2,2′-Dichlorohydrazobenzene(DHB) was prepared in two steps. o-Chloronitrobenzene( OCNB) was at first reduced to 2,2′-dichloroazoxybenzene(DOB) in aqueous medium using 2,3-dichloro-1,4-naphthaquinone(OCNQ) as catalys...2,2′-Dichlorohydrazobenzene(DHB) was prepared in two steps. o-Chloronitrobenzene( OCNB) was at first reduced to 2,2′-dichloroazoxybenzene(DOB) in aqueous medium using 2,3-dichloro-1,4-naphthaquinone(OCNQ) as catalyst with yield of 99.4%, mp 53～56 ℃; DOB was then reduced by formaldehyde to give DHB in aqueous alkaline methanol with yield of 76%, 49% higher than reported, mp 82～83.5 ℃. DHB could be rearranged to 3,3′-dichlorobenzidine in strong acidic medium with yield 91.8%, mp 132～ 134 ℃.展开更多
为提高有机颜料在水中的分散性(D.E.),研究了颜料P.R.254、P.R.255和P.V.19在紫外光照射下的表面改性。经紫外光照射后,颜料在水中的D.E.均得到明显提高,即使经过长时间静置(如24h),其D.E.仍比未处理的样品高。对于P.R.255,D.E.可提高74...为提高有机颜料在水中的分散性(D.E.),研究了颜料P.R.254、P.R.255和P.V.19在紫外光照射下的表面改性。经紫外光照射后,颜料在水中的D.E.均得到明显提高,即使经过长时间静置(如24h),其D.E.仍比未处理的样品高。对于P.R.255,D.E.可提高74.0%;对于P.R.254,D.E.可提高67 4%;对于P.V.19,D E 可提高100.0%。在相同光强度下,对于P.R.255和P.V.19,照射时间越长,颜料的D.E.越好;对于P.R.254,照射时间延长,D.E.下降,但仍比未处理样品高。光强度对颜料D.E.的影响无规律性。还比较了处理后颜料的色光、透明度、墨色及流动性。展开更多
文摘2,2′-Dichlorohydrazobenzene(DHB) was prepared in two steps. o-Chloronitrobenzene( OCNB) was at first reduced to 2,2′-dichloroazoxybenzene(DOB) in aqueous medium using 2,3-dichloro-1,4-naphthaquinone(OCNQ) as catalyst with yield of 99.4%, mp 53～56 ℃; DOB was then reduced by formaldehyde to give DHB in aqueous alkaline methanol with yield of 76%, 49% higher than reported, mp 82～83.5 ℃. DHB could be rearranged to 3,3′-dichlorobenzidine in strong acidic medium with yield 91.8%, mp 132～ 134 ℃.
文摘为提高有机颜料在水中的分散性(D.E.),研究了颜料P.R.254、P.R.255和P.V.19在紫外光照射下的表面改性。经紫外光照射后,颜料在水中的D.E.均得到明显提高,即使经过长时间静置(如24h),其D.E.仍比未处理的样品高。对于P.R.255,D.E.可提高74.0%;对于P.R.254,D.E.可提高67 4%;对于P.V.19,D E 可提高100.0%。在相同光强度下,对于P.R.255和P.V.19,照射时间越长,颜料的D.E.越好;对于P.R.254,照射时间延长,D.E.下降,但仍比未处理样品高。光强度对颜料D.E.的影响无规律性。还比较了处理后颜料的色光、透明度、墨色及流动性。
