Inkjet Recording Material Binder Resin Viscosity Control

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Solution Overview

Problem

Current inkjet recording materials face challenges in achieving high water resistance, surface strength, and ink absorbability, particularly at high printing speeds, due to limitations in binder resin properties and the use of boron compounds, which are toxic and difficult to produce efficiently.

Innovation Solution

A method involving a saponified vinyl acetate-diacetone acrylamide copolymer and a crosslinking agent, where a water-soluble basic compound is added after a lapse of at least 30 minutes to stabilize the viscosity of the coating liquid, preventing permeation into porous inorganic fine particles and ensuring stable ink absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If PVA with polymerization degree of 4000 or higher is used as binder resin, then binding force and aqueous solution viscosity are improved, but production efficiency becomes extremely low and cost increases

Engineering Contradiction:
Improvebinding forceVSAvoidproduction efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The invention changes the polymerization degree parameter of PVA from 4000 or higher to 1700-3500, and adjusts the saponification degree to 87-99 mol%. This parameter optimization achieves the required binding force and viscosity without requiring special production equipment or sacrificing productivity, thus resolving the contradiction between strength and production efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses commercially available PVA with moderate polymerization degree (1700-3500) instead of requiring special high polymerization degree PVA (4000+). This copying approach with standard industrial materials achieves similar performance while maintaining high production efficiency and low cost

Inventive Principle:
Principle #26Copying

2Force

If PVA with polymerization degree of 4000 or higher is used as binder resin, then aqueous solution viscosity is improved, but production efficiency becomes extremely low

Engineering Contradiction:
Improveaqueous solution viscosityVSAvoidproduction efficiency
Core Design Contradiction:
ForceVSProductivity

Solution Approach 1:

The invention optimizes the polymerization degree parameter to 1700-3500 and saponification degree to 87-99 mol%, which provides sufficient aqueous solution viscosity to prevent permeation of inorganic fine particles while maintaining compatibility with standard production processes and high productivity

Inventive Principle:
Principle #35Parameter changes

3Productivity

If higher printing speed is used, then productivity is improved, but physical load on recording material surface increases causing cracking

Engineering Contradiction:
Improveprinting speedVSAvoidsurface strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The invention changes the binder resin parameters (polymerization degree 1700-3500, saponification degree 87-99 mol%) to achieve optimal balance between flexibility and strength, allowing the ink receiving layer to withstand the physical load of high-speed printing without cracking while maintaining high productivity

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If more ink is absorbed per unit area, then high definition is improved, but load on recording material in wet state increases causing cracking

Engineering Contradiction:
Improvehigh definitionVSAvoidsurface strength in wet state
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The invention optimizes the binder resin parameters to provide sufficient binding force and flexibility, enabling the ink receiving layer to absorb more ink for high definition while withstanding the increased wet state load without cracking

Inventive Principle:
Principle #35Parameter changes

5Strength

If crosslinking reaction proceeds rapidly, then binding force is improved, but viscosity of coating liquid increases too much preventing proper coating

Engineering Contradiction:
Improvebinding forceVSAvoidviscosity of coating liquid
Core Design Contradiction:
StrengthVSForce

Solution Approach 1:

The invention adds the crosslinking agent beforehand to the binder resin solution before mixing with inorganic fine particles. This preliminary action allows the crosslinking reaction to start early, building binding force while the system is still fluid enough for proper mixing and coating operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention controls the crosslinking reaction dynamically by adding the crosslinking agent to the binder resin before mixing with particles, allowing the reaction to proceed at a controlled rate that builds strength without causing excessive viscosity increase that would prevent proper coating

Inventive Principle:
Principle #15Dynamics

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 produces an inkjet recording material with excellent water resistance, surface strength, and ink absorbability, enabling high-speed printing without cracking, while avoiding the use of toxic boron compounds and maintaining industrial productivity.

Implementation Method 1

The ink receiving layer contains porous inorganic fine particles, a saponified vinyl acetate-diacetone acrylamide copolymer, and a crosslinking agent

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

a crosslinking agent, wherein a water-soluble basic compound is added to a mixture of an aqueous solution of the saponified vinyl acetate-diacetone acrylamide copolymer and the crosslinking agent

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 3

The porous inorganic material rapidly absorbs ink, prevents ink from bleeding, and thereby serves for the formation of appropriate dots with a perfectly round shape

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2644403B1Method for producing inkjet recording material
Publication Date: 2016.10.05 JAPAN VAM & POVAL CO LTD
  • EP2644403B1 patent drawingFigure 1

AI summary

Provided is a method for producing an inkjet recording material, the method comprising the steps of mixing an aqueous solution of a saponified vinyl acetate-diacetone acrylamide copolymer with a crosslinking agent to give a liquid mixture (a) ; adding a water-soluble basic compound to the liquid mixture (a) after a lapse of at least 30 minutes to give another liquid mixture (b); and mixing the obtained liquid mixture (b) with porous inorganic fine particles to give an ink receiving layer coating liquid and applying the coating liquid to a support, the inkjet recording material being characterized in that the ink receiving layer comprises the porous inorganic fine particles, the saponified vinyl acetate-diacetone acrylamide copolymer, and the crosslinking agent.