An overview of the science and art of encapsulated pigments: Preparation, performance and application

Abstract

Pigments are classified as organic or inorganic based on their chemical composition. 1,2 Typically, organic pigments comprise compounds of carbon elements that participate in covalent bonding, while inorganic pigments consist primarily of ground minerals such as metals, metallic salts (except barium salts of dyes) and metalloid salts, which do not contain carbon bonds. 3 Although some organic pigments may contain inorganic elements as stabilisers, organic pigments are defined primarily based on their congugated carbon bonds (except carbon black). 2 To improve the chemical, thermal, freeze-thaw and dispersion stability of organic pigments upon application, these classes of pigments have been the subject of extensive research over the years due to their obvious advantages. [4][5][6] Typically, the colour strength and optical properties of coated/printed substrates depend largely on the quality of the pigmented ink/paste and the nature of the substrate. The quality of the pigmented ink/paste then rests on the quality of the dispersion system (ie, the degree of the dispersion and its stability). 5,7 Dispersion stability is very important from the point of view of surface coatings and printing systems, especially for encapsulated inks that

Synthesis and Characterization of Waterborne Sulfonate Polyesters

“…Particle size [23] and viscosity [24] are important properties of polyester as a linker. The monomer ratio of synthetic WSP, the average particle radius of polyester, and the viscosity of dispersions at 30% solid content are shown in Table 1.…”

Looking Back to Look Forward

“…They also build a case for more rigorous reporting of experimental information of studies which employ them, because the conventional level of detail is typically insufficient to make sense of the behaviour of reactive dyes within a cellular environment. Other reviews to appear in the last year tackle subjects that are of importance to diverse fields of coloration: research to treat coloration industry wastewater [5], developments in oxidative colorants for the permanent dyeing of hair [6], modification of pigment dispersion properties through encapsulation [7] and technologies that greatly reduce water usage in dyebaths [8].…”

Influence of different dispersants on the quality and stability of aqueous quinacridone magenta pigment dispersion for ink‐jet applications

“…In this respect, dispersing agents play a special role and the performance of the dispersant determines the quality of the finished product 2 . Dispersing agents are composed of a mixture of high‐molecular‐mass surfactants in solvents, being polymers of non‐polar and polar monomers, or non‐polar and/or polar copolymers 10 . The steric stabilisation process of pigment in dispersions includes the anchoring of the hydrophobic part of the dispersant compound to the pigment surface via van der Waals forces, whereas the hydrophilic part is solvated in the polar dispersion medium, leading to steric and electrostatic stabilisation of pigment particles.…”

“…The steric stabilisation process of pigment in dispersions includes the anchoring of the hydrophobic part of the dispersant compound to the pigment surface via van der Waals forces, whereas the hydrophilic part is solvated in the polar dispersion medium, leading to steric and electrostatic stabilisation of pigment particles. The electrostatic repulsion between particles originates from the electrically charged double layer around pigment particles, formed by the adsorbed dispersing agent 9–16 . Choosing the proper dispersing agent and its optimum amount is critical in achieving proper pigment stabilisation, viscosity and colour strength, and was studied in different applications by other authors 3,8–19 …”

“…The electrostatic repulsion between particles originates from the electrically charged double layer around pigment particles, formed by the adsorbed dispersing agent 9–16 . Choosing the proper dispersing agent and its optimum amount is critical in achieving proper pigment stabilisation, viscosity and colour strength, and was studied in different applications by other authors 3,8–19 …”