Nano-scale Boehmite Synthesis via Hydrothermal Crystallization

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Solution Overview

Problem

The development of Boehmite with a nano-scale crystalline structure for use in engineered plastics is challenging due to high production costs and the need for additional processing steps to reduce the average particle size, which is typically greater than 7,000 nanometers, making it unsuitable for applications requiring enhanced properties like flame retardancy.

Innovation Solution

A method involving the formation of Boehmite with an average particle size between 100 nm and 3,000 nm and a crystallite size of 30 nm to 120 nm, using an organic dispersant and adjusting the pH and temperature of the slurry to facilitate crystallization, thereby eliminating the need for additional milling steps and reducing production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional methods are used to produce Boehmite, then production cost increases, but particle size reduction is achieved

Engineering Contradiction:
Improveparticle sizeVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by using highly dispersible Boehmite as a seed material before the main crystallization process. This seed material is prepared in advance to control the nucleation and growth of Boehmite particles during hydrothermal treatment, ensuring the final product achieves the desired nano-scale particle size (100-3000 nm) directly without requiring subsequent milling operations, thereby eliminating additional processing costs

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs parameter changes by optimizing the hydrothermal treatment conditions including temperature (170-220°C), pH (10.0-12.0), and treatment time (1-10 hours). These parameter adjustments control the crystallization process to produce Boehmite with the target particle size range, achieving both precision in particle size control and efficiency in production without expensive additional reduction steps

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If additional milling steps are used to reduce particle size, then particle size is reduced, but production cost increases

Engineering Contradiction:
Improveparticle sizeVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent performs preliminary action by incorporating seed material and optimizing crystallization conditions beforehand, so that the Boehmite particles form with the desired size distribution (100-3000 nm) during the hydrothermal treatment itself. This eliminates the need for subsequent milling operations, maintaining production efficiency while achieving the required particle size precision

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts the particle size control function from a separate post-processing milling step and integrates it into the main hydrothermal synthesis process. By controlling nucleation and growth during synthesis through seed material and parameter optimization, the particle size reduction function is achieved inline, eliminating the need for additional milling equipment and operations

Inventive Principle:
Principle #2Taking out (Extraction)

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 method produces Boehmite with a suitable particle size for use as a flame retardant in engineered plastics, enhancing mechanical durability and thermal stability without the need for additional processing, thus reducing costs and improving performance.

Implementation Method 1

the hydrothermal treatment of aluminum trihydroxide or Gibbsite (i.e., Al2O3-3H2O) at high temperature (200°-250°C) and steam pressure

Methodology Applied
Scientific EffectHydrothermal treatment:

Implementation Method 2

The slurry is heated to a temperature between about 170°C to about 220°C... The crystalline Boehmite product that is formed exhibits an average particle size (d50) that is greater than 100 nanometers and less than 3,000 nanometers

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 3

The method further includes the use of an organic dispersant. This organic dispersant may include without limitation, an acrylic or polyacrylic acid, a salt of acrylic acid, an acrylates copolymer, or a mixture thereof

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 4

the pH of the slurry is adjusted to be between 10.0 and 12.0... The crystalline Boehmite product that is formed exhibits an average particle size (d50) that is greater than 100 nanometers and less than 3,000 nanometers

Methodology Applied
Scientific EffectpH control:

Data Source

PatentEP3230209B1Process for producing nano-scale crystalline boehmite
Publication Date: 2024.08.07 PACIFIC IND DEVELOPMENT CORP
  • EP3230209B1 patent drawingFigure 1
  • EP3230209B1 patent drawingFigure 2
  • EP3230209B1 patent drawingFigure 3A~3B

AI summary

A crystalline Boehmite product and a method of forming said product is provided in which the crystalline Boehmite exhibits an average particle size (d50) that is less than 7,000 nanometers. This method comprises preparing an aqueous slurry by mixing together water, large aluminum oxide precursors, a highly dispersible Boehmite grade, and optionally, an organic dispersing agent; adjusting the pH of the slurry; heating the slurry for a predetermined duration of time; collecting the slurry to form a wet cake; and drying the wet cake to obtain the crystalline Boehmite product. The crystalline Boehmite product may be mixed with a plastic resin to form a flame retardant plastic mixture, which can be subjected to a conventional plastic processing method to form a flame retardant composite.