Lightfast Marker Antifouling Silicone Rubber

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Solution Overview

Problem

Subsea signs made from polymeric antifouling compositions face issues with marker fading due to natural light exposure during storage, leading to reduced visibility and potential fouling, as well as difficulties in bonding with subsea objects.

Innovation Solution

Incorporation of lightfast markers like bismuth vanadate into vulcanized silicone rubber compositions, which are blended using high shear stirrers and vulcanized with fluid organic compounds, creating a chemically stable and non-fading antifouling layer, optionally with a water-impermeable layer and backing sheet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If traditional markers are used in subsea signs, then the signs are visible during storage and use, but the markers fade due to natural light exposure reducing visibility over time

Engineering Contradiction:
ImprovevisibilityVSAvoidmarker durability
Core Design Contradiction:
Illumination intensityVSDuration of action of stationary object

Solution Approach 1:

The patent changes the chemical composition parameter of the markers by using inorganic pigments (iron oxide, chromium oxide, titanium dioxide) instead of traditional organic dyes. This parameter change makes the markers resistant to photodegradation from natural light while maintaining their visibility and color intensity over extended storage periods.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system by incorporating inorganic pigment particles into the silicone rubber matrix. This composite structure combines the lightfastness of inorganic pigments with the flexibility and bonding properties of silicone rubber, achieving both durability and visibility requirements.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If silicone rubber is used for subsea signs, then the material provides excellent water-repelling properties, but the porous structure allows water to pass through reducing reliability

Engineering Contradiction:
Improvewater-repelling propertiesVSAvoidwater impermeability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies a thin film coating (such as fluoropolymer or other impermeable coatings) over the porous silicone rubber surface. This thin film acts as a barrier layer that blocks water penetration while preserving the bulk material's water-repelling properties and antifouling characteristics.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent creates a composite structure combining porous silicone rubber with an impermeable barrier layer. The silicone rubber provides flexibility, bonding, and antifouling properties, while the impermeable layer ensures water tightness, achieving both requirements through material combination.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If fluid organic compounds are incorporated to improve antifouling properties, then aquatic growth is reduced, but the compounds may leach out over time affecting long-term reliability

Engineering Contradiction:
Improveantifouling propertiesVSAvoidlong-term stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses inorganic pigments that do not fade or change color over time, providing permanent visual markers. This eliminates the need for organic compounds that might leach out, as the inorganic pigments remain stable and embedded in the silicone matrix indefinitely.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent changes the chemical stability parameter by selecting inorganic pigments with high resistance to leaching and degradation. These pigments maintain their colorfastness and structural integrity in the marine environment without releasing harmful substances, ensuring long-term reliability.

Inventive Principle:
Principle #35Parameter changes

4Illumination intensity

If white color is used for subsea signs, then visibility is maximized, but camera malfunction occurs due to light reflection

Engineering Contradiction:
ImprovevisibilityVSAvoidcamera interference
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different color properties to different parts of the sign or uses specific spectral characteristics in the marker material that provide high visibility to the human eye while being less reflective in the camera's operational wavelength range, thus achieving local optimization of optical properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the spectral reflectance parameter of the marker material by using inorganic pigments with specific absorption and reflection characteristics. These pigments can be tuned to reflect visible light for human visibility while absorbing or transmitting in the infrared range where ROV cameras operate, eliminating camera interference.

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 resulting signs exhibit extended working lifetimes with enhanced visibility and reduced fouling, eliminating the need for protective covers and improving bonding with subsea objects.

Implementation Method 1

a fluid organic compound which has a tendency to exude out from the surface of the sign when in use, thereby further reducing aquatic growth and fouling of the sign

Methodology Applied
Scientific EffectExusion:

Implementation Method 2

Silicone rubbers, and in particular room temperature vulcanizable silicone rubbers, are known to have excellent water-repelling properties

Methodology Applied
Scientific EffectHydrophobicity: Hydrophobe

Implementation Method 3

one or more lightfast markers wherein the lightfast marker comprises a marker selected from the group consisting of zinc chromate, nickel antimony titanium yellow, cadmium sulphide, lead chromate, hydrated iron oxide, cobalt yellow, bismuth vanadate, aryl-azo compounds, mono-azo compounds, and di-azo compounds

Methodology Applied
Scientific EffectLightfastness:

Data Source

PatentEP2382276B1Polymeric antifouling composition and articles made thereof
Publication Date: 2018.01.17 CHAMPION PARTNERSHIP THE
  • EP2382276B1 patent drawingFigure 1~3
  • EP2382276B1 patent drawingFigure 4~5

AI summary

The invention provides polymeric antifouling compositions and method for their manufacture. Articles or structures comprising the polymeric antifouling compositions are also described. The polymeric antifouling composition comprises a layer containing a vulcanized silicone rubber and one or more light fast markers. In alternative embodiemts the polymeric antifouling compositions further comprises a fluid organic compound that acts as an exuding liquid. The incorporation of the lightfast markers results in a polymeric antifouling composition that is more chemically stable to external influences when compared with those compositions known in the art, and so the described compositions do not fade in colour over time.