Hardcoat Composition with Functionalized Nanoparticles for Scratch Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hardcoat materials for substrates often face a trade-off between scratch resistance and flexibility, with increased flexibility typically decreasing scratch resistance, and there is a need for materials that offer both desirable scratch resistance and flexibility.

Innovation Solution

A hardcoat composition comprising a binder and functionalized nanoparticles, where at least a portion of the nanoparticles are modified with free radical reactive silane and cyano group containing silane, with specific particle size distributions and ratios, to achieve enhanced scratch resistance and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the flexibility of hardcoat material is increased, then the flexibility is improved, but the scratch resistance decreases

Engineering Contradiction:
ImproveflexibilityVSAvoidscratch resistance
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent employs a composite material system consisting of organic binder and inorganic nanoparticle filler (silica, zirconia, or titania) with specific surface treatments. The composite structure allows the organic phase to provide flexibility while the inorganic phase provides scratch resistance, resolving the trade-off between these two properties through synergistic material combination.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes multiple parameters including nanoparticle size distribution (bimodal with 5-50 nm and 50-200 nm ranges), surface treatment composition (silane coupling agents), and filler content (20-80 wt%). By systematically adjusting these parameters, the coating achieves both flexibility and scratch resistance that cannot be obtained by changing a single parameter.

Inventive Principle:
Principle #35Parameter changes

2Strength

If the scratch resistance of hardcoat material is increased, then the scratch resistance is improved, but the flexibility decreases

Engineering Contradiction:
Improvescratch resistanceVSAvoidflexibility
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The composite structure with optimized phase distribution allows the hard inorganic filler to provide scratch resistance while the continuous organic binder matrix maintains flexibility. The silane-treated nanoparticle interface ensures stress transfer without brittle failure, enabling simultaneous achievement of both properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent creates local quality differences through bimodal particle size distribution where smaller particles (5-50 nm) fill matrix voids and larger particles (50-200 nm) provide structural reinforcement. This local optimization throughout the coating enables simultaneous flexibility and scratch resistance.

Inventive Principle:
Principle #3Local quality

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 hardcoat material provides desirable scratch resistance and flexibility, suitable for applications such as portable and non-portable information display articles, while maintaining optical properties and durability.

Implementation Method 1

nanoparticles functionalized by free radical reactive silane (e.g., at least one of 3-methacryloxypropyl-trimethoxysilane, 3-acryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-triethoxysilane, acryloxyethyl-trimethoxysilane, or vinyl triethoxysilane) and cyano group containing silane

Methodology Applied
Scientific EffectSilane coupling: Chemical Bonding

Implementation Method 2

free radical reactive silane (e.g., at least one of 3-methacryloxypropyl-trimethoxysilane, 3-acryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-triethoxysilane, acryloxyethyl-trimethoxysilane, or vinyl triethoxysilane)

Methodology Applied
Scientific EffectFree radical polymerization: Photopolymerisation

Data Source

PatentEP3189107B1Hardcoat and method of making the same
Publication Date: 2018.11.28 3M INNOVATIVE PROPERTIES CO

AI summary

Hardcoat comprising a binder, and in a range from 15 to 95 volume % nanoparticles, wherein at least a portion of the nanoparticles are functionalized by free radical reactive silane and cyano group containing silane. Hardcoats described herein are useful, for example, on portable and non-portable information display articles (e.g., illuminated and non-illuminated display articles).