CA2014975A1 - Resin bound magnet and its production process - Google Patents

Abstract

Abstract A Resin Bound Magnet And Its Production Process This invention relates to a resin bound type magnet and its production process, especially a cylindrical or a thin plate state magnet and its production process. A resin bound type magnet comprising a magnetic powder and an organic resin or further with an additive and its production process wherein it is moulded as a single body in a cylindrical form satisfying a relation of 2DL / d2 ? 1 among the outer diameter (D), the inner diameter (d) and the length (L) of the said magnet, and it also has a radiated anisotropy in the diameter direction. Further this invention is a resin bound type magnet and a production process of a resin bound type magnet by an extrusion moulding of the said magnet with a die in a magnetic field wherein an average particle size r of the magnetic powder satisfies r ? 0.1 t (t ? 1mm) with the thickness t of the moulded article of an anisotropic resin bound type magnet comprising the said magnetic powder and the resin.

Description

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Z~52M 35679 A Resin Bound Magnet And Its Production Process Th1~ lnv~neiQn r~l~t~6 to a r-~ln ~oun~ ~ype maqnot whleh 16 u~-d ~or a mln~atura motor, an ~nco~r, a lino~r ac~uator, Qtc. whlch are appll~
~or el2ctronics- in-trument~, ~tc. and lt6 productlon prOCQ6, e~p~cially ~or a cylindrical or a thln plat~ resln boun~ type ma~net, ~nd it~
production p~ocess by u61ng an extru~lon mouldin~ ~thod.

The re~l~ boun~ type masnet 1~ ~eneraliy pro~uced by ~1~ an ~n~ec~:cn mouidlng method, (2) a pre6~ mouldl~g m~t~od and (3) an extru6lc~
mouldlng proces~.

Among thQce moulding method~, th~ in~ec~ion mouldlng m~thod 1~ to mo~ld a pr~d~t~rmine~ ~hcpe ~y paohlng a ma~n~t eompoaition compr~lng ~ m~gnetlc powd~r and thormopla~tlc rs~ln lnto a d~e ~y ho~tln~ lt at t~mp~ratu~e ~t wh$oh a ~u~cl~nt ~lu$~ity 1~ ~ttainod~

~e pre-~ mouldln~ m~t~o~L 1B A tnoul~lng m-tho~ by p~ ing afte~ ~acl~ng ~ m~ t ~o~po~tlon eomprl~ a msg~etlc pow~r ~n~ 4 thel~ o-Q'Ct~
15 r~ln lnto a die of ~ pr~ mae~lno.

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2 ~ '~ ~! ''` ~i '' The extru6ion mouldln~ mQthod 1~ ~ ~oul~ln~ ~e~h~d by ch~rqln~ a ma~rietlc compo~tlon ln A flul~lz~d ct~te by ~eatln~ a mlxturo of ~ mægn~tlC
po~aer ant a re~in to ~A~e lt ln a ~olten ~at~ by a ~cr~w, a ram or plunger lnto a di-, and. by conver~ n~ ~ t there .

Among the6e moul~n~ m~thod~, the iniection ~oul~ing and the pre66 moul~lng can ~ould a magn~t havin~ an a~lgotropy by apply~ng a ma~netlc 1eld ln the dle At th~ moul~lng ~tep. ~ow~v~r ~ for the in~ectlon mouldln~ method snd 3 proo~ mould~ng metho~ ~or a ~ouldlng of a lonq sl20d magnet of which d~m~n~ i~ rec~ntly belng ~ncroa~d, in ca~e of the in~ectlon ~oul~ing method ~ecau~e o~ an lmpo~6~iilty of ~sck~ng o a magnet compo~ltion in a cavlty ~nd of taking out ~ mouldQd artlcle, etc and ln ca6e o~ the Pre~S moul~ng me~hod 6ince a lQn~th o~ a moul~ed ~rtlc;e i~ determlned by a Etroke of a mouldlng punc~, they have a defec~
that the len~th o~ the moulded article 16 limited. E6peclally ~n ca~e cf a mouldlng o~ a cylindrical ~agnet havins a radiated ~nlsotropy, there 16 a llmitation on the le~th ~ the mou;~e~ articl~, an~ ~ maqne~, o~ which an outerdlat-r (herelna~tQr called a~ D), an lnner ~ia~-t~r (herelnaftQr cell~d a~ ~) and a lcn~th ~h~rQinafter callod a~ L) satl~fy below~ ted ~uatlon, c~n only be ~ould~d.

2D~ / d2 c ~

(~e~er-nce llteratur~. Ma~ Hamano, an ab~tract book on the 9~h ~sting of Sn~ectlon MoUl~lng T~chnolosy o ~gh P~r~or~anc~ Pla6tic Ma6net ~d It~ A~pllcatio~ DQv~lop~nt, P1A9~iC In~u~trY Techni~l Com~ltt~e 19 6 ) , . .
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Accordlngly a~ to a cylindrlcal ma~net which 8ati~ie6 ~DL ~ d2 ~, 1, only 2 kind~ w~re obtainable 1~ on~ wa~ a ~n~le ~oulaa~ mAgndt Wlth an i~otropy o~ w~th a poor magn~t p~ormanc~ ~nd the oth-r waE a one whlch 5 wa6 prepared ~Y ~tlckln~ plural nun~ber of th-~ magnet~ hevin~ a radl a ed an i s ot ropy .

~owever the afor~mantloned cyl~n~r~cal re~ln bound type m~net ~nd 1 productlon proce~ have problom~ lls~2d ~elow, t 1 ) In order to get a hlgh per~orman~e motor or an a~tu~tor by u~l~g an 10 i60tropiC ~,agnet or a ma~net having a performance clo~e to the l~otroplc . .
maSnet, the volume of the ~agnet to be used ha6 to ~e large, ~l~d a miniaturl~atlon and a llght weighin~ o~ the6e in6~rument6 can n~t be s~t~sf.ed.

t 2 ) In case that plural numb~r o~ th~ ma~nets havlng a r~dlcate~
15 anisotropy i6 6tuck, th~re are followin~ prcblem6.

[1~ ~he tlcklnq ~ w~a~ a~a~ t delam~natlon ~nd there is a dan~er of destroying tho bo~ by a r~p~at-~ hot ~nd cold cycle. It has an in~erlor rell~llity ~uch ~ a v~rlation o~ the ~tlchlng ctr6noth, - etc.

C2~ A productlon co~t ~ r~ b~cau~Q o~ a ~t-~ o~ the ctlc~ln~ ln a pro~uctlo~ p~oc~. Furth~rmore the ~tuck ~gnot h~ to ~e ; flni~hQd by ~ cut~ln~ f~r~c-tlon, ~tc ~o ~n~u~e fi dimQnsion~

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accuracy of the ~oulded ~rt~cle ra~ulti~ a ~urCh~r l~crQ~ of the productlon co~t.

; [3] In c~e of the flnl~h by the GU~tl~ ~ab~lcat~on of tho mould~d artlcle, there i~ a pO~ ty of a de~rlor~tlon of the ~agnQt performance by the flnl~h.

(3) A~ for the in~ctio~ moulding me~ho~ and ~he pr~ ould~n~ method, it rQ~ulree ~ ~lxe~ cycl~ of a packin~, ~ mouldlng an~ ~ ~ak~ng out of a magnet compo~itlon to/from a dle ~n the mo~ldlng ~rocR~ nd the productivity 16 limited b~cau~e it 1B baElcall~ a batch typ~ produc~ion o ey5tem. ~t is, therefore, dlflcult to achlev~ ~ r~uctior. of the production c06t.

(4) A~ for the conventional ~xtru~lon mouldinq method, lt 1~ ~ajo-method not to apply ~ maqnetlc f~el~ at the mouldln~ ~tage. ~owever ~n i60troplo magnet can only be att~lned by t~l6 mo~ln~ mhthod.

Accordingly the extruEion mouldlng m~thod, whlch ha~ ~ vory ~gh product~lty dua to an sb~llty of a contlnuou~ opora~lon ~rom a ~up~ly of a raw ~t~risl to ~ r~91pt 0~ ~ ~auldQA ~rtlclQ, snd 18 hbl- to Q~lly mould B long ~iz~d ma~n~t, b-com~ popul~r. P~rt$cul~1y th~r~ are many ro~o~rchq~ to lmprove th~ magn~t p~orm~nc-, e~pocl~lly r-s~rchoc ~n ~n extrwlon ~oula~n~ ~thod ln a m~gnotlc fl~ld ~n ort-r to roform thc m~qnQtlc p~o~rty which h~- b0~n con~l~Qrad to b~ poor.

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~oncerning a mothod to charge a m~gnQ~1c fleld ~t th~ mouldln~ ~tep, as _or a colu~n typ~ m~net, there lc a r~port by ~.~. John~on ~'D~v~loP~er~-ln The ProdUction of Bond~d Rare E~rth-Cobalt Ma~net~ th Int~rnational wo~hop on Rare ~arth-Cobalt Ma~n~t~ ~nd ~helr ~ppllcatlon~, 1981~, an~
a~ for a cyll~drlcal m~gnet, th~rQ ar~ ~thod6 ~hown ln J~pan Pat~..t Lald-Open ~ho 5a-219705 and J~pan Pat~nt ~id-O~en Sho 61-121307.

Bo~h of the~e ~ethods were to form a m~gnet by orien~atin~ an ~nlx o' ea6y magnetiza~lon of a magnetlc pow~e~ to a dlrectlon of o magnQt:c ~leld by cha~çln~ ~ ma~netlc fleld ln ~ dle of ~n Qxtru6lon machlne wh~le a ma~net compo~ltior. wa~ belns pas~e~ througb the ~e, However ~c-example in a method de~cribed ln ~apan Patent Lald-Opan Sho 61-121307, cylindrical magnet ma~ne~ized and orlentated ln a dle wa~ coolo~ ~y a cooling unlt out~i~e the die, a d~rection of the anl~otropy wa6 only for~ed in one directlon and a moulded article havlng a rad~tQ~
ani~otroPY ln a diameter direction co~l~ not be obtalnod. Moreover, when the mGulded article was ext~ded from the die, it6 temperature wa~ ~t~;l hlgh resultln~ a d~tQrloration of ~ ma~n~t p-r~ormahce by ~ dl~ord~r of an orientation of a ma~netic po~der. A~ a re~ult~, it 1~ not attain~ble to set a cyl~ndrlcal ~a~n~t havin~ a high ma~nQt perform~nc~ radl~tsd anl~otroPY evon lf thl~ ~etho~ 1~ appll-d.
:, ~or~ov~r ther- arQ ~olow~ t~ probl-m~ in the ~for~ont~on~d productlon ~ethod.

., , n th- oonvQntl~nal xtru8ion moul~ln~ method ln a ma~n~tlc fleld, a -ctrom~tn~tlc co~ m-rely lnot~ on th~ ~ie and no con~lder~tlon -. .
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ic pald ~or a demaanetl~at,orl of a rnoul~Qd artlcle pro~uc@d. If there 1~
a residual r,~netl~m in a moul~d articlQ, lt 1~ v~!ry dl~f lcult to handle ~n the po~t proce~ ~UCh a~ an a~he~ion a~ a cut ota~ to a cuttQr or othe~ magneti c materlala . F~lrther ~hen a pr-d~lt~rmin~d magn-tlzatlon i8 5 carrie~ ou~ for th~ magn~t, th- r~itu~ gn~tl~m g~v~ 6n unfavorable inf lue~e to a balance of the magnetization.

~2) AC an exampla of ~ ~nouldlng rn~thod ln which th~ ~omacnet~zatlon o~
the extrusion moulded ~rt~cle ~ considered i~ dl~ClOCQt ln Japan P~tent Lald-Open Sho 60-217617, ~owever ~ince the demsgnetizatlon col.l i~
10 Qquipped at a front end cf a ~i~ ln ~hi~ caQe, lt recult~ an extr~melY
large dle and a mouldabllity 16 poor. Especially ~ince a pa~baqe of A
r~w materlal co~po~nd ls~ t~e dl~ 1E long, the moulding 6paec ~ ~ clow a..
the moulding i~elf 1~ al60 difflcult.

(3) When a cylindr~cal magnet havlng a ~adiated anl~otropy l~ moul~ec, ~
15 length of an oriontation ~ectlon on which a ma~notic ~l~ld 1~ ch~rged due to a con~tltution of a n~agr,etic clrcult i~ d-t~!r~lned by ~n inner dl~meter of the moulded artlcl-. However ~lnce a con~ erably hlgh m~gnetlc lield 1~ ~n-rally ro~ulr~ to oriQntate a rar~ earth m~gnet p~wter, the l~n~th o thQ or1-ntatlon hac to b~ ralatlv~ly ~hos~t ln or~er 20 to eharge ~ ~u~lcl~nt ~agn-~lc f ~ R'C the orl-nteltlon ~ection .
Conl~ot~uentlY lt 1~ ntl~lly not ~l- 'co mo~lld a cylln~rlcal magnet w~lth ~ hl~h maon~t ~Qr~ormance h~vlng a ~ ll inn-r d.lcmoter.

~43 When a eolumn type o~ a rh~-t ~lrP~ mould~, th~ l~no'ch of the orlcnt~'clon ~oction ~an ~o ~a~- long ~.n a c~r'ca~n ~ogr-e. However a .` - 6 -:

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gap between pole pl~CQC can not ~ m~de too ~hort ~u~ to a mec~anical ~trength o~ the dle, and thus lt 1~ not ~ble ~o lncr~a~o a magnet~c ~leld to be char~ed at the oriantation too hl~h, ~h~ ~agn~t p~ro~mance of the moulde~ artlcle therefor~ drop6.

In ca~e that a thermopla¢t~c r~ u~e~ ~6 ~ re~in ln thea~orementlonad ~xtru~lon moul~ln~ ~ethod, thQ moul~in~ 1~ c~rr~od out by a 6cl~dlflc-tion wlth cooi~ng o a mol~Qn mlxture after orlen~ating at the front end of thQ dle. when a the~mo~Qttln~ reEln is uc~d ~ a resin, there are methods to ~ould ~y a solidl~ic~lon wlth coolln~ dfter orientatin~ at th~ front end of the ~le as same to the ther~opla~tic reein, and to mould ~ a curlng wlth heatln~ a~ter ~he orien~-ating.
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Ie ca6e of a methcd wit~, t~e ~olldiflcat~on wlth cooling by using the thermo~ettins resln, it i~ nece~ary to heat lt ~o cure the re~in ~ter t~e moulding, Anyhcw even lc the mouldlng i6 done by eltheL^ me'ho~s, a m~gnet moulded l~ ex~rudod -ontlnuou~ly, Qnd lt 14 ~ecess~ry to cut the magnet moulded ln a pre~etermined l~ngth. For the cut, mechan~cal cuttlng method- namely a guillotlne cutt-r cy~t~m or ~ rotary ~aw-tooth .~ ~yet-m wer~ utllized in the conv~ntlon~l m~tho~.
, ~ owever- th- conventlon~l cuttlng matho~ h~d bQlow~ to~ probl-ms.
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~n ca~e of a m~Ghan~ cal cu tln~ metho~ 6~ch ~ th~ guillotlno cu~ter ~y~tem or the rotary ~aw-~ooth oy~tQm, ~ force an~ a vl~rat~on ~re char~ to a maCn~t to bc cut. W~en An uncurQ~ r-0~n ~oun~ type magn-t ~oullc~ by a 6011~1~io~tlon w1th coollng by u~1n~ ~ th-r~osett1ng re~n :

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is cut and ~ ~hln ~h~ckne~ ma~n-t ch~rset~riz~d bY ~n ~t~u610n mould~nq lfi cut, a crack, a breaka~e ~d/or a ~form~tlon o~ the ma~net ~re ~a~er place durlng th~ cut~lnc ~cau6e of ~ brittl~n-s~ an~ a wo~kno~ of th~
magnet to be cut S ~art~cularly When a volum~ ratlo o~ ~he ~gnetlc powder ln ~ re~in bound type ma~n~t 1~ lncr~a~ed ln ordor to im~ro~e a perform~ncQ o~ ~he m gnet, the volume ratlo of th~ ~e~ln ~Rcr~a~ee ~n~ ~he afor~-ntloned pro~lems tend~ to hapPen ~urther 0~611y bQc~use of ~ r~duct~on o~ bondln~ force of the res~n with the ~a~ne~c pow~or Mor~ovGr ln ca~ o the mechenlc~l cut~ing method, a cut du6t i6 u~voldably produce~ In ca~e of ~ rare earth magnet, e~pecial;y a R-Co type magn-t, a treatment Or the cut du~t 1~ ext~emely important ~ecau~e cobalt hac ~ bad e~ect to a human body, and lt requlre6 3 recovery unlt o~ the CUt ~U6t .

rurther amon~ the conv~ntlonal mo~ltlng method6 by u~in~ a thermo~ettirs 15 resln, a pre-s moulding wa~ a cQneral, but an in~oction mouldln~ and an extru~lon mouldin~ were not wldely us~d and a th~rmoplaG~ic rerin w~
commonly used ~ccordln~ly only a fow ~tho~ wore ~va$1~blo to c~r~ ~n uncured ma~n~t by h~t~n~ ~oul~ y th~ ln~eotion ~ouldlnc an~ by thQ extru~ion ~ 20 mouldin~, and tho ~ethod wa~ to ~cur- ~ cyllndr~cal ~h~p- o~ th~ ma~not ,; with a c~t~l~ug~l force by rotatlng a ~1~ a~t~r ~lxln~ lt~ outor ~ . ~
~ ` d~moter to thQ ~1~
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The problem6 of ehe aforadQ6crlb~d conventional t~chnolo~y are ~ummazize a6 below.

Fir6tly lt 16 a u~e o~ a thermopl~lc r~sln Çor moul~lnc a ~a~net ~y an ln~ectlon ~oulding an~ the QXt~U~lon moul~t n~ . ~n ordor to ~a~ a magnet moulded by ~ th~rmopla6tic resin to b~ u6~1e ~von 8t a t~P~aturo a~
around 150C, it~ mouldlng t~mP~r~ture ha~ to b0 ~t 2000r or more.
: ~herefore ~ ~agne~lc pow~er bl-nde~ wlth the reoin i~ xpo~e~ at 6u~h a te~perature.

W~en a rare earth ~a~net, Q~peclally a R-~e-B type m~gn~t i8 u~e~ a6 2 . 10 ma~netic powder, a deter~oratlon o a ma~net perfo~mAnce of the ma~ne~
happen~ due to an oxldatlon o~ the magnetic powder at a hlgh te~perature above 200~c slnce the magnetlc po~der 19 ~a~ily to ~e oxldlze~.
Moreover, the Iher~,oplastic re~in has proble~ on heat resl6t~nce ar.
~olvent resl~tance when compared wlth a thermosetting re~ln.

Next, method~ of the curin~ bY heat~ ng after mouldinq by uclng th~
the~mo~etting re~ln are polnted out. For a moul~n~ by u~lng th~
th~rmo~ttlng resln, lt re~ulre~ th~t th~ r-~ln po~ Q~ ~ ~harmopla~tlc property ln a c~ta~n te~p~ratura r~ion. Novorthel~ thl~ temp-rature ~ ~gion 1~ low~r or hl~h~r th~n th~ th-rm~ettln~ tamp-rature, it t neca~ary to ~ecur- th- hape onco moul~od ln or~r to cure lt.

:; ' n ord-r to ~chlevQ lt, ~-tho~ ~n thc con~on~lonal t~hnolooy ~rQ
~ avail~blQ. ~ow~ver ln ~ convantion~l productlon proc~s o~ ~ cylln~ric~l : ~e6in ~ound type ma~not, ~lnce th~ lnn-r dlamat~r 1~ not ~lxod, ~ ~lxing _ 9 _ ... .
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2~' 9~r!~i iJ , :. ~, . i r ~i~ of the outQr ~i~motar 1~ rot~d wlth a ~a~ple to ~ecure tho ~ha~e durlng ~he e~rlng, and the ~1~ for thlo purpo~e ~ thu~ ro~u1r-d-Furthsrmore ~t 1G difflcult to op~tat~ th~ curin~ treat~nt for loto of ma~n~tc ~y eh~ m~ehod, and it h~ pro~l-m~ ~uch a~ ~ ~urin~ tr-at~ent 5 for a lons ~iæ~d ma6nat moulded by an ~xtru~lon ~oul~lng m-thod i~ al60 dl~flcult, etc.

~urther ln the pa~t, ~8 to A part1el- ize of a magn~tlc pow~er ln a re61n ~cund typ~ m~qnet, a conc~rn of an ox~d~tlon when the ~agnetic powder wa~ flning wa6 con~er-d, but no con6ideratlon of the p~rtlcle lo slze of the maqn~tlc powder from ~ vlewpoint of ~ thickne~ of a ma~nQt moulded article wa~ con6_dere~.

~urther in ordsr to mculd a m~gnet with a thicknes~ of lmm, 1~ wac nece~sary to make the decire~ thlckne~s ~y a cuttlng fabricatlon afte-moulding one with the t~.lckne~ mo~e th~n lmm by a prQc~ moulding or an lS ln~ectlon mouldlng ln advance.

~7~wever the particle E~iZQ 0~ agn~t1 c powder 5~1v~6 a larse lnf luenc:e to the thlckne~ of ~ moul~ t~ clQ o~ ~n ~nlsotroPlc ro~ln boun~ type magr~-t . Namel~ 1~ th~ av~r3~ p~rt~ cl~ ~ ' z- of a m~n~tlc powder Co--not chAn6e, ~n orl-rltation o~ one ~egn~t~c p~t~cl~ ~f~ct- mo~e to a 20 do~rQe o~ tho oriontatlon o~ th~ ~on~t ~y thlnnin~ tho th~clsn-~ o~ 'cho moul~ ei ~rtlcle. ~o~ oxampl~ n ~n ani-ots~oplc ~a~net wlth a thlckn~ of 0 . ~m 1~ ~noul~Q~ th- ~v~r~oe partlcl- ~lz~ o~ the ma~n~t~ c powd~r ic 50~1m, th~ ln~lu~nc~ that one ~yn-tlc pa~t1 clQ qlve6 to ~h~ orlentAtlon læ ~round 10% . Although the ln~luQs~ce 1~ re~uc~d i f . -- ~o -.
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the thlcl~ne6~ of th~ moulded ~rtlc~@ b~comQ~ 0. 5mm or more, the lnflu~nce ls enlarged lf the th~ ckne~ b~com-~ thinn~r. Accor~ ly ~ to the aVQrage part~cle ~lz~ of the m~ne~, ~ pro'Dle~m 10 g-nerated that lt ~houl~l relate to th~ thlckn~c of th~ m~ t moul~led ~r'cicl~.

s ~urther by a conventlonal ~otho ~o moult a m~n~t wlth the thlckne~6 lm~
or lecs, it rellult~ a hl~h proauctlon co~t, ~tc beca-~ce o~ the fabrication procss~ requ~red.

Further, ~ rar~ earth m~net, ~sp~clally ~ raxe aPrth~ron-boror. type magnet wa~ ea611y oxldlze~, and th~re wa~ a problem of a forma~lon o a lo ru~ during lts servic~.

~n ord,e~ to ~olve the problem, a coating method of a resin on the magne~
moulded, a metal pl~tina and a coating of a cer3mic or h resin o~ the ~nagnetlc powder WQre investigated in the p~st.

~ 3owever followlng problem~ ar~ anumerated ln 1;he aforement.ione~
15 conventlonal ~u~t r~ tance techno3ro~y o~ a~ne~.
r' rhe fo~mQr methot ln whlch a r~sln 1~ coat-t on ~ m~ oul~d doe- not havQ an e~ect to n oxidl~tlon o~ th- ma~n-tlc p~wdr~r dur~ng the . ~ mo~l~ln~. ln oth~r wt)rdo, wh~n an ln~sction mould~n~ or an Qxtruslon onoultln~ i- perorm~, th~ ma~n-~ic pow~r ~ ~ sx~o~ undQr ~ high 20 ~mp~ratu~- durln~ l~ne~dln~ of ~ notlc pa~ r ~nt th~ r-~in or .. moul~ln~ th- m~ tlc p~w~r c~ln ~ oxi~lzed ~t 'chl~ ~ta~e r~oultlng po~Elbllity o~ tho mould~ n~ and ~ de~rlor~tlon of ~ m~gnet , -.., .

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performance. Moreov~r ~f a 11ght ~in hole 1~ pre~l~nt ln a coatin~ fllm a~ter the mouldlng, 'chere 1~ a problem th~t ~he ~a~no~c ln01~e ~ lc oxidized from it.

Frorn con610.erlnq thQ6e probl~, the latter In~tho~ ln whl~h a meral 5 platln~ or a coatlng wlth a cQramlc, a r~cin, ~c on th~ magn~tic powder m~y be a mathod to ~olve the afo~em~ntionod pro~l~m~.

Xowever the latter method ~tlll h~ a probl~m. ~rhQ av~ e partlcle ~iiZQ
o~ a magnet~ c powder io c~veral ten mlcron~, lf a ~llm lc coated or. ~t, it~ thlckne~6 ha6 to be 1 mlcron or lel~, and th~r~ore thare ie; a lO problem that the f llm coa~ed ha~ to be extromely tou~h and ~tror.~ly . ~ adhe~lve or it ha~ to e~tabll~h a product~on proce3~ not to remove the fllrn co~ted.
' ~urther ln the pa~t, a thin plate ~t~te re~ n bound type ma~net wa~
malnly produced by a calendar mouldln~ m~thod, an extru~ion mould n~
15 ~nethod and an lnject~on mouldin~ method.

For ~ach mouldlnq method, A mixtu~e kn~ad~d of a ~a~netls powder and a thQrrnopl-et~ e ro~ln ~o u~ and ln ca~- o~ ~ho cal~ntl~r ~nould.ing m~thod, the sfor~e~crll: ~d ~ net ~el~ mat~ri~l ls ~a~e ln ~ thln pl~t0 ct^.te by roll~ns ~th hot roller8.

20 ~sowev~r the pr~duc~lon proc~ o~ th~ ~forem~ntlon~a ~hl pl~t~ stat-~: r~in boun~ typ2 ~n~sn~t h~- ~elow~ tad prcblamo.
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.-. .
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' ' .' ~ ~ "3 ~ , 3 n c~3e o~ the cel~nCar mouldln~ m~thod, Qn l~otrop~c mou~d artlcl~
can only be obt31nad wh~n a rare ~ar~h ma~n~tlc pow~er 1~ u~o~ ~lnc~ lt 16 not po~01ble te ch~rGe a ma~eSic fl~d durlng ~h~ ffloul~lng, and thu6 a magnet performanc~ of th~ ~agn~t le low, ~urther b~c~u~e o~ a h~atlng capaclllty o~ ~he roll~r~, lt 1~ not po66ib~e to u~e a ra~ln hav~n~ ~ very hl~h meltln~ po1nt ~ a blnder, an~
the heat re~l~tance of the mouldcd ~rtlcl~ 18 inferior.

Furthermore lt requiro~ a c~rtaln flexl~llity in tho mouldod artlclOE ~or the moul~ln~, ~nd therofore en amount of a m~gnetlc powder in a raw lo materlal can not b~ con~lderably lAr~e re~ul~ing a low m~gnet per~orm~llce of the moulded art~cle.

/
, ( 2 ) ~ n ca6e 0~ a moul~ln~ of a thln plato etate ma~net by ~n extru610r ~. moulding ~Qthod, an unevenne~ of the moulded art~cle i~ likely to happen ,: due to a dl~rence of thQ oxtru~lon ratc between ~ cenrral poln~ ar.~ ~n ,: 15 outer polnt o~ th~ outl~t o~ the dl~. Accordlngl~ in or~or to pro~uce an ~ cven moul~e~ ~ticle, a co~pl~cated d~cl~n of the pas~a~e ln the tl~ 16 requlred and the ~ie bQC0~6 ~xtr-m~ly expen~ive.

Fur~h~r when the mouldln~ 1~ carrled ou~ ln a m~nQt~c iel~, the g~p betw-en pol~ p~ 0c~ c~n not ~-k- v-ry s~all bQcau~e o~ ~ conc-rn of 20 ~chan~eal ~tr~n~th of th~ nd t~w th~ netlc fi-ld to b~ char~-d ,: ~t tle ~oul~ln~ CUl not ~- v-r~ hC~h. conooquontly ~ m~nat p~r~for~ance o~ moulded 4rtlcl~ rlorat~d.
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~3) In ca~e of ~ ~ouldlng of k ~hln platQ ~te ma~n~t by ~n in~e~tlor.
moulded, lt i6 dlfflcult to mould on~ h~vlno a thl~kn~s of lmm or 1~
~hls 1~ due to ~ ~neration of ~ poor mouldlng by an in~u~icl-nt packing of the mouldln~ raw mate~lal lnto ~ha cavlty of the ~ th- thlckne~c 5 :i6 thln, ~lnc- ~he ~ould~ng r~w m~terlal ha~ a poor ~lu~dity containnln~
A lar~e amo~t Of a ~gnetlc pow~r.

~urther when an anlso~roplc magnot 16 mouldQ~ and if th4 th~ ckne~6 18 t.hin, a moul~ing Wlth a ~ub~tantially ~-otroPY can only be obtalne~

becau~e of an ~f~ect of a Bkin l~yer ~ 0~c~10n where ~he ratlo of the re61n i6 htSh) of the m~net Burfqc~

Fur~her a bl~ mouldeng ~achine iB r~ulred to mould a magnet havlng a large area, and it lc dl~advant~eous f~om a moul~lny cost.

Thl~ lnvent~on, thera~ore, ~6 to ~olve the ~bove~ u~ed proble~, and lts ob~ectiv~ ~6 to p~oVi~e a re~ln ~ound type magnet wlth a hl~h ma~ne' ; 15 performance, a~pecially a lon~ ized c~lindrlGal r-sln bound type m~gnet havlng a r~dlated ~ni0tro~ n~ to provl~ ~ pro~uct~on procQ~ of the magn~t wlth ~ ~oo~ product~v~ty.

, Further the o~ectlv~ 1~ to ~rovl~ ~ pro~ctlon ~roc9-~ of A m~gnet wlth ~ slm~l- cUtting ~-tho~ without a cr~ck, a brQ~k~c and ~ do~ormatlon.
.,.
: 20 rurthermore thl- lnv-ntlo~ a~m~ to provld- pro~u~tton proc--~ wlth impll~yln~ th- product~on ~roce~ ~nd wlth r~ducln~ a co~t, bY ~mproving magn-t ~er~orm~nc~ o~ Qt moul~d by m~an- of -tabll~hln~

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relat~on ~etween a ma~netlc powd~r ~nd ~ thlcknes~ of th~ ~a~net, ~nd ~y moul~lng a ma~net by an ax~ru~on wlth ~up~rlor oxld~tlon rssll~tsnce and weather res i 8 t ance .

Moreo~er thi ~ ~nvantlos~ a~m~ to provide a productlon p~OC-Bf~ wlth ~1 ~ood 5 p~oductlvlt~ for ~ hi~h per~or~a~c~ thln p~ate ~t~tQ r-~ln bound t~rpe rare earth ma~ne~.
. , BR~EF EXPLANAT~ON OF FIGURF.S

Flgure 1 16 a 6ketch of an extrucion mouldln~ ~achlne use~ in Example cf . thi ~ lnvent lon, : 10 F~.gure 2 16 a 6ke~ch of a die oetrucSure for 8n extru~ion moul~ng in ~masne'~c ~leld of a cyllndr~cal re~ln bound ts~pe ma~net u~ed in ExamPle of this lnventlon.
. , .

Flgure 3 ls a ~ketch o~ an ext~usion mouldlng machlne u~ed ln 8x~mple of thi~ lnventlo~.

15 F~ cure 4 1~ ~ oJ~tch o~ ~ p~ o ~gn- ls~tlon unlt u~d ln ~xAmple of thi~ inventlon.

Flgura 5 l~ a g~h ~howln~ a r~l~tlo~ b~tw~-n ~ ma~tlc ~lel~ ~or the ~o~ ln~ ~nd ~ r~ldu~l ~aan~tl~ ~lux d~n~lty o~ th- ~oul~d ~rticle,for c~,-e- wlth and without a ~netlæation o~ a m~onetlc powdor prlor to tho 20 mo~ld~ ng.

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2 ~ .'t3 ; Figure 6 lB a ~ketch of a ~e ~tructur~ for an ~xtru~lon mouldin~ 'n a magnetic fleld of ~ thin plate ~t~te ro6in ~oun~ type magn~t u~ed ln Exa~ple of thl~ lnventlon~

Flgure 7 16 a graph ~howlng a rolation b6tw~Qn a magnetlc ~ield ~or ma~netl~atlon be~ore the mouldlng and a rQ~udlal ~gne~lc flux d~nsity of the moulded artlcle, ~,:
Fi~ure 8 i~ a s~t~h of ~n ~xtrusion mouldln~ ma~hlne ~d ln Exa~ple o~
this ~ventlon.

Flgure 9 is a 6ketch of a dle etr~cture for an ex~ru~lon moul~ng 1~ a m~gnetlc fleld of a cylindrical resln bound type m~gnet u~ed in Ex~mple of thla lnvention.

F~gure 10 16 a cke~ch of an extru-ion ~ouldlng machlne used in Ex~mple ;6 and 17 of this i~vention.
.~ .

gure 11 ~8 a ~k~tch of Example to cut ~nd to m~k~ a thln plate ~ta~e of ~a 15 a cyllndr~cal r-~ln bound type ma~n~t mouldQd bY ~n ~xtruclon ln Ex~mpl~ 16.

., Figure 12 1~ a ~k~tah of a pr~ca unit ~r mould~ng o~ a th~n plate ~tat~
! ~a~not u~d tn ~x~Pl~ 17 of thi~ lnvQntlon.

.}~". ' hl~ ~nv~ntlon 1~ ~ r-~ln bound typ~ magn~t nd it~ p~oduction proc--~ ac . 20 de~crlbed b~low.

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~1 ) A resin bound type magnat compr~ ~lng a ~netic powd.*~ ~n~ an oro~nlc re6in wh~reln ~ t 16 moulded ~8 a ~ln~le body ln ~ ~yllndr~cal ~ors satlEfying a r41atlon ~ c 2D~ / d ,~, 1 5 amon~ 'che outer ~lameter ~D), the ~nner dl~m~r ~d) and the len~th ~L~
o~ the magn~t, ~nd lt ~160 h~6 a ra~iat-d Anl~ot~opy ln th~ diameter , d~ rectlon .

~ 2 ) ~ ~ompo~ltlon o~ a re~in bound ty~e ma~nat o~ the a~orementione~
inventlon comprises a ~agn~tlc powd~r, ~n organlc r~in and an a~d;tlve.

10 ( ~ ) A p~oduction process of ~ r~ir, bound type magnet where~n a raw material for the mouldlng compri6inq ~ maqn~$c powder and an o~ganic resir, 1~ moulded ~y an oxtru6ion by p3~sing throu~l3 a dle lr, hh:ch , . ~
magnetlc field i8 charged while lt 1~ b~lng cured, i~ ~orme~ ~ a lng;e body i~ a cyll~ldrlc~l form ~ati6~ying a ~elatlon ~
2DL / d2 ~ 1 among the outer ~iameter (D), th~ ln~-r ~iameter (d) and the length ~L~
of the ~1 ~agn~t an~ lt ~l~o ha~ a r~ ted ani~otropy in th- ~lameter dir~ctlon.

(4 ) P. co~po~tion of a re~ln bound ty~ magr~-t ln thQ product~ on Prococ~
20 Df ~hQ a~o~-~sntlon-~ lnvontlon com~rllle~ notic Dowd~r, ~r or~nic . r-oln ~n~ an addltlvo.

l5) A productlon proco-ll o r~n ~oun~ typ~ magn~t by an xtruc~on moulding of a moul~ing raw m~tarlal co~prl~ q a m~g~-~lc powd-r and ~n .
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or~anic re~ln wherein a d~e ~tru~ture for mouldln~ 1~ con~tltuted that ~
front ~nd of a m~n~rQl ~-ction 15 p~o~ected n front of an odge of a outer die, ~ m~gn~tlc clrcuit 1~ for~Qd b~tween the ~al~ mandrel ~tion~
~ tro~a~n~tlc coil lnotalle~ at an outor ci~cume~oncQ ~ the ~ oald dle, it 1~ moul~ed ~n a cyllndrlcal form by ; charglng a m~gnetlc flold in the d~e by thc el~ctromagn-~tic co~ nd th- moulded articlo extrud~d 1~ de~agn~tl~od at the ~ront ~d of the ~an~rel .
~, .

( 6 ) A Compo~itlon of the ma~net oÇ the aore~ent~oned lnven~lon compr~ca~
10 a ma~netic powder, an orsanic rs~ln and an addltlve ~ .' , ( 7 ~ - A production proce~ of a rQ~in bound type magn~t ~y an extr:lslon moulding o~ a moulding raw material comprl61ng a mAgnetic powder ar~d an organ~c re6in wherein an clect~oma~etlc coil 16 inçtalled at an ou~er clrcumference of a d ~ ic moulded ln a cylindrical ~orm ~y chargin~ a ~a~n6tic flel8 in the ~io, an ~lectromagnetlc coll with ~n alr-corQ ic al~o in~tallod ~n front of th- a~orementioned olectromagnetic coil to ~n~rate a ma~netlc field ~or ~emagnetl~atlon ~n the ~ electroma~netic coll, and th~ mould-~ articl- xtru~e~ ~B de~a~netized .
) A compo~ltl~n of th- ma~n-t o~ the ~forom~ntlon~d lnv-ntlon comprl~-~
0 ~ mognetlc pow~-r, ~n or~an$c r-~ln ~nd ~n addltlv~
, ~9) A productlon p~oco-- o~ r--ln ~oun~ typ~ n-t whlch 1 con~t~t~t-~ ~y or~ntat~nC ~ ~aon-tlc ~owd~r ln ~ molt-n mlxture o~
~agn-tic pow~-r ~n~ ~ ro~n $n ~ ~ctlon wh~re a ~gn~tlc fl~

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charl~ed at a ~ront ~n~ of a ~le, mould~n~ i~c in a cylindr1cal orm, ~ol~di~yinq lt wlth cooling and Dx~rudin51 1~ wh~rQ~n wh~n 'chQ magnQt cut, the re~in iB cut by mel&ln~ ~y con~ctlng thQ ma~nQt wl~h a he~t~
~ f wlre .

, S ~ 10 ) A p~oductlon proC~B~ of ~ r~ln boun~ typ~ magnet whereir.
compo~itlon of the molt~n ~ixturQ o~ the afor~mentloned lnv~ntlon compri~e6 a masnetic powd~r, ~n organlc re~ln and an ad~ltlve.

~11 ) A productlon proce~; of a ~ln bound type magnet of the aforement~one~ (9) or (lo) wher~ln t~e ~e~n bound ty~e ma~net 15 an 10 160troplc magnet mol2lded by an extru~ion in a cy~indrical form wlthout an orlentatlon.
1~

( 12 l A p2~0ductlon prOCQ1~6 of mouldln~ & ~e~ln bound type magnet ir; a cyllndrical orm by an injectlon moulding or an ~xtr~610rl moulding of El ma~netlc powder and a ~chermoe~ttin~ ln whereln ln orde~^ to cure the ;.. I5 moltRr~ Dlixt~e of ~ m~gnotlc powd-r ~nd ~ re~ln by hee~ing, lt i~ cur~d by hea~cin~ with flxln~ the out~r clrcum~erQnce o~ the cyllndrleal magnet . by a ~lg and thQ inn-r circu~nference by ~n ~la~t~ ~ater~al ~xpand-d by a ga~ .

t1~) A produetl~n proc~c o~ ~ r~ln bound typ~ m~gn-t wherQln ~
compooltlon of tho ~olt~n mlxtur~ of th~ afore~ontlone~ lnventlon comprl--~ a ~i~n~tlc powd-~, an or~nlc r~-ln ~n~ an adtltlv~.

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.' (~4~ A pro~u~tioll proces6 o~ a re~ln bou~d ~ype ~asnet of the aforementlone~ (12) or (13) wherein the aforement~on~d ela~tlc materiai 5 a ~lllcone rubber.

~- (15) A pro~uctlon proce~ o~ ~ re6~n bound type maçnet com~rl~ing a ma~netlc pow~er ~nd ~n or~anlo re~n wherQln a mixture o~ ~ rare earth magnetlc powd~r premagnetlzed ln a ~agnetic f~eld whlch ic ~tron~er than a coerclve force of the ~a~netic powder ~nd ~ org~nic r~01n i~ kneaded, and the ~neade~ mlxtu~Q 1~ moul~ed b~ an extru~ion ln a magnetlc fleld.

. (16) A product~on proce~ of a resin bound ty~e rare eRrth magnet whereln a compo61tlcn of the ma~net of ~he aorementloned ~nvention comprl~eE a masnetlc powder, an organic re6in and an a~ ive. : .
.
s (17) A production process of a resin bound type magnet by an extrusisn moulding of a moulding raw material comprising a magnetic powder and ~:. an organic resin with a die in a magnetic field wherein it is moulded by an application of a slight vibration to the die at the moulding.

) A pro~uctlon proce~s of a re~ln boun~ type rare oa~h ~a~net where~n ~; a compo~itlon of tha ~agnet of the ~or~m~nt~one~ ~vontlon comprl~e~ a gnetic pow~r, n or~anlc re~in and ~n a~ltlvQ.
, ;
tl9) A r-cln boun~ type m ~net compri~lng a ~a~netlc ~o~dor ~n~ 8 resln 20. ~her~n a~ ~vorago p~rtlclQ ~ r o the ~foroment~onod magnetlc powder ~ - .
6atlcfie~
r ~ 0.1 t (t ~ l~m) r, t;' ' t,' i, .

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, .; ' ' . ' ' ' ~ ~ . ' ' 2 ~J r with the thlckne6s t of ~h~ ~ouldQ~ a~t~clc o~ an ~n~ot~o~lc re~ln bo~nd ~ype magnet compri~ln~ the ~ald ma~n~tlc powd~r ~nd th~ ~o~ln.

(20) ~urther~ ~ a re~ln bound ype r~r- o-rth ~net wh~reln a compo~tlon o~ the m~nQ~ of ~he a~orementloned lnventiOn comprl6e6 a magnat~e ~owder, ~n or~anlc r~ and an ~d~itiYe.

(21) A productlon Proce~s of i r~tn ~oun~ ty~e magn~t comprlJlng ~
magnetlc powder ~d a re~ln whaL-eln an ave~age ~artlcl~ ~ze r of ~he aforement~oned masnQt~c powder s~tic~le6 c r ~ 0.1 t ~t S lmm) wtt~. the thicknes6 ~ of the moulded erticle of an ani60trop~c resir. bcund ; type magnet comprl~ing the ~ld ma~netlc powder an~ ~h~ ln, and the magnet i~ produced by an ext~u610n moulding wlth a die in a ~.agnetlc field.

(22~ A production proce~ of a re01n bound type rare arth magnet wh-rel~
a compo~ition of the mfl~na~ o~ the a~oremQntloned ln~entlon co~pri6e~ a magnetlc pow~er, an or~nic r~sin an~ ~n ad~ltlv~.

2~ ) A pro~uct~on ~roc4~c o~ a r~-ln ~oun~ typo magn~t cotnprt ~lng A
~noul~ng of ~ mlxtura o~ a magn~t~c l?owde~ ~.n~ ~n or~ar,le rQ~ln by an ln~ect~on ~oul~lny or an Qxtru~on moul~lng wh-reln a contpound $
20 pr-parQ~ by ch~rgln~ in a lul~a~ln~ ~ch~n~ aft-r malcin~ a v~co~$ty ~i th~ mix~u~- of th~ ~or~on~lone~ ~a~n~t~c pow~r ~n~ or~anic ~e~ln ln a ~tase o~
~5 8 ~pol-~ (ah~ar rat0 ~ 10000 ~X
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(24) A pro~uctlon P~ocQ~ of D r~ln b~und typ~ ma~net wh~in compo61tion of the ma6n~t o~ the aforem~ntlon~ inven~lon comprl0@c a magnotic po~der, ~n or~anic r~ln and an addltlv~.

~25~ A productlon proce~c of B reæln boun~ type ~a~net ln th~ ~n~ntlons of the aforem~ntlonQ~ (23) and ~ wh-r~ln the ~ur~c~ of ~hQ ~agnetle powde~ 1~ coated wlth a metal pl~tln~ or csramlc~.
' , ~26) ~ produc~ion p~oces~ of a thln plate ~tate r~sln bound type r~re earth m~net whe~ln ~ mo~ in~ r~w ma~e~tal com~rlEln~ a ma~netic p~w~er and an or~anie re~ln 1B moulded by an ~xtru~lon ln a cylln~rlc~l m~gnet lo by pas~ino lt throu~h a d~ e, then one or pl~lral polnt6 on the c~rcum~ercnce of: th~ eald cyl~ndr~cal magnet lE/are cut ln a directlon parallel with the central axi~ of the moulde~ artl~le and the mo~llde~
article cut i~ sprQa~ to make lt in a 'ch~n plate ctate.

( 2~ ) A production ~roce6 o~ a re~ln bous~d, type magn~t wh~ein a compo~itlon of tho mo~ld1n~ raw matQ~141 of the aor~montion~d lnvention compri~e~ a mOE~netlc ~owd~r, ~n or6~nlc re~ln ~n~ an ~ditive.

(28) A productlon l~roc-!~ of ~ ln boun~ typç II~ACIn~t ln th~ ~nv~ntlon~
o the a~or-m~n~ionQd (26) ~n~ ~27) ~hore~n th- out~r dl~ter (DJ of th~
cylln~rlcal m~gnot to bQ moul~ by an oact~ on ~n~ thQ ~nnQr dlameter . 20 ~d) ~ntl~y ~ ralQ~lot~ o 0.75 ~ ~ ~ D ~ I. C--2 - : :

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2 ~ $ 7 ~i ~29) A productlon proc~s~ of a thin plate ~t~te ~ln bound type rare e~rth ma~net wh~eln ~ mould~ng r~w m~t-rl~l comprl~ln~ a m~n~t~c powd~r and an orCan1c r~in i~ pa~ae~ ~hrough Q ~ whera ~ netlc fiQld 1~
charged to mould ~ cylindrlc~l ma~net h~vin~ a ra~latqd ~nicotroPy ln the S diameter dirQ~tlon by an ~xtru~ion, than one or ~lural ~olnts on the circumfer~ncQ of tho ~a~ cyl~ndrl~ agn~t l~far4 cu~ ln ~ ~r~ctlon parallel wlth tho c~ntral ax18 of the ~ould~d ~rtlcle an~ th- moul~e~
article cut 1B spread to ma~c~ lt ln a thln plate ~t~te.

130) Furthor a productlon proc~c6 o~ a re~in bound type m~gnet wherein compo61tlon of the moulding raw ma~rial o~ the inventlon of the aforementioned (~9) comprl6st a magnetic powder, an o~ganlc re~in end an . additive. :

~31) A productlon proces~ of a reoln bound t~pe magne~ in the invent10nC
of the aoremontlo~ed (29) and (30~ whereln the outer dlameter ~D) of the cylindrlc~l m~gnat to be mould-d ~y ~n xtrucion ~nd thQ ~nner ~am~t~
~dl ~atl~fy a rel~tlon of ' O.B5 ~ 8 J D c ~, ~ ~ (32) - ~41~ ar- tho~ in whl~h the rna~notlc powdor, the o~-nlc re~in an~
the ad~itlvo~ ~r~ llm~to~ ~or t~i- lnv~ntlon.
.~; ', - .
As or ~ magn~tlc ~owd~r whlch can ~o appllo~ ~n~thl~ ~nv~ntlon, a - errito ~am~ly ~a~n~tlc powd-~ nd ~ o-c~ rth ma~n~tlc ~owd4r uc~ m-on-t~e powd~r eo~poolnc of ~ r~r- ~rth matal ~n~ trancitlon : m-t~ a~nly con~lt~t~no eo~lt ~na ~ron ~ a~ic compoclt~on, or ~ - 23 -,~
. :

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2~
magnetlc powdex co~po6ln~ of a r~r~ oarth mQtal, tran~ltion mQt~l~ mainly con6tltutlng lron ~nd. ~oron ~ a b~-tc compo~itlon, otc ar~ ~n~lnerated.

A~ for an or~anie re~ln whlch can ~e app~lfid ln ~hl~ lnv~ntlon, le c~n be elth~ a ther~opl~tic r-61n or ~ tharmo~ett~n~ r~in, and a~ for the thermopla~tlc resln, for ~xa~ple, a pla~tic ~uch a~ polya~lde, polyprop~lene, polyc~rbonat~, polyph-ny~-nog~lph1de ~PPs), ~tc, an : ela~tomer such a~ chlorlnate~ polyethlene, ~thylQne vinylacetate copolymer (EVA), etc and Eynthetlc rubbe~ are num~a~

A~ for ~he thermo~ettlng r~ln, ~or ~xampl~, ~thylQne ~amlly un~aturatQd polyester re~ln, epoxy recin, etc are ~numerated.

Further a* for the a~ditlve, a lubricant to re~uce an ex~rusion re6i6tance ~t the moul~lng ~uch a~ 3 ~etal Eoap (~inc stearate, calc~lm stearate), wax, etc c~n be u~e~, and a6 ~or th~ ~forementioned clo6~1~nkable thermo6e~tlng re61n, ~n addltive ~uch a~ pqrox1tec whlch l~ ~ccelerate6 the ~locsllnking re~c~ion c~n al~o bQ ured.
,'"
~h~ ~agnotlc powd-r i~ u~ic~ntly ~lxod wlth th- or~anic re-in ~n~ 'ch~
~ltlvc 1f l'c ~c neco~sary. ~rhen tho ~x'curo 1~ cu~ ntly kne~d~d in a ~n~a~lng m~chln~ with heatinç abovo ~ t~pex~tur~ at whloh tho org~nlc : re-in io molt~n, ~ne. lt i- ~F~nulat~ 'rha ~aon~tlo compo~it~on :~ 20 granul~te~ 1~ charge~ ln an ~xtru~1on ~chine, lt 15 ho~ted in a cyl~n8erto ~a~e lt ln ~ ~lu~z~ 6t~t~ an~ ont ~nto ~ ~lo by a ~erQw OL' a . . .
; plur~er. ~he ~a~netic eompo~tlon 1n~ected. ln tho ~o ~ mould-a by un~formlng ~cr~nt~ting) an axi~ oX e~y ~a~n~t$zation of the m~g~etlc ; -- 24 -., .~

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2 Q ~
powder ln th- ~aw m~te~lal to ~ dlrection of a m~netlc 1-1d by pR~ln6 through a dle in whleh a ma~nQtic f$~ charc2~. The maqnQtic co~po~tion i~ olldlfled with eoollng whll~ lt lc in the m~6notlc fleld formed ln the ~ie, an~ lt i~ xtru~d. ~h- moul~d artlcle i~ then cut into a cuitable lenoth. Wh~n 4 eloc~l~nk~ble or~n~c re~ln 1~ u-ed aR a blnder, ~ter ~ dema~netlzatlon o~ the mould-~ artlcle cut, a clo~clinklns o the or6an~ r~sin lc achievcd ~y h~at~n~ or an lrradiatlon (r r~, electron bo~m, tc~. A recln ~ound type maCnet 1 thu6 p~oduced. .

10 Further the moulded ~rtlcle extruded from the ~ie 1~ demagnetiz~d by ch~r~in~ magnetlc ~leld of a rever~e directlon to thc magnetic fiel~
charged ln the dle at the mculdlnç at a front end of the mand ~ h~
.,: . :.
: ~trength o~ the magnetic flQld i~ a~ûctQd by a dictance between ~he mand~el ~nd a yoke of the ~l-ctromaqnetic coil. The moulded artlcle 15 extruded ~rom the die i~ al60 dema~netlzed by chargin~ a magnetlc ~leld for an attenuation by pa~ln~ lt th~ough an electromagnetlc coll for the dema~netlzation. A cyllndric~l r~-in bound ~net i~ thu~ produced.
,. ~" , Further thl~ lnv-nt~on i 6 w~ to facll~t~te ~n orl-nt~tion of ~
n-tlc ~owd r, to lmprov~ th~ n-tlc prop-rty ~nd to r-duce ~n 20 Qxtr w ion r~ tance at th6 moula1ng, an~ ic al~o b~n~flclal to ~ncroacQ
th~ mouldlng ratQ by an appllcatlon o~ a ultra-onlc o~lllator or a m~chanical Ylbration ~uch a~ a vlbrator, tc.
- ~
.~
Accordlng to thi~ In~entlon, by ~eflnln~ an aver~ge partlcle ~lzo o~ a .. m~net~c powd-r w~th a thickne~ of ~n ~nI~otroplc r~c~n bound typ-~....
,i "' - ;! S
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.~.; . , . , . - - ,- . .

:,: -, , -~, ., ~ ... ,: ., magnet moulded article, and th~ ~a~nQt i~ mould~d bY an ~xtru610n, it i~
poc~ible to moul~ ~ thin thiekn~o~ an~sot~oPlc m~net wlthout postfabrlcatlon, ~n~ fur~her a hlah per~ormance ma~n~t 1~ able to mould.

~urther accord.~ng to thl6 1nv~ tion, ~ ha~ RC~I~ to ~revent a S del~mlnation of a eoa~e~ film on th~ 6urf~c~ of a mapn~tlc pow~er and to lmp~ove an oxl~atlon r~ tance of t~e m~gnat moul~ed by kn-a~ln~ ~
~ixture of the msgnetlc powdar ~nd a ~ln a~ter ~tin~ I t to m~e a vifico~lty o~ the mlxt-lre at ~0~ Xpo~a- or l~ prlor ~o th~ ~nead~n~ to ab~or~ the ~olten st~te ~e~in on the ~ur~8ce of th~ magnet$c powder ~0 resultlng a relief of a mechanlcal ~tre~.

Next, ln order 'co rnake a ~hin plat~ ~tate ma~net, one or plural polnt~ on the c~rcum~erence o~ the moulded articl~ ln a cyllndrical form l~ cut in parallel ~th the central axi~ of the moulded 8rticle. ~hen the a~orementioned moulded article cu~ 1~ m~e ~n ~ thln plate 8 ate by u~ing, ~or exnmple, 2 roller~, etc. The mould~d article 1~ then 6011dlfied with coolir~g, ~nd ~ cut lr,to a cuit~blQ len~th.
;

Further a~ an alternatlve m~thod., ~ter cuttln~ ~ cylindrlcal moulded artlcl~ xtrudo~ lnto a ~ult~blo l~n~th, one or ~lural polnt~ on th~
clrcu~sr~nc~ o the anouldod ~rtlol~ i~ cut ln par~ rlth the cQntra 20 . ~xl~ o~ th~ moulded arti~ mould-~ artlcl~. ~ut $E ho~te~ ~n~ it 1~
~pre~d wh~n a v~coBity of 'cha moul~in~ ~rtlclo dro~ 'co m~ke a thln pl~ee st3te.

- 2~ -. .
, , . , ~ ,, -.

2~3 Z, A6 deccril~ed abov~, a mhgn~t of thls lnvont~on 18 ~uperlor to a eonve2,tional ma~n~t, in ~hi~h plur~l m~çlnQtR are tlck-d, ~s~om a vl~wpolnt of a rol~ abllity. Furthermor~ ~y an e~ppl~c~tlon of production pro~4~ o~ thi~ lnvontlon, 5 (~) A cyllnd~lc~l r~ln bound type ~a~net wlth a hlgh ~a~ t peror~ance can bo produc~ wlth a hlgh pro~uctl~ity end ~n oconom~c co~t.
' ( 2 ) slnce no OXC~1613 force or vibratlon 1~ ch~r5Jad ln th~ m~net ~t a c~ttlng step ~y cutting an extrud~d re~ln bound type m~net wlth a wire heate~ by an lclctric rG6ist~nce~ lt 16 po~lbl~ to cut an uncured ma~Jnet lO whlch 1~ very ~rlttl~ and ~ ~hin thickne~ ma~net without ~ crack and a breakage.
'' .

.. (3) A large amount of a thermosett1n~ treatment can be operate~ w~t~, a low coEt~ th~ ~peration becomeE ~aey, and f~rther a dimenslon accura~y of a ~yl~ndrlcal re~1n bo~nd type maCnet can ~ mproYed~
', 15 ~4) It hA~ a cignlflc~nt c~act ~or Q~5tll~incl a cyllntrlc~l m~gn~t h~vlng . a rad.iated ~nl~o~rolpy ir~ met~r ~lroctlon though lt i~ dlfficult to . q~t a ~trorg ~ tic ~ld at the mouldln~.

t5) ~t can b~ ly u--d ~or ~ magn~t~c ~en~or, ~n rseo~-r, an acutu~tor, .
a llnear a~tu~tor whlch r~ulr~ A mlnlturl~atlon, ~ cl~on an~ a hl~h 20 p~r~o~mAnc~

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, Furthe~ according to thl~ lnventlon by te~inln~ th~ ~v~r~ partlclQ ~_ze of the ~açnet~c powde~ by the thlckne~s of t~ dn1~otroplc resin ~o~nd type magnet moul~ed articl~ an~ by mou~lno ~he ~agn~t ~y an ~Xtrusion, lt lC po~Bible to mould ~ thln thlc~ne~6 ~nlsot~opic ma6nQt wi~hout a po~tfabrlcatlon, nd ~t 1~ al30 pb~1bl- ~0 mould ~ ma~n~t with a hi~h perfo~an~e.

~urthermore acco~dlns to thls lnv~ntion by kneadln~ a m1xture of 8 ma~netic powaer an~ a r~ln a~ter he~tln~ lt to make it~ vl~coolt~ at 300 kpoi8e or les6 prior to the ~nead~n~, the re~ln in a molten ~tQte i~
,~ 10 ab60L-~ed on the ~urface o~ the magnQtlc powder, ~nd thus 1~ ha~ effectc ,.- to preve~t t~e coate~ ilm on th0 ~r~aCe of the magnetlc powder by reli0v~ng a mechanical stre~ and to lmp~ove an oxldatlon re~lstance of t~e magnet moulded.

~XAMPLE
,":
15 ~hl6 invention 1~ ~xpla~ned in detall6 in accordanco w$th examplo~ ~hown below.
~:"
~xampl~ 1 Raw mætor~ w-re molterl to mRk- ~I compo~ltlon ~- Bm ~co 0.67~ c-~ o.00 FQ 0,22 zr 0.02~ 8.3S, a~tor c~t~nC, an ~n~ot produc~ w~ ma~n~tl~all 20 ~ure~ by he~t tro~tm~nt, an~ th~n ~ ma~ lc powder-o~ ~t- a~orage p~rtiele ~ize lO~lm wa6 ~rep~r~ by crwhinç the ~ald lngot.

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~, - - . -. . ~ . ~ -.,. ,,, . , ~ . :

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2 ~ ~ ~ 1 r ~ ~

The ma~netlc pow~er, nylon 12 pow~r and z~nc 6t~rat~ pow~er w~re mix~c to ma~e a ratlo of 92 wt%, 7,9 wt% an~ 0.1 wt% r-~p~ct~alY.

. :
: ~he ~lxture wafi kn~a~d by an 2 ~x-~ ~xtr~lsn ~n~a~in~ ~aohlnQ at 260c.

~ he kneaded mate~lal wa~ granul~ o ~Q ~ranul-~ of ~n outer ~ia~eter l - lOm~, they were w ~d ao a r~w ma e~ial co~poun~ 111, and a cyllnd~lcal ~agnet w~c produc~ by an ~xtru~ion ~achlne.

The mouldlny method 1~ explalned in occord3nc~ wlth Figure 1. ~he moul~lng m~chlne ~on~i6t~ of a hopper i~ a raw ~at~rial char~in~ ~ection 101, a cylinder 102, a ~crew 103, an ad~ter plat~ 104 to e~ulp a di.e a' the cylin~er 102, a dle 105 B~ a drlvlnq motor of the serew ~which 1~
not 6hown ln Flgure3, and further an electromagnet~c co~ 10~ to charge a magnet~c fleld ln the dle i~ po~i~ioned at the outside o~ the dle 10~.

A yoke 110 eomprl~in~ a ~notlc mat~rlal is lnstalled a~ound t~.e electroma~netic coll 109.
,' The ~o~ementlon-~ granulata~ r~w m~t~rlal compoun~ wa~ char~e~ ~n the xtruoion ~achin~.

: ~he ~-w ~at~lal ~ompoun~ 111 wa~ hQa~a~ at 263C ln ~h- eyllnder 102 to m~ke lt ln ~ ~luillze~ 8tat~, ~n~ lt ~eD p~tao~ ~hrou~h ~he dle 105. Th~
~1~ etruetur~ hown ln ri~u~- 2.

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` 2~Z~ 3 The dle i~ con~tltu~ by an ou~er ~$~ ~01 and ~ m~ndrel 202. A' ~hOUC~
the o~ter die 16 made of ~ non-magnetlc m~terlal, a rlnq ~h~p~ oUtQ~ dle cectlon magnetic mator$al 201a to l~uce a ~net~c ~lux 1Y ln~t~lle~ at the front Qnd. ~h~ m~ndrel 201 1~ ~160 mad~ of a non-~a~nQt~c m~t~L-~ al ~
and ~urther a mandr~ c~lon magnotlc materi~l 202~ i~ ln~talled at. 1~6 front end.
' ~hen a current 1~ pac~ed throuoh the electro~a~net~c coil 109 i~stal;ed out~lde of the ~le, the ma~netlc flux goner~t-d flow~ alohg6ldQ of a magneti~ flux flow H ~ho~n ln Fl~ure ~y ~n ar~ow ~tnce lt ~en~s to pac~
through a ~agnetic mat~rlal wlth a hl~h magnetlc perme~bl1ity.
Accor~ingly a radiate~ ~hape ma~net~c ~lel~ 1B ~enerate~ in a sp~ce (hQreinaFter called a~ an orlentat~on ~ectlon) between the ront end 2C2a o~ the ~ndrel 202 and ~he rlng shap~ outer die 201a of a magnetlc ~terial ln~talled ln the outer ~le 201. Th~refor~ when a magnetlc compo~ltion pa~e6 through t~e orientatlon sectlon, ~t 1~ moulded Wit~. a pro~l-ess of the orlentation o the magneti~ powder.

In th~ Exa~ple, the ma~netlc ~Qld ~or ~oul~ln~ wa~ 15 KOe, thQ
te~p~ture o~ the die ~t the ~ouldl~u wa- Z~O~C ~n~ the coollns ~a6 porformed by ~ ~orc~ alr ~ooll~ at th~ outl~t ~ctlon o~ th~ ~1Q~

AccordlnglY, ~n orlent~t~ r~w m t-rlal ~omPOun~ wa6 ~oulde~ by an ,., xtru~Tlon wlth ~ ~olldl1eatlon wlth coolln~ at th- outl~ o~ t~ d~e.
Th- ~læ~ o~ th~ ~nould~d ~rticl- t~O.B- th~ out~ lamet-r 32mm, the lnn~r di~meter 30mm, ~d the longth wac cut ~n~o 22mm. ~ n~tic propert~
o~ the moulde~ art~lQ producQ~ w~e ' :., .:, ., 2~

Br - 5.~ KC and ( 8~ ) xax ~ 7 . 3 MGO~ .

~he magnetE thu~ produce~ ~-r- ac~rnblo~ ln 2S unit~ o~ DC snotor, and s contlruou6 operatlon taDt for 500 hour~ ~aGt 1 W~ c~rrl~d out.

5 A~ for a ~o~paratlve ~x~mple for To~t 2, the ra~ sterlal h~vlrlg th2 ~an~
compo61tlon wa~ ~noul~e~d ~y an ~n~ctlon ~n ~ m~netlc ~l~ld and a cyllndr~cal ma~nat of the oUtQr dl8m~ter 32, 5mm, the lnner d~eter 30mm and the length 6m~n wa~ ~oul~a~ m~gnetlc property of the Dloulded article produced was sr ~ 5 . 7 KG and B~) max ~ 7.0 MGO~.
.'' plece~ of the magne~, were ~ticked by an epoxy type a~he6ive, an8 then ~he outer diameter ond the lQngth we~e made at 3;2mm and 22mm ~y a cut:tlng f abric~tlon .
. ' 15 ~he m-~net~ w~re ~ d ln 2S unlt6 o DC motor and the 500 hou-contln lous oporatlon wa~ carrlo~ out a~ ~a~e ~ ~e6t 1. ~h~ te~t re~ult~
wera ehown ln ~la 1.
' -;~
' DC Motor T~te~ D~ Motor ~xhlblt~d a D-tQrlor~o~ Pro~rty ~ .

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~e~t 1 t Example ) 25 0 ~- Tect 2 ( comparative -~ ~ example ~ zs In the ~ 1, thoa~ of whlch th~ mo~or ~howQ~ a ~c~rior~t~d property , 5 w~re ca8e~ that ~-h~ rotation of t~ motor ~to~Q~ or the tor~ue wac : ~roppod due to an ~n~u~f~ci~nt ma~n~tic flux ~vailable by ~ d~ln~nation :~ .
~t tho adh~lv- ar-a of th~ m~n~t~ ~t~cked.

~onsequently by ~n appllcat~ on of the magnet o thi~ vQntion, a rellab~llty o~ the motor c~n ~e lmprov~d.
.
10 ~:xarnple 2 Raw material~ to mahe a compo31tlon ~3 Fe~2 7 ~ ~3 we~e molten, were C-c~6~ed and a quenche~ ribbon wac prQpared ln ~n ~rgon atmo~phere by u~l~gc-a qu~nchl~ ~nd a ribbon rollin~ m~c~ine fro~ t~Q in~ot obtalned. ~he ;. quonehe~ ribbon wa~ coar~ely crush-d, ~a6 ~har~6~ ~n a mould an~ a high 15 t~poraturQ procc mouldln~ wa~ p~r~orm~ b5r applyin~ a pre~au~ o 20 Kg/mm2 for a ~hort tlme t 700 - 800C ln an ar~on atmo~pherc en~lty of th- con-oll~at~t art~el~ w~e ~lmo~t 100%.
~,, .
eon~oll~atod artlcl~ w~ ln ~roc~ wlth ~ hi~h ~m~eraturQ
~rQ~e ~oul~ng ln ~ v~rtle41 ~lrsetlon to the flr-~ ~ro~n~ ~lrection ;, 20 wlth ~ pr~ur~ o~ 10 X~mm2 at 7Q0 - ~OQC ln an ~rgon atmoeph~ro.
~"
~` ~ trl~ely lt wa~ tr~t-~ wlth a dl~ t~
, , s 3 2 ' ' " ' ;' . ' ~' :' ' ` :. ~

. 3 A bulk ma~n~t o~t~ln~ wa~ cru~h~d tc m~e a ma~netic powd~r of hn average partlcle ~iz~ o~ 20~m.

~he ma~net~c ~ow~ar wa~ mix~d w~th a ro~ powd~r c~prl~in~ bl~phenol~
A type ~poxy, novola~ type epoxy and vinylbut~ral-vlnylalcohol copolymel, calclum ~tearate powdQr and s~llca powder ~ ad~tlvec.

The ~atio ln th~ mlxture was the m~sn~tic powder 90 . 3 wt%, the r~6in powder 9.1 wt% and ths ~d~tiv~ 0.6 wt%.

~he mlxture ~as hne~dod by a 2 roll~r ~yp~ m ~, The knea~ed mixture wa6 ~ranulated to an outer dla~te~ of 1 - lOmm granule~ to ma~Q a raw lo materlal compound and was moulded Ln a cylindrlcal magnet by an ~xtru~ion macl~lne a6 Eame a~ ~xample 1, and 1~ wa6 cut and was flre~ a~ter a demagnetization.

~he ~ize of ehe moul~ed a~tlcle wa~ the outer dl~m~ter 22mm and the lnn~
diameter 21mm, and the maçnetlc fleld for the mo~ldln~ wa~ 14 xoe. ~he m~gnetic prop~rty of the mould~d article obtalnad wac Br ~ 6 . ~ ~G ~nd ~ max ~ g.a MGO~.

cono~qu~ntly as ~or th~ pro~uotlon proc~ o~ thl~ lnv~n~$on ~ h$gh ~orform~nce ~A~n~t can ~ obt!ln-~ ovQn a Glo~lln~abl~ thQr~o~ett~n~
res~n 1~ us-d.
-Exampl e 3 .
, .- : .

- - -2 ~ 7 ~

A ~a~ne~ic po~der o~ ~n ~ve~e partlcl~ ~lzo o~ lo~m ~as pr~ar~d by ~he came co~pos~tion ~nd procedure a~ ExamplQ 1.

A coerclve force lHc o~ thls pow~er wa~ ~ XOç. Thi~ sll~d as Powd~r A.

~urth-r a6 or ~he other kin~ o~ pow~ a~nstl ~ pow~r o f an average ~ize of 20~u~ wa~ prepare~ ~y th~ ~me compo~tlon and proc~dure a~
Ex~mplQ 2, A ~oe~ e orce ~Hc of thi~ pow~ w~ 12 Xoe. ~hlc i~
callod as Powder B.

~ owder A, nylon 12 powder an~ zinc ~t~ar~te powd~r were mlx~d to m~ke a rat~o o~ 92 wt~, 7.9 ~t% and 0.1 wt~ re~pec ively.
' Furthe~ PoWde~ J was al80 mlx~ wlth the a~orementlon~d re~in pow~er an~
the addltive to make a ratlo o~ 91 wt%, 8.8 wt~ ~nd 0.2 wt%.

~he6e ~lxture5 were kne~d~ by ~ 2 ~xe~ xtrw lon kna~ng m~hln~ at 260C. The knea~ed mixt~re w~ ~ran~l~t-d to ~ranul~n of an outer 15 ~lameter o~ lOmm to m~k~ a raw ~at~risl com~ound 111, and a cylin~rlcal m~net was ~oul~ y ~ ~roc-dur~ ~xpl~lns~ ~n ~a~pl~ 1 by ~n ~xtr~ion ~ouldln~ m~chlnæ ~ ~hown ~n ~ure 1.
.
~e ~o~ldln~ m~thod ~a~ th~ c~ tho~ a~ Ex~mpla ~ and the ~t~uctu~e wa~ o th- ~m~ to Flg~lr~ xpl~ln~d ln ~x~ple 1.

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~f a ~urrent flow~ ln the ~l~ctrom~n~tlc coll ~qulpp~d out~ld~ of the dle, the ~agnetlc flux g~ner~tod flow6 in the arrow H ln Flgure ~i~ce ~t tend~ to pa~6 throu~h ~ ~a~n-tic ~a~erl~l wlth a hl~h ~gn~tlc permeabillty.

cons~quently ~ ~adlat~d magnetl~ ~leld ~ g~n~r~ted ln the orientatlon ~ectlon whlch l~ a ~ace be~w~en a magn~tic ~terlsl Z02a O~ ~hQ ~andrel and a ma~netlc materlal rlng 20~a in~alle~ ~n the outer ~t e. Th~re ore when a ma~notlc compo61tlon 1~ p~C~n~ throu~h the orlentatlon ~ection,.
i t 16 ~e~n~ moul~Q~ wlth a pro~e6~ of an ~rlentation of the magnetlc powder.

Furthermor~ a ma~netlc field with ~ reverse dlrectlon to the ma~netlc field in the orlent~tion ~ection ie generatQ~ ln a space betwee~ the front end of the ~andrel and the yo~e 110 o~ the coll, Ther~fc:~e a demagnet~zatlon of the moulded article c~n ~e achieved by making the magno~lc fleld O~ thlc a~ac~ a~ a Buit~ble ~tr-ngth wlth an ad~ustment of a di~tance betwe~n the mandrel an~ thQ yoke 110.

n thi~ ~xamPle, tho m~gnætlc flel~ for moul~ing w~ ~4 XO~, the t~mpQr~tllre of the~ at th~ mo~ldln6 was 250C an~ 1:ho cooling w~
~ppli~ ~y a or¢e~ alr ooolln~ to th- outl~t ~ctlor of th~ dlo.

20 By tho abov~, thQ orlentat~d r~w matorl~l co~ound 111 ~6 rnould~O. by ~n ~xtru-lon w~h a ~olldl~icatlon wlth coolln~ at th- outl~t o~ th- ~le. A
strQn~th of th~ a~ne'clzatlorl m~gn~tlc fleld w~ ~d~l~t~d to almo~t the ~ ~5 -- , . .
.,, - . ~:, :. . - -~, - ' , ' . , ' . . . ' . ~,. .
;. -, .

2 ~
6ame to the coerclve force l~c of the maonQtic ~owd~r ln the moulded a~tlcle .

~he ~1ZQ of the moul~d art~ cla w~ the out~r ~l~mo~ar 30m~ an~ the lnner dlameter 29mm. In T~le 2, 6~r~ce ~agnetlc $1Ux ~enci'cla~ for c~se~
5 Teæt 3 and 4 ln which the ~ema~net~zatle~n wag per~o~m~, and ~or C~ICOB
Te6t 5 ~nd 6 wlthout ~he ~ema~nQ'clzstio2~ ~nd chown.

Ta~lQZ

Te6t 3 Example A 20 10 Te6t 4 Example ~ 35 ~e~t 5 Colnparative exsrnple A lS0 .Te6t 6 Comparative . example ~ 220 15 Ex~mple 4 A m~netic pow~er o~ ~n a~Qr~go pa2~t~ ClQ ~lz~ lO~m ~nd iHc ~ Xoe ~
propare~ ~y tha B~ e compo~it~on an~ E~rocQ~ure ~ ~xaa~~ hic pow~r 1~ c~ d ac Pow~r P..

P.c for th- othor kin~ oi~ pow~r, a ~gn-tlc ~o~r o~ an av~rag- particle ~$z~ 20~1a an~ ~ co-rclve ~orc4~ ~c ~2 XO~ w~ ~r~par~ by the ~e '~, :;
~ - 36 -:', .

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~,",' ' ~ ' - ' ' ~ . . , composition ~nd p~o~dure a~ Example 2. ~hl~ ~owd~r 1~ c~lled ~ Powder : B .
.

B~ma to ~xa~pl~ 3, the Powder A was mlx~d wlth nylon 12 po~der ~n~
zlnc ~te~rate pow~r to mak~ ~ ratlo of 92 wt~, 7,9 wt~ ~nd 0.1 wt~
. 5 re~pectively.

Pow~er B wa6 ~180 ~ixad wlth th- ~or-m~ntlon~ r~ln po~er and addit~ve to ma~e a ratlo of 91 wt%, 8.8 wt~ and-0.2 wt% re~pect~v~ly.
, The~e mixture were ~neade~ by a 2 axe6 ~xtru~ion kn~ading mach~ne at . 260~. The knea~ed mixture wa~ ~ranul~ted to granule~ of t~e oute~
dia~eter 1 ~ lOmm to ma~e a raw mat~lAl compound, and a cyl~n~l- ca:
magnet was moulded by an extru~ton mouldlng machine.
. ' ' , ~he mould~n~ method 16 exp'ained in accord~nce w~th Flgure 3.

.. An extru610n mouldln~ maehine of Flg~r~ 3 1~ compo~ed of ~ cim~lar . constitutton to ~n ~xtru-lon mouldln~ ~ch~ne cf Figure 1, ~nd an : .15 ~l~ctromeg~t~c coil 109 i- pocitlon~d out~ldo a dl- to char~e a m~qnetic . ~l~ld in th~ al~, but th-re 1~ a ~f-roncs le ~n ~l~ctromaqn~tic co~l for demagn~t~zatlon 1~ lnstall-d ln ~ront o lt.
, ~h- ~or~mentlon-~ ~ranul~t-~ raw matcr$~1 com~oun~ 111 wac ch~r~e~ ~n t~ ~x~ru~lon mouldln~ m~ahin-. ~hQ r~w mat-r~al oompoun~ 111 wa~ h~at~
~t 2~0C ln th- ~ylin~r 102 to m~k~ lt l~ a ~luid~z~ 6tat~, ~nd ~ wao p~c~d throu~h the di~ 105. ~hs dl~ uctu~ W~8 the ~am~ xplaln~d '':
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2 ~
~n Example 1. Accordinq to thl~ ~nv0ntion, when the magnetlc COmpO~itlO:;
t~ p4~ed through the orlentatlon ~ectlon, lt 1~ ~oulded wlth ~ prog~c~
of an ori~ntation of thQ ma~ne~ic pow~Qr ~a ~ame to Exampl~ 3.

~ n thi6 ~xample, thQ mag~etic flel~ for mouldlng W~B al~o 14 KOe, the temperature o the ~le t the moul~lng wa~ 250C, and th- coolinq wa~
given ~y a force~ alr coollns to the outlet cectlon o~ th~ ~le. Tne orient~ted r~w material compc~nd 111 was moulded by ~n extL~lon by a ~olldificatlon with coolin~ ~t t~e outlet of the die.

The demagnetlzatlon W~6 carrlet out ~y genexating ~ magnetlc fleld for the demagnetlzatlon by turnlng on an ~ttenuat~ pul6e current ln the electr~ma6netic coil 113. The ~trength of the ma~netlc field for t~e demagnetization w~s 30 KOe, ~nd lt wa6 atten~ated with ~0m ~ec. ~h~
ma~netic fie~d ~a~ gen-rated ln the electromagnetic coll 113 ln every 15 ~e~, and the dem~gnetization wa6 carrled out con~inuouEly~ The s~ ze o~
the ~o~lded art~cle wa~ the outer dismeter 3~mm ~nd the inner clameter 2gmm. Surface ma~netlc ~lux d~n61tiec of the moulded artlcle6 fcr ca~
~n whlch the d-m~net~zation was pe~formed (Tost 7 an~ 8) and or ca6e~
-without the demagnetl~atlon (Teet 9 and 10) are ~ho~n ~n Table 3.

~ ahLe 3 ; 20 . ~9~g~
: ~e-t 7 Ex~mple -~A - lO
T-~t 8 Ex~mplQ ~ lS
Te6t 9 comp~r tlve ., :
, ;, ~ . . . ~ . . . . . , . . .

,,. -, --. : ... .. .
. . . . , - , . , ~

2 ~

exampîe A ~50 Te~t 10 Comparative example B 220 A~ lt i 8 clear ~ro~ T~ble, the ~Ur~ac~ ~agne'clc ~ x den~lty whlch 5 remains ln the ~o~ulde~ art~ cle could be dropp~d at 6 ~% by an applicati on of ~he prc~c~so o~ thl~ ~nv~ntlo~. c~n~ec~ ntly th~
~orkabillty at the cu~tlny ~'cep, etc wa~ ~reatly lmproved.

~xample 5 A magnetlc Powder A or Po~der B ~ the 6ame compo~ltlons to ~xa~nple 1 and 10 2, and Ro6~n a ~a thermo~ettlng epoxy ~e~lnJ or Reeln. b (a thermoplaEtlc l-e~n ~'on lZ~ we~e weighed to nlake a de~red vo~ume ratlo, were mixed and a sheet E~ate compound Wa~ prepared by ~ne~ding the mixture by ~assin~ lt th~ou~h a ~ap of a twin roller mill ~epeatedly after cha~:~in~
it ln the m~ll.
:~ .

15 ~he kneadin~ temperature o~ the mixtu~Q ~6 at 90C when R~in a wa~ u~d and at 250C wh~n ~e~ln ~ wa~ u~e~.

Th~n thè compound Wk- c~u-he~ ~nto p~rt~ Cl~B and w~ moul~ed by an ~xtru~lon by pa-~1no throush ~ cyllnds~c~l ~10 by char~in.~ lt ln a ~erew type ~x~ru~lon mou1t~ng m~chlne~

, _ ~9 _ ' ~ , , ~ ~
. :

2 ~ _ . ,. L ~ ~

A ~arrel temperature o~ ~he ~xtruslon ~oulding machine WA8 at 13~c ~c~
Resin a and at 250c ~or ~esin b an~ th~ die temperatu~e w~ the rnould1ns temperat~lre for thQ ~ach ca~e.

~he ext~u6ion tate wa~ 1 mm/~ec.

~he outlet te~per~tur~ of th~ ~ie w~ get ~t ~ ~olldl~c~tlon temperature of the compo~ltion moul~ed. Thl~ temperature ~l~fere~ by th~ proce~6ec.

Re~ln a wa~ u6ed ~or Proce~ 1 and Procesc 2, Proce~s 1 wa~i ~ process to make ~he ~olidl~lc~tl~n wi~h coolln~ at the outlet o~ th~ dle, an~
~roces6 2 w~ a proce~6 to make the cure by heatlng at ~he ~ont end of lo the die. Proce6s 3 was a proee~ to. ~olidify w~th coollng at the outle~
of the die u~ing Resln b. The magnet6 thuE produced were cut by m~tho~
~hown ln Table 4.

: ~ab~ 4 , ~Q~
15 CUttin~ Method 1 Cuttln~ by melting wl~h ^ h-~t~ wlr~
2 Cuttlng by ~ ~uillotln~ cutter ~ystam 3 Rotatlon ~aw tooth -y~te~

~mon~ tha~e, Cuttln~ M~thod 1 w~ cuttlng ~tho~ ~ thl~ lnventlon wh~eln a curr~nt 1~ turn-~ on In a ni~rom~ wir- of a ~am~tor or 0.2mm, lt i6 contacted wlSh ~ ~a~n-t when lt 1B h-3te~ b~ the r~ tancQ ~nd thQ
ma~net 16 cut ~y meltlng wl~h heating.
.:
:: - 40 - ;
. .
' ~' , .' : ' :~
.
, - - - -2 ~
Re~ult~ of the cutting, when th m~vne~ produc~d by ~n~ae prsco~es WQre cu~, were shown ln Table 5.

In th~6 te~t, the magne~ out wa~ ~ c~lln~rlc~l m~gn4t wlth the o;lter diameter 30mm and the lnner dla~et~r 2~mm, And th~ volu~e ratlo of the m~netlc powder wac 60 vo~%~
s~
Although the m~netic Powder A and ~ were u~, both ~howed th~ ~ame re6ult6~

cutting Me~hod 1 excellent 600d ~xcellent 2 b~d ~ad bad 3 or~inary excellent excellent ~he ma~net of Proce6~ 1 waC ~he mo~t ~l~flcult ~ample to cut am~ng the magnet~ o Proce6~ 1 - 3 becau~e lt was the mo~t br$~tle. AR it ~8 cl~ar from Table 5, th~ cuttlng method 1 ~nd ~he çuttinC metho~ 3 c~n b~
~r~ot~cQ~ ~or cutting tho~e ~agnot~, ~nd it la not po~ibl~ to cut lt ~y thQ ~utt~ng mQtho~ 2.
' . .
Exa~le 6 N~xt, r~ult~ o~ cuttln~ when thickn--~ of t~e ~a~not to be ~ouldQd w~
chans~d, were ~own in ~able 6.

. .

. . . . .
~ ~ .

.- . , .
~ , 2 ~ ?7~r ~
The ~nagnetc rhl~ tlma h~lt an outQr ~l~m~ter o~ 30mm, W~iB Q cyllndrieal ma~net ~nd the m~ Q~ pr~parad by Proce~ a~ u~od, The r~aults cf either the tnagnetic Powder A or ~ w~re the samQ.

~L~

S Th~k~L~

Cutting M~thod 1 good excellent excellQnt exoellen~ excellent CUttlng Metho~ 2 I-xcell~nt good ordln ry ~ad bad As one of the ~atures of ~he extru6 lon moul dlng method, it csn be 10 enume~at~d that a thin thlckn~6~- m~net can be moulded. There~ore i t lmportant to cut a thln thlckne~ magnet.

Tn case of the cu'ctin~ Method 3, lt was ~if~loult to cut lf the. ~hl~:kne6 of the magnet boca~e O . Smm or lel3~, and it was not po~ le to cut wher~
:; it wa~ O . lmm ~u~ to ~ format~on o~ craekin~ .

; 15 On the oth~r hand, ln c~ of the Cuttlng Method 1, a thin thlc~nes~
ffl~n~t Clln b~ cut ~inco no xco-~ ~It~B 1- appl$ed to th~ net at th~
cutting ~tep.
, Con~quently it ~ o~ar that t~ cu~tin~ by moltlng. ~lth ~ ~e~tad wl~
i~ an ed~ta~ 'cag~ou~ mothod ~!or th- outtlnq.

~x~mple 7 - 4~ -.. . ..

... . , . ~ . .
',: ~ . : . .:
-: . . : . . .. . . . .

. ;J;

Re~lt~ or the cuttin~ whon the volume ratio of th~ m~n~tlc powder w~
chan~ed were ~how~ ln Table 7.

The maqn~t cut thl~ tlme ha~ the out~r dlnmeter of ~Omm ~n~ the lnner diam~te~ of 29m~, w~ a cylindrical ~n~t pr~pare~ ~y ~roce~ 1. ~ne magnetic powder uoed WA~ the m~gnetlc ~owd~r A

~ Q ~ 70 72.
cutting Method 1 excellent excell~nt excellent e~cellent good lo Cutt1ng Method 2 ordlnary ordina~y bad bad ba~

A6 the volume ratlo of the m~netic powder lncrea~e~, the volum~ rat1c cc ; the resln ~crea~e~ accor~in~ly, and the b~ndlnq ~tren~th ~f the ;-es.n r~
the ~aqnet~c powde~ dropG.

~h~r~ore th~ m~gnet mouldet becom~ brlttle ~ the m~gnetic powder ln~roa~e~. ~hlo tren~ i~ r-mar~a~la ln a c~ce o a~ uncur~d ~ne~
produoe~ by Proc~ 1. A- tho volu~Q ra~-lo o~ tho m~n~tic powder lncr~Q~2~, the m~ t por~orm~nco of tho ~gnat 1~ Lm~roved, and ~h~r~fore lt 1- ~mportant th-t thQ cuttlng c~n ~ rl-~ out eve~ in ca6e o~ larga volu~- ratio of th~ maonQ~lc ~owder.
.~ ~

20 ~n c~-e o~ Cuttlng Metho~ 3, the eutting could not bQ ~r~ctlc-d whQn th~
volu~ rat~o o~ th~ ma~ne~ic powdQr lncre~ed.

on the othel^ hend, ln c~ce of Cuttlng Method 1, the cutting can be carried out even the volum~ rati o o~ thQ magn~tlc powa~r i. 72 vol ~ .
P~ccordlngly, it 1~ clear from th~ re~ul~c~ t~l~t cuttlr~ Metho~ a 6u~er~0~ method ~or the cuttin~ o~ ~ magnet of ~he ~xtru~ion.

s Example 8 An uncur2d cylindrical D~agnet wa~ produced ln ~cor~ance w~ tll ~ollowir;~c to use lt for a curin~ unit o~ this inven ~on.

,~o At fir~t, 60 vol % of a magnet~c poWder of Sm - Ci~l~amily magne'c and 40 vol % o~ a the2mosettln~ rQ~in nlainly comprl~lng.an epoxy xe~in were 10 mlxe~ as~d a co~pourld wa6 prepared by kne~ding lt w~th a -~ller The epoxy re~ln u6ed had a thermopla~tlc re~ion of 100 - lgO~ ln W~
" .E vi~cos~ty s~ddenly droppe8, and it was cured at a tempe~ at.~re cf 200"C.' .

The cornpound p~epar~d wa5 then co~r--ly cru~hed aslt it wa~ char~e~ i n a 15 mo~llt~ny machlne.

AB or the moul~ mach~n~, an ln~ctlon ~oul~lng m~chin~ and an extruslon moul~ln~ m~chlnQ coul~ bQ ~ed, but thQ ~xt~wlon mouldin~
mach~nQ w~o u~ad h~re. Th~ ch~r~-d compound. wa6 heat~d ~t 100 - 150C in th~ moul~ln~ nla~hlne to ~ke lt ln a moltQn ~tat~, th~ m~netlc powder 20w~ orienta~sd ln a dl~, th~ ~ol~en mlxturo wa~ ool~ w~th ~ool~ny ; ~ - 44 -~ . .
., . ~ . ~...... . . . ::
. . . . .

: ' ' ' ' ' ' 2 ~ ~

ac ~t~ 6tate snd ~n uncured cyllndrlcal magr,et w~s prop~red ~fte~- a demagnetlzation.

The ~ize o~ the ~a~nQt wa6 ~he out4r ~la~er 32,emm an~ the ~nner dlameter 31.8mm, and lt wa6 cut ~o make ~t6 leng~h ~t lOOmm.

~n Table 8, ~ co~parlcon of varlou~ curin~ pro~-a~#~ ~e~t ~1 - 13 ~or ~he aforementlon~d uncured cylindrlcal ~agnet 1~ ~hown.

Ta~le_~

Sha~e ~ ~o~t ~est 11 excellent ~ood good 10 Test 1~ exceilent cr~inary ordinary Te~t 13 bad excellent excellent ~e~ the rec~lts o the curin~ proce~ of thl~ inventlon for ~
cylindrical magnet. Na~ely the ~utor circum~e~enc~ of the uncur-d cyl~n~rical ma~net ic fi~d ~y,~n ~laeti~ m~terl~l, ln t~l~ ca~e lt ~as a ~llleone rubber (her~inaf~r e~ an $nnQr body) expan~e~ wlth a gac ~in thia ca~e it w~s air), ~n~ it 1~ eur-~ by hoatln~ ln an oven.

Te~t 12 1~ a conventlonal p~oc~ ln ~Yhlch th~ out~r clraum~r~nc~ lo fixH~ with ~ o~tlon unl4 ~ attashQ~l to the ~, and lt 1~ cure~
by heatl~g ~ith ~ rotatlon ~n th~ c~re~ r~ntlsl ~lr~tlon. T~t 1~ 1 20 ~ pro~ to cur~ thQ cylln~rlcal magnet by h~atln~ by pl~ln~ it ~n an o~rer. ac it ls without thç ~lxing.

-.
~; ~
~. .

2~

~h~ the~moCUrln~ con~i t~on here ~a~ oooc for one hour~ ln N2 atmo6phere, ~h~ eh-pe in Ta~le w~ t~e shape o~ the ~gnot after the cure.

In case of Test 1~, the m~gne'c aft~r the cure 1~ comPl~ltely doÇormed and 5 it ~ obviouc thdt the flxlng of the Gh~pe lo n-c~s~ t the thermoeuring Btep~ On h~ other hsn~, ln ca~es th~t ~he sh~pe 16 flxed, the cyllnd~ic~l form $~ n~rly Xe~, and thUB ~e~t 11 and Tes~ 12 ~re u~eful prooe~6 f~om a vlewpolnt o~ the ~hape.

The operability mean~ an e~alnes~ o~ the operation of the U21it and lts capability for procQ~sln~ a lar~e ~mount of the ~ampie.

In ca~e of Te t 1~, it ta~e~ more tlme for an oper tlon to conn~ct t~.e ~ig h~lth the rotat1 on unit than an operatior. o ~e~t 11 to ln~ert the inner bo8y when compar~d wlth ~st 11 o~ thl6 invention. ~urther~ore from a v~ewpo~nt o~ co~t, Test 12 16 mo~e costy ~cau~e of the 15 requi~ement of the rotation unit. conBequ~nt~y the T~t 11 pro~e~ a superior proces6 to Te6t 12 an~ 13.

Next the aimen~lo~ acc~cy ~t~r tho cur~ whQn 1~ 1~ cura~ by hQntlnq by :~ ~e~t ll and ~e~t ~2 ~- ~ho~n in ~akle 9.

rrect 11 a.oo~ o.o ''' . ~ . -- . . . . -- - - . .
.:
- : : . -2 i, ~ . . . ^ ~

Te6t 12 0 . 07 0 . 04 8efore the cure ~ . OB O . 05 t Un~t: mrn ~

The rotation rate of ~e~ hQre wa~ ~oo rpm. ~c io the ~.~ximum ratQ
: S which can be practic-d by tak~n~ the eoa~t lnto con~i~er~tlon.

~he alrpres~ure of the inner bo~y o~ Tes~ 11 W8~ 1 at~.

The ma~net before tha cure wa~ prep~r~d ~y ~omewhat ~ecrea6in~ it~
d~mQ~lon accuracy ln order to chQck a corr~Gtlon ~bility ~ the dimen6~0n by the cur1 n~ proc~s~ by heatlng .

10 From Tabie 9, it i~ under6tood that the dirnen~lon nccur~cy in corre~::ted by the curing pro~e6~ by heating 6uch as 'rR~st 11 ar,8 Te~t 1~.

Thl6 iE becau~e th~t ln ca~e of T~6~ 11 the ~lr ln the ~nner body i8 expar.ded in the atmocphsre ~ the th-rmocurln~, lt a~Plie~ a ~orce to the ~sgnet reculttng the correctlon of th- di~n610n of the magnet while it . ~5 $~ ln a ther~oplactic ~tate.

P~8 ~or TQBt 12, a ~ntr~ ~u~ orc~ g-~erat~ by th- rotati on h~ a ~imllar Astion, but tho dlmon~ilon ~ccus~y by th~ corr~et~on o~ t 1.1 i~ ~urth-r $mprovQa..

Thi~ ecaU-Q th~t th~ forc- l~y ~xpan~l~on o~ the ~ir 1~ stron~er thsn 20 th~ centrlfu~al ~orcQ r~ultlng ~et'c~r correctlon o~ 'che dlmen~io~. From , :
::

:

2 .~

the cor~ectlon abll~ty os~ the tlmen~lon, ~ o undQr~tood the proce60 o~ Tec~ 11 of ~hlG invention ~ uperior.

Example 9 ~a~ materi~l~ to ~-ke th~ ~an~e co~po~ltion ~ ~ow~r ~ in Exampl~ 3, s~, ~C0 0.6~2 Cu 0.0~ Fa 0.~2 Z~ 0.028) ~.3S wero molten, ~n ln~ot producc~
wa~ magne~cally eurad by a he~t tr~atment ~ter casting, and a m~netic powder havlng the a~r~ragQ p~ clQ ~ize o~ IO,um and tha co~roive orce ~sc of 10 xoe w~- obt~lned by cru~h1ng ~he 6aid ln~ot.

The powder wa~ mixed wi~h nylon 12 powder ~n~ zlnc ctearate pow~e~ tc lo make a ratio o~ 92 wt~., 7.9 wt~ and 0.1 wt% as ~ame to Sxample 3.

The mixture wa~ ma~netized by ~ pul~e magnetizatlon ~mit showl~ in Fi.g~:re :1 4 with usln~ a magn~:tic field of 2~KOe, and it w~ then kneade~ by b :WC
axefi extr-~ion k~eadirl~ machl2lo~. ~~
.~ ,~

~n Figure 4, 301 1~ an electro~agnetic coil, 322 i~ a pulse C~tl r-rlt n-ration po~or ~ouroe, 303 1~ ~ table to a~u~t a hlg~ht of a ~mple ~nd 305 1~ a raw ~t~rial m~o2let~e powd~r, ' . .

Tho l~r.o~d ~lxtur- ~a~ sr~nulate~ to partlclo~ o~ th- out~r dl~ter o~
m to ~aX~ ~ raw mat~r~l compound., an~ 6 cylln~rlcal ~a~n~t wa~
moul~d by wing th- extru~lon ~oul~ln~ ~achln- ~hown ln Irl~ur~ d th~
dle ~hown ln Fi~urQ 2 wlth a ~a~- ~roc~ure ~crlb-d ~bove, .~ , .

--. . .
, . . .
, .....

. . . , ~ . .
.
- .. . . .

?~

~n thls ~xa;nple, tha die temperature st th~ mould~ng wac 250C, ~nd a cooling was carrl~d out by a forcad ail- cool~n~ at the outlet o~ th~ d~e.

Ac~ordlngly, an orl~ntated raw mat~rlal co~pound wac moulded by extru~lon by a ~olldiflcat~o~ with cooiins at the outlet o~ thQ dle.

S The ~lze of the moul~e~ art~cl~ wa~ th~ outer ~iamator 33mm an~ the lnner dlameter 32mm, In Figure 5, a comp~L~i~on of ch~n~Q~ o r~ ual ma~netlc fluX de~sity ~Br) with magnetic ~i~lds ~or mould1ng ~o~ ca~e6 wlth ar.d wlthou~
mag~etization of the rs~ ma~teri~l pow~er be~o~ the mouldinq i~ showr..

10 Fron~ ~igure 5, lt i~ understood th~t a magnet w~th ~ hi~h Br le wi th high degree of t~.e orientation can be prepared by an a~optior. of th~
magnetizatlon for the pow~er prlor to the moulding evQn l the ma~llet~
fiQld ~or the mouldlng 1~ low.

~usthermore a6 ~or the m~gnet p-~ormance at the hlgh magne~ic i-1d ound 15 KOe) ~or ~h~ moul~lng, the ca~eR with the magnet1zat~on ~how~d high~r value~, ~nd it wa~ un~r~tand. that the m~gn-tlzatlon ~o~ the pow~2r pr~or to ~he mouldirl~ h~d A ~ Qr ~f~ct.

.
Ex~mple 1 0 Raw mat~rial~ w-ro molt~n to m~Q a Compol~1 tion o~ ~ 0 . 5 Pr 0 . S tco 0.672 CU 0.08 Fe 0.22 Zr 0~02a) 8.3S, an in~ot produc~d W~ ~a~netic~lly .~..................................... .
.

:. ~
- - .
- ' ` .

cured ~y a heat treat~nt a~ter c~tin~, and maqn~tic pow5ar~ h~vlng a..
average part$cle ~lz~ of ~o~m were obtain~d by cru~hln~ th~ ~ald lngot.

2 kind~ of the ~hgn~tlc powder~ havlng the co~rclvQ ~orc~ IHe 7 KOe and 10 XOe re~pectiaelY wQre prepared by chançlln~ a conài Oion o~ the ~,~a_ 5 treatment.

The6e powder~ were ~ix~ wlth nylon 12 powt~r an~ zlnc ~t~arate powd~1 to make a ratlo of 92 wt~, 7 . 9 wt% and 0 . 1 wt4 re~pectlvely.

The6e magnetlc powder~ were maslle~clzed. by u~ ng a d~ rect c-;rl e:~
electromagnet uni~, and then ~he~ were kneaded by a two axe6 ex~ruff lon . .
10 X.nead~ ng machlne at 260c .
- '. .
~he kneaded mixt~;res were granulated to p~rtlcle6 of the outer ~amet~
- lOmm to make a raw ma~ial compound, ~nd were mouldod by an extru~iior.
lntc ~hln plate state ma~net~ by ucin~ a dle Eh~wn ln Flgure 6.

, ' .
~n the die 401, wh~n a c~lrrent i~ turned on in ~n ~lo~tronlaçnetlc coil 15 403, a ma~natlc ~iel~ v~rtic~l to the pa~ge of a com~oun~ ~n the dle ln genoratlad b~tween tha u~D~r and the lowor ~ol~ pi~ac~ 404. ~hor~fo~a thln plate ~t~t~ ma~net haY~ n~ an orl-nt~tion o~ the ~agnet~ powder to the thlckno~e ~lrectlon ~ molul~-~. By th- way, 40~ i~ a ho~ter.-, ~rh~ ~12e o~ th- mouldO~ axtlcl~ wac t~ ~ wl~th o~ 60mm ~nd th~ ~hickna~
20 of lmm, and the ~t~nsth of th~ ~açnetlc field at the moul~ing wa~ 12 Xoe .

......... ~

.. :-: : - : . , . .. :
::;.~ , . . .

:. , .
. :

In F~ure ~, a relation between th~ 6trenuth of the ma~netlc ~lel~ ~o the magnetizatlon prlor to the mouldlng, and the resldusl ma~netic flux ~en6ity of the moulde~ ~rtlcle 16 ~hown.

~rom the graph, lt wa~ understcod that though thQre W~B no efect o~ the ma~net$zation prlor to th~ mouldln~ lf ~t wa~ ~one ln a ms~netic 1e;~
which was weaker than the coercive force of ~he ma~netic powder, there was an ef~ect to improve th~ magnetic performanc~ 1~ lt ws~ done ~.r. a magnetic ield stronger khan the coetcl~e~for~e.
- : , ~xample 1' lo P.aw materlal6 were molten tc make a compo6itlon of Nd ~3 ~e ~2.7 ~ ~.3, : were ca6ted, and a quenched ribbon was prepared in al~on at~o~phere hy nq a quanch$nq ~nd rl~bon rollln~ mach~ne for the lnqot produc~d.

Th~ quenched r~bbon w~ coar~ly crush~d, lt wa~ ~illed in ~ mould ~r,d .~ hiqh temp-rature pre~ moul~n~ wac carr$o~ out ~n ~rCon ~tmo~h-re . at . ~ ~ 700 - eoooc wlth a pro~sure o~ 20 Kg/cm2 for ~ ~hort tl~eO

The ~on~oli~t~ artlclo obt~ln-~ had a den~lty ~l~oot 100~. ~h-:
aonfolld~tod ~rticl~ o~tain-~ wa~ moulded a~ain by th~ hlgh t~mper~ture ~ p~O~4 mouldln~ in a vertical dl~octlon to ~he lnl~lal prQ~-ing ~lrectlo~

.;
,' ' , ' .
, ~ '' ' ' . " , . ~;
., ' ' " . ' ' ';

in argon atmo6ph~re 6t 700 - ~00~c wlth a 1~ x~/m~2 pr~aure INamelY, dle ~p~et wa6 carri~d out).

A bulk 6tate ma~nQt obtalned wa8 cru~hed ~nd 9 ma~netic pow~r o n Average part~cle ~izo of 20~m wa~ obt~lned. ~he co-rcive force o~ ~he ma~netic p~wder w~ 12 KOe.

The ma~netic powder w~ mlxed with a r~inlng pow~r comprl~ln~ blsphenol A type epox~, novola~ type ~poxy and v$nylbutyr~ nylalcohel copol ~r,~
calclum ~tearate powder ~nd 811~ ca pow~er ~ ~dditi~es to make a ratlo the magnetlc powder 90.3 wt%, t~e r-~ln powder 9.1 w~ ~nd the addltlve 10 O, 6 wt~ respectiv-ly.
' :
The`mixture wa6 ma~netlze~ wlth a 35 XOe magrletic ~leld by u~ing ~ p-tl~e magnetization unit and it ~as kneaded by ~ 2 roller type mill 2~ 91)~.
The kneaded mixtur~ wa çranul~ted to an ot~ter dlamete~ of 1 - 10m~.
~ranul~s to make B r~w materlal compo~nd an~ wak moulded ln a cyl~n~ric~l ma~ne~ b~ an extru~lon m~c~lne ~ ~ame a~ ~x~mple g, .
In thi- ExaDple, tho ~- te~p-ratur~ at the ~oul~in~ wc~ 140C, and th~
6tren~th o~ th- ma~n-tlc ~l~ld ~o~ tt~ ~oul~ino w~ a xo..

The ~lze o~ th~ ~o~ld-d ~tlcl- wa~ th2 out~r dl~m~t-r ~ nd the lnner di~eter 6mm. m~ mouldod ~rtlcle w~ cut ln a ~ult~le length, ~a~
. . .
20 ~ma~notiz~d and w~ r2d ln con~ltlon~ o 200C x 45 ~inutes.
, ~ 52 -~.

~- . ' ' , ' ' ~ -' ~`' ~ ' '''' ' ' .

~hQ m~netic proporty o~ th~ moul~a~ artl~le~ o~t-lne~ Q~t 13 - 15 1~
6hown ln Table 10. ~e~t 14 - 15, the eo~np~r~tlve x~mpleJ we~e a magnetic prop~rty o~ ~ampl~ moulded wlth th~ ne~ic fi~ld ~or th~
mouldlng ~t 8 Ko~ without the ma~netizatlon prlor to th~ moul~lng (~41S-' 14 ) an~ a ~ample m~gnetlc proparty mould~d wlth the m~ tlc fiQld fc-5 the ~nouldin~ at 15 KO~ ~nd a dle of whlch thQ orlent~tlon ~-ctlon at th~
front end waa shorten~ (Te~t 15).

;t",~,Q
: .
. (B~) max .," ~iL (~
-~est 1~ 7.0 ln.4 Te~t 14 4,3 3 5 ~e6t 15 5.1 g,g ,'' .
A~ lt i6 clea~ ~orm ~able ~0, almo~t no ori~ ation 16 ob~erve~ in a t~ ~ comp~rative example Te~t 14, ~n~ the ma~net obt~ined m~rely ~how~ a , ~ 15 pcrformance cloc~, to an lEotroplc one.
~ I
on tha contrar~r ~ hloh per~orman~e ma~net wlth ~ u~ficient oriont~tion o~t~lne~ ~y thia Bxample.

.; .
n cac~ of ~re~t 15, the ~gnotic prop~rty la low ~n rplt~ of lt- hlgh ~gr~Qtic field for tho mou~ v~ d lt io con~ r~d th~t ~ ~uf. ~clent 20 or~ent~t~on of the mel~netlc powdar 1~ 2~0t ntt~ln-~ ~t th~ moul~lng ~lnce th~ l~n~th of the orlsnt~tLon ~-ctlon ~ecomeo extr~m~ly ~hort ~uch a~ lmm .. .. .
I: - 53 _ ., ' "~' .. -.. , ~

!

~ rj ~ f' ^ ;'`, '~' or le6c ln order ~o charge ~ 15 XO~ magn~tic fl~ld at th~ or~entatlor.
sectlon ~ue 'CG itC ~ry ~lne cylindrlc~l ~orm havlrg th~ lnner diam~r of the moulded ~rticle 6mm.

-~ herefore a mouldlng p~oo~ of thl~ inventlon ~ ~ very ~ffectlve5 proce~6 for a oa~e in wh~ch a hi~h ~ tlc ~ld ~or ~oul~in~ i8 no'c a~alned ecau6e o~ ~ llmlt~tlon o~ a mould.~ ar~lcl~ or a ctruc~ual probl~m o~ a dle.

~xampl e 12 In thi6 invention, Powde~- A and E were prepare~ by the ~ame comp~itic~
10 and ~recedure to Example 4, theY were kneaded with the rcsl~
c~rllndrical ma~ne'~ were moulded by ~n ex~ru~lon moul~ing machine af~er çlranulating the kneaded mixture to parti~les havlng the outer dlame~ ~r 1 - lOmm ~o make a raw materlal compound. The moul~ln~ proce66 16 k~ie~
~ u61ng Fi~ure ~.

15 An oxtru~lon moul~lng ~chinQ o~ F~gur~ 8 ha~ a 6imllar compo~ltion to thQ QxtrL~ion ~ouldlng mach~nQ Of ~l~ure 1~ ~owQver, at th~ ~ron~ cnd o~
th~ ~la, 4 ~1QC~8 0~ ultr~on~c occlllat~r (~an~avln typ~) 114 ~r~
ln6t~110d to g~nerete a ~ vlbratlon.
s~

~ e ~os~m~nt~ on-d g~nul~t~ aw mat9rl~1 conlpoun~ 111 w~ ~har~e~ to 20 tho xt~u~lon moulding ~ach~n~ o ~lgura a. ~ho ~aw matori~l eo~pound was h~at~d ln the cyllnder 102 at 260C to ~akQ lt ln a flu$~i~e~ ~tate and lt wa~ p~ed throu~h the ~i~ 105.

: - 5 4 -.

. .
.
-,: .
, `~' ~' ' 2 ~

The die ~tructure wa~ th~ ~ame a~ Flgure 2 xplaine~ 1n ~xample 1.

In this ~xamPle, the mA~netic powder i~ moulded whlle lt 1~ be:r.g orlentatod wh~n the ~a~netlc co~posltlon pa~os through the o~l~n~atlon section. ~he ~l~Cht vlb~tion ~rom the ultr~onio o~cill~tor was transmitted to the ~ront an8 of the die.
, . .
In ~hl~ examplQ, thQ ~asn0tlc fleld :Eor the mouldin~ wac 10 XOe, the dle temperature at the ~ou~ dinç wa~ 205C and the coolln6 w~ ~p~l~ed ~y a ~ forced alr coollns ~o the ou~l~t of the die. Thu~ t~e orienta~ed ~aw : mate~ial co~pound wa6 ~oli~lfie~ with coolln~ at the outlet of the dle and wa6 moulded by an eXt~lOn~ The size of the mo~ldQ~ ~rtlcle wa~ tho outer dlameter of 25mm ~nd the ~nner dlamete~ of 23mm.

Dlferen~e~ of the m~net performance of thQ moulded artlclo th~ mould:r;g rate are shown in ~able 11 for ~a6es of an appllcatiDn o~ the s;i~ht vi~ration (~e6t 16, 17) hnd for case~ o~ no ~pp;'cat~on tTQs~ 19, ~g).
Test 16 snd 17 are th- ca--~ with the ~ ht vibration and To~t 18 ~nd lg ~ ~ are the caoe~ without it.

'"' I~L~

; ' (BH~ m8x Mouldin~ R~ta ," ~a; ~L ~la~l To~t 16 A - 7.5 2.5 T~t 17 B 10.2 2.0 ----~

: 5 , ', ':,"'~
.

.:
, -:
.~ ..

2 ~
Tect lB A 6.7 1.8 Te6t 19 8 8.S 1,5 A~ lt ~ s cle~r fron T~le 11, Example~ howc ~n im~rovQment on ~cth ~f;~ the ~agnetlc property hnd the mouldln~ rat~. It i~ considered that 1~ icdue to an lmprQyed orlent~tlon by ~cilitatlng e rota~lo~ o~ the mavr,e:lc powder by the applicat~on of the ~ ht vihr~tlsn at th~ mouldin~.

~urthermore lt can ~150 be ~aid that th~ ~ouldlng rate 16 lmprovod ~y a reauction o~ the extru~ion re~i~tanc~ by the ~llght vi~r~tlon. ~e rea~cn of the low ~agnetic~pow~er ~i~ not ~u~fi~iently orlent~ted ~eca~se . 10 the magnetic fleld for the moulding whlch ~ao able to ch~r~e wa~ only 10 KOe.

Therefore the moul~ing process o~ thi~ lnvent~on is a particulariy . .
ef~ectlve proces6 for the ca6e in whlch a hi~h ma~netic rield ~or the moui8ing can not be att8inQ~ ~UOE to hape~ of the dl~ or the mcu:~e~
~S article.
.,' :
~xample 1 3 . ,~ .
~eble 12 ~how~ ho~ much degreQ of thQ thickne~ moul~a~le without a ~o~t~ ricatlon ln e~ch moul~ng ~tho~ o~ ~n oxtrw lon ~oul~lNg m~ho~
e pr~is mo~ld~n~ m~tho~ ~nd an in~oction ~oul~ing metho~.
._ -.

~ - 56 -' ~
;
1 , ~ ?~ r ~ ~

Sxtru~an Moul~ing ~ P ~ P P
Pre6s Moul~lng P P
Injectlc~ Moul8in~ P ~ I I I

PO~ le ~ po~sible Magnet6 prepared her~ was r~ng sh~p~d w~th the outer dlameter o~ 30mm~
~nd the mouldin~ were pororm~d With the thlckn~ hown ln ~ble 12.

.
The ma~netic powd~r u6e~ wa~ Sm - Co f~mily rare earth magnetic po~er and as for the ~esin, nyl~n 12 wa~ u6ed ~or the extrus$on mo~ldlng metho~
and the in~ection mouldlng ~ethod, and an epoxy re~ln wa~ u6ed for the pre6~ mouldi~g method~

The m~xing rat~o of the-ma~netlc pow~er an~ the re~ln wa6 90 Wt~ Wt% C~
for the extrusion ~oultlng method and the ln~ectlon ~ouldln~ mathod, ~nd g~ wt ~ ~ wt~ ror th- pr~ moul~in~ m~tho~, ~ 6 under-tood ~ro~ ~able 12, tho ~o~ldln~ w~ not b~ able to p~rform 1~ t~e thlckne~ o~ the ma~notic ~oul~e~ ~rticle becamc thln ~or . . :
the prQ~ mouldin~ metho~ ~ndl the In~octlon ~nou~lnq m~tho~. ~hlc was due to a dlf~lculty So fill ~h0 ~a~notlc pow~r ln a cavlty ~ ~ thc 20 th~ ~kneos ~eo~me thln ~or ~ ~a~- of tho p~ noulO.lng ~ethod, and 1~
c~e o~ th~ ~n~l~ct~on moul~lns m~tho~, ~t ~ould ~l~o not b- moul~d : - 57 - ~ .

_ ........

,-. ,.................... .- :

2 v l ~ ~

becau6e of a dif~lculty to ln~ct a molten mlxture o~ the m~n~tic powde-and the resin ln e cavlty.

o~ the other hahd, ln c~6e of ~h~ extruclon mouldln~ methoa, ~ t~
thlckne~ magnet can be ~oulded ~-cause lt i~ ~oulded b~ contlnuou~l~
S flowins a ~olten ~ixture of ~h~ ma~netlc powder ~nd th- rQcin an~ by sradually conv~r~lng thQ molten ~lxture. Accordln~ it 1~ clear that ~he extru~ion mouldln~ mothod 1~ an Q~ectlve ~etho~ to mould a thi.
thlc~ne-s magnet h~vlng the thleknoc~ o~ lm~ or le~.

Example 14 Next effect~ on mouldlng radlai ma~net wlth a thin thlckne6s bY changi~
the ~a~netic powdor6 ~re ~hown in Table 13.

: ~he masnet ~ was a rln~ shaped ~a~net o~ the outGr dlam~ter 32.~mm, thQ lnner dla~Qter 31.emm and the thlckne s 0.5m~, ~nd lt was moulded by an extrusio~.

e compound w e~ comprlc~d 60 vol % OL ~ m~n-tic powder ~nd 40 ~ol $~. o~
recln ~nd nylon 12 wa~ w -d ~o~ the r~ln.

F~rthor ~- ~or thR magn0tl~ ~ow~ ~, a ~ro ~th m~gnet havlnu a co~poc~tton o~ Co 0.672 Cu 0.0~ F~ 0.22 ~r 0.02~ 8.35 ~a~ usod, ~t w~a ~d~u-t~d to m~kQ th~r~ge ~tlcla o~z~ r or ~ch t~t of ~Q~t 20 - 24 ~nt ~or ~o~p~r~t~xampl-~ ~a~ 25 - 27, an~ the ro~ult~ ar~ ~hown ~n Table ~3.

- 5~ -- ~ -, . , .

- - ~ 2 ~

A~ 6how~ ln Ta~le 13, there w~- a cho.n~e of th~ maqn-t performance o~ the magnet moulded by chan~ing S~ av~ra~ part~ cle ~ zo r of th~ ma5,met' c pow~er. ~y maklng th~ av~ra~e p~r'clcle 8iZ~ r of the m~gnetlc po~der ~mal 1, the m~gneS p~or~nce of the magn~t 1- lmpro~red .

5 An~ a ~u~f iC~ ent ~a~net p~rfo~mAnce w~c o~tcinQd whoen th~ ~vera~e partlcle ~ze r W~8 n~t more th~n 1/10 o~ the t~ cl~.ne66 o~ the magnet moulded a~ticle.

However ln c~se when the ~ve~a~e p~rtlcle ~lze 1~ not leBs than ' /10 o~
the thickne66 of the m~gnet, the ma~net per~orm~nce 1~ low.

~e6t No ~r ~ (BH) max L.~ rxG
~.8a 7, 5 21 20 5 . 95 7 . 8 ~5 22 lo 6 . 18 ~ . 1 23 1 6.33 a.5 - 24 0.1 6.16 ~.0 . 70 5.60 6.5 26 100 -~.01 5.2 ~7 150 4.70 4.5 ~he re~-on why th~ ~bo~/~ r~cultc ~ obtaln~d w~, ln ca~ o the axtru~lon moul~ , the ~n~tl~ ~ow~r ln the ~olt~n ~lxtur~ of th~

;: - 59 _ ' ~ , . -, , " , . . . ..
:: i - : , ~: ~: : : ::

-2 f~ ~ ~! f ; ~
~, '..., . ~

The rea~on why the ~o~e re~ult# we~e o~talned wac, in Ch~Q of th~
extru~ion mo-lldln~, the masn~ic powd~r ln thR molt~n mixture of th¢
m~çnetic powder ~d the re~in wa~ orl~ntat~d ~t a ~oction ln whacl~ a magnetic ~ield w ~ ch~r~ed by ~ac~lng throuch the ps~G~e of a die, ~nd 5 the moulded article wa6 extludQd out~i~e thQ tl~ ~t~r ~oli~l~yi~lç i.t with coolln~ ln the dle by ko~pin~ thet ~t~ta a~ lt i~. Accordin~lY th~
ololterl mixture recelved ~ ~r~ ctlor, forc~ at the cont~ct ~ection With the dle . Thus the orlenta~lon o~ Sho m~lgn~tic pow~e~ at th~ cor~tact ~urf a~
of the molten mlxture wi'ch the dl~ might be ~i60rd~rod. by 'che frict:lon L0 ~or~e whlle it wa~ being ~olid~1ed wi~h coolinc even thouçh the ma~t ~3tlc powder wa6 once or$entated in the die.

When a thin plate ~tate maqnet i3 moul~ed, the ~f ec~ o~ he layer w~lere the sald orientatlon ~9 d~i~order~t become~ cign.ificar~ he thickne~ of the layer i~ related with the p~t~ cle ~lze o~ th~ m~gnetlc ~0-4del: ac 15 well, and a~ the s~e~ult~ the aver~Q ~artlcle clze glve~ an lnfluoltce 'co th~ ma~net per~orn ~nc~ o~ the m~gnet.

A~ lt i~ clear ~rom ~a:ble 13, in o~der to r~ducQ the ln~lu~nce, it i0 app~o~ri~tc thst the av~rage particle ~lze :~ of th- magnetlc powdee i0 1/10 or le~ of the thlcl~ne~G of the m ~netlc moul~ed ~rtlcle.
~' ' .
20 Example 15 Arl alloy havlng a compo~ltlon of Nd 14 Fe 81 B ~ w~e alolten in a cruclble, lt wao cool~ap~ly by a m-ltLpan method and a th~n piece w~
prepar~t .

. .

2 ~ J ~

~he thin pleca wa~ cru~h~ tlll lt h~ .n ~verage partlcl~ ~ize of 35~m, ~nd ocreat~ent~ 'IOWll in Table 14 were proc~ d ther-~ftQr.

TreatmQnt 1 Co~alt-~ho~phorw ~ chromium platln~
Treatment 2 SiO2 coating Treatmen~ 1 wa~ that a~tar crushing the magneti~ powd~, a cobalt-pho~phorus platln~ Wa~ carrlGd OUt in a ~odlum hypopho~pllitQ
reduced ~monla, alkallnQ cob~lt pla~lng bAth, th~n ~ chromat~ treatment w~ performed. by putting the m~n6t~C pow4~r in ~ pota~ium ~lchromat~
bolutlon and a cobalt plating lay-r W8~ ~ormed on the ma~netic powde~:.

'rreatment 2 waE that pure w~tor a~u~ted lt~E ~H wit.h hy~rochlorlc ~cld was m1xed wlth tQt~amethoxy6ll6ne to ma~c an Bp~roximate molar ratio of 4:1, and. a hy~roly~l~ wa~ carri~ OUt by ~tdin~ ethanol to it. A~t~.~r the decompo~itlon an~ an hddition o~ ~ oUr~actant, the magn~tlc powd~r W~
, ~ddQd and W~!L6 ~tir~d ~or ~ ~r~termlned tim~.
`, .

: Then the maqnetlc pow~qr wa~ ~p~r~t~d fro~ thR colution, wa~ dryed and a he~t tre~tmQnt W~6 p~r~orm~d to ~orm S$02 flim on the ~agnsti~ p~wder.

After the ~urface tr~tm~nt, 'ch~ gnetlc ~ow~er an~ the resin to m~k re~tlo of 60 vol 1~ an~ 40 vol ~ wore w-lchad an~ war~ m~ce~, and aftl~r the , : ~ .
'' .

.. : .......... , . ,.............. . . . :, . i : : , , 2 F? ~ FJ ~

mixing, ie wa6 ch~rg~d ln a knQI!~dln5~ m2chine ~o knea~ tt ~d a ~ompound wa~ prepared.

The kn~ading ma~hi~e h~rewlth w~d wal~ a roll~r mlll. Furt~e- a~ for th~
rQ~n u~d, 2 kind~ o~ re~in W~rQ ~oed. one wac ~e~ln a ~hich wac copolymer malnly compri~in~ th~!~mo~ett~ ng tyS~o ~oxy ~ in, and the othe~ ~sin ~ wa~ o thermopla~ic pol3~amida res~n (n~tlon 12).

P.fter cru~hls~g the compoun~ ~roduce~ a~ mo~ by an in~ec~lon moul~ing machln~ or arl extruclon ~ouldin~ machine. In ca~e th~t ~esin a wa6 u6ed, the moulded art~cl~ wa~ he-~Q~ to cure the re~in ~ftel: h~
moul dlng .

Fi~tly ln order to check in whlch 6t~p the ~llm tend~d to ~e removed, a co-~erage rate was ~et~.rmined by taklnq a ~mple ~eor~ ~nd after each ~ep i n the total proce66~

The ma~sietlc ~ow~ u~d h-re wa~ a pl~tlrl6-treatQd on- ~rith the plat~nc ~5 thlcl~ne~6 of l~m, and. the moul lng wa~ car~iod out ~y sn extru~ion mouldin~ machlne. ~hs result~ rQ shown in ~le ~5.

~e result~ ~er~ the ~ame ~or either ca6e~ of Reeis~ a and ~. ~rom Table 15, lt ic cl~ar that the f~lm cov~r~ge rate cud~enly ~rappe~ betw~en be~ore and aft~r th~ knea~ln~. ~n othor ~t~p~, the drop o~ the cov~ra~a rstlo ~ 6mal~ lt w~ ooneidQr~d that ~t ~ao du~ to a protection oE
th~ ~oated flln~ bY thQ mix~ r~ln ~psclally ~ter the kn~a~ing.

~ 62 -. .
,: ,, :
, : - . - ., .

3,~

a~lJ2 15 ~te~ C9~ 95~
~efore mlxing 100 ~fter mixlng ~8efore knoadln~) 95 After kn~adin~ tsefore ~uching)5iO
Aft-r cLucihin~ (sefor~ mouldlnu) 48 After ~oulding 46 On the other hand, be~ore kneading, the ~iolld rGc1~ and m~gnetic powder ~re merely mlxed, th~ re~iin do-c not glve the proteetlon for the ~oated ~ilm, i~nd tharefore the coat-d ~lm i~ mOVQd by ~ tron~ ~t1eeiEi to the : 10 ma~etic pow~er ap~lied du~lng ~he knei~dirlg.
.

Accordln~ly the ~lxtu~e of tho magn-tic powder and the reeiin w~ heated ~efore the kneadln~, and the.n tho kn~adlng wa~i carrled out. The cov~r~
rate~ fter the kn~Ai~ing whlch w~s carr~ e~ out a~!t~r heatirl~ at variou~i ~emp~r~t~lre6 were 6hown ~n 'rable 16.

~5 'rhe tn~netlc powderi herewlth w ed were th~ ~latln~-tr~atea of the plcting t~l~¢~nE~ s of lum ~or ~ t 2~ 3, an~ Te~t 34 thereafter wer~
S102 coated.
' '' ' ' .
R~ln a of th~rmo~ettln~ r~ln wa~ uc~d for the ~o~in. The cov~rag~
rate aft~r the knea~in~ W~B calculat~ a~ttin~ th~ cover~e rate ~efore th- kno~ding ~att~r ~ixln~ 100, and ~h~ ~t~co~ity wa~ a vi~co~ity at . .
:'`, . - 53 ''~

.

, 2~ 7~

a ~h~ar rat~ 100~ ~cl wh~n the mlxtur~ wa~ h~tod ~t ShQ temperatur~
indi.c~tQd .

T~mpe~tur~ Vi~coslty Covera~e Rate ~ ~ ol~
T~st 2B Room ~emp~rature - 50 2~ 50 500 50 32 lO0 7~ 94 ; 34 50 Soo 60 . . .

1S 37 lOo 70 ~8 3~ 120 10 9B

Fro~ Table 16, the mixtura may have th~ v~ccoclty by ho~ing 1t. ~t i~
clear that the coYerage rat~ l~ lmprovQd wh~n the kn~a~in~ 1 ~ perorm~d aftRr heatillg thQ mixturs to m~k- lt in ~ st~te in whlch it h~s the , ~0 vi~coc~ ty. Althouqh the cover-~ ratQ o~ the p~a~e one becomes wors~a than lt o~ the 5io2 coat~d on~ wh~n comparsd in tha ~m~ condition b~c~u~e of lt- w~ak adhe~lon o~ th~ ~llm, ~n ~m~rovement i~ ~Qen when tha .
. .

.. ; . , .....
, ~, .

.

?. ~ r ~' viscos1 ty reache~ 300 kpoise, and below it, the coated film was cuf f lcien'cly protected .

It is con~de~ed that the ~bove re~ult6 ~re o~ta~na~ ~oecau~e as to the removal o~ ~he fllln ~u~ing 'eh~ knakd~n~ lar51~ly $nfluenced by a 5 6treS5 0~ the rolle~ when it i~ ~pplled to a CtatQ in which a ~ufficisnt : heating i6 no~ ~lven whQn the ~lxture ic char~od i~ th~ kneadin~ ma~!h~ne, : and the lnfluenc~ i~ relieve~ by glvlng the vi~co~lty to the m~xture.
.
Next an ox~dation re~i6tance o~ a ma~n~t ~roduc~d by the prod.l~c~lor-proces6 of thls inventlon was inve~t1gated. ~he re~ult~ of ~est 39 and 40 a~ thl~ ~xample~ and Tegt 41 and 42 a~ comp~ratlve example~ are ~how~
in Table 17.

Surface ~reatment OxldatlQ~_Resistan~
Te~t 3~ - TrQatment 1 A
" 2 A

. -- ----~ _ _-- _ _ _ .. _ _ _ ~.. _ _ _ _ _ _ _ . .... _ .. _ 4 1 " 1 C
. 4 2 " 2 E
,................................ .

A ~ Excell-nt B - Goo~
C - ~d , : : :
;

:~ . , . ' ' ~ ' ':,: ' : ' 2 ~

Te6t 41 ~r~d 42 of the comparat~ve xample6 were the ca~a~ ln which tlle kneadlng was carrled out without heatln~ ~ofor- th- kneadis~, an~ t 39 and 40 of ~xatnle6 wer~ c~rrled out ~y h~atln~ at 100 k~ol~e.

~he oxldatlon re~l~tAnce wQ.~ a re~ul~ hfter ~torln~ th~ le in a con~tar~t temperature and const~nt hum~ dlty ovQn t 80C x 95% ~or 100 ho~r~.

~t 1~ eleal that th~ oxidatlon re~l~tance i~ improved by the hoat treatment be~ore th~ k~0~din~.
.

Ex~mple 16 i ', , .
~aw material~ to make a compc~tion of sm (Co 0.672 Cu O.OB Fe 0.2~ zr 0.02~) ~.35 were moltQn, were ca6t~d, ~n lngot produced waR m~netic~
cur-d by a heat tre~tm~ns, an~ then a msgnQ~ic powdQr havlng ~n ave~ açJe par'clcle ~lze of ~O~lm wae o~tained by cruohing it.

r, 'rhe pow~er was mi~ced wlth nylon 12 pow~er and zinC ~t2arate powder to m~ke a ratlo of 92 wt~, ~.B wt~ ~nd 0.1 wt%, re~p~ctively.

~he mixtur~ w~ then kneaded by ~ two axe~ e~ctru~ion knead,ing ma~hine at 260c. rhe kne~d~d mixture wa~ ~rallul~ted to particlas o ~che -o-lt~r di~m-ter of 1 - lOmm to m~ke ~ raw material com~ound, an~ ~ cylin8rlcal - ma5n~S wa~ mould~d. by as~ extmglon ~oul~lir,u ~achina.

l~he mouldlng me'chod i5 ~xplained in ~cco~anc- wlth ~l~ure 10.

:
' ~:;
,, .

... : . - ~ . ::
. . . .. . .

: , . . .
.. .
, . ' . ' : ',: ~ . , Ac shown ln Figure lC, the extrU8~n mould~n~ mBchin~ i6 con~t1~ut~d by a hopper 101 which 1~ a ~oction of ch~rging m~terial, ~ cylin~r 102, a ~crew 103, an a~aptor pl~te 104 to ln~tall a ~la to thQ cyllnd~r sectlon 102, a die 105 and a Orl~rlnu motor for the ~cræ~ (~hlch i~ not ~hows~ ln 5 Figure ) .

~ .
~rhe aforemQntior~d ~s-an-llated raw mat~r~.al compoun~l 111 wa~ char~ed in the extruslon moulding machlne. $h~ raw Ir,atgrlal compound 111 w~ hea~.ed in the cylind2r 102 ~t 250C to m~lk- it ln ~ ~uidlze~d 6~ato, and i~ w~s pa~6~d thro~l~h the dle 105. -10 In thi~ ~xample, the ~ie tempera'cur~ at the mouldins W~ 250C, an~ t;hecoolln~ wa6 ~rrle~ out ~y a .forced ~ir coollnç at the ou'cl~t se~ti Oll of ~he ~lQ. ~he cize o~ th~ moul~d ~rtlcle producQ~ w~ the o~lter dizmeter of 33mm alld the inner di.alneter 4~ 32mm.

The moulded ~rticle was made ln thln plat~ c'cat~ ~y ~ unit chown in ,:. 15 Elyw.~e 11.

Fl~ur- 11 was a drawin~ ew~d from Up~ , 'ch~ cylindrical m-~ul~ed ~rtlcle 112 oxtrude~ from the ~ie 105 wa~ ~plit lnto two e~al ~ tion~
of thQ upl3idQ and th~ d.ownoid9 3~y ~h~ eutter 501~ in~tall~d in front o~
the dle 105, an~ the bl~ect~ oul~d articl~ wor~ ~lould~d into thln plate 5tate maonot by pa~inç ~etwe~n 2 s~tc o 2 rollor~ 502 po~iei~ned in the re~l~war~ o~ th~ cuttQr S01.

;
, ; .

,:

- . . . . .
.:

2 ~ ril r-Then the end surfac~ of the thln pl~t~ c~te ~n~t 503 w~e cut to m~ke lt ln a ~ re~ ~lz~. ~he ~iz~ of the moul~-d artlcle wa~ tho wld~h of 50mm and th~ thlckne~* of lmm. The magnetlc prop6rty of th~ moulded artlcle obtaln~d 1~ ~hown ln Table 18.

5 A~ a compar~tl~e examp3.e, a thln plllte ~t~e mould~d artlcle wa~ mc~lllded by ar, xtru~lon ~y u2lng ~ dl~ which w~ n~r~lly w~d fo~ an extrusion moulding of ~ thln pla~e ~tllte pla~lc, and lt6 maqn~ic property 1 ~hown a~ T~t 44.

A~ ~or the raw m~terial compound, the g~m~ ma~netic powder, ny~c.n 12 powder and zlnc ~t~arat~ powde~ a~ To~t 43 of ~xampl- w~re mlxed to mak~
ratlo o Sl.5 wt~, 8.3 wt~ and 0.~ wt~ re~pectlvely, they ~ere knead.~
~ere gr&nuIate~ nd wera m~ulded for the d,~termlnation of the m~n~tlc prop6rty. l'he ~iæ~ of the moulded ~rtlcle was th- c~me a~ Te~t 43.

15 In T~bla 1~, a moul~.abillty o~ ~xample of thic ~ nventlon ~T~t; 4~ ) arld the compa~atlve example (To~t 44 ~ 1~ alco 8hown wlth the ma~notlc property .
.", ,','~ ~.

('dX~ m~c ~Q21 I~I~L~
T~t 43 (~a~pl~) 2.5 G
.
~e~t 44 ~comp~r~tive . example~ ~, 4 .,~
:

2 ~ ~ ~~ L' b 3 G . Good O ~ Ordin~ry As it i~ cle~r from Table 18, th~re i~ no ~l~nif 1 c~nt ~fer~nce on the ma~netic property b~we~n T~c'~ ~3 o~ ~x~plQ and ~e~t 44 of tho 5 co~parativ~ example, And a m~gno~, havlng it~ ms~n~t perfor~ance e~u;~l to or ~bovQ tho~e obtalnod by tho conv~ntlona~ moul~lng method, car~ ~e moul ~ed .

on th~ othox hand, ~ro~n a vio~polnt o~ th~ moulda~lllty, it W~8 dl~flcult to achleve a ~table mouldlng ~or Te~t 44 of thQ ~ompa~tive example, and lO a rate of an t~ei~cte~ ~rtic.le wa~ hlgh . Furthermore th- f abricat~ on ~ost. of the die :uced ln T~t 44 of the co~a~Aratl~e ex~mple we~ appL~oxl~ateïy 3 tlmes hlgh~r- than th~ dle o~ ~e~t 43 of ~xample, and lt was mt)re exp~n~ive than a total co~t of th~ 4ie an~ thc pre~c unlt of Exa~plo.
~ccordlrlsly, a hi~h per~orm~nce thin plat~ ~tat- re~ln ~oun~ type rar~
15 e~rth magnet can bo p~ oduc~d with a hl~h pro~u~tlvlty by u6ln~ t:h~
mouldln~ mQtho~ of thi6 tll-rentlon.

Example 1 7 , Raw M~toLlalc to mak~ a com~ocltlon of N~ 14 5ro 0.95 Co 0.05) eo.s ~ ~.5 .wero molton, wor~ cA~ted and, a ~uenched rlb~on ~a~ prep~rQd ln an ~:rgon 20 atmo~ph~re l~y ucin~ a Quew~in~ ~nd rl~bon rolllng m~6hlnQ from the ln~ot .
o~talned. : _ : .
.

. . ' '~

. . .

2 ;J _. .. v ~

~he ~uenched rlbbon wac cru~hed and ~ magnatic pow~er o~ An av~L ~ge partlcle ~ize o~ 20~m wa~ obtained.

Thls m~qnetlc powd-r wa~ mlx~d wlth 4 ~e~ln powd~r co~p~l~ln6 b$~Phenol A
type ~poxy, novolaX type ~poxy and vl~ylbutyral-vinylalcohol ¢opolym~r, calcium stearate po~der ~nd ~ a powd~r a~ a~ltlve~ ~o mh~o a ratio of 90.3 wt~, 9.1 wt~, 0.4 wt~ and 0.2 ~t% ro~pectlvely.

The mlxt~lre wa~ kn~adad by a 2 rollor type m~ll at gO~. The kn~aded mixturo was ~anulated to outer ~l~met-r o~ l - lOmm partlclQ~ to m~ke a r~w materlal co~po~nd ~nd wa~ moul~ed In a cyllndr~eAl ~gnet by uGinQ
the extru~lon mould~nq machine ~hown in Flgur~ 10 of the ~orementioned Example 15.

Af~er the moulded articlo was cut lnto ~n appropriate len~th, one ~int on the circumferenco o~ the moulded artlclo w~ al~o cut ln paral~l w~.th itE central ax~s.

~he moulded art$cle wa~ ~ired at 200C for 45 ~illUt~ whlle it wa~ b~lng pr~6~ed to mSke a thln plate ~tatQ by a pre~ unit ~hown in Fl.~ure 12.

: ThQ pre~ unit ~hown in Fi~ure 12 i~ to ~r~ a mould-~ art~cle ~y movlng t~e ~r~-~ plate 601 loc~tsd ~n upp~r po~ltion ~ownwa~d ~ ~hown by ~n arrow. ~he thlckn~ o~ thQ mould-d artlcle 603 i6 ad~u~t~ b~ a Bpacer 602.

....... . . .

~ r 1 ~
;3 The pre6~ unlt ~4a~ placed in ~ firln~ furnace, ~ras heat~d ~nd thQ
afor~mentioned mould~d artl~le w~ ~et on the pre~ plat~ 601~

A pre6c w~ carrled out to m~k~ 2 thin ~late statQ wh~n the v1 sco~ y of the moulded ~rticl0 dropp~d, and lt ~a~ ~urtl~er h-~tQ~ to cro~slink the organic re~ln ln the rnoulde~ artlcl~.

La~tly the dces o~ the mould~d nrtlol* w~r~ cut and a tl~ln pl~t~ ~ta~Q
rna~net with the des~red cl2e wa~ proparod. rhe m~gnetlc property and thQ
sl~race condltion of th~ thln plats ~ta~e moul~d ~rtlcl~ of T~t 4~ -S3, in whlch the sixe6 of the mould~d. article ~xtr~t~d b~r ~n extr-~lon 10 were altered, were 6h~wn in Table 19.

e 1 9 outer D1am~ter In~Qr D~Ams~er (BH) max Surf~c~, ~re~t NQ (~m~ M~e ~ SQ~Q~
49 22 22 0 . 91 5 . O ~ood ; 15 50 22 1~ O. ~24 . 9Good 51 22 16 0 . 73 - ~ad 52 33 25 0 . 76 4 . ~ Good 53 33 23 0.70 ~ d In ~able lS, the llaad~ mark in the E-lrf~c~ conaltion m~ans that lt i~ not ; 20 u~a~le a~ a ma~nat becsuse of a ~orm~tlon o~ c~cks 02 the sur~ace.
,.
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2 r~
~ . ;j AS ~ t 16 cle~r ~rorn Toble 19, i~ thQ ratlo d~D betw~n thc outer di~m~er (D) and the lnner ~l~m~t~r ~d) ~ b~low 0.7g, lt can not ba ~t~ed a~ ~
magnet. ~t 1~ con~dered that thi~ i~ du- to a formatlon o crack~ on the surface by a ~tre~6 ~hQn lt i~ ~crQated to m~ke a ~hir, pla~e 6tate 5 6ince the thickne~ of the cylin~ric~l moul~ed ~rticle lo thick relatlve to the outer dlama~er~

Conc~rning th~ m~gn~t~ c prop~r~y, th~r~ 15 no problem lf d/D 1~ 0 . 7 5 or more.

Accordin~ly ln the mouldl~u metho~ of thl~ ln~J~ntlOn when d/~ i6 limited lo a6 O . 7 5 ~ < 1, a m~gnet having a high ~agnetl~ ~roperty w$thout ~efect~ ~uch a~ the crack, etc c~n be produced.

~xampl e 1 e Raw materlal~ to make a compo~l~lon o~ 8m (Co D, 672 Cu 0 . 0~ Fe 0 . 22 Zr 0.028) e.35 were m~lt:en, were ca~ted, ~n ingot pL~odNc:~d wa~ ma~naticEIlly cur~d ~y a heat treatm~nt, and thQn a m~n2tlc pow~Qr havln~ the ovelag~
partlcle ~ze o~ lOllm wa~ prepared ~y cru~hlng the ingot.

Thl~ pow~eL^ w~s mlxed with nylon 12 pow~er and zl~c ~t~ar~a pewder to ma~e 2 r~tio o~ 92 wt;%, 7.B wt% an~ 0.2 wt96 rerpe~tively.
-: ~, ' . :

2 ~ , r ~

Then the mlxture w~ knaad~d by a two ax~ ~x~ru~ion kneadl~g m chine at260OC. ~he k~Qa~d mlxture waY ~ranulatod to partlcle~ h~vin~ the 3u~r dlameter o~ 1 - lOm~ to m~k~ a r~ matorl~l compound, ant a cyllndrlc 1 magnet w~c mouldQd ~y an ex~ru~ion moul~ing machlne ~hown ln Flgure 1.

The mouldlng msthod wa~ ~he ~am~ me~hot So ~x~ple 1.

As ~ame to Fl~ure 1, thQ ~xtru~lon mouldin~ m chine cOn~iCtB of a hopper 101 ie a r~w ~ae~rlal ch~r~ ctlon, a cylln~er 102, a ~crew 103, an adaptor plate ~04 to equlp a ~le ~t th~ cyllnder, the die l~S and.
drlvin~ ~otor for thQ ~cr~ ~which 1~ not ahown ln ri~re)~ and further lo ~n electromagnetlc coll 109 to charg~ a ma~netlc field ln t~e dle lOr, i~
pofiitioned ~t the out~ide o~ the di~ 105. 106, 107 ~d 108 are heate~.s. '!
.
The aforementlon~d ~r~nul~t~d raw mat~rial oompound 111 wa~ char~ed in the ~xtrucion mouldlng machlnQ. Th~ raw material compound ~aE heat~d in the c~llnder lOZ at ~.60c to m~e lt in a fluldiz~d ~tate, and wac E)~ed through th~ die 105 o~ which structur- w~s ~hown i~ Fi~ure 2.
''' 1a 1E COn~t1tUtQ~ ~Y an OU~r ~ie 201 ~nd a mar~d~:e1 20~. ~he O-~te~
~ie i~ mate O~ a nOn-~ag~-S1C ~at~ria1, ~:iUt a r1n~ ~haPed olagn~tiC
materl~l 201~ ~ B in~tall~d at tho front 6n~ to in~uc~ a magn~tlc flux.
The m~ndr~l 202 ~6 ~l~o ma~e of a non-m gnstlc m3torlal, ~n~ ~t lt~ f.ront en~ 4 magnatlc materi~l 202~ ~ ln~t~ a~ wRll, - When a current iR turne~ on in the el~ct~om~gn~tic eoll ~09 ln~t~lled out~ide th~ di~, the m~net~c f~ux ~en~r~t~ flow~ ~n ~ di~ction of the ; - 73 -:
.; . - :
- :~' .:

' arrow H in F~ure ~inc~ lt tends to ~a~r ln a ma~netlc materi~l ~lth a high m~gnet~c p~rma~bllity. Th~refore ~ r~diated m~etlc 1eld 1 gener~ted. in a ~pace (hereinsfter ~alle~ ~ an orientatlon sectlon]
betwaan the front ~n~ 202a of th~ me~dr~l an~ msgn~ti~ ~t~ri~l ring ~Ola in~talled ln the out~r dle. ~hu~ while a m~ne lc com~o~ltlon p~se~
- throuqh the orl~n~atlon ~ectlon, it ic moul~d with ~ progreeoe of an orientatlon o~ the maonetic ~owder.

In thiE ~xample, the m~netlc 21~1~ o~ th~ moul~lng wa~ lS kOe, the die temper~ture at th~ moul~ing waG Z50c, and tha coolin~ carried out by a forced alr ~oollng at the outlet section o the die, Thu~ the orlentated ~aw m~terial compound 111 wa6 ~oulded by an gxtL~U~ion by a ~olld~flcatlon wlth ~oolln~ at the outlo~ o~ the ~ie. ~he slze of th~
cylindrieal moulded arti.ele wa~ the out~r diameter of 33mm and the ilme~
diamoter of 32mm.

~he moulde~ a~ticle wn~ cut lnto ~ ~ultable l~ngth, wa~ demagn~tized, and further lt wa~ devidad lnto two cqual ~ctlon~ in parallel with th~
~entral ~xi~ of the moul~ed ~rt~cl-. The moul~e~ article wa~ ther made ln a th.t~ plate ~tatc by h~atlng ~t 180C wlth a pre~ unlt aho~l in Flgur~ 12.
.
The pres6 unit 1~ to pra95 a moulded art~cle 603 by mo~inU the p~6 pla~e 601 lochte~ ln upp-r po~itlon downwArd a~ 8~0wn by an ~rrow~ ~he ~hickne~ o~ th~ moulded a~tlcl~ lc ~d~u~t~ ~y ~ ~ac-r 60Z. ~h~ plo~5 unit wa~ pl~c~d ln a flrlng ~urn~eo a~ oum~ ~ff Ex~ple ~7, ~a8 hoated an~
the moul~d artlcle w~ ~et on ~h~ pr-~6 plate.
:

.:

.-:
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. ,. ' , , , ~ ~ ~ r ~ ~ r . ~

A pre66 wa~ carrl-d out tO mak~ a thln ~late ~t~te whQn the v1sco~i~y of th~ moulded article dropped, th- ed~Q~ wera sut, and ~inallY a th1n pl~te ctat~ magnet with th~ de61rad alz~ w~ o~taln~d. Tha slze o~ ~he mould~d artlcle wa~ the wldth o~ 50mm ~nd thQ thlckn~ of lm~. The ~onQtlc propeL-ty of the moulded article obtalned ~n ~ 4 i~ ~ho~ ln T~b~r? ~n.

A~ a comparative example, ~est 5~ wa~ carrl-d out by an ~xtruclon mouldin~ by ucing a dle shown ln rl~uro 6, and ths magn-tlc pro~er~y of th- ~ould~d art~cle in a thin plst~ ~tate i~ ~lso ~hown.

.

A6 for th~ rsw matQrial co~poun~, tho came one to Test ~4 wa~ u~ed.

In the die, wh~n a cUl^r~nt i~ turned on ln ~he electrom~gnetlc coll 403, : a;~agnotic ~ield ~er~ical to the pa~a~e of the co~pound ln ~1e di~
~ormed between uppel an~ lower ~ole piece~ 404. Th~rQfore a thl~ ~late 8tate ma~net o~ whlch th~ ma~n~tic powd-r i~ ori~ntat~d ln thQ thickn~oc dir~ction can b~ m~ulaed. ~he ma~tlc ~lel~ ~t the moul~ln~ wa~ ll koO, . ~ and the cize of the moulded ~rticle wa0 the ~me to rx~mple o~ Te~t ~4.
.

A mould~bllltY i~ al~o ~hown ln Tab1Q 20 with the ~acnetlc property.

~' . ~B~ max ., 're~t 54 t Example ) 7 . S aOod ~e~t 55 t Compar~tlve ~'' .

.
.. . .
' ~ r~

example ) 2, 4 Ordlnary A~ it i ~ cl~ar from ~ e 20, though ~ch~ ~amQ mouldlng r~w materi 1 was u~ed, the comparati~e ~xamplo ~re~t 55 ~howe~ lower magnetlc ~roperty. It wa~ ~oncldered that ~ t wa~ ~ue to cn lm~o0~ itY to enlar~ the s ~a~netlc i~1d o~ the moul~ing becau~ of th~ ctructu~al p~oblom of tho dlo ~n ca~e o the comparat.$v~ xamplQ ~e~t 55 r~cLIlting arl in~ufflolent or~entatlorl of ~he ~ag21otlc powder.

Furthermore it wa~ ver~ dl~f~cult tG achle~e ~ ~tabl~ mouldlr,g in ca~;e of Test 55 o~ the con)p~ratlve example, ~nd it had a hlsh re~ection rat~.
10 Mo~eov-r the fal:rlcatlon co~t of the di e w~d ln the com~arative xhmplQ
're6t 55 wa~; app~oximately 3 tlmec more eXPen~ive than the diQ . u~ed ln Te~t 54 of Example, and it wa~ more co~ty 'chan the tot~l co~t of the Ale and th4 pre~ unlt ln ~xamPle of T~st 54, , : l COn~Qquentl~r, by using the mou~dl~g mQthod o thl~ lm~ellt1 or~, A h~gh 15 pQrfor~ance thln plato ~tate ~:e~in i~ound type rarQ ~rth ma~nQt c~n b produced wlth a ~ood prod~lctl~Jity.

Exa~le 19 Raw matsrial~ to m~ke a comp~-ltlon of SQ~ 13 FQ 82.7 9 4.3 w-r~ molt~rl as ~i~ilar to Example 17, wero ea~ted an8 a ~ucnched rl~bon wa~ pr~pa~-ad ln 20 an ~rgon ~t~o~har~ by u~in~ a ~usnchlng and rlbbon rolllr~g machine rom the in~ot obtain~d.

:

,~ .

.

.
:
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:.- , ~ - , , . . ~ , .

- - - 2 ~

The quenched rlbbon wa~ coaro~ly ~ru~h~d, it wa~ tran~ered to ~ mould, and a high pr-~Eure pra~ mouldln~ wa6 carrl-d out ln ~n arqon atmo~phQr~
at 700 - 800OC wlth a 20 ~mmZ pr~uro ~or a ~hort tlme.
' :
The con~olldated artlcle obt~ined h~d a ~en~lty ~lmo~t loO~ he co~solldat~d artlclo obt~nod wa6 mou~ed ag~in ~y th~ hl~h temPerat~lre pres~ mouldln~ ln a vert~.cal dlrectlon to tho flr~t pro~ln~ dlre~ion in an ar~on at~o6pherç at 700 - aoooC wltll a 10 Kg/m~2 pros~ure (Namely die Up~Qt wa~ carr~ed out).

:, The. bUlk ~tate ma~net w~6 cru~he~ and a ma~net~c powder of an average partlclQ ~ize of 20~m was obt~ln~d.
, The magnet~c powder w~ mlxed wlth ~ XQ~ln po~der comprl~ln~ a m~xtu~e of bl~ph-nol A tYpe epoxy, novola~ type epoxy and vinylbutyral-vlnylalcoho~
~;. copolymer, calclum ~tearate powder and ~llloa powd~r a~ adtitlves to make .~ a ratlo o~ 90.3 wt~, ~.1 wt% and 0.~ wt% and 0.2 wt~ r~6pectivel~.
, ~:~ 15 Then the mixture was kn~ded by a 2 roller type mlll ~t 9oC~ ~he :
kne~dod mixture WaE ~r~nulated to particlo~ of the out~r dl4~ter o~ 1 -....
lOmm to make a r~w mat~rial compoun~, und B cyllndric~ net wa6 mould~ bY u~lng ~n extru~ion mouldlng maehlnQ ~hown ln Flgure 1 and a .~ Ci- chown ln Flcure 2 a~ ~mllar to ~x~mple 18.
', ',.'~
~........................................................ .
he ~oulded ~rticle wac cut $nto a ~ultable l-ngth, wer~ de~agneti7.0d, ~ ~nd further one point on th~ cire~mferencQ p~rallel ~o th~ centr~l dXi~
1~ of th~ moulded artlcle w~o cut. ~hQ moulded ~rtlcl~ w~o flred at 200C
.;
~ - 77 -:.

: ' , 2 ~

for 4S mlnutes whlle it was belng m~de 11~ a thln Plate Btate by a p~ s unit ~lmllar to SxQmple l~ to cro~llink thæ s:rs7anlc r~sln ln the mouitied articl~ .

~h~ ma~n~tic ~rop~l~ti~H o~ the thin plat~ ~t~tQ moulded ~rtlcle~ when 5 Ta~t 56 - 61 were ca~ri~. out bY chano~n~;~ the si2e o~ the mould~d.
articles of the extru~ion mo~lldlng are ~hown ln T~ble 21, ~a~L , Ou'cer Diameter Inner Dlarneter ~H) m~x Te~t N~ .~mm.l. ~ mm ~ MGae ~
56 22 20 0 . gl10 . 2 57 22 19 0, 56 10, 0 58 22 lB o . B2 8 . 2 59 3~ 32 o . 97lo . 4 ~o 33 28 o . ~ lo . 1 61 33 25 o . 7~ 7 . s A~ lt i~ clear from ~able 21, if the ratlo ~/D bQt,W~n the outer diam~ter tD) and thQ llmer dlameter ~ bolow o.B5, tlle m~snatlc property i~
~et~rlor~t-d. It i~ ~on~ldere~ ~hat thle 15 duo to ~ fo~m~tion o~
~l-ord~ on tho ori~rlta~lon o~ th~ m~netlc powde~ while ~t i~ b~in~ made 20 in a thin ~late ~tate b~cau~e th~ thickn~c~ of thQ cylindrica~ mo~ld~
artlcls 1~ thi~k lsl ccnlp~ri~lorl wlth-'ch~ outer ~la~at~r. ~on~Qqu~ntly in th~ ~oul~l~ng ~roc~s o~ thi- lnv-ntlon wh-n th- ~/D l~ llmlt~d a~
O.B5 c d/D ~ 1, ., ' '. ' 2 ~

; - a ~agnet wlth a high ma~llet pe~formance c~n b~ produced.
.

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Claims

(1) A resin bound type magnet comprising a magnetic powder and an organic resin wherein it is moulded as a single body in a cylindrical form satisfying a relation of 2DL / d2 ? 1 among the outer diameter (D), the inner diameter (d) and the length (L) of the magnet, and it also has a radiated anisotropy in the diameter direction.

(2) A resin bound type magnet comprising a magnetic powder, an organic resin and an additive wherein it is moulded as a single body in a cylindrical form satisfying a relation of 2DL / d2 ? 1 among the outer diameter (D), the inner diameter (d) and the length (L) of the magnet, and it also has a radiated anisotropy in the diameter direction.

(3) A production process of a resin bound type magnet wherein a raw material for the moulding comprising a magnetic powder and an organic resin is moulded by an extrusion by passing through a die in which a magnetic field is charged while it is being cured, is formed to a single body in a cylindrical form satisfying a relation of 2DL / d2 ? 1 among the outer diameter (D), the inner diameter (d) and the length (L) of the magnet and it also has a radiated anisotropy in the diameter direction.

(4) A production process of a resin bound type magnet wherein a raw material f or the moulding comprising a magnetic powder, An organic resin and an additive is moulding by an extrusion by passing through a die in which magnetic field is charged while it is being cured, is formed to single body in a cylindrical form satisfying a relation of 2DL < d2 ? 1 among the outer diameter (D), the inner diameter (d) and the length (L) of the magnet and it also has a radiated anisotropy in the diameter direction.

(5) A production process of a resin bound type magnet by an extrusion moulding of a moulding raw material comprising a magnetic powder and an organic resin wherein a die structure for moulding is constituted that a front end of a mandrel section is projected in front of an edge of a outer die, a magnetic circuit is formed among the said mandrel section, the outer die and an electromagnetic coil installed at an outer circumference of the said die, it is moulded in a cylindrical form by charging a magnetic field in the die by the electromagnetic coil, and the moulded article extruded is demagnetized at the front end of the mandrel.

(6) A production process of a resin bound type magnet by an extrusion moulding of a moulding raw material comprising a magnetic powder, an organic resin and an additive wherein a die structure for moulding is constitued that a front end of a mandrel section is projected in front of an edge of a outer die, a magnetic circuit is formed among the said mandrel section, the outer die and an electromagnetic coil installed at an outer circumference of the said die, it is moulded in a cylindrical form by charging a magnetic field in the die by the electromagnetic coil, and the moulded article extruded is demagnetized at the front end of the mandrel.

(7) A production process of a resin bound type magnet by an extrusion moulding of a moulding raw material comprising a magnetic powder and an organic resin wherein an electromagnetic coil is installed at an outer circumference of a die, it is moulded in a cylindrical form by charging a magnetic field in the die by it, an electromagnetic coil with an air-core is also installed in front of the aforementioned electromagnetic coil to generate a magnetic field for demagnetization in the said electromagnetic coil, and the moulded article extruded is demagnetized.

(8) A production process of a resin bound type magnet by an extrusion moulding of a moulding raw material comprising a magnetic powder, an organic resin and an additive wherein an electromagnetic coil is installed at an outer circumference of a die, it is moulded in a cylindrical form by charging a magnetic field in the die by it, an electromagnetic coil with an air-core is also installed in front of the aforementioned electromagnetic coil to generate a magnetic field for demagnetization in the said electromagnetic coil, and the moulded article extruded is demagnetized.

(9) A production process of a resin bound type magnet which is constituted by orientating a magnetic powder in a molten mixture of a magnetic powder and an organic resin in a section where a magnetic field is charged at a front end of a die, moulding it in a cylindrical form, solidifying it with cooling and extruding it wherein when the magnet is cut, the resin is cut by melting by contacting the magnet with a heat wire.

(10) A production process of a resin bound type magnet which is constituted by orientating a magnetic powder in a molten mixture of a magnetic powder, an organic resin and an additive in a section where a magnetic field is charged at a front end of a die, moulding it in a cylindrical form, solidifying it with cooling and extruding it wherein when the magnet is cut, the resin is cut by melting by contacting the magnet with a heated wire.

(11) A production process of a resin bound type magnet of Claim (9) or Claim (10) wherein the resin bound type magnet is an isotropic magnet moulded by an extrusion in a cylindrical form without an orientation.

(12) A production process of moulding a cylindrical resin bound type magnet by an injection moulding or an extrusion moulding of a magnetic powder and a thermosetting resin wherein in order to cure the molten mixture of the magnetic powder and the thermosetting resin by heating, it is cured with fixing the outer circumference of the cylindrical magnet by a jig and the inner circumference by an elastic material expanded by a gas.

(13) A production process of moulding a cylindrical resin bound type magnet by an injection moulding or an extrusion moulding of a magnetic powder, a thermosetting resin and an additive wherein in order to cure the molten mixture of the magnetic powder, the thermosetting resin and the additive by heating, it is cured with fixing the outer circumference of the cylindrical magnet by a jig and the inner circumference by an elastic material expanded by a gas.

(14) A production process of a resin bound type magnet of Claim (12) or Claim (13) wherein the aforementioned elastic material is a silicone rubber.

(15) A production process of a resin bound type magnet comprising a magnetic powder and an organic resin wherein a mixture of the rare earth magnetic powder premagnetized in a magnetic field which is stronger than a coercive force of the magnetic powder and the organic resin are kneaded, and the kneaded mixture is moulded by an extrusion in a magnetic field.

(16) A production process of a resin bound type magnet comprising a magnetic resin, an organic resin and an additive wherein a mixture of the rare earth magnetic powder premagnetized in a magnetic field which is stronger than a coercive force of the magnetic powder, the organic resin and the additive are kneaded, and the kneaded mixture is moulded by an extrusion in a magnetic field.

(17) A production process of a resin bound type magnet by an extrusion moulding of a moulding raw material comprising a magnetic powder and an organic resin with a die in a magnetic field wherein it is moulded by an application of a slight vibration to the die at the moulding.

(18) A production process of a resin bound type magnet by an extrusion moulding of a moulding raw material comprising a magnetic powder, an organic resin and an additive with a die in a magnetic field wherein it is moulded by an application of a slight vibration to the die at the moulding.

(19) A resin bound type magnet comprising a magnetic powder and an organic resin wherein an average particle size r of the aforementioned magnetic powder satisfies r ? 0.1 t (t ? 1mm) with the thickness t of the moulded article of an anisotropic resin bound type magnet comprising the said magnetic powder and the resin.

(20) A resin bound type magnet comprising a magnetic powder, an organic resin and an additive wherein an average particle size r of the aforementioned magnetic powder satisfies r ? 0.1 t (t ? 1mm) with the thickness t of the moulded article of an anisotropic resin bound type magnet comprising the said magnetic powder, resin and additive.

(21) A production process of a resin bound type magnet comprising a magnetic powder and an organic resin wherein an average particle size r of the aforementioned magnetic powder satisfies r ? 0.1 t (t ? 1mm) with the thickness t of the moulded article of an anisotropic resin bound type magnet comprising the said magnetic powder and the resin, and the magnet is produced by an extrusion moulding with a die in a magnetic field.

(22) A production process of a resin bound type magnet comprising a magnetic powder, an organic resin and an additive wherein an average particle size r of the aforementioned magnetic powder satisfies r ? 0.1 t (t ? 1mm) with the thickness t of the moulded article of an anisotropic resin bound type magnet comprising the said magnet powder, the resin and the additive, and the magnet is by an extrusion moulding with a die in a magnetic field.

(23) A production process of a resin bound type magnet comprising a moulding of a mixture of a magnetic powder and an organic resin by an injection moulding or an extrusion moulding wherein a compound is prepared by charging in a kneading machine after making a viscosity ? of the mixture of the aforementioned magnetic powder and organic resin in a state of ? ? 300 [kpoise] (shear rate = 1000 sec-1) by heating.

(24) A production process of a resin bound type magnet comprising a moulding of a mixture of a magnetic powder, an organic resin and an additive by an injection moulding or an extrusion moulding wherein a compound is prepared by charging in a kneading machine after making a viscosity y of the mixture of the aforementioned magnetic powder, organic resin and additive in a state of y ? 300 [kpoise] (shear rate = 1000 sec-1) by heating.

(25) A production process of a resin bound type magnet described in Claim (23) or Claim (24) wherein the surface of the aforementioned magnetic powder is coated with a metal plating or ceramics.

(26) A production process of a resin bound type magnet wherein a moulding raw material comprising a magnetic powder and an organic resin is moulded by an extrusion in a cylindrical magnet by passing it through a die, then one or plural points on the circumference of the said cylindrical magnet is/are cut in a direction parallel with the central axis of the moulded article and the moulded article cut is spread to make it in a thin plate state.

(27) A production process of a resin bound type magnet wherein a moulding raw material comprising a magnetic powder, an organic resin and an additive is moulded by an extrusion in a cylindrical magnet by passing it through a die, then one or plural points on the circumference of the said cylindrical magnet is/are cut in a direction parallel with the central axis of the moulded article and the moulded article cut is spread to make it in a thin plate state.
(28) A production process of a resin bound type magnet described in Claim (26) or Claim (27) wherein the outer diameter (D) and the inner diameter (d) of the aforementioned cylindrical magnet to be moulded by an extrusion satisfy a relation of 0.75 ? d / D < 1.
(29) A production process of a resin bound type magnet wherein a moulding raw material comprising a magnetic powder and an organic resin is passed through a die where a magnetic field is charged to mould a cylindrical magnet having a radiated anisotropy in the diameter direction by an extrusion moulding, the one or plural points on the circumference of the said cylindrical magnet is/are cut in a direction parallel with the central axis of the moulded article and the moulded article cut is spread to make it in a thin plate state.
(30) A production process of a resin bound type magnet wherein a moulding raw material comprising a magnetic powder, an organic resin and an additive is passed through a die where a magnetic field is charged to mould a cylindrical magnet having a rediated anisotropy in the diameter direction by an extrusion moulding, then one or plural points on the circumference of the said cylindrical magnet is/are cut in a direction parallel with the central axis of the moulded article and the moulded article cut is spread to make it in a thin plate state.

(31) A production process of a resin type bound type magnet described in Claim (29) or Claim (30) wherein the outer diameter (D) and the inner diameter (d) of the aforementioned cylindrical magnet to be moulded by an extrusion satisfy a relation of 0.85 ? d / D < 1.

(32) A resin bound type magnetic described in Claim 1, Claim 2, Claim 19 and Claim 20 wherein the aforementioned magnetic powder is selected from magnetic powders of a ferrite family magnet, a magnet having a composition comprising rare earth metal and transition metals mainly constituting cobalt and iron or a magnet having a composition comprising rare earth metal, transition metal mainly constituting iron and boron.

(33) A production process of a resin bound type magnet described in Claim 3 - Claim 10, Claim 12, Claim 13, Claim 15 - Claim 15, Claim 21 - Claim 24, Claim 26, Claim 27, Claim 29 and Claim 30 wherein the aforementioned magnetic powder is selected from magnetic powders of a ferrite family magnet, a magnet having a composition comprising rare earth metal, transition metals mainly constituting cobalt and iron or a magnet having a composition comprising rare earth metal, transition metal mainly constituting iron and boron.

(34) A resin bound type magnet described in Claim 1, Claim 2, Claim 19 and Claim 20 wherein the aforementioned organic resin is a thermoplastic resin or a thermosetting resin.

(35) A production process of a resin bound type magnet described in claim 3 - 10, Claim 12, Claim 13, Claim 15 - 18, Claim 21 - 24, Claim 26, Claim 27, Claim 29 and Claim 30 wherein the a aforementioned organic resin is a thermoplastic resin or a thermosetting resin.

(36) A resin bound type magnet described in Claim 34 wherein the aforementioned thermoplastic resin is selected from one or more of polyamide, polypropylene, polycarbonate, polyphenylenesulphide, chlorinated polyethylene, an elastomer of vinylethylaneacetate copolymer and a synthetic rubber.

(37) A production process of a resin bound type magnet described in Claim 35 wherein the aforementioned thermoplastic resin is selected from one or more of polyamide, polypropylene, polyphenylenesulphid, chlorinated polyethylene, an elastomer of vinylethyleneacetate copolymer and a synthetic rubber.

(38) A resin bound type magnet described in Claim 34 wherein the aforementioned thermosetting resin is an ethylene family unsaturated polyester resin or an apoxy resin.

(39) A production process of a resin bound type magnet described in Claim 35 wherein the aforementioned thermosetting resin an ethylene family unsaturated polyester resin or an epoxy resin.

(40) A resin bound type magnet described in Claim 2 or Claim 20 whereinthe aforementioned additive is selected from one or more of zinc stearate, calcium stearate, wax and peroxides.

(41) A production process of a resin bound typo magnet described in claim 4, Claim 6, Claim 8, Claim 10, Claim 13, Claim 16, Claim 18, Claim 22, Claim 24, Claim 27 and Claim 30 wherein the said additive is selected from one or more of Zinc stearate, calcium stearate, wax and peroxides.