Described herein is a perfluoropolymer and compositions therefrom. The perfluoropolymer is derived from: (a) no more than 88 mol % tetrafluoroethylene monomer; and (b) a complementary amount of a perfluoro (cycloaliphatic methyl vinyl ether) monomer, and has substantially no melting point.

A method for producing a hydroxyl group-containing vinyl ether polymer according to the present invention includes: a step of radical polymerizing at least one vinyl ether selected from vinyl ether having a hydroxyl group represented by the following formula (2):

##STR00001##

wherein R.sup.7 represents an alkylene group which is straight-chained, branched or comprises an alicyclic structure, and p is 1, 2, or 3, in the presence of water as a polymerization solvent and an azo compound represented by the following formula (1) as a polymerization initiator:

##STR00002##

wherein R.sup.1 to R.sup.4 each independently represent a hydrogen atom or an alkyl group and R.sup.5 and R.sup.6 each independently represent an alkoxy group optionally having a substituent group or an alkyl amino group optionally having a substituent group.

A method for producing a hydroxyl group-containing vinyl ether polymer according to the present invention includes: a step of radical polymerizing at least one vinyl ether selected from vinyl ether having a hydroxyl group represented by the following formula (2):

##STR00001##

wherein R.sup.7 represents an alkylene group which is straight-chained, branched or comprises an alicyclic structure, and p is 1, 2, or 3, in the presence of water as a polymerization solvent and an azo compound represented by the following formula (1) as a polymerization initiator:

##STR00002##

wherein R.sup.1 to R.sup.4 each independently represent a hydrogen atom or an alkyl group and R.sup.5 and R.sup.6 each independently represent an alkoxy group optionally having a substituent group or an alkyl amino group optionally having a substituent group.

The disclosure provides an aqueous dispersion that can provide a film having excellent weather resistance and excellent hardness and that has excellent dispersion stability. The aqueous dispersion contains a fluorine-containing polymer that contains: a polymerized unit (a) based on a fluorine-containing monomer; a polymerized unit (b) based on a carboxy group-containing monomer; and a polymerized unit (c) based on a hydroxy group-containing monomer. The polymerized unit (b) is contained in an amount of 4.0 to 14.0 mol % of all polymerized units and the polymerized unit (c) is contained in an amount of 14.0 to 35.0 mol % of all polymerized units.

The disclosure provides an aqueous dispersion that can provide a film having excellent weather resistance and excellent hardness and that has excellent dispersion stability. The aqueous dispersion contains a fluorine-containing polymer that contains: a polymerized unit (a) based on a fluorine-containing monomer; a polymerized unit (b) based on a carboxy group-containing monomer; and a polymerized unit (c) based on a hydroxy group-containing monomer. The polymerized unit (b) is contained in an amount of 4.0 to 14.0 mol % of all polymerized units and the polymerized unit (c) is contained in an amount of 14.0 to 35.0 mol % of all polymerized units.

This disclosure concerns a method of providing a hydrophobic coating on a microfluidic chip that promotes the discrete flow of at least one liquid. It includes applying the hydrophobic coating onto an area of the microfluidic chip. The disclosure further includes a microfluidic chip that provides discrete flow of at least one liquid.

This disclosure concerns a method of providing a hydrophobic coating on a microfluidic chip that promotes the discrete flow of at least one liquid. It includes applying the hydrophobic coating onto an area of the microfluidic chip. The disclosure further includes a microfluidic chip that provides discrete flow of at least one liquid.

A film-forming composition according to the present invention includes: a fluororesin having a repeating unit of the formula (1) and a repeating unit of the general formula (2); and a fluorine-containing solvent. ##STR00001##
In the general formula (2), R.sup.1 represents a C.sub.1-C.sub.15 straight, C.sub.3-C.sub.15 branched or C.sub.3-C.sub.15 cyclic hydrocarbon group in which at least one hydrogen atom may be replaced by a fluorine atom or chlorine atom and which may have a hydroxy group. This film-forming composition is suitably usable for the manufacturing of an organic semiconductor element as the composition can form a fluororesin film on an organic semiconductor film; and the formed film has resistance to an etching solvent during the fine pattern processing of the organic semiconductor film by photolithography etc.

A film-forming composition according to the present invention includes: a fluororesin having a repeating unit of the formula (1) and a repeating unit of the general formula (2); and a fluorine-containing solvent. ##STR00001##
In the general formula (2), R.sup.1 represents a C.sub.1-C.sub.15 straight, C.sub.3-C.sub.15 branched or C.sub.3-C.sub.15 cyclic hydrocarbon group in which at least one hydrogen atom may be replaced by a fluorine atom or chlorine atom and which may have a hydroxy group. This film-forming composition is suitably usable for the manufacturing of an organic semiconductor element as the composition can form a fluororesin film on an organic semiconductor film; and the formed film has resistance to an etching solvent during the fine pattern processing of the organic semiconductor film by photolithography etc.

Method for increasing the smoothness of the free surface area of a PFA film, provided on a component by sequentially exposing it to a temperature higher than its melting temperature so as to melt at least the free surface area, lowering the temperature to solidify the melted portion, remelting the free surface area by exposing it to a temperature of at least the PFA melting temperature and again lowering the temperature. The PFA film may be provided on Al.sub.2O.sub.3, Ni or NiF.sub.2 film.