Production method for fluoropolymer, surfactant for polymerization, and use of surfactant
A method for producing a fluoropolymer which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a surfactant to provide a fluoropolymer. The surfactant includes at least one selected from the group consisting of a surfactant represented by R 1a —CO—R 2a —CO—R 3a —OSO 3 X a and a surfactant represented by R 1b —CO—(CR 2b 2 ) n —(OR 3b ) p —(CR 4b 2 ) q -L-OSO 3 X b .
1. A method for producing a fluoropolymer comprising
polymerizing a fluoromonomer in an aqueous medium in the presence of a surfactant to provide a fluoropolymer,
the surfactant including at least one selected from the group consisting of:
a surfactant (a) represented by the following formula (a):
wherein
R 1a is a linear or branched alkyl group containing one or more carbon atoms or a cyclic alkyl group containing three or more carbon atoms, with a hydrogen atom that binds to a carbon atom therein being optionally replaced by a hydroxy group or a monovalent organic group that contains an ester bond, optionally contains a carbonyl group when containing two or more carbon atoms, and optionally contains a monovalent or divalent heterocycle or optionally forms a ring when containing three or more carbon atoms;
R 2a and R 1a are each individually a single bond or a divalent linking group;
R 1a , R 2a , and R 3a contain six or more carbon atoms in total;
X a is H, a metal atom, NR 4a 4 , imidazolium optionally containing a substituent, pyridinium optionally containing a substituent, or phosphonium optionally containing a substituent, where R 4a s are each H or an organic group and are the same as or different from each other; and
any two of R 1a , R 2a , and R 3a optionally bind to each other to form a ring; and
a surfactant (b) represented by the following formula (b):
wherein
R 1b is a linear or branched alkyl group containing one or more carbon atoms and optionally containing a substituent or a cyclic alkyl group containing three or more carbon atoms and optionally containing a substituent, and optionally contains a monovalent or divalent heterocycle or optionally forms a ring when containing three or more carbon atoms;
R 2b and R 4b are each individually H or a substituent;
R 3b is a C 1 -C 10 alkylene group optionally containing a substituent;
n is an integer of 1 or greater;
p and q are each individually an integer of 0 or greater;
X b is H, a metal atom, NR 5b 4 , imidazolium optionally containing a substituent, pyridinium optionally containing a substituent, or phosphonium optionally containing a substituent, where R 5b s are each H or an organic group and are the same as or different from each other;
any two of R 1b , R 2b , R 3b , and R 4b optionally bind to each other to form a ring; and
L is a single bond, —CO 2 —B—*, —OCO—B—*, —CONR 6b —B—*, —NR 6b CO—B—*, or —CO— other than the carbonyl groups in —CO 2 —B—, —OCO—B—, —CONR 6b —B—, and —NR 6 CO—B—, where B is a single bond or a C 1 -C 10 alkylene group optionally containing a substituent, R 6b is H or a C 1 -C 4 alkyl group optionally containing a substituent, and * indicates the bond to —OSO 3 X b in the formula.
2. The production method according to claim 1 ,
wherein in the formula (a), R 2a and R 3a are each individually a single bond, a linear or branched alkylene group containing one or more carbon atoms, or a cyclic alkylene group containing three or more carbon atoms, with a hydrogen atom that binds to a carbon atom being optionally replaced by a hydroxy group or a monovalent organic group that contains an ester bond.
3. The production method according to claim 1 ,
wherein in the formula (a), R 1a is a C 1 -C 8 linear or branched alkyl group free from a carbonyl group, a C 3 -C 8 cyclic alkyl group free from a carbonyl group, a C 2 -C 45 linear or branched alkyl group containing 1 to 10 carbonyl groups, a C 3 -C 45 cyclic alkyl group containing a carbonyl group, or a C 3 -C 45 alkyl group containing a monovalent or divalent heterocycle.
4. The production method according to claim 1 ,
wherein in the formula (a), R 1a is a group represented by the following formula:
wherein n 11a is an integer of 0 to 10; R 11a is a C 1 -C 5 linear or branched alkyl group or a C 3 -C 5 cyclic alkyl group; R 12a is a C 0 -C 3 alkylene group; and when n 11a is an integer of 2 to 10, R 12a s are the same as or different from each other.
5. The production method according to claim 1 ,
wherein in the formula (a), R 2a and R 3a are each individually an alkylene group free from a carbonyl group and containing one or more carbon atoms.
6. The production method according to claim 1 ,
wherein in the formula (a), R 2a and R 3a are each individually a C 1 -C 3 alkylene group free from a carbonyl group.
7. The production method according to claim 1 ,
wherein in the formula (b), X b is a metal atom or NR 5b 4 , wherein R 5b is defined as described above.
8. The production method according to claim 1 ,
wherein the surfactant has a 1 H-NMR spectrum in which all peak intensities observed in a chemical shift range of 2.0 to 5.0 ppm give an integral of 10% or higher.
9. The production method according to claim 1 , wherein R 1b is a C 1 -C 3 linear or branched alkyl group free from a substituent.
10. The production method according to claim 1 , wherein R 2b is H or a C 1 -C 3 linear or branched alkyl group free from a substituent.
11. The production method according to claim 1 , wherein R 1b is a C 1 -C 3 linear or branched alkyl group free from a substituent, and
R 2b is H or a C 1 -C 3 linear or branched alkyl group free from a substituent.