‘Patented lDec. 8', ‘1925.. '
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> UNITED ‘ STATES
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1,564,414
PATENT OFFICE.
CLAYTON H. HOFF, OF CLEVELAND, OIéIIO. ASSIGNOB TO THE GRASSEILI CHEMICAL_
OOMZPANY, OF CLEVELAND, OHIO, A CORPORATION. 01‘ OHIO.
cnmmm rmrnve.
No Drawing.
Application ?led Qotober- a, 1924. Serial mynama» '
foxid, h droxid,‘ or cyanide, or in the form
‘ To all whom it may concern: _
Be it known that I, CLAYTON M. Horr, a of a sa tvsuch as the sulfate. The cyanide
citizen of the United-States, residing at _. com onent may be- sup lied. in chemical
Cleveland, in the county of Cuyahoga and com ination with the ca ium as ‘cadmium
i 5 State of Ohio, have invented certain new _ cyanide or as ammonium cyanide, or as other 60
and useful Improvements in Cadmium Plat metal cyanides, preferably those of the al
ing, of which the following is a speci?cation. ’ kali metals. , T e ammonium component
Thisinvention relates to the electroplat ma besupplied in the form of ammonium
- 1 ing of cadmium and more particularly to a hy roxide or as a salt such as ammonium
cyanide or‘ sulfate. The ammonium com
In my application Serial No. 686,898,- ?led ponent apparently serves as the agent which
Jan. 17 , 1924. I have disclosed a process of prevents or tends to prevent the deposition
10 composition for that vpurpose.
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electroplating cadmium involving the use of other metals, particularly zinc, along
of an alkaline bath containing chemical com with the cadmium and, may be replaced by
15 binations of cyanide, ammonium and cad¢ ‘other materials _'such as sodium sulfate
\mium, with or without addition agents such and other alkali metal salts.v The alkaline
as gulac which may be prepared for instance reaction of .the bath may be produced by.
by dissolving cadmium oxid or hydroxid or the use of ammonia or an alkali metal hy- '
a salt such as cadmium sulfate in. aqua drox’id. The bath‘ referablyv is made to
20 ammonia and adding?thereto a‘ ‘soluble cy contai'nalso a colloi agent, which tends to
improve the quality ofthe ‘cadmium plate, ‘
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Such .a bath is characterized by the’ fact such as starch, gulac, dextrine, etc.
anide such as sodium cyanide.
' that .from it pure, smooth and uniform deé
posits of cadmium may be pro‘ducedrapidly
The following examples of’bath compo
sitions illustrate my inyention;
25 and ‘quantitatively if des1red,j even \ when
the bath contains other metals such as zinc.
, It is desirable for the chemicals manufac-'v
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v‘ Example
3 oz., cadmium hydroxide, 61/2 to 7 oz.,l
turer to be able to supply- the electroplater
‘with the materials required ready for use, sodium cyanide: 1/; to ,1 oz., caustic soda:
30 but since itis not feasible to ship and-store 1/1, to 1/2 oz., sodium carbonate, and 1 oz.,
the ?nished electro lating bath, it is one aqua ammonia" 26° Bé.- to each gallon of
tomary when possib e to supply ‘the electro
water;
plate'r with a mixture of chemicals ready to
/ be dissolved in ‘water to produce the bath.
35,, It isIt-herefore', an object of my present in
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p
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_Ewample 2.’
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40 oz., cadmium hydroxide: 30 oz, am
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" vention'to provide a dry mixture of chemis monium sulfate: .85 oz., sodium cyanide; 13
'cals suitable vior storage and shipment which oz., sodium hydroxide, and 9 oz., gulac to
- when dissolved in .water, with or vwithout
each 5 gallons of water. ' ‘a
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other materials as‘ will appear hereinafter, 1 From the-foregoing description it is ap
>40 will. give a cadmium lating bath having in parent that compositions having the charac
gene'rai the characteristics of the bath dis teristics of those illustrated in the foregoing
closed'in my ap lication above referred to. examples, that is, beiner alkaline and contain
In the courseto my investigations in this ing» cadmium, ‘ cyanide. ammonium or an
connection for the pur ose of develo 'ing' other agent whiéhtends to prevent the co
' u‘quch a dry mixture in chemicals I ave deposition of. other metals such as zinc ‘with
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ound that baths having-the‘ desired charac 'or'witho'ut an addition ag'enti'such as gulac
teristics may‘ be prepared "in a variety of may be produced in a-great variety of Ways,
that is'bv the use of a great-variety’ of chem
,
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As stated above the bath of my earlier icals; - The relative proportionsof the ingre
ways.
59 application comprises as; essential ingredi dients and the concentration of thegbath may
ents or-components cadmium, ammonium. of coursebe varied without departing from
c anide and an alkaline agent. ' Each of ‘my invention. '
t ese components. may be suppliediin various _ Of the great ‘variety of combinations
forms.
For instance- the - cadmium_ vcom
I -' l6 ponent may be supplied inkthe iformylof the
chemicals ‘indicated >.a_bo_ve' only \a_ vconir?v
paratively few are well» adapted from-an‘
105
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1,664,414
economical and practical standpoint for com
3. A composition adapted for use in the
mercial use; A dry mixture suitable for BIGCtI‘OdBPOSItiOII' of cadmium comprising a
shipment may be composed of for example cadmium, compound, an ammonium com
cadmium hydroxide, ammonium sulfate, so pound, an alkaline agent and a cyanide.
dium cyanide, sodium hydroxide and gulac, 4:. A composition adapted for use in the
.or since the shipment of caustic soda and electrodeposition of cadmium comprising a
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‘cyanide is somewhat objectionable, the elec cadmium compound, an ammonium com~
troplater may be supplied withv a mixture of pound, a caustic alkali, andv an alkali metal‘
cadmium hydroxide, ammoniumsulfate and cyanide.
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gulac with directions as to the quantity
5. A composition adapted for use in the
thereof to’ be dissolved in a given quantity electrodeposition of cadmium comprising .60
of water along with caustic soda and_sodi-um cadmium hydroxide, an ammonium com
‘ cyanide separately supplied. Or the electro pound, an alkaline agent and a cyanide.
plater maybe supplied with a dry mixture 6. A composition adapted for use in the
of cadmium hydroxide, sodium hydroxide, electrodeposition of cadmium comprising
I sodium cyanide and gulac, to which am cadmium hydroxide, ammonium sulfate, an
monia or an ammonium salt, is to be'added alkali metal hydroxide and an alkali metal
‘in the preparation of the bath. These few
cyanide.
examples as given are su?icient for the pur- 20
.
y
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7. A composition ‘of matter adapted for
poses of illustration, it being understood use for the preparation of a cadmium plat-v
ing bath consisting of a dry mixture com!
ticular combinations of chemicals instanced. prising a cadmium compound and a material
‘The electroplating from baths. comprising which tends to preventthe co-plating of zinc.
that the invention is not limited to the par
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the combinations of chemicals described may v8. A composition of matter adapted for
be carried out as disclosed in my prior ap vuse for the preparation of a cadmium plat
. plication, for instance at room temperature ing bath consisting of a dry mixture com 75
25
using a potential of 4 to 6 volts and a cur
rent density of l ampere per 100 square
prising a cadmium compound and an am
monium salt.
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centimeters between electrodes spaced about
30
9. A composition of matter adapted for
15 ‘centimeters apart, and preferably using use for the preparation of a cadmium plat
cadmium anodes with an anode surface area ing bath consisting of a dry mixture com so
' equal'to two or three times the cathode sur
.face area. Known expedients such as agi
prising cadmium hydroxide and ammonium
sulfate.
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tation or clrculatlon or heating or cooling of ~
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10. A composition of matter adapted for
the bath, rotation of the electrodes, etc., may .nse for the preparation-of a cadmium plat
be. employed. ._
40
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ing bath consisting of a dry mixture com
prising a cadmmm compound, a material
1. A composition adapted for use in the which tends to prevent the co-plating of zinc, _
electrodeposition of cadmium comprising a and a material which tends to improve the
cadmium compound, a material which tends ‘quality of cadmium platings.
_ ,
to prevent the co-plating of zinc with cad
11. A composition of matter adapted for
mium, an alkaline agent, a cyanide, and a use for the preparation of a cadmium plat
I claim: a
.
material'which tends to improve the quality ing bath consisting of a dry mixture com
- of cadmium platings.
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prising a cadmium compound, an ammoni- '
.2. A composition adapted for use in the um salt and an addition agent.
\ electrodeposition of cadmium comprising a
12. A dry mixture of cadmium ‘hydrate,
cadmium compound, a material which tends
to prevent the co-plating of zinc with cad
mium,‘an alkaline agent and a cyanide.
ammonium sulfate and gulac. '
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In testimony whereof, I a?ix m signature.
i CLAYTON
.HOFF.
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