12  11  US 9,423,690 B2  aromatic  hydrocarbon-based solvent such as  toluene,  xylene, ethylbenzene, propylbenzene, 1-methylpropylben› zene, 2-methylpropylbenzene, dimethylbenzene, diethyl› benzene, ethylmethylbenzene, trimethylbenzene, ethyldim› ethylbenzene and dipropylbenzene. Among these,  an  aromatic hydrocarbon-based solvent is preferred.  Among these, each R and R’ is preferably an unsubstitued  alkyl group.  The solvent represented by Formula (Sl) is preferably  alkyl acetate, and more preferably butyl acetate, pentyl  acetate or isopentyl acetate.  The solvent represented by Formula (Sl) may be used in  combination with one or more kinds of other organic sol› vents. The combined solvent in this case is not particularly  limited as long as the combined solvent is able to be mixed  without separation from the solvent represented by Formula  (Sl). The solvents represented by Formula (Sl) may be used  in combination with each other, and the solvent represented  by Formula (Sl) may be used in a mixture with a solvent  selected from other ester-based solvents, ketone-based sol› vents, alcohol-based solvents, amide-based solvents, ether› based solvents and hydrocarbon-based solvents. One or  more kinds of the combined solvents may be used, but one  kind of the combined solvent is preferred to obtain a stable  performance. In the case of using a mixture of one or more  kinds of the combined solvents, the mixing ratio of the  solvent represented by Formula (Sl) and the combined  solvent is usually 20:80 to 99:1, preferably 50:50 to 97:3,  more preferably 60:40 to 95:5, and most preferably 60:40 to  90:10 by mass.  A plurality of the solvents may be mixed, or the solvents  may be used in a mixture with a solvent other than those  described above or with water. However, in order to suffi› ciently exhibit the effects of the present invention, the water  content ratio of the entire developer is preferably less than  10% by mass, and it is more preferred that the developer  contains substantially no moisture.  That is, the concentration (the sum in the case of a  multiple mixture) of the organic solvent used in the devel› oper is preferably 50% by mass or more, more preferably  70% by mass or more, and still more preferably 90% by  mass or more. In particular, the developer is preferably a  developer substantially consisting of only an organic sol- vent. In addition, the case of being substantially consisted of  only an organic solvent is the case where the solvent  includes a small amount of surfactants, antioxidants, stabi› lizers, anti-foaming agent, and the like.  Among the solvents, those containing one or more kinds 25  selected from the group consisting of butyl acetate, pentyl  acetate, isopentyl acetate, propylene glycol monomethyl  ether acetate, 2-heptanone and anisole are more preferred.  The organic solvent used as a developer may be prefer› ably an ester based solvent. As the ester based solvent, the  solvents represented by the following Formula (Sl) or the  following Formula (S2) may be preferably used, the solvents  represented by the following Formula (Sl) may be more  preferably used, and alkyl acetate may be particularly pref- erably used, and butyl acetate, pentyl acetate or isopentyl  acetate may be most preferably used.  R’’-----C(=0)---0-R’’’---O-R’’’’  Formula (S2)  In Formula (S2),  R" and R"" each independently represent a hydrogen  atom, an alkyl group, a cycloalkyl group, an alkoxyl group,  an alkoxy carbonyl group, a carboxyl group, a hydroxyl  group, a cyano group or a halogen atom. R" and R"" may be  bond with each other to form a ring.  R" and R"" are preferably a hydrogen atom or an alkyl  group. The alkyl group, the alkoxyl group and the alkoxy› carbonyl group for R" and R"" have preferably 1 to 15  carbon atoms, and the cycloalkyl group has preferably 3 to  15 carbon atoms.  R"’  represents an alkylene group or a cycloalkylene group.  R"’ is preferably alkylene group. The alkylene group for R"’  has preferably 1 to 10 carbon atoms, and the cycloalkylene  group has preferably 3 to 15 carbon atoms.  The alkyl group, the cycloalkyl group, the alkoxyl group  and the alkoxycarbonyl group for R" and R"", the alkylene  group and cycloalkylene group for R"’, and the ring formed  by R" and R"" being bound with each other may be  substituted with a hydroxyl group, a group containing a  carbonyl group (for example, an acyl group, an aldehyde  group, an alkoxycarbonyl, and the like), a cyano group, and  the like.  The alkylene group of R"’ in Formula (S2) may have an  ether bond in the alkylene chain.  Examples of the solvent represented by Formula (S2) may  include propylene glycol monomethyl ether acetate, ethyl› ene glycol monoethyl ether acetate, ethylene glycol mono› propyl ether acetate, ethylene glycol monobutyl ether  acetate, ethylene glycol monophenyl ether acetate, diethyl- ene glycol monomethyl ether acetate, diethylene glycol  monopropyl ether acetate, diethylene glycol monophenyl  ether acetate, diethylene glycol monobutyl ether acetate,  diethylene glycol monoethyl ether acetate, propylene glycol  monoethyl ether acetate, propylene glycol monopropyl ether  acetate, methyl-3-methoxypropionate, ethy 1-3-methoxypro› pionate, ethy 1-3-ethoxypropionate, propy 1-3-methoxypropi› onate,  methoxy  ethyl  acetate,  ethoxy  ethyl  acetate,  2-methoxybutylacetate, 3-methoxybutylacetate, 4-methoxy› butylacetate, 3-methy 1-3-methoxybuty !acetate, 3-ethyl-3- methoxybutylacetate, 2-ethoxybutylacetate, 4-ethoxybuty- Examples of the solvent represented by Formula (S 1) may  include methyl acetate, butyl acetate, ethyl acetate, isopro› pyl acetate, amyl acetate, isoamyl acetate, methyl formate,  ethyl formate, butyl formate, propyl formate, ethyl lactate,  butyl lactate, propyl lactate, ethyl carbonate, propyl carbon› ate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl  pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoac› etate, methyl propionate, ethyl propionate, propyl propi› onate, isopropyl propionate, 2-hydroxy methyl propionate,  2-hydroxy ethyl propionate, and the like.  R and R’ are preferably a hydrogen atom or an alkyl  group. The alkyl group, the cycloalkyl group, the alkoxyl  group and the alkoxycarbonyl group for Rand R’, and the  ring formed by R and R’ being bound with each other may  be substituted with a hydroxyl group, a group containing a  carbonyl group (for example, an acyl group, an aldehyde  group, an alkoxycarbonyl, and the like), a cyano group, and  the like.  The alkyl group, the alkoxyl group and the alkoxycarbo› nyl group for Rand R’ have preferably 1 to 15 carbon atoms,  and the cycloalkyl group has preferably 3 to 15 carbon  atoms.  R and R’ each independently represent a hydrogen atom,  an alkyl group, a cycloalkyl group, an alkoxyl group, an  alkoxy carbonyl group, a carboxyl group, a hydroxyl group,  a cyano group or a halogen atom. Rand R’ may be bond with  each other to form a ring.  In Formula (Sl),  R-----C(=0)---0-R’  Formula (Sl) 