Sunscreen Composition with Composite Silicone Particles for Water Resistance

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Solution Overview

Problem

Conventional sunscreen compositions face challenges in providing high ultraviolet protection while maintaining stability and gentleness on the skin, and they often lack effective water resistance against sweat and water.

Innovation Solution

A sunscreen composition comprising two or more oil-soluble ultraviolet absorbers and composite silicone particles with an average particle diameter of 10 µm or less, along with an electrolyte, is formulated into a water-in-oil (W/O) emulsion to enhance SPF and PFA values, providing improved water resistance and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high concentrations of ultraviolet absorbers are used to enhance ultraviolet protection ability, then SPF and PFA values increase, but the composition may become less stable and more irritating to the skin

Engineering Contradiction:
Improveultraviolet protection effectVSAvoidcomposition stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses a composite system combining multiple oil-soluble ultraviolet absorbers (octyl methoxycinnamate, t-butyl methoxydibenzoyl methane, and 2-hydroxy-4-methoxybenzophenone) with a specific block polymer and nonpolar oil. This composite approach distributes the ultraviolet protection function across multiple components rather than relying on a single high-concentration absorber, thereby maintaining high SPF and PFA values while improving composition stability and reducing skin irritation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the concentration parameters of each ultraviolet absorber within specific ranges: octyl methoxycinnamate (5-15 parts by weight), t-butyl methoxydibenzoyl methane (3-10 parts by weight), and 2-hydroxy-4-methoxybenzophenone (2-8 parts by weight). By carefully controlling these parameters rather than using excessively high concentrations, the patent achieves high ultraviolet protection while maintaining composition stability and skin gentleness.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional sunscreen compositions are used to provide ultraviolet protection, then SPF and PFA values are achieved, but water resistance against sweat and water remains insufficient

Engineering Contradiction:
Improveultraviolet protection effectVSAvoidwater resistance
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent employs an oil-in-water emulsion system where the ultraviolet absorbers are dissolved in the oil phase. This phase structure allows the composition to maintain its ultraviolet protection function while the emulsion droplets provide water resistance. The specific block polymer stabilizes this emulsion structure, ensuring both high SPF/PFA values and excellent water resistance against sweat and water during outdoor activities.

Inventive Principle:
Principle #36Phase transitions

3Reliability

If high SPF and PFA values are targeted for high-exposure outdoor activities, then ultraviolet protection performance improves, but the composition may become less gentle to the skin

Engineering Contradiction:
Improveultraviolet protection performanceVSAvoidskin irritation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent formulates a composite system with three different types of ultraviolet absorbers that work synergistically to provide broad-spectrum protection. This distribution of protection across multiple chemical types reduces the burden on any single ingredient, allowing high SPF and PFA values to be achieved while maintaining skin gentleness through balanced formulation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent carefully controls the concentration parameters of each ultraviolet absorber within optimized ranges, preventing any single component from reaching irritating levels while collectively achieving high ultraviolet protection performance. The total concentration and individual ratios are tuned to balance efficacy and skin compatibility.

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 sunscreen composition achieves superior ultraviolet protection, maintains stability over time, and is gentle on the skin, with enhanced water resistance against sweat and water, making it suitable for both daily use and high-exposure outdoor activities.

Implementation Method 1

The ultraviolet protection performance of a sunscreen agent can be represented by SPF (sun protection factor), which shows the protection index of UV-B (wavelength: 290 to 320 nm), PFA (protection factor of UVA), which shows the protection index of UV-A (wavelength: 320 to 400 nm)

Methodology Applied
Scientific EffectUltraviolet absorption: Absorption (EM radiation)

Implementation Method 2

the sunscreen composition is in the form of a water-in-oil type (W/O) emulsion, and has water resistance against sweat and water

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Data Source

PatentEP2823807B1Sunscreen composition
Publication Date: 2021.03.17 OTSUKA PHARM CO LTD
  • EP2823807B1 patent drawingFigure 1~2

AI summary

The present invention provides a sunscreen composition comprising two or more oil-soluble ultraviolet absorbers and composite silicone particles having an average particle diameter of 10 µm or less.