Asahi Glass Company, Limited

Agc Inc.

Other

Agc Chemicals Europe, Limited

Shinya Higuchi

Yasuhiko Matsuoka

Jun Hoshikawa

Shigeki Kobayashi

Takehiro Kose

Hiroki Nagai

Shiro Ebata

Hiroki Kamiya

Masahiro Takazawa

Masataka Arai

Hidekazu Okamoto

Kazuya Oharu

Shin Tatematsu

Akiko Tanaka

Nobuyuki Yamagishi

Hiroshi Funaki

Yukiko Hattori

Satoru Kuroki

Anthony Eugene Wade

Ariana Claudia Morgovan-Ene

Diane Caine

Mitsuharu Morozumi

Hideo Katsu

Kosuke Shibasaki

Junko Anzai

A method for producing a fluorinated polymer which does not require an emulsifier as an essential component while an aqueous medium with little environmental burden is used. A method for producing a fluorinated polymer, which includes polymerizing a fluorinated monomer selected from tetrafluoroethylene, chlorotrifluoroethylene and vinylidene fluoride, in an aqueous medium in the presence of a first polymer having units based on a compound represented by formula (1): CXY═CR-L-R.

Method for producing fluorine-containing polymer, aqueous dispersion liquid, and fluorine-containing polymer composition

To provide a modified PTFE excellent in heat resistance. The modified polytetrafluoroethylene comprises a polymer having units based on tetrafluoroethylene and a polymer having units based on a fluorine-free monomer, wherein the endothermic amount ratio R calculated by a prescribed method is at least 0.65.

Product, and method for producing stretched porous material

To provide a modified polytetrafluoroethylene excellent in breaking strength. The modified polytetrafluoroethylene comprises a polymer having units based on tetrafluoroethylene and a polymer having units based on a monomer represented by formula (1), wherein the content of the units based on a monomer represented by formula (1) is from 10 to 500 mass ppm, to all units in the modified polytetrafluoroethylene, and the standard specific gravity is from 2.155 to 2.175,CH═CR-L-R  Formula (1):wherein Rrepresents a hydrogen atom or an alkyl group, L represents a single bond, —CO—O—*, —O—CO—*, or —O—, * represents a bonding position to R, and Rrepresents a hydrogen atom, an alkyl group, or a nitrile group.

Modified polytetrafluoroethylene, molded product, and method for producing stretched porous material

To provide a method for producing modified polytetrafluoroethylene, in which formation of a fluorinated oligomer as a by-product is little. A method for producing modified polytetrafluoroethylene which contains substantially no Cfluorinated oligomer containing hydrophilic functional groups and which contains substantially no fluorinated surfactant, the method comprising conducting copolymerization of tetrafluoroethylene and a monomer having a polar group, in a liquid dispersion 1 comprising a polymer containing units derived from a non-fluorinated monomer and an aqueous medium, or in a solution 2 obtainable by mixing at least one member selected from the group consisting of a polyalkylene oxide compound and a hydrocarbon-containing surfactant, with an oxidizing agent, in an aqueous medium, under such a condition that the amount of the monomer having a polar group to be used, is at most 0.150 mass % to the whole amount of tetrafluoroethylene, to obtain modified polytetrafluoroethylene.

Method for producing modified polytetrafluoroethylene, method for producing modified polytetrafluoroethylene powder, and method for producing stretched porous material

A method for producing a modified polytetrafluoroethylene, the method including: polymerizing tetrafluoroethylene in an aqueous medium in which a polymer having units based on a fluorine-free monomer is present. The fluorine-free monomer is a monomer represented by formula (1): CH&#x2550;CR-L-R, where Ris a hydrogen atom or an alkyl group, L is a single bond, &#x2014;CO&#x2014;O&#x2014;*, &#x2014;O&#x2014;CO&#x2014;* or &#x2014;O&#x2014;, * is a bonding position to R, and Ris an alkyl group. To the total amount of tetrafluoroethylene supplied to the polymerization, a proportion of the polymer is from 0.001 to 0.050 mass %.

A modified polytetrafluoroethylene which can be formed under a low extrusion pressure and with which changes of the extrusion pressure are suppressed, even in paste extrusion at a high RR ratio, and its production method. The modified polytetrafluoroethylene having units based on tetrafluoroethylene, 0.020 to 0.040 mass % of units based on a monomer represented by the following formula (1), and 0.003 to 0.080 mass % of units based on a monomer represented by the following formula (2), each based on all units of the modified polytetrafluoroethylene. The monomers of formulae (1) and (2) are represented by: CH&#x2550;CH&#x2014;CF(1), wherein n is from 2 to 6; and CF&#x2550;CFO(LO)Rf (2), wherein L is a perfluoroalkylene group, Rf is a perfluoroalkyl group, and m is an integer of from 0 to 4.

Modified polytetrafluoroethylene and method for producing same

To provide a production method for an aqueous emulsion of modified polytetrafluoroethylene which is environmentally friendly and which is suitable for producing a stretched porous body having excellent breaking strength. A production method for an aqueous emulsion of modified polytetrafluoroethylene, which is a method to obtain an aqueous emulsion of modified polytetrafluoroethylene particles having an average primary particle diameter of from 0.10 to 0.30 &#x3bc;m, by subjecting tetrafluoroethylene and a perfluoroalkyl ethylene to emulsion polymerization in an aqueous medium, using a polymerization initiator, in the presence of a fluorinated anionic surfactant having a LogPOW of from 2.4 to 3.4, wherein the amount of the perfluoroalkyl ethylene to be used, is from 120 to 3,000 ppm to the final production amount of the modified polytetrafluoroethylene; at the initiation of the emulsion polymerization, the entire amount of the perfluoroalkyl ethylene is permitted to be present, and, as the polymerization initiator, either one or both of a combination of a bromate and a bisulfite or sulfite, and a combination of a permanganate and oxalic acid, are used.

Production methods for aqueous emulsion, fine powder and stretched porous body of modified polytetrafluoroethylene

To provide a process for producing a PTFE molding powder having a high bulk density from granular polymer particles without using an emulsifying agent having problems of bioaccumulation and toxicity. A process for producing a polytetrafluoroethylene molding powder, which comprises a step of suspension-polymerizing a monomer containing at least 99.8 mass % of tetrafluoroethylene in an aqueous medium to produce granular polymer particles and a step of milling the granular polymer particles, wherein the aqueous medium contains a compound represented by R(OCF(X)CF)OCF(X)COOM, at a concentration of from 0.5 to 2,000 ppm. Ris a perfluorinated Cmonovalent organic group, Xand Xare fluorine atoms, etc., and Mis an ammonium ion or the like.

Process for producing polytetrafluoroethylene molding powder and process for producing polytetrafluoroethylene agglomerated product

To produce a PTFE aqueous emulsion, whereby the environmental load is little, the stability of the aqueous emulsion is high, and a molded product having high heat resistance can be obtained. A process for producing a PTFE aqueous emulsion, which comprises emulsion-polymerizing tetrafluoroethylene (TFE) by means of at least one fluorinated emulsifier selected from the group consisting of a Cfluorinated carboxylic acid having from 1 to 4 etheric oxygen atoms in its main chain, and its salts, to obtain an aqueous emulsion containing polytetrafluoroethylene (PTFE) microparticles having an average primary particle size of from 0.1 to 0.3 &#x3bc;m, wherein at the beginning of the emulsion polymerization of TFE, a (polyfluoroalkyl)ethylene (a) represented by 'CH&#x2550;CH&#x2014;Rf', and/or a comonomer (b) having a monomer reactivity ratio rof from 0.1 to 8 in copolymerization with tetrafluoroethylene, is incorporated to the emulsion polymerization system, so as to be from 0.001 to 0.01 mass % relative to the final amount of polytetrafluoroethylene produced.

Polytetrafluoroethylene aqueous emulsion and process for its production, polytetrafluoroethylene aqueous dispersion obtainable by using such an aqueous emulsion, polytetrafluoroethylene fine powder, and stretched porous material

To provide a method for producing a PTFE fine powder having a low paste extrusion pressure property by a simple method. The method for producing a PTFE fine power comprises emulsion polymerizing tetrafluoroethylene in the presence of an aqueous medium, a fluorinated surfactant and a radical polymerization initiator, to produce an aqueous PTFE emulsion, and coagulating it in the presence of at least one bulk density-reducing compound selected from the group consisting of ammonia, an ammonium salt and urea in an amount of from 0.4 to 10 parts by mass per 100 parts by mass of PTFE.

Method for producing polytetrafluoroethylene fine powder

The present invention provides a method for producing a polytetrafluoroethylene fine powder, which comprises emulsion polymerizing tetrafluoroethylene in the presence of an aqueous medium, a fluorinated surfactant and a radical polymerization initiator to produce an aqueous polytetrafluoroethylene emulsion, mixing and coagulating the aqueous emulsion to separate a polytetrafluoroethylene fine powder, and then drying the polytetrafluoroethylene fine powder in a wet state in an atmosphere containing ammonia.

To provide an aqueous polytetrafluoroethylene (PTFE) emulsion which does not substantially contain ammonium perfluorooctanoate, and which is obtained by emulsion polymerization. Further, to provide a PTFE fine powder which is obtained from the aqueous PTFE emulsion and is excellent in a paste extrusion processability, and a porous material. An aqueous polytetrafluoroethylene emulsion obtained by carrying out emulsion polymerization of tetrafluoroethylene alone or together with another copolymerizable monomer in an aqueous medium, wherein a fluorinated emulsifier of the formula (1): CFCF(O)mCFCFOCFCOOA wherein X is a hydrogen atom or a fluorine atom, A is a hydrogen atom, an alkali metal or NH4, and m is an integer of 0 or i, is used in an amount of from 1,500 to 20,000 ppm, based on the final yield of polytetrafluoroethylene.

Aqueous polytetrafluoroethylene emulsion, polytetrafluoroethylene fine powder and porous material obtained therefrom

Provided is a process for producing an aqueous fluorinated polymer dispersion having a reduced content of a fluorinated emulsifier by using a weakly basic anion-exchange resin to adsorb and remove a fluorinated emulsifier with excellent efficiency from an aqueous fluorinated polymer dispersion. Also provided is a process for producing an aqueous fluorinated polymer dispersion having a reduced content of a fluorinated emulsifier, wherein the process includes: adding an organic carboxylic acid represented by the following formula (1):Q(CH)(CH(OH))COOH&#x2003;&#x2003;(1)wherein Q is H, CHor COOH, m and n each independently represent 0 or an integer of from 1 to 4, and 4&#x2267;n+m&#x2267;1, to an aqueous fluorinated polymer dispersion containing a fluorinated emulsifier; and then contacting with a weakly basic anion-exchange resin to adsorb and remove the fluorinated emulsifier.

Process for producing aqueous fluorinated polymer dispersion having reduced content of fluorinated emulsifier

To provide a polytetrafluoroethylene (PTFE) aqueous dispersion, which does not substantially contain ammonium perfluorooctanoate and is excellent in mechanical stability, wettability, permeability and coating property, and its product. A PTFE aqueous dispersion comprising from 15 to 70 mass % of PTFE fine particles having an average particle size of from 0.1 to 0.5 &#x3bc;m, from 1&#xd7;10to 0.5 mass %, based on the mass of the PTFE, of a fluorinated emulsifier of the formula (1): XCFCF(O)CFCFOCFCOOA, wherein X is a hydrogen atom or a fluorine atom, A is a hydrogen atom, an alkali metal or NHand m is an integer of 0 or 1, and from 1 to 20 mass %, based on the mass of the PTFE, of a nonionic surfactant.

Polytetrafluoroethylene aqueous dispersion and its product

A fluororesin aqueous dispersion comprising from 20 to 70 mass % of microparticles of a fluororesin and from 1 to 12 mass %, based on the mass of the fluororesin, of a non-ionic surfactant represented by the formula (1):R&#x2014;O-A-X&#x2003;&#x2003;(1)wherein Ris a Calkyl group, O is an oxygen atom, A is a polyoxyalkylene group comprising from 1 to 3 oxybutylene groups and from 5 to 20 oxyethylene groups, and X is a hydrogen atom or a methyl group.

Growing community of inventors

Tokyo, Japan

Shinya Higuchi