Ladder Copolymer Additive for Balanced Coating Surface Properties

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Solution Overview

Problem

Existing additives for controlling surface properties of compositions, such as coatings, often fail to achieve a balanced improvement in slip, levelling, dirt repellency, and self-cleaning properties while minimizing over-coating issues and surface imperfections like craters, and may deteriorate mechanical properties, weathering resistance, and corrosion protection.

Innovation Solution

A polymer comprising at least two polymer backbone chains linked by a polymeric connecting chain with polyether and polysiloxane segments, which are covalently bonded, providing an improved balance of desired and undesired surface properties without negatively affecting mechanical properties or corrosion protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional additives are used to improve surface properties like slip and levelling, then desired surface properties are enhanced, but undesired surface properties like poor over-coating properties and surface imperfections occur

Engineering Contradiction:
Improvesurface properties (slip, levelling)VSAvoidsurface imperfections (poor over-coating, craters)
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The invention uses a composite polymer structure combining polyether segments and polysiloxane segments in a single molecule. The polyether segment provides hydrophilicity and levelling properties, while the polysiloxane segment provides hydrophobicity and slip properties. This composite structure allows simultaneous achievement of desired surface properties without the harmful effects caused by single-function additives.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The polymer exhibits local quality through its segmented structure where different segments perform different functions at different locations. The polyether segment localizes hydrophilic interactions for levelling, while the polysiloxane segment localizes hydrophobic interactions for slip and water repellency. This spatial differentiation of functions resolves the contradiction between improving surface properties and avoiding surface defects.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If additives are used to enhance surface properties, then slip and dirt repellency improve, but mechanical properties and corrosion protection deteriorate

Engineering Contradiction:
Improvesurface properties (slip, dirt repellency)VSAvoidmechanical properties and corrosion protection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention changes the molecular parameters of the additive by using a specific polysiloxane molecular weight range (500-2000 g/mol) and controlling the ratio of polyether to polysiloxane segments. This parameter optimization ensures that the additive provides sufficient surface modification while maintaining compatibility with the coating matrix, thereby preserving mechanical properties and corrosion protection.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If small amounts of polymer are used to control surface properties, then additive efficiency is improved, but achieving balanced surface properties becomes more difficult

Engineering Contradiction:
Improveadditive efficiencyVSAvoidbalance of surface properties
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The polymer molecule performs multiple functions simultaneously: the polyether segment provides levelling and wetting, the polysiloxane segment provides slip and water repellency, and the overall structure maintains coating stability. This multi-functionality in a single molecule allows effective surface property control at low concentrations without compromising the balance between different surface properties.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS12479948B2Ladder copolymer
Publication Date: 2025.11.25 BYK CHEMIE GMBH

AI summary

The invention relates to a polymer comprising a) at least two polymer backbone chains and b) at least one polymeric connecting chain comprising at least two polyether segments and one polysiloxane segment, said polysiloxane segment having a number average molecular weight in the range of 400 to 6000 g/mol, and at least one of the at least two polyether segments being positioned between the polymer backbone chains and the polysiloxane segment, wherein the at least two polymer backbone chains are linked by the at least one polymeric connection chain.