US2021141A - Watermarking composition - Google Patents

Description

Patented Nov. 19, 1935 UNITED STATES ATENT OFFICE National Listing Exchange, a corporation of California Los Angeles, Calif.,

No Drawing. Application May 1, 1933, Serial No. 668,818. ,Renewed March 11, 1935 8 Claims.

This invention relates to what I term a watermarking composition capable of being used on printing presses of various types for the purpose of creating in fibrous sheets such as the various types of papers, a definitely bounded translucency which does not impair the strength and writing or printing characteristics of such fibrous sheets.

Heretofore watermarks have been made in papers during the manufacture of the paper and while the fibers constituting the stock were in a mobile condition. In addition it has been contemplated that representations of watermarks be made upon the finished sheets by the application of waxes and fatty acids thereto but this latter method is not practical inasmuch as a suitable watermarking composition had not been provided heretofore.

It is to be remembered that in order to successfully apply a watermark to a finished sheet of paper, the Watermarking composition must. be adapted for use on various types of printing presses such as, for example, the platen and cylinder press. The composition should have all of the desirable characteristics of a good printing ink. It must work smoothly on the press and have enough body and pitchiness or tack to create a clear, smooth impression which is unmottled. It must create the proper or suitable degree of translucency and at the same time must dry with a suitable surface for pen and ink, typewriting, multigraphing, copywork or printing over the same in any style and with any of the ordinary writing fluids and printing inks. Moreover, the watermarking compound or ink must be easily removed from the press parts and rollers and incapable of drying on the press while in use.

Other requirements of a material of this character are that it does not deteriorate on storage, injure or accumulate on the press rollers or other ink-contacting parts of the press, and that it does not spread in the paper or discolor while in use on the press or in the paper.

The various problems presented have beensolved by the proper combination of ingredients in accordance with this invention. Generally stated, this invention relates to a watermarking composition containing a substantially colorless resin or oleoresin, a solvent, very finely divided mineral matter and a suitable oil, these ingredients being combined with water in what appears to be a colloidal solution or emulsion. The resulting composition may be applied to the ink plate or disc of a press and the watermark printed on the paper just as readily as any surface printing is accomplished.

It is an object of this invention, therefore, to disclose and provide a watermarking composition in the form of an emulsion which is capable of imparting to desired portions of the fibrous sheets a definite translucency without impairing the 5 writing or printing characteristics of such sheets.

Another object of the invention is to disclose and provide a watermarking composition which is stable and which will not deteriorate upon storage.

A further object is to disclose and provide a watermarking composition capable of being used on printing presses without clogging type, injuring the metal parts, or changing in consistency or color during use.

A further object of the invention is to disclose and provide a watermarking composition which when applied to paper will produce a desired transparency or translucency in the specific area to which it is applied without causing spreading 20 and without impairing either the strength or the writing and printing characteristics of the paper.

These and other objects, uses and advantages of the invention will become apparent to those skilled in the art from a contemplation of the in- 25 vention as described hereinafter.

A preferred watermarking composition having all of the desired characteristics may be made from the following ingredients in the proportions stated: a 30 Parts Percent Water solution of ammonium sulfate 7 to 12 (20-40) Finely divided mineral matter 3to 5 8-25) Precipitated chalk lto 2 3 s) 35 Starch or fiour 2to 4 5-15) Oil, such as castor oil 5 to 7 (12-30) Colorless resin or oleo-resin,

such as Canadian balsam 3 to 5 8-20) Solvent for resin and/or oil, such 40 as gum turpentine 2to- 4 5-17) The above proportions are by volume and the proportions and specific ingredients stated have been found to give particularly good re- 45 sults. In making the composition it has been found that the ammonium sulfate solution (preferably containing 1 part of alum to 20 parts of water) is first preferably mixed with the mineral matter and starch and these two ingredients 5 thoroughly incorporated in the solution. A suitable mineral material for use in this composition should be in the form of an impalpable powder which is substantially colorless when wet as, for example, very finely ground glass. It has been 55 found that diatomaceous silica answers these requirements and that form of diatomaceous silica which is the result of calcination in the presence of an alkali salt is particularly adapted because of its whiteness when dry and its ability to become substantially colorless when wet. Flour or dextrin may be used instead of starch but the latter is preferred. After the aqueous suspension and solution of these three ingredients has been formed the oil, solvent, calcium carbonate and resin or oleo-resin such as Canadian balsam, are incorporated into the solution and suspension during agitation. The agitation is continued until all of the ingredients are homogeneously intermixed whereupon it will be found that the mass has assumed the consistency of a salve cap 7 able of being readily used on thediscs, ink plates, rollers and fountains of cylinder and platen types of printing presses. a

The preferred ingredients as indicated hereinabove are an aqueous solution of ammonium sulfate or ammonium alum, Canadian balsam, turpentine, calcined diatomite, starch, castor oil and precipitated chalk but it is to be understood that not only the quantities may be varied but the ingredients may also be varied. For example, any substantially colorless resin or oleo-resin may be substituted for the Canadian balsam, gum Dammar, tragacanth, arabic, sandarac, elemi and pecseed oil, eucalyptus oil, sesame oil, croton oil and oil of peppermint may be used. The precipitated chalk may be eliminated altogether when larger proportions of the diatomite are used but when desired zinc and titanium oxides, magnesium carbonate and lead carbonate may be substituted for the calcium carbonate.

The water solution of ammonium sulfate exerts a stabilizing and emulsifying effect upon the composition. It has been found that borax, sodium carbonate and other water-soluble salts of alkali-forming metals may be used instead of alum, provided they are present in quantities sufficient togive a solution having substantially the same alkalinity as that obtained with am- -monium sulfate. The resulting emulsion is substantiallyneutral, however, and contains the aqueous component in the internal or dispersed phase.

Those skilled in the art are again cautioned that although various substances have been enumerated hereinabove as being capable of use in the composition, they are not to be considered as complete equivalents of the preferred ingredients because the resulting composition will either have a slightly different consistency or it will not handle as readily in actual use, will not store without deterioration, or will have a tendency to discolor during use or upon aging of the watermarked paper. The impairment in properties may be only slight in some cases but in others it may be sufficient to render the composition unsatisfactory when perfect results are desired.

The watermarking composition above described has, as stated, the consistency of a salve or plastic substance and is in the form of an emulsion which will not stratify, segregate or spread upon shipment, handling or storage. It is readily ap- 5 plied to the discs and fountains and even detailed and intricate watermarks'may' be reproduced with fidelity upon the paper.. The oily and resinous constituents of the composition readily permeate the paper completely, this action being greatly facilitated by the aqueous constitu ent ofthe emulsion, but do not spread'and as a result, faithful reproductions of the desired watermark are obtained.

The impalpable mineral matter becomes tenaciously adherent to the surface of the paper in a 'film of imperceptible thickness and furnishes a suitable ink-receiving surface. The composition sets very readily so that the paper may be quickly removed from the press and. stacked as ,high as 20 desired, no extraordinary care being necessary in the handling of the paper. Several days may elapse, however, before a desired writing surface is obtained. q The composition is applicable to the various 25 kinds ofpaper, including rag stock, sulfite stock, etc. Slightly higher proportions of turpentine and resin are used when the composition is' to be applied to rag stock than the proportions employed' in watermarking compositions when such 30 composition is to be applied to sulfite stock. It is to be understood that the watermarking composition need not be applied to writing paper alone nor is it limited to the application" of sim- H ple watermarks. The watermarking composition 35 is eminently suited for the manufactureof so called safety papers adapted for use in checks, legal instruments, promissory notes, etc. ,Attention is called to the fact that the preferred composition is of substantially neutral character and 40 when a safety paper is produced with the watermarking composition of this invention, alterations are impossible inasmuch as in alteringdocuments and in removing writing fluids, it is necessary to f use either an alkali or an acid liquid, or both, 4.5" When a colorless substance, such as phenolphthalein or litmus in powdered form, (or a colorless dye, such as a diazo'dye) is incorporated in the 'composition described hereinabove, the application of either an acid or an alkaline eradicator 50 causes pronounced and permanent changes in the coloring of the paper, thereby immediately giving rise to a'signal indicating an attempted alteration of original writing or printing.

Those skilled in the art will readily appreciate 5 5 consistency, comprising 12% to 30% of oil, 8%

to 25% of'a finely divided substantially colorless mineral matter, 8% to 20% of a resin, 5% to 17% of a solvent for the resin, and 5% to 15% of starch, emulsified with 20% to 40% by volume of an aqueous slightly alkaline solution.

2.'A watermarking composition of the character described in the form of an emulsion and having a suitable printing ink consistency, coinprising between 8% and 20% of 'a resin or 01%- resin, a solvent therefor, finely divided substantially colorless mineral matter and a vegetable oil from the group consisting of castor oil, neatsfoot oil, sperm oil, cottonseed oil, eucalyptus oil,'

sesame oil, croton oil, and oil of peppermint, emulsified with 20% to 40% by volume of a slightly alkaline aqueous solution of salts from the group consisting of aluminum sulfate, borax and sodium carbonate, said watermarking composition being adapted to render paper translucent at point of application without impairing ink-receiving characteristics of the paper.

3. A watermarking-composition in the form of an emulsion and having a suitable printing ink consistency, comprising 12% to 30% of castor oil, 8% to 25% of a finely divided substantially colorless mineral matter, 8% to 20% of Canadian balsam, to 17% of a solvent for the Canadian balsam and 5% to 15% of starch, emulsified with 20% to 40% by volume of an aqueous solution of aluminum sulfate containing 1 part of aluminum sulfate to 20 parts of water;

4. A Watermarking composition of the character described in the form of an emulsion and having a suitable printing ink consistency, comprising between 8% and 20% of a resin or oleoresin, a solvent therefor, between 8% and 25% of finely divided diatomaceous silica, and a vegetable oil, emulsified with a slightly alkaline aqueous solution of salts from the group consisting of aluminum sulfate, borax and sodium carbonate, said composition containing a signalling substance adapted to change in color when said watermarking composition is brought in contact with caustic alkali and acid.

5. A substantially neutral watermarking composition in the form of an emulsion and having a suitabl printing ink consistency, comprising from about 8% to 20% by volume of Canadian balsam, 5% to 17% of turpentine, 8% to 25% of finely divided substantially colorless mineral matter, and from 12% to 30% of castor oil, emulsified with a slightly alkaline aqueous solution of borax, said composition containing a substantially colorless signalling substance reactive to both acids and alkalies.

6. A watermarking composition of the character described having a suitable printing ink consistency and adapted to render paper translucent 5 when applied thereto without impairing ink-receiving characteristics of the paper, said watermarking composition consisting of an intimate mixture of 8% to 20% of Canadian balsam, with turpentine, finely divided substantially colorless 10 mineral matter, and a substantially colorless vegetable oil with 20% to 40% by volume of an aqueous, slightly alkaline solution of salts from the group consisting of aluminum sulfate, borax and sodium carbonate.

7. A watermarking composition of the character described having a suitable printing ink consistency and adapted to render paper translucent when applied thereto without impairing ink-receiving characteristics of the paper, said watermarking composition comprising 8% to 20% by volume of Canadian balsam, 5% to 17% of turpentne, 8% to of finely divided substantially colorless mineral matter, and 12% to of an oil from the group consisting of castor oil, neats- 25 foot oil, sperm oil, eucalyptus oil, sesame oil, cottonseed oil, croton oil and oil of peppermint, intimately mixed with 20% to 40% of an aqueous solution of salts from the group consisting of aluminum sulfate, borax and sodium carbonate. 30

8. A Watermarking composition in the form of an emulsion and having a suitable printing ink consistency, comprising between 8% and 20% of Canadian balsam intimately dispersed and emulsified with turpentine and diatomaceous silica, castor oil, and a slightly alkaline aqueous solution of salts from the group consisting of aluminum sulfate, borax and sodium carbonate, said Watermarking composition being adapted to render paper translucent at point of application without impairing ink-receiving characteristics of the paper.

JOHN C. BOYER.