Aug. 1, 2019  4  US 2019/0235380 Al  [0067]  In regard to divalent linking group having hetero  atom:  group (an aryl group or a heteroaryl group) formed by  removing one hydrogen atom from the aromatic hydrocar› bon ring or aromatic hetero ring has been substituted with an  alkylene group. The number of carbon atoms in the alkylene  group which is bonded to the above-described aryl group or  heteroaryl group is preferably in a range of  1  to  4,  more  preferably  1  or 2, and particularly preferably  1  carbon atom.  [0056]  The divalent hydrocarbon group may have a sub› stituent.  [0068]  The hetero atom in the divalent linking group  having a hetero atom is an atom other than a carbon atom  and a hydrogen atom, and examples thereof include an  oxygen atom, a nitrogen atom, a sulfur atom, and a halogen  atom.  [0069]  In the examples of the divalent linking group  having a heteroatom, preferred examples of the linking  group include -0-, ----C(=O)-O-, ----C(=O)-, or  ---0-C(=O)-O-;  -C(=O)-NH-,  -NH-,  -NH-C(=O)-O-, or -NH-C( NH)- (H may be  substituted with a substituent such as an alkyl group, an acyl  group, or the like);-S-, -S(=O) 2 -, -S(=O) 2 ---0-,  and a group represented by Formula -Y 21 -O-Y 22 -,  _y21_O-,  _y21----C(=O)---O-,  -C(=O)-O› y21_, [Y21----C(=O)-Olm"_y22_, or _y21_ O ----C  (=O)-Y 22  - [in the formulae, Y 21  and Y 22  each indepen› dently represent a divalent hydrocarbon group which may  have a substituent, 0 represents an oxygen atom, and m"  represents an integer of Oto 3].  [0057]  The linear or branched aliphatic hydrocarbon  group serving as a divalent hydrocarbon group may or may  not have a substituent. Examples of the substituent include  a fluorine atom, a fluorinated alkyl group having  1  to 5  carbon atoms which has been substituted with a fluorine  atom, and a carbonyl group.  [0058]  The alicyclic hydrocarbon group in an aliphatic  hydrocarbon group having a ring in the structure thereof, as  the divalent hydrocarbon group, may or may not have a  substituent. Examples of the substituent include an alkyl  group, an alkoxy group, a halogen atom, a halogenated alkyl  group, a hydroxyl group, and a carbonyl group.  [0070]  In a case where the divalent linking group contain› ing a hetero atom is -C(=O)-NH-, -NH-, -NH› C(=O)-O-, or -NH----C(  NH)-, H may be substi› tuted with a substituent such as an alkyl group, an acyl  group, or the like. The substituent (an alkyl group, an acyl  group, or the like) preferably has  1  to  10  carbon atoms, more  preferably  1  to 8 carbon atoms, and particularly preferably  1  to 5 carbon atoms.  [0071]  In Formulae -Y 21 ---0-Y 22 _, _y 21 ---0-,  _y21_C(=O)-O-, -C(=)---O-Y21_, -[Y21----C  (=O)-OJm,,_/2-, or _y21---0-C(=O)-Y22_, y21  and Y 22  each independently represent a divalent hydrocar› bon group which may have a substituent. Examples of the  divalent hydrocarbon group include the same groups as  those described above as the "divalent hydrocarbon group  which may have a substituent" in the explanation of the  above-described divalent linking group.  [0072]  As Y 21 , a linear aliphatic hydrocarbon group is  preferable, a linear alkylene group is more preferable, a  linear alkylene group having  1  to 5 carbon atoms is still  more preferable, and a methylene group or an ethylene  group is particularly preferable.  [0059]  As the alkyl group serving as the substituent, an  alkyl group having  1  to 5 carbon atoms is preferable, and a  methyl group, an ethyl group, a propyl group, an n-butyl  group, or a tert-butyl group is most preferable.  [0060]  As the alkoxy group serving as the substituent, an  alkoxy group having  1  to 5 carbon atoms is preferable, a  methoxy group, an ethoxy group, an n-propoxy group, an  iso-propoxy group, an n-butoxy group, or a tert-butoxy  group is preferable, and a methoxy group or an ethoxy group  is most preferable.  [0061]  Examples of the halogen atom serving as the  substituent include a fluorine atom, a chlorine atom, a  bromine atom, and an iodine atom. Among these, a fluorine  atom is preferable.  [0062]  Examples of the halogenated alkyl group serving as  the substituent include a group in which part or all of the  hydrogen atoms in the alkyl group have been substituted  with halogen atoms.  [0063]  In the alicyclic hydrocarbon group, part of the  carbon atoms constituting the ring structure thereof may be  substituted with a substituent containing a hetero atom. As  the  substituent  containing  a  hetero  atom,  ---0-,  -C(=O)---0-, -S-, -S(=O) 2 -, or -S(=O) 2 - O- is preferable.  [0073]  As Y 22 ,  a linear or branched aliphatic hydrocarbon  group is preferable, and a methylene group, an ethylene  group, or an alkylmethylene group is more preferable. The  alkyl group in the alkylmethylene group is preferably a  linear alkyl group having  1  to 5 carbon atoms, more pref› erably a linear alkyl group having  1  to 3 carbon atoms, and  most preferably a methyl group.  [0074]  In the group represented by Formula -[Y 21 ----C  (=O)-OJm,,-Y 22 -, m" represents an integer of Oto 3,  preferably an integer of  O  to 2, more preferably  O or 1,  and  particularly preferably  1.  In other words, it is particularly  preferable that the group represented by Formula -[Y 21 - C(=O)-OJm,,-Y22- be a group represented by Formula  -Y$^{21}$-C(=O)-O-Y 22 -. Among these, a group repre› sented by Formula -(CH 2 )a,----C(=O)---O-(CH 2 )$_{6}$ ,- is  preferable. In the formula, a’ represents an integer of  1  to  10,  preferably an integer of  1  to 8, more preferably an integer of  1  to 5, still more preferably  1  or 2, and most preferably  1.  b’ represents an integer of  1  to  10,  preferably an integer of  1  to 8, more preferably an integer of  1  to 5, still more  preferably  1  or 2, and most preferably  1.  [0064]  In the aromatic hydrocarbon group serving as a  divalent hydrocarbon group, a hydrogen atom in the aro› matic hydrocarbon group may be substituted with a sub› stituent. For example, the hydrogen atom bonded to the  aromatic ring in the aromatic hydrocarbon group may be  substituted with a substituent. Examples of the substituent  include an alkyl group, an alkoxy group, a halogen atom, a  halogenated alkyl group, and a hydroxyl group.  [0065]  As the alkyl group serving as the substituent, an  alkyl group having  1  to 5 carbon atoms is preferable, and a  methyl group, an ethyl group, a propyl group, an n-butyl  group, or a tert-butyl group is most preferable.  [0066]  Examples of the alkoxy group, the halogen atom,  and the halogenated alkyl group serving as the substituents  are the same as those exemplified as the substituents for  substituting a hydrogen atom in the alicyclic hydrocarbon  group. 