Unlock instant, AI-driven research and patent intelligence for your innovation.

Aqueous solution and method for the formation of a passivation layer

A technology of aqueous solution and passivation layer, applied in the field of aqueous solution, can solve the problems of uneven layer appearance, suboptimal passivation, light gray, etc.

Inactive Publication Date: 2014-01-01
ENTHONE INC
View PDF6 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] However, it is known from the prior art that a hexavalent chromium-free passivation process that produces a black passivation layer has the disadvantage that the appearance of the layer is inhomogeneous and not really dark black, but light gray
Especially when zinc or zinc alloy layers are deposited at low temperatures (e.g. around room temperature), subsequent passivation is often suboptimal

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Aqueous solution and method for the formation of a passivation layer
  • Aqueous solution and method for the formation of a passivation layer
  • Aqueous solution and method for the formation of a passivation layer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach

[0025] According to another embodiment of the invention, the composition comprises a fluoride source. For example, such a fluoride source can be a fluoride salt such as sodium fluoride, potassium fluoride, or a fluoride compound such as sodium hydrofluoride, potassium bifluoride, or ammonium fluoride. Fluoride may be included in the composition at a concentration of 0 mol / l to 0.5 mol / l, preferably between 0 mol / l and 0.05 mol / l. Adding a fluoride source to the composition enhances the optical appearance of the passivation layer and makes the passivation layer appear more uniform and glossy.

[0026] In addition, the present invention also relates to a method for forming a passivation layer on a zinc layer or a zinc alloy layer, said method comprising the following steps:

[0027] depositing a layer of zinc or zinc alloy on the surface of the substrate;

[0028] treating the deposited zinc layer or zinc alloy layer with a treatment aqueous solution comprising a source of tri...

Embodiment 1

[0034] An aqueous composition comprising at least

[0035] Zinc chloride 62g / l;

[0036] Boric acid 25g / l-30g / l; and

[0037] Potassium chloride 210g / l.

[0038] The pH value of the composition as described above is in the range between pH4 and pH6 at room temperature. Preferably, the composition is free of complexing agents.

Embodiment 2

[0040] An aqueous composition comprising at least

[0041] Zinc chloride 62g / l;

[0042] Ammonium chloride 45g / l; and

[0043] Potassium chloride 162g / l.

[0044] The pH value of the composition as described above is in the range between pH4 and pH6 at room temperature. Preferably, the composition is free of complexing agents.

[0045] Optionally, the zinc electrolyte mentioned in embodiment 1 or embodiment 2 may include a brightener. An example of a brightener that may be used in such a zinc electrolyte is an additive sold under the trade name ENTHOBRITE CLZ from Enthone Corporation of West Ham, Connecticut.

[0046] In a preferred embodiment of the method according to the invention, the zinc or zinc alloy layer is deposited from an acidic electrolyte comprising sulfur diethylene glycol ethoxylate. Thiodiethylene glycol ethoxylate may be contained in the electroplating electrolyte at a concentration in the range of 0 mol / l to 1.0 mol / l, preferably in the range of 0.01 mo...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
densityaaaaaaaaaa
viscosityaaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

The present invention generally relates to an aqueous solution for the formation of a passivation layer on a zinc layer or zinc-alloy layer. More particularly, the invention relates to the formation of a black passivation layer on a zinc layer or zinc-alloy layer, which passivation layer is substantially free of hexavalent chromium. Furthermore, the present invention relates to method for the formation of a passivation layer on a zinc layer or zinc-alloy layer, as well as a passivation layer on a zinc layer or zinc-alloy layer itself. The solution used contains trivalent chromium ions, nitrate ions, an organic acid and a dithioglycolate.

Description

[0001] References to related applications [0002] This application claims priority from European application 11155672.6 filed on February 23, 2011, the entire disclosure content of which is incorporated herein by reference. technical field [0003] The present invention generally relates to an aqueous solution for forming a passivation layer on a zinc or zinc alloy layer. More specifically, the present invention relates to forming a black passivation layer on a zinc layer or zinc alloy layer, the passivation layer being substantially free of hexavalent chromium. Furthermore, the invention relates to a method for forming a passivation layer on a zinc layer or a zinc alloy layer, and the passivation layer on the zinc layer or zinc alloy layer itself. Background technique [0004] In the prior art it is known to protect such metal surfaces from corrosion by depositing a protective layer on such metal surfaces. This technique has been known for a long time and is widely used ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C23C22/53C23C22/34C25D5/48
CPCC23C22/53C25D5/48C23C2222/10C25D3/22C23C22/34Y10T428/12792B05D3/107
Inventor 雷内·凡谢克凯斯·理查德·佐内
Owner ENTHONE INC