Aqueous Primer Composition for Inkjet Printing on Non-Absorptive Substrates

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Solution Overview

Problem

Existing inkjet printing technologies face challenges when printing on non-absorptive or low-absorptive substrates, such as polymeric films and ceramics, due to issues like intercolor bleeding, line sharpness problems, dot spreading, and poor adhesion of inkjet inks without binders.

Innovation Solution

An aqueous coating composition is developed, comprising 20-79% by weight of a dispersed polymeric binder, 20-79% by weight of aluminum hydroxide oxide particles, 0.1-10% by weight of dissolved multivalent metal cations, and inorganic and/or organic counteranions, which forms a thin, inkjet-printable primer layer with low coating weight for high-speed inkjet printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional inkjet coating is applied to non-absorptive substrates, then the ink can be absorbed and fixed, but the coating weight becomes too high (at least 15 g/m²) and the process becomes complex

Engineering Contradiction:
Improveink fixationVSAvoidcoating weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent changes the chemical parameters of the primer composition by using a specific polymeric binder with controlled molecular weight (10,000-1,000,000 g/mol) and functional groups, combined with multivalent metal salts, to achieve effective ink fixation at much lower coating weights (0.1-10 g/m²) compared to conventional coatings (≥15 g/m²)

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite primer system combining organic polymeric binders with inorganic multivalent metal salts, where the metal ions crosslink with functional groups on the polymer chains to form a cohesive network structure that provides both adhesion and ink fixation capabilities at reduced coating weights

Inventive Principle:
Principle #40Composite materials

2Weight of stationary object

If the coating weight is reduced to lower costs, then material costs decrease, but adhesion between primer and substrate deteriorates

Engineering Contradiction:
Improvecoating weightVSAvoidadhesion
Core Design Contradiction:
Weight of stationary objectVSStrength

Solution Approach 1:

The patent optimizes the molecular weight parameter of the polymeric binder (10,000-1,000,000 g/mol) and the concentration of multivalent metal salts to achieve maximum adhesion strength at minimal coating weights, where the metal ions form strong crosslinks with polymer functional groups even at low concentrations

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates localized crosslinked regions through multivalent metal salt interactions with functional groups on the polymer chains, concentrating adhesion strength at specific interaction sites rather than requiring uniform high coating weight across the entire primer layer

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If aqueous pigmented inks are used for printing, then environmental friendliness improves, but print quality deteriorates due to intercolor bleeding, line sharpness issues, and dot spreading

Engineering Contradiction:
Improveenvironmental impactVSAvoidprint quality
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent introduces a specially formulated primer layer as an intermediary between the non-absorptive substrate and the aqueous pigmented ink, where the primer's polymeric binder with multivalent metal salts creates a surface that provides both absorption and capillary control to prevent intercolor bleeding and dot spreading while maintaining environmental benefits of aqueous inks

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a porous network structure through the crosslinked polymeric binder and multivalent metal salt complexes in the primer layer, which provides controlled porosity to absorb aqueous ink while the polymer matrix restricts lateral ink flow, preventing dot spreading and maintaining line sharpness

Inventive Principle:
Principle #31Porous materials

4Manufacturing precision

If a primer layer is applied to improve ink adhesion, then printing quality improves, but the coating process becomes more complex and time-consuming

Engineering Contradiction:
Improveprinting qualityVSAvoidcoating process
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent designs a multi-functional primer composition that simultaneously provides substrate adhesion, ink absorption, ink fixation, and surface smoothness control in a single coating layer, eliminating the need for multiple separate coating steps or additional treatment processes

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

5Strength

If the primer layer provides good adhesion, then ink fixation improves, but stickiness (antiblocking properties) deteriorates

Engineering Contradiction:
ImproveadhesionVSAvoidstickiness
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent creates localized crosslinked adhesion zones through multivalent metal salt interactions with polymer functional groups, while the bulk of the primer layer maintains a non-sticky surface morphology, achieving both strong adhesion and good antiblocking properties through spatial differentiation of material properties

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 coating composition enables high-quality inkjet printing with good adhesion between the primer and substrate, no stickiness, and high print resolution, even on non-absorptive substrates, while maintaining a low coating weight to reduce costs.

Implementation Method 1

the adhesion of inkjet inks to such non-adsorptive substrates can be critical

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

comprising (a) from 20 to 79 % by weight of a dispersed polymeric binder, (c) from 0.1 to 10 % by weight of dissolved multivalent metal cations

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 3

comprising (b) from 20 to 79 % by weight of aluminum hydroxide oxide particles

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentEP4324890B1Primer composition for inkjet printing of non- or low-absorptive substrates with aqueous pigmented inks
Publication Date: 2025.02.12 SIHL
  • EP4324890B1 patent drawingFigure 1

AI summary

The present invention is directed to an aqueous coating composition comprising (a) from 20 to 79 % by weight of a dispersed polymeric binder, (b) from 20 to 79 % by weight of aluminum hydroxide oxide particles, and (c) from 0.1 to 10 % by weight of dissolved multivalent metal cations, and (d) inorganic and/or organic counteranions of the metal cations. The aqueous coating composition is to be used for forming an inkjet-printable primer layer on non-absorptive or low-absorptive substrates. Also provided is a method for coating the substrates and inkjet-printing the coated substrates.