Fluorinated Copolymer Salt Composition for Water-Oil Resistance
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Solution Overview
Problem
Conventional water/oil resistant compositions using fluorinated copolymers with perfluoroalkyl groups having at least 8 carbon atoms face issues with agglomeration, pH sensitivity, and odor, while those with fewer than 6 carbon atoms or perfluoropolyether offer inadequate water/oil resistance and environmental concerns.
Innovation Solution
A water/oil resistant composition is developed using a fluorinated copolymer with structural units based on specific monomers, converted to a salt with an organic acid having a pKa of 2.0 to 4.0, such as lactic acid, citric acid, or malic acid, and optionally including adjuvants like anionic paper strength enhancing agents, to achieve improved water/oil resistance and reduced environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fluorinated copolymer with perfluoroalkyl groups having at least 8 carbon atoms is used to achieve adequate water/oil resistance, then water/oil resistance is improved, but agglomerates are likely to be formed and operational trouble occurs
Solution Approach 1:
The patent changes the carbon atom count parameter of perfluoroalkyl groups from ≥8 to 6-7 carbon atoms, and specifies a particular structural formula with n=1 or 2 and specific Z and R group configurations. This parameter optimization maintains water/oil resistance while preventing agglomeration and operational issues.
Solution Approach 2:
The patent uses a copolymer composed of multiple monomer units including perfluoroalkylethyl methacrylate, (meth)acrylate, and vinyl chloride or vinylidene chloride. This composite structure combines the benefits of fluorinated groups for water/oil resistance with other monomers that prevent agglomeration and improve operational stability.
2Ease of manufacture
If acetic acid is used to convert amino groups to form a salt in the fluorinated copolymer, then cost and safety are improved, but the composition becomes sensitive to pH and adjuvants causing agglomeration and loss of water/oil resistance
Solution Approach 1:
The patent changes the pKa parameter of the organic acid from acetic acid (pKa 4.76) to acids with pKa of 2.0-4.0, such as formic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, or their mixtures. This parameter change reduces pH sensitivity and prevents agglomeration while maintaining water/oil resistance stability.
Solution Approach 2:
The patent introduces a specific organic acid as an intermediary substance that mediates between the amino groups of the copolymer and the environment. These acids with pKa 2.0-4.0 provide stable salt formation that is less sensitive to pH changes and anionic adjuvants, preventing agglomeration.
3Object-affected harmful factors
If perfluoropolyether is used as a substitute for longer perfluoroalkyl chains to reduce environmental concerns, then environmental impact is reduced, but water/oil resistance becomes inadequate
Solution Approach 1:
The patent optimizes the perfluoroalkyl chain length parameter to 6-7 carbon atoms (specifically perfluoroalkylethyl groups with n=1 or 2), which is shorter than conventional ≥8 carbon chains but longer than perfluoropolyether. This intermediate length provides adequate water/oil resistance while reducing environmental persistence and bioaccumulation concerns.
Solution Approach 2:
The patent combines perfluoroalkylethyl methacrylate units with other monomer units including (meth)acrylate and vinyl chloride or vinylidene chloride. This composite structure achieves adequate water/oil resistance through the synergistic effect of fluorinated groups and other hydrophobic monomers, allowing the use of shorter, more environmentally friendly perfluoroalkyl chains.
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 composition provides sufficient water/oil resistance to base materials, is less influenced by pH and adjuvants, and has minimal odor, while reducing environmental concerns associated with longer perfluoroalkyl chains.
Implementation Method 1
converted to a salt with an organic acid having a pKa of 2.0 to 4.0
Implementation Method 2
fluorinated copolymer having structural units based on specific monomers... converted to a salt... to achieve improved water/oil resistance
Data Source
AI summary
To provide a water/oil resistant composition which can impart a sufficient water/oil resistance to a base material even though a fluorinated copolymer having an Rf group with at most 6 carbon atoms is used, said water/oil resistance being not substantially influenced by an adjuvant or the pH of dilution water, and which has little odor; an article treated therewith; and processes for their production. A water/oil resistant composition having a fluorinated copolymer dispersed or dissolved in a medium, wherein the fluorinated copolymer is one having one, some or all of amino groups in a fluorinated copolymer comprising structural units based on a monomer (a) having a C1-6 Rf group and structural units based on a monomer (b) having an amino group, converted to form a salt with an organic acid comprising an organic acid having a pKa of from 2.0 to 4.0.