Abstract: A coating composition which contains a fluorinated polymer having a unit (1) represented by —[CX1X2—CY1(Rf1—COOM1)]— and a fluorinated compound represented by CX3X4?CY2(Rf2—COOM2), wherein the content of the fluorinated compound is from 0.1 to 8.0 parts by mass per 100 parts by mass of the fluorinated polymer. X1, X2, X3 and X4 are H, F or Cl, Y1 and Y2 are H, F, Cl, a methyl group or a trifluoromethyl group, Rf1 and Rf2 are a perfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, or an oxyperfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, —COOM1 is —COOH or —COOZ1, and —COOM2 is —COOH or —COOZ2 (wherein Z1 and Z2 are an ammonium ion in which the hydrogen atom may be substituted). The coating composition is suitable for forming a thin antireflection coating layer without increasing its refractive index.

Abstract: To provide a process for producing a fluorinated crosslinked product which is excellent in stability and produces less HF. A process for producing a fluorinated crosslinked product, which comprises irradiating a fluorinated polymer having a unit represented by the following formula (1), with active energy rays having a wavelength of from 150 to 300 nm: wherein X1 and X2 are each independently a hydrogen atom or a fluorine atom, Rf1 is a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms and an etheric oxygen atom between carbon-carbon atoms, Q1 is a single bond or an etheric oxygen atom, and Z1 is OH, OR1 or NR2R3, wherein R1 is an alkyl group, and R2 and R3 are each independently a hydrogen atom or an alkyl group.

Abstract: A coating composition which contains a fluorinated polymer having a unit (1) represented by —[CX1X2—CY1(Rf1—COOM1)]— and a fluorinated compound represented by CX3X4?CY2(Rf2—COOM2), wherein the content of the fluorinated compound is from 0.1 to 8.0 parts by mass per 100 parts by mass of the fluorinated polymer. X1, X2, X3 and X4 are H, F or Cl, Y1 and Y2 are H, F, Cl, a methyl group or a trifluoromethyl group, Rf1 and Rf2 are a perfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, or an oxyperfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, —COOM1 is —COOH or —COOZ1, and —COOM2 is —COOH or —COOZ2 (wherein Z1 and Z2 are an ammonium ion in which the hydrogen atom may be substituted). The coating composition is suitable for forming a thin antireflection coating layer without increasing its refractive index.

Abstract: To provide a process for producing a fluorinated crosslinked product which is excellent in stability and produces less HF. A process for producing a fluorinated crosslinked product, which comprises irradiating a fluorinated polymer having a unit represented by the following formula (1), with active energy rays having a wavelength of from 150 to 300 nm: wherein X1 and X2 are each independently a hydrogen atom or a fluorine atom, Rf1 is a fluoroalkylene group or a fluoroalkylene group having at least two carbon atoms and an etheric oxygen atom between carbon-carbon atoms, Q1 is a single bond or an etheric oxygen atom, and Z1 is OH, OR1 or NR2R3, wherein R1 is an alkyl group, and R2 and R3 are each independently a hydrogen atom or an alkyl group.

Abstract: To provide a coating composition which exhibits excellent followability to a difference in level in its application, and which is capable of forming a coating layer having a low refractive index in a short-wavelength region and exhibiting excellent solubility to an alkaline aqueous solution. A coating composition comprising a solvent and a fluorinated polymer (A) which has a unit represented by —[CX1X2—CY(—Rf—COOM)]— and has a number average molecular weight of from 1,000 to 7,500. X1 and X2 are each independently a hydrogen atom, a fluorine atom or a chlorine atom; Y is a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a trifluoromethyl group; Rf is a branched perfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms, or a branched oxyperfluoroalkylene group which may contain an etheric oxygen atom between carbon-carbon atoms; and M is a hydrogen atom or an ammonium ion which may be substituted.