Multifunctional Paper Coating Ink Absorption

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Solution Overview

Problem

Conventional papers designed for offset printing do not perform well with ink jet and laser printing techniques due to inadequate ink absorption rates and uneven ink distribution, leading to poor image quality and mottling, as they fail to absorb aqueous inks and pigmented inks evenly and retain heat effectively for toner fusion.

Innovation Solution

A paper coating comprising a primary anionic pigment with a narrow particle size distribution, a secondary cationic pigment, hydrophilic styrene-butadiene latex, and a co-binder, which creates a controlled porosity surface that allows for rapid and uniform ink absorption and heat retention, enabling multifunctional printing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional offset printing paper is used, then offset printing quality is maintained, but ink jet absorption rate is insufficient and laser heat retention is poor

Engineering Contradiction:
Improvemultifunctional printing capabilityVSAvoidink absorption uniformity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The coating composition parameters are changed by using a specific binder concentration range (5-15% of dry pigment weight) and controlled porosity (20-40%), which enables the paper to perform well across multiple printing techniques including offset, ink jet, and laser printing

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite coating formulation combining multiple binders (starch and/or latex) with specific pigment ratios and controlled porosity structure, creating a multi-functional surface that adapts to different printing processes while maintaining uniform ink absorption

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If high clay content coating is used, then offset printing absorbency is improved, but ink jet dry time increases and mottling occurs

Engineering Contradiction:
Improveclay contentVSAvoidink jet dry time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The invention changes the coating parameters by limiting clay content to 50 parts per hundred parts dry pigment or less (preferably 20-40 parts), and controlling binder concentration to 5-15% of dry pigment weight, achieving both good offset absorbency and rapid ink jet drying without mottling

Inventive Principle:
Principle #35Parameter changes

3Strength

If high binder concentration is used, then coating strength is improved, but ink absorption rate decreases and dry time increases

Engineering Contradiction:
Improvecoating strengthVSAvoidink absorption time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The invention optimizes binder concentration to 5-15% of dry pigment weight (preferably 8-12%), which provides sufficient coating strength while maintaining rapid ink absorption and acceptable dry times for ink jet printing

Inventive Principle:
Principle #35Parameter changes

4Loss of energy

If paper conducts heat readily, then heat dissipation is improved, but toner fusion temperature is insufficient

Engineering Contradiction:
Improveheat dissipationVSAvoidsurface temperature for toner fusion
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The coating is designed with controlled porosity (20-40%) and specific composition that creates local thermal insulation properties at the paper surface, allowing heat retention for toner fusion while maintaining overall heat dissipation capability

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 achieves rapid ink absorption and uniform ink distribution across multiple printing passes, ensuring high-quality prints with ink jet and laser printers, while maintaining heat for toner fusion, thus addressing the limitations of standard papers in commercial high-speed presses.

Implementation Method 1

The primary pigment includes anionic particles having a particle size distribution where at least 96% of the particles by weight have a particle size less than 2 microns

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

Laser printing applications perform better with a paper base sheet that acts as a thermal insulator. The surface must become sufficiently hot to fuse dry toner to the paper

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

up to 17 weight % of a hydrophilic styrene-butadiene latex based on the weight of the dry pigments

Methodology Applied
Scientific EffectHydrophilic absorption: Hydrophile

Data Source

PatentUS7803224B2Paper and coating medium for multifunctional printing
Publication Date: 2010.09.28 VERSO MINNESOTA WISCONSIN LLC

AI summary

A paper coating includes a combination of a primary pigment and a secondary pigment. The primary pigment includes anionic particles having a particle size distribution where at least 96% of the particles by weight have a particle size less than 2 microns. The secondary pigment is a cationic, grit-free pigment having an average particle size of 3 microns or less. The coating also includes up to 17 weight % of a hydrophilic styrene-butadiene latex based on the weight of the dry pigments and a co-binder. Another embodiment of this invention is a coated base sheet that includes a base sheet to which the above coating has been applied.