Light Aesthetic Sunscreen via Hydrophobic Polyurethane

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Solution Overview

Problem

Conventional sunscreens often have a heavy, oily aesthetic due to high oil content required for effective UV protection, which can discourage users from applying enough product for adequate protection.

Innovation Solution

A sunscreen composition combining at least 10 weight percent UV filters, 0.55 to 1 weight percent hydrophobically modified polyurethane, 0.1 to 0.6 weight percent viscosity increasing polymer, and 0.1 to 0.3 weight percent glyceryl stearate, with a linear complex viscosity of 1500 to 5000 cP at 100 rad/s, providing a light, watery texture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high levels of oil are used to carry UV filters for acceptable SPF, then UV protection is improved, but the aesthetic quality deteriorates due to heavy, oily feel

Engineering Contradiction:
ImproveUV protectionVSAvoidaesthetic quality
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the physical and chemical parameters of the base formulation by incorporating specific polymers (hydrophobically modified polyurethane, taurate copolymers, acrylate crosspolymers) that alter the viscosity and texture profile. These parameter changes enable the formulation to maintain adequate SPF with reduced oil content, achieving both protection and pleasant aesthetic quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material systems combining multiple polymer types (polyurethane, taurate copolymers, acrylate crosspolymers) with UV filters and glyceryl stearate. This composite approach creates a synergistic formulation where the polymer network provides both the vehicle for UV filter delivery and the desired light, watery texture, resolving the contradiction between protection and aesthetics.

Inventive Principle:
Principle #40Composite materials

2Reliability

If high levels of oil are used to carry UV filters for acceptable SPF, then UV protection is improved, but user compliance deteriorates due to unpleasant feel

Engineering Contradiction:
ImproveUV protectionVSAvoiduser compliance
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

By modifying the formulation parameters to include specific polymer concentrations (0.55-1.0% hydrophobically modified polyurethane, 0.1-0.6% viscosity increasing polymer) and controlled oil content, the patent creates a product that maintains protective efficacy while providing a light, watery feel that users find pleasant, thereby improving compliance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The composite formulation combining multiple polymer systems with UV filters creates a synergistic effect where the polymer matrix enables reduced oil content while maintaining spreadability and protection, making the product more adaptable to user preferences and improving compliance.

Inventive Principle:
Principle #40Composite materials

3Reliability

If high levels of oil are used to carry UV filters for acceptable SPF, then UV protection is improved, but the formulation complexity increases

Engineering Contradiction:
ImproveUV protectionVSAvoidformulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent establishes specific parameter ranges for each ingredient (polymer concentrations, oil content, UV filter levels) that optimize the formulation. By controlling these parameters within defined ranges, the patent achieves adequate SPF with simplified formulation architecture, avoiding the need for complex multi-component systems while maintaining both protection and aesthetic quality.

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 offers excellent SPF protection while maintaining a pleasant, non-greasy feel, enhancing user compliance and skin comfort during application.

Implementation Method 1

about 0.55 to about 1 weight percent of a hydrophobically modified polyurethane; about 0.1 to about 0.6 weight percent of a viscosity increasing polymer selected from the group consisting of taurate copolymers and acrylate crosspolymers... with a linear complex viscosity of 1500 to 5000 cP at 100 rad/s

Methodology Applied
Scientific EffectViscosity modification:

Data Source

PatentEP3651732B1Light aesthetic sunscreen compositions
Publication Date: 2024.11.13 KENVUE BRANDS LLC

AI summary

The present invention provides sunscreen composition comprising a hydrophobically modified polyurethane, a viscosity increasing polymer, and glyceryl stearate. This composition has surprisingly light aesthetics while providing excellent UV protection.