The present invention relates to a fluorosurfactant-free emulsion polymerization method for the synthesis of a fluoropolymer, more in particular of a VDF-based polymer.

The present invention discloses a copolymer for a polymer electrolyte, and a gel polymer electrolyte and a lithium secondary battery which include the same. Specifically, the present invention discloses a copolymer for a polymer electrolyte, which includes (A) a fluorine-based polymer, and (B) a unit derived from an acrylate-based monomer or an acrylate-based polymer, wherein the unit derived from the acrylate-based monomer or the acrylate-based polymer is grafted on the fluorine-based polymer, and a weight ratio of the fluorine-based polymer to the unit derived from the acrylate-based monomer or the acrylate-based polymer is in a range of 1:99 to 40:60, and a gel polymer electrolyte in which lithium ion transfer capability is improved by including the same. Also, the present invention may prepare a lithium secondary battery in which high-temperature safety is improved by including the gel polymer electrolyte.

The present invention discloses a copolymer for a polymer electrolyte, and a gel polymer electrolyte and a lithium secondary battery which include the same. Specifically, the present invention discloses a copolymer for a polymer electrolyte, which includes (A) a fluorine-based polymer, and (B) a unit derived from an acrylate-based monomer or an acrylate-based polymer, wherein the unit derived from the acrylate-based monomer or the acrylate-based polymer is grafted on the fluorine-based polymer, and a weight ratio of the fluorine-based polymer to the unit derived from the acrylate-based monomer or the acrylate-based polymer is in a range of 1:99 to 40:60, and a gel polymer electrolyte in which lithium ion transfer capability is improved by including the same. Also, the present invention may prepare a lithium secondary battery in which high-temperature safety is improved by including the gel polymer electrolyte.

Provided is a method for producing a fluorine-containing polymer, comprising polymerizing a fluorine-containing monomer in the presence of a fluorine-free compound (1) represented by general formula (1), a polymerization initiator, and an aqueous medium to produce the fluorine-containing polymer:

CX.sup.1X.sup.2═CX.sup.3—R—Z  General formula (1):

wherein X.sup.1, X.sup.2, and X.sup.3 are each independently H or an alkyl group; R is a single bond or an alkylene group; the total number of carbon atoms of X.sup.1, X.sup.2, X.sup.3, and R is 0 to 5; Z is —SO.sub.3M, —OSO.sub.3M, —P(═O)(OM).sub.2, —OP(O)(OM).sub.2, or —B(OM).sub.2; M is H, a metal atom, NR.sup.1.sub.4, optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium; and R.sup.1 is independently H or an organic group, and any two R.sup.1 may be bonded to each other to form a ring.

Provided is a method for producing a fluorine-containing polymer, comprising polymerizing a fluorine-containing monomer in the presence of a fluorine-free compound (1) represented by general formula (1), a polymerization initiator, and an aqueous medium to produce the fluorine-containing polymer:

CX.sup.1X.sup.2═CX.sup.3—R—Z  General formula (1):

wherein X.sup.1, X.sup.2, and X.sup.3 are each independently H or an alkyl group; R is a single bond or an alkylene group; the total number of carbon atoms of X.sup.1, X.sup.2, X.sup.3, and R is 0 to 5; Z is —SO.sub.3M, —OSO.sub.3M, —P(═O)(OM).sub.2, —OP(O)(OM).sub.2, or —B(OM).sub.2; M is H, a metal atom, NR.sup.1.sub.4, optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium; and R.sup.1 is independently H or an organic group, and any two R.sup.1 may be bonded to each other to form a ring.

A resin composition containing a fluorine-containing polymer and a methacrylate resin. The fluorine-containing polymer and the methacrylate resin have a mass ratio of 35/65 to 95/5. The fluorine-containing polymer contains a vinylidene fluoride unit and a tetrafluoroethylene unit. The vinylidene fluoride unit and the tetrafluoroethylene unit have a mole ratio of 81/19 to 99/1. Also disclosed is a molded article containing the resin composition.

A resin composition containing a fluorine-containing polymer and a methacrylate resin. The fluorine-containing polymer and the methacrylate resin have a mass ratio of 35/65 to 95/5. The fluorine-containing polymer contains a vinylidene fluoride unit and a tetrafluoroethylene unit. The vinylidene fluoride unit and the tetrafluoroethylene unit have a mole ratio of 81/19 to 99/1. Also disclosed is a molded article containing the resin composition.

A method for producing a fluoropolymer which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a surfactant to provide a fluoropolymer, the surfactant being represented by the general formula (1): CR.sup.1R.sup.2R.sup.4—CR.sup.3R.sup.5—X-A, wherein R.sup.1 to R.sup.5 are each H or a monovalent substituent, with the proviso that at least one of R.sup.1 and R.sup.3 represents a group represented by the general formula: —Y—R.sup.6 and at least one of R.sup.2 and R.sup.5 represents a group represented by the general formula: —X-A or a group represented by the general formula: —Y—R.sup.6; and A is the same or different at each occurrence and is —COOM, —SO.sub.3M, or —OSO.sub.3M. Also disclosed is a surfactant for polymerization represented by the general formula (1), a method for producing a fluoropolymer using the surfactant and a composition including a fluoropolymer and the surfactant.

A method for producing a fluoropolymer which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a surfactant to provide a fluoropolymer, the surfactant being represented by the general formula (1): CR.sup.1R.sup.2R.sup.4—CR.sup.3R.sup.5—X-A, wherein R.sup.1 to R.sup.5 are each H or a monovalent substituent, with the proviso that at least one of R.sup.1 and R.sup.3 represents a group represented by the general formula: —Y—R.sup.6 and at least one of R.sup.2 and R.sup.5 represents a group represented by the general formula: —X-A or a group represented by the general formula: —Y—R.sup.6; and A is the same or different at each occurrence and is —COOM, —SO.sub.3M, or —OSO.sub.3M. Also disclosed is a surfactant for polymerization represented by the general formula (1), a method for producing a fluoropolymer using the surfactant and a composition including a fluoropolymer and the surfactant.

A method for producing a fluoropolymer which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a surfactant to provide a fluoropolymer, the surfactant being represented by the general formula (1): CR.sup.1R.sup.2R.sup.4—CR.sup.3R.sup.5—X-A, wherein R.sup.1 to R.sup.5 are each H or a monovalent substituent, with the proviso that at least one of R.sup.1 and R.sup.3 represents a group represented by the general formula: —Y—R.sup.6 and at least one of R.sup.2 and R.sup.5 represents a group represented by the general formula: —X-A or a group represented by the general formula: —Y—R.sup.6; and A is the same or different at each occurrence and is —COOM, —SO.sub.3M, or —OSO.sub.3M. Also disclosed is a surfactant for polymerization represented by the general formula (1), a method for producing a fluoropolymer using the surfactant and a composition including a fluoropolymer and the surfactant.