Drive Belt Textile Adhesion Blocked Isocyanate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Drive belts with styrene butadiene rubber or polychloroprene rubber bases face challenges with heat resistance and adhesive strength between the rubber and textile tension cords, particularly when the tension cords contain condensates from resorcinol, formaldehyde, and latex, leading to weaknesses in both static and dynamic adhesion.
Innovation Solution
A drive belt with a base body made of radically crosslinked polymeric material, featuring a cover layer and substructure with embedded textile tension cords fully or partially equipped with an adhesive containing partially or fully blocked isocyanates, such as hexamethylene diisocyanate (HDI) or 4,4'-methylenebis(phenyl isocyanate) (MDI), which enhances adhesion and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RFL adhesive layer is used for bonding textile tension cords to heat-resistant rubber mixtures, then adhesion is achieved, but adhesive strength is only moderately good
Solution Approach 1:
The patent changes the chemical parameters of the adhesive system by replacing RFL (resorcinol-formaldehyde-latex) with blocked isocyanate adhesives. This parameter change enables significantly improved adhesive strength while maintaining compatibility with heat-resistant rubber mixtures that have low double bond content (<10%). The blocked isocyanates provide better chemical bonding to the textile tension cords without requiring the rubber to have high unsaturation.
2Temperature
If sulfur crosslinking is used to increase crosslinking yield and dynamic stability, then heat resistance is improved, but adhesion to textile tension cords deteriorates
Solution Approach 1:
The patent introduces blocked isocyanate adhesives as an intermediary substance between the sulfur-crosslinked heat-resistant rubber and the textile tension cords. This intermediary layer provides the necessary adhesive bonding function that sulfur crosslinking alone cannot achieve, while allowing the rubber to maintain its heat resistance properties through sulfur crosslinking. The blocked isocyanates bridge the gap between the saturated rubber matrix and the textile reinforcement.
3Temperature
If rubber mixtures with low double bond content are used for heat resistance, then heat resistance is improved, but adhesion to textile tension cords deteriorates
Solution Approach 1:
The blocked isocyanate adhesive serves as a mediator that enables effective bonding to textile tension cords even when the rubber matrix has low double bond content (<10%). The isocyanate groups in the adhesive can form strong bonds with the textile fibers independently of the rubber's unsaturation level, thus decoupling the heat resistance requirement from the adhesion mechanism.
4Reliability
If adhesion promoters based on isocyanates are used to improve adhesion, then adhesive strength is improved, but complexity of adhesive system increases
Solution Approach 1:
The patent simplifies the adhesive system by using blocked isocyanates as the primary adhesive component, replacing or supplementing the RFL system. This parameter change in the adhesive chemistry provides improved adhesion with a more straightforward formulation approach, reducing the need for multiple adhesive layers or complex processing steps while achieving reliable bonding to both the heat-resistant rubber and textile tension cords.
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 use of blocked isocyanates in the adhesive significantly improves static and dynamic adhesion between the rubber and textile tension cords, providing better durability and heat resistance, while reducing the need for additional adhesives and solvent use, thus enhancing the belt's performance and safety.
Implementation Method 1
the textile tension cord is fully or partially equipped with an adhesive which contains at least one partially or fully blocked isocyanate
Implementation Method 2
Surprisingly, such a finished textile tensile cord is distinguished in free-radically crosslinked rubber mixtures by particularly good static and dynamic adhesion
Implementation Method 3
a base body made of a radically crosslinked polymeric material with elastic properties
Implementation Method 4
elastomers based on a free-radically vulcanized rubber mixture
Implementation Method 5
the tension cords are responsible for the strength of the drive belt under tension
Data Source
Figure 1~2
AI summary
The invention relates to a drive belt (1) having a main body made of a radically cross-linked polymer material having elastic properties, comprising a top layer (2) as a belt back and a substructure (5) having a force transmission zone (8), wherein at least one textile tensile strand (4) in cord design is furthermore embedded in the drive belt, wherein the textile tensile strand (4) is completely or partially equipped with an adhesive agent, which comprises at least one partially or completely blocked isocyanate. The drive belt (1) is in particular designed as a V-ribbed belt.