Solid Detergent Composition for Rapid Coacervate Formation

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Solution Overview

Problem

Conventional solid detergents containing cationized hydroxycellulose or cationized guar gum have low water solubility, leading to inadequate coacervate formation and insufficient conditioning effects, especially when amphoteric surfactants or inorganic salts are minimized to maintain the solid form.

Innovation Solution

A solid detergent composition comprising a cationic polymer and an anionic surfactant, where the transmittance of mixed and diluted liquids satisfies specific optical transmittance requirements, enabling coacervate formation without amphoteric surfactants or inorganic salts, thereby enhancing washing and rinsing smoothness and moist feeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cationized hydroxycellulose or cationized guar gum is used as a water-soluble cationic polymer in solid detergent, then the detergent can maintain solid form and shape, but the dissolution rate in water is low and coacervate formation is insufficient

Engineering Contradiction:
Improvesolid form stabilityVSAvoiddissolution rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical structure parameters of the cationic polymer by selecting specific polymers (Polyquaternium-7, Polyquaternium-44, or Polyquaternium-67) with optimized molecular weights and charge densities. This allows the polymer to dissolve rapidly in water while maintaining the ability to form coacervates, resolving the contradiction between solid form stability and dissolution rate.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If amphoteric surfactants or inorganic salts are added to promote coacervate formation, then conditioning effect is improved, but the solid form of detergent becomes difficult to maintain

Engineering Contradiction:
Improvecoacervate formationVSAvoidsolid form integrity
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent extracts and eliminates amphoteric surfactants and inorganic salts from the formulation, relying instead on the optimized cationic polymer-anionic surfactant system to form coacervates. This removes the components that compromise solid form integrity while maintaining coacervate formation capability through alternative mechanisms.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a water-soluble cationic polymer as an intermediary that mediates between the anionic surfactant and water to form coacervates. This intermediary enables coacervate formation without requiring amphoteric surfactants or inorganic salts, thus maintaining solid form integrity while achieving conditioning effects.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Shape

If conventional cationic polymers are used, then solid detergent shape is maintained, but sufficient conditioning effect cannot be achieved within hair washing time period

Engineering Contradiction:
Improvedetergent shape retentionVSAvoidconditioning effect timing
Core Design Contradiction:
ShapeVSLoss of time

Solution Approach 1:

The patent optimizes parameters including selecting cationic polymers with specific molecular weights (10,000-1,000,000), optimizing the ratio of cationic polymer to anionic surfactant (1:1 to 1:10 by weight), and adjusting the degree of ionization. These parameter changes enable rapid dissolution and immediate coacervate formation during the hair washing process, achieving conditioning effects within the available time period while maintaining shape retention.

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 composition forms a coacervate insoluble in water, ensuring effective conditioning and cleansing effects, maintaining shape integrity under varying conditions and improving rinsing smoothness and moist feeling.

Implementation Method 1

Conditioning effects, for example, suppression of hair squeakiness, and good finger-combing in rinsing, and the like can be exerted by deposition of a complex called a coacervate, which is insoluble in water, to the hair, the coacervate being generated by an anionic surfactant and a cationic polymer

Methodology Applied
Scientific EffectCoacervate formation: Coacervate

Implementation Method 2

a coacervate, which is insoluble in water, to the hair, the coacervate being generated by an anionic surfactant and a cationic polymer

Methodology Applied
Scientific EffectElectrostatic interaction: Ion Repulsion/Attraction

Data Source

PatentUS12599551B2Solid detergent composition
Publication Date: 2026.04.14 OSAKA ORGANIC CHEM INDS

AI summary

A solid detergent composition comprising a cationic polymer (A) and an anionic surfactant (B), wherein the cationic polymer (A) and the anionic surfactant (B) satisfy the following requirement I and requirement II: Requirement I: a transmittance of a mixed liquid 1 obtained by mixing the cationic polymer (A), the anionic surfactant (B), and water at a weight ratio of 0.5:12:87.5 to light having a wavelength of 655 nm (optical path length: 1 cm, 25° C.) is 95% or more, and Requirement II: a transmittance of a diluted liquid obtained by mixing the mixed liquid 1 and water at a weight ratio of 1:4 to light having a wavelength of 655 nm (optical path length: 1 cm, 25° C.) is 90% or less.