CN102382218B - Aqueous dispersion of low molecular weight polytetrafluorethyleand and manufacture method thereof - Google Patents
Aqueous dispersion of low molecular weight polytetrafluorethyleand and manufacture method thereof Download PDFInfo
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Abstract
The present invention relates to aqueous dispersion of low molecular weight polytetrafluorethyleand and manufacture method thereof, be directed to a kind of without fluorine-containing surfactant with the low cost method to manufacture the aqueous liquid dispersion of low molecular weight polytetrafluoroethylene (PTFE).Manufacture method involved in the present invention is need not add fluorine-containing surfactant and carry out the method that the emulsion of tetrafluoroethene (TFE) is polymerized or can be polymerized with the emulsion of the monomer of TFE copolymerization and TFE under chain-transferring agent exists in the aqueous medium containing polymerization initiator, it is characterized in that, at least one compound in the group that described chain-transferring agent is the hydrocarbon selecting free hydrogen, carbon number to be 1～3 and the halogenated hydrocarbons that carbon number is 1～3 forms, described polymerization initiator is water-soluble peroxide.
Description
The application is divisional application, and the China national application number of its original application is 200810131815.8, and the applying date is on 06 24th, 2008, and denomination of invention is " aqueous dispersion of low molecular weight polytetrafluorethyleand and manufacture method thereof ".
Technical field
The present invention relates to aqueous dispersion of low molecular weight polytetrafluorethyleand and manufacture method thereof.
Background technology
Molecular weight be less than 600,000 low molecular weight polytetrafluoroethylene (PTFE) (also referred to as PTFE micropowder) have excellence chemical stability, extremely low surface can, it is also difficult to generation fibrillation, thus it is used in the manufacture of plastics, ink, cosmetics, coating, grease etc. (for example, with reference to patent documentation 1) as the additive improving sliding and film coated surface texture at present.
Manufacture method as low-molecular-weight PTFE, known have following method: at high temperature make high molecular PTFE and specific fluoride come in contact method that reaction carries out thermally decomposing is (such as, referring to patent documentation 2), the powder of high molecular PTFE or molded body are irradiated the method (for example, with reference to patent documentation 3) etc. of ionizing radiation.
Be there is the problem generating the harmful side products such as fluohydric acid gas in the high molecular PTFE method thermally decomposed, but also there is the problem making cost high because needing to carry out fine operation.For the method irradiating lonizing radiation, also generate the harmful side products such as fluohydric acid gas, even if also may not be advantageous for from the viewpoint of device-dependent cost and convenience.And then, in the method, it is necessary to the irradiation of the lonizing radiation that close rate is high, but do not permitted by FDA through the lonizing radiation of more than 75kGry or the PTFE of electron beam irradiation, therefore cannot be used for directly and the purposes (for example, with reference to non-patent literature 1) of human contact in the U.S..
As the manufacture method of low-molecular-weight PTFE, under the existence of chain-transferring agent, the method for the TFE direct polymerization as monomer is also known for.Such as, in patent documentation 4, propose the fluorinated alkanes hydrocarbon using carbon number to be 1～3 or the chlorine fluorinated alkanes hydrocarbon method that carries out being polymerized as chain-transferring agent (telogen).
As commercial polymerisation processes, in the method for patent documentation 4, with which kind of method carry out being polymerized and indefinite, but be roughly divided into suspension polymerisation and emulsion polymerization.Low from the viewpoint of the easy of operation, the stricturization of molecular weight distribution, free fluoride ion concentration, polymerization the low-molecular-weight PTFE directly obtained is preferred.
In suspension polymerisation, polymerization initiator is made to disperse in an aqueous medium under chain-transferring agent exists, make to be polymerized as the TFE of monomer or allow to monomer and the TFE with TFE copolymerization to be polymerized, thus the particulate powder of low-molecular-weight PTFE is directly separating (for example, with reference to patent documentation 5 and 6).In the case of suspension polymerization, it is possible to directly obtain the powder of low-molecular-weight PTFE, without using emulsifying agent, it can be difficult to adjust apparent density and the particle diameter of described powder.
On the other hand, in emulsion is polymerized, under chain-transferring agent exists, polymerization initiator and the fluorine-containing surfactant as emulsifying agent is made to disperse in an aqueous medium, make to be polymerized as the TFE of monomer or allow to monomer and the TFE with TFE copolymerization to be polymerized, thus obtain low-molecular-weight PTFE.In this case, different from suspension polymerisation, owing to there is fluorine-containing surfactant, therefore obtain polymer (for example, with reference to patent documentation 7) with the state of the aqueous liquid dispersion of the emulsified particles (also referred to as micelle, primary particle) comprising less than 1 μm.Obtained aqueous liquid dispersion can direct or through after being concentrated and be used for the purposes such as water paint.
When using, with pulverulence, the low-molecular-weight PTFE obtained by emulsion polymerization, it is possible to by powder particle (micropowder) is made in above-mentioned aqueous liquid dispersion condensation.
As the feature of the low-molecular-weight PTFE powder granule obtained by emulsion polymerization, its specific surface area 5m bigger than the specific surface area of the low-molecular-weight PTFE powder granule obtained by suspension polymerisation2/ g～15m2/ g, and soft granules, the surface modification effect therefore such as improving film coated surface texture etc. is higher.Furthermore, it is possible to it is many and to the stable dispersion of host material to obtain oil absorption.And, from the aspect utilizing above-mentioned condensation process conditions can adjust apparent density and particle diameter, it is preferable that be polymerized the low-molecular-weight PTFE powder granule obtained by emulsion.
But, in above-mentioned emulsion polymerization, owing to needing to use the expensive materials such as fluorine-containing surfactant as emulsifying agent, therefore relatively costly.Further, in PTFE granule during remaining surfactant, sometimes result in painted etc..Therefore, seek to carry out the manufacture method of the PTFE being polymerized without these fluorine-containing surfactants.
As carrying out the method be polymerized without fluorine-containing surfactant, use (for example, with reference to non-patent literature 2) that the TFE suspension polymerization that TFE and water-soluble peroxide react is known in an aqueous medium.Patent documentation 8 also describes following content: without surfactant, and carry out TFE polymerization with peroxidating disuccinic acid for polymerization initiator in an aqueous medium, thus obtaining aqueous liquid dispersion.
But, the polymer solids constituent concentration of the aqueous liquid dispersion recorded in the embodiment of patent documentation 8 is very thin, is only 6.5 weight %, if it is considered that productivity ratio, then lacks very much practicality.Further, in patent documentation 8, do not record the data of the interpolation of any hint chain-transferring agent, the emulsifying particle diameter of obtained polymer and molecular weight.
In addition; due to nearest result of study etc.; the worry of the load of environment is become apparent upon by people by perfluoro caprylic acid [PFOA] (it is representational fluorine-containing surfactant) gradually that be polymerized for emulsion; EPA on April 14 in 2003 (Environmental Protection Agency USA), the chemical investigation to PFOA (for example, with reference to non-patent literature 3) was strengthened in expression.
Patent documentation 1: Japanese Unexamined Patent Publication 10-147617 publication
Patent documentation 2: Japanese Laid-Open Patent Publication 61-162503 publication
Patent documentation 3: Japanese Laid-Open Patent Publication 48-78252 publication
Patent documentation 4: Japanese Laid-Open Patent Publication 51-41085 publication
Patent documentation 5: No. 2004/050727 pamphlet of International Publication
Patent documentation 6: Japanese Patent Application 2005-2322 publication
Patent documentation 7: Japanese Unexamined Patent Publication 7-165828 publication
Patent documentation 8: U.S. Patent No. 2,534,058
Non-patent literature 1:FDA file Sec.177.1550
Non-patent literature 2: " fluororesin handbook " (ふ つ element fat Ha Application De Block Star Network) editor: inner river filial piety minister, Nikkan Kogyo Shimbun's (nineteen ninety), 27 pages
Non-patent literature 3:EPA reports " PRELIMINARYRISKASSESSMENTOFTHEDEVELOPMENTALTOXICITYASSOC IATEDWITHEXPOSURETOPERFLUOROOCTANOICACIDANDITSSALT ", the Internet<URL:http: //www.epa.gov/opptintr/pfoa/pfoara.pfd>
Summary of the invention
In view of above-mentioned present situation, it is an object of the invention to provide the method not using fluorine-containing surfactant and manufacture low molecular weight polytetrafluoroethylene with low cost.
The present invention relates to the manufacture method of a kind of low molecular weight polytetrafluoroethylene (PTFE) aqueous liquid dispersion, the method is need not add fluorine-containing surfactant and carry out the method that the emulsion of tetrafluoroethene (TFE) is polymerized or can be polymerized with the emulsion of the monomer of TFE copolymerization and TFE under the existence of chain-transferring agent in the aqueous medium be dispersed with polymerization initiator, described method is characterised by, described chain-transferring agent is for selecting free hydrogen, carbon number is at least one compound in the hydrocarbon of 1～3 and the group of halogenated hydrocarbons that carbon number is 1～3 composition, described polymerization initiator is water-soluble peroxide.
The present invention relates to low-molecular-weight PTFE, it is characterised in that described low-molecular-weight PTFE is obtained by the manufacture method of above-mentioned low-molecular-weight PTFE aqueous liquid dispersion.
The present invention relates to low-molecular-weight PTFE aqueous liquid dispersion, it is characterised in that described low-molecular-weight PTFE aqueous liquid dispersion is to be obtained by the manufacture method of above-mentioned low-molecular-weight PTFE aqueous liquid dispersion.
The present invention relates to low-molecular-weight PTFE aqueous liquid dispersion, it is characterised in that described low-molecular-weight PTFE aqueous liquid dispersion has been substantially free of perfluoro caprylic acid (PFOA) and salt thereof and perfluorinated sulfonic acid (PFOS) and salt thereof.
The present invention relates to low-molecular-weight PTFE powder, it is characterised in that described low-molecular-weight PTFE powder is by obtaining above-mentioned low-molecular-weight PTFE aqueous liquid dispersion condensation.
The present invention relates to low-molecular-weight PTFE powder, it is characterised in that the specific surface area of described low-molecular-weight PTFE powder is 7m2/ g～15m2/ g and be substantially free of perfluoro caprylic acid (PFOA) and salt thereof and perfluorinated sulfonic acid (PFOS) and salt thereof.
The present invention relates to coating, it is characterised in that described coating contains above-mentioned low-molecular-weight PTFE.
The present invention relates to engineering plastics, it is characterised in that described engineering plastics contain above-mentioned low-molecular-weight PTFE.
The present invention relates to cosmetic preparation, it is characterised in that described cosmetic preparation contains above-mentioned low-molecular-weight PTFE.
The present invention relates to grease, it is characterised in that described grease contains above-mentioned low-molecular-weight PTFE.
The present invention relates to toner, it is characterised in that described toner contains above-mentioned low-molecular-weight PTFE.
The present invention relates to coating, it is characterised in that described coating contains above-mentioned low-molecular-weight PTFE powder.
The present invention relates to engineering plastics, it is characterised in that described engineering plastics contain above-mentioned low-molecular-weight PTFE powder.
The present invention relates to cosmetic preparation, it is characterised in that described cosmetic preparation contains above-mentioned low-molecular-weight PTFE powder.
The present invention relates to grease, it is characterised in that described grease contains above-mentioned low-molecular-weight PTFE powder.
The present invention relates to toner, it is characterised in that described toner contains above-mentioned low-molecular-weight PTFE powder.
The following detailed description of the present invention.
The manufacture method of the present invention is characterised by that it carries out emulsion polymerization without fluorine-containing surfactant when, the method can obtain low-molecular-weight PTFE with the state of aqueous liquid dispersion, its low cost of manufacture, is absent from the above-mentioned problem caused by fluorine-containing surfactant of the prior art.
Only using in an aqueous medium in the TFE suspension polymerization that TFE and water-soluble peroxide react without fluorine-containing surfactant, known in reacting initial system, produce core (emulsified particles) in the same manner as carrying out when emulsion is polymerized, but while polymer chain grows, emulsified particles generation coagulation, this agglutinating particle moves on liquid level, reaction carries out (for example, with reference to non-patent literature 2) in the gas phase.
It is generally acknowledged, for this in system without for the polymerization of the TFE of fluorine-containing surfactant, the polymer chain with the hydrophilic end group from water-soluble peroxide generated at the polymerization initial stage, and it has emulsification, therefore forms emulsified particles in an aqueous medium.But it is believed that along with the increase of the polymer solids constituent concentration in the increase of the degree of polymerization and aqueous medium, the emulsification of the polymer chain with hydrophilic end group significantly reduces, therefore the emulsified particles generation coagulation of destabilization.
On the other hand, in the manufacture method of the present invention, surprisingly, even if without fluorine-containing surfactant, reaction system also is able to maintain polyreaction with emulsified state, finally can obtain low-molecular-weight PTFE with the state of the stabilized aqueous dispersion liquid that solid component concentration is about 12 mass %.
And then, through the postprocessing working procedures that the aqueous liquid dispersion obtained with the general emulsion polymerization by use fluorine-containing surfactant is same, low-molecular-weight PTFE powder can be obtained, and this low-molecular-weight PTFE powder can be used for multiple use as various additives.
The mechanism that the manufacture method of the present invention demonstrates such excellent effect is unclear, but it may be speculated that in the polymerization of the present invention, obtain TFE polymer due to situations below with the scattered aqueous liquid dispersion of emulsified particles form stable:
(1) by the reaction of chain-transferring agent, water-soluble peroxide and TFE, there is the hydrophilic end group coming from water-soluble peroxide and there is the polymer chain growth of emulsification, but in the growth course of this polymer chain, chain tra nsfer between chain-transferring agent and polymer chain causes that the growth end of this polymer chain inactivates, therefore generate the TFE polymer of short chain, the reduction of emulsification will not occur along with the increase of the degree of polymerization；
(2) chain transfer ability as the above-claimed cpd of above-mentioned chain-transferring agent is higher, and therefore the degree of polymerization of above-mentioned short chain TFE polymer is relatively low, it is shown that higher emulsifying effectiveness；
(3) after the polymerization initial stage, water-soluble peroxide also continues to decompose, and therefore the above-mentioned short chain TFE polymer with hydrophilic end group is continuously generated.
Namely, in the present invention, the water-soluble peroxide of hydrophilic radical is provided to be polymerized as chain-transferring agent as polymerization initiator the compound that uses chain transfer ability higher owing to using to polymer ends, therefore, it is possible to obtain when without fluorine-containing surfactant that dispersion stabilization is high and the aqueous liquid dispersion of low-molecular-weight PTFE that solid component concentration after polymerization is high.
Above-mentioned " low-molecular-weight PTFE " typically refers to the TFE polymer that number-average molecular weight is less than 600,000.The number-average molecular weight " high molecular PTFE " more than 600,000 demonstrates the distinctive fibrillation characteristic of PTFE (referring to patent documentation 1).The melt viscosity of high molecular PTFE is high, has non melt processable.For high molecular PTFE, showing fibrillation characteristic during used as additive, therefore coagulation easily occurs between PTFE granule, in host material, dispersibility is poor.
It is 1 × 10 that above-mentioned low-molecular-weight PTFE is preferably the melt viscosity at 380 DEG C2(Pa s)～7 × 105The TFE polymer of (Pa s).As long as the melt viscosity of general above-mentioned low-molecular-weight PTFE is within the scope of this, then its number-average molecular weight just in above-mentioned scope (referring to patent documentation 1).
In this manual, low-molecular-weight PTFE refers at the TFE polymer that the melt viscosity of 380 DEG C is in above-mentioned scope.
That is, the present invention relates to the polymerization that can be obtained such low-molecular-weight PTFE by emulsion polymerization.
In this manual, above-mentioned melt viscosity is measure the value obtained as follows: according to ASTMD1238, use flow tester (Shimadzu Seisakusho Ltd.'s manufacture) andMouth die, take 2g and heat the sample after 5 minutes at 380 DEG C in advance, under the load of 0.7MPa, described sample be maintained at described temperature and be measured.Above-mentioned mean molecule quantity is by utilizing said determination method to measure the value that the melt viscosity obtained calculates respectively.
Above-mentioned low-molecular-weight PTFE is preferably the TFE polymer that fusing point is at 324 DEG C～333 DEG C.
In this manual, above-mentioned low-molecular-weight PTFE both can be proplast (TFE homopolymer), it is also possible to be modified Teflon (modified ptfe).
The polymer that above-mentioned TFE homopolymer obtains for only carrying out being polymerized as monomer using tetrafluoroethene (TFE).
Above-mentioned modified ptfe refers to by the polymer that can obtain with the copolymerization of the modified monomer of TFE copolymerization and TFE.
Modified monomer in above-mentioned modified ptfe is not particularly limited, as long as can with the monomer of TFE copolymerization, it is possible to enumerate such as, the perfluoroolefine such as hexafluoropropene (HFP)；The perhaloalkenes such as CTFE (CTFE)；The hydrogeneous fluoroolefins such as trifluoro-ethylene, vinylidene fluoride (VDF)；Perfluoroalkyl vinyl ether；Perfluorobutyl ethylene；Ethylene etc..Additionally, the modified monomer used both can be a kind of, it is also possible to be two or more.
Above-mentioned perfluoroalkyl vinyl ether is not particularly limited, for instance the perfluor unsaturated compound etc. represented with below formula (I) can be enumerated.
CF2=CF-ORf (I)
(in formula, Rf represents perfluorinated organic group.)
In this manual, above-mentioned " perfluorinated organic group " refers to, the hydrogen atom being combined with carbon atom is all substituted by the organic group of fluorine atom.Above-mentioned perfluorinated organic group can also have ether oxygen.
As above-mentioned perfluoroalkyl vinyl ether, it is possible to enumerate such as, in above-mentioned formula (I), Rf represents the perfluor (alkyl vinyl ether) (PAVE) of the perfluoroalkyl that carbon number is 1～10.The carbon number of above-mentioned perfluoroalkyl is preferably 1～5.
As the perfluoroalkyl in above-mentioned PAVE, it is possible to enumerate such as perfluoro-methyl, perfluoro-ethyl, perfluoro propyl, perfluoro butyl, perfluoropentyl, perfluoro hexyl etc., but preferably perfluoroalkyl is the perfluoro propyl vinyl ether (PPVE) of perfluoro propyl.
As above-mentioned perfluoroalkyl vinyl ether, the perfluoroalkyl vinyl ether of perfluor (alkoxyalkyl) group, the Rf that can enumerate Rf in above-mentioned formula (I) to be further carbon number be 4～9 are the perfluoroalkyl vinyl ether of the group that below formula represents
(in formula, m represents the integer of 0 or 1～4.), Rf be the perfluoroalkyl vinyl ether of the group that following formula represents
(in formula, n represents the integer of 1～4.), etc..
As the modified monomer in above-mentioned modified ptfe, it is preferable that HFP, CTFE, VDF, PPVE, ethylene.
In above-mentioned modified ptfe, above-mentioned modified monomer unit is preferably below the 1 mass % of total monomer units, more preferably 0.001 mass %～1 mass %.In this manual, above-mentioned modified monomer unit is a part for the molecular structure of modified ptfe, and it refers to the part from modified monomer；So-called total monomer units refers to the part from all monomers in the molecular structure of modified ptfe.
The manufacture method of the present invention is that the emulsion carrying out TFE when without fluorine-containing surfactant is polymerized the method obtaining stable aqueous liquid dispersion.In this manual, above-mentioned " being polymerized when without fluorine-containing surfactant " refers to, without the fluorine-containing surfactant used in the existing TFE emulsion polymerizations such as the emulsifying agent of fluorine carbon system when polymerization starts and in polymerization.
As mentioned above, compared with being polymerized with the emulsion of existing TFE, not mixing the angle of fluorine-containing surfactant from when polymerization starts and polymerization, the manufacture method of the present invention not only cost is low, and the problem that obtained low-molecular-weight PTFE is also absent from being caused by fluorine-containing surfactant.
In this manual, above-mentioned fluorine-containing surfactant refers to, in molecular structure containing at least 1 fluorine atom fluorochemical in demonstrate surface-active compound.As described fluorine-containing surfactant, the surfactant being made up of by hydrophilic groups such as the replaced hydrocarbon that carbon number is 7～12 of fluorine atom and carboxylic acid, carboxylate, sulfonic acid, sulfonic groups at least 1 hydrogen atom can be enumerated in practical, industrially can enumerate perfluorooctanoic acid, perfluoro caprylic acid sulfonium salt etc..
The manufacture method of the low-molecular-weight PTFE of the present invention is the method carrying out TFE emulsion polymerization under the existence of chain-transferring agent in the aqueous medium be dispersed with water-soluble peroxide.
Above-mentioned aqueous medium is preferably the high-purity pure water after deionization.
In the present invention, at least one compound in the group that above-mentioned chain-transferring agent is the hydrocarbon selecting free hydrogen, carbon number to be 1～3 and the halogenated hydrocarbons that carbon number is 1～3 forms.
It is the hydrocarbon of 1～3 as above-mentioned carbon number, it is possible to enumerate such as methane, ethane, propane, is the halogenated hydrocarbons of 1～3 as above-mentioned carbon number, it is possible to enumerate such as chloromethanes, ethyl chloride etc..Above-mentioned chain-transferring agent is preferably ethane or propane.
In the manufacture method of the present invention, above-mentioned chain-transferring agent can adding disposable interpolation before polymerization initiator, it is also possible to before adding polymerization initiator and above interpolation at twice in the polymerization, it is also possible to is added continuously in system.
The addition of chain-transferring agent has different OK range along with the difference of the polymerizing condition such as addition of its chain transfer ability, reaction temperature, polymerization pressure or polymerization initiator, can not broadly specify, but the addition of this chain-transferring agent is preferably 02 mole of %～20 mole % relative to the TFE existed in reaction system, more preferably 1.0 moles of %～10 mole %.If described addition less than 02 mole of % relative to the TFE existed in reaction system, then may can not get stable aqueous liquid dispersion, and then be likely to can not get the emulsified particles of low-molecular-weight PTFE, and generate high molecular PTFE.If described addition is more than 20 moles of %, it is then below 100Pa s at the melt viscosity of 380 DEG C, vaporization at high temperature composition is more, for such as to substrate carry out the temperature in scattered operation more than 300 DEG C as purposes be inappropriate, purposes is sometimes also restrained.
In the manufacture method of the present invention, as above-mentioned water-soluble peroxide, it is possible to enumerate such as persulfate, water solublity organic peroxide.
As above-mentioned persulfate, it is possible to enumerate such as Ammonium persulfate. (APS), potassium peroxydisulfate (KPS).Known to persulfate is used for the polymerization initiator of TFE, the end group from initiator is mainly carboxyl (such as, patent documentation 3).
As above-mentioned water solublity organic peroxide, it is possible to enumerate such as peroxidating disuccinic acid (DSP), peroxidating diglutaric acid.Described water solublity organic peroxide is the organic peroxide with hydrophilic functional group's (such as carboxyl, sulfonic acid or hydroxyl), when these organic peroxides are used for polymerization initiator, the polymer end groups from initiator is described hydrophilic end group.In the situation of peroxidating disuccinic acid, end group is carboxyl.
As polymerization initiator, both can only use a kind of above-mentioned water-soluble peroxide, it is possible to use two or more.Wherein, it is preferable that polymer end groups is the water-soluble peroxide of carboxyl.If it is considered that the suitable decomposition temperature of described water-soluble peroxide, the simplicity of process, cost, polymer ends structure, then polymerization initiator is more preferably APS, KPS and DSP.
In the present invention, as it has been described above, when any one system in persulfate, water solublity organic peroxide is used for polymerization initiator, the end from initiator becomes hydrophilic radical, even if therefore when being absent from fluorine-containing surfactant, emulsion intercalation method is also good.
Kind that the addition of above-mentioned water-soluble peroxide is heavily dependent on this water-soluble peroxide, the kind of the chain-transferring agent share and addition or the polymerizing condition such as polymerization temperature and polymerization pressure.Therefore, suitable addition is different according to the difference of polymerization system, can not broadly specify, but from generating the angle of the polymer chain with the hydrophilic end group providing emulsification, described water-soluble peroxide is 20ppm～3000ppm preferably with respect to aqueous medium.If above-mentioned addition less than 20ppm relative to aqueous medium, then generates high molecular PTFE sometimes, and can not get the emulsified particles of low-molecular-weight PTFE, as it has been described above, easily occur in substrate that dispersion is bad.
The manufacture method of the present invention carries out preferably under the existence of stabilizer.As stabilizer, it is preferable that paraffin (paraffinwax, carbon number is the hydrocarbon of more than 16), containing fluorocarbon oil, fluoride compound, silicone oil etc., wherein preferred paraffin.Melting point of paraffin wax is preferably generally 40 DEG C～65 DEG C.By carrying out emulsion polymerization in the aqueous medium comprising such stabilizer, it is possible to hinder the coagulation between the emulsified particles generated in polymerization system, it is possible to obtain low-molecular-weight PTFE with the form of more stable emulsified particles.
From the angle more stably making low-molecular-weight PTFE emulsifying, it is preferable that above-mentioned paraffin phase is 0.1 mass parts～12 mass parts for 100 mass parts aqueous mediums.Relative to 100 mass parts aqueous mediums, the preferred lower limit of above-mentioned content is 1 mass parts, and the preferred upper limit is 8 mass parts.
The manufacture method of the present invention is to constitute by carrying out the emulsion polymerization of TFE in containing above-mentioned chain-transferring agent and water-soluble peroxide and the aqueous medium of stabilizer that adds if desired.
In above-mentioned polymerization, the polymerizing condition such as polymerization temperature, polymerization pressure is not particularly limited, it is possible to TFE amount, the kind of modified monomer and the amount of modified monomer or productivity ratio etc. according to using are suitable for selecting.
Above-mentioned polymerization temperature is preferably 5 DEG C～100 DEG C, more preferably 50 DEG C～90 DEG C.
Above-mentioned polymerization pressure is preferably 0.1MPa～3.0MPa.
Above-mentioned emulsion polymerization can start as follows: puts into aqueous medium, chain-transferring agent, monomer and stabilizer if desired in the pressure-resistant reaction vessel be equipped with blender, after adjusting temperature and pressure, adds polymerization initiator, thus starts emulsion polymerization.The polymerization of described emulsion can carry out to when supplying monomer in described aqueous medium on limit.
In above-mentioned polymerization, as above-mentioned monomer, except TFE, it is also possible to modified monomer added as described above.
Preferably while above-mentioned aqueous medium being stirred while carrying out above-mentioned emulsion polymerization, if but stirred by force, then mechanical shear stress causes emulsified particles coagulation, polyreaction carries out at liquid-vapor interface, there is the polymerization caused by suspension polymerisation in result, sometimes can not get the emulsified particles formed by low-molecular-weight PTFE.Therefore, described emulsion be polymerized in, as the reaction scale of polymerizing condition, polymerization temperature and polymerization pressure identical time, compared with the suspension polymerisation of general fluoropolymer, it is preferable that reduce mixing speed.
The mixing speed of above-mentioned emulsion polymerization can not generate condensation granule by observation liquid-vapor interface and carries out suitable selection according to polymerization scale and other polymerizing conditions, is not particularly limited.
In the manufacture method of the present invention, it is possible to obtain the aqueous liquid dispersion (latex, latex) of low-molecular-weight PTFE by carrying out above-mentioned emulsion polymerization.Described aqueous liquid dispersion is usually the emulsified particles of less than 1 μm of low-molecular-weight PTFE to be disperseed in an aqueous medium.
From the viewpoint of dispersion stabilization, it is preferable that the average primary particle diameter of above-mentioned emulsified particles is 100nm～300nm.Although not adding fluorine-containing surfactant, but the manufacture method of the present invention can make average primary particle diameter be 100nm～300nm.
In this manual, above-mentioned " average primary particle diameter " mean diameter of the emulsified particles of low-molecular-weight PTFE not carrying out concentrating after polymerization, diluting, refine etc. in the aqueous liquid dispersion (aqueous liquid dispersion after so-called polymerization) processed is referred to.
Above-mentioned average primary particle diameter is identified below: low-molecular-weight PTFE concentration is adjusted to 0.22 mass % and obtains aqueous liquid dispersion, measure the 550nm projection light transmitance relative to this aqueous liquid dispersion of unit length, and by being measured determining average primary particle diameter to the directed footpath in transmission electron microscope photo, calibration curve is made by above-mentioned transmitance and average primary particle diameter, for as the aqueous liquid dispersion measuring object, measure above-mentioned transmitance, determine its average primary particle diameter based on described calibration curve.
For passing through to carry out the aqueous liquid dispersion that above-mentioned emulsion polymerization is obtained, the solid component concentration being generally possible to make under state after polymerisation low-molecular-weight PTFE is 7 mass %～25 mass %.Consider that productivity ratio, the preferred lower limit of above-mentioned content be 8 mass %, preferred lower limit are 10 mass %.
In this manual, the solid component concentration of low-molecular-weight PTFE is obtained as following ratio: will measure object dry 3 hours at 150 DEG C, obtains the quality (Zg) that the adds thermal residue ratio relative to the quality (Xg) of this mensuration object.
Low-molecular-weight PTFE is also one of present invention, it is characterised in that described low-molecular-weight PTFE is obtained by the manufacture method of the above-mentioned present invention.
The low-molecular-weight PTFE of the present invention can be aqueous liquid dispersion, powder (micropowder) or arbitrary shape.
As it has been described above, the low-molecular-weight PTFE of the present invention is generally 7 × 10 at the melt viscosity of 380 DEG C5Below Pa s.
Above-mentioned melt viscosity is preferably 5 × 104Below Pa s.
Even if the low-molecular-weight PTFE of the present invention is aqueous liquid dispersion, powder or arbitrary shape, also being able to when without existing fluorine-containing surfactant manufacture, therefore the low-molecular-weight PTFE of the present invention has been substantially free of perfluoro caprylic acid (PFOA) and salt thereof and perfluorinated sulfonic acid (PFOS) and salt thereof.If the low-molecular-weight PTFE of the present invention has been substantially free of perfluoro caprylic acid (PFOA) and salt thereof and perfluorinated sulfonic acid (PFOS) and salt thereof, then painted when can suppress molding, therefore it is advantageous for.
In this manual, " being substantially free of " refers to, does not use them as raw material and below the 100ppb that its content is polymer solids component amount.
The aqueous liquid dispersion of above-mentioned low-molecular-weight PTFE both can be through above-mentioned emulsion and had been polymerized the aqueous liquid dispersion that directly obtains, it is also possible to be described aqueous liquid dispersion is concentrated, dilute, the aqueous liquid dispersion after post processing such as refine.Described post processing can utilize existing known method to carry out, and is not particularly limited.Method as described concentration, it is possible to enumerate such as cloud point concentration method (layer partition method).
Above-mentioned aqueous liquid dispersion preferably comprises the low-molecular-weight PTFE granule that average primary particle diameter is 100nm～300nm.
From the viewpoint of treatability etc., in the aqueous liquid dispersion of above-mentioned low-molecular-weight PTFE, it is preferable that the solid component concentration of low-molecular-weight PTFE is 20 mass %～80 mass %.The aqueous liquid dispersion with the solid component concentration in above-mentioned scope can obtain by carrying out concentrating after completing above-mentioned emulsion polymerization.
The powder of above-mentioned low-molecular-weight PTFE can by obtaining above-mentioned aqueous liquid dispersion condensation.That is, above-mentioned powder is to be polymerized the aqueous liquid dispersion obtained for raw material through emulsion, therefore, it is possible to do not carry out the post processings such as pulverizing and obtain described powder, and can control its apparent density and mean diameter.
From the viewpoint of treatability, it is preferable that the mean diameter of above-mentioned low-molecular-weight PTFE powder is 1 μm～30 μm, more preferably 2 μm～20 μm.The mean diameter powder less than 1 μm easily flies upward owing to apparent density is little, and treatability is poor.The mean diameter powder more than 30 μm is difficult to fine dispersion in host material, easily occurs the block of low-molecular-weight PTFE in host material.
For above-mentioned mean diameter, use laser diffraction formula particle size distribution device (laser society of Japan manufactures), do not use cascade, measuring particle size distribution when pressure 0.1MPa, minute 3 seconds, described mean diameter is equal to the particle diameter corresponding with the 50% of obtained particle size distribution integration.
As it has been described above, utilizing the low-molecular-weight PTFE powder that emulsion polymerization obtains is formed by the coagulation of emulsified particles, therefore its specific surface area is generally 7m2/ g～15m2/ g, more than the low-molecular-weight PTFE powder utilizing suspension polymerisation to directly obtain.If described specific surface area is big, then soft granules, for instance the surface modification effect improving film coated surface texture etc. is higher.And it is possible to it is many and to the stable dispersion of host material to obtain oil absorption.Thus, the specific surface area of described low-molecular-weight PTFE is preferably 9m2/ g～15m2/ g.If described specific surface area is less than 7m2/ g, then the fine dispersion in host material is poor.
In this manual, utilize surface analysis meter (trade name: MONOSORB, QUANTACHLROME society manufacture), use 30% nitrogen, 70% helium mixing gas as carrier gas, adopt liquid nitrogen to cool down, utilize BET method measurement the specific area.
As the method that the aqueous liquid dispersion of above-mentioned low-molecular-weight PTFE is carried out condensation, general mechanical shear stress makes emulsified particles coagulation, but from reducing the angle of the polymer remained in after condensation in aqueous phase, preferably in the aqueous liquid dispersion before condensation adding the electrolyte such as nitric acid, sulphuric acid, ammonium nitrate as condensation agent, when using acid in the electrolyte, with the aqueous phase in the alkali such as sodium hydroxide or potassium hydroxide and after condensation and condensation granule after preferred condensation, and preferably further again clean condensation granule with pure water.
The low-molecular-weight PTFE aqueous liquid dispersion and the specific surface area that are substantially free of perfluoro caprylic acid (PFOA) and salt thereof and perfluorinated sulfonic acid (PFOS) and salt thereof are 7m2/ g～15m2/ g and be substantially free of the low-molecular-weight PTFE powder of PFOA, PFOS and their salt and fall within scope of the invention.
Such low-molecular-weight PTFE aqueous liquid dispersion and low-molecular-weight PTFE powder can be readily derived by implementing the manufacture method of the low-molecular-weight PTFE aqueous liquid dispersion of the present invention.
In addition, from the angle being substantially free of nonionic surfactant, the low-molecular-weight PTFE aqueous liquid dispersion of the present invention is different from existing aqueous liquid dispersion, existing aqueous liquid dispersion be utilize nonionic surfactant to make the existing aqueous liquid dispersion stabilisation containing PFOA and PFOS after reduce or remove PFOA and PFOS again and the aqueous liquid dispersion that obtains.
Method as the fluorine-containing surfactant reduced or in removing aqueous liquid dispersion, can enumerate such as, the method (Japanese Unexamined Patent Application Publication 2002-532583 publication) carrying out ion exchange resin treatment, the method (No. 2004/050719 publication of international publication) repeating to utilize the concentration of cloud point, use ultrafiltrationmembrane process method (Japanese Laid-Open Patent Publication 55-120630 publication) etc., even if the present invention does not use these methods, also it is substantially free of PFOA and PFOS.
As it has been described above, the low-molecular-weight PTFE of the present invention obtains when without fluorine-containing surfactant, so there is no problem caused by this surfactant such as the painted grade.Thus, described low-molecular-weight PTFE can be used as additive aptly.
Purposes for above-mentioned additive is not particularly limited, and it can be used as the additive that moulding material, ink, cosmetic preparation, coating, grease, toner are modified aptly.
As above-mentioned moulding material, it is possible to enumerate the engineering plastics such as such as polyoxybenzoyl polyester, polyimides, polyamide, polyamidoimide, polyacetals, Merlon, polyphenylene sulfide.
The low-molecular-weight PTFE of the present invention can be suitably used for such as following purposes as the additive of moulding material: for improving the not viscosity of photocopying roll and the purposes of sliding properties；Improve the purposes of the texture of the engineering plastics products formed such as cover of the sheet surface layer of furniture, the instrument board of automobile, family's electrical article；Improve the sliding of the mechanical part of the generation mechanical frictions such as light main bearing, gear, cam, the button of push-button telephone, projector, camera component, sliding material and the purposes of wearability；And it is used as the processing aid etc. of engineering plastics.
The low-molecular-weight PTFE of the present invention can act as the additive of coating to improve the sliding of varnish and coating.
The low-molecular-weight PTFE of the present invention can act as the additive of cosmetic preparation to improve the sliding etc. of the cosmetics such as foundation cream.
Additionally, the low-molecular-weight PTFE of the present invention is also adapted to improve the purposes of the grease proofness of wax etc. or water proofing property, improve the purposes of the sliding of grease and toner.
Moulding material, coating, cosmetic preparation, grease or the toners such as the engineering plastics containing such low-molecular-weight PTFE are also one of present invention.Additionally, moulding material, coating, cosmetic preparation, grease or the toner such as engineering plastics containing above-mentioned low-molecular-weight PTFE powder are also one of present invention.
The manufacture method of the low-molecular-weight PTFE aqueous liquid dispersion of the present invention is owing to having above-mentioned composition, it is thus able to when not using fluorine-containing surfactant and carries out emulsion polymerization, it is possible to produce with low cost aqueous liquid dispersion and the powder of low-molecular-weight PTFE.The low-molecular-weight PTFE of the present invention is substantially free of PFOA, PFOS and their salt, and it can be used as the additive that moulding material, ink, cosmetics, coating, grease, toner etc. are modified aptly.The specific surface area of the powder obtained by aqueous liquid dispersion is relatively big, for 7m2/ g～15m2/ g, the fine dispersion in host material is good, and surface modification effect is also high.
Detailed description of the invention
The present invention will be described in more detail to enumerate embodiment below, but the present invention is not limited in described embodiment.As long as it addition, not special declaration, " part " and " % " in each embodiment and comparative example refers respectively to " mass parts " and " quality % ".
Comparative example 1
3.2L deionized water and the 3.2g perfluorooctanoic acid (APFO) as fluorine system emulsifying agent, enclosed high pressure still is put in the stainless steel autoclave that internal volume is 6L be equipped with stainless steel anchor type stirring paddle and temperature adjustment sleeve pipe.By repeating the press-in, degassed of more than 2 times nitrogen, the oxygen in removing system, then utilize tetrafluoroethene (TFE) to be pressed into the ethane of 0.8g as chain-transferring agent, pressure in groove is set to 0.10MPa.Under the stirring of 500rpm, by heating up in groove, after temperature reaches 85 DEG C in groove, it is pressed again by TFE, pressure in groove is adjusted 0.80MPa.
TFE is utilized to be pressed in groove the aqueous solution (it dissolves 425mg Ammonium persulfate. (APS) in 20ml deionized water and obtains) as polymerization initiator.The decomposition of polymerization initiator causes that in groove, pressure reduces, and therefore supplies TFE continuously, pressure in groove is maintained 0.80 ± 0.05MPa.Temperature in groove is regulated at 85 ± 1 DEG C by reaction always, speed of agitator is controlled as 500rpm.Stop stirring in the moment that consumption is 800g of TFE, pressure in groove is opened into normal pressure, next replaces gas phase with nitrogen, thus obtaining the aqueous liquid dispersion of low-molecular-weight PTFE.
2g nitric acid is added in the above-mentioned low-molecular-weight PTFE aqueous liquid dispersion of 2000g, its condensation is made by giving violent mechanical shear stress, next the powder of obtained moisture state is washed, then it is filtered, the hot air circulation type drying machine utilizing 160 DEG C dries 18 hours, thus obtains the powder of low-molecular-weight PTFE.
Comparative example 2
In system, do not add APFO and ethane, add and 850mg Ammonium persulfate. (APS) is dissolved in 20ml deionized water the aqueous solution that obtains as polymerization initiator, mixing speed in reaction is controlled at 700rpm, in addition, carries out polyreaction in the same manner as comparative example 1.Stirring is stopped in the moment that consumption is 355g of TFE.The liquid-vapor interface in reaction vessel after polymerisation swims the polymer beads that particle diameter is more than 1000 μm, is therefore reclaimed by described granule.
The powder of obtained moisture state is washed, is then filtered, utilize the hot air circulation type drying machine of 160 DEG C to dry 18 hours, thus obtain the powder of TFE polymer.Powder output obtained after drying is 349g.
Comparative example 3
The addition of ethane is become 2g, the addition of APS is become 850mg, in addition, obtain the aqueous liquid dispersion of PTFE in the same manner as comparative example 1.
Above-mentioned aqueous liquid dispersion is carried out condensation, cleaning, drying process in the same manner as comparative example 1, obtains the powder of low-molecular-weight PTFE.
Embodiment 1
In system, do not add APFO, and to make polymerization initiator and chain-transferring agent be the amount shown in table 1, control the mixing speed in reaction for 700rpm, in addition, to obtain the aqueous liquid dispersion of low-molecular-weight PTFE in the same manner as comparative example 1.In obtained aqueous liquid dispersion, liquid-vapor interface does not almost occur polymer beads.
Above-mentioned aqueous liquid dispersion is carried out condensation, cleaning, drying process in the same manner as comparative example 1, obtains the low-molecular-weight PTFE powder as goal object.
Above-mentioned aqueous liquid dispersion adds the TDS-80C that quality is 6.0 mass % (the first industrial pharmaceutical) relative to low-molecular-weight PTFE as nonionic system surfactant, after pH is adjusted 9.0 by recycling ammonia, stand at the temperature of 65 DEG C in normal pressure, moisture evaporation is thus made to concentrate, so that the solid constituent of low-molecular-weight PTFE reaches 60 mass %.The average primary particle diameter of the PTFE primary particle in the aqueous liquid dispersion after concentration is identical with the aqueous liquid dispersion before concentration.
Embodiment 2
Control to be 600rpm by the mixing speed in reaction, in addition, obtain the aqueous liquid dispersion of low-molecular-weight PTFE similarly to Example 1.In obtained aqueous liquid dispersion, liquid-vapor interface does not almost occur polymer beads.
Above-mentioned aqueous liquid dispersion is carried out similarly to Example 1 condensation, cleaning, drying process, obtains the low-molecular-weight PTFE powder as goal object.
Embodiment 3
Control to be 500rpm by the mixing speed in reaction, in addition, obtain the aqueous liquid dispersion of low-molecular-weight PTFE similarly to Example 1.In obtained aqueous liquid dispersion, liquid-vapor interface does not almost occur polymer beads.Above-mentioned aqueous liquid dispersion is carried out similarly to Example 1 condensation, cleaning, drying process, obtains the powder of the low-molecular-weight PTFE as goal object.
The aqueous liquid dispersion of the low-molecular-weight PTFE obtained in each embodiment and comparative example 1 is carried out the physical property evaluation of following (1)～(2), the powder obtained in each embodiment and each comparative example is carried out the physical property evaluation of following (3)～(7).
(1) solid component concentration in aqueous liquid dispersion (P%)
Aqueous liquid dispersion (Xg) is heated 3 hours at 150 DEG C, utilizes formula based on the thermal residue (Zg) that adds after heating: P=Z/X × 100 (%) determines described solid component concentration (P%).
(2) average primary particle diameter
The concentration of polymer is adjusted to the aqueous liquid dispersion of 0.22 mass %, measure the 550nm projection light transmitance relative to this aqueous liquid dispersion of unit length, and determine average primary particle diameter by measuring the directed footpath in transmission electron microscope photo, calibration curve is made by above-mentioned transmitance and average primary particle diameter, for as the aqueous liquid dispersion measuring object, measure above-mentioned transmitance, determine its average primary particle diameter based on described calibration curve.
(3) apparent density
It is measured according to JISK6891.
(4) mean diameter
Use laser diffraction formula particle size distribution device (laser society of Japan manufactures), do not use cascade, particle size distribution is measured, the particle diameter that described mean diameter is corresponding when being 50% equal to obtained particle size distribution integration when pressure 0.1MPa, minute 3 seconds.
(5) melt viscosity
According to ASTMD1238, use flow tester (Shimadzu Seisakusho Ltd.'s manufacture) andMouth die, take 2g and heat the sample after 5 minutes measuring temperature (340 DEG C or 380 DEG C) in advance, under the load of 0.7MPa, described sample be maintained at described temperature and be measured.
(6) fusing point
Use Differential Scanning Calorimetry determinator RDC220 (DSC) that SIINanoTechnology society manufactures, after using indium, lead to carry out temperature correction as standard sample in advance, about 3mg low-molecular-weight PTFE powder is put in aluminum ware (press seal container), air at 200ml/ minute flows down, heat up with 10 DEG C/min the temperature provinces of 250 DEG C～380 DEG C, with the melting caloric smallest point in described region for fusing point.
(7) specific surface area
Utilize BET method, use surface analysis meter (trade name: MONOSORB, QUANTACHLROME society manufactures), measurement the specific area.Additionally, the mixing gas of use 30% nitrogen, 70% helium is as carrier gas, liquid nitrogen is used to cool down.
Above result is listed in table 1.
[table 1]
The melt viscosity of ※ 1 sample is very high, more than the determination of the upper limit for flow tester (Shimadzu Seisakusho Ltd.'s manufacture).
From result above, in embodiments, can obtain not containing the aqueous liquid dispersion of the emulsified particles containing low-molecular-weight PTFE of APFO and perfluorinated sulfonic acid in the same manner as having carried out the comparative example 1 of emulsion polymerization, but in the comparative example 2 not using ethane, can not get low-molecular-weight PTFE, and can not get the aqueous dispersion as product, it is impossible to utilize emulsion polymerization to react.
Industrial applicibility
The manufacture method of the low-molecular-weight PTFE aqueous liquid dispersion of the present invention is owing to having above-mentioned composition, it is thus possible to manufacture low-molecular-weight PTFE with low cost.The low-molecular-weight PTFE of the present invention can be used as the additive that moulding material, ink, cosmetics, coating, grease, toner etc. are modified aptly.The powder obtained by aqueous liquid dispersion fine dispersion in host material is good, and the modified effect on surface is also high.
Claims (2)
1. a low-molecular-weight PTFE aqueous liquid dispersion, it is characterised in that described low-molecular-weight PTFE aqueous liquid dispersion has been substantially free of perfluoro caprylic acid (PFOA) and salt thereof and perfluorinated sulfonic acid (PFOS) and salt thereof,
Described aqueous liquid dispersion contains the low-molecular-weight PTFE granule that average primary particle diameter is 100nm～300nm,
Described low-molecular-weight PTFE is proplast or modified Teflon,
Described modified Teflon is by the polymer that can obtain with the copolymerization of the modified monomer of tetrafluoroethene copolymerization and tetrafluoroethene, and modified monomer unit is below the 1 mass % of total monomer units.
2. a low-molecular-weight PTFE powder, it is characterised in that the specific surface area of described low-molecular-weight PTFE powder is 7m2/ g～15m2/ g and be substantially free of perfluoro caprylic acid (PFOA) and salt thereof and perfluorinated sulfonic acid (PFOS) and salt thereof,
Low-molecular-weight PTFE is proplast or modified Teflon,
Described modified Teflon is by the polymer that can obtain with the copolymerization of the modified monomer of tetrafluoroethene copolymerization and tetrafluoroethene, and modified monomer unit is below the 1 mass % of total monomer units.
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| JP5338667B2 (en) * | 2007-08-07 | 2013-11-13 | ダイキン工業株式会社 | Low molecular weight polytetrafluoroethylene aqueous dispersion, low molecular weight polytetrafluoroethylene powder and method for producing low molecular weight polytetrafluoroethylene |
| JP5287310B2 (en) * | 2009-02-06 | 2013-09-11 | ダイキン工業株式会社 | Low molecular weight polytetrafluoroethylene aqueous dispersion, low molecular weight polytetrafluoroethylene powder and method for producing low molecular weight polytetrafluoroethylene |
| JP5697308B2 (en) * | 2009-03-02 | 2015-04-08 | ダイキン工業株式会社 | Low molecular weight polytetrafluoroethylene powder and method for producing the same, low molecular weight polytetrafluoroethylene gelled powder, and coating for fixing member |
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| WO2013025916A2 (en) * | 2011-08-16 | 2013-02-21 | Kate Somerville Skincare, Llc. | Dermal rejuvenation compositions and methods |
| EP3000830A1 (en) * | 2011-08-25 | 2016-03-30 | Daikin Industries, Ltd. | Method for producing aqueous polytetrafluoroethylene dispersion |
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| CN113563613A (en) * | 2016-08-04 | 2021-10-29 | 大金工业株式会社 | Process for producing low molecular weight polytetrafluoroethylene |
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| CN107236063B (en) * | 2017-06-14 | 2018-01-23 | 广州华大生物科技有限公司 | A kind of preparation method of low molecular weight polytetrafluoroethylene |
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| CN111601666A (en) * | 2018-01-19 | 2020-08-28 | Ａｇｃ株式会社 | Method for manufacturing metal foil with resin |
| CN111683999B (en) * | 2018-02-07 | 2023-04-28 | 大金工业株式会社 | Process for producing low molecular weight polytetrafluoroethylene-containing composition |
| WO2019156053A1 (en) * | 2018-02-07 | 2019-08-15 | ダイキン工業株式会社 | Manufacturing method for low molecular weight polytetrafluoroethylene, and powder |
| JP7078441B2 (en) * | 2018-04-05 | 2022-05-31 | 三菱鉛筆株式会社 | Polytetrafluoroethylene aqueous dispersion |
| JP7183663B2 (en) * | 2018-09-26 | 2022-12-06 | 富士フイルムビジネスイノベーション株式会社 | Image forming apparatus and process cartridge |
| EP3858456A4 (en) | 2018-09-28 | 2022-07-20 | Daikin Industries, Ltd. | Filter medium for air filter, filter pack, air filter unit, and manufacturing methods therefor |
| US20210340290A1 (en) * | 2018-10-03 | 2021-11-04 | Daikin Industries, Ltd. | Polytetrafluoroethylene production method |
| JP7181480B2 (en) | 2021-02-04 | 2022-12-01 | ダイキン工業株式会社 | Air filter medium, method for manufacturing air filter medium, filter medium for mask, and filter medium for pleated mask |
| EP4353344A1 (en) | 2021-06-04 | 2024-04-17 | Daikin Industries, Ltd. | Air filter medium, pleated filter medium, air filter unit, mask filtering medium, and method of recycling air filter medium |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1692132A (en) * | 2002-07-29 | 2005-11-02 | 3M创新有限公司 | Fluoroelastomer copolymer based on tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene and vinylidene fluoride |
| CN1753939A (en) * | 2003-02-28 | 2006-03-29 | 大金工业株式会社 | Granulated powder of low-molecular polytetrafluoro- ethylene and powder of low-molecular polytetrafluoro- ethylene and processes for producing both |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5141085A (en) * | 1974-10-05 | 1976-04-06 | Daikin Ind Ltd | TETORAFURUORUECHIRENWATSUKUSUNO SEIZOHO |
| US7074862B2 (en) * | 2001-05-02 | 2006-07-11 | 3M Innovative Properties Company | Emulsifier free aqueous emulsion polymerization process for making fluoropolymers |
| CN1289547C (en) * | 2001-05-02 | 2006-12-13 | 3M创新有限公司 | Aqueous emulsion polymerization in presence of ethers as chaine transfer agents to produce fluoropolymers |
| JP2006504844A (en) * | 2002-10-31 | 2006-02-09 | スリーエム イノベイティブ プロパティズ カンパニー | Emulsifier-free aqueous emulsion polymerization to produce copolymers of fluorinated olefins and hydrocarbon olefins |
| US6869997B2 (en) * | 2003-05-06 | 2005-03-22 | Arkema, Inc. | Polymerization of fluoromonomers using a 3-allyloxy-2-hydroxy-1-propanesulfonic acid salt as surfactant |
-
2007
- 2007-06-25 JP JP2007166240A patent/JP5532532B2/en active Active
-
2008
- 2008-06-24 CN CN201110226075.8A patent/CN102382218B/en active Active
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1692132A (en) * | 2002-07-29 | 2005-11-02 | 3M创新有限公司 | Fluoroelastomer copolymer based on tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene and vinylidene fluoride |
| CN1753939A (en) * | 2003-02-28 | 2006-03-29 | 大金工业株式会社 | Granulated powder of low-molecular polytetrafluoro- ethylene and powder of low-molecular polytetrafluoro- ethylene and processes for producing both |
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