Ionic PHA Copolymer Films for Stable Surfactant-Free Keratin Coatings
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Solution Overview
Problem
Existing cosmetic compositions using polyhydroxyalkanoate polymers face challenges in achieving stability in aqueous media without surfactants, particularly with long-chain PHAs, and struggle to provide films with good resistance to oils and sebum while allowing interaction with active agents.
Innovation Solution
The use of polyhydroxyalkanoate copolymers with hydrocarbon-based chains bearing ionic groups, enabling formulation in aqueous media with minimal or no surfactants, resulting in stable compositions that form films with resistance to oils and sebum, and allowing interaction with active agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyhydroxyalkanoate copolymers with long hydrocarbon-based chains are used in cosmetic compositions, then the film resistance to oils and sebum is improved, but the stability in aqueous media deteriorates
Solution Approach 1:
The patent introduces ionic groups at specific positions along the hydrocarbon chain, creating local polar regions within the otherwise non-polar long-chain structure. This local quality change allows the polymer to maintain both oil resistance (from the long hydrocarbon chain) and aqueous stability (from the ionic groups that interact with water molecules)
Solution Approach 2:
The patent creates a composite polymer structure combining hydrocarbon-based chains with ionic groups, effectively merging the properties of hydrophobic long chains (for oil resistance) and hydrophilic ionic groups (for aqueous stability). This composite material approach resolves the contradiction by integrating both functional characteristics into a single polymer molecule
2Ease of operation
If surfactants are added to improve solubility of PHAs in aqueous media, then the ease of operation is improved, but the product complexity increases
Solution Approach 1:
The patent extracts the solubility-enhancing function from separate surfactant components and integrates it directly into the polymer structure itself. By incorporating ionic groups into the PHA copolymer, the solubility function is built-in, eliminating the need for additional surfactant ingredients and simplifying the overall product formulation
Solution Approach 2:
The patent makes the polymer molecule multi-functional by embedding ionic groups that simultaneously provide both structural integrity (as a polymer) and solubility enhancement (as a surfactant would). This universal design allows a single component to perform multiple functions, reducing product complexity
3Duration of action of stationary object
If ionic groups are introduced into PHA copolymers to improve aqueous stability, then the persistence of active agents is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent modifies the chemical parameters of the polymer by introducing ionic groups with specific charge characteristics. These parameter changes (adding charged groups) enhance the polymer's ability to interact with and retain active agents through electrostatic interactions, thereby improving persistence without requiring complex manufacturing processes
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 copolymers provide stable, surfactant-free compositions that form films with good cosmetic properties, including resistance to oils and sebum, and enhance the persistence of active agents on keratin materials.
Implementation Method 1
via the ionic groups, it is possible to make the PHA polymers interact with active agents, notably organic active agents, such as UV screening agents, fluorescent or non-fluorescent chromophores, anti-ageing active agents
Implementation Method 2
obtain a film on keratin materials which has good cosmetic properties, notably good resistance to oils and to sebum
Data Source
AI summary
The present invention relates to a method for treating keratin materials, preferably α) keratin fibres, notably human keratin fibres such as the hair, or β) human skin, in particular the lips, using a composition, preferably a cosmetic composition, comprising a) one or more polyhydroxyalkanoate (PHA) copolymers a) comprising at least two different repeating polymer units chosen from the following units (A) and (B), and also the optical or geometric isomers thereof, the organic or mineral acid or base salts thereof, and the solvates thereof such as hydrates: —[—O—CH(R1)—CH2—C(O)—]— unit (A) —[—O—CH(R2)—CH2—C(O)—]— unit (B) in which polymer units (A) and (B): —R1 and R2 are as defined in the description; and it being understood that: —(A) is different from (B); —the composition comprises an amount of less than or equal to 2% by weight of surfactants, relative to the total weight of the composition.