US3730899A - Powderless etching bath additive - Google Patents

Powderless etching bath additive Download PDF

Info

Publication number
US3730899A
US3730899A US00183660A US3730899DA US3730899A US 3730899 A US3730899 A US 3730899A US 00183660 A US00183660 A US 00183660A US 3730899D A US3730899D A US 3730899DA US 3730899 A US3730899 A US 3730899A
Authority
US
United States
Prior art keywords
etching
acid
bath
etching bath
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00183660A
Other languages
English (en)
Inventor
H Messerschmidt
K Heyman
B Johnsen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3730899A publication Critical patent/US3730899A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F1/00—Etching metallic material by chemical means
    • C23F1/10—Etching compositions
    • C23F1/14—Aqueous compositions
    • C23F1/16—Acidic compositions

Definitions

  • ABSTRACT OF THE DISCLOSURE Etching bath for zinc and magnesium and alloys based thereon comprising an aqueous solution containing an etching amount of nitric acid, and a water-soluble or dispersible, anionic, aliphatic carboxylic acid containing at least one hydrophobic hydrocarbon group with about 8 to 24 carbon atoms and having a sulfonate group depending from a carbon atom in said hydrocarbon group.
  • This invention relates to powderless etching. It more particularly refers to an improved additive composition for use in powderless etching baths.
  • a fiat or cylindrical plate of an acid-soluble metal such as magnesium, zinc or one of their alloys, is coated with a light sensitive coating or enamel.
  • This coated surface is exposed to light through a negative having an image thereon so as to produce an image on the coating.
  • the exposed coated surface is then developed to form an acid-resistant coating corresponding to the image produced by the exposure.
  • This coating may be further hardened by heating and the final acid-resistant image is called the resist.
  • the image bearing surface of the plate is subjected to etching by an acid to remove the metal which is not under the resist and thus to produce the image in relief.
  • Powderless etching is now a well-known, widely practiced technique. It is used to etch photoengraving plates and other similar shaped articles. Zinc, magnesium and alloys based thereon are generally used as the photoengraving plate metals.
  • etching baths made up of aqueous solutions of nitric acid and one or more surfactants are quite suitable for powderless etching of zinc and/ or magnesium.
  • Many technological contributions have been made to this art, such as for example in US. Pats. 2,640,763; 2,640,764; and 2,640,766; according to which the aqueous nitric acid etching baths are modified by the incorporation therein of aliphatic acids, or esters of aliphatic acids with polyhydric aliphatic alcohols, or sulfonates of succinic acid diesters.
  • the most commonly commercially used surfactant in the powderless etching art is a material which is usually referred to in the trade as sulfonated castor oil. This is a commercially available material which is chemically mis-named.
  • the material referred to is actually a sulfated castor-oil, mainly the sulfate ester of n'cinoleic acid (the is the hydroxyl group of ricinoleic acid is esterified with sulfuric acid to add a sulfate group thereon).
  • surfactants which have been recommended in the patent literature in combination with the water-immiscible organic liquid are sulfosuccinates, petroleum sulfonates, alkylaryl sulfonates, sulfated alcohols, sulfated fats and oils other than sulfated castor oil, phosphate esters, polyether non-ionic surfactants, and alkylaryl ether sulfonates.
  • Another objects of this invention are to provide a novel etching bath capable of producing desired depths of etch in all kinds of image areas of combination plates, to porvide an etching bath capable of forming a stable protective film to prevent or retard lateral etching and chipping of relief side walls and a smooth, uniform side Wall permitting easy release from a matrix, besides having visual appeal.
  • a still further object of this invention is to provide an improved etching bath for producing name plates, metal patterns, templates and the like.
  • one important aspect of this invention resides in the use of a water-soluble or water-dispersible anionic aliphatic carboxylic acid or ester thereof containing at least one hydrophobic hydrocarbon group with about 8 to 24 carbon atoms attached to the carboxyl group and at least one sulfonate group attached to a carbon atom in said hydrophobic hydrocarbon group as the surfactant in an aqueous mineral acid etching bath.
  • the mineral acid of an etching bath is generally nitric acid, although mixtures of nitric acid and small quantities of sulfuric, hydrochloric or acetic acids can be beneficial. Suitable amounts of mineral acid range from about 30 to 300 grams per liter of bath with a preferred range from about 70 to 250 grams per liter of bath. A most preferred range is about 80 to 200 grams per liter of bath.
  • the mineral acid components of the powderless etching bath of this invention is per se known.
  • the sulfonated carboxylic acids of this invention are true sulfonates as distinguished from the so called sulfonated oils like sulfonated caster oil which products are actually sulfates or esters of sulfuric acid.
  • the true sulfonates of this invention differ from the sulfates by the fact that in the sulfonate, sulfur is directly linked to a carbon atom rather than through an intermediary oxygen atom as in the sulfate.
  • fatty acids which in their sulfonated condition are useful in this invention are for example caprylic, lauric, stearic, isostearic, behenic, lignoceric acids, undecylenic, oleic, linoleic, linolenic, eleo, stearic, arachidonic acids and the like.
  • Saturated and unsaturated fatty acids which have substituents on their hydrocarbon chains can also be sulfonated to add a sulfonate substituent bonded to a carbon atom thereof.
  • esters, amides and nitriles, chlorides and/or anhydrides of these fatty acids can be sulfonated with ease, and the sulfonation products thus produced are applicable in this invention provided there is a sulfur-carbon bond an provided they hydrolyse in an aqueous acid etching baths into the corresponding sulfonated carboxylic acids.
  • the sulfonated acids of this invention can be pure fatty acids or can be mixtures of fatty acids and/or esters or other derivates thereof such as occur naturally in vegetable, animal or marine oils, fats and waxes or in synthetic fatty acids derived from petroleum, bituminous coal and natural gas. Where mixtures of sulfonated fatty acids are to be used, sulfonation of the fatty acids can be accomplished before and after mixing.
  • sulfonation of fatty carboxylic acids is a well established procedure and can be accomplished by different means as the occasion demands.
  • Saturated fatty acids can be sulfonated directly in the alpha-position by reaction thereof with chlor-sulfonic acid or sulfur trioxide, which may be dissolved in sulphur dioxide, dioxane or chlorinated hydrocarbons.
  • Alpha-sulfonations can also be accomplished less directly by the Strecker reaction of an alpha-bromo fatty acid with sodium sulfite.
  • oleic acid yields predominately ll-sulfo-oleic and 9-hyhydroxy-lO-sulfostearic acids when reacted with a stoichiometric amount of sulfur trioxide.
  • Truly sulfonated ricinoleic acid is obtained by sulfonation with acetyl sulfonic acid which is itself obtained by reacting sulfur trioxide with glacial acetic acid or acetic anhydride.
  • etching baths having the following composition:
  • etching with the baths of the present invention it has been found to be desirable to impinge the bath against the surface to be etched, as by splashing.
  • the etching bath forms a partially acid-resistant film on the resist-free metal surfaces, and when the bath is impinged against the surface to be etched in a direction normal to that surface, the film is broken.
  • the film is generally not broken because of insufiicient striking force and etching of the sides (or under-cutting) is substantially reduced.
  • etching machine of the type disclosed in Pat. No. 2,669.048, issued Feb. 16, 1954, and entitled Etching Machine can be used.
  • this machine elongated paddles dipping into the bath composition intermittently throw, by splashing, the etching bath composition in sheets upwardly against the image bearing side of the object being etched, e.g. a plate.
  • Other types of etching machines known to the art are also applicable.
  • etch factor ratio is defined as the ratio of (1) the depth of the etch adjacent to a line of resist divided by one half of the loss in width of metal immediately beneath the resist using a particular additive to (2) the depth of the etch adjacent to a line of resist divided by one half of the loss in width of metal immediately beneath the resist when only nitric acid is used in the exact concentration as was used with the particular additive:
  • EXAMPLE I An etching bath was made up consisting of 8% by weight of 42 B. nitric acid, 0.45% by weight of 11- sulfo-oleic acid and the balance water. This bath was used to etch magnesium printing plates having a typical, representative resist image thereon. Etching was carried out for 3 minutes in a commercial paddle type etching machine of the type described in US. Pat. No. 2,669,048. The quality of the etched plates was good.
  • the etch factor ratio (EFR) was 11:1.
  • Example I was repeated but an identical weight of commercial sulfated castor oil was substituted for the sulfonated oleic acid. The result was a blanking out of the plate. No improvement was obtained by either decreasing or increasing the amounts of the sulfated castor oil used.
  • EXAMPLE III EXAMPLE IV Example II was repeated with the addition of 0.5% by weight of the heavy aromatic naphtha. This large amount "of naphtha was necessary in order to obtain a barely acceptable plate. Due to partial blanking out of the plate the EFR is not measurable.
  • Example IV was repeated using additions of 0.6% by weight of sulfated castor oil and 0.6% by weight of heavy aromatic naphtha. The resulting plate was acceptable. The etch factor ratio was 8:1.
  • Example III was repeated using sulfated castor oil in place of the 11 sulfo oleic acid. No etching took place and the plate remained blanked out.
  • EXAMPLE VII An etching bath was made up by mixing dilute nitric acid and sulfocaprylic acid in the following proportions:
  • the bath was maintained at 38 C. while being constantly agitated. A paddle speed of 500 r.p.m. was used to etch the plate for 3 minutes. The relief portions of the plate were found to have good sidewall formation and an EFR of 6:1.
  • Example VII was repeated with the addition of 0.02% by weight of a heavy aromatic naphtha (HAN, Humble Oil Co.) to the etching bath.
  • HAN Heavy aromatic naphtha
  • the etched magnesium plates had good quality and an EFR of 6: 1. Concentrations of HAN higher then 0.05% lead to plate degradation.
  • An etching bath for photoengraving plates based on zinc, magnesium or alloys thereof comprising:
  • an etching bath as claimed in claim 1 wherein the acid moiety of said sulrfonated fatty acid is a member selected from the group consisting of caprylic, lauric, stearic, isostearic, behenic, lignoceric, undecylenic, oleic, linoleic linolenic, eleostearic, arachidonic, ricinoleic, 9,10- dihydroxystearic, 10-chlorostearic, 9,10-dichlorostearic, beta-phenylpropionic, 10-phenylundecanoic, and 9,10- dibenzylstearic.
  • An etching bath as claimed in claim 1 comprising water, nitric acid and sulfo-caprylic acid.
  • An etching bath as claimed in claim 1 comprising water, nitric acid, and sulfo-undecylenic acid.
  • An etching bath as claimed in claim 1 comprising water, nitric acid and sulfo-behenic acid.
  • Method of etching a magnesium photoengraving plate comprising contacting the plate surface with an etching bath comprising:

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • ing And Chemical Polishing (AREA)
  • Printing Plates And Materials Therefor (AREA)
  • Photosensitive Polymer And Photoresist Processing (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
US00183660A 1971-09-24 1971-09-24 Powderless etching bath additive Expired - Lifetime US3730899A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US18366071A 1971-09-24 1971-09-24

Publications (1)

Publication Number Publication Date
US3730899A true US3730899A (en) 1973-05-01

Family

ID=22673780

Family Applications (1)

Application Number Title Priority Date Filing Date
US00183660A Expired - Lifetime US3730899A (en) 1971-09-24 1971-09-24 Powderless etching bath additive

Country Status (9)

Country Link
US (1) US3730899A (fr)
JP (1) JPS4841804A (fr)
BE (1) BE788942A (fr)
CA (1) CA977252A (fr)
DE (1) DE2243790A1 (fr)
FR (1) FR2157795B1 (fr)
GB (1) GB1394688A (fr)
IT (1) IT965334B (fr)
NL (1) NL7211952A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992234A (en) * 1973-11-12 1976-11-16 The Dow Chemical Company Powderless etching method for magnesium printing plates
US4855198A (en) * 1986-08-21 1989-08-08 The Dow Chemical Company Photoengraving articles of zinc-free magnesium-based alloys

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1276669A (fr) * 1960-06-09 1961-11-24 Dow Chemical Co Procédé de gravure et solution de morsure perfectionnés

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992234A (en) * 1973-11-12 1976-11-16 The Dow Chemical Company Powderless etching method for magnesium printing plates
US4855198A (en) * 1986-08-21 1989-08-08 The Dow Chemical Company Photoengraving articles of zinc-free magnesium-based alloys

Also Published As

Publication number Publication date
IT965334B (it) 1974-01-31
BE788942A (fr) 1973-01-15
FR2157795B1 (fr) 1975-06-13
GB1394688A (en) 1975-05-21
AU4567972A (en) 1974-01-24
CA977252A (en) 1975-11-04
DE2243790A1 (de) 1973-03-29
JPS4841804A (fr) 1973-06-19
NL7211952A (fr) 1973-03-27
FR2157795A1 (fr) 1973-06-08

Similar Documents

Publication Publication Date Title
US3668131A (en) Dissolution of metal with acidified hydrogen peroxide solutions
US6126755A (en) Metal surface treatment solutions and process
US3730899A (en) Powderless etching bath additive
US2640765A (en) Etching
US2828194A (en) Etching
US3725158A (en) Multi-component powderless etching bath additive
US2882134A (en) Process for aluminum etching
US3736197A (en) Powderless etching bath compositions and additives
US3728180A (en) Powderless etching bath compositions
US3761331A (en) Bath and method for etching aluminum
US3412032A (en) Etching bath composition
US3725159A (en) Powderless etching bath compositions
US2846295A (en) Etching bath
US3935118A (en) Nitric acid system for etching magnesium plates
US2795491A (en) Process for etching aluminum alloy surfaces
US2846294A (en) Etching bath
US2640767A (en) Etching
US3992234A (en) Powderless etching method for magnesium printing plates
US3152083A (en) Powderless etching bath additive
US2925332A (en) Method of etching printing plates
US4032379A (en) Nitric acid system for etching magnesium plates
US2975039A (en) Chemical composition and process for aluminum etching
US3417022A (en) Etching composition and method
US3922229A (en) Powderless etching bath for magnesium printing plates
US2640763A (en) Etching