Abstract: The present invention is drawn to a tetracyclododecene composition having a regulated cyclopentadiene trimer content, whereby addition polymerization with the aid of a Ziegler catalyst can be carried out while preventing gelation caused by a cross-linking reaction. A tetracyclododecene composition regulated with respect to the content of a specific ingredient having a molecular weight of 188 is disclosed, whereby polymers having high glass transition temperatures can be obtained through various polymerizations. Further, the present invention is drawn to a method for producing tetracyclododecene in the presence of an aliphatic solvent having a boiling point close to that of norbornene, which solvent is effective in inhibiting the recovered norbornene from solidifying.

Abstract: A method for producing cyclopentadienes which comprises the step of cyclodehydration of an unsaturated carbonyl compound having a specific chemical structure in a vapor phase in the presence of a specific solid acid catalyst. The cyclopentadienes of the invention can be produced in a high yield from inexpensive starting materials through a simplified reaction process and are useful as intermediate compounds for organic synthesis.

Abstract: This invention provides a method of producing highly pure .alpha.-(3-benzoylphenyl)propionic acid derivatives, which are medicines per sec or which can easily afford the same, from readily available 3-ethylbenzophenone in a very simplified manner efficiently and economically. The method comprises dehydrogenating 3-ethylbenzophenone in vapor phase in the presence of an inert gas and carbonylating the formed 3-ethenylbenzophenone in the presence of a carbonylation catalyst comprising a transition metal complex.

Abstract: A method for producing alkylstyrene which is characterized in that 1,2-di(substituted phenyl)ethane is brought into contact with an acid catalyst at 200.degree. C. to 650.degree. C. in the presence of an inert gas to crack it into alkylstyrene and alkylbenzene. The method of the invention has advantages in that the operation of reaction and separation of reaction mixture are quite easy, the lowering of catalytic activity is small, and unreacted starting material can be reused.

Abstract: Novel compounds of 1,2-di(isobutylphenyl)ethane and 1,2-di(isobutylphenyl)ethylene, method for producing the same and method for preparing 4-isobutylstyrene and .alpha.-(4-isobutylphenyl)propionic acid from any of these compounds. In the preparation of 4-isobutylstyrene from the former two compounds by cracking or disproportionation, the components in the resultant reaction mixture can be separated without difficulty, the formation of by-product isobutylbenzene can be avoided, and the remaining unreacted starting material can be reused for the same reaction without causing any adverse effect on a catalyst.

Abstract: The present invention is directed to a water-soluble organic binder suitable for a ceramic molding method in which a ceramic slurry containing water as a dispersion medium is utilized and with this binder, a ceramic sheet can be prepared which has smooth surfaces, contains no flocculating material, and possesses excellent flexibility and mechanical strength.

Abstract: An effective method for producing highly pure (aryl substituted)carboxylic acid or its salt which comprises the steps of:(I) oxidizing (aryl substituted)aldehyde in an acidic phase in the presence of hypohalogenite; and(II) bringing the oxidized product obtained in the preceding step into contact in a liquid phase with hydrogen in the presence of a catalyst of transistion metal of the group VIII in the periodic table.

Abstract: An effective method for refining 2-(aryl substituted)propionic acid or its salt which is characterized in that 2-(aryl substituted)propionic acid or its salt containing halogenated by-products is brought into contact with hydrogen in a liquid phase containing water under a basic condition at temperatures in the range of 20.degree. C. to 170.degree. C. in the presence of a catalyst of transition metal of the group VIII in the periodic table, thereby dehalogenating said halogenated by-product and producing highly pure 2-(aryl substituted)propionic acid or its salt.

Abstract: Provided is a method for preparing diaryl iodonium salts represented by the formula:[Ar.sub.1 --I.sup..sym. --Ar.sub.2 ]HSO.sub.4.sup..crclbar.wherein Ar.sub.1 and Ar.sub.2 respectively are an aryl group which may be substituted with an electron donor group and which may be the same or different which comprises subjecting a compound represented by the formula Ar.sub.1 --H wherein Ar.sub.1 is as defined above and a compound Ar.sub.2 --I wherein Ar.sub.2 is as defined above to a coupling reaction in a sulfuric acid solution containing an oxidizing agent and diluted with a diluting agent to a concentration of 85% by weight or less at a reaction temperature in the range from -20.degree. to +35.degree. C.