CN1331920C - Granulated powder of low-molecular polytetrafluoro- ethylene and powder of low-molecular polytetrafluoro- ethylene and processes for producing both - Google Patents
Granulated powder of low-molecular polytetrafluoro- ethylene and powder of low-molecular polytetrafluoro- ethylene and processes for producing both Download PDFInfo
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- CN1331920C CN1331920C CNB2004800051578A CN200480005157A CN1331920C CN 1331920 C CN1331920 C CN 1331920C CN B2004800051578 A CNB2004800051578 A CN B2004800051578A CN 200480005157 A CN200480005157 A CN 200480005157A CN 1331920 C CN1331920 C CN 1331920C
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- Prior art keywords
- molecular weight
- low molecular
- powder
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- weight ptfe
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Links
- 229920001343 polytetrafluoroethylene Polymers 0.000 title claims abstract description 403
- 239000004810 polytetrafluoroethylene Substances 0.000 title claims abstract description 391
- 239000000843 powder Substances 0.000 title claims abstract description 311
- 238000000034 method Methods 0.000 title claims abstract description 97
- -1 polytetrafluoro- ethylene Polymers 0.000 title claims abstract description 91
- 229940058401 polytetrafluoroethylene Drugs 0.000 title 2
- 239000002245 particle Substances 0.000 claims abstract description 101
- 238000005469 granulation Methods 0.000 claims description 81
- 230000003179 granulation Effects 0.000 claims description 79
- 239000007788 liquid Substances 0.000 claims description 71
- 239000006185 dispersion Substances 0.000 claims description 49
- 238000004519 manufacturing process Methods 0.000 claims description 44
- 239000013543 active substance Substances 0.000 claims description 36
- 239000002612 dispersion medium Substances 0.000 claims description 17
- 239000000155 melt Substances 0.000 claims description 8
- 238000010557 suspension polymerization reaction Methods 0.000 abstract description 18
- 238000006116 polymerization reaction Methods 0.000 description 50
- 239000000463 material Substances 0.000 description 46
- 238000001879 gelation Methods 0.000 description 43
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 41
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 26
- 238000004945 emulsification Methods 0.000 description 19
- 239000000654 additive Substances 0.000 description 14
- 230000000996 additive effect Effects 0.000 description 14
- 239000012986 chain transfer agent Substances 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 13
- JRKICGRDRMAZLK-UHFFFAOYSA-L persulfate group Chemical group S(=O)(=O)([O-])OOS(=O)(=O)[O-] JRKICGRDRMAZLK-UHFFFAOYSA-L 0.000 description 13
- 238000003756 stirring Methods 0.000 description 13
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 13
- 239000003054 catalyst Substances 0.000 description 12
- 239000007858 starting material Substances 0.000 description 12
- 239000000460 chlorine Substances 0.000 description 11
- 229920001519 homopolymer Polymers 0.000 description 11
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 9
- 239000007787 solid Substances 0.000 description 9
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 8
- 238000009826 distribution Methods 0.000 description 8
- 238000000465 moulding Methods 0.000 description 8
- 125000000962 organic group Chemical group 0.000 description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 7
- 239000003795 chemical substances by application Substances 0.000 description 7
- 239000002609 medium Substances 0.000 description 7
- 238000009834 vaporization Methods 0.000 description 7
- 230000008016 vaporization Effects 0.000 description 7
- 238000000576 coating method Methods 0.000 description 6
- 238000011156 evaluation Methods 0.000 description 6
- 239000012530 fluid Substances 0.000 description 6
- 229930195733 hydrocarbon Natural products 0.000 description 6
- 150000002430 hydrocarbons Chemical class 0.000 description 6
- 239000004215 Carbon black (E152) Substances 0.000 description 5
- 125000004432 carbon atom Chemical group C* 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 5
- 229920006351 engineering plastic Polymers 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000001035 drying Methods 0.000 description 4
- 239000000945 filler Substances 0.000 description 4
- 238000001914 filtration Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 4
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 4
- 239000003960 organic solvent Substances 0.000 description 4
- SNGREZUHAYWORS-UHFFFAOYSA-N perfluorooctanoic acid Chemical compound OC(=O)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)F SNGREZUHAYWORS-UHFFFAOYSA-N 0.000 description 4
- 230000000704 physical effect Effects 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000000926 separation method Methods 0.000 description 4
- 238000010792 warming Methods 0.000 description 4
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 3
- 125000005010 perfluoroalkyl group Chemical group 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 229920002503 polyoxyethylene-polyoxypropylene Polymers 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 230000006641 stabilisation Effects 0.000 description 3
- 238000011105 stabilization Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 239000004160 Ammonium persulphate Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000004438 BET method Methods 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 2
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 2
- 229930182556 Polyacetal Natural products 0.000 description 2
- 239000004962 Polyamide-imide Substances 0.000 description 2
- 239000004642 Polyimide Substances 0.000 description 2
- 239000004734 Polyphenylene sulfide Substances 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- OUUQCZGPVNCOIJ-UHFFFAOYSA-M Superoxide Chemical compound [O-][O] OUUQCZGPVNCOIJ-UHFFFAOYSA-M 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 150000001408 amides Chemical class 0.000 description 2
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 2
- 235000019395 ammonium persulphate Nutrition 0.000 description 2
- 239000012736 aqueous medium Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 125000003236 benzoyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C(*)=O 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- UUAGAQFQZIEFAH-UHFFFAOYSA-N chlorotrifluoroethylene Chemical compound FC(F)=C(F)Cl UUAGAQFQZIEFAH-UHFFFAOYSA-N 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000007334 copolymerization reaction Methods 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000007720 emulsion polymerization reaction Methods 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- 239000003365 glass fiber Substances 0.000 description 2
- 150000002334 glycols Chemical class 0.000 description 2
- 239000004519 grease Substances 0.000 description 2
- 150000005826 halohydrocarbons Chemical class 0.000 description 2
- 238000007602 hot air drying Methods 0.000 description 2
- 150000002500 ions Chemical group 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 125000005009 perfluoropropyl group Chemical group FC(C(C(F)(F)F)(F)F)(F)* 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 229920002312 polyamide-imide Polymers 0.000 description 2
- 229920001707 polybutylene terephthalate Polymers 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 239000004417 polycarbonate Substances 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 229920001721 polyimide Polymers 0.000 description 2
- 229920006324 polyoxymethylene Polymers 0.000 description 2
- 229920000069 polyphenylene sulfide Polymers 0.000 description 2
- 229920001451 polypropylene glycol Polymers 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 230000002285 radioactive effect Effects 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 238000007669 thermal treatment Methods 0.000 description 2
- 238000001149 thermolysis Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 125000002023 trifluoromethyl group Chemical group FC(F)(F)* 0.000 description 2
- MIZLGWKEZAPEFJ-UHFFFAOYSA-N 1,1,2-trifluoroethene Chemical class FC=C(F)F MIZLGWKEZAPEFJ-UHFFFAOYSA-N 0.000 description 1
- 239000004342 Benzoyl peroxide Substances 0.000 description 1
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- PQUCIEFHOVEZAU-UHFFFAOYSA-N Diammonium sulfite Chemical compound [NH4+].[NH4+].[O-]S([O-])=O PQUCIEFHOVEZAU-UHFFFAOYSA-N 0.000 description 1
- 206010013786 Dry skin Diseases 0.000 description 1
- 206010016654 Fibrosis Diseases 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- 239000006057 Non-nutritive feed additive Substances 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 239000004159 Potassium persulphate Substances 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- DFHSLLVEDIHDNI-UHFFFAOYSA-N [Cl].ClC(=C(F)F)F Chemical compound [Cl].ClC(=C(F)F)F DFHSLLVEDIHDNI-UHFFFAOYSA-N 0.000 description 1
- 125000004183 alkoxy alkyl group Chemical group 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 235000019400 benzoyl peroxide Nutrition 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001721 carbon Chemical group 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- VZGDMQKNWNREIO-UHFFFAOYSA-N carbon tetrachloride Substances ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 229910001919 chlorite Inorganic materials 0.000 description 1
- 229910052619 chlorite group Inorganic materials 0.000 description 1
- QBWCMBCROVPCKQ-UHFFFAOYSA-N chlorous acid Chemical compound OCl=O QBWCMBCROVPCKQ-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000006071 cream Substances 0.000 description 1
- 150000001924 cycloalkanes Chemical class 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000007673 developmental toxicity Effects 0.000 description 1
- 231100000415 developmental toxicity Toxicity 0.000 description 1
- VILAVOFMIJHSJA-UHFFFAOYSA-N dicarbon monoxide Chemical compound [C]=C=O VILAVOFMIJHSJA-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 230000004761 fibrosis Effects 0.000 description 1
- 230000003176 fibrotic effect Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 229940103065 helium 70 % Drugs 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 239000000976 ink Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- YWXYYJSYQOXTPL-SLPGGIOYSA-N isosorbide mononitrate Chemical compound [O-][N+](=O)O[C@@H]1CO[C@@H]2[C@@H](O)CO[C@@H]21 YWXYYJSYQOXTPL-SLPGGIOYSA-N 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 235000012204 lemonade/lime carbonate Nutrition 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 125000000740 n-pentyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229940120480 nitrogen 30 % Drugs 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 125000005003 perfluorobutyl group Chemical group FC(F)(F)C(F)(F)C(F)(F)C(F)(F)* 0.000 description 1
- 125000005005 perfluorohexyl group Chemical group FC(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)* 0.000 description 1
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical compound [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 description 1
- 235000019394 potassium persulphate Nutrition 0.000 description 1
- BHZRJJOHZFYXTO-UHFFFAOYSA-L potassium sulfite Chemical compound [K+].[K+].[O-]S([O-])=O BHZRJJOHZFYXTO-UHFFFAOYSA-L 0.000 description 1
- 235000019252 potassium sulphite Nutrition 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000001953 sensory effect Effects 0.000 description 1
- 210000000697 sensory organ Anatomy 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 235000012222 talc Nutrition 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000002966 varnish Substances 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Landscapes
- Processes Of Treating Macromolecular Substances (AREA)
Abstract
The invention provides granulated powder of low-molecular polytetrafluoroethylene which is reduced in the scattering of powder and the adhesion thereof to a hopper; low-molecular polytetrafluoroethylene powder obtained by suspension polymerization; and processes for producing both. The invention relates to granulated powder of low -molecular polytetrafluoroethylene which is characterized by being produced by granulating particles made of low-molecular polytetrafluoroethylene having a number-average molecular weight of 600,000 or below.
Description
Technical field
The present invention relates to low molecular weight polytetrafluoroethylene prilling powder, low molecular weight polytetrafluoroethylpowder powder and their manufacture method.
Background technology
For example use low molecular weight polytetrafluoroethylene with following purpose etc.: by low molecular weight polytetrafluoroethylene is mixed into as additive in the respective material (Xiang Shoucai) such as ink, makeup, thereby reduce the respective material surface friction, improve the purpose of slickness; By low molecular weight polytetrafluoroethylene is mixed in the coating, thereby improve the purpose etc. of the texture of gained film coated surface.
As low molecular weight polytetrafluoroethylene, known and to have obtained by the following method: obtained (for example, open clear 51-41085 communique and the spy opens flat 7-165828 communique) with reference to the spy by emulsion polymerization; By the thermolysis high molecular weight polytetrafluoroethyldispersions obtain (for example, with reference to the spy open clear 49-39642 communique, special fair 7-5744 communique, special public clear 50-15506 communique, the spy opens clear 61-118331 communique and the spy opens clear 61-162503 communique); And obtain (for example, with reference to special public clear 52-25419 communique, special public clear 49-48671 communique, the special flat 2001-513529 communique of table and No. 3766031 specification sheets of United States Patent (USP)) in the moulding bodies of the powder of high molecular weight polytetrafluoroethyldispersions or section etc. by the irradiation radioactive rays.
But, even the powder of low molecular weight polytetrafluoroethylene is to obtain by any one method in these methods, but when respective material is added etc., or powder flies upward or the powder of static electrification attached on the hopper, and have the problem of operability extreme difference.
Low molecular weight polytetrafluoroethylpowder powder flies upward or attached to the such problem on the hopper, thinks that one of them reason is that powder is formed by ultra micron.But, if address this problem and increase ultramicronized particle diameter, the dispersiveness in the time of then can reducing it and be mixed in the respective material as additive.
The low molecular weight polytetrafluoroethylpowder powder that was not in the past had this two specific character does not simultaneously take place promptly that powder flies upward or attached to the so-called operability on the hopper with as this two specific character of good dispersiveness of additive.
Operation is easy from making, the angle of narrow molecular weight distribution is considered, it is desirable to directly obtain low molecular weight polytetrafluoroethylene by polymerization, preferably needn't reduce the subsequent handling of molecular weight.As the method that directly obtains low molecular weight polytetrafluoroethylene by polymerization, known have emulsion polymerization, but also do not know the method (for example, opening flat 7-165828 communique with reference to the spy) for preparing by suspension polymerization.
And as the low molecular weight polytetrafluoroethylene that obtains by polymerization, known specific surface area is arranged is the powder (for example, opening flat 10-1476176 communique with reference to the spy) of 7m2/g～20m2/g.But, this powder have particle easily fly upward, easily attached to the defective on the hopper.
In addition; result etc. in the light of recent researches; Perfluorocaprylic Acid [PFOA] is clear and definite gradually to the suspection of the burden of environment; EPA on April 14 (USEPA) in 2003 the chemistry investigation having delivered to strengthen to PFOA (for example, with reference to EPA report " PRELIMINARY RISK ASSESSMENTOF THE DEVELOPMENTAL TOXICITY ASSOCIATED WITHEXPOSURE TO PERFLUOROOCTANOIC ACID AND ITS SALT ", internet＜URL:http=//www.epa.gov/opptintr/pfoa/pfoara.pfd).
Summary of the invention
In view of above-mentioned present situation, low molecular weight polytetrafluoroethylpowder powder that the invention provides the low molecular weight polytetrafluoroethylene prilling powder that reduced that powder flies upward or hopper is adhered to, obtains by suspension polymerization and their manufacture method.
The present invention relates to the low molecular weight polytetrafluoroethylene prilling powder, it is characterized in that, is to be handled by the low molecular weight polytetrafluoroethylene granulating particles that number-average molecular weight forms smaller or equal to 600,000 low molecular weight polytetrafluoroethylene to obtain.
The present invention relates to the manufacture method of low molecular weight polytetrafluoroethylene prilling powder, it is the manufacture method of handling the low molecular weight polytetrafluoroethylene prilling powder of making described low molecular weight polytetrafluoroethylene prilling powder by the low molecular weight polytetrafluoroethylene granulating particles, it is characterized in that described granulation is handled with aqueous dispersion of low molecular weight polytetrafluorethyleand more than or equal to 80 ℃ and carry out less than 100 ℃ temperature; Described aqueous dispersion of low molecular weight polytetrafluorethyleand is dispersed in described low molecular weight polytetrafluoroethylene particle in the aqueous dispersion medium in the presence of tensio-active agent and obtains.
The present invention relates to the manufacture method of low molecular weight polytetrafluoroethylene prilling powder, it is the manufacture method of handling the low molecular weight polytetrafluoroethylene prilling powder of making described low molecular weight polytetrafluoroethylene prilling powder by the low molecular weight polytetrafluoroethylene granulating particles, it is characterized in that described granulation is handled and carried out with aqueous dispersion of low molecular weight polytetrafluorethyleand; Described aqueous dispersion of low molecular weight polytetrafluorethyleand is each described low molecular weight polytetrafluoroethylene particle to be dispersed in the aqueous dispersion medium to obtain under the condition that has or do not exist tensio-active agent; Described aqueous dispersion of low molecular weight polytetrafluorethyleand contains water-insoluble liquid; With respect to the described low molecular weight polytetrafluoroethylene particle of 100 mass parts, described tensio-active agent is smaller or equal to 5 mass parts.
The present invention relates to low molecular weight polytetrafluoroethylpowder powder, it is characterized in that, at 340 ℃, use melt viscosity that flow velocity tester method measures, and obtain by suspension polymerization smaller or equal to 2500Pas.
The present invention relates to low molecular weight polytetrafluoroethylpowder powder, it is characterized in that, its specific surface area is less than 7m
2/ g uses melt viscosities that flow velocity tester methods measure smaller or equal to 2500Pas at 340 ℃.
The present invention relates to the manufacture method of low molecular weight polytetrafluoroethylpowder powder, it is following method: use chain-transfer agent, make described low molecular weight polytetrafluoroethylpowder powder by suspension polymerization, it is characterized in that, described chain-transfer agent is hydrogen, rudimentary stable hydrocarbon or lower alcohol; Described suspension polymerization be to use polymerization starter at fluid temperature more than or equal to 40 ℃ and carry out less than 100 ℃ temperature; Described polymerization starter is the material that contains persulphate or sulphite and organo-peroxide.
The present invention relates to the manufacture method of low molecular weight polytetrafluoroethylpowder powder, it is following method: use chain-transfer agent, make described low molecular weight polytetrafluoroethylpowder powder by suspension polymerization, it is characterized in that, described chain-transfer agent is hydrogen, rudimentary stable hydrocarbon or lower alcohol; Described suspension polymerization is to use polymerization starter to carry out in the temperature of 5 ℃～40 ℃ of fluid temperatures; Described polymerization starter is the material that contains persulphate or sulphite and/or organo-peroxide and contain redox catalyst.
The present invention relates to low molecular weight polytetrafluoroethylene gelation powder, it is characterized in that it obtains through heat treated; Described heat treated is more than or equal to 250 ℃ and less than 340 ℃ temperature, and low molecular weight polytetrafluoroethylpowder powder is heated.
Below describe the present invention in detail.
Low molecular weight polytetrafluoroethylene prilling powder of the present invention (below, claim " lower molecular weight PTFE prilling powder ") be to handle by the lower molecular weight PTFE granulating particles that low-molecular-weight tetrafluoroethylene ((below, claim " lower molecular weight PTFE ") forms to obtain.
The number-average molecular weight of described lower molecular weight PTFE is smaller or equal to 600,000.If surpass 600,000, then owing to showing fiberization characteristics, easily aggegation, so little sometimes bad dispersibility.The number-average molecular weight of described lower molecular weight PTFE is so long as in above-mentioned scope, and preferred lower limit for example can be 10,000.If less than 10,000, then the volatility height under the high temperature is not suitable for the heat resisting coatings such as coating that must carry out roasting sometimes.
The number-average molecular weight of described lower molecular weight PTFE is according to the melt viscosity that uses flow velocity tester method to record and the corresponding value that calculates.
Described lower molecular weight PTFE, as long as its number-average molecular weight is smaller or equal to 600,000, can be the material that obtains of the aftermentioned polymerization process by lower molecular weight PTFE, the material that obtains by the thermolysis high molecular weight polytetrafluoroethyldispersions, by irradiation radioactive rays any one in the material that high molecular weight polytetrafluoroethyldispersions obtains.
Described lower molecular weight PTFE is proplast [TFE homopolymer] and/or modified Teflon [modified ptfe].
In this specification sheets, described " TFE homopolymer and/or modified ptfe " mean by the TFE homopolymer form and do not contain modified ptfe material, form and do not contain the material of TFE homopolymer or the material that forms by TFE homopolymer and modified ptfe by modified ptfe.
" tetrafluoroethylene " in described " lower molecular weight PTFE " term generally represents described TFE homopolymer, but by above-mentioned " lower molecular weight PTFE " be TFE homopolymer and/or modified ptfe as can be known, tetrafluoroethylene is not limited to the TFE homopolymer in this manual, the part of its " lower molecular weight PTFE " this term that is described.Described " lower molecular weight PTFE " is as a term whole expression TFE homopolymer and/or modified ptfe.
Described TFE homopolymer obtains as monomeric tetrafluoroethylene [TFE] by polymerization only.
Described modified ptfe means the polymkeric substance that is obtained by TFE and properties-correcting agent.
As the properties-correcting agent in the described modified ptfe, so long as can with the material of TFE copolymerization, just be not particularly limited, for example can enumerate: R 1216 perfluoroolefines such as [HFP]; Trifluorochloroethylene chlorine fluoroolefin such as [CTFE]; Trifluoro-ethylenes etc. contain HF hydrocarbon; Perfluoroalkyl vinyl ether etc.
Be not particularly limited as described perfluoroalkyl vinyl ether, can enumerate the represented perfluor unsaturated compound of for example following general formula (I) etc.
CF
2＝CF-ORf (I)
(in the formula, Rf represents the perfluor organic group).In this manual, described " perfluor organic group " means that the hydrogen atom that is bonded on the carbon atom is all replaced by fluorine atom and the organic group that forms.Described perfluor organic group can have ether oxygen.
As described perfluoroalkyl vinyl ether, for example can enumerate in described general formula (I) Rf and represent that carbonatoms is the perfluor (alkyl vinyl ether) [PAVE] of 1～10 perfluoroalkyl.The carbonatoms of described perfluoroalkyl preferred 1～5.
As the perfluoroalkyl in described PAVE, can enumerate for example perfluoro-methyl, perfluor ethyl, perfluoro propyl, perfluoro butyl, perfluor amyl group, perfluoro hexyl etc., but preferred perfluoro propyl.
As described perfluoroalkyl vinyl ether, for example can enumerate in described general formula (I) Rf and be expressed as follows the perfluor (alkoxyalkyl vinyl ether) of organic group or perfluor (alkyl polyoxy alkylidene vinyl ether) etc., described organic group is perfluor (alkoxyalkyl) group, the represented organic group of following formula of carbonatoms 4～9
(in the formula, m represents 0 or 1～4 integer),
The perhaps represented organic group of following formula
(in the formula, n represents 1～4 integer).
As the properties-correcting agent in the described modified ptfe, preferred perfluoroalkyl vinyl ether, trifluorochloroethylene, as perfluoroalkyl vinyl ether, preferred PAVE.
Account for the ratio (quality %) of the total amount of described properties-correcting agent and TFE as properties-correcting agent described in the described modified ptfe, for example using under the situation of described perfluoroalkyl vinyl ether as described properties-correcting agent, usually preferred its proportion is smaller or equal to 1 quality %, more preferably 0.001 quality %～1 quality %.
As described modified ptfe, can use a kind or at least 2 kinds different material on for example number-average molecular weight, copolymerization composition etc., as described TFE homopolymer, can use a kind or at least 2 kinds different material on number-average molecular weight for example.
Polymerization process as described lower molecular weight PTFE is not particularly limited, and can enumerate for example letex polymerization, suspension polymerization etc.
In the polymerization of described lower molecular weight PTFE, can use chain-transfer agent.By using described chain-transfer agent, can adjust the molecular weight of the lower molecular weight PTFE that obtains, can improve as additive dispersive dispersiveness in respective material.
As described chain-transfer agent, so long as hydrogen, rudimentary stable hydrocarbon or lower alcohol are not particularly limited.Can enumerate carbonatomss such as methane, ethane, propane, butane, hexane, hexanaphthene for example as described rudimentary stable hydrocarbon is 1～6 straight chain or cyclic alkane etc., as described lower alcohol, for example can enumerating, carbonatoms such as methyl alcohol, ethanol is alcohol of 1～3 etc.
During the polymerization of described lower molecular weight PTFE, at the molecule chain end of described lower molecular weight PTFE, generate unstable end group, these unstable end groups derive from the chemical structure of polymerization starter described later, above-mentioned chain-transfer agent.Be not particularly limited as described unstable end group, for example can enumerate-CH
2OH ,-COOH ,-COOCH
3Deng.
Described lower molecular weight PTFE has carried out the material after the stabilization to unstable end group.Stabilization method as described unstable end group is not particularly limited, and for example can enumerate by being exposed to make end be converted to trifluoromethyl [CF in the fluoro-gas
3] method etc.
In addition, described lower molecular weight PTFE can carry out terminal amideization.Method as described terminal amideization is not particularly limited, for example can enumerate as the spy open flat 4-20507 communique disclosed, make by in described fluoro-gas, expose waiting method that the fluorine carbonyl [COF] that obtains contacts with ammonia etc.
If described lower molecular weight PTFE has carried out stabilization or terminal amideization to described unstable end group, lower molecular weight PTFE prilling powder of the present invention that then obtains or lower molecular weight PTFE powder of the present invention described later, when being used as the additive of respective material such as relative ink, coating, makeup, be easy to fuse, can improve dispersed with respective material.
As mentioned above, lower molecular weight PTFE prilling powder of the present invention is handled by lower molecular weight PTFE granulating particles and is obtained, hence one can see that, the lower molecular weight PTFE particle that forms by lower molecular weight PTFE among the present invention (below, claim " lower molecular weight PTFE particle ") be the particle of not handling through granulation.
In this manual, the particle of notion in comprising the solid state powder of described " lower molecular weight PTFE particle ", also comprise in the dispersion liquid that obtains by letex polymerization etc. as the dispersate divided particles.
The low molecular weight polytetrafluoroethylpowder powder that forms by described lower molecular weight PTFE particle (below, claim " lower molecular weight PTFE powder "), as mentioned above, it is the aggregate that does not pass through the lower molecular weight PTFE particle of granulation processing, at described lower molecular weight PTFE particle is under the situation of the particle in the solid state powder, and lower molecular weight PTFE powder is a described solid state powder self; At described lower molecular weight PTFE particle is under the situation of divided particles in the dispersion liquid, and lower molecular weight PTFE powder is the aggregate that is equivalent to be separated by ordinary methods such as condensations by described dispersed system the lower molecular weight PTFE particle of the dry powder that obtains.
The preferred median size of described lower molecular weight PTFE powder is 0.5 μ m～20 μ m.
In this manual, the median size of described lower molecular weight PTFE powder is following calculated value: use laser diffraction formula particle size distribution method to measure size-grade distribution, and will be corresponding to the particle diameter of size-grade distribution accumulative total 50% as median size.
Lower molecular weight PTFE prilling powder of the present invention is handled by described lower molecular weight PTFE granulating particles and is obtained.
In the past, the known number average molecular weight is difficult for fibrosis smaller or equal to 600,000 tetrafluoroethylene, be difficult for Fibrotic material and be considered to be difficult to granulation, it is with strange that lower molecular weight PTFE particle is carried out the granulation thing that granulation obtains, but the present invention has realized the granulation of lower molecular weight PTFE particle.
Described granulation is handled and is comprised following operation: with lower molecular weight PTFE particle and blended operations such as the filler of expecting according to aftermentioned to use, tensio-active agent, granulation medium; Using under the situation of described granulation medium the operation that the granulation thing that obtains is separated from the granulation medium; And carry out the exsiccant operation as required.Described granulation medium is that described lower molecular weight PTFE particle is present in wherein to carry out the medium that granulation is handled.Described granulation medium is water and/or organic liquid normally, selects according to the prilling process that uses.Be not particularly limited as described prilling process, for example can enumerate comminution granulation in the water, warm water comminution granulation, emulsification disperse comminution granulation, emulsification warm water comminution granulation, solvent-free comminution granulation, in formula solvent-granulation method etc.Disperse comminution granulation as comminution granulation in the water, emulsification warm water comminution granulation and emulsification, can use the comminution granulation in the manufacture method of lower molecular weight PTFE prilling powder of the present invention described later.
Comminution granulation is following method in the described water: lower molecular weight PTFE particle with after aftermentioned filler dry type is in case of necessity mixed, is added entry, further add water-insoluble liquid then in water, stir and form drop, isolate the lower molecular weight PTFE particle in the drop.Think in described drop, described water-insoluble liquid is between the polymer chain that constitutes lower molecular weight PTFE particle, but by heating, this water-insoluble flowing fluid ratio water is volatilization earlier, described polymer chain aggegation, particlized, thus lower molecular weight PTFE prilling powder formed.Comminution granulation is a method of not using tensio-active agent in the described water.As described water-insoluble liquid, can use with lower molecular weight PTFE prilling powder manufacture method of the present invention described later in spendable water-insoluble liquid phase with material.
Described warm water comminution granulation is to contain or do not containing under the condition of water-insoluble liquid, and the state that is elevated to 30 ℃～100 ℃ in the temperature with described aqueous dispersion medium carries out process for granulating.Described water-insoluble liquid is smaller or equal to 5 quality % of lower molecular weight PTFE aqueous liquid dispersion.
Described emulsification dispersion comminution granulation also can be described as and carry out process for granulating in the described water in the presence of tensio-active agent, be to use lower molecular weight PTFE aqueous liquid dispersion to carry out process for granulating, described lower molecular weight PTFE aqueous liquid dispersion is that lower molecular weight PTFE particle is dispersed in the presence of tensio-active agent in the aqueous medium that has added described water-insoluble liquid and forms.
Described emulsification warm water comminution granulation be the temperature with lower molecular weight PTFE aqueous liquid dispersion be elevated to more than or equal to 80 ℃ and less than 100 ℃ state under carry out process for granulating, described lower molecular weight PTFE aqueous liquid dispersion is that lower molecular weight PTFE particle is dispersed in the presence of tensio-active agent and is added with or does not add in the aqueous medium of described water-insoluble liquid and form.
The particle that obtains by comminution granulation in the described water, disperse particle that comminution granulation obtains and the particle that obtains by emulsification warm water comminution granulation, owing to, fly upward so can suppress powder than the apparent density height of the lower molecular weight PTFE particle of raw material separately by emulsification.
Described solvent-free comminution granulation is to use table and promoting agent aqueous solution replacement water or organic solvent, with the method for this water phase surfactant mixture and lower molecular weight PTFE mix particles.
Described dry type solvent-granulation method is not use tensio-active agent and with the method for organic solvent as the granulation medium.
Handle the lower molecular weight PTFE prilling powder of the present invention that obtains by described granulation, preferred median size is 1 μ m～1500 μ m.
And lower molecular weight PTFE prilling powder of the present invention is compared with lower molecular weight PTFE particle in the past, and powder flowbility is good, can suppress powder and be attached to the hopper wall, and operability is improved.
Lower molecular weight PTFE prilling powder of the present invention is preferably following material (hereinafter referred to as " lower molecular weight PTFE prilling powder (P) "): its median size is that the apparent density of 1 times～400 times of median size of the lower molecular weight PTFE powder that formed by lower molecular weight PTFE particle and lower molecular weight PTFE prilling powder is 1.15 times～4 times of apparent density of the lower molecular weight PTFE powder that formed by lower molecular weight PTFE particle.
Described lower molecular weight PTFE prilling powder (P) since the ratio in averaged particles footpath in described scope, so be difficult for flying upward.
The apparent density of the relative lower molecular weight PTFE powder of apparent density of described lower molecular weight PTFE prilling powder (P) is more preferably greater than equaling 1.2 times, be more preferably less than to equal 3 times.Lower molecular weight PTFE prilling powder of the present invention can satisfy apparent density and be the condition that 1.15 times～4 times condition and median size are 1 times～400 times simultaneously.
Described lower molecular weight PTFE prilling powder (P) is by there being adhesive particle to form, can not only prevent powder disperse or attached on the hopper, and in transportation or when preserving, volume does not increase, and can be designed to small-sized hopper or basin.In this manual, described apparent density is to measure the value that obtains according to JISK6891.
By lower molecular weight PTFE prilling powder manufacture method of the present invention described later (1) or lower molecular weight PTFE prilling powder manufacture method of the present invention (2), can easily obtain lower molecular weight PTFE prilling powder of the present invention (P).
In addition, lower molecular weight PTFE prilling powder of the present invention is preferably following material (hereinafter referred to as " lower molecular weight PTFE prilling powder (Q) "): its median size is that the slope of repose of 1 times～3 times of median size of the lower molecular weight PTFE powder that formed by lower molecular weight PTFE particle and described lower molecular weight PTFE prilling powder is more than 1.1 times or 1.1 times of slope of repose of the lower molecular weight PTFE powder that formed by lower molecular weight PTFE particle.
Described lower molecular weight PTFE prilling powder (Q) is because the ratio at slope of repose forms in described scope and by adhesive particle, so can prevent that powder from dispersing, the processing ease to hopper input raw material the time etc. for example during operation.The ratio at slope of repose for example can be set at 1.1 times～1.5 times.
As mentioned above, the powder for molding that number-average molecular weight is surpassed 600,000 tetrafluoroethylene carried out granulation and the powder for molding granulation thing that obtains in the past, and median size is above 3 times.Lower molecular weight PTFE prilling powder of the present invention can satisfy 1 times～3 times the condition that the slope of repose is lower molecular weight PTFE powder more than or equal to 1.1 times the condition and the median size of lower molecular weight PTFE powder simultaneously.
Lower molecular weight PTFE prilling powder of the present invention (Q) preferably satisfies the aforementioned proportion of the relative lower molecular weight PTFE powder with the slope of repose of median size, and the ratio of its apparent density the same with lower molecular weight PTFE prilling powder of the present invention (P) be 1.15 times～4 times of lower molecular weight PTFE powder.
Lower molecular weight PTFE prilling powder of the present invention (Q) can easily obtain by lower molecular weight PTFE prilling powder manufacture method of the present invention described later (1).
In addition, lower molecular weight PTFE prilling powder of the present invention is preferably following material (below, claim " lower molecular weight PTFE prilling powder (R) "): its median size is the slope of repose of the slope of repose of 10 times～400 times of median size of the lower molecular weight PTFE powder that formed by lower molecular weight PTFE particle and described lower molecular weight PTFE prilling powder less than the lower molecular weight PTFE powder that is formed by lower molecular weight PTFE particle.
Described lower molecular weight PTFE prilling powder (R) is because in described scope, thus not only be difficult for flying upward, and the operability excellence.
Lower molecular weight PTFE prilling powder of the present invention (R) preferably satisfies median size and slope of repose with respect to lower molecular weight PTFE powder aforementioned proportion, and the ratio of its apparent density the same with lower molecular weight PTFE prilling powder of the present invention (P) be 1.15 times～4 times of lower molecular weight PTFE powder.
Lower molecular weight PTFE prilling powder of the present invention (R) can easily obtain by lower molecular weight PTFE prilling powder manufacture method of the present invention described later (2).
In this manual, do not enclose (P), (Q) or (R), only be mentioned under the situation of " lower molecular weight PTFE prilling powder ", be meant whole lower molecular weight PTFE prilling powders, it also comprises any one the lower molecular weight PTFE prilling powder that is not in described lower molecular weight PTFE prilling powder (P), described lower molecular weight PTFE prilling powder (Q) and the lower molecular weight PTFE prilling powder (R) except that comprising described lower molecular weight PTFE prilling powder (P), lower molecular weight PTFE prilling powder (Q) and lower molecular weight PTFE prilling powder (R).
Lower molecular weight PTFE prilling powder of the present invention, for the lower molecular weight PTFE powder that described lower molecular weight PTFE particle forms, specific surface area is less than 7m
2/ g and use melt viscosities that flow velocity tester methods measure smaller or equal to 2500Pas at 340 ℃.Described melt viscosity for example also can be smaller or equal to 1000Pas.In this manual, below, will have the interior specific surface area of described scope and the described lower molecular weight PTFE powder of melt viscosity and be called " lower molecular weight PTFE powder (A) ".
Described lower molecular weight PTFE powder (A), specific surface area is less, can reduce that powder flies upward or attached on the hopper.The preferred upper limit of the specific surface area of described lower molecular weight PTFE powder (A) is 6m
2/ g is limited to 5m on preferred
2/ g is limited to 1m under preferred
2/ g is limited to 2m under preferred
2/ g.
In this manual, specific surface area is to use the specific surface area analysis instrument to measure the value that obtains according to the BET method.
Described lower molecular weight PTFE powder (A) since at 340 ℃ melt viscosity in described scope, so the number-average molecular weight of lower molecular weight PTFE is approximately smaller or equal to 100000.For example also can make described number-average molecular weight smaller or equal to 40000.
In this manual, melt viscosity is according to ASTM D 1238, at 340 ℃, uses flow velocity tester method to measure the value that obtains.
Described lower molecular weight PTFE powder (A) preferably has the melt viscosity in the described scope and has specific surface area in the described scope and the material that obtains by suspension polymerization.
By using described lower molecular weight PTFE powder (A), also can obtain above-mentioned lower molecular weight PTFE prilling powder of the present invention (P), lower molecular weight PTFE prilling powder of the present invention (Q) and lower molecular weight PTFE prilling powder (R).
In this manual, do not enclose (A) or (B) described later, when only mentioning " lower molecular weight PTFE powder ", described lower molecular weight PTFE powder (A), aftermentioned lower molecular weight PTFE powder (B) and the lower molecular weight PTFE powder except that them are not distinguished, be meant the whole lower molecular weight PTFE powder that comprise described lower molecular weight PTFE powder (A) and lower molecular weight PTFE powder (B).
The manufacture method of lower molecular weight PTFE prilling powder of the present invention (1), be method that handle to be made described lower molecular weight PTFE prilling powder by lower molecular weight PTFE granulating particles, it is more than or equal to 80 ℃ and carry out less than 100 ℃ temperature with aqueous dispersion of low molecular weight polytetrafluorethyleand (to call " lower molecular weight PTFE aqueous liquid dispersion (a) " in the following text) that described granulation is handled; Described aqueous dispersion of low molecular weight polytetrafluorethyleand is dispersed in described low molecular weight polytetrafluoroethylene particle in the aqueous dispersion medium in the presence of tensio-active agent and obtains.
The manufacture method of lower molecular weight PTFE prilling powder of the present invention (1) can easily be made lower molecular weight PTFE prilling powder of the present invention (P) and the lower molecular weight PTFE prilling powder of the present invention (Q) in the described lower molecular weight PTFE prilling powder.
In this manual, the method for granulating in the manufacture method (1) of described lower molecular weight PTFE prilling powder can be called " granulation of emulsification warm water " sometimes.
Aqueous dispersion medium in the described lower molecular weight PTFE aqueous liquid dispersion (a) is water or water-miscible organic solvent is dissolved in the material that obtains behind the water, is to make lower molecular weight PTFE particle dispersive dispersion medium in the presence of tensio-active agent.Described aqueous dispersion medium can contain additive commonly used in making the prilling process of water.When lower molecular weight PTFE particle was the dispersate that is scattered in the dispersed system that is obtained by letex polymerization etc., described aqueous dispersion medium can directly use the aqueous dispersion medium in the described dispersed system.
Described lower molecular weight PTFE aqueous liquid dispersion (a) can further contain water-insoluble liquid though be that lower molecular weight PTFE particle is dispersed in the dispersion liquid in the aqueous dispersion medium in the presence of tensio-active agent.
Described lower molecular weight PTFE aqueous liquid dispersion (a) is the dispersion liquid that contains water-insoluble liquid or do not contain water-insoluble liquid, and described water-insoluble liquid is preferably smaller or equal to 5 quality % of described lower molecular weight PTFE aqueous liquid dispersion.If surpass 5 quality %, then make lower molecular weight PTFE prilling powder of the present invention (P) or lower molecular weight PTFE prilling powder of the present invention (Q) and be easy to become difficult.Described lower molecular weight PTFE aqueous liquid dispersion does not more preferably contain water-insoluble liquid in fact, does not further preferably contain water-insoluble liquid.
As long as contained water-insoluble liquid can make lower molecular weight PTFE particle wetting, lower molecular weight PTFE aqueous liquid dispersion (a) can contain this water-insoluble liquid, but does not preferably contain water-insoluble liquid.
As described water-insoluble liquid, as long as be liquid and insoluble under the normal temperature of 30 ℃ of degree to water, just be not particularly limited, but as the lower molecular weight PTFE prilling powder made from the containing ratio in the described scope of the present invention (P) and the water-insoluble liquid of lower molecular weight PTFE prilling powder of the present invention (Q), for example can enumerate hydro carbons such as normal hexane, hexanaphthene, heptane; Methylene dichloride, ethylene dichloride, chloroform etc. contain halohydrocarbon; Nitrogenous liquid such as N-Methyl pyrrolidone; Ester classes such as ethyl acetate; Carbonates such as carbonic acid diethyl diester etc.As described water-insoluble liquid, preferably contain halohydrocarbon, more preferably methylene dichloride.
Tensio-active agent as using in the manufacture method (1) of lower molecular weight PTFE prilling powder of the present invention is not particularly limited, but preferred nonionic surface active agent, the wherein tensio-active agent of preferred polyoxyethylene polyoxypropylene glycol [PPG] class.
As the tensio-active agent of described PPG class, preferably its molecular-weight average is 1000～20000.Described tensio-active agent is preferably greater than the 0.001 quality % that equals described lower molecular weight PTFE particle, is more preferably less than to equal 0.5 quality %, so long as in above-mentioned scope, is more preferably less than and equals 0.1 quality %.
The manufacture method of lower molecular weight PTFE prilling powder of the present invention (1) is that lower molecular weight PTFE aqueous liquid dispersion (a) limit process for granulating is stirred on the limit, can suitably set each condition such as stirring velocity.In the manufacture method (1) of lower molecular weight PTFE prilling powder of the present invention, do not contain under the situation of water-insoluble liquid at lower molecular weight PTFE aqueous liquid dispersion (a), the temperature of described lower molecular weight PTFE aqueous liquid dispersion (a) is preferably less than 100 ℃, is limited to 85 ℃ under preferred.
The manufacture method of lower molecular weight PTFE prilling powder of the present invention (2) is to be handled the manufacture method of the lower molecular weight PTFE prilling powder of making described lower molecular weight PTFE prilling powder by lower molecular weight PTFE granulating particles, and described granulation is handled and carried out with aqueous dispersion of low molecular weight polytetrafluorethyleand (to call " lower molecular weight PTFE aqueous liquid dispersion (b) " in the following text); Described lower molecular weight PTFE aqueous liquid dispersion (b) is described low molecular weight polytetrafluoroethylene particle to be dispersed in the aqueous dispersion medium to obtain under the condition that has or do not exist tensio-active agent; Described lower molecular weight PTFE aqueous liquid dispersion (b) contains water-insoluble liquid; With respect to the described lower molecular weight PTFE particle of 100 mass parts, described tensio-active agent is smaller or equal to 5 mass parts.
The manufacture method of lower molecular weight PTFE prilling powder of the present invention (2) is easily to make the lower molecular weight PTFE prilling powder of the present invention (P) in the described lower molecular weight PTFE prilling powder and the method for lower molecular weight PTFE prilling powder of the present invention (R).
Aqueous dispersion medium in described lower molecular weight PTFE aqueous liquid dispersion (b) be water or water-miscible organic solvent is dissolved in water after the material that obtains, be under the condition that has or do not exist tensio-active agent, can make lower molecular weight PTFE particle dispersive dispersion medium.Described aqueous dispersion medium can contain normally used additive in making the prilling process of water.Described aqueous dispersion medium can be with about the identical material of material described in the explanation of described lower molecular weight PTFE aqueous liquid dispersion (a).
Described lower molecular weight PTFE aqueous liquid dispersion (b) contains water-insoluble liquid.
The amount of described water-insoluble liquid is preferably greater than the 5 quality % that equal described lower molecular weight PTFE aqueous liquid dispersion (b).If less than 5 quality %, then make lower molecular weight PTFE prilling powder of the present invention (P) and lower molecular weight PTFE prilling powder of the present invention (R) and be easy to become difficult.
As described water-insoluble liquid, can enumerate with about the identical material of material described in the explanation of described lower molecular weight PTFE aqueous liquid dispersion (a).
Handle as the granulation under the situation that in described lower molecular weight PTFE aqueous liquid dispersion (b), does not have tensio-active agent, can enumerate comminution granulation in the described water, handle as the granulation under the situation that in described lower molecular weight PTFE aqueous liquid dispersion (b), exists tensio-active agent, can enumerate described emulsification and disperse comminution granulation.
Tensio-active agent as using in the manufacture method (2) of lower molecular weight PTFE prilling powder of the present invention is not particularly limited, and for example can enumerate about the material described in the explanation of described lower molecular weight PTFE aqueous liquid dispersion (a) etc.
Disperse comminution granulation etc. to exist under the situation of tensio-active agent in emulsification, described lower molecular weight PTFE particle with respect to 100 mass parts, described tensio-active agent is preferably 0.001 mass parts～0.5 mass parts, is limited to 0.005 mass parts under preferred, is limited to 0.1 mass parts on preferred.
In the manufacture method (2) of lower molecular weight PTFE prilling powder of the present invention, about water-insoluble liquid and tensio-active agent as mentioned above, the various conditions such as ratio that described lower molecular weight PTFE particle accounts in described lower molecular weight PTFE aqueous liquid dispersion (b), except prilling temperature, the same with the manufacture method (1) of lower molecular weight PTFE prilling powder of the present invention, and can suitably set.
In the manufacture method (2) of lower molecular weight PTFE prilling powder of the present invention, described lower molecular weight PTFE aqueous liquid dispersion (b) is heated up, and preferably smaller or equal to T ℃.In this specification sheets, described T ℃ is the temperature that steam output sharply increases when heating water-insoluble liquid.
By the lower molecular weight PTFE prilling powder that the manufacture method (2) of lower molecular weight PTFE prilling powder of the present invention obtains, because median size is bigger, the slope of repose is little, so be difficult for flying upward and good operability excellent property.
The lower molecular weight PTFE prilling powder that obtains by the manufacture method (2) of lower molecular weight PTFE prilling powder of the present invention, because particle does not fly upward, so can prevent it sneaks into other goods in the operating environment that is present in described lower molecular weight PTFE prilling powder etc. and makes pollutions such as other goods, and adhering on hopper is few, the operability excellence.In addition, the lower molecular weight PTFE prilling powder by the manufacture method (2) of lower molecular weight PTFE prilling powder of the present invention obtains owing to can prevent to fly upward to operating environment, can obtain the good working environment simultaneously.
And, form prilling powder even constitute a large amount of particles of the elementary cell of prilling powder by aggegation, lower molecular weight PTFE prilling powder of the present invention is when mixing with respective material such as engineering plastics to the additive of respective material and in various mixing machines, owing to also decompose to the particle before the granulation easily, we can say dispersiveness and Combination excellence to respective material.For example open in the clear 59-140253 communique disclosed such the spy, when lower molecular weight PTFE prilling powder of the present invention and polybutylene terephthalate [PBT] and glass fibre are together added the single shaft extrusion machine, perhaps as the spy open in the clear 60-223852 communique disclosed, add lower molecular weight PTFE prilling powder of the present invention in the time of in joining extrusion machine, similarly its dispersiveness and Combination are all excellent.
In addition, the powder for molding that number-average molecular weight is surpassed 600,000 tetrafluoroethylene, implementing to handle same granulation with the granulation of carrying out in order to obtain lower molecular weight PTFE prilling powder of the present invention handles, even resulting powder for molding granulation thing with the operation of other materials blended such as resin in, also be difficult to decompose to the particle before the granulation.
Lower molecular weight PTFE powder of the present invention (B) uses melt viscosities that flow velocity tester methods measure smaller or equal to 2500Pas at 340 ℃.
As mentioned above, lower molecular weight PTFE powder of the present invention (B) can be as the lower molecular weight PTFE powder that is formed by lower molecular weight PTFE particle in the lower molecular weight PTFE prilling powder of the present invention, and, can be as the lower molecular weight PTFE powder that forms by lower molecular weight PTFE particle in the lower molecular weight PTFE prilling powder manufacture method of the present invention, hence one can see that, lower molecular weight PTFE powder of the present invention (B) is included in these lower molecular weights PTFE powder, is the material that has the melt viscosity in the described scope in the described lower molecular weight PTFE powder.The melt viscosity of lower molecular weight PTFE powder of the present invention (B) is preferably smaller or equal to 2000Pas.
Lower molecular weight PTFE powder of the present invention (B) can easily obtain by suspension polymerization.As in order to obtain the suspension polymerization of lower molecular weight PTFE powder of the present invention (B), preferably use lower molecular weight PTFE manufacturing method of power of the present invention described later.
Lower molecular weight PTFE powder of the present invention (B) preferably in the melt viscosity in having described scope its specific surface area less than 7m
2/ g.Be limited to 6m on the specific surface area of lower molecular weight PTFE powder of the present invention (B) is preferred
2/ g is limited to 5m on further preferred
2/ g is limited to 1m under preferred
2/ g is limited to 2m under further preferred
2/ g.
Lower molecular weight PTFE powder of the present invention (B) preferably have in the melt viscosity in having described scope with the same scope of described lower molecular weight PTFE powder (A) in specific surface area, and obtain by suspension polymerization.By using suspension polymerization to make, can easily be had the lower molecular weight PTFE powder of interior melt viscosity of described scope and the specific surface area in the described scope simultaneously.
The manufacture method of low molecular weight polytetrafluoroethylpowder powder of the present invention (below, claim " lower molecular weight PTFE preparation method of powder ") be to use chain-transfer agent, make described lower molecular weight PTFE powder by suspension polymerization.
Lower molecular weight PTFE manufacturing method of power of the present invention adopts suspension polymerization, compares with situation about making by letex polymerization, owing to do not need condensation, so method of the present invention is excellent.Lower molecular weight PTFE preparation method of powder of the present invention is applicable to the manufacturing of described lower molecular weight PTFE powder of the present invention (B), but also is applicable to the manufacturing of described lower molecular weight PTFE powder (A).
Described chain-transfer agent is and the identical material of material about explanation in the record of the polymeric of described low molecular weight polytetrafluoroethylene.
0.01 mole of %～0.5 mole % of the gas phase part the when usage quantity of described chain-transfer agent is preferably polymerization and begins.
More than or equal to 40 ℃ and carry out under the situation of described suspension polymerization less than 100 ℃ temperature, the polymerization starter of use is the material that contains persulphate or sulphite and contain organo-peroxide at fluid temperature.
Described " persulphate and sulphite " is called a group, and described " organo-peroxide " is called the b group, as long as select for use at least aly as described polymerization starter from a group and b organize respectively, then can also use other reagent of polymerization initiation.Described persulphate and sulphite, the transformation period is short, just brings into play the effect of polymerization starter when polymerization begins; And described organo-peroxide, the transformation period is longer, and it is slow to begin to bring into play the polymerization starter effect than described persulphate and sulphite.So, can make narrow molecular weight distribution by both combinations.
There is no particular limitation as described persulphate, can enumerate for example ammonium persulphate, Potassium Persulphate etc., there is no particular limitation as described sulphite, can enumerate for example ammonium sulphite, potassium sulfite etc., there is no particular limitation as described organo-peroxide, can enumerate for example benzoyl peroxide, disuccinic acid superoxide, diamyl diacid peroxilde etc.
In addition, except described polymerization starter, also can use redox catalyst described later.
Described " fluid temperature " is the temperature of polymerization liquid.
Temperature 5 ℃～40 ℃ of fluid temperatures is carried out under the situation of described suspension polymerization, and the polymerization starter of use contains persulphate or sulphite and/or organo-peroxide, and contains redox catalyst.By containing redox catalyst, even under 5 ℃～40 ℃ such low temperature, still can react.
Described " contain persulphate or sulphite and/or organo-peroxide, and contain redox catalyst " can be any one in following 5 kinds of combinations: persulphate and redox catalyst, sulphite and redox catalyst, organo-peroxide and redox catalyst, persulphate and organo-peroxide and redox catalyst, sulphite and organo-peroxide and redox catalyst.
Described persulphate, sulphite, organo-peroxide and redox catalyst can use more than 2 kinds or 2 kinds respectively.
Can use above-mentioned material as described persulphate, sulphite and organo-peroxide.
Be not particularly limited as described redox catalyst, can enumerate mixture of for example metal carbonyl-carbon tetrachloride mixture, superoxide-iron (II) compound etc.
Low molecular weight polytetrafluoroethylene gelation powder of the present invention (to call " lower molecular weight PTFE gelation powder " in the following text) obtains through heat treated, described heat treated is meant more than or equal to 250 ℃ and less than 340 ℃ temperature, described low molecular weight polytetrafluoroethylpowder powder is heated.
In described heat treated, preferred lowest temperature is 300 ℃, and preferred upper temperature limit is the fusing point of lower molecular weight PTFE, for example 330 ℃.
Lower molecular weight PTFE gelation powder of the present invention and lower molecular weight PTFE granulation gelation powder can be that all particles to all particles of lower molecular weight PTFE powder or described lower molecular weight PTFE prilling powder fully carries out " gelation fully " state of gelation and the part on a part of particle or the particle carried out in " semi-gelledization " state of gelation any one.
By described heat treated, fuse by a contact between the particle of described lower molecular weight PTFE powder or described lower molecular weight PTFE prilling powder, form the block that is combined into one with weak bonding force on the whole.
In addition, by described heat treated, in each particle of described lower molecular weight PTFE powder or described lower molecular weight PTFE prilling powder, polymeric chain motion increases, and twines mutually, as a result each particle size decreases and shrink and form structure closely often.Compare with the described lower molecular weight PTFE powder or the described lower molecular weight PTFE prilling powder of powder before the heat treated, the apparent density of each particle that obtains by described heat treated, usually increase, so powder flies upward few, and the filling in the hopper is improved by the flowability that improves powder.
For the block that obtains by described heat treated, can carry out pulverization process it is ground into desirable size.Dominant area divides each particle of described lower molecular weight PTFE gelation powder or described lower molecular weight PTFE granulation gelation powder to carry out described pulverization process.
Can also modulate the additive that contains described lower molecular weight PTFE prilling powder, described lower molecular weight PTFE granulation gelation powder, described lower molecular weight PTFE powder or described lower molecular weight PTFE gelation powder.
Described additive can be described lower molecular weight PTFE prilling powder itself, described lower molecular weight PTFE granulation gelation powder itself, described lower molecular weight PTFE powder itself or described lower molecular weight PTFE gelation powder itself, also can be the composite additive that for example also is added with wax etc. except that them.Described interpolation wax and the composite additive that forms for example can be used for ink.
Be fitted in the various respective material according to the described additive of various objectives, as described respective material, for example can enumerate polyoxy benzoyl polyester, polyimide, polymeric amide, polyamide-imide, polyacetal, polycarbonate, polyphenylene sulfide etc. as the engineering plastics of other formed materials; Ink; Coating etc.
Purposes as described additive is not particularly limited, and for example can be used to improve the not stick-slip motion characteristic of photocopying roll; Improve the slickness of makeup such as coating such as ink, varnish, paint or foundation cream etc.And, also be applicable to the purposes of texture of the engineering plastics moulding product such as lid of the sheet surface layer that improves furniture, the dashboard of automobile, tame electrical article; The buttons, projector, camera component, sliding material etc. that improve small-sized load bearing, gear, cam, push-button phone produce the sliding of mechanical part of mechanical friction or the purposes of wear resistance; Improve the purposes of grease proofness such as wax or water-repellancy; Also be applicable to the processing aid of engineering plastics etc.
Described lower molecular weight PTFE prilling powder, described lower molecular weight PTFE granulation gelation powder, described lower molecular weight PTFE powder or described lower molecular weight PTFE gelation powder can obtain the moulding product as formed material.Described moulding product can contain filler and/or oil.Be not particularly limited as described filler, for example can enumerate, engineering plastics such as polyoxy benzoyl polyester, polyimide, polymeric amide, polyamide-imide, polyacetal, polycarbonate, polyphenylene sulfide; Carbon fiber; Glass fibre; Copper powder; Powdered graphite; Lime carbonate; Calcium sulfate; Molybdenumdisulphide; Silicate mineralss such as chlorite, talcum, mica; Metal oxide; Soft metal micro mist etc.
Embodiment
Below enumerate embodiment, illustrate in greater detail the present invention, but the present invention not only is defined in these embodiment.
[polymerization of lower molecular weight PTFE powder]
Polymerization example 1
The 70L deionized water is added in the stainless steel polymerization tank of 150L that possesses stirring awl oar also airtight.After removing jar interior air, add 100g ethane.Adding TFE monomer to a jar internal pressure is 0.5Mpa, is warming up to 85 ℃.After temperature reached 85 ℃ in jar, appending the TFE monomer again and adjusting pressure was 0.8Mpa.The 250ppm/H that adds aqueous solution state
2The ammonium persulphate of O and 250ppm/H
2The disuccinic acid superoxide of O is as polymerization starter, and the monomeric consumption of TFE in jar begins immediately.In the polymerization, being consumed to jar internal pressure is to add TFE to 0.85Mpa behind the 0.7Mpa, repeats this operation, when the TFE feed rate reaches 12kg, stops polyreaction, opens jar, makes a jar internal pressure reach normal pressure.After polyreaction began, the temperature in jar remained at 84.5 ℃～85.5 ℃.To cooling off in the jar after reaching room temperature, with the deionized water washing and filter resulting particle,, thereby obtain lower molecular weight PTFE powder with 170 ℃ heated air circulation type drying machines dryings 12 hours.
Polymerization example 2
Except the add-on of ethane is 140g, similarly operate to obtain lower molecular weight PTFE powder with polymerization example 1.
Polymerization example 3
Except the add-on of ethane is 160g, similarly operate to obtain lower molecular weight PTFE powder with polymerization example 1.
Polymerization example 4
Except the add-on of ethane is 200g, similarly operate to obtain lower molecular weight PTFE powder with polymerization example 1.
Polymerization example 5
Except the add-on of ethane is 60g, similarly operate to obtain lower molecular weight PTFE powder with polymerization example 1.
Polymerization example 6
Except the add-on of ethane is 75g, similarly operate to obtain lower molecular weight PTFE powder with polymerization example 1.
Lower molecular weight PTFE powder for obtaining carries out following evaluation of physical property.
Apparent density
Measure according to JIS K 6891-5.3.
Median size
Using laser diffraction formula particle size distribution device (NEC society system), do not use type grid (cascade), is that 0.1Mpa, minute are to measure size-grade distribution in 3 seconds with pressure, will be corresponding to the particle diameter of size-grade distribution accumulative total 50% as median size.
The vaporization at high temperature rate
10g (expression A gram in following formula) sample is added in the aluminum cup (capacity 50ml, footpath, top 60mm, footpath, bottom 42mm, degree of depth 33mm), to adjust to the heated air circulation type electric furnace of Heating temperature in advance, in 300 ± 2 ℃ nitrogen atmosphere gas, keep quality measurement after 1 hour, calculate the vaporization at high temperature rate according to following formula.
Vaporization at high temperature rate (quality %)=[{ quality after the A-thermal treatment (g) } * 100]/A
Melt viscosity
With flow velocity tester (Shimadzu Seisakusho Ltd.'s system), use the die head of 2 φ-8L, at 340 ℃, heated the 2g sample of 5 minute hands in advance with 340 ℃ of temperature in the 0.7Mpa load measurement.
Specific surface area
By the BET method, use surface-area analyser (trade(brand)name: MONOSORB, QUANTACHROME society system) to measure.In addition, the mixed gas that uses nitrogen 30%, helium 70% cools off with liquid nitrogen as carrier gas.
More than the results are shown in table 1.
| Chain-transfer agent (ethane) addition (g) | Apparent density (g/cm 3) | Median size (μ m) | Vaporization at high temperature rate (%) | Melt viscosity (Pas) (340 ℃) | Specific surface area (m 2/g) | |
| Polymerization example 1 | 100 | 0.35 | 12.4 | 0.223 | 1292 | 3.8 |
| Polymerization example 2 | 140 | 0.28 | 4.2 | 0.456 | 790 | 3.5 |
| Polymerization example 3 | 160 | 0.30 | 4.2 | 0.421 | 242 | 3.5 |
| Polymerization example 4 | 200 | 0.29 | 3.8 | 0.309 | 80 | 2.8 |
| Polymerization example 5 | 60 | 0.44 | 15.4 | 0.333 | 2424 | 4.2 |
| Polymerization example 6 | 75 | 0.39 | 14.8 | 0.284 | 1768 | 4.2 |
As shown in Table 1, if increase the addition of chain-transfer agent ethane, melt viscosity then can diminish.
[granulation of lower molecular weight PTFE powder is handled]
Embodiment 1 makes lower molecular weight PTFE prilling powder by comminution granulation in the water
The 6.0kg ion exchanged water is joined in the 15L stirred pot with awl oar, adjust temperature in advance at 20 ℃～22 ℃ (operation I).Then in stirred pot, add 500g lower molecular weight PTFE powder (apparent density 0.28g/cm
3, median size 3.1 μ m, vaporization at high temperature rate 0.21 quality %, slope of repose 42.1 degree), stir (operation II) with 800rpm～900rpm rotation awl oar.Stir the methylene dichloride (operation III) that 200ml was slowly added in beginning in back 1 minute.Stir after 10 minutes, use 200 purposes sieve, filtering separation liquid and solids component (operation IV).With dry 24 hours of the solids component of filtering separation, then, the exsiccant solids component is cooled to room temperature with 170 ℃ hot-air drying stoves, obtains lower molecular weight PTFE prilling powder (operation V).
For the lower molecular weight PTFE prilling powder that obtains, except the evaluation of carrying out described apparent density and vaporization at high temperature rate, carry out following evaluation of physical property.
Median size
For averaged particles footpath,, go up the identical method mensuration of method that several the 7th row are put down in writing for～13 pages by disclose 12 pages of several down the 6th row of No. 99/12996 brochure with the world according to ASTM D 4894 more than or equal to the powder of 100 μ m.
For median size, adopt the method for in the polymerization example, describing less than the powder of 100 μ m.
The slope of repose
Use powder determinator (trade(brand)name: PN-R, ホ ソ カ ワ ミ Network ロ Application society system), measure based on slope of repose measuring method with tester.
Embodiment 2～5 makes lower molecular weight PTFE prilling powder by comminution granulation in the water
Except the amount of the ethylene dichloride that adds in the operation III of embodiment 1 is changed into 300ml, 400ml, 450ml, the 500ml separately, the method by similarly to Example 1 obtains lower molecular weight PTFE prilling powder.
Embodiment 6 makes lower molecular weight PTFE prilling powder by comminution granulation in the water
Except carrying out stirring in 30 minutes in the operation IV of embodiment 1, the method by similarly to Example 3 obtains lower molecular weight PTFE prilling powder.
Embodiment 7 makes lower molecular weight PTFE prilling powder by comminution granulation in the water
Except with time of 15 minutes the temperature of stirred pot being warming up to 33 ℃ and carry out on this basis 25 minutes the stirring in the operation IV of embodiment 1, the method by similarly to Example 3 obtains lower molecular weight PTFE prilling powder.
Granulation comparative example 1 is made lower molecular weight PTFE prilling powder by comminution granulation in the water
Except in the operation IV of embodiment 1 with time of 15 minutes with the temperature of stirred pot be warming up to 36 ℃ and carry out on this basis stirring in 10 minutes, the method by similarly to Example 3 obtains lower molecular weight PTFE prilling powder.
Embodiment 8 disperses comminution granulation to make lower molecular weight PTFE prilling powder by emulsification
Except in the operation III of embodiment 1 before adding the methylene dichloride of 400ml, add beyond the specific tensio-active agent of amount of the 0.025 quality % be equivalent to lower molecular weight PTFE, the method by similarly to Example 3 obtains lower molecular weight PTFE prilling powder.In addition, following " specific tensio-active agent " is the nonionogenic tenside (trade(brand)name: プ ロ ノ Application #104, Japanese grease society system of polyoxyethylene polyoxypropylene glycols; Molecular-weight average 1670).
Embodiment 9 disperses comminution granulation to make lower molecular weight PTFE prilling powder by emulsification
Except adding was equivalent to the described specific tensio-active agent of amount of 0.010 quality % of lower molecular weight PTFE, the method by similarly to Example 3 obtained lower molecular weight PTFE prilling powder.
Embodiment 10 disperses comminution granulation to make lower molecular weight PTFE prilling powder by emulsification
Except adding was equivalent to the described specific tensio-active agent of amount of 0.005 quality % of lower molecular weight PTFE, the method by similarly to Example 3 obtained lower molecular weight PTFE prilling powder.
Embodiment 11 makes lower molecular weight PTFE prilling powder by emulsification warm water comminution granulation
The 6.0kg ion exchanged water is joined in the 15L stirred pot with awl oar, adjust temperature in advance 20 ℃～22 ℃ (operations 1).Then in stirred pot, add the lower molecular weight PTFE that uses among the 500g embodiment 1, stir (operation 2) with 1000rpm rotation awl oar.Stir the described specific tensio-active agent (operation 3) that beginning added the amount of the 0.025 quality % that is equivalent to lower molecular weight PTFE in back 1 minute.While stirring temperature in the jar is risen to 95 ℃ (operations 4).95 ℃ carry out stirring in 10 minutes after, use 200 mesh sieve filtering separation solids components and liquid (operation 5).With the solids component dry 24 hour (operation 6) of 170 ℃ hot-air drying stoves with filtering separation.The solids component of cooling drying obtains lower molecular weight PTFE prilling powder (operation 7) to room temperature.
Embodiment 12～14 makes lower molecular weight PTFE prilling powder by emulsification warm water comminution granulation
Except the described specific tensio-active agent that adds the amount as shown in table 2 be equivalent to lower molecular weight PTFE in the operation 3 of embodiment 11, the method by similarly to Example 11 obtains lower molecular weight PTFE prilling powder.
Comparative example 1～6
Carry out evaluation of physical property similarly to Example 1 for commercially available lower molecular weight PTFE powder (not granulation product).
More than the results are shown in table 2.And in table, #104 means the nonionogenic tenside (プ ロ ノ Application #104) of described polyoxyethylene polyoxypropylene glycols.
Table 2
| Apparent density (g/cm 3) | Median size (μ m) | Slope of repose (degree) | Vaporization at high temperature rate (%) | Prilling process | The granulation condition | ||||||
| Tensio-active agent | Water-insoluble liquid | Heat up | Churning time (branch) | ||||||||
| Kind | Quality %/polymkeric substance | Kind | Addition (ml) | ||||||||
| Raw material PTFE | 0.280 | 3.1 | 42.1 | 0.21 | - | - | - | - | - | - | - |
| Embodiment 1 | 0.401 | 185 | 48.0 | 0.23 | Granulation in the water | - | - | CH 2Cl 2 | 200 | Do not have | 10 |
| Embodiment 2 | 0.570 | 247 | 37.6 | 0.21 | - | - | CH 2Cl 2 | 300 | Do not have | 10 | |
| Embodiment 3 | 0.620 | 530 | 34.2 | 0.24 | - | - | CH 2Cl 2 | 400 | Do not have | 10 | |
| Embodiment 4 | 0.600 | 664 | 35.3 | 0.28 | - | - | CH 2Cl 2 | 450 | Do not have | 10 | |
| Embodiment 5 | 0.600 | 912 | 34.8 | 0.30 | - | - | CH 2Cl 2 | 500 | Do not have | 10 | |
| Embodiment 6 | 0.684 | 761 | 38.1 | 0.22 | - | - | CH 2Cl 2 | 400 | Do not have | 30 | |
| Embodiment 7 | 0.639 | 569 | 38.6 | 0.24 | - | - | CH 2Cl 2 | 400 | 33℃ | 25 | |
| Granulation comparative example 1 | 0.304 | 5 | 44.1 | 0.30 | Granulation in the water | - | - | CH 2Cl 2 | 400 | 36℃ | 10 |
| Embodiment 8 | 0.594 | 357 | 37.5 | 0.44 | Emulsification disperses granulation | #104 | 0.025 | CH 2Cl 2 | 400 | Do not have | 10 |
| Embodiment 9 | 0.590 | 446 | 36.0 | 0.40 | 0.010 | CH 2Cl 2 | 400 | Do not have | 10 | ||
| Embodiment 10 | 0.607 | 442 | 35.0 | 0.39 | 0.005 | CH 2Cl 2 | 400 | Do not have | 10 | ||
| Embodiment 11 | 0.324 | 4.2 | 49.0 | 0.14 | The granulation of emulsification warm water | #104 | 0.025 | - | - | 95℃ | 10 |
| Embodiment 12 | 0.328 | 3.6 | 53.4 | 0.29 | 2.5 | - | - | 95℃ | 10 | ||
| Embodiment 13 | 0.530 | 4.2 | 50.1 | 0.12 | 0.250 | - | - | 95℃ | 10 | ||
| Embodiment 14 | 0.390 | 3.8 | 49.6 | 0.11 | 0.100 | - | - | 95℃ | 10 | ||
| Comparative example 1 | 0.340 | 3.3 | 46.2 | 0.12 | Not granulation | ||||||
| Comparative example 2 | 0.380 | 5.0 | 47.4 | 0.07 | |||||||
| Comparative example 3 | 0.400 | 4.7 | 46.5 | 0.08 | |||||||
| Comparative example 4 | 0.490 | 7.4 | 42.8 | 0.03 | |||||||
| Comparative example 5 | 0.460 | 7.6 | 54.3 | 0.34 | |||||||
| Comparative example 6 | 0.420 | 12.4 | - | 0.28 | |||||||
As shown in Table 2, the lower molecular weight PTFE prilling powder that the emulsification warm water granulation by embodiment 11～14 obtains, raw material PTFE relatively, its median size is 1.15 times～1.35 times, and its apparent density is 1.15 times～1.9 times, and the slope of repose is 1.1 times～1.3 times.
[gelation of lower molecular weight PTFE powder]
Gelation embodiment 1
Will be in drying that polymerization example 2 obtains lower molecular weight PTFE powder spread out on the stainless steel pallet, it is thick to make it be no more than 20mm, it is added in the heated air circulation type electric furnace that is warming up to 250 ℃ in advance carry out 30 minutes thermal treatment then.After 30 minutes, directly pallet is taken out to place and indoorly put coldly, obtain the powder of lower molecular weight PTFE gelation.
Gelation embodiment 2
Except the temperature with the heated air circulation type electric furnace is set at 300 ℃, similarly operate with gelation embodiment 1, obtain the powder of lower molecular weight PTFE gelation.
Gelation embodiment 3
Except the temperature with the heated air circulation type electric furnace is set at 320 ℃, similarly operate with gelation embodiment 1, obtain the powder of lower molecular weight PTFE gelation.
Gelation embodiment 4
Except the temperature with the heated air circulation type electric furnace is set at 330 ℃, similarly operate with gelation embodiment 1, obtain the powder of lower molecular weight PTFE gelation.
Gelation comparative example 1
Except the temperature with the heated air circulation type electric furnace is set at 340 ℃, similarly operate with gelation embodiment 1, obtain the powder of lower molecular weight PTFE gelation.
Gelation comparative example 2
Except the temperature with the heated air circulation type electric furnace is set at 200 ℃, similarly operate with gelation embodiment 1, obtain the powder of lower molecular weight PTFE gelation.
For the lower molecular weight PTFE gelation powder that obtains, except the mensuration of carrying out described apparent density, median size and melt viscosity, also carry out following physical property measurement.
Melting heat
Use differential scanning formula calorimeter (trade(brand)name: DSC-50, Shimadzu Seisakusho Ltd.'s system), measure the melting peak area.
The sensory evaluation that powder flies upward
Carry out following evaluation by visual detection.
◎ ... do not observe fully and fly upward
Zero ... almost do not observe and fly upward
△ ... observing some amounts flies upward
* ... observe a large amount of flying upward
More than the results are shown in table 3.
Table 3
| Heating temperature (℃) | Apparent density (g/cm 3) | Median size (μ m) | Melt viscosity (Pas) (340 ℃) | Melting heat (mJ/g) | The sense organ test that powder flies upward | |
| Gelation embodiment 1 | 250 | 0.35 | 4.2 | 690 | 71 | ○ |
| Gelation embodiment 2 | 300 | 0.41 | 5.0 | 670 | 74 | ◎ |
| Gelation embodiment 3 | 320 | 0.42 | 5.4 | 710 | 76 | ◎ |
| Gelation embodiment 4 | 330 | 0.55 | 8.2 | 694 | 68 | ◎ |
| Gelation comparative example 1 | 340 | Fusion between powder | ||||
| Gelation comparative example 2 | 200 | 0.30 | 3.6 | 790 | 73 | × |
As shown in Table 3, in gelation embodiment, the high more then apparent density of the temperature of gelation and median size is big more and suppress flying upward of powder.
Utilizability on the industry
Low-molecular-weight PTFE preparation method of powder of the present invention, owing to form by above-mentioned formation, so can obtain flying upward and having improved without powder the low-molecular-weight PTFE powder of operability.
Claims (11)
1. a low molecular weight polytetrafluoroethylene prilling powder is characterized in that, is to be handled by the low molecular weight polytetrafluoroethylene granulating particles that number-average molecular weight forms smaller or equal to 600,000 low molecular weight polytetrafluoroethylene to obtain.
2. low molecular weight polytetrafluoroethylene prilling powder as claimed in claim 1, wherein, the median size of described low molecular weight polytetrafluoroethylene prilling powder is 1 times～400 times of median size of the low molecular weight polytetrafluoroethylpowder powder that formed by the low molecular weight polytetrafluoroethylene particle; The apparent density of described low molecular weight polytetrafluoroethylene prilling powder is 1.15 times～4 times of apparent density of the low molecular weight polytetrafluoroethylpowder powder that formed by the low molecular weight polytetrafluoroethylene particle.
3. low molecular weight polytetrafluoroethylene prilling powder as claimed in claim 1 or 2, wherein, the median size of described low molecular weight polytetrafluoroethylene prilling powder is 1 times～3 times of median size of the low molecular weight polytetrafluoroethylpowder powder that formed by the low molecular weight polytetrafluoroethylene particle; The slope of repose of described low molecular weight polytetrafluoroethylene prilling powder is more than or equal to 1.1 times of the slope of repose of the low molecular weight polytetrafluoroethylpowder powder that is formed by the low molecular weight polytetrafluoroethylene particle.
4. low molecular weight polytetrafluoroethylene prilling powder as claimed in claim 1 or 2, wherein, the median size of described low molecular weight polytetrafluoroethylene prilling powder is 10 times～400 times of median size of the low molecular weight polytetrafluoroethylpowder powder that formed by the low molecular weight polytetrafluoroethylene particle; The slope of repose of described low molecular weight polytetrafluoroethylene prilling powder is less than the slope of repose of the low molecular weight polytetrafluoroethylpowder powder that is formed by the low molecular weight polytetrafluoroethylene particle.
5. as claim 1,2 or 3 described low molecular weight polytetrafluoroethylene prilling powders, wherein, for the low molecular weight polytetrafluoroethylpowder powder that forms by described low molecular weight polytetrafluoroethylene particle, described low molecular weight polytetrafluoroethylene particle
(i) specific surface area is less than 7m
2/ g,
(ii) at 340 ℃, the melt viscosity that uses flow velocity tester method mensuration is smaller or equal to 2500Pas.
6. as claim 1,2 or 4 described low molecular weight polytetrafluoroethylene prilling powders, wherein, for the low molecular weight polytetrafluoroethylpowder powder that forms by described low molecular weight polytetrafluoroethylene particle, described low molecular weight polytetrafluoroethylene particle
(i) specific surface area is less than 7m
2/ g,
(ii) at 340 ℃, the melt viscosity that uses flow velocity tester method mensuration is smaller or equal to 2500Pas.
7. the manufacture method of a low molecular weight polytetrafluoroethylene prilling powder, it is the manufacture method of handling the low molecular weight polytetrafluoroethylene prilling powder of making claim 1,2,3 or 5 described low molecular weight polytetrafluoroethylene prilling powders by the low molecular weight polytetrafluoroethylene granulating particles, it is characterized in that, described granulation handle with aqueous dispersion of low molecular weight polytetrafluorethyleand more than or equal to 80 ℃ and less than 100 ℃ temperature under carry out; Described aqueous dispersion of low molecular weight polytetrafluorethyleand is described low molecular weight polytetrafluoroethylene particle to be dispersed in the aqueous dispersion medium to obtain in the presence of tensio-active agent.
8. the manufacture method of low molecular weight polytetrafluoroethylene prilling powder as claimed in claim 7, wherein, described aqueous dispersion of low molecular weight polytetrafluorethyleand contains or does not contain water-insoluble liquid, and described water-insoluble liquid is smaller or equal to 5 quality % of described aqueous dispersion of low molecular weight polytetrafluorethyleand.
9. the manufacture method of a low molecular weight polytetrafluoroethylene prilling powder, it is the manufacture method of handling the low molecular weight polytetrafluoroethylene prilling powder of making claim 1,2,4 or 6 described low molecular weight polytetrafluoroethylene prilling powders by the low molecular weight polytetrafluoroethylene granulating particles, it is characterized in that described granulation is handled and carried out with aqueous dispersion of low molecular weight polytetrafluorethyleand; Described aqueous dispersion of low molecular weight polytetrafluorethyleand is described low molecular weight polytetrafluoroethylene particle to be dispersed in the aqueous dispersion medium to obtain under the condition that has or do not exist tensio-active agent; Described aqueous dispersion of low molecular weight polytetrafluorethyleand contains water-insoluble liquid; With respect to the described low molecular weight polytetrafluoroethylene particle of 100 mass parts, described tensio-active agent is smaller or equal to 5 mass parts.
10. the manufacture method of low molecular weight polytetrafluoroethylene prilling powder as claimed in claim 9, wherein, described water-insoluble liquid is more than or equal to 5 quality % of aqueous dispersion of low molecular weight polytetrafluorethyleand.
11. as the manufacture method of claim 9 or 10 described low molecular weight polytetrafluoroethylene prilling powders, wherein, with respect to the low molecular weight polytetrafluoroethylene particle of 100 mass parts, described tensio-active agent is 0.001 mass parts～0.5 mass parts.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003054815 | 2003-02-28 | ||
| JP054815/2003 | 2003-02-28 | ||
| JP139311/2003 | 2003-05-16 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1753939A CN1753939A (en) | 2006-03-29 |
| CN1331920C true CN1331920C (en) | 2007-08-15 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004800051578A Expired - Lifetime CN1331920C (en) | 2003-02-28 | 2004-03-01 | Granulated powder of low-molecular polytetrafluoro- ethylene and powder of low-molecular polytetrafluoro- ethylene and processes for producing both |
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| CN (1) | CN1331920C (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5532532B2 (en) * | 2007-06-25 | 2014-06-25 | ダイキン工業株式会社 | Low molecular weight polytetrafluoroethylene aqueous dispersion and process for producing the same |
| CN113563613A (en) * | 2016-08-04 | 2021-10-29 | 大金工业株式会社 | Process for producing low molecular weight polytetrafluoroethylene |
| JP7324148B2 (en) * | 2018-02-07 | 2023-08-09 | ダイキン工業株式会社 | Method for producing composition containing low-molecular-weight polytetrafluoroethylene |
| CN112538125B (en) * | 2020-12-14 | 2022-11-08 | 江西理文化工有限公司 | Preparation method of low molecular weight polytetrafluoroethylene resin |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5228552A (en) * | 1975-08-29 | 1977-03-03 | Asahi Glass Co Ltd | Process for producing pulverized polytetrafluoroethylene powder |
| EP0093404A2 (en) * | 1982-04-30 | 1983-11-09 | Daikin Kogyo Co., Ltd. | Process for preparing tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer |
| JPH10316763A (en) * | 1997-03-17 | 1998-12-02 | Daikin Ind Ltd | Filler-free polytetrafluoroethylene granular powder and its preparation |
| CN1265688A (en) * | 1997-08-01 | 2000-09-06 | 大金工业株式会社 | Process for producing granular polytetrafluoroethylene powder |
| EP1065223A1 (en) * | 1998-02-27 | 2001-01-03 | Asahi Glass Company Ltd. | Process for producing aqueous dispersion containing polytetrafluoroethylene |
| CN1094950C (en) * | 1997-04-24 | 2002-11-27 | 大金工业株式会社 | Granular polytetrafluoroethylene powder and process for producing the same |
-
2004
- 2004-03-01 CN CNB2004800051578A patent/CN1331920C/en not_active Expired - Lifetime
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5228552A (en) * | 1975-08-29 | 1977-03-03 | Asahi Glass Co Ltd | Process for producing pulverized polytetrafluoroethylene powder |
| EP0093404A2 (en) * | 1982-04-30 | 1983-11-09 | Daikin Kogyo Co., Ltd. | Process for preparing tetrafluoroethylene/fluoro(alkyl vinyl ether) copolymer |
| JPH10316763A (en) * | 1997-03-17 | 1998-12-02 | Daikin Ind Ltd | Filler-free polytetrafluoroethylene granular powder and its preparation |
| CN1094950C (en) * | 1997-04-24 | 2002-11-27 | 大金工业株式会社 | Granular polytetrafluoroethylene powder and process for producing the same |
| CN1265688A (en) * | 1997-08-01 | 2000-09-06 | 大金工业株式会社 | Process for producing granular polytetrafluoroethylene powder |
| EP1065223A1 (en) * | 1998-02-27 | 2001-01-03 | Asahi Glass Company Ltd. | Process for producing aqueous dispersion containing polytetrafluoroethylene |
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| CN1753939A (en) | 2006-03-29 |
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