Sunscreen Cosmetic Staining Prevention via Hydrophobic Titanium Oxide

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Solution Overview

Problem

Sunscreen cosmetics with UVA absorbents like hexyl diethylaminohydroxybenzoylbenzoate and octylmethoxy cinnamate often cause staining on clothing due to secondary adhesion, which is difficult to remove with washing, despite their effectiveness in providing UV protection.

Innovation Solution

Blending specific UVA absorbents with hydrophobicized ultrafine particles of titanium oxide, particularly resin spherical powder containing 35% or more of these particles, to create a sunscreen cosmetic that reduces staining while maintaining high UV protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UVA absorbents such as hexyl diethylaminohydroxybenzoylbenzoate or octylmethoxy cinnamate are used in sunscreen cosmetics, then ultraviolet protection effect is improved, but staining on clothing due to secondary adhesion occurs and becomes difficult to remove with washing

Engineering Contradiction:
Improveultraviolet protection effectVSAvoidstaining on clothing
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a water-soluble organic compound as an intermediary substance that specifically interacts with the UVA absorbent. This intermediary prevents the UVA absorbent from adhering to hydrophobic surfaces like clothing, thereby eliminating staining while preserving the UV protection function. The water-soluble compound acts as a mediator between the UVA absorbent and the external environment, changing the adhesion characteristics without compromising protective efficacy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the solubility parameter of the UVA absorbent by combining it with a water-soluble organic compound. This transformation converts the originally hydrophobic UVA absorbent into a more water-compatible formulation, fundamentally altering its adhesion behavior toward hydrophobic materials like clothing while maintaining its ultraviolet absorption capabilities.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If fine particles of zinc oxide and/or titanium oxide are blended into sunscreen cosmetic, then ultraviolet protection effect is enhanced, but staining problem persists

Engineering Contradiction:
Improveultraviolet protection effectVSAvoidstaining on clothing
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The water-soluble organic compound serves as an intermediary that specifically targets and prevents adhesion of the UV protection components to hydrophobic surfaces. By introducing this mediator, the patent resolves the staining issue caused by metal oxide particles while preserving their ultraviolet scattering and blocking functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite formulation combining metal oxide particles (zinc oxide and/or titanium oxide) with a water-soluble organic compound. This composite material integrates the UV protection benefits of metal oxides with the anti-staining properties of the water-soluble compound, achieving both high UV protection and minimal staining on clothing.

Inventive Principle:
Principle #40Composite materials

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 combination of UVA absorbents and hydrophobicized titanium oxide particles in sunscreen cosmetics significantly reduces clothing staining and enhances UV protection, allowing for higher blend ratios without compromising removal during washing.

Implementation Method 1

Important ultraviolet wavelength regions absorbed by sunscreen cosmetics are the UV-A region (320-400 nm) and UV-B region (290-320 nm)

Methodology Applied
Scientific EffectUltraviolet absorption: Absorption (EM radiation)

Implementation Method 2

a sunscreen cosmetic often contains fine particles of zinc oxide and/or titanium oxide, as an ultraviolet scattering agent

Methodology Applied
Scientific EffectScattering: Scattering

Implementation Method 3

resin spherical powder containing inside 35% or more of hydrophobicized ultrafine particles of titanium oxide

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Data Source

PatentEP2481393B1Sunscreen cosmetic
Publication Date: 2016.11.02 SHISEIDO CO LTD
  • EP2481393B1 patent drawingFigure 1~2
  • EP2481393B1 patent drawingFigure 3~4
  • EP2481393B1 patent drawing

AI summary

The present invention provides a sunscreen cosmetic comprising: (1) an UVA absorbent selected from one, two or more from hexyl diethylaminohydroxybenzoylbenzoate, 2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy]-phenyl}-6-(4-methoxyphenyl) -1, 3, 5-triazine, 4-tert-butyl-4-methoxydibenzoylmethane, and 2-hydroxy-4-methoxybenzophenone, and (2) resin spherical powder containing inside 35% or more of hydrophobicized ultra fine particles of titanium oxide. The object of the present invention is to provide a sunscreen cosmetic containing an UVA absorbent and ultrafine particles of titanium oxide wherein staining of clothing due to secondary adhesion is prevented.