• Journal of the Korean Vacuum Society
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• v.6 no.4
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• pp.321-325
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• 1997

Recently, photosensitive color filters have received much attention for their use in the liquid crystal display (LCD) industry. It is well known that chemical and physical properties of polymer surfaces can be modified by special surface treatments. In this work, we have studied the polymer surfaces of LCD blue color filters which were exposed to the UV light during photolithography. A better understanding of the irradiated polymer surfaces is required for the subsequent processes such as plasma etching, ITO electrode deposition, etc. The surface analysis has been undertaken using secondary ion mass spectrometry (SIMS), x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). A significant enrichment of the pigment component and roughening of surface with bubble-like feature have been observed at the modified polymer surface.

• Polymer(Korea)
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• v.31 no.5
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• pp.442-446
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• 2007

Alkali soluble and photo-curable polyesters were prepared from fluorene epoxy acrylate and various aromatic dianhydrides. To make a black matrix for LCD color-filter application, photo-resist solution was made by mixing synthesized polyester as binder, carbon black as pigment, initiator and multifunctional monomer in solvent. Black matrix pattern was formed on the glass substrate by lithography process. In this study, we synthesized various polyester-based binder polymers for LCD color-filter applications, and compared the analytical properties of those polymers and lithography patterns.

• Macromolecular Research
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• v.9 no.6
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• pp.327-331
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• 2001

A new soluble photosensitive poly(amide-co-imide) containing p-phenylenediacryloyl moiety was synthesized and its photoreactivity was characterized. The copolymer was synthesized fromp-phenylenediacryloyl chloride, 4,4-(hexafluoroisopropylidene)diphthalic anhydride and two equivalents of bis(4-aminophenyl) ether in NMP with a subsequent chemical imidization of the resulting poly[amide$\xi$ο-(amic acid)] by acetic anhydride and pyridine. The structure and thermal properties of the polymer were characterized by spectroscopic methods and thermal analyses. The polymer was stable up to 350$\^{C}$, showed good solubility in polar aprotic solvents, and became insoluble after UV irradiation due to the[2+2] cycloaddition of phenylenediacryloyl moiety. Photoreactivity of the polymer was investigated in solution or as a film with respect to the various exposure conditions by UV/Vis spectroscopy. The photosensitivity was noticeably increased with the irradiation temperature, especially in the presense of photosensitizer. The reason for the increased sensitivity was speculated based on the flexibilization of main chain at elevated temperature. Exposure characteristic curves were obtained from the gel fraction experiments after UV irradiation. The sensitivity and contrast at 160$\^{C}$ were measured to be 293 mJ/㎠ and 1.64, respectively.

• Polymer(Korea)
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• v.26 no.6
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• pp.701-709
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• 2002

To synthesize a new positive photosensitive polyimide precursor, parts of carboxylic acid groups in poly (amic acid) were esterified with 4,5-dimethoxy-2-nitrobenzyl bromide in the presence of K$_2$CO$_3$/HMPA followed by the chemical imidization of residual carboxylic acid units. The chemical structure of resulting polymer was characterized by $^1$H-NMR, UV/vis and FT-IR spectroscopic methods, and its thermal properties were examined by DSC and TGA. Upon UV irradiation, 4,5-dimethoxy-2-nitrobenzyl moiety underwent the photodegradation. As a result, the polymer became soluble in alkaline developer due to the formation of carboxylic acid moiety, which was used to make a micron-sized positive pattern. Sensitivity curves were obtained from the gel fraction experiments with respect to the various 4,5-dimethoxy-2-nitrobenzyl ester contents. From those curves, the sensitivity was ranged iron 4000 to 6000 mJ/㎠, and the contrast was measured to be from 3.1 to 4.9.

• Proceedings of the Korean Society of Potoscience Conference
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• spring
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• pp.41-41
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• 1996

• Macromolecular Research
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• v.14 no.3
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• pp.257-260
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• 2006

• Journal of Information Display
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• v.7 no.2
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• pp.6-11
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• 2006

New photopolymers were designed and prepared using the photosensitive polymer binders. Holographic gratings were successfully fabricated in these photopolymer samples by a conventional optical interference method. We also investigated the effect of photocrosslink in the polymer binder on the diffraction behavior of a new photopolymer. The dynamic behavior of the grating formation was monitored by changing exposure intensity in terms of the diffraction efficiency. Particularly, we focused our efforts in observing the variation of diffraction efficiency during a post UV curing process. The surface topographical change of photopolymer layer before and after Vis/UV light exposure was observed by atomic force microscope (AFM). We inscribed the gratings of the glass diffuser on the surface of the photopolymer and investigated their diffusing properties. The diffusers with photopolymer with the main chain polymer binder showed relatively good viewing angle of around ${\pm}30{\circ}$. Two kinds of photopolymer showed similar uniformity of around 47-54%.

• Journal of the Korean Graphic Arts Communication Society
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• v.16 no.3
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• pp.1-13
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• 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 Institute of Telematics and Electronics D
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• v.35D no.4
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• pp.78-83
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• 1998

A small size cartrideg for FET type electrolyte sensor is designed and faricated with much simplified process by using micromachining tenchiques such as silicon etching andglass bonding. Size of the whole cartideg is 2.4cm*2.5cm, and the dead volume of a micro flow-channel in the cartrideg is only 8.5.mu.l. The photosensitive polymer(THB 30) is used to define a micropool and to encapsulate the sensor surface for standardizationof electrolyte sensors. To miniaturize micro flow-channel conventional reference electrode(Ag/AgCl) a differential amplification is introduced using REFET and quasi reference electrode. Refet was fabricated using photosensitive polymer(OMR 83). The fabricated cartridge with built-in pH-ISFET showed good operational characteristics such as linearity and high sensitivity (55.4mV/pH) in a wide pH range(pH2-pH12).

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.480-483
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• 2005

We report on studies of photoalignment of cholesteric liquid crystals on photosensitive phenylon-based polymer. We found that reflective and electro-optical characteristics of cholesteric cells strongly depend on UV exposure doze. The optimized UV treatment of the polymer allowed us to obtain the same quality of alignment on standard rubbed polyimide orientants. At the same time, the photosensitive orientant possesses evident advantage of the effective control of cholesteric textures