Transfer paper for sublimation printing, comprising a cationic agent

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Solution Overview

Problem

Current transfer papers for sublimation printing using inkjet technology face challenges with long drying times, color mixtures, and smudges due to hydrophilic polymer barrier layers, which limit printing speed and quality, and the introduction of fillers increases costs and reduces transfer rates.

Innovation Solution

A transfer paper with a higher proportion of cationic agents, greater than or equal to 8% by dry weight, is used to immobilize ink on the surface, reducing the need for mineral fillers and binders, and enhancing air permeability to facilitate rapid drying and improved printability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a barrier layer based on hydrophilic polymer is used, then ink retention on the surface is improved, but drying time increases and printing speed decreases

Engineering Contradiction:
Improveink retentionVSAvoidprinting speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical composition parameters of the barrier layer by using polymers with lower hydrophilicity (acrylic, polyacrylonitrile, vinylidene chloride) instead of highly hydrophilic polymers (carboxymethyl cellulose, starch, polyvinyl alcohol). This parameter change reduces the polymer's affinity for water-based inks, allowing faster drying while still providing adequate ink retention through the combined action of the barrier layer and cationic agent.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the quantity of cationic agent is increased to improve ink fixation, then print quality improves, but ink transfer by sublimation decreases

Engineering Contradiction:
Improveprint qualityVSAvoidtransfer rate
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent optimizes the cationic agent concentration to a specific range (0.1-5 g/m², preferably 0.3-2 g/m²) and changes the polymer-to-cationic agent ratio. This parameter optimization ensures sufficient ink fixation for high print quality while maintaining adequate sublimation transfer. The low hydrophilicity of the polymer matrix prevents excessive ink absorption, allowing the cationic agent to work effectively at lower concentrations without compromising transfer rate.

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 results in improved printability, higher transfer rates, and reduced smudging, with enhanced optical density and productivity, while maintaining a low paper weight and minimizing the use of additional formulation agents.

Implementation Method 1

The presence of a cationic agent in a higher proportion in the invention surprisingly makes it possible to ensure good transfer by sublimation, the ink being unexpectedly poorly retained in the transfer paper during sublimation

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 2

Sublimation printing allows an image to be provided on a support, such as metal, glass, a plastic surface or fabric, using sublimable inks

Methodology Applied
Scientific EffectSublimation: Sublimation

Data Source

PatentEP3568521B2Transfer paper for sublimation printing, comprising a cationic agent
Publication Date: 2024.01.03 AHLSTROM OYJ

AI summary

The invention relates to transfer paper for sublimation printing, comprising a fibrous substrate, said transfer paper having one or more cationic agents on at least one face thereof, deposited on the fibrous substrate by means of surface treatment, the amount of cationic agent(s) being greater than or equal to 8% by dry weight of the total dry weight of the compound(s) added to the fibrous substrate by means of the surface treatment.