Description
Title of Invention
ADSORBENT, METHOD OF PREPARING SAME$ ADSORBENT FOR WATER
PURIFICATION, MASK, AND ADSORBING SHEET
Technical Field
[OOOl]
The present disclosure relates to an adsorbent, a nietliod of preparing the
10 same, an adsorbent for water purification, a mask and an adsorbing sheet.
Background Art
[0002]
In order to remove a heavy metal such as chromium (Cr) from water, ion
15 exchange resin, chelate resin and zeolite are used in the past (refer to, for example, JP
~~~ H09-187646A, JP 2003-137536A and JP H04-292412A). In order to remove : - .- - -~ -: organics from water, silica gel are used in the past (JP H11-09933 1A). ~~~ ~ ~
Citation List
20 Patent Literature
[0003]
Patent Literature 1 : JP H09-187646A
Patent Literature 2: JP 2003-137536A
Patent Literature 3: JP H04-292412A
25 Patent Literature 4: JP Hll-099331A
Sutumary of Invention
Technical Problem
[0004]
30 However, the ion exchange resin, the chelate resin and the zeolite are
expensive, and a less expensive and high perfomlance adsorbent is strongly
demanded. While the silica gel is problen~atic because it cannot adsorb a larger
organic molecule, a material is demanded whicl~c an adsorb a larger ~nolecule.
[0005]
Accordingly, an object of the present disclosure is to provide a less
5 expensive and 11igl1 perfomlance adsorbent, a method of preparing the same, an
adsorbent for water purification, a mask and an adsorbing sheet by using the above
absorbent.
Solution to Pxoblem
10 [0006]
The adsorbent in accordance with a first embodiment of the present
disclosure for achieving the above object includes:
silica of wllicl~ a raw material is a material originating fiom a plant which
includes silicon; and
-
15 a silane coupling agent which modifies a surface of the silica,
wherein a value of a specific surface area of the silica in accordance with a ~ ~ ~ ~~
nitrogen BET method is 10 I I I ~ /o~r more, and a pore volunle of the silica in
accordance with a BJH tnethod is 0.1 cn131g or more, and preferably 0.2 C I I I ~ / ~o r
~~~~~~ ~~
more.
20 [0007]
The adsorbent in accordance with a second enlbodiment of the present
disclosure for achieving the above object includes:
silica of xvbich a raw material is a material originating from a plant which
includes silicon; and
25 a silane coupling agent which n~odifiesa surface of the silica,
wherein a value of a specific sulface area of the silica in accordance wit11 a
nitrogen BET n~etllodi s 10 III'/~ or more, and, it1 pore size distribution of the silica
obtained by using a non-localized density fut~ctional theory method WDFT
method), a total of volu~neso f pores each having a pore size ranging fi.0111 1 nm to 25
30 nm is 0.1 C I I I ~ /o~r more, and a ratio of a total ofvolu~neso f pores each having a pore
size ranging from 5 nnl to 25 nm to the total of voln~neso f the pores each having the
pore sue ranging fsom 1 ntn to 25 nm is 0.2 or more, preferably 0.5 or more, and
inore preferably 0.7 or more.
[OOOS]
A method of preparing the adsorbent of the first embodirnent of the present
5 disclosure for achieving the above object is a method of preparing an adsorbent in
which a value of a specific surface area of silica in accordance with a nitrogen BET
method is 10 m21g or more, and a pore volume of the silica in accordance with a BJH
method is 0.1 cm3lg or more, and preferably 0.2 cni31g or more, the method including,
in the sequence set forth:
10 obtaining the silica by sinteritig a material originating fsom a plant which
includes silicon; and
modifying a surface of the silica with a silane coupling agent.
[0009] --
A method of p~eparing the adsorbent of the second e~nbodiment of the
15 present disclosure for achieving the above object is a method of preparing an
adsorbent in which a value of a specific surface area of silica in accordance with a
nitrogen BET method is 10 m21g or more, and, in pore size distribution of the silica
obtained by using a non-localized density functional theoly method, a total of
volurnes of pores each having a pore size ranging from 1 nm to 25 nnl is 0.1 cm31g or
20 tnore, and a ratio of a total of volumes of pores each having a pore size ranging fro111
5 nm to 25 nm to the total of volumes of the pores each having tlie pore size ranging
from 1 mil to 25 nm is 0.2 or tnore, preferably 0.5 or more, and more preferably 0.7
or more, the method including, in the sequence set forth:
obtaining the silica by siritering a material originating fiom a plant which
25 includes silicon; and
modifying a surface of the silica with a silane coupling agent.
[OO 1 01
The adsorbent for the water purification of the present disclosure for
achieving the above object includes the adsorbent in accordance with the first
30 embodiment or tlie second embodiment of the present disclosure. The mask of tlie
present disclosure for achieving tlie above object includes the adsorbent in
accordance with the fust embodiment or the second embodiment of the present
disclosure. The adsorbing sheet of the present disclosure for achieving the above
object includes a sheet-shaped member having the adsorbent in accordance wit11 tl~c
first embodiment or the second embodiment of the present disclosure.
5
Advantageous Effects of Invention
[OOll]
In the absorbent and the method of preparing the same, and the adsorbent
for the water purification, the mask and the adsorbing sheet in accordance with the
10 fust embodiment or the second embodiment of the present disclosure, a preparation
cost is low because the material originating from the plant and including the silicon
is used as the raw material. The value of the specific surface area of the adsorbent,
the value of the pore volume and the pore size distribution are specified, and further
because the surface of the silane is modified with the silane coupling agent, the
15 higher adsorbing ability is provided to tlie adsorbent.
Brief Description of Drawings
[0012]
[FIG. 11 FIG. 1 is a graph showing measurement results of the pore size distribution
20 obtained based on the not1 localized density functional theory method in samples of
the adsorbents of Example 1, Reference Example 1, Comparative Example 1A and
Comparative Example 1B.
[FIG. 21 FIG. 2A and FIG2B are a schematic view of a mask of Example 3, and a
view showing a main part of the mask, respectively.
25 [FIG. 31 FIG. 3 is a schematic sectional view of a water purifier in Example 4.
[FIG. 41 FIG. 4A and FIG.4B are a schematic partial sectional view and a schematic
sectional view, respectively, of a bottle in Example 4
[FIG. 51 FIG. 5A and FIG.5B are a schematic partial sectional view and a schematic
view a part of which is removed, respectively, of an alternative example of the bottle
30 in Example 4.
Description of Embodiments
[0013]
Although the present disclosure will be described based on Examples while
referring to the drawings, the present disclosure is not restricted to these Exatnples,
and various nun~eralsa nd materials in Examples are exemplaly. The description will
be conducted according to the following order.
1. The adsorbent, the method of preparing the same, the adsorbent for water
purification, the mask and the adsorbing sheet in accordance with the first
embodiment and the second embodiment of the present disclosure, and the generic
description
2. Example 1 (the adsorbent and the method of preparing the same in accordance
with the fust embodiment and the second embodinlent of the present disclosure
3. Exan~ple2 (the adsorbent for water purification, the mask and the adsorbing sheet
of the present disclosure), an others
- [0014] ~~ -~~
~
In the absorbent in accordance with the fust embodiment or the second
embodinlent of the present disclosure, the adsorbent prepared by the method of
preparing the adsorbent in accordance with the first embodiment or the second
embodiment of the present disclosure, and the adsorbent of the present disclosure
configuring the adsorbent for the water purification, the n~asko r the adsorbing sheet
(these may be also hereinafter referred to as 'adsorbent and the like'), the adsorbent
and the like of the present disclosure can effectively adsorb organics (organic
n~olecules) because the surface of the silane is modified with the silane coupling
agent.
[0015]
The absorbent and the like of the present disclosure may have a form that
the silane coupling agent is treated with acid. The method of preparing the
adsorbent of the present disclosure may have a forn~th at after the surface ofthe silica
is treated with the silane coupling agent, the silane coupling gent is treated with the
5 acid. In these fonns, the adsorbent and the like of the present disclosure can
effectively adsorb, for exanlple, a cation containing metal atom (for example, copper
ion). The acid treatment herein refers to a treatment in which the adsorbent and the
like of the present disclosure is dipped into an inorganic acid such as cl~lorica cid,
sulfuric acid, nitric acid and phosphoric acid. In tliese forms, the silane coupling
10 agent preferably contains at its ternlinal a functional group which bonds to a
desirable metal ion (including a metal atom). Or, after tl~esi lane coupling agent is
treated with silane, the silane coupling agent is preferably provided with a functional
group which bonds to a desirable metal ion (including a metal atom). The
adsorbent and the like of the present disclosure of tliese forms can effectively adsorb
15 an anion and a cation containing a metal atom [for example, an arsenic ion having a
- form of ~ ~ 0 3a2. cb,r omium ion having a form of c r o p , and a lead ion having a
form of pb2+], a mercury ion contained in mercury chloride and nlethyl mercury. An
amino group, a chelate ring in which a metal such as iron (Fe), cobalt (Co) and
copper (Cu) is coordinated to an amino group and the like and a molecule containing
20 sulfur @)-such as a 111~lgroupca n be exemplified as the functional group the silane
couplitig agent contains or the functional group provided to the silane coupling agent.
[0016]
The absorbent of the present disclosure including the above preferable
fol-ms is an absorbent adsorbing organics (for example, an organic molecule and a
25 protein) having a number average tnolecular weight of 1 x lo2 or more, and as a
target, an aliphatic acid (specifically, oleic acid, stearic acid, myristic acid, squalene
and cholesterol, for example), a pigment (for example, Pign~et~Rte d 57:1), a toxin
(microcystrine, aflatoxin B1, nodularin, anatoxin, saxitoxin and Cylindrospermopsin),
~ - ~~- -- ~~ < . ; . , ~ ~ . ~ a pesticide and an- insecticide (for example, simazine, paratliton:.:'. fenobucarb,
30 Carbaryl and cyllalothin), and a proteii~ (alpha-amylase and neuraminidase) are
exemplified.
[0017]
In the absorbent and the like of the present disclosure including the various
preferable forms described above, 3-aminopropylethoxysilane, metl~yltriethoxysilane,
pl~enyltriethoxysilanet,e traethoxysilane, etliyltrioxysilane,
qltriethoxysilane, 3-[2-(2-arninoetl1ylatnino)ethylamino]propyltsimethoxysi1ane, 3-
atninopropyldimethyl~i~etl~oxysilane, 3-aninopropyltritnethoxysilane,
octadecyltritnetl~oxysilane, (3-chloropropyl)tri~~~ethoxysilane, 3-
glycidoxypropyltri~i~etlioxysilane, 3-cyanopropyldimetliyhetl~oxysilane, 3-
heptafluoroisopropoxypropyl trimethoxysilane, vinyltrirnethoxysilane, 2-(3,4-
epoxycyclohexyl)etliyltrimethoxysilane, 3-glycidoxypropyltnetliyldimethoxysilane,
. ~
3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-
glycidoxypropyh~etl~yldimethoxysilane, 3-glycidoxypropyltriethoxysilane, N-2-
(aminoethyl)-3-aminopropylmethyldimetl1oxysilane, N-2-(aminoetliy1)-3-
aminopropyltrimethoxysilane, N-2-(aminoetby1)-3-aminopropyltriethoxysilane 3-
atninopropyltsimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-
-~ ~ dimethyl-butylidene)propylamine, -:N-plienyl-3-a~ninopropyltrin~ethoxysilane, 3-
ureidopropyltriethoxysilane, 3-~i~ercaptopropylmethyldirnethoxysilane, 3-
~nercaptopropyltrimetl~oxysilane, bis(trietlioxysilylpropy1)tetrasulfide and 3-
isocyaoatepropyltriethoxysilane are specifically exemplified.
[0018] - ~~
In tlie adsorbent and the like of the present disclosure including tlie various
preferable fornis described above, the material originating frotn the plant and
containing the silicotl is used as tlte raw material of the silica, and specifically, as tlie
material originating fi-om the plant, chaff of rice (rice plant), barley, wlieat, lye,
Japanese millet and foxtail millet, straw, coffee beans, tea leaves (for example,
leaves of green tea and red tea), sugar canes (for example, bagasse), corns (for
example, cores of corns), fiuit peels (for example, peels of niandarin oranges and
bananas) or reed and "kuki wakameN(sliced seaweed stem) are exemplified and
are not restricted, and further, a vascular bundle plant which is vegetative on land, a
pteridophyte, a b~yophyte, algae and seagrass are exemplified. These materials may
be used singly as the raw material, or a plurality of species can be tnixed atid used.
8/25
The shape and the fonn of tlie material originating froni tlie plant are not especially
restricted and, for example, the chaff and the straw can be used without modification,
or those dry-treated may be used. Further, those subjected to various treahnents
such as a fermentation treatment, a roasting treatment and an extraction treatment
5 during the processing of food and drink such as beer and liquor can be used. In view
of tlie recycling industrial wastes, the straw and the chaff after tlie processing such as
thrashing can be preferably used. The straw and the cliaff after the processing can
be easily obtained in large quantities, for example, at a farmer's cooperative, a
distillery, a food cotnpany and a food processing company.
10 [0019]
In the method of preparing the adsorbent of the present disclosure, the silica
can be obtained by calcining the material originating from the plant and containing
the silicon, for example, at 200 degree C in air. A desired grain size can be obtained
by pulverizing the material originating from the plant depending on necessity and the
15 material can be classified. The material originating fron~th e plant can be ~vasliedin
advance. A desired grain size can be obtained by-pulverizing the obtained silica
depending on necessity and the silica can be classified. Further, the silica fmally
obtained can be subjected to a-disinfection treatment. A fonn, a configuration and a
structure of a furnace for the calcination are free of restriction, and a continuous
20 furnace or a butch furnace can be used. ~ ~ ~ ~-~ ~~ ~ ~~
[OOZO]
In the adsorbing sheet of the present disclosure including the above
preferable forms, a woven fabric and a non-woven fabric are exemplified as a
support men~ber, and cellulose, polypropylene and polyester are exemplified as a
25 material configuring the support member. The forms of tlie adsorbing sheet include
a fom~in which the adsorbent of the present disclosure is sandwiched between the
support ~i~etnbeanr d the support member, and a form in whicl~t he adsorbent is
kneaded into the support member. The fonns of the adsorbing slieet further include a
forn~ in wl~ich the adsorbent of the present disclosurela polymer co~iiposite is
30 sandwiched between the support member and the support member, and a fol-111 in
which the adsorbent of the present disclosureltlie polymer coaiposite is kneaded into
the support member. For example, carboxynitro cellulose is exemplified as the
material configuring the adsorbenffthe polymer composite (polymer).
[0021]
Tile adsorbent of the present disclosure can be used, for example, for
5 purification of water or purification of air, and purification of fluid in a broader sense.
The fomis of usage of the adsorbent of the present disclosure include, for example,
use as a sheet-shaped, use in a state filled in a colunln and a cartridge, use in a state
the adsorbent is shaped to a desired shape by using a binding agent (binder) and use
in a powder state. For use as a depurative and an adsorbent dispersed in a solution,
10 it is used after the surface is treated hydropliilically or l~ydrophobically. For example,
a filter of an air purifying apparatus, a mask, protective gloves and protective shoes
can be cotfigured by the adsorbing sheet of the present disclosure.
roo221
The adsorbent and the like of the present disclosure or tlie silica which is a
15 stating material of the adsorbent and the like of the present disclosure include a ~ ~
plenty of pores. The pores are generally classified into "mesopores" having a-pore ~ .
size from 2 nm to 50 ntn, "~~iacroporesh"a ving a pore size exceeding 50 MI, and
"~~iicropores"h aving a pore size smaller than 2 nm. While the pore volume in
~ ~
accordance with the BJH method is 0.1 cm3lg or more in the adsorbent and the like
20 ofthe present disclosure, it is preferably 0.1 cm3/g or more as mentioned txr&ar-~--~ ~ ~ .
[0023]
The value of the specific surface area in accordance wit11 the nitrogen BET
method (hereinafter sometimes simply referred to as "tlie value of the specific
surface area") in the adsorbent and the like of the present disclosure is preferably and
25 desirably 50 mZ/g or more for obtaining further excellent functionalities.
[0024]
The nitroger1 BET method refers to a method in whicl~ an adsorption
isothe~mis measured by adsorbing and desorbing nitrogen as an adsorption tnolecule
to and from an adsorbent (herein, adsorbent and the like of the present disclosure)
30 and analyzing the measured data in accordance with a BET equation represented by
Equation (I), and a specific surface area and a pore vo1u111e car1 be calculated based
on the above method. Specifically, in case of calculating the value of the specific
surface area in accordance with the nitrogen BET method, the adsorption isotherm is
obtained at first by adsorbing and desorbing the nitrogen as the adsorption molecule
to and from the adsorbent and the like of the present disclosure. Then, [p/{V*(po-
5 p)}] is calculated based on Equation (1) or Equation (1') obtained by transforming
Equation (1) from the adsorption isother111 obtained, and is plotted with regard to an
equilibrium relative pressure (plpo). Then, the plot is regarded as a straight line, and
a slant 's' (= [(C-l)/(C.V,)] and an intercept 'i' (= [l/(C.V,)]l are calculated based
on a least-square approach. Then, V, and 'C' are calculated from the slant 's' and
10 the intercept 'i' based on Equation (2-1) and Equation (2-2). Further, the specific
surface area a,~mis calculated from V,,, based on Equation (3) (refer.t o page 62~to
page 66, a n~anualo f analysis software of BELSORP-mini and BELSORP available
- from Bell Japan Inc.). This nitrogen BET method is a measurement method which
is compliant with JIS R 1626-1996 "Measuring methods for the specific surface area
15 of fine ceramic powders by gas adsorption using the BET method".
[0025]~ ~ ~ . .-.~ . ~ ~~ ~~~.~. . ~ .
va = (vm.C.~)/[(Po-p){l+(C-l) (p/po)}I (1) ~~ ~
[p~~V,(po-p=)~ (lC -1)/(C.Vm)I (P/PO)+[~/(C.V~)I (1')
V, = l/(s+i) (2-1)
20 C = (s/i)+l (2-2) ~. . ~ a&, = Or,.L.a)/22414 (3)
[0026]
Syinbols are as stated below.
V,: amount of adsorption
25 V,: amount of adsorption of single tnolecular layer
p: pressure of nitrogen at equilibrium
pa: pressure of nitrogen at saturation
L: Avogadro number
a: adsorption sectional area of nitrogen
30 [0027]
In case of calculating the pore volume Vp in accordance with the nitrogen
BET method, for example, the adsorption data of the adsorption isother111 obtained is
linear-interpolated, and an amount of adsorption 'V' is obtained at the relative
pressure established as the relative pressure for calculating the pore volume. The
5 pore volume V, can be calculated from the amoutit of adsorption 'V' based on
Equation (4) (refer to page 62 to page 65 of the manual of analysis software of
BELSORP-mini and BELSORP available from Bell Japan Inc.). Hereinafter, the
pore volume in accordance with the nitrogen BET method will be sometimes referred
to as sitnply "pore volun~e".
10 [002S]
Vp= (Vl2241) x (MgI(ra (4)
[0029]
Symbols are as stated below.
V: amount of adsorption at relative pressure
~ ~~ 16 M,: n~olecularw eight of nitrogen
0,: density of nitrogen . ~ -~ ~ ~ ~ ~~ ~
[0030]
The pore size of the mesopore can be, for example, calculated as pore
distribution from i pore volume change rate based on the BJH method. The BJH
20 method is a metliod widely used as a tnetliod for analyzing pore size distribution.
In ca& of analyzing the pore volume distribution in accordance with the BJH metl~od,
a desorption isotherm is at first n~easuredb y adsorbing and desorbing nitrogen as an
adsorption ~nolecule to and from the adsorbent of tlle presetit disclosure. Then,
based on the obtained desorption isot11er111, a thickness of an adsorption layer
25 between a state in which the pore is filled wit11 an adsorption molecules (for exan~ple,
nitrogen) and a state in which the adsorption tnolecules desorb stepwise, and an inner
diameter of the pores (twice core radius) generated on tliis occasion are measured, a
pore radius r, is calculated based on Equation (5), and the pore volu~neis calculated
based on Equation (6). Then, a curve of pore size distribution can be obtained by
30 plotting the pore volume change rate with respect to a pore diameter (2rp) from the
pore radius and the pore volume (refer to page 85 to page 88 of the manual of
analysis sofhvare of BELSORP-mini and BELSORP available om Bell Japan Inc.).
[0031]
r, = t+ rk (5)
5 V,, =& dV.-R,,.dL. c.ZAd (6)
Note that:
Rn= r,2/ ( r h - 1 + dt,J (7)
[0032]
Sytnbols are as stated below.
10 r,: pore radius
rk: core radius (inner diameterl2) when absorption layer having thickness 't' is
adsorbed on inner wall of pore having pore radius r, at its pressure
V,,: pore volume when 'n'th desorption of nitrogen takes place
dV,: amount of change on this occasion
-
15 dt,: amount of change of thickness t, of adsorption layer when 'n'th desorption of
nitrogen takes place
rh: core radius on this occasion
c: fixed value
r,,: pore radius when 'n'tl~ desorption of nitrogen takes place
20 CA,represents an integration value of a pore wall surface area fiom j=l to
j=n-1.
[0033]
The pore size of the n~icroporec an be calculated as the pore distribution
from the pole volume change late with respect to its pore size, for example, in
25 accordance with the MP method. In case of analyzing the pore size distribution UI
accordance with the MP method, the adsolption isotherm is at first obtained by
adsorbing nitrogen on the adsorbent and the like of the present disclosure. Then,
this adsorption isotherm is converted into the pore volume with respect to the
thickness 't' of the adsorption layer (conducting 't' plot). Then, the curve of the pore
30 size distribution can be obtained based on a curvature (an amount of change with
respect to an amount of change of the tl~ickness 't' of the adsorption layer) of this
plot (refer to page 72 to page 73 and page 82 of the matmal of analysis sofhvare of
BELSORP-mini and BELSORP available fro-otn Bell Japan Inc.).
[0034]
In the non-localized density functional theory method (NLDFT method)
5 prescribed in JIS 28831-2:2010, "Pore size distsibution and porosity of powdery
materials (solid materials) - Part 2: Measurenient method of mesopores and
macropores by gas adsorption", and JTS 28831-3:2010, "Pore size distribution and
pore characteristics of powdery materials (solid materials) - Part 3: Measurement
method of micropores by gas adsorption", a sofhvare appended to a11 apparatus for
10 automatically measuring specific surface aredpore size distribution "BELSORPMAX"
available fsom Bell Japan Inc. is used as an analysis sofhvare. Precedent
conditions are such that carbon black is assumed to be a model in the shape of
cylinder, and a distribution function of a pore size distribution parameter is set to be
"non-assumption': and the distribution data obtained are subjected to smoothing ten
-- -- 15 times.
-
[0035]
In the adsorbent and the like of the present disclosure, tlie specific surface
area and thevarious pore volumes are measured in accordance with the nitrogen BET
method for the silica aftes a thermal treatment at 120 degree C for three hours under
20 a reduced pressure.
[Example 11
[0036]
Example 1 relates to an adsorbent in acco~dance with a first embodiment
25 and a second embodiment of the present disclosure, and to a method of preparing the
same. The adsorbent of Example 1 includes silica of which a raw material is a
material originating from a plant which includes silicon, and a silane coupling agent
of which a surface is modified. A value of a specific surface area of the silica in
accordance with tlie nitrogen BET method is 10 ~ i io~r m/or~e, and the pore volume
30 of the silica in accordance with the BJH method is 0.1 cm31g or more, aud preferably
0.2 c1ii3/g or more. The value of the specific surface area of the silica in accorda~ice
with tlie nitrogen BET method is 10 m2lg or more, and, in the pore size distribution
of the silica obtained by using the non-localized density functional theory method
WDFT metliod), the total of tlie volume of the pores having the pore size ranging
from 1 nm to 25 ntii is 0.1 cm31g or more, and the ratio between the total of the
5 volume of the pores having the pore size ranging from 5 nm to 25 nm and the total of
tlie volume of the pores having tlie pore size ranging from 1 nm to 25 nin is 0.2 or
more, preferably 0.5 or more, and more preferably 0.7 or more. The adsorbent of
Exaniple 1 effectively adsorbs the orgaiiics (organic molecules).
[0037]
10 In Exaniple 1, chaff of rice (rice plant) is used as the niaterial originating
from the plant and containing the silicon which is the raw material of the silica. In
tlie metliod of preparing tlie adsorbent in Example 1, after tlie silica is obtained by
calcining the material originating from the plant and containing the silicon, the
surface of the silica is modified with the silane coupling agent. Hereinafter, the
15 modification of the surface of the silica with the silane coupling agent will be
. . .~.. . . 2 . sometimes referred to as "silane coupling treatment" for the sake of convenience. - ~. ~
~~~- - ~ [0038]
In the preparation of tlie adsorbent of Example 1, tlie silica was at fmt
obtained by calcining the chaffwhich was the material originating from tlie plant and
2pgontanipg the silicon, specifically, at 500 degree C for three hours in an atmosphere.
This silica is referred to as "Reference Example 1".
[0039]
Tlien, 0.5 g of the silica of Reference Example 1 was added to 100 ml of
toluene, further 5.0 g of 3-aminopropyltrietlioxysilane was added, and agitation was
25 conducted at 80 degree C for five hours. After filtration for obtaining a solid phase,
the adsorbent of Examplel including the silica of which a surface was modified with
the silane coupling agent was obtained by washing with 100 till of toluene.
[0040]
On the other hand, silica gel [tradename: Silica Gell, Small Granular
30 (White)] available from Wako Kabushiki Kaisl~a was made to be "Coniparative
Example 1A". A sample of "Comparative Example I B was obtained by 111odifying
the surface of the silica gel of Comparative Example 1A with tile silane coupling
agent, similarly to Example 1.
[0041]
The results of obtaining the pore size distribution of the samples of Example
5 1, Reference Example 1, Co~nparativeE xample 1A and Comparative Example 1B in
accordance with @e non-localized density functional theory method (NLDFT
method) are shown in FIG. 1. The ratios between a total of a volume of pores
having a pore size ranging fsom 5 nm to 25 urn and a total of a volume of pores
having a pore size ranging from 1 mn to 25'mihere as slloolvn in Table 1 below. In
10 Table 1, the total of the volurne of the pores having the pore size ranging fsom 1 nm
to 25 nm is designated as "Volume-A" (unit: cm31g), the total of the volurne of the
pores having the pore size ranging from 5 ~n to 20 m is designated as "Volume-B"
(unit: cm31g), and a ratio of Volume-B with respect to Volume-A is designated as
"Ratio". The results of measuring specific surface areas and pore volumes of these
15 samples are shown in Table 2. In Table 2, 'Specific Surface Area' and 'Total Pore
Volume' refer-to the specific surface areas and the total pore volumes in accordance
with the BJH method, and the units thereof are m2/g and cm3/g, respectively. "BJH
method" and "MP method" show the results of volutne measurement of the pores
(mesopores to macropores) in accordance with the BTH method, and the results of
20 volume measurement of the pores (micropores) it1 accordance with the MP method,
respectively, and the units are cm31g. In the measurements, the thel-ma1 treatment
was conducted as a pretreatment to the samples at 120 degree C for three hours under
a reduced pressure.
[Table 21
25 [Table I]
Example 1
Reference Example 1
Comparative Example 1A
Comparative Example 1B
[0043]
Volume-A
0.112
0.232
0.391
0.000
Volume-B
0.111
0.228
0.010
0.000
Ratio
0.991
0.983
0.026
-
As a result of analysis, in Exa~nple 1 in which the silaue coupling treatment
Specific
Surface
Example 1
Reference Example 1
Comparative Example 1A
Comparative Example 1B
was conducted on Reference Example 1, while the specific surface areas, the total
BJH
method
Total Pore
Volume
pore volumes and the values of the BJH method decreased, they were not so
MP metl~od
Area
65
106
702
6.5
5 significant decrease. Only little change was recognized in "Ratio". This is
considered to be based on the peculiar pore shape (structure) of the silica. On tlie
0.198
0.294
0.403
0.013
other hand, in Comparative Example 1B in which the silane coupling treatment was
conducted on the silane of the Comparative Example lA, the specific surface areas,
0.197
0.271
0.138
0.001
the total pore volumes and the values of the BJH method largely decreased as a result
0.00
0.02
0.39
0.002
10 of adsorption of the silat~eco upling agent on the surface.
[0045] ~ ~ ~.
~ ~
After 10 tng of the respective - samples ~ of Example 1, Reference Example 1,
Comparative Exarnple 1A and Co~nparativeE xarnple 1B were taken and added to 40
ml of Alizarine Green aqueous solutions having cot~centration of 0.01 glliter, they
15 were agitated at 100 rpm for one hour. Thereafter, the results shown in Table 3
~~ - ~~~ ~ ~ -
below were obtained as a result of the measurement of amounts of adsorption (tng)
of the Aliiarine Green per 1 g of the Alizarine Green aqueous solution based on a
colorimeter method tnetliod using an ultraviolet-visible spectrop11otometer.
Since the material originating fion~th e plant and containing the silicon is
20 [Table 31
used as tlie raw material in the adsorbent of Example 1,~preparation cost is low.
Example 1
Reference Example 1
Comparative Example IA
Comparative Example IB
20 mg
2 mg
0 mg (detection limit or less)
0 mg (detection limit or less)
Since the value of the specific surface area of the adsorbent, the value of tlie pore
volume and the pore size distribution are prescribed, and the surface of the silica is
tnodified with.tlie silane coupling agent, the high adsorbing ability can he provided
to tlie absorbent.
5
[Example 21
[0048]
Example 2 is an alternative of Example 1. In tlie adsorbent of Exaniple 2,
the terminal of the silane coupling agent includes a functional group which bonds to
10 a desired metal ion (specifically, cluotniutn ion). Alternatively, after the silane
coupling agent is treated with acid, the functional group whicli bonds to the desired
tnetal ion (specifically, chrotniuiii ion) is provided to the terminal of the silane
coupling agent. Specifically, a solid phase was obtained by adding 0.2 g of the
adsorbent of Example 1 to an hydrochloric acid aqueous solutioii (100 cm3) having
15 pH of 1.0 followed by agitation for one liour and filtsation. Then, this solid phase
was added to an aqueous solution prepared by dissolving 3.8g of.FeC13.6H20 into
150 ml ofwater, followed by agitation for one hour. Then, after the solid phase was
obtained by filtration, the adsorbent of Example 2 provided wit11 the functional group
which bonds to the desired nietal ion, at the terminal of the silane coupling agent, by
20 means of washing with pure water. The functio&group has a sttvcturen which
the arnino group is coordinated with iroti.
[0049]
10 nig of tlie respective samples of Example 2, Reference Exaniple 1,
Cotiiparative Example 1A and Coniparative Example 1B were taken, and added to 5
25 ml of a sodium cluoti~atea queous solutioii having concentration of 0.01 % followed
by agitation for one liour. As a result of the measurement of amounts of adsorption
(mg) of tlie clirotnate per 1 g of the sodiutii chromate aqueous solution based on the
colorimeter method using a11 ultraviolet-visible spectropliotonieter, the alnouiit of the
adsorption of Exatnple 2 was 6.7 mg. On tlie other hand, no adsorption could be
30 cotif~tned in Reference Exatiiple 1, Comparative Exatnple 1A and Coniparative
Example 1 B.
[Example 31
[OOSO]
Example 3 relates to the mask and the adsorbing sheet of the present
5 disclosure. The mask of Example 3 includes the adsorbent of Examplel to
Example 2. The adsorbing sheet of Example 3 is configured by the sheet-shaped
member including the adsorbent of Examplel to Example 2, and thesupport member
which supports the sheet-shaped member.
[OOSI]
10 A scliematic view of the mask is shown in FIG. 2A and a schematic
sectional view of a main part (adsorbing sheet) of the mask is shown in FIG. 2B, and
the main part of the mask of Example 3 includes a structure in which the sheetshaped
adsorbent of Example 1 to Exatnple 2 is sandwiched between a non-woven
fabric and a non-woven fabric made of cellulose. In order to make the adsorbent of
15 Example 1 to Example 2 to be sheet-shaped, for example, a method in which an
adsorbent/yolymer composite is formed by using a binder made of carboxynitro--.---- .~
cellulose may be employed. A carbon/polymer composite is made of the adsorbent - ~
.
of Example 1 to Example 2 and the binder, and the binder is made of tlie
carboxynitro cellulose. On the other hand, the adsorbing sheet of Example 3 is
20 made of the sheet-shaped member made of tlie adsorbent of Example 1 t o E m p l e 2 , . , ~
(specifically, adsorbent including the carboxynitro cellulose as polymer
(binder)/polymer composite), and the support member (lion-woven fabric which acts
as the support member sandwiching the sheet-shaped member) supporting the sheetshaped
member. By applying the adsorbent of the present disclosure to tlie
25 adsorbent of the mask, pollen, for example, is considered to be effectively adsorbed
because a protein site of the pollen is adsorbed on the adsorbent.
[Example 41
[OOSZ]
30 Example 4 relates to the adsorbent for the water purification (water purifier).
The adsorbent for the water purification of Example 4 is made of Example 1 to
Exatl~ple 2, and is used for, for example, the water purification and for fluid
purification in a broader sense. Alternatively, active oxygen species (oxidative stress
substance) such as superoxide, hydroxyl radical, hydrogen peroxide and single
oxygen can be removed from the water.
[0053]
A sectional view of the water purifier of Exainple 4 is shown in FIG. 3.
The water purifier of Example 4 is a continueous water purifier, and is the water
purifier directly coupled to a faucet in which the water purifier main body is directly
connected to a top end of the water faucet. 'Ihe water purifier of Example 4
includes the water purifier main body 10, a fist filling section 12 filled with the
adsorbent 11 of Example 1 to Exainple 2 positioned inside of the water purifier main
body 10, and a second filling section 14 filled with cotto11 13. Tap water discharged
Bon~th e water faucet passes from a flow inlet 15 tlxough the adsorbent 11 and the
cotton 13 and is discharged from a flow outlet 16 positioned on the water purifier
main body 10
[0054] ~.
~ ~ . ~~.. ~ . ~. ~ .-
As shown in FIG. 4A which is a schematic partial sectional view, the
adsorbent 11 of Example 1 to Exan~ple2 may be incorporated in a bottle (so-called
PET bottle) 20 having a cap member 30. Specifically, the adsorbent 11 of Example
1 to Example 2 (filtering mediutn 40) is positioned inside of the cap member 30, and
filters 31, 32 are arranged on a liquid flow-in side and a liquid flow-out side of the
cap member 30 such that the filtering t~~ediu4m0 does not flow out. For example,
the liquid (water) is purified and washed by drinking or using the liquid or water
(drinking water or beauty wash) 21 in the bottle 20 after the passage of the filtering ~ ~
medium 40 positioned inside of the cap member 30. The cap tnentber 30 is
ordinarily closed by using a cover not shown UI the drawings.
[0055]
As shown in FIG. 4B which is a schematic sectional view, the adsorbent 11
of Example 1 to Exan~ple2 (filtering nlediun~4 0) may be stored in a bag 50 having
water permeability, and this bag 50 may be tllro-rvn into t11e liquid or water (drinking
water or beauty wash) 21 in the bottle 20. A reference numeral 22 designates a cap
closing a mout11 of the bottle 20.
[0056]
As shown in FIG. 5A which is a schematic sectional view, the adsorbent of
5 Example 1 to Example 2 (filtering medium 40) is stored inside of a straw member 60,
and filters not shown it1 the drawings are arranged on a liquid flow-in side and a
liquid flow-out side of the straw member such that the adsorbent (filtering medium
40) does not flow out. The liquid (water) is purified and washed by drinking the
liquid or water (drinking water) 21 in the bottle 20 after the passage of the adsorbent
10 (filteriug medium 40) of Example 1 to Example 2 positioned inside of the straw
member 60. A reference numeral 61 designates a cap closing a 1nout11 of the bottle
20.
[0057] -
-
As sl~ownin FIG. 5B whic11 is a schematic sectional view a part of which is
15 retnoved, the adsorbent of Example 1 to Example 2 (filtering medium 40) is
positioned inside of a spray member 70, and filters not shown I the drawings are
arranged on a liquid flow-in side and a liquid flow-out side of the spray member 70
such that the adsorbent (filtering medium 40) does not flow out. For example, the
liquid (water) is purified and washed by spraying the liquid or water (drinking water
20 or beauty wash) 21 in the bottle 20 through a spray aperture 70 after the passage of
the adsorbent (filtering medium 40) of Example 1 to Example 2 positioned inside of
the spray member 70 by pushing a pus11 butt011 71 positioued on the spray mernher
70. A refelence numeral 73 designates a cap closing a mouth of the bottle 20.
[0058]
25 Althougl~ the present disclosure has been described based on preferable
Examples, the present disclosure shall not be restricted to these Examples, and
various ~llodificationsm ay he possible. Tlie configurations and the structures of the
mask, the adsorbing sheet and the water purifier described in Examples are
exemplification, and suitably changed. Although the values of the specific surface
30 area and the pore size based on the nitrogen BET method and the NLDFT method,
and the pertinent range of the pore size distribution have beet1 described with respect
to the adsorbent of the present disclosure, the description does not completely deny
the possibility that the values of the specific surface area, and the pore size
distribution get out of the above range. That is, the above pertinent range is an
especially preferable range for obtaining the effects of tlie present disclosure, and if
5 the effects of the present disclosure can be obtained, the values of the specific surface
area and the like may be out of the range in some degee.
Reference Signs List
[0059]
10 10 water purifier main part
11 adsolbent
12 first filling section
13 cotton
14 second filling section
15 15 flow inlet
16 flow outlet
20 bottle
21 liquid or water (drinking water or beauty wash)
22, 61,73 cap
20 30 cap member
31,32 filter
40 adsorbent (filtering medium)
50 bag
60 straw mernber
25 70 spray member
7 1 pus11 button
72 splay ape1 ture

CLAIMS
Claim 1
An absorbent comprising:
silica of which a raw material is a material originating fsom a plant which
5 includes silicon; and
a silane coupling agent which modifies a surface of the silica,
wherein a value of a specific surface area of tlte silica in accordance with a
nitrogen BET methgd is 10 mZlg or more, and a pore volume of the silica in
accordance with a BJH method is 0.1 C I I I ~ /o~r more.
10
Claim 2
An absorbent comprising:
silica of which a raw material is a material originating fsom a plant whiclt
includes silicon; and
15 a silane coupling agent which modifies a surface of the silica,
~ -~ wherein a value of a specific surface area of the silica in accordance with a
.- ~~ ~ ~ nitrogen BET method is 10 m21g or more, and, in pore size distribution of the silica
obtained by using a non-localized density functional theoly method, a total of
volumes of pores each having a pore size ranging from 1 ntn to 25 nm is 0.1 cm31g or
---- ~~ 20 more, and a ratio of a total of volumes of pores each having a pore size ranging from
5 nm to 25 nm to the total of volumes of the pores each having tlte pore size ranging
fsom 1 nm to 25 11111 is 0.2 or more.
Claim 3
25 The absorbent according to clai~n1 or 2, wltereu~th e silane coupling agent
is treated with acid, and contains, at a terminal of the silane coupling agent, a
functional group which bonds to a specified metal ion.
Clai~n4
30 A method of preparing an adsorbent in which a value of a specific surface
area of silica in accordance with a nitrogen BET method is 10 mZlg or more, and a '
pore volume of the silica in accordance with a BJH method is 0.1 cm31g or more, the
method con~prisingi,n the sequence set forth:
obtaining the silica by sintering a material originating from a plant which
includes silicon; and
modifying a surface of the silica with a silane coupling agent.
Claim 5
A method of preparing an adsorbent in whicli a value of a specific surface
area of silica in accordance with a nitrogen BET method is 10 mZlg or more, and, in
10 pore size distribution of the silica obtained by using a non-localized density
functional theory method, a total of volumes of pores each having a pore size ranging
fro111 1 mu to 25 nnl is 0.1 cnl3lg or more, and a ratio of a total of volumes of pores
each having a pore size ranging fiom 5 mn to 25 nlil to the total of volumes of the
pores each having the pore size ranging from 1 nm to 25 nm is 0.2 or more, the
15 method comprising, in the sequence set forth:
~.
~ ~- ~
~ ~~~~ obtaining the silica by sintering a material originating from a plant which
includes silicon; and
modifying a surface of the silica with a silane coupling agent.
20 Claim 6
The method of preparing an adsorbent according to claim 4 or claim 5,
wherein, after modifying the surface of the silica with the silane coupling
agent, the silane coupling agent is treated with acid, and a terminal of the silane
coupling agent is provided with a functional gronp which bonds to a specified metal
25 ion.
An adsorbent for water purification co~nprising the adsorbent according to
any one of claims 1 to 3.
30
Claim 8
Amask comprising the adsorbent according to any one of claims 1 to 3,
Claim 9
An absorbing sheet comprising a sheet-shaped member made of the
5 adsorbent according to any one of claims 1 to 3, and a support member supporting
the sheet-shaped member.