Diacetone-Modified PVA Protective Layer for Heat-Sensitive Recording

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Solution Overview

Problem

Current heat-sensitive recording materials face issues with printing unevenness, inadequate oil and plasticizer resistance, and insufficient productivity due to coating undulation and insufficient water resistance in the protective layer, which affects the quality and fidelity of printed images.

Innovation Solution

The use of diacetone-modified polyvinyl alcohol resin with specific degree of polymerization and saponification in the protective layer, combined with high shear speed coating methods like the rod blade or roller blade method, prevents coating undulation and ensures uniformity, enhancing oil and plasticizer resistance and printability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If diacetone-modified polyvinyl alcohol with high degree of polymerization is used in the protective layer, then water resistance is improved, but coating undulation occurs during application

Engineering Contradiction:

Improvewater resistanceVSAvoidcoating uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the degree of polymerization of diacetone-modified polyvinyl alcohol within the range of 1,000 to 1,800 and the degree of saponification within 90% to 98%. This optimization resolves the contradiction by adjusting molecular weight and hydrolysis degree to achieve both adequate water resistance and coating uniformity without undulation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining diacetone-modified polyvinyl alcohol with specific crosslinking agents and fillers in the protective layer formulation. This composite approach enhances water resistance while the controlled composition prevents coating undulation, achieving both reliability and manufacturing precision simultaneously.

Inventive Principle:

Principle #40Composite materials

2Reliability

If protective layer coating is applied to improve barrier properties, then oil and plasticizer resistance is improved, but coating undulation occurs causing printing unevenness

Engineering Contradiction:

Improvebarrier propertiesVSAvoidprinting uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent resolves this contradiction by changing the parameters of the binder resin, specifically using diacetone-modified polyvinyl alcohol with degree of polymerization of 1,000 to 1,800 and degree of saponification of 90% to 98%. These parameter optimizations ensure the protective layer provides adequate barrier properties while maintaining coating uniformity and preventing printing unevenness.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary approach by carefully selecting and controlling the molecular structure of the binder resin as a mediator between the coating solution and the substrate. This intermediary control ensures proper coating flow and adhesion, preventing undulation while maintaining barrier properties.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If high-speed coating method is used to improve productivity, then coating time is reduced, but coating undulation increases

Engineering Contradiction:

Improvecoating speedVSAvoidcoating uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent resolves this contradiction by changing the rheological parameters of the coating solution through selection of diacetone-modified polyvinyl alcohol with specific degree of polymerization (1,000 to 1,800) and saponification degree (90% to 98%). These parameter changes optimize the coating solution's flow characteristics, enabling high-speed coating without undulation while maintaining uniformity.

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 heat-sensitive recording materials with no printing unevenness, excellent barrier properties, and improved productivity through high-speed coating, ensuring consistent and durable image quality.

Implementation Method 1

a protective layer containing at least a binder resin, wherein the binder resin in the protective layer contains diacetone-modified polyvinyl alcohol resin

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

combined with high shear speed coating methods like the rod blade or roller blade method, prevents coating undulation and ensures uniformity

Methodology Applied

Scientific EffectShear force: Shear Stress

Data Source

PatentUS8147905B2Heat-sensitive recording material and production method thereof

Publication Date: 2012.04.03 RICOH CO LTD

AI summary

To provide a heat-sensitive recording material, including: a substrate; a heat-sensitive color developing layer on the substrate, the heat-sensitive color developing layer containing at least a leuco dye and a developer; and a protective layer on the heat-sensitive color developing layer, the protective layer containing at least a binder resin, wherein the binder resin in the protective layer contains diacetone-modified polyvinyl alcohol resin, the degree of polymerization of the binder resin in the protective layer is 1,000 to 1,800 and the degree of saponification of the binder resin is 90% or greater and less than 98%.