Japan Synthetic Rubber Co., Ltd.

Masatoshi Arakawa

Katuhiro Ishikawa

Ryotaro Ohno

Kazuyoshi Nakazawa

Noboru Yamahara

Hisashi Matsui

Akira Iio

Naoki Andoh

Ituo Nishiwaki

Taro Okumura

Haruo Yamanouchi

Teruo Yoshida

Hayao Yoshioka

A process for producing 1,3-butadiene which comprises feeding a fraction comprising C.sub.4 -paraffins and C.sub.4 -olefins as the main components and being free from isobutene, 1,3-butadiene and C.sub.4 -acetylenes to a dehydrogenation or oxidative dehydrogenation step (step A), where the n-butenes contained therein is converted to 1,3-butadiene; feeding the 1,3-butadiene-containing hydrocarbon fraction thus obtained (fraction C) to an extractive distillation column (column B), in which said fraction C is distilled in an atmosphere of a selective solvent while obtaining a fraction comprising C.sub.4 -paraffins as the main hydrocarbon component from the top of the column; withdrawing a fraction comprising n-butenes as the main component as a side stream from a stage on the upper side of the aforementioned fraction C-feeding stage and on the lower side of the selective solvent-feeding stage and recycling it into step A while withdrawing a fraction comprising 1,3-butadiene as the main hydrocarbon component and also containing the selective solvent from the bottom of column B; and separating 1,3-butadiene from the 1,3-butadiene-containing fraction.

Process for producing 1,3-butadiene

In a process for producing butadiene or isoprene having a high purity comprising a step of treating a C.sub.4 or C.sub.5 hydrocarbon mixture containing butadiene or isoprene by an extractive distillation method in the presence of a selective solvent to obtain crude butadiene or crude isoprene and a step of separating a heavy fraction contained in a small quantity in the thus obtained crude butadiene or crude isoprene by a conventional distillation method in a heavy fraction separating tower, the heat energy can be saved to a great extent by thermally coupling the tower for distilling crude butadiene or crude isoprene used in the above-mentioned extractive-distillation step with the above-mentioned heavy fraction separating tower, namely by feeding a part or the whole of the vapor stream from the top of said tower for distilling crude butadiene or isoprene to said heavy fraction separating tower and feeding a liquid at a rate corresponding to the whole or a part of the reflux rate necessary for the operation of the tower for distilling crude butadiene or crude isoprene, from the heavy fraction separating tower to the tower for distilling crude butadiene or crude isoprene.

Process for producing 1,3-butadiene or 2-methyl-1,3-butadiene having

A process for preparing a carboxylic acid ester of a dicyclopentadiene by reacting the dicyclopentadiene with carbon monoxide and an alcohol in the presence of a cobalt compound catalyst, characterized by carrying out said reaction in the presence of 0.5 mole or more of a pyridine base per mole of the dicyclopentadiene at a temperature of 130.degree. C. or less at a carbon monoxide pressure of preferably at least 20 kg/cm.sup.2. G to hydroesterify the double bond in the norbornene ring, thereby forming a mono-carboxylate of a dicyclopentadiene, and hydroesterifying the monoesterification product as produced or the isolated monoester to the same reaction conditions as above except that the temperature is 160.degree. C. or less to hydroesterify the remaining double bond of the monoester, thereby forming a dicarboxylate of dicyclopentadiene.

Process for preparing carboxylic acid esters of dicyclopentadienes

Unsaturated polyester resin compositions

Methacrylic acid is produced from methacrolein by gaseous phase oxidation in a very high selectivity, when methacrolein, molecular oxygen-containing gas and steam in a molar ratio of methacrolein:molecular oxygen:steam of 1:1-3:0-50 are subjected to reaction at a temperature in the range of 250.degree. to 400.degree. C., at a space velocity of 250 to 3,000 hr.sup.-1 (at 0.degree. C. and 1 atm.) with a novel catalyst having the following composition formula in atomic ratio:

Process for producing methacrylic acid

A process for purifying a crude isoprene containing polymerization inhibiting materials such as acetylenes and sulfur compounds to produce high purity or polymerization grade isoprene comprising distilling the crude isoprene in the presence of at least one member selected from saturated hydrocarbons containing 6 to 8 carbon atoms, withdrawing the polymerization inhibiting materials as an overhead fraction and obtaining purified isoprene as a bottom fraction.

Process for purification of isoprene

A novel cyclopentadiene derivative of the general formula: ##STR1## wherein R.sup.1 is hydrogen, a mono- to tetra-hydric alcohol moiety having 1 to 12 carbon atoms, a metal of Groups Ia, IIa and IIb of the Periodic Table, an ammonium group or an organic amine residue; R.sup.2, R.sup.3, and R.sup.4 are independently hydrogen or alkyl groups having 1 to 6 carbon atoms; R.sup.a, R.sup.b, and R.sup.c are independently hydrogen or alkyl groups having 1 to 3 carbon atoms; m is 0 or 1; and n is an integer of 1 to 4. This cyclopentadiene derivative is comparable or even superior to natural rosin in effectiveness as an emulsifier for use in the production of SBR and ABS resins or as a sizing agent in paper making.

Cyclopentadiene derivative

A novel compound represented by the formula, ##STR1## WHEREIN R is a hydrogen or an alkyl group having 1 to 3 carbon atoms, said four R's being the same or different; R.sup.1 is hydrogen, an alkali metal, an ammonium group, a mono-to tetra-hydric aliphatic alcohol moiety having 1 to 12 carbon atoms, or an organic amine residue; n is an integer of 1 to 4; and R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are independently hydrogen or alkyl groups having 1 to 6 carbon atoms or R.sup.2 and R.sup.3 may form a ring when taken together. Said novel compound has properties similar to those of natural rosin or a disproportionated rosin, and is useful as a vehicle for coating compositions and printing inks, as an emulsifier for emulsion polymerization, and as a sizing agent.

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Yokkaichi, Japan

Masatoshi Arakawa