Hot Melt Adhesive Composition Using Crystalline Block Composite Compatibilizer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hot melt adhesives based on high flow, low crystallinity polyethylene polymers face challenges in maintaining cohesive properties under elevated temperatures due to the inherent incompatibility between polyethylene and propylene-based polymers, leading to suboptimal performance in applications like book binding and packaging.
Innovation Solution
A hot melt adhesive composition is developed that includes a blend of ethylene-based and propylene-based polymers, with a crystalline block composite (CBC) compatibilizer, which improves blending and adhesion properties by incorporating a crystalline ethylene-based polymer, a crystalline alpha-olefin-based polymer, and a block copolymer, along with optional tackifiers, waxes, and oils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyethylene polymer is blended with propylene-based polymer to improve cohesive properties, then heat resistance and cohesion are improved, but blending compatibility deteriorates due to inherent incompatibility between polyethylene and polypropylene
Solution Approach 1:
The patent introduces a polyethylene-polypropylene block copolymer as a compatibilizer that acts as an intermediary between polyethylene and polypropylene phases. This block copolymer contains both polyethylene blocks and polypropylene blocks, allowing it to interact with both incompatible polymers and improve blending compatibility while maintaining the cohesive properties provided by the propylene-based polymer.
Solution Approach 2:
The patent creates a composite adhesive system combining polyethylene polymer, propylene-based polymer, and polyethylene-polypropylene block copolymer. This composite approach allows the system to benefit from the high flow and low crystallinity of polyethylene, the heat resistance and cohesion of propylene-based polymer, and the compatibilizing effect of the block copolymer, achieving a balance of multiple properties.
2Ease of manufacture
If high flow, low crystallinity polyethylene polymer is used to achieve excellent processability and adhesive performance, then processability and adhesive performance are improved, but heat stress resistance deteriorates
Solution Approach 1:
The patent merges polyethylene polymer with propylene-based polymer in a blended system. The propylene-based polymer contributes higher heat resistance and improved cohesion, while the polyethylene polymer maintains excellent processability and adhesive performance. The combination allows the adhesive to achieve both ease of manufacture and heat stress resistance.
Data Source
Figure 1~2
Figure 3~4A
Figure 4B~4C
AI summary
A hot melt adhesive composition includes (A) 20-95 wt％ of a polymer component including an ethylene-based polymer and a propylene based polymer, the ethylene-based polymer being present in an amount greater than 30 wt％, based on a total weight of the polymer component, and (B) 1-60 wt％ of a crystalline block composite comprising (1) a crystalline ethylene based polymer, (2) a crystalline alpha-olefin based polymer derived from at least one of a C3-10 α olefin, and (3) a block copolymer comprising 10-90 wt％ of a crystalline ethylene block comprising 90 or more wt％ units derived from ethylene and comprising 10-90 wt％ of a crystalline alpha-olefin block comprising 90 or more wt％ units derived from at least one of a C3-10 α olefin, (C) Optionally, from greater than zero to 70 wt％ tackifier, and (D) Optionally, from greater than zero to 40 wt％ of at least one selected from the group of a wax and an oil.