Retroreflective articles containing adhesive compositions including styrenic block co-polymers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional retroreflective materials fail to maintain adequate retroreflectivity after 50 wash cycles, as they do not meet the required average coefficient of retroreflection of at least 100 cd/lx/m² as per the ISO 6330 Method 6N test protocol, necessitating an improvement in wash durability.
Innovation Solution
The development of retroreflective articles featuring a binder layer comprising a tackifier and an elastomer, such as styrenic block copolymers, with a layer of optical elements partially embedded, and an application layer that enhances durability, including a rubber elastomer binder layer and a reflective layer between the optical elements and the binder layer, ensuring wash durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional solvent-based or water-based coating chemistry is used for retroreflective materials, then the materials can be manufactured with conventional processes, but the retroreflectivity deteriorates after 50 wash cycles
Solution Approach 1:
The patent changes the chemical composition parameters of the binder layer by using rubber elastomer adhesive compositions with specific tackifiers and polymers, replacing traditional solvent-based or water-based coating chemistry. This parameter change in material composition enables the retroreflective material to maintain retroreflectivity after repeated wash cycles.
Solution Approach 2:
The patent creates a composite binder layer system combining rubber elastomer adhesive compositions with specific tackifiers (petroleum, pine, or coal tar-based) and polymers. This composite material structure provides both adhesion to the substrate and durability through washing, resolving the contradiction between conventional manufacturing and wash durability.
2Manufacturing precision
If the binder layer uses traditional coating chemistry, then the manufacturing process is simple and conventional, but the average coefficient of retroreflection falls below 100 cd/lx/m² after 50 wash cycles
Solution Approach 1:
The patent specifies precise compositional parameters for the rubber elastomer adhesive composition, including the type of tackifier (petroleum, pine, or coal tar-based) and polymer content. These parameter specifications ensure that the retroreflective material maintains an average coefficient of retroreflection of at least 100 cd/lx/m² after 50 wash cycles while remaining manufacturable.
3Stability of the object's composition
If the optical elements are fully embedded in the binder layer, then the structure is more stable, but the retroreflective performance decreases
Solution Approach 1:
The patent applies local quality by creating a binder layer where optical elements are partially embedded rather than fully embedded. This partial embedding provides localized stability where needed while maintaining retroreflective performance in other areas, resolving the contradiction between structural stability and retroreflectivity.
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 achieves wash durability by maintaining a minimum RA of at least 100 cd/lx/m² after 50 wash cycles, enhancing the longevity and effectiveness of retroreflective materials in safety applications.
Implementation Method 1
Reflective materials or articles improve wearer conspicuity by returning incident light back toward a light source
Data Source
AI summary
There is provided retroreflective articles comprising a binder layer comprising an adhesive composition comprising at least one tackifier and at least one elastomer selected from at least one of natural rubbers and synthetic rubbers, and a layer of optical elements at least partially embedded in a major surface of the binder layer. There are also provided articles of clothing using the presently disclosed retroreflective articles and methods for preparing the retroreflective articles.