CA1045075A - Bright tin-nickel alloy plating electrolyte - Google Patents
Bright tin-nickel alloy plating electrolyteInfo
- Publication number
- CA1045075A CA1045075A CA197,770A CA197770A CA1045075A CA 1045075 A CA1045075 A CA 1045075A CA 197770 A CA197770 A CA 197770A CA 1045075 A CA1045075 A CA 1045075A
- Authority
- CA
- Canada
- Prior art keywords
- group
- nickel
- salt
- plating liquid
- nickel alloy
- 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.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/56—Electroplating: Baths therefor from solutions of alloys
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/56—Electroplating: Baths therefor from solutions of alloys
- C25D3/60—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of tin
Abstract
BRIGHT TIN-NICKEL ALLOY PLATING ELECTROLYTE
ABSTRACT OF THE DISCLOSURE
A bright tin-nickel alloy plating electrolyte consists essentially of an aqueous main plating liquid containing a stannous salt, a nickel salt and an alkali-metal pyrophosphate, with a brightener additive in such main plating liquid which is a compound having a plurality of amino groups as its only functional groups, for example, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, pentamethylenediamine, hexamethylenediame, hydrazine, quanidine, urea or thiourea. The bright tin-nickel alloy plating electrolyte may further contain ammonia or an ammonium salt, and the electrolyte, with or without the addition of the ammonia or ammonium salt,may further have added thereto a compound containing an -SX group (in which X represents hydrogen, sodium or potassium), a peptone and/or protein, or a neutral amino acid which is free of sulphur or a salt thereof.
ABSTRACT OF THE DISCLOSURE
A bright tin-nickel alloy plating electrolyte consists essentially of an aqueous main plating liquid containing a stannous salt, a nickel salt and an alkali-metal pyrophosphate, with a brightener additive in such main plating liquid which is a compound having a plurality of amino groups as its only functional groups, for example, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, pentamethylenediamine, hexamethylenediame, hydrazine, quanidine, urea or thiourea. The bright tin-nickel alloy plating electrolyte may further contain ammonia or an ammonium salt, and the electrolyte, with or without the addition of the ammonia or ammonium salt,may further have added thereto a compound containing an -SX group (in which X represents hydrogen, sodium or potassium), a peptone and/or protein, or a neutral amino acid which is free of sulphur or a salt thereof.
Description
1~S~75 S0526 BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates generally to a bright tin-nickel plating electrolyte, ancl moxe particularly to an aqueous pyrophosphate electroplating bath for obtaining a bright tin-nickel alloy plating.
Description of the Prior Art An acid fluoride bath is generally used for achieving a tin-nickel alloy plating, but an electroplated layer formed from such bath is very brittle and is apt to crack when a stress is exerted thereon, for example, due to flexing o~ the plating substrate. Further, a tin-nickel alloy acid bath including a fluoride is disadvantageous in that it requires difficult and expensive treatment of exhaust fumes and of the aqueous bath prior to discharge thereof into the atmosphere and adjacent sewer or waterway~ respectively, for avoiding pollution oE the environment.
It is also known to provide a tin-nickel alloy plating electrolyte which has, as its main component, an aqueous plating liquid containing a stannous salt, a nickel salt and an alkali-metal pyrophosphate, with the addition thereto, as a brightening agent, of ammonium citrate and/or gelating, an a-amino acid such as glycine, or an ~amino acld and a mercaptan derivative. However, such aqueous pyrophosphate bath, even when containing one or more of the mentioned brightening agents, is incapable o~ producing a tin-nickel alloy plating of high brightness.
Field of the Invention The present invention relates generally to a bright tin-nickel plating electrolyte, ancl moxe particularly to an aqueous pyrophosphate electroplating bath for obtaining a bright tin-nickel alloy plating.
Description of the Prior Art An acid fluoride bath is generally used for achieving a tin-nickel alloy plating, but an electroplated layer formed from such bath is very brittle and is apt to crack when a stress is exerted thereon, for example, due to flexing o~ the plating substrate. Further, a tin-nickel alloy acid bath including a fluoride is disadvantageous in that it requires difficult and expensive treatment of exhaust fumes and of the aqueous bath prior to discharge thereof into the atmosphere and adjacent sewer or waterway~ respectively, for avoiding pollution oE the environment.
It is also known to provide a tin-nickel alloy plating electrolyte which has, as its main component, an aqueous plating liquid containing a stannous salt, a nickel salt and an alkali-metal pyrophosphate, with the addition thereto, as a brightening agent, of ammonium citrate and/or gelating, an a-amino acid such as glycine, or an ~amino acld and a mercaptan derivative. However, such aqueous pyrophosphate bath, even when containing one or more of the mentioned brightening agents, is incapable o~ producing a tin-nickel alloy plating of high brightness.
-2 lr~s~75 SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a bright tin-nickel alloy plating electrolyte which is capable of producing a plating layex of improved toughness, 1exi-bility and brightness.
Another object is to provide a bright tin-nickel alloy plating electrolyte, as aforesaid, which is free of any fluorides so as to minimize the ecological problems resulting from its use.
A further object is to provide a bright tin-nickel alloy plating electrolyte having, as its main component, an aqueous plating liquid containing stannous a-~ liquid salts and an alkali-metal pyrophosphate, with a ~rightener additive which results in a plating layer of extremely high brightness.
The present invention is based on the discovery that the brightness of the plating layer formed from a tin-nickel alloy plating electrolyte having, as its main component, an aqueous pLating liquid containing stannous and nickel salts and an alkali-metal pyrophosphate, can be greatly enhanced by adding to such main plating liquid, as a brightener additive, at least one compound containing a plurality of amino groups as its only functional groups.
The bright tin-nickel alloy plating electrolyte according to this invention, as aforesaid, may further have ammonia or an ammonium salt advantageously added to its main plating liquid in addition to the previously mentioned essential compound containing a plurality of amino groups as i~s only functional groups. The electrolyte according to this invention, wi~ or without the addition .
~ 4 ~ 7 S
of ammonia or ammonium salts thereto, may further advantageou31y contain a compound having an -SX group, in which X represents hydrogen, sodium or potassium, peptone and/or a protein, or a neutral amino acid without sulphur or a sal.t of such neutral amino acid.
In the bright tin-nickel alloy plating electrolyte according to the inventi on, the stannous salt may be present in the main plating liquid in an amount between 2 and 20 g/l., calcu-lated as stannous ion; the nickel salt may be present in the main plating liquid in an amount between 5 and 30 g/l., calculated as nickel ion, and the alkali-metal pyrophosphate may be present in the main plating liquid in an amount between 150 and 600 g/l. The alkali-metal pyrophosphate o~ the main plating liquid may be, for example, potassium pyrophosphate or sodium pyrophosphate, while the stannous and nickel salts o such main plating liquid may be respectively stannous pyrophosphake, stannous chloride, stannous sulfate or the like, and nickel pyrophosphate, nickel chloride, nickel sulfate or the like.
The brightener additive which is essentially added to the main plating liquid and which, in accordance with this invention, contains a plurality of ami-no groups as its only functional groups may be advantageously selected from the group consisting of ethylene-diamine, 1,2-propanediamine, 1,3-propanediamine, 194-butanediamine, pentamethylenediamine, hexamethylenediamine, hydrazine, guanidine, urea and thiourea. The amount of such brightener additive introduced into the main plating liquid is preferably between 0.1 and 100 g/L.
of the main plating liquid.
.
.
: ' :
~ ~ 5~ 7 S
In the case where ammonia is added to the plating electrolyte, it may be in the form of 28% aqueous ammonia in the amount between 5 and lOO g/l. of the main plating liquid. When ammonium salt is added, such addition may be ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium citra~e, a~monium tartrate, ammonium acetate or the like, and is present in an amount between 1.0 and 150 g/l. of the main plating liquid.
The compound having an -SX group which may be optionally added to the bright tin-nickel alloy plating electrolyte according to this inventlon may be advantageously selected from among dithioammelide, 4-amino-3,5-dimercapto-4,1,2-~riazol, ethylene thiuram monosul~ide, 2,5-dimercapto-1,3,4-thiazol, thiocarbohydrazide, hydrazoldithiodicarvoneamide, ethylene-bis-dithiocarbomic acid soda and the like, and is added in an amount between 0.01 and 5 g/l. of the main plating liquid.
When peptone and/or protein is added to the electrolyte, the amount thereof is between 0.1 and 10 gll. of the main plating liquid. The protein thus added may be, for example, glue, gelatine or gluten. The peptone and/or protein is preferably dissolved in water, in an aqueous solution of potassium pyrophosphate or in an alcohol, such as, methanol or ethanol, before being added to the main plating liquid of the electrolyte.
When a neutral amino acid without sulphur is added to the electrolyte according to this invention, such additive may be advantageously selected from glycine, alanine, serine,Q~in~b~Tyri~
acid, leucine, isoleucine, proline, hydroxyproline, phenyl-alinine, thyroxine, triptophan and the like, and is added in an amount ~5~7S
greater than a. Ql mol~l. of the main plating li~Uid. -i T~e pH of the plat~ng electrolyte i~ adjusted to within t~e range of 8 to 12 with aqueous ammon~a solution, ^-caustic potash, pyrophosphoric acid and the like.
In its broadest aspect, the invention provides a bright tin-nickel alloy plating electrolyte having a pH in the range from 8 to 12 and consisting essentially of an aqueous main plating liquid containing:
a. a stannous salt selected from the group consisting of stannous pyrophosphate, stannous chloride and stannous sulfate, and which is present in said main plating liquid in an amount between 2 and 20 g/l. calcula~ed as stannous ion;
b. a nickel salt selected from the group consisting of nickel pyrophosphate, nickel chloride and nickel suIfate, -and which lS present in said maln plating liquid in an amount b~tween 5 and 30 g/l. calculated as nickel ion;
c. an alkali-metal pyrophosphate selected from the group consisting of potassium pyrophosphate and sodium pyrophosphate, and which is present in said main plating liquid in an amount between 150 and 600 g/l;
d. at least one brightener additive in said plating liquid in an amount between 0.1 and 100 g/l of said main plating liquid and being selected from the group consisting of ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, pentamethylenediamine, hexamethylenediamine, hydrazine, guanidine, urea and,thiourea; and ;
., ,. , :..... ~.
e. at least one further additive selected from the group consisting o~ a compound hav~ng at least one-SX group -`~
(where X represents hydrogen, sod~um or potassium~, peptone, -derived protein, neutral amino acid free of sulfur and neutral amino acid salt free of sulfur; the said compound . ' ;
.. , .; , .. .. ,,, , , . . .. ~, ., ... , . , ., ., , : .
slr375 having at least one -SX group is present in said main plating liquid in an amount between 0.01 and g 5/1, the said peptone and derived protein is present in an amount between 0.1 and 10 g/l, and the said neutral amino acid and salt of thereof is present in an amount greater than 0.01 mol/1.
The invention is further described with reference to the following specific examples thereof:
Example 1 An aqueous main plating liquid is provided contain-ing 200 g/l. of potassium pyrophosphate, 30 g/1. o~ stannous pyrophosphate and 50 g/1. of nickel pyrophosphate. Such main plating liquld has added thereto 15 g/l. of ethylenediamine, which is added as an 85% aqueous solution of the latter, and the pH of the resulting plating electrolyte is adjusted to a value of 9.5. The plating electrolyte is then subjected to mechani-cal agitation at 30C with a carbon anode and a brass plate plated with a bright nickel layer as a cathode. A current with an average cathode current density of 0.5 A/dm2 is made to flow for three minutes to carry out electrolytic plating. As a result, a bright tin-nickel alloy (containing 67.2% tin) with a bright stainless color is obtained.
Examples 2, 3 and 4 The procedures described above in Example 1 are repeated but with the further addition to the main plating liquid of ammonium chloride (Examples 2 and 4) or aqueous am-monia (Example 3) and with the substitution of nickel chloride for the nickel pyrophosphate (Examples 3 and 4), and the results thereof are as shown on Table 1 below. , 'i; '~
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-6a -5~7~
TABLE l Examples :L 2 3 4 . . .
Potassium pyrophosphate g/l. 200 200 200 200 Stannous pyrophosphate g/l. 30 30 30 30 Nickel pvrophosphate g/l. 50 50 - . .. ... ... ... . -Nickel chloride _ g/l. 40 40 ~;
Ethylenediamine of æ5% g/l. 15 15 25 25 Ammonium chloride /l. 20 50 - -A ueous ammonia of 28% cc/l 20 q ... _ ._ .
~H 9.5 9.5 9.5 9 5 , .
Temperature C 30 30 30 30 ._ . .. . _ _ . ' '.' :.
A~itation Yes Yes No No -_._ ~ ., .
Current denslty _ _ A/dm20.5 0.5 0.5 0.5 Anode __ _ Carbon Carbon Carbo_ Carbon ~`
Amount of tin contained in deposited alloy __ _ % 67.2 62.1 66.3 67.1 . ,;.
Appearance Bright Bright Bright Bright stain- stain- stain- stain- ;
less less less less :
color colox color color tOmilar __ _ white _ ;
The procedure of Examples l, 2, 3 and 4 are repeated, but using, in turn,hydrazine, 1,2-propanediamine, 1,3-propane- -diamine, 1,4-butanediamine, guanidine, urea, thiourea, pen-tamethylenediamine and hexamethylenediame, in place of the ethylene diamine, and, in each case, a bright tin-nickel alloy plating similar in appearance to the platings obtained in Examples 1, 2, 3 and 4 on Table 1 is obtained.
-5~75 Examples 5, 6, 7,8 and 9 The procedures described ln Example 1 are repeated, but with nickel chloride replacing the nickel pyr~phosphate (Examples 7, 8 and 9), and with the further addition of a com-pound having an -SX group, to wit, 2,5-dimercapto-1,3,4-thiazol (Examples 5, 6 and 9), dithioammelide (Examples 7 and 9) and hydrazodithiodicarvoneamide (Example 8), and the propor-tions and results of such additives are as shown on Table 2 below.
Examples ~_5 6 7 8 9 Potassium ;' pyrophosphate g/l. 20C 200 200 200 200 Stannous pyrophosphate g/l. 3C 30 30 30 30 Nickel pyrophosphate g/l. 5C 50 Nickel ;
chloride g/l. ___ 40 40 40 ' Ethylenediamine .
of 85% g/l. 0.8 0.8 0.8 0.8 1 ' 2,5-dimercapto-1,3,4-thiazol g/l. 0.5 0.5 0.5 Dithioammelide g/l. 1 0.5 _ Hydrazodithiodi-carvoneamide g/l. 1 -' _ _ , pH 9.5 9.5 9.5 9.5 9.5 ~-;
Temperature C 35 35 35 35 35 Agitation Yes Yes Yes Yes Yes Current density 2 ~,~
A/dm 0.5 0.2 0.5 0.5 0.5 :~
Amount of tin contained ir. deposited alloy % 72.1 71.5 73.1 70.1 70.3 ~ppearance Bright' Bri~ht Bri~ht Bri~ht Bri~ht stain- staln- staln- staln- staln-less less less less less ~' cQlor color color color color wl-th wlth wlth wlth wlth _ _____ _ black black black black black .": ' ~ 507S
: Examples 10,11~12,13 and 14 ~ :
The procedures of Examp~e 1 are repeated, but with j the further addition of a compound having an -SX group, to wit, 2,5-dimercapto-1,3,4-thiazol (Examples 10,12,13 and 14) and/or ,~ -- dithioammelide (Examples 11,13 and 14) and of either ammonium chloride ~Examples 10,11 and 14) or aqueous ammonia (Examples 12 and 13), and the proportions and results of such further additives '~ , , !~ ~-are as shown on Table 3 below.
Examples ~1 1 1 2 1 3 14 Potassium Pyrophosphate Vtl 200 200 7 200 200 200 r ~ ~ _ Stannous pyrophosphate ~Jl. 30 30 30 30 _ 30 .~
ickel PYrophosphate _ ~/l. 50 50 50 ¦ :
; Nickel chloride~/1. 40 40 __ Ethylenediamine of . ~:
85% . ~/1. 0.8 0.8 0.8 _ 0.8 0.8 , ------ 2,5-dimercapto- .
1,3,4-thiazol gL~ 0.5 . _0.5 0.5 Dithioammelide~/1. 0.5 0.5 0,5 Ammonium chloride ~L~ 50 5 Q
Aqueous ammonia of 28% cc/l. 30 30 - ~ :
.9.5 9.5 9.5 9.5 9.5 Temperature C 35 35 35 35 35 A~itation Yes . Yes Yes Yes Yes ~' - - , . . _._ . _ ~ '"
Current density A/dm2 0.5 0.. 5 _ 0.5 0 5 0.5 ~ -Amount of tin contained .
in deposited alloy % 1 67.8 64 264.8 63.5 65 4 Bright Bright Bright Bright Bright ~:
Appearance stainless stain- ~stain- stain- stain- ~, color less less less less color color color color t - ~ _ _ . ''` ~ '~
_9 ~ :
~',' .
,~
1.
l~S~75 Examples 15, 16 and 17 The procedures of Example 1 are repeated, but with the further addition of peptone (Examples 15 and 17) or pro-tein in the form of glue (Example 16) and also of ammonium chloride (Example 17) and the proportions and results of such additives are as shown on Table 4 below.
. . . _ Examples . . .
.. :~
Potassium pyrophosphate g/l. 200 200 200 _._ , _ .
Stannous pyrophosphate g/l. 30 30 30 ._ _ __ _ Nickel pyrophosphate g/l. 50 50 ._ . ~ .. . :,, Nickel chloride g/l. 40 ~-~ . . . .
Ethylenediamine of 85%g/l. 0.5 0.5 15 - ;:.
Peptone g/l. 1 1 `
Glue g/l. 1 Ammonium chloride g/l. 20 __ ..................................................... :~'~
pH 9.5 9.5 9.5 _ -- ---- _ .", Temperature C 35 35 35 ' . ._ .__ . _ . _ __~
Agitation Yes Yes _ _ Yes _ __ Current density A/dm 0.3 0.3 0.3 `
.. _ . _ . .. __ :~.~,;, .
Amount of tin contained in deposited alloy % 68.2 67.3 65.4 , Appearance Bright Bright Bright stainless stainless stainless ' color color color `
with with black black ..... _ _~
~4S~5 ``
Examples 18 and 19 -The procedures of Example 1 are repeated, but with the further addition of a neutral amino acid free of sulphur or a salt thereof, to wit, sodium glycine (Example 18) or ~
alanine (Example 19), and also of aqueous ammonia (Example 19), ;
and the proportions and results of such further additions are as shown on Table 5 below.
Examples Reference Potassiumpyrophosphate g/l. 200 200 200 Stannous pyrophosphate g/l. 30 30 30 Nickel pyrophosphate g/l.50 50 50 Ethylenediamine of 85% g/l. 0.8 _ 0.8 Sodium glycine g/l. 7 7 Alanine g/l. ~ 8 ;.
Aqueous ammonia of 2~% cc/l.; 30 pH 9.5 9.5 9.5 Temperature C _35 ~ 35 35 Agitation Yes Yes Yes 2 _ Current density A/dm0.5 0.5 0.5 .
Anode carbon carbon carbon Amount of tin contained in deposited alloy % 67.4 ~68.2 84.2 Appearance Briyht Bright Grey stainless stainless with ;
color color bright _ ness ... . . . .
7~
Reference 1 In ord~r to demonstrate the essential character of the additive compound having a plurality of amino groups as its only func~ional groups, the procedure of Example 18 was repeated, but with the ethylenediamine being omitted from the plating electrolyte and, as shown on Table 5 above, the resulting pla~ing layer was grey in color and devoid of brightness.
Thus, it will be apparent that, by the addition to the main plating liquid, containing stannous salt, nickel salt and an alkali-metal pyrophosphate~ of a compound having a plurality ~
amino groups as i~s only ~unctional groups, the present invention produces a bright tin-nickel alloy plating layer with a brightness that cannot be obtained with prior plating electrolytes Further, it will be apparent that the brightness of the tin-nickel alloy plating layer is urther enhanced by also adding to the electrolyte a compound having an -SX group (in which X represents hydrogen, sodium or potassium), peptone and/or protein, or a neutral amino acid free of sulphur.
Finally, the further addition of ammonia or ammonium salt to the plating electrolyte according to this invention is shown to provide the bright plating layer with white color.
Al~hough specific examples of the invention have been described in detail herein, it is to be understood that the invention is not limited to those precise examples which are intended to be illustrative, and that a person skilled in the art may effect various changes and variations or modifications in the given examples without departing frnm the scope or spirit of the inven~on as defined in the appended claims.
~12-
Accordingly, it is an object of this invention to provide a bright tin-nickel alloy plating electrolyte which is capable of producing a plating layex of improved toughness, 1exi-bility and brightness.
Another object is to provide a bright tin-nickel alloy plating electrolyte, as aforesaid, which is free of any fluorides so as to minimize the ecological problems resulting from its use.
A further object is to provide a bright tin-nickel alloy plating electrolyte having, as its main component, an aqueous plating liquid containing stannous a-~ liquid salts and an alkali-metal pyrophosphate, with a ~rightener additive which results in a plating layer of extremely high brightness.
The present invention is based on the discovery that the brightness of the plating layer formed from a tin-nickel alloy plating electrolyte having, as its main component, an aqueous pLating liquid containing stannous and nickel salts and an alkali-metal pyrophosphate, can be greatly enhanced by adding to such main plating liquid, as a brightener additive, at least one compound containing a plurality of amino groups as its only functional groups.
The bright tin-nickel alloy plating electrolyte according to this invention, as aforesaid, may further have ammonia or an ammonium salt advantageously added to its main plating liquid in addition to the previously mentioned essential compound containing a plurality of amino groups as i~s only functional groups. The electrolyte according to this invention, wi~ or without the addition .
~ 4 ~ 7 S
of ammonia or ammonium salts thereto, may further advantageou31y contain a compound having an -SX group, in which X represents hydrogen, sodium or potassium, peptone and/or a protein, or a neutral amino acid without sulphur or a sal.t of such neutral amino acid.
In the bright tin-nickel alloy plating electrolyte according to the inventi on, the stannous salt may be present in the main plating liquid in an amount between 2 and 20 g/l., calcu-lated as stannous ion; the nickel salt may be present in the main plating liquid in an amount between 5 and 30 g/l., calculated as nickel ion, and the alkali-metal pyrophosphate may be present in the main plating liquid in an amount between 150 and 600 g/l. The alkali-metal pyrophosphate o~ the main plating liquid may be, for example, potassium pyrophosphate or sodium pyrophosphate, while the stannous and nickel salts o such main plating liquid may be respectively stannous pyrophosphake, stannous chloride, stannous sulfate or the like, and nickel pyrophosphate, nickel chloride, nickel sulfate or the like.
The brightener additive which is essentially added to the main plating liquid and which, in accordance with this invention, contains a plurality of ami-no groups as its only functional groups may be advantageously selected from the group consisting of ethylene-diamine, 1,2-propanediamine, 1,3-propanediamine, 194-butanediamine, pentamethylenediamine, hexamethylenediamine, hydrazine, guanidine, urea and thiourea. The amount of such brightener additive introduced into the main plating liquid is preferably between 0.1 and 100 g/L.
of the main plating liquid.
.
.
: ' :
~ ~ 5~ 7 S
In the case where ammonia is added to the plating electrolyte, it may be in the form of 28% aqueous ammonia in the amount between 5 and lOO g/l. of the main plating liquid. When ammonium salt is added, such addition may be ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium citra~e, a~monium tartrate, ammonium acetate or the like, and is present in an amount between 1.0 and 150 g/l. of the main plating liquid.
The compound having an -SX group which may be optionally added to the bright tin-nickel alloy plating electrolyte according to this inventlon may be advantageously selected from among dithioammelide, 4-amino-3,5-dimercapto-4,1,2-~riazol, ethylene thiuram monosul~ide, 2,5-dimercapto-1,3,4-thiazol, thiocarbohydrazide, hydrazoldithiodicarvoneamide, ethylene-bis-dithiocarbomic acid soda and the like, and is added in an amount between 0.01 and 5 g/l. of the main plating liquid.
When peptone and/or protein is added to the electrolyte, the amount thereof is between 0.1 and 10 gll. of the main plating liquid. The protein thus added may be, for example, glue, gelatine or gluten. The peptone and/or protein is preferably dissolved in water, in an aqueous solution of potassium pyrophosphate or in an alcohol, such as, methanol or ethanol, before being added to the main plating liquid of the electrolyte.
When a neutral amino acid without sulphur is added to the electrolyte according to this invention, such additive may be advantageously selected from glycine, alanine, serine,Q~in~b~Tyri~
acid, leucine, isoleucine, proline, hydroxyproline, phenyl-alinine, thyroxine, triptophan and the like, and is added in an amount ~5~7S
greater than a. Ql mol~l. of the main plating li~Uid. -i T~e pH of the plat~ng electrolyte i~ adjusted to within t~e range of 8 to 12 with aqueous ammon~a solution, ^-caustic potash, pyrophosphoric acid and the like.
In its broadest aspect, the invention provides a bright tin-nickel alloy plating electrolyte having a pH in the range from 8 to 12 and consisting essentially of an aqueous main plating liquid containing:
a. a stannous salt selected from the group consisting of stannous pyrophosphate, stannous chloride and stannous sulfate, and which is present in said main plating liquid in an amount between 2 and 20 g/l. calcula~ed as stannous ion;
b. a nickel salt selected from the group consisting of nickel pyrophosphate, nickel chloride and nickel suIfate, -and which lS present in said maln plating liquid in an amount b~tween 5 and 30 g/l. calculated as nickel ion;
c. an alkali-metal pyrophosphate selected from the group consisting of potassium pyrophosphate and sodium pyrophosphate, and which is present in said main plating liquid in an amount between 150 and 600 g/l;
d. at least one brightener additive in said plating liquid in an amount between 0.1 and 100 g/l of said main plating liquid and being selected from the group consisting of ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, pentamethylenediamine, hexamethylenediamine, hydrazine, guanidine, urea and,thiourea; and ;
., ,. , :..... ~.
e. at least one further additive selected from the group consisting o~ a compound hav~ng at least one-SX group -`~
(where X represents hydrogen, sod~um or potassium~, peptone, -derived protein, neutral amino acid free of sulfur and neutral amino acid salt free of sulfur; the said compound . ' ;
.. , .; , .. .. ,,, , , . . .. ~, ., ... , . , ., ., , : .
slr375 having at least one -SX group is present in said main plating liquid in an amount between 0.01 and g 5/1, the said peptone and derived protein is present in an amount between 0.1 and 10 g/l, and the said neutral amino acid and salt of thereof is present in an amount greater than 0.01 mol/1.
The invention is further described with reference to the following specific examples thereof:
Example 1 An aqueous main plating liquid is provided contain-ing 200 g/l. of potassium pyrophosphate, 30 g/1. o~ stannous pyrophosphate and 50 g/1. of nickel pyrophosphate. Such main plating liquld has added thereto 15 g/l. of ethylenediamine, which is added as an 85% aqueous solution of the latter, and the pH of the resulting plating electrolyte is adjusted to a value of 9.5. The plating electrolyte is then subjected to mechani-cal agitation at 30C with a carbon anode and a brass plate plated with a bright nickel layer as a cathode. A current with an average cathode current density of 0.5 A/dm2 is made to flow for three minutes to carry out electrolytic plating. As a result, a bright tin-nickel alloy (containing 67.2% tin) with a bright stainless color is obtained.
Examples 2, 3 and 4 The procedures described above in Example 1 are repeated but with the further addition to the main plating liquid of ammonium chloride (Examples 2 and 4) or aqueous am-monia (Example 3) and with the substitution of nickel chloride for the nickel pyrophosphate (Examples 3 and 4), and the results thereof are as shown on Table 1 below. , 'i; '~
lj,;
-6a -5~7~
TABLE l Examples :L 2 3 4 . . .
Potassium pyrophosphate g/l. 200 200 200 200 Stannous pyrophosphate g/l. 30 30 30 30 Nickel pvrophosphate g/l. 50 50 - . .. ... ... ... . -Nickel chloride _ g/l. 40 40 ~;
Ethylenediamine of æ5% g/l. 15 15 25 25 Ammonium chloride /l. 20 50 - -A ueous ammonia of 28% cc/l 20 q ... _ ._ .
~H 9.5 9.5 9.5 9 5 , .
Temperature C 30 30 30 30 ._ . .. . _ _ . ' '.' :.
A~itation Yes Yes No No -_._ ~ ., .
Current denslty _ _ A/dm20.5 0.5 0.5 0.5 Anode __ _ Carbon Carbon Carbo_ Carbon ~`
Amount of tin contained in deposited alloy __ _ % 67.2 62.1 66.3 67.1 . ,;.
Appearance Bright Bright Bright Bright stain- stain- stain- stain- ;
less less less less :
color colox color color tOmilar __ _ white _ ;
The procedure of Examples l, 2, 3 and 4 are repeated, but using, in turn,hydrazine, 1,2-propanediamine, 1,3-propane- -diamine, 1,4-butanediamine, guanidine, urea, thiourea, pen-tamethylenediamine and hexamethylenediame, in place of the ethylene diamine, and, in each case, a bright tin-nickel alloy plating similar in appearance to the platings obtained in Examples 1, 2, 3 and 4 on Table 1 is obtained.
-5~75 Examples 5, 6, 7,8 and 9 The procedures described ln Example 1 are repeated, but with nickel chloride replacing the nickel pyr~phosphate (Examples 7, 8 and 9), and with the further addition of a com-pound having an -SX group, to wit, 2,5-dimercapto-1,3,4-thiazol (Examples 5, 6 and 9), dithioammelide (Examples 7 and 9) and hydrazodithiodicarvoneamide (Example 8), and the propor-tions and results of such additives are as shown on Table 2 below.
Examples ~_5 6 7 8 9 Potassium ;' pyrophosphate g/l. 20C 200 200 200 200 Stannous pyrophosphate g/l. 3C 30 30 30 30 Nickel pyrophosphate g/l. 5C 50 Nickel ;
chloride g/l. ___ 40 40 40 ' Ethylenediamine .
of 85% g/l. 0.8 0.8 0.8 0.8 1 ' 2,5-dimercapto-1,3,4-thiazol g/l. 0.5 0.5 0.5 Dithioammelide g/l. 1 0.5 _ Hydrazodithiodi-carvoneamide g/l. 1 -' _ _ , pH 9.5 9.5 9.5 9.5 9.5 ~-;
Temperature C 35 35 35 35 35 Agitation Yes Yes Yes Yes Yes Current density 2 ~,~
A/dm 0.5 0.2 0.5 0.5 0.5 :~
Amount of tin contained ir. deposited alloy % 72.1 71.5 73.1 70.1 70.3 ~ppearance Bright' Bri~ht Bri~ht Bri~ht Bri~ht stain- staln- staln- staln- staln-less less less less less ~' cQlor color color color color wl-th wlth wlth wlth wlth _ _____ _ black black black black black .": ' ~ 507S
: Examples 10,11~12,13 and 14 ~ :
The procedures of Examp~e 1 are repeated, but with j the further addition of a compound having an -SX group, to wit, 2,5-dimercapto-1,3,4-thiazol (Examples 10,12,13 and 14) and/or ,~ -- dithioammelide (Examples 11,13 and 14) and of either ammonium chloride ~Examples 10,11 and 14) or aqueous ammonia (Examples 12 and 13), and the proportions and results of such further additives '~ , , !~ ~-are as shown on Table 3 below.
Examples ~1 1 1 2 1 3 14 Potassium Pyrophosphate Vtl 200 200 7 200 200 200 r ~ ~ _ Stannous pyrophosphate ~Jl. 30 30 30 30 _ 30 .~
ickel PYrophosphate _ ~/l. 50 50 50 ¦ :
; Nickel chloride~/1. 40 40 __ Ethylenediamine of . ~:
85% . ~/1. 0.8 0.8 0.8 _ 0.8 0.8 , ------ 2,5-dimercapto- .
1,3,4-thiazol gL~ 0.5 . _0.5 0.5 Dithioammelide~/1. 0.5 0.5 0,5 Ammonium chloride ~L~ 50 5 Q
Aqueous ammonia of 28% cc/l. 30 30 - ~ :
.9.5 9.5 9.5 9.5 9.5 Temperature C 35 35 35 35 35 A~itation Yes . Yes Yes Yes Yes ~' - - , . . _._ . _ ~ '"
Current density A/dm2 0.5 0.. 5 _ 0.5 0 5 0.5 ~ -Amount of tin contained .
in deposited alloy % 1 67.8 64 264.8 63.5 65 4 Bright Bright Bright Bright Bright ~:
Appearance stainless stain- ~stain- stain- stain- ~, color less less less less color color color color t - ~ _ _ . ''` ~ '~
_9 ~ :
~',' .
,~
1.
l~S~75 Examples 15, 16 and 17 The procedures of Example 1 are repeated, but with the further addition of peptone (Examples 15 and 17) or pro-tein in the form of glue (Example 16) and also of ammonium chloride (Example 17) and the proportions and results of such additives are as shown on Table 4 below.
. . . _ Examples . . .
.. :~
Potassium pyrophosphate g/l. 200 200 200 _._ , _ .
Stannous pyrophosphate g/l. 30 30 30 ._ _ __ _ Nickel pyrophosphate g/l. 50 50 ._ . ~ .. . :,, Nickel chloride g/l. 40 ~-~ . . . .
Ethylenediamine of 85%g/l. 0.5 0.5 15 - ;:.
Peptone g/l. 1 1 `
Glue g/l. 1 Ammonium chloride g/l. 20 __ ..................................................... :~'~
pH 9.5 9.5 9.5 _ -- ---- _ .", Temperature C 35 35 35 ' . ._ .__ . _ . _ __~
Agitation Yes Yes _ _ Yes _ __ Current density A/dm 0.3 0.3 0.3 `
.. _ . _ . .. __ :~.~,;, .
Amount of tin contained in deposited alloy % 68.2 67.3 65.4 , Appearance Bright Bright Bright stainless stainless stainless ' color color color `
with with black black ..... _ _~
~4S~5 ``
Examples 18 and 19 -The procedures of Example 1 are repeated, but with the further addition of a neutral amino acid free of sulphur or a salt thereof, to wit, sodium glycine (Example 18) or ~
alanine (Example 19), and also of aqueous ammonia (Example 19), ;
and the proportions and results of such further additions are as shown on Table 5 below.
Examples Reference Potassiumpyrophosphate g/l. 200 200 200 Stannous pyrophosphate g/l. 30 30 30 Nickel pyrophosphate g/l.50 50 50 Ethylenediamine of 85% g/l. 0.8 _ 0.8 Sodium glycine g/l. 7 7 Alanine g/l. ~ 8 ;.
Aqueous ammonia of 2~% cc/l.; 30 pH 9.5 9.5 9.5 Temperature C _35 ~ 35 35 Agitation Yes Yes Yes 2 _ Current density A/dm0.5 0.5 0.5 .
Anode carbon carbon carbon Amount of tin contained in deposited alloy % 67.4 ~68.2 84.2 Appearance Briyht Bright Grey stainless stainless with ;
color color bright _ ness ... . . . .
7~
Reference 1 In ord~r to demonstrate the essential character of the additive compound having a plurality of amino groups as its only func~ional groups, the procedure of Example 18 was repeated, but with the ethylenediamine being omitted from the plating electrolyte and, as shown on Table 5 above, the resulting pla~ing layer was grey in color and devoid of brightness.
Thus, it will be apparent that, by the addition to the main plating liquid, containing stannous salt, nickel salt and an alkali-metal pyrophosphate~ of a compound having a plurality ~
amino groups as i~s only ~unctional groups, the present invention produces a bright tin-nickel alloy plating layer with a brightness that cannot be obtained with prior plating electrolytes Further, it will be apparent that the brightness of the tin-nickel alloy plating layer is urther enhanced by also adding to the electrolyte a compound having an -SX group (in which X represents hydrogen, sodium or potassium), peptone and/or protein, or a neutral amino acid free of sulphur.
Finally, the further addition of ammonia or ammonium salt to the plating electrolyte according to this invention is shown to provide the bright plating layer with white color.
Al~hough specific examples of the invention have been described in detail herein, it is to be understood that the invention is not limited to those precise examples which are intended to be illustrative, and that a person skilled in the art may effect various changes and variations or modifications in the given examples without departing frnm the scope or spirit of the inven~on as defined in the appended claims.
~12-
Claims (6)
1. A bright tin-nickel alloy plating electrolyte having a pH in the range from 8 to 12 and consisting essentially of an aqueous main plating liquid containing:
a. a stannous salt selected from the group con-sisting of stannous pyrophosphate, stannous chloride and stannous sulfate, and which is present in said main plating liquid in an amount between 2 and 20 g/l. calculated as stannous ion;
b. a nickel salt selected from the group consisting of nickel pyrophosphate, nickel chloride and nickel sulfate, and which is present in said main plating liquid in an amount between 5 and 30 g/l. calculated as nickel ion;
c. an alkali-metal pyrophosphate selected from the group consisting of potassium pyrophosphate and sodium pyrophosphate, and which is present in said main plating liquid in an amount between 150 and 600 g/l;
d. at least one brightener additive in said plating liquid in an amount between 0.1 and 100 g/l of said main plating liquid and being selected from the group consisting of ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, pentamethylenediamine, hexamethylene-diamine, hydrazine, guanidine, urea and thiourea; and e. at least one further additive selected from the group consisting of a compound having at least one-SX group where X represents hydrogen, sodium or potassium), peptone, derived protein, neutral amino acid free of sulfur and neutral amino acid salt free of sulfur; the said compound having at least one-SX group is present in said main plating liquid in an amount between 0.01 and 5 g/l, the said peptone and derived protein is present in an amount between 0.1 and 10 g/l, and the said neutral amino acid and salt of thereof is present in an amount greater than 0.01 mol/l.
a. a stannous salt selected from the group con-sisting of stannous pyrophosphate, stannous chloride and stannous sulfate, and which is present in said main plating liquid in an amount between 2 and 20 g/l. calculated as stannous ion;
b. a nickel salt selected from the group consisting of nickel pyrophosphate, nickel chloride and nickel sulfate, and which is present in said main plating liquid in an amount between 5 and 30 g/l. calculated as nickel ion;
c. an alkali-metal pyrophosphate selected from the group consisting of potassium pyrophosphate and sodium pyrophosphate, and which is present in said main plating liquid in an amount between 150 and 600 g/l;
d. at least one brightener additive in said plating liquid in an amount between 0.1 and 100 g/l of said main plating liquid and being selected from the group consisting of ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, pentamethylenediamine, hexamethylene-diamine, hydrazine, guanidine, urea and thiourea; and e. at least one further additive selected from the group consisting of a compound having at least one-SX group where X represents hydrogen, sodium or potassium), peptone, derived protein, neutral amino acid free of sulfur and neutral amino acid salt free of sulfur; the said compound having at least one-SX group is present in said main plating liquid in an amount between 0.01 and 5 g/l, the said peptone and derived protein is present in an amount between 0.1 and 10 g/l, and the said neutral amino acid and salt of thereof is present in an amount greater than 0.01 mol/l.
2. A bright tin-nickel alloy plating electrolyte according to claim 1, in which said compound having at least one-SX group is selected from the group consisting of dithio-ammelide, 4-amino-3, 5-dimercapto-1 t 2,4-thiadiazole, ethylene thiuram monosulfide, 2,5-dimercapto-1,3,4-thiadiazole, thio-carbohydrazide, hydrazo-dithiodicarbonamide, an- ethylene-bis-dithiocarbamic acid sodium salt.
3. A bright tin-nickel alloy plating electrolyte according to claim 1, in which said derived protein is selected from the group consisting of glue, gelatine and gluten.
4. A bright tin-nickel alloy plating electrolyte according to claim 1, in which said neutral amino acid free of sulfur and salt of thereof are selected from the group consisting of glycine, alanine, serine, amino-butyric acid, leucine, isoleucine, proline, hydroxyproline, phenylalanine, thyroxine and tryptophan, and salts thereof.
5. A bright tin-nickel alloy plating electrolyte according to claim 1, in which said main plating liquid further contains an additive selected from the group consisting of ammonia and ammonium salts, and in which saia further additlve is present in said main plating liquid in the amount between 5 and 100 g/l. in the case of ammonia calculated as a 28 percent aqueous ammonia solution, and between 1 and 150 g/l.
in the case of ammonium salts.
in the case of ammonium salts.
6. A bright tin-nickel alloy plating electrolyte according to claim 5, in which said ammonium salt is selected from the group consisting of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium citrate, ammonium tartrate and ammonium acetate.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4377673A JPS5347060B2 (en) | 1973-04-19 | 1973-04-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1045075A true CA1045075A (en) | 1978-12-26 |
Family
ID=12673146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA197,770A Expired CA1045075A (en) | 1973-04-19 | 1974-04-18 | Bright tin-nickel alloy plating electrolyte |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US3887444A (en) |
| JP (1) | JPS5347060B2 (en) |
| CA (1) | CA1045075A (en) |
| DE (1) | DE2419024A1 (en) |
| FR (1) | FR2226478B1 (en) |
| GB (1) | GB1441542A (en) |
| NL (1) | NL7405390A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114059114A (en) * | 2021-12-16 | 2022-02-18 | 厦门华弘昌科技有限公司 | Cyanide-free low-temperature black tin-nickel alloy electroplating solution and electroplating process |
Families Citing this family (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4033835A (en) * | 1975-10-14 | 1977-07-05 | Amp Incorporated | Tin-nickel plating bath |
| JP2586688B2 (en) * | 1990-05-07 | 1997-03-05 | 上村工業株式会社 | Electroplating method of glass-metal composite |
| US5538617A (en) * | 1995-03-08 | 1996-07-23 | Bethlehem Steel Corporation | Ferrocyanide-free halogen tin plating process and bath |
| US5654108A (en) * | 1995-05-22 | 1997-08-05 | Baldwin Hardware Corporation | Article having a protective coating simulating brass |
| US5552233A (en) * | 1995-05-22 | 1996-09-03 | Baldwin Hardware Corporation | Article having a decorative and protective multilayer coating simulating brass |
| CA2176892C (en) * | 1995-05-22 | 2002-10-29 | Stephen R. Moysan, Iii | Article having a decorative and protective coating simulating brass |
| US5667904A (en) * | 1995-05-22 | 1997-09-16 | Baldwin Hardware Corporation | Article having a decorative and protective coating simulating brass |
| US5783313A (en) * | 1995-12-22 | 1998-07-21 | Baldwin Hardware Corporation | Coated Article |
| US5693427A (en) * | 1995-12-22 | 1997-12-02 | Baldwin Hardware Corporation | Article with protective coating thereon |
| US6106958A (en) * | 1997-04-30 | 2000-08-22 | Masco Corporation | Article having a coating |
| US5989730A (en) * | 1997-04-30 | 1999-11-23 | Masco Corporation | Article having a decorative and protective multi-layer coating |
| US5952111A (en) * | 1997-04-30 | 1999-09-14 | Masco Corporation | Article having a coating thereon |
| US6033790A (en) * | 1997-04-30 | 2000-03-07 | Masco Corporation | Article having a coating |
| US6004684A (en) * | 1997-04-30 | 1999-12-21 | Masco Corporation | Article having a protective and decorative multilayer coating |
| US5948548A (en) * | 1997-04-30 | 1999-09-07 | Masco Corporation | Coated article |
| US5985468A (en) * | 1997-04-30 | 1999-11-16 | Masco Corporation | Article having a multilayer protective and decorative coating |
| US5879532A (en) * | 1997-07-09 | 1999-03-09 | Masco Corporation Of Indiana | Process for applying protective and decorative coating on an article |
| US6268060B1 (en) | 1997-08-01 | 2001-07-31 | Mascotech Coatings, Inc. | Chrome coating having a silicone top layer thereon |
| US6015482A (en) * | 1997-12-18 | 2000-01-18 | Circuit Research Corp. | Printed circuit manufacturing process using tin-nickel plating |
| WO2010009718A2 (en) * | 2008-07-23 | 2010-01-28 | Dechema Gesellschaft Für Chemische Technik Und Biotechnologie E.V. | Component made of an unalloyed or low-alloy steel, method for protecting said components against coke deposition or metal dusting |
| DE102010055968A1 (en) | 2010-12-23 | 2012-06-28 | Coventya Spa | Substrate with corrosion-resistant coating and process for its preparation |
| CN105568331A (en) * | 2016-01-21 | 2016-05-11 | 张颖 | Roll strip type electroplating method for crystallizer roll surface |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3772168A (en) * | 1972-08-10 | 1973-11-13 | H Dillenberg | Electrolytic plating of tin-nickel, tin-cobalt or tin-nickel-cobalt on a metal base and acid bath for said plating |
-
1973
- 1973-04-19 JP JP4377673A patent/JPS5347060B2/ja not_active Expired
-
1974
- 1974-04-12 US US460527A patent/US3887444A/en not_active Expired - Lifetime
- 1974-04-17 GB GB1680174A patent/GB1441542A/en not_active Expired
- 1974-04-18 CA CA197,770A patent/CA1045075A/en not_active Expired
- 1974-04-19 DE DE2419024A patent/DE2419024A1/en not_active Withdrawn
- 1974-04-19 FR FR7413754A patent/FR2226478B1/fr not_active Expired
- 1974-04-19 NL NL7405390A patent/NL7405390A/xx not_active Application Discontinuation
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114059114A (en) * | 2021-12-16 | 2022-02-18 | 厦门华弘昌科技有限公司 | Cyanide-free low-temperature black tin-nickel alloy electroplating solution and electroplating process |
| CN114059114B (en) * | 2021-12-16 | 2023-02-10 | 厦门华弘昌科技有限公司 | Cyanide-free low-temperature black tin-nickel alloy electroplating solution and electroplating process |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2226478B1 (en) | 1976-12-17 |
| NL7405390A (en) | 1974-10-22 |
| GB1441542A (en) | 1976-07-07 |
| JPS49130332A (en) | 1974-12-13 |
| DE2419024A1 (en) | 1974-11-07 |
| FR2226478A1 (en) | 1974-11-15 |
| US3887444A (en) | 1975-06-03 |
| JPS5347060B2 (en) | 1978-12-18 |
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