Cellulose Nanocrystal Microparticles with Bound Pigment
Solution Overview
Problem
The cosmetics industry faces challenges in creating natural, sustainable, and effective pigments that combine the lightfastness and durability of inorganic pigments with the vibrancy and processability of dyes, while also addressing concerns about nanoparticle safety and skin tone matching.
Innovation Solution
The development of microparticles comprising agglomerated carboxylated, sulfated, or phosphated cellulose nanocrystals with bound pigment nanoparticles, which are produced through a spray-drying process, offering a range of skin tones and improved skin feel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inorganic pigments are used to achieve lightfastness and durability, then color stability is improved, but processing difficulty increases and color brilliance decreases
Solution Approach 1:
The patent creates composite microparticles consisting of cellulose nanocrystals as the core matrix with pigment nanoparticles dispersed throughout. This composite structure combines the lightfastness of inorganic pigments with the processability and solubility benefits of the cellulose matrix, resolving the contradiction between durability and ease of manufacture
Solution Approach 2:
The patent segments the pigment into nanoparticle form (1-100 nm) and disperses it within the cellulose nanocrystal matrix. This segmentation allows the pigment to be distributed at the molecular level throughout the microparticle, improving both processing characteristics and color brilliance while maintaining the lightfastness of the inorganic pigment components
2Reliability
If inorganic pigments are used to achieve durability, then color permanence is improved, but particle size reduction requires intensive milling
Solution Approach 1:
The patent applies preliminary action by pre-synthesizing the pigment nanoparticles to the required size (1-100 nm) before incorporation into the cellulose matrix. This preliminary size reduction eliminates the need for intensive milling of the final microparticles, as the pigment is already in the optimal nanoparticle form during microparticle formation through spray-drying
Solution Approach 2:
The patent changes the particle size parameter of the pigment from conventional micron-scale to nanoparticle scale (1-100 nm). This parameter change fundamentally alters the processing requirements, allowing direct incorporation into the cellulose matrix without intensive milling, while simultaneously improving color brilliance and reducing aggregation
3Manufacturing precision
If pigment nanoparticles are used to improve color brilliance, then color strength is improved, but safety concerns increase
Solution Approach 1:
The patent uses cellulose nanocrystals as an intermediary matrix that encapsulates and binds the pigment nanoparticles. This intermediary structure provides a biocompatible, natural barrier between the nanopigment particles and the skin, addressing safety concerns while allowing the nanoparticle form to maintain its color brilliance and strength
Solution Approach 2:
The patent changes the size parameter of the final microparticles to the micrometer scale (1-100 μm), which is significantly larger than the nanoparticle threshold (1 μm = 1000 nm). This parameter change ensures that while the pigment itself is in nanoparticle form (providing color brilliance), the final applied particle size is in the safe micrometer range, reducing penetration concerns
4Adaptability or versatility
If multiple pigments are mixed to achieve skin tone matching, then color range is improved, but formulation complexity increases
Solution Approach 1:
The patent uses the concentration parameter of pigment nanoparticles within the microparticles as a tuning variable for skin tone matching. By adjusting the amount of pigment loaded into each microparticle (rather than mixing multiple pigment types), the formulation achieves a wide range of skin tones while maintaining simplicity in the formulation structure
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
These microparticles provide vibrant, lightfast colors with enhanced skin feel and a wide range of skin tones, reducing the need for multiple pigments and improving the naturality index, while ensuring stability and safety by binding pigment nanoparticles to cellulose nanocrystals.
Implementation Method 1
drying said aqueous suspension to produce the microparticles
Data Source
AI summary
Microparticles comprising carboxylated, sulfated, or phosphated cellulose nanocrystals (CNCs) and pigment nanoparticles are provided. In these particles, the cellulose nanocrystals and the pigment nanoparticles are agglomerated together thereby forming said microparticle, and wherein the pigment nanoparticles are bound to the surface of the cellulose nanocrystals. Cosmetic preparations comprising these microparticles are also provided. Finally, a method for producing the microparticles is provided. The method comprises the steps of a) producing an aqueous suspension of carboxylated, sulfated, or phosphated CNCs with pigment nanoparticles bound thereto; and b) drying said aqueous suspension to produce the microparticles.