CA2106289C - Electrically conductive polymer gel and the method for manufacturing the same and an organism-use electrode with the use thereof - Google Patents

Abstract

An electrically conductive polymer gel is composed a crosslinked polyacrylamide polymer including electrolytic salt, water and polyhydric alcohol uniformly dissolved therein, the water and the polyhydric alcohol being major components of said polymer gel. The polyacrylamide series polymer in the gel has properties of hydrophilic and nonelectrolyte. Therefore, a desirable connection between the gel and the electrode can be achieved with low impedance. Moreover, the polyhydric alcohol reduces the drying speed of the electrically conductive polymer gel, thereby preventing an increase in the impedance due to the dryout of the gel. Therefore, the electrically conductive polymer gel of the present invention permits an accurate measurement of an electrical phenomenon in the organism for long periods of time.

Description

8 ~

ELEC~rRICALliY C~NUlJ~;1 1V~ pOT~ G~L ~D rHE METHOD FOR
~N~FACTURIN~; T~E S~ME AND ~ ORt~MI.~M-USE ELECTRODE WITH
THE USE q~RROF
~ : ;
FIELD OF THE l~Y~N'l'~O~ ,.
The pre~ent invention relates to an electrically cond~ctive polymer gel for use as a ~ensor element for a ~ht~ ty sensor, a pressu~e sensor etc., a ~olid .
el~¢trolyte solution for elec.tric cap2citor, battery, :etc., and as an organism-use electrode :and the method ~or , ~ t~rin~ the:same and an org~ni~ use electrode with the usa of the electrically conductive polymer gel, more specL~ically, :relate~ to an el~c$rically con~uctive polymer gel fr~ the acryl~ ~de series which shows a low ~ nce for lon~:periods.of time and w~ich has a strong adhesLve p opelLy:and the method for manu~acturing the ~same and an orcJ~ use electrode with the u~e of the : ; .
:

~ ~ :
. . .

' - 2 - 21~28~
,.

. . .

electrically conductive polymer gel.
, ~, .

RA~GROU~D OF THE lNV~h~10 Electrically con~n~tiYe polymer gel itself may be usQd a~ a~ electrolytic c~p~c~tor a~d a ~olid electrolyte solution ~or electric capacitor, batte~y, etc., or may be used by fc- i ng it to adhere to an electrode *1~ ~-t for a humidity sensor, a pres~ure sensor, e~c., and as an org~ni~ use electrode.
. In the medical field, in order to condllct an a~p ~pliate treatment, the potential of an organism is often measured by an electrocardiogram, elect~.yo9l~m~
brain waves, et~. Blectrical treatment by ~n! ittlng an electric si~nal into the orgAn;~ also increases. In the above meashL~~ ~ t or treatment, the orgAni~l uso electr~de which ~erves as ~ medium be~ on :the org~ni~ and an extern~l equipment play~ an i~por~nt role.

:
For ~yA~7~r~ e~ when measuring the po~en~ial of arl organism, the org~n~ use ele~-~Lode must be brought in direct contact with a part of the organi~m in order to derlve an effective u~e of a weak electrLc signal to be tran~ ted to tha electrocardiogram, etc. However, direct contact be l~ cn th~ elec: L ode and the iskin of the organism doe~ not per~it a d0sirablQ electris~ ction.
, , .
,i'."

; !i' , ' I
' ~ ,': " ~

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

-:' 3 '~0~28~ :

An unstable junction between th~s org~ni! use electrode and the skin of the organism causes a complicated poten~ial and impe~l~nGe. Thus, an electric ~ignal cannot be detected as::curately.
In order to counteract the abo~e problem, the following method has been proposed: the org~ni! use electrode i~ co~nected to a part of the ~kin o~ the organism through an electrically conducti~e polym~r gel which permits an electric signal to be sent from the ~rganism to the ext~rn~l e~uipment by ki n~ the org~n~ use electrode in stable contact ~ith the skin of i~
the organism without sti l~ting ito ~ n the above method, for e~ample, electrically co~ ctive polymer gel from the 8crylic acid sodium series with a ~ope~y of shape retention may be used. This electrically con~n~ti~e pol~m~r ~el ca~ b~ formed be~orehand in predet~ ~ned thicknes3 and ~h~pe, and it is ~sed by ~o: 1nq it to adh~re to a~ el ctrode eleme~t ~o be one in~egral p8rt. The abo~e organism-use electrode 1~
co~venient since it is disposahle and it elimi~ates the ~, .
application process.
~ IIo..-v~!, the above electrically ~n~1lctive polymer ~ gel from the ~crylic acid sodium series present~ t~e ~.
~ollowing probl~

;
~ ~ .

. ., . ..

- 4 - 2~28~

For ~- ~le, when measuring the electrocardiogramr a ~ul-ent flow of an electrocardiogram signal is:
ele~!Lr~ -~ive in heart - ti~sue - sXin - electrically conductive polymer gel - electrode eiement - lead wire amplifier in the electrocardiogram - lead wire - electrode ~ t - electrically Con~!cti~e polymer gel - skin -ti~sue ~ ele~L~ ive i~ the heart. In this case, current flows f rom the organi~m to the electrically conductive polymer gel as ions move. On the other h~nd, cuLIent flows from the electrode ele~nt to the.r ~l;fier by free electrons. Additionally~ ions and free electxons can be freely e~h~ged betwqen the surface of ~ha elec~rode element and the electrically c~n~uctive polymer gel.
The electrically c~n~c~ive polymex gel ~rom the acrylic acid ~odium serie~ has a p.v~e.Ly of hydrophili~
nature, and the polymer thereof i~ elec~rolytic and electrically conductive~ Thus, the comple~ con~unction between the electrically conducti~e polymer gel and metal eries in general~ cannot be achie~ed due to an ele tric repulsion beL~-cen the electrode Pl - t of metal series in g~n~ral. ~lO~e~V~Ll an e~ch~e ~eL~en ions and free electrons c~nnot be ~ully carried out. As a result ~ an impedance on the inter~ace increases, and precise ;:,"~ ' ' ~ .
~, , : I ' " ' ' I : : " ' ' ' ' ' ' , '. ' ' ' " ' ' . ' '". ' : : . : ' ' ' ' ' ' ' ' ' ' 2~6~89 measurement o~ the electrical ph~n~ - -nn of the org~ni !
cannot be e~ured.
~ he Japanese Laid-Open Patent Publication 15728/1981 (ToXllk~isho 56-157~8) discloses an electrically conducti~e material which include 70 ~ by weight glyc~line and .
thorium chloride in nonele~trolyte polyacxylamide.
HG.._Ver, this electrically conducti~e material is hard and shows lzrge impedancs ~ince it does not include li~uid of low viscosity such as water.
In order to counteract the above problem, the ~p~nese Examined Laid Open Patenk Publication 22839/1986 (~Oh~ sh~ 61-22839) discloses an eleckrically co~ucLi~e polymer gel which includes sllcrose and a large guan~ity of water in the polyacrylamide. ~aving no~electrolyte, ~hape retenti~e and flexible nature, the ~unction between the electrode element and the ~kin of ~he org~ can be im~oYed, ~here~y re~lci ng the impe~nce. ~:
~ owe~er, this electrically ~on~ucti~e polymex gel presents another problema sucrose cannot ~ ess the evaporation of wa~er, resulting in an increase in the :.
i~ed~nce as it dries out in relatively short periods of time. Thus, the electrical rh~n; - ~n in the organism cannot be measured ac~rately over longer periods of time. ;, MoreoYer, l3ince the tacki n~ss o~ the electrically ~ . , .

6 2 P ~

.
conducti~e polymer gel is low, a de~irable adhesi~e property to the electrode element canno~ be ensured and A ' part of gel may separate from kin or from the electrode element while being u~ed. No ~ve~, a hot ~pot is likely to appear between the gel and the ~kin. In order to ~event the separation of the gel and the appearance of the hot ~pot, it i~ required to restrict the degree of freedom of the target organism.
For the electrode element, cAr~on~ Ag~gCl, germansilver ~alloy consi~ting of C~, Ni or Zn) may be use~ according to the use for which it i6 int~n~e~.
Howe~er, the ~ ~ -~nt Cu of ~ermansil~er is corroded by water, electrolyte, e~c., and ths corrosion of Cu is ,7.~.
~pe~ited ~y the acrylamide o~ the electrically conducti~e polymer gel, resulting in an incre se of ~he I ~ n~P.
Fo~ thi~ reason, the electrode cannot be used many ~i~es.
llo VY~t it i8 not possible to fo~m be orehand the : ele~Ll~de element and 9~ -n~ilYer a~ one integral part.
. ~'', .
: SUN~A~Y QF ~ Nv~ ON
In order to ov~L~ ~ thQ above problem~ raised in ~he ~onv~nLional electrically ~on~nctive polymer gel from the polyacrylamide series, e~rnest research and development have been ma~e.

'' .
', ' ' ,:

~ - 7 - 2~6289 Therefore, a principal ob~ect of the present invention is to provide an electrically conductive pol~mer gel having Lmproved properties.
More ~pecifically, an ob~ect of the present i~vention is to provide an electrically conducti~e polymer gel which shows a low ~ nce and which permits an accurate mea~u~ even with th~ use of a weak electric signal.
Another vb~ect of the pre~ent invention is to provide . .
an elactrically con~llotive polymer gel which shows low impe~nce for lo~g period of time and which permits a repetitiYe use ther20f without reducing the measur-ng accura ::y.
Yet another ob~ect of the prese~t inve~tion is to pro~ide a~ electrically oon~llcti~e poly~er gel which p e~el~t~ an increase in the ~ o~ the interfac~ in csntac~ with an elec~rode el~e~t.
Yet ano~her obje~t of the present invenkion is to pro~id~ an ele~trically conductive pol~mex gel ha~ing :desirable tackine s and an ability to adhere to an electrode elemant or a target organism, which permi~ a s~fe u~e thereo~ for the orgAni~ without separating.
~ Yet another ob~ect of the present invention i~ .to provide an electrically conducti~e polymer gel which ~ever.Ls ero~ion of the ele~-L~ode elem~nt and which :' - 8 - 2 1 1~ 2 8 ~

maintains a low Lmpedance for long periods o~ tLme.
Yet another object of the present inven~ion i~ to provide an electrically conduct:ive polymer gel which en3ures a ~afe use thereof ~or the organism by ini i zing a free re~idual ~ s{uantity.
Yet another object of the present invention is to provide a method ~or effectively manu~acturing an electrically conducti~ve polyltlex gel having the above p~ ope~ es by the polymerization and cro~sl ~ nk~ n~ of the g~l .
~ et another object o~ the pre~ent invention is ~o providQ an ~..~ oved org~n1! use ele~ode with the use of the ele~tr~cally conductive polymer gel having the above p.o~elLies.
~ h~ electri~ally cnn~uctive polymer gel of the pre~ent inYentio~ i~ ch~racteriz~d in that electrolytic salt is unii~ormly con~ine~ în a cros~l ~nke~l lnpolya~ryl~m~P polymer which incl~de~ at least water, penekrant such as polyhydric alcohol, etc., a~ major .' ..
components. The elec~rically conducti~e pol~er gel of ~he prasent ln~ention is al~o characterized in that a~
epoxy cro~linker and metallic ion ~e~l ~ng compound which has ~apox pre~ure ak room temperature are uniformly cont~; ne~ therei:n.

:
::

- 9 - 2:1.0~,89 According to the method for manufacturing the electrically conductive pol~mer gel o~ the present invention, it is obtained ~y pol~nerizing and cross~ink;
~he monomer bl~n~ i ~g solution including at le~st polymerizable mor- -~ from the acry1. ;~e series, cros~l inkAhle ~nr -~ ~ water, penetrant ~uch as polyhydric alcohol, etc.~ and electrolytic salt. The monome~
bl~n~ing ~olution ~ay include an epoxy cross~;nk~r and a metallic ion ~ealing compound which has vapor pressure at room t~ ~-r~ture.
A further ob~ect o~ the present invention is to ;,~, pro~ide an org~nil use electrode c~ ,_se~ of the ~lectrically conductive polymer gel and ~he .electrode ~ i -element.
; ~..
BRIEF r~scRTpTIoN C~F ~rHE DR~WI~GS
Fig. 1 i~ an PYrl~n~tory view ~ho~in~ the cond~tioals ::
, for mea~uring es~e~Liv~ imr~nce~ of ~he elec~rically ~:

~on~tctive pol~mer gel of the present invention.

Fig. 2 i~ an electric circuit diagram of the explanatory view of Fig. 1.

:Fig. 3 is a graph showing a cha~ge per day of % by ~eight.

: ~lg. 4 i~ a graph ~howing a change per da~ of .
. .
.',~;' ~.

lo- 2~289 impedance.
Fig. 5 i~ a cro s~sectional ~iew of the orgAn 1 s- ~8e electrode.

DESCRIPTION OF ~E EMBOD~ S
An electrically c~n~l-c~ive polymer gel in a~cordance with the present invention 1~ composed o~ a polymer from the acrylr ~e series obt~ine~ ~y perfo ;ng polymerization and crossl inkin~ o~ ~ ~ ' ~~ blen~in~
solution by the use of a polymerization initiator. ~he electrically conductive polymer gel is suitably used as an electrode by f,~- i n~ it to adhere to an electrode element such as AgJAgcll g~rr-n~ilver, cArhon, etc., to be one ~lnte~r~l part. The electrically con~nc*ive polymer gel is also~used a~ ~en~or ~1- Ls for a temperature sensor~ a pre3s~re ~e~sor, eta., and i5~ ~used as th- ~alid ;eIectrolyte~ ~olution ~or~ a~ ~elx~trolytic capacitor, a battery,~etc. ~he ~ ~ blending solution contain~ at least: polymerizable ~ from the acrylamide ~erie~

copolymer~ crosslin'k~h~e ~ monomer~ alectrolytic ~altsO
penetrant and water~ In order to obtain an e1-ctriaally Qn~lctive:polymer gel whi.ch i~ ~ot easily dried out, the polyhydric 'alcohol is :added as a penetrant. For the .

~ mon~m~r blending solution whic~ includes the polyhydric 11~ 2~ 8~

alcohol as a penetrant, the water and the polyhydric alcohol are the ma~or c~ , PntS. In order to obtain an electrically conductive polymer gel which has a strong adhe~ive pY~e~Ly, an epoxy cros~link~ which is reactive ~o the amide group of the side chain i~ added to the ~ blending solutLon. Th~ epoxy crossl;nk~r i~
reactive to the amide group of the side chain. . In order to obtain an electrically condu~tive polymer ~el hav~ng a property of corxosive resistant, the metallic ion se~l ~ ng ~. ~s~,ld is added. ~dditi~n~ly~ a~tiseptiCt disinfectant, stabilizer, perfume, interf~ci~ active agent, coloring agent and other agent msy be added to the ele~trically conductive pol~mer gel if necessary.
For example, acryl~ , me~hacry~- iA~, etc., whi h are water ~oluble and non-electrolytic, can be used as the polymeriza~le ~onomer fro~ the acxylamide ~eries. For the crossl~n~hle ~~~ ~ , the follow~lng m~terial~ may be .
used: N, Ni _ methyl~n~hisacrylamidet ~, N/ - '. ' m~thyl~n-~b~ h~c~ id~ Nr ~ et:h~l~n~ x~ylamid~
N,N,-etylPn~b~ -thacrylamide, 1,2-diacrylamide ethylene ."
glyco}, di(~rlpoly~acrylate, di(tripoly~me~hacryla~e, e~c. ..
For the electroly~ic sal~, all the salt~ ~c~ n~
sodium chloride, potas~i~m chloride, ~ne~um chloride, .~;
etc., may be used. Hos. v~L~ the salt which has polyatomic '.', j, .

:
. .

- 12 - 23.0~8~

and small molecular weight is preferable. In particular t the chloride having polyatomic ancl small molecular weight is de3irable for an electrode elem~ent of Ag/AgCl.
For the penetrant, monosac~r~e, polysac~h~T~e and polyhydric alcohol such as sorbitol, glycol, glyceline, ~tc., ~ay be u~ed.
There is no lLmitation on the way to carry out the poly -ri~tion and the crossl inking, When using the ~ree-radical polymexizati3n initiator~ the poly~erization initiator ~rom the azo series ~uch as a~o~is cyano valeric acid, azobis amidine propane 2 hydro~hloride, etc., ~ay be used. The xedox initiator compo~ed of ~1) the re~nc~r ~uch as the ferrous sul~ate, sodium dithio~ite, osul~ite, etc., and (2) the peroxide ~uch as hydrogen peroxide, peLo~o disulfate, e~c., may be used as wel}.
Note that tAe pol~eri~ation initiator ~rom the azo series and th~ redox initiator may be ~sed alo~e or ~ogether. It i8 also po~ible to carxy out polym~rization by the ~ pro~ection of light beam, electron beam, ~ltraviolet xay, ~ .
. ~ etc.
~ he following materials may be u~ed a~ the epoxy cros~ ~nker: th0 ethyle~e glycol diglycidyl ether (112 WPE); polyethylene glycol diglycidyl ~ther (n=2; 150 WPE, n~4; 195 WPE, n=9; 280 Wl'-, n-13; 400 WP~, n-22; 600 - ' ' ' ~'.
', ' ~ ' ~ 13 - 21~28~

WPE); triglycidyl 2 hydL~y~hyl isocyanurate (250 WPE); ~ :
trimethylolpropane polyglycidyl ether (140 WPE); glyceline polyglycidyl ether (150 WPE); ~orbitol polyglycidyl ether (170 WPE); etc. It should be noted here that the epoxy crosslink~r has preferably weight per epoxy number of not:~:
l~s~ than 200 WPE. :.
The ~ollowing materi A l~ may be u~ed as the matallic ion se~l~ng compound under the condition of vapor pressure at roo~ ~ dtures benzotriazole having a ~apor pre sure o~ 0.04 mmXg at 30 ~C; tolyltriazole; dicyclohexyl ammonium nitrite having a ~apor pres~ure of O.Q004 mmff~ at :
21 ~C; cyclohexyl amine cArh~n~te havi~g a ~apor pressure of a.4 mmxg at 25 ~C; di-i~op~o~yl a~m~nium nitrite having a vapor pressure of 3.006 mm~g at 20~ C; etcO The benzotri~zole and the tolyltriazole plev~nL Gu and Al from belng C~L ~ Oded. On the other hand, the dicycl~h~Yyl ,~ r am~onium nitrit~ ~1ev~ts Fe, Ni/ Cr and Sn fro~ being .~,i COLLOded. The cyclohexyl amlne c~r~on~e p~ev~n~ Fe and Pb from being co~loded. S~ rly, the di~i80~LOPY1 a~monium nitrite p,ev~nLs FQ ~rom being COL loded.
When the electrically conduc~ive polymer gel shows low imp~ nce and the accuracy thereo~ Lov~d, the ~iul~Le,~ due to the CCOL~ O~iOn i5 no~. negligible~ .;
There~ore, the metallic ~on e~lin~ compound i~ preferably '., ' ,~
1:
~' .... ~.. . . . .... . . . . .. . .. .

- 14 - 210~89 added.
The following deals with the pel~erLLage composition of the electrically conducti~e polymer gel of he present inven~ion. Hereinafter, % by weight is rs~erred to as %.
The ~lcenLage composition o:E the acry~ r ;~e in the eleotrically conductive polymer gel is preferably set within a range of 13 % ~o 25 ~. ~he reaso~ ~hy the lower llmit o~ the acrylamlde ~e~c~n~a~e composition is set ~o 13 % is based on the fact that when the electri~ally cnn~ltctive polymer gel is prepared with the acry~Aride monomer amount of less than 13 %, the xatio of the polymer main ~in~ to the gel i8 too low to ebtain the gel body ha~ing sufficient adhesive ~ o~elLy. Thus, the electrolyte solut.ion w~lch i~ se~le~ in the ~esh structure of the gel body cannot be m~in~i n~ under ~table cond~tion. 0~ the ot~er hand, th~ rea~on why the upper limlt of the açrylamide yeL~en~age composition is set 'to ~5 ~ is based on the fact that when ~he electrically . .
cnn~ucti~e polym~r gel is prepared wikh the acry~Am;~e monomer gua~tL~y of abora 2S %, the gel bodiy having su~fi~i~nt polymer gel strength and adhesive property can be obtAine~, wh.Lle the mesh structure o~ the gel body becomes to close i50 that the adhesive funa~ion decreases and the absolute iamount of the eleotrolyte sol~tion which .

.

'' . ' .. : .. .. . . . . . . . :. .' . ' .. . i . . : . .. . , ' - 15 - 2~6289 can be sealed by the mesh is little, thereby ~ ki n~ it impo~sible to prepare the target low Lmpedance electri~ally conductive polymer gel.
The ~e~.-entage composition of the crosslink~hle ~ ~ r in the electrically con~nctlve polymer gel is ~et within a range of 0.001 % to 0.3 ~, , preferably, withi~ a range of 0.01 ~ to 0.2 % for the ~ollowing reasons:
~ 1~ When the p~ entage compo~ition of the cross I i nk~hl e monomer is above 0.3 ~, the ~r of mesh crossl ;nk~n~ points connecting the main ch~;nc incresses/~ d' thereby obt~ni~g a gel body having appare~tly a high gel strength. ~fn~ev~l ~ the fragility ~ectility) of the gel :.
body increa~es which is likely to cause the amputation and bxeakdown due to the e~tension and compression; ~:
(2) ~he i~crease of the crosslink~n~ points develop~
the ~ydLOphObic ~tate of the ~ain ~hA~n~ thereby ~k~n~ , ~t impossible to maintain the electrolyte 801ution which 1~ sealed in the mesh structure of the gel body under stable conditio~, ThexefQre, the electrolyte ~olution is ea~ily separated from the gel body; ';

(3) The follow-up with respect to the motion i~
d due to a drop in the degree o~ ~reed~m of the main ~hAin~ as tha crosslinking points increa 9; and ~j ~4) When the percentage composi~ion o~ the '~ '.

~, .

~ ,' ':
~ . ' '.. ' ,; ' _ 16 - 21~ 9 cro~slink~hle ~ - is less than 0.001 %, it is impos~ible to obtain the gel.
The penetrant in the electrically con~llcti~e polymer gel is preferably set within a range of 20 % to 65 %. The lower limit o~ the pe~ce..tage composition is set to 20 ~, because when i~ is set below 20 %, it dries out ak a high spesd, and a~ the gel canno~ bs maint~i~e~ over time.
Therefore, when ~easuring a biopotential, the lmpe~nce of the gel body increa es. With the increase in the i~pe~nce, an accuracy of the ~easuy~ t decrea~s, and thu~ an accurate measuL~- ~ t cannot be carried eut over long p~i o~ of time. On the contrary, the upper limit ~f the percentage composition of the pe~etrant is set to 65 ~
hec~n~e whe~ above ~5 %, the gel body cannot be aasily dried out; ho.-ev~l, the ~neLl~nt cannot be kept ~table ~n the me~h structure con~ ing the gel bo~y, and '~he bleed o~ the gel body occur~ which lo~rs ~he adhesive ~o~el~y. ~oreover, the relati~Q qu~ntity o~ water . .
bec~mes too low to obtain the target low ~re~nce eIectrically conductive poly~r gel.
The el ctrytic sal~s in the electrically con~llctive polymer gel ie preferably ~e~ within the range of 2 ~ to ., -:~ 15 ~6~ more pre~e!rably, within a range of 2 % to 8 D6 ~or ~he~ ollowing reason: ~he electrolytic neutral ~alts has :

,;
.: .

-_ 17 ~ 2~ ~28 ~

a great effect on the im~edance o~ the gel body in its correlation to the quantity of water, and plays an LmpOrtant role to de~r~-ne the ~uality of the electrode.
Specifically, when the percentage cl ,wsition of the electrolytic neutral ~alts is below 2 ~, the ~re~nce ~~ ~s too hi~h to obtain a desirabla electrode. On the other hand, when the pe~ce~tage composition thexeof is abo~e 15 %, it falls ~yond the range which the elec~rolytic dissociation is permitted. ~his mean~ that the addition of the salt~ becomes wast~ful which only l~wers percentage compositions of other components.
Addltionally, when the electrolytic salt is dissolved into the 1 ~ ~ ~ r blending solution, if the electrolytic salt i8 mixed after breaking it Into pieces, it i~ ef~iciently dissolved by making the time req~ired for digsolvi~g shorter~
: The water in the electrically c~n~l~ctive pol~ar gel i~ ~et within a range of 20 ~ to 6S %, pre~erabl~, in a rango of 30 % to 65 ~ for tha ~ollowing rea~ons: When the . pe~ tage cc ,osition o~ water is set below 20~ can be achie~ed; howe~er, the ~uantity of water in th~ gel body h~ 'r ~ too little to obtain a desirable electrical co~uotor, and thu~ a high imre~nC~ gel body ca~no~ ~e obtained. On ~he other handj when the compo~itio~ ratio '~

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

~ 18 - 21~628~

is abo~e 65 ~, although a desirable electrically eonductive L~o~esLy can be achieved, the water cannot be kept in the mesh under the stable condition, and thu~ is is dries out guickly. As a result, the impedance of the ~el body increases during the measurement of a biopotential, which re~uce~ the mea~uring accurscy, thereby - ki n~ it LmpOSS ~ble to carxy out an accurate ~easurement oYer lonser periods of time. Accord~ng ~o the electrically conductive polymer gel, tha watex in the gel i8 used for dissolving other ~ ts. This i~ one of the reason why a low impe~nce can be en~ure~.
The epoxy cros81i~k9r is ~et withi~ a range o.f 0.05 %
to 0.3 % , preferably, within ~ range of 0.08 % ~o 0.25 %.
~his is becausQ whe~ it ~alls below 0.05 %, a sufficient adhesi~e prop~rty cannot be ensured. On the other ha~d t~ ' whe~ it i~ set a~ov~ 0.3 ~, it bsc~ s hard, f ~ e, and :~
~he desirabla adhe~ive ~o~a Ly cannot be obt~
~ he me~allic ion ~1 in~ co~pound is set within the percentage c~ ~sition of 0.05 % to 15 ~ for the ~ollowing reason: Nhen it i8 sat ~elo~ 0.05 %~ it hardly contribute to ~l~V~t the occurre~ce of corrosion. On the other .
hand, whe~ it is set above 15 %, the ble~ng solution is no more polymerized.
~ ccording to the ~anufacturing method of the pros t . :"
' .

- 19 2~106289 invention, the ~ r blending solution is prepared in the following mAnn~r First, an acryl~ ;~e ~ ~ ~ or an aqueous solution thereof, a cr.ossl i nk~hle m~nr - ~ a penetrank such as polyhydric alcohol, electrolytic salts, etc., were prepared. Then, after ~ ng a predetermined quantity o~ water, the above co~ponent~.were mixed by ~.irring~ thereby obt~ining a mono~er blending solution in w~ich the abovP ,~ ts ar~ uniformly dissolved. For the -- r - r bl~n~ i ng solution which includes po~yhydric alcohol as a penetrant, the water and the pol~hydric ~lcohol are the major s- ~onent~. As a note, the quantity o~ water is preferably set slightly larger than that reguired for di~svlving the other ~ ent~. ~hen, after ~i n~ a polymeri~ation initiator, the monomer bl 9n~
solution 1~ heated up so as to carry out the polym~2~tio~ and the ~rosslin~in~f ther~by manufa~turing an electrically c~ucti~e polymer gel. ~hen the heating t~ ,- ture is S2t within the range of 40 ~C to 90 ~C, ~he poly ~ri ~tion cro881 Inkin~ i~ almo~t completed within five minutes. However, it i~ pre~erable to keep heating for one hour to two hours so that the res~ l monomer doe~ not ~X~ee~l 20 ppm. ~he heating by ovens and heating by contacting are used as the way o~ heating.. In order.to prepare a polya~lr gel of sheet type h~ving ~ thickness Of - 20 - 21~89 1 mm to 2 mm, the polymer gel i~ sandwiched between two ~he ~ 1 plates which are heated up for spreading the polymer gel to form it in a ~heet, and heating it from both surfaces. With ~he applica~ion of hea~, the polymeriza~lon and ~rossl ~nking Of the monomer bl~n~ing solution i8 uniformly carried o~t, and the unifo~m physical characteristics of the whole polymer gal can be achieved. ~dditionally~ by providing net like rein forcing member made of fiber a~ the reinfor~ing member ln an middle portion of the monomer bl~n~i ng solution or on the sllrface thereof when carrying out polarization and cross~i nk~ ng~ the electrically conductive polymer gel integrally formed with the rei~forcing m~terial in the d~le portio~ or on th~ surface can be obt~ n~ which shows unifor~ characteristic and an ~n~i le ~r ~.g~h.
Fig. 5 8hows o~e ~ e of the slectrically ~onductive pol~er gel u~ed a~ a~ organiBm-use electrode.

, The org~nil ~se electrode is arranged ~uch that a sur~ace er 14 ~s integrated b~ ~h~r~ ng to an electrically c~n~nctive polymer ~el 11. The electricall~ ~n~ctive :
polymer gel 11 has a diameter of 40 mm and its middle .:
portLon is provided with a n~t 12 ~or reinforcing thereof.
The sur~ace mff~ber 14 is made of film which is provlded so: ' as to su..o~-d a:n electrode ~1~ ~ t 13. A top portion of .

' ::~' - 21 - ~ 28g the electrode element 13 is ~ecllred by a hook 15 for conn~cting a lead wire (not shown). ~he other surface of the electrically conductive polymer gel 11 adhares to a .. ,vr1ble sheet 16.
Fox the el~ctrode element, a plythylene terephthalate resin film or an acrylonitril~-styrene resin film which is coated with ~g/AgC1 powder or Ag, ~g/AgCl, or carbon paste, or elec~rically con~uctive rubber may be used.
The configuration and ef~ects of the electrically con~nc~iYe polymer gel will be descrihe~ below.
"
EXAMPLES 1 - 8 ~ND COMPARISON EXAMPLES 1 - 4 :
Impe~nce measurements were carried out with respec~
to electrically con~ncti~e polymex gels fro~ the acry~ series (examples 1 ; 8) and elec~ri~Ally co~c~ive polymer gel8 from polyac~ylic a~id 80dium serLes (comr~r~so~ examples 1 and 2) 50 a~ to ~1 ~r; fy the differences in electrical ~lo~el~ie~
First, (A) % of 40 ~ acryl ide monomer aqueous ~olution as the polymerizable monomer, (B) % of methyl~n~hi~crylamide powder as a crosslink~le --r ~ G) % of-glyceline as the polyhydric alcohol, (S~ ~
% of sodium chloride a~ the electrolytic neutral salts were prepared. Then, af~er ~ the L~ - ining ~, :: ' : '' i . : . ~ ' ~ . . ! , . . . . .

- 22 - .
21~62~9 ;

percentage composition of water, t:he above materi~ls were mixed so a~ to be dissolved, thereby ob~in;n~ a transparent ~ ~ ~ - bl~nA i n~ solution.
T~en, the obtAin~ ~~ C - blending solution was mixed with C, % of 4 % potassium pe~o~odisulfate aqueous solution (a~ the polymerization initiator~ and C2 % of 2 ~
potas~ium pyl'o~ulfite. ~hereafter, the int~ te portion was pro~ided with a net ~ade o~ polyester monofilr - L and was heated up to 8S ~C for two hours, thereby presenting an electrically co~ ctive polymer gel having a thickness of 1 mm.
Next, the electrically condnctive polymer gel -nn~ACtured in the above -nn~r was formed SQ as ~o be a sample square o~ 20 mm, and ~he impe~Ance zl (ohm.) o~ th~
3ingle gel wa~ mea~ured. The detailed descript~on of the me surement was de~rihad below. Firs~, the sample was cQnne~ted to a signal genera-tor and o~cilloscope by a cQ~ l cable, and thk si~nal generator was ad~usted as followss (1) the o~L~u~ signal ~ B 10 Vp_p; ~2) the ouL~uL signaI has a sinusoidal wava form; and (3) the frequency is 10 Hz.
After the ad~ustment7 as ~hown in Fig. 1, ouL~
terminals of th~ siynal generator 1 are .connec~ed to co~ l cabl-s 2. On of the coA~;al cable 2 was " ~,' '~, .

-- 23 - 2~7,89 ~ -:

conn~cted to a resistor 3 having resi~,tance of R=lM-ohm, and one end of the co~i A l cablle 2 wa~, connected to a sil~er electrode 4a while one end of the other coaxial cable 2 was connected to a 5ilver electrode 4b. ~he silver electrode 4b and silver electrode 4a are paired with each other. The electrodes 4a and 4b w~re respectively adhered to the sample 5.

The plu~ illpUt t~ ~ ni~l 1 and the minus illput ~ nP 1 of tha osf~illoscope (OSC) 6 were respecti~ely connecte~ to the ~QA~i Al cables 2. RespectiY~ ends of the C~iAl cables 2 were connected to sil~er electrodes 4c and 4d.
~hen ~oltage was applied to the ample 5 from the signal genera~or 1, a drop in ~roltage V3 due to the sample 5 was measured by the oscilloscope 6.
~ h~ relationship ~nong the ~lgnal generator 1, sample S and the o~cilloscope 6 are equii~alen~ to a cîrcui~
diagram of Fig. 2 . ~ For example, when it ~as assumed tha~
the ouL~L voltage o~ the signal ~en~rator 1 was Vl, nce Z 1 of t~e ~a~ple 5 ~ras~ gi-ren by the following rela~io~al eq-la~ion (1): Iz¦ = R x V~/(Vl - V~) ... (1).
:Imre~l~nce Z1 (ohm) was ob~A ine~ by supplying the voltag~ V~ obtained by the oscillo5cope 6, resistance R=l (M-ohm) and voltage Vl=10 tV)-Further, t~o :pairs o~ circular samples wi~h a .
.
.:
- .
, . .
- ~

- ~4 -2~1628~

diameter of 20 mm of the electrically conductive polymer gel to whi~h circular Ag/A~Cl electrode elements with a ~;r -~er o~ 10 mm were adhered respectively were prepared.
The respective gels were made in contact with one another 80 as to form an electrode pair, and the impe~nce ZAg~
(oihm) of the alectrode pair was measured. Similarly, two pairs of circular 3amples with a ~ Ler of 24 mm of the electrically conductive polymer gel to which circu~ar o~ho~ electrode elements with a Ai; ~~er of 20 mm were adhered respecti~ely were prep red. The respective gels were made in contact with one another ~o as to form an electrode pair, and the ~ nce Z~ ~o~m) of the ~l~ctrode pair was measured. The abo~e method for pr~pAr~ n~ the Qlec~rods pair is hereinafter refarred to as a sample preparing method.
By changing ~A), ~B), (G), (S), (Cl) and (C~) ~ of respective compositio~s of th~ eleetrically con~nctive polymer gels ~examples 1 - 8) of Table 1, respective e~nces %lt ZAgCl and 2c (ohm) were measured. The measured results are shown in Table 2.

, .: .

~,", .
~,.. .
:

:
: , .

- 25 - 2~ 8~

COMPOSITION T~BL~3 A B ~ S ~ 1 C z Example 1 33 0 .10 30 8 . 0 5 . 0 5 . 0 Example 2 45 0 .10 2S 8 . 0 5 . 0 5 . 0 Exampl~ 36 0 0 . 10 2 0 8 0 0 S . 0 5 . 0 Exampl~ 4 33 0.05 50 6.0 4.5 4.0 Example 5 45 0 . 05 ~0 6 . 0 4 . 5 4, O
Example 6 60 0.05 20 6.0 4.5 J.0 Example 7 30 0.06 4~ .0 4.5 4.5 Example 8 35 0 . 07 50 2 . 0 4, 5 4 . 5 ,~
- : ' .

,~ :

~'; .
' ' - 26 - 2~2~9 ~ABLE 2 IN~?F.n~

Z ~ gCl Zc Exampl~ 1 22 ~B 33 Example 2 2Ç lû~ 44 Example 3 33 127 51 Example 4 59 145 65 Example 5 40 90 37 ~ .
13xample 640 118 45 Example 7 61 172 67 Example 87 7 18 0 8 0 -,'. '.
.
qh~n, (A~a)% of 4896 acrylic acid sodium aqueous solution ~ was substitutod ~or acrylamide of example 1,; and other c~mpo~ition~ (B~, ~G), t83, (C1 3 and ~ ~C~3)% were ~h~ng~ as the comparison example~ 1 and 2 of ~ab1e 3 in order to measure ~he re~pec~iv~ i~pe~ es Z 1, ZAg~l and : :~. ZC (ohm). The mea~ur~3d results are shown in Table 4.

.ir ~

~ , ' , ~ ; , '' ': ~
;,: ' ~: : : .:
, .' :.

.

- 27 - 2~ 89 COMPOSITION TABLE

A~a B G S C1 C2 C; ~ -ri8On r- - ~ le 1 410.27 30 0 5.5 4.0 S:~ompari~oIl Exs~nple 2 500 . 25 40 0 5 . 54 . O

.

I~PED~NCE . .

Z lZ~gcI ~C
Comparison 60 340 47 r - _ l e 1 Ct , ~~ ~on 55 370 80 E~c~ple 2 :
~ ,, ,:
, :
." .

~~ :

.
.

- 28 - ~10~s~89 According to the results of the meas~ - ts, i~ was clArif ied that each electrically cQTld~ctive polymer gel from ~he acryl~de s~ries ~examE~les 1 - 8) has a lower i.mre~3~nce than those from the acrylic acid sodium seri~s (c- r~,-rison ~~ _]e~3 1 and 2~. In particular, i~npe~Ances ZAgCl of the eLe.;L~ ode pair which was fonned b~ tha gels in contact with each other by the use of the Ag/AgCl : .
electrode were extremely be lowered based on the.fact that the imre~Anc~os ZAgCl (ohm) of the ~lr~t through eighth ~- _les fall in a range of 90 ohm to 180 ohm while 1thc~se o~ the first and second ~ on ç~ ,1 es are respectively 340 ohm and 370 ohm. ~ccordingly, the : -electrical phenQm~na derived in the orga~i~m can be more accurately 2~easured with the use of the electric:ally conduc:tive polymer gel from the acryl: ~le series than tha collv~ntlonal ~lect:r~cally con~lctive poly~er gel from the acrylic acid sodium serie~.
Next, a change per day oi~ impe~nce of ~1 ) the electrically con~stive polymex gels iErom the acryl; i d~
series (~ ~rle5 3 _ 5) and (2) those frorll .

ac~ m~ ~le/sucrose series matrix ( c~ ~ -rison examples 3 : .:

and 4) ~as measured in order ta clarify ~he di~ference~. :
First, the electrically c~n~llcti~re polymer gels from the acrylamideilsucro~e ~erie~3 matrix were prepared in the '-:
:,', : .

- 29 _ 210~ 9 following manner: First, 15 % of acrylamide mono~er powder (100 % pure), 0.04 % of N, ~'-methyle~ebisacryl~mide powder as a crossl inkAhle ~ and 25 % of sucrose powder for enhancing the adhesive property were prepared.
Then, a~ter adding ~7.46 % of wat:er, the abo~e materials were mixed so as to be dissol~ed, thereby obt~ning the monomer blending solution.
Then, 1,00 % of 2 % ammonium pero~o~i~ulfate aqueous solution (O.02 ~ pure) as the poly ~ ~z~tion initiator, and 1.50 ~ nf 2 % t~L! -Ihylethyl~e~i~mide aqueous solution ~0.03 % pure~ are added ~o the monomer blen~ i ng solution and mlxed. Thereafter, the polymeri~ation cro851inki n~ was carried out with respect to the ~ixed solution at ronm tl r~r~tures for one hour so as to obtain an electrically con~l~ctive polymer gel having a thickness ~f 1 mm (comparison example 3).
Subs~quQntly, 15.0 % of acry~ e monomer, 0.03 % of N, N~-~ethylpnehisAc~yla~ide/ 33 ~ of sucrose po..'~r were prepared. Thent after ~ing 49.47 % of water, the above ~at~ri~ls w~re mi~ed ~o as to be dissolved, thereby ob~i n i ng a monomer blPn~; n~ solu~ion. As a resul~, an electrically con~u~tive polymer gel having a thickness of 1 mm in accoxdance with comparison ~Amrle ~ was manufactured.

' ' ' .

:
.
';

_ 30 _ 2~0~89 ~ I~he elec~rically conductive polymer gels of example~
3 and 5 havi~g the percentage compo~itions of Table 1 and the electrically conductive polymer gel of comparison ex- ~les 3 and 4 were set uslder the condition of:
temperature 23 ~C; and humidity 65~ hen, a change pex day of % by weight and a ch.nge per day of ~ ,~A~nces Z~ohm) wers measured in order to clar~fy the differences of the gel~ Simultaneou~ly, the ~ree re;~idual ~nomer ratio (Q~ ppm was mea~red by the high-per~ormance liquid chromatography (HPLC). Table 5 shows the measured ~ by weight, and q'able 6 shows the imre~nces and the free residual : - f - r ratio ~Q) ppm. Here, "~ I'able 6 indicate~ that the measu.l ~ t could not carried out, and "~D" indicates that the free residual mon~mer ratio ~Q) ppm i8 not mure than the.detoction limlt of the instr~ment (20 ppm)-,.

; . ''' ";

~ .
' ' 31 2~ ?,89 :

&~ PER DAY OF % BY W~IG~T

Before First Second Third Fourth Fif~h Drying Day Day Day Day Day Example 3 100.0 91.0 85.3 89.5 78.8 78.3 Example 5 100 . 0 93 . 8 89 . 9 87 . 0 85 . 0 83 . 4 Cc~n~rAri~n ~ ~
r ~ le 3 100.0 ~5O5 74.4 61.8 54.0 49.2 Comparison :
~xample 4 100 . 0 84 . S 73 . 0 65 . 2 60 . 7 57 . 6 ....

T~L~ 6 G~ PER DAI OF IMPEDA~CE
:, Before ~irst Secon~l Third Fourth Fifth 3:)rying Day Day Day~: ~ Day Day Q
15~ pl~ 3 33 10~ 145 162~; 173: 18 ~: ~ E~1Q:~ 5 40 ~ 90 12~ 130 ~ 135 : ~ 140 ~: comparison ~ ~
13xample~ 3 3~û: 2,80 0 s,soo 8,000 12,000 17~ûbO 24,000 . ;, co~parison :~ - ~
Example; 4~ 550 2, 950 18, 0û0 ~ 18, aoo : : :
; l:

:

- 32 - 21~ 8~ i Q indicates the ratio of the free residual monomer (unit: ppm). ~ ?
ND indicated that the free residual - I -~ is not more than the det~ction limit o~ t.he equipment (2b ppm3.
Figs. 3 and 4 represent graphically the results of measuL. -. ~s shown in Tables S and 6. A~ shown in the figures, the elec~rically con~lctive polymer gel which does not include polyhydric alcohol but includes ~ucrose ::
(c~ r~son examples 3 and 4) were dri~d out in shorter period of time than the electrically ~on~ctive polymer gel which includes polyhydric alcohol (examples 3 and 5).
Moreover, ln c ~- r; son examples 3 an~ 4, as being dried, ~ ce instantly shows rapid in~rease as the gel was been dried. On the other hand, in ~mples 3 and 5, low impedance w~s ~aint~i n~ over long periods of t~e. The ~Yperiment~ prove that the electrically con~ctive:polymer : .:
gel of the~present invention enables elec~rical ph~n~menon ~o be mea~ured ~ore precisely o~er longer periods of ~Lme . t,~
c~mpared with the electric~lly conduc~ive pol~mer gel of acrylamide-sucroFt~-aqueous ~atrix. .
~he ratio of free residual ~n - ~Q) ppm in :.
compari~on examples 3 ~nd 4 reached ~4,000 - 18,000 ppm;
whereas, the ratio of the frae residual - . r (Q) ppm in , . . .
~rl es 3 and 5 was below the detection limit of the .~

' ' :' ' ,~ ' .

.;

2~06~9 device (20 ppm). The electrically conductive polymer gel obt~i~e~ by polymerizing and crossl in~ng the acry~Ami~e monomer blending solution was required ~hat the free xesidual ~ ~r ratio thereof was preferably lowe~ed below 100 ppm, more pre~erably below 50 ppm since the : .
a~ryl: ;~e ~ was regaxded as a spec;fic chemical ma~ l. The ~lectrically con~l~ctive pol~mer gel of acrylamide-sucrose-aqueous matrix in compAri~on examples 3 and 4 was not suitable for use in the organism; ~hereas, :
the electrically con~n~tive pol~er gel of the presen~
examples permits a highly safe use thereof.
,~ .

In lieu vf polyhydric al~ohol, ele~trolytic salt in~i example. S, the polymerization initiator of example 9 includes 6-5~ of C~ and 4~5 % o~ C3 as a polymerization initiator. O~her than the above, ~ha gel of ~he present. ;
:inYention is the sama as the pre~ious example. S~ rly, the impedance, a ~hange per day of the impedance, and a chan~2 pPr day of % by weight were measured. The results of measu c ~s are shown in Tables 7a a~d 7b.
Specifica~:Ly, the di~ferences of ~he pexcentage aompo6itions are as ~ollow : 4 ~ o~ sodium chloride in example 9; 4 ~ of sodium chloride and 40 % of diglycerol .:

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

2 8 .9 in example 10; 40 % of decaglycerol laurate and 4 96 of sodium chloride in example 11; 30 % o~ glycerol and 4 % o~
~;odium chloride and 10 % of magnesium chloride in e~ample 12; 4 % o~ - ~e~ium chloride in - 1 e 13; and 4 ~6 of pota~sium chloride in example 13.

TABLE 7a Impedance Change/Day of Impe~l~n~e Z ~zAgcl ZCFirstSecond Third Day Day Day E~cample 9 20 10539 75 114 237 Example 10 20105 39 103 231 Example 11 20105 39 130 299 - .-}3xample 1218 98 37 96 135 170 . - ~' 13xample 1325 12045 82 163 252 IBx~pl~ 22115 40 82 146 2~6 ~, :
.
~ .

, ~
''~,.' '.

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

TABLE 7b t'tTA~G~D~Y OF 96 B~r WEIGRq~ B~ DkY ~
Be~oreFirst Second Tqlird Drying Day Day Day Example 9 100.0 ~g.~ 83.3 79.3 Exiample 10 100 . 086 . 0 79 . 5 ~xii~nple 11 100 . 0 84 .1 77 . 4 Example 12 100.0 88.7 84.5 82.6 i~
E~cample 13 100 . 089 . 9 83 . 7 79 . 6 Fxample 14 ï00 ~ 088 . 9 83 .1 79 . 0 .:
' As described, diglycerol alld decaglycerol laurate ~ere used as polyhydric alcohol, and - ~n~sium chloride . .
and po~assium ~hl ~ri ~e (example lû l~ ~ were :used as:
~loctroly~ic 8 11:. However, as in ~e ca~e o~ ex~nple 9 t a great change~ per day of the împ~Ant~C~ was not obsen~d, .
: and low 1 ~)~'9nc9 was maintA~ne~3. D~b~e~Y~x, the obt~ine~
elec~rically conducti~e gel was Ilot dried out easily.

, - EXAMPLES 15 - 23 AND COMPARISON E~A~PI.ES 5 - 12 ~..
.
~ ea3ursments of the i ~ nce and adhesi~Je ~L~pel Ly were carried out with respect to elec~rically conductive polymer g els which includo the epQXy crossl ;nk~r (examples . .
:.

:

.
:

2~0~289 15 - 21) and electrically c~nflu~tive polymer gels which include neither the epoxy cross:Linker nor crossl inkin~
monomer (examples 22 and 23 and comparison examples S and 6) and electrically conductive pol~mer gels from acryl- ~~e-sucrose-aqueous series matrix (comparison ,~
examples 7 - 10) in order to ~l ~ri fy the di~ferences of electric ~.u~eriies and of adha~iv~ propertie~
~ ir3t, [~) % of 40 % acrylamide monomer aqueous ~olution (~s polymerizable ~ B) ~ of N~-methylenebi~acxylamide power (as cros~linkable :"
- ), (EP) % of the ethylene glycol diglycidyl ether (n=~2; 600 WPE) (a~ epoxy crosslinker), (G) % of glycerol ~hich is the polyhydric alcohol ~as the penetrant); and (S) % of sodlum ohloride ~as electrolytic salt) were prepared. ~hen, after ~ ng the remaining percantage co~posi~lon of water (as solYent) ~ the above materials were ~ xed so a~ to be dissolved. As a re5ult~ a ~;
colorless transparent ~-, - blPnAing solutiûn was . :j obt~ne~. .
Then, the ob~ine~ --t - b~n~ing solution w s :' mixed with Cl % of 4 % potassium pe o~odisul~ate agueûus solution tas the polymerization initiator) and C~ % of 2 ~
potassium ~y o~l~ite aqueous solut~on. Thereafter, a net was set as in pre~ious first example, and the ml~ture was ..:
i'.

_ 37 ~ 2 8 9 heated up for two hours at 85 ~C , thereby presenting an elsctrically conductive polymer gel having a thic~nes~ of 1 ~;~. ' Further, two paixs of circular samples with a diameter of 20 mm of the electrically condnctive polymer gel to which circular Ag/AgCl electrode elements with a diameter of 10 mm were adhered respec~ivel~ were prepared.
The respective gels were made in cont~c~ wi~h one another ~o as to form an electrode pair, and the ~ ~e~nce ZAgCl (okm) o~ the electrode pair was measured. S; il~rl~ two pairs of circular samples with a ~.~ -.Ler of 24 mm of the electrically co~ ctive polymer gel to which circular ~-cArhQ~ electrode elements.with a diameter of 20 mm ware adhered raspectively wexe prepared.. The respecti~e gels were made in cont~t with one another ~o as to form an ~le~L~o~e pair, a~ the impe~An~S Zlr ZAgCl a~d ZC (ohm) of ~he el~ctrode pair were mea~ured.
~ sing a 8ample of the electrically c~n~ ti~e polymer gel, an adhe~i~e (~) g was measur~d ~y vertiaal tensile :. ' testing ~the l~i n~ end of the Jig made of S~S has a cylindrical ~hape with a diameter o~ 12 mm), and using a sample (20 mm x 120 mm) r an adhe~ive (J~ g was mea~ured by 90~ p~A~ in~ test de~cribed in JIS adhesive tape and adhesive sheet testing Z0237-1980.
. ' .
,',;

'"',' ' : :
.:

- 38 ~ 6.~
,,,,~,.

~rhe respecti~e perce~tage compositions (A), (l3), ~ r (EY~, ~G), (S), (~j and (C2~ 96 o:E the eleckrically chn~ltctive polymer gel are changedL as in the example~ 15 - :
21 of Table 8, and impe~i~nces Z l t ZAgCl and ZC ( ohm) and adhesi~es (~;) g and (L) g were measured. Simultaneously, the ratio o~ the fr~e residual - ~ - (Q) ppm were mea~ured by thS~ EIPLC. The re~ults of msasu ~ - L9 are shown in Table 9. :

.
~ABLE 8 COl~POSI~ION q~ABLE
~. .
A B E~ G S C1 C~ ,.
}:xample 15 33 0 . 015 0 .10 50 2 . 0 5 . 0 4 . 0 E:xampl~ 15 40 0 . 015 0 . 12 45 3 . 0 4 . 0 4 ~:xample 17 450 . 015 0 .14 35 4 . 0 4 . 0 3 . û
Example 18 600 . 015 û .16 25 .5 . 0 3 ~ 0 3 . O
~:xample 19 . 33 0 . 020 0 .14 30 6 ~ 0 5 . 0 5 . 0 Example 20 400 . 020 0 .16 25 8 . 0 4 . 0 4 . 0 Example 21 450 . 020 0 .18 30 6 . 0 4 . 0 4 . 0 ....
.,~ .

_ 39 ~ 2 ~ 9 Impedance ~dhesive Z 12AgCl ZC ~; L Q
Example lS 65 83 37 380 . 103 ND
}:xample 16 50 88 40 423 126 ND
Example 17 42 91 42 448 2i7 ND .
Example 18 38 102 45 351 189 ND
Example 1$ 28 93 35 362 78 ND ~:
13xample 20 26 84 27 373 1û2 ND
Example 21 42 89 38 40~ 135 ND
- : .
In the abo~ve Table, ND indicates that the detec~ion : .
limit of the eqUipmeDt is not m~re than ~0 ppm. :
q~3he respective ~elce~l,age compositions (A), (B), (EP3, (G3 ~ (S~, (Cl ) and (C2 ) % o:f~ the electrically :.
condllctive polymer gel were ch~rlged as showrl in Table lO , and ~ nC98 Z 1 J ZAgCl and ZC ~ o~un) f the ratio of tha ~ree residual monomer ( Q ) ppm of the gel which does not inrlude the epos~y ~05~ nkP~r in accordance with examples 22 and 23 aIld o~: the gel which doe~ not include ~
methyl~n~ r~Aqcrylamide . a~ a s:ro~sl i nk~hl e mono~ner in ~ ;
accordance: with ~ on ,- _ 1 cas 5 and 6 qnd ~he~i~es ~ :
(~3 g and ~L3 g ~re measured. The results o~ the ::
:
~: measurement~ are a~ ~hown in Table 11. ~; .

_ 40 ~ , 8 9 q~ABLE 1 0 CONPOSITIO~ T~E

A B EP G S C1 C 2 .
Example 22 330 . 020 0 505 . 0 5 . 05 . U
~le 23 450.050 0 404.0 3.0 3.0 Comparison , ' Example 5 33 0 0.10 303.0 4.0 4.0 : 7 Ct~w~rArison : .
E~ample 6 45 0 ~ 0 . 18 20 2 . 0 5 . 0 5 . 0 ,;

~.'.

~mpe~l~nce AdhesiYe , . i ~ 1 ZAgiCl ZC K L ~i . B .
Exa~ple 22 62 . 127 5~ 1~8 32 i Example 23~ 38 102 37 135 27 ~ ' .
: ~ ~Compari~on no gel ~, Exa~ple 5 ~ ob~ e~ ~ ~
.
::Cc ,.-risvn no gel ~.Y~mrl e 6 ~ obt~ etl ,.
:
~: : ~ ' ' ;' ~, : ' ' : :
, . .
. .

.

! .1 8 9 ~1 :

~ ext, electrically conductive polymer gels from the acryl~m~e/sucrose series are manufacLuled (comparison examples 7 - 10~, and i ~ nces (Zl), (ZAgCl) and (ZC) (ohm) nd adhesives (K) and (~) were measured.
First/ (A~) ~ of 100 % acrylamide monomer powder (100 ~ pure) a~ a polymerizable mono~er, (B) ~ of N,N'-methylenebi~acrylamide powder ~as cro~s~ink~hle ~ er), (~) ~ of sucrose powder a~ a tackifier were prepared, and after ~;n~ (W~ % of water, the a~ove materials were ~ixed so as to be dissolved, thereby ob~i n i ng a ~on~ - bl~n~; ng solution~ Then, the obt~ine~
--I - blendin~ solution wa~ mi~ed with (Ca ) ~ of 2 %
potassium peroxodi~ulfate aqueou~ solution (as the poly - ~~tion initiator) and (C~) % of 2 %
N,~,~'r~'-tetramethylathyl~n~ ne agueous solution are ~ ~dded and ~i~ed. The mixture was polymerized and ~cro~slinked ~ox one hour at room te~.~e~ule, there~y ;i obt~i n ~ n~ an electricall~ conductive polymer gel having a ~
: thickness of 1 mm.
The respective percentage ,_- ositio~s tA33, (B), ~M) : ~ (W~, (Cs) and ~C~ ~ of the electrically conductive polymer gel are changed a~ in the c~ ,- ri ~on examples 7 -10 of Table 12~ and impedances Z1t ZAgCl and ZC (ohm) and -adhesive~ ~) g ~nd (~ g were measured. Sim~ltaneously~
:
,. ,', ':
-, - 42 ~ 89 the ratio of free residual monomer (Q) ppm were mea~ured by a high ~peed liquid type chro:matograph~. The resul~s of m~asurement~ are shown in Table 13.

TAB~E 12 COMPOSITION ~BLE

A3 B M W ~ a C ~. ;
Comparison . .
Example 7 15.0 0.04 25 57.46 1.0 1.5 Comparison . i Example ~ 15.6 0.042 26 55.86 1.0 1.5 Co~parison Ex~mple 9 15.0 0.03 33 49.47 1.0 1.5 C~s~n r---, l e 10 15 . 6 0 . 031 3~ . 3 47 . 57 l . 0 1. 5 '~ ' ' ' "
''' .

,'.
.....

_ 43 ~ 6~

~l~BL~3 1 3 Residual Impedance Adhesive ~r__ Z IZAgCl ZC :g L Q
C n,, -ri SO~
Exam~la 7 360 650 37 112 21 24, 000 Compari~on ~xample 8 370 680 400 124 25 22,000 Comparison rle g s50 830 570 137 32 18,000 , C ri 80n Example 10 570880 600131 29 18, 000 .
., . , :' ~rom the results of the mea~ ts, in examples 15 -21, the imre~l~nces Z I, ZAgCl and ZC t ohm) ar*
respecti~ely in r;~tn~S o~ 26 o}~ to 6~ ohm, of 83 ohm to 1~2 ohm and of 27 ohm ~o 45 ohm. Sin<:e the }nea~lLred:
m~ e~Ances are not signi~ica~tly dif r~n~ from *he ~po~n~e8 ~ AgCl ancl ZC ~ohm) o~ examples ~2 and 23, it is p~ d that th~ epo~ crossl 1nk~r doQ~ not afIect . .
the e}ectrical l!. o~ ies.
On the other hand, adhesives (x) g and ~ of ;. . .
.
examples 15 :- 21 are raspectively in a range o~ 351 5;1 to 44~ g and of 78 g to 217- g, and adhesives (:~) g ahd ~II) g ,;
of compari~on 4:~amples 7 - 10 are respectively in a range ; ~:
o:E 112 g to 158 g and of 21 g to 32 g. q~he results of ~ .

.

_ 44 - 2~ ,8~

~Yp~'~; ts show that the adhesive of examples 15 - 21 is more that double the adhe~i-re of conlr~rl snn examples 5 -12. Thus, the electrically cnn~luctive polymer gel of the present: ~-r~; ~ L which indudes epoxy crossl ;nk~r has a ,~lL~pe~ Ly of high acUlesive while main~i n;n~ low; ~-'Ance.
~ h~ ratio of the free residual monomer (Q) ppm in c~mpari~on examples 7 - 10 reac:hed 18,000 ~ 24,000 ppm;
whereas, the ratio o~ the f ree re~idual - ~. - ( Q ) in ~ le5 15 - 21 is below the detecltion limit of ~he de~r~ ce ( 2 0 ppm ) . Theref ore, the slec:trically conductive polymer gels of acrylamide-sucrose-a~ueous matrix in c~nmr~ri son examples 7 lO are not suitable for use in the org~n i .~m; whereas, the electrically con~ncti~re pol~mer gel of ~he p~e~enL axamples pennits a~ highly sa~e use thereof in the organism.

.
E:~AMPLES ~ 4 --2 7 In ~ es 24 - 27, di~ferent penetrants are used:
glyc:erol (~ - r, le 24); glllco~a as a pene~:ant (example 25); ~ructose (example 26); and sucrose ~e~ample 27~. The reqpective percentage composition (A), (B), ~EP), (G3, Cl) and (C2) % ~ oi~ the electric~lly conductive polymer gel w~3re ehanged as shown in table 1~, and ' ces Z 1 J ZAgCl and ~ (ohm), adhesives (R~ g and (I,) , , " ;,,, ""-, , ~ .: ""
., . .~ .... . . . . . .
: I : : I,, f, . - ' , , -- 4 5 -- 2 1 &~ 8 9 g, a change per day of weight % by drying and a change per day of i ~ nce were measured. The results of mea~ ~ ~ ts axe shown in Table5 15a - l5c ~ -~BLE 1 4 CO~IPOSITION ~ E

Examiple 2445 0.015 0.14 40 4.0 6~0 4.5 Ex2mple 2545 0 . 015 0 o 14 40 4 . 0 6 . 0 4 . 5 Bxample 2645 0 . 015 0 .14 4~ 4 . 0 6 . 0 4 . 5 ~xample 2745 0 . 015 0 .14 40 4 . 0 6 . 0 4 . 5 ~ABLE 15a . ~, ' Rbility Befora Drying Adhesi~e Z 1Z~gC:l ZC X L ~
~:x~iple 24 20 1053~ 450 198 l ~ 2~ 20 105 39 432 lS9 .
::
Example 26 20 105 39 418 192 E~ample 27 20 . . 98 37 428 190 , ,~
'.

. ,:
' ' .,:

,.

- 46 - 21 ~89 ~ABLE 1 5b Change~Day of WQight 96 by Dryiny Before First Second Fifth l:)rying Day Day Day Example 24 100 . 0 89 . 2 83 . 3 79 . 3 Example 25 100 . 0 83 . 8 77 . 9 70 . 8 Exa~nple 26 100 . 0B2 . 2 76 . 5 73 . 4 Example 27 100 . 0 83 . 6 78 . 6 75 .1 TABI,E 15 ' Change~Day of T _-~Ance ~irs~ . sec~ hird ~ :
Day Day l:~ay .:
132ample 2476 152 . 246 E~camplç~ ~5 : 138 ~ 286 690 .
13xampl~ 25 168 341 500 :
Example 27 141 262 405 '.

~ ' ,', , ~ ,:
: ; . ~

- :
, :.,.. ; .:. ;, :. . . . ,.: , ::
- , , , .,, . ! -- 47 - 2~ ~6~89 The electrically ~ondl~ctiYe polymer gels in which glucose, fructose and sucrose were respeckively used as penetrant in lieu of gl~cerol ~how approximately same adhesive as the eleckrically co,nductive polymer gel in which glycerol was used. Howevler, the differences are sig~ificant in a change per day of ~ by weight by dr~in~
and in a change per ~ay of the ~ ,~f~nce, and the electrically co~uctive polymer gel which contains glycerol i~ the be~t followed ~y that contains sucro~e, fructose and glucose in this order.

Impedance measurement~ ~re carried out with respect to electrically cn~nctive poly~er gels which include~ the tallic io~ se~ d (ex~mples 28 37~ and electrically con~lcti~e polym~r gels which includes no metallic ion sealing cvmpou~d (s~rles 38 and 39) so a~ lI't' to clari~y th~ dif~erences of ele~tric propertie~ and of corrosivi~y.
Firs~, (A) % of 40 % acryl A~l de ~ - aqueou~
~olution as polymeri~able monomer, (B) % of ~N'-me~hyl~bi~A~rylr i~ powder (as cro~ nk~hle mo~omer) ~ ~G) ~ Of glycerol (polyhydric alcohol~ as cenetr~t, (S~ ~ o~ ~odium chloride as electroly~ic ~alt, ;~

, .' ' ':

y ~

_ 48 - ~.0~289 ( I ) % of benzotriazole or tolyltriazole as a metalli~ ion se~ ng ~ ~ d were prepared. ~t~r ~ n~ remaining wt % of water as a solvent, the abo~ m2t~r;i~1~ were ~xed so as to be dissolved, thereby ob~A~nin~ a colorless ~ransparent ~ b] ~n~; n~ solution .
Then, the obt~ i ne~ blending solution was mixed with (S~) % of 4 % potas~ium ye~ odisulfate aqueous solution (a~ the polymerization initiator) and (C~) 96 of 2 % pota~sium pyrosulfite aqueous solutioTI,, and a net is set in the same -nn~r as the example 1. Thereafter, the mixture was heated up for two hour~ at 85 ~C, thereby manufacturing an electrioally con~ctive polymer gel havillg a t-h ~ ckn~ss of 1 n m .
~ e~t, two pairs of circular ~ample~ with a ~ l.er o~ 20 mm of the electrically c~ucti~e polymer gel to which circular ~g/A~Cl electrode elements with a diametar of 1~0 ~ were adhered respec:ti vely wsre prepared . q~he respecti~e gels were made in contact with one another so as ~ to form an electrode pair, and the impedance ZA~Cl (ohm) o~ the3 electrode pair was maasured. Similarly, two pairs of c~ rcular ~amples with a cliam~ter o~ 24 mm of the electric:ally co:nductive polymer gal to which circular cArbon elec~J..ode elemen~s with a ~ Ler o~E 20 mm were adhered respecti.~ely were prepared. ~he respective gels ;

"

:: :

- 4g - 210~89 were made in contact ~ith one another ~o as to form a~
electroda pair, and the impe~nces Z1, ZAgCl and ZC ~ohm) of the electrode pair were measured.
The sample of the electrically con~l7ctive polymer gel was lr- in~ted on the ~ ilver cube, and left it at room t ~ tuxe and humidity (25 ~C and 50 %). Then, after 24, 48 and 168 hours, the state o~ the germansilver and the change in color of electrically con~llcti~e polymer gel and Germa~ sil~er were observed. The observed sta~es are classified into five s~age~- nA~ no cha~ge was observed; "B" ~ubtle change was ob~e~ved; "C" a mark slightly remains on the germansilver and the gel ~lightly changed in color; ~D~ a mark remains on the gexmansilver and the gel changed in color. Addit;on~lly, when the gel wa not ~an~.a~ed and thu~ mea~u~ could not carxied out, it is dsnoted as no gel generated n~
: The respective ~e.centsge compositions (A), (B), ~Ç3, (S), (I~, (C1) and (C a ~ % of the electrically conductive polymer gel are changed as in the exampl~s ~8 - 39 of ~able 16, and i~pe~n~es Z1, ZAg~l and ZC (ohm) and ~o~ si~ity-were measured and observed. The results of ~measurements are shown in ~able 17.

: .
" , ,~ "
.~

'~
. , , so 210~89 COMP05ITIO~ TA13LE

A B G D E Cl Cq ;Imrle 28 33 0.10 30;3.0 0.1 5.05.0 Example 29 45 0.10 25~.0 0.5 5.05.0 pl~ 30 60 ~.10 208.0 1.0 5.05.~
~YA~r1~ 31 33 0.05 506.0 1.5 4.54.0 Example 32 45 0.05 404.0 2.,0 4~54.0 ~xample 33 S0 0 . 05 20 4 . 0 2 . 54 . 5 4 . 0 r ~le ~4 30 0.06 40~.0 5.0 4.54.5 ~x~unple 35 35 ~.~? 402.0 lo.o 4.5. 4.5 E~ample 3~ 33 0.05 50~.0 0.05 4.54.0 ;q~rle 37 33 ~.05 3~6.~ 15.0 d~.54.0 ~a~nple 38 45 0 . 05 40 4 . 0 0 . 04 . 5 4 - 0 Bxample 3g 60 . 0 . 05 20 6 . 0 0 . 04 . 5 4 . 0 ~ : .

: ' ~: : , _ 51 - 210~89 ., IMPEDANCE

Z 1 ZAgCl ZC Corrosivity ~1. B .
Example 28 22 10841 ES ; !
Example 29 26 li247 B
r~ e 30 33 13558 A
Example 31 61 18760 A
Example 3 24 0 1134 0 A
Exam~?le 33 25 89 28 . ~ .
:Exaraple 34 61 18073 P~ ~ .
~xample 35 77 1898S ~
rl:e 36 62 177~9 C :
Exa~ple 37 ~ no gel :obt;~ i n e 38 36 97 29 D
Examplo 39 40 128 51 D
:~ : ~ : : .

. ~

, . .
:: :

. : . .~, ~: ~
..

- 52~ 289 From the results of the mea~u ~ t~, in example~ 28 - 37, the impedances Z 1, 2A~3Cl and ZC ( ohm) are respectively in ranges of 22 ohm to 77 OhmJ of 89 ohm to 18 9 Ohm and of 2 8 ohm ~to 8 5 ohm . Since the measured i~re~lAnc~s are app:roximately ~he same as the imrer1~nce~

Zl~ ~AgC~l and 5,~ tohm) of ~- _les 38 and 39, it i~ v-ad ~hat ~he matallic ion seAl ing compoulld has no effec~ on the electriciill properties. ~5 ~or ~orrosi~rity, the corrosivity in examplQs 28 - 37 was ~A~ o~ NB~ ~ Whereias~
the corrosi~ity in examples 38 and 39 without the metallic io}l seAl ~n~ C~ ulld wag nD" ~ The experlment ~c,ved that the metallir: ion ~e~ g c, _ aund - i u~ ve3 the co~ ~ osivity.
Additionall~, when the metallic ion ~ 1 in~ c _ _u~d was et to 15 % (example 37), no gel was gener~ted, and when the mëtallic iorl 8~ in~ compolmd was ~et ~o 0.05 ~
e 36), the c.~ ivity wa~ "cn. Thus, the ~tallic ion se~ 1 î ng ~ und i~ p~e~erably ~et within a rang~3 of :0.05 96 - lS % by wsight ~n order ~o manllfact~lre ~he electrically conductive polymer gel having d~sirable corrosivity .

E~LES 4 a - 51 Impedancc, corrosi~r1ty and adhesi~ o~e L~ l.y were _ 53 - 2~ g9 measured and observed with respect to electrically con~ltctive pol~mer g~ls whioh islclude~ the metallic ion ~ 11 n~ u-~d and adhesive properties ~hereo~ is i~creased by ~he epoxy crossl ink~r ~e~amples 40 - 47) and with respec~ to electrically con~lctive polymer gels which include~ no m~tallic ion se~1 ~n~ C~ ~.und ~examples 48 -51) so as to clarify the differen~es o~ electrical property, corrosivity and adhesive pLopeL~y.
First, wt % of the polyethylena glycol diglycidyl ether (n ~ 22;600WPE) was added ~o ~he monomer bl~n~;n~
~olu~ion ha~ing ~e~ce.~age composi~ion~ of (A), ~B), (~), ts~ (I), (C1) and (~ a8 8hown in Table 1S. ~hen, the electr~cally conductive gels of e~ J es 40 - 51 were manufa~LuLed a~ in the same manner a~ exa~ple l, and i~r~ C~ z 1, ZAgCl and ZC (ohm) and col~osivity were ~mea~ured and ob erved. As to corrosivi~y, the state of the ele~t~ically conductive polymar gel i5 deno~ed as corro~ivi~y 1 and that o~ electxode of ge- n~ilver ~or organism i~ denoted as corrosivity 2. The rQsult3 of ~ea.~rYment and obaerv~tioh ~re Yhown in Table 19.

' .,' ' , :; . ' i' ''' ~,,.

- S4 - 2~ 9 COMPOSITION T~3LE

A B G S I Cl Cq EP
~:xample 40 33 0~015 50 2.0 3.05,0 4.0 O.10Exampl~ 41 400.015 45 3.0 2.0 4.04.0 0.14 Example 42 450.018 40 4.0 1.0 4.n 3.û 0.I8 Example 43 600.018 25 5.0 0.5 3.03.0 0.16 E:xampl~ 44 33 0 ~ 020 3~ 6 . 0 4 . 05 . 0 5 . 0 :~cample 45 400 . 020 25 8 . 0 5 . 0 4 . 03 . 0 0 .16 Exampl~ 46 ~50 . 020 30 ~ . 010 . 0 ~ . 0 0 ~ 18 _le 47 330.02û 50 5.0 0.1 5.05.0 0.10 _~ 48 ~50.020 40 4.0 0.~ 3.03~.0 0.12 49 330-0~0 30 3.0 a.o 4.0~.0 0.14 ~rle 50 ~~00.015 40 4.0 0.0 4.û 4.0 0.1~
Example 51 450 . 015 30 2 . 0 0 . 0 5 ;05 . 0 0 .18 . ' ,, ' , '.
:, ' .
, , :: . ' ~' ' ' ,, .

_ 55 ~ 6 2 8 9 .

TAB~E 1 9 IMP3 :DANCE

Corro- Cvrrs-z 1 Zagcl ZC I N sivi~?~ 1 8i~rity 2 r 1~ 4065 95 40 382 109 A A
Example 4148 97 42 4~5 129 A A
:E:xample 42 43 103 45 450 207 A ~ ,,.
Example 4336 115 ~7 355 191 A A
Example 4430 106 38 364 80 A A
Example 4538 94 27 377 108 ~ ~ ~
Example 4642 100 40 408 137 ~ ~ A
13xa~nple 47 62 92 56 357 77 C C
.
i3xample 4837 sa 41 359 93 D
xal~ple 4935 87 : 40 360 :75 D C
;
B~pl~ 5~~ 3889 40 36~ 111 D C
Exampl~3 51~:3993 ~51: ~389 137 D ~ ~ C

.
. . .

From the results of the meas~ t~, in examples 40 - 47, the impedances ~~, Z~lgcl and ZC (ohm) are respecti~ely in ranges of 30 ohm to 65 ohm, of 82 ohm to 115 ohm and of 27 ohm~to 56 ohm. Since the mea ured imr~noes are approximately the same ~s the ~ Anc~~
Zl, ZAg~l and ZC (ohm) of examples 48 - 51, it i~ ~Io~ed that the e~istence and amount of the me~allic ~on s~l 1n~
o~mpound have ~o effect on the electrical properties. The adhesives (L) g and (~) g o~ the gels in examples 40 - 47 are re~pectively in ranges of 355 g to 450 g and of 77 g to 207 g. Since the mea ured adhesive properties are appro~ima~ely the same as the the adhesives (~) g and (~) g of examples 48 - Sl, it is ~loved that the existence and amo~n~ of the metallic ion se~ling co~pound have no e~ect on the electrical pxvpQrties o~ the electrically co~ ctiYe polymer gels including ~ e epoxy cro~ n~
As ~or corrvsi~ity, the coll~sivities l and 2 in examples 4G - 46 were ~A", wherea~, those in examples 48 51 witho~t the metallic ion ~e~lin~ ~ompound were "C" or ~Dn ~ The exper~m2nt ~ov~d that the metallic ion 8eAl lng compound improve~ the corrosivity. Addi~-~on~lly, when ~he ~talllc ion se~ling ~c ~ ~nd wa~ set 0.1 ~ (example 43), the co~l~sivity was ~C~ . Thus, ~he metal~ic ion se~l; n~

:: ~
c~ und is p:referably set above 0.1% in order to ' . : : . .
,:

. .

: ~ , - 57 _ 8 ~

manu~acture ~he electrically co~n~tive polymer gel having desirable corrosi~ity. ~,~
As described in detail abo~e, the electrically ~ conducti~e pol~mer gel of the present in~ention includes ~ ~
large guant~y of water and polyhydric alcohol as ma~or i.-~ - e~ts and electrolytic salt in the polyacrylamide ~.
ssr;e~ polymer. Thu~, ~he gel itself shows low i~re~Ance.
The electrically conductive ~ol~mer gel is u~ed as an org~n1 ~ u~e ele~L~d3 by formin~ it to ~dhere to an electrode ele~ent to be one integral part.
The polyacrylamide series polymer has ~o~elLies o~
hydrophilic and nonal~ctrolyte. Thus, electric repulsion ~eL~_cn the polyacrylr ifle series poly~er and metal series ele~ ude el~en~ are not likely to occur ~nd imre~nce on '~
. -. .; .
the contact in~er~ace will not inc~ease much. ~en if an ;:
~ de g~oup ~ n~u~ralized in . gel bcdy ~nd proton ~hift . . .
OC~ ho 8y~t~m of reaction ~ esent~d by ~ e ~ .
following ~ormu1a can be inferred be~ n th~ ~el and a , . m~tal (s~ch as Ag~ of the ele LL~de ~lement. . ~: .

n R--C -NH z + Ma~ C-NH ) M H

k1~k~ ' '' ': ' :

.:
:; , .
.

~. : ., . . .: . .. '. ~ '. . -- 5B - 2106.~89 ~ hus, the electrica:l ly conf1uctive polymer gel of the pre~ent in~ention has th~3 following ad~rantageoug characteri~ics: the impedance l:h~reof i~ low; a tlssirable electrical contact can be achieved with ele~;l.Lode ~
and the ~ e~nce as a whole is low. With ~he proper~y of low ~ nce, thz electrically con~ucti~e pol~mer gel p~rmits accurate measu~ ~ t even with weak elec:tric signal.
According to the electrically conductive pol~ner gel of the present invcntion, since the polyhydr~c alcohol in the gel lowers the drying speed o~ the gel, an incre~se in the i~ ?ed~nce as drying . out can be ~L~vel~ted- As a resultr the electri cally con~luctive pol~ner g~l o~ the present invenkion permits arl accllrate mea~u~. ~ t of an electric pheno~enon generated in org~n i s -, etc ., under longQr p~rics~l~ of use.
~: The ele~:tr~ cally ~on~ tive polymer gel o:e the present i~en~ion i~ composed of a polyacry~ e ~eries polymer cro sl inkPf~ at leask b~r an epoxy cros~ k~r~
which includa water, penetrallt and electrolytic salk uni~ormly dissolved thexein ~ the water and the penetrant being ma~or co~nponents o~ the polymer gel. The eI0c~rically con~luctive, polymer gel is used. as an - , org~ RT~ use electrode by ~orming it to adhere to an ::

,, ,; . i; , .. ' . : ' ; ' ,' ' . .. ,.,, . ' ' . ' , :', . , . , . . , ,, ! ,' . . . .

_ 59 21.06~89 . .
ele~trode element to be one integral part. lIo~eov~Y, as . ~L~s~nted by the following chemical fc ~-1 A f khe electrically conductive polymer gal of the presenk in~rention permit~ an ad~us 1, of the crossl ink;n~
distance with the u~e of arl epo~ cro~l ink~-. ThUs, ~esirable vl~co~ity and ~esiva ~Lo~ y of the electri~al}y conductive poly~er ~ 3l can be achieved.

.; ' CONH~ { CC)NH ~ CON
~ C-- = C~
O C-OH O ~ t::-OH~2 '' ,.~.

.~. ', ~ er~ore, a~ a ~esi~hle contact ~et.. ~he gal aIld an el~el,Lod~a ele3llen~ can be achie~ed, a~ ~c~r~te ~ea ~ --t ca~a b0 cs~ e~ out :fro~Q a~ ob~ecti~re of the . .
~easuremen~ ~ch as a 6kin ~ur~ace without re~n~i nq the ~egree of ~reedorA of a target org2nisml .
:.
The electrically conduc:ti~re polymer gel of the ~, prasent: in rention may ~~er include a metallic ion ;;
~39~ 3 c L ~ which }las vapor pres~ at room te~mperature. ~he electrically con~ eti~e polymer ~el is .

:

.~

_ 60 - 2~ 9 used as an org~ni~ use element b~y fo ;n~ it adhere to an electxode element to be one integ:ral part.
Moreo~er, the metallic ion sealing compound of the electrically conductive polymer gel seal~ the metallic ionJ the corrosion of ~he electrod2 element can be .:
.e~nLed. There~ore, since PlectromotiYe force genexated due to corrosion c~n be ~l~v~..ted, o~u~le~ce of.erro~ due to the ele~L~ ~Live ~orce will not occur. This permits the organism-use electrode to be repetitively used or u~ed ~or long p~rl o~ of time. i1O~eoveL, the gel can be used by ~r ~ n~ it to adhere to the elecL~de eleme~t beforehand.
More spe~fically, in the case where benzotriazole is u~ed as a metallic ion Se2l ing Cl ~ d and CO~PeL i6 inclu~ed in the electrode element, since ~he benzotriazole a~ a metallic ion se~l~ ng compound has wapor pressure at around room t _- ~ture, the benzotriazole serves as a ru8t ~r~van~ive. Thus, the coppeL is ionized, in the same t ~Q, the co~pel he~~ --e cupric be~zotria~ole, ~hereby forming a transpar~nt molecular coat on the elec~ode ~;
el2ment surf ce. Since a ~orrosive envi~ t is shut ,;.
of~ ~y the molecular-coat, a change in color ~hereo~ in~o v~rdigr$~ can be ~seven~ed.
~ s aforementioned, according to tha method for ' .
: .
.

.
, i .

-- 61 - 2~289 man~lfac~uring the electrically conducti~e pol~mer gel o~
the present inventîen, the electr:Lcally con~lctive polymer gel is ob~ ed by polymerizing and crossl in~in~ the ~ - blending solution ~ncluding at least acry~ e series polymerizable ~ r, crosslin~hle monomer, water, polyhydric alcohol, penetrant and e}ectrolytic salt. The monomer ~l~n~in~ solution may include an epoxy crossl~nker and metallic ion ~e~l;n~ ce~ d.
Since the -~ hl~n~ing ~ol~tion includes water, each ~ , ~nt i~ the solution can be uni~ormly dissolved ~herein. The polymerization a~d crossli nki n~ reaction~
occur by applying heat or pro~ecting electron beam or .. ..
light. ~hus, the gel can ba ~nllf~cLuled in relatively . .
simple ~nn~. Additionally, if the ~e~c~nLage c~ nt of water 18 set just enough for bl~n~in~ other componen~s, the :slectric~lly condl7c~ive polymar gel can be used ::wi~hou~ after ~reatment, i.e~, taking out an excessive ~ ~ :quanti~y of water a~ter po7~ri~ng a~d cros81~nk~n~
~ ~: reAction8.
The org~ni- use electrode element usi~g the : ~ ~ electrically conductive polymer gel of the present : invention pe~mits an accurate mea~ur~ment under longer ~::periods of use. Since the corrosion of the electrode ele~ent can be ~l~vented~ the electrode el~ment can be .. ~.
,!
rl ' 7~, ~: : ' ' 6~ - 2~7~9 , used for longer time or repetitively u~ed without measurement errors. Moreo~er, the electrode element using the ele~trically con~uctive pol~mer gel of the pre~ent in~ention is suitable as a org~ni! use element for its excellent ability to adhere to the ~kin of the organism.
The inven~ion being ~hus descrlhe~ will be obvivus that the same way b~ ~aried in many ways. Such ~riat.ions are no~ to be regarded a~ a depaxture from the spirit and ~cope of the invent~on, and all isuch -~ification a~ would be obviou~ to one 6~ille~ in the art are i~ended to be included within the scope of ~he following cl~im8- ~

~'~," ,'.
~, .

, ' , .

.
j' ' ' : " .

:: '', :. ''.

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

Claims (19)

1. An electrically conductive polymer gel composition comprising: 13 to 25 weight percent of a crosslinked polyacrylamide polymer, a mixture of 20 to 65 weight percent of a polyhydric alcohol penetrant and of water, and 2 to 15 weight percent of an electrolytic salt uniformly dissolved in said mixture, all percentages based on the weight of the entire gel; said mixture of water and said polyhydric alcohol penetrant being the major component of said polymer gel.

2. An electrically conductive polymer gel composition as set forth in claim 1, consisting essentially of 13 to 25 weight percent of said polyacrylamide polymer; 20 to 65 weight percent of said polyhydric alcohol; 20 to 65 weight percent of water; and 2 to 15 weight percent of said electrolytic salt.

3. An electrically conductive polymer gel composition as set forth in claim 1 or 2, in which the polyacrylamide polymer is crosslinked at least by an epoxy crosslinker.

4. An electrically conductive polymer gel composition as set forth in claim 1 or 2, in which the polyacrylamide polymer is crosslinked by at least an epoxy crosslinker, and the epoxy crosslinking causes said gel to have improved adhesion as compared to the same composition in which the acrylamide polymer is otherwise crosslinked.

5. An electrically conductive polymer gel composition as set forth in claim 3 or 4, wherein said epoxy crosslinker is about 0.05 to 0.3 weight percent of said composition.

6. An electrically conductive polymer gel composition as set forth in any one of claims 1 to 5, including a metallic ion sealing compound which has a vapor pressure at room temperature.

7. An electrically conductive polymer gel composition as set forth in claim 6, wherein said metallic ion sealing compound is about 0.05 to 15 weight percent of said composition.

8. An integral unit comprising an electrically conductive polymer gel composition as set forth in any one of claims 1 to 7, adhered to an electrode element.

9. A sensor element comprising an electrically conductive polymer gel composition as set forth in any one of claims 1 to 7.

10. A solid electrolyte solution comprising an electrically conductive polymer gel composition as set forth in any one of claims 1 to 7.

11. A method for manufacturing an electrically conductive polymer gel composition comprising: polymerizing and crosslinking a monomer blending solution including 20 to 65 weight percent of a polyhydric alcohol penetrant, an acrylamide polymerizable monomer, a crosslinkable monomer, water and 2 to 15 weight percent of an electrolytic salt;

wherein the combination of said water and said polyhydric alcohol is the major component of said polymer gel composition.

12. A method for manufacturing an electrically conductive polymer gel composition comprising: polymerizing and crosslinking a monomer blending solution including an acrylamide polymerizable monomer, a crosslinkable monomer, 20 to 65 weight percent of a penetrant, water, 2 to 15 weight percent of an electrolytic neutral salt, and an epoxy crosslinker.

13. A method for manufacturing electrically conductive polymer gel composition as set forth in claim 11 or 12, wherein the components of said gel composition comprise: 13 to 25 weight percent of said acrylamide polymer, 0.001 to 0.3 weight percent of said crosslinkable monomer, 20 to 65 weight percent water, 20 to 65 weight percent of said penetrant, and 2 to 15 weight percent of said electrolytic salt.

14. A method for manufacturing an electrically conductive polymer gel composition as set forth in claim 11, 12 or 13, including polymerizing and crosslinking the monomer blending solution at a temperature range of 50°-90°C.

15. A method for manufacturing an electrically conductive polymer gel composition as set forth in claim 11, 12 or 13, including polymerizing and crosslinking the monomer blending solution for 1-2 hours at a temperature range of 40°-90°C.

16. A method for manufacturing an electrically conductive polymer gel composition as set forth in any one of claims 11 to 15, including polymerizing and crosslinking the monomer blending solution disposed between a pair of thermal plates positioned to heat said monomer blending solution from both surfaces.

17. A method for manufacturing electrically conductive polymer gel composition as set forth in any one of claims 11 to 16, including polymerizing and crosslinking the monomer blending solution while having a net-like reinforcing material submersed in or placed on a surface of the monomer blending solution.

18. A method for manufacturing an electrically conductive polymer gel composition as set forth in any one of claims 11 to 17, wherein said monomer blending solution includes metallic ion sealing compound which has a vapor pressure at room temperature.

19. An electrode system comprising an electrically-conductive polymer gel composition as defined in any one of claims 1 to 7, and an electrode element in electrical contact with said gel and adapted to make contact with an organism through said gel.