2,6-Dihydroxybenzoic Acid Curing Agent for Foundry Molds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing foundry mold curing agents, particularly those using sulfonic acid or sulfuric acid, generate significant sulfur dioxide gas during the casting process, which negatively impacts the working environment and can result in gas defects in the casting, while reducing the acid content to minimize this issue often compromises mold hardening speed and strength.
Innovation Solution
A curing agent composition comprising 2,6-dihydroxybenzoic acid, which acts as an acid catalyst to improve mold hardening speed and strength without generating sulfur dioxide gas, is used in conjunction with an acid-hardening resin and refractory particulate materials to form a sand composition for making foundry molds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sulfonic acid or sulfuric acid is used as a curing agent, then mold hardening speed and strength are improved, but sulfur dioxide gas emission increases
Solution Approach 1:
The patent changes the chemical composition parameter of the curing agent from sulfur-containing acids (sulfonic acid, sulfuric acid) to a sulfur-free acid (hydroxybenzoic acid or its salts). This parameter change maintains the acid-catalyzed hardening function while eliminating sulfur dioxide gas generation, thus resolving the contradiction between mold strength and harmful emissions.
Solution Approach 2:
The patent employs a simpler, more environmentally friendly curing agent (hydroxybenzoic acid or its salts) that can be easily replaced and does not generate persistent harmful emissions. This substitution prioritizes environmental protection and worker safety over the use of more aggressive sulfur-containing acids.
2Object-generated harmful factors
If the content of sulfonic acid is decreased to reduce sulfur dioxide gas, then sulfur dioxide emission is reduced, but mold hardening speed is lowered
Solution Approach 1:
The patent changes the acid type parameter from sulfonic acid to hydroxybenzoic acid or its salts, which provides sufficient catalytic activity for hardening without generating sulfur dioxide. This parameter change allows maintaining fast hardening speed while eliminating sulfur emissions, resolving the contradiction between emission reduction and hardening performance.
Solution Approach 2:
The patent introduces hydroxybenzoic acid or its salts as an intermediary curing agent that mediates between the need for fast hardening (requiring strong acid) and the need to eliminate sulfur dioxide emissions. This intermediary substance provides the necessary catalytic function without the harmful side effects of sulfur-containing acids.
3Object-generated harmful factors
If the content of sulfonic acid is decreased to reduce sulfur dioxide gas, then sulfur dioxide emission is reduced, but mold strength is lowered
Solution Approach 1:
The patent changes the curing agent composition parameter to use hydroxybenzoic acid or its salts instead of sulfonic acid. This parameter change maintains sufficient mold strength by providing adequate acid catalysis for resin hardening while completely eliminating sulfur dioxide gas generation, thus resolving the contradiction between strength and emission reduction.
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 use of 2,6-dihydroxybenzoic acid in the curing agent composition significantly reduces sulfur dioxide gas emission during casting, enhances mold hardening speed and strength, and improves the overall casting quality by eliminating gas defects, thereby improving the working environment and casting outcomes.
Implementation Method 1
2,6-dihydroxybenzoic acid, which acts as an acid catalyst to improve mold hardening speed and strength
Implementation Method 2
The use of 2,6-dihydroxybenzoic acid in the curing agent composition significantly reduces sulfur dioxide gas emission during casting
Data Source
AI summary
A curing agent composition for making foundry molds, comprising 2,6-dihydroxybenzoic acid. In a sand composition for making foundry molds, it is preferable to use simultaneously: an acid-hardening resin which contains both a binder composition for making foundry molds which comprises one or more 5-position-substituted furfural compounds selected from the group consisting of 5-hydroxymethylfurfural and 5-acetoxymethylfurfural, and the curing agent composition for making foundry molds which comprises 2,6-dihydroxybenzoic acid. It is preferable that the content of 2, 6-dihydroxybenzoic acid in the curing agent composition is 10 to 80wt%.