group, n-propoxy group, iso-propoxy group, n-butoxy group or tert-butoxy group, and most preferably a methoxy group or an ethoxy group. 

[0337] Examples of the halogen atom as the substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable. 

[0338] Example of the halogenated alkyl group as the sub› stituent for the aromatic hydrocarbon group includes a group in which part or all of the hydrogen atoms within the afore› mentioned alkyl group have been substituted with the afore› mentioned halogen atoms. 

[0339] The aliphatic hydrocarbon group for X may be either a saturated aliphatic hydrocarbon group, or an unsat› urated aliphatic hydrocarbon group. Further, the aliphatic hydrocarbon group may be linear, branched or cyclic. 

[0340] In the aliphatic hydrocarbon group for X, part of the carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent group containing a hetero atom, or part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent group containing a hetero atom. 

[0341] As the "hetero atom" for X, there is no particular limitation as long as it is an atom other than carbon and hydrogen. Examples ofhetero atoms include a halogen atom, an oxygen atom, a sulfur atom and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom and a bromine atom. 

[0342] The substituent group containing a hetero atom may consist of a hetero atom, or may be a group containing a group or atom other than a hetero atom. 

[0343] Specific examples of the substituent group for sub› stituting part of the carbon atoms include ---0-, -C(=O)---0-, ----C(=O)-, ---O-C(=O)---0-, -C(=O)-NH-, -NH- (the H may be replaced with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)$_{2}$- and -S(=O)$_{2}$-O-. When the aliphatic hydrocarbon group is cyclic, the aliphatic hydrocarbon group may contain any of these substituent groups in the ring struc› ture. 

[0344] Examples of the substituent group for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (=0) and a cyano group. 

[0345] The aforementioned alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group or tert-butoxy group, and most pref› erably a methoxy group or an ethoxy group. 

[0346] Examples of the aforementioned halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable. 

[0347] Example of the aforementioned halogenated alkyl group includes a group in which part or all of the hydrogen atoms within an alkyl group of 1 to 5 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group) have been substituted with the aforementioned halogen atoms. 

[0348] As the aliphatic hydrocarbon group, a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic ali› phatic hydrocarbon group ( aliphatic cyclic group) is prefer› able. 

[0349] The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15, and most preferably 1 to 10. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group and a docosyl group. 

[0350] The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbu› tyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpen› tyl group, a 3-methylpentyl group and a 4-methylpentyl group. 

[0351] The unsaturated hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 5, still more preferably 2 to 4, and most preferably 3. Examples oflinear monovalent unsaturated hydrocarbon groups include a vinyl group, a propenyl group (an ally! group) and a butynyl group. Examples of branched monovalent unsaturated hydrocarbon groups include a 1-methylpropenyl group and a 2-methylpro› penyl group. 

[0352] Among the above-mentioned examples, as the unsaturated hydrocarbon group, a propenyl group is particu› larly desirable. 

[0353] The aliphatic cyclic group may be either a monocy› clic group or a polycyclic group. The aliphatic cyclic group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, still more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. 

[0354] As the aliphatic cyclic group, a group in which one or more hydrogen atoms have been removed from a monocy› cloalkane or a polycycloalkane such as a bicycloalkane, tri› cycloalkane or tetracycloalkane can be used. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloal› kane such as adamantane, norbomane, isobornane, tricyclo› decane or tetracyclododecane. 

[0355] When the aliphatic cyclic group does not contain a hetero atom-containing substituent group in the ring structure thereof, the aliphatic cyclic group is preferably a polycyclic group, more preferably a group in which one or more hydro› gen atoms have been removed from a polycycloalkane, and a group in which one or more hydrogen atoms have been removed from adamantane is particularly desirable. 

[0356] When the aliphatic cyclic group contains a hetero atom-containing substituent group in the ring structure thereof, the hetero atom-containing substituent group is pref› erably -0-, ----C(=O)-O-, -S-, -S(=O)$_{2}$ - or -S(=O)$_{2}$---0-. Specific examples of such aliphatic cyclic groups include groups represented by formulas (Ll) to (L5) and (Sl) to (S4) shown below. 

