US2346970A - Bitumen and ink made therefrom - Google Patents

Description

Patented Apr. 18, 1944 BITUMEN AND INK MADE THEREFROM Wilbur. L. Jones, New York, N. Y., assignor to Interchemical Corporation. New York, N. Y., a

corporation of Ohio No Drawing. Application May 24, 1941, Serial No. 395,053

6 Claims.

This invention relates to asphaltic intaglio inks such as are used for printing the typical gravure sections of the Sunday newspapers, and is directed particularly to such an ink containing a fiuxed petroleum pitch obtained from Venezuela petroleum, and to the fiuxed bitumen per se.

conventionally, inks for printing Sunday rotogravure supplements are made by dissolving gil- I sonite (or some other bitumen of the same type) in a volatile solvent; these are printed by intaglio process at high speeds. In order to get the desired press speeds, the inks are made with very volatile solvents (approximating the vola-' tility of benzene) and are printed from presses equipped with closed fountains. Because of the toxicity of benzene, it has been necessary to use similar strong solvents may be used.

Many products which would make acceptable substitutes for gilsonite, when used with benzene as the solvent, are completely unsatisfactory when. used in the petroleum naphtha active solvent mixtures which must be used. Some are insoluble; others are soluble, but dry without gloss, indicating precipitation during drying; and others retain the solvent tenaciously, and do not dry because of their poor solvent release.

A bitumen which has been suggested as a replacement for gilsonite is a petroleum pitch known as Aruba bitumen. It is obtained as a still bottom in the high temperature distillation of Venezuela petroleums, in the refineries at Aruba, N. W. I. It has the following approximate composition:

Per cent Water 5to8 Volatile matter (dry basis) 74.24 Fixed carbon 25.35 Ash 0.41

Sulfur 4.80

Soluble in CS2 percent 99.70 Soluble in S0lvesso#2 do 99.80 Specific gravity at 60 F 1.117

Flash point F 600 to 635 This bitumen dissolves in benzene to give a satisfactory gravure ink, of considerably higher color value than a similar ink made from gilsonite. However, the bitumen cannot be used in gravure inks, because it is insoluble in the mixtures of petroleum and active solvents used in present day gravure inks.

I have discovered that Aruba bitumen can be converted into a satisfactory base for gravure inks by fiuxing '75 or less parts by weight of the bitumen with about one-fourth of its weight of a fatty acid pitch (such as the various stearin pitches, rosin pitch, and particularly tall oil pitch) in combination with 5 or more parts by Weight of a natural asphalt of the gilsonitegrahamite family.

If substantially less than one-quarter part of fatty acid pitchis used per part of "Aruba" bitumen (e. g.-one fifth), the fiuxed product obtained is insoluble in the desired solvent mixtures; if substantially more is used (e. g.one third), the product obtained is too soft, and dries too slowly because of solvent retention. If the fluxed mixture of bitumens contains over of Aruba, inks made therefrom yield prints with insuflicient gloss; it is therefore necessary to include at least 5% of a natural bitumen of the gilsonite-grahamite family in the final product, to get enough gloss without substantially departin from the necessary Aruba" fatty acid pitch ratio.

In general, I prefer to keep the added gilsonite to a minimum, since the use of more gilsonite decreases the improvement in color strength obtained by the use of the fluxed mixture, and increases the cost.

The mixture can be made by merely melting the three ingredients together, keeping the temperature as low as possible. Low temperature fluxing is most advantageously obtained by melting the flux, and then adding the Aruba and gilsonite; by this method, a temperature of 200 C. need not be exceeded.

Typical fluxed mixtures are:

EXAMPLE 1 Flared bitumen Per cent Tall oil pitch 18 Gilsonite 9 Aruba bitumen '73 are melted together, in order given, at 200 C. The fiuxed mass has a melting point of C. This can be made into an ink by dissolving- Parts by weight Fluxed bitumen 35 Methyl ethyl ketone 13 Lactol spirits (10w solvency petroleum naphtha-evaporation rate approximating that of benzene) 52 The ink is ready to run; its gloss and drying speed are very good, and it is considerably stronger in tone than the same ink made withgilsonite.

Emu: 2

. Per cent Tall oil pitch 18 Cuban grahamite 10 Aruba bitumen 72 is made as in Example 1. The fiuxed pitch has a melting point of 193 C. It is made into an ink as in Example 1.

EXAMPLE 3 Percent Stearin pitch 18 Cuban grahamite 10 Aruba bitumen 72 This yields an ink, when made up as in Example 1, which is' superior to an ink made with gilsonite, but not quite as satisfactory as the inks of EX- amples l and 2.

Examples can of course be multiplied indefinitely without departing from the scope of my invention, which is defined in the claims. In particular, various fatty acid pitches can be used to replace those shown, although tall oil pitch is preferred. The known natural bitumens of the giisonite-grahamite class can be used.

In making the inks, the solvents may be varied. In the preferred use of my new bitumen compositions, they are dissolved in solvent mixtures consisting predominantly of petroleum hydrocarbons having the volatility of benzene, and a minor proportion (from 5 to about 30%) of an active ketone or ester having a similar volatility (methyl ethyl ketone, acetone,'methyl ethyl and isopropyl acetates, etc.). Pigments may be used ,with these inks, as desired. Furthermore, the

fluxed bitumens disclosed may be used in other compositions to replace gilsonite (e. g., typographic inks, paints) with good success.

I claim:

1. A bitumen particularly useful as a substitute for gilsonite in intaglio printing inks, consisting essentially of a major portion of a mixture of about 4 parts by weight of "Aruba" bitumen and 1 part by weight of fatty acid pitch, and a minor portion, comprising at least 5% by weight of the composition, of a. natural asphalt of the gilsonite-grahamite group, the Aruba not exceeding by weight of the composition.

2. Abitumen particularly useful as a substitute for gilsonite in intaglio printing inks, consisting essentially of a major, portion of a mixture of about 4 parts by weight of Aruba bitumen and 1 part by weight of tall oll pitch, and a minor portion, comprising at least 5% by weight of the composition, of a natural asphalt of the gilsonitegrahamite group, the Aruba not exceeding 75% by weight of the composition.

3. A bitumen consisting of a fluxed mixture of about 72 parts by weight of "Aruba bitumen, 18 parts tall oil pitch, and 10 parts of a natural bitumen of the gilsonite-grahamite group.

4. An intaglio ink comprising a solution of the bitumen of claim 1 in a solvent consisting predominantly of a petroleum hydrocarbon mixture having an evaporation rate approximating that of benzene, and a minor proportion of an oxygenated solvent of the class consisting of ketones and esters having similar volatility.

5. An intaglio ink comprising a solution of the bitumen of claim 2 in a solvent consisting predominantly of a petroleum hydrocarbon mixture having an evaporation rate approximating that of benezene, and a minor proportion of an oxygenated solvent of the class consisting of ketones and esters having similar volatility.

6. An intaglio ink comprising a solution of the bitumen of claim 3 in a solvent consisting predominantly of a petroleum hydrocarbon mixture having an evaporation rate approximating that of benzene, and a minor proportion of an oxygenated solvent of the class consisting of ketones and esters having similar volatility.

WILBUR L. JONES.