# US 2024/0200219 A1 · Electroplating composition for depositing a chromium or chromium alloy layer on a substrate

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- Number: US 2024/0200219 A1
- Document ID: US20240200219A1
- Status: Published application
- Kind: A1
- Application number: 18/557,972
- Filed: 2022-04-29
- Published: 2024-06-20
- Earliest claimed: 2021-04-30
- Assignees: Atotech Deutschland GmbH
- Applicants: Atotech Deutschland GmbH & Co. KG
- Inventors: Oleksandra YEVTUSHENKO; Anke WALTER; Simon PAPE
- Web page: https://patentgrep.com/patent/US20240200219A1

## CPC

- C25D 3/06: from solutions of trivalent chromium
- C25D 3/08: Deposition of black chromium {, e.g. hexavalent chromium, CrVI}
- C25D 5/627: {Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance}
- C25D 15/00: Electrolytic or electrophoretic production of coatings containing embedded materials, e.g. particles, whiskers, wires
- C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR

## Abstract

The present invention refers to an electroplating composition for depositing a chromium or chromium alloy layer on a substrate, said composition comprising (i) trivalent chromium ions, (ii) at least one complexing agent for the trivalent chromium ions, and (iii) at least one kind of oxide-hydroxide particles; a method for depositing a respective chromium and chromium alloy layer; a respective use of said particles; and respective substrates comprising such a chromium or chromium alloy layer.

## Claims

### Claim 1

An electroplating composition for depositing a chromium or chromium alloy layer on a substrate, said composition comprising:
(i) trivalent chromium ions,
(ii) at least one complexing agent for the trivalent chromium ions, and
(iii) at least one kind of oxide-hydroxide particles.

### Claim 2 (depends on 1)

The electroplating composition of claim 1, having a pH ranging from 4.1 to 7.0.

### Claim 3 (depends on 1)

The electroplating composition according to claim 1, wherein the at least one kind of oxide-hydroxide particles comprises aluminum.

### Claim 4 (depends on 1)

The electroplating composition according to claim 1, wherein the at least one kind of oxide-hydroxide particles comprises AlO(OH).

### Claim 5 (depends on 1)

The electroplating composition according to claim 1, wherein (iii) has a total amount ranging from 0.1 g/L to 200 g/L, based on the total volume of the electroplating composition.

### Claim 6 (depends on 1)

The electroplating composition according to claim 1, wherein the at least one kind of oxide-hydroxide particles have a particle size D50 ranging from 0.1 μm to 15 μm.

### Claim 7

A method for depositing a chromium or chromium alloy layer on a substrate, the method comprising the following steps:
(a) providing the substrate,
(b) providing an electroplating composition for depositing a chromium or chromium alloy layer, the composition comprising:
(i) trivalent chromium ions,
(ii) at least one complexing agent for the trivalent chromium ions, and
(iii) at least one kind of oxide-hydroxide particles,
(c) contacting the substrate with said electroplating composition and applying an electrical current such that the chromium or chromium alloy layer is deposited on at least one surface of said substrate.

### Claim 8 (depends on 7)

The method of claim 7, wherein in step (c) the chromium or chromium alloy layer, respectively, has a thickness in a range from 1.1 μm to 500 μm.

### Claim 9 (depends on 7)

The method of claim 7, wherein in step (c) the chromium or chromium alloy layer, respectively, has a L* value of 70 or less, defined by CIELAB.

### Claim 10 (depends on 7)

The method of claim 7, wherein in step (c) the chromium or chromium alloy layer, respectively, has, defined by CIELAB, an a* value ranging from −2 to +2 and/or a b* value ranging from −2 to +2.

### Claim 11 (depends on 7)

The method of claim 7, wherein after step (c) the chromium or chromium alloy layer, respectively, has a hardness (HV) ranging from 650 to 950.

### Claim 12

(canceled)

### Claim 13

A substrate comprising a chromium or chromium alloy layer, the substrate further comprising
optionally at least one pre-coating between the substrate and said chromium or chromium alloy layer, respectively,
wherein the chromium or chromium alloy layer, respectively, comprises at least one kind of oxide-hydroxide particles.

### Claim 14 (depends on 13)

The substrate of claim 13, wherein the chromium or chromium alloy layer, respectively, has a L* value of 70 or less, defined by CIELAB.

### Claim 15

A substrate comprising a chromium or chromium alloy layer, the substrate further comprising
optionally at least one pre-coating between the substrate and said chromium or chromium alloy layer, respectively,
wherein the chromium or chromium alloy layer, respectively,
comprises carbon,
has a L* value of 70 or less, defined by CIELAB, and
has a thickness of 4 μm or more.