• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.391-394
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• 2003

It is inevitable that reconsideration of the use of lead oxides in the electronics industry be undertaken as long as detrimental effects to the environment remain. To solve this problem, many recent studies on Pb-free compositions for PDP (plasma display panel) dielectric layers and also sealing glass compositions have been made. The present study was conducted to investigate whether the alternative systems for leadfree low firing glasses, detailed below, are available for use in PDP materials. The results suggest that low-melting phosphate glasses would be suitable as an alternative material for the Pb-based dielectric layer, sealants and barrier ribs in PDP.

• Journal of the Korean Ceramic Society
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• v.26 no.6
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• pp.829-835
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• 1989

Devitrifing solder glasses in a specific group of glass ceramic materials are extensively used in hermetically sealing alumina electronics packages. Preferred frit glass compositions of this study consist of 37~40wt% PbO, 35~40wt% ZnO, 18~20wt% B2O3, 1~3wt% SiO2, 0~6wt% TiO2. The coated frit glasses crystallize during firing and form a strong hermetic seal. DTA and X-ray diffraction were used to characterize crystallization of the glass frit. Frit seal containing 2wt% TiO2 has crystallization temperature of 550~57$0^{\circ}C$ with surface nucleation. Frit seal containing 6wt% TiO2 has crystallization temperature of 515~5$25^{\circ}C$ with bulk nucleation, and the main crystalline phase was perovskite lead titanate having minus expansion coefficient. The average activation energy for the crystallization calculated from Ozawa equation was 65$\pm$10kcal/mol.

• Analytical Science and Technology
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• v.20 no.1
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• pp.41-48
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• 2007

The determination method for the trace lead and cadmium in glass materials was developed by ICP-AES. The lead- and cadmium-DDTC chelates were formed by adding Na-DDTC (sodium diethyldithiocarbamate) as a chelating agent and extracted into MIBK (methyl-isobutyl ketone). Direct measuring of the trace lead and cadmium in glass was not possible because of the interferences of matrix elements as Na, Si, Mg and Ca of glasses unless solvent extraction of lead and cadmium was applied. This procedure was confirmed to be valid quantitative method of Pb and Cd analysis in glass did not influence of sample matrix, by applying it procedure to artifact sample and NIST SRM 1412.

• Nuclear Engineering and Technology
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• v.56 no.10
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• pp.4050-4055
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• 2024

This research intends to utilize melt-quenching technique in order to examine the radiation shielding capability of 10 % Mo, 10 % Na2O, 20 % PbO, and 60 % B₂O₃ glass system, with varying CaO, TiO₂, CuO, Fe₂O₃ or Mo. XCOM and MCNP simulations were utilized to analyze the radiation shielding properties of the fabricated glasses. The results revealed CuO having the superior MAC of 49.91 cm²/g, then Fe₂O₃ with 49.24 cm²/g, followed by CaO with 49.10 cm²/g, and TiO₂ with 48.49 cm²/g as the least. CuO and Fe₂O₃ were confirmed to have least HVL compared to CaO and TiO₂. The value of the lead equivalent thickness showed fluctuation against the gamma energy, where it raisess within the photoelectric region and falls after the photoelectric region. The data reveal that, the lead equivalent thickness at 0.1 MeV were 7.88 cm, 7.86 cm, 7.81 cm and 7.80 cm for TiO₂, Fe₂O₃, CaO, and CuO in the same order, respectively. The transmission factor (TF) raises as the gamma energy raises, having TiO₂ as the highest with 76.068 %, while the radiation protection efficiency dropped as the energy raises.

• Journal of the Korean Chemical Society
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• v.12 no.2
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• pp.65-80
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• 1968

The physico-chemical properties of nine selected thallium borosilicate glasses and other 21 supplementary compositions were investigated. Their composition-property curves are found to be in many respects analogous to those of other borosilicate glasses containing lithia, soda, and lead oxide. It is indicated that certain minima found in the composition-property curves of thallium borosilicate glasses might be caused by a change in boron coordination as has been observed to occur in the $Na_2O-B_2O_3-SiO_2$ glasses. Typical effects of thallium ions on the borosilicate glass are summarized as follows: 1) Addition of thallium ions increased density, refractive index, water solubility, linear coefficient of thermal expansion, and dielectric constant. 2) Increased concentration of thallium decreased the softening point of the glasses, caused fluorescence under ultraviolet radiation and smeared out the absorption edges up to $15{\mu}$ in the infrared region. An extensive liquid immiscibility was found by replication electron microscope technique in the $Tl_2O-B_2O_3-SiO_2$ system. The immiscibility covers a composition range roughly from 55 wt. % Tl2O to the binary system $B_2O_3-SiO_2.$ By acid treatment, it was found that the immiscible glass consists of separate silica-rich and boron-rich phases.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.3
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• pp.157-167
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• 2021

Lead (Pb) is one of the key trace elements, exhibiting a peculiar partitioning behavior into silicate melts in contact with minerals. Partitioning behaviors of Pb between silicate mineral and melt have been known to depend on melt composition and thus, the atomic structures of corresponding silicate liquids. Despite the importance, detailed structural studies of Pb-bearing silicate melts are still lacking due to experimental difficulties. Here, we explored the effect of lead content on the atomic structures, particularly the evolution of silicate networks in Pb-bearing sodium metasilicate ([(PbO)_x(Na₂O)_1-x]·SiO₂) glasses as a model system for trace metal bearing natural silicate melts, using ²⁹Si solid-state nuclear magnetic resonance (NMR) spectroscopy. As the PbO content increases, the ²⁹Si peak widths increase, and the maximum peak positions shift from -76.2, -77.8, -80.3, -81.5, -84.6, to -87.7 ppm with increasing PbO contents of 0, 0.25, 0.5, 0.67, 0.86, and 1, respectively. The ²⁹Si MAS NMR spectra for the glasses were simulated with Gaussian functions for Qⁿ species (SiO₄ tetrahedra with n BOs) for providing quantitative resolution. The simulation results reveal the evolution of each Qⁿ species with varying PbO content. Na-endmember Na₂SiO₃ glass consists of predominant Q² species together with equal proportions of Q¹ and Q³. As Pb replaces Na, the fraction of Q² species tends to decrease, while those for Q¹ and Q³ species increase indicating an increase in disproportionation among Qⁿ species. Simulation results on the ²⁹Si NMR spectrum showed increases in structural disorder and chemical disorder as evidenced by an increase in disproportionation factor with an increase in average cation field strengths of the network modifying cations. Changes in the topological and configurational disorder of the model silicate melt by Pb imply an intrinsic origin of macroscopic properties such as element partitioning behavior.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.699-704
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• 2001

Until recently, disposal to landfill has been the most convenient way to deal with the increasing amount of residues the shredding industries produce. But the shortage of such disposal sites and the risk that liquid drained from these waste dusts may pollute ground water have increased the environmental pressures to find more effective solutions. The present study is an alternative approach that suggests identifying waste dusts characteristics and selecting an appropriate binder for hazardous materials to reduce the amount of contaminants (mainly lead) that were leaking into the soil. Investigations on the characteristics of automobiles waste dusts show that these materials are composed mainly of cottons and sponge like substances, plastics, rubber, glasses and gravel, metals, and electric wires. Besides, the percentage in weight of organic (inflammable) materials is about 70% and the lead contamination, which has not a ionic but a particulate nature, is particularly remarkable in cottons and sponge like materials. Binding additives such as K-20 and sodium carbonate were not effective but the addition of 5 % of cement (in weight of the investigated sample) followed by a 3-minute stirring and a 4-hour storage could drastically reduce the run off of lead below the maximum authorized level. No addition of water was necessary in this method.

• 보존과학연구
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• s.32
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• pp.113-121
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• 2011

Four glass beads from Hakso-ri site, O'chang were analyzed for thirteen oxides with SEM/EDS and lead isotope ratios with TIMS respectively. These samples were classified to potash glass system($K_2O-CaO-SiO_2$) with HCLA(High CaO, Low $Al_2O_3$). However three samples with above 4% for lead could be classified to potash-lead ($K_2O-PbO-CaO-SiO_2$)glass system and it seemed that coloring agent for greenish blue was Cu. Lead isotope ratio data for four samples did not make a group but scattered to the space respectively. It needs more study for compositions and lead iosotope data of potash-lead glasses with regions and ages.

• Korean Journal of Materials Research
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• v.19 no.11
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• pp.613-618
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• 2009

We designed new compositions for lead free and low temperature sealing glass frit of $ZnO-V_2O_5-P_2O_5$ system, which can be used for PDP (Plasma Display Panel) or other electronic devices. The $ZnO-V_2O_5-P_2O_5$ system can be used as a sealing material at temperatures even lower than 430$^{\circ}C$. This system, however, showed lower bonding strength with glass substrate compared to commercialized Pb based sealing materials. So, we added $TiO_2$ as a promoter for bonding strength. We examined the effect of $TiO_2$ addition on sealing behaviors of $ZnO-V_2O_5-P_2O_5$ glasses with the data for flow button, wetting angle, temporary & permanent residual stress of glass substrate, EPMA analysis of interface between sealing materials and glass substrate, and bonding strength. As a result, sealing characteristics of $ZnO-V_2O_5-P_2O_5$ system glasses were improved with $TiO_2$ addition, but showed a maximum value at 5 mol% $TiO_2$ addition. The reason for improved bonding characteristics was considered to be the chemical interaction between glass substrate and sealing glass, and structural densification of sealing glass itself.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.371-380
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• 2004

The history of the glasses can say that we began with the development of the typography. Glasses were made for the first time from the skin which they tied. We came to make the rim as the horn tree afterwards or bone. And the snail glasses make the lens as the modification or glass and to put to connect the two to large snail was developed. The rim after he brought lots of style change. The development of the Bridge and eyewear form of the Temple of an entry today began to come out. The development of and various design and material. We reached practical style. development of design concentration new fashion trend lead can make it eyewear company and designer's. A rim of various style through historical development course because we have a present time's rim analysis. We try to try to investigate a method element of the glass design with a final cause form of the design in the viewpoint of the facility.