The present invention relates to a fluororesin including a residue unit represented by a following general formula (1) and having a haze value equal to or less than 2% of a heat-press molded product (thickness 1 mm) with a small haze value of a melt-molded product and a method for producing the same.

##STR00001##

In the formula (1), Rf.sub.1, Rf.sub.2, Rf.sub.3 and Rf.sub.4 each independently represent one of the groups consisting of a fluorine atom, a linear perfluoroalkyl group having 1 to 7 carbon atoms, a branched perfluoroalkyl group having 3 to 7 carbon atoms, and a cyclic perfluoroalkyl group having 3 to 7 carbon atoms, the perfluoroalkyl group may have an ethereal oxygen atom, Rf.sub.1, Rf.sub.2, Rf.sub.3 and Rf.sub.4 may be linked to each other to form a ring having 4 or more and 8 or less carbon atoms, and the ring may include an ethereal oxygen atom. The present invention further relates to a method for producing fluororesin particles that each include a fluorine-containing aliphatic ring structure. The method comprises a precipitation step of lowering a solution temperature of a fluororesin (A) solution in which a fluororesin (A) including a fluorine-containing aliphatic ring structure is dissolved in a solvent (B), to precipitate particles of the fluororesin (A). The method is excelling in productivity and making it possible to remove foreign matter.

The present invention relates to a fluororesin including a residue unit represented by a following general formula (1) and having a haze value equal to or less than 2% of a heat-press molded product (thickness 1 mm) with a small haze value of a melt-molded product and a method for producing the same.

##STR00001##

In the formula (1), Rf.sub.1, Rf.sub.2, Rf.sub.3 and Rf.sub.4 each independently represent one of the groups consisting of a fluorine atom, a linear perfluoroalkyl group having 1 to 7 carbon atoms, a branched perfluoroalkyl group having 3 to 7 carbon atoms, and a cyclic perfluoroalkyl group having 3 to 7 carbon atoms, the perfluoroalkyl group may have an ethereal oxygen atom, Rf.sub.1, Rf.sub.2, Rf.sub.3 and Rf.sub.4 may be linked to each other to form a ring having 4 or more and 8 or less carbon atoms, and the ring may include an ethereal oxygen atom. The present invention further relates to a method for producing fluororesin particles that each include a fluorine-containing aliphatic ring structure. The method comprises a precipitation step of lowering a solution temperature of a fluororesin (A) solution in which a fluororesin (A) including a fluorine-containing aliphatic ring structure is dissolved in a solvent (B), to precipitate particles of the fluororesin (A). The method is excelling in productivity and making it possible to remove foreign matter.

A method for producing a composition including a step A of performing ultrafiltration, microfiltration, dialysis membrane treatment, or a combination thereof on a composition containing water and a fluoropolymer. The fluoropolymer is a polymer having a structural unit M3 derived from a monomer represented by general formula (1):

CX.sub.2═CY(—CZ.sub.2—O—Rf-A)  (1)

where X is the same or different and is —H or —F; Y is —H, —F, an alkyl group, or a fluorine-containing alkyl group; Z is the same or different and is —H, —F, an alkyl group, or a fluoroalkyl group; 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; and A is —COOM, —SO.sub.3M, —OSO.sub.3M, or —C(CF.sub.3).sub.2OM, wherein M is as defined herein; provided that at least one of X, Y, and Z includes a fluorine atom.

A method for producing a composition including a step A of performing ultrafiltration, microfiltration, dialysis membrane treatment, or a combination thereof on a composition containing water and a fluoropolymer. The fluoropolymer is a polymer having a structural unit M3 derived from a monomer represented by general formula (1):

CX.sub.2═CY(—CZ.sub.2—O—Rf-A)  (1)

where X is the same or different and is —H or —F; Y is —H, —F, an alkyl group, or a fluorine-containing alkyl group; Z is the same or different and is —H, —F, an alkyl group, or a fluoroalkyl group; 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; and A is —COOM, —SO.sub.3M, —OSO.sub.3M, or —C(CF.sub.3).sub.2OM, wherein M is as defined herein; provided that at least one of X, Y, and Z includes a fluorine atom.

Provided are a method for producing a composition for forming an interlayer for nanoimprint, the method including a filtering step of filtering a precursor composition 1 including a resin having a polymerizable group with a filter, a step of adding a solvent to the precursor composition 1 after the step to obtain a precursor composition 2, and a filtering step of filtering the precursor composition 2 with a filter, in which a proportion of a total solid content of the obtained composition is 0.1% to 1.0% by mass; a method for producing a laminate formed of the composition for forming an interlayer; an imprint pattern producing method using the composition for forming an interlayer; and a method for manufacturing a device, which includes the imprint pattern producing method.

Provided are methods for the purification of polymer solutions. In particular, the method enables the separation of impurities from an oxazoline polymer solution by raising the temperature of the polymer solution above its lower critical solution temperature (LCST), wherein a water rich phase and a polymer rich phase separation occurs. The phases are then separated with the polymer rich phase containing a lower amount of impurities than before separation.

Provided are methods for the purification of polymer solutions. In particular, the method enables the separation of impurities from an oxazoline polymer solution by raising the temperature of the polymer solution above its lower critical solution temperature (LCST), wherein a water rich phase and a polymer rich phase separation occurs. The phases are then separated with the polymer rich phase containing a lower amount of impurities than before separation.

A method of forming articles from acrylonitrile-butadiene-styrene, the method comprising: feeding a monomer stream comprising a petrochemical monomer into a reactor; contacting the petrochemical monomer with a polymerization activator within the reactor to produce a polymerized stream comprising rubber, latex, or a combination thereof and withdrawing the polymerized stream from the reactor; passing the polymerized stream through a filter to produce a filtered product stream, wherein the filter is a continuously self-cleaning filter; passing the filtered product stream through a grafting unit comprising acrylonitrile and styrene to produce acrylonitrile-butadiene-styrene; and forming an article from the acrylonitrile-butadiene-styrene, wherein the article is an extruded sheet, a molded part, or a combination thereof.

A method of forming articles from acrylonitrile-butadiene-styrene, the method comprising: feeding a monomer stream comprising a petrochemical monomer into a reactor; contacting the petrochemical monomer with a polymerization activator within the reactor to produce a polymerized stream comprising rubber, latex, or a combination thereof and withdrawing the polymerized stream from the reactor; passing the polymerized stream through a filter to produce a filtered product stream, wherein the filter is a continuously self-cleaning filter; passing the filtered product stream through a grafting unit comprising acrylonitrile and styrene to produce acrylonitrile-butadiene-styrene; and forming an article from the acrylonitrile-butadiene-styrene, wherein the article is an extruded sheet, a molded part, or a combination thereof.

A method for separating polybutene, the method including: (1) introducing a polybutene solution into a distillation column, the solution including polybutene, a halogenated hydrocarbon solvent, and a non-polar hydrocarbon solvent and having a viscosity of 1 cp to 50 cp measured at 25° C. using a rotational viscometer; (2) collecting an upper stream including the halogenated hydrocarbon solvent and a portion of the non-polar hydrocarbon solvent from an upper portion of the distillation column, and collecting a lower stream including the polybutene and a remaining portion of the non-polar hydrocarbon solvent from a lower portion of the distillation column, where the lower stream has a viscosity of 10 cp to 150 cp; and (3) separating the remaining portion of the non-polar hydrocarbon solvent and the polybutene from the lower stream.