Composition containing fluorine-containing polymer, method for producing fluorine-containing polymer, and ultraviolet light-emitting element lens containing fluorine-containing polymer

A method for producing a fluorine-containing polymer (A), comprising

• a polymerization step of polymerizing a fluorine-containing monomer (M) represented by formula (M):
• wherein R1 to R4 each independently represent a fluorine atom, a C1-C5 perfluoroalkyl group, or a C1-C5 perfluoroalkoxy group
• in the presence of the fluorine-containing monomer (M), a polymerization initiator (B), and a solvent (D) to produce a fluorine-containing polymer (A) as a precipitate,
• wherein the fluorine-containing polymer (A) comprises as a main component a structural unit represented by formula (A):
• wherein R1 to R4 are as defined above,
• a value (RA) of a solubility index R, calculated based on the Hansen solubility parameters of the solvent (D) and the Hansen solubility parameters of the fluorine-containing polymer (A), is 4 or more,
• a value (RB) of a solubility index R, calculated based on the Hansen solubility parameters of the solvent (D) and the Hansen solubility parameters of the polymerization initiator (B), is 9 or less when the mass percentage of fluorine atoms in the polymerization initiator (B) is less than 50 mass %, and is 6 or less when the same mass percentage is 50 mass % or more,
• a value (RC) of a solubility index R, calculated based on the Hansen solubility parameters of the solvent (D) and the Hansen solubility parameters of the decomposed product (C) of the polymerization initiator (B), is 9 or less when the mass percentage of fluorine atoms in the decomposed product (C) is less than 50 mass %, and is 6 or less when the same mass percentage is 50 mass % or more, and
• the solubility index R is calculated according to the following equation:
• R
• =
• {
• 4
• ×
• (
• δ
• ⁢
• D
• 1
• -
• δ
• ⁢
• D
• 2
• )
• 2
• +
• (
• δ
• ⁢
• P
• 1
• -
• δ
• ⁢
• P
• 2
• )
• 2
• +
• (
• δ
• ⁢
• H
• 1
• -
• δ
• ⁢
• H
• 2
• )
• 2
• }
• 0
• .
• 5
• wherein δD1, δP1, and δH1 respectively represent a dispersion parameter, a polarity parameter, and a hydrogen bonding parameter in the Hansen solubility parameters of element 1, and δD2, δP2, and δH2 respectively represent a dispersion parameter, a polarity parameter, and a hydrogen bonding parameter in the Hansen solubility parameters of element 2.

A composition comprising a fluorine-containing polymer (A1) produced as a precipitate by polymerizing a fluorine-containing monomer (M1) represented by formula (M1):

• in the presence of the fluorine-containing monomer (M1), a polymerization initiator (B), and a solvent (D),
• wherein the fluorine-containing polymer (A1) comprises as a main component a structural unit represented by formula (A1):
• the fluorine-containing monomer (M1) contains at least one compound selected from the group consisting of
• a compound represented by formula (N1):
• and
• a compound represented by formula (N2):
• in an amount of 0.0001 to 10 mass % based on the mass of a starting monomer;
• a value (RA1) of a solubility index R, calculated based on the Hansen solubility parameters of the solvent (D) and the Hansen solubility parameters of the fluorine-containing polymer (A1), is 4 or more;
• a value (RB) of a solubility index R, calculated based on the Hansen solubility parameters of the solvent (D) and the Hansen solubility parameters of the polymerization initiator (B), is 9 or less when the mass percentage of fluorine atoms in the polymerization initiator (B) is less than 50 mass %, and is 6 or less when the same mass percentage is 50 mass % or more;
• a value (RC) of a solubility index R, calculated based on the Hansen solubility parameters of the solvent (D) and the Hansen solubility parameters of the decomposed product (C) of the polymerization initiator (B), is 9 or less when the mass percentage of fluorine atoms in the decomposed product (C) is less than 50 mass %, and is 6 or less when the same mass percentage is 50 mass % or more;
• and
• the solubility index R is calculated according to the following equation:
• R
• =
• {
• 4
• ×
• (
• δ
• ⁢
• D
• 1
• -
• δ
• ⁢
• D
• 2
• )
• 2
• +
• (
• δ
• ⁢
• P
• 1
• -
• δ
• ⁢
• P
• 2
• )
• 2
• +
• (
• δ
• ⁢
• H
• 1
• -
• δ
• ⁢
• H
• 2
• )
• 2
• }
• 0
• .
• 5
• wherein δD1, δP1, and δH1 respectively represent a dispersion parameter, a polarity parameter, and a hydrogen bonding parameter in the Hansen solubility parameters of element 1, and δD2, δP2, and δH2 respectively represent a dispersion parameter, a polarity parameter, and a hydrogen bonding parameter in the Hansen solubility parameters of element 2.