Modified Propylene Copolymer Low Melting Point
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Solution Overview
Problem
Propylene-based waxes tend to have higher rigidity and solidity compared to ethylene-based waxes, making them difficult to handle when their melting point is lowered, and existing production methods like slurry or solution polymerization are not productive, while thermal decomposition is more advantageous for producing waxes with low melting points but can result in sticky products.
Innovation Solution
A modified propylene-α-olefin copolymer is produced by thermally decomposing a propylene-C4+α-olefin copolymer and grafting polar groups, which reduces the melting point, inhibits crosslinking reactions, and maintains crystallinity and hardness, allowing for high compatibility with other resins and fillers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the melting point of propylene-based wax is lowered, then energy saving effects are achieved, but the wax becomes rubbery and difficult to handle
Solution Approach 1:
The patent changes the chemical composition parameters by introducing C4+α-olefin units (5-40 mol%) into the propylene-based polymer structure. This compositional parameter change enables the wax to achieve low melting point (60-110°C) while maintaining crystallinity and handleability, resolving the contradiction between low temperature performance and ease of operation.
Solution Approach 2:
The patent creates a composite polymer structure combining propylene units with C4+α-olefin units in a copolymer configuration. This composite material approach allows simultaneous achievement of low melting point and retained crystallinity, preventing the rubbery behavior that would otherwise occur at low temperatures.
2Productivity
If thermal decomposition is used to produce propylene-based wax with low melting point, then productivity is improved, but the wax becomes sticky
Solution Approach 1:
The patent introduces polar groups (carboxyl, hydroxyl, or isocyanate groups) at specific locations within the polymer structure through graft modification. This local quality change at the molecular level enables the wax to maintain low melting point and high productivity while eliminating stickiness through improved intermolecular interactions.
Solution Approach 2:
The patent uses graft modification as an intermediary process between thermal decomposition and final product formation. This intermediary step introduces functional groups that mediate the properties of the wax, converting the sticky thermal decomposition product into a non-sticky final product with improved handling characteristics.
3Adaptability or versatility
If polar groups are introduced into polyolefin wax, then compatibility with polar resins is improved, but polymerization activity is degraded due to catalyst poisoning
Solution Approach 1:
The patent performs graft modification after the polymerization process is complete. This preliminary action sequence allows the polymer to be first synthesized using active transition metal catalysts, then subsequently modified to introduce polar groups. This approach avoids catalyst poisoning during polymerization while still achieving the desired polarity for resin compatibility.
Solution Approach 2:
The patent separates the polymerization process from the polar group introduction process into distinct sequential steps. This segmentation allows each process to be optimized independently: polymerization uses active catalysts without interference, while polar group introduction occurs afterward through graft modification, resolving the contradiction between maintaining polymerization activity and achieving resin compatibility.
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 modified propylene-α-olefin copolymer achieves a low melting point without stickiness, retains crystallinity, and exhibits high hardness and compatibility, making it suitable for various applications including coatings, moldable resin compositions, and hot melt compositions.
Implementation Method 1
a propylene-based wax having an appropriate number of vinylidene groups can be produced by, for example, thermally decomposing a copolymer containing a propylene unit as well as a C4+α-olefin unit
Implementation Method 2
modified propylene-α-olefin copolymer is produced by thermally decomposing a propylene-C4+α-olefin copolymer and grafting polar groups
Data Source
AI summary
The purpose of the present invention is to provide a polar-group-containing propylene-type wax having excellent properties including a low melting point. A modified propylene-(α-olefin) copolymer (A) according to the present invention is produced by grafting at least one compound selected from an unsaturated carboxylic acid, a derivative of the unsaturated carboxylic acid and an unsaturated sulfonic acid salt onto a propylene-(α-olefin) copolymer (A1) and has an acid value of 1 to 100 KOHmg/g, wherein the propylene-(α-olefin) copolymer (A1) comprises 60 to 95 mol % of a propylene-derived constituent unit (a) and 5 to 40 mol % of a constituent unit (b) derived from an α-olefin having 4 or more carbon atoms, and satisfies the specific requirements (i) to (iii).