Foamed Opacifying Layer Composition to Reduce Carbon Black Soiling

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Solution Overview

Problem

Existing light-blocking articles, such as blackout curtains and shades, face challenges with weight, flexibility, launderability, and the risk of dark opacifying agents escaping during handling or sewing, leading to unwanted staining and reduced reflectivity.

Innovation Solution

A method involving a foamable aqueous composition with porous particles, a binder material with a glass transition temperature below 25°C, surfactants, and opacifying colorants, aerated to a specific density, applied to a substrate, dried, and then densified and cured to form a foamed opacifying layer, with an optional functional composition of spacer particles and tinting materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If very thick foam coatings are used to block light with light scattering pigments, then light blocking performance is improved, but weight increases

Engineering Contradiction:
Improvelight blocking performanceVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent uses a composite structure with a light-absorbing black or grey foamed layer sandwiched between two light-scattering white foamed layers. This composite material approach achieves superior light blocking performance with thinner overall coating, thereby reducing weight compared to using only light scattering pigments in thick foam.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention applies different functional layers at different locations: the outer white layers provide light scattering at the surfaces, while the inner black layer provides light absorption in the middle. This localized functional distribution achieves effective light blocking with reduced material thickness and weight.

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If carbon black layer is used to reduce weight, then weight is reduced, but carbon black becomes fugitive and soils other layers during sewing or laundering

Engineering Contradiction:
ImproveweightVSAvoidcarbon black soiling
Core Design Contradiction:
Weight of moving objectVSObject-generated harmful factors

Solution Approach 1:

The carbon black layer is nested or sandwiched between two white foamed layers. This nested structure physically confines the carbon black within the middle layer, preventing it from migrating to the outer surfaces during sewing or laundering, thereby eliminating the soiling problem while maintaining weight reduction benefits.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The white outer layers act as protective barriers that prevent carbon black from escaping beforehand. These encapsulating layers cushion against potential carbon black migration during handling, sewing, or laundering processes.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If three or more separate coating operations are used to create light absorbing middle layer, then light blocking performance is improved, but manufacturing productivity decreases and unit costs increase

Engineering Contradiction:
Improvelight blocking performanceVSAvoidmanufacturing productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent combines the light-absorbing and light-scattering functions into a single multi-layer foam coating composition that can be applied in one coating operation. The composition includes dispersed black pigment particles within a white foamed matrix, allowing simultaneous achievement of light absorption and scattering in a single application step, thereby improving manufacturing productivity and reducing unit costs.

Inventive Principle:
Principle #5Merging (Combining)

4Illumination intensity

If light colored foam coatings are used, then reflectivity is improved, but light blocking performance deteriorates

Engineering Contradiction:
ImprovereflectivityVSAvoidlight blocking performance
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The invention assigns different optical functions to different layers: the outer white layers provide high reflectivity and light scattering at the surfaces, while the inner black layer provides light absorption. This local functional differentiation allows the light-colored outer surfaces to maintain high reflectivity while the internal black layer ensures effective light blocking.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The composite structure combines light-scattering white foam material with light-absorbing black pigment particles in a single coating system. The white matrix provides reflectivity and scattering, while the dispersed black particles provide absorption, achieving both high reflectivity and effective light blocking simultaneously.

Inventive Principle:
Principle #40Composite materials

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 reduces sticking issues, enhances flexibility, maintains light reflectivity, and minimizes the escape of opacifying agents, resulting in lighter, more flexible, and effective light-blocking materials with improved launderability and surface resistance.

Implementation Method 1

a binder material having a glass transition temperature (Tg) of less than 25° C.

Methodology Applied
Scientific EffectGlass transition:

Implementation Method 2

aerating it to provide a foamed aqueous composition having a foam density of at least 0.1 g/cm3 and up to and including 0.5 g/cm3

Methodology Applied
Scientific EffectFoaming: Foam

Implementation Method 3

an opacifying colorant different from all the one or more (c) additives, which opacifying colorant absorbs electromagnetic radiation having a wavelength of at least 380 nm and up to and including 800 nm

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 4

porous particles, each porous particle comprising a continuous polymeric phase and discrete pores dispersed within the continuous polymeric phase

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 5

one or more additives comprising a surfactant

Methodology Applied
Scientific EffectSurface tension reduction: Surfactant

Data Source

PatentUS10696814B2Method of making light-blocking articles
Publication Date: 2020.06.30 EASTMAN KODAK CO

AI summary

Foamed, opacifying elements are prepared using a foamable aqueous composition containing porous particles and an opacifying colorant. This composition is aerated, disposed onto a substrate, and dried. The dry foamed composition is densified, and cured in either order. At some point after the drying feature, a functional composition is disposed onto either the dry foamed composition or the opacifying layer, and dried. This functional composition has either or both of: (i) inorganic or organic spacer particles having a mode particle size of 1 to 100 μm, and which inorganic or organic spacer particles resist melt flow at a pressure of up to and including 100 psi (689.5 kPa) and a temperature of up to and including 220° C.; and (iii) a tinting material comprising a pigment, dye, or a combination thereof. The (i) inorganic or organic spacer particles and the (iii) tinting material are different materials.