Particle Dispersion and Process for Forming a Particle Dispersion

Simple SummaryContent extracted from patent full text and abstract with AI.

This invention describes a process for making particle dispersions that yield homogenous films when dried, effectively overcoming the 'coffee ring effect' (uneven deposit patterns seen when droplets dry). The key is to coat solid core particles (such as metal oxides or polymers) with a monolayer of an interfacially-active, soluble polymer, and then thoroughly remove any unbound polymer. The resulting particle dispersion, which uses suitable organic solvents, produces uniform films as the droplets dry, without edge ring formation or inhomogeneity.

Use CasesContent extracted from patent full text and abstract with AI.

• Inkjet printing of functional or decorative coatings to provide uniform color and material distribution.
• Manufacturing of thin films for optical, electronic, or sensor devices where consistent film morphology is critical.
• Coating processes in the production of solar cells, LEDs, and display technologies.
• Formulation of lab-on-chip diagnostic sensors that require precise particle deposition.
• Preparation of uniform pigment or dye coatings on textiles, glass, ceramics, and plastics.
• Spray drying or casting processes in pharmaceuticals where uniformity of deposited drug particles is needed.

BenefitsContent extracted from patent full text and abstract with AI.

• Prevents the coffee ring effect, ensuring uniform film or coating thickness.
• No need for customized substrates, surfactants, or particle shapes—works across many materials and solvents.
• Enhanced control over material deposition improves product quality and performance, especially in printed electronics and coatings.
• Versatile method applicable to a wide range of core particle and polymer types.
• Reduced defects in coatings and better reproducibility in manufacturing.
• Method is compatible with standard industrial deposition techniques (e.g., inkjet printing, spray drying, spin coating).

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

The present invention relates to a process for producing a particle dispersion comprising the steps of: a) providing a dispersion consisting of a solvent and solid core particles, b) providing a solution of a soluble, interfacially-active polymer having a molecular weight of more than 5 kDa, c) mixing said dispersion of solid core particles with said polymer solution, d) removing free polymer from the obtained mixture; wherein in step a) the solvent is selected from an organic solvent, a mixture of at least two organic solvents or a mixture of at least one organic solvent with water; wherein in step c), the amount of the soluble, interfacially-active polymer mixed with said dispersion of solid core particles exceeds the amount of polymer required to coat the surface of each of the solid core particles with a monolayer of the polymer; wherein step d) is repeated until the requirement described by the following formula is fulfilled: STdisp−18mN/m/STsolv−18mN/m>0.90, with STdisp being the surface tension of the modified particle dispersion in [mN/m] and STsolv being the surface tension of the pure solvent or solvent mixture in [mN/m]; and wherein the solvent or solvent mixture contained in the dispersion of solid core particles is miscible with the solvent or solvent mixture contained in the polymer solution. The present invention also relates to a particle dispersion exhibiting a homogenous drying pattern as well as a film made thereof and the use of the non-aqueous particle dispersion.