Sunscreen UV Filter Stain Reduction via Solubility Modification

Solution Overview

Problem

Existing sunscreen preparations containing non-water-soluble UV-A filters like 4-(tert-butyl)-4'-methoxydibenzoylmethane cause stubborn stains on light-colored textiles and are difficult to wash out, leading to discoloration and premature aging of fabrics.

Innovation Solution

A cosmetic preparation combining 4-(tert-butyl)-4'-methoxydibenzoylmethane with cellulose gum, iminodisuccinate, and diethylenetriaminepenta(methylenephosphonic acid)/DTPMP, which enhances the washability of UV light protection filters from textiles by reducing textile staining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If non-water-soluble UV-A filters like 4-(tert-butyl)-4'-methoxydibenzoylmethane are used in sunscreen preparations, then UV protection efficacy is improved, but textile staining increases and washability deteriorates

Engineering Contradiction:

ImproveUV protection efficacyVSAvoidtextile staining

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces water-soluble UV-A filters (phenylbenzimidazole sulfonic acid and/or terephthalidenedicamphorsulfonic acid) as intermediary substances to replace or supplement the non-water-soluble filter. These intermediary filters provide the necessary UV protection while being water-soluble, thus preventing textile staining and improving washability without compromising protection efficacy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical parameter of the UV-A filter from non-water-soluble to water-soluble by selecting specific chemical compounds (phenylbenzimidazole sulfonic acid and/or terephthalidenedicamphorsulfonic acid) that have different solubility properties. This parameter change resolves the contradiction between protection efficacy and textile staining.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If non-water-soluble UV-A filters are used in sunscreen preparations, then UV protection efficacy is improved, but ease of washing from textiles deteriorates

Engineering Contradiction:

ImproveUV protection efficacyVSAvoidwashability from textiles

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces water-soluble UV-A filters (phenylbenzimidazole sulfonic acid and/or terephthalidenedicamphorsulfonic acid) as intermediary substances to replace or supplement the non-water-soluble filter. These intermediary filters provide the necessary UV protection while being water-soluble, thus preventing textile staining and improving washability without compromising protection efficacy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical parameter of the UV-A filter from non-water-soluble to water-soluble by selecting specific chemical compounds (phenylbenzimidazole sulfonic acid and/or terephthalidenedicamphorsulfonic acid) that have different solubility properties. This parameter change resolves the contradiction between protection efficacy and textile staining.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP3153151B1Sunscreen having reduced tendency to cause 4-(tert.-butyl)-4 - methoxydibenzoylmethan stains on textiles

Publication Date: 2021.08.11 BEIERSDORF AG

AI summary

Cosmetic preparation containing 4-(tert-butyl)-4'-methoxydibenzoylmethane and at least two additives selected from the group of the compounds cellulose gum, iminodisuccinate, 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2(1 H)-pyridone (piroctone) and diethylenetriaminepenta(methylenephosphonic acid)/DTPMP.