Two-Layer Hair Cosmetic Segmentation for Stability
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Solution Overview
Problem
Existing two-layer separate type hair cosmetics, particularly the emulsion layer/aqueous layer type, face challenges in achieving temporal stability, appropriate separation rate, beautiful appearance, and improved hair manageability and feel, with issues such as cloudy aqueous layers and difficulty in maintaining a homogeneous state.
Innovation Solution
A non-aerosol two-layer separate type hair cosmetic composition comprising a silicone with specific particle diameter and degree of polymerization, combined with a water-soluble cationic polymer, and an organic carboxylic acid or its salt, to create a stable oil-in-water emulsion layer and aqueous layer, ensuring proper separation and transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large amount of oily component is incorporated to enhance protection and manageability, then hair performance is improved, but the cosmetic becomes difficult to keep storage stable and the feel for touch deteriorates
Solution Approach 1:
The cosmetic is divided into two separate layers (emulsion layer and aqueous layer) that remain distinct during storage but can be homogenized by shaking before use. This segmentation allows incorporation of oily components in the emulsion layer without compromising storage stability, while still providing the desired hair protection performance when applied.
2Reliability
If the cosmetic is formulated as emulsion type to incorporate large amount of oily component, then hair performance is improved, but the feel for touch deteriorates due to large amount of emulsifier
Solution Approach 1:
By separating the cosmetic into two distinct layers, the emulsifier content can be minimized in the emulsion layer while still achieving effective oil incorporation. The aqueous layer contains minimal emulsifier, preventing the sticky feel associated with high emulsifier content, yet the system maintains the ability to deliver oily components to the hair for protection and manageability.
3Stability of the object's composition
If the cosmetic is formulated as two-layer separate type to incorporate large amount of oily component, then storage stability is improved, but the layers separate immediately even when shaken
Solution Approach 1:
The patent optimizes specific parameters including the HLB value of the emulsifier (5-15), the ratio of emulsion layer to aqueous layer (95:5 to 50:50), and the molecular weight of the polymer (10,000-1,000,000). These parameter adjustments create appropriate interfacial tension and viscosity characteristics that allow the layers to remain separated during storage but form a stable homogeneous mixture when shaken, maintaining the homogeneous state throughout the application process.
4Ease of operation
If the emulsion layer is made stable to maintain homogeneous state during application, then application performance is improved, but the separation time becomes too long
Solution Approach 1:
The patent carefully balances the emulsifier concentration (0.1-10% by mass) and polymer concentration (0.01-5% by mass) to achieve optimal viscosity and interfacial properties. This parameter optimization ensures that the emulsion layer has sufficient stability to maintain homogeneity during the brief application period, yet the overall system separates within an acceptable time frame (typically several minutes to an hour) after application, allowing for efficient repeated use.
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 temporal stability, appropriate separation rate, beautiful appearance, and improved hair manageability and smoothness, with the silicone and cationic polymer maintaining particle size and stability, and the organic carboxylic acid aiding in secondary agglomerate formation for effective separation.
Implementation Method 1
a silicone with a number-average degree of polymerization of from 300 to 20,000 having a number-average particle diameter of from 0.05 to 20 μm... consists of an oil-in-water emulsion layer and an aqueous layer
Implementation Method 2
a water-soluble cationic polymer with a weight-average molecular weight of from 50,000 to 1,000,000... anionic and nonionic polymers, an anionic polymer is preferable
Implementation Method 3
further comprising from 0.05 to 5 mass% of an organic carboxylic acid or a salt thereof as component (C)... The pH of the cosmetic composition is from 2 to 6.5, preferably from 3 to 5.5
Implementation Method 4
can be homogenized by shaking immediately before use, and is separated again after standing still for a while
Data Source
AI summary
A non-aerosol two-layer separate type hair cosmetic composition containing components (A) and (B) at a mass ratio (A)/(B) of from 0.2 to 10: (A) a silicone with a number-average degree of polymerization of from 300 to 20,000 having a number-average particle diameter of from 0.05 to 20 µm, selected from the group consisting of dimethicone, dimethiconol, and amino-modified silicone and in an amount of from 0.1 to 6 mass% (B) a water-soluble cationic polymer with a weight-average molecular weight of from 50,000 to 1,000,000, selected from the group consisting of polyquaternium-6, polyquaternium-7, polyquaternium-16, and polyquaternium-22, wherein the composition consists of an oil-in-water emulsion layer and an aqueous layer.