Fluorinated-containing macroinitiator and production process for the same
Provided is a fluorine-containing macroinitiator, particularly a fluorine-containing macroinitiator that enables production of a fluorine-containing block copolymer containing a non-fluorine vinyl-based monomer having a long side chain. The fluorine-containing macroinitiator includes a polymer represented by the following formula (1) and having a number-average molecular weight of 3,000 to 100,000. In the following formula (1), R 2 , R 3 and R 4 are each a specific group, and Q is a polymer segment composed of a structural unit represented by the following formula (2). In the following formula (2), R 1 is a hydrogen atom or a methyl group, Rf is a fluoroalkyl group having a specific structure, and k is an appropriate integer that is not 0.
1. A fluorine-containing macroinitiator comprising:
a polymer represented by the following formula (1) and having a number-average molecular weight of 3,000 to 100,000,
wherein R 2 is a straight-chain alkyl group of 1 to 18 carbon atoms,
R 3 and R 4 are each independently a hydrogen atom or an alkyl group of 1 to 3 carbon atoms, and any one of R 3 and R 4 may contain one carboxyl group, and
Q is a polymer segment composed of a structural unit represented by the following formula (2):
wherein R 1 is a hydrogen atom or a methyl group,
Rf is a fluoroalkyl group represented by the following formula (3) or a fluoroalkyl group represented by the following formula (4), and
k is an appropriate integer that is not 0,
wherein n is an integer of 1 to 6,
wherein a is an integer of 0 to 3, b is an integer of 1 to 2, n′ is an integer of 1 to 6,
—C n′ F 2n′+1 group is bonded to CH 2 group of —(CF 2 CH 2 ) b — group, and
—(CF 2 CF 2 ) a — group is bonded to CF 2 group of —(CF 2 CH 2 ) b — group.
2. The fluorine-containing macroinitiator as defined in claim 1 , wherein in the formula (2), the Rf is a fluoroalkyl group represented by the formula (4), and a is 1 or 2.
3. The fluorine-containing macroinitiator as defined in claim 1 , wherein in the formula (2), the Rf is a fluoroalkyl group represented by the formula (3), and n is 4 or 6.
4. A production process for the fluorine-containing macroinitiator as defined in claim 1 , comprising:
a step of polymerizing a fluorine-containing (meth)acrylic ester represented by the following formula (6) by the use of an azo-based radical polymerization initiator in the presence of a trithiocarbonic ester compound represented by the following formula (5):
wherein R 2 is a straight-chain alkyl group of 1 to 18 carbon atoms, and
R 3 and R 4 are each independently a hydrogen atom or an alkyl group of 1 to 3 carbon atoms, and any one of R 3 and R 4 may contain one carboxyl group,
wherein R 1 is a hydrogen atom or a methyl group, and
Rf is a fluoroalkyl group represented by the following formula (3) or a fluoroalkyl group represented by the following formula (4),
wherein n is an integer of 1 to 6,
wherein a is an integer of 0 to 3, b is an integer of 1 to 2, n′ is an integer of 1 to 6,
—C n′ F 2n′+1 group is bonded to CH 2 group of —(CF 2 CH 2 ) b — group, and
—(CF 2 CF 2 ) a — group is bonded to CF 2 group of —(CF 2 CH 2 ) b — group.
5. The production process as defined in claim 4 , wherein the polymerization is carried out in one of a borosilicate tempered glass reaction container or a stainless steel reaction container.
6. The production process as defined in claim 4 , wherein in the formula (2), the Rf is a fluoroalkyl group represented by the formula (4), and a is 1 or 2.
7. The production process as defined in claim 4 , wherein in the formula (2), the Rf is a fluoroalkyl group represented by the formula (3), and n is 4 or 6.