U.S. patent application number 15/349426 was filed with the patent office on 2017-03-02 for method of manufactring an antibacterial filter comprising copper-based compound particles.
The applicant listed for this patent is BS SUPPORT CO., LTD.. Invention is credited to Seung Woo BAEK, Mun Sun KIM.
Application Number | 20170056802 15/349426 |
Document ID | / |
Family ID | 58097486 |
Filed Date | 2017-03-02 |
United States Patent
Application |
20170056802 |
Kind Code |
A1 |
BAEK; Seung Woo ; et
al. |
March 2, 2017 |
METHOD OF MANUFACTRING AN ANTIBACTERIAL FILTER COMPRISING
COPPER-BASED COMPOUND PARTICLES
Abstract
Provided is a method of manufacturing an antibacterial filter
including copper-based compound particles. The method comprises the
steps of preparing a porous medium containing minute pores allowing
a fluid to pass therethrough and coating copper sulfide particles
on inner surfaces of the minute pores of the porous medium. The
sulfur compound particles have a chemical structure of
Cu.sub.xS.sub.y (wherein x/y=0.8 to 1.5).
Inventors: |
BAEK; Seung Woo; (Anyang-si,
KR) ; KIM; Mun Sun; (Ansan-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BS SUPPORT CO., LTD. |
Suwon-si |
|
KR |
|
|
Family ID: |
58097486 |
Appl. No.: |
15/349426 |
Filed: |
November 11, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15218395 |
Jul 25, 2016 |
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15349426 |
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PCT/KR2014/003630 |
Apr 25, 2014 |
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15218395 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01D 2239/0442 20130101;
B01D 2257/70 20130101; B01D 2253/304 20130101; B01D 2239/1208
20130101; A61L 2/232 20130101; B01D 2257/708 20130101; B01D 2257/91
20130101; A61L 2209/14 20130101; A61L 2/238 20130101; B01D
2239/0464 20130101; B01D 2239/045 20130101; B01D 2255/20761
20130101; A61L 9/16 20130101; B01D 39/1676 20130101; B01D 2251/608
20130101; B01D 53/72 20130101; B01D 2257/90 20130101; B01D 2253/311
20130101; B01D 39/2051 20130101; B01D 2258/06 20130101; B01D
39/2093 20130101; B01D 2239/0478 20130101; B01D 46/0028 20130101;
B01D 2253/1128 20130101; B01D 2259/4508 20130101; B01D 2275/30
20130101 |
International
Class: |
B01D 46/00 20060101
B01D046/00; B01D 39/16 20060101 B01D039/16; A61L 2/232 20060101
A61L002/232; A61L 9/16 20060101 A61L009/16; A61L 2/238 20060101
A61L002/238 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 6, 2014 |
KR |
10-2014-0013372 |
Claims
1. A method of manufacturing an antibacterial filter including
copper-based compound particles, comprising the steps of: preparing
a porous medium containing minute pores allowing a fluid to pass
therethrough; and coating copper sulfide particles on inner
surfaces of the minute pores of the porous medium, wherein the
sulfur compound particles have a chemical structure of
Cu.sub.xS.sub.y (wherein x/y=0.8 to 1.5).
2. The method in claim 1, wherein the copper sulfide particles are
formed by synthesizing a copper sulfide (CuS) and a copper sulfate
(CuSO.sub.4) in a molar ratio of 1:1.
3. The method in claim 2, wherein the copper sulfide (CuS) and the
copper sulfate (CuSO.sub.4) are synthesized in an aqueous solution
of 10 to 80.degree. C.
4. The method in claim 1, wherein the porous medium has a porosity
of 10 to 40%.
5. The method in claim 1, wherein the porous medium is prepared
using a supercritical fluid.
6. The method in claim 1, wherein the antibacterial filter has an
antibacterial activity of 1.times.10.sup.4 counts/ml to
1.times.10.sup.6 counts/ml.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. Ser. No.
15/218,395, filed on Jul. 25, 2016, which is a continuation in part
of PCT Application No. PCT/KR2014/003630 filed on Apr. 25, 2014,
which claims priority to and the benefit of Korean Application No.
10-2014-0013372 filed on Feb. 6, 2014, in the Korean Patent Office,
the entire contents of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an antibacterial filter
including a copper-based compound, and more particularly to an
antibacterial filter including a copper-based compound that uses a
copper-based compound having electrical conductivity to improve
antibacterial and deodorizing activities.
[0003] A filter, as a means for removing noxious substances from a
fluid, is a device for separating contaminants through pores by way
of porosity. There are various types of filters in accordance with
their intended use, including ceramic filters, polymer filters,
etc. The indoor air contains different microorganisms, such as
bacteria, fungi, viruses, or the like. Such microorganisms floating
in the air cause airborne infection or environmental diseases and
thus act injuriously on the health. The microorganisms contained in
the indoor air can be primarily removed through air filters used to
eliminate dust. But, the microorganisms, having a tenacious hold on
life, proliferate on the surface of the filter to produce
biologically generated volatile organic compounds harmful to the
human body or reenter the room.
[0004] To solve the above-mentioned problem, there has recently
been suggested a technique for preventing proliferation of
microorganisms with an application of inorganic antibacterial
preparations, e.g., silver, copper, gold, TiO.sub.2, etc. or an
organic antibacterial preparation, e.g., catherchine, chitosan,
phytoncide, Hosta capitata Nakai extract, shrubby sophora extract,
ginko biloba leaf extract, herb extract, pine tree leaf extract,
maple leaf extract, etc., on the surface of a filter. For example,
Korea Patent No. 843191 discloses a filter containing
nanoparticles. Silver is excessively expensive despite its high
antibacterial effect and ease of use. Like silver, sulfur is known
to possess high antibacterial activity. But, the application of
sulfur into practical use is much limited, because sulfur has
unsolved problems of toxic properties and difficulty of
processing.
BRIEF SUMMARY OF THE INVENTION
[0005] It is an object of the present invention to provide an
antibacterial filter including a copper-based compound that is
relatively inexpensive, easy to process, non-toxic and excellent in
antibacterial and deodorizing activities.
[0006] To achieve the object of the present invention, there is
provided an antibacterial filter including a copper-based compound
that comprises: a porous medium containing minute pores available
for a fluid to pass through; and copper sulfide applied on the
surface of the porous medium by coating or dispersed in the porous
medium, the sulfur compound having a chemical structure of
Cu.sub.xM.sub.y (where M is any one selected from Group 15 to 17
elements of the periodic table; and x/y=0.8 to 1.5).
[0007] In the antibacterial filter of the present invention, M is
any one selected from the group consisting of S, F and Cl.
Preferably, the sulfur compound is copper sulfide. Further, the
porous medium comprises any one selected from the group consisting
of ceramic, a metal and a polymer. Preferably, the porous medium
comprises a polymer. Furthermore, the porosity of porous medium is
10 to 40%, and the porous medium is prepared using a supercritical
fluid. In this regard, the antibacterial filter has an
antibacterial activity of 1.times.10.sup.4 counts/ml to
1.times.10.sup.6 counts/ml, and a deodorizing activity of 90 to
98%.
Effects of Invention
[0008] According to the antibacterial filter including a
copper-based compound of the present invention, the use of a sulfur
compound contributes to making the antibacterial filter at a
relatively low cost with ease of processing and non-toxicity.
Further, the sulfur compound including copper sulfide is excellent
in antibacterial and deodorizing activities, and its application
makes it possible to improve the antibacterial and deodorizing
activities of the antibacterial filter.
BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWING
[0009] FIG. 1 is a photograph showing copper sulfide particles
applied in the present invention.
[0010] FIG. 2 is an XRD graph showing the crystalline structure of
copper sulfide applied in the present invention.
[0011] FIG. 3 is a 30,000.times. microscopic image showing the
copper sulfide applied in the present invention.
[0012] FIG. 4 is a photograph showing the porous antibacterial
filter prepared using a chemical foaming agent and copper sulfide
according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Hereinafter, the preferred embodiments of the present
invention will be described in detail with reference to the
accompanying drawings. It is to be understood, however, that the
present invention may be embodied in various forms not to be
interpreted as limiting. The embodiments of the present invention
are provided for those skilled in the art to understand the present
invention more completely.
[0014] In the embodiments of the present invention, a sulfur
compound including copper sulfide is used to provide an
antibacterial filter that is relatively inexpensive, easy to
process, non-toxic, and excellent in antibacterial and deodorizing
activities. For this, a description will be given as to an
antibacterial filter using a sulfur compound dispersed in or
applied to a porous medium and, more specifically, to its
antibacterial and deodorizing activities. On the other hand, the
antibacterial filter of the present invention may be manufactured
by applying a coating of the sulfur compound on the surface of a
porous medium through deposition or dyeing or mixing particles of
the sulfur compound with the porous medium.
[0015] The antibacterial filter of the present invention not only
does the antibacterial activity to eliminate toxic microorganisms
through the holes in the porous medium, but also the deodorizing
activity to remove a foul odor. The material for the porous medium
may be a polymer, a ceramic, or a metal, preferably a polymer.
Specific examples of the polymer include polyurethane resin, nylon
resin, etc.; those of the ceramic may include zeolite, silica,
alumina, zirconium phosphate, etc.; and those of the metal include
aluminum, etc. The porous medium contains minute pores, through
which a fluid passes. The pore size or the porosity of the porous
medium may vary depending on the environment in which the
antibacterial filter of the present invention is used. In the
embodiment of the present invention, a porous medium comprised of a
polymer is given as a preferred example. But, the porous medium may
be comprised of a ceramic or a metal within the scope of the
present invention.
[0016] A chemical foaming agent, liquid nitrogen, or a
supercritical fluid may be incorporated into the porous medium to
form pores. More specifically, while extruded at a temperature
higher than the melting temperature by 30 to 40.degree. C., a
polymer resin used as a matrix for the porous medium is mixed with
a chemical foaming agent, liquid nitrogen, or supercritical carbon
dioxide that is side-fed. As the polymer resin is extruded, the
evaporated foaming agent, nitrogen or carbon dioxide is released
into the air to form pores.
[0017] The copper-based compound applied to the embodiment of the
present invention is preferably copper sulfide (CuS). Copper
sulfide is prepared by reacting copper sulfate (CuSO.sub.4) with a
salt selected from sulfides, fluorides, and chlorides in an aqueous
phase at mole ratio of 1:1 at 10 to 80.degree. C. In this regard,
the synthesis is performed under the condition that the synthesized
particle of copper sulfide has a chemical structure of
Cu.sub.xS.sub.y (where x/y is 0.8 to 1.5). Specific examples of the
sulfides available in the present invention may include sodium
sulfide, iron sulfide, potassium sulfide, zinc sulfide, etc.;
specific examples of the fluorides available in the present
invention may include sodium fluoride, iron fluoride, potassium
fluoride, zinc fluoride, etc.; and specific examples of the
chlorides available in the present invention may include sodium
chloride, iron chloride, potassium chloride, zinc chloride, etc. In
this case, the copper sulfide synthesized from sodium sulfide and
copper sulfate is most excellent in the antibacterial activity.
[0018] When the reaction temperature is less than 10.degree. C. in
the synthesis of copper-based particles, the reactivity of copper
sulfate and the salt decreases to deteriorate the deodorizing
activity despite the good antibacterial activity. When the reaction
temperature exceeds 80.degree. C., the reaction rate is extremely
high so as to increase the density of the crystals on the surface
of copper sulfide and the concentration of copper, resulting in
good deodorizing activity and poor antibacterial activity. Further,
the ratio x/y of the copper-based particles less than 0.8 leads to
excessively high concentration of sulfur (S), consequently with
good antibacterial activity and poor deodorizing activity. The
ratio x/y of the copper-based particles greater than 1.5
contributes to an increase in the concentration of copper (Cu),
which improves the deodorizing activity and deteriorates the
antibacterial activity.
[0019] Hereinafter, a description will be given as to the process
for manufacturing an antibacterial filter in two methods: applying
a coating of copper sulfide as a sulfur compound to a porous
medium; or dispersing copper sulfide particles in a porous
medium.
[0020] <Antibacterial Filter with Copper Sulfide Coating>
[0021] The method for applying a coating of copper sulfide to a
porous medium according to an embodiment of the present invention
involves stirring a predetermined amount of copper sulfide in a
solvent such as isopropyl alcohol (IPA) at the room temperature for
several hours to prepare a coating solution with good
dispersability. Then, the coating solution is applied to the porous
medium by dip coating. The coated porous medium is dried for
several hours to scores of hours and then subjected to an annealing
process at T.sub.c to T.sub.m for scores of minutes. In order to
obtain a filter with good antibacterial and deodorizing activities,
the procedures are repeatedly performed in the same manner as
described above to form a coating of copper sulfide at high
concentration on the surface of the porous medium.
[0022] <Antibacterial Filter with Dispersed Copper Sulfide
Particles>
[0023] A porous medium of copper sulfide may have pores made by
using a foaming agent or adding liquid nitrogen or a supercritical
fluid. More specifically, while extruded at a temperature higher
than the melting temperature of the resin by about 30 to 40.degree.
C., the polymer resin used as a matrix for the porous medium and
copper sulfide are mixed sufficiently with a chemical foaming
agent, liquid nitrogen, or supercritical carbon dioxide that is
side-fed. As the polymer resin mixed with copper sulfide is
extruded, a filter comprising a porous medium of copper sulfide
with pores is completed. The porosity of the filter is suitably 10
to 40%, more preferably 20 to 30%. When the porosity is less than
10%, the contact area is too small to display a good deodorizing
activity. When the porosity is greater than 40%, it is hard to get
a filter form. The porosity may be controlled by the weight ratio
of the resin to the foaming agent, the temperature, the rotating
speed of the screw, the retention time, the L/D ratio (where L is
the length of the compounder screw; and D is the diameter of the
screw), etc.
[0024] When a chemical foaming agent is used, it has a lower
evaporation temperature than the thermoplastic resin used as a
matrix and thus kept in the gas state while moved by the screw.
During the extrusion, the chemical foaming agent is released into
the air to form pores. In the case of using liquid nitrogen or a
supercritical fluid, which is supplied under high pressure, it is
designed to maintain high pressure in the extrusion step. In other
words, the liquid nitrogen or supercritical fluid supplied by side
feeding is sufficiently mixed with the resin and then extruded. In
the extrusion step, the evaporated nitrogen and carbon dioxide are
released into the air to form pores. The chemical foaming agent is
in wide use, because it is relatively inexpensive and requires a
simple facility. But, the use of the chemical foaming agent
possibly causes a pyrolysis of the resin and makes it hard to
control the fine pores uniform. The liquid nitrogen or
supercritical carbon dioxide costs high but advantageously enables
it to make minute pores uniform.
[0025] An exemplary method for manufacturing the antibacterial
filter of the present invention is given as follows. CuSO.sub.4 and
Na.sub.2S in an amount of one mole each are added to distilled
water and stirred to prepare an aqueous solution, which is then put
into an isothermal reactor at 50.degree. C. to synthesize copper
sulfide (CuS) as shown in FIG. 1. In this regard, the x/y ratio is
1.02. The copper sulfide thus obtained has the crystalline
structure peculiar to copper sulfide as shown in FIG. 2, and its
particle image magnified by a factor of 30,000 is presented in FIG.
3. Referring to FIG. 3, there appears no peak for the sulfur, which
does not have a crystalline structure, whereas peaks for the copper
appear at 55, 65, 99, 125, and 137 degrees. The copper sulfide thus
prepared is mixed with the nylon resin to form an antibacterial
filter as shown in FIG. 4.
[0026] The activity evaluation of the antibacterial filter prepared
in the embodiment of the present invention is performed in the
manner as follows.
[0027] (1) Average Particle Diameter
[0028] The average particle diameter of the copper sulfide and
metal particles is measured with a particle size analyzer (ELS-Z2,
Otsuka Electronics Co., Japan).
[0029] (2) Antibacterial Activity A culture medium with Escherichia
Coli (ATCC 25922) is put in contact with a specimen and incubated
at 25.degree. C. for 24 hours. After incubation, the bacterial
growth is determined to evaluate the antibacterial effect of the
specimen.
[0030] (3) Deodorizing Activity
[0031] 1 g of the copper-based particles is put into a reactor and
then 10,000 ng/ml of gaseous formaldehyde is injected. After 5
minutes, the concentration of the formaldehyde eliminated is
determined to evaluate the deodorizing effect of the copper-based
particles. The concentration of the remaining gaseous formaldehyde
is determined with a gas chromatograph (Agilent 6890, Aglient
Technologies Inc., U.S.A).
[0032] (4) Copper/Sulfur Component
[0033] The copper-to-sulfur molar ratio of the copper sulfide
particles is determined with an inductively coupled plasma mass
spectrometer (Agilent 7500, Aglient Technologies Inc., U.S.A.).
[0034] (5) Porosity
[0035] The porosity (%) (=[(D.sub.i-D.sub.p)/D.sub.i].times.100,
where D.sub.i is the density of the filter without pores; and
D.sub.p is the density of the filter with pores) of the porous
filter is determined by measuring the density of the specimen. The
density measurement is performed with an electronic scale (XP204V,
Mettler-Toledo Co., Swiss).
[0036] The copper sulfide used in the antibacterial filter
according to the embodiment of the present invention has the
antibacterial activity of 1.times.10.sup.4 counts/ml to
1.times.10.sup.6 counts/ml, and the deodorizing activity of 90 to
98%. Further, the copper/sulfur ratio, i.e., x/y ratio is 0.8 to
1.5, and the porosity is suitably 10 to 40%, more preferably 20 to
30% Accordingly, the antibacterial filter of the present invention
makes the use of the properties of copper sulfide to secure the
antibacterial and deodorizing effects required to antibacterial
filters. Furthermore, copper sulfide is relatively inexpensive,
easy to process, and non-toxic, so the antibacterial filter using
copper sulfide is considered to be more useful than the
conventional antibacterial filters using silver.
[0037] Although the preferred embodiments of the present invention
have been described in detail, it is understood that the present
invention should not be limited to these exemplary embodiments but
various alternatives can be made by those skilled in the art within
the spirit and scope of the present invention as hereinafter
claimed.
* * * * *