Aqueous Polyolefin Dispersion for Paper Barrier Coatings
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Solution Overview
Problem
Current aqueous polyolefin dispersions do not provide suitable barrier properties for paper and carton applications, specifically lacking in grease-resistance, water resistance, and water vapor resistance, while also requiring a balance between viscosity and solids content for efficient processing.
Innovation Solution
An aqueous polyolefin dispersion comprising 50-100 wt.% of a mixture of ethylene and (meth)acrylic acid copolymers, another polymer, and optional additives, with a Melt Flow Index (MFI) below 10 g/10min, achieved through specific polymer selection and processing conditions, allowing for high-volume efficiency and good processability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the solids content of the dispersion is increased to improve volume efficiency, then less water ballast needs to be transported and processed, but the viscosity becomes too high making the dispersion difficult to process
Solution Approach 1:
The patent applies parameter changes by carefully controlling the Melt Flow Index (MFI) of the polyolefin polymer within a specific range (5-50 g/10min at 190°C, 2.16 kg load) and optimizing the solids content (10-60 wt%). This parameter optimization allows the dispersion to achieve both high volume efficiency and good processability, resolving the contradiction between these two requirements.
2Ease of manufacture
If conventional polyolefin dispersions are used for paper coating, then the coating can be applied using conventional water-based coating processes, but the barrier properties (grease-resistance, water resistance, water vapor resistance) are insufficient
Solution Approach 1:
The patent employs composite materials by combining polyolefin polymer with specific additives including surfactants (0.1-5 wt%), thickening agents (0.1-5 wt%), and optional pigments (0.1-5 wt%). This composite formulation enhances the barrier properties of the coating while maintaining compatibility with conventional water-based coating processes, thus resolving the contradiction between ease of manufacture and reliability of barrier properties.
3Ease of operation
If the Melt Flow Index of the polyolefin is increased to improve processability, then the dispersion becomes easier to handle, but the barrier properties and coating quality deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the Melt Flow Index (MFI) of the polyolefin to a specific range (5-50 g/10min at 190°C, 2.16 kg load). This controlled parameter range ensures that the dispersion maintains both adequate processability and effective barrier properties, resolving the contradiction between these two requirements.
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 dispersion provides excellent barrier properties, high dispersion stability, and combines high-volume efficiency with good processability, enhancing the quality of paper and carton products by improving grease-resistance, water resistance, and water vapor resistance.
Implementation Method 1
The polyolefin dispersion can be applied to paper using conventional processes for water-based coatings... the applied aqueous dispersion is easy to process... providing an economically attractive alternative
Implementation Method 2
after removal of the water the solid content of the aqueous polyolefin dispersion X has a Melt Flow Index (MFI) lower than 10 g/10min
Data Source
AI summary
The invention relates to an aqueous polyolefin dispersion X comprising a. from 50 to 100 wt.% of an aqueous dispersion A comprising the following ingredients: i. from 41 to 99 wt.% of A1, a mixture of different types of copolymers of ethylene and (meth)acrylic acid, ii. from 1 to 59 wt.% of A2, another polymer or a mixture of other polymers, each not being a copolymer of ethylene and (meth)acrylic acid and each containing structure units of ethylene, iii. from 0 - 35 wt.% of additive not being A1 or A2, b. from 0 to 50 wt.% of a compound B, where compound B is a material dispersible or soluble in water and different from any of the ingredients of dispersion A, wherein - the wt.% of A and B is based on the solid content of the whole aqueous polyolefin dispersion X, - the wt.% of the ingredients of dispersion A is based on the solid content of dispersion A, - the sum of the wt.% of ingredients i) to iii) of dispersion A is 100% and wherein after removal of the water the solid content of the aqueous polyolefin dispersion X has a Melt Flow Index (MFI) lower than 10 g/10min.