Patent Application
20150064372
1. Field of the Disclosure
The present subject matter relates to heat transfers that feature anti-dye migration enhancements, particularly for use on color dye sublimated apparel such as sportswear fabrics, clothing and accessories. The present subject matter is especially suitable for transfers having a color ink layer protected by a support sheet suitable for use in heat-transferable labeling and the like.
2. Description of Related Art
Transfer decoration, labels, patches, tags, identification placards, embellishments and the like are widely used for a variety of different applications including logos, trademarks, keyboard symbols, whether numeric, alphabetic or alphanumeric or other symbols, sports designs, logos and names, clothing design details, accents and backgrounds, artwork and the like. In some applications, these decorative components are in the nature of heat transfer labels suitable for application on color dye sublimated fabrics, clothing and accessories. Such decorative components often concern so-called “soft goods,” a term generally understood in the art. Examples include clothing, upper bodywear, lower bodywear, headwear, footwear, outerwear, underwear, garments, sportswear fabrics, other sheet goods, banners, flags, athletic or sport clothing and uniforms, government uniforms, organization uniforms, accessories (e.g. belts, hats, scarves, etc.) therefor and combinations thereof.
Production of such soft goods or the like can include the use of dye sublimation techniques for fabrics. It is recognized that dye sublimated fabrics are remarkable due to their vivid color appearance, while being flexible in process manufacturing. These can be referred to as sublimated fabrics, which typically use heat-resistant synthetic fabrics that allow dyes of the “disperse dye” category to diffuse in the fabric fibers when subjected to heat. Typical synthetic fibers suitable for such a dye diffusion approach include polyesters, polyamides, nylons, and combinations of such materials with cotton and/or stretchable or resilient materials such as spandex or elastane or Lycra® and the like. Sublimated fabrics are a particular challenge for heat transfer labels, the significant challenge being that diffusion-driven dyes have a tendency to migrate from the base fabric and can migrate to and through the transfer or label, thereby altering its face color or intended appearance as well as impacting or damaging the appearance of the surrounding fabric. It is believed that the dye diffusion process is thermodynamically driven by the dye concentration gradient and that same is facilitated by heat encountered from a variety of sources during manufacture and use.
The art has recognized that this problem can be addressed through the use of anti-dye migration techniques. Such techniques can include the use of a so-called barrier layer that is often positioned in contact with the label or heat transfer when applied to the fabric. Often dye migration resistant heat transfers or labels feature a barrier layer based on highly chemically absorbent materials such as activated carbon. Even with such advances, dye diffusion often occurs along the outer perimeter of the heat transfer or label, creating what is at times referred to as the “halo effect” creating an undesirable ring around the outside of the transfer.
Following are examples of previous attempts to solve the “halo effect” problem. U.S. Patent Application Publication No. 2012/0121869 includes a dye migration preventing layer in a decoration piece, this layer being arranged between the decoration piece and the lower layer typical for such a decoration piece that can take the form of an emblem, badge, appliqué, sticker or the like. Such a decoration piece when used is attached to polyester fabric such as clothing dyed by using dispersion dye or sublimation printing. One of the features of this approach is to insure the dye migration preventing layer has an outer profile that is the same as that of the decoration or design piece.
Dinescu et al. U.S. Patent Publication No. 2012/0040154 combines a breathability feature with heat transfer labels that include a dye blocking layer as well as a so-called white layer, along with a clear layer, this labeling approach being intended for fabric containing thermal sublimation dyes. This recognizes that a thermal sublimation dye will migrate through the adhesive layer on which the label is attached to the fabric and into the white layer or the indicia layer when heated, such as during thermal transfer processing, which can cause the color of the white layer or the indicia layer to be contaminated. By this approach, the dye blocking layer is provided in an effort to stop the thermal sublimation dye from contaminating the white layer or the indicia layer. Such dye barriers include the use of activated carbon.
U.S. Pat. No. 7,238,644 concerns a laminate for printing in order to color a resin layer by allowing a sublimable dyeing agent to permeate into the inside of a resin layer through heating. This laminate includes an inner layer that is a coloring resin layer having strong affinity with a sublimable dyeing agent in an attempt to prevent transfer of the dyeing agent and of the sublimable dyeing agent having been printed.
There are several aspects of the present subject matter which may be embodied separately or together in the devices and systems described and claimed below. These aspects may be employed alone or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude the use of these aspects separately or the claiming of such aspects separately or in different combinations as may be set forth in the claims appended hereto.
In one aspect of this disclosure, a heat transferable label is provided that has a support portion releasably secured to a transfer portion. The transfer portion includes a color ink layer with a decorative face opposite the releasably secured support portion, a multi-layer barrier having a first barrier layer with a first perimeter, the first barrier layer overlying the color ink layer, and a second barrier layer overlying the first barrier layer and having a second perimeter extending beyond the first perimeter to provide an overhang with respect to the first barrier layer. A hot melt adhesive layer overlies the second barrier layer of the multi-layer barrier.
In another aspect, of this disclosure, a heat transferable label is provided that has a support portion releasably secured to a transfer portion. The transfer portion includes a color ink layer with a decorative face opposite the releasably secured support portion, a transition layer overlying the color ink layer, the transition layer having a third perimeter, a multi-layer barrier having a first barrier layer with a first perimeter, the first barrier layer overlying the color ink layer, and a second barrier layer overlying the first barrier layer and having a second perimeter extending beyond the first perimeter to provide an overhang with respect to the first barrier layer. A hot melt adhesive layer overlies the second barrier layer of the multi-layer barrier.
In a further aspect of this disclosure, a heat transferable label is provided that has a support portion releasably secured to a transfer portion. The transfer portion includes a color ink layer with a decorative face opposite the releasably secured support portion, a white ink layer overlying the color ink layer and having a fourth perimeter, a multi-layer barrier having a first barrier layer with a first perimeter, the first barrier layer overlying the color ink layer, and a second barrier layer overlying the first barrier layer and having a second perimeter extending beyond the first perimeter to provide an overhang with respect to the first barrier layer. A hot melt adhesive layer overlies the second barrier layer of the multi-layer barrier.
In an added aspect of this disclosure, a heat transferable label is provided that has a support portion releasably secured to a transfer portion. The transfer portion includes a color ink layer with a decorative face opposite the releasably secured support portion, a white ink layer overlying the color ink layer and having a fourth perimeter, a multi-layer barrier having a first barrier layer with a first perimeter, the first barrier layer overlying the color ink layer, and a second barrier layer overlying the first barrier layer. A hot melt adhesive layer overlies the second barrier layer of the multi-layer barrier and has a third perimeter extending beyond the first perimeter, thereby defining a recess gap at the perimeter edge of the first barrier layer. The second barrier layer has a second perimeter extending beyond the first perimeter to provide an overhang margin with respect to the first barrier layer, which overhang margin lies within the recess gap.
In an additional aspect, the disclosure relates to a transfer for application to color dye sublimated sportswear fabrics, the transfer including a support sheet releasably secured to a transfer label having a color ink layer with a decorative face opposite the releasable support sheet, an intermediate layer and an adhesive layer on the outside face, the disclosure including the placement of the multi-layer barrier between the intermediate layer and the adhesive layer.
Other features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description of the various embodiments and specific examples, while indicating preferred and other embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.
These as well as other objects and advantages of this invention, will be more completely understood and appreciated by referring to the following more detailed description of the presently preferred exemplary embodiments of the invention in conjunction with the accompanying drawings, of which:
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriate manner.
With further reference to the typical prior art transfer that is illustrated in
With further reference to the multi-layer barrier 38, same includes a first barrier layer 41 and a second barrier layer 42. In this illustrated embodiment, the first barrier layer is printed to include a recess gap 43. The second barrier layer cooperates with this structure by being printed with a perimeter margin or overhang 44, thereby providing the second barrier layer with an area size and shape that is the same as, or slightly in excess of, the white color layer so that the white color layer 36 is coincident in size and shape or is slightly overlapped by the size and shape of the second barrier layer 42. Where the size of the second barrier layer 42 is larger so as to create this type of overhang margin 44, the width of the overhang should be no greater than 0.2 mm in excess of the perimeter size and shape of the first barrier layer 41.
The second embodiment illustrated in
With more particular reference to the multi-layer barrier 58, same includes alternating sequences of first and second barrier layers. This repetitive approach has the advantage that each barrier layer can be thinner, allowing more flexing inasmuch as the more stretchable polymers of the first barrier layer can compensate for what is a thinner more rigid second barrier. As discussed herein, the polymer film of the first barrier layer typically is more flexible than the polymer film of the second barrier layer. This repeating-layers approach allows the second barrier layer to be thinner than when only a single first and second barrier layer pair are provided, as in the embodiment of
More than the illustrated two pairs of first barrier layers 61, 61a and second barrier layers 62, 62a can be provided. For example, the embodiment can have up to ten first and second barrier layer pairs sandwiched on top of each other. However many the number of pairs, the diffusing dyes need to pass through a multitude of absorb and defect sequences before any halo effect appearances. Generally, each pair of first and second barrier layers is configured to provide a recess gap 63 and an overhang margin 64 substantially as provided in the first embodiment depicted in
The transfer construction of the third embodiment that is illustrated in
With more particular reference to the multi-layer barrier 78, the second barrier layer 82 does not cover the entire area of the first barrier layer 81; instead, the second barrier layer has what might be considered to be an inside wall 83 that defines a void in the second barrier layer 82. In the case of a transfer that is circular in plan view, the second barrier layer 82 takes the form of an edge ring having an overhang margin 84 that fills recess gap 83 defined along the perimeter of the first barrier layer 81 that is smaller than the extreme periphery of the white ink layer 76. In this illustrated embodiment, the first barrier layer 81 fills the void defined by the inside wall 85 of the second barrier layer 82. This thicker portion of the first barrier layer 81 does not detrimentally affect flexibility and bendability of the transfer of this third embodiment since the polymer of the first barrier layer exhibits flexibility and/or stretchability in excess of that of the polymer of the second barrier layer 82, a substantial portion of which is in effect replaced by polymer of the first barrier layer 81.
The structure and relationship between first barrier layer 101 and second barrier layer 102 is substantially the same as that for first barrier layer 81 and second barrier layer 82 in
It will be appreciated that the specific embodiments illustrated herein can be supplemented, particularly with respect to a transfer portion that can be considered a heat transfer label composed of a series of sandwiched layers. These layers can include the color art design layer, or color heat layer depicted in the drawings, which provides the artwork or other indicia or coloration or design that identifies the particular label. A background layer or transition layer such as the white ink layers described herein typically is included to provide background attributes to the color art design layer. One or more clear layers can be included for reasons generally known in the art. Functional layers such as the adhesive layers and barrier layers shown and described herein are included. This transfer or heat transfer label is transferrable onto a fabric support upon heat and pressure application in the manner known in the art.
In order to facilitate protection and delivery of the transfer portion of the label, a support portion typically is provided which has the function of a label carrier that provides mechanical strength to the label assembly allowing handling such as being wound up in a roll for storage, stacking, and as a label feed for mechanized operations. Basically, the support portion is a sheet carrier and a release layer. Typical sheet carriers are cellulosic or polymeric film. A typical release layer is a low melting temperature, thinly coated film on a sheet carrier that facilitates peeling of the transfer portion from the sheet carrier when the heat transfer is completed. An example of a carrier is an “O6” liner which is thermally stabilized polyethylene terephthalate (PET) of about 5 mil thickness coated with an amide wax-based heat-induced release layer, commercialized by Avery Dennison Retail Brand and Information Services Division (RBIS Division) of Westborough, Mass.
Concerning manufacture of label or transfer assemblies generally discussed herein, it is typical for each layer to be coated, typically printed, on top of a previous layer in order to form sandwich-type structures as shown in the drawings hereof. Generally, these layers are printed in reverse order, top to bottom, and typically the color ink or color art design layer is printed mirror imaged, left to right. Component layers in such sandwiches are polymeric films containing other ingredients such as color pigments, waxes, other polymers, additives, fillers and the like, generally discussed in greater detail herein. With further reference to the printing approach that is typically used in these instances, the layers are generated by printing inks that are subsequently cured and dried. Usually these inks are based on a water vehicle or a solvent vehicle that is dispersed or dissolved in one or several components such as polymers, additives, pigments, ink additives and the like. Examples of ink additives in this regard include humectants, rheology modifiers, surface tension modifiers, leveling agents, release agents, and so forth.
Also used in the manufacture of these labels typically are color layers and precursor inks, often water and solvent-based screen inks. Examples of a suitable such inks are those based on polyurethane polymers, a specific screen ink being AGILITY™ color screen set available from Avery Dennison (RBIS Division). Regarding the first dye barrier layers described herein, each is based on a polymeric media that is incompatible or partially compatible with the dispersed dyes used by color sublimation techniques. Usually such polymeric media contain additives or fillers that are able to adsorb effectively the dye molecules. As generally discussed herein, absorbent fillers of this type may exhibit a color, typically a dark color, that causes concern for placement of such barriers in the label assembly.
Examples of polymers for the first barrier layer are solvent-based or water-based polyurethanes exhibiting good elastic and stretch properties, for example having an elongation at break of better than 100 percent. These polymers typically are of a relatively high molecular weight, in excess of 100,000, exhibit good mechanical properties, such as tensile strength of greater than 10 MPa and a tensile strength of less than 60 MPa. Usually these suitable polymers for the first barrier layer have a melt range of greater than 150° C., often of 175° C. or greater. An example of a suitable polymer in this regard is IMPRANIL® DLU, which is a water-based polyurethane derived from a polyether and polycarbonate diols.
Fillers suitable for the first barrier layer are highly adsorbent, such as activated carbons and composites between activated carbon and molecular sieves. Activated carbon is known to remove impurities from fluids, whether liquid or gaseous, by a process called adsorption. In this context, adsorption is a surface phenomenon that results in the accumulation of molecules on the surface of the internal pores of an activated carbon. Suitable activated carbons for this purpose have a surface area in the range of 600 to 1600 square meters per gram and a total pore volume between 0.9 and 1.8 Ml/g. An especially suitable particle size range is between 0.5 and 80 microns, an even more suitable range being between 1 and 50 microns, an especially suitable range being between 5 and 20 microns.
Ink barriers of the type described herein for the first dye barrier may contain additives such as thickeners, surfactants, dispersants, cross-linkers, and so forth. In terms of additive choice, preference is given to those that are polymeric or contain molecules much larger than the average pore dimension of the carbon, so they will not be adsorbed and render the activated carbon ineffective. As an example, IMPRANIL® DLU used as a binder has a high molecular weight and good mechanical properties and thus would not require cross-linking with small reactive species that would contaminate the adsorbent coating material.
The first barrier layer of the present embodiments can have thicknesses varying between about 5 and about 500 microns. A more specific suitable range is between about 10 and about 200 microns, with an especially suitable range being between about 15 and about 100 microns. The second layer of the multi-layer dye barrier described herein is based on a polymeric media that is incompatible with the chemical nature of dispersed dyes used in sublimation coloring of textiles and the like. Compatibility or incompatibility between a polymer and a small molecular species such as a solvent or a dye can be measured according to the Hildebrand solubility parameter expressed in (calories/cm3)1/2, and requires comparable values of this property between the polymer and the solvent. Varied properties exhibited by the polymeric layer are expressed by the amount of containment or chemical migratory species that penetrate the layer per unit time and area.
Although useful in assessing the polymer/solvent interaction, the solubility parameters cannot be applied accurately to polar polymers and small organic molecules. Other useful measures of barrier properties for polymers are density and melt point (Tg, crystallinity). Generally, the higher these properties, the better the dye barrier properties that are manifested. One polymer useful for the second barrier layers described herein is polyvinylidyene chloride (PVDC), same being a homopolymer of vinylidene chloride, which exhibits outstanding barrier properties against water, oxygen and other chemical species. The particular polyvinylidyene chloride particularly useful as the second barrier layer polymer has a melting point of 202° C. and a Tg of −17° C., while the density at 25° C. ranges between 1.67 and 1.97 g/cm3, depending on crystalinity. Other polymers derived from vinylidene chloride can be useful. Other polymers for the second barrier layer include copolymers of vinylidene dichloride with acrylic and vinyl monomers, such as: methylmethacrylate, methylacrylate, butylacrylate and methacrylate, as well as acrylonitrile, acrylics acid, methacrylic acid, among others. Printing approaches for applying this second barrier layer to the label assembly is by printing, such as by screen printing, although other printing and coating methods are also possible, for example: graveure, flexography, offset printing, coating using a slot die, Meyer rod, digital printing, lamination and so forth.
These polymers used for the second barrier layer are suitable in the form of water-based emulsions with solid contents of 30-60 percent. Polymers of this type are made of inks and mixed with other components such as fillers, pigments and additives such as other barrier components, rheology modifiers, surfactants and so forth. Additives particularly suitable include EXPANCEL® microspheres from Akzo Nobel. Such microspheres in the second barrier layer increase not only the diffusion path of a migratory dye, but also improve softness and flexibility of rigid barrier polymers such as PVDC. These types of microspheres are dispersions of gas-filled polymeric microcapsules. Examples of suitable grades for such microcapsules are known as WU and WE. In an especially suitable combination, the microspheres should contain polymeric microcapsule walls made of PVDC and/or its copolymers. Suitable particle sizes for unexpanded EXPANCEL® microspheres range from about 6 to about 15 microns, with onset for expansion temperature range being from 80 to 120° C. A typical second dye barrier film will contain between about 1 to 20 percent of these microspheres, or between 2 and 10 percent, or between 3 and 7 percent.
Other additives for the second dye barrier film include high surface area inorganic fillers. These include amorphous silicas such as fumed silica with particles ranging from about 5 to about 50 microns and surface areas from between 10 and 1,000 m2/g. Suitable silica additives of this type are available from Evonik-Degussa and under the AEROSIL® trademark and from Cabot under the CAB-O-SIL brand. When included, the second dye barrier film will contain 1 to 50 percent silicon, or 5 to 30 percent silica, or 5 to 20 percent of silica. Another effective filler category or molecular sieves can be, for example, zeolites. These are alumina silicates with natural or synthetic origins that are characterized by regular and repetitive atomic core structure. Especially suitable are zeolites with a pore diameter less than 13 Angstroms and a particle size distribution between 1 and 100, or 5 and 40, or 5 and 10 microns. An example of molecular sieves or zeolites for this purpose are SYLOSIL® from W.R. Grace Company.
It will be appreciated that, due in large measure to the nature of the fillers used in formulating this second dye barrier layer, the color of such layer, upon drying and curing, is white or is otherwise lightly colored. Optionally, pigment fillers such as titanium dioxide and optical brighteners can be added to enhance layer whiteness. The thickness of this second dye barrier layer ranges between 5 and 500 microns, typically between 10 and 200 microns, and most typically between 15 and 100 microns.
With further reference to the adhesive layer described in connection with the present embodiments, this has a modulus suitable to withstand high temperature wash tests such as those required by some apparel manufacturers. Adhesive also has to have suitable adhesion to synthetic fibers. Usually, the adhesive is continuously printed or flood coated to a thickness that can range between 20 and 500 microns. In most applications, the adhesive needs to melt and flow in the fabric texture at a temperature of between 250 and 350° F. (approximately 121 to 177° C.) when heated for 5 to 50 seconds.
An example of a commercial hot-melt adhesive suitable for this purpose is AGILITY® transfer adhesive, available from Avery Dennison (RBIS Division). In the approaches described herein, the adhesive margin is printed to match or exceed the largest margin of the color background layer or the second barrier layer.
Other embodiments, besides those illustrated herein, may also be employed without departing from the scope of the present disclosure. For example, the label can be of a perimeter shape desired for a particular purpose other than the generally circular or cylindrical labels associated with a patch or insignia, for example, taking the form of a decorative embellishment, company logo, or artwork. Other options include enhancing the flexibility of the label or the like by minimizing the thickness and area covered by the second barrier layer, thereby providing improved label performance in terms of being able to better follow bendability or flow of the substrate to which the label is attached, such as fabric or clothing.
It will be understood that the embodiments described above are illustrative of some of the applications of the principles of the present subject matter. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter, including those combinations of features that are individually disclosed or claimed herein. For these reasons, the scope hereof is not limited to the above description but is as set forth in the following claims, and it is understood that claims may be directed to the features hereof, including as combinations of features that are individually disclosed or claimed herein.
