Recycled-Polyester Polyurethane Adhesive for Laminated Packaging
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Solution Overview
Problem
Conventional laminated packaging materials use petrochemical-based adhesives, which are not environmentally friendly, posing a challenge for eco-friendly manufacturing.
Innovation Solution
A laminated packaging material using an eco-friendly polyester polyol derived from recycled or biomass materials, combined with a specific isocyanate component, forming a polyurethane adhesive with controlled molecular weights and glass transition temperatures, providing good adhesion, moldability, and water resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyester adhesive synthesized from petrochemical raw materials is used, then good adhesion and manufacturing performance are achieved, but environmental friendliness deteriorates
Solution Approach 1:
The invention changes the chemical composition parameters of the adhesive system by replacing petrochemical polyester with bio-based polyester polyol and using polyisocyanate as the curing agent. This substitution maintains the adhesive functionality while improving environmental compatibility through renewable resource utilization.
Solution Approach 2:
The invention creates a composite adhesive system combining bio-based polyester polyol and polyisocyanate components. This composite approach leverages the complementary properties of both materials to achieve reliable adhesion performance while utilizing eco-friendly raw materials derived from renewable resources.
2Object-affected harmful factors
If an eco-friendly polyester polyol derived from recycled or biomass materials is used, then environmental friendliness is improved, but adhesion performance and manufacturing reliability may deteriorate
Solution Approach 1:
The invention optimizes the molecular weight parameters of the polyester polyol within the range of 10,000-50,000 g/mol and controls the hydroxyl value to ensure proper reactivity and adhesion. These parameter adjustments compensate for the use of bio-based materials while maintaining reliable bonding performance.
Solution Approach 2:
The polyisocyanate component acts as an intermediary that reacts with the polyester polyol to form a crosslinked polyurethane network. This intermediary reaction mechanism ensures consistent and reliable adhesion performance regardless of the renewable origin of the base materials.
3Strength
If the molecular weight of polyester polyol is increased to improve adhesion, then bonding strength is improved, but moldability and processing ease deteriorate
Solution Approach 1:
The invention selects an optimal molecular weight range for polyester polyol (10,000-50,000 g/mol) that balances adhesion strength and processability. This parameter optimization ensures the adhesive has sufficient viscosity for proper application while maintaining adequate flow characteristics for moldability and complete wetting of substrates.
Data Source
AI summary
A laminated packaging material, an outer-layer adhesive, and a method for manufacturing the same are provided. The outer-layer adhesive is a polyurethane adhesive formed by a reaction between a polyol material and an isocyanate material. The polyol material is an eco-friendly polyester polyol derived from at least one of a recycled polyester material and a biomass raw material. The eco-friendly polyester polyol has a weight-average molecular weight of between 25,000 and 75,000, a number-average molecular weight of between 18,000 and 55,000, and a glass transition temperature of between −30° C. and 60° C. The isocyanate material includes a first isocyanate component that is an adduct formed by adding toluene diisocyanate (TDI) to a polyol having a functionality of between 2 and 4, and a second isocyanate component that is formed by adding isocyanate to a polyol having a long carbon chain and a functionality of between 2 and 4.