Photosensitive Resin Composition for High-Resolution Liquid-Repellent Films

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Solution Overview

Problem

Silicone-based water-repellent materials exhibit inadequate reactivity and crosslink density, leading to poor liquid repellency and resolution during patterning, especially in inkjet recording heads, which affects print quality over time.

Innovation Solution

A photosensitive resin composition comprising specific epoxy resins and a cationic polymerization catalyst, such as sulfonium salts, is used to enhance reactivity and achieve high liquid repellency and resolution during patterning, forming a durable liquid-repellent anti-fouling film.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If silicone compounds are used as water-repellent materials, then environmental safety is improved, but reactivity and crosslink density are insufficient

Engineering Contradiction:
Improveenvironmental safetyVSAvoidreactivity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses composite materials by combining silicone compounds with epoxy resins in a photosensitive resin composition. This composite approach allows the material to maintain the environmental safety of silicone while gaining the reactivity and crosslinking capability of epoxy resins through photopolymerization.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical composition parameters by incorporating specific ratios of silicone compounds (0.1-10 mass%) and epoxy resins with different epoxy equivalents (50-500 g/eq) into the photosensitive resin composition, optimizing both reactivity and liquid repellency properties.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If photoexposure dose or photopolymerization initiator is increased to improve crosslink density, then liquid repellency is improved, but resolution during patterning deteriorates

Engineering Contradiction:
Improveliquid repellencyVSAvoidresolution during patterning
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent optimizes the epoxy equivalent parameter of the epoxy resin (50-500 g/eq) and the photoexposure dose (100-1000 mJ/cm²) to achieve the desired balance between crosslink density and patterning resolution, avoiding the need to excessively increase initiator concentration.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent discards the conventional approach of simply increasing photopolymerization initiator concentration and instead recovers optimal performance by adjusting the epoxy resin characteristics and photoexposure parameters.

Inventive Principle:
Principle #34Discarding and recovering

3Duration of action of stationary object

If crosslink density is increased to improve liquid repellency, then durability is improved, but patterning resolution deteriorates

Engineering Contradiction:
ImprovedurabilityVSAvoidpatterning resolution
Core Design Contradiction:
Duration of action of stationary objectVSManufacturing precision

Solution Approach 1:

The patent creates a composite photosensitive resin composition that achieves both high crosslink density for durability and good patterning resolution through the synergistic combination of silicone compounds, epoxy resins, and photopolymerization initiators.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical structure parameters by selecting epoxy resins with specific epoxy equivalents (50-500 g/eq) and controlling the silicone compound content (0.1-10 mass%) to achieve optimal crosslink density without compromising patterning resolution.

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 composition ensures high liquid repellency and good resolution during patterning, maintaining print quality in inkjet recording heads over long-term use.

Implementation Method 1

a photosensitive resin composition comprising a silicone compound and an epoxy resin, and a cationic polymerization catalyst

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

silicone compounds are water-repellent materials that do not comprise fluorine, but which still exhibit an excellent liquid repellency

Methodology Applied
Scientific EffectLiquid repellency: Hydrophobe

Data Source

PatentEP4691782A1Photosensitive resin composition, liquid-repellent Anti-fouling film, and inkjet recording head
Publication Date: 2026.02.11 CANON KK
  • EP4691782A1 patent drawingFigure 1A~1B
  • EP4691782A1 patent drawingFigure 2A~2H
  • EP4691782A1 patent drawingFigure 3A~3C

AI summary

A photosensitive resin composition comprising: an epoxy resin (A) represented by formula (1); an epoxy resin (B) that has an epoxy equivalent of 500 g/eq. or less and that is different from the epoxy resin (A) represented by formula (1); and a cationic polymerization catalyst, where, in formula (1), R1, R2, R3, R4, and X1 are each independently an alkyl group with carbon numbers of 1 to 12, an aryl group with carbon numbers of 6 to 12, or an epoxy-comprising group; X2 is an epoxy-comprising group; m + n is an integer from 1 to 60; and a sequence of a structure of parentheses marked with m and a sequence of a structure of parentheses marked with n may be random or block.