JP2011518079A - How to apply pressure-sensitive shrinkage labels to articles - Google Patents

Abstract

Pressure sensitive shrink labels, particularly pressure sensitive labels having excellent compatibility with containers having complex shapes, and methods of applying such labels are provided. The method of applying a label (12) to an article (10) comprises the steps of: preparing an article having a surface (16) comprising at least one composite curved surface; (i) a heat shrinkable film having an inner surface and an outer surface; ii) providing a label comprising a pressure sensitive adhesive layer on the inner surface of the heat shrinkable film and having a first edge and a contact area; contacting the adhesive layer in the contact area of the label with the article; Heat and pressure are applied simultaneously to the label in the direction from the contact area to the first edge so that the first edge of the label adheres to the article and the label shrinks to fit the composite curved surface of the article. Heat and pressure are applied by a heated air source, a flow control mechanism, and at least one hot air knife assembly including one or more hot air slots.
[Selection] Figure 1

Description

  The present invention relates to a pressure sensitive shrinkage label. More specifically, the present invention relates to a pressure sensitive label having excellent compatibility with containers having complex shapes, and a method for applying such a label.

It is common practice to label containers or bottles to provide information such as container supplier or container contents. Such containers and bottles are available in a variety of shapes and sizes to hold many different materials such as detergents, drugs, personal care products, motor oils, beverages and the like.
Polymer film materials and film face materials have been described for use as labels in various fields. Polymer labels are increasingly in demand in many applications, and in particular, transparent polymer labels are in increasing demand because of the unlabeled appearance of decorated glass and plastic containers. Paper labels impede visibility of the container and / or the contents within the container. Transparent polymer labels enhance the visual beauty of containers and thus products, and are much more than paper labels in the package decoration market, as consumer product companies are constantly trying to enhance the appearance of their products. It is growing rapidly. Polymer film labels also have excellent mechanical properties such as tensile strength and abrasion resistance.

  In many cases, conventional pressure sensitive adhesive (PSA) labels are difficult to adhere smoothly to curved and / or complex containers without wrinkles, dirt, or flaking on curved surfaces. is there. The label size of a typical PSA label is limited so that it does not become larger than 1/4 inch away from the curved edge (starting point) of the container or article. Generally, shrink sleeve labels are used on these types of composite containers. The labeling operation requires the formation of a heat-shrinkable film tube or sleeve placed and heated on the container in order to shrink the heat-shrinkable film to fit the size and shape of the container. It is implemented using. Alternatively, the container is a shrink label using a process in which the shrink film is applied directly to the container from a continuous roll of film material and then heat is applied to match the packaged label to the container. Will be completely packaged. However, a label defect may occur during a labeling operation of a bottle having a simple shape or a complex shape during the pasting step or during the step after pasting. These misapplied labels result in a large amount of disposal or extra processing steps that can be expensive.

US Patent Provisional Application No. 60 / 910,282 US Patent Application No. 60 / 938,019 PCT / US08 / 59397 US patent application Ser. No. 12 / 237,761 US Pat. No. 5,264,532 US Pat. No. 5,164,444 US Pat. No. 5,623,011 US Pat. No. 6,306,982 US Pat. No. 5,705,551 US Pat. No. 5,232,958 U.S. Pat. No. 3,239,478 US Pat. No. 3,251,905 US Pat. No. 3,390,207 U.S. Pat. No. 3,598,887 U.S. Pat. No. 4,219,627 US Pat. No. 3,639,521 U.S. Pat. No. 4,208,356 U.S. Pat. No. 3,113,986 U.S. Pat. No. 4,226,952 U.S. Pat. No. 4,578,429 U.S. Pat. No. 4,657,970 U.S. Pat. No. 4,795,782 US Pat. No. 6,153,288 US Pat. No. 6,106,982

“Polymer Science and Engineering Encyclopedia Volume 13”, “Wiley-Interscience Publishers” (New York, USA, 1988) "Polymer Science and Technology Volume 1", "Interscience Publishers" (New York, USA, 1964) “Polymer Science and Engineering Encyclopedia Volume 2” (1985), “John Wiley & Sons, Inc.”, New York, USA, pages 325-326 J. et al. E. McGrath “Block Copolymer Science and Technology”, Dale J. Edited by Meie, “Harwood Academic Publishers”, 1979, pp. 1-5

  The present invention provides a pressure sensitive adhesive label that can be applied to containers and articles on complex shapes and composite curved surfaces with less material and lower cost than those in shrink sleeves or shrink wrap labels. In addition, the labels of the present invention allow a user to expand the display or graphic area of conventional pressure sensitive labels on containers and articles having complex shapes and / or complex curved surfaces.

A label for application on a curved or non-flat surface comprising a heat shrink film and a pressure sensitive adhesive is provided. In one embodiment, a pressure sensitive adhesive label for application on a surface having at least one composite curved surface is provided, the label having an inner surface and an outer surface, and a machine direction and a transverse direction, and at least at 90 ° C. A heat-shrinkable film having a final shrinkage ratio S of at least 10% in one direction and a shrinkage ratio of S ± 20% in the other direction, and a pressure-sensitive adhesive layer on the inner surface of the heat-shrinkable film. Including. Shrink films have moderately balanced shrinkage in both the machine direction and the transverse direction. In one embodiment, the film has a final shrinkage S of at least 10% in at least one direction at 90 ° C. and the shrinkage in the other direction is S ± 10%. The label can further include a release liner removably adhered to the adhesive layer.
Also included is an article having a surface including at least one composite curved surface, a heat-shrinkable film having an inner surface and an outer surface, a pressure-sensitive adhesive layer on the inner surface of the heat-shrinkable film, and affixed to at least one composite curved surface. An article carrying a label is provided, including a pressure sensitive label to be applied.

  A method is provided for applying a label to an article having a surface having at least one composite curved surface. The method comprises: (a) providing an article having a surface comprising at least one composite curved surface; (b) (i) a heat shrinkable film having an inner surface and an outer surface; and (ii) on the inner surface of the heat shrinkable film. Providing a label having a pressure sensitive adhesive layer and having a central portion and a peripheral portion; (c) contacting the central portion of the label with the adhesive layer; and (d) from the central portion relative to the label. Applying pressure outwardly to the surrounding portion and attaching at least a portion of the label to at least one composite curved surface of the article; and (e) applying heat to at least a portion of the label, Shrinking the portion to adhere the label to the article. During or after application of heat, the label can be further squeezed or wiped to fully adhere the label to the article and remove any residual defects in the label.

  In one aspect of the invention, a method is provided for labeling an article, the method comprising providing an article having a surface that includes at least one composite curved surface; and (i) heat shrinkable having an inner surface and an outer surface. Providing a label comprising a film and (ii) a layer of a pressure sensitive adhesive on the inner surface of the heat shrinkable film and having a first edge and a contact area; and contacting the adhesive layer in the contact area with the article Applying heat and pressure to the label in a direction from the contact area to the first edge so that the first edge of the label adheres to the article and the label shrinks to fit the composite curved surface of the article. Applying simultaneously, heat and pressure are applied by a heated air source, a flow control mechanism, and at least one hot air knife assembly including one or more hot air knife slots.

In one embodiment, the label includes a center and a second edge opposite the first edge, and the contact area is near or at the center of the label. In another embodiment, the label includes a second edge opposite the first edge, and the contact area is near the second edge of the label.
Heat and pressure can be applied to the label by a hot air knife assembly that includes at least two hot air knife slots that rotate outwardly from the center of the label to the first and second edges to affix the label to the article.
In one embodiment of the method of the present invention, the first hot air knife slot applies heat and pressure to the center of the label outwardly toward the first edge of the label, and the second hot air knife slot is Heat and pressure are applied to the center of the label outwardly toward the second edge of the label. The article can be rotated approximately 180 ° prior to application of heat and pressure to the label by the second hot air knife slot.

It is the front view compared with the pressure-sensitive label of the prior art of the container in which the label of this invention was affixed. It is a figure of the label pasted container before the heat application to a label. It is a figure of the label pasted container before the heat application to a label. It is a figure of the label pasted container after the heat application to a label. It is a figure of the label pasted container after the heat application to a label. It is a figure of embodiment of the container which has the complicated shape and compound curved surface to which the label of this invention was affixed. It is a figure of embodiment of the container which has the complicated shape and compound curved surface to which the label of this invention was affixed. It is a figure of embodiment of the container which has the complicated shape and compound curved surface to which the label of this invention was affixed. It is a figure of embodiment of the container which has the complicated shape and compound curved surface to which the label of this invention was affixed. FIG. 6 is a front view of an embodiment of a container having an irregular surface. FIG. 6 is a front view of an embodiment of a container having an irregular surface. FIG. 3 is a three-dimensional view of a portion of a labeled article having a composite curved surface. It is the schematic of the process of affixing a label on the articles | goods which have a composite curved surface. It is the schematic of the process of affixing a label on the articles | goods which have a composite curved surface. It is the schematic of the process of affixing a label on the articles | goods which have a composite curved surface. It is the schematic of the process of affixing a label on the articles | goods which have a composite curved surface. FIG. 3 is a schematic diagram of an embodiment of a process for applying a label to an article using a moving beam. FIG. 3 is a schematic diagram of an embodiment of a process for applying a label to an article using a moving beam. FIG. 2 is a schematic view of an air knife assembly for simultaneously applying heat and pressure to a label. FIG. 2 is a schematic view of an air knife assembly for simultaneously applying heat and pressure to a label. FIG. 6 is a schematic diagram of a process for applying a label to an article using a plurality of air knife slots. FIG. 6 is a schematic diagram of a process for applying a label to an article using a plurality of air knife slots. FIG. 6 is a schematic diagram of a process for applying a label to an article using a plurality of air knife slots. FIG. 6 is a schematic diagram of a process for applying a label to an article using a plurality of air knife slots. FIG. 6 is a schematic diagram of a process for applying a label to an article using a plurality of air knife slots.

  Provided is a pressure sensitive adhesive label that can improve the appearance of the container and article to which the label is attached by adapting to the contour of the container or article and providing a large display appearance. Currently, end users and product designers need to change their designs to meet the constraints of traditional product decoration techniques. The labels of the present invention provide designers with a greater degree of freedom to generate more in-store appeal and communicate more information in product design.

  Containers and articles having composite curved surfaces generally need to be completely packaged with a shrink film in order to add labels or decorations to these articles. The labels of the present invention can be extended over complex curved surfaces without having to completely package the article. This partial label coating affects product cost as well as product appearance. Typical pressure sensitive labels cannot be applied to containers and articles without the undesirable dirt and wrinkles of the label. “Dirt” is defined as the accumulation of excess label material that separates and rises from the article to which the label is applied.

  The labels of the present invention provide significant processing advantages over conventional shrink labels. For example, the pressure sensitive shrink labels of the present invention allow for more conventional printing and secondary processes such as foiling and foil stamping. If a general shrink label is to be printed under the surface, the label of the present invention can be surface printed, thereby increasing the color quality, sharpness and texture of the printed image. The label film can be printed by aqueous flexographic printing, UV flexographic printing, UV convex version printing, UV screen printing, solvent gravure printing, and foil stamping.

  The pressure sensitive label includes (a) a heat shrinkable polymer film having an inner surface and an outer surface, and a machine direction and a transverse direction, and (b) a pressure sensitive adhesive layer on the inner surface of the heat shrinkable film. The shrinkage of the heat-shrinkable polymer film is balanced in the machine direction and the transverse direction. In at least one direction, the final shrinkage (S) at 90 ° C. is at least 10%, and the shrinkage in the other direction is S ± 20%. As a specific example of balanced shrinkage, if the shrinkage in the machine direction is 40% at 105 ° C., the shrinkage in the transverse direction at 105 ° C. is 40% ± 20%, or 20% to 60%. It is in the range. In one embodiment, the final shrinkage (S) is at least 10% at 90 ° C. and the shrinkage in the other direction is S ± 10%. As used herein, the term “final shrinkage” refers to the maximum shrinkage measured by ASTM method D1204 that a film can obtain at a particular shrinkage temperature.

  The label is not provided as a shrink sleeve or shrink tube that encloses the entire article, or as a shrink wrap label that wraps around the article and forms a seam where the ends of the label meet. The labels of the present invention can be provided in a variety of shapes that are compatible with the articles or containers to which they are applied, and in conventional container construction and label design, with conventional pressure sensitive labels or shrink wrap or shrink sleeve labels. Gives container designers more freedom. The label can be cut into the desired shape by any known method including, for example, die cutting and laser cutting. In one embodiment, the label is stamped into a specific configuration that compensates for the shrinkage of the label and the shape of the article to which the label is applied.

  Since the label is compatible, the posting or graphic area of the container to which the label is applied can be further extended onto the container edge and the composite curved area of the container. The label can be 10% to 30% larger than the standard PSA label. As used herein, the term “composite curved surface” means a surface that does not have a direction in which no curvature exists. For example, a spherical surface or an ellipsoidal surface has curvature in all directions and thus has a complex curved surface. On the other hand, the cylinder has a surface with at least one direction in which no curvature exists. Thus, a simple cylinder does not have a complex curved surface.

FIG. 1 shows an extended posting area of the pressure sensitive shrink label of the present invention. The bottle 10 has a pressure sensitive shrink label 12 bonded to itself. Dashed line 14 indicates the outer boundary of a standard pressure sensitive label. A standard (ie, non-shrink) pressure sensitive label cannot extend over the area 16 (the area between the inner dashed line and the outer solid line) 16 having a compound curved surface of the bottle. When the label 12 is first applied to the bottle 10, dirt and folds may form near the periphery of the label in the area having the compound curved surface 16 of the bottle.
With the pressure sensitive label affixed to the container, heat is applied as necessary to remove any labeling defects such as dirt, fringing edges, and wrinkles. In one embodiment, pressure and / or sweeping can be used in addition to applying heat to remove any defects.

  2A-2D, the label of the present invention and the method of applying the label are illustrated. In FIGS. 2A and 2B, a label 12 comprising a shrink film with a continuous layer of pressure sensitive adhesive is applied to a container 10 having a compound curved surface around the outer periphery of the container and then swept. No heat is applied to the label. The label 12 extends over the compound curved surface 16 and a dart 18 is formed near the periphery 20 of the label. 2C and 2D show the container of FIGS. 2A-2B with the label affixed after heat has been applied to the label. Dirt 18 has been removed and label 12 fits the compound curved surface of container 10 near label periphery 20 without any defects.

The article or container to which the label is applied can be supplied in various forms or shapes. Non-limiting examples of suitable articles include containers with and without stoppers, trays, lids, toys, appliances and the like. The article or container can be made of any conventional polymer, glass, or metal such as aluminum. Examples of suitable polymeric materials include density polyethylene (HDPE), low density polyethylene (LDPE), polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride, polycarbonate, nylon, fluorinated ethylene propylene, polystyrene, and the like. Articles or containers can be made by many different processes known in the art such as blow molding, injection molding, thermoforming, rotational molding and the like.
Useful containers include, for example, bottles with stoppers at the top of the bottles, inverted bottles with stoppers at the bottom of the bottles, bottles with pump dispensers or frothing dispensers, tubes with stoppers, and inverted bottles with stoppers.

The container or article can have a transparent appearance. In one embodiment, the container or article has a translucent appearance. A translucent appearance can be obtained, for example, by the treatment of transparent containers or articles, the addition of components such as dyes and pearlescent agents to the base polymer, the use of polypropylene and / or polyethylene mixed with fining agents. . The treatment includes, for example, spray coating, sandblasting, and molding surface treatment.
The container or article can include artistic features including, for example, texture, relief, lenticular lens, color, hologram, matte color, or matte color. The surface of the container or article can be treated prior to labeling. For example, the surface of the container or article can be flame treated or a pre-coating can be added.

  Each of FIGS. 3A, 3B, and 3C shows a container having a complex shape and a complex curved surface. FIG. 3A is a front view of a container 30a having a symmetrical spherical shape, which has a tapered area 32 at the top and a wider convex area 33 toward the bottom. In general, a shrink sleeve is used to provide a functional label on the container. In the present invention, the pressure-sensitive shrinkable label 31 can be smoothly attached to the container 30a without the appearance of a label defect. FIG. 3B is a front view of a container 30b having an asymmetric shape, with one side of the container having both a concave area 34 and a convex area 35, the opposite side being substantially similar along the length of the container. It is curved by the method. The conventional method of attaching the label to the container 30b is to apply the shrink sleeve label so as to conform to the complicated shape of the container. The pressure sensitive shrinkable label 31 can be affixed to the container 30b so as to provide a sufficient posting area with significantly less label material. FIG. 3C is a front view of a container 30c which is an inverted bottle having a stopper 36 at the bottom and a label 31 attached to the front surface. FIG. 3D is a side view of the container 30c. Area 37 within the dashed line indicates the outer boundary of a standard pressure sensitive label that can be applied to the container. Since the application of one continuous standard pressure sensitive label will result in the formation of dirt and pleat defects, the complex shape of this container requires two separate standard pressure sensitive labels to decorate the container. And The pressure sensitive shrink label 31 can cover a very large area, thereby providing more design options to the product designer.

  Each of FIGS. 4A and 4B shows a container having an irregular surface. FIG. 4A is a front view of a container 40a having raised lines that swell along one side of the container. The opposite side of the container has a smooth surface. FIG. 4B is a front view of a container 40b having a plurality of rings 43 recessed in the outer circumferential direction along the length of the container. It should be noted that cylindrical articles having compound curved areas such as containers 40a and 40b are not excluded from the articles claimed in this application.

  FIG. 5 is a schematic three-dimensional view of a portion where a container label is attached. The container 50 has a surface including a complex curved surface. A label 52 is affixed to the container and covers a portion of the composite curved area. Line 54 shows the outer boundary where a typical pressure sensitive label can be applied without the formation of defects in the label. Area 56 shows a large signage area that can be obtained using the labels of the present invention without the formation of wrinkles, edge lifts, or dirt.

Shrink Film The polymer film useful in the label construction of the present invention has balanced shrink properties. The balanced shrinkage property is that when the label is applied on the curved surface, it first tightens the dart and wrinkle formed in the label, and sweeps the dart and wrinkle with minimal graphic distortion of the label. Enable. Films with unbalanced shrinkage, that is, films with high shrinkage in one direction and only low to moderate shrinkage in the other direction, should remove dirt in one direction However, it is not particularly useful because it worsens the formation of dirt in the other direction. Useful films with balanced shrinkage allow a greater variety of label shapes to be applied to a greater variety of container shapes.

  In one embodiment, the polymer film has a final shrinkage (S) measured by ASTM procedure D1204 of at least 10% in at least one direction at 90 ° C. and the shrinkage in the other direction is S ± 20%. is there. In another embodiment, the film has a final shrinkage (S) of from about 10% to about 50% in at least one direction at 70 ° C. and the shrinkage in the other direction is ± 20%. In one embodiment, the final shrinkage (S) is at least 10% at 90 ° C. and the shrinkage in the other direction is S ± 10%. In one embodiment, the onset shrink temperature of the film is in the range of about 60 ° C to about 80 ° C.

  The shrink film must be heat shrinkable and nevertheless should be sufficiently rigid to be removed using conventional labeling equipment and processes including printing, die cutting, and label transfer. . The required film stiffness depending on the size of the label depends on the size of the label, the application speed, and the labeling equipment being used. In one embodiment, the shrink film has a stiffness measured by an L & W stiffness test of at least 5 mN in the machine direction (MD). In one embodiment, the shrink film has a stiffness of at least 10 mN or at least 20 mN. The stiffness of the shrink film is important for proper distribution of the label on the release plate at high line speeds.

In one embodiment, in the automatic labeling process, the stamped label is applied to the article or container at a line speed of at least 100 units per minute, at least 250 units per minute, or at least 500 units per minute.
In one embodiment, the shrink film has a 2% secant modulus measured by “ASTM D882” of about 20,000 psi (poundsper squire inch) to about 400,000 psi in the machine direction (MD) and ) Direction (TD) has a 2% secant modulus from about 20,000 psi to about 400,000 psi. In another embodiment, the 2% secant modulus of the film is from about 30,000 to about 300,000 in the machine direction and from about 30,000 to about 300,000 in the transverse direction. The film may have a lower coefficient in the transverse direction than in the machine direction so that the label can be easily removed (MD) while maintaining a sufficiently low coefficient in TD for compatibility and / or compression reasons. it can.

The polymer film can be made by conventional processes. For example, the film can be manufactured using a double bubble process, a tenter process, or can include a blow molded film.
Shrink films useful in labels can be single layer or multi-layer structures. Single or multilayer shrink films can be formed from polymers selected from polyesters, polyolefins, polyvinyl chloride, polystyrene, polylactic acid, copolymers, and blends thereof.

  Polyolefins include homopolymers or copolymers of olefins that are aliphatic hydrocarbons having one or more carbon-carbon double bonds. Olefins include alkenes, cyclohexenes, including 1-alkenes, also known as α-olefins such as 1-butene, and internal alkenes having a carbon-carbon double bond at the non-terminal carbon atom of the carbon chain such as 2-butene. And cyclic olefins having one or more carbon-carbon double bonds, such as norbornadiene, and two or more carbon-carbon double bonds, such as 1,4-butadiene and isoprene. A cyclic polyene which is a non-cyclic aliphatic hydrocarbon. Polyolefins are alkene homopolymers from a single alkene monomer, such as polypropylene homopolymer, the first mentioned alkene from at least one alkene monomer and one or more additional olefin monomers. Alkene copolymers such as propylene-ethylene copolymers and propylene-ethylene-butadiene copolymers, cyclic olefin homopolymers from a single cyclic olefin monomer, at least one cyclic olefin monomer and one or more The first listed cyclic olefins from these additional olefin monomers include the cyclic olefin copolymers which are the main composition of this copolymer, as well as any mixtures of these olefin polymers.

In one embodiment, the shrink film includes a core layer and at least one skin layer. The skin layer can be a printable skin layer. In one embodiment, the multilayer shrink film includes a core layer and two skin layers, and is printable on at least one skin layer. The multilayer shrink film can be a coextruded film.
The film can range in thickness from 0.5 to 20 mils (mils, thousandths of an inch), 0.5 to 12 mils, 0.5 to 8 mils, or 1 to 3 mils. Differences in the layers of the film can include differences in thermoplastic polymer components, additive components, orientation, thickness, or combinations thereof. The thickness of the core layer can be 50 to 95%, 60 to 95%, or 70 to 90% of the thickness of the film. The thickness of the skin layer or the combination of the two skin layers can be 5-50%, 5-40%, or 10-30% of the film thickness.

  The film can be further processed on one side or both the upper and lower sides to enhance performance with respect to printability or adhesion to the adhesive. The treatment includes, for example, applying a surface coating such as lacquer, applying a high energy discharge including corona discharge to the surface, applying a flame treatment to the surface, or any combination of these treatments. In an embodiment of the invention, the film is processed on both sides, and in another embodiment, the film is processed using a corona discharge on one side and flame treated on the other side.

  The layer of shrink film can contain pigments, fillers, stabilizers, photoprotective agents, or other suitable modifiers as needed. The film can include an anti-stick additive, a slip additive, and an antistatic agent. Useful antiblocking agents include inorganic particles such as clay, talc, calcium carbonate, and glass. Sliding additives useful in the present invention include polysiloxanes, waxes, fatty acid amides, fatty acids, metal soaps, and particulates such as silica powder, synthetic amorphous silica powder, and polytetrafluoroethylene powder. Antistatic agents useful in the present invention include alkali metal sulfonates, polyether modified polydiorganosiloxanes, polyalkylphenylsiloxanes, and tertiary amines.

  In one embodiment, the shrink film is microperforated to allow trapped air to be released from the interface between the label and the article to which the label is attached. In another embodiment, the shrink film is permeable to allow fluid to flow out of the adhesive or out of the surface of the article. In one embodiment, exhaust pores or slits are provided in the shrink film.

Adhesives Descriptions of useful pressure sensitive adhesives can be found in “Polymer Science and Engineering Encyclopedia Vol. 13,” “Wiley-Interscience Publishers” (New York, USA, 1988). Further descriptions of useful PSA can be found in “Polymer Science and Technology Volume 1”, “Interscience Publishers” (New York, USA, 1964). Conventional PSAs including acrylic-based PSA, rubber-based PSA, and silicone-based PSA are useful. The PSA can be a solvent based adhesive or a water based adhesive. A hot melt adhesive can be used. In one embodiment, the PSA includes an acrylic emulsion adhesive.

The adhesive and the film surface to which the adhesive is applied have sufficient affinity to allow good adhesive fixing. In one embodiment, the adhesive is selected so that the label can be completely removed from the PET container by 24 hours after application. The adhesive is also selected so that the adhesive component does not transfer into the film.
In one embodiment, the adhesive can be formed from an acrylic-based polymer. The present invention contemplates that any acrylic-based polymer that can form an adhesive layer with sufficient tack to adhere to a substrate can provide functionality. In certain embodiments, as disclosed in US Pat. No. 5,264,532, the acrylic polymer for the pressure sensitive adhesive layer contains from about 4 to about 12 carbon atoms in the alkyl group. Including those formed from the polymerization of at least one alkyl acrylate monomer present in an amount of about 35-95% by weight of the polymer or copolymer. Optionally, the acrylic-based pressure sensitive adhesive can be formed from a single polymer species.

  As taught in US Pat. No. 5,264,532, which is incorporated herein by reference, the glass transition temperature of a PSA layer containing an acrylic polymer determines the amount of polar monomer or “hard monomer” in the copolymer. It can be changed by adjusting. The higher the weight percentage of hard monomer in the acrylic copolymer, the higher the glass transition temperature. Hard monomers considered useful in the present invention include vinyl esters, carboxylic acids, and methacrylates in weight concentrations ranging from about zero to about 35 weight percent of the polymer.

  PSA is acrylic-based, US Pat. No. 5,164,444 (acrylic emulsion), US Pat. No. 5,623,011 (tackifying acrylic emulsion), and US Pat. No. 6,306,982. As taught in. The adhesive can be a rubber base such as that taught in US Pat. No. 5,705,551 (rubber hot melt). Also, the adhesive is a radiation curable mixture of monomer, initiator and other components, such as US Pat. No. 5,232,958 (UV curable acrylic), US Pat. No. 5,232,958 (EB cured). ). The disclosures of these patents relate to acrylic adhesives and are incorporated herein by reference.

  In the present invention, commercially available PSA is useful. Examples of these adhesives are available as "HM-1597, HL-2207-X, HL-2115-X, HL-2193-X" from "H. B. Fuller Company", St. Paul, Minnesota, USA. Contains hot melt PSA. Other useful commercially available PSAs include those available from “Century Adhesives Corporation”, located in Columbus, Ohio. Another useful acrylic PSA comprises a mixture of emulsion polymer particles and dispersed tackifier particles generally described in Example 2 of US Pat. No. 6,306,982. The polymer is made by emulsion polymerization of 2-ethylhexyl acrylate, vinyl acetate, dioctyl maleate, and acrylic and methacrylic comonomers, as described in US Pat. No. 5,164,444, and has a weight average diameter. Results in a latex particle size of about 0.2 microns and a gel content of about 60%.

  A commercial example of a hot melt adhesive is H2187-01 sold by "Ato Findley, Inc." of Wauwatosa, Wisconsin, USA. In addition, rubber base block copolymer PSA as described in US Pat. No. 3,239,478 can be utilized in the adhesive construction of the present invention, which patent is such hot, which is more fully described below. For reasons of disclosure of the melt adhesive, it is incorporated herein by reference.

In another embodiment, the pressure sensitive adhesive represents a rigid thermoplastic phase or block in which A is non-rubbery, glassy, or crystalline at room temperature but is flowable at elevated temperatures, and B is the temperature of use. Or when representing soft blocks that are rubbery or elastic at room temperature, represented by diblock structures AB, triblock AB, radial structures or bonded structures (AB) _n , and combinations thereof Useful rubber-based elastomeric materials including linear, branched, bonded, or radial block copolymers. These thermoplastic elastomers can include from about 75% to about 95% by weight of rubbery segments and from about 5% to about 25% by weight of non-rubbery segments.

  Non-rubbery segments or rigid blocks include polymers of monocyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons, and more specifically vinyl substituted aromatics that can be essentially monocyclic or bicyclic. Contains hydrocarbons. Rubber-like materials such as polyisoprene rubber, polybutadiene rubber, and styrene butadiene rubber can be used to form the rubbery blocks or segments. Particularly useful rubbery segments include ethylene / butylene copolymers or ethylene / propylene copolymer polydiene rubbers and saturated olefin rubbers. Saturated olefin rubbers can be obtained from polybutadiene and the corresponding unsaturated polyalkylenes such as polyisoprene by hydrogenation thereof.

  Vinyl aromatic hydrocarbon and conjugated diene block copolymers that can be utilized include any that exhibit elastic properties. The block copolymer can be a diblock, triblock, multiblock, star block, polyblock, or bonded block copolymer. Throughout this specification, the terms diblock, triblock, multiblock, polyblock, and bonded or bonded blocks related to the structural characteristics of block copolymers are referred to as “Polymer Science and Engineering Encyclopedia Volume 2” (1985), “ John Wiley & Sons, Inc. ", New York, USA, pages 325-326, and E. McGrath “Block Copolymer Science and Technology”, Dale J. It is assumed that the usual meanings given in the literature as given in Meie, “Harwood Academic Publishers”, 1979, page 1-5 are given.

Such block copolymers can contain conjugated dienes having various ratios to vinyl aromatic hydrocarbons, including those containing up to about 40% by weight of vinyl aromatic hydrocarbons. Accordingly, when A is a polymer block comprising a vinyl aromatic hydrocarbon or a conjugated diene / vinyl aromatic hydrocarbon tapered copolymer, and B is a rubbery polymer block of a conjugated diene, AB , A-B-A, A-B-A-B, B-A-B, (AB) _0,1,2,... , Linear, radial synonym having a structure represented by a formula such as BA, Alternatively, asymmetric multiblock copolymers can be utilized.

  Block copolymers include, for example, sequential addition of monomers exemplified in U.S. Pat. Nos. 3,251,905, 3,390,207, 3,598,887, and 4,219,627, It can be prepared by any of the known block polymerization or copolymerization techniques including monomer fractional addition or coupling techniques. As is well known, a tapered copolymer block uses a difference between a copolymerization reaction rate of a conjugated diene monomer and a copolymerization reaction rate of a vinyl aromatic hydrocarbon monomer, and thereby uses a conjugated diene monomer and a vinyl aromatic hydrocarbon. It can be incorporated into multi-block copolymers by copolymerizing a mixture with monomers. Various patents, including US Pat. Nos. 3,251,905, 3,639,521, and 4,208,356, describe the preparation of multiblock copolymers containing tapered copolymer blocks. The disclosures of which are incorporated herein by reference.

  Conjugated dienes that can be utilized to prepare polymers and copolymers are those containing from 4 to about 10 carbon atoms, more usually from 4 to 6 carbon atoms. Examples of these include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, chloroprene, 1,3-pentadiene, 1,3-hexadiene, and the like. Including those from. Mixtures of these conjugated dienes can be used.

Examples of vinyl aromatic hydrocarbons that can be utilized to prepare copolymers include styrene, as well as o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methyl Various substituted styrenes such as styrene, β-methylstyrene, p-isopropylstyrene, 2,3-dimethylstyrene, o-chlorostyrene, p-chlorostyrene, o-bromostyrene, 2-chloro-4-methylstyrene Including.
Many of the above-described copolymers of conjugated dienes and vinyl aromatic compounds are commercially available. The number average molecular weight of the block copolymer prior to hydrogenation is from about 20,000 to about 500,000, or from about 40,000 to about 300,000.

The average molecular weight of the individual blocks within the copolymer can vary within certain limits. In most cases, the vinyl aromatic block will have a number average molecular weight on the order of about 2000 to about 125,000, or between about 4000 and 60,000. The conjugated diene block will have a number average molecular weight of about 10,000 to about 450,000, or about 35,000 to 150,000, either before or after hydrogenation.
Also, prior to hydrogenation, the vinyl content of the conjugated diene moiety is generally from about 10% to about 80%, or from about 25% to about 65%, and the modified block copolymer exhibits rubbery elasticity. In particular, it is 35% to 55%. The vinyl content of the block copolymer can be measured using nuclear magnetic resonance.

Specific examples of diblock copolymers include styrene-butadiene (SB), styrene-isoprene (SI), and hydrogenated derivatives thereof. Examples of triblock polymers include styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), α-methylstyrene-butadiene-α-methylstyrene, and α-methylstyrene-isoprene α-methylstyrene. . Examples of commercially available block copolymers useful as adhesives in the present invention include those available from “Kraton Polymers LLC” under the trademark KRATON.
Upon hydrogenation of an SBS copolymer containing rubbery segments of a mixture of 1,4 isomers and 1,2 isomers, a styrene-ethylene-butylenestyrene (SEBS) block copolymer is obtained. Similarly, hydrogenation of SIS polymers yields styrene-ethylenepropylene-styrene (SEPS) block copolymers.

  Selective hydrogenation of block copolymers can be carried out by a variety of known processes including hydrogenation in the presence of Raney nickel and noble metals such as platinum, palladium, and catalysts such as soluble transition metal catalysts. A suitable hydrogenation step that can be used is that the diene-containing polymer or copolymer is dissolved in an inert hydrocarbon diluent such as cyclohexane and hydrogenated by reaction with hydrogen in the presence of a soluble hydrogenation catalyst. It is a process. Such techniques are described in US Pat. Nos. 3,113,986 and 4,226,952, the disclosures of which are incorporated herein by reference. Such hydrogenation of the block copolymer produces a selective hydrogenated copolymer having a residual unsaturated content of about 0.5% to about 20% of the original unsaturated content before hydrogenation within the polydiene block. It is implemented in such a manner and range.

  In one embodiment, the conjugated diene portion of the block copolymer is at least 90%, often at least 95% saturated, while the vinyl aromatic portion is not significantly hydrogenated. In particular, useful hydrogenated block copolymers are hydrogenated products of styrene-isoprene-styrene block copolymers such as styrene- (ethylene / propylene) -styrene block polymers. When the polystyrene-polybutadiene-polystyrene block copolymer is hydrogenated, the ratio of 1,2-polybutadiene to 1,4-polybutadiene in the polymer is desirably from about 30:70 to about 70:30. When such block copolymers are hydrogenated, the resulting product resembles a normal copolymer block (EB) of ethylene and 1-butene. As noted above, when a conjugated diene is used as isoprene, the resulting hydrogenation product resembles a normal copolymer block (EP) of ethylene and propylene.

  Many selective hydrogenated block copolymers are commercially available from “Kraton Polymers” under the common name of “Kraton G.”. An example is “Kraton G1652”, a hydrogenated SBS triblock containing 30 wt% styrene endblocks and an intermediate block that is a copolymer of ethylene and 1-butene (EB). A low molecular weight version of G1652 is available under the name “Kraton G1650”. “Kraton G1651” is another SEBS block copolymer containing about 33% by weight styrene. “Kraton G1657” is a SEBS diblock copolymer containing about 13% by weight styrene. This styrene content is lower than the styrene content in “Kraton G1650” and “Kraton G1652”.

In another embodiment, the selective hydrogenated block copolymer is of the formula:
B _n (AB) _o A _p
Where n = 0 or 1, o is 1 to 100, p is 0 or 1, and each B is primarily a number average molecular weight of about 20,000 to about 450,000 prior to hydrogenation. Wherein each A is primarily a polymerized vinyl aromatic hydrocarbon block having a number average molecular weight of from about 2000 to about 115,000, wherein the A block is about From 5% to about 95% by weight, the unsaturation of block B is lower than 10% of the original unsaturation. In other embodiments, the unsaturation of block B is reduced to less than 5% of the original value when subjected to hydrogenation, and the average unsaturation of the hydrogenated block copolymer is reduced to less than 20% of the original value. To do.

  The block copolymer can be obtained by reacting an α, β-olefinically unsaturated monocarboxylic acid or dicarboxylic acid reagent with a selective hydrogenated block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene as described above. Base polymers can be included. The reaction of the carboxylic acid reagent in the conjugated block copolymer can occur in solution or by a melting step in the presence of a free radical initiator.

  The preparation of various selective hydrogenated block copolymers of conjugated dienes and vinyl aromatic hydrocarbons conjugated with carboxylic acid reagents is described in US Pat. Nos. 4,578,429, 4,657,970, and , 795,782, and the disclosures relating to the selective hydrogenated block copolymers of conjugated conjugated dienes and vinyl aromatic compounds of these patents and the preparation of such compounds include: Which is incorporated herein by reference. U.S. Pat. No. 4,795,782 describes and provides an example of the preparation of a block copolymer that is joined by a solution process and a melting process. U.S. Pat. No. 4,578,429 describes "Kraton G1652" (SEBS) polymer, maleic anhydride and 2,5-dimethyl-2,5-di (t-butylperoxy) by a melting reaction in a twin screw extruder. ) Includes examples of bonding with hexane.

Examples of commercially available maleated selective hydrogenated copolymers of styrene and butadiene include “Kraton FG1901X”, FG1921X, and FG1924X, often referred to as maleated selective hydrogenated SEBS. FG1901X contains about 1.7 wt% bound succinic anhydride functionality and about 28 wt% styrene. FG1921X contains about 1% by weight bound succinic anhydride functionality and 29% by weight styrene. FG1901X contains about 13% styrene and about 1% bound succinic anhydride functionality.
Useful block copolymers are also available from “Nippon Zeon Co.” located in 2-1 Marunouchi, Chiyoda-ku, Tokyo, Japan. For example, “Quintac 3530” is available from “Nippon Zeon” and is considered to be a linear styrene-isoprene-styrene block copolymer.

  Unsaturated elastic polymers and other polymers and copolymers that are essentially non-sticky can be made sticky when formulated with an external tackifier. Generally, the tackifier is an elastic polymer adhesive when present at a concentration ranging from about 40% to about 90%, or from about 45% to about 85% by weight of the total adhesive composition. Hydrocarbon resins, wood resins, rosins, rosin derivatives, and the like that give pressure sensitive adhesive properties to these formulations. Compositions containing less than about 40% by weight tackifier additive generally do not exhibit sufficient “quick stick” or initial adhesion to function as a pressure sensitive adhesive and are therefore essentially tacky Does not have sex. On the other hand, a composition having an excessively high concentration of tackifying additive generally exhibits an excessively low cohesive strength in the most intended application of the construction made according to the present invention.

It is contemplated that any tackifier known to those skilled in the art that is compatible with the elastomeric polymer composition can be used for this embodiment of the invention. One such tackifier that has been found to be useful is a synthetic polyterpene resin that is liquid at room temperature and is sold by “Goodyear Tire and Rubber Company” located in Akron, Ohio, USA. “Wingtak 10”. “Wingtak 95” is a synthetic tackifier resin that is also available from Goodyear, which primarily contains polymers from piperylene and isoprene. Other suitable tackifying additives are “Escorez 1310” and C ₅ -C ₉ (aromatically modified aliphatic) resins, both aliphatic hydrocarbon resins manufactured by Exxon, Irving, Texas, USA. “Escorez 2596” can be included. Of course, as will be appreciated by those skilled in the art, a variety of different tackifying additives can be used to practice the present invention.

  In addition to the tackifier, other additives can be included in the PSA to provide desirable properties. For example, plasticizers can be included, and these plasticizers are known to reduce the glass transition temperature of adhesive compositions containing elastic polymers. An example of a useful plasticizer is “Shellflex 371”, a naphthenic base manufacturing oil available from “Shell Lubricants” located in Texas, USA. Antioxidants can also be included in the adhesive composition. Suitable antioxidants include “Irgafos 168” and “Irganox 565” available from Ciba-Geigy located in Hawthorne, New York. Cutting agents such as waxes and surfactants can be included in the adhesive.

  The pressure sensitive adhesive can be added from a solvent, emulsion, or suspension, or added as a hot melt. The adhesive can be added to the inner surface of the shrink film by any known method. For example, the adhesive can be applied by die coating, curtain coating, spraying, immersion, rolling, gravure printing, or flexographic printing techniques. The adhesive can be applied to the shrink film in a continuous layer, a discontinuous layer, or a pattern. The pattern covering adhesive layer substantially covers the entire inner surface of the film. As used herein, “substantially covering” is intended to mean that the pattern is continuous across the surface of the film, and is only applied within the strip along the leading or trailing edge of the film. Or adhesives added as “spot welds” on the film.

In one embodiment, an adhesion inhibitor is added to a portion of the adhesive layer to allow the label to adhere to a complex shaped article. In one embodiment, the adhesive layer can slide on the surface of the article while the label is being applied, and / or air trapped at the interface between the label and the article can leak. In order to achieve this, a non-adhesive material such as ink dots or microbeads is added to at least a portion of the adhesive surface.
A single layer adhesive can be used, or multiple adhesive layers can be used. Depending on the shrink film used and the article or container to which the label is attached, the first adhesive layer adjacent to the shrink film and the surface to be attached to the article or container that provides sufficient tack, peel strength, and shear strength It may be desirable to use a second adhesive layer having the above different composition.

  In one embodiment, the pressure sensitive adhesive has sufficient shear or cohesive strength to prevent excessive shrinkage of the label when adhered to the article under the effect of heat after placement of the label on the article. Sufficient peel strength to prevent the film from floating off the article, and stickiness or grip to allow sufficient adhesion of the label to the article during the labeling operation. In one embodiment, the adhesive moves with the label when the shrink film shrinks upon application of heat. In another embodiment, the adhesive holds the label in place so that the label does not move as the shrink film shrinks.

  The heat-shrinkable film can include other layers in addition to the single-layer or multilayer heat-shrinkable polymer film. In one embodiment, a thin metal film metallized coating is deposited on the surface of the polymer film. The heat-shrinkable film can include a printing layer on the polymer film. The print layer can be positioned between the heat shrink layer and the adhesive layer, or the print layer can be positioned on the outer surface of the shrink layer. In one embodiment, the film is reverse printed with a design, image, or text so that the printed side of the skin is in direct contact with the container to which the film is applied. In this embodiment, the film is transparent.

  The labels of the present invention can include a layer of an ink receptive composition that enhances the printability of the polymer shrink layer or, if present, the metal layer, i.e., print layer quality is obtained. A variety of such compositions are known in the art, and generally these compositions comprise a binder and a pigment such as silica or talc dispersed within the binder. The presence of pigments shortens the drying time of some inks. Such ink receptive compositions are described in US Pat. No. 6,153,288 (Shih et al.), The disclosure of which is incorporated herein by reference.

  The print layer can be an ink layer or a graphic layer, and the print layer can be a monochrome or multicolor print layer depending on the message to be printed and / or the intended drawing design. These messages and / or intended graphic designs include serial numbers, variable imprinted data such as barcodes, trademarks, and the like. The thickness of the print layer is generally in the range of about 0.5 microns to about 10 microns, in one embodiment in the range of about 1 micron to about 5 microns, and in another embodiment about 3 microns. . Inks used in the printing layer include commercially available water-based inks, solvent-based inks, or radiation curable inks. Examples of these inks are "Sun Sheen" (Sun Sheen product identified as an alcohol-dilutable polyamide ink), "Suntex MP" (acrylic coated substrate, PVDC coated substrate, and polyolefin film. Sun Chemical products identified as solvent-based inks formulated for), X-Cel (“Water Ink Technologies” products identified as aqueous film inks for printing film substrates), “Uvirith AR-109 Rubine Red” ("Daw Ink" product identified as UV ink), and CLA91598F ("Sun Chemical" product identified as multi-bonded black solvent based ink).

  In one embodiment, the printing layer comprises a polyester / vinyl ink, a polyamide ink, an acrylic ink, and / or a polyester ink. The print layer may be formed on one or more desired areas of the film with an ink composition comprising, for example, a resin of the type described above, a suitable pigment or dye, and one or more suitable volatile solvents. It can be formed in a conventional manner by performing gravure printing, flexographic printing, UV flexographic printing, or the like. After the addition of the ink composition, the volatile solvent component of the ink composition evaporates, leaving only the non-volatile ink component, forming a printed layer.

  The adhesion of the ink to the surface of the polymer shrink film or, if present, the metal layer can be improved as needed by techniques known to those skilled in the art. For example, as described above, an ink primer or other ink adhesion promoter can be added to the metal layer or polymer film layer prior to ink application. Alternatively, the surface of the polymer film can be corona treated or flame treated to improve the adhesion of the ink to the polymer film layer.

  Useful ink primers can be clear or opaque, and these primers can be solvent-based or water-based. In one embodiment, the primer has radiation curable (eg, UV). The ink primer can include lacquers and diluents. Lacquers are based on one or more polyolefins, polyamides, polyesters, polyester copolymers, polyurethanes, polysulfones, polyvinylidene chloride, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, sodium or zinc salts or ethylene methacrylic acid based It can be composed of ionomers, polymethylmethacrylates, acrylic polymers and copolymers, polycarbonates, polyacrylonitrile, ethylene-vinyl acetate copolymers, and mixtures of two or more of these. Examples of diluents that can be used include alcohols such as ethanol, isopropanol, and butanol, esters such as ethyl acetate, propyl acetate, and butyl acetate, aromatic hydrocarbons such as toluene and xylene, acetone and methyl ethyl ketone. Such ketones, aliphatic hydrocarbons such as heptane, and mixtures thereof. The ratio of lacquer to diluent depends on the viscosity required for the application of the ink primer, and selection of such viscosity is within the skill of the art. The ink primer layer can have a thickness from about 1 micron to about 4 microns, or from about 1.5 microns to about 3 microns.

  A transparent polymer protective topcoat or overcoat layer can be present in the labels of the present invention. The protective topcoat or overcoat layer imparts desirable properties to the label before and after it is attached to a substrate such as a container. In some embodiments, the presence of a transparent topcoat layer over the print layer imparts additional properties such as antistatic properties, stiffness, and / or weather resistance, and the topcoat comprises the print layer. For example, it can be protected from the weather, sunlight, wear, moisture, water and the like. A transparent topcoat layer can enhance the properties of the underlying print layer, resulting in a glossy and gorgeous image. Transparent protective layers that provide protection can be designed to be abrasion resistant, radiation resistant (eg UV), chemical resistant, heat resistant, so that the label and especially the printed layer can be such a factor. Protects against degradation by The protective overcoat can also contain an antistatic agent or anti-tacking agent to provide easy handling when the label is affixed to the container at high speed. The protective layer can be added to the printed layer by techniques known to those skilled in the art. The polymer film can be deposited from a solution, added as a pre-formed film (laminated on the printing layer), or the like.

  If a transparent topcoat or overcoat layer is present, this layer can have a single layer structure or a multilayer structure. The thickness of the protective layer is generally in the range of about 12.5 microns to about 125 microns, and in one embodiment in the range of about 25 microns to about 75 microns. Examples of topcoat layers are described in US Pat. No. 6,106,982, which is incorporated herein by reference.

The protective layer can include polyolefins, thermoplastic polymers of ethylene and propylene, polyesters, polyurethanes, polyacryls, polymethacryls, epoxies, vinyl acetate homopolymers, copolymers or terpolymers, ionomers, and mixtures thereof.
The transparent protective layer can contain UV light absorbers and / or other light stabilizers. Among useful UV light absorbers is a bound amine absorber available from “Ciba Specialty Chemical” under the trade name “Tinuvin”. The light stabilizers that can be used are “Tinuvin 111”, “Tinvin 123”, (bis- (1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl sebacate)), “Tinuvin 622”. ”(Dimethyl succinate polymer with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol),“ Tinuvin 770 ”, (bis- (2,2,6,6-tetra sebacate) Methyl-4-piperidinyl) and a bound amine light stabilizer available from “Ciba Specialty Chemical” under the trade name “Tinvin 783.” Still other light stabilizers are “Chemassorb”, especially “Chemassorb 119”. And “Chemassorb 944” Constrained amine light stabilizer available from “Ciba Specialty Chemical.” The concentration of UV light absorber and / or light stabilizer ranges up to about 2.5 wt%, and in one embodiment about 0 0.05% to about 1% by weight.

  The transparent protective layer can contain an antioxidant. Any antioxidant useful for making thermoplastic films can be used. These antioxidants include bound phenol and organic phosphorous acid. Examples include those available from “Ciba Specialty Chemical” under the trade names “Irganox 1010”, “Irganox 1076”, or “Irgafos 168”. The concentration of the antioxidant in the thermoplastic film can be in the range of up to about 2.5 wt%, and in one embodiment is in the range of about 0.05 wt% to about 1 wt%. can do.

  A release liner can be adhered to the adhesive layer to protect the adhesive layer during shipping, storage, and handling prior to application of the label to the substrate. The liner allows efficient handling of a series of individual labels until the point at which the labels are die-cut, the matrix is peeled from the layer of facestock material, and individual labels are successively removed onto the labeling line To. The release liner can have a non-adhesive material such as a relief surface and / or microbeads or printing ink dots added to the surface of the liner.

The process of applying a process label to an article or container involves unconventional operations and equipment. The process begins with a conventional dispensing device that separates the label from the release liner by a release plate or tip that presents the adhesive-exposed label to the container or article to be decorated. Referring to FIGS. 6A-6D, a label 62 having a central portion 61 and a peripheral portion 63 surrounding the central portion and having an outer boundary defined by the label edge initially applies pressure to the central portion of the label. Thereby contacting the container 60. By having an initial adhesive point 64 located towards the center portion of the label rather than the leading edge or surrounding portion of the label, any dirt or wrinkles formed between the leading and trailing edges of the label to be applied are more even Distribution becomes easy. Furthermore, it facilitates the removal of dirt or soot by applying heat.

For articles having both a composite curved surface and a relatively flat area, the label can be initially contacted with the container near or within a relatively flat area of the container surface rather than on the composite curved surface.
In one embodiment, the label is preheated to soften the shrink film and / or activate the adhesive layer.
To obtain intimate contact between the label and the container or article, use a series of brushes, rollers, wipers, rubber wipes, pneumatic rollers, or moving beams on the transferred label, as indicated by arrow 65 As shown, pressure is applied in the center outward direction. This process is referred to herein as label “wiping”. The wiping movement from the center to the edge drives any air trapped under the label to the outer edge, as indicated by arrow 66, and creates a smaller, more evenly distributed dart on the edge of the label. generate. As the label covers the complex curved surface of the article, excess label material generally accumulates in the form of dirt, folds, grooves, bubbles, and other sticking defects in the peripheral portion of the label. Heat is applied to at least a portion of the label so that the label adheres completely and smoothly to the container as shown in FIG. 6D.

  In one embodiment, pressure is applied to the label using a moving beam system equipped with a foam roller or a foam covered beam. The foam roller or beam applies a downward pressure in the longitudinal direction relative to the center area of the label, then proceeds to the outer edge of the label, and any air trapped under the label, as well as pleats, wrinkles, and Introduce other defects to the outer edge of the label. This embodiment is illustrated in FIG. 7 where a container 70 having an affixed label 71 is positioned on the lower foam block 72a of the moving beam. The upper foam block 72b applies a downward pressure against the label 71 on the container 70 so that air is drawn from below the central portion of the label when the label and container are compressed between the foam blocks of the moving beam. Push to the outer edge of the label.

  With the label applied and the initial sweep completed, heating at least a portion of the label to shrink the dirt and / or wrinkles removes dirt and defects in the excess label material. The label can be heated by passing through a thermal tunnel, forced air, steam tunnel, direct contact thermal pad or form. In one embodiment, the label is heated to a temperature of at least 40 ° C. In one embodiment, the label is heated to at least 60 ° C, at least 70 ° C, or at least 80 ° C.

Subsequent label sweeps can be performed to remove any residual dirt or soot in the label. Again, pressure is applied to the center of the label in the outward direction of the label. The second sweep can be performed using a series of rollers, wipers, rubber wipes, brushes, pneumatic rollers, or moving beams. This subsequent wiping can be performed simultaneously with or subsequent to the application of heat to the label.
When applying the label to the article or container, the label can be adhered to the article by first applying pressure in the contact area of the label and then over the label in the direction of the first edge of the label. Pressure is applied. The contact area can be in the center of the label or can be close to the second edge of the label opposite the first edge. For example, initial contact can occur at the center of the label, and then pressure is applied in an outward direction to the edge or outer edge of the label. Alternatively, the first contact can occur near one edge of the label, and then pressure is applied across the label to the opposite edge of the label. When applying a label to an article or container, it is desirable to move excess label material, i.e., dirt or folds, to at least one label edge. Excess material is generally moved in the direction of the composite curved surface, where heat applied to the label causes the label to shrink, and the label conforms to the composite curved surface and removes any dirt or wrinkles formed. Make it possible. Heat and pressure can be applied to the label simultaneously.

  In one embodiment of the present invention, a method of labeling an article comprises the steps of: providing an article having a surface that includes at least one composite curved surface; and (ii) a heat shrinkable film having an inner surface and an outer surface; Providing a label comprising a layer of pressure sensitive adhesive on the inner surface of the heat shrinkable film and having a first edge and a contact area; contacting the adhesive layer in the contact area with the article; Heat and pressure are simultaneously applied to the label in the direction from the contact area to the first edge so that the first edge adheres to the article and the label shrinks to conform to the composite curved surface of the article. And a pressure is applied by at least one hot air knife assembly including a heated air source, a flow control mechanism, and one or more hot air knife slots. The contact area can be located at or near the center of the label. Alternatively, the contact area may be close to the second edge of the label opposite the first edge.

  FIG. 8 illustrates an embodiment of the invention in which a hot air knife assembly is used to label the article or container. The label can be affixed to one or both sides of the container. For illustrative simplicity, the label is affixed only to one side of the container of FIG. The hot air knife assembly includes a hot air source, a flow control mechanism, and one or more hot air knife slots. As shown in FIG. 8A, the two hot air knife slots 84 a and 84 b direct high-speed hot air to the center region 83 c of the label 82. The label 82 is first affixed to the central region 83c of the container 81 by a standard stripping tip dispensing process (not shown), leading edge (first edge 83a) and trailing edge (second edge 83b). Is not fastened. The labeled container is transported by a conveyor to an air knife assembly. Depending on the size and configuration of the container, heat and pressure can be applied to the label using additional hot air knife slots and / or hot air assemblies. As shown in FIG. 8B, the hot air knives 84a and 84b rotate outward to direct the hot air from the center region 83c of the label toward the first edge 83a and the second edge 83b of the label 82. When hot air is pressed against the label 82, the air between the label and the container 81 is pushed to the label edges 83a, 83b to smooth the label and eliminate or reduce air bubbles under the label. Hot air directed at the label 82 softens the label and causes the label to contract. Simultaneous application of heat and pressure from the air knife slots 84a, 84b to the label forces the label 82 to conform to the surface of the container 81 including the composite curved surface of the container. An optional subsequent heating step can be used to further shrink the label. The advantage of this method is that there is no direct contact with the label so that it is unlikely to introduce surface defects to the label. The ability to obtain high speed processing through excellent heat transfer to the label and continuous heat recovery of the hot air knife assembly is also an advantage. Using this method, labels can be applied to various containers and article shapes without the need for tool changes.

FIG. 9 illustrates an embodiment in which a plurality of air knife slots and / or air knife assemblies are used to apply a label to a container or article in a series of stages. The label can be affixed to one or both sides of the container. For illustrative simplicity, the label is affixed only to one side of the container of FIG. The hot air knife assembly includes a hot air source, a flow control mechanism, and one or more hot air knife slots. In the starting stage shown in FIG. 9A, the hot air knife slot 94 directs high-speed hot air to the central region 93 c of the label 92. The label 92 is first applied to the central region 93c of the container 91 by a standard stripping tip dispensing process (not shown) and has a leading edge (first edge 93a) and a trailing edge (second edge 93b). Is not fastened. The labeled container is transported by a conveyor to an air knife assembly. As shown in 9B, when the container 91 is conveyed by the conveyor beyond the air knife slot 94, the hot air is pressed against the label 92 against the first edge 93a of the label, heating the label and heating the container 91. While the second edge 93b is not adapted and / or fastened. The container is then rotated approximately 180 ° as shown at 9C. As shown in FIG. 9D, the container 91 with the label 92 adhered is then conveyed to a second hot air slot 95, which directs the hot air from the label center 93c to the second edge 93b with respect to the label 92. And heat the label to conform it to the face of the container 91 as shown at 9E. Depending on the size and configuration of the container, heat and pressure can be applied to the label using additional hot air knife slots and / or hot air assemblies. An optional subsequent heating step can be used to further shrink the label.
The labeled articles of the present invention are not limited to personal care products, household chemical products, food and beverage products, toys, electronic devices, pharmaceuticals, healthcare products, industrial products, and electrification. It can be used for various applications including products.

EXAMPLES The following examples are intended only to illustrate the methods and embodiments according to the present invention and therefore should not be construed as limiting the claims.

  The pressure sensitive shrink label consists of a 3 mil thick low density polyethylene multilayer shrink film named CorrTuff from “Sealed Air”. The film is coated with an acrylic emulsion adhesive S692N from "Avery Dennison". The adhesive is held on glassine paper BG-40 silicone coated release liner. The label is oversized and has a size of approximately 5 x 3.5 inches, which is 20% larger than the industry standard recommended label size for the bottle to which the label is applied.

A 15 oz "Johnson & Johnson Baby Lotion" bottle with a compound curved surface is filled with water, closed and processed at 100 bottles per minute (BPM) through a "Label-Air 9000" series labeling machine Is done. This labeling machine has a “Label-Air 2115-CD” labeling machine head with a high torque stepper motor drive along with twin feed screws with matching upper and lower belts. The label is squeezed with a moving beam-type wiping system that provides a force directed straight out from the center to guide air trapped under the label and the resulting dirt / pleat defect to the edge of the label. The Oversized labels affixed to bottles initially produce small dirt and folds that cannot be tolerated around the perimeter of the label. The labeled bottles are then processed through a Leister hot forced air conveyor wiping system at 100 bpm. High-speed 260 ° C. hot air heats the bottles and labels to 50 ° C., causing the dirt and pleats of excess label material to shrink and remove until the bottle surface is reached. The label is swept with a moving beam for good label contact. The dirt shrinks and is easily swept and flattened after heat is applied.
Finished with a larger label area and more graphic content, the pre-labeled bottle is smooth without the dirt, folds, ridges, or wrinkle defects present in typical oversized pressure sensitive labels Wiped out. Dirt does not return over time. Table 1 below shows the characteristics of the label components.

  According to the process described in Example 1, a 2 mil thick polypropylene multilayer shrink film named “CZPA 200” from Innovia is applied to a bottle having a composite curved surface. After the initial sweep, a medium size dart is formed. High speed hot air heats the bottles and labels to 100 ° C. The dirt shrinks and is easily swept and flattened after heat is applied. Dirt does not return over time.

  According to the process described in Example 1, a pressure sensitive shrink label composed of a 2 mil thick polylactic acid monolayer shrink film named “EARTHFIRST PLA” from “Plastic Suppliers” is applied to a bottle having a composite curved surface. . After the initial sweep, a medium size dart is formed. High speed hot air heats the bottles and labels to 70 ° C. The dirt shrinks and is easily swept and flattened after heat is applied. Dirt does not return with time.

Comparative Example 4
According to the process described in Example 1, a pressure sensitive shrinkage label composed of a 2 mil thick machine direction oriented polypropylene single layer rotational shrinkage fixing film from “Avery Dennison” is applied to a bottle having a composite curved surface. High-speed hot air heats bottles and labels to 70 ° C. The darts formed on the top and bottom of the label shrink under the application of heat and are easily wiped away, but the darts formed on the leading and trailing edges remain. The removed dirt does not return over time.

Comparative Example 5
A pressure sensitive shrinkage label composed of a 1.9 mil thick transversely oriented polyvinyl chloride monolayer film named “Penta Label” from Kloeckner according to the process described in Example 1 is applied to a bottle having a composite curved surface. It is done. High speed hot air heats the bottles and labels to 60 ° C. The darts formed on the leading and trailing edges of the label shrink under the application of heat and are easily wiped, whereas the darts formed on the top and bottom of the label remain. The removed dirt does not return over time.

Comparative Example 6
A 2 mil thick transversely oriented glycol modified polyethylene terephthalate (PETG) single layer film named “Fusion 1775E” from Mitsubishi is affixed to a bottle with a composite curved surface according to the process described in Example 1. High-speed hot air heats bottles and labels to 50 ° C. The darts formed on the leading and trailing edges of the label shrink under the application of heat and are easily wiped, whereas the darts formed on the top and bottom of the label remain. The removed dirt does not return over time.

Comparative Example 7
According to the process described in Example 1, a 1.4 mil thick machine direction oriented polyvinyl chloride monolayer film named MF-L243 / 01 from Kloechner is applied to a bottle having a composite curved surface. High speed hot air heats the bottles and labels to 60 ° C. The film is not compatible with the container. The initial sweep is incomplete and many darts are formed in all directions. Dirt and ridges remain after heat application and the second sweep. The film exhibits excessive shrinkage.

Comparative Example 8
According to the process described in Example 1, a 2.0 mil thick polypropylene multilayer film named BTNY from Vifan is applied to a bottle having a composite curved surface. High speed hot air heats the bottles and labels to 100 ° C. The formed dart does not shrink completely at high temperatures and does not completely flatten even when wiped. Dirt returns with time.

Comparative Example 9
A 3.4 mil thick medium density polyethylene (MDPE) multilayer film named “PE 85” from “Charter Films” is applied to a bottle with a composite curved surface according to the process described in Example 1. High speed hot air heats the bottles and labels to 100 ° C. The formed dart does not shrink completely at high temperatures, and does not completely flatten when swept. Dirt returns with time.

(Table 1)

(Table 1 continued)

(Table 1 continued)

  Although the present invention has been described in terms of its preferred embodiments, it should be understood that various modifications of these embodiments will become apparent to those skilled in the art upon reading this specification. Accordingly, it is to be understood that the invention disclosed herein is intended to include such modifications as fall within the scope of the appended claims.

10 Article 12 Label 16 Surface including at least one compound curved surface

Claims (22)

A method of attaching a label to an article,
Providing an article having a surface comprising at least one composite curved surface;
Providing a label comprising (i) a heat-shrinkable film having an inner surface and an outer surface; and (ii) a pressure-sensitive adhesive layer on the inner surface of the heat-shrinkable film and having a first edge and a contact area. Stages,
Contacting the adhesive layer in the contact area of the label with the article;
The first edge of the label adheres to the article and the label shrinks to fit the composite curved surface of the article in a direction from the contact area to the first edge. Applying heat and pressure simultaneously to at least one hot air knife assembly including a heated air source, a flow control mechanism, and one or more hot air knife slots;
A method comprising the steps of:   The label includes a center and a second edge opposite the first edge, and the contact area is near or at the center of the label. Item 2. The method according to Item 1.   The method of claim 1, wherein the label includes a second edge opposite the first edge, and the contact area is close to the second edge of the label. .   The hot air knife assembly includes at least two hot air knife slots that rotate outwardly from the center of the label to the first and second edges to apply the label to the article. The method of claim 2.   A first hot air knife slot applies heat and pressure to the center of the label to the first edge of the label, and a second hot air knife slot applies heat and pressure to the center of the label. 3. The method of claim 2, wherein a is applied to the second edge of the label.   6. The method of claim 5, further comprising rotating the article approximately 180 degrees prior to the application of heat and pressure to the label by the second hot air knife slot. The label is provided with a release liner bonded to the adhesive layer,
Separating the release liner from the label prior to contacting the label with the article;
The method according to any one of claims 1 to 6, further comprising:   The method of any one of claims 1 to 7, wherein the label is heated to a temperature of at least 40C.   9. The heat-shrinkable film according to claim 1, wherein the heat-shrinkable film includes a film selected from polyester, polyolefin, polyvinyl chloride, polystyrene, polylactic acid, copolymers thereof, and blends thereof. 2. The method according to item 1.   The method according to any one of claims 1 to 9, wherein the heat-shrinkable film comprises polyolefin.   11. A method according to any one of the preceding claims, wherein the heat shrinkable film comprises a multilayer film having a core layer and at least one skin layer.   12. A method according to any one of the preceding claims, wherein the stiffness of the film is at least 5 mN in the machine direction. The label further includes a printed layer between the heat shrinkable film and the adhesive layer,
The heat shrinkable film is transparent,
The method according to any one of claims 1 to 12, characterized in that:   14. A method according to any one of the preceding claims, wherein the label further comprises a printed layer on the outer surface of the heat shrinkable film.   The method of claim 14, wherein the label further comprises a protective layer overlying the printed layer.   The method according to any one of claims 1 to 15, wherein the adhesive layer comprises an emulsion adhesive.   The method according to any one of claims 1 to 16, wherein the adhesive layer includes a hot melt adhesive.   The method according to claim 1, wherein the adhesive layer includes a solvent-based adhesive.   The method according to any one of claims 1 to 18, wherein the pressure-sensitive adhesive layer is continuous.   19. A method according to any one of claims 1 to 18, wherein the pressure sensitive adhesive layer is patterned and the pattern substantially covers the inner surface of the film.   The heat-shrinkable film has a machine direction and a transverse direction, the film has a final shrinkage rate S of at least 10% in at least one direction at 90 ° C., and the shrinkage rate in the other direction is S 21. The method according to any one of claims 1 to 20, wherein the method is ± 20%.   The method according to any one of claims 1 to 21, further comprising heating the label following the simultaneous application of heat and pressure to the label by the hot air knife assembly.

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