US2368157A - Printing process - Google Patents

Description

Patented Jan. 30,. 1945 PRINTING PROCESS Frank '1. Ortolano, New Orleans, La, asslgnor to Rheem Manufacturing Company, Richmond, Calif., a corporation of California No Drawing. Application October 18, 1941,

Serial No. 415,643

1 Claim. (Cl. fill-4B6) The invention relates to printing materials and processes and has for its principal object the provision of a material and process particularly adapted for printing upon surfaces coated with a lacquer film and which will provide a speedy, rapidly drying,. durable printed impression.

Another object of the invention is to provide a printing material and process of the character described in which the ink is set upon the lacquer surface by absorption of the ink solvent by the lacquer out of the ink, thereby enabling the latter to rapidly set up.

A further object of the invention is to provide in a printing material and process of the character described, the combination of a fast drying ink and a slow solvent which will prevent drying of the ink on the rollers, type, plates or other parts of the printing apparatus and yet function bythe process of absorption as above noted to rapidly set the ink upon contact with the lacquer surface.

The invention possesses other objects which with the foregoing will be set forth in the. following description of the preferred forms of the invention. It is to be understood, however, that I do not limit myself to said description, as I may adopt variations, from said forms within the scope of the invention as set forth in the claim.

enable a rapid setting up of the ink upon the The material and process may be used on hisquer films deposited by lacquers of various formula and consistency as obtainable on the market. The manufacture of lacquers is a highly developed art in itself and since the invention may be used with substantially all the varying grades and types of lacquers availableon. the a market, applicant is not concerned with any particular type of lacquer. Generally it may be stated that the process may be used with any pyroxylin, nitro-cellulose and probably cellulose acetate type of lacquer, the dry film of which is readily soluble with lacquer thinner, butyl alcohol, butylcellosolve, Cellosolve and other solvents of this type.

Similarly substantially anyof the so-called fast drying inks may be used in the present invention. A relatively large number of such inks are available on the market and their specific manufacture and formula is generally a trade secret. Generally it may be stated that substantially any ink having a relatively highly volatile vehicle may be used, as for example those formed by grinding pigments into synthetic vehicles having no linseed oil or varnish properties. However, the type of ink herein denoted as a fast drying ink is well known in'the art and insofar as applicant is aware, substantially any of these fast drying inks may be used.

In accordance with the present invention 1 incorporate in the fast drying ink a relatively slow solvent or plasticizer which is miscible with the fast drying ink and retains the same in a wet state upon exposure to the atmosphere even for protracted periods and which hasthe particular quality of being rapidly absorbed into the lacquer film upon contact therewith. By reason of this inclusion, the ink may be used on conventional types of printing apparatus and the ink will remain wet on the latter for hours without appreciable change of tack or viscosity. Upon application to the lacquer film, however, the slow solvent is extracted from the ink by absorption into the lacquer film, thereby permitting the ink to set up rapidly within a period of a few seconds and varying from live to ten seconds, depending upon the amount of ink applied and proportions used. Several slow solvents may be used in the present invention. Because of their common chemical properties these solvents are frequently classed together and include dibutyl phthalate, butyl Cellosolve, Cellosolve, dimethyl phthalate, triethylene glycol. Probably additional slow solvents may be used having the speciflc qualities of firstly being miscible with a fast drying ink to retard its setting, and secondly being readily and substantially completely absorbable in a lacquer film. Of the above enumerated group I have found that dibutyl phthalate is preferable at least in connection with the fast drying inks tested.

The proportion of slow, solvent to fast drying ink may be varied somewhat within the test that the amount of solvent must be sufficiently largev 2 a,sos,1sv

completely removed from the ink by the lacquer film contaetedand consequently the ink will remain wet and tack for an appreciable period or time. I have found that a good average working range may be obtained by incorporating one part 5 Y of slow solvent to approximately nine parts 01' fast drying ink. For example, the combinationof fifty c. c. dibutyl phthalate to. one pound (453 grams) oi fast drying ink, denoted in the trade as casing ink, aflorded an excellent working ma- 1o terial both from the standpoint of delayed drying on the rolls and type or rubber printing plates of the printing apparatus and from the standpoint of a rapid setting up and drying of the ink on the lacquer film. This combination may be 15 adjusted for lower or higher viscosity of the ink by incorporating a minimum of approximately forty c. c. dibutyl phthalate per pound 01' ink for the higher viscosity and a maximum 01 approximately sixty c. c. dibutyl phthalate per pound for go athinviscositv ink.

The present material and process can be used for printing on substantially any lacquered surface whether the lacquer be applied to pap wood, glass. metal, etc. One important use to whichthematerialandprocesshasbeenputis intheprintingotbombswheretheinkisapplied gylcol, said retardant being incorporated in said ink in an amount sumcient to maintain said ink inawet tackystateforaprotractedpetiodin the order 01 several hours when said ink is spread in a thinfilm on printing type; mlying said ink v to said lacquer film. and setting said ink on said film within about 10 seconds at atmospheric temperatures by evaporation oi said solvent and absorption 01' said retardant into said lacquer mm.

FRANK T. ORTOLANO.