CA1331689C - Ozone decomposing material and ozone decomposing apparatus using the ozone decomposing material - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
An ozone decomposing material comprises an ozone decomposing agent and a support material for supporting thereon the ozone decomposing agent by adsorption, and an ozone decomposing apparatus comprising the above ozone decomposing material and an ozone decomposing agent supply means for supplying the ozone decomposing agent to the support material, by which the ozone decomposing agent is adsorbed.

Description

-OZONE DECOMPOSING MATERIAL AND OZONE DECOMPOSING APPARATUS
USING THE OZONE DECOMPOSING MATERIAL

BACKGROUND OF TH~ INVENTION

The present invention relates to an ozone decomposing material for decomposing ozone and an ozone decomposing apparatus using the ozone decomposing material, which can be ~;~
employed, for instance, not only in electrostatic coping machines provlded with a corona charger and laser printers, : , , .
but also in waterworks and sewerage systems, and an `~
apparatus for activat~ng the surface of synthetic resin -films for improving the ink receptivity and adhesiveness~
~; thereof.
ozone is generated, for instance, in the above-;~ mentioned apparatus and ls toxic to humans when breathing ~ air containing more than 0.1 ppm of ozone for a long period i ~ ~
of time. According to the safety standards for ozone to humans proposed by Japanese Association of Industrial .,.~, ~ .
ealth~, ACGIH (American Conference of Governmental Industrial and Hygienists),~and OSHA tOccupational Safety and He~al~h Administration~), the permissible maximum average ~-~-m ~ concentration of ozone in the air is 0.1 ppm when breathing the air ~or 8 hourls. Many! apRaratus for indus~trial use are produced by observing these standards. Ozone has a ch~racteristic;pungent~ddor, and the odor is noticeable even ?~

:, at concentrations as low as 0.01 to 0.0~ ppm. Some operators of an ~ndustrial apparatus which generates o~one at such oncentrations may complain about the odor. When the concentra~ion amounts to ab~ut 0.05 ppm, it has an unpleasa~t o~o~, and when the concen~ratlon exce~ds 0.1 ppm, it is irritat~ng to mucus membranes of the eyes and respirator~ orga~s.
Further, ozone is a powerful oxidizing a~ent which oxidizes and deteriorates organic materials. There~ore, it is desirable that the concentration of ozone be as low a~ -possible, not only to humans, but also to industrial apparatus and devices.
Conventional~y, various ozone decomposin~ materials and ozone decom20sing apparatus have been invented.
However, when preparing an ozone decomposing apparatus is made, the ozone decomposin~ performance, the pressure loss and the flow rate of the air from which ozone is eliminated, the humidit~ condi~ions, and the deterioration of the ozone decomposin~ material with time, have to take into consideration. However }t is extremely difficult to make an ~, ozone decomposing apparatus and an ozone decomposing material which satisfy the above-mentioned cond~tions as a ~:~ whole. ~, , , ~ . , !
Electrophotographic cop~ing machines including a ~orona ,~ ~
charger and air clean~rs generate ozone at low ` ~ - 2 -:' ;

- ~:

concentrations. Most of th~m are provided with an ozone decomposing apparatus in the shape of a filter, in which an ozone decomposlng member made of, for instance, an activated carbon filter, is employed.
~ owever, the aoncentration o~ the ozone generated in the aurrently e~p~oyed PPC is about ~ ppm or less and a honeycomb-like activated carbon filter for decomposing the ozone at such low concentrations deteriora~e with time to a not negligible extent and lasts only for several months.
Further a large size corona charger ~or activating the surface of a resin film, and sterilizat~on apparatus using -~
an ultra-violet light source and decolorization apparatus ~ -generate ozone at high concentrations. ~or decomposing 020ne at a high concentration, a large amount of granular active carbon, metal catalysts, organic compound~ such as manganese dioxide, and mixtures thereof Are employed.
However, the ozone decomposing performance of these agents is not yet satlsfactory.
Furthermore, when a variety of filters such as actlva~ed carbon filter and Hopcalite filter a~e employed, the ai~r containlng ozone has to be passed through such a filter. When the density of the ~ilter is increased, the -~
~ozone abso,rptionland ~ecomposition pe~formanpe is also !: ~
iocreased. However, the air aannot be passed through the ~ :
filter smoothly, since the pressure loss is increased as 3 - ~-, ~. ..
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well. As a result, the problem is caused that the problem is caused that the temperature within the apparatus inaluding t~e ozone decomposing filter is disadvantageously elevated. The elevation of the t~mperature w~thln the apparatus will eventuall~ shorten th~ life ~f the apparatus.
On the contraryr when the den~ity of the filter i5 decreased, the ozone adsorption and decomposing performance is also decreased.
In any event, it is necessary to provide a powerful suction apparatus or blower ~n order to cause the ozone- : -containing air to pass through the filler. However, such suction apparatus or blowsr causes noise. Furthermore, in order to minimize the elevation o the temperature within the ozone ~enerating apparatus, a cooling apparatus is also ~ .
necessary, ~o that apparatus including the conventional .:
020ne decomposin~ apparatus ls:aostly as a whole. Further there is a demand for a small:slze, powerul o~one decomposing apparat~s for use in the activation of the :~
surfa~e~of resin fllms:and sterlsation apparaeus~ ~owever, ~;
such a demand is not yet met. : ~-SU~Y OF THE INVENTION~

`It i~ therefor'ei~a firsitio~ject o~ the pregent invention to p~ovide~an improve:d ozone decomposing materlaL, the ozone decomposing performance of~which lasts for an extended _ -;
:

period of time, which ozone decomposing material comprises, preferably, any of the te~penold ozone decomposing agents (as disclosed in J~panese Laid Open Patent Application 61-64315 and Japanese Laid-Open Patent App~ication 61-2~2268) and a Bupport material by which the ozone decomposing agent is adsorbsd.
A second obi~ct of the prescnt inventio~ is to provide an ozone decomposLng apparatus in which the above ozone decomposing material is employed, for which ~he ozone~ ~ .
decomposing performance i- max1~ized and the pressure loss of the air to be passed through th¢ ozone decomposing apparatus is minimized. :~
The first object of the present invention is attained ~:
by an ozone decomposing material comprising any of the :-f above-~entioned terpenoid ozone decomposing agents and a :;
support material for the ozone deaompos~ng agent, which may be in a granular, honeycomb-like or ~ibrous form, or in any ~:~ other structure, and which may~be madè of any materials,;~
prefera~ly~a material having ozone decomposing performance ;~
itselr,~suah as`activated~:carbon, metal catalysts and norganL~;materlals,~whlch:absorb the ~zone decomposing:~ :
~ sgent at the surfaoe thereaf or in the porous portions . ~ :thereof. ~ ,. , i j i ! ' ` ~"`
Th-e second ob~ect of the present invention is attained ~ ~.
f~ by an ozone deaomposing~apparatus~whi:ch comprises a first ~ ~`

~, .
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container containing therein a terpenoid ozone decomposing agent, and a second container containin~ therein a supp~rt material for the ozo~e decomposing agent, which first and second containers are connected to each other through an air ~low path by ~hi~h the vapor o~ the terpenoid ozone decomposing agent is transported onto ~he support material so as to be adsorbed thereon. The ozone decompo~ing apparatus is constructed in such a fashion that the ozone decomposing agent is ca~sed to be dispersed in the form of vapor throughout the air to be subjected to ozone decomposing treatment by utllizing the energy of the air which is moved onto the ozone decomposing material, and the ozone decomposing agent is constantly adsorbed by the support material, whereby the ozone decomposing performance is caused to last for an extended pe~iod of time.

BRIEF D~SCRIPTION OF THE DRAWINGS :

In the drawings, Fig. 1 is an:illustrative diag~am in explanation of the steps through which the ozone decomposing performance of activated carbon is decreased wh~le in use.

Fig. 2 i8 a schematiic diagram of an ozone ~ecomposing apparatus 100 according to the present invention :~
.: `

Fig. 3 is a schematic perspective view of the main portion of the ozone decomposing apparatus as shown in Fig.

2.
Fig. 4 i8 a schematic perspective view of a container ~or an oz~ne decomposlng agent in the ozone decomposing apparatus as shown in Fig. 2.
Fig. S is a schematia perspective view o~ another container fox an ozone decomposing agen~ ior use in the ozone decamposing apparatus as sho~n in ~ig. 2. -:
Fig. 6 is a schematic diagram of an ozone deaomposing ~ ~
apparatus 200 accordiing to the present invention. ~ .
Fig. 7 is a graph showing the ozone decomposing per~ormance obtained by the pre~ent invention an~ that :~
obtained by the conventlonal ozone decomposing apparatus.
Fi~. 8 is a schematic perspective vie~ of an ozone decomposing apparatus 300 according to the presene invention :
Fi~. 9 is a section taken on line X - X of Fig. 8.
Fig. 10 is a schematic perspective view of a conta~ner ;; --~.
or~aD ozone decomposing agent in the ozone decomposing s ~
apparatus 300 shown in Fig. 9.
:Figs. 11 through~13 schematically show the application e~xamples of the ozone decomposing apparatus 300 according to ~.
the ,present!invention~

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The terpenoid compounds employed as ozone decomposing agent in the present invention are such terpenoids having a general formula of CmH2n+l40p(m = 9 ~15, n - O ~4, p = O~
2~, which are readily oxidized by o~one. It is consldered that a representative example of terpenoid compounds, d-limonene, reacts with ozone as follows:

:

~ + O, ~ ~ H~O ~ ~ + O, H3 H2 H3 H2 H3 H~

In the present invention, when as a support material ~or the ozone decomposing agent, a support material having an ozone decomposing performance, such as activated carbon, is used in combination with any of the abvove terpenoid compounds, the deterioration of the ozone decomposing .
~ material can be minimized.
`~`` Specific examples of the terpenoid compounds ~ .:
represented by the above general formula are as follows:

9H14 ! santene;
~ ~ .
9H14 cryptone;
9 16 cyclogeraniolene;
, ~ ~

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8 - :

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CloH14o: safranal, perillaldehyde, carvone, pi~eritenone, myrtenal, umbellulone, ve~benone and pinocarvone;

c1oH~6: B-myrcene, ocimene, limon~ne, dipentene, isolimonene, ~erpin~ne, phellandrene, 2,8,~ p-menthadLene, syLve~ene, aarene plnen~, ci~mph~nene, bornylene, fenchene and orthodene; ~ -C1~H16O: citral, tegetone, artemisia~etone, isoartemisiaket~ne, cyclocitral, perillyl alcohol, carveol, phellandral, piperitone, pulegone, isopulegone, carvenone, dihydrocarvone, ~: carvotanacetone, pinol, sabinol, pinoci~rveol, .. . .
myrtenol, vervenol and cis-3-hexenol;
~: C1oH1~O~ diosphenol and ascarid~le;

.~ C1oH18O: Linaloo}, geraniol, cyclogeraniol, nerol, ~:~ lavandulol, cltronellal, 2,6~-dimethyl-7-octene-4 one-dyhyd~ocarveol, pulegol, isopulegol, piperitol, terpineol and terpinenol~

C1oHl8 : menthene;

, Cl0~2oo: -tr ~ llol~

- :

Cl1H180: nopol;

C13H200: ionone and parmone;

C14H220: ironet 15H24: bisabolene, zlngiberene, curcumene, cadinene, isocadinene, sesquibenihene, selinene, caryophyllene, metrosiderene, aromadedrene, cedreen, copaene, longifolene and santalene;

15H240: lanceol, sesguibenihiol, partheniol and santalol;

l5H260: farnesol, nerolLdol, elemol, cadinol, eudesmol, quaiol, carotol and cedrol;
C15N220: atlantone, turmerone, cyperone, eremophilone and vetivone.

In the above terpenoLd aompounds represented by the general formula Cm~2n+140p(m = 9 ~15, n = O ~ 4, p = O ~ 2), slnce the terpenoid compounds having 8 or less carbon atoms are in the form of vapor at room temperature, it is extremly difficult,to mai~tain such ! terpenoid compoun~s at a low concentration, so that there is the risk that the ~
concentration is easily~increased. Further such terpenoid : -compounds are not only liable to catch fire, but also havean ex~remely unpleasant odor. On the other hand, the terpenoid compounds having 16 or more ~arbon atoms are not easlly evaporated, therefore the ozone decomposin~
perfoxmance is hardly obtained.
In the above listed terpenoid aompounds, llmonene is particularly pre~erable for use in the present ~nvention since it has the most slgnificant ozone decomposing performance. As a commercial product of limonene, "Odo-Raser Compound" (Trademark) made by Vaportek Inc. in the state of wisconsin in the United States, is preferable : -for use, which is a mixt~re of a variety of terpineol type vegetable extracts.
Each of the above terpenoid oompounds can be used a~
is by placing the compound in a contalner for an ozone decomposlng agent. It is preferable that the terpenoid compound be employed by containing it an an alcoholic gel or a water-soluble gel so as to cont~ol the e~aporation rate of he terpernoide compound.
When the tervenoid compound is contained in the abo~e-mentioned alcohol~gel, at~is pre~erable that the terpenoid ~:
compound be in the r:a~ge of 1 to 80 partç by weight, more preferably in the range of 20 to 50 parts by weight; an alcohol in the range of 10 to 97 parts by weight, more preferably in the range of 40 to :60 parts by weigh~; and a i i~, ~:: :
`,` ~ ~ ~ - 1 1 -saturated solution (about 25~) of dibenzylidene sorbitol or a phosphoric acSd bis~4-t-butyl-phenyl) sodiu~ in N-methyl-2-pyrrolidone in the ~ange of 1 to 10 parts by weight, to 100 ~arts by weight of the ozone decomposing a~en'~ .
Further, as an auxlliary ~elation agent, it is preferable to add to the above ozone decomposing agent a 2 to ~%-benzyl alcohol solution of a cellulose derivative or a 2 to 5~benzyl alcohol of polyvinyl pyrrolidone.
Furthermore, glyaols and qlycerin may be added to the above ~:
for controlling the gelation rate.
As a water-soluble gelation agent, sodium polyacrylate, sodiw~ alginate, qelatin, agar, gelan gum, and succinoglucan may be omployed. As an auxil~ary gelation agen~ for such water-soluble ~elat~on a~ents, cellulose derivatives can be employed. In this case, lt is preferable tha~ the amount of the terpenoid compound be in the ran~e of about ~O to 50 . ~-~
, ~ --.~ wt.~
As the support:material for the ozone decomposing agent for;use in the present in~eneion, any materials can be ~-~
employed so long as;they~allo~ the~air to pass theretnrough and are capable of holding or :adsoxbing an ozone decomposing ,,,,, ~ ~, agent such as terpenoid compounds at the surface thereof.
~: Examples of such ma~erials are~honeycomb-like cera~,ics and honeycomb-like oera~lcs:iibers (made~of cordierite) - .,, ~ 12 -!` ' `S ' -`-.

'~' . ' tTrademark "Honeycle" made by Nichiasu Corporation), and activated carbon.
of the above materials, activated carbon is one of the most preferable material~ since it not only ~raps or adsorbs the ~erpenoid compounds at the surface thereof, but al90 ha~ !
the func~ion of decomposing oxone to some extent. ~n other words, activated carbon has adsorptivity not only for the terpenoid ozone decomposing agent, but also for ozone. In particular, honeycomb-like paper in whiah honeycomb~like activated carbon is contained during the manufacturing of the paper is preferable for use in the prsent invention.
When the terpenoid compound is adsorbed in the activate~ --~arbon, the ozone decomposing performance is enhanced by the :-synergism of the two when 020ne comes into contact with the :~
ter~enoid compound which is adsorbed by activated carbon.
Activated carbon, which is considered to be one of the : best support materials for the terpenoid ~ompounds, has numerous fine holes having a radius of about 100 A, which is . -considered to adsorb ozone and decompose the same. ~owever, ~- 030ne iS S0 extremely strong an oxidizing agent that the surface o~ activated car~on or the surface of the fine holes thereof is oxidized in the course of the adsorption of ozone, following the steps as,illus~rated in Fig. 1.

'~
~ .
. -: .

, ` .

Eventually, the oxidizing performance of the activated carbon is significantly decreased.
Tests for investigating the synergism of activated carbon and terpenoid for decomposition of ozone will now be explained.

~Test 1}
An activated carbon filter which had been used for about 25 hours in an electrophotographic copying machine, corresponding to the time required for makinq about 10,000 copies in the copying machine, was adsorbed with about 6 wt.% of terpenoid (d-limonene) and subjected to an ozone decomposing test in which the filter was incorporated in an experimental copy making machine and copies were made continuously. The amount of the ozone dischargQd from the copying machinQ per hour during the copy making procQs~ was 0.7 mQ/hr.

[Te-t 2]
T~st 1 was repeated except that-the activated carbon fllter employed in Test 1 was replaced by an activated `~ carbon filter which had been used for 25 hours, without ~ ab~orption of the terpenoid,employed in Test 1. The amo!unt :.
of the ozone discharged from the copying machine per hour during the COW making process was 4.0 mQ/hr.

~`X

tTest 3~
Test 1 was repeated except that the activated carbon filter employed in Test 1 was removed. The amount of the ozone discharged from the copying machine per hour during 5 the copy making process was 13.4 mQ/hr.
The above data indicate that the ozone decomposing performance of the used activated carbon can be significantly recovered by the adsorption of terpenoid.
It is considered from the above data that when 10 aativated ¢arbon is employed in the present invention, terpenoid is adsorbed by the surface of the fine pores of the activated carbon, and when ozone comes into contact with the actlvated carbon, the ozone is decomposed before the activated carbon is oxidized. Therefore, if terpenoid 15 is constantly supplied onto the activated carbon, the docompo~ition rato of ozono i8 improved and tho detQrioration of the activated carbon can be prevented.
Fig. 2 illustrate~ an example of an ozone decomposing apparatus 100 according to the present invention, in which 20 an ozone decomposing mat-rial according to the preoent invention is employed. In the figure, reference numeral 1 -~ indi¢ates an air duct in which the air from which ozone is to be oliminatad flow:o in the diroction of thejarrow. In the air duct 1, a container 2a containing therein a -~ - 15 -`:
~ `

X
, ~

, f ' ' . ` !' ' ~ , i 1~31689 terpenoid ozone decomposing agent 3 is dlsposed upstream of the air flow. Reference numeral 6a indicates a hole made in the container 2, from which the vapor of the terpenoid ozone dec~mposing agent 3 comes out. A honeycomb-like activ~ted carbon filter 4, wh~ch ~erves not only as a ~upport ~aterial for the ozone decomposing agent, but also as an ozone decomposing element, ~s d~sposed down~tream of the air flow.
Be~ween the container 2a and the activated ~iarbon filter 4, a fan S is disposed. By the ventilating force of the fan 5, the vapor of the terpenoid ozone decomposin~ agent 3 is dispersed from ~he container 2a and caused to be adsorbed throuqhou~ the acti~rated carbon filter 4.
Fig. 3 is a perspec~ive ~riew of the main portion of the ozone decomposing apparatus as shown in Fig. 2. Fig. 4 is a~ enlarged perspective view of the container 2. In these figures, reference n~meral 7 indicates a guide plate for dispersing the vapor of the terpenoid 020ne decomposing agent 3 uniformly.
Fig. 5 shows another examp~e of t~e container ~or the terpenoid ozone decomposing agent 3, a container 2b, in which a pl~rality of holes 6b are made.
When the concentration of 020ne is high, for instance, ~:~
100 ppm or more, as in an apparat~s for activatin~ the " , , ~
~-~ surface of resin films and a sterilization apparatus for .
~,.
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~ 16 -. .
.~
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`' ``' ' ' ~ ' ` ~ : ' ' ~ " ' ' ':; ' ' ! ~ ~ ; ~ i i ' ~ . ~ .

waterworks and sewage-trea~ment systems, it is pref erable to place the ozone d~compo~ing filter 4 (comprising any of granular activated carbon, honeycomb-like activated carbon, and fibrous acti~a~ed carbon) and the container 2a or 2b ~or the terpenoid ozone decomposing agent 3 alternati~ely in the air duct 1, th~eby constructln~ an ozone d~composing apparatus 200, as illu~trated in Flg. 6. Ihis ozone decomposLnq appar4tus ~orks better than the conventional ozone deaomposing apparatus. Further, this apparatus is not only less expensive, but also smaller in si~e than the conventional ozone decomposing apparatus.
In particular, when the concentr~tion of ozone is, for instance, as high as S00 ppm or more, ~ince the ozone cannot be decomposed to 0.1 ppm by a singl¢ step, the 020ne . .
decomposlng apparatus as illustra~ed in Pig. 6 is effective in which ozone is decomposed step by step by use of a plurali~y of combinations o~ the ozone decomposing agent 3 contained ln the container:2a or 2b and the ozone decomposing ~ilter 4. The number of the contai~ers 2a or 2b ~.
and the 020ne decomposing fllters 4, the length of the ai~
duct l, tho power of~the~fan 5, and the number of the holes :~ made~in each container 2b are dete~mined in accordance with the desired o,~one deç~ompositiQn rate.~ ;
' ~ As in an electrophotographic copying machine, when the ozone decomposinq fi~ltor 4, the fan S and th~ terpenoid .... .
, ~ :

.
.

container 20 are closely disposed, it is preferable to use the guide plate 7 for guiding the vapor of t~e terpenoid ozone decomposing agent 3 onto the entire sur~ace of the ozone decomposin~ fllt~r 4.

Example l-l A honeycomb-lLke activated carbon filter ~made by Toyobo Co.,~td.), which was used in an electrophotographic ~opying machine for a period of time correspondin~ to the time required for making about 15,000 copies in the cop~ing machine, was.placed together with d-limonene in a desiccator for 2 days, so that d-limonene was adsorbed by the used activated carbon filter. The wei~ht ratio of the absorbed amount of d-limonene to the weight o~ the activated carbon was 1 to 17, that is, lg of d-limenene was adsorbed by 17g of activated carbo~.
': .
{Measurement ll ~ :
Air containing ozone was caused to flow, without .. - .
incorporating the above activated carbon therein, through an ~ :
air duct at a flow rate of 1 m/sec and the amount of ozone which was accumulated for 1 hour at the outlet thereo~ was measured by.an ozonelanalyze~ ~Trademark `'Monito,r Labs Ozone Analyzer 4BlOE). The ~esult was 14.0 m~/hr.

~;

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, :, tMea8urement 2]
Measurement 1 was repeated except that the above-mentioned used activated carbon filter, without d-limonene being absorbed therein, was incorporated in the 5 air duct, 80 that the amount of ozone at the out}et was measured by the same ozone analyzer. The result wa~
5.0 mQ/hr.

tMea8urement 3~
Measurement 1 was repeated except that the above-mentioned d-limonene absorbed, activated carbon filter was incorporated in the alr duct, so that the amount of ozone at the outlet was measured by the same ozone analyzer. The result was 1.0 mQ/hr.
Exampl- 1-2 Hydroxy propylcellulose was added at a concentration of 3% to purified benzyl alcohol and the mixture wa~
sub~eot-d to high speed stirrinq, 80 that hydroxy 0 propylcellulose was dls~o1ved in benzyl alcohol.
40 parts by weight of the above solution, 40 parts by weight of d-limonene, and 15 parts by weight of propylene ~ glyco} were ~ixed anq~the mixture was 6tirred 810wly.
- 5 parts by weight of a saturated solution of Z5 dibenzylidenesorbitol in N-methyl-2-pyrrolidone were dropwise added to the above ~ixture and stirred for 10 : ' - 19 -` ` :~r t t ~ :.r;;
~ r~ ~ 3 1331~89 minites to prepare a viscous liquid. This vicous liquid was allowed to stand at room tempexature for 1 hour, ~hereby a jelly-like gelled terpenoid ozone decomposing agent was o~tained.
In the air duct as illustrated ln Fig. 2, the same actlvated carbon filter as that emplo~ed in Example 1-1, the fan S, and ~he container 2a containln~ therein the above prepared terpenoid ozone decomposing agent 3, having an opening 6 with a diamete~ of 2 mm, were placed. Air containing ozone was then ca~sed to flow through the air duct at a flow rate of 1 m/sec. :~:
B~ use of the same ozone analyzer as that employed in -~
Example 1-1, the concentration of ozone at the outlet was :
measured. Initially the concentration of ozone was 0.02 ppm. ~his concentration was maintained for 5 hours.
The above indicates that the deterioration o~ the activated carbon filter ~as prevented by the supply of ~-d-limonene from the container 2a.
. ~
- The evaporation amount of the terpe~oid per~hour at :
~:~ 20C at the above flow rate of the air was 0.1 g and the amount of the terpneoide contained in the container was lOOq.
.~ ~
Therefore, if it is Lncorporated in an electro~
photographic photoqonduqtor! which is operated for 5~hours~ a ~: : da~, the ozone decomposing agent will last for abou~ 20Q
day5.
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The pressure loss through the activatéd carbon filter in the air duct was 2 mm/H20. This pressure 108s was not changed at ali.

Example 1-3 A gas discharqe outlet of an apparatus for activating the sur~ace of a resin film (~or example, polyester film and polethylene ~ilm) was connected to the air duct of the ozone decomposing apparatus as illustrated in Fig. 6.
The concentration of ozone dlscharged from the gas discharge outlet of the apparatus was 500 ppm. The diameter of the air duct was lO0 mm and the length of the duct was 3 m. In this air duct, lO activated carbon filters ~Trademark "TAK Filter 800 Cell" made by Tokyo Roki.Company, 1td.) were placed and lO contalners (50 x 50 ~ 5 mm) made of a 1exible thin aluminum plate, with 3 openings having a diameter of 2 mm, were fixed to the bottom of the air duct ~y use of a duplex adhesive tape as illust~ated in Fig. 6.
The flow rate of the discharged air at the outlet of the duct was 0.5 m~sec. The pressure loss by each filter ~ was 4 mm~H O.
;:~ 2 ~ .
When only the activated carbon filters were incorporated, the oæone decomposing ratio was decreased to : 45% ~n 25 hours ~s s~owh by curve B in Fig.. 7. In contrast ~
to this, when t~e containers containing the terpenoid were ::

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~.
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placed in combination with the ~ctivated carbon filters, the ozone decomposing ratio was ma~ntain~d at gS% as shown by curve A in Fig. 7. It is considered that such high ozone tecomposing per~ormance for an extended period o~ t~me was attdined since the terpenoid (d-limonene) was eva~orated from the openings o~ the 10 contain~rs and the vapor was absorbed by the activated ~arbon, so that d-limonene was oxidized ~y ozone, thereby decomposing ozone, ~efore the activated carbon was oxidized.
Fig. 8 shows a fu~ther example of an ozone d~composing apparatus 300 acc~rding to the present invention. ~ ;~
The ozone decomposing apparatus 300 comprises an upper ozone decomposing material holding por~ion A and a lower ozone decomposing agent holding portion B, which are held by an external wall 12. The ozone decom~osing material holding portion A comprises, for instance, an activated carbon f~lter 13 wlth an vacant portion 1~ (as shown Ln Fig. 9), and ~he ozone decomposing agent holding portion B comprises , ~:
~r,,~ a con~ainer 14 in which, for instance, a ge}led terpenoid ~: ozone decomposing aqent 17 is contained. The ozone -decomposing agent holding portion B includes an opening ~1 nrougn wnlcn tne vapor os a ~erpenold os the gelled .-~
~erpenoid ozone decomposin~jagent l? comes out and is ! ~
di~persed. The vapor of the te~penoid is dispersed through ~ ~ ' `~'` ~ ' ' ~,,";~

the vacan~ portion 19 and absorbed by the activated carbon filter 13.
In this ozone decomposing apparatu~, the size of the opening 11 of ~he contaLner 14 and the shape of the vacant portion 19 are chan~ed, depending, for ~nstance, upon the volatility of ~he terpenoid and the degree o~ the gellation o the gelled terpenoid ozone decompo3$ng agent in such a manner that the consumption of the terpenoid and the supply of ~he same are well balanced.
The container 14 includes a window 20 with a use limit ~
line 18 thereon, through which the amount of the residual ~;
gelled terpenoid ozone decomposing agent 17 ca~ be seen.
W~en the amount of the gelled t~rpeno~d 17 is decreased ~èlow ~he level indi~ated by the use limit line 18, the gelled terpenoid ozon~ decomposing agent 17 is discarded.
FLg. 9 ls a se~tion taken on line X - X in Fig. 8. As shown in this figure, an opening rod 16 is held by a rod support member 30 so as to be movable in the direction of ; ~ the arrow. The openLng 11 of the container 1~ is closed ~
w~th an aluminum sealing~sheet 15. ~he outer ~all lZ is ~ -made o~,~for instance, an elastic plastic film, metal foil or adheslve tape. When the oute~ wall 12 is depre~ieed in - ~ the direction of the arrow so as to move down the openin~
rod 16, a hole is mad~ in the aluminum sealing sheet 15, so that the closed~opening l1;is~opened. The resul~ is that .;~ :: ~

~ 23 -.
:
i~

the vapor of the terpenoid component evaporated fro~ the gelled terpenoid spreads throughout the activated carbon filter 13 through the vacant portion 19.
Fig. 10 is a perspective ~iew of the container 14 for the ~elled ~erpenold. As m~ntion~d prev~ously, th~ opening 11 in the upper surface of the contalner 14 i~ ~ealed by the aluminum seallng sheet 15, and ~hen the opening rod 16 i&
pushed in the direction o~ the arrow, a hole is made ln the aluminum sealing sheet 15 so that the covered opening ll is opened. As a matter of course, a plurality of openings can be formed in the upper surface of the container 14 when ~.
necessary. In general, when the air does not flow above the openin~ 11, the dispersion rate of the vapor of the terpenoid component from the openinq ll~depends upon the vapor pressure of the terpenoid component since the diameter of ~he opening 11 is as small as 1 to 3 mm.
However, when the air flows above the openLng 11, the -~ .
,~ ' dispersion rate of the vapor o~ the terpenoid component '~
significantly Lncreases depending upon the difference ~
bet~een~,the pressure withln the,container 14 and the '`''' pressure outside the container 14.
Fi~. 11 is a schematic illustxation of an ozone ~ decomposing apparatus 400 according to the present '~;': ~ invention, which is suitable for use with an apparatus for ::
~ activating the surface~o~:resin films for impro~ement of the -, ~::: ;~- ~

~ 24 : ~ .
. ~ ~
. -ink recep~ivi~y and adhesiveness, and a sterilization appara~us for waterworks and sewage-treatment system~ from which ozone is generated with a conc~ntration of 500 ppm or moxe. In this ozone decomposing apparatus, a plurality of the ozone decomposln~ apparat~s shown t n Fig. 8 thraugh Fig. :.
10 are incorp~ated in an air duct 1 as shown in ~ig. ll.
In this sense, th~s apparatus i8 much sLmpler in structure as compared with conventional ozonei decomposing systems for use with the above~mentioned ap~aratus.
~ ig. 12 is ~ diag~am of a test apparatus for investigating the performance of the ozone decomposing apparatus 300 shown in~Fig. 8 ~hen it is used for a corona ~harging apparatus 115 of an electrophotographic copying ~i.
machine, in which test apparatu~ a blower 114 is provided bet~een the corona charging apparatus 115 and the ozone decomposing appar~tus 300.
Fig. 13 schematicall~ show~ an electrophotographic copying machine in which the ozone decomposing apparatus shown in Fig. ~ is incorporated.
In both the ozone decomposing apparatus 400 as shown in .:
`~ Fig. 11 and the ozone decomposing appara~us incorporated in the electrophotographic copying apparatus 300 shown in Fig.
11, the timing for exchang~n~,the used gel~ed terpenoid with a new gelled terpenoid can be checked from the : previously mentioned use limit line 18 in the window 20.

~, ~
~ 25 ~:

133168~
Example 2-1 The ozone decomposing apparatus 300 as shown in Fig. 8 through Fig. 10 was constructed in the following manner:
A pair of honeycomb-like activated carbon filters (80 S mm (H) x 80 mm (W) x 10 mm (P)) (made by Toyobo Co., Ltd.), with a gap of 10 mm therebetween, were fixed to a container (80 x 30 x 30 mm) containing 50 g of a gelled terpenoid by use of an adhesive tape. As the gelled terpenoid ozone decomposing agent, the same ozone 10 decomposing agent as that prepared in Example 1-2 was employed.
The container was made of transparent polypropylene, with an opening having a diameter of 2 mm made in the upper side thereof. The opening was sealed by an aluminum 15 foil. An opening rod, made of wood, having a length of 80 mm and a tip having a diamQter of 1.8 mm, was supported by use of an adhesive tape and an opening rod support member in ~uch a configuration as illustrated in Fig. 9.

20 Examp}e 2-2 A honeycomb-likQ a¢tivated carbon filter (made by , .
Toyobo Co., Ltd.) was used in a conventional electropho~tographiclcopying~machinQ~ for a period of time corrQsponding to the time for making about 15,000 copiQs 25 in the~elQctrophotographic copying machlne, whereby a first used honeycomb-like activated carbon filter was prepared.

`~

In the same manner, a second used honeycomb-like aativated carbon filter was prepared. The second used honeycomb-~ike activated aarbon filter was placed together with the ~elled terpenoid prepared in Example 1-2 in a ~e~iccator for 1 day, so that the terpenoid was adsorbed by the second used honeycomb-llke activated carbon filter.
The first activated carbon fil~er free from the terpenoid and the second a~tivated carbon filter with ~he terpenoid absorbed therein were successively incorporated in an electrophoto~raphic copying tes~ machine as illustra~ed 1n ~ig. 13.
The air flow rate at an air outlet of ~he test machine, at which any of the above activated carbon filters was incorporat~d, ~as 1 m/sec. The amount of the ozone discharqed from the test copying machine was measured by Monitor Labs Ozone Anal~2er 8410E.
~Test 4]
The test copying machine was run without incorporati~g any activated carbon filter.

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Test 5l he test copying machine was run with the first activated carbon fLlter!incorporated therein.

t Test 6 ]
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The test copyinS~ machine was run wi~ch the second activated carbon f ilter incorporated therein .

~ he amounts of ozone discharged ~rom the copying machine in the above tests were as follows: ~.

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:, . . ,. - ~. :. r: :.'. - , . . ;.~ : :` `:':: - i : .

1331~89 . ., Test 4 Test 5 Test 6 (without Filter) (with First Filter) (~ith Second ~ilterl 1st day 14.0 mQ/hr 5.0 mQ/hr 1.0 mQ/hr ;:
_ .
~nd day 14.~ mQ/hr 5.1 m2/h~ 1.1 m~hr _ .-, _., 3rd day 14.0 mQ/hr 5.3 m~/hr 0.9 mQ/hr 5th da~ 14.0 m~/hr 5.8 mQ/hr 0,~ r In the above tests, on ~he first day, the data were obtained one hour after the starting of the copying mach~ne and thereafter the copying machine ~as run for S hours. On the second day, the third day and the fifth day, the data.
were obtained 10 minutes after the starting of the copying machine and thereafter the aop~ing machine was run for 5 hours.
The first activated carbon filter free from the terpenoid had ozone decomposing performance to some extent.
However, the ozone decomposing performance gradually decreased as can be seen from the aboYe.
~ n contrast to this, the second activated carbo~ filter with the terpenoid adsorbed therebY maintained high ozone decomposing performance for an extended period of time, possibly because the terpenoid was continuously supplied to th~ activated carbon filter.

i .

Example 2-3 1331689 The following two types o~ used acti~ated carbon filters were prepared with the 8ame shape and ~truature as in the used activated carbon filter emploYed in Example 2 EActivated Ca~on F~lter Al A ~one~comb-like filter with activated carbon deposited on paper fibers.

[Activated Carbon Filter B3 - A honeycomb-like filter with activated c?~rbon contained in ceramics.
~.
The above two types acti~?ted carbon filters A and B - .
were employed individually and in combination with the s~me gelled terpenoid employed in Example 1-2, ~hereby ~he following four different ozone decomposin~ apparatuses were set up and lncorporated in the:test apparatus as shown in .
Fig. 12. They are Ozone Decomposing Apparatus A (Activated Car~on Filter A + Gelled Terpenoide), Ozone Decomposing , ~ :
Apparat~s A'~Activated Carbon Filter A only), Ozone Decomposing Apparatus ~ (ActLvated Carbon Filter B + Gelled Terpenolde), and ozone ~ecomposing Apparatus B' (Activated ~-~ Carbon Filter B' only).

The ozone decomposing cond~tions were as ~ollows:

~ .

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Air ~low rate at the outlet: 0.8 m/sec Te~perature and humidity; 20 to 25C, 60 to 80%R~
Pressure loss; 2 mm/H~O
Ozone detection Appara~us: ozone Analyzer 8410E
Measurement position: within an area of 10 cm from the air outl~t Amoun~ of ozone ~nerated: 25 m~/hr within an area of 10 cm from ~he air outlet without ozone decomposing apparatus Concentration of ozone 1.0 to 1.2 ppm within an generated: area of 10 cm from the air outlet without ozone deco~posing apparatus Met~od of measuring the concentration of ozone: same as in Example 2-2 Evaporation rate of terpenoid: 0.1 g/hr at the above air flow rate from an opening having a diameter of 2 mm, and 0.01 g/hr from the opening when no air flows thereabove The results of the above measurement were as follows:
. .... , ~
Ozone Decomposing Concentration of Ozone (ppm) ~ Apparatu~ :- .
;.: 1st Day 2nd Day 3rd Day 5th Day : .-:~ A 0.10 0.10 0.08 0.07 .-~- ~ ~
A' 0.10 0.10 0~11 0.14 .~ .. .. .
: s 0.10 0.10 0.10 0.06 ,. _ ! ~ ~ . . . . . l : ~' 0.10 0.1~ 0.1Z 0.13 ~:
~. , ~: - 31 -~:

~:

~ he above results indicate that the terpenoid which evaporates from the opening of the container is ads~rbed by any of the above activated carbon filters, regardless of t~ie kind and shape ~hereof, so that the ozone decomposing:~`
performance of each of the activated ca~bon filters A and B
is maintained.

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. - 32 -.-

Claims (7)

1. An ozone decomposing apparatus, comprising an external wall enclosing an upper ozone material decomposing portion and a lower ozone decomposing agent holding portion positioned directly below said upper portion, said external wall having open sides to permit ozone bearing air to flow horizontally through the upper portion;
an activated carbon filter in said upper portion;
and a volatile ozone decomposing agent in said lower portion, whereby vapors of the ozone decomposing agent rise and are absorbed by the activated carbon filter, and whereby ozone in ozone bearing air is decomposed by the ozone decomposing agent absorbed in the activated carbon filter.

2. The apparatus of Claim l wherein said ozone decomposing agent comprises gelled terpenoid.

3. The apparatus of Claim 1 including a container in said lower portion, the ozone decomposing agent being held in said container.

4. The apparatus of Claim 3 wherein said activated carbon filter comprises two-filter portions separated in a direction of flow of the ozone bearing air through said open sides so as to form a vacant portion therebetween, and wherein said container has an upper opening at a bottom of said vacant portion, whereby the vapors can reach said activated carbon filter via said vacant portion.

5. The apparatus of Claim 4 including a sealing sheet covering said upper opening, and piercing means in said vacant portion for piercing said sealing sheet.

6. The apparatus of Claim 5 wherein said piercing means comprise a vertically mounted rod having one end abutting said external wall and another end adjacent said sealing sheet, whereby said rod may be moved to pierce said sealing sheet by pressing said external wall.

7. The apparatus of Claim 3 wherein said container includes a transparent window having a horizontal line to indicate a level of the ozone decomposing agent in said container.