Resin Etching Composition Using Manganese and Halogen Oxoacids

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Chromic acid-containing etching solutions used in electroplating resin molded articles are hazardous and pose environmental concerns due to toxic hexavalent chromium, requiring complex waste disposal processes, and safer alternatives that maintain film adhesion are lacking.

Innovation Solution

An etching composition comprising an aqueous solution of inorganic acids, manganese salts, and halogen oxoacids or their salts is used to form an electroless plating film with high adhesion on resin molded articles, eliminating the need for chromic acid and simplifying waste disposal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If chromic acid mixture is used for etching treatment, then plating film adhesion is improved, but workplace safety deteriorates and waste disposal complexity increases

Engineering Contradiction:
Improveplating film adhesionVSAvoidtoxicity of hexavalent chromium
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters of the etching solution by replacing chromic acid with a specific combination of inorganic acid, manganese salt, and halogen oxoacid salt. This parameter substitution maintains the etching effectiveness and plating film adhesion while eliminating the toxicity of hexavalent chromium, thus resolving the contradiction between adhesion and safety.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the harmful chromic acid system into a beneficial alternative by using manganese salt and halogen oxoacid salt combination. The new composition achieves similar or superior etching performance without the harmful effects, effectively transforming a harmful process into a safe one while maintaining the desired plating film adhesion.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If chromic acid mixture is used for etching treatment, then plating film adhesion is improved, but waste disposal complexity increases

Engineering Contradiction:
Improveplating film adhesionVSAvoidwaste disposal process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the chemical parameters of the etching solution to use environmentally friendly components (inorganic acid, manganese salt, halogen oxoacid salt) that do not require complex reduction and neutralization processes. This parameter change simplifies waste disposal while maintaining plating film adhesion performance.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If chromic acid-containing etching solution is avoided, then workplace safety is improved, but plating film adhesion deteriorates

Engineering Contradiction:
Improveworkplace safetyVSAvoidplating film adhesion
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention introduces an intermediary combination of chemicals (inorganic acid, manganese salt, and halogen oxoacid salt) that serves as a mediator between the safe working environment requirement and the plating film adhesion requirement. This intermediary composition achieves both safety and adhesion performance simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention uses a composite chemical system combining inorganic acid, manganese salt, and halogen oxoacid salt to achieve the desired plating film adhesion without relying on single-component chromic acid systems. This composite approach provides both safety and performance benefits.

Inventive Principle:
Principle #40Composite materials

4Object-affected harmful factors

If safer etching solution is used, then workplace safety is improved, but plating film adhesion is insufficient

Engineering Contradiction:
Improveworkplace safetyVSAvoidplating film adhesion
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention optimizes the concentration parameters and composition ratios of the safer etching solution (inorganic acid: 20-1200 g/l, manganese salt: 0.01-10 g/l, halogen oxoacid salt: 1-200 g/l) to achieve adequate plating film adhesion while maintaining workplace safety. This parameter optimization resolves the contradiction between safety and adhesion.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution enables the formation of electroless plating films with excellent adhesion and appearance on various resin materials, improving workplace safety and facilitating environmentally friendly waste management by avoiding hazardous chromic acid use.

Implementation Method 1

a composition comprising an aqueous solution containing 20 to 1,200 g/l of at least one inorganic acid selected from the group consisting of sulfuric acid and hydrochloric acid; 0.01 to 10 g/l of a manganese salt; and 1 to 200 g/l of at least one component selected from the group consisting of halogen oxoacids, halogen oxoacid salts, persulfate salts, and bismuthate salts

Methodology Applied
Scientific EffectChemical etching: Oxidation

Data Source

PatentEP2009142B8Composition for etching treatment of resin molded article
Publication Date: 2013.08.14 OKUNO CHEM IND CO LTD

AI summary

The present invention provides a composition for the etching treatment of a resin molded article. The composition is composed of an aqueous solution containing 20 to 1,200 g/l of an inorganic acid, 0.01 to 10 g/l of a manganese salt, and 1 to 200 g/l of at least one component selected from the group consisting of halogen oxoacids, halogen oxoacid salts, persulfate salts, and bismuthate salts. The etching composition of the invention is a novel etching solution capable of forming a plating film having a good adhesion to various resin molded articles made of ABS resins or the like, and can be used in place of chromic acid mixtures. The composition is highly safe so that the liquid waste is easily disposed of.