Solvent-Based Adhesion Promoter with Extended Open Time
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solvent-based adhesion promoter compositions face issues with storage stability, open time, and UV stability due to the high reactivity of organosilanes, leading to inhomogeneities and rapid hydrolysis and condensation, especially under humid and warm conditions, which affects the durability of adhesive bonds.
Innovation Solution
A one-component adhesion promoter composition comprising 40-80% silane-terminated polyurethane polymer, 4-20% organosilane or organotitanate, 0-3% drying agent, and 40-80% solvent, with additional components like carbon black and UV markers, which provides improved storage stability and UV resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high reactivity organosilanes are used in adhesion promoter compositions, then adhesion bonding performance is improved, but storage stability deteriorates due to rapid condensation and precipitation
Solution Approach 1:
The patent introduces silane-modified polyurethane polymers as intermediary compounds that bridge the gap between adhesion performance and storage stability. These polymers contain reactive silane groups that provide bonding capability while the polyurethane matrix acts as a stabilizing carrier, preventing rapid condensation during storage. The modified polymer serves as a mediator that maintains reactivity for adhesion while suppressing unwanted side reactions.
Solution Approach 2:
The invention employs composite material structure by combining silane-modified polyurethane polymers with traditional adhesion promoters and solvents in a formulated composition. This composite approach integrates the bonding advantages of organosilanes with the stabilizing properties of polyurethane matrices, creating a material that exhibits both high adhesion performance and improved storage stability through synergistic effects.
2Strength
If organosilane content is increased to improve adhesion, then bonding strength is enhanced, but open time is reduced due to rapid hydrolysis and condensation
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure of polyurethane polymers through silane modification, creating a new class of polymers with altered reactivity characteristics. This structural modification changes the kinetic parameters of the system, allowing the composition to maintain high bonding strength while exhibiting extended open time through controlled hydrolysis and condensation rates.
3Ease of operation
If conventional adhesion promoters are used, then application is simple, but UV stability is insufficient leading to bond degradation under prolonged UV exposure
Solution Approach 1:
The invention extracts and addresses the UV stability deficiency by incorporating specific UV-stabilizing components into the adhesion promoter formulation. This extraction approach isolates the UV protection function from the base adhesion promoter system, adding it as a targeted functional element that prevents bond degradation under UV exposure while maintaining the simplicity of one-component application.
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 composition achieves exceptional adhesion properties with extended open time and high UV stability, ensuring stable adhesive bonds under demanding environmental conditions.
Implementation Method 1
the silanes hydrolyze and condense very rapidly under the influence of atmospheric humidity
Implementation Method 2
they often undergo condensation with one another after a short time
Implementation Method 3
The rapid evaporation of the solvents further allows rapid work and cycle times
Data Source
AI summary
Adhesion promoter compositions, containing: a) between 40 and 80 parts by weight of a binder composition, including i) 20-40 wt % of at least one silane-terminated polyurethane polymer STP, which can be obtained from at least one polyol P, aliphatic polyisocyanate I and organosilane OS1, ii) 4-20 wt % of at least one organosilane OS2 and/or organotitanate OT, iii) 0-3 wt % of at least one desiccant, iv) 40-80 wt % of solvent L1; b) between 0-30 parts by weight of industrial carbon black; c) between 0-1 parts by weight of UV marker; d) so much of solvent L2 that sum of a)-d) is 100 parts by weight; OS1 having secondary amino, mercapto or hydroxyl group on organic moiety and the at least one STP having been produced in absence of OS2, and the at least one P having an average OH functionality of at least 2 and equivalent weight of at most 500.