Emulsion Polymerization Process for Vinyl Ester Dispersions

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Solution Overview

Problem

Existing emulsion polymerization processes face challenges in achieving rapid polymerization while maintaining product properties, particularly at high temperatures, which often result in increased viscosities and impaired performance characteristics such as reduced molecular weight and abrasion resistance.

Innovation Solution

The process involves emulsion polymerization of free-radically polymerizable ethylenically unsaturated monomers at temperatures between 100° C to 160° C, using emulsifiers and minimal protective colloid amounts, allowing for over 60% of total conversion to occur within this temperature range, thereby reducing reaction times by more than 50% without compromising product quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If emulsion polymerization is performed at high temperatures (100-160°C) to reduce reaction time, then productivity increases, but molecular weight and abrasion resistance deteriorate

Engineering Contradiction:
Improvepolymerization rateVSAvoidabrasion resistance
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent applies parameter changes by optimizing the temperature range to 100-160°C and controlling the polymerization to achieve at least 60% conversion within this range. This specific parameter window allows rapid polymerization while maintaining adequate polymer strength and abrasion resistance, resolving the contradiction between productivity and strength.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs dynamic control of the polymerization process by monitoring conversion extent and adjusting conditions to maintain temperature within the optimal 100-160°C range throughout the reaction. This dynamic approach ensures high productivity is achieved without sacrificing molecular weight and abrasion resistance.

Inventive Principle:
Principle #15Dynamics

2Duration of action of moving object

If emulsion polymerization is performed at high temperatures to shorten reaction time, then duration of action decreases, but molecular weight decreases

Engineering Contradiction:
Improvepolymerization timeVSAvoidmolecular weight
Core Design Contradiction:
Duration of action of moving objectVSQuantity of substance

Solution Approach 1:

The patent changes the temperature parameter to the optimized range of 100-160°C and controls the process to achieve at least 60% conversion within this range. This parameter optimization enables significantly reduced polymerization time while maintaining adequate molecular weight, resolving the contradiction between duration and molecular weight.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If high conversion is achieved rapidly at elevated temperatures, then productivity increases, but product performance properties deteriorate

Engineering Contradiction:
Improveconversion rateVSAvoidperformance properties
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent optimizes the temperature parameter to the specific range of 100-160°C and controls the process to achieve at least 60% conversion within this range. This optimized parameter set enables high conversion rates while maintaining full performance properties including adhesion, flexibility, and durability, thus resolving the contradiction between productivity and reliability.

Inventive Principle:
Principle #35Parameter changes

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

This approach enables the production of polymers with similar or slightly lower molecular weights while maintaining full performance properties, offering more economic and efficient preparation of vinyl ester polymer dispersions with reduced polymerization times and improved operational economics.

Implementation Method 1

free-radically polymerizable ethylenically unsaturated monomers selected from the group of the monoesters or diesters of ethylenically unsaturated monocarboxylic or dicarboxylic acids with alkanols, vinyl esters and/or vinylaromatics

Methodology Applied
Scientific EffectThermal decomposition: Thermolysis

Implementation Method 2

One particular problem, however, is the removal of heat during the exothermic polymerization

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentUS8053511B2Process for preparing polymer dispersions, the resulting dispersions and their use
Publication Date: 2011.11.08 CELANESE SALES GERMANY

AI summary

A description is given of a process of emulsion polymerization of free-radically polymerizable ethylenically unsaturated monomers selected from the group of the monoesters or diesters of ethylenically unsaturated monocarboxylic or dicarboxylic acids with alkanols, vinyl esters and/or vinylaromatics and, if desired, further monomers copolymerizable therewith, at least 60% of the total conversion in the polymerization taking place at a temperature of 100° C. to 160° C., the polymerization being performed in the presence of emulsifiers and an amount of 0% to 1% by weight, based on the total amount of the monomers used, of protective colloid.The process can be used to obtain significantly faster conversions for comparable quality of the process products.The dispersions obtained can be employed in a wide variety of different applications, such as binders for paints or as adhesives.