• Elastomers and Composites
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• 제34권2호
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• pp.147-155
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• 1999

고무와 혼합된 왁스는 고무 표면으로 이동하여 방어막을 형성한다. 일반적으로 고무의 오존화를 방지하기 위해 오존노화방지제를 왁스와 함께 사용하고 있다. 다양한 종류의 왁스가 첨가된 천연고무 가류물을 이용하여 왁스막이 오존노화방지제의 이동에 미치는 영향을 연구하였다 오존노화방지제로 IPPD (N-isopropyl-N'-phenyl-p-phenylenediamine), HPPD (N-l,3-dimethylbutyl-N'-phenyl-p-phenylenediamine), SBPPD (N,N'-di(sec-butyl)-p-phenylenediamine), 그리고 DMPPD (N,N'-di(1,4-dimethylpentyl)-p-phenylenediamine)를 사용하였다. 노화방지제 이동 실험은 $60^{\circ}C$ 와 $80^{\circ}C$에서 10, 20, 30일간 실시하였다. 노화방지제의 이동속도는 고무가류물에 왁스가 없을 때가 있을 때보다 빨랐으며 분자량이 큰 왁스가 혼합되었을 때가 분자량이 작은 왁스가 혼합되었을 때보다 느렸다. DMPPD와 SBPPD의 이동속도가 HPPD와 IPPD의 이동속도보다 빨랐다.

• Elastomers and Composites
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• 제35권1호
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• pp.38-45
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• 2000

NR, SBR, BR 둥 3가지 고무로 이루어진 가류물에서 고무 조성비가 노화방지제의 이동 거동에 미치는 영향에 대해 연구하였다. 3가지 고무 중 2가지의 함량은 동일하게 하였고 나머지 하나만 다르게 하였다. IPPD와 HPPD를 오존노화방지제로 사용하였다. 실험은 $60^{\circ}C$에서 21일간 방치하는 것과 옥외에서 4개월간 방치하는 것으로 진행하였다. 노화방지제의 이동 속도는 고무 조성비가 NR/SBR/BR = 1/1/0.2에서 1/1/1로 증가함에 따라 증가하다가 1/1/1에서 최대를 나타내 후 다시 감소하였다. 3가지 고무로 이루어진 가류물에서 고무 조성비에 따른 노화방지제의 이동 거동의 변화는 고무와 노화방지제 간의 친화력, 고무에 대한 노화방지제의 융해도, 그리고 이질 고무간에 형성된 경계면 등으로 설명할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제19권10호
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• pp.1121-1124
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• 1998

• Elastomers and Composites
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• 제34권2호
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• pp.156-176
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• 1999

Rubber chemicals such as accelerators, antidegradants, vulcanizing agents, processing agents and retarders are very important to the production and protection of tires and rubber goods. The use of accelerators and antidegradants are evaluated in various tire components. This paper will focus on how to vulcanize tires economically and maintain the physical properties of each tire component without severe degradation due to oxygen, heat and ozone. Also, new non-nitrosoamine accelerators and non-staining antiozonants will be discussed. Lastly, the future requirements of antidegradants and accelerators in the tire industry will be reviewed. Tires have been vulcanized with Sulfenamides as primary accelerators and either Guamdine's or Thiurams as secondary accelerators to achieve proper properties at service conditions. However, interior components such as the carcass can be vulcanized with Thiazoles as a primary accelerator to cure faster than the external components. Using the combination of Sulfenamide with secondary accelerators in a tire tread compound and the combination of a Thiazole and Guanidine in a carcass compound will be presented with performance data. Uniroyal Chemical and another Rubber Chemical Manufacturer have developed, "Tetrabenzyl Thiuram Disulfide," (TBzTD) as a non-Nitrosoamine accelerator, which could replace Nitrosoamine generating Thiurams. This new accelerator has been evaluated in a tread compound as a secondary accelerator. Also, Flexsys has developed N-t-butyl-2-benzothiazole Sulfenamide (TBSI) as a non-Nitrosoamine accelerator which could replace 2-(Morpholinothio) -benzothiazole (MBS), a scorch delayed Sulfendamide accelerator. TBSI has been evaluated in a Natural Rubber (NR) belt skim compound vs. MBS. An optimum low rolling resistant cure system has been developed in a NR tread with Dithiomorpholine (DTDM). Also, future requirements for developing accelerators will be discussed such as the replacement of DTDM and other stable crosslink systems. Antidegradants are divided into two different types for use in tire compounds. Internal tire compounds such as apex, carcass, liner, wire breaker, cushion, base tread and bead compounds are protected by antioxidants against degradation from oxygen and heat due to mechanical shear. The external components such as sidewall, chafer and cap tread com-pounds are protected from ozone by antiozonants and waxes. Various kinds of staining and non-staining antioxidants have been evaluated in a tire carcass compound. Also, various para-phenylene diamine antiozonants have been evaluated in a tire sidewall compound to achieve the improved lifetime of the tire. New non-staining antiozonants such as 2, 4, 6-tris-(N-1, 4-dimethylpentyl-p-phenylene diamine) 1, 3, 5 Trizine (D-37) and un-saturated Acetal (AFS) will be discussed in the tire sidewall to achieve better appearance. The future requirements of antidegradants will be presented to improve tire performance such as durability, better appearance and longer lasting tires.