Letterpress printing ink

Abstract

A non-petroleum base newspaper letterpress printing ink comprising a blend of Gilsonite (uintaite) flakes and tall oil fatty acid together with carbon black pigment. The proportions of the Gilsonite and the tall oil fatty acid may be varied, as viscosity requirements change due to differences in press speeds, newsprint characteristics, and the like. The ink thus has readily adjustable viscosity, together with an enhanced flow and penetration characteristics, while being extremely economical to manufacture.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

Printing inks, particularly letterpress 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.

SUMMARY OF THE INVENTION

According to the present invention, a non-petroleum base letterpress 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".

DESCRIPTION OF THE PREFERRED EMBODIMENTS

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.

Procedure

70 Parts by weight of FA-1 grade tall oil fatty acids are heated with 30 parts of 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 pigment is dispersed within the blend with a Morehouse Mill. The "Elftex" 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 tall oil fatty acid as a final step if necessary. This ink had the following physical properties:

EXAMPLE I

A. Formulation of "ANPA-247" Letterpress Ink:

__________________________________________________________________________ PERCENTAGEMATERIAL SOURCE by WEIGHT__________________________________________________________________________ELftex - 8 Cabot Corporation 10Carbon Black 125 High Street Boston, MA 0211070/30 FA-1 Gilsonite Arizona Chemical Corporation 87.8Blend Wayne, NJ 07670Milori Blue Toner 910B Dainichiseika Color & 2.2 Chemical Company 20 Hook Mountain Road Pine Brook, NJ 07058TOTAL 100which breaks down to: Carbon 10.0% Toner 2.2% Gilsonite 26.3% Tall Oil 61.5% Fatty Acid* TOTAL 100.0%__________________________________________________________________________*FA-1 Tall Oil Fatty Acid, specified as follows:Product Characteristics Specification Typical LotColor, Gardner, 1963 9 max 5Acid Value 190 min 194Saponification Value 197Iodine Value 131Composition:Moisture, % Less than 0.1Ash, % Less than 0.001Rosin Acids, % 5.0 max 4.5Unsaponifiables, % 3.0 max 2.7Fatty Acids Total, % 92.8Fatty Acid Composition:Linoleic, Non-Conjugated, % 34Linoleic, Conjugated, % 9Oleic, % 44Saturated, % 5Other Fatty Acids, % 8Specific Gravity, 25.degree./25.degree. C. 0.906Weight Per Gallon, 25.degree. C., Lbs. 7.53Viscosity, Gardner-Holdt, 25.degree. C. AViscosity, SUS, 100.degree. F. 100Flash Point, Open Cup, .degree.F. 400Fire Point, Open Cup, .degree.F. 440TYPICAL PROPERTIES OF CABOT FURNACE PROCESSCARBON BLACKS FOR PRINTING INK APPLICATIONS Oil (DBP) Surface Area Particle Absorption Tinting Volatile Fixed Nigrometer (N.sub.2 S.A.) Size cc/100 grams Strength Content CarbonFluffy Pellets Index m.sup.2 /gm Millimicrons Fluffy Pellets Index % %__________________________________________________________________________ ELFTEX .RTM. Pellets 90 75 27 -- 123 99 1.0 92.5 ELFTEX .RTM. Pellets 115 90 66 27 -- 115 100 1.0 92.5ELFTEX 8 90 85 27 103 -- 100 1.0 99.0ELFTEX 12 93 45 37 95 -- 73 1.0 99.0__________________________________________________________________________ The above data in no way constitute a specification or certification for any particular shipment or shipments, but simply represent typical values based on analyses of spot samples from actual recent production of these grades. MOGUL, BLACK PEARLS, REGAL, ELFTEX, STERLING, and VULCAN are registered trademarks for carbon blacks manufactured by Cabot Corporation

B. Physical Properties of ANPA-247--Example I:

______________________________________Inkometer Tack (400 RPM) 2Viscosity, Brookfield 25.degree. C. 43.2 PoisesNAPIRI Grindometer 0Flow 45.degree. Inclined Plane 6 Inches/Minute______________________________________

C. Environmental Data:

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

D. Comparison with Commercial Letterpress Inks:

The Harrisburg Patriot and Evening News showed ANPA-247 ink to print well, to be low-misting, and to have high mileage. Laboratory tests at ANPA/RI for rub off, viscosity and tack, shown in the following table, point out the differences between it and standard letterpress ink, as used at The Patriot and Evening News.

It was noted at The Patriot that the inks were quicker drying than the standard news inks and did not dirty the pipe rollers on the press, as did conventional slow drying inks when high press speeds are used. Rub off of dried inks on the hands and on the other newspapers in a stack is another property which is minimal.

______________________________________RUB-OFF, VISCOSITY, TACK OF ANPA-247 - Example I(Andersson and Sorenson Rub Tests) Brookfield Inkometer Viscosity TackINK Rub-off % Poises 400 R.P.M.______________________________________ANPA-247 0.52 43.2 2.0Standard Ink 2.53 31.5 1.75______________________________________

EXAMPLE II

A. Formulation of ANPA-247B Letterpress Ink:

The foregoing Example I refers to runs on regular letterpress. The 247B ink, which was made to run on an Anilox press, was formulated as follows:

______________________________________ % byMATERIAL SOURCE WEIGHT______________________________________Elftex Pellets 115 Carbon Cabot Corporation 18.1Black Pigment 125 High Street Boston, MA 02110Gilsonite (Zeco 11A) Ziegler Chemical 16.4 & Mineral Corp. P.O. Box 455 Great Neck, NY 11021FA-1 Grade Tall Oil Fatty 65.5Acids 100.0______________________________________

These formulations increase mileage of the ink significantly, compared to commercial letterpress ink.

The ANPA-247B blend can also be used for offset inks. An ink with about 20% carbon content and the remainder being the above-described blend, has been printed successfully on a Goss Urbanite offset press.

B. Comparison with Commercially Available Oil Base Inks:

The Easton (PA) Express, when running ANPA-247 non-petroleum ink, had pointed out that the mileage for the ink was very good. By their estimates, it was at least 30% better. Consequently, a sample of their regular production oil base ink was obtained and a comparison was run on the two inks on a Hoe Letterpress.

Each ink was run on about 900 lbs., or one roll of paper, and the amounts of ink were weighed before and after the run to determine the amount consumed. The same plates and impression pressures were used. ANPA-247 produced 35% more pages per pound at a comparable solids print density of 0.98, which is the density used at The Express.

It is apparent from the above formula tabulation that the amount of Gilsonite in the ink may be varied from about 16% to about 25%. If the Gilsonite content is reduced significantly, strike thru and smearing of the newsprint are accentuated. If the Gilsonite content is increased significantly above 25%, viscosity will increase to the extent that poor flow and uneven lay or coverage will result in printed copy. Also, less mileage will ensue, since the amount of pigment will need to be reduced in order to allay the increased viscosity, inasmuch as pigment content increases viscosity. Thus, reduction in pigment content would decrease mileage.

EXAMPLE III

______________________________________Carbon black pigment 17%Gilsonite (uintaite) 18.6%Tall oil fatty acid 64.4%______________________________________

The foregoing example was used at Allentown Call, providing a fluid ink for printing at higher speeds with good results.

In printing with contemporary high speed presses, which may produce 80,000 impressions per hour, one cannot use inks which require oxidation or drying so as to prevent smear. The present ink is adapted to have a special viscosity, enabling it to be absorbable in contemporary newsprint. The Gilsonite ingredient enhances the viscosity, such that there is less penetration into the newsprint fibers while eliminating smearing. The Gilsonite may be obtained commercially at $0.11 per pound. The letterpress ink may be formulated, so as to have a viscosity in the range of 20-500 poises. Operating at press speeds of 50,000 impressions per hour, it was found that the ink having a viscosity of 90 poises did not dry fast enough. Ink viscosity of approximately 35 poises was approximately correct. In addition, the "flow" characteristics of the ink, that is, the ability to flow over the plate surfaces while covering the dots on the plate, is a critical parameter. It is found that at a plate temperature of 25.degree. C. (77.degree. F.), enough Gilsonite must be employed to retard the flow within a sufficient range.

Flow characteristics and viscosities of various ink formulations have been determined, as follows:

______________________________________Formulation %______________________________________ FLOW IN INCHES 25.degree. C. (77.degree. F.) Ink 287B 283 247-1 276 293______________________________________FA-1 66.2 64.14 56.4 66.1 70.1Carbon 9.5 17.02 19.8 16.2 12.3ZECO 11A 24.3 18.54 23.8 17.7 17.6______________________________________TIME, MINUTES Ink 287B 283 247-1 276______________________________________1 61/8 3 11/8 33/8 91/42 81/4 41/8 17/8 43/4 121/43 93/4 5 23/8 53/4 143/4______________________________________

BROOKFIELD VISCOSITY

The lower limit of viscosity and upper limit of flow has not been determined to date. The ink appears to have less strike-through even at low viscosities and a 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-over 1000 poises may be suitable. The over 1000 poises ink would be the upper limit 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 related, of course, to the density of the newspaper stock and the thickness of the page, as well as press speed.

A low viscosity letterpress and flexographic ink formulated for fast drying and decreased set-off onto other sheets of paper in the folded newapaper is:

EXAMPLE IV

______________________________________Carbon black pigment 12.3%Gilsonite (uintaite) 17.6%Tall oil fatty acid 70.1% 100%______________________________________

EXAMPLE V

______________________________________Material Percentage______________________________________70/30 Fatty Acid/Gilsonite 75.3Carbon Black (115 Pellets) 6.1Toner 0.8FA-1 Fatty Acid 17.8______________________________________

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

Claims

1. A letterpress printing ink composition consisting essentially of:

a. Carbon black pigment in the range 6.0 to 19.8%

b. Gilsonite in the range 16.4 to 26.3%, and

c. Tall oil fatty acid in the range 52.7 to 70.5%.

2. A letterpress printing ink composition as in claim 1, wherein said Gilsonite and tall oil fatty acids are blended by heating at approximately 300.degree. F. prior to cooling, filtering and dispersing with carbon black pigment.

3. A letterpress printing ink composition consisting essentially of:

a. Carbon black pigment 10%

b. Gilsonite 26.3%

c. Tall oil fatty acid 61.5%, and

d. Black toner 2.2%.

4. A letterpress printing ink composition consisting essentially of:

a. Carbon black in the form of carbon black pellets pellets 115: 17.0%

b. tall oil fatty acid: 64.4%

c. Gilsonite tall oil blend: 18.6%.

5. A letterpress printing ink composition consisting essentially of:

a. Carbon black pigment in the range 6 to 19.8%

b. Tall oil fatty acid and Gilsonite in the proportional range 70/30 to 80/20.