US3489794A

US3489794A - Esters of acetylenic dibasic alcohols and lower aliphatic dicarboxylic acids having at least one hydroxyl or amino substituent

Info

Publication number: US3489794A
Application number: US573185A
Authority: US
Inventors: Richard P Cope Jr
Original assignee: Cowles Chemical Co
Current assignee: Cowles Chemical Co
Priority date: 1963-10-30
Filing date: 1966-08-18
Publication date: 1970-01-13
Anticipated expiration: 1987-01-13
Also published as: US3306831A; DE1496767B2; DE1496767A1; NL143281B; NL6614095A

Description

United States Patent US. Cl. 260-482 9 Claims ABSTRACT OF THE DISCLOSURE Esters especially useful as brightening agents in electro plating baths are prepared by reacting (A) a substituted aliphatic carboxylic acid having two to four carbon atoms and at least one substituent selected from the group consisting of hydroxyl and amino groups and (B) an acetylenic dibasic alcohol having not more than eight carbon atoms and a structure in which the hydroxyl groups are attached to the terminal carbon atoms and the acetylenic bond is not associated with the terminal carbon atoms.

This application is a division of application Ser. No. 319,982 filed Oct. 30, 1963, which matured into US. Patent 3,306,831 issued Feb. 28, 1967.

This invention relates, in general, to novel electroplating brightener materials, electrolyte compositions and methods of electroplating. More particularly, this inven tion relates to novel ester products which have utility as additives to nickel, cobalt, nickel-cobalt and copper plating electrolytes.

Bright nickel, cobalt, and nickel-cobalt alloy coatings may be achieved by buflfing dull electrodeposits to a high luster. However, certain organic compounds may be added to standard plating baths to produce bright deposits initially and eliminate the necessity for bufling. Such baths are known as bright plating baths and the additives are known as brighteners. The formulation of bright plating baths is complex and the complexity is compounded by further additions or formulations to make the deposit ductile and to attain a leveling action in the bath in order to cover surface imperfections, all in a wide current density range.

Addition agents are also employed in copper plating electrolytes for grain refinement, brightness, leveling and to improve other properties of the copper deposit. Some addition agents contain sulfur and while they function effectively as brightening agents the codeposition of sulfur tends to make the copper deposits brittle. Other ad ditives are effective grain refining agents at lower temperatures but lose their effectiveness at elevated temperatures.

Accordingly, it is the general object of this invention to provide a new class of materials which may be employed as additives in copper, nickel, cobalt and nickelcobalt alloy electroplating baths.

A more specific object of this invention is to provide electrolytes from which bright, ductile and leveled nickel, cobalt and nickel-cobalt alloy coatings may be electrodeposited easily and consistently.

Another object of this invention is to provide methods for eleetrodepositing bright, ductile and leveled coatings of nickel, cobalt and nickel-cobalt alloys.

Yet another object of this invention is to provide electrolytes and methods for electrodepositing fine grained, lustrous and ductile copper coatings over a wide plating bath temperature range.

It has now been discovered that a novel class of materials may be prepared by the reaction of (A) a hydroxy or amine substituted aliphatic carboxylic acid having from two to four carbon atoms with (B) at least one acetylenic dibasic alcohol having not more than eight carbon atoms. The alcohols have the structural formula:

in which X is selected from the group consisting of:

Examples of suitable acids include glycine and betaalanine and lactic, alpha-hydroxy propionic, beta-hydroxy propionic, alpha-hydroxy-gamma-amino butyric, malic, glycolic, tartaric, beta-hydroxy butyric and aspartic acids.

Acetylenic dibasic alcohols having not more than eight carbon atoms and a structure in which the hydroxyl groups are attached to the terminal carbon atoms and the acetylenic bond is not associated with the terminal carbon atoms may be employed. Examples of suitable alcohols include butynediol, octadiynediol, 3-methy1- pentynediol-2, hexadiyne-2,4-diol-1,6-hexa-3 yne-1,6-diol and pentyne-l,5-diol.

The reaction is conducted in an aromatic hydrocarbon liquid. The charge of acid and alcohol is refluxed in a vessel equipped with a water trap. After the reaction is completed, i.e., when the theoretical water of condensation has been accumulated in the trap, the aromatic hydrocarbon in the reacted charge is removed by vacuum evaporation. The residue is diluted with water and carbon treated to remove traces of the aromatic hydrocarbon and other impurities. This reaction product, without further purification, may be added to electroplating baths as a brightening agent. It is believed that the reaction product is essentially or primarily the ester of the described hydroxy and/or amino substituted acids and the described acetylenic alcohols. It is also believed that these esters are eflicacious brighteners as described hereinbelow. Side reactions apparently take place and, as noted, the reaction product itself may be employed to avoid the cost of purification.

The following examples will specifically illustrate the reaction product brighteners, electrolytes and plating methods in accordance with this invention but should not be considered as limitations on the scope of the invention.

EXAMPLE I About 0.1 mole of glycine and 0.1 mole of butynediol are intimately mixed and placed in a 500 ml. flask. The mixture is covered with 300 ml. of dry toluene. The flask is fitted with a water trap and a reflux condenser. The reaction mixture is refluxed for 40 hours. During this time, about 0.1 mole of water is collected in the water trap. The toluene is decanted from the brown residue in the flask. The residual toluene is then removed by vacuum stripping. The residue in the flask is dispersed in water and filtered to remove the insoluble polymeric material. The resultant brown musty smelling liquid is employed as an additive to electroplating baths or electrolytes as outlined in the examples hereinbelow.

3 EXAMPLE II About 1 mole of threonine and 1 mole of octadiynediol are reacted in the manner outlined in Example I, hereinabove. The resulting tan solution is employed as an additive in the examples outlined hereinbelow.

EXAMPLE III About 0.15 mole of alanine is ground together with 0.1 mole of sublimed butynediol. The mixture is placed in a 500 ml. flask and covered with 300 ml. of dry benzene. The reaction mixture is distilled until about 0.1 mole of water is collected in the Water trap. The benzene is removed by distillation under reduced pressure. The resulting brown solid is dispersed in water, carbon treated and filtered. The product is a brown solution and is employed as an additive to electroplating baths in the examples hereinbelow.

EXAMPLE IV About 1.5 mole of lbeta-aminobutyric acid and 1 mole of butynediol are reacted in toluene until 1.3 mole of water is collected in the water trap. The toluene is decanted and stripped from the solid by vacuum distillation. The residue is dispersed in water. The solution is filtered and the filtered solution is employed as an additive in the examples below.

EXAMPLE V About 0.8 mole of beta-aminopropionic acid and 1 mole of butynediol are reacted in xylene by refluxing the charge for about 60 hours. In this time, about 0.85 mole of water is collected in the trap. The xylene is decanted. The residual xylene is vacuum stripped and the residue is dispersed in water. The solution is filtered and the filtered solution is employed as an additive in the examples below.

EXAMPLE VI baths as illustrated by the following specific examples:

' EXAMPLE v11 NiSO .6H O oz./gal 40.0 NiCl .6H O oz./gal.. 6.5 H BO oz./gal 5.0

Reaction product of glycine and butynediol, based on 100% solids oz./gal 0.002 Temperature C 150 pH 3.4

A S-ampere Hull Cell panel is plated for 5 minutes from this bath. The nickel electrodeposit is hazy-bright, leveled and fairly ductile.

EXAMPLE VIII A 3-ampere Hull Cell panel is plated from this .bath. The panel is bright and leveled in the current density range of 10 to 140 amps/sq. ft. Moreover, the electrodeposit was highly ductile.

EXAMPLE IX NiCl .6H O oz./gal 30.0 H BO oz./gal 5.5 Disodium salt of 2,5-benzenedisulfonic acid oz./gal 3.0 Saccharin oz./gal 0.1 Reaction product of threonine and octadiynediol, based on solids oz./gal 0.0015 Temperature F 150 pH 3.8

The deposit of nickel from this bath will be full-bright in the range of 5 to 300 amps/sq. ft. The deposit will be ductile and have a fair degree of leveling.

EXAMPLE X CoSO 7H O oz./gal 65 NaCl oz./gal 2 H 30 oz./gal 6 Reaction product of malic acid and octadiynediol,

based on 100% solids oz./gal 0.03 Temperature F pH 3.8

A leveled and fairly ductile deposit is obtained. The deposit will be bright in the current density range from 10 to 200 amps. sq./ft.

EXAMPLE XI NiSO -6H O oz./gal 32 NiCl 6H O oz./gal 4 CoSO -7H O oz./gal 0.4 H BO oz./gal 4 (NH SO oz./gal 0.1 Sodium salt of 2,7-naphthalenedisulfonic acid oz./ gaL 2.0 Reaction product of alanine and butynediol, based on 100% solids oz./gal 0.2 Temperature F 140 pH 3.8

The nickel-cobalt alloy electrodeposit on a 3-ampere Hull Cell panel is full-bright and leveled.

EXAMPLE XII NiSO 61-1 0 oz. /gal 40.0 NiCl 6H O oz./gal 6.0 H BO oz./gal 5.0 Trisodium-1,3,6-naphthalenetrisulfonic acid oz./gal 3.0 Saccharin oz./gal 0.15 Reaction product of glycine and butynediol, based on 100% solids oz./gal 0.015 Temperature "F pH 3 .55

The deposit from this bath is mirror-bright and highly leveled over a current density range of 10 to 350 amps./ sq. ft. Moreover, the deposit is ductile.

The concentration of the described class of reaction products should range from about 0.001 to 0.02 ounce per gallon when employed in nickel, cobalt or nickelcobalt alloy plating electrolytes. The foregoing concentration range should be employed both with and without additional additives. Additional additives, known in the art ar d to be described hereinafter may be employed to further improve other properties of the deposit. A concentration below about 0.001 ounce per gallon will not produce a significant improvement in brightness while concentrations above about 0.02 ounce per gallon, especially in the absence of other additives such as saccharin and the sodium styrene sulfonate to be described herein below, may produce deposits with evidence of stress cracking. The optimum concentration range is from about 0.004 to 0.01 ounce per gallon.

It has also been discovered that sodium styrene sulfonate is effective in brightening the deposits of nickel, cobalt and nickel-cobalt alloys from their respective electrolytes. A full-bright leveled but somewhat brittle electrodeposit is produced in standard baths with no other additives. Other additives, as for example saccharin, may be employed in combination with the sodium styrene sulfonate to further improve the properties of the deposit. Saccharin, for example, will further improve the leveling power of the bath.

The combination of sodium styrene sulfonate and the heretofore described reaction product additives produce especially desirable and surprisingly attractive electrodeposits of nickel, cobalt and nickel-cobalt alloys. A mirror-bright, ductile, leveled deposit with a surprising depth of color will be produced by electrolytes employing this combination of additives. The concentration of sodium styrene sulfonate, both with and without additional additives should range from about 0.005 to 1.0 ounce per gallon, the optimum range being from about 0.01 to 0.75 Ounce per gallon.

For example, nickel may be plated in accordance with the following specific illustrations.

EXAMPLE XIII NiSO 6H O oz./gal 40.0 NiCl 6H O oz./gal 6.5 H BO oz./gal 5.0 Saccharin oz./gal 0.134 Sodium styrene sulfonate oz./gal 0.5 Temperature F 150 pH 3.8

A 3-ampere Hull Cell panel is plated in this bath for five minutes. A full-bright, leveled but somewhat brittle electrodeposit is produced.

EXAMPLE XIV NiSO -6H O oz./gal 40.0 NiCl 6H O oz./gal 6.5 H BO oz./gal 5.0 Saccharin oz./gal 0.134 Reaction product of glycine and butynediol, based on 100% solids of./gal 0.004 Sodium styrene sulfonate oz./gal 0.01 Temperature F 150 pH 3.8

A 3-ampere Hull Cell panel is plated in this bath for five minutes. The panel is mirror-bright, highly leveled and ductile. The bath has excellent throwing power.

I have also discovered that the reaction product of glycine and butynediol is an effective grain refining agent in copper electrolytes. In copper plating baths, the concentration of the glycine-butynediol reaction product should range from about 0.002 to 0.07 ounce per gallon and preferably from about 0.004 to 0.05 ounce per gallon. This additive is an effective grain refining agent at elevated temperatures, e.g. at 140 E, where some other additives lose their efiicacy.

For example, copper may be plated in accordance with the following specific illustration.

EXAMPLE XV A 3-ampere Hull Cell panel is plated from the above bath. The panel is ductile, finely grained and semi-bright. The bath has excellent throwing power.

While there have been shown and described what are presently considered to be the preferred embodiments of the invention, modifications thereto will readily occur to those skilled in the art. It is not desired, therefore, that the invention be limited to the specific arrangements shown and described and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

I claim as my invention:

1. An ester of (A) an alkanoic acid having from 2 to 4 carbon atoms and at least one substituent selected from the group consisting of hydroxyl and amino groups and (B) an acetylenic dibasic alcohol having not more than 8 carbon atoms and a structure in which the hydroxyl groups are attached to the terminal carbon atoms and the acetylenic bond is not associated with the terminal carbon atoms.

2. An ester as claimed in claim 1 which is water soluble and in which (A) is an alkanoic acid having from 2 to 4 carbon atoms and at least one substituent selected from the group consisting of hydroxyl and amino groups and (B) is an acetylenic dibasic alcohol containing not more than 8 carbon atoms and having the formula:

HOCH X-CH OH in which X is selected from the group consisting of 3. An ester as claimed in claim 1 in which (A) glycine and (B) is butynediol.

4. An ester as claimed in claim 1 in which (A) potassium acid tartrate and (B) is butynediol.

5. An ester as claimed in claim 1 in which (A) threonine and (B) is octadiynediol.

6. An ester as claimed in claim 1 in which (A) alanine and (B) is butynediol.

7. An ester as claimed in claim 1 in which (A) malic acid and (B) is octadiynediol.

'8. An ester as claimed in claim 1 in which (A) beta-aminobutyric acid and (B) is butynediol.

9. An ester as claimed in claim 1 in which (A) i beta-aminopropionic acid and (B) is butynediol.

References Cited UNITED STATES PATENTS 2,164,188 6/1939 Groll et al 260--484 XR 2,520,750 8/ 1950 Wilkinson 260488 2,809,988 10/1957 Heininger 260 484 XR 2,901,516 8/1959 Wynn 260-488 XR 3,041,256 6/1962 Kleiner et al. 20449 XR 3,107,222 10/1963 Riggs 252389 3,226,426 12/1965 Hopkins et al. 260482 3,306,831 2/1967 Cope 204-43 OTHER REFERENCES Kampschulte et al., Chem. Ab. vol. 53: 21,292f (1959). Hanson-Van Winkle-Munning Co., Chem. Ab. vol. 55: 24,331('b) (1961).

LORRAINE A. WEINBERGER, Primary Examiner ALBERT P. HALLUIN, Assistant Examiner US. Cl. X.R. 260484