A monomer having formula (I):

##STR00001##

wherein in formula (I), groups and variables are the same as described in the specification.

A method for producing a fluorosulfonyl group-containing compound to obtain a compound represented by the following formula 5 from a compound represented by the following formula 1 as a starting material and a method for producing a fluorosulfonyl group-containing monomer in which the fluorosulfonyl group-containing compound is used:

##STR00001##

wherein R.sup.1 and R.sup.2 are a C.sub.1-3 alkylene group, and R.sup.F1 and R.sup.F2 are a C.sub.1-3 perfluoroalkylene group.

A fluorosulfonyl group-containing polymer having units represented by the following formula u1, a sulfonic acid group-containing polymer having fluorosulfonyl groups in the fluorosulfonyl group-containing polymer converted into sulfonic acid groups, its production method and its applications:

##STR00001##

wherein R.sup.F1 and R.sup.F2 are a C.sub.1-3 perfluoroalkylene group.

Described herein is a millable fluorinated block copolymer having at least one A block and at least one B block, wherein the A block is a semi-crystalline segment comprising repeating divalent monomeric units derived from TFE, HFP and VDF; and the B block is a segment comprising repeating dilvalent monomeric units derived from HFP and VDF; and wherein the millable fluorinated block copolymer has a modulus of 0.1 to 2.5 MPa at 100 C.

Described herein is a millable fluorinated block copolymer having at least one A block and at least one B block, wherein the A block is a semi-crystalline segment comprising repeating divalent monomeric units derived from TFE, HFP and VDF; and the B block is a segment comprising repeating dilvalent monomeric units derived from HFP and VDF; and wherein the millable fluorinated block copolymer has a modulus of 0.1 to 2.5 MPa at 100 C.

The present invention relates to a heating plate for an electric hair iron and a method for manufacturing the same. More specifically, the present invention relates to a heating plate for an electric hair iron having a soft synthetic resin inserted therein, wherein an aluminum heating plate having a plurality of grooves formed in a longitudinal direction on the front surface is ejected and the soft synthetic resin is inserted into the front surface and both sides of the aluminum heating plate which is in a state of being inserted into a mold such that part of the soft synthetic resin is insertedly integrated into the grooves. The soft synthetic resin is injected from the rear of the aluminum heating plate to the front surface thereof when injecting the soft synthetic resin such that a uniformly even soft synthetic resin layer is formed without generation of bubbles on the front surface by injecting. Accordingly, a hollow through-hole is formed between the grooves of the aluminum heating plate such that heat is uniformly transferred, and a ceramic coating layer is formed inside the groove such that heat is evenly transferred across the soft synthetic resin layer.

The present invention relates to a heating plate for an electric hair iron and a method for manufacturing the same. More specifically, the present invention relates to a heating plate for an electric hair iron having a soft synthetic resin inserted therein, wherein an aluminum heating plate having a plurality of grooves formed in a longitudinal direction on the front surface is ejected and the soft synthetic resin is inserted into the front surface and both sides of the aluminum heating plate which is in a state of being inserted into a mold such that part of the soft synthetic resin is insertedly integrated into the grooves. The soft synthetic resin is injected from the rear of the aluminum heating plate to the front surface thereof when injecting the soft synthetic resin such that a uniformly even soft synthetic resin layer is formed without generation of bubbles on the front surface by injecting. Accordingly, a hollow through-hole is formed between the grooves of the aluminum heating plate such that heat is uniformly transferred, and a ceramic coating layer is formed inside the groove such that heat is evenly transferred across the soft synthetic resin layer.

A fluoropolymer of a monomer (I) represented by the general formula (I), wherein a content of a polymerization unit (I) derived from the monomer (I) is 50% by mass or more based on all polymerization units constituting the fluoropolymer:

CX.sub.2?CXORfSO.sub.3MGeneral formula (I)

wherein X is independently F or CF.sub.3; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and having an ether bond or a keto group; and M is H, a metal atom, NR.sup.7.sub.4, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent, wherein R.sup.7 is H or an organic group. Also disclosed are an aqueous solution and coating composition containing the fluoropolymer.

A fluoropolymer of a monomer (I) represented by the general formula (I), wherein a content of a polymerization unit (I) derived from the monomer (I) is 50% by mass or more based on all polymerization units constituting the fluoropolymer:

CX.sub.2?CXORfSO.sub.3MGeneral formula (I)

wherein X is independently F or CF.sub.3; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and having an ether bond or a keto group; and M is H, a metal atom, NR.sup.7.sub.4, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent, wherein R.sup.7 is H or an organic group. Also disclosed are an aqueous solution and coating composition containing the fluoropolymer.

A process for producing a liquid composition, which includes holding a fluorinated polymer having SO.sub.2F groups at from 140 to 160 C. for at least 45 minutes, cooling it to less than 110 C. at a rate of at least 50 C./min, converting the SO.sub.2F groups in the fluorinated polymer to ion exchange groups to obtain a fluorinated polymer having ion exchange groups, and mixing the fluorinated polymer having ion exchange groups and a liquid medium.