• Journal of the Korean Graphic Arts Communication Society
• /
• v.18 no.1
• /
• pp.113-120
• /
• 2000

A previous paper was reported in being sensetized photopolymer, poly(vinyl cinnamoyl acetate) (PVCiA)1) with some squarylium dyes such as 1,3-bis(4 or 6-trifluouomethy1-1,3,3-trimethylindo) squarylium dyes(TFSQ). Here, we synthesized new 1,3-bis(4 or 6-nitro-1,3,3-trimethylindo) squarylium dyes(NISQ) to sensetize photopolymer, such as poly(vinyl cinnamoyl acetate). Absorption's coefficient of (NISQ8) is 8.5x105, the sensitivity of PVCiA added with NISQ8(3%) was highly sensitized 8 times than not added, and 2 times than TFSQ8(3%). Maybe, high absorption'scoefficient and red shift of NISQs with strongly withdrawing group to TFSQs afford to the high sensitivity of PVCiA.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.21 no.2
• /
• pp.55-65
• /
• 2003

A novel evaluation method is investigated for UV curing process in printing system. The method is based on the measurement of conducivity change by the photopolymerization of UV curable inks and paints. It is found that the decrease of conductivity is caused by photopolymerization of epoxy monomer during UV curing process of ink film and the by the rate of UV curing. It is possible to make the dynamical evaluation the curing rate of UV curable ink in curing process by this method.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.22 no.2
• /
• pp.111-122
• /
• 2004

The purpose of this study was to investigate the possibility of application of microwave energy for the fabrication of polymer/clay nanocomposite. APES/Clay nanocomposites were prepared at $130^{\circ}C$ for 30min with various amount of MMT or OMMT used the melt-intercalation method applied the classical and microwave heating source. APES/Clay samples were characterized by the means of X-ray diffractometry (XRD), transmitted electron microscopy (TEM) differential scanning calorimetry (DSC), and rheometric dynamic analysis (RDA). It was found that intercalated or exfoliated state of the samples could be controlled by the clay type, clay content, and heating type.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.16 no.3
• /
• pp.1-13
• /
• 1998

Some photopolymer, poly(vinyl cinnamoyl acetate)(PVCiA) was synthesized by esterification of polymer(vinyl alcohol(PVA) with monochloroacetic acid, followed by reaction poly(vinyl monochloroacetate)(PVChA) and potassium cinnamate. When esterification of PVA with monochloroacetic acid was reacted in the dimethyl sulfoxide(DMSO), in the synthesis of PVChA, it is very good yield and the successive cinnamoyl acetoxyl esterification of PVCiA can be successfully synthesized. But PVCiA is low photosensitive polymer if not added photosensitizing dyes. Here, we synthesized photosensitizing dyes. trifluoromethylindol squarylium dye derivatives(TFSQ). Indolization of 3-trifluoromethylphenyl-hydrazine formed 4- and 6-substituted indoles, the rate of 4- and 6-substituted indoles is close to unity. Absorption's coefficient of 1,3-bis(4-trifluoromethyl-1,3,3-trimethylindol) squarylium dye(TFSQ) is 7.57$\times$10\ulcorner, PVCiA added with TFSQ(3%) was highly sensitized six times than not added.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.13 no.1
• /
• pp.39-55
• /
• 1995

There has been an enormous emergence of imaging systems dedicated to hardcopy and softcopy color-appearance comparisons. Pre-press industry use the CRT as a soft proofing device to preview and aid with color corrections and changes before producing the final printed image. Color DTP system is required an accurate image-matching between CRT-image and printed image. In other to develop the color DTP,CRT calibration and CRT color transform to CIE color system are necessary. In this paper, we described a method CRT color transform to CIELab color system using RGB image raw data. Experimental results show that described method is useful valid of color image matching.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.13 no.2
• /
• pp.1-17
• /
• 1995

Organic thin film electroluminescene devices were fabricated using by molecularly doped method with N,N`-diphenyl-N,N`-bis(3-methylphenyl)-1,1`-biphenyl-4,4`-diamine(TPD) as a hole transport material, tris(8-quinolinolate) aluminium(III)(Alq3) as an emitting and electron transport agent, fluorescent squarylium(SQ) dye as a dopant, and poly(methylmethacrylate) as polymer materials. A cell structure of ITO/TPD-PMMA/Alq3-dopant/Mg was employed. The EL spectrum covers a wide range of the visible region and orange emission os observed. Two peaks at 520 and 660nm correspond to the emissions 620nm Alq3 and SQ dye, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.315-318
• /
• 2001

The optical and dielectric properties of TiO$_2$ thin films prepared with mixtures of Epoxy, bits-(4, 4'-p-toluenesulfonylacidic isoproplylidene)-cyclohexadiol and UVI 6990 in dry sol-gel process were investigated. The absorption peak of the films was showed at 360nm. Photocurrent of the thin films doped with 50 wt% of TiO$_2$was higher than that of nondoped thin films. Energy gap was lowered from 3.6 to 3.3 eV with increasing amount of TiO$_2$. Relative dielectric constants of samples were 1.5 to 3 and showed a characteristics of lower dielectric materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.870-873
• /
• 2001

The electron drift mobilitity of poly(4,4'-cyclohexylidenediphenyl carbonate)(PC-Z) doped with 3,5-dimethyl-3',5'-di-t-butylstilbenequinone(MBSQ) was measured by the time-of-flight technique. Energy gap of the polymer doped with 25wt% of MBSQ was 3.1 eV. The electron drift mobility was 2.98${\times}$10$\^$-6/$\textrm{cm}^2$/V$.$s at 293K. The electric field and temperature dependences of the electron drift mobility were discussed with Poole-Frenkel and Arrhenius formulations. The activation energy(E$\_$0/), Poole-Frenkel coefficient(${\beta}$) and effective temperature(T$\_$eff/) of the mobility are 0.815 eV, 1.73${\times}$10$\_$-4/ eV$.$cm$\^$1/2//V$\_$1/2/ and 6.43${\times}$10$^2$K, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.760-763
• /
• 2002

Nanoparticle size of Titanium dioxide thin films was prepared by novel method. Particle size and surface structure of $TiO_2$ thin films were investigated by atomic force microscopy(AFM), scanning electron microscopy(SEM). All thin films process were prepared at room temperature. Particle size was reduced from 100 to 30nm with increasing amount of $Ti[OCH(CH_3)_2]_4$ observed by AFM images. All thin films were irradiated for 5 minutes by white light. Increasing the annealing temperature, particles size was increased. In the $TiO_2$(40%) thin films was annealed at $300^{\circ}C$ for 30minutes, the particle size was about 10nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.756-759
• /
• 2002

Nanoparticles of titanium dioxide$(TiO_2)$ were prepared by photochemical synthesis. Surface structure, morphology and particle size of $TiO_2$ thin films were investigated by UV-VIS spectrophotometer, scanning electron microscopy(SEM) and transmission electron microscopy(TEM). All process was prepared at room temperature. The absorption peak of the films was showed at 360nm and $TiO_2$ nanopaticle size was observed at about 20~30nm. Electron diffraction ring patterns of $TiO_2$ nanoparticles and crystallographic spacing were observed by TEM. As a result, crystallographic spacing was about 3.6A in HR-TEM micrographs.