코발트 보로아실레이트, 코발트 나프테네이트 및 코발트 스테아레이트가 첨가된 고무와 황동이 피복된 스틸코드의 접착성질을 조사하여 접착증진제로서 코발트 염의 기능을 고찰하였다. 고무/황동증착막 접착시편에서 접착층의 구조와 상태를 조사하여, 코발트 염의 첨가 효과를 설명하였다. 코발트 염의 첨가로 가황직후 접착성질은 향상되었으나, 금속 기준으로 첨가량이 0.16phr보다 많아져도 접착성질은 더 이상 향상되지 않았다. 코발트 염 첨가량이 많아지면, 열화처리 후 접착성질은 코발트 염이 첨가되지 않은 고무에 비해 크게 저하되었다. 코발트 염의 음이온에 따라 열화방법에 대한 접착성질 변화 거동이 달랐다. 세 종류의 코발트 염 중에서는 첨가량이 0.16phr로 많지 않을 때 코발트 보로아실레이트 첨가 고무에서, 가황직후뿐 아니라 열, 습윤, 염수열화 후에도 접착성질이 좋았다. 고무/황동증착막 접착시편의 깊이별 성분분포로부터 코발트 염 첨가로 인한 구리황화물 생성 촉진이나, 과량 첨가로 인한 구리황화물의 과도한 성장을 관찰할 수 있었다. 접착성질과 고무/황동증착막 조사 결과로부터 접착증진제로서 코발트 염 기능을 접착계면에서 구리황화물 생성 촉진과 계면 고무의 가교도 향상에 따른 상승 효과로 설명할 수 있었다.

The effect of cobalt salt addition on the adhesion between rubber compound and brass-plated steel cord was studied using cobalt boroacylate, cobalt naphthenate and cobalt stearate to discuss the function of cobalt salt as an adhesion promoter. The composition and state of the adhesion layer at rubber/brass thin-film sample were also investigated. The unaged adhesion properties were improved by addition of cobalt salt, but the further improvement was not observed with increase in the loading of cobalt salt above 0.16 phr as metal. The aged adhesion properties of the rubber compound with high levels of cobalt salt was poor compared with those of cobalt salt-free rubber compound. The decreasing behavior in the adhesion properties with aging treatment varied with the anion species of cobalt salt. The rubber compound with low loading of cobalt boroacylate as 0.16 phr showed the best adhesion properties at unaged state as well as after thermal, humid, and salt solution aging treatments. The acceleration of copper sulfide formation with the addition of cobalt salt and excessive formation of copper sulfide with high levels of cobalt salt were observed from rubber/brass thin-film samples. The promotion role of cobalt salt in the adhesion might be summarized as the synergy effects due to the acceleration of the formation of copper sulfide at the adhesion interface and the enhancement of the crosslinking density of rubber compound attached to the adhesion layer.

Cobalt Salt Adhesion Promoter Rubber Compounds Steel Cord Adhesion Interface Auger Electron Spectroscopy

van Ooij WJ, Rubber Chem. Technol., 52, 605 (1979)
van Ooij WJ, Weening WE, Murray PF, Rubber Chem. Technol., 54, 227 (1981)
van Ooij WJ, Rubber Chem. Technol., 51, 52 (1978)
Haemer G, Mollet J, Rubber Chem. Technol., 51, 371 (1978)
van Ooij WJ, Biemond MEF, Rubber Chem. Technol., 57, 686 (1984)
Barker LR, NR Technol., 12, 77 (1981)
Seo G, Kim MH, Jeon GS, Oh SC, Noh IK, HWAHAK KONGHAK, 28(1), 77 (1990)
Chandra AK, Biswas A, Mukhopadhyay R, Gupta BR, Bhowmick AK, Plast. Rubber Comp. Process. Appl., 22, 249 (1994)
Chandra AK, Biswas A, Mukhopadhyay R, Bhowmick AK, J. Adhes., 44(3), 177 (1994)
Dietrick MI, Emmert DE, Lederer DA, Adhes. Age, Sep., 27 (1977)
Hamed GR, Huang J, Rubber Chem. Technol., 64, 285 (1991)
Tate PER, Rubber World, April, 37 (1985)
Peterson A, Dietrick MI, Rubber World, Aug., 24 (1984)
Dietrick MI, Emmert DE, Lederer DA, J. Elast. Plast., 9, 77 (1977)
Barnhart RR, McKinstry PH, J. Elast. Plast., 10, 216 (1978)
Van Ooij WJ, Kautsch. Gummi Kunstst., 30, 739 (1977)
van Ooij WJ, Kautsch. Gummi Kunstst., 30, 833 (1977)
van Ooij WJ, Kleinhesselink A, Appl. Surf. Sci., 4, 324 (1980) 
Kurbatov GG, Beshenkov VG, Zaporozchenko VI, Surf. Interface Anal., 17, 779 (1991) 
Kurbatov GG, Zaporozchenko VI, Gorayev VM, Beshenkov VG, Gofman AM, Kukharenko YA, Goryaev VM, Mittwoch Sektion B, Summaries of International Rubber Conference '91, Essen, 24-27 June, p. 161 (1990)
Hammer GE, Shemenski RM, Hunt JD, J. Vac. Sci. Technol. A, 12(4), 2388 (1994) 
Coppens W, Chambaere Lievens H, Presented at the Rubbercon'87 Meeting of the Plastics and Rubber Institute, 45A, Harrogate, UK (1987)
Seo G, J. Adhes. Sci. Technol., 11(11), 1433 (1997)
Jeon GS, Sohn BY, Jeon DJ, Cho PL, Seo G, HWAHAK KONGHAK, 34(4), 519 (1996)
Mark JE, Erman B, Eirich FR, "Science and Technology of Rubber," Academic Press, New York (1994)
CocheT P, Butcher D, Bomal Y, Kautsch. Gummi Kunstst., 48(5), 353 (1995)
van Ooij WJ, Rubber Chem. Technol., 57, 421 (1984)