Epoxy Urethane Backing Treatment for Abrasive Adhesion

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Solution Overview

Problem

Conventional coated abrasive articles face issues with the abrasive layer separating from the backing due to frictional heating, which is exacerbated by volatiles emitted from partially cured backing treatments like resole phenolic resins, leading to porosity and interference with curing processes.

Innovation Solution

A curable composition comprising 20-65% epoxy resin, 29-75% polyfunctional urethane (meth)acrylate, 0.1-15% novolac resin, dicyandiamide, a photoinitiator, and optional epoxy cure catalyst is applied to the backing, which is then partially cured to enhance adhesion and stability of the abrasive layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional backing treatments (resole phenolic resins, urea-formaldehyde, melamine formaldehyde) are used, then good adhesion to make layers is achieved, but volatiles are emitted causing porosity and interfering with curing

Engineering Contradiction:
ImproveadhesionVSAvoidvolatiles emission
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the backing treatment by using epoxy resin (20-65 wt%), polyfunctional urethane (meth)acrylate (29-75 wt%), and novolac resin (0.1-15 wt%), replacing conventional resole phenolic resins. This parameter change eliminates volatile emission while maintaining adhesion strength through the specific chemical properties of the new composition.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite backing treatment material combining epoxy resin, polyfunctional urethane (meth)acrylate, and novolac resin in specific proportions. This composite material integrates the adhesive properties of epoxy with the curing characteristics of urethane (meth)acrylate and the structural benefits of novolac resin, achieving both strong adhesion and zero volatile emission.

Inventive Principle:
Principle #40Composite materials

2Productivity

If frictional heating occurs during use, then abrasive action is performed, but the abrasive layer separates from the backing

Engineering Contradiction:
Improveabrasive actionVSAvoidlayer separation
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies a backing treatment layer beforehand that acts as a thermal buffer and strong bonding interface. This treatment layer, composed of epoxy and polyfunctional urethane (meth)acrylate, absorbs thermal stress from frictional heating during abrasive action, preventing the abrasive layer from separating from the backing by cushioning the thermal impact in advance.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent changes the thermal and adhesive parameters of the backing treatment by using high-epoxy-content materials (20-65 wt%) with excellent thermal stability and adhesion. These material parameters enable the backing to withstand frictional heating without causing layer separation, maintaining composition stability during productive abrasive action.

Inventive Principle:
Principle #35Parameter changes

3Strength

If partially cured backing treatments are applied, then adhesion is achieved, but porosity is increased and curing is interfered with

Engineering Contradiction:
ImproveadhesionVSAvoidporosity control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent changes the curing behavior parameters by using polyfunctional urethane (meth)acrylate (29-75 wt%) which offers controlled curing kinetics. This allows the backing treatment to achieve adequate adhesion during partial curing while minimizing volatile emission and porosity formation, enabling precise control over the curing process without compromising manufacturing quality.

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

The solution provides improved adhesion between the abrasive layer and the backing, reducing the likelihood of separation during use and enhancing the overall performance and durability of the coated abrasive articles.

Implementation Method 1

e) photoinitiator

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

a) from 20 to 65 percent by weight of epoxy resin preparable by reaction of epichlorohydrin with at least one of bisphenol A or bisphenol F; b) from 29 to 75 percent by weight of polyfunctional urethane (meth)acrylate

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentEP1904577B1Composition, treated backing, and abrasive articles containing the same
Publication Date: 2011.10.19 3M INNOVATIVE PROPERTIES CO
  • EP1904577B1 patent drawingFigure 1~3

AI summary

A curable composition comprises epoxy resin preparable by reaction of epichlorohydrin with at least one of bisphenol A or bisphenol F, polyfunctional urethane (meth)acrylate, dicyandiamide and photoinitiator. The curable composition is useful for preparing treated backings and coated abrasive articles.