Anhydrous Sunscreen Composition Using Lipophilic Polyamide Polycondensate

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Solution Overview

Problem

Existing anhydrous sunscreen compositions face challenges in achieving high sun and UVA protection factors while maintaining a fluid, transparent, and stable formula, as they often become thick and heterogeneous during storage.

Innovation Solution

A fluid anhydrous composition comprising hydrocarbon oil (30-99.8% by weight), lipophilic organic UV filters, linear C1-C3 mono-alcohols, and lipophilic polyamide polycondensates, which ensures a cosmetically acceptable medium for effective UV protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lipophilic polyamide polycondensates are used in anhydrous sunscreen compositions to increase sun protection factor, then SPF and UVA protection improve, but the formula becomes thick and heterogeneous during storage

Engineering Contradiction:

Improvesun protection factorVSAvoidformula stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical parameters of the polyamide polycondensate by specifying precise molecular weight ranges (1,000-50,000 g/mol), functional group compositions (amide, carboxyl, hydroxyl groups in specific ratios), and structural characteristics. These parameter changes enable the polymer to provide high SPF while maintaining formula stability during storage.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite formulation by combining lipophilic polyamide polycondensates with specific concentrations of UV filters (5-30% w/w), hydrocarbon oils, and other cosmetic ingredients. This composite approach allows the system to achieve both high sun protection factors and stable, homogeneous formula characteristics during storage.

Inventive Principle:

Principle #40Composite materials

2Reliability

If UV filter concentration is increased to achieve higher SPF and UVA protection factors, then protection efficacy improves, but the formula becomes less fluid and more viscous

Engineering Contradiction:

Improveprotection efficacyVSAvoidfluidity

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent optimizes the concentration parameters of UV filters within specific ranges (5-30% w/w) and adjusts the molecular weight and functional composition of the polyamide polycondensate. These parameter changes allow the formulation to achieve high protection efficacy while maintaining acceptable fluidity and ease of application.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The lipophilic polyamide polycondensate acts as an intermediary substance that enhances the performance of UV filters. By incorporating the polycondensate with specific amide, carboxyl, and hydroxyl group compositions, the system achieves high SPF and UPA protection factors without requiring excessive UV filter concentrations that would compromise fluidity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If polyamide polymer concentration is increased to improve sun protection, then SPF increases, but the composition becomes too thick and forms gels

Engineering Contradiction:

Improvesun protection factorVSAvoidformula consistency

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent precisely controls the molecular weight parameter of the polyamide polycondensate (1,000-50,000 g/mol) and the concentration of functional groups (amide, carboxyl, hydroxyl). These parameter changes allow the formulation to achieve high SPF values while preventing gel formation and maintaining appropriate formula consistency for cosmetic application.

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 achieves high sun protection factor (SPF) and UVA protection factor (FP UVA PPD) values, remaining stable and cosmetically pleasant, exceeding previous formulations in terms of SPF and UVA protection efficacy.

Implementation Method 1

at least one lipophilic polyamide polycondensate... ensure protection of the skin and keratin materials against UV radiation

Methodology Applied

Scientific EffectUV absorption: Absorption (EM radiation)

Implementation Method 2

at least one lipophilic organic UV filter... filter this UV-B radiation... filter UV-A radiation

Methodology Applied

Scientific EffectUV absorption: Absorption (EM radiation)

Data Source

PatentEP2236173B2Anhydrous oleoalcoholic liquid filtering composition including a lipophilic polyamide polycondensate

Publication Date: 2015.11.25 LOREAL SA

AI summary

The present invention relates to a fluid anhydrous composition comprising, in a cosmetically acceptable medium: a) at least one hydrocarbon oil, b) at least one lipophilic organic UV filter, c) at least one linear C1-C3 monoalcohol, in particular ethanol, and d) at least one lipophilic polyamide polycondensate. The present invention also relates to the use of said composition for the manufacture of products for the cosmetic treatment of skin, nails, hair, eyelashes, eyebrows, and/or scalp, in particular skincare products, sunscreens, makeup, and perfumes.