Nitric acid system for etching magnesium plates
AssigneePhilip A. Hunt Chemical Corporation
InventorsDavid L. Czirr, Harry Kroll
Life of this patent
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Abstract
A one-step powderless high-speed process for producing photoengraved letter-press printing and pattern plates from magnesium and alloys thereof by etching such plates in a machine that directs against a surface of the plate droplets of an etching liquid comprising an aqueous solution of a strong inorganic acid and adjuvants.
Claims33
A method for etching bare areas of a magnesium plate, other portions of which are covered with an etch-resist pattern, said method comprising directing against the surface of said plate, in a direction having a substantial component perpendicular to said surface, an etching liquid including
- (I) a strong inorganic acid,
- (II) at least one liquid fatty monocarboxylic acid having from 6 to 26 carbon atoms which is substantially nonreactive with the inorganic acid,
- (III) at least one organophosphonic acid,
- (IV) at least one alkylaryl sulfonic acid,
- (V) at least one surfactant or coupling agent, and
- (VI) water.
A method for etching bare areas of a magnesium plate, other portions of which are covered with an etch-resist pattern, said method comprising directing against the surface of said plate, in a direction having a substantial component perpendicular to said surface, an etching liquid including
- (I) a strong inorganic acid,
- (II) at least one liquid fatty monocarboxylic acid having from 6 to 26 carbon atoms which is substantially nonreactive with the inorganic acid,
- (III) at least one polycarboxylic acid having from 2 to 10 carbon atoms,
- (IV) at least one alkylaryl sulfonic acid,
- (V) at least one surfactant or coupling agent,
- (VI) at least one salt of an acyclic or an alicyclic amine having at least 6 carbon atoms, and there being essentially absent from the etching liquid sulfonates and sulfates of fatty monocarboxylic acids, and
- (VII) water.
A method for etching bare areas of a magnesium plate, other portions of which are covered with an etch-resist pattern, said method comprising directing against the surface of said plate, in a direction having a substantial component perpendicular to said surface, an etching liquid including
- (I) a strong inorganic acid,
- (II) at least one liquid fatty monocarboxylic acid having from 6 to 26 carbon atoms which is substantially nonreactive with the inorganic acid,
- (III) at least one polycarboxylic acid having from 2 to 10 carbon atoms and at least one organophosphonic acid,
- (IV) at least one alkylaryl sulfonic acid,
- (V) at least one surfactant or coupling agent,
- (VI) at least one salt of an acyclic or an alicyclic amine having at least 6 carbon atoms, and there being essentially absent from the etching liquid sulfonates and sulfates of fatty monocarboxylic acids, and
- (VII) water.
Dependencies are inferred from the claim text.