• Textile Coloration and Finishing
• /
• v.27 no.4
• /
• pp.245-260
• /
• 2015

The effect of salt milling process on the crystal size, morphology, and color characteristics of C.I. Pigment Red 57:1 was studied. The primitive morphology and color properties of the pigment after synthesis were studied in the former series work. The size and morphology of primary particles and the second aggregation features should be considered because they are very important to determine pigment quality. We compared the primary morphology of pigment particles before drying with the secondary aggregated morphology of pigment particles after drying and salt milling process. Morphological properties were investigated by particle size analysis, X-ray diffraction, and scanning electron microscopy and color measurement was carried out. Significant reduction in particle size as well as enhanced crystallite size after salt milling process was observed. This result might give a difference in color of the pigment, turning into brighter and more blue-toned red color. It was revealed that synthesis condition affect the morphology and color of the pigment even after milling. Increase in HCl concentration in the synthesis process enhanced crystal size and quality forming bluer-red pigments but an increase in $CaCl_2$ concentration resulted in more amorphous crystals forming darker-red pigments after salt milling.

• Clean Technology
• /
• v.23 no.4
• /
• pp.408-412
• /
• 2017

Pigment red 53:1 is a dye used in various products as a component of the inks, suspected of being carcinogenic. Thus, the environmental and occupational issues related to it are important. The enzyme-based approach with reusability has advantages to consume less energy and generate less harsh side- products compared to the conventional strategies including separations, microbe, and electrochemical treatment. The degradation of Pigment red 53:1 by the lignin peroxidase immobilized on the surface of magnetic particles has been studied. The immobilization of the peroxidase was conducted on magnetic particle surface with the treatment of polyethyleneimine, glutaraldehyde, and the peroxidase, in sequence. The immobilization was confirmed using X-ray photon spectroscopy. The absorbance peak of the pigment was monitored at 495 nm of UV/Vis spectrum with respect to time to calculate the catalytic activities of the pigment for the immobilized lignin peroxidase. For the comparison, the absorbance of the lignin peroxidase free in solution was also monitored. The catalytic rate constant values for the free lignin peroxidases and the immobilized those were 0.51 and $0.34min^{-1}$, respectively. The reusable activity for the immobilized lignin peroxidase was kept to 92% after 10 cycles. The stabilities for heat and storage were also investigated for both cases.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.825-827
• /
• 2002

The polymer encapsulation of white inorganic $TiO_2$ pigment particles was prepared by a two stage dispersion polymerization technique for applications in electrophoretic displays (EPDs). In order to give functionality for inorganic pigment particles in the EPD, we have investigated the density of the polymer encapsulated $TiO_2$ particles. The average density of the polymer encapsulated $TiO_2$ particles was 2.2 at 25$^{\circ}C$. The average density of the polymer encapsulated $TiO_2$ particles is suitable to 1.7, due to density matching with suspending media. Therefore, we will attempt density compatibility of dispersion polymerization technique for encapsulation of $TiO_2$ particles in suspending media.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.969-971
• /
• 2007

The black/white electronic ink containing high mobility white nano particles and the organic black pigment particles dispersed in dielectric fluid were prepared. A charge control agent affects the electrophoretic zeta potentials of white particle, which show the maximum value in zeta potential. The electronic ink panel fabricated with the charged white particles and the black particles exhibits more than 15:1 contrast ratio at 10V.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.3
• /
• pp.1-8
• /
• 2012

The effects of several factors including organic pigment blending and calending conditions on the surface and optical properties of coated paper were investigated. When clay and calcium carbonate are blended in the ratio of 7 to 3, highest smoothness and relative sediment volume were obtained. When organic pigments were added to the mixture of clay and calcium carbonate, the relative sediment volume did not changed significantly. However, when organic pigments were added to calcium carbonate, sheet gloss and smoothness were improved, and showed the better results than that obtained from the mixture of organic pigment and clay. When organic pigment is blended with clay, the particles of organic pigment are buried in the packing structure of coating layer. However, the particle shape of calcium carbonate is quite different from that of clay, and the aspect ratio of calcium carbonate is similar to that of organic pigment. Thus organic pigment particles are not buried and improved effectively the physical characteristics of coating layer. When the hollow sphere pigment was blended, opacity and sheet gloss were improved significantly. Even though the coating color applied was reduced, the similar level of opacity was maintained. Also, if particle size and void volume are increased, gloss is improved, because coating layer is easily transformed in calendering. Therefore, even though lower pressure was applied during calendering, the smoothness of surface of coating layer was improved, and the decrease of void volume in coating layer was reduced, and the quality of coated sheet can be improved.

• Journal of Conservation Science
• /
• v.35 no.6
• /
• pp.664-669
• /
• 2019

Yeonpyo-beob is a method of manufacturing pigments using bamboo trunk and glue solution. Glue solutions of concentrations 1, 5, and 10% were employed to manufacture pigments, and the characteristics of pigment manufacturing were analyzed according to these concentrations. The pigment manufacturing process can be divided into holding and drying phases. The holding phase involves the sedimentation of relatively large particles, whereas the drying phase involves the sedimentation of small particles. The layers formed during the drying phase have almost similar forms regardless of the concentration of the glue solution. If the concentration of the glue solution is low in the holding phase, the particles are mixed and the formation of a layer is difficult. In contrast, when the concentration of the glue solution is higher, the layer of the pigment is more distinct. These results confirmed that the differences in viscosity due to the variation in the concentration of the glue solution affect the sedimentation velocity of the pigment particles, thereby affecting the formation of the layer of the pigment and the pigment manufacture. Consequently, applying 10% glue solution to reduce the sediment velocity is deemed suitable for the stratification of the pigment particles and the manufacture of pigments.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.4
• /
• pp.127-135
• /
• 2015

Artists have been used animal glues for a long time as binding and sizing materials of paintings in many countries including Korea. Since animal glues as a binding material lose their own adhesive strength by aging, pigment particles or pigment layers are easily detached from painting surface. Restaurators prefer to use animal glues for consolidation of pigment particles or pigment layers because artists use animal glues as a binder for their painting works. It is widely known that animal glues have different characteristics such as viscosity, stability on water etc. But there are still a few requirements to consider their stabilities for the restoration of paintings. Therefore, this study was aimed to evaluate of stability and efficiency of animal glue applications. The efficiency of animal glue application was decreased with increasing the concentration of animal glue solution. This result means the simple tendency, but does not representative data for other animal glues made from same raw materials. In most cases, the surface and mechanical characteristics of animal glues are dependent on some factors, like viscosity and concentration of animal glue solution.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.828-830
• /
• 2002

In this study, we have investigated a simple process of preparation of white pigment particles by physical coating with functionalized wax for the electrophoretic display. We will discuss, especially, the implementation of bistable pigment providing high mobility by using unique charge control agent and also optical properties of wax coated $TiO_2$ particles.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.11
• /
• pp.1513-1520
• /
• 2010

A bacterium capable of producing melanin pigment in the presence of L-tyrosine was isolated from a crop field soil sample and identified as Klebsiella sp. GSK based on morphological, biochemical, and 16S rDNA sequencing. The polymerization of this pigment occurs outside the cell wall, which has a granular structure as melanin ghosts. Chemical characterization of the pigment particles showed then to be acid resistant, alkali soluble, and insoluble in most of the organic solvents and water. The pigment got bleached when subjected to the action of oxidants as well as reductants. This pigment was precipitated with $FeCl_3$, ammoniacal silver nitrate, and potassium ferricynide. The pigment showed high absorbance in the UV region and decreased absorbance when shifted towards the visible region. The melanin pigment was further charecterized by FT-IR and EPR spectroscopies. A key enzyme, 4-hydroxyphenylacetic acid hydroxylase, that catalyzes the formation of melanin pigment by hydroxylation of L-tyrosine was detected in this bacterium. Inhibition studies with specific inhibitors, kojic acid and KCN, proved that melanin is synthesized by the DOPA-melanin pathway.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.14 no.2
• /
• pp.81-99
• /
• 1996

The characteristics of printing inks are affected, to a greater or lesser extent, by the size and distribution of the pigment particles in the dispersion. Color strength, transparency and gloss increase with a decrease in particle size of pigments and with an increase in surface area of pigments. On the contrary, opacity and lightfastness tend to increases with an increase in particle size of pigments and with a decrease in surface are and particle size if pigments on the physical properties of printing ink which made up vehicles for sheet fed and organic pigment Lake Red C(C.I Pigment Red 53:1) that different surface area and particle size.