Polyvinyl Alcohol Stabilized Acrylic Polymers Dispersion
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Solution Overview
Problem
Conventional polyvinyl alcohol stabilization methods for (meth)acrylic ester polymers in aqueous dispersions and water-redispersible powders are not effective, leading to instability and the need for ecologically and health-wise problematic emulsifiers, while specific modified polyvinyl alcohols are complex and expensive to prepare.
Innovation Solution
The use of conventional unmodified polyvinyl alcohols to stabilize (meth)acrylic ester polymers in the form of aqueous dispersions or water-redispersible powders, with specific monomer compositions and polymerization processes to achieve stable, finely divided particles, eliminating the need for emulsifiers and simplifying the preparation process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional polyvinyl alcohol is used to stabilize (meth)acrylic ester polymers, then the protective colloid is simple and inexpensive, but the dispersion stability is insufficient and coarse particles form
Solution Approach 1:
The patent changes the parameters of the (meth)acrylic ester polymer composition, specifically incorporating vinyl esters of carboxylic acids with 5-15 carbon atoms (1-30 wt%) together with conventional (meth)acrylic esters. This compositional parameter change enables conventional polyvinyl alcohol to effectively stabilize the dispersion, resolving the contradiction between using simple protective colloids and achieving adequate dispersion stability.
2Stability of the object's composition
If emulsifiers are used to stabilize (meth)acrylic ester copolymers, then dispersion stability is improved, but ecological and health safety deteriorates due to irritating or sensitizing action
Solution Approach 1:
The patent extracts and eliminates emulsifiers from the system by demonstrating that conventional polyvinyl alcohol alone can provide sufficient stabilization for (meth)acrylic ester polymers containing vinyl esters. This removes the harmful substances while maintaining dispersion stability, directly resolving the contradiction between stability and safety.
3Stability of the object's composition
If specific modified polyvinyl alcohols are used to stabilize (meth)acrylic ester polymers, then dispersion stability is achieved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent replaces expensive, complex modified polyvinyl alcohols with conventional, inexpensive polyvinyl alcohol that requires no special synthesis or modification. This substitution achieves the same stabilization function while eliminating the complexity and cost of preparing specialized protective colloids.
4Ease of operation
If conventional polyvinyl alcohol stabilizes (meth)acrylic ester polymers, then the protective colloid is simple to use, but particle size control deteriorates resulting in coarse particles
Solution Approach 1:
The patent changes the polymer composition parameters by incorporating vinyl esters of carboxylic acids with 5-15 carbon atoms (1-30 wt%) into the (meth)acrylic ester polymer system. This compositional modification enables conventional polyvinyl alcohol to effectively control particle size and prevent coarse particle formation, resolving the contradiction between ease of use and manufacturing precision.
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 provides stable, finely divided polyvinyl alcohol-stabilized (meth)acrylic ester polymers with improved storage stability and mechanical properties, suitable for construction applications, without the use of emulsifiers, and can be produced using established methods, enhancing economic viability.
Implementation Method 1
Aqueous dispersions or water-redispersible powders of polymers based on ethylenically unsaturated monomers... are typically stabilized with protective colloids, such as polyvinyl alcohol
Implementation Method 2
Such polymer dispersions are typically prepared by aqueous emulsion polymerization of ethylenically unsaturated monomers, for example batchwise (discontinuously) in stirred polymerization reactors or else continuously
Implementation Method 3
Dispersion powders can be prepared by spray drying aqueous polymer dispersions with the addition of drying aids, such as polyvinyl alcohol
Data Source
AI summary
Polyvinyl alcohol-stabilized (meth)acrylic ester polymers, processes for preparing and uses for the same. Where the polyvinyl alcohol-stabilized (meth)acrylic ester polymers have particle sizes Dw of from 100 to 900 nm in the form of aqueous dispersions or water-redispersible powders. Where the (meth)acrylic ester polymers are based on(a) 1% to 30% by weight of one or more vinyl esters of carboxylic acids having 5 to 15 carbon atoms,(b) 20% to 80% by weight of one or more (meth)acrylic esters, wherein the homopolymer of which has a glass transition temperature Tg of ≤20° C.,(c) 10% to 70% by weight of one or more (meth)acrylic esters, wherein the homopolymer of which has a glass transition temperature Tg of ≥50° C., and(d) optionally one or more further ethylenically unsaturated monomers.The percentages by weight are based on the total weight of the (meth)acrylic ester polymers.