Peelable NBR Ink Composition for Durable Erasability on Non-Porous Surfaces

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Solution Overview

Problem

Existing aqueous erasable writing ink compositions for non-porous substrates face challenges with erasability over time and ink leakage, particularly at elevated temperatures or under mechanical stress, and do not provide a satisfactory deposit quality in terms of wettability, opacity, and vividness.

Innovation Solution

Aqueous peelable ink compositions using acrylonitrile butadiene rubber (NBR) and/or hydrogenated acrylonitrile butadiene rubber (HNBR) combined with an anionic surfactant and a coloring agent in water, which form a peelable film on non-porous substrates, ensuring good deposit quality and erasability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If conventional aqueous erasable writing ink compositions are used, then the ink can be applied to non-porous substrates, but erasability deteriorates after a long period of time

Engineering Contradiction:
Improveerasability durationVSAvoiderasability reliability
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters by using specific film-forming polymers (acrylic polymers with specific molecular weights and compositions), anionic surfactants, and controlled pH levels (8-11) to maintain erasability over extended periods. This resolves the contradiction by modifying the ink's chemical properties to prevent permanent bonding with non-porous substrates while ensuring long-term peelability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite ink system combining multiple components: film-forming polymers, anionic surfactants, coloring agents, and water, with specific ratios and synergistic interactions. This composite formulation ensures both good deposit quality and sustained erasability, resolving the contradiction between permanent deposit and long-term erasability.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If the ink composition provides good deposit quality and color opacity, then the written mark is vivid and clear, but ink leakage may occur

Engineering Contradiction:
Improvedeposit qualityVSAvoidink leakage
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent optimizes viscosity parameters (3-10 mPa.s) and surface tension through anionic surfactant addition to control ink flow and prevent leakage while maintaining good deposit quality. The pH control (8-11) also prevents ink migration and leakage on non-porous substrates.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The anionic surfactant acts as an intermediary substance that improves wetting and adhesion of the polymer film to the substrate, enabling good deposit quality without leakage. It mediates between the ink components and the substrate surface, ensuring proper bonding without excessive penetration.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the ink composition uses standard viscosity for felt-tip markers, then the ink flows properly through the capillary feed system, but achieving good erasability becomes difficult

Engineering Contradiction:
Improveink flowVSAvoiderasability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent sets viscosity within a specific range (3-10 mPa.s) that balances capillary flow in the marker with the formation of a cohesive, peelable film on the substrate. This parameter optimization ensures both ease of operation and reliable erasability simultaneously.

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 ink composition provides a peelable, erasable mark on non-porous substrates with good wettability, opacity, and vividness, while preventing ink leakage, even under stress conditions, and is suitable for standard felt-tip markers.

Implementation Method 1

contain an anionic surfactant which improves the wettability of the ink composition on the substrate

Methodology Applied
Scientific EffectSurface tension reduction: Surfactant

Implementation Method 2

When the ink composition is applied to substrates, more specifically a non-porous substrate, the water evaporates and the polymer provides a coalesced film (also named residue or deposit) on the surface of the substrate

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

the polymer provides a coalesced film (also named residue or deposit) on the surface of the substrate

Methodology Applied
Scientific EffectCoalescence: Coagulation

Data Source

PatentUS12617959B2Peelable ink composition for non-porous substrates
Publication Date: 2026.05.05 SOCIETE BIC SA

AI summary

An aqueous peelable ink composition substrate comprising: (a) at least one film-forming elastomeric polymer, (b) at least one anionic surfactant, (c) at least one coloring agent, and (d) water, wherein the film-forming elastomeric polymer is acrylonitrile butadiene rubber (NBR) and/or hydrogenated acrylonitrile butadiene rubber (HNBR), and a method for preparing such an aqueous peelable ink composition.