The fluorine-containing copolymer of the present invention includes: a structural unit (A) represented by the following formula (1); and at least one selected from the group consisting of a structural unit (B) represented by the following formula (2), a structural unit (C) represented by the following formula (3), and a structural unit (D) represented by the following formula (4):

##STR00001##

in the formula (1), R.sub.ff.sup.1 to R.sub.ff.sup.4 each independently represent a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms, and R.sub.ff.sup.1 and R.sub.ff.sup.2 are optionally linked to form a ring;

##STR00002##

in the formula (2), R.sup.1 to R.sup.3 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms, R.sup.4 represents a perfluoroalkyl group having 1 to 7 carbon atoms, the perfluoroalkyl group optionally has a ring structure, one or some of the fluorine atoms are optionally substituted by a halogen atom other than a fluorine atom, and one or some of fluorine atoms in the perfluoroalkyl group are optionally substituted by a halogen atom other than a fluorine atom;

##STR00003##

in the formula (3), R.sup.5 to R.sup.8 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms, the perfluoroalkyl group optionally has a ring structure, one or some of the fluorine atoms are optionally substituted by a halogen atom other than a fluorine atom, and one or some of fluorine atoms in the perfluoroalkyl group are optionally substituted by a halogen atom other than a fluorine atom; and

##STR00004##

in the formula (4), Z represents an oxygen atom, a single bond, or —OC(R.sup.19R.sup.20)O—, R.sup.9 to R.sup.20 each independently represent a fluorine atom, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkoxy group having 1 to 5 carbon atoms, one or some of the fluorine atoms are optionally substituted by a halogen atom other than a fluorine atom, one or some of fluorine atoms in the perfluoroalkyl group are optionally substituted by a halogen atom other than a fluorine atom, one or some of fluorine atoms in the perfluoroalkoxy group are optionally substituted by a halogen atom other than a fluorine atom, s and t are each independently 0 to 5, and s+t represents an integer of 1 to 6 (when Z is —OC(R.sup.19R.sup.20)O—, s+t is optionally 0).

An ultraviolet-curable liquid developer contains a cationically polymerizable liquid monomer, a photoinitiator, and a toner particle insoluble in the cationically polymerizable liquid monomer. The cationically polymerizable liquid monomer is a vinyl ether compound, and the photoinitiator is a compound having a particular structure.

Liquid radiation curable compositions are disclosed which are suitable for hybrid (i.e. cationic and free-radical) polymerization when processed via additive fabrication equipment utilizing sources of actinic radiation with peak spectral intensities in the UV/vis region. Also disclosed are methods of creating three-dimensional parts via additive fabrication processes utilizing sources of actinic radiation with peak spectral intensities in the UV/vis region employing liquid radiation curable compositions suitable for hybrid polymerization, and the parts cured therefrom.

Liquid radiation curable compositions are disclosed which are suitable for hybrid (i.e. cationic and free-radical) polymerization when processed via additive fabrication equipment utilizing sources of actinic radiation with peak spectral intensities in the UV/vis region. Also disclosed are methods of creating three-dimensional parts via additive fabrication processes utilizing sources of actinic radiation with peak spectral intensities in the UV/vis region employing liquid radiation curable compositions suitable for hybrid polymerization, and the parts cured therefrom.

A method for manufacturing polymer fine particles having a narrow particle diameter distribution without any particular limitations on the raw materials and the like. To achieve this purpose, this method for manufacturing polymer fine particles includes polymerizing a vinyl monomer using a dispersion polymerization method, wherein the amount of water in the reaction liquid in the polymerizing is no more than 30,000 ppm, the reactor for carrying out the polymerizing is a stirring tank reactor, the stirring blade attached to the stirring rotation shaft of the stirring tank reactor is one type selected from a large wide blade and a large lattice blade, and the tip speed of the stirring blade is no more than 1.0 m/sec.

A method for manufacturing polymer fine particles having a narrow particle diameter distribution without any particular limitations on the raw materials and the like. To achieve this purpose, this method for manufacturing polymer fine particles includes polymerizing a vinyl monomer using a dispersion polymerization method, wherein the amount of water in the reaction liquid in the polymerizing is no more than 30,000 ppm, the reactor for carrying out the polymerizing is a stirring tank reactor, the stirring blade attached to the stirring rotation shaft of the stirring tank reactor is one type selected from a large wide blade and a large lattice blade, and the tip speed of the stirring blade is no more than 1.0 m/sec.

A secondary battery electrode has excellent characteristics. As a binder for a secondary battery electrode, a crosslinked polymer or salt thereof having a carboxyl group is used. The crosslinked polymer or salt includes 30 mass % or more and not more than 100 mass % of a structural unit derived from an ethylenically unsaturated carboxylic acid monomer and a metal ion content of the crosslinked polymer or salt thereof is not more than 100 ppm or less.

A secondary battery electrode has excellent characteristics. As a binder for a secondary battery electrode, a crosslinked polymer or salt thereof having a carboxyl group is used. The crosslinked polymer or salt includes 30 mass % or more and not more than 100 mass % of a structural unit derived from an ethylenically unsaturated carboxylic acid monomer and a metal ion content of the crosslinked polymer or salt thereof is not more than 100 ppm or less.

To provide a method for producing crosslinked rubber excellent in tensile strength and transparency.

The method for producing crosslinked rubber of the present invention is a method for producing crosslinked rubber, which comprises crosslinking a fluorinated copolymer in a composition containing the fluorinated copolymer, a crosslinking agent, a crosslinking co-agent and an acid acceptor, wherein the fluorinated copolymer is a copolymer having units based on tetrafluoroethylene and units based on propylene, in the composition, the content of the crosslinking agent is from 0.03 to 1.5 parts by mass to 100 parts by mass of the fluorinated copolymer, the content of the crosslinking co-agent is from 0.1 to 3.5 parts by mass to 100 parts by mass of the fluorinated copolymer, and the total light transmittance of the crosslinked rubber is from 60 to 100%.

To provide a method for producing crosslinked rubber excellent in tensile strength and transparency.

The method for producing crosslinked rubber of the present invention is a method for producing crosslinked rubber, which comprises crosslinking a fluorinated copolymer in a composition containing the fluorinated copolymer, a crosslinking agent, a crosslinking co-agent and an acid acceptor, wherein the fluorinated copolymer is a copolymer having units based on tetrafluoroethylene and units based on propylene, in the composition, the content of the crosslinking agent is from 0.03 to 1.5 parts by mass to 100 parts by mass of the fluorinated copolymer, the content of the crosslinking co-agent is from 0.1 to 3.5 parts by mass to 100 parts by mass of the fluorinated copolymer, and the total light transmittance of the crosslinked rubber is from 60 to 100%.