Dark Infrared-Transmitting Ink for Black Solar Module Sheets

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing infrared-light-transmitting dark color inks used in solar cell modules, such as those containing carbon black or oxazine pigments, either absorb near-infrared light leading to heat generation or fail to provide a true black appearance, thereby reducing electric power generation efficiency.

Innovation Solution

An infrared-light-transmitting dark color ink comprising a pigment component with a brown pigment and a phthalocyanine pigment, which transmits near-infrared light and provides a dark color appearance, is developed, along with a laminated infrared-light-reflecting sheet structure that includes a reflective layer and a dark color layer to enhance electric power generation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If carbon black is used to provide a dark color appearance, then design attractiveness is improved, but near infrared light is absorbed causing heat generation and reduced electric power generation efficiency

Engineering Contradiction:
Improvecolor appearanceVSAvoidelectric power generation efficiency
Core Design Contradiction:
ShapeVSLoss of energy

Solution Approach 1:

The patent changes the chemical composition parameters of the pigment from carbon black to a specific combination of organic pigments (oxazine pigment with 20-80 wt% and violet pigment with 20-80 wt%). This parameter change allows the ink to maintain dark color appearance while transmitting near infrared light, thus resolving the contradiction between design attractiveness and energy efficiency.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If oxazine pigment is used to transmit infrared light, then electric power generation efficiency is improved, but the color appearance becomes violet rather than black

Engineering Contradiction:
Improveelectric power generation efficiencyVSAvoidcolor appearance
Core Design Contradiction:
Loss of energyVSShape

Solution Approach 1:

The patent creates a composite pigment system by combining oxazine pigment (which transmits infrared light) with violet pigment. This composite material approach allows the ink to maintain infrared transmission properties for improved power generation efficiency while achieving a dark color appearance close to black through the synergistic effect of the pigment combination.

Inventive Principle:
Principle #40Composite materials

3Temperature

If a white resin layer with infrared reflectivity is added to suppress heat generation, then temperature increase is reduced, but the structure becomes more complex requiring multiple layers and adhesives

Engineering Contradiction:
Improvetemperature increaseVSAvoidstructure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for separate white resin layers and adhesive layers by incorporating infrared transmission functionality directly into the dark color ink formulation. This single-layer solution replaces the multi-layer structure, reducing structural complexity while maintaining temperature control through infrared light transmission.

Inventive Principle:
Principle #2Taking out (Extraction)

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 suppresses heat generation by near-infrared light absorption and maintains design attractiveness, thereby improving the electric power generation efficiency of solar cell modules.

Implementation Method 1

the pigment component contains a brown pigment and a dark color pigment composed of a phthalocyanine pigment... transmits near infrared light

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentEP4729585A1Infrared-light-transmitting ink of dark color, and infrared-light-reflecting sheet obtained using same
Publication Date: 2026.04.22 DAI NIPPON PRINTING CO LTD
  • EP4729585A1 patent drawingFigure 1
  • EP4729585A1 patent drawingFigure 2
  • EP4729585A1 patent drawingFigure 3

AI summary

In order to satisfy the demand of consumers regarding design attractiveness, an infrared-light-transmitting dark color ink is provided, the ink having a black appearance and attaining high design attractiveness and, despite this, having sufficient infrared-light-transmitting property. The infrared-light-transmitting dark color ink transmits near infrared light having wavelengths of 750-1,500 nm, and comprises a resin component and a pigment component that comprises both a brown pigment, e.g., a benzimidazolone pigment, and a phthalocyanine pigment.