Oil-in-Water Cosmetic Emulsion Stabilization via Crosspolymer Segmentation
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Solution Overview
Problem
Existing oil-in-water emulsified cosmetics face challenges in achieving high ultraviolet ray protection while maintaining stability and providing a fresh, watery sensation, as high ultraviolet absorber content can cause stickiness and destabilize the emulsion.
Innovation Solution
Incorporating a crosspolymer with (meth)acrylamidealkylsulfonic acid or its salt, dialkyl (meth)acrylamide, and (meth)acrylic acid ester structural units, along with anionic and nonionic surfactants, and methylene bis-benzotriazolyl tetramethylbutylphenol, to stabilize the oil phase and enhance the ultraviolet ray-protecting effect while minimizing surfactant content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If large amounts of ultraviolet absorbers are added to achieve high ultraviolet ray protection, then the ultraviolet ray-protecting effect is improved, but the cosmetic creates discomfort including stickiness and destabilizes the emulsion
Solution Approach 1:
The patent divides the ultraviolet protection function into two segments: an oil-soluble ultraviolet absorber (c) for UV absorption and a crosspolymer (e) for emulsion stabilization. This segmentation allows each component to perform its specific function without the harmful effects of using excessive ultraviolet absorbers alone.
Solution Approach 2:
The crosspolymer (e) containing (meth)acrylamidealkylsulfonic acid acts as an intermediary substance that stabilizes the emulsion structure. It mediates between the oil phase containing ultraviolet absorbers and the aqueous phase, preventing emulsion destabilization while allowing the ultraviolet absorbers to maintain their protective function.
2Reliability
If water-soluble ultraviolet absorbers are added to reduce ultraviolet absorber content while maintaining protection, then the ultraviolet ray-protecting effect is maintained, but the emulsion stability is lowered because water-soluble ultraviolet absorbers are electrolytes that affect the emulsified state
Solution Approach 1:
The crosspolymer (e) serves as an intermediary that counteracts the destabilizing effect of water-soluble ultraviolet absorbers (electrolytes) on the emulsion. It maintains the emulsified state even in the presence of electrolytes, allowing water-soluble ultraviolet absorbers to be used without compromising emulsion stability.
Solution Approach 2:
The patent changes the chemical structure parameters of the polymer component by selecting a specific crosspolymer containing (meth)acrylamidealkylsulfonic acid with particular molecular weight and composition ratios. This parameter optimization enables the polymer to effectively stabilize the emulsion against electrolyte-induced destabilization.
3Stability of the object's composition
If a considerable amount of surfactant is added to achieve a more stable emulsified state and minimize stickiness, then the emulsion stability is improved, but the cosmetic creates a heavy, creamy sensation and lacks a fresh and watery sensation
Solution Approach 1:
The crosspolymer (e) acts as a superior intermediary compared to conventional surfactants. It provides emulsion stabilization through steric hindrance and electrostatic repulsion mechanisms, achieving stability with minimal surfactant content and preserving the fresh, watery sensation during application.
Solution Approach 2:
The patent optimizes the molecular weight and composition parameters of the crosspolymer (e) to achieve maximum emulsion stabilization efficiency. This allows for minimal surfactant content while maintaining stability, thereby preserving the desired sensory characteristics of fresh and watery sensation.
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 solution provides an oil-in-water emulsified cosmetic with excellent stability, high ultraviolet ray protection, and a fresh, watery sensation during application, without stickiness, effectively addressing the limitations of previous formulations.
Implementation Method 1
an oil-in-water emulsified cosmetic comprising... (b) an anionic surfactant... (e) a crosspolymer including a (meth)acrylamidealkylsulfonic acid or its salt
Implementation Method 2
an oil-soluble ultraviolet absorber (c), a water-soluble ultraviolet absorber (d)... preventing and/or reducing the effects of UV radiations onto the keratinic materials
Data Source
AI summary
An oil-in-water emulsified cosmetic comprising in a cosmetically acceptable medium, (a) an aqueous phase, (b) an anionic surfactant, (c) an oil-soluble ultraviolet absorber, (d) a water-soluble ultraviolet absorber and (e) a crosspolymer including a (meth)acrylamidealkylsulfonic acid or its salt, a dialkyl (meth)acrylamide and a (meth)acrylic acid ester as structural units.