DE2005254A1 - Process for the preparation of an iridescent chromium coating - Google Patents

Description

PATENT LAWYERS

DR.-ING. H. FINCKE 'DIPL.-IN6, H. BOHR DIPL.-ING. S. STAEGER

Firnr'J ti

B MUNICH ö, MOlltntroe 31

! SSbT Chemicals Ine,

Haw York, Ii.Y., V.St.A,

Yerfossren to make a

Obromttfearsug ©

Priority 6.2.1969 V-St.A.

Pie invention relates eloh to aiaea. aeuen decorative Katsllbelagj on one of these rubbers aets Bac! "üDaai2i ^ aset2un ^ and on a procedure for Horetel" lung τοπ solohon Metallbelägea «The invention relates to sie Insbösonclöro open. decorative electrolytic deposited Obromübarsü ^ e, the Irldlsierende Blgeaochaften

BATH ORIGINAL

009834/1705

According to the invention, a bath is used which contains a hexavalent chromium compound and a marine molybdenum compound ₉ to divide out an electrolytically coated object with an ear surface which reflects light in such a way that an iridescent rainbow effect is produced.

The aqueous chrome plating solution according to the invention can be used can be prepared from commercially available chromic acid solutions part of the chromic acid used in the bath composition is replaced by a salt of hexavalent chromium, such as sodium bromate, sodium dichromate, potassium chromate, Potassium dichromate, strontium chromate,! Iaenesiumdichrotaat, Lanthaachromat, Lanthandiehromat, etc. in many cases it may be advantageous to use one or more such salts in order to improve the composition or the acidity of the to control aqueous chrome plating bath.

Bs can structural connection every Holy, which is soluble in the bath composition and the seohswertiges Chrome shows warden to prepare a chrome object used as a component in the aqueous Verchromungebad that • in iridisierendas appearance has * Molybdäneäure is • ine particularly bevorsugte connection, di "in the baths "- * ■ ammanautting can be used" Typically , the ololyboaic acid can be used as the ammonium complex of koIybdenoxid, which contains about 8.5 aew ,. £ ammonium ions and about 85 (Jaw .- ^ molybdenum oxide Ready-made molybdenum compounds that can be used are sodium molybdate and phosphomolybdanic acid

UBW.

BATH ORIGINAt-

009834/1705

Catalysts can also be introduced into the water reservoir to regulate non-oil concentrations of the active constituents during the electrolytic deposition. For example, sulfates, fluoride and Icoraplexe fluoride can be used. % n typi-θ rather catfish, fluoailicates, pluoborato,? luo) iluiainate _s pluotltanate and fluoairconate can be introduced into the hot chromium plating bath without the irldiselling love reflective properties of the new decorative, electrolytic chromium coatings affecting

Suitable neutralizers and / or buffers can be used in the Baduu composition according to the invention can also be used * Det are · examples of such neutralizers or Buffers are phosphates, borates, sulfonates and carboxylates In addition, can catalyst ions such as those given above be used in sufficient quantities? there they also have their catalytic properties as Serve as a neutralizer or buffer.

A typical bath composition, the ϋβ & 3 inventive method for producing an electrolyte sheet iridescent chromium deposition can be used contains chromic acid in an amount of 50 to 600 gTl as CrO * in combination with a marine molybdenum compound in an amount of 2 to 140 g / l as MOO «· Other auxiliary materials can also be used in the bathroom. incorporated «to earth ·

Sine spesleile bathroom composition can be the following components contained in the specified quantities

BATH ORIGINAL 009834/1705

Chromic acid 300 g / l sulfate 1.2 g / l Molybdic acid (85 wt .- /,) 110 g / l concentrated Ammonium hydroxide 20 ral / 1

When a sulfate catalyst anion is used as a component in the iridi « If a brominating bath is used, the Amount of sulfate ions typically 0.3 to 3.0 g / l be « wear. Other typical ranges for preferred catalyst anions and buffers are as follows:

label 1

Fluoride 0.1-1.0 g / l

Silicofluorid 0.5 - 5.0 g / l

Phosphate 0.35-3.5

Acetate 2.0-20 g / l

You can use catalyst and / or buffer anions individually or used in combination, the combined amount a of said catalyst ions from 0.3 to 30 g / l, based on the weight of the entire bath omen settlement.

Other typical materials that produce regulatory buffer ions are triobloroossetic acid, succinic anhydride, Adipic acid and sodium aluminate. The components mentioned can be used in amounts in the iridescent chromium bath of the invention (based on the total weight of the composition) of 0 to 40 g / 1 can be used.

BADORiGfNAL 009834/1705

In one - igidizing. Chromic acid (CrO ^) to (calculated) molybdenum trioxide (MoO ^) can be between 3% and 40% in the chromic acid bath according to the invention . chromic acid (GrO ^) and ^J 40 to 70 g / l aiolyMänsäure (rioo *) contain "M can be amounts of chromic acid as GrO ^ 50 big 600 g / l vorwendet.? or2? ttgsr ?? sise be Bathrooms- tinting © t, contains 225 to 275 g / l chromic acid and 50 to 80 g / l molybdic acid © *

The iridized upper coverings produced according to the invention may contain mounds from an orifice, which have an average height above the surface of 0.025 to 5 / t, with the shells being close by and arranged in half-overlapping strips? ssnä the stripes are arranged in acmäfeernd parallel Ϊ / © 1β © to each other around the Ägdorop bring about the iridescent ear surface, which are about 70 to 1500 stripes of m / mm and 6 x 10 bia β % 10 hills of chromabis coating on each of ² surfaces. On these iridescent ears aaeehließßßd know that additional metals would be made of solsheo metals, such as nickel? Copper, chromium, etc. can be applied to the color or the Eefltkiioas ·,

or pw; aodifl8t «veB · - Xn -ähiiliöhör: M @ lm eehs or anor, .saiii9oh9 Belöge 'vexvendei ^ erdea ^ uro de» dekoa? atiT # ß Hegenfeogenöff © fet aaf einia f # il the surface or on ta? Overall surface to vary.

Hanger ,· ·-

; a ka? ei0f örmigfiinQueriofettii; ^ and

BATHROOM ORIGINAL

ems * a

or a tell near a sphere. The mean height of the hillocks on the chromium deposit is measured from the plane which joins the set of points which intersect the minimum and maximum of the surface on which the hills are located. Microscopic examination of the surface shows that the hills can be completely separated from one another, the distances between the hills being three to four as large as the diameter of the hills. The mounds can touch or overlap one another to form continuous stripes or semi-continuous stripes, the stripes being arranged in an approximately parallel position, somewhat like rows of vacations lying on a given surface and following the shape of that surface ". It is assumed that the parallel arrangements (which are not necessarily linear) produce an effect such as that obtained by diffraction of a grating using parallel lines. It has been found that particularly striking dazzling effects are achieved in an iridescent chrome-plated object the 6 χ 10 to 6 χ 10 ⁸ Htigel 'tfefefRet, which have an average height of 0.025 to 5 / U, with the hills arranged on the surface of the iridescent, chrome-plated object, a row of continuous sharks, which connect the centers of the hills, outline a network of lines, and the network of lines contains at least 790 parallel lines per linear cm, measured by the intersection points on a straight line in any direction a length of 1 cm from the center of a given hill the Iridislerendea, verahrtratea surface is sucked · Sine such a line of 1 0 »length ₀ that of any given one Hill on the

009834/1708

chrome-plated surface is drawn _f cuts at least about 790 approximately parallel strips of hills, these strips of hills being connected by lines drawn from the centers of the hills lying on these parallel strips.

The shiny iridescent chrome plating can be characterized by the fact that it has a surface on «« orphans that contain temples from chrome subscriptions, with the average height of the hills being approximately 0.075 to 2.5 / u and where the average distance between two approximately parallel neighboring Strip of hills (measured by the average distance between two lines separating the centers of each connecting the hill of each strip) about 2.5yu amounts to. Particularly brilliant iridescent Chroraabacheidüngen are obtained when the average height the hill is approximately 0.087 / u and the average distance between two approximately parallel, adjacent strips of hills (measured by the average distance between two lines which the Connecting the center of the hills of each strip) is approximately 2.9 to 3.0 / u.

The invention is further illustrated by the following examples explained. .

example 1

A TercbroiBUiigsbad for an iridescent chrome plating was made by having the following ingredients placed in the specified concentrations in water

0 0 9 83 4/1705 BAD ORIGINAL

were (all concentrations are in g / l of the total

Solution given, unless otherwise stated) s

Chromic acid (GrO ₃ ) 250 g / 1

Moly Male Acid (85 #) 50 "

Fluoride (P * ") 0.3 ^w

Sulfate (S0 ₄ ^a ) 1.0

Acetate (C ₂ H ₅ O ₂ ") 10.4

Phosphate (PO ₄ ⁵ ) 0.1

A steel strip was chrome-plated in the above solution by passing a current through the bath, the metal strip serving as an electrode. The absorption time was 5 minutes and the temperature was 40-45 ° C. Ί) ύτ verchromti ) Gegenataod was taken out of the bath, washed and dried. Sr showed an iridescent effect in sunlight and in artificial light »

Example 2

Example 1 was repeated using a nickel-plated steel strip was used as an electrode. The temperature

was 49 ⁰ O and the treatment lasted 15 minutes. DIo

2 Current density was approximately 20 A / dra · the one obtained

Chromed item showed in sunlight and artificial Light iridescent effects · Similar iridescent effects Surfaces were already at a cut-off zoite of 1 minute received.

BATH ORIGINAL

009834/1705

Example 2

Am Bod for a © irldlaiereade chrome plating was thereby prepared by introducing the following ingredients into water in the specified conversations

Chromic acid (CrO-j) 300 g / l

Molybdic acid (85 # _? MoO ₅ ) - 60 «♦ Sulphate (SO ₄ ³ ) T, 2'- *

Fluoride (| ΓΚ- ° * 4 * '

Phoepbat (PO ^) 0 ^ 6 ^H

Acetate (ΟοΗ-χΟο ") 15'- 17 g / l

Am made by die casting? Handle for eift lato «mobil was used as a BX electrode and placed in the above bath

immersed »There was an electrolysis through ä & n su coated» aegenstaad «·

led «The temperature of the bath was 44 ⁰ C. A © iridislereftde Vörohjpomwng aims at the handle of the automobile. ■■ · .- ■ - ". '■ ·

His base composition for an iridescent admiration «· mmg was isergeöttllt ■, inöeai the following na β« bed parts la de » m $ 0® $ §mm komatre.ti« etp In, - Waever has been »

00 9834/1 70S

250 fO S / 50 , 3 ti 1 , 4 " 0 M. 0 η 14th η

Chromic Acid (CrO ₅ ) Molybdic Acid (85 #, M0O3)

Sulfate ³ ) fluoride

Phosphate (PO ₄ ") acetate (C ₂ H ₃ O ₂ ^- ")

Bin coppered strip was immersed as an anode in dae above bath, and a current was passed through the felt Lönung at 44 ⁰ C. An iridescent chrome plating was obtained on the copper strip.

The following examples 5 to 20 were carried out in a Hull cell to show that iridescent 7 ear holes can be achieved using the method according to the invention over a wide range of current diaphragms. In the following Table 2 the K0n2e11.tr. '.''Functions (in g / l, unless otherwise stated) for every bed part in the chrome plating are given, and the terms are also given and conditions attached. In the spring example, a standard chromaagaseit of 5 slots was used and the temperature was kept at 43 to 44 ⁰ for comparison

ersielea. Me total length of the standard Hall cell used was 100 am.

BATH ORIGINAL

009834/1706

ί O
CD Components
concentration
6/1 CrO ₃ KoO ₃ 2.5
'2.0 Table 2 C ₂ H ₃ O ₂ Current io d.
Standard hull
aadcro ZgIHc (A) 12th 200525A U)
OO BeiopieT ^ Br *
5
6th 500
400 140
119 0.9 0
0 ITa ₂ O (60 s / 1)
ITa ₂ O (51 ß / 1) Longitudinal dor _Ββ _
rena from- YY * -
divorce ^KUG ""
idHall- ^{s <m}
Cell (mm) ^^ 7th 250 42.5 0.46 PO ₄ 15.6 P "(0.3 ß / 1) 8th 53 excellent
Dear
45 ^M. -a 8th 128 21.8 0.29 0
0 9.7 ZrPg (0.31 e / 1) 8th 60 out- ο
cn 9 80 8.5 0 0.7 10.6 p ~ (0.10 g / i) 8th 56 loaned 10 300 50 1.2 0.36 18th sip | (6.0 e / i) 8th 58. " 11 300 60 0.9 0.22 0 CaCO ₃ (40-55 ß / 1 8th 68 « 12th 250 50 0.8
1.1 0.42 15.6 P * (0.3 ßA) 8th
8th 50 excellent
"Hnh 13th
14th 200
300 45
60 0.9 0 0
0 Ha ₂ O (7.6 ßA)
. O 8th 70 extra large 15th 250 42 ,, 5 0.9 0.7 15.6 SiPg (0.9 e / i) 8th 52 prematurely
Dear
45 ^M. 16 250 42.5 0.9 0
0.7 15.6 TiPg (0.75 g / l) 8th 60 except » 17th 250 42.5 0.6 0.7 15.6 ZrPg (0.6 g / 1) 8th 62 » 18th 250 42.5 0.6
1.0 0.7 15.6 AlPj (1.2 e / 1) 8th
12th 61 ^w 19 (otandard) 250
20 (atandard) 250 0
0 0.7 15.6
14.6
* SiPg (0.9 ß / 1)
* ~ (0.3 6/1) 59 " 0.7 0 ordinary
Chrome plating
0 no iridi
floating
Bifects 0.7
0.4

«Rt 12 -

Table 2 clearly shows that excellent or extraordinary results are "obtained" when the compositions of Examples 5 to 18 are used, whereas in Examples 19 and 20 ordinary chrome-plating was obtained when the high-quality chromium was removed from the bath tubs. In the table, a rating of "excellent" is selected if a distance of 40 mm in the Hull cell shows an uninterrupted indication. Its continuous iridescent stretch of more than 55 mm in length is classified as "exceptional". In each case the iridescent effect was obtained in natural sunlight as well as in artificial light (incandescent lamp and fluorescent light).

BATH ORIGINAL

00933 / ♦ / 1705

Claims (1)

(Π) Process for the Herotallung of i ^ idisiarondon chrome coatings, characterized in that a current is carried out from an anode to a cathode a väsarigo chrome solution that at least a chromium compound that contains Chromium castallion ions fCir provides a electrolytic deposition of chromium, and contains a six-valued © molybdenum compound 2, Verfahret according to claim 1, dädusrch gekenn draws that as a hexavalent molybdenum compound dung molybdic acid, sodium molybdate, phosphomolybdic acid, Amaoniujaaolybdate or Arnntoniuniparamolybäat before uses 3. The method according to claim 1 «thereby g β k e η η zeic b η ο t that the aechewertige molybdön terbine tion in a weight of 2 g molybdenum compound, printed out ala MoO3, 1 aqueous chromium plating solution present. 4. Method naoli Anepruoh 1 _f characterized in that the aqueous Verohronmngßlösung contains 50 to 600 g / l of chromic acid. 5. The method according to claim 1, characterized by geke η η that the aqueous chromium solution 50 to 500 ß / 1 Cbrometiure and 2 bio 150 g / l MolybdSmvor bond, pressed out ale WoO ₃ contains. 009834/1705 H " 6. Wttesrigos electrolytic chrome plating, which provides an iridescent chrome plating, characterized in that 50 to 600 g / l chromic acid ele CrO ₃ and 2 to 140 ß / 1 Llolybdenoäuro ale UoO, contains » 7 · Bath according to Claim 6, characterized in that the catalyst anion used is a sulfate Contains pluoride and / or a complex pluoriü. 8. Bad nech claim 6, characterized gefcennzo lc h -net that co at least one anion from the group Pluoailikate, Fluoborate, Pluoaluminate, Pluotitanate and contains pluozirconets. 9. Bath according to claim 6, characterized in that there is at least one up to about 30 g / l Anions from the group fluosilicate, pluoborate, fluoaluminate, pluotitanate and fluoconate contains. 10. Aqueous electrolytic Terohromungsbad for Absoheidurtß τοη iridlaierendem chromium, thereby g β k β η η -seiebnet that it is 225 to 275 g / l chromic acid ula CrO ₅ , 30 to 80 g / l thiolybd & nsfiure üls LIoO ,, 0.7 to 1 , 2 g / l sulfation, 0.2 organic 0.9 g / l fluoride ion, 0.5 to 1.2 g / l phosphate ion and 12 to 19 g / l acetate ion. 11. Iridlsierender chrome object, characterized in that the surface rorchromte HUGEL au »Cbromabechoidungen having an average highs on the surface of 0,025 bio 5 _y u beeitat, wherein BATH ORIGINAL 00983 A / 1705 the Httg * l in neighboring and calibrated half-overlapping Stripes are arranged and the stripes run approximately parallel, eo that a surface with 70 to 1500 Strips / min. 12 «Iridious chrome-plated object, thereby Gemany rejects that the surface of the c 8 Subject has approximately 6 χ 10 to 6 χ 10 mounds of chroo scales per cm, the mounds having an average height τοη 0.025 to 5 / U and on the Surface of the iridescent chrome-plated object in which Υ / θ ie ο are arranged that a series of continuous lines connecting the hills form a network * plant of lines, whereby the network of lines at least approximately 790 parallel lines per linear approx contains, gerneeeen through the intersection of a straight line Llnl · which in any sighting a distance of 1 cm Center of a «given hill of an iridescent one Surface is drawn * 13. The article according to claim 11, characterized in that the average height of the Cttromhügel uagof & hr 0.075 to 2.5 / U and that the average distance between 2 approximately parallel, neighboring strips of hills, measured by the distance between two lines that form the centers the hill el nee connect each strip, roughly amounts to. EAD ORIGINAL 0 0 9 8 3 4/1 7 0 B. 14 · Item according to Anopruoh 11 _t characterized in that the average height of the CbromhUgel is approximately 0.087 / U and that the average Abotand between two approximately parallel, adjacent strips of hills 2.9 bie 3.0 / u bot carries. 13. Object according to claim 11, characterized in that at least part of the iridescent chromoboron surface has a further coating. BAD ORiGIMAL 009834/1705