現(xiàn)行各國的精萘標準中都有酸洗比色指標，對萘中某些雜質(zhì)來說，它是一個很敏感的定性指標；從工藝原理上講，精萘廠家認為其精制不論是采用靜態(tài)或動態(tài)結(jié)晶，都是利用萘與雜質(zhì)的結(jié)晶點不同進行分離，那么殘留在萘中的雜質(zhì)組分也應類似，酸洗比色后的顏色基調(diào)應該比較接近。

The current standards for refined naphthalene in various countries have acid washing colorimetric indicators, which are sensitive qualitative indicators for certain impurities in naphthalene; From the perspective of process principle, the refined naphthalene manufacturer believes that whether it uses static or dynamic crystallization for refining, it is separated by using the different crystallization points of Cai and impurities. Therefore, the remaining impurity components in Cai should also be similar, and the color tone after acid washing and colorimetry should be relatively similar.

國內(nèi)現(xiàn)行采用結(jié)晶法生產(chǎn)精茶的酸洗比色情況顏色不一，紅黃紫灰等五顏六色。萘精制無論是化學法或物理法，硫茚均為主要雜質(zhì)。如果顯色基團是硫茚的話，顏色基調(diào)應該統(tǒng)一，就不會出現(xiàn)紅黃紫灰，說明可能還存在別的顯色基團即其它雜質(zhì)。對精萘中可能存在的某些雜質(zhì)分別做酸洗比色試驗，硫茚為主要顯色基團，酸化后顏色為紫紅色。硫茚含量越高，試樣反應后顏色越深，但硫茚不是唯一的顯色基團。

The current use of crystallization method in the production of refined tea in China varies in color compared to acid washing, with various colors such as red, yellow, purple, and gray. Naphthalene refining, whether through chemical or physical methods, is mainly composed of sulfur indene as an impurity. If the chromogenic group is sulfhydrin, the color tone should be uniform, so that there will be no red, yellow, purple, or gray, indicating that there may be other chromogenic groups or impurities present. Perform acid washing colorimetric tests on certain impurities that may exist in refined naphthalene, with thionines as the main chromogenic group and the color after acidification being purple red. The higher the content of thionines, the darker the color of the sample after reaction, but thionines are not the only chromogenic group.

硫茚比恭容易磺化，在80C下和濃硫酸反應即產(chǎn)生:一元二元二元磺酸混合物。在酸的催化作用下硫茚本身易聚合。

Thiindene is more prone to sulfonation than Gong, and reacts with concentrated sulfuric acid at 80C to produce a binary sulfonic acid mixture. Under the catalysis of acids, thionines themselves are prone to polymerization.

雖然硫茚是精萘中的主要雜質(zhì)和顯色基團，但是影響精萘酸洗比色和使用性能的還有存在于茶中的不飽和化合物，也是顯色基團，主要是甲基茚和甲基氧茚，如二甲基氧茚與濃硫酸作用后生成二元三元四元的聚合體，二甲基茚與濃硫酸作用后聚合成1~50個以上單體連接的聚合體。

Although thioindene is the main impurity and color developing group in refined naphthalene, the unsaturated compound existing in tea also affects the color comparison and use performance of refined naphthalene in acid pickling. It is also a color developing group, mainly methylindene and methyloxyindene. For example, after the reaction of dimethyloxyindene with concentrated sulfuric acid, binary ternary quaternary polymers are generated, and after the reaction of dimethylindene with concentrated sulfuric acid, more than 1~50 monomers are polymerized.

其采用酸洗法精制就是此化學原理。在精恭中由于不飽和化合物的含量低，組份復雜，用常規(guī)檢驗方法直接測定有困難，但是可以通過測定精萘中表示不飽化合物的“碘價”來反應它們含量大小。

The use of acid washing method for refining is based on this chemical principle. Due to the low content of unsaturated compound in refined naphthalene and the complex composition, it is difficult to directly determine them with conventional inspection methods, but their content can be determined by determining the "iodine value" of the unsaturated compounds in refined naphthalene.

萘酚的生產(chǎn)實踐證明，用酸洗法生產(chǎn)的二級精萘(酸洗法比結(jié)晶法一般硫茚含量偏高，但不飽和化合物含量低)，硫茚含量在1.2%~1.5%。

The production practice of naphthol proves that the secondary refined naphthalene produced by acid washing method (the acid washing method is higher than the crystallization method, but the content of unsaturated compound is lower), and the content of thioindene is 1.2%~1.5%.

萘酚生產(chǎn)正常，而用不飽和化合物含量.高(即碘價高)的精萘生產(chǎn)萘酚，會產(chǎn)生樹脂狀物，影響過濾甚至堵塞管道等問題。這說明不飽和化合物對精茶的酸洗比色和使用性能會產(chǎn)生很大的影響。更多相關內(nèi)容就來我們網(wǎng)站http://gaozhifeng.com咨詢吧!

The production of naphthol is normal, but the production of naphthol with refined naphthalene with high unsaturated compound content (i.e. high iodine price) will produce resinous substances, affect filtration and even block pipes. This shows that unsaturated compound will have a great impact on the pickling colorimetry and use performance of refined tea. For more related content, come to our website http://gaozhifeng.com Consult!