• 제목/요약/키워드: Phosphate coating

검색결과 126건 처리시간 0.034초

INTUMESCENT INORGANIC AND ORGANIC COATINGS

  • Kodolov, V.I.;Mikhalkina, T.M.;Shuklin, S.G.;Bystrov, S.G.;Larionov, K.I.
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.130-137
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    • 1997
  • Intumescent inorganic and organic coatings which dintr one from the other by the type of gas formers and the mechanisms of foam formation have been obtained and investigated. Inorganic intumescent coatings are the compositions based on water glass and mineral additives with different dispersity. Mineral additives contain adsorbed and absorbed water and carbonates which are destructed with the carbon dioxide and water evolution during the flame action on coating. The decreasing of mineral additives particle sizes under the mechanical milling with the fraction precipitation promotes the foam coke formation with less defects. Here the main structure of comparing compositions does not change. In organic coatings based on epoxy-polymers the polyammonium phosphate additive is used. It is the cabonization catalyst and the foam agent. The polyammonium phosphate of various dispersity employed is uniformly distributed on the polymeric matrix. The decreasing of the particle sizes leads to the increasing of the fire resistant properties of the intumescent coa-ting. The fire resistant analysis of the coating during more than an hour: the coating back side the temperature on plastic or wooden materials does not exceed 423K, and on metal-573K.

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Development and Stability Evaluation of Enteric Coated Diclofenac Sodium Tablets Using AquaPolish E.

  • Zaid, A.N.;Fadda, A.M.;Nator, S.;Qaddumi, A.
    • Journal of Pharmaceutical Investigation
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    • 제41권4호
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    • pp.211-215
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    • 2011
  • The aim of this study was to develop a stable enteric coated diclofenac sodium (DFS) tablets using Aqua-Polish E without using a subcoat. DFS uncoated tablets were manufactured through the non direct compression process. AquaPolish E white aqueous coating dispersion was used as enteric coating material. This film forming polymer is a mixture of selected polymethacrylic/ethylacrylate copolymers. The stability of the obtained enteric coated tablets was evaluated according to ICH guidelines. No signs of disintegration or cracking was observed when they placed in 0.1N HCl solution (pH1.2), but they were completely disintegrated within 10 minutes when they placed in buffered solution at pH6.8. Dissolution test was also conducted by placing tablets in 0.1 N HCl for 2 hours and then 1 hour in phosphate buffer at pH 6.8. Less than 0.9 % of drug was released in the acidic phase and up to 97% in the basic medium. These findings suggest that aqueous enteric coating with AquaPolish E system is an easy and economical approach for preparing stable DFS enteric coat without the use of a subcoating layer.

Flame-retardant Coating of Cotton Fabric via UV curing of DMEP

  • Jang, Jin-Ho;Kim, Young-Min;Jeong, Yong-Kyun;Nam, Young Sik
    • 한국염색가공학회지
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    • 제19권5호
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    • pp.1-7
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    • 2007
  • A new UV-curable coating was carried out to impart the flame-retardant property to cotton fabric using Bis[2-(methacryloyloxy)ehtyl]phosphate(DMEP) and 2-hydroxy-2-methyl-1-phenyl-propan-l-one(HMPP) as a UV-curable monomer and a photoinitiator, respectively. The cotton fabrics were applied with various amounts of DMEP and HMPP via padding and UV irradiation, and the optimal concentrations of DMEP and HMPP in the formulation were 40%(w/w) and 7%omp respectively. A limiteed oxygen index(LOI) up to 28.9 was obtained for the UV-cured fabric, which may occur through a condensed phase mechanism as verified by the increased residue number with increased application level. The characterization of the UV-cured coating was made by IR analysis, thermo-gravimetric analysis, LOI test, and scanning electron microscopy.

산지초지 개량에 관한 연구 III. 종자 Coating에 의한 겉뿌림 초지육성 (Studies on the Improvement of Mountainous Pasture III. Effect of seed coating on oversown pasture)

  • 이인덕
    • 한국초지조사료학회지
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    • 제4권3호
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    • pp.194-200
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    • 1984
  • 종자(種子) coating이 겉뿌린 목초(牧草)의 정착개체수(定着個體數), 초기생육(初期生育) 및 수량(收量)에 미치는 영향을 구명(究明)코저 60% lime, 20% Phosphate 및 20% peatmoss(w/w)의 증량피복재료(增量被覆材料)와 13% arabic gum및 2% methyl cellulose (w/v)를 접착제(接着劑)로 사용(사용)하여 종자(種子)와 피복재료(被覆材料)의 무게 44를 1 : 20(w/w)으로 coating하여 pot, soil box 및 field에서 시험(試驗)한 결과(結果)는 다음과 같다. 1. 종자(種子) coating은 겉뿌린 수준(水準)의 초기(初期) 생육(生育)을 촉진(促進)하였다(Table 2와 3). 2. 종자(種子) coating은 겉뿌린 목초(牧草)의 초기(初期) 정착개체수(定着個體數)를 15%정도 증가시켰고, orchardgrass, perennial ryegrass 및 kentucky bluegrass의 정착개체수(定着個體數)를 증가시킨 반면 대립종(大粒種)의 tall fescue 및 소립종(小粒種)의 ladino clover에는 큰 차이(差異)가 없었다. 3. 종자(種子) coating은 겉뿌린 목초(牧草)의 식생비율(植生比率)을 증가시켰다. 4. 종자(種子) coating은 겉뿌림 초지(草地)의 조성당년(造成當年)의 건물수량(乾物收量)을 17%정도 증가시켰다(P<0.05). 5. 종자(種子) coating시(時) 증량피복물질(增量被覆物質)은 토양(土壤) 및 식물체(植物體)의 화학성분(化學成分)에 영향을 주었다(Table 8). 6. 환경조건이 불량(不良)한 지역(地域)에서의 겉뿌림 초지개량시(草地改良時) 종자(種子) coating은 관행적(慣行的)인 겉뿌림 방법보다 목초(牧草)의 정착개체수(定着個體數), 초기생육(初期生育) 및 수량(收量)을 증가시킬 수 있는 확실한 방법(方法)이라 할 수 있다.率)과의 관계를 주의깊게 고려해야 할 것이다. 생산(生産)할 수 있다고 사료(思料)된다.향이 없었으나 골목 $m^3$당 접종량(接種量) 4.0kg구가 1.63g로 가장 큰 것으로 나타났다.과(結果)를 종합(綜合)해 보면 전호(前胡)의 용도별(用途別) 적정(適正) 재식거리(栽植距離)는 채소형(菜蔬型) $30\times20cm$, 약재형(藥材型) $60\times30cm$, 채소(菜蔬) 약재(藥材) 복합형(複合型) $45\times20cm$에서 지하부(地下部) 생육(生育)이 양호(良好)하면서 생엽(生葉) 및 건근(乾根) 수량(收量)이 증수(增收)되는 경향(傾向)을 보였다.퇴비(堆肥) 등(等) 유기질(有機質) 비료(肥料) 시용(施用)이 효고적(效果的)이었다.DS-PAGE법(法)으로 단백질(蛋白質) 양상을 등숙시기별(等熟時期別)로 조사(調査)한 결과(結果) 두 계통간(系統間) 질적(質的)인 차이(差異)는 보이지 않았으나 시기별(時期別)로는 양적차이(量的差異)를 나타냈다.間)에는 부(負)(-)의 상관(相關)이 있다.($P{\leq}0.01%$). 5. NEL 및 starch value 환경온도(環境溫度)가 상승(上昇)됨에 따라 감소(減少)된다. 4 엽기(葉期) sorghum식물(植物)의 환경온도(環境溫度)를 달리 하였을 때 NEL가치(價値)는 각각(各各) 4.87MJ($30/25^{\circ}C$), 5.46MJ($25/20^{\circ}C$) 및 5.81MJ/kg($18/8^{\circ}C$)로 변(變)하여 고온(高溫)에서 net energy lactation 축적(蓄積)이 크게 감소(減少)되었다.다. 그러나 기온(氣溫)이 낮은 조건(條件)에서는 예취관리(刈取管理)에 따른 비구조성(非構造性) 탄수화물(炭水化物)의 함량변화(含量變化)

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레진접착제를 도포한 상아질에 대한 합착용 시멘트의 전단결합강도 (SHEAR BOND STRENGTH OF LUTING CEMENTS TO DENTIN TREATED WITH RESIN BONDING AGENTS)

  • 김교철;최부병
    • 대한치과보철학회지
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    • 제36권1호
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    • pp.26-49
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    • 1998
  • The purpose of this study was to confirm the formation of hybrid layer and resin tags in dentin tissue and the possibility of bonding between luting cements used for the prosthesis and the resinous surface coated with resin bonding agents to prevent the dentin hypersensitivity after abutment preparation. Some resin bonding agents, which may have the possibility of bonding with polyacrylic acid as a liquid ingredient of polycarboxylate and glass ionomer cements, were selected. All-Blond desensitizer containing NTG-GMA and BPDM, Scotch-Bond Multipurpose plus containing HEMA, and XR-bond containing organophosphate were selected as a coating agent. Dental cements were zinc phosphate, polycarboxylate, and glass ionomer cement. After the exposed dentin surface of premolars was ethced with 10% phosphoric acid and coated with resin bonding agents, the morphology of treated surfaces and the resin tags and hybrid layers on sectioned surfaces were observed by SEM. Shear bond strength between the resin bonding agents and 3 kinds of cements was measured 24 hours after bonding. On the debonded surfaces of the shear bond strength tested specimens, the cement tags and the bonding sites between the resin materials and cements were examined by SEM. Following conclusions were drawn : 1. Coating of dentin with resin bonding agents had no effect on the shear bond strength of zinc phosphate cement. 2. Both of polycarboxylate and glass ionomer cements showed the increased shear bond strength by the dentinal coating with Scotch-Bond Multipurpose plus containing HEMA. However, in the case of dentinal coating with some agents containing NTG-GMA and BPDM or organophosphate, polycarboxylate cement exhibited the lowered shear bond strength, and glass ionomer cement showed the unchanged shear bond strength. 3. Complete obstructions of dentinal tubules were observed on the dentin coated with All-Bond desensitizer or XR-bond, but distinct shape of the orifices of dentinal tubules was observed consistently on the dentin coated with Scotch-Bond Multipurpose plus. 4. The hybrid layer was thickest on the dentin coated with All-Bond desensitizer, and the length of resin tags was longest on the dentin coated with Scotch-Bond Multipurpose plus. 3. On the debonded specimens which had been bonded with polycarboxylate cement or glass ionomer cement after coating with Scotch-Bond Multipurpose plus, the cement tags and the bonding sites between the resinous surface and the cements could be examined.

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3가 크롬황산염의 크로메이트에 의한 아연도금내식성 증대 (Enlargement of Anti-corrosion of Zinc Plating by the Trivalent Chromium Sulfate Conversion Coating)

  • 이철태
    • 공업화학
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    • 제18권3호
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    • pp.296-302
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    • 2007
  • 6가 크롬의 크로메이트 코팅제의 대체를 위한 3가 크롬의 크로메이트 코팅용액의 제조에 관한 것이다. 본 연구에서 제안된 코팅제는 3가 크롬원으로서 $KCr(SO_4)_2$를 35~45 g/L, 인산계 화합물로서 $NaH_2PO_4$를 20~30 g/L을 주성분으로 하고 여기에 금속계 황산화물로서 $CoSO_4$ 10~20 g/L, $ZnSO_4$ 10~20 g/L의 조성으로 구성된 것이다. 이 제안된 3가 크롬 코팅용액을 사용하여 pH 2.0~2.2, 상온에서 담지시간 20~25 s의 조건하에 시안아연도금체에 코팅된 피막은 염수분무시험결과 5% 백청발생까지 120 h 이상 견디는 우수한 내식성을 발현하였다.

Bioactivity of Calcium Phosphate Ceramic Coatings on Metallic Implants

  • Kim, Cheol-Sang;Ducheyne, P.
    • 대한의용생체공학회:의공학회지
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    • 제11권1호
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    • pp.5-12
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    • 1990
  • Calcium phosphate ceramics have been applied intensively to orthopaedic and dental implants by virtue of their osteoconductive nature. In an attempt to enhance the bone implant intergrity and Eta utility, these ceramics are deposited onto the porous surface of metallic implants. The coating procedure and the ensuing phase transformations of the ceramic alter the mechanical properties and surface chemistry of the ceramic layers as well as those of the substrate. These structural and compositional differences are directly related to the interaction mechanisms at the surface-active ceramicbone interface. Material and processing induced influences on dissolution, electrokinetic behavior, ceramic-metallic substrate interface and boRe growth enhancement are presented.

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Hybrid Coextrusion and Lamination Process for Macrochanneled Bioceramic Scaffolds

  • Koh, Young-Hag;Bae, Chang-Jun;Kim, Hyoun-Ee
    • 한국세라믹학회지
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    • 제41권7호
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    • pp.497-502
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    • 2004
  • A hybrid coextrusion and lamination process has been developed to fabricate macrochanneled bioceramic scaffolds. This process was mainly composed of three steps (i.e., coextrusion of thermoplastic compound, lamination, and thermal treatment), forming unique pore channels in dense bioceramic body. Pore channels were formed by removing carbon black material, while calcium phosphate or Tetragonal Zirconia Polycrystals (TZP) with a calcium phosphate coating layer were used as dense body. Two kinds of pore structures were fabricated; that is, the pore channels were formed in uni- or three-directional array. Such macrochanneled bioceramic scaffolds exhibited the precisely controlled pore structure (pore size, porosity, and interconnection), offering excellent mechanical properties and cellular responses.

Effects of phosphating bath compositions on the formation and structure of zinc phosphate conversion coatings on magnesium alloy AZ31

  • Phuong, Nguyen Van;Lee, Kyuhwan;Chang, Doyon;Moon, Sungmo
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2012년도 춘계학술발표회 논문집
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    • pp.322-323
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    • 2012
  • This study discussed the formation of phosphate conversion coatings on AZ31 Mg alloy (AZ31) from the zinc phosphating bath with various concentrations of sodium fluoride (NaF). The effects of NaF on the formation, structure, composition and electrochemical behavior of the phosphate coatings were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD) weight balances, open circuit potential (OCP) transients, potentiodynamic polarization curves and immersion test. The coatings were composed of two layers: an outer $Zn_2(PO_4)_3.4H_2O$ (hopeite) crystal layer and an inner amorphous of $MgZn_2(PO_4)_2$. NaF concentration is emphasized to be highly effective in the formation of the hopeite crystal and etching and coating rates. Potentiodynamic polarization and immersion test showed that the coatings formed in the zinc phosphating bath with addition of NaF have much higher corrosion resistance than bare AZ31.

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Anticorrosive Ability and Mechanism of Hydroxyapatite Pigment

  • Park, J.H.;Lee, G.D.;Nishikata, A.;Tsuru, T.
    • Corrosion Science and Technology
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    • 제4권1호
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    • pp.15-18
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    • 2005
  • Hydroxyapatite(HAp) was synthesized using the waste sludge from semiconductor process and used as an anticorrosive pigment. The water absorption of coating pigmented with anticorrosive pigment and the corrosion at interface between coating and substrate were monitored using AC impedance techniques. The anticorrosive performance of HAp was compared with those of red lead(RL) and zinc potassium chromate(ZPC), which have been known as representative anticorrosive pigments. The amount of absorbed water in ZPC- and HAp- pigmented coatings was much higher compared to that in RL-pigmented and unpigmented film. However, it seems that the water absorbed into HAp- or ZPC-pigmented film is beneficial to anticorrosive function. The anticorrosive performance of HAp is superior or at least comparable to those of ZPC and RL. The excellent anticorrosive properties of HAp can be explained by its passivating ability, caused by the reaction of the soluble component of HAp with Fe to form iron phosphate in the presence of water.