BAM (Butyl acrylate monomer) 의 함양에 따른 수계 점착제의 물성 비교

박선희,김진철,박재우,노승만 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

점착제(Pressure sensitive adhesives, PSAs)는 접착제의 한 부분으로, 라벨용 수요 다음으로 디스플레이용 점착제에 관련한 연구가 꾸준히 진행되어 오고 있다. 점탄성적인 거동을 나타내는 점착제는 초기점착력(tack), 접착력(adhesion), 응집력(shear strength)의 성질을 지닌다. 본 연구에서는 초기점착력과 접착력과 관련있는 고분자의 유리전이온도(Tg)를 BAM(Butyl acrylate monomer)와 2-EHA(2-ethyl hexyl acrylate)의 비율 변화로 상관관계를 알아보았다. 상대적으로 유리전이온도가 높은 BA의 함양이 높을수록 합성된 점착제의 유리전이온도가 높았고, 초기점착력과 접착력 또한 증가하는 것을 Ball Tack tester와 UTM을 이용하여 관찰하였다. 합성된 수계점착제의 분산안정성을 Turbiscan을 통해 알아보았고, 실제 여러 온도 조건에서의 사용적합성에 대해서 알아보았다. 본 연구를 통해 얻은 다양한 결과를 토대로 수계점착제의 디스플레이용 보호필름 적용에 대한 가능성을 제안하고자 한다.

궤도조건에 따른 휠레일 점착력 변동과 활주발생의 연구

이남진(Nam-Jin Lee),강철구(Chul-Goo Kang),이원상(Won-Sang Lee) 한국철도학회 2014 한국철도학회 학술발표대회논문집 Vol.2014 No.5

철도차량의 추진/제동시 차륜과 레일 사이에 작용하는 점착력은 차륜의 미끄러짐 여부를 결정짓는 주요한 요소 중 하나이다. 차륜과 레일간의 최대 점착력은 차륜 궤도간 조합, 궤도 오염도, 차량의 상태 등에 따라 결정되며, 한 개의 윤축에 작용한 제동/추진력이 종방향 최대 점착력 보다 크면 해당 차륜에 활주가 발생한다. 활주현상과 궤도조건의 영향 분석을 위해 본 논문에서는 차량 동역학 모델과 제동시스템 모델에 대해 통합 제동시뮬레이션을 수행하여, 다양한 궤도조건에 대해 종방향 점착력과 활주 발생을 검토하고, 궤도조건이 최대 점착력과 활주발생에 미치는 영향을 확인한다. Adhesion force applied in the contact patch between wheel and rail is one of the most important factors that determine wheel slide occurrence during braking or traction. The adhesion force of wheel-rail contact is influenced by a geometrical interface between wheel and rail, contamination of rail surfaces, vehicle status, track conditions, and environmental factors. If the applied brake/traction force is bigger than the allowable maximum adhesion force, the wheelset slides. In this paper, the dynamic model of a railway vehicle and mathematical model of a brake system are built for co-simulations. Through co-simulations with various track conditions, the effects of track conditions on adhesion force and wheel slide occurrence are investigated.

서로 다른 측쇄 종류를 가진 주 단량체에 따른 수성 아크릴계 점착제의 물리적 특성

신혜린,김유리,김경실,박종권 한국응용과학기술학회 2020 한국응용과학기술학회지 Vol.37 No.6

In this study, water-based acrylic adhesives as copolymers with acrylic acid, 2-hydroxyethyl acrylate were synthesized using ethyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate as the main monomers. Prepared water-based acrylic adhesive was compared to physical properties such as solid content, average particle size distribution, initial adhesive force, maximum adhesive force, peel strength, and heat resistance. 본 연구에서는 수성 아크릴계 점착제의 물성에 대한 주 단량체의 측쇄 사슬의 영향을 비교하기 위해 주 단량체로 각각 ethyl acrylate, 2-ethylhexyl acrylate, lauryl methacrylate를 사용하여 acrylic acid, 2-hydroxyethyl acrylate와 공중합체를 합성하여 수성 아크릴 점착제를 제조하였다. 제조한 수성 아크릴 점착제의 고형분, 평균입도분포, 초기점착력, 최대점착력, 박리강도, 내열점착력 등의 물리적 특성을 비교 하였다.

Estimation Study on the Wheel/Rail Adhesion Coefficient of Railway Vehicles Using the Scaled Adhesion Tester

김민수(Min Soo Kim),김경희(Kyung Hee Kim),권석진(Seok Jin Kwon) Korean Society for Precision Engineering 2015 한국정밀공학회지 Vol.32 No.7

Railway vehicles driven by wheels obtain force required for propulsion and braking by adhesive force between wheels and rails, this adhesive force is determined by multiplying adhesion coefficient of the friction surface by the applied axle load. Because the adhesion coefficient has a peak at certain slip velocity, it is important to determine the maximum values of the friction coefficient on the contact area. But this adhesive phenomenon is not clearly examined or analyzed. Thus we have developed new test procedure using the scaled adhesion test-bench for analyzing of the adhesion coefficient between wheel and rail. This adhesion test equipment is an experimental device that contacts mutually with twin disc which are equivalent to wheels and rails of railway vehicles.

리프터의 점착력이 분말 처리된 지문의 품질에 미치는 영향

최고운,황윤정,김채원,유제설 한국콘텐츠학회 2019 한국콘텐츠학회논문지 Vol.19 No.5

The purpose of this study was to observe the influence of adhesive force of lifter on powdered fingermark. First, an experiment was conducted to measure the adhesive force of five kinds of lifters. Second, each fingermark deposited on slide glass was developed using four kinds of powders. Then, these were transferred to lifter, and the quality of the transferred fingermark was observed. As a result of measuring the adhesive force of the lifter using the ASTM D3121-17 rolling ball tack method, the difference in adhesion between the lifters except the gelatin lifter was small. Also, it was confirmed that the quality of the transferred fingermark was not significantly related to the adhesive force of the lifter. However, if the quality of the transferred fingermark is not good when transferring to a gelatin lifter which is a lifter having a weak adhesive force, additional transfer is possible. 본 연구에서는 리프터의 점착력이 분말 처리된 지문에 미치는 영향에 대하여 알아보고자 하였다. 먼저 5종의 리프터의 점착력을 측정하는 실험을 수행하였다. 그런 다음 4종의 분말로 슬라이드 글라스에 유류된 지문을 현출하고 리프터로 전사한 뒤, 전사된 지문의 품질을 측정하였다. ASTM D3121-17 (Rolling ball tack test) 방법을 사용하여 리프터의 점착력을 측정한 결과, 젤라틴 리프터를 제외한 다른 리프터 간의 점착력 차이는 근소하였다. 또한, 전사된 지문의 품질은 리프터의 점착력과 유의한 관계가 없음을 확인하였다. 그러나 약한 점착력을 가진 젤라틴 리프터로 전사할 경우 전사된 지문의 품질이 좋지 않다면 추가적인 전사가 가능하다는 장점이 있다.

철도차량장치의 점착력 추정에 의한 Anti-Slip 제어

김길동,이호용,안태기,홍재성,한석윤,전기영 한국철도학회 2003 한국철도학회논문집 Vol.6 No.4

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.

전사공정을 위한 UV 경화성 범프형 스탬프의 점착특성 평가

정연우(Yeon-Woo Jeong),김경식(Kyung-Shik Kim),이충우(Chung-Woo Lee),이재학(Jae-Hak Lee),김재현(Jae-Hyun Kim),김광섭(Kwang-Seop Kim) 한국트라이볼로지학회 2016 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.32 No.3

Future electronics such as electronic paper and foldable cellphone are required to be flexible and transparent and should have a high performance. In order to fabricate the flexible electronics using flexibility transfer process, techniques for transferring various devices from rigid substrate onto flexible substrate by elastomeric stamp, have been developed. Adhesion between the elastomeric stamp and various devices is crucial for successful transfer process. The adhesion can be controlled by the thickness of the stamp, separation velocity, contact load, and stamp surface treatment. In this study, we fabricated the bump shape stamp consisting of a UVcurable polymer and investigated the effects of curing condition, separation velocity, and contact load on the adhesion characteristics of bumps. The bumps with hemispherical shape were fabricated using a dispensing process, which is one of the ink-jet printing techniques. Curing conditions of the bumps were controlled by the amount of UV irradiation energy. The adhesion characteristics of bumps are evaluated by adhesion test. The results show that the pull-off forces of bumps were increased and decreased as UV irradiation energy increased. For UV irradiation energies of 300 and 500 mJ/㎠, the pull-off forces were increased as the separation velocity increased. The pull-off forces also increased with the increase of contact load. In the case of UV irradiation energy above 600 mJ/cm2, however, the pull-off forces were not changed. Therefore, we believe that the bump shape stamp can be applied to roll-based transfer process and selective transfer process as an elastomeric stamp.

Thermal wetting 현상이 탄소나노튜브-금속박막 계면의응착력에 미치는 영향에 관한 분자 시뮬레이션 연구

이상훈,김현준 한국트라이볼로지학회 2023 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.39 No.1

This study presents a molecular simulation of adhesion control between carbon nanotube (CNT) and Ag thin film deposited on silicon substrate. Rough and flat Ag thin film models were prepared to investigate the effect of surface roughness on adhesion force. Heat treatment was applied to the models to modify the adhesion characteristics of the Ag/CNT interface based on thermal wetting. Simulation results showed that the heat treatment altered the Ag thin film morphology by thermal wetting, causing an increase in contact area of Ag/CNT interface and the adhesion force for both the flat and rough models changed. Despite the increase in contact area, the adhesion force of flat Ag/CNT interface decreased after the heat treatment because of plastic deformation of the Ag thin film. The result suggests that internal stress of the CNT induced by the substrate deformation contributes in reduction of adhesion. Contrarily, heat treatment to the rough model increases adhesion force because of the expanded contact area. The contact area is speculated to be more influential to the adhesion force rather than the internal stress of the CNT on the rough Ag thin film, because the CNT on the rough model contains internal stress regardless of the heat treatment. Therefore, as demonstrated by simulation results, the heat treatment can prevent delamination or wear of CNT coating on a rough metallic substrate by thermal wetting phenomena.

테이프 점착면 상 잠재지문의 현출 전 처리방법

김성윤,전충현 한국과학수사학회 2014 과학수사학회지 Vol.8 No.2

접착 테이프 3종을 대상으로 테이프의 비점착면과 점착면에 잠재지문이 각각 유류되어 있는 경우, 점착면 테이프 분리 방법으로 ① 인위적인 방법, ② 현재의 박리제 사용방법 및 ③ 새로운 방법인 질소 건 사용방법 등 3가지 전처리 방법으로 점착면을 분리하여 잠재지문 현출효율을 각각 확인하였다. 테이프 3종의 비점착면에 3가지 방법을 이용하여 분리한 경우에는 모두 점착면 분리가 가능하였지만, ①인위적인 방법과, ② 현재 사용되고 있는 박리제 전처리 방법에 비교하여, ③ 새로운 방법인 질소 건을사용한 방법이 특징점 수가 약 2배 정도 뛰어난 것으로 확인되었다. 그러나, 점착면에 유류된 잠재지문을 분리 후 현출하는 경우, ② 박리제를 사용한 방법에서는 분리와 지문형태 식별은 가능하지만, ① 인위적인 방법과, ③ 질소 건을 사용한 방법은 테이프 점착면 분리가 불가능하였다.

철도차량장치의 점착력 추정에 의한 Anti-Slip 제어

김길동(Gil-Dong Kim),이호용(Ho-Yong Lee),안태기(Tae-Ki Ahn),홍재성(Jai-Sung Hong),한석윤(Suk-Youn Han),전기영(Kee-Young Jeon) 한국철도학회 2003 철도저널 Vol.6 No.4

In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.