WO2020199160A1

WO2020199160A1 - Logistic labels

Info

Publication number: WO2020199160A1
Application number: PCT/CN2019/081262
Authority: WO
Inventors: Weiyu Zhang; Qihong Liu
Original assignee: Avery Dennison Corporation
Priority date: 2019-04-03
Filing date: 2019-04-03
Publication date: 2020-10-08
Also published as: CN210667489U; CN111785154A

Abstract

A label comprises an adhesive layer (4) disposed beneath a detachable multi-layer film (7) composition. The multi-layer film (7) of the label comprises a thermal layer (10) for receiving printing and can be disassembled upon application of an appropriate force. The multi-layer film (7) does not comprise any adhesive, which renders it easy to be disassembled when needed and also function consistently under different environmental conditions. The multi-layer film (7) is produced by a co-extrusion process, which is cost-effective and efficient.

Description

LOGISTIC LABELS

FIELD

This disclosure relates to a label comprising a detachable multi-layer film composition with an adhesive layer disposed beneath it. The multi-layer film composition can be disassembled with ease upon application of an appropriate force. The multi-layer film composition has a specific configuration and components, which provides for the disassembly and promotes consistent performance of the label under different environmental conditions.

BACKGROUND

Labels for different applications often require different configurations and compositions. Logistic labels are those used to label postal packages. It is desirable for logistic labels to possess both good printability, so that mailing information is clearly visible, and good adhesion, so that they can remain securely attached to the package during shipment and storage. It is also desirable that the portion of the label that contains the mailing information can be detached from the substrate upon delivery, such that the mail carrier can retain the detached portion for record keeping and proof of delivery. The detached portion used for record-keeping needs to be non-sticky for the ease of record-keeping. Lastly, it is also desirable for the label to be able to perform consistently under different environmental conditions as packages affixed with such labels often need to be shipped over long distance across a wide range of climates.

Conventional logistic labels are expensive to manufacture and they perform poorly under different environmental conditions. These labels typically each contains at least five layers: a direct thermal paper which include the mailing information, a water-borne adhesive, a middle layer, a permanent adhesive layer, and a liner. FIG. 1A shows an example of a conventional label having: a direct thermal paper 1, a detachable adhesive layer 2, a middle layer 3, an adhesive layer 4, and a liner 5. The water-borne adhesive is used to keep the portion of the label that displays the mailing information securely attached to the package during shipment and storage. Once the water-borne adhesive is detached from the package and becomes dry, it becomes non-sticky and the detached portion can be kept for records. FIG. 1B illustrates what occurs to the conventional label when a mail carrier separates the portion containing the mailing information from the rest of the label: layer 2 and layer 3 become separated from one another, which produces i) a detached portion comprising the direct thermal paper (layer 1) with printed mailing information) and the water-borne adhesive layer (layer 2) ; and ii) an attached portion comprising the middle layer (layer 3) and the permanent adhesive layer (layer 4) , which remains affixed to the package.

There are a number of drawbacks associated with the conventional logistic labels. First, using the water-borne adhesive and the thermal paper in the label may create problems during package shipment. For example, the water-borne adhesive, as well as the thermal paper, may absorb water and expand in a high humidity environment, and lose water and shrink in a low humidity environment. This will cause the label to deform and even detach from the substrate. Another drawback associated with the conventional logistic label is that separate processes, in some cases, performed by different manufacturers, are required to produce the individual layers of the label. This may increase production costs significantly. Thus, a need exists for logistic labels that efficiently disassemble into a detached portion and an attached portion; are weather-resistant, e.g., being able to perform consistently under different environmental conditions; and can be manufactured in a cost-effective manner.

SUMMARY OF THE INVENTION

In some embodiments, this disclosure provides a label comprising: a multi-layer film composition comprising: a first layer, a filler layer, and a second layer, and an adhesive layer, wherein the multi-layer film composition does not comprise any adhesive. The first layer, the filler layer and the second layer may be produced by a co-extrusion process.

In some embodiments, the detachable multi-layer film composition further comprises a direct thermal layer. In some embodiments, the multi-layer film composition does not comprise fibrous materials. In some embodiments, the direct thermal layer comprises an inorganic filler, a color developer, a color former, a lubricant, or combinations thereof. In some embodiments, the first layer and/or second layer comprise one or more resins selected from the group consisting of polypropylene (PP) , polyethylene (PE) , polystyrene (PS) and polyethylene terephthalate (PET) . In some embodiments, the filler layer is located between the first layer and the second layer, wherein the second layer is configured to be applied to a substrate. In some embodiments, the first layer is thicker than the second layer.

The first layer may have a thickness ranging from 10 to 100 μm. The second layer has a thickness of 5 to 50 μm. In some embodiments, when a force is applied to dissemble the label affixed to a package, the first layer is detached from the package and the second layer remain attached to the package. In some embodiments, when the force is applied, the filler is also dissociated from the package. In some embodiments, when the force is applied, the filler remains attached from the package.

In some embodiments, the adhesive layer is disposed beneath the multi-layer film layer. The adhesive layer may comprise a pressure sensitive adhesive. In some embodiments, the adhesive layer has a thickness ranging from 5 to 50 μm. In some embodiments, the liner has a thickness ranging from 10 to 80 μm. The label may further comprise a liner disposed beneath the adhesive layer.

The detachable multi-layer film layer may have a thickness ranging from 33 to 350 μm. The filler layer may have a thickness of 1 to 50 μm. In some embodiments, the ratio of the thickness of the first layer to the second layer ranges from 10: 1 to 1: 1. In some embodiments, the ratio of the thickness of the second layer to the filler layer ranges from 10: 1 to 1: 1. In some embodiments, the filler layer comprises calcium carbonate, clay, silica, titania, or combinations thereof.

In some embodiments, the direct thermal layer is configured to receive printing. Printing on the direct thermal layer may be one or more of the following: thermal transfer printing, flexo printing, and letterpress printing. In some embodiments, the peel strength of adhesive layer of the label ranges from 15 to 300 N/inch. In some embodiments, the bond force between the first layer and the filler layer ranges from 10 to 400 g/inch.

The label of any of the embodiments above may be used on a postal package.

Also provided in this disclosure is a multi-layer film composition comprising: a first layer, a filler layer, and a second layer, wherein the detachable multi-layer film composition does not comprise any adhesive. In some embodiments, wherein the first layer, the filler layer and the second layer are produced by a co-extrusion process. In some embodiments, the multi-layer film composition further comprises a direct thermal layer. In some embodiments, the multi-layer film composition does not comprise fibrous materials. In some embodiments, this disclosure provides a labeled package comprising a label of any of the preceding claims or a multi-layer film composition of any of the preceding claims.

Also provided in this disclosure is a method of producing a label comprising: producing a multi-layer film composition by a co-extrusion process, wherein the multi-layer film composition comprises a first layer, a filler layer, and a second layer, wherein the multi-layer film composition does not comprise any adhesive, and disposing the multi-layer film composition as a layer over an adhesive layer. In some embodiments, the method further comprises disposing a liner underneath the adhesive layer. In some embodiments, the method further comprises disposing a direct thermal layer over the multi-layer film composition layer, wherein the direct thermal layer is configured to receive printing. In some embodiments, the method further comprises printing information on the direct thermal layer via thermal transfer printing, flexo printing, or letterpress printing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows an example of a conventional label having: a direct thermal paper 1, a detachable adhesive layer 2, a middle layer 3, an adhesive layer 4, and a liner 5.

FIG. 1B shows an example of a conventional label being dissembled when a mail carrier separates the portion containing the mailing information from the rest of the label: layer 2 and layer 3 become separated from one another, which produces i) a detached portion comprising the direct thermal paper (layer 1) with printed mailing information) and the water-borne adhesive layer (layer 2) ; and ii) an attached portion comprising the middle layer (layer 3) and the permanent adhesive layer (layer 4) , which remains affixed to the package.

FIG. 2A shows an exemplary embodiment of a label of this disclosure. The label contains a multi-layer film composition 7, an adhesive layer 4, and a liner 5. The multi-layer film composition layer 7 comprises a direct thermal layer 10, a first layer 11, a filler layer 12, and a second layer 13.14 refers to the combination of the first layer, the filler layer, and the second layer.

FIG. 2B shows an exemplary embodiment label of this disclosure being dissembled, when a mail carrier separates the portion containing the mailing information from the rest of the label.

Layers

10 and 11 become dissociated from the substrate upon exertion of an appropriate force, and layers 12, 13 and 4, remain on the substrate when the force is applied.

FIG. 3A illustrates a co-extrusion process that may be used to produce the first layer, the filler layer, and the second layer of the multi-layer film composition of the label. FIG. 3B shows stretching of the layers after they are produced by the co-extrusion process to form the multi-layer film composition.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to a logistic label comprising a detachable multi-layer film composition with an adhesive layer disposed beneath it. The multi-layer film composition comprises a first layer, a filler layer, and a second layer, all of which can be produced simultaneously by a cost-effective co-extrusion process. The label has good adhesion properties and remains intact and affixed to the substrate in the absence of an external force. When subjected to an appropriate external force, such as peeling, the multi-layer film disassembles, which results in the label being separated into two portions: i) a detached portion, which is separated from the substrate; and ii) an attached portion, which remains affixed to the substrate. Importantly, the multi-layer film layer does not comprise any adhesive, which advantageously minimizes the possibility of deformation when the label is subjected to different environmental conditions. The multi-layer film may also comprise a non-fibrous, direct thermal layer, which possess good printing quality and can be used for displaying printed information.

For purpose of this disclosure, the terms “over” and “beneath” refer to the relative positions of two layers that are in direct contact with each other. For example, in FIG. 2B, layer 10 is over layer 11, and layer 11 is beneath layer 10. For avoidance of doubt, layer 10 is not over layer 12.

For purposes of this disclosure, the term “detached” refers to two layers or portions of the label that were previously in direct contact with one another and have become separated and no longer in direct contact. The term “attached” , used interchangeably with the term “affixed” , refers to layers or portions of a label that are in direct contact with one another. For example, in FIG. 2B, after the disassembling of the label, layer 10 remains attached to layer 11, but layer 11 is detached from layer 12.

For purposes of this disclosure, the term “associated” refers to two objects that are connected to each other directly, or indirectly through an intermediate. The term “dissociated” refers to two objects that are not connected either directly or indirectly. For example, in FIG. 2B, after the disassembling of the label, layer 10 and/or layer 11 are dissociated from the substrate, while layer 12 remains associated with the substrate (via layer 13) .

As disclosed herein, when subjected to an appropriate force, the label is separated into two portions: an attached portion and a detached portion. The portion that remains attached to the substrate is the attached portion; and the other portion that is dissociated from the substrate is the detached portion. The detached portion may be referred to as such even when the label was still intact, e.g., before the exertion of the external force to disassemble the label.

Unless expressly stated to the contrary, the orientation of the layers disclosed herein is defined in a way such that the bottom of the label is the portion that is closest to the substrate when contacting the substrate, and the top of the label is the portion that is farthest away from the substrate.

Detachable multi-layer film composition

The multi-layer film composition of the label is disposed over the adhesive layer of the label. The multi-layer film composition comprises a first layer, a filler layer, a second layer, and optionally a direct thermal layer. The filler layer is located between the first layer and the second layer. The second layer is configured to be applied to a substrate, for example, a postal package.

Unlike conventional logistic labels described above, the multi-layer film composition of the label disclosed herein does not comprise any adhesives, e.g. water-born adhesives, which advantageously avoids deformation problems associated with having adhesives in the detachable portion of the label, as discussed above. The first layer, the second layer, and the filler layer can be produced by a co-extrusion process, which allows the layers to have sufficient bonding force to connect, without the need of using an adhesive. Not including an adhesive in the detachable portion of the label also reduces the production cost of the label significantly.

FIG. 2A shows an exemplary embodiment of the label of this disclosure. The label contains a multi-layer film composition 7, an adhesive layer 4, and a liner 5. The multi-layer film composition layer 7 comprises a direct thermal layer 10, a first layer 11, a filler layer 12, and a second layer 13.14 refers to the combination of the first layer, the filler layer, and the second layer. As shown below and in FIG. 2B, some layers, e.g., layers 10 and 11, may constitute an detached portion, which becomes dissociated from the substrate upon exertion of an appropriate force, and some layers, e.g., layers 12, 13 and 4, may constitute an attached portion, which remains on the substrate when the force is applied.

The first layer and the second layer of the multi-layer film composition may comprise the same or different compositions, and they may comprise one or more resins selected from the group consisting of polypropylene (PP) , polyethylene (PE) , polystyrene (PS) , and polyethylene terephthalate (PET) . In some embodiments, both the first layer and the second layer comprise polypropylene.

The first layer may have a thickness that ranges from 10 to 100 μm, e.g., from 20 to 80 μm, from 30 to 70 μm, from 40 to 80 μm, or from 50 to 75 μm. In terms of upper limits, the thickness of the first layer may be less than 100 μm, less than 80 μm, less than 75 μm, or less than 70 μm. In terms of lower limits, the thickness of the first layer may be greater than 10 μm, greater than 20 μm, greater than 30 μm, or greater than 40 μm.

The second layer may have a thickness that ranges from 5 to 50 μm, e.g., from 6 to 40 μm, from 8 to 30 μm, from 10 to 20 μm, or from 12 to 25 μm. In terms of upper limits, the thickness of the second layer may be less than 50 μm, less than 40 μm, less than 30 μm, or less than 25 μm. In terms of lower limits, the thickness of the second layer may be greater than 5 μm, greater than 6 μm, greater than 8 μm, or greater than 10 μm. In some cases, the second layer 13 is thicker than the first layer. As further discussed below, when the mail carrier exerts a force in an attempt to separate a portion of the label to keep as a record of delivery, the first layer 11 is dissociated from the substrate and the second layer 13 remains attached to the substrate.

In some embodiments, the ratio of the thickness of the first layer to the thickness of the second layer typically ranges from 10: 1 to 1: 1, e.g., from 8: 1 to 1.2: 1, from 7: 1 to 1.5: 1, from 5: 1 to 1.5: 1 or about 2: 1. In terms of upper limits, the ratio is less than 10: 1, less than 8: 1, less than 7: 1, or less than 5: 1. In terms of lower limits, the ratio is greater than 1: 1, greater than 1.2: 1, or greater than 1.5: 1.

The inventors have discovered that maintaining the thickness of the two layers within the appropriate ranges and ratios as described above surprisingly has a number of advantages, including the ability to withstand the exerted force and minimizing the production cost. The first layer and the second layer can be of equal thickness. In some cases, however, there are advantages to the first layer being thicker than the second layer. For example, the first layer may be relatively thick so that it has sufficient strength to withstand the exerted force and will not break. The second layer may be relatively thin so that it does not affect the appearance of the substrate. This is particularly useful in scenarios where the substrate itself comprises useful information that needs to be visible; having a relatively thin second layer can avoid compromising the visibility.

The multi-layer film composition disclosed herein comprises a filler layer, which is typically located between the first and the second layers. Non-limiting examples of materials that can be used in the filler layer include calcium carbonate, clay, silica, titania, tale, organo-clay, glass fibers, marble dust, cement dust, feldspar, silica or glass, fumed silica, silicates, alumina, various phosphorus compounds, ammonium bromide, titanium dioxide, antimony trioxide, antimony trioxide, zinc oxide, zinc borate, barium sulfate, silicones, aluminum silicate, calcium silicate, glass microspheres, chalk, mica, wollastonite, ammonium octamolybdate, intumescent compounds and mixtures of two or more of these materials. The filler layer may also carry or contain various surface coatings or treatments, such as silanes, fatty acids, and the like. Still other fillers can include flame-retardant agents, such as the halogenated organic compounds. In certain embodiments, the filler layer may include one or more thermoplastic elastomers that are compatible with the other constituents of the layer, such as etherified melamine, hydroxylated polyester, polyester-melamine, and other suitable elastomers.

Inserting a filler layer between the first layer and second layer advantageously allows easy separation of the first layer (together with the direct thermal layer, as described below) from the second layer (which will remain attached to the substrate) when a user applies an appropriate force to the label.

The inventors have found that it is advantageous to maintain the thickness of the filler layer within appropriate ranges to achieve the balanced performance properties of: i) the first layer, the filler layer and the second layer can maintain sufficient bonding to one another in the absence of an external force, and ii) the first layer and the second layer can be easily separated upon the exertion of an appropriate force. A higher value in thickness allows easier separation of the first and second layers when such separation is desired, e.g., when an appropriate force is applied, but a very high value in thickness may weaken the bond between the layers in the multi-layer composition such that portions of it becomes loose when separation is not intended. The filler layer of the logistic labels disclosed herein may have a thickness that ranges from 1 to 50 μm, from 2 to 45 μm, from 5 to 40, from 8 to 35 μm, or from 10 to 30 μm. In terms of upper limits, the thickness of the filler layer is less than 50 μm, less than 45 μm, less than 40 μm, or less than 35 μm. In terms of lower limits, the thickness of the filler layer is greater than 1 μm, greater than 2 μm, greater than 5 μm, or greater than 8 μm.

In some embodiments, the ratio of the thickness of the second layer to the thickness of the filler layer typically ranges from 50: 1 to 1: 1, e.g., from 20: 1 to 1.2: 1, from 10: 1 to 1.5: 1, e.g., from 8: 1 to 2: 1, from 7: 1 to 3: 1, or about 2: 1. In terms of upper limits, the ratio is less than 50: 1, less than 20: 1, less than 10: 1, or less than 8: 1. In terms of lower limits, the ratio is greater than 1: 1, greater than 1.2: 1, or greater than 1.5: 1.

The multi-layer film composition may further comprise a direct thermal layer directly coated on the first layer. In some embodiments, the direct thermal layer is configured to receive printing. Unlike conventional logistic labels, the detached portion (for example,

layer

1 and 2 as shown in FIG. 1B) comprises a direct thermal paper (or in some cases, a direct thermal layer coated on a paper layer) for printing, the multi-layer film composition of the logistic label disclosed herein does not comprise any fibrous materials, e.g., plant fibers, including but not limited to, paper. Thus, in some embodiments, the multi-layer film composition is non-fibrous. As compared to fibrous materials, using any of the above-mentioned materials in the direct thermal layer not only confers excellent printing quality, but also minimizes water absorption from a humid environment and ensures consistent performance of the label across different environmental conditions.

The direct thermal layer is configured to receive printing. In some embodiments, the direct thermal layer may comprise an ink-receptive composition that is utilized to form the printable information. A variety of such compositions is known in the art, and these compositions generally include a binder and a pigment, such as silica or talc, dispersed in the binder. Optionally, the direct thermal layer comprises a crosslinker CX-100 (DSM’s polyfunctional aziridine liquid crosslinker) . A number of such ink-receptive compositions are described in US Patent No. 6,153,288, the disclosure of which is hereby incorporated by reference. Printable information can be deposited on the direct thermal layer using various printing techniques, such as screen printing, dot-matrix, ink jet, laser printing, laser marking, thermal transfer, and so on. In some cases, the direct thermal layer is receptive to thermal transfer printing, flexo printing, letterpress printing, and/or ribbon printing.

In some cases, the direct thermal layer may be a layer that utilizes activatable inks, e.g., stimulus-activatable inks, such as (for example) laser-activated, pressure-activated, or temperature-activated inks.

The inks used for printing on the direct thermal layer may vary widely and may include commercially available water-based, solvent-based or radiation-curable inks. Examples of these inks include Sun Sheen (a product of Sun Chemical identified as an alcohol dilutable polyamide ink) ,

MP (a product of Sun Chemical identified as a solvent-based ink formulated for surface printing acrylic coated substrates, PVDC coated substrates and polyolefin films) , X-Cel (a product of Water Ink Technologies identified as a water-based film ink for printing film substrates) , Uvilith AR-109 Rubine Red (a product of Daw Ink identified as a UV ink) and CLA91598F (a product of Sun Chemical identified as a multibond black solvent-based ink) .

The direct thermal layer of the label may comprise an inorganic filler, a color developer, a color former, a lubricant, or combinations thereof. Non-limiting examples of inorganic fillers include Kaolin, calcium carbonate, silicon dioxide, and combinations thereof. Non-limiting examples of developers include bispheol-S, bispheol-A, 2-Anilino-3-methyl-6-dibutylaminofluorane, and 2-Anilino-3-methyl-6-dibutylaminofluorane, and combinations thereof. Non-limiting examples of color formers include 2-Anilino-3-methyl-6-dibutylaminofluorane. Non-limiting examples of lubricants include Zinc stearate and Calcium stearate, and combinations thereof.

The direct thermal layer may be applied onto the first layer of the multi-layer film composition by any known techniques in the art, such as spray, roll, brush, or other techniques. The direct thermal layer can be formed by depositing, by gravure printing or the like, on the first layer.

The detachable multi-layer film composition may be applied as a layer, over the adhesive layer of the label, and the multi-layer film composition layer may have a thickness ranging from 33 to 350 μm, e.g., from 35 to 320 μm, from 40 to 300 μm, from 50 to 280 μm, or from 80 to 250 μm. In terms of upper limits, the thickness of the multi-layer film composition layer is less than 350 μm, less than 320 μm, less than 300 μm, or less than 280 μm. In terms of lower limits, the thickness of the multi-layer film composition layer is greater than 33 μm, greater than 35 μm, greater than 40 μm, or greater than 50 μm.

Disassembling the multi-layer film composition

The multi-layer film composition is configured such that it can be disassembled into the attached portion and the detached portion with ease, e.g., the first layer can be dissociated from the substrate, while leaving the second layer and the adhesive layer remain associated with the substrate. In cases where the multi-layer film also comprises a direct thermal layer, which is affixed to the first layer, the direct thermal layer may also be dissociated from the substrate. The detached portion thus comprises the first layer and the direct thermal layer. As described below, in some cases, the detached portion further comprises the filler layer, or a portion of the filler layer. In some cases, the detached portion does not comprise the filler layer or any portion thereof.

FIG. 2B shows one exemplary configuration of the label that has been disassembled. In this embodiment, the second layer 11 is detached from the filler layer 12, which results in a detached portion comprising a direct thermal layer and the first layer. Other configurations (not illustrated in figures) can also be used for this disclosure. For example, in some embodiments, the filler layer 12 can be separated from the second layer 13, which results in a detached portion comprising the direct thermal layer 10, the first layer 11, and the filler layer 12. In some embodiments, the filler layer 12 breaks, resulting the detached portion comprising a direct thermal layer, a first layer, and a portion of the filler layer.

The adhesive layer

The label disclosed herein comprises an adhesive layer that is disposed beneath the multi-layer film composition. The adhesive layer is not a part of the multi-layer film composition. The adhesive used in the adhesive layer may vary widely and may comprise any adhesive that is effective in binding the label to an external surface of the substrate to which the label may be affixed. In some cases, the adhesive is a pressure sensitive adhesive ( “PSA” ) . For example, the PSA may comprise an epoxy resin, a polymeric resin, a hydroxyl group substituted acrylic polymer, or a polyacrylate, or mixtures thereof. In some cases, the polymeric resin comprises epoxy resin and one or more additional polymeric resins. Polymeric resins that are suitable for the use in the first adhesive layer may include melamine resin or epoxy resin. In some cases, the PSA may comprise a polyacrylate-based PSA. In some cases, the PSA may comprise a high-strength or rubber-modified acrylic PSA, copolymers of alkyl acrylates that have a straight chain of from 4 to 12 carbon atoms and a minor proportion of a highly polar copolymerizable monomer such as acrylic acid, ultraviolet curable PSAs.

The adhesive layer of the label may also comprise a crosslinker, a tackifier, or combinations thereof.

The adhesive layer of the label may have a thickness that ranges from 5 to 50 μm, e.g., from 6 to 45 μm, from 8 to 40 μm, from 10 to 35 μm, or from 12 to 32 μm. In terms of upper limits, the thickness of the adhesive layer is less than 50 μm, less than 45 μm, less than 40 μm, or less than 35 μm. In terms of lower limits, the thickness of the adhesive layer is greater than 5 μm, greater than 6 μm, greater than 8 μm, or greater than 10 μm.

The adhesive used in the adhesive layer of the labels disclosed herein demonstrates good mechanical performance, e.g., high peel strength, such that the adhesive layer can remain affixed to the package, when a force is exerted causing a portion of the label becomes detached. Peel strength is the average force required to remove an adhesive laminated under specified conditions on a substrate, from the substrate at constant speed and at a specified angle. Peel strength evaluations can be performed by testing 180° stainless steel peel for 20 minutes and for 24 hours according to the FINAT Test Method 1 (2018) ( “FINAT-1” ) . In some embodiments, the adhesive with a sufficient peel strength is selected such that the label remains affixed to the substrate during storage and shipment.

In some embodiments, the adhesive demonstrates a peel strength in the range of 15 to 300 N/inch when applied on stainless steel substrate, according to the FINAT-1 method. For example, the adhesive may demonstrate a peel strength ranging from 18 N/inch to 250 N/inch, from 20 N/inch to 220 N/inch, from 25 N/inch to 200 N/inch, and from 30 N/inch to 180 N/inch. In terms of upper limits, the adhesive demonstrated a peel strength of less than 300 N/inch, less than 250 N/inch, less than 220 N/inch, or less than 200 N/inch on stainless steel substrate. In terms of lower limits, the adhesive demonstrated peel strength of greater than 15 N/inch, greater than 18 N/inch, greater than 20 N/inch, or greater than 25 N/inch, on the stainless steel substrate.

Commercial products suitable for use as the adhesive include

80-115 A available from National Starch and Chemical Co. or Aroset ^TM 1860-Z-45 available from Ashland Specialty Chemical Company.

Optionally, the label disclosed herein comprises one or more primer layers, which may be disposed between the adhesive layer and the second layer, between the second layer and the filler layer, between the filler layer and the first layer.

Liner

In some embodiments, the label further includes a releasable liner ( “liner” ) disposed beneath the adhesive layer. The liner may function as a protective cover such that the liner remains in place until the label is ready for attachment to an object. If a liner is included in the label, a wide array of materials and configurations can be used for the liner. In many embodiments, the liner is a paper or paper-based material. In many other embodiments, the liner is a polymeric film of one or more polymeric materials. Typically, at least one face of the liner is coated with a release material such as a silicone or silicone-based material. As will be appreciated, the release material-coated face of the liner is placed in contact with the otherwise exposed face of the adhesive layer. Prior to application of the label to a surface of interest, the liner is removed; thereby expose the adhesive face of the label. The liner can be in the form of a single sheet. Alternatively, the liner can be in the form of multiple sections or panels.

The liner used in the label may have a thickness ranging from 10 to 80 μm, e.g., from 12 to 75 μm, from 15 to 70 μm, from 18 to 65 μm, or from 20 to 60 μm. In terms of upper limits, the thickness of the liner is less than 80 μm, less than 75 μm, less than 70 μm, or less than 65 μm. In terms of lower limits, the thickness of the liner is greater than 10 μm, greater than 12 μm, greater than 15 μm, or greater than 18 μm.

Various additives can also be added to one or more of the first layer, the filler layer, the second layer, the adhesive layer, or liner layers to obtain a certain desired characteristic. These additives can include, for example, one or more waxes, surfactants, talc, powdered silicates, filler agents, defoamers, colorants, antioxidants, UV stabilizers, luminescents, crosslinkers, buffer agents, anti-blocking agents, wetting agents, matting agents, antistatic agents, acid scavengers, flame retardants, processing aids, extrusion aids, and others.

Co-extrusion process to produce the multi-layer film composition

All layers, except for the direct thermal layer, in the multi-layer film composition can be produced by a co-extrusion process. For example, the first layer, the filler layer, and the second layer may be co-extruded. The co-extrusion process allows simultaneously manufacture of the three layers, which significantly saves cost. . The co-extrusion process also allows the first layer, the filler layer, and the second layer to be able to bond together without the need of using an adhesive, which beneficially eliminates the need for adhesive between the layers. For example, the bond force between the first layer and the filler layer may range from 10 to 400 g/inch, e.g., from 20 to 350 g/inch, from 30 to 300 g/inch, from 35 to 250 g/inch, or from 40 to 200 g/inch, as measured by FINAT FTM 3 test (2019) . In terms of upper limits, the bond force may be less than 400 g/inch, less than 350 g/inch, less than 300 g/inch, or less than 250 g/inch. In terms of lower limits, the bond force may be greater than 10 g/inch, greater than 20 g/inch, greater than 30 g/inch, or greater than 35 g/inch.

A co-extrusion process generally known and is a combination of multiple extrusion processes that occur simultaneously to produce multiple, separate layers of materials. In each extrusion process, raw materials, such as the materials used to form the first layer, the filler layer, or second layer, are pushed through a die to form the desired layer. After the three layers (the first layer, the filler layer, and the second layer) are formed, they are combined and stretched in the machine direction to improve the mechanical characteristics of the multi-layer film composition. An illustration of an example of the co-extrusion process is shown in FIG. 3A and FIG. 3B.

Methods of producing the labels

The present invention also relates to methods of producing a logistic label. The method of producing a label may comprise: producing a multi-layer film composition by a co-extrusion process, wherein the multi-layer film composition comprises a first layer, a filler layer, and a second layer, wherein the multi-layer film composition does not comprise any adhesive, and disposing the multi-layer film composition as a layer over an adhesive layer. In some embodiments, the method further comprises disposing a liner underneath the adhesive layer. In some embodiments, the method further comprises disposing a direct thermal layer over the multi-layer film composition layer, wherein the direct thermal layer is configured to receive printing. In some embodiments, the method further comprises printing information on the direct thermal layer via thermal transfer printing, flexo printing, or letterpress printing.

The co-extrusion process for producing the multi-layer composition is described above. The PSA can be produced by methods well known in the art, for example, by dissolving in a solvent, a base polymer, a tackifier, a crosslinker, or combinations thereof. In some embodiments, the wet pressure-sensitive adhesive produced as such is coated directly onto the co-extruded multi-layer film composition layer. In some embodiments, the coating is performed by transfer coating, in which the adhesive is first coated onto a release liner (as described above) , and dried. The dried adhesive/liner is then laminated with the multi-layer film layer to produce a label.

Various methods for coating pressure sensitive adhesives are well known, for example, as disclosed in Manufacturing Pressure-Sensitive Adhesive Products: A Coating and Laminating Process, available at adhesivesmag. com/articles/86079-manufacturing-pressure-sensitive-adhesive-products-a-coating-and-laminating-process, the content of which is hereby incorporated by reference in its entirety. Coating can be performed by knife over roll, slot die, or comma coating. Once coated, the adhesive may be dried in an oven having multiple temperature zones, e.g., at least 2 zones, at least 3 zones, at least four zones, at least five zones, or at least six zones. The temperature zones may range from 30 ℃ to 200 ℃, e.g., from 40 ℃ to 150 ℃ or from 60 ℃ to 130 ℃. The temperature may increase from the first to last zone, though multiple zones may be at the same temperature. The rate of solvent evaporation increases with temperature. The drying time can be at least 2 minutes, at least 4 minutes, at least 6 minutes, at least 8 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes, at least 40 minutes, at least 50 minutes, or at least 1 hour.

Labeling substrates

Although the disclosure describes labeling postal packages, the label can be used to label any other substrates in any other applications, in particular applications where it is desirable that a portion of the label can be separated from the rest of the label.

The labels can be affixed to a surface of the substrate in a batch, continuous, or semi-continuous fashion. Prior to application, one or more liners can be removed from the labels, thereby exposing the adhesive face of the labels. The adhesive face of the label is then contacted with the container (s) or article (s) and the labels applied thereto. Adhering may also include one or more operations of pressing or otherwise applying a pressing force against the label to promote contact and/or adhesion with the container; activating and/or curing of the adhesive such as by heating and/or exposure to UV light; and/or drying operations. The present disclosure also provides labeled substrates, e.g., labeled articles, container, etc.

Embodiments

This disclosure is further illustrated by the following exemplary embodiments.

Embodiment 1: A label comprising: a multi-layer film composition comprising a first layer, a filler layer, and a second layer, and an adhesive layer, wherein the multi-layer film composition does not comprise any adhesive.

Embodiment 2: The label of claim 1, wherein the first layer, the filler layer and the second layer are produced by a co-extrusion process

Embodiment 3: The label of any of the preceding embodiments, wherein the multi-layer film composition further comprises a direct thermal layer.

Embodiment 4: The label of embodiment 3, wherein the multi-layer film composition does not comprise fibrous materials.

Embodiment 5: The label of any of the preceding embodiments, wherein the direct thermal layer comprises an inorganic filler, a color developer, a color former, a lubricant, or combinations thereof.

Embodiment 6: The label of any of the preceding embodiments, wherein the first layer and/or second layer comprise one or more resins selected from the group consisting of polypropylene (PP) , polyethylene (PE) , polystyrene (PS) and polyethylene terephthalate (PET) .

Embodiment 7: The label of any of the preceding embodiments, wherein the filler layer is located between the first layer and the second layer, and wherein the second layer is configured to be applied to a substrate.

Embodiment 8: The label of any of the preceding embodiments, wherein the first layer is thicker than the second layer.

Embodiment 9: The label of any of the preceding embodiments, wherein the first layer has a thickness ranging from 10 to 100 μm.

Embodiment 10: The label of any of the preceding embodiments, wherein the second layer has a thickness of 5 to 50 μm.

Embodiment 11: The label of any of the preceding embodiments, wherein when a force is applied to dissemble the label affixed to a package, the first layer is detached from the package and the second layer remain attached to the package.

Embodiment 12: The label of embodiment 11, wherein when the force is applied, the filler is also dissociated from the package.

Embodiment 13: The label of embodiment 11, wherein when the force is applied, the filler remains attached from the package.

Embodiment 14: The label of any of the preceding embodiments, wherein the adhesive layer is disposed beneath the multi-layer film layer.

Embodiment 15: The label of any of embodiments 7-8, wherein the liner is disposed beneath the adhesive layer.

Embodiment 16: The label of any of the preceding embodiments, wherein the adhesive layer comprises a pressure sensitive adhesive.

Embodiment 17: The label of any of the preceding embodiments, wherein the adhesive layer has a thickness ranging from 5 to 50 μm.

Embodiment 18: The label of any of the preceding embodiments, wherein the liner has a thickness ranging from 10 to 80 μm.

Embodiment 19: The label of any of the preceding embodiments, wherein the detachable multi-layer film layer has a thickness ranging from 33 to 350 μm.

Embodiment 20: The label of any of the preceding embodiments, wherein the filler layer has a thickness of 1 to 50 μm.

Embodiment 21: The label of any of the preceding embodiments, wherein the ratio of the thickness of the first layer to the second layer ranges from 10: 1 to 1: 1.

Embodiment 22: The label of any of the preceding embodiments, wherein the ratio of the thickness of the second layer to the filler layer ranges from 50: 1 to 1: 1.

Embodiment 23: The label of any of the preceding embodiments, wherein the filler layer comprises calcium carbonate, clay, silica, titania, or combinations thereof.

Embodiment 24: The label of any of the preceding embodiments, wherein the direct thermal layer is configured to receive printing.

Embodiment 25. The label of any of the preceding claims, wherein the direct thermal layer is configured to receive thermal transfer printing, flexo printing, and/or letterpress printing.

Embodiment 26: The label of any of the preceding embodiments, wherein the peel strength of adhesive layer of the label ranges from 15 to 300 N/inch.

Embodiment 27: The label of any of the preceding claims, wherein the bond force between the first layer and the filler layer ranges from 10 to 400 g/inch.

Embodiment 28: The label of any of the preceding embodiments, wherein the label is for use on a postal package.

Embodiment 29: A multi-layer film composition comprising: a first layer, a filler layer, and a second layer, wherein the detachable multi-layer film composition does not comprise any adhesive.

Embodiment 30: The multi-layer film composition of embodiment 29, wherein the first layer, the filler layer and the second layer are produced by a co-extrusion process.

Embodiment 31: The multi-layer film composition of embodiment 29 or 30, wherein the detachable multi-layer film composition further comprises a direct thermal layer.

Embodiment 32: The multi-layer film composition of any of the embodiments 29-31, wherein the multi-layer film composition does not comprise fibrous materials.

Embodiment 33: A labeled package comprising a label of any of the preceding embodiments or a multi-layer film composition of any of the preceding embodiments.

Embodiment 34: A method of producing a label comprising: producing a multi-layer film composition by a co-extrusion process, wherein the multi-layer film composition comprises a first layer, a filler layer, and a second layer, wherein the multi-layer film composition does not comprise any adhesive, and disposing the multi-layer film composition as a layer over an adhesive layer.

Embodiment 35: The method of embodiment 34, wherein the method further comprises disposing a liner underneath the adhesive layer.

Embodiment 36: The method of embodiment 34 or 35, wherein the method further comprises disposing a direct thermal layer over the multi-layer film composition layer, wherein the direct thermal layer is configured to receive printing.

Embodiment 37: The method of any of the embodiments 34-36, wherein the method further comprises printing information on the direct thermal layer via thermal transfer printing, flexo printing, and/or letterpress printing.

While the invention has been described in detail, modifications within the spirit and scope of the invention will be readily apparent to those of skill in the art. In view of the foregoing discussion, relevant knowledge in the art and references discussed above in connection with the Background and Detailed Description, the disclosures of which are all incorporated herein by reference. In addition, it should be understood that aspects of the invention and portions of various embodiments and various features recited below and/or in the appended claims may be combined or interchanged either in whole or in part. In the foregoing descriptions of the various embodiments, those embodiments which refer to another embodiment may be appropriately combined with other embodiments as will be appreciated by one of skill in the art. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit.

Claims

A label comprising:

a multi-layer film composition comprising

a first layer,

a filler layer, and

a second layer, and

an adhesive layer,

wherein the multi-layer film composition does not comprise any adhesive.
The label of claim 1, wherein the first layer, the filler layer and the second layer are produced by a co-extrusion process.
The label of any of the preceding claims, wherein the detachable multi-layer film composition further comprises a direct thermal layer.
The label of claim 3, wherein the multi-layer film composition does not comprise fibrous materials.
The label of any of the preceding claims, wherein the direct thermal layer comprises an inorganic filler, a color developer, a color former, a lubricant, or combinations thereof.
The label of any of the preceding claims, wherein the first layer and/or second layer comprise one or more resins selected from the group consisting of polypropylene (PP) , polyethylene (PE) , polystyrene (PS) and polyethylene terephthalate (PET) .
The label of any of the preceding claims, wherein the filler layer is located between the first layer and the second layer, and wherein the second layer is configured to be applied to a substrate.
The label of any of the preceding claims, wherein the first layer is thicker than the second layer.
The label of any of the preceding claims, wherein the first layer has a thickness ranging from 10 to 100 μm.
The label of any of the preceding claims, wherein the second layer has a thickness of 5 to 50 μm.
The label of any of the preceding claims, wherein when a force is applied to dissemble the label affixed to a package, the first layer is detached from the package and the second layer remain attached to the package.
The label of claim 11, wherein when the force is applied, the filler is also dissociated from the package.
The label of claim 11, wherein when the force is applied, the filler remains attached from the package.
The label of any of the preceding claims, wherein the label further comprises a liner disposed beneath the adhesive layer.
The label of any of the preceding claims, wherein the adhesive layer is disposed beneath the multi-layer film layer.
The label of any of the preceding claims, wherein the adhesive layer comprises a pressure sensitive adhesive.
The label of any of the preceding claims, wherein the adhesive layer has a thickness ranging from 5 to 50 μm.
The label of any of the preceding claims, wherein the liner has a thickness ranging from 10 to 80 μm.
The label of any of the preceding claims, wherein the detachable multi-layer film layer has a thickness ranging from 33 to 350 μm.
The label of any of the preceding claims, wherein the filler layer has a thickness of 1 to 50 μm.
The label of any of the preceding claims, wherein the ratio of the thickness of the first layer to the second layer ranges from 10: 1 to 1: 1.
The label of any of the preceding claims, wherein the ratio of the thickness of the second layer to the filler layer ranges from 50: 1 to 1: 1.
The label of any of the preceding claims, wherein the filler layer comprises calcium carbonate, clay, silica, titania, or combinations thereof.
The label of any of the preceding claims, wherein the direct thermal layer is configured to receive printing.
The label of any of the preceding claims, wherein the direct thermal layer is configured to receive thermal transfer printing, flexo printing, and/or letterpress printing.
The label of any of the preceding claims, wherein the peel strength of adhesive layer of the label ranges from 15 to 300 N/inch.
The label of any of the preceding claims, wherein the bond force between the first layer and the filler layer ranges from 10 to 400 g/inch.
The label of any of the preceding claims, wherein the label is for use on a postal package.
A multi-layer film composition comprising:

a first layer, a filler layer, and a second layer,

wherein the detachable multi-layer film composition does not comprise any adhesive.
The multi-layer film composition of claim 29, wherein the first layer, the filler layer and the second layer are produced by a co-extrusion process.
The multi-layer film composition of any of claims 29-30, wherein the detachable multi-layer film composition further comprises a direct thermal layer.
The multi-layer film composition of any of claims 29-31, wherein the multi-layer film composition does not comprise fibrous materials.
A labeled package comprising a label of any of the preceding claims or a multi-layer film composition of any of the preceding claims.
A method of producing a label comprising: producing a multi-layer film composition by a co-extrusion process, wherein the multi-layer film composition comprises a first layer, a filler layer, and a second layer, wherein the multi-layer film composition does not comprise any adhesive, and disposing the multi-layer film composition as a layer over an adhesive layer.
The method of claim 34, wherein the method further comprises disposing a liner underneath the adhesive layer.
The method of claim 34 or 35, wherein the method further comprises disposing a direct thermal layer over the multi-layer film composition layer, wherein the direct thermal layer is configured to receive printing.
The method of any of claims 34-36, wherein the method further comprises printing information on the direct thermal layer via thermal transfer printing, flexo printing, or letterpress printing.