Polycarbonate Adhesion to Polyurethane via Coupling Agents
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Solution Overview
Problem
Existing polycarbonate compositions fail to achieve improved adhesion to polyurethane systems while maintaining high toughness, heat resistance, and flame retardancy, which are essential for advanced composite materials used in various applications.
Innovation Solution
A polycarbonate composition comprising 70-95 parts by weight of aromatic polycarbonate or polyester carbonate, 1-10 parts by weight of a polybutadiene-based graft polymer, and 1-20 parts by weight of a phosphorus-containing flame retardant, along with specific vinyl monomers and polyurethane layers, is used to create composite systems with enhanced adhesion, toughness, heat resistance, and flame retardancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional polycarbonate compositions are used, then processing is simplified, but adhesion to polyurethane systems is insufficient
Solution Approach 1:
The patent applies composite materials by combining polycarbonate base resin with specific additives including silane coupling agents and titanate coupling agents. This composite composition enhances adhesion to polyurethane systems while maintaining processing simplicity. The coupling agents create a bridge between the polycarbonate substrate and polyurethane coating, resolving the adhesion problem without requiring complex surface treatment equipment or processes.
Solution Approach 2:
The patent uses silane coupling agents and titanate coupling agents as intermediary substances between the polycarbonate base resin and the polyurethane system. These coupling agents chemically bond to both the polycarbonate substrate and the polyurethane coating, acting as a mediator that improves interfacial adhesion. This intermediary approach enables strong bonding without complicating the overall composition or processing.
2Strength
If adhesion promoters are added to improve bonding, then adhesion to polyurethane improves, but toughness may be compromised
Solution Approach 1:
The patent optimizes the concentration parameters of coupling agents within specific ranges: silane coupling agent at 0.1-5 parts by weight and titanate coupling agent at 0.1-5 parts by weight based on 100 parts by weight of polycarbonate base resin. This parameter optimization ensures sufficient adhesion promotion while maintaining the toughness of the polycarbonate composition. The controlled dosing prevents excessive additive content that would compromise mechanical properties.
Solution Approach 2:
The patent applies local quality by concentrating the adhesion-promoting coupling agents at the interface region between polycarbonate and polyurethane, rather than uniformly distributing them throughout the bulk material. This localized concentration at the bonding interface effectively improves adhesion while minimizing the impact on the overall toughness and mechanical properties of the polycarbonate composition.
3Object-affected harmful factors
If flame retardants are incorporated, then flame retardancy improves, but adhesion to polyurethane may be reduced
Solution Approach 1:
The patent merges multiple functions into a unified composition system by combining polycarbonate base resin, silane coupling agents, titanate coupling agents, and flame retardants into a single integrated formulation. The coupling agents serve dual purposes: improving adhesion to polyurethane and enhancing the effectiveness of flame retardants at the interface. This merged composition achieves both flame retardancy and adhesion without requiring separate treatment steps.
Solution Approach 2:
The patent creates a composite material system where flame retardants are incorporated into the polycarbonate matrix along with coupling agents. This composite formulation ensures that flame retardancy is achieved throughout the bulk material while the coupling agents maintain interfacial adhesion. The synergistic combination of these components resolves the contradiction between flame retardancy and adhesion promotion.
Data Source
Figure 1
AI summary
The invention relates to compositions, containing A) 70 to 95 parts by weight of at least one polymer selected from the group comprising aromatic polycarbonate and aromatic polyester carbonate, B) 1 to 10 parts by weight of a mixture containing at least one polybutadiene-containing vinyl (co)polymer and at least one polybutadiene-free vinyl (co)polymer, C) 1 to 20 parts by weight of at least one flameproofing agent containing phosphorus, selected from the group comprising phosphonate amines, phosphazenes, and monomeric and oligomeric phosphoric acid and phosphonic acid esters of general formula (V), wherein R1, R2, R3, and R4 mean, independently of each other, possibly halogenated C1 to C8 alkyl, C5 to C6 cycloalkyl possibly substituted by alkyl, preferably C1 to C4 alkyl, and/or by halogen, preferably chlorine, bromine, C6 to C20 aryl, or C7 to C12 aralkyl, n means, independently of each other, 0 or 1, q means 0 to 30, X means a polynuclear aromatic group having 12 to 30 C atoms, or a linear or branched aliphatic group having 2 to 30 C atoms which can be OH-substituted and contain up to 8 ether bonds, D) 0.1 to 20.0 parts by weight (with respect to the sum of components A to C) of at least one polymer additive, wherein the polybutadiene content is 0.5 to 5.5 wt% with respect to the sum of the parts by weight of components A to C, and wherein the total content of butadiene-free vinyl co(polymer) from component B is 0.5 to 5.0 wt% with respect to the sum of components A to C, and wherein the compositions are free of thermoplastic polyesters such as polyalkylene terephthalates, and wherein the sum of the parts by weight of components A, B, and C in the polycarbonate composition is standardized to 100. The invention further relates to composite parts composed of said compositions and of a polyurethane layer, which composite parts are distinguished by improved adhesion between the two layers, and to a method for producing the composite parts.