Pre-treatment Coating Durability for Inkjet Printing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Traditional pre-treatment coatings for inkjet printing lack durability when used in applications with high surface contact, such as packaging, leading to image quality degradation.

Innovation Solution

A pre-treatment coating comprising an evaporable solvent, a matrix with polyvalent salt, low Tg latex, and high Tg latex, and wax particles with sizes greater than the matrix thickness, which enhances image durability and adhesion of aqueous inkjet inks on low porosity media.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional pre-treatment coatings are used for inkjet printing, then image quality can be achieved, but durability and scratch resistance are insufficient under high surface contact conditions

Engineering Contradiction:
ImprovedurabilityVSAvoidscratch resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The pre-treatment coating uses a composite formulation combining multiple latex types (low Tg and high Tg), polyvalent salt, and wax particles. This composite structure provides both durability and scratch resistance by leveraging the complementary properties of each component - the latex matrix provides adhesion and flexibility, while the wax particles provide scratch resistance and surface protection.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The coating incorporates wax particles with specific size ranges (0.1-10 micrometers) that are larger than the matrix thickness, creating localized protective zones within the coating structure. This local concentration of wax particles at strategic positions provides enhanced scratch resistance precisely where surface contact occurs, while maintaining overall coating durability.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If pre-treatment coatings are applied to improve image quality, then optical density and print quality are enhanced, but the coating lacks durability for packaging applications with high surface contact

Engineering Contradiction:
Improveimage qualityVSAvoiddurability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The coating combines low Tg latex (providing flexibility and adhesion for image quality), high Tg latex (providing structural integrity), and wax particles (providing durability). This composite material simultaneously achieves high image quality through proper ink interaction and enhanced durability through the protective wax component.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The coating formulation specifies precise parameter ranges: low Tg latex (Tg below high Tg latex), high Tg latex (Tg 80-150°C), and wax particle sizes (0.1-10 micrometers). These controlled parameter changes optimize both image quality and durability, allowing the coating to perform well in packaging applications with high surface contact.

Inventive Principle:
Principle #35Parameter changes

3Strength

If wax particles with size greater than matrix thickness are used, then scratch resistance and durability are improved, but coating formulation complexity increases

Engineering Contradiction:
Improvescratch resistanceVSAvoidcoating formulation complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent defines specific parameter ranges for the coating components to manage complexity: wax particles (0.1-10 micrometers), low Tg latex (5-30 wt%), high Tg latex (30-70 wt%), and polyvalent salt (5-20 wt%). By establishing these clear parameter boundaries, the formulation achieves enhanced scratch resistance while maintaining manufacturability and ease of application.

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 coating provides excellent durability, scratch resistance, and retention of print quality by preventing color bleed and maintaining image quality on coated and uncoated media, especially for aqueous inkjet printing on low porosity surfaces.

Implementation Method 1

an evaporable solvent, a matrix, and a wax... The evaporable solvent can be water or other solvent or solvent system that is readily removable by drying, evaporation, heating

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

the use of wax particles in pre-treatment coatings can provide excellent durability, thereby preserving the quality of the printed image even with more significant surface to surface contact

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

The pre-treatment coatings... provide exceptional results when used in conjunction with uncoated media... providing a high image quality that is valuable for printing applications

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP2762534B1Pre-treatment coating
Publication Date: 2019.03.06 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP2762534B1 patent drawingFigure 1~2

AI summary

The present disclosure provides pre-treatment compositions and related methods. As such, a pre-treatment coating for a print medium can include an evaporable solvent, a matrix, and a wax. The matrix can include from 5 wt% to 20 wt% of a fixer, from 5 wt% to 20 wt% of a low Tg latex, and from 30 wt% to 80 wt% of a high Tg latex. The wax can include from 5 wt% to 30 wt% of a wax. The weight percentages of the matrix and the wax are based on a total amount present in the pre-treatment coating after removal of solvent.