Powderless etching bath for magnesium printing plates

Claim 2

A BATH COMPOSITION FOR ETCHING PHOTOENGRAVING PLATES OF MAGNESIUM OR ALLOYS THEREOF WHICH COMPRISES WATER AND, PER LITER OF BATH: A. FROM ABOUT 70 GRAM TO ABOUT 360 GRAMS OF 42* BAUME NITRIC ACID, B. FROM ABOUT 0.25 GRAM TO ABOUT 5 GRAMS OF A SULFATED FATTY ACID ESTER HAVING FROM 10 TO 24 CARBON ATOMSS IN THE ACID MOIETY AND FROM 1 TO 12 CARBON ATOMS IN THE ALCOHOL MOIETY. C. FROM ABOUT 0.25 GRAM TO ABOUT 6 GRAMS OF A FIRST STRUCTED OR OLEFINICALLY UNSATURATED CARBOXYLIC ACID WHICH COMPRISES A HYDROXY-UNSUBSTITUTED MONOCARBOXYLIC ACID OF FROM 2 TO 6 CARBON ATOMS, OR A POLYCARBOXYLIC OR HYDROXYSUBSTITUTED MONOCARBOXYLIC ACID OF FROM 2 TO 8 CARBON ATOMS, D. FROM ABOUT 2 GRAMS TO ABOUT 25 GRAMS OF A POLYHYDRIC ALCOHOL OF FROM 2 TO 10 CARBON ATOMS OR AN ETHER DERIVATIVE THEREOF, E. FROM ABOUT 2 GRAMS TO ABOUT 15 GRAMS OF A SECOND SATURATED OR OLEFINICALLY UNSATURATED CARBOXYLIC ACID WHICH COMPRISES AT LEAST ONE HYDROXY-UNSUBSTITUTED MONOCARBOXYLIC ACID HAVING FROM 8 TO 24 CARBON ATOMS, AND F. FROM ABOUT 025 GRAM TO ABOUT 4 GRAMS OF AN ALKYLARYLSULFONATE SELECTED FROM THE GROUP CONSISTING OF THE ALKYLBENZENESULFONATES WHEREIN THE ALKYL PORTION CONTAINS FROM 8 TO 18 CARBON ATOMS AND THE ALKYLNAPHTHALENESULFONATES WHEREIN THE ALKYL PORTION CONTAINS FROM 3 TO 18 CARBON ATOMS.

Claim 3

The etching bath of claim 1 wherein the first saturated or olefinically unsaturated carboxylic acid is selected from the group consisting of saturated hydroxy monocarboxylic acids, saturated dicarboxylic acids, and saturated hydroxy tricarboxylic acids.

Claim 4

The etching bath of claim 1 wherein the first saturated or olefinically unsaturated carboxylic acid is selected from the group consisting of glycolic, lactic, adipic, malic, tartaric, and citric acids.

Claim 5

The etching bath of claim 1 wherein the polyhydric alcohol or ether derivative is a glycol ether.

Claim 6

The etching bath of claim 1 wherein the polyhydric alcohol or ether derivative thereof is selected from the group consisting of diethylene glycol n-butyl ether, diethylene glycol ethyl ether, ethylene glycol n-butyl ether, ethylene glycol phenyl ether, triethylene glycol methyl ether, and triethylene glycol butyl ether.

Claim 7

The etching bath of claim 1 wherein the second saturated or olefinically unsaturated carboxylic acid consists of, per liter of bath, from about 2 grams to about 15 grams of at least one saturated or olefinically unsaturated hydroxy-unsubstituted monocarboxylic acid having 18 carbon atoms and from about 0.05 gram to about 1 gram of at least one saturated hydroxy-unsubstituted monocarboxylic acid of from 8 to 12 carbon atoms.

Claim 8

The etching bath of claim 1 wherein the second saturated olefinically unsaturated carboxylic acid is oleic acid.

Claim 9

The etching bath of claim 1 wherein the second saturated or olefinically unsaturated carboxylic acid consists of one or more saturated acids.

Claim 10

The etching bAth of claim 1 wherein the second saturated or olefinically unsaturated carboxylic acid is isostearic acid.

Claim 11

The etching bath of claim 1 wherein the alkylarylsulfonate is an alkylbenzenesulfonate wherein the alkyl portion contains from 8 to 18 carbon atoms.

Claim 12

The etching bath of claim 1 wherein the alkylarylsulfonate is an alkylnaphthalenesulfonate wherein the alkyl portion contains from 3 to 18 carbon atoms.

Claim 13

The etching bath of claim 1 wherein from about 140 grams to about 285 grams of 42* Baume nitric acid are employed per liter of bath.

Claim 14

The etching bath of claim 1 wherein from about 1 gram to about 3.5 grams of the sulfated fatty acid ester are employed per liter of bath.

Claim 15

The etching bath of claim 1 wherein from about 0.5 gram to about 2 grams of the first saturated or olefinically unsaturated carboxylic acid are employed per liter of bath.

Claim 16

The etching bath of claim 1 wherein from about 3 grams to about 10 grams of the polyhydric alcohol or ether derivative thereof are employed per liter of bath.

Claim 17

The etching bath of claim 1 wherein from about 5 grams to about 10 grams of the second saturated or olefinically unsaturated carboxylic acid are employed per liter of bath.

Claim 18

The etching bath of claim 1 wherein from about 0.5 gram to about 2 grams of the alkylarylsulfonate are employed per liter of bath.

Claim 19

The etching bath of claim 6 wherein from about 5 grams to about 10 grams of the monocarboxylic acid having 18 carbon atoms and from about 0.12 gram to about 0.15 gram of a saturated monocarboxylic acid of from 8 to 12 carbon atoms or a mixture thereof are employed per liter of bath.

Claim 20

The etching bath of claim 6 wherein the acid having 18 carbon atoms is oleic acid.

Claim 21

The etching bath of claim 6 wherein the acid having 18 carbon atoms consists of a saturated acid.

Claim 22

The etching bath of claim 6 wherein the acid having 18 carbon atoms is isostearic acid.

Claim 23

The etching bath of claim 6 wherein the saturated monocarboxylic acid of from 8 to 18 carbon atoms is comprised of a blend of capric and caprylic acids.

Claim 24

The etching bath of claim 22 wherein the acid having 18 carbon atoms is oleic acid.

Claim 25

The etching bath of claim 22 wherein the acid having 18 carbon atoms is isostearic acid.

Claim 26

The etching bath of claim 22 wherein the first saturated or olefinically unsaturated carboxylic acid is selected from the group consisting of hydroxy monocarboxylic acids, dicarboxylic acids, and hydroxy tricarboxylic acids.

Claim 27

The etching bath of claim 25 wherein the polyhydric alcohol or ether derivative thereof is a glycol ether.

Claim 28

The etching bath of claim 22 wherein the acid having 18 carbon atoms consists of a saturated acid.

Claim 29

The etching bath of claim 27 wherein the first saturated or olefinically unsaturated carboxylic acid is selected from the group consisting of hydroxy monocarboxylic acids, dicarboxylic acids, and hydroxy tricarboxylic acids.

Claim 30

The etching bath of claim 28 wherein the polyhydric alcohol or ether derivative thereof is a glycol ether.

Claim 31

The etching bath composition of claim 22 which comprises water and, per liter of bath: a. from about 140 grams to about 285 grams of 42* Baume nitric acid; b. from about 1 to about 3.5 grams of a sulfated fatty acid ester having from 10 to 24 carbon atoms in the acid moiety and from 1 to 12 carbon atoms in the alcohol moiety; c. from about 0.5 to about 2 grams of tartaric acid; d. from about 3 grams to about 10 grams of diethylene glycol n-butyl ether; e. from about 5 grams to about 10 grams of isostearic acid; f. from about 0.12 gram to about 0.15 gram of a blend of caprylic and capric acids; and g. from about 0.5 grams to about 2 grams of a dodecylbenzenesulfonate salt.

Claim 32

An additive composition adapted for use in admixture with aqueous nitric acid as a bath for the powderless etching of printing plates of magnesium or magnesium alloys, which bath is essentially free from organic water immiscible liquids which are substantially unreactive with the aqueous acid bath, said additive composition comprising, based on the total weight of said additive composition: a. from about 4.9 to about 6 weight percent of a sulfated fatty acid ester having from 10 to 24 carbon atoms in the acid moiety and from 1 to 12 carbon atoms in the alcohol moiety; b. from about 1.95 to about 2.45 weight percent of a first saturated or olefinically unsaturated carboxylic acid which comprises a hydroxy-unsubstituted monocarboxylic acid of from 2 to 6 carbon atoms, or a polycarboxylic or hydroxy-substituted monocarboxylic acid of from 2 to 8 carbon atoms; c. from about 16 to about 20 weight percent of a polyhydric alcohol of from 2 to 10 carbon atoms of an ether derivative thereof; d. from about 12 to about 14.6 weight percent of a second saturated or olefinically unsaturated carboxylic acid which comprises at least one hydroxy-unsubstituted monocarboxylic acid having from 8 to 24 carbon atoms; and e. from about 2.4 to about 3 weight percent of an alkylarylsulfonate selected from the group consisting of the alkylbenzenesulfonates wherein the alkyl portion contains from 8 to 18 carbon atoms and the alkylnaphthalenesulfonates wherein the alkyl portion contains from 3 to 18 carbon atoms; and f. the balance to 100 weight percent, substantially water.

Claim 33

An additive composition adapted for use in admixture with aqueous nitric acid as a bath for the powderless etching of printing plates of magnesium or magnesium alloys, which bath is essentially free from organic water immiscible liquids which are substantially unreactive with the aqueous acid bath, said additive composition comprising, based on the total weight of said additive composition: a. from about 4.9 to about 6 weight percent of a sulfated fatty acid ester having from 10 to 24 carbon atoms in the acid moiety and from 1 to 12 carbon atoms in the alcohol moiety; b. from about 1.95 to about 2.45 weight percent of a first saturated or olefinically unsaturated carboxylic acid which comprises a hydroxy-unsubstituted monocarboxylic acid of from 2 to 6 carbon atoms, or a polycarboxylic or hydroxy-substituted monocarboxylic acid of from 2 to 8 carbon atoms; c. from about 16 to about 20 weight percent of a polyhydric alcohol of from 2 to 10 carbon atoms of an ether derivative thereof; d. from about 12 to about 14.6 weight percent of a second saturated or olefinically unsaturated carboxylic acid which comprises at least one hydroxy-unsubstituted monocarboxylic acid having from 8 to 24 carbon atoms; and e. from about 2.4 to about 3 weight percent of an alkylarylsulfonate selected from the group consisting of the alkylbenzenesulfonates wherein the alkyl portion contains from 8 to 18 carbon atoms and the alkylnaphthalenesulfonates wherein the alkyl portion contains from 3 to 18 carbon atoms; and f. the balance to 100 weight percent, substantially water.

Claim 34

The additive composition of claim 31 wherein the second saturated or olefinically unsaturated carboxylic acid component comprises, based on the total weight of said second carboxylic acid component, from about 97.25 to about 98.25 weight percent of an hydroxy-unsubstituted monocarboxylic acid having 18 carbon atoms and from about 1.75 weight percent to about 2.75 weight percent of a saturated hydroxy-unsubstituted monocarboxylic acid having from 8 to 12 carbon atoms or a mixture thereof.

Claim 35

The additive composition of claim 31 wherein the second saturated or olefinically unsaturated carboxylic acid component consists of from about 97.25 to about 98.25 weight percent of a saturated hydroxy-unsubstituted monocarboxylic acid having 18 carbon atoms and from about 1.75 weight percent to about 2.75 weight percent of a saturated hydroxy-unsubstituted monocarboxylic acid having from 8 to 12 carbon atoms or a mixture thereof.

Claim 36

The additive composition of claim 32 wherein the first saturated or olefinically unsaturated carboxylic acid is selected from the group consisting of saturated hydroxy monocarboxylic acids, saturated dicarboxylic acids, and saturated hydroxy tricarboxylic acids, and, wherein the polyhydric alcohol or ether derivative thereof is a glycol ether.

Claim 37

The additive composition of claim 33 wherein the first saturated or olefinically unsaturated carboxylic acid is selected from the group consisting of saturated hydroxy monocarboxylic acids, saturated dicarboxylic acids, and saturated hydroxy tricarboxylic acids, and, wherein the polyhydric alcohol or ether derivative thereof is a glycol ether.

Claim 38

The additive composition of claim 34 wherein the additive is comprised of: a. about 5.4 weight percent of the sulfated fatty acid ester; b. about 2.2 weight percent of the first saturated or olefinically unsaturated carboxylic acid; c. about 18 weight percent of the glycol ether; d. about 13 weight percent of the saturated or olefinically unsaturated hydroxy-unsubstituted monocarboxylic acid having 18 carbon atoms; e. about 0.3 weight percent of the saturated hydroxy-unsubstituted monocarboxylic acid having 8 to 12 carbon atoms or the mixture thereof; f. about 2.7 weight percent of the alkylarylsulfonate; and g. the balance to 100 weight percent, substantially water.

Claim 39

The additive composition of claim 36 wherein the first saturated or olefinically unsaturated carboxylic acid is tartaric acid, the glycol ether is diethylene glycol n-butyl ether, and the second saturated or olefinically unsaturated carboxylic acid consists of about 97.75 weight percent isostearic acid and about 2.25 weight percent of a mixture of 8- to 12-carbon unsaturated hydroxy-unsubstituted monocarboxylic acids comprised of capric acid and caprylic acid.