• 한국응용과학기술학회지
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• 제10권1호
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• pp.49-55
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• 1993

Ground Calcium Carbonate, among paper coating pigments, will influence less dispersant demand, less binder demand, increase coating solids from 58% to 70%, which means high speed coating, less shrinkage during drying, less energy consumption, more uniform coverage of fibers. The quality point of view of Ground Calcium Carbonate, brightness, particle size, Particle size distribution, hardness, impurities content are important. More important factors of Ground Calcium Carbonate which influence the paper coating process are dispersion mechanisms and their effects. The study was made to investigate the effect of Ground Calcium Carbonate dispersion by sodium salt of polyacrylate dispersant composition and dispersion condition. Basic tests such as physical, optical and chemical were perfumed, and dispersion effects were investigated by different conditions. The results showed that the type of dispersant affected the dispersion effects, and the Ground Calcium Carbonate has critical dispersant demand.

• Elastomers and Composites
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• 제46권3호
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• pp.231-236
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• 2011

본 연구에서는 폴리아크릴레이트/카본나노튜브 복합체를 제조하고 전극재료로서의 응용가능성을 알아보았다. 복합체의 전기전도도는 MWNT의 함량에 따라 증가하였고 시트의 두께가 두꺼워 질수록 증가하였으며 MWNT 50 wt% 함량에서 0.36 ${\Omega}$/sq의 표면저항값이 얻어졌다. 복합체의 열분해온도는 폴리아크릴레이트에 비해 MWNT의 함량에 따라 증가하였으며 50 wt%의 MWNT 복합체 함량에서 $15^{\circ}C$의 증가가 관찰되었다. 복합체의 저장탄성율의 경우도 MWNT의 함량에 따라 증가하였고 특히, 고온에서의 증가가 뚜렷하였다. 폴리아크릴레이트의 열팽창거동은 온도의 증가에 따라 $20^{\circ}C$ 부근부터 수축이 된 반면, 복합체의 경우는 수축되지 않고 약간 팽창하는 경향을 보였다. 복합체의 형태학을 관찰한 결과 폴리아크릴레이트 내에서 MWNT의 분산이 잘 이루어 진 것을 알 수 있었다.

• 한국인쇄학회지
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• 제30권1호
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• pp.35-45
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• 2012

Polyacrylate dispersion(emulsion) as adhesive material was superior in quality such as preservation characteristics and reversibility. The tapes for repairing archival documents manufactured with four different types of formulation resulted in pH 7~8.8, soluble solid 50~52%, and viscosity 1,300~2,500 cps. Sample 4 of those was most excellent. Probably, sample 4 included inorganic materials such as MgO, silica gel, and zeolite. For selecting carrier of tape, tracing papers, were applied for manufacturing tapes and tested for adhesive strength and peel strength. Adhesive strength of tracing papers, was 3.1~3.8(N/10mm), 2.2~2.8(N/10mm), and 1.7-2.3(N/10mm), respectively. Peel strength was similar in all samples. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $105^{\circ}C$ and $80^{\circ}C$ 65% for 7 days.

• 접착 및 계면
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• 제9권1호
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• pp.16-21
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• 2008

이온성작용기를 갖는 수분산 폴리우레탄은 내수성이 약하기 때문에 수분에 노출된 환경에서의 사용이 제한된다. 폴리우레탄과 아크릴 고분자로 구성된 하이브리드 에멀젼을 수분산 폴리우레탄(PUD)을 emulsifier로 사용하고 아크릴 단량체들을 에멀젼 중합하여 제조하였다. 먼저 양이온성 PUD의 합성은 IPDI, PTMG1000, MDEA, AA가 사용되었고, 아크릴 단량체는 MMA와 n-BA를 사용하여 공중합하였다. PUD와 아크릴 단량체들의 중합비율에서 아크릴 단량체의 양이 증가할수록 내수성 및 인장강도가 좋아졌다. 결론적으로 단순 혼합된 에멀젼보다 하이브리드된 에멀젼이 더 우수한 물성을 나타내었다.

• Corrosion Science and Technology
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• 제14권5호
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• pp.213-217
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• 2015

Recently, household electronic industries require environmentally-friendly and highly functional steels in order to enhance the quality of human life. Customers especially require both excellent corrosion and abrasion resistant anti-fingerprint steels for digital TV panels. Thus POSCO has developed new functional electro-galvanized steels, which have double coated layers with organic-inorganic composites on the zinc surface of the steel for usage as the bottom chassis panel of TVs. The inorganic solution for the bottom layer consists of inorganic phosphate, magnesium, and zirconium compounds with a small amount of epoxy binder, and affords both improved adhesion properties by chemical conversion reactions and corrosion resistance due to a self-healing effect. The composite solution for the top layer was prepared by fine dispersion of organic-inorganic ingredients that consist of a urethane modified polyacrylate polymer, hardener, silica sol and a titanium complex inhibitor in aqueous media. Both composite solutions were coated on the steel surface by using a roll coater and then cured through an induction furnace in the electro-galvanizing line. New anti-fingerprint steel was evaluated for quality performance through such procedures as the salt spray test for corrosion resistance, tribological test for abrasion resistance, and conductivity test for surface electric conductance regarding to both types of polymer resin and coating weight of composite solution. New composite coated anti-fingerprint steels afford both better corrosion resistance and abrasion properties compared to conventional anti-fingerprint steel that mainly consists of acrylate polymers. Detailed discussions of both composite solutions and experimental results suggest that urethane modifications of acrylate polymers of composite solutions play a key role in enhanced quality performances.

• Corrosion Science and Technology
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• 제12권1호
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• pp.1-6
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• 2013

Recently Digital TV industry has drastically been moving the illuminating system, which causes an obvious product change from PDP and LCD to LED model to provide high-definition image. Due to strong competition in the digital industry, TV manufacturers make a great efforts to reduce production cost by using low-priced materials such as steels instead of aluminum and plastic etc. In this paper we have developed a new low-priced electrogalvanized steel sheet, which has a black resin composite layer, to substitute conventional high-priced PCM steel and plastic mold for rear cover panel in the digital TV. The black resin composite was prepared by mechanical dispersion of the mixture solution that consists of high solid polyester resin, melamine hardener, black pigment, micronized silica paste, polyacrylate texturing particle and miscellaneous additives. The composite solution was coated on the steel sheet using roll coater followed by induction furnace curing and cooling. Although the coated layer has a half thickness compared to the conventional PCM steels having $23{\mu}m$ thickness, it exhibits excellent quality for the usage of rear cover panel. The new steel sheet was applied to test products to get quality certification from worldwide electronic appliance customers. Detailed discussion provides in this paper including preparation of composite solution, roll coating technology, induction curing technology and quality evaluation from customers.

• 공업화학
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• 제5권3호
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• pp.395-405
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• 1994

Carbon black(이하 CB로 약함) 표면에 존재하는 각종 작용기(-OH, OC,<-COOH)를 n-butyl lithium을 반응활성화제로 활성화시킨 후 아크릴레이트 및 메타크릴레이르 단량체들을 음이온 그라프트 중합하여 CB-그라프트 생성물을 얻었다. 이 CB-그라프트 생성물을 비용매를 이용한 침전법과 원심분리기를 사용하여 호모폴리머를 분리시켜 반응시간과 온도에 따른 그라프트 효율 등을 구한 결과, CB-polyacrylates의 경우 그라프트율이 20~30% 정도로 낮았지만 CB-polymethacrylate의 경우 150~200% 정도의 매우 높은 그라프트율의 CB- grafted polymer를 얻을 수 있었다. 또한, 각 반응온도에서 CB와 단량체들의 음이온 중합은 대체로 1~2시간 정도에서 평형상태를 이루었으며, 온도가 높아짐에 따라 전환율과 그라프트율은 약간의 증가를 보였다. 콜로이드 분산성 시험을 한 결과 열건조 전에는 각 호모폴리머의 양용매 중에서 매우 안정한 분산성을 나타냈으며, 열건조 후에도 CB-polymethacrylate의 경우에는 대부분의 polymethacrylate 양용매에 대해 매우 양호한 안정성을 보였다. CB 표면에서의 그라프트 중합체의 확인은 적외선 스펙트럼에 의해 행하였다. Four-probe 방법에 의한 CB-grafted polymer의 저항값 측정에서는 그라프트율이 높을수록 저항값이 증가함을 알 수 있었다.