Offset Printing Ink

1. Field of the Invention

Printing inks, particularly newspaper printing inks which have a non-petroleum base, which are environmentally acceptable while providing reduced misting with extra mileage and good quality.

2. Description of the Prior Art

Discussed in a PRIOR ART STATEMENT being submitted separately.

According to the present invention, a non-petroleum base offset ink is formulated from carbon black pigment and a blend of Gilsonite (uintaite) with tall oil fatty acid. The resultant printing ink provides an ink having enhanced viscosity, flow and penetration characteristics, while being exceptionally economical to manufacture. As a result, the ink is highly suitable for printing at contemporary press speeds, is quick drying and, thus, avoids the conventional problems of offset and "strike thru".

The present ink, having a non-petroleum base, is without dependence upon a diminishing petroleum supply, is environmentally acceptable and competitive in cost with the materials used in commercial letterpress and offset inks.

A typical formulation includes:

The acid fountain solution had a pH of 3.5-4.0 and was made from Varn Products Company concentrate.

FA-1 Tall Oil Fatty Acid (Arizona Chemical Company), is specified as follows:

Procedure:

FA-1 grade tall oil fatty acid is heated with ZECO 11 A grade Gilsonite from Ziegler Chemical Corporation at 300.degree. F. After solution of the solid Gilsonite, the blend is cooled and filtered. After the blend is made, carbon black pigment in the form of Elftex 115 pellets, Cabot Corporation, is dispersed within the blend with a Morehouse Mill. The carbon black pellets were ground to a National Printing Ink Research Institute grindometer reading of one (1). Viscosity adjustment can be made by adding small amounts of the tall oil fatty acid as a final step, if necessary.

Gilsonite has been the subject of long-term animal studies which indicate that it is a non-toxic, non-carcinogenic organic substance. In accordance with Section 710.4 of the Toxic Substance Control Act, Gilsonite, as a naturally occurring mineral, is automatically included in the initial inventory. The Chemical Abstract Registry Number is 12002-43-6.

Elftex carbon black pellets are a product of Cabot Corporation, 125 High Street, Boston, Mass. 02110, with properties for printing ink applications described as follows:

Physical characteristics of the ink formulations have been determined as follows:

Milori Blue 910 B is manufactured by Diacolor Division of Dainichiseika Color & Chemicals and is described as follows:

This product is recommended for use in Nitrocellulose, Polyamid, Quickset, Heatset, and Alkyd systems, where it offers high gloss, high speed dispersibility and low viscosity. Can be used for toning of heatset and quickset black inks.

Bentone 128 is a gellant product of NL Industries, Inc., Industrial Chemicals Division, P.O. Box 700, Hightstown, NJ 08520, with properties described as follows: "a special montmorillonite clay that has been organically modified. This rheological additive is designed for non-polar printing inks and will also gel inks containing solvents of intermediate polarity (from "Bentone 128-a rheological additive specifically designed for printing inks, DS-471, June 1978").

The foregoing Example I offset printing ink formulation may be employed with a tap water fountain, comprised as follows:

The Amway L.O.C. (Liquid Organic Cleaner), was manufactured by Amway Corporation, Ada, Mich., U.S.A., and is described as an all purpose liquid cleaner from a specially processed organic base derived from pure coconut oil.

The lower limit of viscosity and upper limit of flow have not been determined to date. The ink appears to have less strike-through even at low viscosities and at long flow length versus petroleum inks.

Principal advantages of the ink include the capability of printing at high press speeds, the low cost of formulation and the elimination of petroleum. The ingredient, Gilsonite, may be fed to animals and indeed, fatty acids are edible.

It is found that letterpress and offset inks having a viscosity in the range 20 to 1000 poises may be suitable. It appears that 1000 poises would be the upper limit for a printing ink when the inking cylinder actually contacts a reservoir of ink. Ink of such viscosity would be difficult to pump in some modern press usage. The ink viscosity is correlated, of course, to the density of the newspaper stock and the thickness of the page, as well as press speed.

Manifestly, various proportions of the Gilsonite and tall oil ingredients may be employed without departing from the spirit of invention.