Mar. 26, 2015  105  US 2015/0086912 Al  [0434]  The concentration of the solute in a reaction solution  is 5% by mass to 70% by mass, and preferably 10% by mass  to 50% by mass. The reaction temperature is usually 10°  C. to  150°  C., preferably 30°  C. to 120°  C., and more preferably 40°  C. to 100°  C.  [0435]  The reaction time is usually 1 hour to 48 hours,  preferably 1 hour to 24 hours, and more preferably 1 hour to  12 hours.  [0436]  After completion of the reaction, the reaction solu› tion is allowed to be cooled to room temperature and purified.  The purification may be performed by normal methods, and  these methods can be applied to the invention. For example, a  liquid-liquid extraction method of applying water washing or  combining it with an appropriate solvent to remove the  residual monomers or oligomer components; a purification  method in a solution state, such as ultrafiltration of extracting  and removing only the polymers having a molecular weight  not more than a specific value; a reprecipitation method of  dropwise adding the reaction solution into a poor solvent to  solidify the resin in the poor solvent, to thereby remove the  residual monomers and the like; and a purification method in  a solid state, such as washing of a resin slurry with a poor  solvent after separation of the slurry by filtration. For  example, the resin is precipitated as a solid by contacting the  reaction solution with a solvent in which the resin is sparingly  soluble or insoluble (poor solvent) in a volumetric amount of  10 times or less, preferably from 10 to 5 times, the reaction  solution.  [0437]  The solvent used at the operation of precipitation or  reprecipitation from the polymer solution (precipitation or  reprecipitation solvent) may be sufficient ifit is a poor solvent  for the polymer, and the solvent which can be used may be  appropriately selected from a hydrocarbon, a halogenated  hydrocarbon, a nitro compound, an ether, a ketone, an ester, a  carbonate, an alcohol, a carboxylic acid, water, and a mixed  solvent containing these solvents, according to the kind of the  polymer. Of these solvents, a solvent containing at least an  alcohol ( especially, methanol or the like) or water is preferred  as the precipitation or reprecipitation solvent.  [0438]  The amount of the precipitation or reprecipitation  solvent used may be properly selected considering the effi› ciency, yield and the like, but the amount used is generally  100 to 10,000 parts by mass per 100 parts by mass of the  polymer solution, preferably 200 to 2,000 parts by mass, and  more preferably from 300 to 1,000 parts by mass.  [0439]  The temperature in precipitation or reprecipitation  may be arbitrarily selected considering the efficiency or oper› ability, but is generally on the order of 0°  C. to 50°  C.,  preferably in the vicinity of room temperature (for example,  approximately 20°  C. to 35°  C.). The precipitation or repre› cipitation operation may be performed using commonly  employed mixing vessel such as stirring tank by a known  method such as a batch system and a continuous system.  [0440]  The precipitated or reprecipitated polymer is usu› ally subjected to commonly employed solid-liquid separation  such as filtration and centrifugation, then dried and used. The  filtration is performed using a solvent resisting filter element  preferably under pressure. The drying is performed under  atmospheric pressure or reduced pressure (preferably under  reduced pressure) at a temperature of approximately 30°  C. to  100°  C., and preferably on the order of30°  C. to 50°  C.  [0441]  Incidentally, after the resin is once precipitated and  separated, the resin may be again dissolved in a solvent and  then brought into contact with a solvent in which the resin is  [0451]  Specific examples of the hydrophobic resins (HR)  are shown below.  [0450]  The content of the hydrophobic resin (HR) in the  composition is preferably 0.01 % by mass to 15% by mass,  more preferably 0.05% by mass to 8% by mass, and still more  preferably 0.1 % by mass to 7% by mass., based on all the  solid content in the composition of the invention.  [0449]  Also, the hydrophobic resin (HR) may be used  alone, or two or more kinds may be used in combination.  [0448]  The standard polystyrene equivalent weight average  molecular weight of the hydrophobic resin (HR) is preferably  1,000 to 100,000, more preferably 1,000 to 50,000, and still  more preferably 2,000 to 15,000.  [0447]  Since the hydrophobic resin (HR) is localized on the  film surface, it is preferred to contain a group having a fluo› rine atom, a group having a silicon atom, or a hydrocarbon  group having 5 or more carbon atoms. These groups may be  contained in the main chain of the resin or may be substituted  on the side chain.  [0446]  Differently from the resin (P) as above, the actinic  ray-sensitive or radiation-sensitive resin composition of the  invention may contain a hydrophobic resin (HR). When expo› sure is performed by filling a liquid having a refractive index  higher than that of air ( e.g., pure water or the like) between a  photosensitive film and a lens, that is, in the case of perform› ing immersion exposure, or in the case of obtaining a negative  pattern by using an organic developer as the developer, the  hydrophobic resin (HR) is preferably used.  [2] Hydrophobic Resin (HR)  [0445]  The addition amount of the resin (P) for use in the  invention is preferably 30% by mass to 100% by mass, more  preferably 50% by mass to 99.95% by mass, and especially  preferably 70% by mass to 99 .90% by mass, on the basis of all  the solid contents of the composition. (In this specification,  mass ratio is equal to weight ratio.)  [0444]  These resins (P) may be used as mixture of two or  more kinds.  [0443]  The polydispersity (Mw/Mn) of the resin (P) is pref› erably 1.0 to 3.0, more preferably 1.0 to 2.5, and still more  preferably 1.0 to 2.0. The weight average molecular weight  and polydispersity of the resin (P) are defined in terms of  polystyrene by the GPC method.  [0442]  The weight average molecular weight of the resin  (P) for use in the invention is preferably 1,000 to 200,000,  more preferably 2,000 to 50,000, and still more preferably  2,000 to 20,000.  sparingly soluble or insoluble. That is, there may be used a  method comprising, after the completion of radical polymer› ization reaction, bringing the polymer into contact with a  solvent in which the resin is sparingly soluble or insoluble, to  precipitate a resin (step a), separating the resin from the  solution (step b), anew dissolving the resin in a solvent to  prepare resin solution A (step c ), bringing the resin solution A  into contact with a solvent in which the resin is sparingly  soluble or insoluble in a volumetric amount of less than 10  times (preferably 5 times or less) the resin solution A, to  precipitate a resin solid (step d), and separating the precipi› tated resin ( step e ). 