Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Aqueous,alkaline,cyanide-free bath for the galvanic deposition of zinc and zinc alloy coatings

a technology of zinc alloy coating and alkali bath, applied in the field of alkali galvanic bath, can solve the problems excessive thickness of zinc layers in areas of high current density, and uneven layer thickness distribution of zinc layers obtained according to these documents

Inactive Publication Date: 2010-09-23
ATOTECH DEUT GMBH
View PDF6 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The invention provides an electroplating bath for zinc and zinc alloy coatings that results in high brightness and good layer thickness distribution at high current efficiency. The use of specific copolymers and brightening agents in combination with a polymer results in improved layer thickness distribution and increased current efficiency. The electroplating bath is a combination of zinc ions, hydroxide ions, a polymer, and a pyridinium compound. The polymer used in the bath is a soluble copolymer that is obtained by reaction of N,N-bis-[(dialkylamino)-alkyl]-ureas with α,ω-dihaloalkanes. The electroplating bath is a combination of different soluble polymers of general formula I. The technical effects of the invention are improved brightness and current efficiency of zinc and zinc alloy coatings.

Problems solved by technology

However, they have the disadvantage that their current efficiency is always 100% across a wide range of current densities.
However, in the case of substrates having a complex geometry, this results in excessively thick zinc layers in areas of high current density and to thin zinc layers in areas of low current density.
DE 25 25 264 and U.S. Pat. No. 3,884,774 describe such electrolytes; however, the zinc layers obtained according to these documents do not show a uniform layer thickness distribution.
A disadvantage of this method is the high concentration of reducing sugars which results in increased COD and TOC contents in the effluent water.

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,alkaline,cyanide-free bath for the galvanic deposition of zinc and zinc alloy coatings
  • Aqueous,alkaline,cyanide-free bath for the galvanic deposition of zinc and zinc alloy coatings
  • Aqueous,alkaline,cyanide-free bath for the galvanic deposition of zinc and zinc alloy coatings

Examples

Experimental program
Comparison scheme
Effect test

preparation example 1

Synthesis of 1-(4′-methoxy-benzyl)-3-carbamoyl-pyridinium-chloride

[0066]In a 100 ml round-bottom flask with reflux condenser, 60 ml of water, 9.2 g of nicotinic acid amide (98%) (0.0738 mol), 11.68 g of 4-methoxybenzylchloride (99%) (0.07378 mol) are heated under reflux for 24 hours. After completion of the reaction, the water is removed in vacuo and the residue is taken up in 200 ml of ethanol and heated under reflux for another hour. The reaction mixture is then cooled to 4° C. and the white solid obtained is removed by filtration and dried in vacuo. This yielded 16.92 g of a white solid (82.26% of the theoretical yield).

preparation example 2

Synthesis of 1-(4′-chloro-benzyl)-3-carbamoyl-pyridinium-chloride

[0067]In a 100 ml round-bottom flask with reflux condenser, 60 ml of ethanol, 10 g of nicotinic acid amide (98%) (0.0802 mol), 13.05 g of 4-chloro-benzylchloride (99%) (0.0802 mol) are heated under reflux for 24 hours. After completion of the reaction, the solid residue is heated in an ethanol / methanol mixture for another 15 minutes and then cooled to 4° C. The solid obtained is removed by filtration and dried in vacuo. This yielded 18.82 g of a white solid (82.87% of the theoretical yield).

preparation example 3

Synthesis of 1,1′-(xylenyl)-3,3′-bis-carbamoyl-bis-pyridinium-dichloride

[0068]In a 100 ml round-bottom flask with reflux condenser, 60 ml of ethanol, 10 g of nicotinic acid amide (98%) (0.0802 mol), 7.16 g of α,α′-dichloro-p-xylene (98%) (0.0401 mol) are heated under reflux for 24 hours. After completion of the reaction, the solid residue is heated in 200 ml of an ethanol / methanol mixture for another 15 minutes and then cooled to 4° C. The resulting solid is removed by filtration and dried in vacuo. This yielded 12.29 g of a white solid (73.13% of the theoretical yield).

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
concentrationaaaaaaaaaa
concentrationaaaaaaaaaa
current densityaaaaaaaaaa
Login to View More

Abstract

The invention relates to an aqueous, alkaline cyanide-free electrolyte bath for de-positing zinc and zinc alloy coatings on substrate surfaces comprising (a) a source for zinc ions and optionally a source for further metal ions, (b) hydroxide ions, (c) a polymer of general formula I which is soluble in the bath and (d) at least one pyridinium compound of general formula II or III. The electrolyte bath is suitable for the galvanic deposition of bright and even zinc and zinc alloy coatings.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an aqueous, alkaline galvanic bath without addition of cyanide ions as complexing agents for the deposition of zinc and zinc alloy coatings, which bath contains as additives bis-(N,N-diaminoalkyl)urea-α,ω-dihaloalkyl copolymers or oligomers and 3-carbamoyl pyridinium compounds quaternized in the 1-position. Furthermore, the invention relates to a process for the deposition of bright and even zinc and zinc alloy coatings in which the bath is used.BACKGROUND OF THE INVENTION[0002]The zinc deposition from cyanide-containing alkaline solution has had a significant market share for many years. However, increasingly stringent statutory requirements regarding the disposal of used zinc and zinc alloy electrolyte baths and the consequent strict control regarding waste water have resulted in increased interest in cyanide-free zinc and zinc alloy electrolytes.[0003]Such metal coatings are used for improving corrosion properties and f...

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(United States)
IPC IPC(8): C25D3/56C25D3/22
CPCC07D213/82C25D3/565C25D3/22
Inventor BRUNNER, HEIKOKOHLMANN, LARSHABIG, ELLENTHOM, KONSTANTINVOGEL, ROLAND
Owner ATOTECH DEUT GMBH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com