US2625496A - Decalcomania for metal transfers - Google Patents

Description

Jan. 13, 1953 D. D. SWIFII' ET AL 2,625,496

DECALCOMANIA FOR METAI; TRANSFERS Filed Sept. 30, 1950 GOLD LEAF WATER SOLUBLE GUM PA PER INVEN TOR. DONALD D. SWIFT Q BY JaH/v 1K0 LER ATTORNEY Patented Jan. 13, 1953 DECALCOMANIA FOR METAL TRANSFERS Donald D. Swift, West Hartford, and John J. j Kohler, Hartford, Conn., assignors to M. Swift & Sons, Inc., Hartford, Conn., a corporation of Connecticut Application September 30, 1950, Serial No. 187,841

. 1 I The invention relate to decalcomanias and their manufacture.

Summary According to our invention, decalcomanias for applying metal decorations to articles, either as continuous or all over coatings, or in the form of designs, patterns or lettering, comprise a paper transfer sheet and metal foil held together with an adhesive comprising a water-soluble gum and a butadiene-acrylonitrile polymer. More specifically our decalcomania comprises a composite of the following layers of material arranged in the order stated: (1) a paper transfer sheet, (2) a water-soluble adhesive, (3) a butadieneacrylonitrile polymer, (4) metal foil. The metal foil may for example be gold, tin, copper, aluminum, or alloys of these or other metals.

A special application of the invention which has shown considerable promise is a decal for gilding. This decal comprises a paper transfer sheet and gold leaf held together with an adhesive comprising a water-soluble gum and a butadiene-acrylonitrile polymer, or comprises a composite of the following layers of material: (1) a paper transfer sheet, (2) a water-soluble adhesive, (3) a butadiene-acrylonitrile polymer, (4) gold leaf (or gold leaf design).

In one form of the invention there is a layer of lacquer between the butadiene polymer and the metal foil.

The method of making the metal decal preferably comprises applying a coating of butadieneacrylonitrile polymer to the metal surface of a composite metal foil transfer sheet comprising metal foil carried on a transfer sheet such as provided by a cellulose acetate backing, and applying a coating of butadiene-acrylonitrile polymer to a composite paper transfer sheet comprising a water-absorbent paper coated with a watersoluble adhesive, pressing the two composite sheets together with the butadiene-acrylonitrile coatings in juxtaposition to adhere the metal foil transfer sheet to the paper-transfer sheet, and after adherence is obtained, removingthe transfer portion or cellulose acetate backing of the metal foil transfer sheet to produce a decalcomania comprising the layers of material as described above.

In the drawing the figure is a perspective view of a portion of a decalcomania formed in accordance with our invention and comprising a composite of the following layers of material in the order stated: a paper transfer sheet, a water 6 Claims. (01. 154-463) soluble gum, a butadiene-acrylonitrile polymer, and gold leaf or other metal foil.

Description Decalcomanias, or decals as they are sometimes called for short, are made ordinarily by printing designs on paper coated with a water-soluble adhesive. When the decal is moistened the coating softens and permits separation of the printed design from the surface of the paper either by sliding off the transfer by pulling the paper from underneath it, or in the case of direct transfers where an adhesive is applied over the surface of the printing, the decal is moistened and pressed against the surface to which the transfer is to be applied and the paper is slid from the top of the transfer instead of from the bottom. Direct transfers are printed in reverse when they are to be applied to opaque surfaces or to the outside of Windows, but are printed right side up when they are to be applied to the inside of windows or of a transparent object where the design or' lettering is to be viewed through the glass.

In another type of decal known as a varnish transfer a coat of lacquer or varnish is stenciled on the paper before printing, and after printing another coat of lacquer or varnish is stenciled over the printing. In applying this type of decal, varnish is applied either to the transfer or to the surface to which it is to be affixed, and after the varnish becomes tacky the decal is applied and smoothed out with a squeegee or soft cloth. After drying, the paper is peeled off.

Our invention is applicable to all of these types of transfers. That is, decals made in accordance with our invention can be used either as slide-off transfers, direct transfers or varnish transfers. Also it is to be understood that the terms decalcomania or decal as used herein include plainor solid colors as well as designs and lettering. In fact our invention is especially suited to the gilding or metalizing of surfaces with metal leaf to produce a solid or all-over coating capable of stretching into intimate contact with the surface irregularities of configurations of the object to which the decal is applied. Thus the characteristics of our product render it particularly well adapted to the transfer of metal foils to surfaces having designs in either intaglio or relief.

' Our decals comprise a paper transfer sheet coated in succession with a water-soluble adhesive, a butadiene-acrylonitrile polymer and metal foil. There may be a layer of lacquer between the butadiene polymer and the metal foil, and

althdugh this is not necessary in the case of a direct transfer it may be desirable in the case of a slide-off transfer. The decal paper employed may be one of the types available on the market today, for example either a simplex paper or lithotransfer paper which are in common use. The simplex paper comprises a smooth book paper coated with a water-soluble adhesive. The lithotransfer paper consists of paper coated first with a watch-soluble adhesive and then with lactruer. The water-soluble adhesive may be starch, gum arable, gum tragacanth, dextrin, gelatin or mixtures of the same, or may consist of a synthetic organic compound such as hydroxyethyl cellulose, carboxymethyl cellulose or polyvinyl alcohol which are soluble in water and have adhesive properties. We prefer the mixture of starch and gum arabic in the usual proportions as commonly employed in the production of ordinary decal papers.

Starting with a conventional dec'al paper, we first apply a coating of a butadiene-acrylonitrile polymer or its natural or synthetic equivalent in a suitable solvent such as methyl ethyl ketone, by spraying, roller coating or otherwise. Such solutions are generally known as buna-N solutions, buna-N being essentially a buta-diene-acrylonitrile polymer. The butadiene-acrylonitrile solution used generally is modified with a small percentage of a phenolic resin. Alternatively such a solution may be sprayed on the metal surface of a composite metal foil transfer sheet consisting of metal foil adhered to a cellulose acetate backing by a film of wax or the like. We have found that the best results are obtained if the buna-N solution is sprayed both on the decal paper and the metal composite.

Following the application of the buna-N solution, the composite papertrans'fe sheet and composite metal foil transfer sheet are pressed together, and after adherence is obtained the cellulose acetate transfer portion of the metal foil transfer sheet is removed.

We have found that optimum results are obtained with a buna-N film thickness of between 0.000% to 0.0007 gram per square inch. It is preferableto apply approximately one-half of the total film thickness on the metal foil and the other half on the decal paper, but if desired a bima-N film of between 0.0004 to 0.0007 gram Per Square inch can be applied entirely to the metal foil surface alone or to the decal paper surface alone.

The paper foil composites can be'brou'ght together two or three minutes after the buna-N film has been applied. However the length of time between application of the filth and pressing does not appear to be critical, as we have found for example that the two composites can be brought together at least as long as 43 hours after application. We prefer to bring the two composites together between 4 and 5 hours after coating, and thisprocedure has been found to produce optimum results in most cases.

Reference has been made to the metal foil composite consisting of a foil adhered to a cellulose acetatebacking'by means of a film of wax or the like. The method of manufacturing such composites is well known and forms no part of the present invention, and the composites are available on the market today as copper foil transfers, gold leaf transfers, etc., these being the type of transfers which are employed in applyinggold leaf, silverleaf, aluminum-foil, copper foil. etc. to the shelf backs and covers of books, and to leather goods and other objects with the use of hot stamping dies. Other metal foil composites may be used, specifically nickel foil, a 14 karat gold-tin alloy, and a 20 karat gold-tin alloy, for example. The metal foils or leaf, and more particularly the gold leaf, may range in thickness from one to six milliontlis of an inch, generally averaging between two and three millionths of an inch.

From the foregoing description the manufacturer or artisan will understand how to select or make up the decal paper, and he will of course make his selection of the metal foil transfer according to the kind of decal he wishes to make. Also we have taught him to apply a buna-N type film either to the adhesive or lacque coated surface of the paper or metal surface of the metal foil transfer, and preferably to both such surfaces, and how thick this film or these films should be. Finally we have shown how the two composite sheets are brought together and pressed into adhering relationship. As to this last procedure we have found that it is convenient to stack a number of pairs of the composite sheets in a pile in a press. No heat is applied during the pressing operation. All that the operator need do is spin down the wheel of the press and bring it up tight as would be done in ordinary letterpress or bookbinding operations, and the like. If desired, a mechanical o hydraulic press may be employed. Fifteen to thirty minutes later the decals will be ready to be removed from the press, and the two composite sheets of each pair will be found to be firmly united by the lbuna-N film. However the length of time the sheets are left in the press is not critical. Grdinarily the workman willprepare the stacks for the presses during the day, and shortly before quitting time he will clamp the stacks in the presses and leave them overnight for removal the following morning when he-starts work. However this procedure is of course entirelyoptional.

Following removal of the cellulose acetate film the decal is ready fo use; except in those cases where it is intended for application by direct transfer face down on an unsized surface, in which event a thin coating of a suitable water soluble adhesive is applied to the metal surface of the decal by-spraying or roller coating. This adhesive may beany of those previously described with reference to the coated decal paper.

By way of further exemplification, we cite the following specific examples of :the practice of our invention:

1. A24 K gold fo'ilof tw'o millionths of an inch in thickness on a cellulose acetate carrier was coated with abutadiene acrylonitrile film of 0.0003 gram per square inch in thickness. A sheet of paper which had been previously sized with a water soluble gumwas also coated with a butadiene acrylor'iitrile mm of 0.0003 gm. per square inch. Both coated surfaces were allowed to dry forten minutes and then brought together with the fauna-N surfaces contacting each other. This assembly was placed in a press and held there for fifteen minutes .at room temperature. At the end of the pressing period the cellulose acetate carrier was removed. This left a composite consisting ofgold bonded to the buna-N, which in turn was bonded to the water solublegurn coated paper.

2. A 24.K-go1d foil, three millionths of an inch thick and supported on a cellulose acetate carrier was made to contact a buna-N surface which had previously been coated to a thickness of 0.0006 gram per square inch on water soluble gum coated absorbent paper. The composite was placed infa press for one half hour and then removed. The cellulose acetate carrier was stripped from the composite, leaving the gold in adherence with the buna-V surface on the water soluble gum ofthe absorbent paper.

3. An aluminum foil two millionths of an inc thick, supported on a cellophane carrier, .was coated with buna-N to a film thickness of 0.0007 gram per square inch. It was then brought in contact with a water soluble, presized absorbent paper. The composite was placed in a press for twenty minutes, and on withdrawal from the press the cellophane carrier was stripped free from the composite. The sheet was cut by hand to shape for decorating a picture frame.

4. An absorbent paper which had previously been coated with a water soluble gum and then coated with a cellulose nitrate lacquer was thereafter coated with buna-N to a thickness of 0.0006 gram per square inch. The buna-N surface was brought into contact with the surface of a 24K gold foil two millionths of an inch thick supported on a cellulose acetate carrier. The composite was placed in a mechanical press for fifteen minutes. It was then withdrawn from the press, and the cellulose acetate carrier was stripped from the composite. The sheet of foil so preparedwas L of surfaces to produce a solid or all-over coating capable of stretching into intimate contact with the surface irregularities of the object to be decorated. We have found that even where such surfaces are quite irregular as, for example, in a picture frame having a design molded in intaglio i or relief, the decal is sufficiently flexible to conform with the irregularities of the surface. The metalleaf with its buna-N backing exhibits a certain degree of resiliency. It does not seem to be possible to achieve comparable results in the absence of the use of the butadiene-acrylonitrile polymer, for without this the metal leaf breaks up and shows cracks or fissures. However even with very thin gold leaf, when the metal is supported as we have described, it remains permanently flexible. When subjected to tension it stretches in an all-over pattern as though each molecule of the metal were stretched rather than in a pattern of normally visible cracks such as occur when thin metal foil or leaf has been stretched beyond its ultimate strength. The explanation of the results attained in this regard is necessarily somewhat theoretical, but in any event we have found that decals made in the manner described produce excellent decorative 60 2,49 77 effects on a Wide variety of objects with either smooth or irregular surfaces.

Our decals can be used in a great many ways, that is by following any of the various techniques known to the art for the application of ordinary decals.

The terms and expressions which we have employed are used in a descriptive and not a limiting sense, and we have no intention of excluding such equivalents of the invention described, or of portions thereof, as fall within the purview of the claims.

We claim:

1. A decalcomania comprising a paper transfer sheet and metal foil held together with an adhesive comprising a layer of water soluble gum and a layer of butadiene-acrylonitrile polymer.

2. A decalcomania comprising a composite of the following layers of material arranged in the order stated: (1) a paper transfer sheet, (2) a Water soluble adhesive, (3) a butadiene-acrylonitrile polymer, (4) metal foil.

3. A decalcomania comprising a paper transfer sheet and gold leaf held together with an adhesive comprising a layer of Water soluble gum and a layer of outadiene-acrylonitrile polymer.

4. A decalcomania comprising a composite of the following layers of material arranged in the order stated: (1) a paper transfer sheet, (2) a water soluble adhesive, (3) a butadiene-acrylonitrile polymer, (4) gold leaf.

5. A decalcomania comprising a composite of the following layers of material arranged in the order stated: (1) a paper transfer sheet, (2) a water soluble adhesive, (3) a butadiene-acrylonitrile polymer, (4) lacquer, (5) metal foil.

6. A decalcomania comprising a, composite of the following layers of material arranged in the order stated: (1) a paper transfer sheet, (2) a water soluble adhesive, (3) a butadiene-acrylonitrile polymer, (4) lacquer, (5) gold leaf.

DONALD D. SWIFT. JOHN J. KOI-ILER.

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

UNITED STATES PATENTS Number Name Date 1,096,822 Brandt May 19, 1914 1,137,278 Peterson Apr. 27, 1915 1,213,926 McManus Jan. 30, 1917 1,376,737 Tscheike May 3, 1921 1,591,844 Kosai July 6, 1926 2,044,922 Swift et al June 23, 1936 2,099,641 Bach et a1 Nov. 16, 1937 2,354,073 Swift July 18, 1944 2,364,674 Swift Dec. 12, 1944 Chmiel Dec. 20, 1949

Claims (1)

1. A DECALCOMANIA COMPRISING A PAPER TRANSFER SHEET AND METAL FOIL HELD TOGETHER WITH AN ADHESIVE COMPRISING A LAYER OF WATER SOLUBLE GUM AND A LAYER OF BUTADIENE-ACRYLONITRILE POLYMER.

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