Cinmethylin Polyurea Microcapsules for Controlled Herbicide Release

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Solution Overview

Problem

Existing cinmethylin formulations exhibit high volatility, leading to environmental and health hazards, reduced efficacy due to rapid concentration loss, and require high application amounts to maintain activity, while also relying on expensive and ecologically incompatible vinylpyrrolidone copolymers.

Innovation Solution

Microencapsulation of cinmethylin in a polyurea shell based on diphenylmethane diisocyanate or its oligomers, with specific weight ratios of cinmethylin to polyurea material and isocyanate compounds, optimizing volatility and release rates for sustained herbicidal activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cinmethylin is used in conventional formulations, then herbicidal activity is achieved, but volatility increases leading to environmental and health hazards

Engineering Contradiction:

Improveherbicidal activityVSAvoidvolatility

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention divides the cinmethylin formulation into two distinct parts: a core containing the cinmethylin active ingredient and a shell made of polyurea material. This segmentation encapsulates the volatile herbicide within a protective matrix, preventing its direct release into the environment while maintaining its herbicidal function. The core-shell structure effectively isolates the harmful volatile component from the external environment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention employs a polyurea shell as a flexible protective barrier around the cinmethylin core. This shell acts as a rate-controlling membrane that allows controlled release of the active ingredient while preventing rapid volatilization. The shell's properties can be adjusted to optimize both protection against volatility and controlled release for sustained herbicidal activity.

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If cinmethylin is applied in high amounts to maintain activity, then herbicidal efficacy is ensured, but concentration loss due to volatility increases

Engineering Contradiction:

Improveherbicidal efficacyVSAvoidconcentration loss

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The invention performs preliminary encapsulation of cinmethylin in the polyurea shell before application. This pre-protection prevents volatility-related concentration loss during storage and application, ensuring that the full intended concentration reaches the target site without premature loss to the atmosphere.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The polyurea shell provides continuous protection against volatility while enabling controlled release of cinmethylin over time. This ensures sustained herbicidal activity without the need for reapplication, maintaining effective concentrations at the target site continuously rather than in intermittent pulses.

Inventive Principle:

Principle #20Continuity of useful action

3Stability of the object's composition

If vinylpyrrolidone copolymers are used as emulsifiers, then particle stability is improved, but manufacturing cost increases and ecological compatibility decreases

Engineering Contradiction:

Improveparticle stabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the problematic vinylpyrrolidone copolymer emulsifier from the formulation. Instead of using this expensive and ecologically incompatible substance, the invention relies on the polyurea shell structure itself to provide stability and control release, thereby removing the need for additional emulsifying agents and reducing both cost and environmental impact.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The polyurea shell serves multiple functions simultaneously: it provides structural stability to the microcapsules, controls the release rate of cinmethylin, and eliminates the need for separate emulsifiers. This self-sufficient design reduces formulation complexity and removes dependence on expensive auxiliary chemicals like vinylpyrrolidone copolymers.

Inventive Principle:

Principle #25Self-service

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 formulation achieves a balanced volatility and release profile, reducing environmental and health risks while maintaining effective herbicidal activity with lower concentrations, eliminating the need for vinylpyrrolidone copolymers.

Implementation Method 1

a polyurea shell, wherein the shell comprises a polyaddition product of diphenylmethane diisocyanate or an oligomer thereof and at least one amine having at least two primary amino groups

Methodology Applied

Scientific EffectPolyaddition:

Implementation Method 2

release the pesticide at sufficiently low rates

Methodology Applied

Scientific EffectDiffusion: Diffusion

Data Source

PatentUS12376586B2Microcapsules comprising cinmethyln in the core and a polyurea derived from diphenylmethane diisocyanate or an oligomer thereof

Publication Date: 2025.08.05 BASF AGRO BV

AI summary

The present invention relates to microcapsules comprising a core, wherein the core comprises cinmethylin, and a polyurea shell, wherein the shell comprises a polyaddition product of diphenylmethane diisocyanate or an oligomer thereof and at least one amine having at least two primary amino groups; to a composition comprising such microcapsules; to a method for preparing such microcapsules or such a composition; to a composition obtainable by said preparation method; and to the use of such microcapsules or compositions for controlling undesired vegetation.