Cyanide-free silver plating method

A cyanide-free silver plating and coating technology, applied in the field of electroplating, can solve the problems of unsatisfactory appearance of the coating and poor stability of the plating solution, etc.

Inactive Publication Date: 2015-02-11
SHENZHEN ZHONGYU ZHAORI TECH
View PDF7 Cites 9 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Almost all traditional silver plating solutions contain highly toxic cyanide, but most of the current research on cyanide-free

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0005] a. Cyanide-free silver plating on copper:

[0006] Acid degreasing: degreasing the product, the acid degreasing formula is: 98% sulfuric acid 100cc, OP-1025g / L5-10min

[0007] Chemical polishing: polish the cleaned product after degreasing, chemical polishing formula: 98% sulfuric acid 3cc, OP-1013cc, alcohol 13C C, thiourea 10g / L, citric acid 100g / L

[0008] Activation: Activate the cleaned product after polishing. The formula of the activation solution is: 98% sulfuric acid 100cc

[0009] Pre-soaking: Pre-soaking the cleaned product after activation with cyanide-free silver plating recycled water

[0010] Cyanide-free silver plating: direct silver-plating on pre-soaked products, formula of cyanide-free silver plating: hydantoin 150-300g / L, silver nitrate 20-30g / L, sulfamic acid 50-150g / L, potassium hydroxide 65 ~125g / L, salicylic acid 1g / L, 22 bipyridine 0.8g / L, alanine 1g / L, imidazole 1g / L, the operating conditions are: temperature 18~40℃, pH value 10~12, cathode ...

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

No PUM Login to view more

Abstract

The invention discloses a silver nitrate-dimethyl hydantoin system cyanide-free silver plating process, and belongs to the field of electrosilvering. A plating solution is prepared as follows: the concentration of dimethyl hydantoin is 50-200 g/L; the concentration of silver nitrate is 8-30 g/L; the concentration of sulfamic acid is 50-150 g/L; the concentration of potassium hydroxide is 65-125 g/L; and components and contents of a brightening agent are as follows: 1 g/L of salicylic acid, 0.8 g/L of 22 dipyridyl, 1 g/L of alanine, and 1 g/L of imidazole. The substances are diluted to 1 L with water or distilled water to become the brightening agent. The plating solution is excellent in stability; silver ions in the plating solution are not replaced with such monometals as copper and nickel and alloy substrates; the silver preplating or the silver dipping is not needed for plating pieces; plating layers have the characteristics of excellent binding force, brightness, smooth surface, good tarnishing resistance, corrosion resistance and wear resistance; and the cyanide-free silver plating can compete with or even be superior to the cyaniding silver plating in some respects, satisfies the requirements for the application in such fields as the decorative electroplating and the functional electroplating, and has higher promotion and application values.

Description

(1) Technical field [0001] The invention relates to a cyanide-free electroplating silver process. The silver coating obtained by the method has fine crystals, bright surface and good binding force, and belongs to the technical field of electroplating. (2) Background technology [0002] Electroplated silver is widely used in electrical appliances, electronics, communication equipment and instrumentation manufacturing industries. With the rapid development of my country's electronics industry, not only the demand for silver plating is increasing, but also the scope of application is becoming wider and wider. Almost all traditional silver plating solutions contain highly toxic cyanide, but most of the current research on cyanide-free silver plating has defects such as poor stability of the plating solution and unsatisfactory appearance of the plating. (3) Contents of the invention [0003] In order to overcome the above defects, after long-term efforts, the bright silver pla...

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
IPC IPC(8): C25D3/46
CPCC25D3/46
Inventor 李兴文
Owner SHENZHEN ZHONGYU ZHAORI TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap