An object is to provide a method for easily producing maleimide (MI) in which trace amounts of residual acid components as impurities in a crude MI are efficiently reduced, that is, the acid value is sufficiently reduced. <1> A method for producing purified MI, comprising reducing an acid value of crude MI by 50% or more, by adding carbodiimide (CDI) to a solution comprising the crude MI to react an acid component in the crude MI with the CDI. <2> The method for producing purified MI, comprising adding 0.5% by mass or more and 8% by mass or less of the CDI with respect to a mass of the crude MI for reaction. <3> The method for producing purified MI, wherein the CDI is N,N-diisopropyl carbodiimide (DIC). <4> The method for producing purified MI, comprising removing a urea derivative of the CDI (CDI-U) by-produced when reacting the acid component in the crude MI with the CDI.

A dehydration catalyst for preparing N-substituted maleimide, which may minimize formation of by-products, is reusable because its activity is not reduced significantly even after being reused several times, and may maintain its reaction activity for a long time, a preparation method thereof, and a method of preparing N-substituted maleimide, are provided.

A dehydration catalyst for preparing N-substituted maleimide, which may minimize formation of by-products, is reusable because its activity is not reduced significantly even after being reused several times, and may maintain its reaction activity for a long time, a preparation method thereof, and a method of preparing N-substituted maleimide, are provided.

Disclosed is a non-destructive universal method of functionalization of graphitic carbonaceous materials that enables their alignment, cross-linking, and effective integration into composite materials.

Disclosed is a non-destructive universal method of functionalization of graphitic carbonaceous materials that enables their alignment, cross-linking, and effective integration into composite materials.

Here are described compounds for use as electrode additives or as salts in electrolyte compositions, and their methods of preparation. Also described are electrochemical cells comprising the compounds as electrode additives or as salts in electrolyte compositions.

Here are described compounds for use as electrode additives or as salts in electrolyte compositions, and their methods of preparation. Also described are electrochemical cells comprising the compounds as electrode additives or as salts in electrolyte compositions.

The present invention relates to a synthesis method of N-substituted maleimides using a non-homogeneous solid acid catalyst, and particularly, a synthesis method of N-substituted maleimides with high synthesis yield by using a zirconium(IV) hydrogen phosphate as a catalyst, by which, the loss of the catalyst is minimized, the separation and recovering processes of the catalyst are simplified, in case when the activity of the separated and recovered catalyst is decreased, the complete regeneration of the catalyst is possible via washing or firing, and solvents that could be used during a washing process of the catalyst are not limited.

Provided are a polymerizable compound having at least one monovalent group (A), a polymerizable composition containing the polymerizable compound, a liquid crystal composite prepared from the polymerizable composition, and a liquid crystal device having the polymerizable composition.

##STR00001##

In monovalent group (A), R.sup.1 and R.sup.2 are independently hydrogen, halogen or alkyl having 1 to 20 carbons, and in the alkyl, at least one piece of CH.sub.2 may be replaced by O or S, and at least one piece of (CH.sub.2).sub.2 may be replaced by CHCH, and in the groups, at least one hydrogen may be replaced by halogen.

Provided are a polymerizable compound having at least one monovalent group (A), a polymerizable composition containing the polymerizable compound, a liquid crystal composite prepared from the polymerizable composition, and a liquid crystal device having the polymerizable composition.

##STR00001##

In monovalent group (A), R.sup.1 and R.sup.2 are independently hydrogen, halogen or alkyl having 1 to 20 carbons, and in the alkyl, at least one piece of CH.sub.2 may be replaced by O or S, and at least one piece of (CH.sub.2).sub.2 may be replaced by CHCH, and in the groups, at least one hydrogen may be replaced by halogen.