Dip-Molded Latex Film Donning Properties via Degraded Starch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polymer latex compositions for dip-molded articles, such as gloves, require a two-step process to achieve improved donning properties, which is costly and complicated, and do not maintain tensile properties effectively.
Innovation Solution
A polymer latex composition is developed through free-radical emulsion polymerization in the presence of degraded polysaccharides, using specific weight percentages of aliphatic conjugated dienes, unsaturated nitriles, ethylenically unsaturated acids, and aromatic vinyl compounds, allowing for a single-step process that enhances donning properties without compromising tensile strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a two-step process is used to prepare dip-molded articles with improved donning properties, then the donning properties are improved, but the process complexity and cost increase
Solution Approach 1:
The patent combines the functions of two separate latices into a single polymer latex composition. The first lacle provides tensile strength and elasticity, while the second lacle provides donning properties. By merging these into one composition with specific monomer ratios (acrylonitrile 10-40 wt.%, styrene 30-60 wt.%, butadiene 10-40 wt.%) and degraded starch (1-10 wt.%), the patent eliminates the need for a two-step process while maintaining both tensile properties and improved donning properties.
Solution Approach 2:
The single polymer latex composition performs multiple functions simultaneously: it provides the structural integrity and tensile strength required for dip-molded articles, while also providing improved donning properties through the combination of specific monomers and degraded starch. This multi-functional composition replaces the need for separate specialized latices.
2Strength
If high amounts of vinyl aromatic monomers are used in polymer latex compositions, then the tensile properties are maintained, but the donning properties are not improved
Solution Approach 1:
The patent optimizes the parameter ratios of different monomers in the polymer latex composition. Specifically, it limits vinyl aromatic monomers (styrene) to 30-60 wt.%, acrylonitrile to 10-40 wt.%, and butadiene to 10-40 wt.%, while adding degraded starch at 1-10 wt.%. This parameter optimization allows the composition to achieve both adequate tensile properties and improved donning properties, unlike compositions with high amounts of vinyl aromatic monomers alone.
Solution Approach 2:
The patent creates a composite polymer latex system by combining multiple monomers (acrylonitrile, styrene, butadiene) with degraded starch in specific proportions. This composite approach allows the material to exhibit both the mechanical strength from the polymer matrix and the improved donning properties from the degraded starch, overcoming the limitations of single-component systems.
3Ease of operation
If a coating composition is applied in a second step to improve donning properties, then the donning and putting-off properties are improved, but the production cost and time increase
Solution Approach 1:
The patent merges the coating step into the primary latex composition step. By incorporating degraded starch (1-10 wt.%) and optimizing the monomer composition during the initial polymerization, the resulting single latex composition provides both structural integrity and improved donning properties, eliminating the need for a separate coating application step and reducing production time.
Solution Approach 2:
The patent performs the donning property enhancement action preliminarily by incorporating degraded starch and optimizing monomer ratios during the polymerization stage. This preliminary incorporation ensures that the donning properties are built into the base material itself, eliminating the need for subsequent coating steps to achieve the desired properties.
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 production of dip-molded articles with improved donning properties and maintained tensile strength in a standard single-step process, reducing production complexity and cost.
Implementation Method 1
a polymer latex composition for dip-molding applications comprising the reaction product obtained by free-radical emulsion polymerization in aqueous medium of ethylenically unsaturated monomers
Data Source
AI summary
A polymer latex composition for dip-molding applications includes the reaction product obtained by free-radical emulsion polymerization in aqueous medium of ethylenically unsaturated monomers including; (a) 19.9 to 90 wt.-% of at least one aliphatic conjugated diene; (b) 9.9 to 80 wt.-% of at least one unsaturated nitrile; (c) 0.1 to 10 wt.-% of at least one ethylenically unsaturated acid; (d) 0 to 19 wt.-% of at least one aromatic vinyl compound, and (e) 0 to 20 wt.-% of at least one further ethylenically unsaturated compound different from any of compounds (a) to (d), the weight percentages being based on the total amount of monomers, wherein the emulsion polymerization is conducted in presence of a degraded polysaccharide having a DE of 2 to 90 measured according to ISO 5377 (Dec. 15, 1981) to a method for making said polymer latex composition, to a curable polymer latex compound including said polymer latex composition, to a method for making dip molded latex films employing said curable polymer latex compound, to a film made from said polymer latex composition and to articles including said film or being coated with said polymer latex composition.