US 2019/0235380 Al  14  Aug. 1, 2019  -continued  [ca-r-10]  [0193]  As the branched aliphatic hydrocarbon group, a  branched alkylene  group  is  preferable,  and specific  examples thereof include alkylalkylene groups, for example,  alkylmethylene groups such as -CH(CH$_{3}$ )-,  --CH  (CH 2 CH$_{3}$)-,  ----C(CH$_{3}$ ) 2 -,  ----C(CH$_{3}$)(CH 2 CH$_{3}$)-,  ----C(CH$_{3}$)(CH 2 CH 2 CH$_{3}$)-, and ----C(CH 2 CH$_{3}$ ) 2 -; alkyl› ethylene groups such as ----CH(CH$_{3}$)CH 2 -,  -CH(CH$_{3}$)CH  (CH$_{3}$ )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH$_{3}$)CH 2 -, and  ----C(CH 2 CH$_{3}$ ) 2 ----CH 2 -; alkyltrimethylene groups such as  ----CH(CH$_{3}$)CH 2 CH 2 - and ----CH 2 CH(CH$_{3}$)CH 2 -; and  alkyltetramethylene  groups  such  as  -CH(CH$_{3}$ )  CH 2 CH 2 CH 2 - and -CH 2 CH(CH$_{3}$)CH 2 CH 2 -. As the  alkyl group in the alkylalkylene group, a linear alkyl group  having  1  to 5 carbon atoms is preferable.  [0186]  Examples of the cyclic aliphatic hydrocarbon  group of R’ 201  include an aliphatic hydrocarbon group con› taining a ring in the structure thereof.  [0185]  Specific examples of the aromatic hydrocarbon  group of R’ 201  include a group (an aryl group such as a  phenyl group, a naphthyl group, or an anthracenyl group)  formed by removing one hydrogen atom from the aromatic  ring; a group (an arylalkyl group such as a benzyl group, a  phenethyl group, a 1-naphthylmethyl group, a 2-naphthyl› methyl group, a 1-naphthylethyl group, or a 2-naphthylethyl  group) in which one hydrogen atom in the aromatic ring has  been substituted with an alkylene group; a group formed by  removing one hydrogen atom from a ring (such as anthra› quinone) in which some hydrogen atoms constituting the  aromatic ring have been substituted with an oxo group and  the like; and a group formed by removing one hydrogen  atom from an aromatic hetero ring (such as 9H-thioxanthene  or 9H-thioxanthen-9-one). The alkylene group (an alkyl  chain in the arylalkyl group) preferably has  1  to  4  carbon  atom, more preferably  1  or 2 carbon atoms, and particularly  preferably  1  carbon atom.  [0192]  As the linear aliphatic hydrocarbon group, a linear  alkylene group is preferable, and specific examples thereof  include a methylene group [-CH 2 -], an ethylene group  [-(CH 2 ) 2 -], a trimethylene group [-(CH 2 )$_{3}$ -],  a tetram› ethylene group [-(CH 2 )$_{4}$ -]  and a pentamethylene group  [-(CH2)s-l- [0191]  The number of carbon atoms in the linear or  branched aliphatic hydrocarbon group which may be bonded  to an alicyclic hydrocarbon group is preferably in a range of  1  to  10,  more preferably in a range of  1  to 6, still more  preferably in a range of  1  to  4,  and most preferably in a range  of  1  to 3.  [0190]  Among these examples, as the cyclic aliphatic  hydrocarbon group of R 1201 , a group formed by removing  one or more hydrogen atoms from a monocycloalkane or a  polycycloalkane is preferable, a group formed by removing  one hydrogen atom from a polycycloalkane is more prefer› able, an adamantyl group or a norbornyl group is particularly  preferable, and an adamantyl group is most preferable.  [0184]  Specific examples of the aromatic ring contained in  the aromatic hydrocarbon group of R 1201  include benzene,  fluorene, naphthalene, anthracene, phenanthrene, biphenyl,  an aromatic hetero ring in which part of the carbon atoms  constituting any of these aromatic rings have been substi› tuted with hetero atoms, and a ring in which some hydrogen  atoms constituting any of these aromatic rings or aromatic  hetero rings have been substituted with an oxo group.  Examples of the hetero atom in the aromatic hetero rings  include an oxygen atom, a sulfur atom, and a nitrogen atom.  [0183]  The aromatic hydrocarbon group of R 1201  is a  hydrocarbon group having an aromatic ring. The number of  carbon atoms in the aromatic hydrocarbon group is prefer› ably in a range of 3 to 30, more preferably in a range of 5  to 30, still more preferably in a range of 5 to 20, particularly  preferably in a range of 6 to 15, and most preferably in a  range of 6 to  10.  Here, the number of carbon atoms thereof  does not include the number of carbon atoms in the sub› stituent.  [0189]  The alicyclic hydrocarbon group may be a poly› cyclic group or a monocyclic group. As the monocyclic  alicyclic hydrocarbon group, a group formed by removing  one or more hydrogen atoms from a monocycloalkane is  preferable. The number of carbon atoms of the monocy› cloalkane is preferably in a range of 3 to 6, and specific  examples of such a monocycloalkane include cyclopentane  and cyclohexane. As the polycyclic alicyclic hydrocarbon  group, a group formed by removing one or more hydrogen  atoms from a polycycloalkane is preferable, and the number  of carbon atoms of the polycycloalkane is preferably in a  range of 7 to 30. Among polycycloalkanes, a polycycloal› kane having a bridged ring polycyclic skeleton, such as  adamantane, norbomane, isobornane, tricyclodecane, or tet› racyclododecane, and a polycycloalkane having a fused ring  polycyclic skeleton, such as a cyclic group having a steroid  skeleton are more preferable.  [0182]  It is preferable that the cyclic group be a cyclic  hydrocarbon group, and the cyclic hydrocarbon group may  be an aromatic hydrocarbon group or an aliphatic hydrocar› bon group. The aliphatic hydrocarbon group indicates a  hydrocarbon group that has no aromaticity. Further, the  aliphatic hydrocarbon group may be saturated or unsatu› rated. In general, it is preferable that the aliphatic hydrocar› bon group be saturated.  [0181]  Cyclic group which may have substituent:  [0180]  In Formulae (ca-r-1) to (ca-r-1O), R 120 1,s each  independently represent a hydrogen atom, a cyclic group  which may have a substituent, a chain alkyl group which  may have a substituent, or a chain alkenyl group which may  have a substituent.  [0188]  The alicyclic hydrocarbon group preferably has 3  to 20 carbon atoms and more preferably 3 to 12 carbon  atoms.  [0187]  Examples of the aliphatic hydrocarbon group con› taining a ring in the structure thereof include an alicyclic  hydrocarbon group ( a group formed by removing one hydro› gen atom from an aliphatic hydrocarbon ring), a group in  which an alicyclic hydrocarbon group is bonded to the  terminal of a linear or branched aliphatic hydrocarbon  group, and a group in which an alicyclic hydrocarbon group  is interposed in a linear or branched aliphatic hydrocarbon  group.  [0179]  [In the formulae, R’ 201 ’s each independently rep› resent a hydrogen atom, a cyclic group which may have a  substituent, a chain alkyl group which may have a substitu› ent, or a chain alkenyl group which may have a substituent.]  0  AR,201 