the molded product and the label (P molded product - label ) 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.
• the RFID inlay used in this embodiment may have a known configuration and is not particularly limited.
• 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 the IC chip and writes information to the IC chip by non-contact communication with a reader/writer.
• 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 the adhesive layer.
• the RFID inlay used in this embodiment may have a 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 the adhesive layer.
• the resin contained in the outermost layer of the molded body is a non-polar resin such as polypropylene or polyethylene
• the support or sealing resin of the RFID inlay is a polar resin such as polyethylene terephthalate. This is preferable because the adhesion of the molded body to polar resins is low, making it easier to satisfy the adhesive strength relationship of the present invention described above.
• the substrate layer contains a thermoplastic resin.
• the thermoplastic resin contained in the substrate layer include olefin-based resins, ester-based resins, amide-based resins, polyvinyl chloride resins, polystyrene resins, and polycarbonate resins.
• 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.
• the thermoplastic resin of the substrate layer may be a mixture of two or more kinds.
• olefin-based resins examples include propylene-based resins and ethylene-based resins. From the standpoint of moldability and mechanical strength, propylene-based resins are preferred.
• Propylene-based resins are not particularly limited as long as propylene is used as the main monomer.
• isotactic polymers or syndiotactic polymers obtained by homopolymerizing propylene can be used.
• propylene- ⁇ -olefin copolymers which are copolymers of propylene as the main component with ⁇ -olefins such as ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene, can also be used.
• the term "main component” refers to a monomer that constitutes 50% by mass or more of the monomers that constitute the copolymer.
• the monomer components of the copolymer may be a binary or ternary or higher multi-component system, and may be a random copolymer or a block copolymer.
• Propylene homopolymers and propylene copolymers may also be used in combination. Among these, propylene homopolymers are preferred as the main raw material for the base layer because they are easy to handle.
• ethylene-based resins examples include high-density polyethylene having a density of 0.940 to 0.965 g/ cm3 , medium-density polyethylene having a density of 0.920 to 0.934 g/ cm3 , linear low-density polyethylene having a density of 0.900 to 0.920 g/ cm3 , copolymers mainly composed of ethylene and copolymerized with ⁇ -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.
• ⁇ -olefins such as propylene, butene, hexene, heptene, oc
• ester resin examples include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.
• amide resins examples include nylon-6, nylon-6,6, nylon-6,10, and nylon-6,12.
• the content of the thermoplastic resin in the base layer is preferably 50% by mass or more, and 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, which will be described later, within a range that does not affect the strength or moldability.
• the base layer may contain a filler.
• a filler By containing a filler, voids are easily formed inside the base layer with the filler as a core, and the whiteness or opacity can be increased.
• the filler that can be used in the base layer include inorganic fillers, organic fillers, etc. Various fillers may be used alone or in combination of two or more kinds.
• 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.
• heavy calcium carbonate, clay, and diatomaceous earth are preferred because they have good pore formability and are inexpensive.
• the surface of the inorganic filler may be treated with a surface treatment agent such as a fatty acid to improve dispersibility.
• examples of the organic filler include those made of a resin that is incompatible with the thermoplastic resin contained in the base layer.
• the thermoplastic resin is an olefin-based resin
• examples of the organic filler include organic particles of 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, melamine resin, or the like that are incompatible with the thermoplastic resin.
• the inorganic fillers or organic fillers may be used alone or in combination of two or more.
• the filler content in the base layer is preferably 10% by mass or more, and more preferably 15% by mass or more. Furthermore, from the viewpoint of increasing the uniformity of the molding of the base layer, the filler content in the base 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 base layer, the filler content in the base layer may be less than 10% by mass, or may be 0% by mass.
• the average particle diameter of the inorganic or organic filler is preferably 0.01 ⁇ m or more, more preferably 0.05 ⁇ m or more, and even more preferably 0.1 ⁇ m or more. From the viewpoint of imparting mechanical strength such as tear resistance, the average particle diameter of the inorganic or organic filler is preferably 15 ⁇ m or less, more preferably 5 ⁇ m or less, and even more preferably 2 ⁇ m or less.
• the average particle diameter of the inorganic filler is the volume average particle diameter (cumulative 50% particle diameter) D50 corresponding to 50% of the cumulative volume measured by a particle measuring device, for example, a laser diffraction type particle size distribution measuring device ( Microtrac , manufactured by Nikkiso Co., Ltd.).
• the average particle diameter of the organic filler is the average dispersed particle diameter when dispersed in a thermoplastic resin by melt kneading and dispersion.
• the average dispersed particle diameter can be obtained by observing a cut surface of a thermoplastic resin film containing an organic filler with an electron microscope, measuring the maximum diameter of at least 10 particles, and taking the average value thereof. Note that the average particle diameter in this embodiment is the above-mentioned volume average particle diameter.
• 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 may be 0%.
• the specific gravity of the label is small and the porosity of the base material 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 under an electron microscope.
• the filler content or porosity can be selected according to the transparency, whiteness, specific gravity, etc. required for the laminate.
• the base layer may contain components such as antioxidants such as sterically hindered phenols, phosphorus, amines, and sulfur-based antioxidants, light stabilizers such as sterically hindered amines, benzotriazoles, and benzophenones, dispersants, and antistatic agents, depending on the required physical properties.
• antioxidants such as sterically hindered phenols, phosphorus, amines, and sulfur-based antioxidants
• light stabilizers such as sterically hindered
• the thickness of the base layer is preferably 20 ⁇ m or more, and more preferably 40 ⁇ m or more. From the viewpoint of reducing the weight of the label, the thickness of the base layer is preferably 200 ⁇ m or less, and more preferably 150 ⁇ m or less.
• the base layer may have a single layer structure or a multilayer structure.
• the base layer is preferably in the form of a sheet, and may be unstretched or stretched.
• the material and configuration of the label of this embodiment are not particularly limited as long as it has the above-mentioned base layer and has the above-mentioned adhesive strength with the molded body. Such a label exhibits good peelability in the recycling process.
• the label may have, for example, a heat seal layer on the surface of the base layer facing the molded body.
• the outermost layer of the label facing the molded body may have a coating layer that has a function of adjusting the adhesive strength of the label.
• a first embodiment is a label 20 having a coating layer 22 on the surface of the base layer 21 facing the molded product 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 product 30, as shown in FIG. 3. Both of these are embodiments in which the coating layer 22 is on the outermost layer (outermost layer) of the label facing the molded product 30.
• FIG. 5 there is a label 20 having a base layer 21 and a brittle heat seal layer 23.
• the label 20 and the molded body 30 are thermally fused together by the heat seal layer 23.
• 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). The following explains each in order.
• the first embodiment is an example in which the label does not have a heat seal layer, which will be described later, and is an example in which the label is attached to the molded body by in-mold molding such as injection molding (FIG. 1).
• the label can be attached by in-mold molding without providing a heat seal layer to the label, as long as the molding temperature is relatively high and the resin pressure during molding is high, such as injection molding.
• the "main component” refers to a resin that occupies 50% by mass or more of the thermoplastic resin contained in the layer.
• the label 20 having the coating layer 22 when peeled off from the molded body 30, the label 20 peels off at the interface with the molded body 30.
• the coating layer may have the effect of adjusting the adhesive strength (P molding-label ) between the molded body and the label to a desired value, and the material is not limited within the range of such an effect.
• the coating layer is preferably a layer containing a polar resin that does not have heat sealability (hereinafter, may be simply referred to as "polar resin").
• polar resin a polar resin that does not have heat sealability
• not having heat sealability 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 has the effect of suppressing the thermal fusion of the molded body to the base layer and adjusting the adhesive strength (P molding - label ) between the molded body and the label to a desired value.
• the effect of adjusting the adhesive strength (P molding - label ) between the molded body and the label by the coating layer containing a polar resin is particularly remarkable.
• Examples of polar resins that do not have heat sealability include ethyleneimine resins, and cationic polymer-type antistatic agents having an ammonium salt structure, a phosphonium salt structure, or the like.
• Examples of the ethyleneimine-based resin include polyethyleneimine, poly(ethyleneimine-urea), ethyleneimine adducts of polyamine polyamides, alkyl-modified products, 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 of these.
• 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.
• the thickness of the coating layer containing the polar resin is preferably 0.01 ⁇ m or more, more preferably 0.02 ⁇ m or more, and even more preferably 0.03 ⁇ m or more, in order to appropriately reduce the adhesion between the outermost layer of the molded body and the base layer. It is also preferable that the thickness is 1.5 ⁇ m or less, more preferably 1.0 ⁇ m or less, and even more preferably 0.5 ⁇ m or less.
• 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. It is preferable that the surface of the substrate on which the coating layer is to be formed is activated by a corona discharge treatment so that the adhesion and wettability of the coating layer are improved.
• a release varnish layer can also be used as the coating layer.
• release varnish include varnishes to which silicone resins have been added, and varnishes to which fluorine compounds have been added.
• the release varnish layer is preferably provided at an area ratio of about 40 to 80% relative to 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 ⁇ m or more, more preferably 0.5 ⁇ m or more, in order to appropriately reduce the adhesive strength between the outermost layer of the molded body and the substrate layer.
• the thickness is 10 ⁇ m or less, and more preferably 5 ⁇ m or less.
• the coating layer only needs to have the effect of adjusting the adhesive strength (P molded body-label ) between the molded body and the label to a desired value, and the layer thickness may vary, and may be arranged in a non-uniform shape such as a dot shape.
• the label in a labeled molded article produced using a molding method such as blow molding in which the molding temperature is not so high and the resin pressure during molding is not so high, the label preferably has a heat seal layer.
• the heat seal layer include known ones, and it is preferable that the heat seal layer contains a thermoplastic resin having a low melting point of about 60 to 130°C.
• thermoplastic resin used in the heat seal layer include low- or medium-density polyethylene having a density of 0.900 to 0.935 g/cm 3 , linear polyethylene having a density of 0.880 to 0.940 g/cm 3 , ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid alkyl ester copolymer, ethylene-methacrylic acid alkyl ester copolymer having an alkyl group with 1 to 8 carbon atoms, and polyethylene-based resins having a melting point of 60 to 130° C., such as metal salts of ethylene-methacrylic acid copolymers such as Zn, Al, Li, K, and Na.
• low- or medium-density polyethylene having a crystallinity of 10 to 60% measured by the X-ray method and a number average molecular weight of 10,000 to 40,000, or linear polyethylene are preferred.
• the heat seal layer may have a single layer structure or a multilayer structure.
• the thickness of the heat seal layer (total thickness in the case of a multilayer structure) is preferably 0.5 ⁇ m or more, more preferably 0.7 ⁇ m or more, and even more preferably 1 ⁇ m or more.
• the thickness is preferably 10 ⁇ m or less, more preferably 7 ⁇ m or less, and even more preferably 5 ⁇ m or less. Therefore, the thickness of the heat seal layer is preferably 0.5 to 10 ⁇ m, more preferably 0.7 to 7 ⁇ m, and even more preferably 1 to 5 ⁇ m.
• the coating layer In order to adjust the adhesive strength between the heat seal layer and the molded body to a desired range, it is preferable to provide a coating layer on the surface of the heat seal layer facing the molded body.
• the coating layer include the same layers as those listed in the first embodiment, and the preferred layers are also the same.
• ⁇ Third embodiment label having a base layer and a brittle heat seal layer>
• This embodiment is a case where the label has a heat seal layer that is brittle and has low strength.
• the label can be peeled off from the molded article by the 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.
• thermoplastic resin composition which is the molten molded article material, penetrates into the openings in the heat seal layer surface, so that the layer is firmly attached to the molded article surface by the anchoring effect, but since the heat seal layer itself is brittle and has low strength, it can be easily peeled off from the molded article by the cohesive failure of the layer.
• the heat seal layer 23 is peeled off so that a part 23a of the heat seal layer is peeled off together with the label 20, and another part 23b of the heat seal layer remains on the molded article, as shown in FIG. 6.
• the heat seal layer which is a porous resin layer with an open surface (hereinafter, sometimes simply referred to as a "porous heat seal layer”), is preferably produced by stretching a resin composition containing a thermoplastic resin and a filler.
• a resin composition containing a thermoplastic resin and a filler.
• Thermoplastic resins include, for example, blends of crystalline polypropylene and thermoplastic resins incompatible with the crystalline polypropylene resin.
• the degree of crystallinity of the crystalline polypropylene resin is usually 65% or more, preferably 66% or more, and particularly preferably 67 to 80%. If the degree of crystallinity is 65% or more, the compatibility between the amorphous part contained in the crystalline polypropylene resin and the incompatible thermoplastic resin is less likely to progress, making it easier to achieve the effect of initial interfacial peeling, and making it possible to appropriately reduce the stress (adhesive strength) required for peeling. In addition, if the degree of crystallinity is 80% or less, it is easy to obtain commercially.
• the degree of crystallinity can be determined, for example, by the method described in the pamphlet of International Publication No. 2012/002510.
• 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. Two or more of these can also be mixed and used. Of these, it is preferable to use polyethylene resin from the standpoint of chemical resistance, production costs, and the like.
• the filler contained in the porous heat seal layer can be the same as those listed in the base layer section, but it is particularly preferable that the porous heat seal layer contains an inorganic filler whose surface has been hydrophobized.
• an inorganic filler that has been hydrophobized By using an inorganic filler that has been hydrophobized, interfacial peeling between the filler and the crystalline polypropylene is more likely to occur, making it possible to provide a label that is easier to separate from the molded product.
• Examples of the surface treatment agent used in the above hydrophobic treatment include paraffin, fatty acid having 12 to 22 carbon atoms, or a salt thereof.
• the average particle size of the filler is preferably 0.1 ⁇ m or more, more preferably 0.2 ⁇ m or more, and is preferably 5 ⁇ m or less, more preferably 2 ⁇ m or less, and even more preferably 0.5 ⁇ m or less. Since fine and uniform pores can be formed in the porous heat seal layer, the average particle size is preferably relatively small, and light calcium carbonate having uniform particle size and shape is preferably used.
• the porous heat seal layer contains a blend of a crystalline polypropylene resin and a thermoplastic resin that is incompatible with the crystalline polypropylene resin, usually at 30 to 60% by mass, preferably at 35 to 50% by mass, and a filler, usually at 40 to 70% by mass, preferably at 50 to 65% by mass.
• the heat seal layer is preferably stretched in at least one axial direction.
• the porous heat seal layer can be made to have many interconnected pores inside. Therefore, when a label having this layer is attached to a molded body, even if air remains between the heat seal layer and the molded body, it is pushed out through the interconnected pores into the resin and discharged to the outside, so it is less likely to remain between the two and cause swelling in the label, which is preferable.
• 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.
• surface opening rate refers to the area ratio that is occupied by pores in the observation area when the surface of the heat seal layer facing the molded body is observed with an electron microscope.
• the porosity of the porous heat seal layer is preferably 20 to 65%, more preferably 30 to 55%, and particularly preferably 35 to 50%. If the porosity is 20% or more, sufficient adhesiveness tends to be easily obtained. If the porosity is 60% or less, the layer is unlikely to break during stretch molding.
• the surface opening rate and porosity can be determined by the method described in International Publication No. 2012/002510.
• the porous heat seal layer may contain a filler dispersant or various known additives as necessary, provided that the effects of the present invention are not impaired.
• the heat seal layer may be a single layer or may have a multi-layer structure.
• each layer may be a single layer or a laminate of multiple layers, and a printing layer (print-receiving layer) may be provided on the surface of the base layer opposite the heat seal layer.
• the label may have layers other than those described above, as long as the effects of the present invention are not impaired.
• Each layer may be unstretched or stretched. Layers with or without stretching and with different numbers of stretching axes may be combined, and it is preferable that one or more layers are stretched.
• the heat seal layer may have a variation in thickness, and may have a specific shape embossed on the surface by embossing, which will be described later.
• the method for producing the label of this embodiment is not particularly limited, and the label can be produced, for example, by forming a film of a base layer and an optional layer such as a heat seal layer, and laminating them.
• Examples of the method for forming the film of each layer include film forming methods such as extrusion molding (cast molding) using a T-die, inflation molding using a round die, and calendar molding using a rolling roll.
• the method for laminating each film examples include a coextrusion method, an extrusion lamination method, a coating method, etc., and these methods can be combined.
• the coating layer is preferably formed by a coating method.
• the surface of the heat seal layer may be embossed. By forming projections and recesses on the surface of the heat seal layer by embossing, it is possible to suppress the occurrence of blisters when a label is attached to a molded article.
• Each layer may be a non-stretched film or a stretched film.
• each layer may be stretched individually before lamination, or may be stretched together after lamination.
• the non-stretched layer and the stretched layer may be stretched again after lamination.
• the stretching method can be appropriately selected from known methods such as a longitudinal stretching method utilizing the difference in peripheral speed between rolls, a transverse stretching method utilizing a tenter oven, and a sequential biaxial stretching method combining these methods.
• the molded body of the present embodiment is not particularly limited as long as it contains a thermoplastic resin at least in the surface layer. It is preferable that the molded body is composed of a thermoplastic resin not only in the surface layer but also in the whole body, because it is advantageous in manufacturing.
• the thermoplastic resin of the molded body include high-density polyethylene, polypropylene, polyester, polystyrene, polyvinyl chloride, polycarbonate, etc., and among them, high-density polyethylene, polypropylene, polyester, and polystyrene are suitable.
• the labeled molded body of this embodiment can be obtained, for example, by direct blow molding, in which a molten resin parison is compressed 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 body is injected into a mold using an injection device and then cooled and solidified.
• direct blow molding in which a molten resin parison is compressed 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 body is injected into a mold using an injection device and then cooled and solidified.
• labeled molded products can be obtained by differential pressure molding. After placing a label and an RFID inlay on the inner surface of the lower female die of a differential pressure molding die, the label is fixed to the inner wall of the die by suction, and then the thermoplastic resin composition for producing the molded product is introduced above the lower female die, and the label is fused integrally to the outer wall of the molded product by differential pressure.
• Either vacuum molding or compressed air molding can be used for differential pressure molding, but generally, differential pressure molding that uses both in combination and utilizes plug assist is preferred.
• 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 to the RFID inlay is in contact with the inner wall of the mold, and then molding may be performed, or an RFID inlay may be placed on the label in the mold, and then a thermoplastic resin composition may be introduced into the mold to mold.
• the adhesive strength between the molded product and the RFID inlay is due to the compatibility between the thermoplastic resin contained in the outermost layer of the molded product and the thermoplastic resin contained in the surface that contacts the outermost layer of the molded product, such as the support layer of the RFID inlay or the sealing resin.
• the adhesive strength between the molded product and the RFID inlay can be kept low by using resins that are poorly compatible with each other.
• the RFID inlay may be adhered or placed and molded onto the surface of the heat seal layer.
• the shape of the molded product of this embodiment is not limited, and includes various molded products obtained by the above-mentioned production method, such as bottles, cups, squeeze containers, container lids, boxes, and other molded products of various shapes.
• the labeled molded body of this embodiment can be easily separated into the molded body, the label, and the RFID inlay by a general recycling process. In a general recycling process, the collected used molded body is crushed into flakes by a crusher, and then the molded body and the label are separated by utilizing the difference in specific gravity. In the labeled molded body of this embodiment, the label is easily peeled off from the molded body in the crushing process.
• the IC chip and RFID antenna parts contained in the RFID inlay are also separated from the molded body and label flakes, which have different specific gravities.
• the molded body flakes and label flakes can be collected with high purity, and high recyclability can be achieved.
• Example 1 As the material 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 shape through a die, and cooled to 70° C. in a cooling device to obtain a single-layer unstretched film. After heating this unstretched film to 145° C., it was stretched 5 times in the longitudinal direction by utilizing the peripheral speed difference between multiple rolls to obtain a longitudinal uniaxially stretched film.
• materials for forming the porous heat seal layer were melt-kneaded in an extruder set at 250°C, consisting of 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, dispersants.
• the materials were extruded into a sheet through a die and laminated on one side of the longitudinally uniaxially stretched film.
• the porous heat seal layer was guided between a metal cooling roll with a #150 line gravure embossing and a matte rubber roll so that the porous heat seal layer side was in contact with the metal cooling roll, and the two were joined by narrow pressure while the embossing pattern was transferred to the porous heat seal layer side.
• the laminate was cooled by the cooling roll to obtain a two-layer structure.
• the obtained 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)/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 ⁇ m, of which the thickness of the porous heat seal layer was 6 ⁇ m, and the porosity of the porous heat seal layer was 60%.
• an RFID inlay (support thickness 60 ⁇ m, antenna thickness 20 ⁇ m, IC chip thickness 140 ⁇ m) with an antenna and 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 punched out into a rectangle 70 mm wide and 90 mm long, to obtain a label with an RFID inlay attached.
• Example 2 Label production and molding were carried out in the same manner as in Example 1, 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 third embodiment.
• Example 3 Labels with RFID inlays attached were manufactured in the same manner as in Example 1, except that the size of the labels was changed to a rectangle of 120 mm wide and 150 mm long, and molded articles were obtained by the following direct blow molding method instead of injection molding. Note that "Blow” in Table 2 stands for direct blow molding.
• a direct blow molding machine (Tahara Corporation, machine name: TPF-706B-E1) and a mold capable of molding a container with a capacity of 3 L were used, and the label was placed on one side of the mold so that the porous heat seal layer of the label faced the cavity side (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, which was then introduced between the halves of the mold and the halves were then clamped.
• 0.5 MPa compressed air was supplied into the parison, which expanded the parison and caused it to adhere closely to the mold to form a container shape and to adhere the label to it.
• the halves were then cooled with 20°C cooling water for 20 seconds. After cooling, the mold was opened to obtain a labeled molded body of the third embodiment.
• Example 4 A label was produced and molded in the same manner as in Example 3, except that the resin for forming a molded body, HDPE-3 shown 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.
• 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.
• 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.
• Example 7 As the material 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 shape through a die, and cooled to 70° C. in a cooling device to obtain a single-layer unstretched film. After heating this unstretched film to 145° C., it was stretched 5 times in the longitudinal direction by utilizing the peripheral speed difference between multiple rolls to obtain a longitudinal uniaxially stretched film.
• the obtained uniaxially longitudinally 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 ⁇ m.
• a corona discharge treatment was performed on one side of the obtained base layer using a corona discharge treatment device (manufactured by Kasuga Electric Co., Ltd., device name: HF400F).
• a corona discharge treatment device manufactured by Kasuga Electric Co., Ltd., device name: HF400F.
• the gap between an aluminum discharge electrode having a length of 0.8 m and a treater roll was set to 5 mm, the line treatment speed was 15 m/min, and the applied energy density was 4200 J/ m2 .
• PEI (30 mass% aqueous solution), which is a coating layer material, was applied to the side on which the corona discharge treatment was performed so that the solid content after drying was 0.2 g/ m2 .
• a bar coater was used for coating.
• 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 ⁇ m.
• 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 (the resin side of the molded body) and fixed onto the mold by suction. After that, injection molding was performed in the same manner as in Example 1 to obtain a labeled molded body of the first embodiment.
• 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.
• Example 9 As the material 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 shape through a die, and cooled to 70° C. in a cooling device to obtain a single-layer unstretched film. After heating this unstretched film to 145° C., it was stretched 5 times in the longitudinal direction by utilizing the peripheral speed difference between multiple rolls to obtain a longitudinal uniaxially stretched film.
• the 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 longitudinally uniaxially stretched film.
• the heat seal layer was guided between a metal cooling roll with a #150 line gravure embossing 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 narrow pressure while the embossed pattern was transferred to the heat seal layer side, and the laminate was cooled by the cooling roll to obtain a laminate with a two-layer structure.
• 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 ⁇ m, of which the heat seal layer was 3 ⁇ m thick.
• a corona discharge treatment was performed on the heat seal layer surface of the obtained laminated resin film using a corona discharge treatment device (manufactured by Kasuga Electric Co., Ltd., device name: HF400F).
• a corona discharge treatment device manufactured by Kasuga Electric Co., Ltd., device name: HF400F.
• the gap between an aluminum discharge electrode having a length of 0.8 m and a treater roll was set to 5 mm, the line treatment speed was 15 m/min, and the applied energy density was 4200 J/m 2.
• PEI (30 mass% aqueous solution), which is a coating layer material, was applied to the surface on which the corona discharge treatment was performed so that the solid content after drying was 0.2 g/m 2.
• a bar coater was used for coating.
• the film was dried in an oven to obtain a laminated resin film (second embodiment) having a base layer and a heat seal layer, and having a coating layer on the molded body side surface of the heat seal layer.
• the thickness of the heat seal layer at this time was 3 ⁇ m, and the thickness of the coating layer was 0.2 ⁇ m.
• Example 2 the label was prepared and molded in the same manner as in Example 1 to obtain a labeled molded product of the second embodiment.
• the labels produced in each of the Examples and Comparative Examples 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.
• the cut surface was metallized by metal deposition, and then the cross-sectional thicknesses of the heat seal layer and the coat layer were photographed at 3000 times magnification using a scanning electron microscope (manufactured by JEOL Ltd., device name: Neoscope JCM-6000) to measure the thickness.
• 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 area of the void region partitioned by the thermoplastic resin composition was divided by the area of the entire observation region to calculate the cross-sectional porosity. The inorganic filler in the voids observed in the cross-sectional image was treated as a void.
• the labeled portion of the molded article was cut into a 15 mm wide strip 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 measured by T-peeling at a tensile strength of 300 mm/min using a tensile tester (manufactured by A&D Co., Ltd., device name: Tensilon RTG-1225).
• the adhesive strength between the RFID inlay and the molded article was very weak, and it was impossible to evaluate the adhesive strength.
• the RFID inlay peeled off from the molded article. This is thought to be because the support of the RFID inlay was a polyethylene terephthalate (polar resin) film, while the resin for forming the molded article was polyolefin (non-polar resin), and therefore they were hardly (substantially) adhered to each other.
• polar resin polyethylene terephthalate
• non-polar resin non-polar resin
• 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.
• A1, A2 or A3 was judged to be suitable for practical use.
• A1 The RFID inlay is peeled off from the molded body and adhered to the label.
• A2 The RFID inlay is peeled off from the molded body and partially peeled off from the label.
• A3 The RFID inlay is peeled off from the molded body and also peeled off from the label.
• C The RFID inlay does not peel off from the molded body.
• Table 2 shows the configuration of the labeled molded article and the evaluation results.
• Example 1 to 6 the state of the labeled molded body after crushing was such that a thin layer of the porous heat seal layer that had undergone cohesive failure remained on the surface of the crushed molded body pieces, but the label's base layer and RFID inlay were not present.
• the RFID inlay and the label were adhered to the crushed label pieces, but the brittle heat seal layer was destroyed by the shearing force during the crushing test, and some of the RFID inlay pieces peeled off from the label pieces.
• the adhesive for the RFID inlay to an easy-adhesive type in Example 6 the label pieces and RFID inlay pieces after crushing could be completely separated.
• the RFID inlay was completely peeled off from the molded body in the crushing test.
• the adhesive strength between the RFID inlay and the molded body was very weak, and when a measurement sample containing the RFID inlay was cut into a strip 15 mm wide, 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, there was almost (substantially) no adhesion between the molded body and the RFID inlay.
• the labels were completely peeled off from the molded articles in the crushing test, and no heat seal layer or layer derived from the label remained on the surface of the molded article piece.
• This is considered to be the result of the polar resin contained in the coating layer not showing adhesiveness to the polyolefin (non-polar resin) which is the main component of the molded article, and therefore the coating layer played a role in reducing the adhesiveness between the label and the molded article and adjusting the adhesive strength to the range specified in the present invention.
• the adhesive strength between the RFID inlay and the molded body in Examples 7 and 8 was similar to that in Examples 1 to 6, and the RFID inlay was completely peeled off from the molded body in the crushing test. In addition, because the adhesion between the RFID inlay and the label was strong, the RFID inlay was attached to the crushed label pieces.
• the labeled molded product of Comparative Example 1 had a higher adhesive strength between the label and the molded product than Examples 1 to 9. This is believed to be because the heat seal layer was firmly attached to the molded product. Furthermore, with the labeled molded product of Comparative Example 1, the label and the molded product could not be separated after the crushing test.

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