• Title/Summary/Keyword: 황변현상

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Textile Yellowing in Consumer′s Affairs (섬유제품의 황변 원인 분석과 대책)

  • 암전빈
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2003.04a
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    • pp.3-26
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    • 2003
  • 소비자의 불만사고는 일상생활에 있어서 안전ㆍ위생ㆍ품질ㆍ기능ㆍ법규(표시)ㆍ기준ㆍ판매 방법ㆍ계약 등의 여러 가지 문제점을 다루고 있으며, 소비자의 이익 보호 및 증진을 주목적으로 하고 있다. 섬유 제품의 품질기능에 대한 불만은 소비자의 제의에 의해 현상별로 구분하면 $\ulcorner$색의 변화$\lrcorner$$\ulcorner$손상$\lrcorner$$\ulcorner$형태 변화$\lrcorner$$\ulcorner$표면 변화$\lrcorner$ 등의 $\ulcorner$외관ㆍ태의 변화$\lrcorner$$\ulcorner$봉제$\lrcorner$$\ulcorner$기타$\lrcorner$ 로 분류된다. (중략)

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A study on the development and the physical properties of Epoxy Putty for earthenware restoration (토기 복원용 Epoxy Putty 개발 및 물성에 관한 연구)

  • Bae, Jin Soo;Cheong, Da Som;Kim, Woo Hyun;Kang, Seok In;Wi, Koang Chul
    • Journal of Conservation Science
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    • v.30 no.1
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    • pp.103-109
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    • 2014
  • This study aimed to develop materials to compensate for problems of restoration for lost parts and material problems in the conservation treatment. First, there are several problems with existing materials as follows: secondary damage due to the high shrinkage rate and low adhesive strength, sense of difference due to the severe yellowing, remelting due to irreversibility of materials, processability due to the high strength, sag due to the prolonged setting time in the work process and surface contamination of artifacts due to tools or gloves. In order to solve these problems, this study set developmental goals after understanding the types and physical properties based on epoxy resin among the currently used restoration materials of pottery and earthenware. The developed epoxy resin is epoxy putty, which is cured within 5 minutes, for earthenware restoration. In the earthenware restoration method, the epoxy putty enhanced the workability by quickly curing in paste form and compensated disadvantages such as surface contamination. In addition, the use of white micro-balloon for the epoxy stock solution made coloring easier and weight lighter, and a restoration material with low shrinkage and superior processability was developed.

Study on the Property and Applicability of the Bisphenol-A Type Epoxy Putty According to the Mix of Filler (개발된 Bisphenol-A계 Epoxy Putty의 충전제 배합에 따른 물성 및 적용성에 관한 연구)

  • Wi, Koang-Chul;Oh, Seung-Jun
    • Journal of Conservation Science
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    • v.32 no.4
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    • pp.459-469
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    • 2016
  • The goal of this study was to examine property changes induced by the choice of filler used with an epoxy resin that was developed in 2014 to restore cultural assets and consider the applicability of the resin as a restorative agent. The properties of putty mixed with 9 types of fillers and as-developed resins were compared with those of existing materials with regard to stability, superiority and applicability. The potential of the putty as an alternative material was also examined. The materials produced the best adhesiveness, color change and hardness results when mixed with lime. Micro balloon produced the best wear rates and hardening times, while diatomite produced the best tensile and compressive strengths. A plaster and white mineral pigment mixture produced the best specific gravity. Every material except for lime exhibited about 2.5-20 times higher wear rates than the existing material, which is thought to exhibit an excellent cutting force. The hardening time was enhanced by about 0.5-9 times to improve convenience. The stability of the relic was also ensured by improving hand staining without any shrinkage or deformation. The material exhibited about 0.5-27 times less yellowing. Thus, it is thought to be a material that can reduce property changes and reduce the degree of relic fatigue which occurs during reprocessing and sense of difference from relic.

A Study of the Yellowing Phenomenon in the Laser Patterning of Silver Nanowire (은 나노와이어 레이저 패터닝 시 발생하는 황변 현상에 대한 연구)

  • Hwang, June Sik;Park, Jong Eun;Yang, Min Yang
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.1
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    • pp.94-97
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    • 2015
  • In this study, we introduce a yellowing phenomenon in silver nanowire laser patterning and attempt to understand the cause of this phenomenon. Silver nanowire is a promising alternative to indium tin oxide as a transparent electrode owing to its flexibility. Additionally, silver nanowire can be easily patterned by laser ablation, which is free of dangerous chemicals. However, a yellowish color change reducing visibility is observed on the patterned area of the silver nanowires, and this yellowing phenomenon prevents the use of silver nanowire as a transparent electrode material. We concluded that resolidified debris of melted and evaporated silver nanowires after laser ablation causes the color change of the electrode. Further research is needed to determine a means of mitigating this yellowing phenomenon.

Physical Properties and Flame Retardancy of PU Coatings Polymerized with Two Different Types of Isocyanates and Dichloro-Polyester Polyol (두 종류의 이소시아네이트와 디클로로-폴리에스테르 폴리올로부터 중합한 PU 난연도료의 도막물성 및 난연성)

  • 양인모;김성래;박형진;함현식;우종표
    • Polymer(Korea)
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    • v.26 no.2
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    • pp.193-199
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    • 2002
  • The dichloro-polyester polyol (DCBAO) which was synthesized in our earlier work was cured at room temperature with two different type of curing agents including Desmodur N-3300 and Desmodur L-75 to get a polyurethane flame-retardant coatings (DCBAO/N-3300=DEBAN and DCBAO/L-75=DCBAL). We could not observe any deterioration of physical properties of the flame-retardant PU coatings (UCBAN and DCBAL) in comparison with the conventional PU coatings. Thermal resistance of DCBAL-type flame-retardant coatings, which was measured by yellowness index difference, was inferior to that of DCBAL-type PU coatings. We believe that this phenomena is attributed to the poor thermal resistance of Desmodur L-75 isocyanate. It was observed that the LOI values were 25∼26% for the PU coatings containing 20∼30 wt% of 2,4-dichlorobenzoic acid.

Change of Physical Properties of Under Wear by Repeated Washing. (반복 세탁에 따른 내의류의 물성변화에 관한 연구)

  • Song, Kyoung-Hun;Lee, Mun-Soo
    • The Journal of Natural Sciences
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    • v.8 no.1
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    • pp.137-143
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    • 1995
  • The purpose of this study is to investigate the change of shrinkage, tensile strength, elasticity, light-fastness and color-fastness of 100% cotton upper under wear after acidic treatment and repeated washing and drying. Both of warp and welt were shrinked, especially in the early washing stage. Tensile strength was not weakened by 15 times of repeated washing. Hunter whiteness(HW) of white-underwear decreased, but color difference($\Delta$E) and yellow index(YI) increased corresponding to the frequency of washing and sunlight drying. The discoloration of color-underwear was significant in the early stage.

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Alkalic Effects on Dyeing of Nylon, Rayon, Wool blended Fabrics (나일론과 천연섬유 복합소재의 염색 시 알칼리에 따른 영향 연구)

  • Kim, Ji-Yeon;Kang, Suk-Hee;Min, Mun-Hong;Kim, Moon-Jung;Lee, Dong-Eun;Kim, Byoung-Yeol
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2012.03a
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    • pp.107-107
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    • 2012
  • 3종 복합소재인 양모와 나일론, 레이온의 염색공정은 먼저 알칼리 욕에서 반응성염료로 레이온을 염색한 후, 산성욕에서 산성염료로 양모와 나일론을 염색하는 것이 일반적이다. 그런데 양모, 나일론, 레이온은 알칼리에 민감하므로 면 염색 시 적용되는 강알칼리인 수산화나트륨을 사용하면 섬유의 취화로 인하여 강도와 촉감저하 등의 문제가 발생하게 된다. 따라서 본 연구에서는 알칼리 중 탄산나트륨과 중탄산나트륨을 사용하여 염료를 투입하지 않고 염색공정을 거친 후 백도와 인장강도를 측정하여 황변 및 강도 변화 여부를 알아보았다. 레이온 70%, 양모 19%, 나일론 11%의 혼용율을 가지는 전처리 된 편물(130$g/m^2$, 32 inch, 18 gauge)에 탄산나트륨(시약 1급) 20g/l과 중탄산나트륨(시약 1급) 20g/l 각각을 투입하고 반응성염색공정($60^{\circ}C$, 60 min)으로 처리한 경우와 반응성 염색 후 산성염색공정($98^{\circ}C$, 60 min)으로 처리한 경우로 나누어 측색을 통해 백도와 L, a, b값을 측정하고 KS K 0521에 따라 인장강도 시험을 실시하였다. 그 결과, 탄산나트륨 투입시 백도 값이 중탄산나트륨에 비해 10% 정도 낮아지고 L, a, b값도 상대적으로 yellow 방향으로 이동해 있는 것으로 나타났다. 이것은 황변이 일어남을 의미하며 육안으로 확인하였다. 또한 인장강도 측정결과를 통해 소다회 처리 시 중조에 비해 30% 정도의 강도 저하가 일어남을 확인할 수 있었다. 그러나 반응성염색 후 산성염색을 거치게 되면 황변과 강도 저하 현상이 회복되는 경향을 나타내었다. 즉, 천연/나일론 편물을 반응성염색 시 알칼리로 탄산나트륨을 사용하면 염색공정 상에서 중탄산나트륨에 비해 황변이 일어나 염료 고유의 색상 발현에 영향을 줄 수 있고 강도 또한 30% 정도 저하되지만, 후에 산성염색 공정을 거치면 산 조건과 욕중 효과를 통해 일부 개선됨을 확인하였다. 이와 별도로 이번에는 시판되는 반응성염료 5종과 산성염료 3종을 조합하여 탄산나트륨과 중탄산나트륨 투입에 따른 염색실험을 실시하고 측색(DataColor SF600 광원D65, Strength)을 통해 염착량을 비교하였다. 그 결과, 중탄산나트륨으로 염색하면 탄산나트륨에 비해 모두 염착량이 저하되었으며, 염료의 구조적 차이와 컬러별로도 그 차이는 다양하였다. 그 중 저온에너지형 반응성염료는 탄산나트륨 투입에 비해 47~60% 정도로 가장 양호하였으며, 일부 반응성염료는 20%까지 떨어지는 값을 나타내었다. 이것은 탄산나트륨보다 중탄산나트륨의 알칼리 정도가 낮으므로 반응성염료의 염착이 적은 것으로 생각되며, 저에너지형 반응성염료의 경우에는 낮은 온도나 알칼리 조건에서도 상대적으로 높은 고착률을 나타내므로 적절한 반응성염료의 선택을 통해 그 차이를 극복할 수 있을 것으로 사료된다. 이상의 결과를 통해 탄산나트륨과 중탄산트륨의 알칼리 정도가 강도와 염착량에 미치는 영향의 차이를 고려하여 최적의 현장 처방을 선정해야 함을 알 수 있었다.

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Effects of Growth Retardants on the Growth of Creeping Bentgrass (식물생장억제제가 Creeping Bentgrass의 생육에 미치는 영향)

  • 김석준;손기철;김두환;이재필
    • Asian Journal of Turfgrass Science
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    • v.12 no.3
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    • pp.173-182
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    • 1998
  • This study was conducted to evaluate the effect of plant growth inhibitors on "Penncross" creeping bentgrass in the green of golf course for increasing the summer quality. Chlormequat chloride (C) 250$\times$, 500$\times$, 1000$\times$, daminozide (D) 50$\times$, 100$\times$, 200$\times$, paclobutralzol (P) 1000$\times$, 2000$\times$, 4000$\times$, trinexpac-ethyl (T) 1000$\times$, 2000$\times$, 4000$\times$, uniconazole (U) 25$\times$, 50$\times$, 100$\times$ with three concentrations, respectively, were applied to creeping bentgrass. The leaf length, leaf width, and internode length of stolon were inhibited by all plant growth retardants applied as compared to that of control in which D-50, T-2000, and trinexpac-ethyl were the most effective among treatments on the inhibition of leaf length and internode length of stolen, respectively. Leaf thickness increased more in the treatments of C-250, D-50. T-2000 and T-4000 than any other treatments. On the other hand, shoot density which was represented by number of leaves per unit area was found to be the highest in P-2000 and P-4000 treatment. In this case, all plant growth retardants with no significant differences showed increase of 15-20% in density as compared to control. Total dry weight increment was higher in P-2000 and P-4000 while leaf dry weight increment was higher in T-4000. and U-25 and 50 than other treatments. According to the visual evaluation for the purpose of turf quality measurement, it was found that paclo-butralzol, trinexpac-ethyl and uniconazole were not suitable for green maintenance and extension because of making leaves to yellow. In conclusion, it was postulated that C-250, D-50, and T-4000 had possibility to use practically in the green area of golf course.lf course.

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Examination of Color Difference in Elastic Pavement that uses EPDM Chip using Ultraviolet Ray Accelerated Weathering Test (자외선 촉진 내후성 시험에 의한 EPDM Chip을 사용한 탄성포장의 색차분석)

  • Hong, Chang Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1D
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    • pp.91-98
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    • 2011
  • Recently, the usage of elastic paving using EPDM Chip instead of pedestrian sidewalk blocks or permeable concrete used mostly for pedestrian walk, trails and in parks has been increassed as it can absorb impact during walking and produce wide range of colors and designs. However, the properties of EPDM Chip including elasticity and durability are decreased when exposed to ultraviolet ray and scenic paving functions through various colors are lowered due to the yellowing phenomenon. In this study, ultraviolet ray accelerated weathering test has been conducted to analyze the color changes in EPDM Chip and polyurethane resin, which are the main ingredients of elastic paving, when exposed to ultraviolet ray. The color differences are quantitatively analyzed through the color value coordination of the colored space by using the color difference scheme. The experimental results show that the color changes in BL polyurethane resin which is used most frequently at present was larger than that of EPDM Chip. Moreover, the total color difference, ${\Delta}E$, of BC polyurethane resin are 3.162 on the $14^{th}$ day of commencement of acceleration, which is 6 times greater color change resistance against ultraviolet ray than that of BL polyurethane resin with total color difference of 20.639. Therefore, the usage of BC polyurethane resin, which is manufactured to have chain-type molecular structure by using the isocyanate as the HMDI at the time of producing polymer, as binder in elastic paving with EPDM Chip is found to be a highly efficient method of restraining the color changes due to the ultraviolet ray.

Determination of Processing Parameters Affecting the Conversion and Thermal Stability of Photocurable Acrylate-based Binder (아크릴계 광바인더의 전환율과 열안정성 향상을 위한 공정변수 결정)

  • Kim, Byungchul;Seo, Dong Hak;Chae, Heon-Seung;Shin, Seunghan
    • Applied Chemistry for Engineering
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    • v.23 no.1
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    • pp.18-22
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    • 2012
  • Photocurable binder for a transparent glass fiber composite was prepared with alicyclic methacrylate and fluorene-based diacrylate. ANOVA (analysis of variance) analysis was used to know main factors affecting the conversion of photocurable binder. It showed radiation intensity and photoinitiator (PI) concentration were main factors. The conversion of photocurable binder was simply increased with radiation intensity. Its increment however was abated with increasing PI concentration. We found that average conversion of the binder measured by FTIR-ATR was 87% when it was exposed to $5J/cm^2$ of UV dose with 5 wt% of PI. Oxime ester type PI was very effective to get a high degree of conversion, but it caused a yellowing problem. Owing to post-baking process, UV cured film showed an improved thermal stability by increase of conversion and removal of volatile organic compounds. TG% at $260^{\circ}C$ of film cured with 5 wt% of PI (TPO+MBF) and $5J/cm^2$ of UV radiation increased from 95.4 to 99.0% by post-baking at $230^{\circ}C$ for 5 min.