Tire Coating Adhesion and CO2 Defect Resolution
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Solution Overview
Problem
Existing tire coatings using liquid polyurethane reaction mixtures can cause defects due to carbon dioxide release and may discolor due to antioxidant and wax migration, while polyurethane compositions face adhesion issues with vulcanized tires.
Innovation Solution
A crosslinkable composition combining polysulfide polymers, thermoplastic polymers with hydroxyl groups, and polyisocyanates is applied to vulcanized tires, forming a flexible, strongly adherent, and non-staining coating that withstands tire deformations and provides a glossy appearance, while preventing ozone degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid polyurethane reaction mixture is applied to tire surface, then coating can be formed, but carbon dioxide release causes surface defects
Solution Approach 1:
The patent extracts and eliminates the harmful carbon dioxide generation mechanism from the coating formulation by using pre-polymerized polyurethane resin instead of liquid polyurethane reaction mixtures that release CO2 during curing, thereby preventing surface defects while maintaining coating integrity
Solution Approach 2:
The patent converts the potential harm of CO2 release into a benefit by selecting a coating system (polyurethane resin with isocyanate crosslinking) that not only avoids CO2 generation but also provides superior adhesion and flexibility, turning a problematic curing mechanism into an advantageous one
2Reliability
If polyurethane coating is applied to vulcanized tire, then coating can be formed, but adhesion to tire surface is poor
Solution Approach 1:
The patent changes the chemical parameters of the coating system by using polyurethane resin with specific functional groups that can chemically interact with the vulcanized rubber surface, and adjusts crosslinking density to optimize both adhesion and flexibility for strong bonding
Solution Approach 2:
The patent creates a composite coating system combining polyurethane resin with isocyanate crosslinking agents and flexible polymers, forming a multi-component system that achieves superior adhesion to vulcanized rubber while maintaining the required flexibility for tire application
3Reliability
If antioxidant and wax are present in tire rubber, then tire performance is improved, but they migrate to surface causing discoloration
Solution Approach 1:
The patent introduces the polyurethane coating layer as an intermediary barrier between the tire rubber composition and the external environment, preventing antioxidant and wax migration to the surface while allowing the tire to maintain its performance-enhancing additives in the rubber matrix
Solution Approach 2:
The patent applies the coating layer in advance to create a protective barrier that prevents the anticipated discoloration problem before it occurs, stopping the migration of antioxidants and waxes to the surface before they can cause aesthetic degradation
4Shape
If coating layer is applied to tire, then appearance is improved, but coating must withstand tire deformations
Solution Approach 1:
The patent designs the coating system with dynamic properties by incorporating flexible polymers and optimizing crosslinking density to allow the coating to deform elastically with the tire during use, then recover its original state, maintaining appearance while withstanding mechanical stresses
Solution Approach 2:
The patent employs a flexible polyurethane coating film that can accommodate tire deformations through its inherent elasticity and flexibility, allowing the thin film to stretch and conform to tire shape changes without cracking or delaminating
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 coating layer ensures excellent adhesion, prevents discoloration, and maintains the tire's appearance without defects, offering protection against ozone and deformation, while allowing for a colored and glossy finish.
Implementation Method 1
a crosslinkable composition obtained by mixing a first component comprising at least one polysulfide polymer and at least one thermoplastic polymer having at least one hydroxyl group, with a second component comprising at least one polyisocyanate
Data Source
AI summary
A tire includes at least one outer structural element, wherein the at least one outer structural element is at least partially coated by at least one coating layer including a crosslinked composition obtained by reacting: (a) at least one polysulfide polymer; (b) at least one thermoplastic polymer having at least one hydroxyl group; with (c) at least one polyisocyanate. Preferably, the at least one structural element is at least one of the tire sidewalls.