Electrode composition for electrolysis of water

This invention relates an electrode composition for electrolysis of water, which is comprised of a panel of which one surface is made from electric conductive material and another surface is made from non electric conductive material. Plural holes are bored through said panel, and two said panels are arranged so as to hold a diaphragm between the surface of non-electric conductive material of each panel. And electrolysis reaction occurs at outer side of an anode and cathode of said electrode composition.

BACKGROUND OF THE INVENTION 
This invention relates to an electrode which is used for electrolysis of 
water or water which includes electrolytes, and more particularly relates 
to an electrode for electrolysis to produce acid and alkaline ionized 
water. 
DESCRIPTION OF THE PRIOR ART 
A method to produce acid and alkaline ionized water by electrolysis of 
water or water which includes electrolytes is a well-known technique. And 
by using this technique, a manufacturing method of healthy drinking water 
or germ-free water is becoming popular. Many methods and much equipment 
has been proposed in the prior art, such as Japanese patent publication 
4-28239 and, 4-57394, Japanese Laid-open publication 6-47376, 6-55173 and 
6-246268. Construction of an apparatus for producing ionized water is 
characterized as installing a cathode and an anode in water or water which 
includes electrolytes with a distance, and, separating the two electrodes 
with a diaphragm disposed between the two electrodes. 
Usually, to perform at high electrolysis efficiency, the distance between 
the cathode and the anode is designed to be as short as possible. As an 
electrolysis reaction occurs at the surfaces of the two electrodes in 
water or water which includes electrolytes, acid and alkaline ion and 
gases are generated in two narrow spaces between the electrodes and the 
diaphragm. To obtain high electrolysis efficiency, the generated ions must 
be dispersed smoothly into water, or water which includes electrolytes, 
and the generated gases must be diffused quickly. Consequently, the 
construction of the apparatus becomes more complicated in order to satisfy 
these conditions. The object of this invention is to provide an apparatus 
for electrolysis which improves the electrolysis efficiency by shortening 
the distance between the two electrodes to be as small as possible and to 
accomplish a smooth dispersion of generated ions and a quick diffusion of 
generated gases, and also to simplify a construction of an apparatus for 
electrolysis. 
SUMMARY OF THE INVENTION 
Thereupon, since a conventional apparatus for electrolysis of water has a 
problem due to its complicated construction, the inventor has conducted 
intensive studies to solve this problem, and has accomplished this 
invention. That is, the electrode of this invention is characterised as 
follows: An electrode composition for electrolysis of water, comprising a 
panel of which one surface is made from electric conductive material and 
another surface is made from non-electric conductive material, plural 
holes are bored through said panel, two said panels are arranged so as to 
hold a diaphragm between surface of non-electric conductive material of 
each panel, and electrolysis reaction occurs at outer side of an anode and 
cathode of said electrode composition.

DETAILED DESCRIPTION OF THE INVENTION 
When a voltage is applied across a cathode and an anode which are placed in 
water, electrons transfer between the surfaces of the electrodes and 
electrolytically dissociated water or electrolyte. In the case where NaCl 
is used as an electrolyte, oxygen gas and/or chlorine gas, is generated on 
the anode side and hydrogen ion and hydronium ion are generated 
simultaneously in the fluid, thus the fluid becomes acidic. On the cathode 
side, hydrogen gas and simultaneously hydroxide ion are generated, and so 
the fluid becomes alkaline. Electrons which transferred from cathode to 
fluid, migrate in the fluid and come to the anode. That is, an electric 
current flows from anode to cathode. 
As reactions which generate ions and gases are taking place closely at the 
surfaces of cathode and anode, the concentration of ions surrounding the 
electrodes become higher. That is, a gradient of ionic concentration is 
caused. Generally, it is understood that generated substances close to the 
electrodes such as ions or others, are transferred or dispersed by a 
driving force generated by a gradient of concentration, a gradient of 
electric potential and by convection of fluid, and a diaphragm stretched 
between cathode and anode acts to prevent water on the cathode side and 
water on the anode side from mixing. 
In the case of using a conventional face to face panel shape electrode, 
electrolysis actively progresses at the surfaces of the cathode and the 
anode which face a diaphragm located between the two electrodes, and ion 
and gas are generated at each electrode. The generated gas forms tiny 
bubbles and diffuses from the fluid existing between the electrode and the 
diaphragm, and cation and anion are dispersed by effects of gradient of 
concentration, gradient of electric potential and convection of fluid. 
Mixing of the two fluid can be prevented by a diaphragm, however, as there 
is a gradient of electric potential, ions which exist in the fluid 
transfer by electrophoresis through a diaphragm to the other electrode. 
This physical phenomenon is put to practical use, for example, in the case 
of the production of NaOH by electrolysis of NaCl. In this case, the 
generation of NaOH becomes possible by a transportation of sodium ion from 
the anode side to the cathode side by the electrophoresis phenomenon. The 
object of this invention is to produce an acid ionized water and alkaline 
ionized water, and to achieve this object the generated cation and the 
generated anion must stay on their respective sides of the diaphragm so as 
to make their respective concentrations higher. So the transfer of ions 
from one electrode to another electrode is not desirable in this 
invention. 
An important point of this invention is that the cathode and the anode are 
not arranged facing each other but are arranged back to back. As the side 
of the electrode which faces the other electrode a non-electric conductive 
material is used, and a diaphragm is arranged between the electrodes, and, 
an electrolysis reaction taking place at the outer surface of the 
electrodes and generates ions and gases. At this time, as electric current 
flows through holes bored in each electrode and through the diaphragm to 
the outer surface of the opposite electrode, a gradient of electric 
potential only exists in the fluid between the holes and the diaphragm, 
and does not exist in the fluid at the outer electrode surface side. 
Therefore, the generated ions disperse far from each electrode by effect 
of gradient of concentration and by convection, and ions that exist close 
to the holes bored in the electrode partially transfer to the opposite 
electrode by the effect of the gradient of electric potential. Thus, the 
generated gases are easily diffused from the fluid far from diaphragm. 
In the electrolysis process, electrons transfer through the fluid between 
cathode and anode. The distance between electrodes, a diaphragm, and in 
the case of back to back electrode, holes bored in the electrodes are the 
main causes of electric resistance. To improve efficiency of electric 
power usage for performing the electrolysis, it is desirable to make the 
distance between electrodes narrower so as to decrease the electric 
resistance. However, in the case of a face to face electrode construction, 
because it is necessary to consider the transfer of fluid between 
electrodes and diffusion of gases, there is a limitation on the distance. 
In the case of the back to back electrode construction of this invention, 
only the electrically non-conductive material and the diaphragm exist 
between the two electrodes, and so it is not necessary to consider the 
transfer of fluid and diffusion of gases between the two electrodes. 
Therefore, in this case, the distance between the two electrodes is equal 
to the sum total of the thickness of the two electrodes, the two 
electrically non-conductive layers and the diaphragm. 
Turning to FIG. 1, the surface 1 of the panel is composed of an 
electrically conductive material such as copper, lead, nickel, chrome, 
titanium, gold, platinum, iron-oxyde and graphite. Preferably it is 
composed of platinum. It is desirable to use a thin plate of metal of 
5-100 micron thickness, and more desirably a plate of titanium having 
0.1-5 milli meter thickness on which surface platinum is plated. Surface 2 
of the panel is composed of an electrically non-conductive resin, such as 
polyethylene resin, polypropylene resin, polystyrene resin, 
polyethyleneterephthalate resin, polyethylenechloride resin, ABS resin 
acrylic resin, epoxy resin, teflon resin, ceramic, natural rubber, SBR, 
silicone rubber, chloroprene rubber, fiber reinforced plastic plate or a 
thin film of an electrically non-conductive paint or synthetic resins. The 
surfaces 1 and 2 are tightly stuck to each other, and form a panel for use 
as a cathode or an anode. 
Holes 3 are bored through the panel so as to be arranged on all active area 
for electrolysis reaction, and surface area of the one hole is from 1 to 
500 mm.sup.2. The ratio of surface area of the holes to that of the 
electrode is 10-90%, and is preferably 30-70%. Material of the diaphragm 4 
is generally a non-woven cloth made from asbestos, glass wool, polyvinyl 
chloride fiber, polyvinylidene chloride fiber, polyester fiber or Kevlar 
fiber, or an unglazed ceramic plate, a sheet of paper or a film of 
ion-exchange resins. The diaphragm 4 is held between surfaces 2 of the 
anode and the cathode. Anode, cathode and diaphragm can be arranged 
independently, or the diaphragm can be stuck tightly to the surfaces 2 of 
the electrodes. Also, it is possible to put a spacer (not indicated in the 
drawing) made from electrically non-conductive materials, between the 
diaphragm and the electrodes to have a possibility of fluid existing 
between surface 2 and diaphragm 4. 
By using the back to back construction of this invention, because the 
distance between anode and cathode can be shortened to the sum total of 
thickness of the electrodes, the insulators and the diaphragm, it is 
possible to improve the efficiency of electric power for electrolysis. 
And, since there is no generation of ions and gas between the electrode 
and the diaphragm, the threat of that inconsistency of electric current 
caused by increased electric resistance due to the gas in the fluid or in 
diaphragm can be ignored. 
Generated ions on the back to back surface electrode of this invention 
disperse far from the electrodes of the effect of gradient of 
concentration and by convection, and the transfer power to the opposite 
electrode by effect of gradient of electric potential is not strong. 
Therefore, the transfer of generated anion and cation to the opposite 
electrode is less, and consequently concentration of the object ion can be 
raised effectively. 
In the case of a conventional electrolysis method, plates of the electrodes 
and a diaphragm must be held independently. However, in the case of this 
invention, as it is possible to assemble them in simplified construction 
by sticking a diaphragm tightly or through the medium of spacer to an 
electrode, a holder to attach the electrode to an electrolysis vessel can 
be simplified. Therefore, the possibility for modification of electrode 
design is extended, and it becomes possible to manufacture not only a flat 
shape electrode but also a modified shape electrode such as having curved 
surface, spherical surface or angled shape. 
While the preferred form of the present invention has been described, it is 
to be understood that modifications will be apparent to those skilled in 
the art without departing from the spirit of the invention. 
The scope of the invention, therefore, is to be determined solely by the 
following claims. 
DETAILED DESCRIPTION OF EXAMPLE 
This invention is further illustrated in the following examples, however it 
is to be understood that the invention is not intended to be limited to 
these examples. 
FIG. 1 and FIG. 2 are illustrations of the composite electrode construction 
7 which is characterized as simplified by sticking an electrode closely to 
a diaphragm and arranged in an electrically non-conductive frame 6 having 
contact points 5 for anode and cathode. FIG. 3 is an illustration showing 
the electrode construction 7 which is arranged in an electrolysis chamber 
8, so as to prevent leaking of contained fluid from the contact portion of 
the chamber and the electrode. 
EXAMPLE-1 
An aqueous solution which includes 0.03 wt % of NaCl is prepared as a 
testing fluid to be electrolyzed. Two sheets of titanium plate of 1 mm 
thickness on the surface of which a thin layer of platinum is plated are 
prepared as the material of the panel and polyethylene film of 0.2 mm 
thickness is spread over one surface of said platinum plated titanium 
plates to forms the panels. 
Holes of 5 mm diameter are bored in each panel as shown in FIGS. 1 and 2. 
The distance between the centers of the holes is 7.7 mm and the ratio of 
surface area of holes to whole area is 33%. The two panels are arranged so 
that the polyethylene sides face and hold a 0.17 mm thick membrane filter 
(Yumikron MF-60B, Yuasa Co., Ltd, Japan) as a diaphragm between them. The 
said membrane filter is a polyolefin coated highly porous polyester film. 
Thus the electrode composition of this invention is assembled. 
A 100 mm.times.100 mm size sheet of the electrode composition is placed at 
the center of a one liter capacity electrolysis chamber 8. The water 
solution, which includes 0.03 wt % of NaCl, is poured into both separated 
spaces of the electrolysis chamber formed by the electrode, and mixing and 
leaking of the water solution can be perfectly prevented by the electrode 
composition. 
Direct current of 13 volts constant voltage is applied, and pH and 
oxidation-reduction potential are measured according to the progress of 
time at the anode side and the cathode side by using pH meter and ORP 
meter. Also, the electric current is measured by ammeter. An electric 
power efficiency, until the pH of the anode side water becomes 2.7 is 
calculated. The electric power efficiency obtained by this experiment is 
5.1 watt.multidot.hour/L, and other results are shown in Table. 1. 
EXAMPLE-2 
The diameter of the holes in the panels is changed to 7 mm and the distance 
between centers of the holes is set up to 10 mm. In this case, the ratio 
of the surface area of holes to the whole area is 44%. Using the same 
electrolysis equipment and the same conditions, electrolysis is carried 
out. The obtained results are shown in Table. 2. 
In this case, the electric power efficiency to obtain pH 2.7 acid ionized 
water is 3.4 watt.multidot.hour/L, and it exceeds the result obtained in 
example-1. The effect of a larger hole surface area is obvious. 
EXAMPLE-3 
A 0.17 mm thick membrane filter (Yumicron-60B) is used as a diaphragm, and 
the same panel as in example-2 are used to assemble the electrode 
construction. A 360 mm.times.500 mm size sheet of the electrode 
composition is prepared and placed at the center of a 100 liter capacity 
electrolysis chamber. The same water solution as in example-1 is poured 
into the chamber, and direct current of a constant 15 amperes is applied. 
The obtained results are shown in Table. 3. 
This experiment simulates an actual application of the invention. And as 
good electrical power efficiency is obtained, it seems that this invention 
has a good possibility of actual use. 
TABLE 1 
______________________________________ 
anode cathode 
time volt current ORP ORP 
(min) (volt) (mA) pH (mV) pH (mV) 
______________________________________ 
0 12.8 245 7.32 +458 7.32 
+458 
15 13.9 360 2.88 +1025 11.14 
-804 
30 14.2 320 2.54 +1088 11.57 
-862 
60 14.5 280 2.32 +1128 11.79 
-884 
120 14.7 170 2.18 +1173 11.95 
-895 
______________________________________ 
Electric power efficiency (pH 2.7) 5.1 Watt .multidot. Hour/L 
TABLE 2 
______________________________________ 
anode cathode 
time volt current ORP ORP 
(min) (volt) (mA) pH (mV) pH (mV) 
______________________________________ 
0 20.0 500 7.68 +203 7.68 
+203 
5 20.5 500 2.92 +910 10.58 
-773 
10 20.5 450 2.66 +894 
20 20.5 500 2.35 +1010 11.44 
-867 
30 20.6 500 2.20 +1027 11.55 
40 21.0 500 2.08 +1037 11.58 
-874 
60 21.0 430 1.99 +1086 11.64 
-881 
80 21.0 450 1.96 +1099 11.84 
100 21.0 450 1.94 +1108 12.00 
-882 
120 21.0 450 1.92 +1121 12.01 
-880 
______________________________________ 
Electric power efficiency (pH 2.7) 3.4 Watt .multidot. Hour/L 
TABLE 3 
______________________________________ 
anode cathode 
time volt current ORP ORP 
(min) (volt) (mA) pH (mV) pH (mV) 
______________________________________ 
0 29.3 15.0 7.54 +502 7.54 
+502 
10 28.5 15.0 4.33 +906 
20 26.5 15.0 2.98 +1052 10.27 
-100 
30 25.3 15.0 2.66 +1104 
40 24.8 15.0 2.57 +1117 
50 24.1 15.0 2.45 +1130 11.34 
-888 
60 23.8 15.0 2.38 +1138 
70 23.2 14.8 2.31 +1144 
90 22.8 14.7 2.21 +1151 
100 22.8 14.8 2.18 +1155 
______________________________________ 
Electric power efficiency (pH 2.7) 4.4 Watt .multidot. Hour/L 
When water or water including electrolytes is ionized to the lower level 
than pH2.7, it is almost perfectly sterilized and can be used as germ-free 
water. And the electric power efficiency to obtain water of pH lower than 
2.7 is better than that of by conventional electrolysis method which is 
assumable as 8-10 watt.multidot.hour/L, around. By using the electrode 
composition of this invention, germ-free water can be easily and 
economically obtained, which can be applied as mass consumption in a 
hospital or others. 
While the preferred form of the present invention has been described, it is 
to be understood that modifications will be apparent to these skilled in 
the art without departing from the spirit of the invention. 
The scope of the invention, therefore, is to be determined solely by the 
following claims.