Microencapsulated pigments

One of the main arms of high added value products is the development of properties that directly affect the safety and comfort of users. One of the ways to accomplish this is by using microencapsulation processes to impart new functionalities and properties to textiles (Anon, 2008). Thermochromic microencapsulated pigments bear the potential for medical application in terms of registering elevated body temperature of patients, thus allowing easier monitoring and point of care diagnosis. 

A.L. German, Microencapsulated pigments and fillers, in Microspheres Microcapsules S, Liposomes, Vol. 1, Preparation g. Chemical Applications, R. Arshady (Ed.), Citus Books, London, 1999, Chap. 17, pp. 457-486. 

Today s requirements for dispersibility and dispersion stability of pigment-base ink jet inks require an extremely high level of performance. Dainippon Ink and Chemicals has developed new microencapsulation technologies for the solution of such problems [5]. Their microencapsulated pigments exhibit concentrated polymer layers on the pigment surfaces. The encapsulation polymers used are basically methacryhc acid-methacrylate ester copolymers. 

Coating techniques Pharmaceuticals, food, fertilizers and agricultural chemicals (control of release), microencapsulation of pigments, etc. 

Pigments Fluid bed agglomeration, spray drying, compaction + crushing and screening, microencapsulation Caking, build-up, flow problems... 

Most efforts have been put into developing natural colours with improved stability towards low pH, light and heat and with increased brightness of the different pigments. The technologies that have been applied are microencapsulation, addition of antioxidants, emulsions and oil snspensions. 

Miyatake, M. Tenmaya, E. Ohashi, T. Kawasaki, M. Water-based microencapsulated mixed pigment dispersions for inks and coatings. JP 01115976, 1989. 

Wikstrom, J., Elomaa, M., Syvajarvi, H., Kuokkanen, J., Yliperttula, M., Honkakoski, R, Urtti, A., 2008. Alginate-based microencapsulation of retinal pigment epithelilal ceU line for cell therapy. Biomaterial 29, 869-876. 

Ersus S, Yurdagel U. Microencapsulation of anthocyanin pigments of black carrot (DaucuscarotaL.) by spray drier. J Food Eng. 2007 80(3) 805-812. 

This chapter presents selected solutions in food packaging where microencapsulation technologies have been applied such as (1) flavor releasing, (2) coloring agents and pigments, (3) antimicrobial, and (4) insect or rodent resistance. 

The most popular method of pigments encapsulation is spray-drying. Many papers present information about microencapsulation by spray-drying, and this method is most frequently used to protect pigments obtained from vegetables, fruits, flowers, and plants, for example, black carrot, curcumin, beetroot, or roselle. Application of natural polymers as shell to protect beetroot color increased the half-life of spray dried dye about three times, whilst pink color was stabile for about 8 weeks. In case of red roselle pigments stabilization, after microencapsulation, it was acceptable to extend the storage time under different water activities up to 4 months. ... 

Wang, X., Lu Zhaoxin, L., and Pengxia, L. 2009. Study on microencapsulation of curcumin pigments by spray drying. Eur. Food Res. Technol. 229 391-396. 

Janiszewska, E. and Wlodarczyk, J. 2013. Influence of spray drying condition on beetroot pigments retention after microencapsulation process. Acta Agrophys. 20(2) 343-356. 

Synonyms Butylated polyvinylpyrrolidone DeMbn Polymer of butylated vinylpyrrolidone Uses Moisture barrier, adhesive, protective colloid, film-former, and microencapsulating resin in cosmetics pigment dispersant solubilizer for dyes sludge/detergent dispersant in petroleum industry protec-... 

Core materials in microcapsules may exist in the form of either a solid, liquid or gas. The core materials are used most often in the form of a solution, dispersion or emulsion. Compatibility of the core material with the shell is an important criterion for enhancing the efficiency of microencapsulation, and pretreatment of the core material is very often carried out to improve such compatibility. The size of the core material also plays an important role for diffusion, permeability or controlled-release applications. Depending on applications, a wide variety of core materials can be encapsulated, including pigments, dyes, monomers, catalysts, curing agents, flame retardants, plasticizers and nanoparticles. 

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