Electrostatic Cosmetic Coating Adhesion

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Solution Overview

Problem

Existing methods for forming cosmetic coatings on skin using electrostatic spraying result in insufficient adhesion, leading to color transfer to clothes during friction, as the coatings lack a protective layer to prevent sticking and transfer.

Innovation Solution

A method involving electrostatic spraying of a composition containing volatile substances and water-insoluble polymers to form a porous coating with a deposit of fibers on the skin, providing a protective layer that enhances adhesion and prevents color transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If electrostatic spraying is used to form cosmetic coating on skin, then the coating can be applied efficiently and uniformly, but the adhesion between skin and coating is insufficient leading to color transfer

Engineering Contradiction:
Improvecoating application efficiencyVSAvoidcoating adhesion
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention uses a composite coating system consisting of a base cosmetic layer and a top clear coating layer. The clear coating layer is formed by electrostatic spraying of a composition containing volatile substances and water-insoluble polymers. This composite structure combines the cosmetic properties of the base layer with the adhesive and protective properties of the clear layer, resolving the contradiction between application efficiency and adhesion reliability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The clear coating layer forms a porous structure that allows it to bond effectively with the base cosmetic layer while maintaining flexibility and adhesion to the skin. The porous nature of the coating, formed through the electrostatic spraying process with specific polymer compositions, enhances the mechanical interlocking with skin surface irregularities, thereby improving adhesion without sacrificing application efficiency.

Inventive Principle:
Principle #31Porous materials

2Reliability

If a protective layer is added to improve adhesion, then color transfer is prevented, but the coating structure becomes more complex

Engineering Contradiction:
Improvecoating adhesionVSAvoidcoating structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention applies a clear coating layer specifically to the areas where cosmetic application is desired, rather than uniformly coating the entire skin surface. This localized application approach provides the necessary adhesion and protection only where needed, maintaining simplicity in the overall system while improving reliability at the critical interface between cosmetic and skin.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention modifies the chemical composition parameters of the clear coating layer by using specific volatile substances (50-98 mass%) and water-insoluble polymers (2-50 mass%) with particular molecular weights and saponification rates. These parameter optimizations allow the coating to achieve high adhesion with a relatively simple single-layer structure, avoiding the need for complex multi-layer systems.

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 method effectively prevents color transfer and sticking of cosmetics to clothes by forming a porous coating with improved adhesion to the skin, ensuring the cosmetics remain on the skin even during friction.

Implementation Method 1

an electrostatic spraying step of electrostatically spraying a composition directly onto a skin surface

Methodology Applied
Scientific EffectElectrostatic deposition: Electrostatic Deposition

Implementation Method 2

The composition contains component (a) one or more volatile substances selected from water, alcohols, and ketones

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3366271B1Method for producing coating film
Publication Date: 2023.12.13 KAO CORP
  • EP3366271B1 patent drawingFigure 1~2

AI summary

The present invention relates to preventing color transfer and sticking of powder-containing cosmetics to clothes or the like. A coating formation method of the present invention includes an electrostatic spraying step of electrostatically spraying a composition directly onto a skin surface onto which powder-containing cosmetics have been applied, thereby forming a coating on the skin. The composition contains a component (a) and a component (b) below. It is preferable that the method further includes a liquid agent applying step of applying a liquid agent containing one or more selected from water and oils that are in liquid form at 20°C on the skin onto which the powder-containing cosmetics have been applied, wherein the liquid agent applying step is performed subsequent to the electrostatic spraying step. (a) One or more volatile substances selected from water, alcohols, and ketones; and (b) a polymer having a coating formation ability.