DHHB Solidification via Shear and Seed Crystals

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for solidifying hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (DHHB) are inefficient, leading to non-uniform particle shapes and sizes, poor caking properties, and low space-time yield, making them economically disadvantageous and challenging to handle.

Innovation Solution

Applying a shear rate of 800 s−1 or more to the liquid DHHB melt, combined with the addition of seed crystals, accelerates crystallization, resulting in uniform particle shapes and sizes, improved flowability, and enhanced storage stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional crystallization methods (tubs or drums) are used for DHHB, then the process is simple to operate, but the space-time yield is low and particle uniformity is poor

Engineering Contradiction:
Improvespace-time yieldVSAvoidparticle shape and size uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by introducing seed crystals before the main crystallization process. The seed crystals provide pre-formed nucleation sites that guide the crystallization process, ensuring uniform particle formation from the beginning. This preliminary preparation of nucleation sites resolves the contradiction by enabling both high productivity (through controlled rapid crystallization) and manufacturing precision (through uniform particle growth on seed crystals).

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs parameter changes by controlling temperature profiles and adding nucleating agents during crystallization. By precisely adjusting these parameters, the process achieves rapid crystallization (improving space-time yield) while maintaining uniform particle morphology (improving manufacturing precision). The controlled parameter changes enable simultaneous optimization of both productivity and particle uniformity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional crystallization methods are used for DHHB, then the process equipment is simple, but the caking properties are poor due to non-uniform particles

Engineering Contradiction:
Improvecaking propertiesVSAvoidparticle shape and size uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

By introducing seed crystals as a preliminary action, the patent ensures that crystallization occurs uniformly on pre-formed nuclei rather than randomly. This results in particles with consistent shapes and sizes, which directly improves caking properties and handling characteristics. The preliminary preparation of uniform nucleation sites resolves the contradiction between reliability and manufacturing precision.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If DHHB melt is cooled without shear application, then the process requires less energy input, but crystallization occurs very slowly over weeks

Engineering Contradiction:
Improvecrystallization speedVSAvoidenergy input for shear application
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by introducing seed crystals that provide ready-made nucleation sites. This eliminates the need for prolonged waiting periods for spontaneous nucleation, dramatically accelerating crystallization from weeks to hours or minutes. The energy invested in shear application is offset by the massive time savings, resolving the contradiction between productivity and energy use.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses seed crystals as an intermediary substance that mediates the crystallization process. These seed crystals act as catalysts for phase transition, enabling rapid crystallization without requiring excessive energy input. The intermediary seed crystals resolve the contradiction by providing an efficient pathway for crystallization that balances speed and energy consumption.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If high shear rate is applied to DHHB melt with seed crystals, then crystallization is accelerated significantly, but the process complexity increases

Engineering Contradiction:
Improvesolidification timeVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

By introducing seed crystals as a preliminary action, the patent enables rapid crystallization when combined with shear application. The seed crystals prepare the system for fast phase transition, allowing the shear energy to be efficiently converted into crystallization kinetics. This resolves the contradiction by providing a mechanism that justifies the increased process complexity through dramatically improved productivity.

Inventive Principle:
Principle #10Preliminary action

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 process significantly reduces the time required for solidification, increases efficiency, and produces DHHB in the form of pourable or flowable particles, pastilles, or flakes with improved handling characteristics and storage stability.

Implementation Method 1

applying a shear rate of 800 s−1 or more to liquid hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate

Methodology Applied
Scientific EffectShear-induced crystallization: Shear Stress

Implementation Method 2

adding seed crystals of hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate

Methodology Applied
Scientific EffectNucleation: Nucleation

Data Source

PatentUS20240150276A1Solidification of hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate
Publication Date: 2024.05.09 BASF SE

AI summary

The present invention relates to a process for the solidification of hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (INCI diethylamino hydroxybenzoyl hexyl benzoate, DHHB), wherein the process comprises the step of (a) applying a shear rate of 800 s−1 or more to liquid hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate and (b) adding seed crystals of hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate.