Protective Layer with Polymeric Beads for Ink Durability

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Solution Overview

Problem

Pigmented ink images on recording media are susceptible to scratching and abrasion due to ink pigments aggregating on the surface, leading to reduced durability.

Innovation Solution

A recording medium with a protective layer containing polymeric beads of average size greater than 10 µm and a coat weight of less than 3 gsm, allowing ink pigments to penetrate and reside below the surface, enhancing durability against external forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pigmented ink is applied to recording media, then images can be formed, but ink pigments aggregate on the surface making them susceptible to scratching and abrasion

Engineering Contradiction:
Improveimage durabilityVSAvoidscratching and abrasion susceptibility
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent moves ink pigments from a two-dimensional surface aggregation state to a three-dimensional subsurface distribution state by creating a protective layer with controlled porosity and particle size. The ink pigments penetrate through the protective layer and reside in the subsurface region, changing the spatial dimension of pigment location from surface to depth, thereby protecting against scratching and abrasion while maintaining image quality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If a protective layer is added to protect ink pigments, then durability against scratching and abrasion is improved, but the layer may block ink pigment penetration and reduce image quality

Engineering Contradiction:
Improvescratch and abrasion resistanceVSAvoidimage quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The protective layer is designed with porous structure containing polymeric beads of specific size range (0.1 µm to 10 µm). These pores allow ink pigment particles to penetrate through the protective layer and reach the subsurface region. The porous structure resolves the contradiction by providing both mechanical protection (through the protective layer framework) and pigment penetration pathways (through the pores), thereby maintaining image quality while improving durability.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The protective layer is formulated as a composite material containing polymeric beads dispersed in a binder matrix. This composite structure provides mechanical strength and scratch resistance from the binder while the polymeric beads create pore spaces for ink pigment penetration. The composite nature allows simultaneous achievement of protection and image quality.

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If polymeric beads with larger particle size are used in the protective layer, then ink pigment penetration is facilitated, but the coat weight increases reducing the protective layer effectiveness

Engineering Contradiction:
Improveink pigment penetrationVSAvoidprotective layer coat weight
Core Design Contradiction:
Manufacturing precisionVSWeight of stationary object

Solution Approach 1:

The patent optimizes the particle size parameter of polymeric beads within a specific range (0.1 µm to 10 µm, with average size of 1 µm to 5 µm preferred). This parameter optimization ensures sufficient pore size for ink pigment penetration while maintaining low coat weight (0.1 gsm to 5 gsm, preferably 0.5 gsm to 2 gsm). By carefully controlling these parameters, the patent achieves both effective pigment penetration and lightweight protective layer.

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 increases the durability of images by preventing ink pigments from being readily smeared or removed, providing robustness to scratches and abrasion through the use of a protective layer that allows ink pigments to pass through and reside below the surface.

Implementation Method 1

The size of the polymeric beads and the coat weight of the protective layer enable pores and channels of a sufficient size in the protective layer to allow the passage of ink pigments there through into and/or below the lower portion of the protective layer

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP2804761B1Recording medium having a protective layer
Publication Date: 2019.03.06 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP2804761B1 patent drawingFigure 1A~1B
  • EP2804761B1 patent drawingFigure 2
  • EP2804761B1 patent drawingFigure 3

AI summary

A recording medium includes a protective layer and a porous ink receiving layer. The protective layer includes a first binder and a first set of polymeric beads. The first set of polymeric beads has an average volume-based particle size equal to or greater than ten microns. The protective layer has a coat weight equal to or less than three grams per square meter. The recording medium also includes a porous ink receiving layer including a first set of pigments and a second binder.