One-Step Polymer Composite Coating for Plastic Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing clay/polymer composite films for packaging are inefficient, requiring cumbersome processes, surfactants, or organic solvents, which result in poor barrier performance and bonding strength, and are not environmentally friendly.
Innovation Solution
A one-step process involving in-situ polymerization of poly(acrylic acid) copolymers with clay and silane modified clay, using a mixture of acrylic monomers and silane coupling agents, to create a polymer composite suspension that enhances bonding strength and barrier properties without surfactants or organic solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silane modified clay composites are used to improve barrier performance, then oxygen and moisture barrier properties are enhanced, but the preparation process becomes complex requiring surfactants and multiple steps
Solution Approach 1:
The patent combines multiple functions into a single polymer matrix system. The polymer simultaneously acts as the continuous phase, the dispersing medium for clay, and the bonding agent, eliminating the need for separate surfactant systems and multiple preparation steps while maintaining effective barrier performance through clay dispersion.
Solution Approach 2:
The polymer component is designed to perform multiple functions: it serves as the continuous matrix phase, provides dispersion medium for the clay fillers, and acts as the bonding agent attaching clay to the substrate. This multi-functionality eliminates the need for separate surfactants and simplifies the overall preparation process.
2Stability of the object's composition
If surfactants are used to disperse silanes in aqueous clay suspension, then dispersion is improved, but bonding strength to polymer matrix is reduced
Solution Approach 1:
The patent removes surfactants from the system entirely. Instead of using surfactants to achieve dispersion, the invention relies on the polymer matrix itself to disperse and bond with the clay fillers, thereby eliminating the harmful effect of surfactants on bonding strength while maintaining suspension stability.
Solution Approach 2:
The polymer acts as an intermediary between the clay fillers and the substrate. It provides the dispersion function that surfactants would otherwise provide, while simultaneously maintaining strong bonding to the substrate, thus serving as a dual-function mediator that resolves the contradiction between dispersion stability and bonding strength.
3Productivity
If multiple silanes are mixed in one pot of aqueous clay suspension, then process efficiency is improved, but reaction between silanes reduces surface treatment efficacy
Solution Approach 1:
The patent removes the aqueous suspension medium and replaces it with a polymer-based system. This eliminates the premature silane reaction problem that occurs in aqueous environments, allowing multiple silanes to be combined in one pot without interference, thereby maintaining both high efficiency and high surface treatment quality.
Solution Approach 2:
The invention changes the fundamental parameter of the dispersion medium from aqueous to polymeric. This parameter change prevents premature silane reactions while allowing multiple silanes to be effectively combined, thus resolving the contradiction between process efficiency and surface treatment quality.
4Ease of manufacture
If conventional coating processes are used, then existing equipment can be utilized, but barrier performance and transparency are insufficient
Solution Approach 1:
The patent uses composite materials consisting of polymer matrix with dispersed clay fillers. This composite structure provides both the required barrier performance and transparency while maintaining compatibility with conventional coating processes, thus resolving the contradiction between ease of manufacture and barrier performance.
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 process results in high transparency, improved bonding strength, and effective moisture and oxygen barrier properties for plastic films, reducing manufacturing costs and environmental impact while simplifying the production process.
Implementation Method 1
a poly (acrylic acid) (PAA) copolymer is synthesized in-situ optionally in the presence of other polymers and in the presence of clay
Implementation Method 2
modification of clay surfaces with organic compounds such as silanes
Implementation Method 3
the presence of nanoclay fillers in polymer matrix increases the tortuosity of the diffusive path for a penetrate molecule, thus providing an excellent barrier property
Data Source
AI summary
This invention relates to a a one-step process for making a polymer composite suspension for coating plastic films characterized in that a first polymer is synthesized in-situ optionally in the presence of other polymers and in the presence of clay. Preferably the polymer composite suspension comprises a) 1.0 to 11.0 wt % of clay or silane modified clay, b) 0.1 to 10.0 wt % of poly (acrylic acid), which is a copolymer of acrylic acid (AA) with at least one other monomer selected from 2-ethylhexyl acrylate (EHA), β-carboxyethyl acrylate (β-CEA), methacrylamidoethyl ethylene urea (WAM II) and ethoxylated behenyl methacrylate (β-EM), c) 1.0 to 15.0 wt % of other polymers, preferably poly (vinyl alcohol) and d) 70 to 97 wt % of water or mixture of water with 2-propanol. The coating films made from the suspensions show good barrier capabilities against water vapor and oxygen can be used to make barrier layers on or within plastic films for packaging applications. The invention also relates to methods for making silane modified clay usable in the process for making the suspensions.