Process for selective hydrogenation of styrene-conjugated diene block polymer

Abstract

This invention is selection hydrogenization method of phenylethene-conjugated diene block copolymer. In the hydrogenization, catalyst promoter could be added in the proportion of 1:1- 1:5 with compound like phenyl phthalate. catalyst promoter's structure is as followings: R1 means C1-C3 acroleic acid, R2,R3,R4,R5 represent H or C1-C3 acroleic acid respectively. This invention is advantageous in short hydrogenization time (60 minutes), high product efficiency (>=98%)and high white content.

Description

technical field [0001] The present invention relates to a method for selective hydrogenation of a styrene-conjugated diene block polymer. Background technique [0002] The earliest method used for the selective hydrogenation of styrene-conjugated diene block polymers is iron, cobalt, nickel carboxylates (general formula [R(CO) 2 M]) or the reaction product of an alkoxy compound (such as alcohol, etc.) and an organometallic compound as the main catalyst, organometallic compounds such as lithium, magnesium, aluminum, such as n-, sec-butyllithium, triisobutylaluminum, diisobutyl Hydrogenation reaction such as US3,333,024, US3,431,323 is carried out by using base or diethylaluminum chloride etc. as co-catalyst. [0003] In 1980, Japanese scientist Kishiomot first applied for the application of metallocene catalytic hydrogenation, such as US4,501,857. With the progress of metal-organic chemistry, coordination chemistry and synthesis technology, various metallocene catalysts hav...

AI Technical Summary

Problems solved by technology

USA6,040,390 catalyst system for selective hydrogenation of unsaturated bonds in block copolymers consists of dicyclopentadiene dithienyl (which can be thienyl, 4-methylthienyl, 3-methylthienyl, 2,4 -Dimethylthienyl, 4-ethylthienyl, 3-ethylthienyl, 2,4-diethylthienyl) titanium composition, its structure is shown in (b), wherein: R 1 , R 2 , R 3 It is hydrogen or low-carbon alkane group, which can be the same or different; the catalyst does not need to add a reducing agent, the process reproducibility is good, the catalyst system has a strong ability to resist interference from impurities, and when a small amount of impurities exist, it will not affect the catalytic activity of the catalyst , the reaction condition of this method is that the amount of catalyst is 0.1mmol / 100g活性聚合物 ~2mmol / 100g活性聚合物 , The polymer molecular weight ranges from 500 to 1,000,000, the polymer concentration is 5wt% to 25wt%, the reaction temperature is 50°C to 140°C, and the reaction pressure is 2kgf / cm 2 ~30kgf / cm 2 , The reaction time is several minutes to 100 hours, but the hydrogenation degree of SEBS in this method is difficult to guarantee, and the preparation of the catalyst is complicated

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