HEUR Polymer Endcapped with Aryl Ether Alkoxylate for Tinted Paint Viscosity

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Solution Overview

Problem

Standard hydrophobically modified alkylene oxide polymers, such as HEURs, experience significant viscosity loss when colorants are added to paint formulations, leading to poor sag resistance and undesirable paint behavior like runs and drips in tinted coatings.

Innovation Solution

A hydrophobically modified alkylene oxide polymer with a specific hydrophobic fragment structure, which is endcapped with an aryl ether alkoxylate block copolymer, is used to stabilize viscosity in tinted coatings, preventing the loss of viscosity when colorants are added.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If standard hydrophobically modified alkylene oxide polymers (HEURs) are used as rheology modifiers, then good flow and sag resistance are provided, but viscosity decreases significantly when colorant is added

Engineering Contradiction:

Improvesag resistanceVSAvoidviscosity stability upon tinting

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses a composite structure where a hydrophobic fragment ( Structure I) is attached to a hydrophobically modified alkylene oxide polymer. This composite construction combines the rheology-modifying properties of HEURs with the viscosity-stabilizing properties of the specific hydrophobic fragment, enabling both sag resistance and viscosity stability upon tinting.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent modifies the molecular structure parameters of the alkylene oxide polymer by introducing a specific hydrophobic fragment with defined structural features (Ar1, Ar2, X, R1, R2 groups). This structural parameter change enables the polymer to maintain viscosity stability while providing sag resistance, resolving the contradiction between flow control and viscosity retention upon tinting.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If colorant is added to paint formulations to achieve desired coloration, then color depth is improved, but viscosity loss occurs leading to runs and drips

Engineering Contradiction:

Improvecolor depthVSAvoidsag resistance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The hydrophobic fragment acts as an intermediary structure that interacts with both the alkylene oxide polymer backbone and the colorant molecules. This intermediary structure prevents direct adverse interactions between colorant and the polymer that would cause viscosity loss, thereby maintaining sag resistance even in deeply tinted formulations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent introduces a specific local structural feature (the hydrophobic fragment with Ar1, Ar2, X, R1, R2 groups) at a particular location on the polymer chain. This local structural modification provides targeted functionality to maintain viscosity stability in the presence of colorant, without affecting the overall rheology-modifying properties of the polymer.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11472921B2Alkylene oxide polymer endcapped with an aryl ether alkoxylate block copolymer

Publication Date: 2022.10.18 ROHM & HAAS CO

AI summary

The present invention relates to a compound comprising a hydrophobically modified poly(oxyalkylene-urethane) having a hydrophobic fragment represented by Structure I:where Ar1, Ar2; R1, m, and n are defined herein. The compound of the present invention provides viscosity stability upon tinting for paints containing a hydrophobically modified poly(oxyalkylene-urethane) rheology modifier, more particularly a HEUR rheology modifier.