Elastomeric Composite Crumb Size Control via Tackifying Resin
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Solution Overview
Problem
The production of elastomeric composites often results in excessively small crumb sizes, leading to process difficulties such as plugging of equipment, reduced product recovery, and increased dry time, due to the formation of 'crumb' during polymerization and mixing processes, which complicates the handling and viability of elastomeric nanocomposites.
Innovation Solution
A process involving polymerization of olefins in the presence of a catalyst, followed by solution or slurry polymerization, where a solvent-rich slurry is stripped with water or steam to produce a solvent-lean slurry with a crumb of elastomeric composite, and optionally incorporating a tackifying resin to control crumb size distribution, reducing the presence of salt carboxylic acids to minimize crumb size issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solution or slurry polymerization is used to produce elastomeric composites, then the composite can be produced with improved properties, but the crumb size becomes excessively small causing process difficulties
Solution Approach 1:
The patent changes physical parameters including crumb size distribution (targeting 0.33-3.5 cm nominal diameter), solvent content (reducing to less than 0.5 phr salt of C8-C20 carboxylic acid), and moisture content (reducing to below 1 phr) to resolve the contradiction between producing elastomeric composites with improved properties and avoiding excessively small crumb sizes that cause processing issues
2Manufacturing precision
If crumb size is reduced to increase surface area for better composite properties, then material performance improves, but equipment plugging and reduced product recovery occur
Solution Approach 1:
The patent establishes an optimal crumb size parameter range (nominal diameter of 0.33 to 3.5 cm) that balances manufacturing precision and productivity. This parameter change prevents equipment plugging while maintaining adequate surface area for composite quality, and improves product recovery rates by avoiding excessively fine particles that are difficult to handle and recover
3Stability of the object's composition
If small crumb size is produced, then more complete mixing and dispersion are achieved, but dry time increases and throughput rates decrease
Solution Approach 1:
The patent optimizes the crumb size parameter to a specific range (0.33-3.5 cm nominal diameter) that provides sufficient surface area for complete mixing and dispersion of fillers while maintaining adequate particle size to reduce drying time. This balanced parameter ensures both mixing uniformity and reasonable processing time
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
This method effectively increases the crumb size distribution, improving processability and product viability by reducing the percentage of small crumb sizes, enhancing the production of elastomeric composites and nanocomposites, and achieving improved impermeability features for applications like tire innerliners and medical stoppers.
Implementation Method 1
The solvent-rich slurry is stripped with water, steam, or a combination thereof to produce a solvent-lean slurry comprising a crumb of the elastomeric composite
Data Source
AI summary
To obtain an elastomeric composite crumb having a majority of the particle size distribution greater than 0.33 cm, the crumb is obtained by a process whereby the elastomeric composite comprises less than about 0.5 phr of a salt of a C8 to C20 carboxylic acid, or 10 to 20 phr of a tackifying resin or a combination of both an absence of carboxylic acid and the presence of the tackifying resin. The use of one or both methods permits control of crumb particle size distribution in emulsion or solution processes for producing elastomeric nanocomposites. The elastomeric composite is also disclosed.