Sulfur-Free Elastomer Gloves via Carboxyl Crosslinking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing synthetic rubber gloves lack effective crosslinking agents that do not cause delayed IV-type hypersensitivity and provide sufficient mechanical properties, such as tensile strength and elongation, without using sulfur or sulfur-containing compounds.
Innovation Solution
A method involving the use of acrylonitrile-butadiene unsaturated carboxylic acid elastomers, where unsaturated carboxylic acid end groups form covalent bonds and ionic bonds with zinc oxide to create a crosslinked composition that does not include sulfur, ensuring the gloves do not cause hypersensitivity and possess improved dynamic viscoelasticity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sulfur and sulfur-containing vulcanization accelerators are used for crosslinking synthetic rubber gloves, then mechanical properties such as tensile strength and elongation are improved, but delayed IV-type hypersensitivity is caused
Solution Approach 1:
The invention extracts and removes sulfur and sulfur-containing compounds from the crosslinking system. Instead of using traditional sulfur-based vulcanization, the patent employs alternative crosslinking agents such as metal oxides (zinc oxide, magnesium oxide) or carboxylic acid crosslinking systems that do not involve sulfur, thereby eliminating the harmful effect of hypersensitivity while maintaining crosslinking functionality
Solution Approach 2:
The invention changes the chemical parameters of the crosslinking system by substituting sulfur-based crosslinking agents with non-sulfur alternatives. This includes using metal oxides as crosslinking agents or employing carboxylic acid end groups that can form crosslinks without sulfur, fundamentally altering the chemical composition to remove the harmful element while preserving the desired mechanical properties
2Object-affected harmful factors
If zinc oxide is used as a crosslinking agent without sulfur, then hypersensitivity is avoided, but tensile strength and mechanical properties are insufficient
Solution Approach 1:
The invention creates a composite crosslinking system that combines zinc oxide with other substances to achieve adequate mechanical properties. This includes using zinc oxide in combination with carboxylic acid-containing polymers, or combining it with small amounts of non-sulfur crosslinking agents, creating a composite system that provides both the hypersensitivity-free benefit and sufficient tensile strength
Solution Approach 2:
The invention introduces intermediary substances that facilitate crosslinking when used with zinc oxide. These intermediaries, such as carboxylic acid groups or other functional groups, act as mediators that enable effective crosslinking between polymer chains in the presence of zinc oxide, thereby achieving adequate mechanical properties without requiring sulfur
3Object-affected harmful factors
If synthetic rubber latex is used instead of natural rubber latex, then hypersensitivity caused by latex protein is avoided, but barrier property is inferior
Solution Approach 1:
The invention changes the physical and chemical parameters of synthetic rubber gloves to improve barrier properties. This includes optimizing the thickness, density, and molecular structure of the synthetic rubber material, as well as controlling the crosslinking density to achieve appropriate porosity and barrier performance, thereby compensating for the inherently lower barrier properties of synthetic rubber compared to natural rubber
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 resulting gloves exhibit enhanced tensile stress, breaking strength, and elongation without causing hypersensitivity, with a glass transition temperature increase and improved elastic modulus, indicating better crosslinking density and barrier properties.
Implementation Method 1
a part of the carboxyl group is covalently crosslinked by reacting an end group of the unsaturated carboxylic acid of the elastomer with another end group of the unsaturated carboxylic acid of the elastomer
Implementation Method 2
residual carboxyl group is crosslinked by forming ionic bond through zinc oxide
Implementation Method 3
A rubber glove of desired thickness is dried and crosslinked under heated temperature condition
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An elastomer composition comprising, an emulsion which comprises 25-30 weight % of acrylonitrile, 62-71 weight % of butadiene and 4-8 weight % of unsaturated carboxylic acid (total 100 weight %), wherein crosslink is formed by a bond through at least a part of substituent which is possessed by said unsaturated carboxylic acid, and residual substituent of at least one part of substituent which is possessed by said unsaturated carboxylic acid is left in state of free, further Mooney viscosity (ML(1+4)(100°C)) of the crosslinked product is 100-220, wherein thin film gloves composed of said elastomer does not contain sulfur which is a crosslinking agent and sulfur composition which is a vulcanization accelerator, thickness is 0.05-0.15mm, gloves swelling ratio at gloves formation is 240-320, tensile stress is 22-35 MPa, elongation to break is 480-620% and tensile stress at 500% elongation is 15-35 MPa.