Abrasion-Resistant Coating Composition for Tintable Transparent Plastics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transparent plastics used in applications like glazing and lenses are prone to marring and scratching due to their poor abrasion resistance, and existing abrasion-resistant coatings lack formability and tintability, necessitating coatings that provide both abrasion resistance and formability while allowing for tint addition post-curing.
Innovation Solution
Aqueous-organic solvent mixtures containing hydrolysis products and partial condensates of epoxy functional silanes, diol functional organopolysiloxanes, and multifunctional crosslinkers, with specific molar ratios and additives like silylated multifunctional anhydrides, enable the creation of coatings that are abrasion-resistant, formable, and tintable, allowing for post-curing tinting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If abrasion resistant coatings are applied to transparent plastics, then abrasion resistance is improved, but formability deteriorates (coatings crack or craze when bent)
Solution Approach 1:
The patent applies parameter changes by carefully controlling the molar ratio of epoxy functional silane to multifunctional crosslinker (from about 10:1 to about 1:10) and adjusting the aqueous-organic solvent mixture composition. These parameter adjustments optimize the crosslinking density and network structure to achieve both abrasion resistance and formability simultaneously
Solution Approach 2:
The patent uses composite materials by combining epoxy functional silane with diol functional organopolysiloxane in the coating formulation. This composite approach creates a synergistic effect where the silane provides abrasion resistance while the polysiloxane contributes to flexibility and formability, resolving the contradiction between hardness and bendability
2Strength
If conventional coating compositions are cured on substrate, then abrasion resistance is achieved, but tintability deteriorates (tint cannot be added after curing)
Solution Approach 1:
The patent applies preliminary action by incorporating a blocked isocyanate into the coating composition before curing. The blocked isocyanate remains dormant during initial curing but becomes activated later, enabling post-curing tinting operations. This preliminary inclusion of the blocking agent allows subsequent modification without compromising the cured coating's integrity
Solution Approach 2:
The patent uses parameter changes by controlling the ratio of epoxy functional silane to blocked isocyanate and adjusting the curing conditions. These parameter adjustments ensure that the coating maintains its abrasion resistance while creating chemical pathways that allow tint penetration and bonding after the initial cure
3Weight of moving object
If transparent plastics are used instead of glass, then weight is reduced and shatter resistance is improved, but abrasion resistance deteriorates (plastics mar and scratch easily)
Solution Approach 1:
The patent applies composite materials by formulating a coating that combines epoxy functional silane (for hardness and abrasion resistance) with diol functional organopolysiloxane (for flexibility and adhesion). This composite coating structure allows it to bond effectively to lightweight plastic substrates while providing the abrasion resistance typically associated with heavier, more rigid materials
Solution Approach 2:
The patent uses parameter changes by optimizing the molar ratios of coating components (epoxy functional silane to multifunctional crosslinker from about 10:1 to about 1:10) and controlling the aqueous-organic solvent mixture composition. These parameter adjustments tailor the coating's mechanical properties to match the substrate, achieving high abrasion resistance on lightweight plastic surfaces
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 coatings exhibit excellent abrasion resistance, formability, and tintability, maintaining optical clarity and durability, suitable for applications in transportation and ophthalmic industries, with improved resistance to environmental factors.
Implementation Method 1
an amount of water sufficient to hydrolyze the epoxy functional silane, the diol functional organopolysiloxane, and the multifunctional crosslinker
Data Source
AI summary
Processes for tinting a transparent, abrasion-resistant coating that is coated on at least one surface of a substrate are provided. The processes include coating the substrate with a transparent, tintable, abrasion-resistant coating composition, curing the coating composition on the substrate, and tinting the cured coating by immersing the cured coating in a dye bath for a period of time.