• Transactions on Electrical and Electronic Materials
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• v.18 no.4
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• pp.203-206
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• 2017

The effect of the content of microsilica and nanosilica continuously modified with hydroxy silane and epoxy-modified silicone in cycloaliphatic epoxy/microsilica/nanosilica composites (EMNCs) on the mechanical and water repellent properties was evaluated. Surface-modified micro- and nanosilica was well-mixed with a cycloaliphatic epoxy resin in the presence of polyester-modified polydimethylsiloxane (PEM-PDMS) as a dispersing agent using an ultrasonicator. Tensile and flexural tests were carried out using a universal testing machine (UTM). The water repellent property was evaluated by contact angle measurements of water on the composite surface. Tensile strength of the composite could be enhanced by 32.2% up to 91.4 MPa, and the flexural strength was raised to 122.0 MPa, which is 38.8% higher than that of neat epoxy. The contact angle of water on the composite was as high as $104.1^{\circ}$.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.6
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• pp.590-596
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• 2002

The resin : metal interface is at the basis of most bonding failures in resin-bonded prosthesis. Although debonding has been a problem with adhesive fixed partial dentures, various dentists classify them as long-term restorations. The advantages of resin-bonded fixed partial dentures include minimal tooth reduction and the possibility of rebonding. if resin-bonded protheses can be easily rebounded, it is of clinical importance to know if the lutingagents rebond as well the second time as they did originally. Several retentive systems for resin-to-metal bonding have recommended. Treatments such as electrolytic etching and silicone coating, despite the good result of bond strength, have proved to be time-consuming and technique-sensitive. Therefore a simple and more reliable method is desirable. This study evaluated the effect of metal surface treatments on the rebond strength of panavia 21 cement to a nickel-chromium(Ni-Cr) alloy. The samples were received the following surface treatments : Group No.1 (control or served as the control) treatment with sandblasting with 50um aluminum oxide and ultrasonically cleaned for 10minutes in double-deionized water, Group No.2 were no surface treatments. Group No.3 were treated with metal primer. Group No.4 were treated with sandblasting as previously described, and then metal priming. From the analysis of the results, the following conclusions were drawn. 1. Sandblasting and metal priming appears to be an effective method for treatment of metal after accidental debonding. 2. Group without surface treatment had significantly lower bond strengths compared with other groups. 3. The combination of sandblasting and metal priming may not develop superior bonding strengths compared with other techniques that used the Ni-Cr alloys. 4. Combination of cohesive and adhesive failures were the most common type observed. The results support the use of sandblasting as a viable procedure when rebonding accidentally lost adhesive partial denture. We concluded that sandblasting and metal priming of metal surface before bonding could provide the adequate bond strength during rebonding of resin-bonded fixed partial denture.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.851-856
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• 2017

The mechanical properties of coating resin on stainless steel were measured by SEM, FT-IR spectra, tensile properties, mole ％ of [NCO/OH], and particle size analyzer. Growing concerns in the environment-friendly coating resin, we have synthesized the solvent-free coating resin to be coating on metals such as stainless steel. The properties of the synthesized coating resin to be contained polyols, MDI, silicone surfactant, fillers and vegetable oil(castor oil), that they have highly stronger in intensity and longer durability than general coating resin of polyurethane resin on stainless steel. The rigid segments of polyurethane in mechanical properties of coatings were due to unsaturated vegetable oil and the increase mole % of [NCO/OH]. In conclusion, the coating microstructure with castor oil can be good material for coatings of anticorrosion of metal substrates such as stainless steel.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.3 s.151
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• pp.481-486
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• 2006

There are attempts to utilize Hanji for apparel material, but, the reason that the strength and durability of Hanji decrease to a great extent in the wet condition, restricts the usability of Hanji. In order to improve the resistance against water, Hanji was treated with silicone type water repellent agents. The treatment was carried out by conventional pad-dry-cure method. The optimum treatment condition was obtained by varying the concentration of repellent agent, curing temperature and time. Water repellency was tested by spray rating method. Wet and dry tensile strength, tearing resistance and abrasion resistance were examined after the treatment. Flexural stiffness and wrinkle recovery angles of hanji were also measured. In result, the optimum condition of treatment was at resin concentration of 40g/l, catalyst concentration of 20g/l(half of resin concentration), curing temperature of 160$^{circ}C$, curing time of 120 sec. Flexural stiffness of Hanji was hardly increased and wrinkle recovery angle of Hanji was improved a little by resin treatment. After the treatment, in dry condition, tensile strength and tearing resistance were little changed but abrasion resistance was improved. In wet condition, tensile strength, tearing strength and abrasion resistance were improved.

• Transactions on Electrical and Electronic Materials
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• v.2 no.4
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• pp.19-23
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• 2001

In this paper, design considerations and manufacturing procedure of 200 class insulation system with polyimide(Kapton) main insulation and silicone resin VPI process on the traction motor thor EMU will be reviewed. The performance test and the long life evaluation test that prove stability and reliability of Insulation system for traction motor will also be introduced.

• Textile Coloration and Finishing
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• v.1 no.1
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• pp.35-46
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• 1989

Experiments described in which cotton fabrics at different stages of chemical processing were abraded to different extents on a Stoll Abrasion Tester with three different abradants, namely, a worsted fabric, flax fabric and silicon carbide paper. The four different plain-weave cotton fabrics selected were 1) desized, 2) scoured and bleached, 3) mercerized, 4) resin-treated. The surface abrasive damages of treated fabrics were observed by SAM, and load-elongation percent retentions of abraded samples were measured by Instrong Tester. The result were as follows: 1. The maximum percent retention of load-elongation with three different abradants was exhibited by the scoured and bleached fabrics and the minimum by the resin finished fabric. 2. The electron micrographs of four different cotton fabrics abraded by flax, worsted fabric abradants for 900 rubs showed a large number of criss-crossing stray fibers in fabric structure. It may be the molecular adhesion for frictional resistance to be explained. 3. The electron micrographs of four different cotton fabrics abraded by silicone carbide abradants showed the form of busing or mashing fibers in fabric structure. The above might be on the basis of the ploughing theory.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.639-642
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• 2002

A new PDP barrier rib formation technique was investigated utilizing transparent soft maid made of silicon resin. Transparent soft mold was fabricated by pouring a silicone resin into the base mold made with photosensitive glass. The photosensitive barrier rib paste was coated on the glass substrate and dried in a 90 $^{\circ}C$ convection oven for 20min. The transparent soft mold was pressed on top of the semi-dry barrier rib layer and then irradiated with a UV lamp to a total dose of $900{\sim}1000mJ/cm^2$ The soft maid was then removed from the pressed barrier rib by winding up and fine pattern of barrier rib was obtained. The photosensitive barrier rib paste makes the demolding easy due to reduced interfacial forces and shrinking of paste materials.

• Electrical & Electronic Materials
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• v.7 no.1
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• pp.64-72
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• 1994

본 고는 현재 전기적 응용을 위한 수지 절연물의 진공/가압 수지-주형처리 분야에서 가장 앞선 기술과 연구개발력을 보유하고 있는 스위스의 Ciba-Geigy사와 최신의 진공성형 시스템을 개발, 생산하고 있는 독일의 Hedrich사 및 진공주형/자동가압 성형장비를 생산하는 스위스의 Vogel사 등을 최근에 방문하여 Epoxy, Polyurethane, Polyester 및 Silicone 수지 등의 수지절연시스템을 가지고 구조적으로 기포가 없으며 전기적, 기계적, 열적특성이 매우 우수하고 매끄러운 표면이 요구되는 수지 mold제품을 생산하는데 적용되고 있는 진공 수지-주형처리기술의 현황과 아울러 경화시간을 크게 단축시켜 생산자동화가 가능한 최신의 자동가압겔화(Automatic pressure gelation)/주입몰드공정(Injection molding process)의 특징 및 기술개발현황에 대해 파악한 내용을 소개하고자 한다.

• 보존과학연구
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• s.17
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• pp.39-47
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• 1996

In this research, many effects were examined by testing of adhesive intensity and accelerated weathering with synthetic resins for the conservation treatment of cracks and damaged parts of Kyound Chun-Sa10-story Pagodas, the National Treasure No. 86.It was tested with two kinds of Epoxy resins, Acrylic, Silicone resin, and five kinds of Acetics vinyl resins, and then which was ensured a successful result with Epoxy resins. According to these consequences, they are determined to treat damaged parts with Epoxy resin.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.475-478
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• 1999

The thermal properties of epoxy resin/siloxane for the electrical insulation were investigated by using dynamic DSC run method. As the heating rate increased, the peak temperature on dynamic DSC curve increased. From the linear relation on the Kissinger plot the curing reaction activation energy and pre-exponential factor could be obtained. The curing activation energy from the straight line of the Kissinger plot was 46.72 kJ/mol.