315  US 9,323,150 B2  316  Each ofR$_{6}$c and R 7 c represents a hydrogen atom or an alkyl  group. The alkyl group preferably has 1 to 6 carbon atoms.  Each of  Rx  and  RY  independently represents an alkyl group,  a 2-oxoalkyl group, an alkoxycarbonylmethyl group, an ally!  group or a vinyl group. Each of these atomic groups prefer- ably has 1 to 6 carbon atoms.  Any two or more ofR$_{1}$c to R 7 c may be bonded to each other  to thereby form a ring structure.  Rx  and  RY  may be bonded to  each other to thereby form a ring structure. Each of these ring  structures may contain an oxygen atom, a sulfur atom, an  ester bond and/or an amido bond.  x- as a moiety of general formula  (ZI-3)  is as defined  above in connection with general formula  (ZI).  As particular examples of the compounds  (ZI-3),  there can  be mentioned compounds shown as examples in sections  0047 and 0048 of JP-A-2004-233661 and sections 0040 to  0046 of JP-A-2003-35948.  Further, compounds (ZI-4) will be described below.  Compounds (ZI-4) are compounds containing any of cat› ions of general formula (ZI -4) below. The compounds (ZI -4)  are effective in the suppression of outgassing.  In general formula (ZI-4),  each of R 1  to R 13  independently represents a hydrogen  atom or a substituent.  It is preferred for at least one of R  $^{1 }$to  R 13  to be a substituent containing an alcoholic hydroxyl  group. Herein, the term "alcoholic hydroxyl group" means a  hydroxyl group bonded to a carbon atom of an alkyl group.  Z represents a single bond or a bivalent connecting group.  When R 1  to R$^{13 }$are substituents containing an alcoholic  hydroxyl group, it is preferred for R$^{1 }$to R$^{13 }$to represent the  groups of the formula -(W-Y), wherein Y represents a  hydroxyl-substituted alkyl group and W represents a single  bond or a bivalent connecting group.  As preferred examples of the alkyl groups represented by  Y,  there can be mentioned an ethyl group, a propyl group and  an isopropyl group. Most preferably, Y contains the structure  of ----CH$_{2}$CH$_{2}$OH.  The bivalent connecting group represented by W is not  particularly limited. Preferably, Wis a single bond or a biva› lent group as obtained by replacing with a single bond any  hydrogen atom of an alkoxy group, an acyloxy group, an  acylamino group, an alkyl- or arylsulfonylamino group, an  alkylthio group, an alkylsulfonyl group, an acyl group, an  alkoxycarbonyl group or a carbamoyl group. More prefer› ably, W is a single bond, or a bivalent group as obtained by  replacing with a single bond any hydrogen atom of an acyloxy  group, an alkylsulfonyl group, an acyl group or an alkoxycar› bonyl group.  When R $^{1 }$to R $^{13 }$represent substituents containing an alco› holic hydroxyl group, the number of carbon atoms contained  in each of the substituents is preferably in the range of2 to 10,  more preferably 2 to 6 and most preferably 2 to 4.  Each of the substituents containing an alcoholic hydroxyl  group represented by R  1  to R  13  may contain two or more  alcoholic hydroxyl groups. The number of alcoholic hydroxyl  groups contained in each of the substituents containing an  alcoholic hydroxyl group represented by R 1  to R$^{13 }$is in the  range of 1 to 6, preferably 1 to 3 and more preferably 1.  The number of alcoholic hydroxyl groups contained in  each of the compounds of general formula (ZI-4) as the sum  of those of R $^{1 }$to R $^{13 }$is in the range of 1 to 10, preferably 1 to  6 and more preferably 1 to 3.  When R 1  to R 13  do not contain any alcoholic hydroxyl  group, as the substituents represented by R$^{1 }$to R 13 , there can  be mentioned, for example, a halogen atom, an alkyl group, a  cycloalkyl group, an alkenyl group, a cycloalkenyl group, an  alkynyl group, an aryl group, a heterocyclic group, a cyano  group, a nitro group, a carboxyl group, an alkoxy group, an  aryloxy group, a silyloxy group, a heterocyclic oxy group, an  acyloxy group, a carbamoyloxy group, an alkoxycarbony› loxy group, an aryloxycarbonyloxy group, an amino group  (including an anilino group), an ammonia group, an acy- lamino group, an aminocarbonylamino group, an alkoxycar› bonylamino group, an aryloxycarbonylamino group, a sulfa› moylamino group, an alkyl- or arylsulfonylamino group, a  mercapto group, an alkylthio group, an arylthio group, a  heterocyclic thio group, a sulfamoyl group, a sulfa group, an  alkyl- or arylsulfinyl group, an alkyl- or arylsulfonyl group,  an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl  group, a carbamoyl group, an aryl- or heterocyclic azo group,  an imido group, a phosphino group, a phosphinyl group, a  phosphinyloxy  group,  a  phosphinylamino  group,  a  phosphono group, a silyl group, a hydrazino group, a ureido  group, a boronic acid group (-B(OH)$_{2}$ ),  a phosphato group  (-OPO(OH)$_{2}$), a sulfato group (---OSO$_{3}$H) and any of other  substituents known in the art.  When R 1  to R 13  do not contain any alcoholic hydroxyl  group, each of R 1  to R$^{13 }$preferably represents a hydrogen  atom, a halogen atom, an alkyl group, a cycloalkyl group, an  alkenyl group, a cycloalkenyl group, analkynyl group, an aryl  group, a cyano group, a carboxyl group, an alkoxy group, an  aryloxy group, an acyloxy group, a carbamoyloxy group, an  acylamino group, an aminocarbonylamino group, an alkoxy› carbonylamino group, anaryloxycarbonylamino group, a sul- famoylamino group, an alkyl-or arylsulfonylamino group, an  alkylthio group, an arylthio group, a sulfamoyl group, an  alkyl- or arylsulfonyl group, an aryloxycarbonyl group, an  alkoxycarbonyl group, a carbamoyl group, an imido group, a  silyl group or a ureido group.  When R 1  to R 13  do not contain any alcoholic hydroxyl  group, each ofR$^{1 }$to R$^{13 }$more preferably represents a hydro› gen atom, a halogen atom, an alkyl group, a cycloalkyl group,  a cyano group, an alkoxy group, an acyloxy group, an acy- !amino group, an aminocarbonylamino group, an alkoxycar› bonylamino group, an alkyl- or arylsulfonylamino group, an  alkylthio group, a sulfamoyl group, an alkyl- or arylsulfonyl  group, an alkoxycarbonyl group or a carbamoyl group.  When R 1  to R 13  do not contain any alcoholic hydroxyl  group, each ofR $^{1 }$to R$^{13 }$most preferably represents a hydro› gen atom, an alkyl group, a cycloalkyl group, a halogen atom  or an alkoxy group.  R10 