US1489357A - Printing ink - Google Patents

Description

- manently retaining t Patented Apr 8, 1924.

g ET STATES WILLIAM J. MCELROY, OF NEW YORK, AND JOHN CLARKE, 0F KANHASSET, NEW YORK, ASSIGNORS TO ALCHEIBUC GOLD COMPANY, INC., A CORPORATION OF NEW YORK.

PRINTING INK.

Ho Drawing.

To all whom it may concern:

Be it known that we, WILLIAM J. Mo- ELRoY, a citizen of the United States, and a resident of the borough of Manhattan, city, county, and State of New York, and J OHN CLARKE, a citizen of the United States, and a resident of the village of Manhasset, town of North Hempstead, county of Nassau, and State of New York, have invented a new and useful Improvement in Printing Inks, of which the following is a description, as well as of the manner and rocess of making, constructing, compounding, and using the same, in such full, clear, concise, and exact terms as to enable an erson skilled. in the art or science to whic it appertains or with which it is most nearly connected to make, construct, compound, and use the same.

Our invention relates generally to printing inks and particularly to those having metallic powders as their pigments.

The objects of our invention are the production of improved printing inks adapted for general use and more especially for use in embossing and die-printing upon bookcloth, leather and other materials commonly used for book-casings; particular objects are the production of inks of this class which shall be adapted for application by a heated die, plate or other impression member, reheated to embossing temperatures. and w ich shall be characterized by the qualities of drying immediately under the relatively high temperatures preferred in embossing metallic powders; and having properties 0 strongly adhering to and covering smoothly, evenly and completely the surface upon which they are stamped; of bein rendered lustrous by the heat of the meta by which they are impressed u on such object; of pereir original color and luster without tarnishing or :tading; of high boiling point and of low volatility.

Further objects are the rovision of an ink with the foregoing qu ities which can be mixed ready for use by the manufacturer and which will not corrode or otherwise deteriorate in the container, and which, when acka ed, and transported shall remain in its original state with its qualities and both its ph sical and chemical conditions unimpaired even atter long lapse of it Our present invention consists in the dis covery that printing inks such as set forth in our Patent No. 1,450,692, may attain the Application filed July 25, 1922. Serial No. 677,429.

desired attributes above recited, particularly as to covering and luster qualities to a highly superior de ree by employing as the metallic pigment to mixed with the highly viscous vehicle described, a mixture of bronze powders, such mixture being composed of bronze owder of the fineness customarily employed in making inks, namely, that exam led by the grade known commercially as emmerdingers Special No.. 1, to which has been added a more comminuted powder exampled by the grade known generally in the trade as lining. We have further discovered that with such com osite powder, the heavybodied pigment ve .icles referred to in our aforesaid patent, and whose composition is hereinafter exampled, combine to make an ink in which the powdered metallic pigment, by virtue of the amount thereof in a state of fine subdivision, and by virtue of the high viscosity of the vehicle, will tend to remain in suspension as long as the ink is fluid.

The stamped or embossed or printed impression obtained with this ink affords a moreintense igmentation, and. when dried, is more pliab 0 than that obtainable either with the coarser particles used alone or with the finer articles used alone. This is apparently ause the former leaves microscopic interstices between the articles, while the latter roduces too smootli or fiat a surface to re ect light in the manner the coarser individual particles do when present, hence the desired glance or brilliance of luster is lacking. vThe best results are attained by the use of the two grades in substantially their: relative proportions hereinafter examp e As an example of the preferred proportions of-the ingredients named, we take, by weight,

per cent terpineol and 5 per cent rosm oil, and stir ough y mixed.

With 84 per cent of this mixture we incorporate 16 per cent of powdered cumarone resin e. g., that known under the trade name of umar, and warm this mixture upon a water-bath at centigrade, stirring meanwhile, until the Cumar is thoroughly dissolved, which will result in about 20 minutes with vigorous stirring. The batch is then allowed to cool. From this batch we hire onethird and add thereto two'thirds of powder, both by weight This mir until thorture is then stirred until the bronze powder is thoroughly and evenly incorporated. The ink resulting is .of past-y and semi-fluid consistenc similar to that of printing inks genera 1y.

As the metallic pigment above intended, we prefer a mixture of bronze powder of the grade known commercially as Hemmerdingers Special No. 1, with 80 per cent of which is mixed 2.0 per cent of the finer grade of bronze powders known generally in the trade as lining, a more finely comminuted species of such powders, such species being that produced in the process of usual manufacture of bronze powders by air-floating from the mill those particles which have been reduced to the state of subdivision of fine, almost impalpable, dust.

The proportions above exampled may be varied somewhat without appreciable variation of the product. I

While thus specifying terpineol and rosin oil as the constituents preferred of our binder solvent vehicle, we wish to be understood as typifying thereby a binder vehicle having the desired properties as such, first, of an active solvent of the synthetic resins named; second, as of the desired bodyadapted to maintain the bronze powders in sustained suspension; third, as of the requisite degree of volatility to be driven off by the temperature used in embossing metallic pigments to impart the desired luster thereto; fourth, affording that degree of plasticity and elasticity to the impression which w ll prevent its cracking; fifth, the necessary neutrality which will preserve the metallic particles from corrosion on standing when mixed in ink form; sixth, which shall not cause the impressed characters to tarnish; and seventh, which shall be colorless or of such color as will not detract from the desired metallic luster. Within the limitations imposed by these criteria, the binder vehicle may be any of the suitable solvents or combinations thereof. This printing composition is primarily intended for printing book covers which, when of cloth, are prepared as cases with a strong coating of glue to hold the cloth to the backing. s the boiling point of the vehicle specified is approximately 428 Fahrenheit, the impression temperature must suffice to drive off the volatile solvent, that the impression may be dry, but must not be so high as to draw the glue through the cloth and thereby cause blisters in the impression or darken it. Preferably,

therefore, the described composition should be used as an ink at a temperature substantially that of the boiling point of the solvent vehicle. As will be obvious, however, the ink set forth may be used at lower tempera tures, or cold, and the impression artificially dried thereafter,

By virtue of the comparatively high spe clfic gravity of the synthetic resins produced as condensation products of naphtha, and the heavy body of the solvent therefor herein named, the solution obtained affords an especially valuable vehicle for the metallic pigments in that the tendency of the bronze powder to settle is checked and a persistent suspension thereof is attained.

Having thus described the preferred embodiment of cum invention and the best method now known to us of producing and usefully applying same, we claim:

1. A printing composition comprising a finely divided metallic igment consisting of a mixture of the less ne grade of bronze powders with a substantial quantity of the finer grade of bronze powders resultant from re-grinding the former grade added thereto, a neutral binder, a viscous solvent for said binder of low volatility, the dissolved binder constitutin a vehicle for the pigment of such viscosity that the pigment tends to remain in suspension therein.

2. A printing composition comprising a binder, a highly viscous solvent therefor of low volatilit and a powdered metallic pigment consisting of a mixture of bronze powders of two grades of fineness, the quantity ratio between the grades being substantially four of one grade to one of thefiner grade by weight, the latter grade being of the fineness of linings.

3. A printing ink containin pigment consisting in part of ders of the grade known as linings, such part substantially exceeding the percentage of this grade normally present in bronze owders which have not been subject to air oating.

4. A 1pr a metal ic a metallic ronze powinting ink composition containing pigment comprising a mixture of bronze powders of two grades of fineness, as

follows: 80 per cent of a grade coarser than that identified as lining and per cent of lining, Cumar, and a solvent for said Cumar adapted to maintain the metallic pigment in suspension.

WILLIAM J. MoELROY. JOHN CLARKE.