Method for making and using hot stamp tape

Abstract

A web of indeterminate length carrying thermally transferable material, usually referred to as hot stamp tape, is structured to provide an improved simulated wood grain pattern on a substrate after transfer to the substrate of transferable portions of the tape. The web or tape may be provided in sheet form. The structure comprises "ticks" or discrete linearly oriented spots of material having low specular reflectivity coated on a matte carrier sheet, as by printing, and a layer coated thereon to provide the top layer of the transferred material, which replicates the surface of the carrier sheet and the coated ticks or spots.

Description

FIELD

This invention relates to hot stamp tapes and more particularly to webs comprising heat transferable coatings.

PRIOR ART

The instant invention represents an improvement on the disclosures of the following patents:

______________________________________U.S. Pat. No. Patentee Classification______________________________________3,467,538 Best 117-83,054,715 White 156-2333,252,847 Morgan 156-2333,434,862 Luc 156-234X______________________________________

SUMMARY

Simulated woodgrain patterns have been provided on many surfaces in recent years. Examples include countertops, wall panels, cupboard doors, radio cabinets and the like. Many of these have been provided by printing a woodgrain pattern on paper, laminating the paper to a substrate and covering the paper with a layer of synthetic resinous material. This has been particularly true in the case of countertops and wall panels.

In other instances, a woodgrain pattern has been provided in a transferable layer of a hot stamp tape (or web) and then, by hot stamp transfer, the transferable portion including the woodgrain patterned layer has been transferred to and adhered to a substrate.

More recently, in order to better simulate the grain of wood, it has become common to emboss linearly oriented spaced-apart depressions into the surface during or after transfer, the embossed portions being referred to in the art as "ticks". Alternatively it has been well-known to provide the substrate with such "ticks" by molding or embossment prior to applying a coating thereto and then forcing the coating down into the "ticks".

"Ticks" which have been provided in this manner have aided in providing a realistic simulation of a wood grain but have not been considered to provide optimum simulation.

In accordance with the present invention, it has been found that a highly non-specularly reflective surface portion of a coated surface more nearly simulates to the eye the natural "tick" appearing in actual woodgrain than does a mere depression. The actual "ticks" in actual wood appear to be partially depressed as is the case with embossment. However, they also differ very markedly; that is, to an extremely high degree, in specular reflectivity with respect to the portions of wood immediately adjacent the "ticks". This latter property appears to be far more important in providing optimum simulation of the grain patterns of actual wood than does providing a depression as in the case of either embossment or molding of depressions in the substrate.

Thus, both the discovery involved in recognizing this fact and also the structure and method for providing improved simulated wood grain patterns constitute parts of the instant invention. Prior to the instant invention, it had not been possible to provide simulation of such nonspecular reflectivity characteristics.

Accordingly, I shall describe a preferred embodiment of my invention to provide "ticks" which are substantially or nearly non-specularly reflective; that is, have a specular reflectance below a value of 25% at 60.degree..

I first provide a carrier sheet or web which may be any carrier sheet or web of the prior art; for example, a polyester film such as "Mylar" (trademark of DuPont), a polyester film such as "Melinex" (trademark of Imperial Chemical Industries), or a web of cellophane or cellulose acetate or paper. I prefer to utilize a polyester film, particularly "Mylar" and I have found that to provide optimum results, I may provide this film as matte surfaced Mylar. A matte-surfaced Mylar may be provided by incorporating an inert particulate substance in the formulation during early stages of manufacture which affects the surface during later biaxial orientation or by embossment or sandblasting or chemical coating.

The carrier may then be coated on one surface with discrete spaced apart portions or "ticks" of a layer of synthetic resinous material in such fashion as to provide on the surface of each "tick", a surface having very low specular reflectance. If desired, a primer coat may first be applied in the pattern of the "ticks" and the "tick" coat applied on top of and in register with the primer coat. Coating may be accomplished by any suitable means such as by silk screening or spraying through a mask or by gravure printing or printing from the surfaces of characters. The composition is one which shrinks during drying to provide a sufficiently crinkled or otherwise irregular and non-glossy surface to provide the desired low degree of specular reflectivity. The discrete spaced apart portions or "ticks" are non-heat-transferably adherently attached to the carrier sheet, so that they will not transfer from the carrier sheet when subjected to the heat and pressure of the transfer operation.

A release coating may then be applied which may be of conventional form and may thus be based on paraffin wax or the like. The normal characteristics of a release coating are that it melts or softens at a temperature below that of other layers in the sheet so that neither the carrier portion which remains behind or the transferred portion (which may be one layer or may be as many as eight or 10 layers) is melted or softened, except that the surface of the layer adjacent the substrate is sufficiently softened or made sufficiently tacky to provide adherence to the substrate.

Extreme thinness of the release coating is absolutely essential if not entirely critical. Thus, the release coating must be relatively thin relative to the size of the bumps in the nearly non-specularly reflective surface of the coated "ticks", to permit subsequent replication of these "bumps".

A layer of replicating synthetic resinous material is then coated relatively thickly over the release coating so that the thickness of each heretofore coated "tick" is either somewhat less or at least not much greater than the thickness of this newly coated layer, the newly coated layer being of synthetic resinous material suited to replicate the surface of the carrier sheet and the surfaces of the heretofore coated ticks. This layer may carry coloring material or may be transparent and may be adapted to be adhered directly to a substrate or may be provided with additional layers which may comprise coloring material and/or tackiness characteristics for providing adherence to a substrate.

For example, it is normal to provide a simulated woodgrain pattern as a plurality of printings of different colors overlying each other and a coating is necessary for each such color. Coatings embodying all these colors may be placed over the replicating coating and the last of such color-containing coatings or an additional coating may be of a composition that provides the desired degree of tackiness during heat transfer to provide adhesion to the substrate.

Although carrier sheets either having a high degree of specular reflectivity, that is, being highly glossy or having a matte surface, that is, having a lower degree of specular reflectivity, have been described, the carrier sheet surface may have any suitable degree of specular reflectivity desired for any particular purpose.

This invention is not limited to providing simulated woodgrain patterns but may be utilized to provide any desired pattern having coated surface portions which vary greatly in specular reflectivity. Thus, on a carrier sheet having high, medium or low specular reflectivity, there may be coated not only one group of "ticks" having a particular set of surface characteristics, but there may also be coated additional groups of "ticks" to provide any desired number of groups, each group having a particular surface characteristic or characteristics which need not be the same as that of any other group coated thereon.

The replicatory coat then replicates all characteristics of all the surfaces presented by all such "ticks" or other coating portions coated thereon, plus the uncoated exposed portions of the carrier sheet.

OBJECTS

It is, therefore, an object to provide a hot stamp tape or web suitable for providing an improved simulated woodgrain pattern on a substrate.

Another object is such a web comprising coating "ticks" having low specular reflectivity and a replicating coating adapted to provide portions having corresponding low specular reflectivity after transfer.

Another object is to provide such a replicatory coat with two different degrees of reduced specular reflectivity.

Further objects will become apparent from the description.

DRAWINGS

In the drawings like reference numerals refer to like parts and:

FIG. 1 is a cross-sectional schematic view of one embodiment of the method and article of the invention;

FIG. 2 is a cross-sectional schematic view of the embodiment of FIG. 1 after completion of the process;

FIG. 3 is a cross-sectional schematic view of another embodiment of the process and article;

FIG. 4 is a cross-sectional schematic view of the embodiment of FIG. 3 after completion of the process.

DESCRIPTION

Referring now to FIG. 1, a carrier sheet A may be provided with primer coat portions B which may be provided thereover with tick coat portions C. A release coat D may then be provided and overlying the release coat there may be provided respectively a replicating layer E, an abrasion resistant layer F, a second abrasion resistant layer G, a color coat H, another color coat I, and an adherence promoting coat J.

Heat as indicated by arrows 10 and pressure as indicated by arrows 11 may be applied to force the laminar assembly 13, consisting of layers A thru J as described, against substrate 14. After thus applying heat and pressure, the carrier sheet and layers B and C and D attached thereto, may be removed to provide the article of FIG. 2, wherein areas of low specular reflectance are indicated at 15 and areas of specular reflectance differing therefrom are indicated at 16.

In FIG. 3 is shown an embodiment corresponding to that of FIG. 1 wherein many layers are omitted, layer E provides a combination replicating, release, color, and adherence coat. In FIG. 4 is shown the article which remains after completing the process of FIG. 3 and removing sheet A having coating C attached thereto.

Coatings B and C are preferably applied by gravure printing but may be applied by silk screen printing, letter press printing, or the like. All other coats or layers may be applied by any suitable coating means such as by Meyer rod or reverse roller coater.

Below are given specific examples of suitable formulations for each coating layer together with particular characteristics thereof.

The carrier sheet which is preferably in web or tape form may be, as described above, a polyester film such as Mylar or a web of cellophane or cellulose accetate or paper. Mylar having a thickness of from 1/2 mil to 2 mils is preferred. For a preferred embodiment, it is desired to provide matte Mylar having a specular reflectance at 60.degree. to the horizontal in accordance with ASTM standard D523 of 35% to 60% but in certain embodiments glossy or non matte Mylar which has a specular reflectance determined in like manner of on the order of above 90% and generally on the order of 95% or above may be used.

In Table I are shown the layers present in the various examples. Since the following three layers carrier sheet, "tick" cart, and replicating cart are present in all examples, these are not included in the table so that Table I only relates to nine examples although thirteen examples are presented; in the examples 10, 11, 12, and 13, the only layers present are carrier, tick coat, and replicating coat.

The primer coat as provided serves the purpose of providing for improved adherence between the tick coat and the carrier sheet and it may be omitted if adherence of the tick coat to the carrier sheet is adequate without the presence of the primer coat.

The release coat is generally preferably of a material such as a wax or the like; either natural wax, paraffin wax, or a mixture thereof, or a mixture of wax with other substances, may be used; but it is generally a waxy substance characterized by having a softening range rather than a clear softening point. The softening range or softening point of the release coat is generally preferably lower than the melting or softening points of the carrier sheet and all other layers in the laminar assembly so that when subjected to heat the softness of the release coat when heated permits the replicating coat to be released therefrom.

The replicating coat may in suitable instances be provided with release properties so that when subjected to suitable heat and pressure during hot stamping it is suitably released from the carrier sheet without the presence of a separate and a distinct release coat.

Abrasion resisting coats have the obvious function of providing enhanced abrasion resistance and either or both may be omitted if the replicating layer provides sufficient abrasion resistance in and of itself. Color coats are generally printed on. Generally at least two color coats are necessary if a suitable wood grain or simulated wood grain pattern is to be provided and often three color coats may suitably be utilized for the purpose of providing an attractive and suitable simulated wood grain pattern; however, for providing other patterns which are not simulated wood grain patterns, it may in many instances be suitable to provide only a single color coat or to provide sufficient coloring material in the replicating layer so that no individual color coat is necessary. In some instances, in fact, if no color is desired in the surface finish, no coloring material at all need be incorporated. The purpose of the adherence layer is to promote or improve adherence of the laminar assembly to a substrate, and an adherence coat need be provided only if the adherence is otherwise unsatisfactory.

In Table I, the presence of an "X" in a column indicates that a coating or layer is present in the example heading the column, and the absence of an "X" indicates the absence of a corresponding layer.

TABLE I______________________________________ Example______________________________________Coat: 1 2 3 4 5 6 7 8 9______________________________________B primer X X X X X XD release X X X X X XF abrasion XG abrasion XH color X X X X X X X X XI color X X X X X X X XJ adherence X X______________________________________

Examples 1 to 8 are suitable for providing two-color patterns, if the color coats are printed, which may be simulated wood-grain patterns, simulated leather patterns and the like.

__________________________________________________________________________Coat B-Primer Coat,parts by weight Example__________________________________________________________________________ 1 2 3 4 5 6__________________________________________________________________________dimethyl formamide 45 45Goodyear "Vitel" soluble 10 5polyester resin, PE 200Union Carbide VAGH vinyl resin 10 5Union Carbide VMCH vinyl resin 10 10dioxane 45 45 62chloroform 45 45 33tetrahydro furan 45 95 45cure temp., .degree. F. 250 250 275 250 250 275cure time, seconds 7 7 7 7 7 7thickness or wt., wet, 4 3 6 8 9 6 lbs. per ream__________________________________________________________________________ Coat C__________________________________________________________________________Tick Coat, parts by weight (dry thickness 5 to 20 microns)__________________________________________________________________________ ExampleIngredient or Condition 1 2 3 4 5 6 7 8 9 10 11 12 13__________________________________________________________________________American Cyanamid "Beetle" urea formaldehyde resin, 212-9 20 10American Cyanamid "Beetle" urea formaldehyde resin, 220-8 20 12 12American Cyanamid Melmac, Melamine resin, 243-3 25 18HCl 1 .5 1 .5 .3Union Carbide VMCH vinyl resin 13.5 20copolymer of 85% to 88% vinyl chloride,10.8% to 14.2% vinyl acetate, and 0.8%to 1.2% maleic acidRohm and Haas AT-50 thermosetting acrylic 30 12Johns Manville Celite diatomaceous earth 9 11 10 8 10Monsanto Santocel FRC, fumed silica 2 3 5 3Union Carbide VAGD vinyl resin 11copolymer of 89.5% to 91.5% vinylchloride, 2.0% to 5.3% vinyl acetate,and 5.2% to 6.5% vinyl alcoholUnion Carbide VAGH vinyl resin 11 11same as VAGD vinyl resin excepthigher molecular weightaluminum silicate 6 4p-toluene sulfonic acid 2 1methyl isobutyl ketone 40 35 13 45 34zylol 70 59 28.5 27 85butanol 40Dow Corning 704 silicone resin 1 1benzene 31 55 50 35 40 74.5 53 32.5 35 45Bakelite 2774 ERL catalyst 1 1polyurethane, prepolymer 13 13cure time 1 1 30 2 2 1.5 24 24 1 45 20 20 50 min. min. min. min. min. min. hrs. hrs. min. sec. sec. sec. sec.cure temp., .degree. F. 350 350 250 300 300 325 120 120 250 245 275 275 240__________________________________________________________________________ Coat D______________________________________Release Coat, parts by weight, 1 to4 pounds per ream, wet______________________________________ Example 1 2 3 4______________________________________petroleum wax, C.sub.43 H.sub.88 5 .5petroleum wax, C.sub.41 H.sub.84 4mantan wax 7 5ethyl hydroxyethyl 4cellulosebenzene 95 96 50 48CCl.sub.4 93 45methyl ethyl ketone 48trichloroethylene 99.5______________________________________ Coat E__________________________________________________________________________Replicating Coat, parts by weight__________________________________________________________________________ Example 1 2 3 4 5 6 7 8 9 10 11* 12** 13*Union Carbide VYHHvinyl resin 17 12 4 15 4copolymer of about 13% vinylacetate and about 87% vinylchloride, medium molecularweightNitrocellulose, 1/2 sec. R.S. 18 13 5 3Methyl methacrylate, medium molecular wt. 20 15 14 12 13 14 20 10TiO.sub. 2 17Iron oxide red 15 10butanol 55 28benzene 50 88 29 80 41 35 34 80 80acetone 33 27 58 85 41 55 34 66cure time, seconds 40 40 30 30 27 25 30 10 10 5 7 10 10cure temp., .degree. F. 180 180 200 200 205 200 200 225 230 240 220 215 215coating weights, wet pounds/ream 30 40 30 45 10 12 15 30 20 20 20 40 4__________________________________________________________________________ *single uniform color **clear Coat F______________________________________Abrasion Coat Example 1, parts by weight______________________________________Polyethylene, micronized 7Union Carbide vinyl resin VYNS 14medium-high molecular weight copolymerof 9.5% to 11.5% vinyl acetate andbalance vinyl chlorideacetone 50benzene 29 cure: 5 seconds at 260.degree. F. coating weight, wet: 15 lbs./ream______________________________________ Coat G______________________________________Abrasion Coat Example 1, parts by weight______________________________________Methyl methacrylate 10aluminum oxide 8acetone 78 cure: 30 seconds at 200.degree. F. coating weight, wet: 45 lbs./ream______________________________________ Coat H__________________________________________________________________________First Color Coat, parts by weight (cureat 180.degree. F. to 220.degree. F. for 4 to 20 seconds)__________________________________________________________________________ Example 1 2 3 4 5 6 7 8 9**__________________________________________________________________________Methyl methacrylate 10 20 15Vinyl Chloride resin 10 12Nitrocellulose, 1/2 sec RS 9 12Me methacrylate - Bu methacrylate co- polymer 21 16TiO.sub. 2 1.2 3 16Molybdate orange .5 1 4carbon black 1 .5 1.2 2 .5 .7 1 1 1acetone 88.5 48.6 78 30.5 29.3 81 37 21benzene 88.5 21methanol 28 60 58 21coating weights, wet, lbs./ream * * * * * * * * 40__________________________________________________________________________ *depends on pattern **single color Coat I__________________________________________________________________________Second Color Coat, parts by weight(coating weights depend on pattern, cure at 180.degree. F. to 220.degree.F. for 4to 20 seconds)__________________________________________________________________________ Example 1 2 3 4 5 6 7 8__________________________________________________________________________Vinyl chloride resin 10 20 8 22Me methacrylate-butylmethacrylate copolymer 10 20 8 22Iron oxide redMolybdate orange 5 10 4 9 4 4 4 4Chrome yellow 5 10 2 1 3 12 3 12TiO.sub.2 1 1 2 1 3 1 3carbon black 1 2 1 1 1 1acetone 79 60 44 83 58benzene 82 83 58methanol 22__________________________________________________________________________ Coat J______________________________________Adherence Coat, parts by weight______________________________________ Example 1 2______________________________________Methyl methacrylate - butyl methacrylate copolymer 20Nitrocellulose, 1/2 sec R.S. 15Tricresyl phosphate 5 6octyl alcohol 40 40pentane 25 29acetone 10 10cure time, minutes 2 2cure temp., .degree. F. 120 120coating weight, wet, lbs./ream 15 50______________________________________

Further embodiments and variations will be apparent to those skilled in the art and are intended to be included within the scope of the invention.

Claims

1. In a method for forming on a substrate a finish having a surface in which discrete spaced apart portions vary in specular reflectance from the remaining portions of the surface, the steps of:

providing a heat-resistant, flexible, foldable carrier sheet having a surface having a predetermined specular reflectance;

coating onto said carrier sheet surface a plurality of discrete spaced apart portions of a synthetic resinous material, said spaced apart portions being coated onto the carrier in a fluid condition and shrunk during drying to form irregularly-shaped surfaces remote from the surface of the carrier sheet and having a lower specular reflectance than that of the uncoated portion of the carrier sheet surface, said spaced apart portions being so adherently attached to the carrier sheet that they will not transfer from the carrier when heat and pressure are applied thereto;

coating over the surface of the carrier sheet and said spaced apart portions a transferable replicating layer comprising a coating of sufficient thickness of a synthetic resinous material to replicate both the specular reflectance of the uncoated portion of the carrier sheet surface and the specular reflectance of the remote surfaces of said spaced apart portions without said spaced apart portions transferring from the carrier sheet;

providing an adherence coat for adhering the transferable replicating layer to a substrate;

pressing the carrier sheet and the replicating layer against the substrate and applying heat to adhere the replicating layer to the substrate; and

releasing the carrier sheet and said adherently attached spaced apart portions from the surface of the replicating layer to provide the replicating layer as a surface finish attached to the substrate and having a plurality of discrete spaced apart portions having a lower specular reflectance than the remaining portion of the surface finish.

2. The method according to claim 1 including providing a simulated wood grain finish by coating at least two printed pigmented layers over the replicating layer when said replicating layer is in contact with the carrier sheet, the replicating layer being a clear coat so that the pigmented layers are visible through it.

3. The method according to claim 1 including forming said spaced apart portions from a thermosetting synthetic resinous material.

4. The method according to claim 1 including forming said spaced apart portions from a synthetic resinous material having a fine particulate filler.

5. The method according to claim 4 including coating said spaced apart portions so they have a dry thickness in the range of about 5 to about 20 microns.

6. In a method for forming on a substrate a finish having a surface in which discrete spaced apart portions vary in specular reflectance from the remaining portions of the surface, the steps of:

providing a heat-resistant, flexible, foldable carrier sheet having a surface having a predetermined specular reflectance;

coating onto said carrier sheet surface a plurality of discrete spaced apart portions of a synthetic resinous material having a fine particulate filler, said spaced apart portions being coated directly onto the carrier in a fluid condition and shrunk during drying to form irregularly-shaped surfaces remote from the surface of the carrier sheet and having a lower specular reflectance than that of the uncoated portion of the carrier sheet surface, said spaced apart portions being so adherently attached to the carrier sheet that they will not transfer from the carrier when heat and pressure are applied thereto;

coating over the surface of the carrier sheet and said spaced apart portions a transferable replicating layer comprising a coating of sufficient thickness of a synthetic resinous material to replicate both the specular reflectance of the uncoated portion of the carrier sheet surface and the specular reflectance of the remote surfaces of said spaced apart portions without said spaced apart portions transferring from the carrier sheet;

providing an adherence coat for adhering the transferable replicating layer to a substrate;

pressing the carrier sheet and the replicating layer against a substrate and applying heat to adhere the replicating layer to the substrate; and

releasing the carrier sheet and said adherently attached spaced apart portions from the surface of the replicating layer to provide the replicating layer as a surface finish attached to the substrate and having a plurality of discrete spaced apart portions having a lower specular reflectance than the remaining portion of the surface finish.

7. The method according to claim 6 including coating said spaced apart portions so they have a dry thickness in the range of about 5 to about 20 microns.

8. The method according to claim 7 including forming said spaced apart portions from a thermosetting synthetic resinous material.

9. The method according to claim 8 including providing a simulated wood grain finish by coating at least two printed pigmented layers over the replicating layer when said replicating layer is in contact with the carrier sheet, the replicating layer being a clear coat so that the pigmented layers are visible through it.

10. The method according to claim 6 including forming said spaced apart portions from a thermosetting synthetic resinous material.

11. A method for making a hot transfer sheet comprising a carrier sheet and transferable material on one side of the carrier sheet, in which said transferable material is releasable from the carrier sheet and said transferable material is adherently attachable to a substrate in response to heat and pressure, the method comprising the steps of:

providing a heat-resistant, flexible, foldable carrier sheet having a surface having a predetermined specular reflectance;

coating onto said carrier sheet surface a plurality of discrete spaced apart portions of a synthetic resinous material, said spaced apart portions being coated onto the carrier in a fluid condition and shrunk during drying to form irregularly-shaped surfaces remote from the surface of the carrier sheet and having a lower specular reflectance than that of the uncoated portion of the carrier sheet surface, said spaced apart portions being so adherently attached to the carrier sheet that they will not transfer from the carrier when heat and pressure are applied thereto;

coating over the surface of the carrier sheet and said spaced apart portions a transferable replicating layer comprising a coating of sufficient thickness of a synthetic resinous material to replicate both the specular reflectance of the uncoated portion of the carrier sheet surface and the specular reflectance of the remote surfaces of said spaced apart portions without said spaced apart portions transferring from the carrier sheet; and

providing an adherence coat for adhering the transferable replicating layer to a substrate;

the carrier sheet and replicating layer being adherently attachable to a substrate, with the carrier sheet and said spaced apart portions being releasable from the surface of the replicating layer in response to the application of heat and pressure, without the spaced apart portions transferring from the carrier sheet, so that the surface of the replicating layer provides a surface finish having a plurality of discrete spaced apart portions having a lower specular reflectance than the remaining portion of the surface finish.

12. The method according to claim 11 including forming said spaced apart portions from a thermosetting synthetic resinous material.

13. The method according to claim 11 including providing a simulated wood grain finish by coating at least two printed pigmented layers over the replicating layer when said replicating layer is in contact with the carrier sheet, the replicating layer being a clear coat so that the pigmented layers are visible through it.

14. The method according to claim 11 including forming the spaced apart portions from a synthetic resinous material having a fine particulate filler.

15. The method according to claim 14 including coating said spaced apart portions so they have a dry thickness of between about 5 to about 20 microns.

16. The method according to claim 14 including forming said spaced apart portions from a thermosetting synthetic resinous material.