Interpenetrating Polymer-Wax Fertilizer Coatings for Growth-Matched Release

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Solution Overview

Problem

Existing coated fertilizers have low utilization rates due to mismatched nutrient release with plant growth patterns and environmental losses, resulting in only about 40% absorption by plants, with the remainder being lost.

Innovation Solution

A coated fertilizer with interpenetrating domains of 50-80% polymer and 20-50% wax domains, comprising polybutylene succinate and polylactic acid, is manufactured by dissolving the components in solvents, applying them to fertilizer granules, and heating to form a coating that matches plant growth rates and improves mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional coated fertilizers are used, then nutrient release is slowed, but plant absorption efficiency remains low at about 40% due to mismatched release patterns

Engineering Contradiction:
Improvefertilizer utilization rateVSAvoidnutrient loss to environment
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent changes the physical and chemical parameters of the coating by creating an interpenetrating domain structure with specific polymer-to-wax ratios (50:50 to 80:20). This structural parameter change enables the coating to release nutrients in a pattern that matches plant growth rates, improving absorption efficiency from 40% to potentially higher levels while reducing environmental losses through volatilization and leaching.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials consisting of biodegradable polymers (polybutylene succinate and/or polylactic acid) combined with waxes in specific proportions. This composite structure creates interpenetrating domains where the polymer provides structural integrity and controlled degradation, while the wax domains provide moisture resistance and additional controlled release mechanisms, together achieving superior fertilizer utilization.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If coating materials are applied to fertilizer granules, then dust production is reduced, but mechanical strength may be compromised

Engineering Contradiction:
Improvedust productionVSAvoidgranule mechanical strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent applies local quality by creating distinct interpenetrating domains within the coating where polymer-rich regions provide mechanical strength and adhesion to the granule surface, while wax-rich regions provide moisture resistance and dust suppression. This localized functional differentiation allows the coating to simultaneously improve dust control and maintain granule strength.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The composite material system of biodegradable polymers and waxes in interpenetrating domains provides both mechanical integrity for strength and surface properties for dust reduction. The polymer matrix binds the granule surface while the wax components fill pores and create a protective barrier, achieving both dust suppression and strength maintenance.

Inventive Principle:
Principle #40Composite materials

3Duration of action of stationary object

If slow-release coatings are applied, then nutrient availability is extended, but release rate may not match plant growth patterns

Engineering Contradiction:
Improvenutrient availability durationVSAvoidmatch to plant growth rate
Core Design Contradiction:
Duration of action of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by designing a coating that actively adapts its release characteristics to match plant growth patterns. The biodegradable polymer matrix degrades over time in response to environmental conditions, dynamically adjusting pore structure and permeability to release nutrients at rates that correspond to increasing plant demand throughout the growth season, rather than following a fixed release schedule.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses parameter changes in the coating's physical structure through controlled biodegradation. As the polymer matrix degrades, parameters such as porosity, hydrophilicity, and molecular weight change over time, enabling the coating to transition from a slower initial release to a more accelerated release that matches the sigmoidal plant growth curve, improving adaptability to plant needs.

Inventive Principle:
Principle #35Parameter changes

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 interpenetrating domains coating enhances fertilizer utilization by closely matching nutrient release to plant growth, improving mechanical strength, and reducing environmental losses, with less than 70% nitrogen release after 7 days and lower weight loss.

Implementation Method 1

at least partially dissolving a polymer and a wax in an organic solvent to form a coating composition

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 2

evaporating the organic solvent from the at least partially coated fertilizer granules to form dried at least partially coated fertilizer granules

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

heating the dried at least partially coated fertilizer granules at a temperature effective to at least partially melt the wax to form a coating comprising interpenetrating domains comprising polymer domains and wax domains

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3377461B1Coated granular fertilizers, methods of manufacture thereof, and uses thereof
Publication Date: 2025.08.06 SABIC AGRI NUTRIENTS CO
  • EP3377461B1 patent drawingFigure 1A~4B

AI summary

A coated fertilizer comprising a fertilizer granule and a coating disposed on a surface of the fertilizer granule, wherein the coating comprises interpenetrating domains comprising polymer domains and wax domains. A method of making the coated fertilizer is also disclosed.