US2567067A - Pressure sensitive decalcomania and method of making the same - Google Patents

Description

Sept. 4, 1951 A. F. GRUPP EIAL 2,567,067

PRESSURE SENSITIVE DECALCOMANIA AND METHOD OF MAKING THE SAME Filed Nov. 29, 1947 C-CLEAF' LA CQUEI? PRO 750 H vs com P-COL 0/? PRINT/N6 f/IIIII/IIII/III/IIlIIIIII/IIIIIIlI/(IlIl/IIII/IllldlIII/IIIIl/A AC Tl VA TIN G COAT W" 7 m N X CARRIER 51/551 R- RES/NOUS ADHESIVE, D- WATER SOLUBLE NORMALLY NON-TACKY AND cum (05x TRINE) NON-PRESSURE SENSITIVE omnh S-SEALER COAT @ZfreaZFGr Harry 6.150%

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Patented Sept. 4, 1951 PRESSURE SENSITIVE DECALCOMANIA AND METHOD OF MAKING THE SAME Alfred F. Grupp, Glen Ellyn, Harry G. Rathkeand Elwood S. Talan, Chicago, Ill., and Elmore Watts, Mission, Kans., assignors to The Meyer- ,cord 0.0., Chicago, 111., a corporation of Illinois Application November 29, 1947, SerialNo. 788,816

.16 .Claims. 1

This invention relates to a novel transfer of the decalcomania type and to amethod of manufacturing the same.

*Heretofore, pressure sensitive decalcomanias have been produced and used with varying degrees ,of success. Generally, in the use of such decal'comanias, a paper backing is removed from the 'decalcoma-nia in the usualmarmer by soaking in water thereby exposing a tacky, pressure sensitive, adhesive layer which may be applied directly to the surface to "be decorated. Upon'the application of pressure, the'transfer is caused to adhere to the surface.

Pressure sensitivity has long been recognized as a desirable property in a decalcomania since it-provides a quick, effective-and simple means for applying the transfer without the necessity of using solvents and specialadhesives. :However, numerous difilculties and disadvantages have been encountered and they "have made it impossible heretofore "to producea satisfactoryipressure sensitive decalcomania in :a quick, inexpensive, and simple manner. For example-the pressure sensitive adhesives, which :remain tacky during production and over an extended portion of the life of the :decalcomania, are not directly printable and normally require-the application of a sealer coating over the adhesive layer in order to *overcome the tackiness and to provide aiirm, nontacky surface capable of receiving an imprint without running and without adhering to the printing :rolls or screens. Moreover, :during the manufacturing process, the'resul-tant wet transfer .sheets possess a high degree of tack and consequently are notstackable necessitating the .pro-

vision of elaborate and bulky drying .racks .to permit the individual decalcomania sheets to be .stored out ofcontact with .eachother until .ap

;.plication of the sealer coating. 1

Another disadvantage possessed by the known types of pressure sensitive decalcomanias is that the adhesive tends to remain in a normally tacky condition for some-period of time after application to a suriace thereby permitting the decalcomanias to be removed without destruction thereof. Such ease of removal is highlyundesira- .ble particularly Where it is necessary .to guard against theft and re-use. It has also been found that the pressure sensitivity and normal tackiness of such adhesive layers finally disappear and the adhesive becomes dry and cracks after a considerable period .of time with the result that the -decalccmania becomes loosened and often falls from the surface to which it :hasbeenor-igzinal-ly applied. v

One object of the present invention is to pro-- vide a novel decalcomania transfer which has pressure sensitive properties in the adhesive layer but which is not subject to the many disadvantages and difficulties previouly associated with the production of a pressure sensitive type decalcomania.

Another objectof the invention is to provide a decalcomania which has pressure sensitive properties and yet is readily stackable during its manufacture, particularly after the application of the adhesive layer.

Another object of the invention is to provide a decalcomania having pressure sensitive properties but which does not require the use of .a sealer layer.

Still another objectis to'provide a decalcomania of the pressure sensitive type in which the adhesive layer, after being applied to the carrier paper, quickly dries to a substantially dry, nontacky, and non-pressure sensitive adhesive thereby permitting the sheets to be stacked during production without adhering to each other while awaiting application of the design prints, the adhesive layer, however, being of such properties as to become pressuresensitive and tacky upon application of additional layers thereover.

A still further object of the invention is to provide a novel decalcomania which possesses pressure sensitive properties serving to provide a preliminary adhesive "bond for holding the decalcomania in place when first applied to a surface and which, with the passage of time, develops a permanent, tough, strong, scratch resistant, adhesive. bond with said surface.

An additional object of the invention is to provide a novel decalcomania of the pressure sensitive type in which the degree of tack or pressure sensitivity of the adhesive may be controlled or varied in accordance with the uses to which the decalcomania is to be putand thereby adapting it forapplication to awide variety of rough, porous, plastic, or metallic surfaces.

Another object of the invention is to provide a novel decalcomania in which the adhesive stratum as initially applied is normally non-tacky and non-pressure sensitive but which, after the application of subsequent layers, is converted by the action of plasticizing oils "in said subsequent layers to a tacky, pressure sensitive stratum.

A decalcomania transfer consists ordinarily of a relatively heavy absorbent type paper backing coated with a water soluble adhesive or gum to which are applied a plurality of additional strata or films such as a water insoluble adhesive layer,

a transfer design in color, and a protective coating. The decalcomania of the present invention difiers from the decalcomanias previously known by the provision of a plurality of independent but interacting layers of which one layer comprises a resinous, normally non-pressure sensitive material and of which at least one other layer contains one or more plasticizers capable of migrating or diffusing into the resinous layer to convert the latter into a tacky, pressure sensitive adhesive. Inasmuch as the potential pressure sensitivity of the adhesive layer does not develop until after migration of the plasticizing oils has occurred, it will be apparent that our decalcomania is based upon what may be characterized as a delayed action principle, and as a result we are able to avoid the printing and stacking difilculties previously encountered in the production of a pressure sensitive decalcomania.

The major component of the adhesive layer of our decalcomania is a thermoplastic, water insoluble, non-oxidizing resin which is normally nontacky and non-pressure sensitive but which is capable of being converted by the action of a suitableplasticizer to a tacky, pressure sensitive condition. The adhesive stratum is applied in the form of a solution of the resin in a suitable quick-drying solvent or vehicle. After evaporation of the solvent which occurs after the lapse of a very short time, the dry adhesive layer is non-tacky and non-pressure sensitive and may be stacked or printed upon in the customary manner without difliculty; In one embodiment of the invention an activating lac'quer or coating containing an appropriate and predetermined amount of plasticizer for the resin may be applied preferably directly over the adhesive layer, although the juxtaposition of the adhesive and activating strata is not essential, and after a suitable period of time has elapsed, the plasticizing oils will have migrated or diffused into the adhesive layer converting the resinous constituent thereof to a tacky, pressure sensitive material. In other embodiments of the invention no special activating layer is employed, but the normal plasticizer content of the various layers of printing lacquers forming the transfer design is sufilcient to migrate into the resinous adhesive layer and render it tacky. The plasticizing oils thus serve to create tackiness in the adhesive layer as well as to maintain the lacquers in a flexible state but the tackiness of the adhesive layer does not in any way prevent the activating lacquer or the printing lacquers from drying to a non-tacky state. By varying the resin content of the adhesive layer, the thickness of the layer, and the amount and character of the plasticizer in the activating and later printed layers, the degree of tackiness or pressure sensitivity may be controlled within definite limits.

The mechanism and structure of the decalcomanias of the present invention will become more apparent by reference to the drawing wherein several alternative arrangements embodying the migration principle are illustrated in cross-section with the various strata or films shown in exaggerated thickness for the sake of clarity.

Similar reference characters are employed to designate corresponding strata throughout the several views, the letter B referring generally to a paper backing, D to a water soluble gum such as dextrine, R to a water insoluble, resinous adhesive layer which is originally non-pressure sensitive but later assumes pressure sensitive characteristics, A to an activating coating containin which the activating coat is applied over the color printing layer and the adhesive layer is superimposed directly over the activating coat.

Fig. 4 is still another embodiment of the invention in which no special activating layer is employed and in which the migratory plasticizing oils are supplied in the layers of printing lacquer applied over the resinous adhesive layer.

Fig. 5 shows a "reserve type decalcomania in which the resinous adhesive layer is applied directly over the printing layer and no special activating layer is employed.

Referring to the form of decalcomania shown in Fig. 1, the layer B is a paper backing or carrier of the absorbent type well known to the decalcomania art. This paper is surfaced with a layer D of a water soluble adhesive or gum such as dextrine, gelatine, gum tragacanth, etc. which, upon wetting with water, will permit the paper base or backing to be removed from the transfer.

Over the layer D is applied by printing or screening in the usual manner a film R of a thermoplastic, non-oxidizing, water insoluble, normally non-tacky and non-pressure sensitive resin in solution in a suitable quick-drying solvent. The resins which may be employed in the adhesive layer R may be of a, relatively wide variety. The synthetic resins which may be used are the phenolic base resin-s, the vinyl acetate or chloride resins, the cellulose acetate or nitrate resins, and

the polyvinyl alcohol resins, to mention only a few. Likewise, the hydrocarbon resins such as terpene polymers, styrene polymers, etc., and the coal tar distillate resins such as the coumaroneindene resins, including polycoumarone, polyindone and copolymers of coumarone with indene and their homologs, may also serve effectively. A typical composition which may be employed for the adhesive coating is as follows:

Per cent Paracoumarone-indene resin (in solution) 48.6 Inert, transparent pigment 1.6 Dibutyl phthalate 0.1 Butyl Cellosolve (Z-butoxy ethanol) 1.2 Hydrocarbon solvent 48.5

Another adhesive composition which has been found to give excellent results is as follows:

Per cent Paracoumarone-indene resin (in solution) Ethyl cellulose 20 After the solution of the resin has been applied over the layer D, the solvent evaporates leaving behind a residual dry layer R which is non-tacky and non-pressure sensitive. It is an important feature of our invention that the solvent selected cacao-av stage of their production. We have'foun'd that'b'y selecting a solvent of appropriate volatility or by blending several solvents to obtain thedesired degree of volatility, we can achieve a workable dry condition of the layer R in a relatively :short time, e. g. 15 to '20 minutes or less. Thereafter, the sheets may be stacked one on top of the other while awaiting application of the design layers,

thus eliminating the necessity of space-consum- 'ing drying and separating racks.

Over the layer R is then printed orscreened an activating layer A Whose active constituent is a jplasticizer or a mixture of plasticizers havingan afiinity for and capable of acting uponor reacting with the resinous component or the adhe'sive'layer R to impart to the latter the desired de'gree'of tack'and pressure sensitivity. The activatin layer is preferably in the form o'f 'a solution, such as a nitro-cellulose lacquer, comprising a suitable solvent and a sufficient amount o'f-an appropriate plasticizer to migrate or diffuse from the activating'layer A to the adhesive layer R. Many types 'of plasticizers may be employed including the phthalate esters, such as dibutyl phth'alateand 'diphenyl phthalate; the car-boxylic acid esters such as triacetin, butyl oleate, butyl acetyl ricinoleate, dibutyl sebacate, glyceryl sebacate, methyl abietate, and triethyl-ene glycol hexoate; the phosphate esters such as tributyl phosphate, tri- -cresyl phosphate, and diphenyl mono-(o-xenyl) phosphate, etc. In general, however, the selection and the formulation of the plasticizing components of the activating layer A are correlated with the type of resin in the adhesive layer R to obtain the desired degree of pressure sensitivity.

We have obtained excellent results by employing for the activating layer A a normal outdoor lacquer containing glyceryl 'sebacate as a plasticizer. Another and more specific formula which we have found to be suitable for use in the layer A, particularly when the first adhesive composition specifically disclosed above is employed in the layer R, is as follows:

Per cent Nitro-cellulose 1550 D'ibutyl phthalate 1.4 Castor oil 21.0 Butyl Cellosolve (2-butoxy ethanol) 46.7 Talc 1519 The foregoing composition is particularly useful where a clear activating coat is desired. In in.- stances Where it may be desirable to employ an opaque activating layer to provide, for example, a white background for the subsequent color print layers, the following activating layercomposition may be used:

As soon as the activating layer A, containing the plasticizer for the resin 'in'the layer R, is

resin in the adhesive layer and that migration occursregardless of the relative positions of the two layers in the decalcomania provided, of course, that there .is no sealing or isolating'stratum interposed between the activating and ad'- hesive layers which would prohibit the passage of the plasticizer. The plasticizer, reaching the adhesive layer in'a relatively short time, imparts tacky and pressure sensitive properties to the resinous ingredient. The migration henomenon of the plasticizer continues over a relatively long period of time, e. g.'from 2 to 30 days, and the degree of pressure sensitivity in the adhesive layer .R increases with the extent of migration. The solvent contained 'in the activating layer assists and initiates the migration of the plasticizer by preconditioning or penetrating the'dry adhesive film ahead of the plasticizer and by providing, in effect, a softer and more receptive stratum for entry of the plasticizer.

With a given combination of resin in the layer R and plasticizer in the layer A, the degree of pressure sensitivity of the layer R may be controlled within specified limits dependent upon the particular use or intended application of the finished decalcornania. For example, if the final decalcomania is to be employed on a relatively smooth hard surface such as glass, only a moderate degree of pressure sensitivity in the layer "R will be required, but if the decalcomania .is to be applied to relatively rough or difficult surfaces, such as fruit skins or wood surfaces-ahig-her degree of pressure sensitivity will be desired. In the decalcomania comprising the present invention, accurate control over the degree of pressure sensitivity in the adhesive layer R may be exercised by varying the respective amounts of the resin in the layer R and of the plasticizer in the layer A. If, for example, the finished decalcomanias are to be applied to the rough, waxy outer surfaces of oranges, it may be desirable to employ for the activating layer A a steppedup "lacquer, i. e. a nitrocellulose lacquer to which has been added a greater than normal amount of plasticizer. For other uses, the normal plasticizer content of the lacquer may suffice. In addition, the ultimate degree of pressure sensitivity of the layer R may also be regulated by the resin content of the layer Rand also by the relative thicknesses of the layers R and A.

After the activating layer A has dried to *a non-tacky condition, the desired transfer design layer P is applied the'reover in any of the wellknownmanner's, such as by printing, screening, or lithographi'ng. Usually, the transfer design is a composite design formed by superimposing various colored layers until the desired finaldesign is obtained, such various design printings being indicated by the single layer P in the several figures of the drawing. A protective outer coating C of clear lacquer may then be added where necessary or desirable to protect the printed design during handling and storage of the decalcomani'as. The colored inks employed in the application of the layer P are ordinarily which will-also migrate or diffuse through the activating layer A into the adhesive layer R and thereby assist in converting the resinous layer to a tacky, pressure sensitive condition. It is to be noted, however, that although the resinous adhesive layer R becomes tacky and pressure sensitive, the later lacquer layers, including the activating layer A and the design layers P, are not in any way prevented from becoming non-tacky and'from remaining in a tough flexible state.

A decalcomania produced in the manner abovedescribed and according to the layer arrangement shown in Fig. l is applied in much the same manner as the conventional slip-ofi" transfer. The decalcomania is first dipped in water or the backing B is otherwise wetted with water to soften the gummy layer D. When the water soluble layer D has dissolved suificiently, the adhesive layer R and the layers superimposed thereon are released, and the backing sheet B is slid off exposing the pressure sensitive layer R. The decalcomania is then applied by pressing the tacky layer R into contact with the surface to be decorated. The pressure sensitivity of the layer R provides a firm initial bonding action which is highly satisfactory in causing the design to adhere readily to all types of difiicult surfaces.

- However, in contrast with the known types of pressure sensitive decalcomanias, the volatile components in the pressure sensitive layer R evaporate with the passage of time, and by gradual drying and polymerization of the resinous constituents, the layer R develops into a permanent, tough, strong, scratch resistant bond with the decorated surface. Thus, it will be seen that the initial pressure sensitive bond afforded by the tacky layer R is converted by a chemical bonding reaction, after the lapse of time, to a permanent, hard, flexible bond with the underlying surface.

In Fig. 2 a'slightly modified form of decalcomania embodying the migration principle of the present invention is illustrated. The backing or carrier sheet B coated with the water soluble adhesive layer D and the resinous adhesive layer R are the same as in the transfer illustrated in Fig. 1. However, in this embodiment of the invention the color printing ink layer P is applied directly over the adhesive layer R after the latter has dried. The activating layer A is applied directly on the design layer P and serves also to protect the printed design thereby eliminating the necessity for a separate protective coating C. In this form of the invention the plasticizing oils in the activating layer A migrate or diffuse downwardly through the printed design layer P, which does not impede or prevent the desired migratory action, and pass in combination with the plasticizer contained in the inks of the layer P into the adhesive layer R. A decalcomania of the type of Fig. 2 may be applied to a surface in the same manner as described above in connection with Fig. 1 and with the same satisfactory results.

A different type of decalcomania embodying the migration principle is illustrated in Fig. 3. This form of transfer may be characterized as a reverse type of decalcomania in that the color printing layer P is applied directly over the water soluble adhesive layer D carried by the backing sheet B, and the activating layer A and the resinous adhesive layer R are applied in the stated order over the printing layer P. Migration of the plasticizing oils from the layers A and P then occurs in an upward direction into the adhesive layer R imparting tack and pres- 8 sure sensitivity to the latter. In this form of the invention a water soluble sealer coat S, such as a water soluble glue, gum acacia, dextrine, etc., is applied over the layer R to permit the decalcomaniato be readily handled and stored. In the application of this type of decalcomania,

'the transfer is wetted with water on both sides thereby dissolving the layer D to permit the transfer to be removed from the backing sheet B and also dissolving the top layer S to expose the tacky, pressure sensitive layer R by means of which the transfer is caused to adhere initially to the desired surface in the manner hereinbefore described.

Figs. 4 and 5 constitute modified forms of the decalcomania of the present invention in which no special activating layer is employed and where tack of a relatively low degree is desired. In the embodiment shown in Fig. 4 the color printing layer P is applied directly over the resinous adhesive layer R and the natural plasticizing components present in the inks employed to form the layer P migrate downwardly into the layer R imparting the desired tack and pressure sensitivity thereto. A protective coating C is provided to prevent injury to the printed design P.

In Fig. 5, a reverse type decalcomania is illustrated in which no special activating layer is used. The color print P is applied directly to the dextrine coating D of the backing sheet B, and the adhesive layer R is superimposed on the layer P. The plastioizing components in the inks of the layer P migrate upwardly to the layer R converting the latter to a tacky, pressure sensitive state. As in the reverse type decalcomania described in connection with Fig. 3, the form of the invention illustrated in Fig. 5 also requires a final Water soluble sealer coating S for protecting the pressure sensitive layer R until it is desired to use the transfer. The decalcomania shown in Figs. 4 and 5 are used in the same manner described above in connection with Figs. 1 and 3, respectively, and the adhesive layers, after lapse of time, form relatively dry, tough, flexible bonds.

Although several forms of decalcomanias with the component layers thereof in various arrangements have been disclosed in Figs. 1 to 5, inclusive, of the drawing, and several specific examples as to the constituent elements of the adhesive layer and the activating layer have been given, it is apparent that modifications in the adaptation of the migration principle may be resorted to without departing from the scope of the invention as defined in the appended claims.

We claim:

1. A method of forming a pressure sensitive decalcomania which comprises separately applying in predetermined sequence over one side of a releasable backing an adhesive material comprising a solution of a thermoplastic resin in a volatile solvent and an activating material comprising a plasticizer-containing lacquer, permittin the first-applied material to dry to a normally non-tacky and non-pressure sensitive state prior to application of the other of said materials, thereafter permitting said other material to dry to a'normally non-tacky and non-pressure sensitive state whereby to form separate and initially non-pressure sensitive resinous and lacquer layers disposed in superimposed relation one above the other on said backing, said lacquer layer containing a suilcient quantity of a readily migratable plasticizer to render said resinous layer tacky and pressure ensitive, and allowing said. plasticizer to migrate to the resinous layer thereby converting the latter to a tacky and pressure sensitive condition.

2. The method of claim 1 further characterized in that said resin comprises a coumaroneindene resin.

3. A method of forming a pressure sensitive decalcomania having a water permeable backing with a water soluble film thereon which comprises applying over said film a solution comprising a thermoplastic resin in a volatile solvent, permitting said solution to dry to form a normally non-tacky and non-pressure sensitive resinous layer, subsequently applying thereover a lacquer containing a sufficient quantity of a readily migratable plasticizer to render said resinous layer tacky and pressure sensitive, and allowing said plasticizer to migrate to the resinous layer thereby converting the latter to a tacky and pressure sensitive condition.

4. A method of forming a pressure sensitive decalcomania having a water permeable backing with a water soluble film thereon which comprises applying over said film a solution com-prising a thermoplastic resin in a volatile solvent, permitting said solution to dry to form a normally non-tacky and non-pressure sensitive resinous layer, subsequently applying directly thereover a plasticizer-containing lacquer, permitting said lacquer to dry to form a non-pressure sensitive lacquer layer, thereafter applying a transfer design directly over said lacquer layer, said lacquer layer containing a suflicient quantity of a readily migratable plasticizer to render said resinous layer tacky and pressure sensitive, and allowing said plasticizer to migrate to the resinous layer thereby converting the latter to a tacky and pressure sensitive condition.

5. A method of forming a pressure sensitive decalcomania having a water permeable backing with a water soluble film thereon which comprises applying over said film a solution comprisin a thermoplastic resin in a volatile solvent, permitting said solution to dry to form a normally non-tacky and non-pressure sensitive resinous layer, applying directly thereover a transfer design film, permitting the latter film to dry, subsequently applying directly over the design film a lacquer containing a suflicient quantity of a readily migratable plasticizer to render said resinous layer tacky and pressure sensitive, and allowing said plasticizer to migrate through said transfer design film to said resinou layer and thereby convert the latter to a tacky pressure sensitive condition.

6. A method of forming a pressure sensitive decalcomania having a water permeable backing with a Water soluble film thereon which comprises applying a transfer design over said film, applying a plasticizer-containing lacquer layer directly over said design, applying directly over said lacquer layer a solution comprising a thermoplastic resin in a volatile solvent, permitting said solution to dry to form a normally nontacky and non-pressure sensitive resinous layer, said lacquer layer containing a sufficient quantity of a readily migratable plasticizer to render said resinous layer tacky and pressure sensitive, and allowing said plasticizer to migrate to the resinou layer thereby converting the latter to a tacky and pressure sensitive condition.

7. A method of forming a pressure sensitive 10 decalcomania having a water permeable backing with a water soluble film thereon which comprises applying over said film a solution comprising a thermoplastic resin in a volatile solvent, permitting said solution to dry to form a normally non-tacky and non-pressure sensitive resinous layer, applying directly thereover a transfer design layer comprising a lacquer containing a suflicient quantity of a readily migratable plasticizer to render said resinou layer tacky and pressure sensitive, and allowing said plasticizer to migrate from said design layer to said resinous layer and thereby convert the latter to a tacky pressure sensitive condition.

8. A method of forming a pressure sensitive decalcomania having a water permeable backing with a water soluble film thereon which comprises applying a transfer design over said film, subsequently applying directly over said transfer design a solution comprising a thermoplastic resin in a volatile solvent, thereafter permitting said solution to dry to form a normally nontacky and non-pressure sensitive resinous laye said transfer design comprising a lacquer containing a suflicient quantity of a readily migratable plasticizer to render said resinous layer tacky and pressure sensitive, and allowing said plasticizer to migrate to said resinous layer and thereby convert the latter to a tacky pressure sensitive condition.

9. A decalcomania of the pressure sensitive type prepared in accordance with the method 01. claim 1.

10. A decalcomania of the pressure sensitive type prepared in accordance with the method of claim 2.

11. A decalcomania of the pressure sensitive type prepared in accordance with the method of claim 3.

12. A decalcomania of the pressure sensitive type prepared in accordance with the method of claim 4.

13. A decalcomania of the pressure sensitive type prepared in accordance with the method of claim 5.

14. A decalcomania of the pressure sensitive type prepared in accordance with the method of claim 6.

15. A decalcomania of the pressure sensitive type prepared in accordance with the method of claim 7.

16. A decalcomania of the pressure sensitive type prepared in accordance with the method of claim 8.

ALFRED F. GRUPP.

HARRY C. RATHKE. ELWOOD S. TALAN. ELMORE WATTS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,627,407 Reese May 3, 1927 1,780,021 Laws Oct. 28, 1930 1,826,228 Tull Oct. 6, 1931 2,104,025 Davis Jan. 4, 1938 2,271,413 Braverman Jan. 27, 1942 2,359,185 Wysong Sept. 26, 1944 2,409,564 Heinecke et al. Oct. 15, 1946 2,453,052 Van Etten Nov. 2, 1948

Claims (1)

1. 5. A METHOD OF FORMING A PRESSURE SENSITIVE DECALCOMANIA HAVING A WATER PERMEABLE BACKING WITH A WATER SOLUBE FILM THEREON WHICH COMPRISES APPLYING OVER SAID FILM A SOLUTION COMPRISING A THERMOPLASTIC RESIN IN A VOLATILE SOLVENT, PERMITTING SAID SOLUTION TO DRY TO FORM A NORMALLY NON-TACKY AND NON-PRESSURED SENSITIVE RESINOUS LAYER, APPLYING DIRECTLY OVER THE TRANSFER DESIGN FILM, PERMITTING THE LATTER FILM TO DRY, SUBSEQUENTLY APPLYING DIRECTLY OVER THE DESIGN FILM A LACQUER CONTAINING A SUFFICIENT QUANTITY OF A READILY MIGRATABLE PLASTICIZER TO RENDER SAID RESINOUS LAYER TACKY ADN PRESSURE SENSITIVE, AND ALLOWING SAID PLASTICIZER TO MIGRATE THROUGH SAID TRANSFER DESIGN FILM TO SAID RESINOUS LAYER AND THEREBY CONVERT THE LATTER TO A TACKY PRESSURE SENSITIVE CONDITION.

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