UV Curable Ink for Plastic Glazing Panels

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Solution Overview

Problem

Commercially available UV inks used for plastic glazing panels in automotive windows are not compatible with protective coating systems, leading to premature delamination and microcracking due to incomplete curing of opaque inks, which affects adhesion and durability.

Innovation Solution

A method involving the use of UV curable ink with a composition of 40-75% acrylate oligomers and monomers, 1-6% photoinitiator, and 5-20% N-vinyl-2-Pyrrolidone, cured from both sides with UV radiation, followed by application of a weatherable layer and an abrasion-resistant layer using vacuum deposition techniques to enhance adhesion and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If UV curable ink is used to mark plastic window, then productivity increases due to faster curing time, but adhesion and compatibility with protective coating system deteriorates

Engineering Contradiction:
Improvecuring timeVSAvoidadhesion
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of the UV curable ink by incorporating specific adhesion promoters and adjusting the ratio of monomers to oligomers. This changes the chemical parameters to ensure proper adhesion to both the plastic substrate and the protective coating system while maintaining UV curability and fast curing time.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite ink formulation combining multiple components: UV curable monomers, oligomers, adhesion promoters, and pigments. This composite material approach allows the ink to simultaneously achieve fast curing, strong adhesion to the plastic window, and compatibility with the protective coating system, resolving the contradiction between productivity and reliability.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If opaque ink is applied to plastic window, then decorative marking and opacity requirements are met, but complete curing is difficult to accomplish

Engineering Contradiction:
ImproveopacityVSAvoidcuring completeness
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies UV radiation from both sides of the plastic window (front and back surfaces) to cure the opaque ink. This dimensional approach allows UV light to penetrate through the opaque ink layer from either direction, ensuring complete curing throughout the ink thickness while maintaining the required opacity for decorative purposes.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent uses the plastic window substrate as an intermediary that transmits UV radiation through to the back side of the ink layer. The plastic material acts as a mediator that allows UV light to pass through and cure the ink from the opposite surface, enabling complete curing of opaque ink while maintaining its decorative opacity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If protective coating system is applied over ink, then weathering and scratch protection is provided, but ink delamination and microcracking occur

Engineering Contradiction:
Improveweathering protectionVSAvoidinterface adhesion
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent performs preliminary actions by properly curing the UV ink before applying the protective coating system. The ink is fully cured from both sides of the window to ensure it is ready to receive the coating. Additionally, the ink formulation includes adhesion promoters that are prepared in advance to ensure bonding readiness, preventing delamination when the protective coating is applied.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent adjusts the chemical parameters of the ink formulation by incorporating specific adhesion promoters and controlling the monomer-oligomer ratio. These parameter changes ensure that the cured ink has proper surface properties and chemical bonding capability to adhere strongly to both the plastic substrate and the protective coating system, preventing interface delamination and microcracking while allowing the coating to provide weathering protection.

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 method ensures complete curing and adhesion of the ink to the plastic panel, providing high opacity, weatherability, and abrasion resistance, meeting automotive industry standards and regulatory requirements.

Implementation Method 1

curing the ink in the shape of the printed pattern using UV radiation directed at the ink from both the A-side and B-side

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

curing the weatherable layer

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP2144739B1A plastic glazing panel having UV curable printed pattern and process for making the same
Publication Date: 2013.02.13 EXATEC LLC
  • EP2144739B1 patent drawingFigure 1
  • EP2144739B1 patent drawingFigure 2
  • EP2144739B1 patent drawingFigure 3

AI summary

An economical method of manufacturing a plastic glazing panel having a decorative marking and/or opaque border printed from a UV curable ink is presented. This economical method includes the steps of forming a plastic panel; printing an opaque pattern from an ink, the pattern having an A-side and a B-side with the B-side being in contact with the plastic panel; curing the ink in the shape of the printed pattern using UV radiation directed at the ink from both the A-side and B-side; applying a weatherable layer on the B-side of the ink and on the plastic panel; curing the weatherable layer; and depositing an abrasion resistant layer onto the weatherable layer.