Photopolymerizable Ink Composition for Low Viscosity and High Strength

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing photopolymerizable compositions for inkjet inks face challenges in forming coating films with low viscosity, high strength, and processing suitability while avoiding skin sensitization issues.

Innovation Solution

A photopolymerizable composition incorporating diethyleneglycoldimethacrylate and alkoxy-modified (meth)acrylic acid esters with an average polymerization degree of the alkoxy part of 9 or higher, which prevents cracking and chipping during processing, and includes caprolactone-modified dipentaerythritol hexaacrylate or ethyleneoxide-modified trimethylol propane trimethacrylate for improved strength and low viscosity, ensuring negative skin sensitization results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional photopolymerizable compositions are used, then coating film strength can be improved, but skin sensitization problems occur and processing suitability deteriorates

Engineering Contradiction:
Improvecoating film strengthVSAvoidskin sensitization
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical parameters by selecting specific photopolymerizable compounds (diethyleneglycoldimethacrylate with n=2 and alkoxy-modified (meth)acrylic acid ester with n≥9) that have different molecular structures from conventional acrylates, thereby achieving high strength without skin sensitization

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite photopolymerizable composition combining diethyleneglycoldimethacrylate and alkoxy-modified (meth)acrylic acid ester in specific ratios (30-70 wt% and 70-30 wt% respectively), creating a material that leverages the complementary properties of both compounds to achieve high strength and low sensitization simultaneously

Inventive Principle:
Principle #40Composite materials

2Strength

If conventional photopolymerizable compositions are used, then coating film strength can be improved, but viscosity increases and processing suitability deteriorates

Engineering Contradiction:
Improvecoating film strengthVSAvoidprocessing suitability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The invention optimizes the viscosity parameter by using alkoxy-modified (meth)acrylic acid ester with n≥9, which has lower viscosity compared to conventional short-chain acrylates, while maintaining high strength through the specific molecular structure

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies different chain lengths and structures to different components: diethyleneglycoldimethacrylate provides crosslinking density for strength, while the long-chain alkoxy-modified ester provides low viscosity for processing, with each component having optimized local properties

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If spray coating or brush coating is used instead of inkjet printing, then coating film formation is easier, but light resistance and strength cannot be achieved without skin sensitization

Engineering Contradiction:
Improvecoating film formationVSAvoidlight resistance and strength
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention changes the chemical composition parameters to include specific photopolymerizable compounds that provide both ease of application and high performance, making inkjet printing as effective as spray or brush coating while adding the benefit of digital precision

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention enables inkjet printing to replicate the performance of conventional spray or brush coating methods by using specially formulated photopolymerizable inks that cure to form durable, light-resistant films, thus copying the functional outcome with a more precise and controllable process

Inventive Principle:
Principle #26Copying

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 achieves a coating film with high strength and processing suitability without skin sensitization, suitable for inkjet inks with viscosities between 2 to 150 mPa·s, maintaining durability and flexibility, and can be used in various ejection heads with ease.

Implementation Method 1

a photopolymerizable composition including diethyleneglycoldimethacrylate and alkoxy-modified (meth)acrylic acid ester having an n not less than 9

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP2796519B1Photopolymerizable inkjet ink composition and ink cartridge
Publication Date: 2021.07.07 RICOH CO LTD
  • EP2796519B1 patent drawingFigure 1~2
  • EP2796519B1 patent drawing

AI summary

A photopolymerizable composition includes diethyleneglycoldimethacrylate and alkoxy-modified (meth)acrylic acid ester having an n not less than 9. The n is an average polymerization degree of an alkoxy part of the (meth)acrylic acid ester.